mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Toshiaki Makita](/assets/img/avatar_default.png)
Otherwise we end up with attempting to send packets from down devices
or to send oversized packets, which may cause unexpected driver/device
behaviour. Generic XDP has already done this check, so reuse the logic
in native XDP.
Fixes: 814abfabef
("xdp: add bpf_redirect helper function")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1064 lines
29 KiB
C
1064 lines
29 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Linux Socket Filter Data Structures
|
|
*/
|
|
#ifndef __LINUX_FILTER_H__
|
|
#define __LINUX_FILTER_H__
|
|
|
|
#include <stdarg.h>
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/linkage.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/cryptohash.h>
|
|
#include <linux/set_memory.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/if_vlan.h>
|
|
|
|
#include <net/sch_generic.h>
|
|
|
|
#include <uapi/linux/filter.h>
|
|
#include <uapi/linux/bpf.h>
|
|
|
|
struct sk_buff;
|
|
struct sock;
|
|
struct seccomp_data;
|
|
struct bpf_prog_aux;
|
|
struct xdp_rxq_info;
|
|
struct xdp_buff;
|
|
|
|
/* ArgX, context and stack frame pointer register positions. Note,
|
|
* Arg1, Arg2, Arg3, etc are used as argument mappings of function
|
|
* calls in BPF_CALL instruction.
|
|
*/
|
|
#define BPF_REG_ARG1 BPF_REG_1
|
|
#define BPF_REG_ARG2 BPF_REG_2
|
|
#define BPF_REG_ARG3 BPF_REG_3
|
|
#define BPF_REG_ARG4 BPF_REG_4
|
|
#define BPF_REG_ARG5 BPF_REG_5
|
|
#define BPF_REG_CTX BPF_REG_6
|
|
#define BPF_REG_FP BPF_REG_10
|
|
|
|
/* Additional register mappings for converted user programs. */
|
|
#define BPF_REG_A BPF_REG_0
|
|
#define BPF_REG_X BPF_REG_7
|
|
#define BPF_REG_TMP BPF_REG_2 /* scratch reg */
|
|
#define BPF_REG_D BPF_REG_8 /* data, callee-saved */
|
|
#define BPF_REG_H BPF_REG_9 /* hlen, callee-saved */
|
|
|
|
/* Kernel hidden auxiliary/helper register for hardening step.
|
|
* Only used by eBPF JITs. It's nothing more than a temporary
|
|
* register that JITs use internally, only that here it's part
|
|
* of eBPF instructions that have been rewritten for blinding
|
|
* constants. See JIT pre-step in bpf_jit_blind_constants().
|
|
*/
|
|
#define BPF_REG_AX MAX_BPF_REG
|
|
#define MAX_BPF_JIT_REG (MAX_BPF_REG + 1)
|
|
|
|
/* unused opcode to mark special call to bpf_tail_call() helper */
|
|
#define BPF_TAIL_CALL 0xf0
|
|
|
|
/* unused opcode to mark call to interpreter with arguments */
|
|
#define BPF_CALL_ARGS 0xe0
|
|
|
|
/* As per nm, we expose JITed images as text (code) section for
|
|
* kallsyms. That way, tools like perf can find it to match
|
|
* addresses.
|
|
*/
|
|
#define BPF_SYM_ELF_TYPE 't'
|
|
|
|
/* BPF program can access up to 512 bytes of stack space. */
|
|
#define MAX_BPF_STACK 512
|
|
|
|
/* Helper macros for filter block array initializers. */
|
|
|
|
/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
|
|
|
|
#define BPF_ALU64_REG(OP, DST, SRC) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = 0 })
|
|
|
|
#define BPF_ALU32_REG(OP, DST, SRC) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_OP(OP) | BPF_X, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = 0 })
|
|
|
|
/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
|
|
|
|
#define BPF_ALU64_IMM(OP, DST, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
#define BPF_ALU32_IMM(OP, DST, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_OP(OP) | BPF_K, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
|
|
|
|
#define BPF_ENDIAN(TYPE, DST, LEN) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = LEN })
|
|
|
|
/* Short form of mov, dst_reg = src_reg */
|
|
|
|
#define BPF_MOV64_REG(DST, SRC) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU64 | BPF_MOV | BPF_X, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = 0 })
|
|
|
|
#define BPF_MOV32_REG(DST, SRC) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_MOV | BPF_X, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = 0 })
|
|
|
|
/* Short form of mov, dst_reg = imm32 */
|
|
|
|
#define BPF_MOV64_IMM(DST, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU64 | BPF_MOV | BPF_K, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
#define BPF_MOV32_IMM(DST, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_MOV | BPF_K, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
|
|
#define BPF_LD_IMM64(DST, IMM) \
|
|
BPF_LD_IMM64_RAW(DST, 0, IMM)
|
|
|
|
#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_LD | BPF_DW | BPF_IMM, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = (__u32) (IMM) }), \
|
|
((struct bpf_insn) { \
|
|
.code = 0, /* zero is reserved opcode */ \
|
|
.dst_reg = 0, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = ((__u64) (IMM)) >> 32 })
|
|
|
|
/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
|
|
#define BPF_LD_MAP_FD(DST, MAP_FD) \
|
|
BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
|
|
|
|
/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
|
|
|
|
#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
|
|
|
|
#define BPF_LD_ABS(SIZE, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
|
|
.dst_reg = 0, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
|
|
|
|
#define BPF_LD_IND(SIZE, SRC, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
|
|
.dst_reg = 0, \
|
|
.src_reg = SRC, \
|
|
.off = 0, \
|
|
.imm = IMM })
|
|
|
|
/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
|
|
|
|
#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = OFF, \
|
|
.imm = 0 })
|
|
|
|
/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
|
|
|
|
#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = OFF, \
|
|
.imm = 0 })
|
|
|
|
/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
|
|
|
|
#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = OFF, \
|
|
.imm = 0 })
|
|
|
|
/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
|
|
|
|
#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = OFF, \
|
|
.imm = IMM })
|
|
|
|
/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
|
|
|
|
#define BPF_JMP_REG(OP, DST, SRC, OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_OP(OP) | BPF_X, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = OFF, \
|
|
.imm = 0 })
|
|
|
|
/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
|
|
|
|
#define BPF_JMP_IMM(OP, DST, IMM, OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_OP(OP) | BPF_K, \
|
|
.dst_reg = DST, \
|
|
.src_reg = 0, \
|
|
.off = OFF, \
|
|
.imm = IMM })
|
|
|
|
/* Unconditional jumps, goto pc + off16 */
|
|
|
|
#define BPF_JMP_A(OFF) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_JA, \
|
|
.dst_reg = 0, \
|
|
.src_reg = 0, \
|
|
.off = OFF, \
|
|
.imm = 0 })
|
|
|
|
/* Relative call */
|
|
|
|
#define BPF_CALL_REL(TGT) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_CALL, \
|
|
.dst_reg = 0, \
|
|
.src_reg = BPF_PSEUDO_CALL, \
|
|
.off = 0, \
|
|
.imm = TGT })
|
|
|
|
/* Function call */
|
|
|
|
#define BPF_CAST_CALL(x) \
|
|
((u64 (*)(u64, u64, u64, u64, u64))(x))
|
|
|
|
#define BPF_EMIT_CALL(FUNC) \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_CALL, \
|
|
.dst_reg = 0, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = ((FUNC) - __bpf_call_base) })
|
|
|
|
/* Raw code statement block */
|
|
|
|
#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
|
|
((struct bpf_insn) { \
|
|
.code = CODE, \
|
|
.dst_reg = DST, \
|
|
.src_reg = SRC, \
|
|
.off = OFF, \
|
|
.imm = IMM })
|
|
|
|
/* Program exit */
|
|
|
|
#define BPF_EXIT_INSN() \
|
|
((struct bpf_insn) { \
|
|
.code = BPF_JMP | BPF_EXIT, \
|
|
.dst_reg = 0, \
|
|
.src_reg = 0, \
|
|
.off = 0, \
|
|
.imm = 0 })
|
|
|
|
/* Internal classic blocks for direct assignment */
|
|
|
|
#define __BPF_STMT(CODE, K) \
|
|
((struct sock_filter) BPF_STMT(CODE, K))
|
|
|
|
#define __BPF_JUMP(CODE, K, JT, JF) \
|
|
((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
|
|
|
|
#define bytes_to_bpf_size(bytes) \
|
|
({ \
|
|
int bpf_size = -EINVAL; \
|
|
\
|
|
if (bytes == sizeof(u8)) \
|
|
bpf_size = BPF_B; \
|
|
else if (bytes == sizeof(u16)) \
|
|
bpf_size = BPF_H; \
|
|
else if (bytes == sizeof(u32)) \
|
|
bpf_size = BPF_W; \
|
|
else if (bytes == sizeof(u64)) \
|
|
bpf_size = BPF_DW; \
|
|
\
|
|
bpf_size; \
|
|
})
|
|
|
|
#define bpf_size_to_bytes(bpf_size) \
|
|
({ \
|
|
int bytes = -EINVAL; \
|
|
\
|
|
if (bpf_size == BPF_B) \
|
|
bytes = sizeof(u8); \
|
|
else if (bpf_size == BPF_H) \
|
|
bytes = sizeof(u16); \
|
|
else if (bpf_size == BPF_W) \
|
|
bytes = sizeof(u32); \
|
|
else if (bpf_size == BPF_DW) \
|
|
bytes = sizeof(u64); \
|
|
\
|
|
bytes; \
|
|
})
|
|
|
|
#define BPF_SIZEOF(type) \
|
|
({ \
|
|
const int __size = bytes_to_bpf_size(sizeof(type)); \
|
|
BUILD_BUG_ON(__size < 0); \
|
|
__size; \
|
|
})
|
|
|
|
#define BPF_FIELD_SIZEOF(type, field) \
|
|
({ \
|
|
const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
|
|
BUILD_BUG_ON(__size < 0); \
|
|
__size; \
|
|
})
|
|
|
|
#define BPF_LDST_BYTES(insn) \
|
|
({ \
|
|
const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
|
|
WARN_ON(__size < 0); \
|
|
__size; \
|
|
})
|
|
|
|
#define __BPF_MAP_0(m, v, ...) v
|
|
#define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
|
|
#define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
|
|
#define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
|
|
#define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
|
|
#define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
|
|
|
|
#define __BPF_REG_0(...) __BPF_PAD(5)
|
|
#define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
|
|
#define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
|
|
#define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
|
|
#define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
|
|
#define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
|
|
|
|
#define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
|
|
#define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
|
|
|
|
#define __BPF_CAST(t, a) \
|
|
(__force t) \
|
|
(__force \
|
|
typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long), \
|
|
(unsigned long)0, (t)0))) a
|
|
#define __BPF_V void
|
|
#define __BPF_N
|
|
|
|
#define __BPF_DECL_ARGS(t, a) t a
|
|
#define __BPF_DECL_REGS(t, a) u64 a
|
|
|
|
#define __BPF_PAD(n) \
|
|
__BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2, \
|
|
u64, __ur_3, u64, __ur_4, u64, __ur_5)
|
|
|
|
#define BPF_CALL_x(x, name, ...) \
|
|
static __always_inline \
|
|
u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
|
|
u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \
|
|
u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \
|
|
{ \
|
|
return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
|
|
} \
|
|
static __always_inline \
|
|
u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
|
|
|
|
#define BPF_CALL_0(name, ...) BPF_CALL_x(0, name, __VA_ARGS__)
|
|
#define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__)
|
|
#define BPF_CALL_2(name, ...) BPF_CALL_x(2, name, __VA_ARGS__)
|
|
#define BPF_CALL_3(name, ...) BPF_CALL_x(3, name, __VA_ARGS__)
|
|
#define BPF_CALL_4(name, ...) BPF_CALL_x(4, name, __VA_ARGS__)
|
|
#define BPF_CALL_5(name, ...) BPF_CALL_x(5, name, __VA_ARGS__)
|
|
|
|
#define bpf_ctx_range(TYPE, MEMBER) \
|
|
offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
|
|
#define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2) \
|
|
offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
|
|
|
|
#define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \
|
|
({ \
|
|
BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE)); \
|
|
*(PTR_SIZE) = (SIZE); \
|
|
offsetof(TYPE, MEMBER); \
|
|
})
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
/* A struct sock_filter is architecture independent. */
|
|
struct compat_sock_fprog {
|
|
u16 len;
|
|
compat_uptr_t filter; /* struct sock_filter * */
|
|
};
|
|
#endif
|
|
|
|
struct sock_fprog_kern {
|
|
u16 len;
|
|
struct sock_filter *filter;
|
|
};
|
|
|
|
struct bpf_binary_header {
|
|
u32 pages;
|
|
/* Some arches need word alignment for their instructions */
|
|
u8 image[] __aligned(4);
|
|
};
|
|
|
|
struct bpf_prog {
|
|
u16 pages; /* Number of allocated pages */
|
|
u16 jited:1, /* Is our filter JIT'ed? */
|
|
jit_requested:1,/* archs need to JIT the prog */
|
|
undo_set_mem:1, /* Passed set_memory_ro() checkpoint */
|
|
gpl_compatible:1, /* Is filter GPL compatible? */
|
|
cb_access:1, /* Is control block accessed? */
|
|
dst_needed:1, /* Do we need dst entry? */
|
|
blinded:1, /* Was blinded */
|
|
is_func:1, /* program is a bpf function */
|
|
kprobe_override:1, /* Do we override a kprobe? */
|
|
has_callchain_buf:1; /* callchain buffer allocated? */
|
|
enum bpf_prog_type type; /* Type of BPF program */
|
|
enum bpf_attach_type expected_attach_type; /* For some prog types */
|
|
u32 len; /* Number of filter blocks */
|
|
u32 jited_len; /* Size of jited insns in bytes */
|
|
u8 tag[BPF_TAG_SIZE];
|
|
struct bpf_prog_aux *aux; /* Auxiliary fields */
|
|
struct sock_fprog_kern *orig_prog; /* Original BPF program */
|
|
unsigned int (*bpf_func)(const void *ctx,
|
|
const struct bpf_insn *insn);
|
|
/* Instructions for interpreter */
|
|
union {
|
|
struct sock_filter insns[0];
|
|
struct bpf_insn insnsi[0];
|
|
};
|
|
};
|
|
|
|
struct sk_filter {
|
|
refcount_t refcnt;
|
|
struct rcu_head rcu;
|
|
struct bpf_prog *prog;
|
|
};
|
|
|
|
#define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi)
|
|
|
|
#define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
|
|
|
|
struct bpf_skb_data_end {
|
|
struct qdisc_skb_cb qdisc_cb;
|
|
void *data_meta;
|
|
void *data_end;
|
|
};
|
|
|
|
struct sk_msg_buff {
|
|
void *data;
|
|
void *data_end;
|
|
__u32 apply_bytes;
|
|
__u32 cork_bytes;
|
|
int sg_copybreak;
|
|
int sg_start;
|
|
int sg_curr;
|
|
int sg_end;
|
|
struct scatterlist sg_data[MAX_SKB_FRAGS];
|
|
bool sg_copy[MAX_SKB_FRAGS];
|
|
__u32 flags;
|
|
struct sock *sk_redir;
|
|
struct sock *sk;
|
|
struct sk_buff *skb;
|
|
struct list_head list;
|
|
};
|
|
|
|
/* Compute the linear packet data range [data, data_end) which
|
|
* will be accessed by various program types (cls_bpf, act_bpf,
|
|
* lwt, ...). Subsystems allowing direct data access must (!)
|
|
* ensure that cb[] area can be written to when BPF program is
|
|
* invoked (otherwise cb[] save/restore is necessary).
|
|
*/
|
|
static inline void bpf_compute_data_pointers(struct sk_buff *skb)
|
|
{
|
|
struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
|
|
|
|
BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
|
|
cb->data_meta = skb->data - skb_metadata_len(skb);
|
|
cb->data_end = skb->data + skb_headlen(skb);
|
|
}
|
|
|
|
static inline u8 *bpf_skb_cb(struct sk_buff *skb)
|
|
{
|
|
/* eBPF programs may read/write skb->cb[] area to transfer meta
|
|
* data between tail calls. Since this also needs to work with
|
|
* tc, that scratch memory is mapped to qdisc_skb_cb's data area.
|
|
*
|
|
* In some socket filter cases, the cb unfortunately needs to be
|
|
* saved/restored so that protocol specific skb->cb[] data won't
|
|
* be lost. In any case, due to unpriviledged eBPF programs
|
|
* attached to sockets, we need to clear the bpf_skb_cb() area
|
|
* to not leak previous contents to user space.
|
|
*/
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
|
|
BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
|
|
FIELD_SIZEOF(struct qdisc_skb_cb, data));
|
|
|
|
return qdisc_skb_cb(skb)->data;
|
|
}
|
|
|
|
static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
|
|
struct sk_buff *skb)
|
|
{
|
|
u8 *cb_data = bpf_skb_cb(skb);
|
|
u8 cb_saved[BPF_SKB_CB_LEN];
|
|
u32 res;
|
|
|
|
if (unlikely(prog->cb_access)) {
|
|
memcpy(cb_saved, cb_data, sizeof(cb_saved));
|
|
memset(cb_data, 0, sizeof(cb_saved));
|
|
}
|
|
|
|
res = BPF_PROG_RUN(prog, skb);
|
|
|
|
if (unlikely(prog->cb_access))
|
|
memcpy(cb_data, cb_saved, sizeof(cb_saved));
|
|
|
|
return res;
|
|
}
|
|
|
|
static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
|
|
struct sk_buff *skb)
|
|
{
|
|
u8 *cb_data = bpf_skb_cb(skb);
|
|
|
|
if (unlikely(prog->cb_access))
|
|
memset(cb_data, 0, BPF_SKB_CB_LEN);
|
|
|
|
return BPF_PROG_RUN(prog, skb);
|
|
}
|
|
|
|
static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
|
|
struct xdp_buff *xdp)
|
|
{
|
|
/* Caller needs to hold rcu_read_lock() (!), otherwise program
|
|
* can be released while still running, or map elements could be
|
|
* freed early while still having concurrent users. XDP fastpath
|
|
* already takes rcu_read_lock() when fetching the program, so
|
|
* it's not necessary here anymore.
|
|
*/
|
|
return BPF_PROG_RUN(prog, xdp);
|
|
}
|
|
|
|
static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
|
|
{
|
|
return prog->len * sizeof(struct bpf_insn);
|
|
}
|
|
|
|
static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
|
|
{
|
|
return round_up(bpf_prog_insn_size(prog) +
|
|
sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
|
|
}
|
|
|
|
static inline unsigned int bpf_prog_size(unsigned int proglen)
|
|
{
|
|
return max(sizeof(struct bpf_prog),
|
|
offsetof(struct bpf_prog, insns[proglen]));
|
|
}
|
|
|
|
static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
|
|
{
|
|
/* When classic BPF programs have been loaded and the arch
|
|
* does not have a classic BPF JIT (anymore), they have been
|
|
* converted via bpf_migrate_filter() to eBPF and thus always
|
|
* have an unspec program type.
|
|
*/
|
|
return prog->type == BPF_PROG_TYPE_UNSPEC;
|
|
}
|
|
|
|
static inline u32 bpf_ctx_off_adjust_machine(u32 size)
|
|
{
|
|
const u32 size_machine = sizeof(unsigned long);
|
|
|
|
if (size > size_machine && size % size_machine == 0)
|
|
size = size_machine;
|
|
|
|
return size;
|
|
}
|
|
|
|
static inline bool bpf_ctx_narrow_align_ok(u32 off, u32 size_access,
|
|
u32 size_default)
|
|
{
|
|
size_default = bpf_ctx_off_adjust_machine(size_default);
|
|
size_access = bpf_ctx_off_adjust_machine(size_access);
|
|
|
|
#ifdef __LITTLE_ENDIAN
|
|
return (off & (size_default - 1)) == 0;
|
|
#else
|
|
return (off & (size_default - 1)) + size_access == size_default;
|
|
#endif
|
|
}
|
|
|
|
static inline bool
|
|
bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
|
|
{
|
|
return bpf_ctx_narrow_align_ok(off, size, size_default) &&
|
|
size <= size_default && (size & (size - 1)) == 0;
|
|
}
|
|
|
|
#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
|
|
|
|
static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
|
|
{
|
|
fp->undo_set_mem = 1;
|
|
set_memory_ro((unsigned long)fp, fp->pages);
|
|
}
|
|
|
|
static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
|
|
{
|
|
if (fp->undo_set_mem)
|
|
set_memory_rw((unsigned long)fp, fp->pages);
|
|
}
|
|
|
|
static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
|
|
{
|
|
set_memory_ro((unsigned long)hdr, hdr->pages);
|
|
}
|
|
|
|
static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
|
|
{
|
|
set_memory_rw((unsigned long)hdr, hdr->pages);
|
|
}
|
|
|
|
static inline struct bpf_binary_header *
|
|
bpf_jit_binary_hdr(const struct bpf_prog *fp)
|
|
{
|
|
unsigned long real_start = (unsigned long)fp->bpf_func;
|
|
unsigned long addr = real_start & PAGE_MASK;
|
|
|
|
return (void *)addr;
|
|
}
|
|
|
|
int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
|
|
static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return sk_filter_trim_cap(sk, skb, 1);
|
|
}
|
|
|
|
struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
|
|
void bpf_prog_free(struct bpf_prog *fp);
|
|
|
|
bool bpf_opcode_in_insntable(u8 code);
|
|
|
|
struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
|
|
struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
|
|
gfp_t gfp_extra_flags);
|
|
void __bpf_prog_free(struct bpf_prog *fp);
|
|
|
|
static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
|
|
{
|
|
bpf_prog_unlock_ro(fp);
|
|
__bpf_prog_free(fp);
|
|
}
|
|
|
|
typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
|
|
unsigned int flen);
|
|
|
|
int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
|
|
int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
|
|
bpf_aux_classic_check_t trans, bool save_orig);
|
|
void bpf_prog_destroy(struct bpf_prog *fp);
|
|
|
|
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
|
|
int sk_attach_bpf(u32 ufd, struct sock *sk);
|
|
int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
|
|
int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
|
|
int sk_detach_filter(struct sock *sk);
|
|
int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
|
|
unsigned int len);
|
|
|
|
bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
|
|
void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
|
|
|
|
u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
|
|
#define __bpf_call_base_args \
|
|
((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
|
|
__bpf_call_base)
|
|
|
|
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
|
|
void bpf_jit_compile(struct bpf_prog *prog);
|
|
bool bpf_helper_changes_pkt_data(void *func);
|
|
|
|
static inline bool bpf_dump_raw_ok(void)
|
|
{
|
|
/* Reconstruction of call-sites is dependent on kallsyms,
|
|
* thus make dump the same restriction.
|
|
*/
|
|
return kallsyms_show_value() == 1;
|
|
}
|
|
|
|
struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
|
|
const struct bpf_insn *patch, u32 len);
|
|
|
|
static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
|
|
unsigned int pktlen)
|
|
{
|
|
unsigned int len;
|
|
|
|
if (unlikely(!(fwd->flags & IFF_UP)))
|
|
return -ENETDOWN;
|
|
|
|
len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN;
|
|
if (pktlen > len)
|
|
return -EMSGSIZE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
|
|
* same cpu context. Further for best results no more than a single map
|
|
* for the do_redirect/do_flush pair should be used. This limitation is
|
|
* because we only track one map and force a flush when the map changes.
|
|
* This does not appear to be a real limitation for existing software.
|
|
*/
|
|
int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
|
|
struct xdp_buff *xdp, struct bpf_prog *prog);
|
|
int xdp_do_redirect(struct net_device *dev,
|
|
struct xdp_buff *xdp,
|
|
struct bpf_prog *prog);
|
|
void xdp_do_flush_map(void);
|
|
|
|
void bpf_warn_invalid_xdp_action(u32 act);
|
|
|
|
struct sock *do_sk_redirect_map(struct sk_buff *skb);
|
|
struct sock *do_msg_redirect_map(struct sk_msg_buff *md);
|
|
|
|
#ifdef CONFIG_BPF_JIT
|
|
extern int bpf_jit_enable;
|
|
extern int bpf_jit_harden;
|
|
extern int bpf_jit_kallsyms;
|
|
|
|
typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
|
|
|
|
struct bpf_binary_header *
|
|
bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
|
|
unsigned int alignment,
|
|
bpf_jit_fill_hole_t bpf_fill_ill_insns);
|
|
void bpf_jit_binary_free(struct bpf_binary_header *hdr);
|
|
|
|
void bpf_jit_free(struct bpf_prog *fp);
|
|
|
|
struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
|
|
void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
|
|
|
|
static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
|
|
u32 pass, void *image)
|
|
{
|
|
pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
|
|
proglen, pass, image, current->comm, task_pid_nr(current));
|
|
|
|
if (image)
|
|
print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
|
|
16, 1, image, proglen, false);
|
|
}
|
|
|
|
static inline bool bpf_jit_is_ebpf(void)
|
|
{
|
|
# ifdef CONFIG_HAVE_EBPF_JIT
|
|
return true;
|
|
# else
|
|
return false;
|
|
# endif
|
|
}
|
|
|
|
static inline bool ebpf_jit_enabled(void)
|
|
{
|
|
return bpf_jit_enable && bpf_jit_is_ebpf();
|
|
}
|
|
|
|
static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
|
|
{
|
|
return fp->jited && bpf_jit_is_ebpf();
|
|
}
|
|
|
|
static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
|
|
{
|
|
/* These are the prerequisites, should someone ever have the
|
|
* idea to call blinding outside of them, we make sure to
|
|
* bail out.
|
|
*/
|
|
if (!bpf_jit_is_ebpf())
|
|
return false;
|
|
if (!prog->jit_requested)
|
|
return false;
|
|
if (!bpf_jit_harden)
|
|
return false;
|
|
if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static inline bool bpf_jit_kallsyms_enabled(void)
|
|
{
|
|
/* There are a couple of corner cases where kallsyms should
|
|
* not be enabled f.e. on hardening.
|
|
*/
|
|
if (bpf_jit_harden)
|
|
return false;
|
|
if (!bpf_jit_kallsyms)
|
|
return false;
|
|
if (bpf_jit_kallsyms == 1)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
|
|
unsigned long *off, char *sym);
|
|
bool is_bpf_text_address(unsigned long addr);
|
|
int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
|
|
char *sym);
|
|
|
|
static inline const char *
|
|
bpf_address_lookup(unsigned long addr, unsigned long *size,
|
|
unsigned long *off, char **modname, char *sym)
|
|
{
|
|
const char *ret = __bpf_address_lookup(addr, size, off, sym);
|
|
|
|
if (ret && modname)
|
|
*modname = NULL;
|
|
return ret;
|
|
}
|
|
|
|
void bpf_prog_kallsyms_add(struct bpf_prog *fp);
|
|
void bpf_prog_kallsyms_del(struct bpf_prog *fp);
|
|
|
|
#else /* CONFIG_BPF_JIT */
|
|
|
|
static inline bool ebpf_jit_enabled(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline void bpf_jit_free(struct bpf_prog *fp)
|
|
{
|
|
bpf_prog_unlock_free(fp);
|
|
}
|
|
|
|
static inline bool bpf_jit_kallsyms_enabled(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline const char *
|
|
__bpf_address_lookup(unsigned long addr, unsigned long *size,
|
|
unsigned long *off, char *sym)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline bool is_bpf_text_address(unsigned long addr)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
|
|
char *type, char *sym)
|
|
{
|
|
return -ERANGE;
|
|
}
|
|
|
|
static inline const char *
|
|
bpf_address_lookup(unsigned long addr, unsigned long *size,
|
|
unsigned long *off, char **modname, char *sym)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
|
|
{
|
|
}
|
|
|
|
static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
|
|
{
|
|
}
|
|
#endif /* CONFIG_BPF_JIT */
|
|
|
|
void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp);
|
|
void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
|
|
|
|
#define BPF_ANC BIT(15)
|
|
|
|
static inline bool bpf_needs_clear_a(const struct sock_filter *first)
|
|
{
|
|
switch (first->code) {
|
|
case BPF_RET | BPF_K:
|
|
case BPF_LD | BPF_W | BPF_LEN:
|
|
return false;
|
|
|
|
case BPF_LD | BPF_W | BPF_ABS:
|
|
case BPF_LD | BPF_H | BPF_ABS:
|
|
case BPF_LD | BPF_B | BPF_ABS:
|
|
if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
|
|
return true;
|
|
return false;
|
|
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
|
|
{
|
|
BUG_ON(ftest->code & BPF_ANC);
|
|
|
|
switch (ftest->code) {
|
|
case BPF_LD | BPF_W | BPF_ABS:
|
|
case BPF_LD | BPF_H | BPF_ABS:
|
|
case BPF_LD | BPF_B | BPF_ABS:
|
|
#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
|
|
return BPF_ANC | SKF_AD_##CODE
|
|
switch (ftest->k) {
|
|
BPF_ANCILLARY(PROTOCOL);
|
|
BPF_ANCILLARY(PKTTYPE);
|
|
BPF_ANCILLARY(IFINDEX);
|
|
BPF_ANCILLARY(NLATTR);
|
|
BPF_ANCILLARY(NLATTR_NEST);
|
|
BPF_ANCILLARY(MARK);
|
|
BPF_ANCILLARY(QUEUE);
|
|
BPF_ANCILLARY(HATYPE);
|
|
BPF_ANCILLARY(RXHASH);
|
|
BPF_ANCILLARY(CPU);
|
|
BPF_ANCILLARY(ALU_XOR_X);
|
|
BPF_ANCILLARY(VLAN_TAG);
|
|
BPF_ANCILLARY(VLAN_TAG_PRESENT);
|
|
BPF_ANCILLARY(PAY_OFFSET);
|
|
BPF_ANCILLARY(RANDOM);
|
|
BPF_ANCILLARY(VLAN_TPID);
|
|
}
|
|
/* Fallthrough. */
|
|
default:
|
|
return ftest->code;
|
|
}
|
|
}
|
|
|
|
void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
|
|
int k, unsigned int size);
|
|
|
|
static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
|
|
unsigned int size, void *buffer)
|
|
{
|
|
if (k >= 0)
|
|
return skb_header_pointer(skb, k, size, buffer);
|
|
|
|
return bpf_internal_load_pointer_neg_helper(skb, k, size);
|
|
}
|
|
|
|
static inline int bpf_tell_extensions(void)
|
|
{
|
|
return SKF_AD_MAX;
|
|
}
|
|
|
|
struct bpf_sock_addr_kern {
|
|
struct sock *sk;
|
|
struct sockaddr *uaddr;
|
|
/* Temporary "register" to make indirect stores to nested structures
|
|
* defined above. We need three registers to make such a store, but
|
|
* only two (src and dst) are available at convert_ctx_access time
|
|
*/
|
|
u64 tmp_reg;
|
|
void *t_ctx; /* Attach type specific context. */
|
|
};
|
|
|
|
struct bpf_sock_ops_kern {
|
|
struct sock *sk;
|
|
u32 op;
|
|
union {
|
|
u32 args[4];
|
|
u32 reply;
|
|
u32 replylong[4];
|
|
};
|
|
u32 is_fullsock;
|
|
u64 temp; /* temp and everything after is not
|
|
* initialized to 0 before calling
|
|
* the BPF program. New fields that
|
|
* should be initialized to 0 should
|
|
* be inserted before temp.
|
|
* temp is scratch storage used by
|
|
* sock_ops_convert_ctx_access
|
|
* as temporary storage of a register.
|
|
*/
|
|
};
|
|
|
|
#endif /* __LINUX_FILTER_H__ */
|