// public function definitions
void *arpd(void *threadarg) {
assert(threadarg);
struct thread_context *context;
struct thread_context *contexts;
struct arpd_data *data;
struct in_addr *my_addr;
int rv;
struct transaction *transaction = NULL;
struct ethernet_pkt *etherpkt;
struct arp_pkt *arp;
struct netmap_ring *rxring;
void *ring_idx;
uint32_t dispatcher_idx;
struct msg_hdr *msg_hdr;
context = (struct thread_context *)threadarg;
contexts = context->shared->contexts;
data = context->data;
rxring = data->rxring;
dispatcher_idx = context->shared->dispatcher_idx;
my_addr = &context->shared->inet_info->addr;
rv = arpd_init(context);
if (!rv) {
pthread_exit(NULL);
}
printf("arpd[%d]: initialized\n", context->thread_id);
// signal to main() that we are initialized
atomic_store_explicit(&context->initialized, 1, memory_order_release);
// main event loop
for (;;) {
// read all the incoming packets
while (tqueue_remove(context->pkt_recv_q, &transaction,
&ring_idx) > 0) {
etherpkt = (struct ethernet_pkt *) NETMAP_BUF(rxring,
rxring->slot[(uint32_t)ring_idx].buf_idx);
arp = (struct arp_pkt*) etherpkt->data;
if (!arp_is_valid(arp)) {
send_msg_transaction_update_single(&contexts[dispatcher_idx],
(uint32_t)ring_idx);
continue;
}
if (arp->arp_h.ar_op == ARP_OP_REQUEST) {
if (arp->tpa.s_addr != my_addr->s_addr) {
send_msg_transaction_update_single(&contexts[dispatcher_idx],
(uint32_t) ring_idx);
continue;
}
printf("R)");
arp_print_line(arp);
// send_pkt_arp_reply could fail when xmit queue is full,
// however, the sender should just resend a request
send_pkt_arp_reply(context->pkt_xmit_q, &arp->spa, &arp->sha);
} else { // ARP_OP_REPLY
if (!arp_reply_filter(arp, my_addr)) {
send_msg_transaction_update_single(&contexts[dispatcher_idx],
(uint32_t) ring_idx);
continue;
}
printf("R)");
arp_print_line(arp);
// TODO: also check against a list of my outstanding arp requests
// prior to insertion in the arp cache
recv_pkt_arp_reply(arp, data->arp_cache, contexts);
}
send_msg_transaction_update_single(&contexts[dispatcher_idx],
(uint32_t) ring_idx);
} // while (packets)
// resend outstanding requests and refresh expiring entries
update_arp_cache(data->arp_cache, contexts, context->pkt_xmit_q);
// TODO: read all the messages
rv = squeue_enter(context->msg_q, 1);
if (!rv)
continue;
while ((msg_hdr = squeue_get_next_pop_slot(context->msg_q)) != NULL) {
switch (msg_hdr->msg_type) {
case MSG_ARPD_GET_MAC:
recv_msg_get_mac((void *)msg_hdr, data->arp_cache,
contexts, context->pkt_xmit_q);
break;
default:
printf("arpd: unknown message %hu\n", msg_hdr->msg_type);
}
}
squeue_exit(context->msg_q);
usleep(ARP_CACHE_RETRY_INTERVAL);
} // for (;;)
pthread_exit(NULL);
}
int
main(int argc, char *argv[])
{
struct event recv_ev;
char *dev;
int c, debug;
FILE *fp;
dev = NULL;
debug = 0;
while ((c = getopt(argc, argv, "di:h?")) != -1) {
switch (c) {
case 'd':
debug = 1;
break;
case 'i':
dev = optarg;
break;
default:
usage();
break;
}
}
argc -= optind;
argv += optind;
if (argc == 0)
arpd_init(dev, 0, NULL);
else
arpd_init(dev, argc, argv);
if ((fp = fopen(PIDFILE, "w")) == NULL)
err(1, "fopen");
if (!debug) {
setlogmask(LOG_UPTO(LOG_INFO));
if (daemon(1, 0) < 0) {
unlink(PIDFILE);
err(1, "daemon");
}
}
fprintf(fp, "%d\n", getpid());
fclose(fp);
chmod(PIDFILE, 0644);
event_init();
event_set(&recv_ev, pcap_fileno(arpd_pcap), EV_READ,
arpd_recv, &recv_ev);
event_add(&recv_ev, NULL);
/* Setup signal handler */
if (signal(SIGINT, terminate_handler) == SIG_ERR) {
perror("signal");
return (-1);
}
if (signal(SIGTERM, terminate_handler) == SIG_ERR) {
perror("signal");
return (-1);
}
event_dispatch();
return (0);
}
