Add more sanity checks and logging to DAD

[odhcp6c.git] / src / ra.c

diff --git a/src/ra.c b/src/ra.c
index f1a5f7fdb5747d0160283adff8a2dc9c43db12b1..7d1ded0199a512eca16828b86d32d75c75b44bab 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -1,12 +1,28 @@
+/**
+ * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
 #include <fcntl.h>
 #include <stdio.h>
 #include <signal.h>
 #include <string.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <syslog.h>
 #include <unistd.h>
 
 #include <net/if.h>
+#include <arpa/inet.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
@@ -125,7 +141,7 @@ static bool ra_deduplicate(const struct in6_addr *any, uint8_t length)
 {
        struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, length, 0, *any, 0, 0};
        struct odhcp6c_entry *x = odhcp6c_find_entry(STATE_RA_PREFIX, &entry);
-       if (x) {
+       if (x && IN6_ARE_ADDR_EQUAL(&x->target, any)) {
                odhcp6c_random(&x->target.s6_addr32[2], 2 * sizeof(uint32_t));
        } else if (odhcp6c_find_entry(STATE_IA_NA, &entry)) {
                dhcpv6_request(DHCPV6_MSG_DECLINE);
@@ -151,17 +167,23 @@ bool ra_rtnl_process(void)
                        struct in6_addr *addr = NULL;
                        if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ifa) || ifa->ifa_index != if_index ||
                                        (nh->nlmsg_type == RTM_NEWADDR && !(ifa->ifa_flags & IFA_F_DADFAILED)) ||
-                                       (nh->nlmsg_type == RTM_DELADDR && !(ifa->ifa_flags & IFA_F_TENTATIVE)))
+                                       (nh->nlmsg_type == RTM_DELADDR && !(ifa->ifa_flags & IFA_F_TENTATIVE)) ||
+                                       (nh->nlmsg_type != RTM_NEWADDR && nh->nlmsg_type != RTM_DELADDR))
                                continue;
 
                        ssize_t alen = NLMSG_PAYLOAD(nh, sizeof(*ifa));
                        for (struct rtattr *rta = (struct rtattr*)&ifa[1]; RTA_OK(rta, alen);
                                        rta = RTA_NEXT(rta, alen))
-                               if (rta->rta_type == IFA_LOCAL && RTA_PAYLOAD(rta) >= sizeof(*addr))
+                               if (rta->rta_type == IFA_ADDRESS && RTA_PAYLOAD(rta) >= sizeof(*addr))
                                        addr = RTA_DATA(rta);
 
-                       if (addr)
+                       if (addr) {
+                               char ipbuf[INET6_ADDRSTRLEN];
+                               inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
+                               syslog(LOG_WARNING, "duplicate address detected: %s (code: %u:%x)",
+                                               ipbuf, (unsigned)nh->nlmsg_type, (unsigned)ifa->ifa_flags);
                                found |= ra_deduplicate(addr, ifa->ifa_prefixlen);
+                       }
                }
        }
        return found;
@@ -216,13 +238,15 @@ bool ra_process(void)
                struct icmpv6_opt *opt;
                icmpv6_for_each_option(opt, &adv[1], &buf[len]) {
                        if (opt->type == ND_OPT_MTU) {
-                               update_proc("conf", "mtu", ntohl(*((uint32_t*)&opt->data[2])));
+                               uint32_t *mtu = (uint32_t*)&opt->data[2];
+                               update_proc("conf", "mtu", ntohl(*mtu));
                        } else if (opt->type == ND_OPT_ROUTE_INFORMATION && opt->len <= 3) {
                                entry.router = from.sin6_addr;
                                entry.target = any;
                                entry.priority = pref_to_priority(opt->data[1]);
                                entry.length = opt->data[0];
-                               entry.valid = ntohl(*((uint32_t*)&opt->data[2]));
+                               uint32_t *valid = (uint32_t*)&opt->data[2];
+                               entry.valid = ntohl(*valid);
                                memcpy(&entry.target, &opt->data[6], (opt->len - 1) * 8);
 
                                if (entry.length > 128 || IN6_IS_ADDR_LINKLOCAL(&entry.target)
@@ -236,7 +260,7 @@ bool ra_process(void)
                                struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt;
                                entry.router = any;
                                entry.target = pinfo->nd_opt_pi_prefix;
-                               entry.priority = 0;
+                               entry.priority = 256;
                                entry.length = pinfo->nd_opt_pi_prefix_len;
                                entry.valid = ntohl(pinfo->nd_opt_pi_valid_time);
                                entry.preferred = ntohl(pinfo->nd_opt_pi_preferred_time);
@@ -262,7 +286,8 @@ bool ra_process(void)
                                entry.router = from.sin6_addr;
                                entry.priority = 0;
                                entry.length = 128;
-                               entry.valid = ntohl(*((uint32_t*)&opt->data[2]));
+                               uint32_t *valid = (uint32_t*)&opt->data[2];
+                               entry.valid = ntohl(*valid);
                                entry.preferred = 0;
 
                                for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) {