use requests only for creating new host entries, not for refreshing them

[project/relayd.git] / main.c

diff --git a/main.c b/main.c
index 407c8c2..2f3bae8 100644 (file)
--- a/main.c
+++ b/main.c
@@ -36,10 +36,14 @@ LIST_HEAD(interfaces);
 int debug;
 
 static int host_timeout;
+static int host_ping_tries;
 static int inet_sock;
 static int forward_bcast;
 static int forward_dhcp;
 
+uint8_t local_addr[4];
+int local_route_table;
+
 struct relayd_pending_route {
        struct relayd_route rt;
        struct uloop_timeout timeout;
@@ -135,7 +139,7 @@ static void del_host(struct relayd_host *host)
        free(host);
 }
 
-static void fill_arp_request(struct arp_packet *pkt, struct relayd_interface *rif,
+static void fill_arp_packet(struct arp_packet *pkt, struct relayd_interface *rif,
                              const uint8_t spa[4], const uint8_t tpa[4])
 {
        memset(pkt, 0, sizeof(*pkt));
@@ -157,7 +161,7 @@ static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr
 {
        struct arp_packet pkt;
 
-       fill_arp_request(&pkt, rif, rif->src_ip, ipaddr);
+       fill_arp_packet(&pkt, rif, rif->src_ip, ipaddr);
 
        pkt.arp.arp_op = htons(ARPOP_REQUEST);
        memcpy(pkt.arp.arp_spa, rif->src_ip, ETH_ALEN);
@@ -207,15 +211,24 @@ static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
 {
        struct arp_packet pkt;
 
-       fill_arp_request(&pkt, rif, spa, tpa);
+       fill_arp_packet(&pkt, rif, spa, tpa);
 
        pkt.arp.arp_op = htons(ARPOP_REPLY);
-       memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
-       memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
+       if (tha) {
+               memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
+               memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
 
-       DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
-               rif->ifname, IP_BUF(pkt.arp.arp_tpa),
-               IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
+               DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
+                       rif->ifname, IP_BUF(pkt.arp.arp_tpa),
+                       IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
+       } else {
+               memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
+               memset(pkt.arp.arp_tha, 0, ETH_ALEN);
+
+               DPRINTF(2, "%s: sending gratuitous ARP: "IP_FMT" is at ("MAC_FMT")\n",
+                       rif->ifname, IP_BUF(pkt.arp.arp_tpa),
+                       MAC_BUF(pkt.eth.ether_shost));
+       }
 
        sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
                (struct sockaddr *) &rif->sll, sizeof(rif->sll));
@@ -232,7 +245,7 @@ static void host_entry_timeout(struct uloop_timeout *timeout)
         * When the timeout is reached, try pinging the host a few times before
         * giving up on it.
         */
-       if (host->rif->managed && host->cleanup_pending < 2) {
+       if (host->rif->managed && host->cleanup_pending < host_ping_tries) {
                send_arp_request(host->rif, host->ipaddr);
                host->cleanup_pending++;
                uloop_timeout_set(&host->timeout, 1000);
@@ -342,7 +355,14 @@ static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pk
        if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
                return;
 
-       relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
+       if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
+               send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
+               return;
+       }
+
+       host = find_host_by_ipaddr(NULL, pkt->arp.arp_spa);
+       if (!host || host->rif != rif)
+               relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 
        host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 
@@ -361,6 +381,7 @@ static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pk
 
 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 {
+       struct relayd_interface *to_rif;
        struct relayd_host *host;
 
        DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
@@ -372,8 +393,19 @@ static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
        if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
                relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
 
-       if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
+       if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4)) {
+               /*
+                * locally initiated lookup, relay as gratuitous ARP
+                * to all other interfaces
+                */
+               list_for_each_entry(to_rif, &interfaces, list) {
+                       if (rif == to_rif)
+                               continue;
+
+                       send_arp_reply(to_rif, pkt->arp.arp_spa, NULL, pkt->arp.arp_spa);
+               }
                return;
+       }
 
        host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
        if (!host)
@@ -638,9 +670,11 @@ static int usage(const char *progname)
                        "       -R <gateway>:<net>/<mask>\n"
                        "                       Add a static route for <net>/<mask> via <gateway>\n"
                        "       -t <timeout>    Host entry expiry timeout\n"
+                       "       -p <tries>      Number of ARP ping attempts before considering a host dead\n"
                        "       -T <table>      Set routing table number for automatically added routes\n"
                        "       -B              Enable broadcast forwarding\n"
                        "       -D              Enable DHCP forwarding\n"
+                       "       -L <ipaddr>     Enable local access using <ipaddr> as source address\n"
                        "\n",
                progname);
        return -1;
@@ -650,6 +684,7 @@ int main(int argc, char **argv)
 {
        struct relayd_interface *rif = NULL;
        struct in_addr addr, addr2;
+       bool local_addr_valid = false;
        bool managed;
        int ifnum = 0;
        char *s, *s2;
@@ -663,11 +698,13 @@ int main(int argc, char **argv)
                return 1;
        }
 
-       host_timeout = 60;
+       host_timeout = 30;
+       host_ping_tries = 5;
        forward_bcast = 0;
+       local_route_table = 0;
        uloop_init();
 
-       while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:")) != -1) {
+       while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
                switch(ch) {
                case 'I':
                        managed = true;
@@ -685,6 +722,11 @@ int main(int argc, char **argv)
                        if (host_timeout <= 0)
                                return usage(argv[0]);
                        break;
+               case 'p':
+                       host_ping_tries = atoi(optarg);
+                       if (host_ping_tries <= 0)
+                               return usage(argv[0]);
+                       break;
                case 'd':
                        debug++;
                        break;
@@ -706,6 +748,14 @@ int main(int argc, char **argv)
                        }
                        relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
                        break;
+               case 'L':
+                       if (!inet_aton(optarg, &addr)) {
+                               fprintf(stderr, "Address '%s' not found\n", optarg);
+                               return 1;
+                       }
+                       memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
+                       local_addr_valid = true;
+                       break;
                case 'R':
                        s = strchr(optarg, ':');
                        if (!s)
@@ -755,6 +805,9 @@ int main(int argc, char **argv)
        signal(SIGUSR1, die);
        signal(SIGUSR2, die);
 
+       if (local_addr_valid)
+               local_route_table = route_table++;
+
        if (relayd_rtnl_init() < 0)
                return 1;