odhpc6c: status code support in reply

[odhcp6c.git] / src / ra.c

diff --git a/src/ra.c b/src/ra.c
index 9c1ed74d4ee4e89b90702ae8f33554ff34706bff..c870279abae3f70730dc3aee17719a25168df726 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -67,6 +67,10 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
        val = 255;
        setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
 
+       // Receive multicast hops
+       val = 1;
+       setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
+
        // Bind to one device
        setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 
@@ -75,21 +79,6 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
        fcntl(sock, F_SETOWN, ourpid);
        fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
 
-       if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
-               // Autodetect interface-id if not specified
-               FILE *fp = fopen("/proc/net/if_inet6", "r");
-               if (fp) {
-                       char addrbuf[33], ifbuf[16];
-                       while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) {
-                               if (!strcmp(ifbuf, if_name)) {
-                                       script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf);
-                                       break;
-                               }
-                       }
-                       fclose(fp);
-               }
-       }
-
        // Send RS
        signal(SIGALRM, ra_send_rs);
        ra_send_rs(SIGALRM);
@@ -131,20 +120,49 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 bool ra_process(void)
 {
        bool found = false;
-       uint8_t buf[1500];
+       bool changed = false;
+       uint8_t buf[1500], cmsg_buf[128];
        struct nd_router_advert *adv = (struct nd_router_advert*)buf;
-       struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0};
+       struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
        const struct in6_addr any = IN6ADDR_ANY_INIT;
 
+       if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
+               // Autodetect interface-id if not specified
+               FILE *fp = fopen("/proc/net/if_inet6", "r");
+               if (fp) {
+                       char addrbuf[33], ifbuf[16];
+                       while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) {
+                               if (!strcmp(ifbuf, if_name)) {
+                                       script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf);
+                                       break;
+                               }
+                       }
+                       fclose(fp);
+               }
+       }
+
        while (true) {
                struct sockaddr_in6 from;
-               socklen_t from_len = sizeof(from);
-               ssize_t len = recvfrom(sock, buf, sizeof(buf), MSG_DONTWAIT, &from, &from_len);
+               struct iovec iov = {buf, sizeof(buf)};
+               struct msghdr msg = {&from, sizeof(from), &iov, 1,
+                               cmsg_buf, sizeof(cmsg_buf), 0};
+
+               ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
                if (len < 0)
                        break;
                else if (len < (ssize_t)sizeof(*adv))
                        continue;
 
+               int hlim = 0;
+               for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
+                               ch = CMSG_NXTHDR(&msg, ch))
+                       if (ch->cmsg_level == IPPROTO_IPV6 &&
+                                       ch->cmsg_type == IPV6_HOPLIMIT)
+                               memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
+
+               if (hlim != 255)
+                       continue;
+
                // Stop sending solicits
                if (rs_attempt > 0) {
                        alarm(0);
@@ -166,7 +184,7 @@ bool ra_process(void)
                        entry.priority = pref_to_priority(0);
                entry.valid = router_valid;
                entry.preferred = entry.valid;
-               odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+               changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
                // Parse ND parameters
                if (ntohl(adv->nd_ra_reachable) <= 3600000)
@@ -198,7 +216,7 @@ bool ra_process(void)
                                        continue;
 
                                if (entry.priority > 0)
-                                       odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+                                       changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
                        } else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) {
                                struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt;
                                entry.router = any;
@@ -215,7 +233,7 @@ bool ra_process(void)
                                        continue;
 
                                if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)
-                                       odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
+                                       changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
 
                                if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ||
                                                pinfo->nd_opt_pi_prefix_len != 64)
@@ -224,7 +242,7 @@ bool ra_process(void)
                                entry.target.s6_addr32[2] = lladdr.s6_addr32[2];
                                entry.target.s6_addr32[3] = lladdr.s6_addr32[3];
 
-                               odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
+                               changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
                        } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) {
                                entry.router = from.sin6_addr;
                                entry.priority = 0;
@@ -236,7 +254,7 @@ bool ra_process(void)
                                for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) {
                                        memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)],
                                                        sizeof(entry.target));
-                                       odhcp6c_update_entry(STATE_RA_DNS, &entry);
+                                       changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry);
                                }
                        }
                }
@@ -252,5 +270,5 @@ bool ra_process(void)
        if (found)
                odhcp6c_expire();
 
-       return found;
+       return found && changed;
 }