- for (;;) {
- ssize_t bytes;
- struct msghdr msg;
- struct cmsghdr *cmsg;
- struct ucred *ucred;
- struct iovec iov;
- struct nlmsghdr *p;
- uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred))];
- struct {
- struct nlmsghdr hdr;
- struct ifaddrmsg ifaddrmsg;
- uint8_t payload[16*1024];
- } resp;
-
- memset(&iov, 0, sizeof(iov));
- iov.iov_base = &resp;
- iov.iov_len = sizeof(resp);
-
- memset(&msg, 0, sizeof(msg));
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = cred_buffer;
- msg.msg_controllen = sizeof(cred_buffer);
- msg.msg_flags = 0;
-
- bytes = recvmsg(fd, &msg, 0);
- if (bytes < 0) {
- r = -errno;
- goto finish;
- }