add support for multiple prefixes with distinct IAIDs

[odhcp6c.git] / src / ra.c

diff --git a/src/ra.c b/src/ra.c
index aa03ff4d3ab8f6235b38aa8f069c785d3486a10e..570ff6fef28c7e5950c989d79b365a6844835982 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -13,6 +13,7 @@
  */
 
 #include <fcntl.h>
+#include <ifaddrs.h>
 #include <stdio.h>
 #include <signal.h>
 #include <string.h>
@@ -24,6 +25,7 @@
 #include <net/if.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
 
@@ -59,13 +61,23 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 {
        const pid_t ourpid = getpid();
        sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+       if (sock < 0)
+               return -1;
+
        if_index = if_nametoindex(ifname);
+       if (!if_index)
+               return -1;
+
        strncpy(if_name, ifname, sizeof(if_name) - 1);
        lladdr = *ifid;
 
        rtnl = socket(AF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_ROUTE);
+       if (rtnl < 0)
+               return -1;
+
        struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
-       connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel));
+       if (connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)) < 0)
+               return -1;
 
        int val = RTNLGRP_LINK;
        setsockopt(rtnl, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &val, sizeof(val));
@@ -150,6 +162,7 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 
 bool ra_link_up(void)
 {
+       static bool firstcall = true;
        struct {
                struct nlmsghdr hdr;
                struct ifinfomsg msg;
@@ -161,19 +174,22 @@ bool ra_link_up(void)
 
        do {
                read = recv(rtnl, &resp, sizeof(resp), MSG_DONTWAIT);
-               if (!NLMSG_OK(&resp.hdr, read) || resp.hdr.nlmsg_type != RTM_NEWLINK ||
+               if (read < 0 || !NLMSG_OK(&resp.hdr, (size_t)read) ||
+                               resp.hdr.nlmsg_type != RTM_NEWLINK ||
                                resp.msg.ifi_index != if_index)
                        continue;
 
                bool hascarrier = resp.msg.ifi_flags & IFF_LOWER_UP;
-               if (nocarrier && hascarrier)
+               if (!firstcall && nocarrier != !hascarrier)
                        ret = true;
 
                nocarrier = !hascarrier;
+               firstcall = false;
        } while (read > 0);
 
        if (ret) {
-               syslog(LOG_NOTICE, "carrier up event on %s", if_name);
+               syslog(LOG_NOTICE, "carrier => %i event on %s", (int)!nocarrier, if_name);
+
                rs_attempt = 0;
                ra_send_rs(SIGALRM);
        }
@@ -181,27 +197,66 @@ bool ra_link_up(void)
        return ret;
 }
 
+static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data, size_t len)
+{
+       struct icmp6_hdr *hdr = (struct icmp6_hdr*)data;
+       struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
+
+       if (hlim != 255 || len < sizeof(*hdr) || hdr->icmp6_code)
+               return false;
+
+       switch (hdr->icmp6_type) {
+       case ND_ROUTER_ADVERT:
+               if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
+                       return false;
+
+               opt = (struct icmpv6_opt*)((struct nd_router_advert*)data + 1);
+               break;
+
+       default:
+               return false;
+       }
+
+       icmpv6_for_each_option(opt, opt, end)
+               ;
+
+       return opt == end;
+}
+
 bool ra_process(void)
 {
        bool found = false;
        bool changed = false;
+       bool has_lladdr = !IN6_IS_ADDR_UNSPECIFIED(&lladdr);
        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, 0, 0};
+       struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
        const struct in6_addr any = IN6ADDR_ANY_INIT;
 
-       if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
+       if (!has_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);
+               struct ifaddrs *ifaddr, *ifa;
+
+               if (getifaddrs(&ifaddr) == 0) {
+                       for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+                               struct sockaddr_in6 *addr;
+
+                               if (ifa->ifa_addr == NULL || ifa->ifa_addr->sa_family != AF_INET6)
+                                       continue;
+
+                               addr = (struct sockaddr_in6*)ifa->ifa_addr;
+
+                               if (!IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr))
+                                       continue;
+
+                               if (!strcmp(ifa->ifa_name, if_name)) {
+                                       lladdr = addr->sin6_addr;
+                                       has_lladdr = true;
                                        break;
                                }
                        }
-                       fclose(fp);
+
+                       freeifaddrs(ifaddr);
                }
        }
 
@@ -212,9 +267,10 @@ bool ra_process(void)
                                cmsg_buf, sizeof(cmsg_buf), 0};
 
                ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
-               if (len < 0)
+               if (len <= 0)
                        break;
-               else if (len < (ssize_t)sizeof(*adv))
+
+               if (!has_lladdr)
                        continue;
 
                int hlim = 0;
@@ -224,7 +280,7 @@ bool ra_process(void)
                                        ch->cmsg_type == IPV6_HOPLIMIT)
                                memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
 
-               if (hlim != 255)
+               if (!ra_icmpv6_valid(&from, hlim, buf, len))
                        continue;
 
                // Stop sending solicits
@@ -250,6 +306,10 @@ bool ra_process(void)
                entry.preferred = entry.valid;
                changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
+               // Parse hoplimit
+               if (adv->nd_ra_curhoplimit)
+                       update_proc("conf", "hop_limit", adv->nd_ra_curhoplimit);
+
                // Parse ND parameters
                if (ntohl(adv->nd_ra_reachable) <= 3600000)
                        update_proc("neigh", "base_reachable_time_ms", ntohl(adv->nd_ra_reachable));