msg.msg_controllen = sizeof(cmsg6);
len = recvmsg(u->fd, &msg, flags);
- if (len < 0) {
- fprintf(stderr, "%s:%s[%d]\n", __FILE__, __func__, __LINE__);
+ if (len == -1) {
+ perror("read failed");
return;
}
for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL && ifindex == -1; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {