1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 */ 8#ifndef _UAPI__LINUX_BPF_H__ 9#define _UAPI__LINUX_BPF_H__ 10 11#include <linux/types.h> 12#include <linux/bpf_common.h> 13 14/* Extended instruction set based on top of classic BPF */ 15 16/* instruction classes */ 17#define BPF_JMP32 0x06 /* jmp mode in word width */ 18#define BPF_ALU64 0x07 /* alu mode in double word width */ 19 20/* ld/ldx fields */ 21#define BPF_DW 0x18 /* double word (64-bit) */ 22#define BPF_XADD 0xc0 /* exclusive add */ 23 24/* alu/jmp fields */ 25#define BPF_MOV 0xb0 /* mov reg to reg */ 26#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */ 27 28/* change endianness of a register */ 29#define BPF_END 0xd0 /* flags for endianness conversion: */ 30#define BPF_TO_LE 0x00 /* convert to little-endian */ 31#define BPF_TO_BE 0x08 /* convert to big-endian */ 32#define BPF_FROM_LE BPF_TO_LE 33#define BPF_FROM_BE BPF_TO_BE 34 35/* jmp encodings */ 36#define BPF_JNE 0x50 /* jump != */ 37#define BPF_JLT 0xa0 /* LT is unsigned, '<' */ 38#define BPF_JLE 0xb0 /* LE is unsigned, '<=' */ 39#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */ 40#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */ 41#define BPF_JSLT 0xc0 /* SLT is signed, '<' */ 42#define BPF_JSLE 0xd0 /* SLE is signed, '<=' */ 43#define BPF_CALL 0x80 /* function call */ 44#define BPF_EXIT 0x90 /* function return */ 45 46/* Register numbers */ 47enum { 48 BPF_REG_0 = 0, 49 BPF_REG_1, 50 BPF_REG_2, 51 BPF_REG_3, 52 BPF_REG_4, 53 BPF_REG_5, 54 BPF_REG_6, 55 BPF_REG_7, 56 BPF_REG_8, 57 BPF_REG_9, 58 BPF_REG_10, 59 __MAX_BPF_REG, 60}; 61 62/* BPF has 10 general purpose 64-bit registers and stack frame. */ 63#define MAX_BPF_REG __MAX_BPF_REG 64 65struct bpf_insn { 66 __u8 code; /* opcode */ 67 __u8 dst_reg:4; /* dest register */ 68 __u8 src_reg:4; /* source register */ 69 __s16 off; /* signed offset */ 70 __s32 imm; /* signed immediate constant */ 71}; 72 73/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */ 74struct bpf_lpm_trie_key { 75 __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ 76 __u8 data[0]; /* Arbitrary size */ 77}; 78 79struct bpf_cgroup_storage_key { 80 __u64 cgroup_inode_id; /* cgroup inode id */ 81 __u32 attach_type; /* program attach type */ 82}; 83 84/* BPF syscall commands, see bpf(2) man-page for details. */ 85enum bpf_cmd { 86 BPF_MAP_CREATE, 87 BPF_MAP_LOOKUP_ELEM, 88 BPF_MAP_UPDATE_ELEM, 89 BPF_MAP_DELETE_ELEM, 90 BPF_MAP_GET_NEXT_KEY, 91 BPF_PROG_LOAD, 92 BPF_OBJ_PIN, 93 BPF_OBJ_GET, 94 BPF_PROG_ATTACH, 95 BPF_PROG_DETACH, 96 BPF_PROG_TEST_RUN, 97 BPF_PROG_GET_NEXT_ID, 98 BPF_MAP_GET_NEXT_ID, 99 BPF_PROG_GET_FD_BY_ID, 100 BPF_MAP_GET_FD_BY_ID, 101 BPF_OBJ_GET_INFO_BY_FD, 102 BPF_PROG_QUERY, 103 BPF_RAW_TRACEPOINT_OPEN, 104 BPF_BTF_LOAD, 105 BPF_BTF_GET_FD_BY_ID, 106 BPF_TASK_FD_QUERY, 107 BPF_MAP_LOOKUP_AND_DELETE_ELEM, 108 BPF_MAP_FREEZE, 109}; 110 111enum bpf_map_type { 112 BPF_MAP_TYPE_UNSPEC, 113 BPF_MAP_TYPE_HASH, 114 BPF_MAP_TYPE_ARRAY, 115 BPF_MAP_TYPE_PROG_ARRAY, 116 BPF_MAP_TYPE_PERF_EVENT_ARRAY, 117 BPF_MAP_TYPE_PERCPU_HASH, 118 BPF_MAP_TYPE_PERCPU_ARRAY, 119 BPF_MAP_TYPE_STACK_TRACE, 120 BPF_MAP_TYPE_CGROUP_ARRAY, 121 BPF_MAP_TYPE_LRU_HASH, 122 BPF_MAP_TYPE_LRU_PERCPU_HASH, 123 BPF_MAP_TYPE_LPM_TRIE, 124 BPF_MAP_TYPE_ARRAY_OF_MAPS, 125 BPF_MAP_TYPE_HASH_OF_MAPS, 126 BPF_MAP_TYPE_DEVMAP, 127 BPF_MAP_TYPE_SOCKMAP, 128 BPF_MAP_TYPE_CPUMAP, 129 BPF_MAP_TYPE_XSKMAP, 130 BPF_MAP_TYPE_SOCKHASH, 131 BPF_MAP_TYPE_CGROUP_STORAGE, 132 BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, 133 BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, 134 BPF_MAP_TYPE_QUEUE, 135 BPF_MAP_TYPE_STACK, 136 BPF_MAP_TYPE_SK_STORAGE, 137}; 138 139/* Note that tracing related programs such as 140 * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT} 141 * are not subject to a stable API since kernel internal data 142 * structures can change from release to release and may 143 * therefore break existing tracing BPF programs. Tracing BPF 144 * programs correspond to /a/ specific kernel which is to be 145 * analyzed, and not /a/ specific kernel /and/ all future ones. 146 */ 147enum bpf_prog_type { 148 BPF_PROG_TYPE_UNSPEC, 149 BPF_PROG_TYPE_SOCKET_FILTER, 150 BPF_PROG_TYPE_KPROBE, 151 BPF_PROG_TYPE_SCHED_CLS, 152 BPF_PROG_TYPE_SCHED_ACT, 153 BPF_PROG_TYPE_TRACEPOINT, 154 BPF_PROG_TYPE_XDP, 155 BPF_PROG_TYPE_PERF_EVENT, 156 BPF_PROG_TYPE_CGROUP_SKB, 157 BPF_PROG_TYPE_CGROUP_SOCK, 158 BPF_PROG_TYPE_LWT_IN, 159 BPF_PROG_TYPE_LWT_OUT, 160 BPF_PROG_TYPE_LWT_XMIT, 161 BPF_PROG_TYPE_SOCK_OPS, 162 BPF_PROG_TYPE_SK_SKB, 163 BPF_PROG_TYPE_CGROUP_DEVICE, 164 BPF_PROG_TYPE_SK_MSG, 165 BPF_PROG_TYPE_RAW_TRACEPOINT, 166 BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 167 BPF_PROG_TYPE_LWT_SEG6LOCAL, 168 BPF_PROG_TYPE_LIRC_MODE2, 169 BPF_PROG_TYPE_SK_REUSEPORT, 170 BPF_PROG_TYPE_FLOW_DISSECTOR, 171 BPF_PROG_TYPE_CGROUP_SYSCTL, 172 BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, 173}; 174 175enum bpf_attach_type { 176 BPF_CGROUP_INET_INGRESS, 177 BPF_CGROUP_INET_EGRESS, 178 BPF_CGROUP_INET_SOCK_CREATE, 179 BPF_CGROUP_SOCK_OPS, 180 BPF_SK_SKB_STREAM_PARSER, 181 BPF_SK_SKB_STREAM_VERDICT, 182 BPF_CGROUP_DEVICE, 183 BPF_SK_MSG_VERDICT, 184 BPF_CGROUP_INET4_BIND, 185 BPF_CGROUP_INET6_BIND, 186 BPF_CGROUP_INET4_CONNECT, 187 BPF_CGROUP_INET6_CONNECT, 188 BPF_CGROUP_INET4_POST_BIND, 189 BPF_CGROUP_INET6_POST_BIND, 190 BPF_CGROUP_UDP4_SENDMSG, 191 BPF_CGROUP_UDP6_SENDMSG, 192 BPF_LIRC_MODE2, 193 BPF_FLOW_DISSECTOR, 194 BPF_CGROUP_SYSCTL, 195 BPF_CGROUP_UDP4_RECVMSG, 196 BPF_CGROUP_UDP6_RECVMSG, 197 __MAX_BPF_ATTACH_TYPE 198}; 199 200#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE 201 202/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command 203 * 204 * NONE(default): No further bpf programs allowed in the subtree. 205 * 206 * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, 207 * the program in this cgroup yields to sub-cgroup program. 208 * 209 * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, 210 * that cgroup program gets run in addition to the program in this cgroup. 211 * 212 * Only one program is allowed to be attached to a cgroup with 213 * NONE or BPF_F_ALLOW_OVERRIDE flag. 214 * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will 215 * release old program and attach the new one. Attach flags has to match. 216 * 217 * Multiple programs are allowed to be attached to a cgroup with 218 * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order 219 * (those that were attached first, run first) 220 * The programs of sub-cgroup are executed first, then programs of 221 * this cgroup and then programs of parent cgroup. 222 * When children program makes decision (like picking TCP CA or sock bind) 223 * parent program has a chance to override it. 224 * 225 * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups. 226 * A cgroup with NONE doesn't allow any programs in sub-cgroups. 227 * Ex1: 228 * cgrp1 (MULTI progs A, B) -> 229 * cgrp2 (OVERRIDE prog C) -> 230 * cgrp3 (MULTI prog D) -> 231 * cgrp4 (OVERRIDE prog E) -> 232 * cgrp5 (NONE prog F) 233 * the event in cgrp5 triggers execution of F,D,A,B in that order. 234 * if prog F is detached, the execution is E,D,A,B 235 * if prog F and D are detached, the execution is E,A,B 236 * if prog F, E and D are detached, the execution is C,A,B 237 * 238 * All eligible programs are executed regardless of return code from 239 * earlier programs. 240 */ 241#define BPF_F_ALLOW_OVERRIDE (1U << 0) 242#define BPF_F_ALLOW_MULTI (1U << 1) 243 244/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the 245 * verifier will perform strict alignment checking as if the kernel 246 * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set, 247 * and NET_IP_ALIGN defined to 2. 248 */ 249#define BPF_F_STRICT_ALIGNMENT (1U << 0) 250 251/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the 252 * verifier will allow any alignment whatsoever. On platforms 253 * with strict alignment requirements for loads ands stores (such 254 * as sparc and mips) the verifier validates that all loads and 255 * stores provably follow this requirement. This flag turns that 256 * checking and enforcement off. 257 * 258 * It is mostly used for testing when we want to validate the 259 * context and memory access aspects of the verifier, but because 260 * of an unaligned access the alignment check would trigger before 261 * the one we are interested in. 262 */ 263#define BPF_F_ANY_ALIGNMENT (1U << 1) 264 265/* When BPF ldimm64's insn[0].src_reg != 0 then this can have 266 * two extensions: 267 * 268 * insn[0].src_reg: BPF_PSEUDO_MAP_FD BPF_PSEUDO_MAP_VALUE 269 * insn[0].imm: map fd map fd 270 * insn[1].imm: 0 offset into value 271 * insn[0].off: 0 0 272 * insn[1].off: 0 0 273 * ldimm64 rewrite: address of map address of map[0]+offset 274 * verifier type: CONST_PTR_TO_MAP PTR_TO_MAP_VALUE 275 */ 276#define BPF_PSEUDO_MAP_FD 1 277#define BPF_PSEUDO_MAP_VALUE 2 278 279/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative 280 * offset to another bpf function 281 */ 282#define BPF_PSEUDO_CALL 1 283 284/* flags for BPF_MAP_UPDATE_ELEM command */ 285#define BPF_ANY 0 /* create new element or update existing */ 286#define BPF_NOEXIST 1 /* create new element if it didn't exist */ 287#define BPF_EXIST 2 /* update existing element */ 288#define BPF_F_LOCK 4 /* spin_lock-ed map_lookup/map_update */ 289 290/* flags for BPF_MAP_CREATE command */ 291#define BPF_F_NO_PREALLOC (1U << 0) 292/* Instead of having one common LRU list in the 293 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list 294 * which can scale and perform better. 295 * Note, the LRU nodes (including free nodes) cannot be moved 296 * across different LRU lists. 297 */ 298#define BPF_F_NO_COMMON_LRU (1U << 1) 299/* Specify numa node during map creation */ 300#define BPF_F_NUMA_NODE (1U << 2) 301 302#define BPF_OBJ_NAME_LEN 16U 303 304/* Flags for accessing BPF object from syscall side. */ 305#define BPF_F_RDONLY (1U << 3) 306#define BPF_F_WRONLY (1U << 4) 307 308/* Flag for stack_map, store build_id+offset instead of pointer */ 309#define BPF_F_STACK_BUILD_ID (1U << 5) 310 311/* Zero-initialize hash function seed. This should only be used for testing. */ 312#define BPF_F_ZERO_SEED (1U << 6) 313 314/* Flags for accessing BPF object from program side. */ 315#define BPF_F_RDONLY_PROG (1U << 7) 316#define BPF_F_WRONLY_PROG (1U << 8) 317 318/* flags for BPF_PROG_QUERY */ 319#define BPF_F_QUERY_EFFECTIVE (1U << 0) 320 321enum bpf_stack_build_id_status { 322 /* user space need an empty entry to identify end of a trace */ 323 BPF_STACK_BUILD_ID_EMPTY = 0, 324 /* with valid build_id and offset */ 325 BPF_STACK_BUILD_ID_VALID = 1, 326 /* couldn't get build_id, fallback to ip */ 327 BPF_STACK_BUILD_ID_IP = 2, 328}; 329 330#define BPF_BUILD_ID_SIZE 20 331struct bpf_stack_build_id { 332 __s32 status; 333 unsigned char build_id[BPF_BUILD_ID_SIZE]; 334 union { 335 __u64 offset; 336 __u64 ip; 337 }; 338}; 339 340union bpf_attr { 341 struct { /* anonymous struct used by BPF_MAP_CREATE command */ 342 __u32 map_type; /* one of enum bpf_map_type */ 343 __u32 key_size; /* size of key in bytes */ 344 __u32 value_size; /* size of value in bytes */ 345 __u32 max_entries; /* max number of entries in a map */ 346 __u32 map_flags; /* BPF_MAP_CREATE related 347 * flags defined above. 348 */ 349 __u32 inner_map_fd; /* fd pointing to the inner map */ 350 __u32 numa_node; /* numa node (effective only if 351 * BPF_F_NUMA_NODE is set). 352 */ 353 char map_name[BPF_OBJ_NAME_LEN]; 354 __u32 map_ifindex; /* ifindex of netdev to create on */ 355 __u32 btf_fd; /* fd pointing to a BTF type data */ 356 __u32 btf_key_type_id; /* BTF type_id of the key */ 357 __u32 btf_value_type_id; /* BTF type_id of the value */ 358 }; 359 360 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */ 361 __u32 map_fd; 362 __aligned_u64 key; 363 union { 364 __aligned_u64 value; 365 __aligned_u64 next_key; 366 }; 367 __u64 flags; 368 }; 369 370 struct { /* anonymous struct used by BPF_PROG_LOAD command */ 371 __u32 prog_type; /* one of enum bpf_prog_type */ 372 __u32 insn_cnt; 373 __aligned_u64 insns; 374 __aligned_u64 license; 375 __u32 log_level; /* verbosity level of verifier */ 376 __u32 log_size; /* size of user buffer */ 377 __aligned_u64 log_buf; /* user supplied buffer */ 378 __u32 kern_version; /* not used */ 379 __u32 prog_flags; 380 char prog_name[BPF_OBJ_NAME_LEN]; 381 __u32 prog_ifindex; /* ifindex of netdev to prep for */ 382 /* For some prog types expected attach type must be known at 383 * load time to verify attach type specific parts of prog 384 * (context accesses, allowed helpers, etc). 385 */ 386 __u32 expected_attach_type; 387 __u32 prog_btf_fd; /* fd pointing to BTF type data */ 388 __u32 func_info_rec_size; /* userspace bpf_func_info size */ 389 __aligned_u64 func_info; /* func info */ 390 __u32 func_info_cnt; /* number of bpf_func_info records */ 391 __u32 line_info_rec_size; /* userspace bpf_line_info size */ 392 __aligned_u64 line_info; /* line info */ 393 __u32 line_info_cnt; /* number of bpf_line_info records */ 394 }; 395 396 struct { /* anonymous struct used by BPF_OBJ_* commands */ 397 __aligned_u64 pathname; 398 __u32 bpf_fd; 399 __u32 file_flags; 400 }; 401 402 struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */ 403 __u32 target_fd; /* container object to attach to */ 404 __u32 attach_bpf_fd; /* eBPF program to attach */ 405 __u32 attach_type; 406 __u32 attach_flags; 407 }; 408 409 struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */ 410 __u32 prog_fd; 411 __u32 retval; 412 __u32 data_size_in; /* input: len of data_in */ 413 __u32 data_size_out; /* input/output: len of data_out 414 * returns ENOSPC if data_out 415 * is too small. 416 */ 417 __aligned_u64 data_in; 418 __aligned_u64 data_out; 419 __u32 repeat; 420 __u32 duration; 421 __u32 ctx_size_in; /* input: len of ctx_in */ 422 __u32 ctx_size_out; /* input/output: len of ctx_out 423 * returns ENOSPC if ctx_out 424 * is too small. 425 */ 426 __aligned_u64 ctx_in; 427 __aligned_u64 ctx_out; 428 } test; 429 430 struct { /* anonymous struct used by BPF_*_GET_*_ID */ 431 union { 432 __u32 start_id; 433 __u32 prog_id; 434 __u32 map_id; 435 __u32 btf_id; 436 }; 437 __u32 next_id; 438 __u32 open_flags; 439 }; 440 441 struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */ 442 __u32 bpf_fd; 443 __u32 info_len; 444 __aligned_u64 info; 445 } info; 446 447 struct { /* anonymous struct used by BPF_PROG_QUERY command */ 448 __u32 target_fd; /* container object to query */ 449 __u32 attach_type; 450 __u32 query_flags; 451 __u32 attach_flags; 452 __aligned_u64 prog_ids; 453 __u32 prog_cnt; 454 } query; 455 456 struct { 457 __u64 name; 458 __u32 prog_fd; 459 } raw_tracepoint; 460 461 struct { /* anonymous struct for BPF_BTF_LOAD */ 462 __aligned_u64 btf; 463 __aligned_u64 btf_log_buf; 464 __u32 btf_size; 465 __u32 btf_log_size; 466 __u32 btf_log_level; 467 }; 468 469 struct { 470 __u32 pid; /* input: pid */ 471 __u32 fd; /* input: fd */ 472 __u32 flags; /* input: flags */ 473 __u32 buf_len; /* input/output: buf len */ 474 __aligned_u64 buf; /* input/output: 475 * tp_name for tracepoint 476 * symbol for kprobe 477 * filename for uprobe 478 */ 479 __u32 prog_id; /* output: prod_id */ 480 __u32 fd_type; /* output: BPF_FD_TYPE_* */ 481 __u64 probe_offset; /* output: probe_offset */ 482 __u64 probe_addr; /* output: probe_addr */ 483 } task_fd_query; 484} __attribute__((aligned(8))); 485 486/* The description below is an attempt at providing documentation to eBPF 487 * developers about the multiple available eBPF helper functions. It can be 488 * parsed and used to produce a manual page. The workflow is the following, 489 * and requires the rst2man utility: 490 * 491 * $ ./scripts/bpf_helpers_doc.py \ 492 * --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst 493 * $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7 494 * $ man /tmp/bpf-helpers.7 495 * 496 * Note that in order to produce this external documentation, some RST 497 * formatting is used in the descriptions to get "bold" and "italics" in 498 * manual pages. Also note that the few trailing white spaces are 499 * intentional, removing them would break paragraphs for rst2man. 500 * 501 * Start of BPF helper function descriptions: 502 * 503 * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key) 504 * Description 505 * Perform a lookup in *map* for an entry associated to *key*. 506 * Return 507 * Map value associated to *key*, or **NULL** if no entry was 508 * found. 509 * 510 * int bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags) 511 * Description 512 * Add or update the value of the entry associated to *key* in 513 * *map* with *value*. *flags* is one of: 514 * 515 * **BPF_NOEXIST** 516 * The entry for *key* must not exist in the map. 517 * **BPF_EXIST** 518 * The entry for *key* must already exist in the map. 519 * **BPF_ANY** 520 * No condition on the existence of the entry for *key*. 521 * 522 * Flag value **BPF_NOEXIST** cannot be used for maps of types 523 * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all 524 * elements always exist), the helper would return an error. 525 * Return 526 * 0 on success, or a negative error in case of failure. 527 * 528 * int bpf_map_delete_elem(struct bpf_map *map, const void *key) 529 * Description 530 * Delete entry with *key* from *map*. 531 * Return 532 * 0 on success, or a negative error in case of failure. 533 * 534 * int bpf_probe_read(void *dst, u32 size, const void *src) 535 * Description 536 * For tracing programs, safely attempt to read *size* bytes from 537 * address *src* and store the data in *dst*. 538 * Return 539 * 0 on success, or a negative error in case of failure. 540 * 541 * u64 bpf_ktime_get_ns(void) 542 * Description 543 * Return the time elapsed since system boot, in nanoseconds. 544 * Return 545 * Current *ktime*. 546 * 547 * int bpf_trace_printk(const char *fmt, u32 fmt_size, ...) 548 * Description 549 * This helper is a "printk()-like" facility for debugging. It 550 * prints a message defined by format *fmt* (of size *fmt_size*) 551 * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if 552 * available. It can take up to three additional **u64** 553 * arguments (as an eBPF helpers, the total number of arguments is 554 * limited to five). 555 * 556 * Each time the helper is called, it appends a line to the trace. 557 * The format of the trace is customizable, and the exact output 558 * one will get depends on the options set in 559 * *\/sys/kernel/debug/tracing/trace_options* (see also the 560 * *README* file under the same directory). However, it usually 561 * defaults to something like: 562 * 563 * :: 564 * 565 * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> 566 * 567 * In the above: 568 * 569 * * ``telnet`` is the name of the current task. 570 * * ``470`` is the PID of the current task. 571 * * ``001`` is the CPU number on which the task is 572 * running. 573 * * In ``.N..``, each character refers to a set of 574 * options (whether irqs are enabled, scheduling 575 * options, whether hard/softirqs are running, level of 576 * preempt_disabled respectively). **N** means that 577 * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED** 578 * are set. 579 * * ``419421.045894`` is a timestamp. 580 * * ``0x00000001`` is a fake value used by BPF for the 581 * instruction pointer register. 582 * * ``<formatted msg>`` is the message formatted with 583 * *fmt*. 584 * 585 * The conversion specifiers supported by *fmt* are similar, but 586 * more limited than for printk(). They are **%d**, **%i**, 587 * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**, 588 * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size 589 * of field, padding with zeroes, etc.) is available, and the 590 * helper will return **-EINVAL** (but print nothing) if it 591 * encounters an unknown specifier. 592 * 593 * Also, note that **bpf_trace_printk**\ () is slow, and should 594 * only be used for debugging purposes. For this reason, a notice 595 * bloc (spanning several lines) is printed to kernel logs and 596 * states that the helper should not be used "for production use" 597 * the first time this helper is used (or more precisely, when 598 * **trace_printk**\ () buffers are allocated). For passing values 599 * to user space, perf events should be preferred. 600 * Return 601 * The number of bytes written to the buffer, or a negative error 602 * in case of failure. 603 * 604 * u32 bpf_get_prandom_u32(void) 605 * Description 606 * Get a pseudo-random number. 607 * 608 * From a security point of view, this helper uses its own 609 * pseudo-random internal state, and cannot be used to infer the 610 * seed of other random functions in the kernel. However, it is 611 * essential to note that the generator used by the helper is not 612 * cryptographically secure. 613 * Return 614 * A random 32-bit unsigned value. 615 * 616 * u32 bpf_get_smp_processor_id(void) 617 * Description 618 * Get the SMP (symmetric multiprocessing) processor id. Note that 619 * all programs run with preemption disabled, which means that the 620 * SMP processor id is stable during all the execution of the 621 * program. 622 * Return 623 * The SMP id of the processor running the program. 624 * 625 * int bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags) 626 * Description 627 * Store *len* bytes from address *from* into the packet 628 * associated to *skb*, at *offset*. *flags* are a combination of 629 * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the 630 * checksum for the packet after storing the bytes) and 631 * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\ 632 * **->swhash** and *skb*\ **->l4hash** to 0). 633 * 634 * A call to this helper is susceptible to change the underlying 635 * packet buffer. Therefore, at load time, all checks on pointers 636 * previously done by the verifier are invalidated and must be 637 * performed again, if the helper is used in combination with 638 * direct packet access. 639 * Return 640 * 0 on success, or a negative error in case of failure. 641 * 642 * int bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size) 643 * Description 644 * Recompute the layer 3 (e.g. IP) checksum for the packet 645 * associated to *skb*. Computation is incremental, so the helper 646 * must know the former value of the header field that was 647 * modified (*from*), the new value of this field (*to*), and the 648 * number of bytes (2 or 4) for this field, stored in *size*. 649 * Alternatively, it is possible to store the difference between 650 * the previous and the new values of the header field in *to*, by 651 * setting *from* and *size* to 0. For both methods, *offset* 652 * indicates the location of the IP checksum within the packet. 653 * 654 * This helper works in combination with **bpf_csum_diff**\ (), 655 * which does not update the checksum in-place, but offers more 656 * flexibility and can handle sizes larger than 2 or 4 for the 657 * checksum to update. 658 * 659 * A call to this helper is susceptible to change the underlying 660 * packet buffer. Therefore, at load time, all checks on pointers 661 * previously done by the verifier are invalidated and must be 662 * performed again, if the helper is used in combination with 663 * direct packet access. 664 * Return 665 * 0 on success, or a negative error in case of failure. 666 * 667 * int bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags) 668 * Description 669 * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the 670 * packet associated to *skb*. Computation is incremental, so the 671 * helper must know the former value of the header field that was 672 * modified (*from*), the new value of this field (*to*), and the 673 * number of bytes (2 or 4) for this field, stored on the lowest 674 * four bits of *flags*. Alternatively, it is possible to store 675 * the difference between the previous and the new values of the 676 * header field in *to*, by setting *from* and the four lowest 677 * bits of *flags* to 0. For both methods, *offset* indicates the 678 * location of the IP checksum within the packet. In addition to 679 * the size of the field, *flags* can be added (bitwise OR) actual 680 * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left 681 * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and 682 * for updates resulting in a null checksum the value is set to 683 * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates 684 * the checksum is to be computed against a pseudo-header. 685 * 686 * This helper works in combination with **bpf_csum_diff**\ (), 687 * which does not update the checksum in-place, but offers more 688 * flexibility and can handle sizes larger than 2 or 4 for the 689 * checksum to update. 690 * 691 * A call to this helper is susceptible to change the underlying 692 * packet buffer. Therefore, at load time, all checks on pointers 693 * previously done by the verifier are invalidated and must be 694 * performed again, if the helper is used in combination with 695 * direct packet access. 696 * Return 697 * 0 on success, or a negative error in case of failure. 698 * 699 * int bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index) 700 * Description 701 * This special helper is used to trigger a "tail call", or in 702 * other words, to jump into another eBPF program. The same stack 703 * frame is used (but values on stack and in registers for the 704 * caller are not accessible to the callee). This mechanism allows 705 * for program chaining, either for raising the maximum number of 706 * available eBPF instructions, or to execute given programs in 707 * conditional blocks. For security reasons, there is an upper 708 * limit to the number of successive tail calls that can be 709 * performed. 710 * 711 * Upon call of this helper, the program attempts to jump into a 712 * program referenced at index *index* in *prog_array_map*, a 713 * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes 714 * *ctx*, a pointer to the context. 715 * 716 * If the call succeeds, the kernel immediately runs the first 717 * instruction of the new program. This is not a function call, 718 * and it never returns to the previous program. If the call 719 * fails, then the helper has no effect, and the caller continues 720 * to run its subsequent instructions. A call can fail if the 721 * destination program for the jump does not exist (i.e. *index* 722 * is superior to the number of entries in *prog_array_map*), or 723 * if the maximum number of tail calls has been reached for this 724 * chain of programs. This limit is defined in the kernel by the 725 * macro **MAX_TAIL_CALL_CNT** (not accessible to user space), 726 * which is currently set to 32. 727 * Return 728 * 0 on success, or a negative error in case of failure. 729 * 730 * int bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags) 731 * Description 732 * Clone and redirect the packet associated to *skb* to another 733 * net device of index *ifindex*. Both ingress and egress 734 * interfaces can be used for redirection. The **BPF_F_INGRESS** 735 * value in *flags* is used to make the distinction (ingress path 736 * is selected if the flag is present, egress path otherwise). 737 * This is the only flag supported for now. 738 * 739 * In comparison with **bpf_redirect**\ () helper, 740 * **bpf_clone_redirect**\ () has the associated cost of 741 * duplicating the packet buffer, but this can be executed out of 742 * the eBPF program. Conversely, **bpf_redirect**\ () is more 743 * efficient, but it is handled through an action code where the 744 * redirection happens only after the eBPF program has returned. 745 * 746 * A call to this helper is susceptible to change the underlying 747 * packet buffer. Therefore, at load time, all checks on pointers 748 * previously done by the verifier are invalidated and must be 749 * performed again, if the helper is used in combination with 750 * direct packet access. 751 * Return 752 * 0 on success, or a negative error in case of failure. 753 * 754 * u64 bpf_get_current_pid_tgid(void) 755 * Return 756 * A 64-bit integer containing the current tgid and pid, and 757 * created as such: 758 * *current_task*\ **->tgid << 32 \|** 759 * *current_task*\ **->pid**. 760 * 761 * u64 bpf_get_current_uid_gid(void) 762 * Return 763 * A 64-bit integer containing the current GID and UID, and 764 * created as such: *current_gid* **<< 32 \|** *current_uid*. 765 * 766 * int bpf_get_current_comm(char *buf, u32 size_of_buf) 767 * Description 768 * Copy the **comm** attribute of the current task into *buf* of 769 * *size_of_buf*. The **comm** attribute contains the name of 770 * the executable (excluding the path) for the current task. The 771 * *size_of_buf* must be strictly positive. On success, the 772 * helper makes sure that the *buf* is NUL-terminated. On failure, 773 * it is filled with zeroes. 774 * Return 775 * 0 on success, or a negative error in case of failure. 776 * 777 * u32 bpf_get_cgroup_classid(struct sk_buff *skb) 778 * Description 779 * Retrieve the classid for the current task, i.e. for the net_cls 780 * cgroup to which *skb* belongs. 781 * 782 * This helper can be used on TC egress path, but not on ingress. 783 * 784 * The net_cls cgroup provides an interface to tag network packets 785 * based on a user-provided identifier for all traffic coming from 786 * the tasks belonging to the related cgroup. See also the related 787 * kernel documentation, available from the Linux sources in file 788 * *Documentation/cgroup-v1/net_cls.txt*. 789 * 790 * The Linux kernel has two versions for cgroups: there are 791 * cgroups v1 and cgroups v2. Both are available to users, who can 792 * use a mixture of them, but note that the net_cls cgroup is for 793 * cgroup v1 only. This makes it incompatible with BPF programs 794 * run on cgroups, which is a cgroup-v2-only feature (a socket can 795 * only hold data for one version of cgroups at a time). 796 * 797 * This helper is only available is the kernel was compiled with 798 * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to 799 * "**y**" or to "**m**". 800 * Return 801 * The classid, or 0 for the default unconfigured classid. 802 * 803 * int bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) 804 * Description 805 * Push a *vlan_tci* (VLAN tag control information) of protocol 806 * *vlan_proto* to the packet associated to *skb*, then update 807 * the checksum. Note that if *vlan_proto* is different from 808 * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to 809 * be **ETH_P_8021Q**. 810 * 811 * A call to this helper is susceptible to change the underlying 812 * packet buffer. Therefore, at load time, all checks on pointers 813 * previously done by the verifier are invalidated and must be 814 * performed again, if the helper is used in combination with 815 * direct packet access. 816 * Return 817 * 0 on success, or a negative error in case of failure. 818 * 819 * int bpf_skb_vlan_pop(struct sk_buff *skb) 820 * Description 821 * Pop a VLAN header from the packet associated to *skb*. 822 * 823 * A call to this helper is susceptible to change the underlying 824 * packet buffer. Therefore, at load time, all checks on pointers 825 * previously done by the verifier are invalidated and must be 826 * performed again, if the helper is used in combination with 827 * direct packet access. 828 * Return 829 * 0 on success, or a negative error in case of failure. 830 * 831 * int bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) 832 * Description 833 * Get tunnel metadata. This helper takes a pointer *key* to an 834 * empty **struct bpf_tunnel_key** of **size**, that will be 835 * filled with tunnel metadata for the packet associated to *skb*. 836 * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which 837 * indicates that the tunnel is based on IPv6 protocol instead of 838 * IPv4. 839 * 840 * The **struct bpf_tunnel_key** is an object that generalizes the 841 * principal parameters used by various tunneling protocols into a 842 * single struct. This way, it can be used to easily make a 843 * decision based on the contents of the encapsulation header, 844 * "summarized" in this struct. In particular, it holds the IP 845 * address of the remote end (IPv4 or IPv6, depending on the case) 846 * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also, 847 * this struct exposes the *key*\ **->tunnel_id**, which is 848 * generally mapped to a VNI (Virtual Network Identifier), making 849 * it programmable together with the **bpf_skb_set_tunnel_key**\ 850 * () helper. 851 * 852 * Let's imagine that the following code is part of a program 853 * attached to the TC ingress interface, on one end of a GRE 854 * tunnel, and is supposed to filter out all messages coming from 855 * remote ends with IPv4 address other than 10.0.0.1: 856 * 857 * :: 858 * 859 * int ret; 860 * struct bpf_tunnel_key key = {}; 861 * 862 * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0); 863 * if (ret < 0) 864 * return TC_ACT_SHOT; // drop packet 865 * 866 * if (key.remote_ipv4 != 0x0a000001) 867 * return TC_ACT_SHOT; // drop packet 868 * 869 * return TC_ACT_OK; // accept packet 870 * 871 * This interface can also be used with all encapsulation devices 872 * that can operate in "collect metadata" mode: instead of having 873 * one network device per specific configuration, the "collect 874 * metadata" mode only requires a single device where the 875 * configuration can be extracted from this helper. 876 * 877 * This can be used together with various tunnels such as VXLan, 878 * Geneve, GRE or IP in IP (IPIP). 879 * Return 880 * 0 on success, or a negative error in case of failure. 881 * 882 * int bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags) 883 * Description 884 * Populate tunnel metadata for packet associated to *skb.* The 885 * tunnel metadata is set to the contents of *key*, of *size*. The 886 * *flags* can be set to a combination of the following values: 887 * 888 * **BPF_F_TUNINFO_IPV6** 889 * Indicate that the tunnel is based on IPv6 protocol 890 * instead of IPv4. 891 * **BPF_F_ZERO_CSUM_TX** 892 * For IPv4 packets, add a flag to tunnel metadata 893 * indicating that checksum computation should be skipped 894 * and checksum set to zeroes. 895 * **BPF_F_DONT_FRAGMENT** 896 * Add a flag to tunnel metadata indicating that the 897 * packet should not be fragmented. 898 * **BPF_F_SEQ_NUMBER** 899 * Add a flag to tunnel metadata indicating that a 900 * sequence number should be added to tunnel header before 901 * sending the packet. This flag was added for GRE 902 * encapsulation, but might be used with other protocols 903 * as well in the future. 904 * 905 * Here is a typical usage on the transmit path: 906 * 907 * :: 908 * 909 * struct bpf_tunnel_key key; 910 * populate key ... 911 * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0); 912 * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); 913 * 914 * See also the description of the **bpf_skb_get_tunnel_key**\ () 915 * helper for additional information. 916 * Return 917 * 0 on success, or a negative error in case of failure. 918 * 919 * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags) 920 * Description 921 * Read the value of a perf event counter. This helper relies on a 922 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of 923 * the perf event counter is selected when *map* is updated with 924 * perf event file descriptors. The *map* is an array whose size 925 * is the number of available CPUs, and each cell contains a value 926 * relative to one CPU. The value to retrieve is indicated by 927 * *flags*, that contains the index of the CPU to look up, masked 928 * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to 929 * **BPF_F_CURRENT_CPU** to indicate that the value for the 930 * current CPU should be retrieved. 931 * 932 * Note that before Linux 4.13, only hardware perf event can be 933 * retrieved. 934 * 935 * Also, be aware that the newer helper 936 * **bpf_perf_event_read_value**\ () is recommended over 937 * **bpf_perf_event_read**\ () in general. The latter has some ABI 938 * quirks where error and counter value are used as a return code 939 * (which is wrong to do since ranges may overlap). This issue is 940 * fixed with **bpf_perf_event_read_value**\ (), which at the same 941 * time provides more features over the **bpf_perf_event_read**\ 942 * () interface. Please refer to the description of 943 * **bpf_perf_event_read_value**\ () for details. 944 * Return 945 * The value of the perf event counter read from the map, or a 946 * negative error code in case of failure. 947 * 948 * int bpf_redirect(u32 ifindex, u64 flags) 949 * Description 950 * Redirect the packet to another net device of index *ifindex*. 951 * This helper is somewhat similar to **bpf_clone_redirect**\ 952 * (), except that the packet is not cloned, which provides 953 * increased performance. 954 * 955 * Except for XDP, both ingress and egress interfaces can be used 956 * for redirection. The **BPF_F_INGRESS** value in *flags* is used 957 * to make the distinction (ingress path is selected if the flag 958 * is present, egress path otherwise). Currently, XDP only 959 * supports redirection to the egress interface, and accepts no 960 * flag at all. 961 * 962 * The same effect can be attained with the more generic 963 * **bpf_redirect_map**\ (), which requires specific maps to be 964 * used but offers better performance. 965 * Return 966 * For XDP, the helper returns **XDP_REDIRECT** on success or 967 * **XDP_ABORTED** on error. For other program types, the values 968 * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on 969 * error. 970 * 971 * u32 bpf_get_route_realm(struct sk_buff *skb) 972 * Description 973 * Retrieve the realm or the route, that is to say the 974 * **tclassid** field of the destination for the *skb*. The 975 * indentifier retrieved is a user-provided tag, similar to the 976 * one used with the net_cls cgroup (see description for 977 * **bpf_get_cgroup_classid**\ () helper), but here this tag is 978 * held by a route (a destination entry), not by a task. 979 * 980 * Retrieving this identifier works with the clsact TC egress hook 981 * (see also **tc-bpf(8)**), or alternatively on conventional 982 * classful egress qdiscs, but not on TC ingress path. In case of 983 * clsact TC egress hook, this has the advantage that, internally, 984 * the destination entry has not been dropped yet in the transmit 985 * path. Therefore, the destination entry does not need to be 986 * artificially held via **netif_keep_dst**\ () for a classful 987 * qdisc until the *skb* is freed. 988 * 989 * This helper is available only if the kernel was compiled with 990 * **CONFIG_IP_ROUTE_CLASSID** configuration option. 991 * Return 992 * The realm of the route for the packet associated to *skb*, or 0 993 * if none was found. 994 * 995 * int bpf_perf_event_output(struct pt_reg *ctx, struct bpf_map *map, u64 flags, void *data, u64 size) 996 * Description 997 * Write raw *data* blob into a special BPF perf event held by 998 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf 999 * event must have the following attributes: **PERF_SAMPLE_RAW** 1000 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
1001 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. 1002 * 1003 * The *flags* are used to indicate the index in *map* for which 1004 * the value must be put, masked with **BPF_F_INDEX_MASK**. 1005 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** 1006 * to indicate that the index of the current CPU core should be 1007 * used. 1008 * 1009 * The value to write, of *size*, is passed through eBPF stack and 1010 * pointed by *data*. 1011 * 1012 * The context of the program *ctx* needs also be passed to the 1013 * helper. 1014 * 1015 * On user space, a program willing to read the values needs to 1016 * call **perf_event_open**\ () on the perf event (either for 1017 * one or for all CPUs) and to store the file descriptor into the 1018 * *map*. This must be done before the eBPF program can send data 1019 * into it. An example is available in file 1020 * *samples/bpf/trace_output_user.c* in the Linux kernel source 1021 * tree (the eBPF program counterpart is in 1022 * *samples/bpf/trace_output_kern.c*). 1023 * 1024 * **bpf_perf_event_output**\ () achieves better performance 1025 * than **bpf_trace_printk**\ () for sharing data with user 1026 * space, and is much better suitable for streaming data from eBPF 1027 * programs. 1028 * 1029 * Note that this helper is not restricted to tracing use cases 1030 * and can be used with programs attached to TC or XDP as well, 1031 * where it allows for passing data to user space listeners. Data 1032 * can be: 1033 * 1034 * * Only custom structs, 1035 * * Only the packet payload, or 1036 * * A combination of both. 1037 * Return 1038 * 0 on success, or a negative error in case of failure. 1039 * 1040 * int bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len) 1041 * Description 1042 * This helper was provided as an easy way to load data from a 1043 * packet. It can be used to load *len* bytes from *offset* from 1044 * the packet associated to *skb*, into the buffer pointed by 1045 * *to*. 1046 * 1047 * Since Linux 4.7, usage of this helper has mostly been replaced 1048 * by "direct packet access", enabling packet data to be 1049 * manipulated with *skb*\ **->data** and *skb*\ **->data_end** 1050 * pointing respectively to the first byte of packet data and to 1051 * the byte after the last byte of packet data. However, it 1052 * remains useful if one wishes to read large quantities of data 1053 * at once from a packet into the eBPF stack. 1054 * Return 1055 * 0 on success, or a negative error in case of failure. 1056 * 1057 * int bpf_get_stackid(struct pt_reg *ctx, struct bpf_map *map, u64 flags) 1058 * Description 1059 * Walk a user or a kernel stack and return its id. To achieve 1060 * this, the helper needs *ctx*, which is a pointer to the context 1061 * on which the tracing program is executed, and a pointer to a 1062 * *map* of type **BPF_MAP_TYPE_STACK_TRACE**. 1063 * 1064 * The last argument, *flags*, holds the number of stack frames to 1065 * skip (from 0 to 255), masked with 1066 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set 1067 * a combination of the following flags: 1068 * 1069 * **BPF_F_USER_STACK** 1070 * Collect a user space stack instead of a kernel stack. 1071 * **BPF_F_FAST_STACK_CMP** 1072 * Compare stacks by hash only. 1073 * **BPF_F_REUSE_STACKID** 1074 * If two different stacks hash into the same *stackid*, 1075 * discard the old one. 1076 * 1077 * The stack id retrieved is a 32 bit long integer handle which 1078 * can be further combined with other data (including other stack 1079 * ids) and used as a key into maps. This can be useful for 1080 * generating a variety of graphs (such as flame graphs or off-cpu 1081 * graphs). 1082 * 1083 * For walking a stack, this helper is an improvement over 1084 * **bpf_probe_read**\ (), which can be used with unrolled loops 1085 * but is not efficient and consumes a lot of eBPF instructions. 1086 * Instead, **bpf_get_stackid**\ () can collect up to 1087 * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that 1088 * this limit can be controlled with the **sysctl** program, and 1089 * that it should be manually increased in order to profile long 1090 * user stacks (such as stacks for Java programs). To do so, use: 1091 * 1092 * :: 1093 * 1094 * # sysctl kernel.perf_event_max_stack=<new value> 1095 * Return 1096 * The positive or null stack id on success, or a negative error 1097 * in case of failure. 1098 * 1099 * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed) 1100 * Description 1101 * Compute a checksum difference, from the raw buffer pointed by 1102 * *from*, of length *from_size* (that must be a multiple of 4), 1103 * towards the raw buffer pointed by *to*, of size *to_size* 1104 * (same remark). An optional *seed* can be added to the value 1105 * (this can be cascaded, the seed may come from a previous call 1106 * to the helper). 1107 * 1108 * This is flexible enough to be used in several ways: 1109 * 1110 * * With *from_size* == 0, *to_size* > 0 and *seed* set to 1111 * checksum, it can be used when pushing new data. 1112 * * With *from_size* > 0, *to_size* == 0 and *seed* set to 1113 * checksum, it can be used when removing data from a packet. 1114 * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it 1115 * can be used to compute a diff. Note that *from_size* and 1116 * *to_size* do not need to be equal. 1117 * 1118 * This helper can be used in combination with 1119 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to 1120 * which one can feed in the difference computed with 1121 * **bpf_csum_diff**\ (). 1122 * Return 1123 * The checksum result, or a negative error code in case of 1124 * failure. 1125 * 1126 * int bpf_skb_get_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size) 1127 * Description 1128 * Retrieve tunnel options metadata for the packet associated to 1129 * *skb*, and store the raw tunnel option data to the buffer *opt* 1130 * of *size*. 1131 * 1132 * This helper can be used with encapsulation devices that can 1133 * operate in "collect metadata" mode (please refer to the related 1134 * note in the description of **bpf_skb_get_tunnel_key**\ () for 1135 * more details). A particular example where this can be used is 1136 * in combination with the Geneve encapsulation protocol, where it 1137 * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper) 1138 * and retrieving arbitrary TLVs (Type-Length-Value headers) from 1139 * the eBPF program. This allows for full customization of these 1140 * headers. 1141 * Return 1142 * The size of the option data retrieved. 1143 * 1144 * int bpf_skb_set_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size) 1145 * Description 1146 * Set tunnel options metadata for the packet associated to *skb* 1147 * to the option data contained in the raw buffer *opt* of *size*. 1148 * 1149 * See also the description of the **bpf_skb_get_tunnel_opt**\ () 1150 * helper for additional information. 1151 * Return 1152 * 0 on success, or a negative error in case of failure. 1153 * 1154 * int bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags) 1155 * Description 1156 * Change the protocol of the *skb* to *proto*. Currently 1157 * supported are transition from IPv4 to IPv6, and from IPv6 to 1158 * IPv4. The helper takes care of the groundwork for the 1159 * transition, including resizing the socket buffer. The eBPF 1160 * program is expected to fill the new headers, if any, via 1161 * **skb_store_bytes**\ () and to recompute the checksums with 1162 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ 1163 * (). The main case for this helper is to perform NAT64 1164 * operations out of an eBPF program. 1165 * 1166 * Internally, the GSO type is marked as dodgy so that headers are 1167 * checked and segments are recalculated by the GSO/GRO engine. 1168 * The size for GSO target is adapted as well. 1169 * 1170 * All values for *flags* are reserved for future usage, and must 1171 * be left at zero. 1172 * 1173 * A call to this helper is susceptible to change the underlying 1174 * packet buffer. Therefore, at load time, all checks on pointers 1175 * previously done by the verifier are invalidated and must be 1176 * performed again, if the helper is used in combination with 1177 * direct packet access. 1178 * Return 1179 * 0 on success, or a negative error in case of failure. 1180 * 1181 * int bpf_skb_change_type(struct sk_buff *skb, u32 type) 1182 * Description 1183 * Change the packet type for the packet associated to *skb*. This 1184 * comes down to setting *skb*\ **->pkt_type** to *type*, except 1185 * the eBPF program does not have a write access to *skb*\ 1186 * **->pkt_type** beside this helper. Using a helper here allows 1187 * for graceful handling of errors. 1188 * 1189 * The major use case is to change incoming *skb*s to 1190 * **PACKET_HOST** in a programmatic way instead of having to 1191 * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for 1192 * example. 1193 * 1194 * Note that *type* only allows certain values. At this time, they 1195 * are: 1196 * 1197 * **PACKET_HOST** 1198 * Packet is for us. 1199 * **PACKET_BROADCAST** 1200 * Send packet to all. 1201 * **PACKET_MULTICAST** 1202 * Send packet to group. 1203 * **PACKET_OTHERHOST** 1204 * Send packet to someone else. 1205 * Return 1206 * 0 on success, or a negative error in case of failure. 1207 * 1208 * int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index) 1209 * Description 1210 * Check whether *skb* is a descendant of the cgroup2 held by 1211 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. 1212 * Return 1213 * The return value depends on the result of the test, and can be: 1214 * 1215 * * 0, if the *skb* failed the cgroup2 descendant test. 1216 * * 1, if the *skb* succeeded the cgroup2 descendant test. 1217 * * A negative error code, if an error occurred. 1218 * 1219 * u32 bpf_get_hash_recalc(struct sk_buff *skb) 1220 * Description 1221 * Retrieve the hash of the packet, *skb*\ **->hash**. If it is 1222 * not set, in particular if the hash was cleared due to mangling, 1223 * recompute this hash. Later accesses to the hash can be done 1224 * directly with *skb*\ **->hash**. 1225 * 1226 * Calling **bpf_set_hash_invalid**\ (), changing a packet 1227 * prototype with **bpf_skb_change_proto**\ (), or calling 1228 * **bpf_skb_store_bytes**\ () with the 1229 * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear 1230 * the hash and to trigger a new computation for the next call to 1231 * **bpf_get_hash_recalc**\ (). 1232 * Return 1233 * The 32-bit hash. 1234 * 1235 * u64 bpf_get_current_task(void) 1236 * Return 1237 * A pointer to the current task struct. 1238 * 1239 * int bpf_probe_write_user(void *dst, const void *src, u32 len) 1240 * Description 1241 * Attempt in a safe way to write *len* bytes from the buffer 1242 * *src* to *dst* in memory. It only works for threads that are in 1243 * user context, and *dst* must be a valid user space address. 1244 * 1245 * This helper should not be used to implement any kind of 1246 * security mechanism because of TOC-TOU attacks, but rather to 1247 * debug, divert, and manipulate execution of semi-cooperative 1248 * processes. 1249 * 1250 * Keep in mind that this feature is meant for experiments, and it 1251 * has a risk of crashing the system and running programs. 1252 * Therefore, when an eBPF program using this helper is attached, 1253 * a warning including PID and process name is printed to kernel 1254 * logs. 1255 * Return 1256 * 0 on success, or a negative error in case of failure. 1257 * 1258 * int bpf_current_task_under_cgroup(struct bpf_map *map, u32 index) 1259 * Description 1260 * Check whether the probe is being run is the context of a given 1261 * subset of the cgroup2 hierarchy. The cgroup2 to test is held by 1262 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. 1263 * Return 1264 * The return value depends on the result of the test, and can be: 1265 * 1266 * * 0, if the *skb* task belongs to the cgroup2. 1267 * * 1, if the *skb* task does not belong to the cgroup2. 1268 * * A negative error code, if an error occurred. 1269 * 1270 * int bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags) 1271 * Description 1272 * Resize (trim or grow) the packet associated to *skb* to the 1273 * new *len*. The *flags* are reserved for future usage, and must 1274 * be left at zero. 1275 * 1276 * The basic idea is that the helper performs the needed work to 1277 * change the size of the packet, then the eBPF program rewrites 1278 * the rest via helpers like **bpf_skb_store_bytes**\ (), 1279 * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ () 1280 * and others. This helper is a slow path utility intended for 1281 * replies with control messages. And because it is targeted for 1282 * slow path, the helper itself can afford to be slow: it 1283 * implicitly linearizes, unclones and drops offloads from the 1284 * *skb*. 1285 * 1286 * A call to this helper is susceptible to change the underlying 1287 * packet buffer. Therefore, at load time, all checks on pointers 1288 * previously done by the verifier are invalidated and must be 1289 * performed again, if the helper is used in combination with 1290 * direct packet access. 1291 * Return 1292 * 0 on success, or a negative error in case of failure. 1293 * 1294 * int bpf_skb_pull_data(struct sk_buff *skb, u32 len) 1295 * Description 1296 * Pull in non-linear data in case the *skb* is non-linear and not 1297 * all of *len* are part of the linear section. Make *len* bytes 1298 * from *skb* readable and writable. If a zero value is passed for 1299 * *len*, then the whole length of the *skb* is pulled. 1300 * 1301 * This helper is only needed for reading and writing with direct 1302 * packet access. 1303 * 1304 * For direct packet access, testing that offsets to access 1305 * are within packet boundaries (test on *skb*\ **->data_end**) is 1306 * susceptible to fail if offsets are invalid, or if the requested 1307 * data is in non-linear parts of the *skb*. On failure the 1308 * program can just bail out, or in the case of a non-linear 1309 * buffer, use a helper to make the data available. The 1310 * **bpf_skb_load_bytes**\ () helper is a first solution to access 1311 * the data. Another one consists in using **bpf_skb_pull_data** 1312 * to pull in once the non-linear parts, then retesting and 1313 * eventually access the data. 1314 * 1315 * At the same time, this also makes sure the *skb* is uncloned, 1316 * which is a necessary condition for direct write. As this needs 1317 * to be an invariant for the write part only, the verifier 1318 * detects writes and adds a prologue that is calling 1319 * **bpf_skb_pull_data()** to effectively unclone the *skb* from 1320 * the very beginning in case it is indeed cloned. 1321 * 1322 * A call to this helper is susceptible to change the underlying 1323 * packet buffer. Therefore, at load time, all checks on pointers 1324 * previously done by the verifier are invalidated and must be 1325 * performed again, if the helper is used in combination with 1326 * direct packet access. 1327 * Return 1328 * 0 on success, or a negative error in case of failure. 1329 * 1330 * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum) 1331 * Description 1332 * Add the checksum *csum* into *skb*\ **->csum** in case the 1333 * driver has supplied a checksum for the entire packet into that 1334 * field. Return an error otherwise. This helper is intended to be 1335 * used in combination with **bpf_csum_diff**\ (), in particular 1336 * when the checksum needs to be updated after data has been 1337 * written into the packet through direct packet access. 1338 * Return 1339 * The checksum on success, or a negative error code in case of 1340 * failure. 1341 * 1342 * void bpf_set_hash_invalid(struct sk_buff *skb) 1343 * Description 1344 * Invalidate the current *skb*\ **->hash**. It can be used after 1345 * mangling on headers through direct packet access, in order to 1346 * indicate that the hash is outdated and to trigger a 1347 * recalculation the next time the kernel tries to access this 1348 * hash or when the **bpf_get_hash_recalc**\ () helper is called. 1349 * 1350 * int bpf_get_numa_node_id(void) 1351 * Description 1352 * Return the id of the current NUMA node. The primary use case 1353 * for this helper is the selection of sockets for the local NUMA 1354 * node, when the program is attached to sockets using the 1355 * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**), 1356 * but the helper is also available to other eBPF program types, 1357 * similarly to **bpf_get_smp_processor_id**\ (). 1358 * Return 1359 * The id of current NUMA node. 1360 * 1361 * int bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags) 1362 * Description 1363 * Grows headroom of packet associated to *skb* and adjusts the 1364 * offset of the MAC header accordingly, adding *len* bytes of 1365 * space. It automatically extends and reallocates memory as 1366 * required. 1367 * 1368 * This helper can be used on a layer 3 *skb* to push a MAC header 1369 * for redirection into a layer 2 device. 1370 * 1371 * All values for *flags* are reserved for future usage, and must 1372 * be left at zero. 1373 * 1374 * A call to this helper is susceptible to change the underlying 1375 * packet buffer. Therefore, at load time, all checks on pointers 1376 * previously done by the verifier are invalidated and must be 1377 * performed again, if the helper is used in combination with 1378 * direct packet access. 1379 * Return 1380 * 0 on success, or a negative error in case of failure. 1381 * 1382 * int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta) 1383 * Description 1384 * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that 1385 * it is possible to use a negative value for *delta*. This helper 1386 * can be used to prepare the packet for pushing or popping 1387 * headers. 1388 * 1389 * A call to this helper is susceptible to change the underlying 1390 * packet buffer. Therefore, at load time, all checks on pointers 1391 * previously done by the verifier are invalidated and must be 1392 * performed again, if the helper is used in combination with 1393 * direct packet access. 1394 * Return 1395 * 0 on success, or a negative error in case of failure. 1396 * 1397 * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr) 1398 * Description 1399 * Copy a NUL terminated string from an unsafe address 1400 * *unsafe_ptr* to *dst*. The *size* should include the 1401 * terminating NUL byte. In case the string length is smaller than 1402 * *size*, the target is not padded with further NUL bytes. If the 1403 * string length is larger than *size*, just *size*-1 bytes are 1404 * copied and the last byte is set to NUL. 1405 * 1406 * On success, the length of the copied string is returned. This 1407 * makes this helper useful in tracing programs for reading 1408 * strings, and more importantly to get its length at runtime. See 1409 * the following snippet: 1410 * 1411 * :: 1412 * 1413 * SEC("kprobe/sys_open") 1414 * void bpf_sys_open(struct pt_regs *ctx) 1415 * { 1416 * char buf[PATHLEN]; // PATHLEN is defined to 256 1417 * int res = bpf_probe_read_str(buf, sizeof(buf), 1418 * ctx->di); 1419 * 1420 * // Consume buf, for example push it to 1421 * // userspace via bpf_perf_event_output(); we 1422 * // can use res (the string length) as event 1423 * // size, after checking its boundaries. 1424 * } 1425 * 1426 * In comparison, using **bpf_probe_read()** helper here instead 1427 * to read the string would require to estimate the length at 1428 * compile time, and would often result in copying more memory 1429 * than necessary. 1430 * 1431 * Another useful use case is when parsing individual process 1432 * arguments or individual environment variables navigating 1433 * *current*\ **->mm->arg_start** and *current*\ 1434 * **->mm->env_start**: using this helper and the return value, 1435 * one can quickly iterate at the right offset of the memory area. 1436 * Return 1437 * On success, the strictly positive length of the string, 1438 * including the trailing NUL character. On error, a negative 1439 * value. 1440 * 1441 * u64 bpf_get_socket_cookie(struct sk_buff *skb) 1442 * Description 1443 * If the **struct sk_buff** pointed by *skb* has a known socket, 1444 * retrieve the cookie (generated by the kernel) of this socket. 1445 * If no cookie has been set yet, generate a new cookie. Once 1446 * generated, the socket cookie remains stable for the life of the 1447 * socket. This helper can be useful for monitoring per socket 1448 * networking traffic statistics as it provides a unique socket 1449 * identifier per namespace. 1450 * Return 1451 * A 8-byte long non-decreasing number on success, or 0 if the 1452 * socket field is missing inside *skb*. 1453 * 1454 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx) 1455 * Description 1456 * Equivalent to bpf_get_socket_cookie() helper that accepts 1457 * *skb*, but gets socket from **struct bpf_sock_addr** context. 1458 * Return 1459 * A 8-byte long non-decreasing number. 1460 * 1461 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx) 1462 * Description 1463 * Equivalent to bpf_get_socket_cookie() helper that accepts 1464 * *skb*, but gets socket from **struct bpf_sock_ops** context. 1465 * Return 1466 * A 8-byte long non-decreasing number. 1467 * 1468 * u32 bpf_get_socket_uid(struct sk_buff *skb) 1469 * Return 1470 * The owner UID of the socket associated to *skb*. If the socket 1471 * is **NULL**, or if it is not a full socket (i.e. if it is a 1472 * time-wait or a request socket instead), **overflowuid** value 1473 * is returned (note that **overflowuid** might also be the actual 1474 * UID value for the socket). 1475 * 1476 * u32 bpf_set_hash(struct sk_buff *skb, u32 hash) 1477 * Description 1478 * Set the full hash for *skb* (set the field *skb*\ **->hash**) 1479 * to value *hash*. 1480 * Return 1481 * 0 1482 * 1483 * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen) 1484 * Description 1485 * Emulate a call to **setsockopt()** on the socket associated to 1486 * *bpf_socket*, which must be a full socket. The *level* at 1487 * which the option resides and the name *optname* of the option 1488 * must be specified, see **setsockopt(2)** for more information. 1489 * The option value of length *optlen* is pointed by *optval*. 1490 * 1491 * This helper actually implements a subset of **setsockopt()**. 1492 * It supports the following *level*\ s: 1493 * 1494 * * **SOL_SOCKET**, which supports the following *optname*\ s: 1495 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, 1496 * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**. 1497 * * **IPPROTO_TCP**, which supports the following *optname*\ s: 1498 * **TCP_CONGESTION**, **TCP_BPF_IW**, 1499 * **TCP_BPF_SNDCWND_CLAMP**. 1500 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. 1501 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**. 1502 * Return 1503 * 0 on success, or a negative error in case of failure. 1504 * 1505 * int bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags) 1506 * Description 1507 * Grow or shrink the room for data in the packet associated to 1508 * *skb* by *len_diff*, and according to the selected *mode*. 1509 * 1510 * There are two supported modes at this time: 1511 * 1512 * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer 1513 * (room space is added or removed below the layer 2 header). 1514 * 1515 * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer 1516 * (room space is added or removed below the layer 3 header). 1517 * 1518 * The following flags are supported at this time: 1519 * 1520 * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size. 1521 * Adjusting mss in this way is not allowed for datagrams. 1522 * 1523 * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**, 1524 * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**: 1525 * Any new space is reserved to hold a tunnel header. 1526 * Configure skb offsets and other fields accordingly. 1527 * 1528 * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**, 1529 * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**: 1530 * Use with ENCAP_L3 flags to further specify the tunnel type. 1531 * 1532 * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*): 1533 * Use with ENCAP_L3/L4 flags to further specify the tunnel 1534 * type; *len* is the length of the inner MAC header. 1535 * 1536 * A call to this helper is susceptible to change the underlying 1537 * packet buffer. Therefore, at load time, all checks on pointers 1538 * previously done by the verifier are invalidated and must be 1539 * performed again, if the helper is used in combination with 1540 * direct packet access. 1541 * Return 1542 * 0 on success, or a negative error in case of failure. 1543 * 1544 * int bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags) 1545 * Description 1546 * Redirect the packet to the endpoint referenced by *map* at 1547 * index *key*. Depending on its type, this *map* can contain 1548 * references to net devices (for forwarding packets through other 1549 * ports), or to CPUs (for redirecting XDP frames to another CPU; 1550 * but this is only implemented for native XDP (with driver 1551 * support) as of this writing). 1552 * 1553 * All values for *flags* are reserved for future usage, and must 1554 * be left at zero. 1555 * 1556 * When used to redirect packets to net devices, this helper 1557 * provides a high performance increase over **bpf_redirect**\ (). 1558 * This is due to various implementation details of the underlying 1559 * mechanisms, one of which is the fact that **bpf_redirect_map**\ 1560 * () tries to send packet as a "bulk" to the device. 1561 * Return 1562 * **XDP_REDIRECT** on success, or **XDP_ABORTED** on error. 1563 * 1564 * int bpf_sk_redirect_map(struct bpf_map *map, u32 key, u64 flags) 1565 * Description 1566 * Redirect the packet to the socket referenced by *map* (of type 1567 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and 1568 * egress interfaces can be used for redirection. The 1569 * **BPF_F_INGRESS** value in *flags* is used to make the 1570 * distinction (ingress path is selected if the flag is present, 1571 * egress path otherwise). This is the only flag supported for now. 1572 * Return 1573 * **SK_PASS** on success, or **SK_DROP** on error. 1574 * 1575 * int bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) 1576 * Description 1577 * Add an entry to, or update a *map* referencing sockets. The 1578 * *skops* is used as a new value for the entry associated to 1579 * *key*. *flags* is one of: 1580 * 1581 * **BPF_NOEXIST** 1582 * The entry for *key* must not exist in the map. 1583 * **BPF_EXIST** 1584 * The entry for *key* must already exist in the map. 1585 * **BPF_ANY** 1586 * No condition on the existence of the entry for *key*. 1587 * 1588 * If the *map* has eBPF programs (parser and verdict), those will 1589 * be inherited by the socket being added. If the socket is 1590 * already attached to eBPF programs, this results in an error. 1591 * Return 1592 * 0 on success, or a negative error in case of failure. 1593 * 1594 * int bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta) 1595 * Description 1596 * Adjust the address pointed by *xdp_md*\ **->data_meta** by 1597 * *delta* (which can be positive or negative). Note that this 1598 * operation modifies the address stored in *xdp_md*\ **->data**, 1599 * so the latter must be loaded only after the helper has been 1600 * called. 1601 * 1602 * The use of *xdp_md*\ **->data_meta** is optional and programs 1603 * are not required to use it. The rationale is that when the 1604 * packet is processed with XDP (e.g. as DoS filter), it is 1605 * possible to push further meta data along with it before passing 1606 * to the stack, and to give the guarantee that an ingress eBPF 1607 * program attached as a TC classifier on the same device can pick 1608 * this up for further post-processing. Since TC works with socket 1609 * buffers, it remains possible to set from XDP the **mark** or 1610 * **priority** pointers, or other pointers for the socket buffer. 1611 * Having this scratch space generic and programmable allows for 1612 * more flexibility as the user is free to store whatever meta 1613 * data they need. 1614 * 1615 * A call to this helper is susceptible to change the underlying 1616 * packet buffer. Therefore, at load time, all checks on pointers 1617 * previously done by the verifier are invalidated and must be 1618 * performed again, if the helper is used in combination with 1619 * direct packet access. 1620 * Return 1621 * 0 on success, or a negative error in case of failure. 1622 * 1623 * int bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size) 1624 * Description 1625 * Read the value of a perf event counter, and store it into *buf* 1626 * of size *buf_size*. This helper relies on a *map* of type 1627 * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event 1628 * counter is selected when *map* is updated with perf event file 1629 * descriptors. The *map* is an array whose size is the number of 1630 * available CPUs, and each cell contains a value relative to one 1631 * CPU. The value to retrieve is indicated by *flags*, that 1632 * contains the index of the CPU to look up, masked with 1633 * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to 1634 * **BPF_F_CURRENT_CPU** to indicate that the value for the 1635 * current CPU should be retrieved. 1636 * 1637 * This helper behaves in a way close to 1638 * **bpf_perf_event_read**\ () helper, save that instead of 1639 * just returning the value observed, it fills the *buf* 1640 * structure. This allows for additional data to be retrieved: in 1641 * particular, the enabled and running times (in *buf*\ 1642 * **->enabled** and *buf*\ **->running**, respectively) are 1643 * copied. In general, **bpf_perf_event_read_value**\ () is 1644 * recommended over **bpf_perf_event_read**\ (), which has some 1645 * ABI issues and provides fewer functionalities. 1646 * 1647 * These values are interesting, because hardware PMU (Performance 1648 * Monitoring Unit) counters are limited resources. When there are 1649 * more PMU based perf events opened than available counters, 1650 * kernel will multiplex these events so each event gets certain 1651 * percentage (but not all) of the PMU time. In case that 1652 * multiplexing happens, the number of samples or counter value 1653 * will not reflect the case compared to when no multiplexing 1654 * occurs. This makes comparison between different runs difficult. 1655 * Typically, the counter value should be normalized before 1656 * comparing to other experiments. The usual normalization is done 1657 * as follows. 1658 * 1659 * :: 1660 * 1661 * normalized_counter = counter * t_enabled / t_running 1662 * 1663 * Where t_enabled is the time enabled for event and t_running is 1664 * the time running for event since last normalization. The 1665 * enabled and running times are accumulated since the perf event 1666 * open. To achieve scaling factor between two invocations of an 1667 * eBPF program, users can can use CPU id as the key (which is 1668 * typical for perf array usage model) to remember the previous 1669 * value and do the calculation inside the eBPF program. 1670 * Return 1671 * 0 on success, or a negative error in case of failure. 1672 * 1673 * int bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size) 1674 * Description 1675 * For en eBPF program attached to a perf event, retrieve the 1676 * value of the event counter associated to *ctx* and store it in 1677 * the structure pointed by *buf* and of size *buf_size*. Enabled 1678 * and running times are also stored in the structure (see 1679 * description of helper **bpf_perf_event_read_value**\ () for 1680 * more details). 1681 * Return 1682 * 0 on success, or a negative error in case of failure. 1683 * 1684 * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen) 1685 * Description 1686 * Emulate a call to **getsockopt()** on the socket associated to 1687 * *bpf_socket*, which must be a full socket. The *level* at 1688 * which the option resides and the name *optname* of the option 1689 * must be specified, see **getsockopt(2)** for more information. 1690 * The retrieved value is stored in the structure pointed by 1691 * *opval* and of length *optlen*. 1692 * 1693 * This helper actually implements a subset of **getsockopt()**. 1694 * It supports the following *level*\ s: 1695 * 1696 * * **IPPROTO_TCP**, which supports *optname* 1697 * **TCP_CONGESTION**. 1698 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. 1699 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**. 1700 * Return 1701 * 0 on success, or a negative error in case of failure. 1702 * 1703 * int bpf_override_return(struct pt_reg *regs, u64 rc) 1704 * Description 1705 * Used for error injection, this helper uses kprobes to override 1706 * the return value of the probed function, and to set it to *rc*. 1707 * The first argument is the context *regs* on which the kprobe 1708 * works. 1709 * 1710 * This helper works by setting setting the PC (program counter) 1711 * to an override function which is run in place of the original 1712 * probed function. This means the probed function is not run at 1713 * all. The replacement function just returns with the required 1714 * value. 1715 * 1716 * This helper has security implications, and thus is subject to 1717 * restrictions. It is only available if the kernel was compiled 1718 * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration 1719 * option, and in this case it only works on functions tagged with 1720 * **ALLOW_ERROR_INJECTION** in the kernel code. 1721 * 1722 * Also, the helper is only available for the architectures having 1723 * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing, 1724 * x86 architecture is the only one to support this feature. 1725 * Return 1726 * 0 1727 * 1728 * int bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval) 1729 * Description 1730 * Attempt to set the value of the **bpf_sock_ops_cb_flags** field 1731 * for the full TCP socket associated to *bpf_sock_ops* to 1732 * *argval*. 1733 * 1734 * The primary use of this field is to determine if there should 1735 * be calls to eBPF programs of type 1736 * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP 1737 * code. A program of the same type can change its value, per 1738 * connection and as necessary, when the connection is 1739 * established. This field is directly accessible for reading, but 1740 * this helper must be used for updates in order to return an 1741 * error if an eBPF program tries to set a callback that is not 1742 * supported in the current kernel. 1743 * 1744 * *argval* is a flag array which can combine these flags: 1745 * 1746 * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out) 1747 * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission) 1748 * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change) 1749 * 1750 * Therefore, this function can be used to clear a callback flag by 1751 * setting the appropriate bit to zero. e.g. to disable the RTO 1752 * callback: 1753 * 1754 * **bpf_sock_ops_cb_flags_set(bpf_sock,** 1755 * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)** 1756 * 1757 * Here are some examples of where one could call such eBPF 1758 * program: 1759 * 1760 * * When RTO fires. 1761 * * When a packet is retransmitted. 1762 * * When the connection terminates. 1763 * * When a packet is sent. 1764 * * When a packet is received. 1765 * Return 1766 * Code **-EINVAL** if the socket is not a full TCP socket; 1767 * otherwise, a positive number containing the bits that could not 1768 * be set is returned (which comes down to 0 if all bits were set 1769 * as required). 1770 * 1771 * int bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags) 1772 * Description 1773 * This helper is used in programs implementing policies at the 1774 * socket level. If the message *msg* is allowed to pass (i.e. if 1775 * the verdict eBPF program returns **SK_PASS**), redirect it to 1776 * the socket referenced by *map* (of type 1777 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and 1778 * egress interfaces can be used for redirection. The 1779 * **BPF_F_INGRESS** value in *flags* is used to make the 1780 * distinction (ingress path is selected if the flag is present, 1781 * egress path otherwise). This is the only flag supported for now. 1782 * Return 1783 * **SK_PASS** on success, or **SK_DROP** on error. 1784 * 1785 * int bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes) 1786 * Description 1787 * For socket policies, apply the verdict of the eBPF program to 1788 * the next *bytes* (number of bytes) of message *msg*. 1789 * 1790 * For example, this helper can be used in the following cases: 1791 * 1792 * * A single **sendmsg**\ () or **sendfile**\ () system call 1793 * contains multiple logical messages that the eBPF program is 1794 * supposed to read and for which it should apply a verdict. 1795 * * An eBPF program only cares to read the first *bytes* of a 1796 * *msg*. If the message has a large payload, then setting up 1797 * and calling the eBPF program repeatedly for all bytes, even 1798 * though the verdict is already known, would create unnecessary 1799 * overhead. 1800 * 1801 * When called from within an eBPF program, the helper sets a 1802 * counter internal to the BPF infrastructure, that is used to 1803 * apply the last verdict to the next *bytes*. If *bytes* is 1804 * smaller than the current data being processed from a 1805 * **sendmsg**\ () or **sendfile**\ () system call, the first 1806 * *bytes* will be sent and the eBPF program will be re-run with 1807 * the pointer for start of data pointing to byte number *bytes* 1808 * **+ 1**. If *bytes* is larger than the current data being 1809 * processed, then the eBPF verdict will be applied to multiple 1810 * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are 1811 * consumed. 1812 * 1813 * Note that if a socket closes with the internal counter holding 1814 * a non-zero value, this is not a problem because data is not 1815 * being buffered for *bytes* and is sent as it is received. 1816 * Return 1817 * 0 1818 * 1819 * int bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes) 1820 * Description 1821 * For socket policies, prevent the execution of the verdict eBPF 1822 * program for message *msg* until *bytes* (byte number) have been 1823 * accumulated. 1824 * 1825 * This can be used when one needs a specific number of bytes 1826 * before a verdict can be assigned, even if the data spans 1827 * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme 1828 * case would be a user calling **sendmsg**\ () repeatedly with 1829 * 1-byte long message segments. Obviously, this is bad for 1830 * performance, but it is still valid. If the eBPF program needs 1831 * *bytes* bytes to validate a header, this helper can be used to 1832 * prevent the eBPF program to be called again until *bytes* have 1833 * been accumulated. 1834 * Return 1835 * 0 1836 * 1837 * int bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags) 1838 * Description 1839 * For socket policies, pull in non-linear data from user space 1840 * for *msg* and set pointers *msg*\ **->data** and *msg*\ 1841 * **->data_end** to *start* and *end* bytes offsets into *msg*, 1842 * respectively. 1843 * 1844 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a 1845 * *msg* it can only parse data that the (**data**, **data_end**) 1846 * pointers have already consumed. For **sendmsg**\ () hooks this 1847 * is likely the first scatterlist element. But for calls relying 1848 * on the **sendpage** handler (e.g. **sendfile**\ ()) this will 1849 * be the range (**0**, **0**) because the data is shared with 1850 * user space and by default the objective is to avoid allowing 1851 * user space to modify data while (or after) eBPF verdict is 1852 * being decided. This helper can be used to pull in data and to 1853 * set the start and end pointer to given values. Data will be 1854 * copied if necessary (i.e. if data was not linear and if start 1855 * and end pointers do not point to the same chunk). 1856 * 1857 * A call to this helper is susceptible to change the underlying 1858 * packet buffer. Therefore, at load time, all checks on pointers 1859 * previously done by the verifier are invalidated and must be 1860 * performed again, if the helper is used in combination with 1861 * direct packet access. 1862 * 1863 * All values for *flags* are reserved for future usage, and must 1864 * be left at zero. 1865 * Return 1866 * 0 on success, or a negative error in case of failure. 1867 * 1868 * int bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) 1869 * Description 1870 * Bind the socket associated to *ctx* to the address pointed by 1871 * *addr*, of length *addr_len*. This allows for making outgoing 1872 * connection from the desired IP address, which can be useful for 1873 * example when all processes inside a cgroup should use one 1874 * single IP address on a host that has multiple IP configured. 1875 * 1876 * This helper works for IPv4 and IPv6, TCP and UDP sockets. The 1877 * domain (*addr*\ **->sa_family**) must be **AF_INET** (or 1878 * **AF_INET6**). Looking for a free port to bind to can be 1879 * expensive, therefore binding to port is not permitted by the 1880 * helper: *addr*\ **->sin_port** (or **sin6_port**, respectively) 1881 * must be set to zero. 1882 * Return 1883 * 0 on success, or a negative error in case of failure. 1884 * 1885 * int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta) 1886 * Description 1887 * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is 1888 * only possible to shrink the packet as of this writing, 1889 * therefore *delta* must be a negative integer. 1890 * 1891 * A call to this helper is susceptible to change the underlying 1892 * packet buffer. Therefore, at load time, all checks on pointers 1893 * previously done by the verifier are invalidated and must be 1894 * performed again, if the helper is used in combination with 1895 * direct packet access. 1896 * Return 1897 * 0 on success, or a negative error in case of failure. 1898 * 1899 * int bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags) 1900 * Description 1901 * Retrieve the XFRM state (IP transform framework, see also 1902 * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*. 1903 * 1904 * The retrieved value is stored in the **struct bpf_xfrm_state** 1905 * pointed by *xfrm_state* and of length *size*. 1906 * 1907 * All values for *flags* are reserved for future usage, and must 1908 * be left at zero. 1909 * 1910 * This helper is available only if the kernel was compiled with 1911 * **CONFIG_XFRM** configuration option. 1912 * Return 1913 * 0 on success, or a negative error in case of failure. 1914 * 1915 * int bpf_get_stack(struct pt_regs *regs, void *buf, u32 size, u64 flags) 1916 * Description 1917 * Return a user or a kernel stack in bpf program provided buffer. 1918 * To achieve this, the helper needs *ctx*, which is a pointer 1919 * to the context on which the tracing program is executed. 1920 * To store the stacktrace, the bpf program provides *buf* with 1921 * a nonnegative *size*. 1922 * 1923 * The last argument, *flags*, holds the number of stack frames to 1924 * skip (from 0 to 255), masked with 1925 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set 1926 * the following flags: 1927 * 1928 * **BPF_F_USER_STACK** 1929 * Collect a user space stack instead of a kernel stack. 1930 * **BPF_F_USER_BUILD_ID** 1931 * Collect buildid+offset instead of ips for user stack, 1932 * only valid if **BPF_F_USER_STACK** is also specified. 1933 * 1934 * **bpf_get_stack**\ () can collect up to 1935 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject 1936 * to sufficient large buffer size. Note that 1937 * this limit can be controlled with the **sysctl** program, and 1938 * that it should be manually increased in order to profile long 1939 * user stacks (such as stacks for Java programs). To do so, use: 1940 * 1941 * :: 1942 * 1943 * # sysctl kernel.perf_event_max_stack=<new value> 1944 * Return 1945 * A non-negative value equal to or less than *size* on success, 1946 * or a negative error in case of failure. 1947 * 1948 * int bpf_skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header) 1949 * Description 1950 * This helper is similar to **bpf_skb_load_bytes**\ () in that 1951 * it provides an easy way to load *len* bytes from *offset* 1952 * from the packet associated to *skb*, into the buffer pointed 1953 * by *to*. The difference to **bpf_skb_load_bytes**\ () is that 1954 * a fifth argument *start_header* exists in order to select a 1955 * base offset to start from. *start_header* can be one of: 1956 * 1957 * **BPF_HDR_START_MAC** 1958 * Base offset to load data from is *skb*'s mac header. 1959 * **BPF_HDR_START_NET** 1960 * Base offset to load data from is *skb*'s network header. 1961 * 1962 * In general, "direct packet access" is the preferred method to 1963 * access packet data, however, this helper is in particular useful 1964 * in socket filters where *skb*\ **->data** does not always point 1965 * to the start of the mac header and where "direct packet access" 1966 * is not available. 1967 * Return 1968 * 0 on success, or a negative error in case of failure. 1969 * 1970 * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) 1971 * Description 1972 * Do FIB lookup in kernel tables using parameters in *params*. 1973 * If lookup is successful and result shows packet is to be 1974 * forwarded, the neighbor tables are searched for the nexthop. 1975 * If successful (ie., FIB lookup shows forwarding and nexthop 1976 * is resolved), the nexthop address is returned in ipv4_dst 1977 * or ipv6_dst based on family, smac is set to mac address of 1978 * egress device, dmac is set to nexthop mac address, rt_metric 1979 * is set to metric from route (IPv4/IPv6 only), and ifindex 1980 * is set to the device index of the nexthop from the FIB lookup. 1981 * 1982 * *plen* argument is the size of the passed in struct. 1983 * *flags* argument can be a combination of one or more of the 1984 * following values: 1985 * 1986 * **BPF_FIB_LOOKUP_DIRECT** 1987 * Do a direct table lookup vs full lookup using FIB 1988 * rules. 1989 * **BPF_FIB_LOOKUP_OUTPUT** 1990 * Perform lookup from an egress perspective (default is 1991 * ingress). 1992 * 1993 * *ctx* is either **struct xdp_md** for XDP programs or 1994 * **struct sk_buff** tc cls_act programs. 1995 * Return 1996 * * < 0 if any input argument is invalid 1997 * * 0 on success (packet is forwarded, nexthop neighbor exists) 1998 * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the 1999 * packet is not forwarded or needs assist from full stack 2000 *
2001 * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags) 2002 * Description 2003 * Add an entry to, or update a sockhash *map* referencing sockets. 2004 * The *skops* is used as a new value for the entry associated to 2005 * *key*. *flags* is one of: 2006 * 2007 * **BPF_NOEXIST** 2008 * The entry for *key* must not exist in the map. 2009 * **BPF_EXIST** 2010 * The entry for *key* must already exist in the map. 2011 * **BPF_ANY** 2012 * No condition on the existence of the entry for *key*. 2013 * 2014 * If the *map* has eBPF programs (parser and verdict), those will 2015 * be inherited by the socket being added. If the socket is 2016 * already attached to eBPF programs, this results in an error. 2017 * Return 2018 * 0 on success, or a negative error in case of failure. 2019 * 2020 * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags) 2021 * Description 2022 * This helper is used in programs implementing policies at the 2023 * socket level. If the message *msg* is allowed to pass (i.e. if 2024 * the verdict eBPF program returns **SK_PASS**), redirect it to 2025 * the socket referenced by *map* (of type 2026 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and 2027 * egress interfaces can be used for redirection. The 2028 * **BPF_F_INGRESS** value in *flags* is used to make the 2029 * distinction (ingress path is selected if the flag is present, 2030 * egress path otherwise). This is the only flag supported for now. 2031 * Return 2032 * **SK_PASS** on success, or **SK_DROP** on error. 2033 * 2034 * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags) 2035 * Description 2036 * This helper is used in programs implementing policies at the 2037 * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. 2038 * if the verdeict eBPF program returns **SK_PASS**), redirect it 2039 * to the socket referenced by *map* (of type 2040 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and 2041 * egress interfaces can be used for redirection. The 2042 * **BPF_F_INGRESS** value in *flags* is used to make the 2043 * distinction (ingress path is selected if the flag is present, 2044 * egress otherwise). This is the only flag supported for now. 2045 * Return 2046 * **SK_PASS** on success, or **SK_DROP** on error. 2047 * 2048 * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) 2049 * Description 2050 * Encapsulate the packet associated to *skb* within a Layer 3 2051 * protocol header. This header is provided in the buffer at 2052 * address *hdr*, with *len* its size in bytes. *type* indicates 2053 * the protocol of the header and can be one of: 2054 * 2055 * **BPF_LWT_ENCAP_SEG6** 2056 * IPv6 encapsulation with Segment Routing Header 2057 * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, 2058 * the IPv6 header is computed by the kernel. 2059 * **BPF_LWT_ENCAP_SEG6_INLINE** 2060 * Only works if *skb* contains an IPv6 packet. Insert a 2061 * Segment Routing Header (**struct ipv6_sr_hdr**) inside 2062 * the IPv6 header. 2063 * **BPF_LWT_ENCAP_IP** 2064 * IP encapsulation (GRE/GUE/IPIP/etc). The outer header 2065 * must be IPv4 or IPv6, followed by zero or more 2066 * additional headers, up to **LWT_BPF_MAX_HEADROOM** 2067 * total bytes in all prepended headers. Please note that 2068 * if **skb_is_gso**\ (*skb*) is true, no more than two 2069 * headers can be prepended, and the inner header, if 2070 * present, should be either GRE or UDP/GUE. 2071 * 2072 * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs 2073 * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can 2074 * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and 2075 * **BPF_PROG_TYPE_LWT_XMIT**. 2076 * 2077 * A call to this helper is susceptible to change the underlying 2078 * packet buffer. Therefore, at load time, all checks on pointers 2079 * previously done by the verifier are invalidated and must be 2080 * performed again, if the helper is used in combination with 2081 * direct packet access. 2082 * Return 2083 * 0 on success, or a negative error in case of failure. 2084 * 2085 * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len) 2086 * Description 2087 * Store *len* bytes from address *from* into the packet 2088 * associated to *skb*, at *offset*. Only the flags, tag and TLVs 2089 * inside the outermost IPv6 Segment Routing Header can be 2090 * modified through this helper. 2091 * 2092 * A call to this helper is susceptible to change the underlying 2093 * packet buffer. Therefore, at load time, all checks on pointers 2094 * previously done by the verifier are invalidated and must be 2095 * performed again, if the helper is used in combination with 2096 * direct packet access. 2097 * Return 2098 * 0 on success, or a negative error in case of failure. 2099 * 2100 * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta) 2101 * Description 2102 * Adjust the size allocated to TLVs in the outermost IPv6 2103 * Segment Routing Header contained in the packet associated to 2104 * *skb*, at position *offset* by *delta* bytes. Only offsets 2105 * after the segments are accepted. *delta* can be as well 2106 * positive (growing) as negative (shrinking). 2107 * 2108 * A call to this helper is susceptible to change the underlying 2109 * packet buffer. Therefore, at load time, all checks on pointers 2110 * previously done by the verifier are invalidated and must be 2111 * performed again, if the helper is used in combination with 2112 * direct packet access. 2113 * Return 2114 * 0 on success, or a negative error in case of failure. 2115 * 2116 * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len) 2117 * Description 2118 * Apply an IPv6 Segment Routing action of type *action* to the 2119 * packet associated to *skb*. Each action takes a parameter 2120 * contained at address *param*, and of length *param_len* bytes. 2121 * *action* can be one of: 2122 * 2123 * **SEG6_LOCAL_ACTION_END_X** 2124 * End.X action: Endpoint with Layer-3 cross-connect. 2125 * Type of *param*: **struct in6_addr**. 2126 * **SEG6_LOCAL_ACTION_END_T** 2127 * End.T action: Endpoint with specific IPv6 table lookup. 2128 * Type of *param*: **int**. 2129 * **SEG6_LOCAL_ACTION_END_B6** 2130 * End.B6 action: Endpoint bound to an SRv6 policy. 2131 * Type of *param*: **struct ipv6_sr_hdr**. 2132 * **SEG6_LOCAL_ACTION_END_B6_ENCAP** 2133 * End.B6.Encap action: Endpoint bound to an SRv6 2134 * encapsulation policy. 2135 * Type of *param*: **struct ipv6_sr_hdr**. 2136 * 2137 * A call to this helper is susceptible to change the underlying 2138 * packet buffer. Therefore, at load time, all checks on pointers 2139 * previously done by the verifier are invalidated and must be 2140 * performed again, if the helper is used in combination with 2141 * direct packet access. 2142 * Return 2143 * 0 on success, or a negative error in case of failure. 2144 * 2145 * int bpf_rc_repeat(void *ctx) 2146 * Description 2147 * This helper is used in programs implementing IR decoding, to 2148 * report a successfully decoded repeat key message. This delays 2149 * the generation of a key up event for previously generated 2150 * key down event. 2151 * 2152 * Some IR protocols like NEC have a special IR message for 2153 * repeating last button, for when a button is held down. 2154 * 2155 * The *ctx* should point to the lirc sample as passed into 2156 * the program. 2157 * 2158 * This helper is only available is the kernel was compiled with 2159 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 2160 * "**y**". 2161 * Return 2162 * 0 2163 * 2164 * int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle) 2165 * Description 2166 * This helper is used in programs implementing IR decoding, to 2167 * report a successfully decoded key press with *scancode*, 2168 * *toggle* value in the given *protocol*. The scancode will be 2169 * translated to a keycode using the rc keymap, and reported as 2170 * an input key down event. After a period a key up event is 2171 * generated. This period can be extended by calling either 2172 * **bpf_rc_keydown**\ () again with the same values, or calling 2173 * **bpf_rc_repeat**\ (). 2174 * 2175 * Some protocols include a toggle bit, in case the button was 2176 * released and pressed again between consecutive scancodes. 2177 * 2178 * The *ctx* should point to the lirc sample as passed into 2179 * the program. 2180 * 2181 * The *protocol* is the decoded protocol number (see 2182 * **enum rc_proto** for some predefined values). 2183 * 2184 * This helper is only available is the kernel was compiled with 2185 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 2186 * "**y**". 2187 * Return 2188 * 0 2189 * 2190 * u64 bpf_skb_cgroup_id(struct sk_buff *skb) 2191 * Description 2192 * Return the cgroup v2 id of the socket associated with the *skb*. 2193 * This is roughly similar to the **bpf_get_cgroup_classid**\ () 2194 * helper for cgroup v1 by providing a tag resp. identifier that 2195 * can be matched on or used for map lookups e.g. to implement 2196 * policy. The cgroup v2 id of a given path in the hierarchy is 2197 * exposed in user space through the f_handle API in order to get 2198 * to the same 64-bit id. 2199 * 2200 * This helper can be used on TC egress path, but not on ingress, 2201 * and is available only if the kernel was compiled with the 2202 * **CONFIG_SOCK_CGROUP_DATA** configuration option. 2203 * Return 2204 * The id is returned or 0 in case the id could not be retrieved. 2205 * 2206 * u64 bpf_get_current_cgroup_id(void) 2207 * Return 2208 * A 64-bit integer containing the current cgroup id based 2209 * on the cgroup within which the current task is running. 2210 * 2211 * void *bpf_get_local_storage(void *map, u64 flags) 2212 * Description 2213 * Get the pointer to the local storage area. 2214 * The type and the size of the local storage is defined 2215 * by the *map* argument. 2216 * The *flags* meaning is specific for each map type, 2217 * and has to be 0 for cgroup local storage. 2218 * 2219 * Depending on the BPF program type, a local storage area 2220 * can be shared between multiple instances of the BPF program, 2221 * running simultaneously. 2222 * 2223 * A user should care about the synchronization by himself. 2224 * For example, by using the **BPF_STX_XADD** instruction to alter 2225 * the shared data. 2226 * Return 2227 * A pointer to the local storage area. 2228 * 2229 * int bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags) 2230 * Description 2231 * Select a **SO_REUSEPORT** socket from a 2232 * **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*. 2233 * It checks the selected socket is matching the incoming 2234 * request in the socket buffer. 2235 * Return 2236 * 0 on success, or a negative error in case of failure. 2237 * 2238 * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level) 2239 * Description 2240 * Return id of cgroup v2 that is ancestor of cgroup associated 2241 * with the *skb* at the *ancestor_level*. The root cgroup is at 2242 * *ancestor_level* zero and each step down the hierarchy 2243 * increments the level. If *ancestor_level* == level of cgroup 2244 * associated with *skb*, then return value will be same as that 2245 * of **bpf_skb_cgroup_id**\ (). 2246 * 2247 * The helper is useful to implement policies based on cgroups 2248 * that are upper in hierarchy than immediate cgroup associated 2249 * with *skb*. 2250 * 2251 * The format of returned id and helper limitations are same as in 2252 * **bpf_skb_cgroup_id**\ (). 2253 * Return 2254 * The id is returned or 0 in case the id could not be retrieved. 2255 * 2256 * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 2257 * Description 2258 * Look for TCP socket matching *tuple*, optionally in a child 2259 * network namespace *netns*. The return value must be checked, 2260 * and if non-**NULL**, released via **bpf_sk_release**\ (). 2261 * 2262 * The *ctx* should point to the context of the program, such as 2263 * the skb or socket (depending on the hook in use). This is used 2264 * to determine the base network namespace for the lookup. 2265 * 2266 * *tuple_size* must be one of: 2267 * 2268 * **sizeof**\ (*tuple*\ **->ipv4**) 2269 * Look for an IPv4 socket. 2270 * **sizeof**\ (*tuple*\ **->ipv6**) 2271 * Look for an IPv6 socket. 2272 * 2273 * If the *netns* is a negative signed 32-bit integer, then the 2274 * socket lookup table in the netns associated with the *ctx* will 2275 * will be used. For the TC hooks, this is the netns of the device 2276 * in the skb. For socket hooks, this is the netns of the socket. 2277 * If *netns* is any other signed 32-bit value greater than or 2278 * equal to zero then it specifies the ID of the netns relative to 2279 * the netns associated with the *ctx*. *netns* values beyond the 2280 * range of 32-bit integers are reserved for future use. 2281 * 2282 * All values for *flags* are reserved for future usage, and must 2283 * be left at zero. 2284 * 2285 * This helper is available only if the kernel was compiled with 2286 * **CONFIG_NET** configuration option. 2287 * Return 2288 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 2289 * For sockets with reuseport option, the **struct bpf_sock** 2290 * result is from *reuse*\ **->socks**\ [] using the hash of the 2291 * tuple. 2292 * 2293 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 2294 * Description 2295 * Look for UDP socket matching *tuple*, optionally in a child 2296 * network namespace *netns*. The return value must be checked, 2297 * and if non-**NULL**, released via **bpf_sk_release**\ (). 2298 * 2299 * The *ctx* should point to the context of the program, such as 2300 * the skb or socket (depending on the hook in use). This is used 2301 * to determine the base network namespace for the lookup. 2302 * 2303 * *tuple_size* must be one of: 2304 * 2305 * **sizeof**\ (*tuple*\ **->ipv4**) 2306 * Look for an IPv4 socket. 2307 * **sizeof**\ (*tuple*\ **->ipv6**) 2308 * Look for an IPv6 socket. 2309 * 2310 * If the *netns* is a negative signed 32-bit integer, then the 2311 * socket lookup table in the netns associated with the *ctx* will 2312 * will be used. For the TC hooks, this is the netns of the device 2313 * in the skb. For socket hooks, this is the netns of the socket. 2314 * If *netns* is any other signed 32-bit value greater than or 2315 * equal to zero then it specifies the ID of the netns relative to 2316 * the netns associated with the *ctx*. *netns* values beyond the 2317 * range of 32-bit integers are reserved for future use. 2318 * 2319 * All values for *flags* are reserved for future usage, and must 2320 * be left at zero. 2321 * 2322 * This helper is available only if the kernel was compiled with 2323 * **CONFIG_NET** configuration option. 2324 * Return 2325 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 2326 * For sockets with reuseport option, the **struct bpf_sock** 2327 * result is from *reuse*\ **->socks**\ [] using the hash of the 2328 * tuple. 2329 * 2330 * int bpf_sk_release(struct bpf_sock *sock) 2331 * Description 2332 * Release the reference held by *sock*. *sock* must be a 2333 * non-**NULL** pointer that was returned from 2334 * **bpf_sk_lookup_xxx**\ (). 2335 * Return 2336 * 0 on success, or a negative error in case of failure. 2337 * 2338 * int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags) 2339 * Description 2340 * Push an element *value* in *map*. *flags* is one of: 2341 * 2342 * **BPF_EXIST** 2343 * If the queue/stack is full, the oldest element is 2344 * removed to make room for this. 2345 * Return 2346 * 0 on success, or a negative error in case of failure. 2347 * 2348 * int bpf_map_pop_elem(struct bpf_map *map, void *value) 2349 * Description 2350 * Pop an element from *map*. 2351 * Return 2352 * 0 on success, or a negative error in case of failure. 2353 * 2354 * int bpf_map_peek_elem(struct bpf_map *map, void *value) 2355 * Description 2356 * Get an element from *map* without removing it. 2357 * Return 2358 * 0 on success, or a negative error in case of failure. 2359 * 2360 * int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags) 2361 * Description 2362 * For socket policies, insert *len* bytes into *msg* at offset 2363 * *start*. 2364 * 2365 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a 2366 * *msg* it may want to insert metadata or options into the *msg*. 2367 * This can later be read and used by any of the lower layer BPF 2368 * hooks. 2369 * 2370 * This helper may fail if under memory pressure (a malloc 2371 * fails) in these cases BPF programs will get an appropriate 2372 * error and BPF programs will need to handle them. 2373 * Return 2374 * 0 on success, or a negative error in case of failure. 2375 * 2376 * int bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 pop, u64 flags) 2377 * Description 2378 * Will remove *pop* bytes from a *msg* starting at byte *start*. 2379 * This may result in **ENOMEM** errors under certain situations if 2380 * an allocation and copy are required due to a full ring buffer. 2381 * However, the helper will try to avoid doing the allocation 2382 * if possible. Other errors can occur if input parameters are 2383 * invalid either due to *start* byte not being valid part of *msg* 2384 * payload and/or *pop* value being to large. 2385 * Return 2386 * 0 on success, or a negative error in case of failure. 2387 * 2388 * int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y) 2389 * Description 2390 * This helper is used in programs implementing IR decoding, to 2391 * report a successfully decoded pointer movement. 2392 * 2393 * The *ctx* should point to the lirc sample as passed into 2394 * the program. 2395 * 2396 * This helper is only available is the kernel was compiled with 2397 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to 2398 * "**y**". 2399 * Return 2400 * 0 2401 * 2402 * int bpf_spin_lock(struct bpf_spin_lock *lock) 2403 * Description 2404 * Acquire a spinlock represented by the pointer *lock*, which is 2405 * stored as part of a value of a map. Taking the lock allows to 2406 * safely update the rest of the fields in that value. The 2407 * spinlock can (and must) later be released with a call to 2408 * **bpf_spin_unlock**\ (\ *lock*\ ). 2409 * 2410 * Spinlocks in BPF programs come with a number of restrictions 2411 * and constraints: 2412 * 2413 * * **bpf_spin_lock** objects are only allowed inside maps of 2414 * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this 2415 * list could be extended in the future). 2416 * * BTF description of the map is mandatory. 2417 * * The BPF program can take ONE lock at a time, since taking two 2418 * or more could cause dead locks. 2419 * * Only one **struct bpf_spin_lock** is allowed per map element. 2420 * * When the lock is taken, calls (either BPF to BPF or helpers) 2421 * are not allowed. 2422 * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not 2423 * allowed inside a spinlock-ed region. 2424 * * The BPF program MUST call **bpf_spin_unlock**\ () to release 2425 * the lock, on all execution paths, before it returns. 2426 * * The BPF program can access **struct bpf_spin_lock** only via 2427 * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ () 2428 * helpers. Loading or storing data into the **struct 2429 * bpf_spin_lock** *lock*\ **;** field of a map is not allowed. 2430 * * To use the **bpf_spin_lock**\ () helper, the BTF description 2431 * of the map value must be a struct and have **struct 2432 * bpf_spin_lock** *anyname*\ **;** field at the top level. 2433 * Nested lock inside another struct is not allowed. 2434 * * The **struct bpf_spin_lock** *lock* field in a map value must 2435 * be aligned on a multiple of 4 bytes in that value. 2436 * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy 2437 * the **bpf_spin_lock** field to user space. 2438 * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from 2439 * a BPF program, do not update the **bpf_spin_lock** field. 2440 * * **bpf_spin_lock** cannot be on the stack or inside a 2441 * networking packet (it can only be inside of a map values). 2442 * * **bpf_spin_lock** is available to root only. 2443 * * Tracing programs and socket filter programs cannot use 2444 * **bpf_spin_lock**\ () due to insufficient preemption checks 2445 * (but this may change in the future). 2446 * * **bpf_spin_lock** is not allowed in inner maps of map-in-map. 2447 * Return 2448 * 0 2449 * 2450 * int bpf_spin_unlock(struct bpf_spin_lock *lock) 2451 * Description 2452 * Release the *lock* previously locked by a call to 2453 * **bpf_spin_lock**\ (\ *lock*\ ). 2454 * Return 2455 * 0 2456 * 2457 * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk) 2458 * Description 2459 * This helper gets a **struct bpf_sock** pointer such 2460 * that all the fields in this **bpf_sock** can be accessed. 2461 * Return 2462 * A **struct bpf_sock** pointer on success, or **NULL** in 2463 * case of failure. 2464 * 2465 * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk) 2466 * Description 2467 * This helper gets a **struct bpf_tcp_sock** pointer from a 2468 * **struct bpf_sock** pointer. 2469 * Return 2470 * A **struct bpf_tcp_sock** pointer on success, or **NULL** in 2471 * case of failure. 2472 * 2473 * int bpf_skb_ecn_set_ce(struct sk_buf *skb) 2474 * Description 2475 * Set ECN (Explicit Congestion Notification) field of IP header 2476 * to **CE** (Congestion Encountered) if current value is **ECT** 2477 * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6 2478 * and IPv4. 2479 * Return 2480 * 1 if the **CE** flag is set (either by the current helper call 2481 * or because it was already present), 0 if it is not set. 2482 * 2483 * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk) 2484 * Description 2485 * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state. 2486 * **bpf_sk_release**\ () is unnecessary and not allowed. 2487 * Return 2488 * A **struct bpf_sock** pointer on success, or **NULL** in 2489 * case of failure. 2490 * 2491 * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) 2492 * Description 2493 * Look for TCP socket matching *tuple*, optionally in a child 2494 * network namespace *netns*. The return value must be checked, 2495 * and if non-**NULL**, released via **bpf_sk_release**\ (). 2496 * 2497 * This function is identical to **bpf_sk_lookup_tcp**\ (), except 2498 * that it also returns timewait or request sockets. Use 2499 * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the 2500 * full structure. 2501 * 2502 * This helper is available only if the kernel was compiled with 2503 * **CONFIG_NET** configuration option. 2504 * Return 2505 * Pointer to **struct bpf_sock**, or **NULL** in case of failure. 2506 * For sockets with reuseport option, the **struct bpf_sock** 2507 * result is from *reuse*\ **->socks**\ [] using the hash of the 2508 * tuple. 2509 * 2510 * int bpf_tcp_check_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) 2511 * Description 2512 * Check whether *iph* and *th* contain a valid SYN cookie ACK for 2513 * the listening socket in *sk*. 2514 * 2515 * *iph* points to the start of the IPv4 or IPv6 header, while 2516 * *iph_len* contains **sizeof**\ (**struct iphdr**) or 2517 * **sizeof**\ (**struct ip6hdr**). 2518 * 2519 * *th* points to the start of the TCP header, while *th_len* 2520 * contains **sizeof**\ (**struct tcphdr**). 2521 * 2522 * Return 2523 * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative 2524 * error otherwise. 2525 * 2526 * int bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags) 2527 * Description 2528 * Get name of sysctl in /proc/sys/ and copy it into provided by 2529 * program buffer *buf* of size *buf_len*. 2530 * 2531 * The buffer is always NUL terminated, unless it's zero-sized. 2532 * 2533 * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is 2534 * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name 2535 * only (e.g. "tcp_mem"). 2536 * Return 2537 * Number of character copied (not including the trailing NUL). 2538 * 2539 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 2540 * truncated name in this case). 2541 * 2542 * int bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) 2543 * Description 2544 * Get current value of sysctl as it is presented in /proc/sys 2545 * (incl. newline, etc), and copy it as a string into provided 2546 * by program buffer *buf* of size *buf_len*. 2547 * 2548 * The whole value is copied, no matter what file position user 2549 * space issued e.g. sys_read at. 2550 * 2551 * The buffer is always NUL terminated, unless it's zero-sized. 2552 * Return 2553 * Number of character copied (not including the trailing NUL). 2554 * 2555 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 2556 * truncated name in this case). 2557 * 2558 * **-EINVAL** if current value was unavailable, e.g. because 2559 * sysctl is uninitialized and read returns -EIO for it. 2560 * 2561 * int bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len) 2562 * Description 2563 * Get new value being written by user space to sysctl (before 2564 * the actual write happens) and copy it as a string into 2565 * provided by program buffer *buf* of size *buf_len*. 2566 * 2567 * User space may write new value at file position > 0. 2568 * 2569 * The buffer is always NUL terminated, unless it's zero-sized. 2570 * Return 2571 * Number of character copied (not including the trailing NUL). 2572 * 2573 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain 2574 * truncated name in this case). 2575 * 2576 * **-EINVAL** if sysctl is being read. 2577 * 2578 * int bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len) 2579 * Description 2580 * Override new value being written by user space to sysctl with 2581 * value provided by program in buffer *buf* of size *buf_len*. 2582 * 2583 * *buf* should contain a string in same form as provided by user 2584 * space on sysctl write. 2585 * 2586 * User space may write new value at file position > 0. To override 2587 * the whole sysctl value file position should be set to zero. 2588 * Return 2589 * 0 on success. 2590 * 2591 * **-E2BIG** if the *buf_len* is too big. 2592 * 2593 * **-EINVAL** if sysctl is being read. 2594 * 2595 * int bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res) 2596 * Description 2597 * Convert the initial part of the string from buffer *buf* of 2598 * size *buf_len* to a long integer according to the given base 2599 * and save the result in *res*. 2600 * 2601 * The string may begin with an arbitrary amount of white space 2602 * (as determined by **isspace**\ (3)) followed by a single 2603 * optional '**-**' sign. 2604 * 2605 * Five least significant bits of *flags* encode base, other bits 2606 * are currently unused. 2607 * 2608 * Base must be either 8, 10, 16 or 0 to detect it automatically 2609 * similar to user space **strtol**\ (3). 2610 * Return 2611 * Number of characters consumed on success. Must be positive but 2612 * no more than *buf_len*. 2613 * 2614 * **-EINVAL** if no valid digits were found or unsupported base 2615 * was provided. 2616 * 2617 * **-ERANGE** if resulting value was out of range. 2618 * 2619 * int bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res) 2620 * Description 2621 * Convert the initial part of the string from buffer *buf* of 2622 * size *buf_len* to an unsigned long integer according to the 2623 * given base and save the result in *res*. 2624 * 2625 * The string may begin with an arbitrary amount of white space 2626 * (as determined by **isspace**\ (3)). 2627 * 2628 * Five least significant bits of *flags* encode base, other bits 2629 * are currently unused. 2630 * 2631 * Base must be either 8, 10, 16 or 0 to detect it automatically 2632 * similar to user space **strtoul**\ (3). 2633 * Return 2634 * Number of characters consumed on success. Must be positive but 2635 * no more than *buf_len*. 2636 * 2637 * **-EINVAL** if no valid digits were found or unsupported base 2638 * was provided. 2639 * 2640 * **-ERANGE** if resulting value was out of range. 2641 * 2642 * void *bpf_sk_storage_get(struct bpf_map *map, struct bpf_sock *sk, void *value, u64 flags) 2643 * Description 2644 * Get a bpf-local-storage from a *sk*. 2645 * 2646 * Logically, it could be thought of getting the value from 2647 * a *map* with *sk* as the **key**. From this 2648 * perspective, the usage is not much different from 2649 * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this 2650 * helper enforces the key must be a full socket and the map must 2651 * be a **BPF_MAP_TYPE_SK_STORAGE** also. 2652 * 2653 * Underneath, the value is stored locally at *sk* instead of 2654 * the *map*. The *map* is used as the bpf-local-storage 2655 * "type". The bpf-local-storage "type" (i.e. the *map*) is 2656 * searched against all bpf-local-storages residing at *sk*. 2657 * 2658 * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be 2659 * used such that a new bpf-local-storage will be 2660 * created if one does not exist. *value* can be used 2661 * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify 2662 * the initial value of a bpf-local-storage. If *value* is 2663 * **NULL**, the new bpf-local-storage will be zero initialized. 2664 * Return 2665 * A bpf-local-storage pointer is returned on success. 2666 * 2667 * **NULL** if not found or there was an error in adding 2668 * a new bpf-local-storage. 2669 * 2670 * int bpf_sk_storage_delete(struct bpf_map *map, struct bpf_sock *sk) 2671 * Description 2672 * Delete a bpf-local-storage from a *sk*. 2673 * Return 2674 * 0 on success. 2675 * 2676 * **-ENOENT** if the bpf-local-storage cannot be found. 2677 */ 2678#define __BPF_FUNC_MAPPER(FN) \ 2679 FN(unspec), \ 2680 FN(map_lookup_elem), \ 2681 FN(map_update_elem), \ 2682 FN(map_delete_elem), \ 2683 FN(probe_read), \ 2684 FN(ktime_get_ns), \ 2685 FN(trace_printk), \ 2686 FN(get_prandom_u32), \ 2687 FN(get_smp_processor_id), \ 2688 FN(skb_store_bytes), \ 2689 FN(l3_csum_replace), \ 2690 FN(l4_csum_replace), \ 2691 FN(tail_call), \ 2692 FN(clone_redirect), \ 2693 FN(get_current_pid_tgid), \ 2694 FN(get_current_uid_gid), \ 2695 FN(get_current_comm), \ 2696 FN(get_cgroup_classid), \ 2697 FN(skb_vlan_push), \ 2698 FN(skb_vlan_pop), \ 2699 FN(skb_get_tunnel_key), \ 2700 FN(skb_set_tunnel_key), \ 2701 FN(perf_event_read), \ 2702 FN(redirect), \ 2703 FN(get_route_realm), \ 2704 FN(perf_event_output), \ 2705 FN(skb_load_bytes), \ 2706 FN(get_stackid), \ 2707 FN(csum_diff), \ 2708 FN(skb_get_tunnel_opt), \ 2709 FN(skb_set_tunnel_opt), \ 2710 FN(skb_change_proto), \ 2711 FN(skb_change_type), \ 2712 FN(skb_under_cgroup), \ 2713 FN(get_hash_recalc), \ 2714 FN(get_current_task), \ 2715 FN(probe_write_user), \ 2716 FN(current_task_under_cgroup), \ 2717 FN(skb_change_tail), \ 2718 FN(skb_pull_data), \ 2719 FN(csum_update), \ 2720 FN(set_hash_invalid), \ 2721 FN(get_numa_node_id), \ 2722 FN(skb_change_head), \ 2723 FN(xdp_adjust_head), \ 2724 FN(probe_read_str), \ 2725 FN(get_socket_cookie), \ 2726 FN(get_socket_uid), \ 2727 FN(set_hash), \ 2728 FN(setsockopt), \ 2729 FN(skb_adjust_room), \ 2730 FN(redirect_map), \ 2731 FN(sk_redirect_map), \ 2732 FN(sock_map_update), \ 2733 FN(xdp_adjust_meta), \ 2734 FN(perf_event_read_value), \ 2735 FN(perf_prog_read_value), \ 2736 FN(getsockopt), \ 2737 FN(override_return), \ 2738 FN(sock_ops_cb_flags_set), \ 2739 FN(msg_redirect_map), \ 2740 FN(msg_apply_bytes), \ 2741 FN(msg_cork_bytes), \ 2742 FN(msg_pull_data), \ 2743 FN(bind), \ 2744 FN(xdp_adjust_tail), \ 2745 FN(skb_get_xfrm_state), \ 2746 FN(get_stack), \ 2747 FN(skb_load_bytes_relative), \ 2748 FN(fib_lookup), \ 2749 FN(sock_hash_update), \ 2750 FN(msg_redirect_hash), \ 2751 FN(sk_redirect_hash), \ 2752 FN(lwt_push_encap), \ 2753 FN(lwt_seg6_store_bytes), \ 2754 FN(lwt_seg6_adjust_srh), \ 2755 FN(lwt_seg6_action), \ 2756 FN(rc_repeat), \ 2757 FN(rc_keydown), \ 2758 FN(skb_cgroup_id), \ 2759 FN(get_current_cgroup_id), \ 2760 FN(get_local_storage), \ 2761 FN(sk_select_reuseport), \ 2762 FN(skb_ancestor_cgroup_id), \ 2763 FN(sk_lookup_tcp), \ 2764 FN(sk_lookup_udp), \ 2765 FN(sk_release), \ 2766 FN(map_push_elem), \ 2767 FN(map_pop_elem), \ 2768 FN(map_peek_elem), \ 2769 FN(msg_push_data), \ 2770 FN(msg_pop_data), \ 2771 FN(rc_pointer_rel), \ 2772 FN(spin_lock), \ 2773 FN(spin_unlock), \ 2774 FN(sk_fullsock), \ 2775 FN(tcp_sock), \ 2776 FN(skb_ecn_set_ce), \ 2777 FN(get_listener_sock), \ 2778 FN(skc_lookup_tcp), \ 2779 FN(tcp_check_syncookie), \ 2780 FN(sysctl_get_name), \ 2781 FN(sysctl_get_current_value), \ 2782 FN(sysctl_get_new_value), \ 2783 FN(sysctl_set_new_value), \ 2784 FN(strtol), \ 2785 FN(strtoul), \ 2786 FN(sk_storage_get), \ 2787 FN(sk_storage_delete), 2788 2789/* integer value in 'imm' field of BPF_CALL instruction selects which helper 2790 * function eBPF program intends to call 2791 */ 2792#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x 2793enum bpf_func_id { 2794 __BPF_FUNC_MAPPER(__BPF_ENUM_FN) 2795 __BPF_FUNC_MAX_ID, 2796}; 2797#undef __BPF_ENUM_FN 2798 2799/* All flags used by eBPF helper functions, placed here. */ 2800 2801/* BPF_FUNC_skb_store_bytes flags. */ 2802#define BPF_F_RECOMPUTE_CSUM (1ULL << 0) 2803#define BPF_F_INVALIDATE_HASH (1ULL << 1) 2804 2805/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags. 2806 * First 4 bits are for passing the header field size. 2807 */ 2808#define BPF_F_HDR_FIELD_MASK 0xfULL 2809 2810/* BPF_FUNC_l4_csum_replace flags. */ 2811#define BPF_F_PSEUDO_HDR (1ULL << 4) 2812#define BPF_F_MARK_MANGLED_0 (1ULL << 5) 2813#define BPF_F_MARK_ENFORCE (1ULL << 6) 2814 2815/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */ 2816#define BPF_F_INGRESS (1ULL << 0) 2817 2818/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */ 2819#define BPF_F_TUNINFO_IPV6 (1ULL << 0) 2820 2821/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */ 2822#define BPF_F_SKIP_FIELD_MASK 0xffULL 2823#define BPF_F_USER_STACK (1ULL << 8) 2824/* flags used by BPF_FUNC_get_stackid only. */ 2825#define BPF_F_FAST_STACK_CMP (1ULL << 9) 2826#define BPF_F_REUSE_STACKID (1ULL << 10) 2827/* flags used by BPF_FUNC_get_stack only. */ 2828#define BPF_F_USER_BUILD_ID (1ULL << 11) 2829 2830/* BPF_FUNC_skb_set_tunnel_key flags. */ 2831#define BPF_F_ZERO_CSUM_TX (1ULL << 1) 2832#define BPF_F_DONT_FRAGMENT (1ULL << 2) 2833#define BPF_F_SEQ_NUMBER (1ULL << 3) 2834 2835/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and 2836 * BPF_FUNC_perf_event_read_value flags. 2837 */ 2838#define BPF_F_INDEX_MASK 0xffffffffULL 2839#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK 2840/* BPF_FUNC_perf_event_output for sk_buff input context. */ 2841#define BPF_F_CTXLEN_MASK (0xfffffULL << 32) 2842 2843/* Current network namespace */ 2844#define BPF_F_CURRENT_NETNS (-1L) 2845 2846/* BPF_FUNC_skb_adjust_room flags. */ 2847#define BPF_F_ADJ_ROOM_FIXED_GSO (1ULL << 0) 2848 2849#define BPF_ADJ_ROOM_ENCAP_L2_MASK 0xff 2850#define BPF_ADJ_ROOM_ENCAP_L2_SHIFT 56 2851 2852#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 (1ULL << 1) 2853#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 (1ULL << 2) 2854#define BPF_F_ADJ_ROOM_ENCAP_L4_GRE (1ULL << 3) 2855#define BPF_F_ADJ_ROOM_ENCAP_L4_UDP (1ULL << 4) 2856#define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \ 2857 BPF_ADJ_ROOM_ENCAP_L2_MASK) \ 2858 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT) 2859 2860/* BPF_FUNC_sysctl_get_name flags. */ 2861#define BPF_F_SYSCTL_BASE_NAME (1ULL << 0) 2862 2863/* BPF_FUNC_sk_storage_get flags */ 2864#define BPF_SK_STORAGE_GET_F_CREATE (1ULL << 0) 2865 2866/* Mode for BPF_FUNC_skb_adjust_room helper. */ 2867enum bpf_adj_room_mode { 2868 BPF_ADJ_ROOM_NET, 2869 BPF_ADJ_ROOM_MAC, 2870}; 2871 2872/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */ 2873enum bpf_hdr_start_off { 2874 BPF_HDR_START_MAC, 2875 BPF_HDR_START_NET, 2876}; 2877 2878/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */ 2879enum bpf_lwt_encap_mode { 2880 BPF_LWT_ENCAP_SEG6, 2881 BPF_LWT_ENCAP_SEG6_INLINE, 2882 BPF_LWT_ENCAP_IP, 2883}; 2884 2885#define __bpf_md_ptr(type, name) \ 2886union { \ 2887 type name; \ 2888 __u64 :64; \ 2889} __attribute__((aligned(8))) 2890 2891/* user accessible mirror of in-kernel sk_buff. 2892 * new fields can only be added to the end of this structure 2893 */ 2894struct __sk_buff { 2895 __u32 len; 2896 __u32 pkt_type; 2897 __u32 mark; 2898 __u32 queue_mapping; 2899 __u32 protocol; 2900 __u32 vlan_present; 2901 __u32 vlan_tci; 2902 __u32 vlan_proto; 2903 __u32 priority; 2904 __u32 ingress_ifindex; 2905 __u32 ifindex; 2906 __u32 tc_index; 2907 __u32 cb[5]; 2908 __u32 hash; 2909 __u32 tc_classid; 2910 __u32 data; 2911 __u32 data_end; 2912 __u32 napi_id; 2913 2914 /* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */ 2915 __u32 family; 2916 __u32 remote_ip4; /* Stored in network byte order */ 2917 __u32 local_ip4; /* Stored in network byte order */ 2918 __u32 remote_ip6[4]; /* Stored in network byte order */ 2919 __u32 local_ip6[4]; /* Stored in network byte order */ 2920 __u32 remote_port; /* Stored in network byte order */ 2921 __u32 local_port; /* stored in host byte order */ 2922 /* ... here. */ 2923 2924 __u32 data_meta; 2925 __bpf_md_ptr(struct bpf_flow_keys *, flow_keys); 2926 __u64 tstamp; 2927 __u32 wire_len; 2928 __u32 gso_segs; 2929 __bpf_md_ptr(struct bpf_sock *, sk); 2930}; 2931 2932struct bpf_tunnel_key { 2933 __u32 tunnel_id; 2934 union { 2935 __u32 remote_ipv4; 2936 __u32 remote_ipv6[4]; 2937 }; 2938 __u8 tunnel_tos; 2939 __u8 tunnel_ttl; 2940 __u16 tunnel_ext; /* Padding, future use. */ 2941 __u32 tunnel_label; 2942}; 2943 2944/* user accessible mirror of in-kernel xfrm_state. 2945 * new fields can only be added to the end of this structure 2946 */ 2947struct bpf_xfrm_state { 2948 __u32 reqid; 2949 __u32 spi; /* Stored in network byte order */ 2950 __u16 family; 2951 __u16 ext; /* Padding, future use. */ 2952 union { 2953 __u32 remote_ipv4; /* Stored in network byte order */ 2954 __u32 remote_ipv6[4]; /* Stored in network byte order */ 2955 }; 2956}; 2957 2958/* Generic BPF return codes which all BPF program types may support. 2959 * The values are binary compatible with their TC_ACT_* counter-part to 2960 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT 2961 * programs. 2962 * 2963 * XDP is handled seprately, see XDP_*. 2964 */ 2965enum bpf_ret_code { 2966 BPF_OK = 0, 2967 /* 1 reserved */ 2968 BPF_DROP = 2, 2969 /* 3-6 reserved */ 2970 BPF_REDIRECT = 7, 2971 /* >127 are reserved for prog type specific return codes. 2972 * 2973 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and 2974 * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been 2975 * changed and should be routed based on its new L3 header. 2976 * (This is an L3 redirect, as opposed to L2 redirect 2977 * represented by BPF_REDIRECT above). 2978 */ 2979 BPF_LWT_REROUTE = 128, 2980}; 2981 2982struct bpf_sock { 2983 __u32 bound_dev_if; 2984 __u32 family; 2985 __u32 type; 2986 __u32 protocol; 2987 __u32 mark; 2988 __u32 priority; 2989 /* IP address also allows 1 and 2 bytes access */ 2990 __u32 src_ip4; 2991 __u32 src_ip6[4]; 2992 __u32 src_port; /* host byte order */ 2993 __u32 dst_port; /* network byte order */ 2994 __u32 dst_ip4; 2995 __u32 dst_ip6[4]; 2996 __u32 state; 2997}; 2998 2999struct bpf_tcp_sock { 3000 __u32 snd_cwnd; /* Sending congestion window */
3001 __u32 srtt_us; /* smoothed round trip time << 3 in usecs */ 3002 __u32 rtt_min; 3003 __u32 snd_ssthresh; /* Slow start size threshold */ 3004 __u32 rcv_nxt; /* What we want to receive next */ 3005 __u32 snd_nxt; /* Next sequence we send */ 3006 __u32 snd_una; /* First byte we want an ack for */ 3007 __u32 mss_cache; /* Cached effective mss, not including SACKS */ 3008 __u32 ecn_flags; /* ECN status bits. */ 3009 __u32 rate_delivered; /* saved rate sample: packets delivered */ 3010 __u32 rate_interval_us; /* saved rate sample: time elapsed */ 3011 __u32 packets_out; /* Packets which are "in flight" */ 3012 __u32 retrans_out; /* Retransmitted packets out */ 3013 __u32 total_retrans; /* Total retransmits for entire connection */ 3014 __u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn 3015 * total number of segments in. 3016 */ 3017 __u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn 3018 * total number of data segments in. 3019 */ 3020 __u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut 3021 * The total number of segments sent. 3022 */ 3023 __u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut 3024 * total number of data segments sent. 3025 */ 3026 __u32 lost_out; /* Lost packets */ 3027 __u32 sacked_out; /* SACK'd packets */ 3028 __u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived 3029 * sum(delta(rcv_nxt)), or how many bytes 3030 * were acked. 3031 */ 3032 __u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked 3033 * sum(delta(snd_una)), or how many bytes 3034 * were acked. 3035 */ 3036}; 3037 3038struct bpf_sock_tuple { 3039 union { 3040 struct { 3041 __be32 saddr; 3042 __be32 daddr; 3043 __be16 sport; 3044 __be16 dport; 3045 } ipv4; 3046 struct { 3047 __be32 saddr[4]; 3048 __be32 daddr[4]; 3049 __be16 sport; 3050 __be16 dport; 3051 } ipv6; 3052 }; 3053}; 3054 3055#define XDP_PACKET_HEADROOM 256 3056 3057/* User return codes for XDP prog type. 3058 * A valid XDP program must return one of these defined values. All other 3059 * return codes are reserved for future use. Unknown return codes will 3060 * result in packet drops and a warning via bpf_warn_invalid_xdp_action(). 3061 */ 3062enum xdp_action { 3063 XDP_ABORTED = 0, 3064 XDP_DROP, 3065 XDP_PASS, 3066 XDP_TX, 3067 XDP_REDIRECT, 3068}; 3069 3070/* user accessible metadata for XDP packet hook 3071 * new fields must be added to the end of this structure 3072 */ 3073struct xdp_md { 3074 __u32 data; 3075 __u32 data_end; 3076 __u32 data_meta; 3077 /* Below access go through struct xdp_rxq_info */ 3078 __u32 ingress_ifindex; /* rxq->dev->ifindex */ 3079 __u32 rx_queue_index; /* rxq->queue_index */ 3080}; 3081 3082enum sk_action { 3083 SK_DROP = 0, 3084 SK_PASS, 3085}; 3086 3087/* user accessible metadata for SK_MSG packet hook, new fields must 3088 * be added to the end of this structure 3089 */ 3090struct sk_msg_md { 3091 __bpf_md_ptr(void *, data); 3092 __bpf_md_ptr(void *, data_end); 3093 3094 __u32 family; 3095 __u32 remote_ip4; /* Stored in network byte order */ 3096 __u32 local_ip4; /* Stored in network byte order */ 3097 __u32 remote_ip6[4]; /* Stored in network byte order */ 3098 __u32 local_ip6[4]; /* Stored in network byte order */ 3099 __u32 remote_port; /* Stored in network byte order */ 3100 __u32 local_port; /* stored in host byte order */ 3101 __u32 size; /* Total size of sk_msg */ 3102}; 3103 3104struct sk_reuseport_md { 3105 /* 3106 * Start of directly accessible data. It begins from 3107 * the tcp/udp header. 3108 */ 3109 __bpf_md_ptr(void *, data); 3110 /* End of directly accessible data */ 3111 __bpf_md_ptr(void *, data_end); 3112 /* 3113 * Total length of packet (starting from the tcp/udp header). 3114 * Note that the directly accessible bytes (data_end - data) 3115 * could be less than this "len". Those bytes could be 3116 * indirectly read by a helper "bpf_skb_load_bytes()". 3117 */ 3118 __u32 len; 3119 /* 3120 * Eth protocol in the mac header (network byte order). e.g. 3121 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD) 3122 */ 3123 __u32 eth_protocol; 3124 __u32 ip_protocol; /* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */ 3125 __u32 bind_inany; /* Is sock bound to an INANY address? */ 3126 __u32 hash; /* A hash of the packet 4 tuples */ 3127}; 3128 3129#define BPF_TAG_SIZE 8 3130 3131struct bpf_prog_info { 3132 __u32 type; 3133 __u32 id; 3134 __u8 tag[BPF_TAG_SIZE]; 3135 __u32 jited_prog_len; 3136 __u32 xlated_prog_len; 3137 __aligned_u64 jited_prog_insns; 3138 __aligned_u64 xlated_prog_insns; 3139 __u64 load_time; /* ns since boottime */ 3140 __u32 created_by_uid; 3141 __u32 nr_map_ids; 3142 __aligned_u64 map_ids; 3143 char name[BPF_OBJ_NAME_LEN]; 3144 __u32 ifindex; 3145 __u32 gpl_compatible:1; 3146 __u64 netns_dev; 3147 __u64 netns_ino; 3148 __u32 nr_jited_ksyms; 3149 __u32 nr_jited_func_lens; 3150 __aligned_u64 jited_ksyms; 3151 __aligned_u64 jited_func_lens; 3152 __u32 btf_id; 3153 __u32 func_info_rec_size; 3154 __aligned_u64 func_info; 3155 __u32 nr_func_info; 3156 __u32 nr_line_info; 3157 __aligned_u64 line_info; 3158 __aligned_u64 jited_line_info; 3159 __u32 nr_jited_line_info; 3160 __u32 line_info_rec_size; 3161 __u32 jited_line_info_rec_size; 3162 __u32 nr_prog_tags; 3163 __aligned_u64 prog_tags; 3164 __u64 run_time_ns; 3165 __u64 run_cnt; 3166} __attribute__((aligned(8))); 3167 3168struct bpf_map_info { 3169 __u32 type; 3170 __u32 id; 3171 __u32 key_size; 3172 __u32 value_size; 3173 __u32 max_entries; 3174 __u32 map_flags; 3175 char name[BPF_OBJ_NAME_LEN]; 3176 __u32 ifindex; 3177 __u32 :32; 3178 __u64 netns_dev; 3179 __u64 netns_ino; 3180 __u32 btf_id; 3181 __u32 btf_key_type_id; 3182 __u32 btf_value_type_id; 3183} __attribute__((aligned(8))); 3184 3185struct bpf_btf_info { 3186 __aligned_u64 btf; 3187 __u32 btf_size; 3188 __u32 id; 3189} __attribute__((aligned(8))); 3190 3191/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed 3192 * by user and intended to be used by socket (e.g. to bind to, depends on 3193 * attach attach type). 3194 */ 3195struct bpf_sock_addr { 3196 __u32 user_family; /* Allows 4-byte read, but no write. */ 3197 __u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write. 3198 * Stored in network byte order. 3199 */ 3200 __u32 user_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write. 3201 * Stored in network byte order. 3202 */ 3203 __u32 user_port; /* Allows 4-byte read and write. 3204 * Stored in network byte order 3205 */ 3206 __u32 family; /* Allows 4-byte read, but no write */ 3207 __u32 type; /* Allows 4-byte read, but no write */ 3208 __u32 protocol; /* Allows 4-byte read, but no write */ 3209 __u32 msg_src_ip4; /* Allows 1,2,4-byte read an 4-byte write. 3210 * Stored in network byte order. 3211 */ 3212 __u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write. 3213 * Stored in network byte order. 3214 */ 3215}; 3216 3217/* User bpf_sock_ops struct to access socket values and specify request ops 3218 * and their replies. 3219 * Some of this fields are in network (bigendian) byte order and may need 3220 * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h). 3221 * New fields can only be added at the end of this structure 3222 */ 3223struct bpf_sock_ops { 3224 __u32 op; 3225 union { 3226 __u32 args[4]; /* Optionally passed to bpf program */ 3227 __u32 reply; /* Returned by bpf program */ 3228 __u32 replylong[4]; /* Optionally returned by bpf prog */ 3229 }; 3230 __u32 family; 3231 __u32 remote_ip4; /* Stored in network byte order */ 3232 __u32 local_ip4; /* Stored in network byte order */ 3233 __u32 remote_ip6[4]; /* Stored in network byte order */ 3234 __u32 local_ip6[4]; /* Stored in network byte order */ 3235 __u32 remote_port; /* Stored in network byte order */ 3236 __u32 local_port; /* stored in host byte order */ 3237 __u32 is_fullsock; /* Some TCP fields are only valid if 3238 * there is a full socket. If not, the 3239 * fields read as zero. 3240 */ 3241 __u32 snd_cwnd; 3242 __u32 srtt_us; /* Averaged RTT << 3 in usecs */ 3243 __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ 3244 __u32 state; 3245 __u32 rtt_min; 3246 __u32 snd_ssthresh; 3247 __u32 rcv_nxt; 3248 __u32 snd_nxt; 3249 __u32 snd_una; 3250 __u32 mss_cache; 3251 __u32 ecn_flags; 3252 __u32 rate_delivered; 3253 __u32 rate_interval_us; 3254 __u32 packets_out; 3255 __u32 retrans_out; 3256 __u32 total_retrans; 3257 __u32 segs_in; 3258 __u32 data_segs_in; 3259 __u32 segs_out; 3260 __u32 data_segs_out; 3261 __u32 lost_out; 3262 __u32 sacked_out; 3263 __u32 sk_txhash; 3264 __u64 bytes_received; 3265 __u64 bytes_acked; 3266}; 3267 3268/* Definitions for bpf_sock_ops_cb_flags */ 3269#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) 3270#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) 3271#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2) 3272#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently 3273 * supported cb flags 3274 */ 3275 3276/* List of known BPF sock_ops operators. 3277 * New entries can only be added at the end 3278 */ 3279enum { 3280 BPF_SOCK_OPS_VOID, 3281 BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or 3282 * -1 if default value should be used 3283 */ 3284 BPF_SOCK_OPS_RWND_INIT, /* Should return initial advertized 3285 * window (in packets) or -1 if default 3286 * value should be used 3287 */ 3288 BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an 3289 * active connection is initialized 3290 */ 3291 BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an 3292 * active connection is 3293 * established 3294 */ 3295 BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a 3296 * passive connection is 3297 * established 3298 */ 3299 BPF_SOCK_OPS_NEEDS_ECN, /* If connection's congestion control 3300 * needs ECN 3301 */ 3302 BPF_SOCK_OPS_BASE_RTT, /* Get base RTT. The correct value is 3303 * based on the path and may be 3304 * dependent on the congestion control 3305 * algorithm. In general it indicates 3306 * a congestion threshold. RTTs above 3307 * this indicate congestion 3308 */ 3309 BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered. 3310 * Arg1: value of icsk_retransmits 3311 * Arg2: value of icsk_rto 3312 * Arg3: whether RTO has expired 3313 */ 3314 BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. 3315 * Arg1: sequence number of 1st byte 3316 * Arg2: # segments 3317 * Arg3: return value of 3318 * tcp_transmit_skb (0 => success) 3319 */ 3320 BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state. 3321 * Arg1: old_state 3322 * Arg2: new_state 3323 */ 3324 BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after 3325 * socket transition to LISTEN state. 3326 */ 3327}; 3328 3329/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect 3330 * changes between the TCP and BPF versions. Ideally this should never happen. 3331 * If it does, we need to add code to convert them before calling 3332 * the BPF sock_ops function. 3333 */ 3334enum { 3335 BPF_TCP_ESTABLISHED = 1, 3336 BPF_TCP_SYN_SENT, 3337 BPF_TCP_SYN_RECV, 3338 BPF_TCP_FIN_WAIT1, 3339 BPF_TCP_FIN_WAIT2, 3340 BPF_TCP_TIME_WAIT, 3341 BPF_TCP_CLOSE, 3342 BPF_TCP_CLOSE_WAIT, 3343 BPF_TCP_LAST_ACK, 3344 BPF_TCP_LISTEN, 3345 BPF_TCP_CLOSING, /* Now a valid state */ 3346 BPF_TCP_NEW_SYN_RECV, 3347 3348 BPF_TCP_MAX_STATES /* Leave at the end! */ 3349}; 3350 3351#define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ 3352#define TCP_BPF_SNDCWND_CLAMP 1002 /* Set sndcwnd_clamp */ 3353 3354struct bpf_perf_event_value { 3355 __u64 counter; 3356 __u64 enabled; 3357 __u64 running; 3358}; 3359 3360#define BPF_DEVCG_ACC_MKNOD (1ULL << 0) 3361#define BPF_DEVCG_ACC_READ (1ULL << 1) 3362#define BPF_DEVCG_ACC_WRITE (1ULL << 2) 3363 3364#define BPF_DEVCG_DEV_BLOCK (1ULL << 0) 3365#define BPF_DEVCG_DEV_CHAR (1ULL << 1) 3366 3367struct bpf_cgroup_dev_ctx { 3368 /* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */ 3369 __u32 access_type; 3370 __u32 major; 3371 __u32 minor; 3372}; 3373 3374struct bpf_raw_tracepoint_args { 3375 __u64 args[0]; 3376}; 3377 3378/* DIRECT: Skip the FIB rules and go to FIB table associated with device 3379 * OUTPUT: Do lookup from egress perspective; default is ingress 3380 */ 3381#define BPF_FIB_LOOKUP_DIRECT (1U << 0) 3382#define BPF_FIB_LOOKUP_OUTPUT (1U << 1) 3383 3384enum { 3385 BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */ 3386 BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */ 3387 BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */ 3388 BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */ 3389 BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */ 3390 BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */ 3391 BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */ 3392 BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */ 3393 BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */ 3394}; 3395 3396struct bpf_fib_lookup { 3397 /* input: network family for lookup (AF_INET, AF_INET6) 3398 * output: network family of egress nexthop 3399 */ 3400 __u8 family; 3401 3402 /* set if lookup is to consider L4 data - e.g., FIB rules */ 3403 __u8 l4_protocol; 3404 __be16 sport; 3405 __be16 dport; 3406 3407 /* total length of packet from network header - used for MTU check */ 3408 __u16 tot_len; 3409 3410 /* input: L3 device index for lookup 3411 * output: device index from FIB lookup 3412 */ 3413 __u32 ifindex; 3414 3415 union { 3416 /* inputs to lookup */ 3417 __u8 tos; /* AF_INET */ 3418 __be32 flowinfo; /* AF_INET6, flow_label + priority */ 3419 3420 /* output: metric of fib result (IPv4/IPv6 only) */ 3421 __u32 rt_metric; 3422 }; 3423 3424 union { 3425 __be32 ipv4_src; 3426 __u32 ipv6_src[4]; /* in6_addr; network order */ 3427 }; 3428 3429 /* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in 3430 * network header. output: bpf_fib_lookup sets to gateway address 3431 * if FIB lookup returns gateway route 3432 */ 3433 union { 3434 __be32 ipv4_dst; 3435 __u32 ipv6_dst[4]; /* in6_addr; network order */ 3436 }; 3437 3438 /* output */ 3439 __be16 h_vlan_proto; 3440 __be16 h_vlan_TCI; 3441 __u8 smac[6]; /* ETH_ALEN */ 3442 __u8 dmac[6]; /* ETH_ALEN */ 3443}; 3444 3445enum bpf_task_fd_type { 3446 BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */ 3447 BPF_FD_TYPE_TRACEPOINT, /* tp name */ 3448 BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */ 3449 BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */ 3450 BPF_FD_TYPE_UPROBE, /* filename + offset */ 3451 BPF_FD_TYPE_URETPROBE, /* filename + offset */ 3452}; 3453 3454struct bpf_flow_keys { 3455 __u16 nhoff; 3456 __u16 thoff; 3457 __u16 addr_proto; /* ETH_P_* of valid addrs */ 3458 __u8 is_frag; 3459 __u8 is_first_frag; 3460 __u8 is_encap; 3461 __u8 ip_proto; 3462 __be16 n_proto; 3463 __be16 sport; 3464 __be16 dport; 3465 union { 3466 struct { 3467 __be32 ipv4_src; 3468 __be32 ipv4_dst; 3469 }; 3470 struct { 3471 __u32 ipv6_src[4]; /* in6_addr; network order */ 3472 __u32 ipv6_dst[4]; /* in6_addr; network order */ 3473 }; 3474 }; 3475}; 3476 3477struct bpf_func_info { 3478 __u32 insn_off; 3479 __u32 type_id; 3480}; 3481 3482#define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10) 3483#define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff) 3484 3485struct bpf_line_info { 3486 __u32 insn_off; 3487 __u32 file_name_off; 3488 __u32 line_off; 3489 __u32 line_col; 3490}; 3491 3492struct bpf_spin_lock { 3493 __u32 val; 3494}; 3495 3496struct bpf_sysctl { 3497 __u32 write; /* Sysctl is being read (= 0) or written (= 1). 3498 * Allows 1,2,4-byte read, but no write. 3499 */ 3500 __u32 file_pos; /* Sysctl file position to read from, write to. 3501 * Allows 1,2,4-byte read an 4-byte write. 3502 */ 3503}; 3504 3505#endif /* _UAPI__LINUX_BPF_H__ */ 3506