diff options
Diffstat (limited to 'samples/bpf/cookie_uid_helper_example.c')
| -rw-r--r-- | samples/bpf/cookie_uid_helper_example.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c index cc3bce8d3aac..54958802c032 100644 --- a/samples/bpf/cookie_uid_helper_example.c +++ b/samples/bpf/cookie_uid_helper_example.c @@ -167,7 +167,7 @@ static void prog_load(void) static void prog_attach_iptables(char *file) { int ret; - char rules[100]; + char rules[256]; if (bpf_obj_pin(prog_fd, file)) error(1, errno, "bpf_obj_pin"); @@ -175,8 +175,13 @@ static void prog_attach_iptables(char *file) printf("file path too long: %s\n", file); exit(1); } - sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT", - file); + ret = snprintf(rules, sizeof(rules), + "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT", + file); + if (ret < 0 || ret >= sizeof(rules)) { + printf("error constructing iptables command\n"); + exit(1); + } ret = system(rules); if (ret < 0) { printf("iptables rule update failed: %d/n", WEXITSTATUS(ret)); |