diff options
| author | Hou Tao | 2021-12-10 22:16:49 +0800 |
|---|---|---|
| committer | Alexei Starovoitov | 2021-12-11 17:40:23 -0800 |
| commit | c5fb19937455095573a19ddcbff32e993ed10e35 (patch) | |
| tree | 3b6d784c20323c61580a632867415377c4dd4205 /kernel/bpf | |
| parent | 259172bb6514758ce3be1610c500b51a9f44212a (diff) | |
bpf: Add bpf_strncmp helper
The helper compares two strings: one string is a null-terminated
read-only string, and another string has const max storage size
but doesn't need to be null-terminated. It can be used to compare
file name in tracing or LSM program.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211210141652.877186-2-houtao1@huawei.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/helpers.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 19fecfeaa9c2..8babae03d30a 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -565,6 +565,20 @@ const struct bpf_func_proto bpf_strtoul_proto = { }; #endif +BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2) +{ + return strncmp(s1, s2, s1_sz); +} + +const struct bpf_func_proto bpf_strncmp_proto = { + .func = bpf_strncmp, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_MEM, + .arg2_type = ARG_CONST_SIZE, + .arg3_type = ARG_PTR_TO_CONST_STR, +}; + BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino, struct bpf_pidns_info *, nsdata, u32, size) { @@ -1378,6 +1392,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_for_each_map_elem_proto; case BPF_FUNC_loop: return &bpf_loop_proto; + case BPF_FUNC_strncmp: + return &bpf_strncmp_proto; default: break; } |