diff options
Diffstat (limited to 'include/linux/filter.h')
| -rw-r--r-- | include/linux/filter.h | 1545 |
1 files changed, 1545 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h new file mode 100644 index 000000000..efc42a6e3 --- /dev/null +++ b/include/linux/filter.h @@ -0,0 +1,1545 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Linux Socket Filter Data Structures + */ +#ifndef __LINUX_FILTER_H__ +#define __LINUX_FILTER_H__ + +#include <linux/atomic.h> +#include <linux/bpf.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/set_memory.h> +#include <linux/kallsyms.h> +#include <linux/if_vlan.h> +#include <linux/vmalloc.h> +#include <linux/sockptr.h> +#include <crypto/sha1.h> +#include <linux/u64_stats_sync.h> + +#include <net/sch_generic.h> + +#include <asm/byteorder.h> +#include <uapi/linux/filter.h> + +struct sk_buff; +struct sock; +struct seccomp_data; +struct bpf_prog_aux; +struct xdp_rxq_info; +struct xdp_buff; +struct sock_reuseport; +struct ctl_table; +struct ctl_table_header; + +/* 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. */ +#define BPF_REG_AX MAX_BPF_REG +#define MAX_BPF_EXT_REG (MAX_BPF_REG + 1) +#define MAX_BPF_JIT_REG MAX_BPF_EXT_REG + +/* unused opcode to mark special call to bpf_tail_call() helper */ +#define BPF_TAIL_CALL 0xf0 + +/* unused opcode to mark special load instruction. Same as BPF_ABS */ +#define BPF_PROBE_MEM 0x20 + +/* unused opcode to mark call to interpreter with arguments */ +#define BPF_CALL_ARGS 0xe0 + +/* unused opcode to mark speculation barrier for mitigating + * Speculative Store Bypass + */ +#define BPF_NOSPEC 0xc0 + +/* 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 }) + +/* Special form of mov32, used for doing explicit zero extension on dst. */ +#define BPF_ZEXT_REG(DST) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = DST, \ + .off = 0, \ + .imm = 1 }) + +static inline bool insn_is_zext(const struct bpf_insn *insn) +{ + return insn->code == (BPF_ALU | BPF_MOV | BPF_X) && insn->imm == 1; +} + +/* 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 operations: + * + * BPF_ADD *(uint *) (dst_reg + off16) += src_reg + * BPF_AND *(uint *) (dst_reg + off16) &= src_reg + * BPF_OR *(uint *) (dst_reg + off16) |= src_reg + * BPF_XOR *(uint *) (dst_reg + off16) ^= src_reg + * BPF_ADD | BPF_FETCH src_reg = atomic_fetch_add(dst_reg + off16, src_reg); + * BPF_AND | BPF_FETCH src_reg = atomic_fetch_and(dst_reg + off16, src_reg); + * BPF_OR | BPF_FETCH src_reg = atomic_fetch_or(dst_reg + off16, src_reg); + * BPF_XOR | BPF_FETCH src_reg = atomic_fetch_xor(dst_reg + off16, src_reg); + * BPF_XCHG src_reg = atomic_xchg(dst_reg + off16, src_reg) + * BPF_CMPXCHG r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg) + */ + +#define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = OP }) + +/* Legacy alias */ +#define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF) + +/* 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 }) + +/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */ + +#define BPF_JMP32_REG(OP, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP32 | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */ + +#define BPF_JMP32_IMM(OP, DST, IMM, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP32 | 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 }) + +/* Convert function address to BPF immediate */ + +#define BPF_CALL_IMM(x) ((void *)(x) - (void *)__bpf_call_base) + +#define BPF_EMIT_CALL(FUNC) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_CALL, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = BPF_CALL_IMM(FUNC) }) + +/* 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 }) + +/* Speculation barrier */ + +#define BPF_ST_NOSPEC() \ + ((struct bpf_insn) { \ + .code = BPF_ST | BPF_NOSPEC, \ + .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(sizeof_field(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__)); \ + typedef u64 (*btf_##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 ((btf_##name)____##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 +#if BITS_PER_LONG == 64 +# define bpf_ctx_range_ptr(TYPE, MEMBER) \ + offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1 +#else +# define bpf_ctx_range_ptr(TYPE, MEMBER) \ + offsetof(TYPE, MEMBER) ... offsetof(TYPE, MEMBER) + 8 - 1 +#endif /* BITS_PER_LONG == 64 */ + +#define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE) \ + ({ \ + BUILD_BUG_ON(sizeof_field(TYPE, MEMBER) != (SIZE)); \ + *(PTR_SIZE) = (SIZE); \ + offsetof(TYPE, MEMBER); \ + }) + +/* A struct sock_filter is architecture independent. */ +struct compat_sock_fprog { + u16 len; + compat_uptr_t filter; /* struct sock_filter * */ +}; + +struct sock_fprog_kern { + u16 len; + struct sock_filter *filter; +}; + +/* Some arches need doubleword alignment for their instructions and/or data */ +#define BPF_IMAGE_ALIGNMENT 8 + +struct bpf_binary_header { + u32 size; + u8 image[] __aligned(BPF_IMAGE_ALIGNMENT); +}; + +struct bpf_prog_stats { + u64_stats_t cnt; + u64_stats_t nsecs; + u64_stats_t misses; + struct u64_stats_sync syncp; +} __aligned(2 * sizeof(u64)); + +struct sk_filter { + refcount_t refcnt; + struct rcu_head rcu; + struct bpf_prog *prog; +}; + +DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key); + +extern struct mutex nf_conn_btf_access_lock; +extern int (*nfct_btf_struct_access)(struct bpf_verifier_log *log, const struct btf *btf, + const struct btf_type *t, int off, int size, + enum bpf_access_type atype, u32 *next_btf_id, + enum bpf_type_flag *flag); + +typedef unsigned int (*bpf_dispatcher_fn)(const void *ctx, + const struct bpf_insn *insnsi, + unsigned int (*bpf_func)(const void *, + const struct bpf_insn *)); + +static __always_inline u32 __bpf_prog_run(const struct bpf_prog *prog, + const void *ctx, + bpf_dispatcher_fn dfunc) +{ + u32 ret; + + cant_migrate(); + if (static_branch_unlikely(&bpf_stats_enabled_key)) { + struct bpf_prog_stats *stats; + u64 start = sched_clock(); + unsigned long flags; + + ret = dfunc(ctx, prog->insnsi, prog->bpf_func); + stats = this_cpu_ptr(prog->stats); + flags = u64_stats_update_begin_irqsave(&stats->syncp); + u64_stats_inc(&stats->cnt); + u64_stats_add(&stats->nsecs, sched_clock() - start); + u64_stats_update_end_irqrestore(&stats->syncp, flags); + } else { + ret = dfunc(ctx, prog->insnsi, prog->bpf_func); + } + return ret; +} + +static __always_inline u32 bpf_prog_run(const struct bpf_prog *prog, const void *ctx) +{ + return __bpf_prog_run(prog, ctx, bpf_dispatcher_nop_func); +} + +/* + * Use in preemptible and therefore migratable context to make sure that + * the execution of the BPF program runs on one CPU. + * + * This uses migrate_disable/enable() explicitly to document that the + * invocation of a BPF program does not require reentrancy protection + * against a BPF program which is invoked from a preempting task. + */ +static inline u32 bpf_prog_run_pin_on_cpu(const struct bpf_prog *prog, + const void *ctx) +{ + u32 ret; + + migrate_disable(); + ret = bpf_prog_run(prog, ctx); + migrate_enable(); + return ret; +} + +#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 bpf_nh_params { + u32 nh_family; + union { + u32 ipv4_nh; + struct in6_addr ipv6_nh; + }; +}; + +struct bpf_redirect_info { + u32 flags; + u32 tgt_index; + void *tgt_value; + struct bpf_map *map; + u32 map_id; + enum bpf_map_type map_type; + u32 kern_flags; + struct bpf_nh_params nh; +}; + +DECLARE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info); + +/* flags for bpf_redirect_info kern_flags */ +#define BPF_RI_F_RF_NO_DIRECT BIT(0) /* no napi_direct on return_frame */ + +/* 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) > sizeof_field(struct sk_buff, cb)); + cb->data_meta = skb->data - skb_metadata_len(skb); + cb->data_end = skb->data + skb_headlen(skb); +} + +/* Similar to bpf_compute_data_pointers(), except that save orginal + * data in cb->data and cb->meta_data for restore. + */ +static inline void bpf_compute_and_save_data_end( + struct sk_buff *skb, void **saved_data_end) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + *saved_data_end = cb->data_end; + cb->data_end = skb->data + skb_headlen(skb); +} + +/* Restore data saved by bpf_compute_data_pointers(). */ +static inline void bpf_restore_data_end( + struct sk_buff *skb, void *saved_data_end) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + cb->data_end = saved_data_end; +} + +static inline u8 *bpf_skb_cb(const 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(sizeof_field(struct __sk_buff, cb) != BPF_SKB_CB_LEN); + BUILD_BUG_ON(sizeof_field(struct __sk_buff, cb) != + sizeof_field(struct qdisc_skb_cb, data)); + + return qdisc_skb_cb(skb)->data; +} + +/* Must be invoked with migration disabled */ +static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog, + const void *ctx) +{ + const struct sk_buff *skb = ctx; + 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_save_cb(const struct bpf_prog *prog, + struct sk_buff *skb) +{ + u32 res; + + migrate_disable(); + res = __bpf_prog_run_save_cb(prog, skb); + migrate_enable(); + 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); + u32 res; + + if (unlikely(prog->cb_access)) + memset(cb_data, 0, BPF_SKB_CB_LEN); + + res = bpf_prog_run_pin_on_cpu(prog, skb); + return res; +} + +DECLARE_BPF_DISPATCHER(xdp) + +DECLARE_STATIC_KEY_FALSE(bpf_master_redirect_enabled_key); + +u32 xdp_master_redirect(struct xdp_buff *xdp); + +static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, + struct xdp_buff *xdp) +{ + /* Driver XDP hooks are invoked within a single NAPI poll cycle and thus + * under local_bh_disable(), which provides the needed RCU protection + * for accessing map entries. + */ + u32 act = __bpf_prog_run(prog, xdp, BPF_DISPATCHER_FUNC(xdp)); + + if (static_branch_unlikely(&bpf_master_redirect_enabled_key)) { + if (act == XDP_TX && netif_is_bond_slave(xdp->rxq->dev)) + act = xdp_master_redirect(xdp); + } + + return act; +} + +void bpf_prog_change_xdp(struct bpf_prog *prev_prog, struct bpf_prog *prog); + +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, SHA1_BLOCK_SIZE); +} + +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_access_ok(u32 off, u32 size, u32 size_default) +{ + return size <= size_default && (size & (size - 1)) == 0; +} + +static inline u8 +bpf_ctx_narrow_access_offset(u32 off, u32 size, u32 size_default) +{ + u8 access_off = off & (size_default - 1); + +#ifdef __LITTLE_ENDIAN + return access_off; +#else + return size_default - (access_off + size); +#endif +} + +#define bpf_ctx_wide_access_ok(off, size, type, field) \ + (size == sizeof(__u64) && \ + off >= offsetof(type, field) && \ + off + sizeof(__u64) <= offsetofend(type, field) && \ + off % sizeof(__u64) == 0) + +#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) + +static inline void bpf_prog_lock_ro(struct bpf_prog *fp) +{ +#ifndef CONFIG_BPF_JIT_ALWAYS_ON + if (!fp->jited) { + set_vm_flush_reset_perms(fp); + set_memory_ro((unsigned long)fp, fp->pages); + } +#endif +} + +static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) +{ + set_vm_flush_reset_perms(hdr); + set_memory_ro((unsigned long)hdr, hdr->size >> PAGE_SHIFT); + set_memory_x((unsigned long)hdr, hdr->size >> PAGE_SHIFT); +} + +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); + +void bpf_prog_free_linfo(struct bpf_prog *prog); +void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, + const u32 *insn_to_jit_off); +int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog); +void bpf_prog_jit_attempt_done(struct bpf_prog *prog); + +struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); +struct bpf_prog *bpf_prog_alloc_no_stats(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_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); +void sk_reuseport_prog_free(struct bpf_prog *prog); +int sk_detach_filter(struct sock *sk); +int sk_get_filter(struct sock *sk, sockptr_t optval, 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 *)) \ + (void *)__bpf_call_base) + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); +void bpf_jit_compile(struct bpf_prog *prog); +bool bpf_jit_needs_zext(void); +bool bpf_jit_supports_subprog_tailcalls(void); +bool bpf_jit_supports_kfunc_call(void); +bool bpf_helper_changes_pkt_data(void *func); + +static inline bool bpf_dump_raw_ok(const struct cred *cred) +{ + /* Reconstruction of call-sites is dependent on kallsyms, + * thus make dump the same restriction. + */ + return kallsyms_show_value(cred); +} + +struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, + const struct bpf_insn *patch, u32 len); +int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt); + +void bpf_clear_redirect_map(struct bpf_map *map); + +static inline bool xdp_return_frame_no_direct(void) +{ + struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + + return ri->kern_flags & BPF_RI_F_RF_NO_DIRECT; +} + +static inline void xdp_set_return_frame_no_direct(void) +{ + struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + + ri->kern_flags |= BPF_RI_F_RF_NO_DIRECT; +} + +static inline void xdp_clear_return_frame_no_direct(void) +{ + struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + + ri->kern_flags &= ~BPF_RI_F_RF_NO_DIRECT; +} + +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 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); +int xdp_do_redirect_frame(struct net_device *dev, + struct xdp_buff *xdp, + struct xdp_frame *xdpf, + struct bpf_prog *prog); +void xdp_do_flush(void); + +/* The xdp_do_flush_map() helper has been renamed to drop the _map suffix, as + * it is no longer only flushing maps. Keep this define for compatibility + * until all drivers are updated - do not use xdp_do_flush_map() in new code! + */ +#define xdp_do_flush_map xdp_do_flush + +void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act); + +#ifdef CONFIG_INET +struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk, + struct bpf_prog *prog, struct sk_buff *skb, + struct sock *migrating_sk, + u32 hash); +#else +static inline struct sock * +bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk, + struct bpf_prog *prog, struct sk_buff *skb, + struct sock *migrating_sk, + u32 hash) +{ + return NULL; +} +#endif + +#ifdef CONFIG_BPF_JIT +extern int bpf_jit_enable; +extern int bpf_jit_harden; +extern int bpf_jit_kallsyms; +extern long bpf_jit_limit; +extern long bpf_jit_limit_max; + +typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); + +void bpf_jit_fill_hole_with_zero(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); +u64 bpf_jit_alloc_exec_limit(void); +void *bpf_jit_alloc_exec(unsigned long size); +void bpf_jit_free_exec(void *addr); +void bpf_jit_free(struct bpf_prog *fp); +struct bpf_binary_header * +bpf_jit_binary_pack_hdr(const struct bpf_prog *fp); + +void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns); +void bpf_prog_pack_free(struct bpf_binary_header *hdr); + +static inline bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) +{ + return list_empty(&fp->aux->ksym.lnode) || + fp->aux->ksym.lnode.prev == LIST_POISON2; +} + +struct bpf_binary_header * +bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **ro_image, + unsigned int alignment, + struct bpf_binary_header **rw_hdr, + u8 **rw_image, + bpf_jit_fill_hole_t bpf_fill_ill_insns); +int bpf_jit_binary_pack_finalize(struct bpf_prog *prog, + struct bpf_binary_header *ro_header, + struct bpf_binary_header *rw_header); +void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header, + struct bpf_binary_header *rw_header); + +int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, + struct bpf_jit_poke_descriptor *poke); + +int bpf_jit_get_func_addr(const struct bpf_prog *prog, + const struct bpf_insn *insn, bool extra_pass, + u64 *func_addr, bool *func_addr_fixed); + +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 && bpf_capable()) + 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_jit_blinding_enabled(struct bpf_prog *prog) +{ + return false; +} + +static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp) +{ + return false; +} + +static inline int +bpf_jit_add_poke_descriptor(struct bpf_prog *prog, + struct bpf_jit_poke_descriptor *poke) +{ + return -ENOTSUPP; +} + +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_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 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; + union { + u32 args[4]; + u32 reply; + u32 replylong[4]; + }; + struct sk_buff *syn_skb; + struct sk_buff *skb; + void *skb_data_end; + u8 op; + u8 is_fullsock; + u8 remaining_opt_len; + 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. + */ +}; + +struct bpf_sysctl_kern { + struct ctl_table_header *head; + struct ctl_table *table; + void *cur_val; + size_t cur_len; + void *new_val; + size_t new_len; + int new_updated; + int write; + loff_t *ppos; + /* Temporary "register" for indirect stores to ppos. */ + u64 tmp_reg; +}; + +#define BPF_SOCKOPT_KERN_BUF_SIZE 32 +struct bpf_sockopt_buf { + u8 data[BPF_SOCKOPT_KERN_BUF_SIZE]; +}; + +struct bpf_sockopt_kern { + struct sock *sk; + u8 *optval; + u8 *optval_end; + s32 level; + s32 optname; + s32 optlen; + /* for retval in struct bpf_cg_run_ctx */ + struct task_struct *current_task; + /* Temporary "register" for indirect stores to ppos. */ + u64 tmp_reg; +}; + +int copy_bpf_fprog_from_user(struct sock_fprog *dst, sockptr_t src, int len); + +struct bpf_sk_lookup_kern { + u16 family; + u16 protocol; + __be16 sport; + u16 dport; + struct { + __be32 saddr; + __be32 daddr; + } v4; + struct { + const struct in6_addr *saddr; + const struct in6_addr *daddr; + } v6; + struct sock *selected_sk; + u32 ingress_ifindex; + bool no_reuseport; +}; + +extern struct static_key_false bpf_sk_lookup_enabled; + +/* Runners for BPF_SK_LOOKUP programs to invoke on socket lookup. + * + * Allowed return values for a BPF SK_LOOKUP program are SK_PASS and + * SK_DROP. Their meaning is as follows: + * + * SK_PASS && ctx.selected_sk != NULL: use selected_sk as lookup result + * SK_PASS && ctx.selected_sk == NULL: continue to htable-based socket lookup + * SK_DROP : terminate lookup with -ECONNREFUSED + * + * This macro aggregates return values and selected sockets from + * multiple BPF programs according to following rules in order: + * + * 1. If any program returned SK_PASS and a non-NULL ctx.selected_sk, + * macro result is SK_PASS and last ctx.selected_sk is used. + * 2. If any program returned SK_DROP return value, + * macro result is SK_DROP. + * 3. Otherwise result is SK_PASS and ctx.selected_sk is NULL. + * + * Caller must ensure that the prog array is non-NULL, and that the + * array as well as the programs it contains remain valid. + */ +#define BPF_PROG_SK_LOOKUP_RUN_ARRAY(array, ctx, func) \ + ({ \ + struct bpf_sk_lookup_kern *_ctx = &(ctx); \ + struct bpf_prog_array_item *_item; \ + struct sock *_selected_sk = NULL; \ + bool _no_reuseport = false; \ + struct bpf_prog *_prog; \ + bool _all_pass = true; \ + u32 _ret; \ + \ + migrate_disable(); \ + _item = &(array)->items[0]; \ + while ((_prog = READ_ONCE(_item->prog))) { \ + /* restore most recent selection */ \ + _ctx->selected_sk = _selected_sk; \ + _ctx->no_reuseport = _no_reuseport; \ + \ + _ret = func(_prog, _ctx); \ + if (_ret == SK_PASS && _ctx->selected_sk) { \ + /* remember last non-NULL socket */ \ + _selected_sk = _ctx->selected_sk; \ + _no_reuseport = _ctx->no_reuseport; \ + } else if (_ret == SK_DROP && _all_pass) { \ + _all_pass = false; \ + } \ + _item++; \ + } \ + _ctx->selected_sk = _selected_sk; \ + _ctx->no_reuseport = _no_reuseport; \ + migrate_enable(); \ + _all_pass || _selected_sk ? SK_PASS : SK_DROP; \ + }) + +static inline bool bpf_sk_lookup_run_v4(struct net *net, int protocol, + const __be32 saddr, const __be16 sport, + const __be32 daddr, const u16 dport, + const int ifindex, struct sock **psk) +{ + struct bpf_prog_array *run_array; + struct sock *selected_sk = NULL; + bool no_reuseport = false; + + rcu_read_lock(); + run_array = rcu_dereference(net->bpf.run_array[NETNS_BPF_SK_LOOKUP]); + if (run_array) { + struct bpf_sk_lookup_kern ctx = { + .family = AF_INET, + .protocol = protocol, + .v4.saddr = saddr, + .v4.daddr = daddr, + .sport = sport, + .dport = dport, + .ingress_ifindex = ifindex, + }; + u32 act; + + act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, bpf_prog_run); + if (act == SK_PASS) { + selected_sk = ctx.selected_sk; + no_reuseport = ctx.no_reuseport; + } else { + selected_sk = ERR_PTR(-ECONNREFUSED); + } + } + rcu_read_unlock(); + *psk = selected_sk; + return no_reuseport; +} + +#if IS_ENABLED(CONFIG_IPV6) +static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol, + const struct in6_addr *saddr, + const __be16 sport, + const struct in6_addr *daddr, + const u16 dport, + const int ifindex, struct sock **psk) +{ + struct bpf_prog_array *run_array; + struct sock *selected_sk = NULL; + bool no_reuseport = false; + + rcu_read_lock(); + run_array = rcu_dereference(net->bpf.run_array[NETNS_BPF_SK_LOOKUP]); + if (run_array) { + struct bpf_sk_lookup_kern ctx = { + .family = AF_INET6, + .protocol = protocol, + .v6.saddr = saddr, + .v6.daddr = daddr, + .sport = sport, + .dport = dport, + .ingress_ifindex = ifindex, + }; + u32 act; + + act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, bpf_prog_run); + if (act == SK_PASS) { + selected_sk = ctx.selected_sk; + no_reuseport = ctx.no_reuseport; + } else { + selected_sk = ERR_PTR(-ECONNREFUSED); + } + } + rcu_read_unlock(); + *psk = selected_sk; + return no_reuseport; +} +#endif /* IS_ENABLED(CONFIG_IPV6) */ + +static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex, + u64 flags, const u64 flag_mask, + void *lookup_elem(struct bpf_map *map, u32 key)) +{ + struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + const u64 action_mask = XDP_ABORTED | XDP_DROP | XDP_PASS | XDP_TX; + + /* Lower bits of the flags are used as return code on lookup failure */ + if (unlikely(flags & ~(action_mask | flag_mask))) + return XDP_ABORTED; + + ri->tgt_value = lookup_elem(map, ifindex); + if (unlikely(!ri->tgt_value) && !(flags & BPF_F_BROADCAST)) { + /* If the lookup fails we want to clear out the state in the + * redirect_info struct completely, so that if an eBPF program + * performs multiple lookups, the last one always takes + * precedence. + */ + ri->map_id = INT_MAX; /* Valid map id idr range: [1,INT_MAX[ */ + ri->map_type = BPF_MAP_TYPE_UNSPEC; + return flags & action_mask; + } + + ri->tgt_index = ifindex; + ri->map_id = map->id; + ri->map_type = map->map_type; + + if (flags & BPF_F_BROADCAST) { + WRITE_ONCE(ri->map, map); + ri->flags = flags; + } else { + WRITE_ONCE(ri->map, NULL); + ri->flags = 0; + } + + return XDP_REDIRECT; +} + +#endif /* __LINUX_FILTER_H__ */ |