libbpf: Add pathname_concat() helper

Move snprintf and len check to common helper pathname_concat() to make the
code simpler.

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1663828124-10437-1-git-send-email-wangyufen@huawei.com
This commit is contained in:
Wang Yufen 2022-09-22 14:28:44 +08:00 committed by Andrii Nakryiko
parent e0401dce5e
commit e588c116df

View file

@ -2097,19 +2097,30 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf,
return true;
}
static int pathname_concat(char *buf, size_t buf_sz, const char *path, const char *name)
{
int len;
len = snprintf(buf, buf_sz, "%s/%s", path, name);
if (len < 0)
return -EINVAL;
if (len >= buf_sz)
return -ENAMETOOLONG;
return 0;
}
static int build_map_pin_path(struct bpf_map *map, const char *path)
{
char buf[PATH_MAX];
int len;
int err;
if (!path)
path = "/sys/fs/bpf";
len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
if (len < 0)
return -EINVAL;
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map));
if (err)
return err;
return bpf_map__set_pin_path(map, buf);
}
@ -7968,17 +7979,9 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
continue;
if (path) {
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path,
bpf_map__name(map));
if (len < 0) {
err = -EINVAL;
err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map));
if (err)
goto err_unpin_maps;
} else if (len >= PATH_MAX) {
err = -ENAMETOOLONG;
goto err_unpin_maps;
}
sanitize_pin_path(buf);
pin_path = buf;
} else if (!map->pin_path) {
@ -8016,14 +8019,9 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
char buf[PATH_MAX];
if (path) {
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path,
bpf_map__name(map));
if (len < 0)
return libbpf_err(-EINVAL);
else if (len >= PATH_MAX)
return libbpf_err(-ENAMETOOLONG);
err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map));
if (err)
return libbpf_err(err);
sanitize_pin_path(buf);
pin_path = buf;
} else if (!map->pin_path) {
@ -8041,6 +8039,7 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
{
struct bpf_program *prog;
char buf[PATH_MAX];
int err;
if (!obj)
@ -8052,17 +8051,9 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
}
bpf_object__for_each_program(prog, obj) {
char buf[PATH_MAX];
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
if (len < 0) {
err = -EINVAL;
err = pathname_concat(buf, sizeof(buf), path, prog->name);
if (err)
goto err_unpin_programs;
} else if (len >= PATH_MAX) {
err = -ENAMETOOLONG;
goto err_unpin_programs;
}
err = bpf_program__pin(prog, buf);
if (err)
@ -8073,13 +8064,7 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
err_unpin_programs:
while ((prog = bpf_object__prev_program(obj, prog))) {
char buf[PATH_MAX];
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
if (len < 0)
continue;
else if (len >= PATH_MAX)
if (pathname_concat(buf, sizeof(buf), path, prog->name))
continue;
bpf_program__unpin(prog, buf);
@ -8098,13 +8083,10 @@ int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
bpf_object__for_each_program(prog, obj) {
char buf[PATH_MAX];
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name);
if (len < 0)
return libbpf_err(-EINVAL);
else if (len >= PATH_MAX)
return libbpf_err(-ENAMETOOLONG);
err = pathname_concat(buf, sizeof(buf), path, prog->name);
if (err)
return libbpf_err(err);
err = bpf_program__unpin(prog, buf);
if (err)