alarm(TIMER_RESOLUTION);
}
-static void
-read_icmp_data(struct host_entry * p)
+void
+read_icmp_data(struct host_entry * host)
{
- int cc, iphdrlen, delay;
- socklen_t fromlen;
- struct sockaddr_in from;
- struct ip * ip;
- struct icmp * icmp;
- struct timeval tv;
- unsigned char buf[MAXPACKETSIZE];
+ struct timeval now;
+ gettimeofday(&now, NULL);
- gettimeofday(&tv, (struct timezone *) NULL);
-
- fromlen = sizeof(from);
- if ((cc = recvfrom(p->socket, buf, sizeof(buf), 0, (struct sockaddr *)&from, &fromlen)) < 0) {
- if (errno != EINTR) fprintf(stderr, "WARN: Error reading ICMP data from %s.\n", p->name);
+ struct sockaddr_in from;
+ socklen_t fromlen = sizeof(from);
+ int bytes;
+ unsigned char packet[IP_PACKET_MAX_BYTES]; /* Use char so this can be aliased later. */
+ if ((bytes = recvfrom(host->socket, packet, sizeof(packet), 0, (struct sockaddr *) &from, &fromlen)) < 0) {
+ if (errno != EINTR) fprintf(stderr, "WARN: Error reading ICMP data from %s.\n", host->name);
return;
}
- /* check IP header actual len */
- ip = (struct ip *) buf;
- iphdrlen = ip->ip_hl << 2;
- icmp = (struct icmp *) (buf + iphdrlen);
+ struct ip * ip = (struct ip *) packet;
+ int iphdrlen = ip->ip_hl << 2;
+ struct icmp * icmp = (struct icmp *) (packet + iphdrlen);
- if (cc < iphdrlen + ICMP_MINLEN) {
- fprintf(stderr, "WARN: Received short packet from %s.\n", p->name);
+ if (bytes < iphdrlen + ICMP_MINLEN) {
+ fprintf(stderr, "WARN: Received short packet from %s.\n", host->name);
return;
}
- if (icmp->icmp_type == ICMP_ECHOREPLY && icmp->icmp_id == (getpid() & 0xFFFF) && icmp->icmp_seq == p->socket) {
-
- memcpy(&p->last_ping_received, &tv, sizeof(tv));
-
- timeval_diff(&tv, (struct timeval *) &icmp->icmp_data[0]);
- delay = tv.tv_sec * 1000 + (tv.tv_usec / 1000);
-
- if (verbose) printf("INFO: Got ICMP reply from %s.\n", p->name);
- if (!p->host_up) {
- if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", p->name);
- p->host_up = true;
+ if (icmp->icmp_type == ICMP_ECHOREPLY && icmp->icmp_id == (getpid() & 0xFFFF) && icmp->icmp_seq == host->socket) {
+ memcpy(&host->last_ping_received, &now, sizeof(now));
+ if (verbose) printf("INFO: Got ICMP reply from %s.\n", host->name);
+ if (!host->host_up) {
+ if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", host->name);
+ host->host_up = true;
if (!fork()) {
- system(p->up_cmd);
+ system(host->up_cmd);
exit(EXIT_SUCCESS);
- } else {
- wait(NULL);
}
}
} else {
- /* TODO: Do anything here? */
+ /* The packet isn't what we expected. Ignore it and move on. */
}
}