diff options
Diffstat (limited to 'include/linux/filter.h')
| -rw-r--r-- | include/linux/filter.h | 99 |
1 files changed, 91 insertions, 8 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 024fd03e5d18..4457b383961c 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -37,16 +37,101 @@ #define BPF_CALL 0x80 /* function call */ #define BPF_EXIT 0x90 /* function return */ +/* Placeholder/dummy for 0 */ +#define BPF_0 0 + +/* 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 11 +#define MAX_BPF_REG __MAX_BPF_REG + +/* 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_8 /* BPF program can access up to 512 bytes of stack space. */ #define MAX_BPF_STACK 512 -/* Arg1, context and stack frame pointer register positions. */ -#define ARG1_REG 1 -#define CTX_REG 6 -#define FP_REG 10 +/* bpf_add|sub|...: a += x, bpf_mov: a = x */ +#define BPF_ALU64_REG(op, a, x) \ + ((struct sock_filter_int) {BPF_ALU64|BPF_OP(op)|BPF_X, a, x, 0, 0}) +#define BPF_ALU32_REG(op, a, x) \ + ((struct sock_filter_int) {BPF_ALU|BPF_OP(op)|BPF_X, a, x, 0, 0}) + +/* bpf_add|sub|...: a += imm, bpf_mov: a = imm */ +#define BPF_ALU64_IMM(op, a, imm) \ + ((struct sock_filter_int) {BPF_ALU64|BPF_OP(op)|BPF_K, a, 0, 0, imm}) +#define BPF_ALU32_IMM(op, a, imm) \ + ((struct sock_filter_int) {BPF_ALU|BPF_OP(op)|BPF_K, a, 0, 0, imm}) + +/* R0 = *(uint *) (skb->data + off) */ +#define BPF_LD_ABS(size, off) \ + ((struct sock_filter_int) {BPF_LD|BPF_SIZE(size)|BPF_ABS, 0, 0, 0, off}) + +/* R0 = *(uint *) (skb->data + x + off) */ +#define BPF_LD_IND(size, x, off) \ + ((struct sock_filter_int) {BPF_LD|BPF_SIZE(size)|BPF_IND, 0, x, 0, off}) + +/* a = *(uint *) (x + off) */ +#define BPF_LDX_MEM(sz, a, x, off) \ + ((struct sock_filter_int) {BPF_LDX|BPF_SIZE(sz)|BPF_MEM, a, x, off, 0}) + +/* if (a 'op' x) goto pc+off */ +#define BPF_JMP_REG(op, a, x, off) \ + ((struct sock_filter_int) {BPF_JMP|BPF_OP(op)|BPF_X, a, x, off, 0}) + +/* if (a 'op' imm) goto pc+off */ +#define BPF_JMP_IMM(op, a, imm, off) \ + ((struct sock_filter_int) {BPF_JMP|BPF_OP(op)|BPF_K, a, 0, off, imm}) + +#define BPF_EXIT_INSN() \ + ((struct sock_filter_int) {BPF_JMP|BPF_EXIT, 0, 0, 0, 0}) + +static inline int size_to_bpf(int size) +{ + switch (size) { + case 1: + return BPF_B; + case 2: + return BPF_H; + case 4: + return BPF_W; + case 8: + return BPF_DW; + default: + return -EINVAL; + } +} + +/* Macro to invoke filter function. */ +#define SK_RUN_FILTER(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) struct sock_filter_int { __u8 code; /* opcode */ @@ -97,9 +182,6 @@ static inline unsigned int sk_filter_size(unsigned int proglen) #define sk_filter_proglen(fprog) \ (fprog->len * sizeof(fprog->filter[0])) -#define SK_RUN_FILTER(filter, ctx) \ - (*filter->bpf_func)(ctx, filter->insnsi) - int sk_filter(struct sock *sk, struct sk_buff *skb); u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx, @@ -223,6 +305,7 @@ enum { BPF_S_ANC_VLAN_TAG, BPF_S_ANC_VLAN_TAG_PRESENT, BPF_S_ANC_PAY_OFFSET, + BPF_S_ANC_RANDOM, }; #endif /* __LINUX_FILTER_H__ */ |