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author | 2014-05-08 14:10:51 -0700 | |
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committer | 2014-05-12 00:23:55 -0400 | |
commit | 9739eef13c926645fbf88bcb77e66442fa75d688 (patch) | |
tree | d6934c95e5eae0027f755caf5ea7c1ab2aede94e /include/linux/filter.h | |
parent | Merge branch 'sctp_sysctl' (diff) | |
download | linux-9739eef13c926645fbf88bcb77e66442fa75d688.tar.gz linux-9739eef13c926645fbf88bcb77e66442fa75d688.tar.bz2 linux-9739eef13c926645fbf88bcb77e66442fa75d688.zip |
net: filter: make BPF conversion more readable
Introduce BPF helper macros to define instructions
(similar to old BPF_STMT/BPF_JUMP macros)
Use them while converting classic BPF to internal
and in BPF testsuite later.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/filter.h')
-rw-r--r-- | include/linux/filter.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index ed1efab10b8f..4457b383961c 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -79,6 +79,57 @@ enum { /* BPF program can access up to 512 bytes of stack space. */ #define MAX_BPF_STACK 512 +/* 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) |