linux/tools/testing/selftests/net/psock_fanout.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright 2013 Google Inc.
   4 * Author: Willem de Bruijn (willemb@google.com)
   5 *
   6 * A basic test of packet socket fanout behavior.
   7 *
   8 * Control:
   9 * - create fanout fails as expected with illegal flag combinations
  10 * - join   fanout fails as expected with diverging types or flags
  11 *
  12 * Datapath:
  13 *   Open a pair of packet sockets and a pair of INET sockets, send a known
  14 *   number of packets across the two INET sockets and count the number of
  15 *   packets enqueued onto the two packet sockets.
  16 *
  17 *   The test currently runs for
  18 *   - PACKET_FANOUT_HASH
  19 *   - PACKET_FANOUT_HASH with PACKET_FANOUT_FLAG_ROLLOVER
  20 *   - PACKET_FANOUT_LB
  21 *   - PACKET_FANOUT_CPU
  22 *   - PACKET_FANOUT_ROLLOVER
  23 *   - PACKET_FANOUT_CBPF
  24 *   - PACKET_FANOUT_EBPF
  25 *
  26 * Todo:
  27 * - functionality: PACKET_FANOUT_FLAG_DEFRAG
  28 */
  29
  30#define _GNU_SOURCE             /* for sched_setaffinity */
  31
  32#include <arpa/inet.h>
  33#include <errno.h>
  34#include <fcntl.h>
  35#include <linux/unistd.h>       /* for __NR_bpf */
  36#include <linux/filter.h>
  37#include <linux/bpf.h>
  38#include <linux/if_packet.h>
  39#include <net/if.h>
  40#include <net/ethernet.h>
  41#include <netinet/ip.h>
  42#include <netinet/udp.h>
  43#include <poll.h>
  44#include <sched.h>
  45#include <stdint.h>
  46#include <stdio.h>
  47#include <stdlib.h>
  48#include <string.h>
  49#include <sys/mman.h>
  50#include <sys/socket.h>
  51#include <sys/stat.h>
  52#include <sys/types.h>
  53#include <unistd.h>
  54
  55#include "psock_lib.h"
  56
  57#define RING_NUM_FRAMES                 20
  58
  59/* Open a socket in a given fanout mode.
  60 * @return -1 if mode is bad, a valid socket otherwise */
  61static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
  62{
  63        struct sockaddr_ll addr = {0};
  64        int fd, val;
  65
  66        fd = socket(PF_PACKET, SOCK_RAW, 0);
  67        if (fd < 0) {
  68                perror("socket packet");
  69                exit(1);
  70        }
  71
  72        pair_udp_setfilter(fd);
  73
  74        addr.sll_family = AF_PACKET;
  75        addr.sll_protocol = htons(ETH_P_IP);
  76        addr.sll_ifindex = if_nametoindex("lo");
  77        if (addr.sll_ifindex == 0) {
  78                perror("if_nametoindex");
  79                exit(1);
  80        }
  81        if (bind(fd, (void *) &addr, sizeof(addr))) {
  82                perror("bind packet");
  83                exit(1);
  84        }
  85
  86        val = (((int) typeflags) << 16) | group_id;
  87        if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val))) {
  88                if (close(fd)) {
  89                        perror("close packet");
  90                        exit(1);
  91                }
  92                return -1;
  93        }
  94
  95        return fd;
  96}
  97
  98static void sock_fanout_set_cbpf(int fd)
  99{
 100        struct sock_filter bpf_filter[] = {
 101                BPF_STMT(BPF_LD+BPF_B+BPF_ABS, 80),           /* ldb [80] */
 102                BPF_STMT(BPF_RET+BPF_A, 0),                   /* ret A */
 103        };
 104        struct sock_fprog bpf_prog;
 105
 106        bpf_prog.filter = bpf_filter;
 107        bpf_prog.len = sizeof(bpf_filter) / sizeof(struct sock_filter);
 108
 109        if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
 110                       sizeof(bpf_prog))) {
 111                perror("fanout data cbpf");
 112                exit(1);
 113        }
 114}
 115
 116static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
 117{
 118        int sockopt;
 119        socklen_t sockopt_len = sizeof(sockopt);
 120
 121        if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
 122                       &sockopt, &sockopt_len)) {
 123                perror("failed to getsockopt");
 124                exit(1);
 125        }
 126        *typeflags = sockopt >> 16;
 127        *group_id = sockopt & 0xfffff;
 128}
 129
 130static void sock_fanout_set_ebpf(int fd)
 131{
 132        static char log_buf[65536];
 133
 134        const int len_off = __builtin_offsetof(struct __sk_buff, len);
 135        struct bpf_insn prog[] = {
 136                { BPF_ALU64 | BPF_MOV | BPF_X,   6, 1, 0, 0 },
 137                { BPF_LDX   | BPF_W   | BPF_MEM, 0, 6, len_off, 0 },
 138                { BPF_JMP   | BPF_JGE | BPF_K,   0, 0, 1, DATA_LEN },
 139                { BPF_JMP   | BPF_JA  | BPF_K,   0, 0, 4, 0 },
 140                { BPF_LD    | BPF_B   | BPF_ABS, 0, 0, 0, 0x50 },
 141                { BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 2, DATA_CHAR },
 142                { BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 1, DATA_CHAR_1 },
 143                { BPF_ALU   | BPF_MOV | BPF_K,   0, 0, 0, 0 },
 144                { BPF_JMP   | BPF_EXIT,          0, 0, 0, 0 }
 145        };
 146        union bpf_attr attr;
 147        int pfd;
 148
 149        memset(&attr, 0, sizeof(attr));
 150        attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
 151        attr.insns = (unsigned long) prog;
 152        attr.insn_cnt = sizeof(prog) / sizeof(prog[0]);
 153        attr.license = (unsigned long) "GPL";
 154        attr.log_buf = (unsigned long) log_buf,
 155        attr.log_size = sizeof(log_buf),
 156        attr.log_level = 1,
 157
 158        pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
 159        if (pfd < 0) {
 160                perror("bpf");
 161                fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
 162                exit(1);
 163        }
 164
 165        if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
 166                perror("fanout data ebpf");
 167                exit(1);
 168        }
 169
 170        if (close(pfd)) {
 171                perror("close ebpf");
 172                exit(1);
 173        }
 174}
 175
 176static char *sock_fanout_open_ring(int fd)
 177{
 178        struct tpacket_req req = {
 179                .tp_block_size = getpagesize(),
 180                .tp_frame_size = getpagesize(),
 181                .tp_block_nr   = RING_NUM_FRAMES,
 182                .tp_frame_nr   = RING_NUM_FRAMES,
 183        };
 184        char *ring;
 185        int val = TPACKET_V2;
 186
 187        if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
 188                       sizeof(val))) {
 189                perror("packetsock ring setsockopt version");
 190                exit(1);
 191        }
 192        if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
 193                       sizeof(req))) {
 194                perror("packetsock ring setsockopt");
 195                exit(1);
 196        }
 197
 198        ring = mmap(0, req.tp_block_size * req.tp_block_nr,
 199                    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 200        if (ring == MAP_FAILED) {
 201                perror("packetsock ring mmap");
 202                exit(1);
 203        }
 204
 205        return ring;
 206}
 207
 208static int sock_fanout_read_ring(int fd, void *ring)
 209{
 210        struct tpacket2_hdr *header = ring;
 211        int count = 0;
 212
 213        while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
 214                count++;
 215                header = ring + (count * getpagesize());
 216        }
 217
 218        return count;
 219}
 220
 221static int sock_fanout_read(int fds[], char *rings[], const int expect[])
 222{
 223        int ret[2];
 224
 225        ret[0] = sock_fanout_read_ring(fds[0], rings[0]);
 226        ret[1] = sock_fanout_read_ring(fds[1], rings[1]);
 227
 228        fprintf(stderr, "info: count=%d,%d, expect=%d,%d\n",
 229                        ret[0], ret[1], expect[0], expect[1]);
 230
 231        if ((!(ret[0] == expect[0] && ret[1] == expect[1])) &&
 232            (!(ret[0] == expect[1] && ret[1] == expect[0]))) {
 233                fprintf(stderr, "warning: incorrect queue lengths\n");
 234                return 1;
 235        }
 236
 237        return 0;
 238}
 239
 240/* Test illegal mode + flag combination */
 241static void test_control_single(void)
 242{
 243        fprintf(stderr, "test: control single socket\n");
 244
 245        if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
 246                               PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
 247                fprintf(stderr, "ERROR: opened socket with dual rollover\n");
 248                exit(1);
 249        }
 250}
 251
 252/* Test illegal group with different modes or flags */
 253static void test_control_group(void)
 254{
 255        int fds[2];
 256
 257        fprintf(stderr, "test: control multiple sockets\n");
 258
 259        fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 260        if (fds[0] == -1) {
 261                fprintf(stderr, "ERROR: failed to open HASH socket\n");
 262                exit(1);
 263        }
 264        if (sock_fanout_open(PACKET_FANOUT_HASH |
 265                               PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
 266                fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
 267                exit(1);
 268        }
 269        if (sock_fanout_open(PACKET_FANOUT_HASH |
 270                               PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
 271                fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
 272                exit(1);
 273        }
 274        if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {
 275                fprintf(stderr, "ERROR: joined group with wrong mode\n");
 276                exit(1);
 277        }
 278        fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
 279        if (fds[1] == -1) {
 280                fprintf(stderr, "ERROR: failed to join group\n");
 281                exit(1);
 282        }
 283        if (close(fds[1]) || close(fds[0])) {
 284                fprintf(stderr, "ERROR: closing sockets\n");
 285                exit(1);
 286        }
 287}
 288
 289/* Test creating a unique fanout group ids */
 290static void test_unique_fanout_group_ids(void)
 291{
 292        int fds[3];
 293        uint16_t typeflags, first_group_id, second_group_id;
 294
 295        fprintf(stderr, "test: unique ids\n");
 296
 297        fds[0] = sock_fanout_open(PACKET_FANOUT_HASH |
 298                                  PACKET_FANOUT_FLAG_UNIQUEID, 0);
 299        if (fds[0] == -1) {
 300                fprintf(stderr, "ERROR: failed to create a unique id group.\n");
 301                exit(1);
 302        }
 303
 304        sock_fanout_getopts(fds[0], &typeflags, &first_group_id);
 305        if (typeflags != PACKET_FANOUT_HASH) {
 306                fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);
 307                exit(1);
 308        }
 309
 310        if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id) != -1) {
 311                fprintf(stderr, "ERROR: joined group with wrong type.\n");
 312                exit(1);
 313        }
 314
 315        fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);
 316        if (fds[1] == -1) {
 317                fprintf(stderr,
 318                        "ERROR: failed to join previously created group.\n");
 319                exit(1);
 320        }
 321
 322        fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |
 323                                  PACKET_FANOUT_FLAG_UNIQUEID, 0);
 324        if (fds[2] == -1) {
 325                fprintf(stderr,
 326                        "ERROR: failed to create a second unique id group.\n");
 327                exit(1);
 328        }
 329
 330        sock_fanout_getopts(fds[2], &typeflags, &second_group_id);
 331        if (sock_fanout_open(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_UNIQUEID,
 332                             second_group_id) != -1) {
 333                fprintf(stderr,
 334                        "ERROR: specified a group id when requesting unique id\n");
 335                exit(1);
 336        }
 337
 338        if (close(fds[0]) || close(fds[1]) || close(fds[2])) {
 339                fprintf(stderr, "ERROR: closing sockets\n");
 340                exit(1);
 341        }
 342}
 343
 344static int test_datapath(uint16_t typeflags, int port_off,
 345                         const int expect1[], const int expect2[])
 346{
 347        const int expect0[] = { 0, 0 };
 348        char *rings[2];
 349        uint8_t type = typeflags & 0xFF;
 350        int fds[2], fds_udp[2][2], ret;
 351
 352        fprintf(stderr, "\ntest: datapath 0x%hx ports %hu,%hu\n",
 353                typeflags, PORT_BASE, PORT_BASE + port_off);
 354
 355        fds[0] = sock_fanout_open(typeflags, 0);
 356        fds[1] = sock_fanout_open(typeflags, 0);
 357        if (fds[0] == -1 || fds[1] == -1) {
 358                fprintf(stderr, "ERROR: failed open\n");
 359                exit(1);
 360        }
 361        if (type == PACKET_FANOUT_CBPF)
 362                sock_fanout_set_cbpf(fds[0]);
 363        else if (type == PACKET_FANOUT_EBPF)
 364                sock_fanout_set_ebpf(fds[0]);
 365
 366        rings[0] = sock_fanout_open_ring(fds[0]);
 367        rings[1] = sock_fanout_open_ring(fds[1]);
 368        pair_udp_open(fds_udp[0], PORT_BASE);
 369        pair_udp_open(fds_udp[1], PORT_BASE + port_off);
 370        sock_fanout_read(fds, rings, expect0);
 371
 372        /* Send data, but not enough to overflow a queue */
 373        pair_udp_send(fds_udp[0], 15);
 374        pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
 375        ret = sock_fanout_read(fds, rings, expect1);
 376
 377        /* Send more data, overflow the queue */
 378        pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
 379        /* TODO: ensure consistent order between expect1 and expect2 */
 380        ret |= sock_fanout_read(fds, rings, expect2);
 381
 382        if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
 383            munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
 384                fprintf(stderr, "close rings\n");
 385                exit(1);
 386        }
 387        if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
 388            close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
 389            close(fds[1]) || close(fds[0])) {
 390                fprintf(stderr, "close datapath\n");
 391                exit(1);
 392        }
 393
 394        return ret;
 395}
 396
 397static int set_cpuaffinity(int cpuid)
 398{
 399        cpu_set_t mask;
 400
 401        CPU_ZERO(&mask);
 402        CPU_SET(cpuid, &mask);
 403        if (sched_setaffinity(0, sizeof(mask), &mask)) {
 404                if (errno != EINVAL) {
 405                        fprintf(stderr, "setaffinity %d\n", cpuid);
 406                        exit(1);
 407                }
 408                return 1;
 409        }
 410
 411        return 0;
 412}
 413
 414int main(int argc, char **argv)
 415{
 416        const int expect_hash[2][2]     = { { 15, 5 },  { 20, 5 } };
 417        const int expect_hash_rb[2][2]  = { { 15, 5 },  { 20, 15 } };
 418        const int expect_lb[2][2]       = { { 10, 10 }, { 18, 17 } };
 419        const int expect_rb[2][2]       = { { 15, 5 },  { 20, 15 } };
 420        const int expect_cpu0[2][2]     = { { 20, 0 },  { 20, 0 } };
 421        const int expect_cpu1[2][2]     = { { 0, 20 },  { 0, 20 } };
 422        const int expect_bpf[2][2]      = { { 15, 5 },  { 15, 20 } };
 423        const int expect_uniqueid[2][2] = { { 20, 20},  { 20, 20 } };
 424        int port_off = 2, tries = 20, ret;
 425
 426        test_control_single();
 427        test_control_group();
 428        test_unique_fanout_group_ids();
 429
 430        /* find a set of ports that do not collide onto the same socket */
 431        ret = test_datapath(PACKET_FANOUT_HASH, port_off,
 432                            expect_hash[0], expect_hash[1]);
 433        while (ret) {
 434                fprintf(stderr, "info: trying alternate ports (%d)\n", tries);
 435                ret = test_datapath(PACKET_FANOUT_HASH, ++port_off,
 436                                    expect_hash[0], expect_hash[1]);
 437                if (!--tries) {
 438                        fprintf(stderr, "too many collisions\n");
 439                        return 1;
 440                }
 441        }
 442
 443        ret |= test_datapath(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_ROLLOVER,
 444                             port_off, expect_hash_rb[0], expect_hash_rb[1]);
 445        ret |= test_datapath(PACKET_FANOUT_LB,
 446                             port_off, expect_lb[0], expect_lb[1]);
 447        ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
 448                             port_off, expect_rb[0], expect_rb[1]);
 449
 450        ret |= test_datapath(PACKET_FANOUT_CBPF,
 451                             port_off, expect_bpf[0], expect_bpf[1]);
 452        ret |= test_datapath(PACKET_FANOUT_EBPF,
 453                             port_off, expect_bpf[0], expect_bpf[1]);
 454
 455        set_cpuaffinity(0);
 456        ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
 457                             expect_cpu0[0], expect_cpu0[1]);
 458        if (!set_cpuaffinity(1))
 459                /* TODO: test that choice alternates with previous */
 460                ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
 461                                     expect_cpu1[0], expect_cpu1[1]);
 462
 463        ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,
 464                             expect_uniqueid[0], expect_uniqueid[1]);
 465
 466        if (ret)
 467                return 1;
 468
 469        printf("OK. All tests passed\n");
 470        return 0;
 471}
 472