/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#ifndef _UAPI__LINUX_BPF_H__
#define _UAPI__LINUX_BPF_H__

#include <linux/types.h>
#include <linux/bpf_common.h>

/* Extended instruction set based on top of classic BPF */

/* instruction classes */
#define BPF_ALU64       0x07    /* alu mode in double word width */

/* ld/ldx fields */
#define BPF_DW          0x18    /* double word */
#define BPF_XADD        0xc0    /* exclusive add */

/* alu/jmp fields */
#define BPF_MOV         0xb0    /* mov reg to reg */
#define BPF_ARSH        0xc0    /* sign extending arithmetic shift right */

/* change endianness of a register */
#define BPF_END         0xd0    /* flags for endianness conversion: */
#define BPF_TO_LE       0x00    /* convert to little-endian */
#define BPF_TO_BE       0x08    /* convert to big-endian */
#define BPF_FROM_LE     BPF_TO_LE
#define BPF_FROM_BE     BPF_TO_BE

#define BPF_JNE         0x50    /* jump != */
#define BPF_JSGT        0x60    /* SGT is signed '>', GT in x86 */
#define BPF_JSGE        0x70    /* SGE is signed '>=', GE in x86 */
#define BPF_CALL        0x80    /* function call */
#define BPF_EXIT        0x90    /* function return */

/* Register numbers */
enum {
        BPF_REG_0 = 0,
        BPF_REG_1,
        BPF_REG_2,
        BPF_REG_3,
        BPF_REG_4,
        BPF_REG_5,
        BPF_REG_6,
        BPF_REG_7,
        BPF_REG_8,
        BPF_REG_9,
        BPF_REG_10,
        __MAX_BPF_REG,
};

/* BPF has 10 general purpose 64-bit registers and stack frame. */
#define MAX_BPF_REG     __MAX_BPF_REG

struct bpf_insn {
        __u8    code;           /* opcode */
        __u8    dst_reg:4;      /* dest register */
        __u8    src_reg:4;      /* source register */
        __s16   off;            /* signed offset */
        __s32   imm;            /* signed immediate constant */
};

/* BPF syscall commands, see bpf(2) man-page for details. */
enum bpf_cmd {
        BPF_MAP_CREATE,
        BPF_MAP_LOOKUP_ELEM,
        BPF_MAP_UPDATE_ELEM,
        BPF_MAP_DELETE_ELEM,
        BPF_MAP_GET_NEXT_KEY,
        BPF_PROG_LOAD,
        BPF_OBJ_PIN,
        BPF_OBJ_GET,
        BPF_PROG_ATTACH,
        BPF_PROG_DETACH,
};

enum bpf_map_type {
        BPF_MAP_TYPE_UNSPEC,
        BPF_MAP_TYPE_HASH,
        BPF_MAP_TYPE_ARRAY,
        BPF_MAP_TYPE_PROG_ARRAY,
        BPF_MAP_TYPE_PERF_EVENT_ARRAY,
        BPF_MAP_TYPE_PERCPU_HASH,
        BPF_MAP_TYPE_PERCPU_ARRAY,
        BPF_MAP_TYPE_STACK_TRACE,
        BPF_MAP_TYPE_CGROUP_ARRAY,
        BPF_MAP_TYPE_LRU_HASH,
        BPF_MAP_TYPE_LRU_PERCPU_HASH,
};

enum bpf_prog_type {
        BPF_PROG_TYPE_UNSPEC,
        BPF_PROG_TYPE_SOCKET_FILTER,
        BPF_PROG_TYPE_KPROBE,
        BPF_PROG_TYPE_SCHED_CLS,
        BPF_PROG_TYPE_SCHED_ACT,
        BPF_PROG_TYPE_TRACEPOINT,
        BPF_PROG_TYPE_XDP,
        BPF_PROG_TYPE_PERF_EVENT,
        BPF_PROG_TYPE_CGROUP_SKB,
        BPF_PROG_TYPE_CGROUP_SOCK,
        BPF_PROG_TYPE_LWT_IN,
        BPF_PROG_TYPE_LWT_OUT,
        BPF_PROG_TYPE_LWT_XMIT,
};

enum bpf_attach_type {
        BPF_CGROUP_INET_INGRESS,
        BPF_CGROUP_INET_EGRESS,
        BPF_CGROUP_INET_SOCK_CREATE,
        __MAX_BPF_ATTACH_TYPE
};

#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE

/* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
 * to the given target_fd cgroup the descendent cgroup will be able to
 * override effective bpf program that was inherited from this cgroup
 */
#define BPF_F_ALLOW_OVERRIDE    (1U << 0)

#define BPF_PSEUDO_MAP_FD       1

/* flags for BPF_MAP_UPDATE_ELEM command */
#define BPF_ANY         0 /* create new element or update existing */
#define BPF_NOEXIST     1 /* create new element if it didn't exist */
#define BPF_EXIST       2 /* update existing element */

#define BPF_F_NO_PREALLOC       (1U << 0)
/* Instead of having one common LRU list in the
 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
 * which can scale and perform better.
 * Note, the LRU nodes (including free nodes) cannot be moved
 * across different LRU lists.
 */
#define BPF_F_NO_COMMON_LRU     (1U << 1)

union bpf_attr {
        struct { /* anonymous struct used by BPF_MAP_CREATE command */
                __u32   map_type;       /* one of enum bpf_map_type */
                __u32   key_size;       /* size of key in bytes */
                __u32   value_size;     /* size of value in bytes */
                __u32   max_entries;    /* max number of entries in a map */
                __u32   map_flags;      /* prealloc or not */
        };

        struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
                __u32           map_fd;
                __aligned_u64   key;
                union {
                        __aligned_u64 value;
                        __aligned_u64 next_key;
                };
                __u64           flags;
        };

        struct { /* anonymous struct used by BPF_PROG_LOAD command */
                __u32           prog_type;      /* one of enum bpf_prog_type */
                __u32           insn_cnt;
                __aligned_u64   insns;
                __aligned_u64   license;
                __u32           log_level;      /* verbosity level of verifier */
                __u32           log_size;       /* size of user buffer */
                __aligned_u64   log_buf;        /* user supplied buffer */
                __u32           kern_version;   /* checked when prog_type=kprobe */
        };

        struct { /* anonymous struct used by BPF_OBJ_* commands */
                __aligned_u64   pathname;
                __u32           bpf_fd;
        };

        struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
                __u32           target_fd;      /* container object to attach to */
                __u32           attach_bpf_fd;  /* eBPF program to attach */
                __u32           attach_type;
                __u32           attach_flags;
        };
} __attribute__((aligned(8)));

/* BPF helper function descriptions:
 *
 * void *bpf_map_lookup_elem(&map, &key)
 *     Return: Map value or NULL
 *
 * int bpf_map_update_elem(&map, &key, &value, flags)
 *     Return: 0 on success or negative error
 *
 * int bpf_map_delete_elem(&map, &key)
 *     Return: 0 on success or negative error
 *
 * int bpf_probe_read(void *dst, int size, void *src)
 *     Return: 0 on success or negative error
 *
 * u64 bpf_ktime_get_ns(void)
 *     Return: current ktime
 *
 * int bpf_trace_printk(const char *fmt, int fmt_size, ...)
 *     Return: length of buffer written or negative error
 *
 * u32 bpf_prandom_u32(void)
 *     Return: random value
 *
 * u32 bpf_raw_smp_processor_id(void)
 *     Return: SMP processor ID
 *
 * int bpf_skb_store_bytes(skb, offset, from, len, flags)
 *     store bytes into packet
 *     @skb: pointer to skb
 *     @offset: offset within packet from skb->mac_header
 *     @from: pointer where to copy bytes from
 *     @len: number of bytes to store into packet
 *     @flags: bit 0 - if true, recompute skb->csum
 *             other bits - reserved
 *     Return: 0 on success or negative error
 *
 * int bpf_l3_csum_replace(skb, offset, from, to, flags)
 *     recompute IP checksum
 *     @skb: pointer to skb
 *     @offset: offset within packet where IP checksum is located
 *     @from: old value of header field
 *     @to: new value of header field
 *     @flags: bits 0-3 - size of header field
 *             other bits - reserved
 *     Return: 0 on success or negative error
 *
 * int bpf_l4_csum_replace(skb, offset, from, to, flags)
 *     recompute TCP/UDP checksum
 *     @skb: pointer to skb
 *     @offset: offset within packet where TCP/UDP checksum is located
 *     @from: old value of header field
 *     @to: new value of header field
 *     @flags: bits 0-3 - size of header field
 *             bit 4 - is pseudo header
 *             other bits - reserved
 *     Return: 0 on success or negative error
 *
 * int bpf_tail_call(ctx, prog_array_map, index)
 *     jump into another BPF program
 *     @ctx: context pointer passed to next program
 *     @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
 *     @index: index inside array that selects specific program to run
 *     Return: 0 on success or negative error
 *
 * int bpf_clone_redirect(skb, ifindex, flags)
 *     redirect to another netdev
 *     @skb: pointer to skb
 *     @ifindex: ifindex of the net device
 *     @flags: bit 0 - if set, redirect to ingress instead of egress
 *             other bits - reserved
 *     Return: 0 on success or negative error
 *
 * u64 bpf_get_current_pid_tgid(void)
 *     Return: current->tgid << 32 | current->pid
 *
 * u64 bpf_get_current_uid_gid(void)
 *     Return: current_gid << 32 | current_uid
 *
 * int bpf_get_current_comm(char *buf, int size_of_buf)
 *     stores current->comm into buf
 *     Return: 0 on success or negative error
 *
 * u32 bpf_get_cgroup_classid(skb)
 *     retrieve a proc's classid
 *     @skb: pointer to skb
 *     Return: classid if != 0
 *
 * int bpf_skb_vlan_push(skb, vlan_proto, vlan_tci)
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_vlan_pop(skb)
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_get_tunnel_key(skb, key, size, flags)
 * int bpf_skb_set_tunnel_key(skb, key, size, flags)
 *     retrieve or populate tunnel metadata
 *     @skb: pointer to skb
 *     @key: pointer to 'struct bpf_tunnel_key'
 *     @size: size of 'struct bpf_tunnel_key'
 *     @flags: room for future extensions
 *     Return: 0 on success or negative error
 *
 * u64 bpf_perf_event_read(&map, index)
 *     Return: Number events read or error code
 *
 * int bpf_redirect(ifindex, flags)
 *     redirect to another netdev
 *     @ifindex: ifindex of the net device
 *     @flags: bit 0 - if set, redirect to ingress instead of egress
 *             other bits - reserved
 *     Return: TC_ACT_REDIRECT
 *
 * u32 bpf_get_route_realm(skb)
 *     retrieve a dst's tclassid
 *     @skb: pointer to skb
 *     Return: realm if != 0
 *
 * int bpf_perf_event_output(ctx, map, index, data, size)
 *     output perf raw sample
 *     @ctx: struct pt_regs*
 *     @map: pointer to perf_event_array map
 *     @index: index of event in the map
 *     @data: data on stack to be output as raw data
 *     @size: size of data
 *     Return: 0 on success or negative error
 *
 * int bpf_get_stackid(ctx, map, flags)
 *     walk user or kernel stack and return id
 *     @ctx: struct pt_regs*
 *     @map: pointer to stack_trace map
 *     @flags: bits 0-7 - numer of stack frames to skip
 *             bit 8 - collect user stack instead of kernel
 *             bit 9 - compare stacks by hash only
 *             bit 10 - if two different stacks hash into the same stackid
 *                      discard old
 *             other bits - reserved
 *     Return: >= 0 stackid on success or negative error
 *
 * s64 bpf_csum_diff(from, from_size, to, to_size, seed)
 *     calculate csum diff
 *     @from: raw from buffer
 *     @from_size: length of from buffer
 *     @to: raw to buffer
 *     @to_size: length of to buffer
 *     @seed: optional seed
 *     Return: csum result or negative error code
 *
 * int bpf_skb_get_tunnel_opt(skb, opt, size)
 *     retrieve tunnel options metadata
 *     @skb: pointer to skb
 *     @opt: pointer to raw tunnel option data
 *     @size: size of @opt
 *     Return: option size
 *
 * int bpf_skb_set_tunnel_opt(skb, opt, size)
 *     populate tunnel options metadata
 *     @skb: pointer to skb
 *     @opt: pointer to raw tunnel option data
 *     @size: size of @opt
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_change_proto(skb, proto, flags)
 *     Change protocol of the skb. Currently supported is v4 -> v6,
 *     v6 -> v4 transitions. The helper will also resize the skb. eBPF
 *     program is expected to fill the new headers via skb_store_bytes
 *     and lX_csum_replace.
 *     @skb: pointer to skb
 *     @proto: new skb->protocol type
 *     @flags: reserved
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_change_type(skb, type)
 *     Change packet type of skb.
 *     @skb: pointer to skb
 *     @type: new skb->pkt_type type
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_under_cgroup(skb, map, index)
 *     Check cgroup2 membership of skb
 *     @skb: pointer to skb
 *     @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
 *     @index: index of the cgroup in the bpf_map
 *     Return:
 *       == 0 skb failed the cgroup2 descendant test
 *       == 1 skb succeeded the cgroup2 descendant test
 *        < 0 error
 *
 * u32 bpf_get_hash_recalc(skb)
 *     Retrieve and possibly recalculate skb->hash.
 *     @skb: pointer to skb
 *     Return: hash
 *
 * u64 bpf_get_current_task(void)
 *     Returns current task_struct
 *     Return: current
 *
 * int bpf_probe_write_user(void *dst, void *src, int len)
 *     safely attempt to write to a location
 *     @dst: destination address in userspace
 *     @src: source address on stack
 *     @len: number of bytes to copy
 *     Return: 0 on success or negative error
 *
 * int bpf_current_task_under_cgroup(map, index)
 *     Check cgroup2 membership of current task
 *     @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
 *     @index: index of the cgroup in the bpf_map
 *     Return:
 *       == 0 current failed the cgroup2 descendant test
 *       == 1 current succeeded the cgroup2 descendant test
 *        < 0 error
 *
 * int bpf_skb_change_tail(skb, len, flags)
 *     The helper will resize the skb to the given new size, to be used f.e.
 *     with control messages.
 *     @skb: pointer to skb
 *     @len: new skb length
 *     @flags: reserved
 *     Return: 0 on success or negative error
 *
 * int bpf_skb_pull_data(skb, len)
 *     The helper will pull in non-linear data in case the skb is non-linear
 *     and not all of len are part of the linear section. Only needed for
 *     read/write with direct packet access.
 *     @skb: pointer to skb
 *     @len: len to make read/writeable
 *     Return: 0 on success or negative error
 *
 * s64 bpf_csum_update(skb, csum)
 *     Adds csum into skb->csum in case of CHECKSUM_COMPLETE.
 *     @skb: pointer to skb
 *     @csum: csum to add
 *     Return: csum on success or negative error
 *
 * void bpf_set_hash_invalid(skb)
 *     Invalidate current skb->hash.
 *     @skb: pointer to skb
 *
 * int bpf_get_numa_node_id()
 *     Return: Id of current NUMA node.
 *
 * int bpf_skb_change_head()
 *     Grows headroom of skb and adjusts MAC header offset accordingly.
 *     Will extends/reallocae as required automatically.
 *     May change skb data pointer and will thus invalidate any check
 *     performed for direct packet access.
 *     @skb: pointer to skb
 *     @len: length of header to be pushed in front
 *     @flags: Flags (unused for now)
 *     Return: 0 on success or negative error
 *
 * int bpf_xdp_adjust_head(xdp_md, delta)
 *     Adjust the xdp_md.data by delta
 *     @xdp_md: pointer to xdp_md
 *     @delta: An positive/negative integer to be added to xdp_md.data
 *     Return: 0 on success or negative on error
 */
#define __BPF_FUNC_MAPPER(FN)           \
        FN(unspec),                     \
        FN(map_lookup_elem),            \
        FN(map_update_elem),            \
        FN(map_delete_elem),            \
        FN(probe_read),                 \
        FN(ktime_get_ns),               \
        FN(trace_printk),               \
        FN(get_prandom_u32),            \
        FN(get_smp_processor_id),       \
        FN(skb_store_bytes),            \
        FN(l3_csum_replace),            \
        FN(l4_csum_replace),            \
        FN(tail_call),                  \
        FN(clone_redirect),             \
        FN(get_current_pid_tgid),       \
        FN(get_current_uid_gid),        \
        FN(get_current_comm),           \
        FN(get_cgroup_classid),         \
        FN(skb_vlan_push),              \
        FN(skb_vlan_pop),               \
        FN(skb_get_tunnel_key),         \
        FN(skb_set_tunnel_key),         \
        FN(perf_event_read),            \
        FN(redirect),                   \
        FN(get_route_realm),            \
        FN(perf_event_output),          \
        FN(skb_load_bytes),             \
        FN(get_stackid),                \
        FN(csum_diff),                  \
        FN(skb_get_tunnel_opt),         \
        FN(skb_set_tunnel_opt),         \
        FN(skb_change_proto),           \
        FN(skb_change_type),            \
        FN(skb_under_cgroup),           \
        FN(get_hash_recalc),            \
        FN(get_current_task),           \
        FN(probe_write_user),           \
        FN(current_task_under_cgroup),  \
        FN(skb_change_tail),            \
        FN(skb_pull_data),              \
        FN(csum_update),                \
        FN(set_hash_invalid),           \
        FN(get_numa_node_id),           \
        FN(skb_change_head),            \
        FN(xdp_adjust_head),

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
 * function eBPF program intends to call
 */
#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
enum bpf_func_id {
        __BPF_FUNC_MAPPER(__BPF_ENUM_FN)
        __BPF_FUNC_MAX_ID,
};
#undef __BPF_ENUM_FN

/* All flags used by eBPF helper functions, placed here. */

/* BPF_FUNC_skb_store_bytes flags. */
#define BPF_F_RECOMPUTE_CSUM            (1ULL << 0)
#define BPF_F_INVALIDATE_HASH           (1ULL << 1)

/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
 * First 4 bits are for passing the header field size.
 */
#define BPF_F_HDR_FIELD_MASK            0xfULL

/* BPF_FUNC_l4_csum_replace flags. */
#define BPF_F_PSEUDO_HDR                (1ULL << 4)
#define BPF_F_MARK_MANGLED_0            (1ULL << 5)

/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
#define BPF_F_INGRESS                   (1ULL << 0)

/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
#define BPF_F_TUNINFO_IPV6              (1ULL << 0)

/* BPF_FUNC_get_stackid flags. */
#define BPF_F_SKIP_FIELD_MASK           0xffULL
#define BPF_F_USER_STACK                (1ULL << 8)
#define BPF_F_FAST_STACK_CMP            (1ULL << 9)
#define BPF_F_REUSE_STACKID             (1ULL << 10)

/* BPF_FUNC_skb_set_tunnel_key flags. */
#define BPF_F_ZERO_CSUM_TX              (1ULL << 1)
#define BPF_F_DONT_FRAGMENT             (1ULL << 2)

/* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
#define BPF_F_INDEX_MASK                0xffffffffULL
#define BPF_F_CURRENT_CPU               BPF_F_INDEX_MASK
/* BPF_FUNC_perf_event_output for sk_buff input context. */
#define BPF_F_CTXLEN_MASK               (0xfffffULL << 32)

/* user accessible mirror of in-kernel sk_buff.
 * new fields can only be added to the end of this structure
 */
struct __sk_buff {
        __u32 len;
        __u32 pkt_type;
        __u32 mark;
        __u32 queue_mapping;
        __u32 protocol;
        __u32 vlan_present;
        __u32 vlan_tci;
        __u32 vlan_proto;
        __u32 priority;
        __u32 ingress_ifindex;
        __u32 ifindex;
        __u32 tc_index;
        __u32 cb[5];
        __u32 hash;
        __u32 tc_classid;
        __u32 data;
        __u32 data_end;
};

struct bpf_tunnel_key {
        __u32 tunnel_id;
        union {
                __u32 remote_ipv4;
                __u32 remote_ipv6[4];
        };
        __u8 tunnel_tos;
        __u8 tunnel_ttl;
        __u16 tunnel_ext;
        __u32 tunnel_label;
};

/* Generic BPF return codes which all BPF program types may support.
 * The values are binary compatible with their TC_ACT_* counter-part to
 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
 * programs.
 *
 * XDP is handled seprately, see XDP_*.
 */
enum bpf_ret_code {
        BPF_OK = 0,
        /* 1 reserved */
        BPF_DROP = 2,
        /* 3-6 reserved */
        BPF_REDIRECT = 7,
        /* >127 are reserved for prog type specific return codes */
};

struct bpf_sock {
        __u32 bound_dev_if;
        __u32 family;
        __u32 type;
        __u32 protocol;
};

#define XDP_PACKET_HEADROOM 256

/* User return codes for XDP prog type.
 * A valid XDP program must return one of these defined values. All other
 * return codes are reserved for future use. Unknown return codes will result
 * in packet drop.
 */
enum xdp_action {
        XDP_ABORTED = 0,
        XDP_DROP,
        XDP_PASS,
        XDP_TX,
};

/* user accessible metadata for XDP packet hook
 * new fields must be added to the end of this structure
 */
struct xdp_md {
        __u32 data;
        __u32 data_end;
};

#endif /* _UAPI__LINUX_BPF_H__ */