Add more sanity checks and logging to DAD

diff --git a/src/ra.c b/src/ra.c
index c572c130ebe3bbedf62ebac3909de81ceebcf52e..7d1ded0199a512eca16828b86d32d75c75b44bab 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -18,9 +18,11 @@
 #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>
@@ -165,7 +167,8 @@ 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));
@@ -174,8 +177,13 @@ bool ra_rtnl_process(void)
                                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;