Handle duplicate address detection failures.

We get notified when duplication is detected on the route socket. For
privacy addresses simply generate a new random address. If we have
soii enabled increase the dad counter on the prefix and generate a new
address. For eui64 addresses nothing can be done.

4 files changed, 161 insertions, 34 deletions

diff --git a/sbin/slaacd/engine.c b/sbin/slaacd/engine.c
index 961e1b115b6..b2955ea2ff5 100644
--- a/sbin/slaacd/engine.c
+++ b/sbin/slaacd/engine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: engine.c,v 1.27 2018/06/20 14:55:29 florian Exp $	*/
+/*	$OpenBSD: engine.c,v 1.28 2018/07/23 06:14:14 florian Exp $	*/
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -106,6 +106,7 @@ enum proposal_state {
 	PROPOSAL_CONFIGURED,
 	PROPOSAL_NEARLY_EXPIRED,
 	PROPOSAL_WITHDRAWN,
+	PROPOSAL_DUPLICATED,
 };
 
 const char* proposal_state_name[] = {
@@ -114,6 +115,7 @@ const char* proposal_state_name[] = {
 	"CONFIGURED",
 	"NEARLY_EXPIRED",
 	"WITHDRAWN",
+	"DUPLICATED",
 };
 
 const char* rpref_name[] = {
@@ -130,6 +132,7 @@ struct radv_prefix {
 	int			autonomous;
 	uint32_t		vltime;
 	uint32_t		pltime;
+	int			dad_counter;
 };
 
 struct radv_rdns {
@@ -261,11 +264,10 @@ struct dfr_proposal	*find_dfr_proposal_by_id(struct slaacd_iface *,
 			     int64_t);
 struct dfr_proposal	*find_dfr_proposal_by_gw(struct slaacd_iface *,
 			     struct sockaddr_in6 *);
-void			 find_prefix(struct slaacd_iface *, struct
-			     address_proposal *, struct radv **, struct
-			     radv_prefix **);
+struct radv_prefix	*find_prefix(struct radv *, struct radv_prefix *);
 int			 engine_imsg_compose_main(int, pid_t, void *, uint16_t);
 uint32_t		 real_lifetime(struct timespec *, uint32_t);
+void			 merge_dad_couters(struct radv *, struct radv *);
 
 struct imsgev		*iev_frontend;
 struct imsgev		*iev_main;
@@ -392,6 +394,8 @@ engine_dispatch_frontend(int fd, short event, void *bula)
 	struct dfr_proposal		*dfr_proposal = NULL;
 	struct imsg_del_addr		 del_addr;
 	struct imsg_del_route		 del_route;
+	struct imsg_dup_addr		 dup_addr;
+	struct timeval			 tv;
 	ssize_t				 n;
 	int				 shut = 0;
 #ifndef	SMALL
@@ -546,6 +550,31 @@ engine_dispatch_frontend(int fd, short event, void *bula)
 				start_probe(iface);
 			}
 			break;
+		case IMSG_DUP_ADDRESS:
+			if (imsg.hdr.len != IMSG_HEADER_SIZE +
+			    sizeof(dup_addr))
+				fatal("%s: IMSG_DUP_ADDRESS wrong length: %d",
+				    __func__, imsg.hdr.len);
+			memcpy(&dup_addr, imsg.data, sizeof(dup_addr));
+			iface = get_slaacd_iface_by_id(dup_addr.if_index);
+			if (iface == NULL) {
+				log_debug("IMSG_DUP_ADDRESS: unknown interface"
+				    ", ignoring");
+				break;
+			}
+
+			addr_proposal = find_address_proposal_by_addr(iface,
+			    &dup_addr.addr);
+
+			if (addr_proposal) {
+				/* XXX should we inform netcfgd? */
+				addr_proposal->state = PROPOSAL_DUPLICATED;
+				tv.tv_sec = 0;
+				tv.tv_usec = arc4random_uniform(1000000);
+				addr_proposal->next_timeout = 0;
+				evtimer_add(&addr_proposal->timer, &tv);
+			}
+			break;
 		default:
 			log_debug("%s: unexpected imsg %d", __func__,
 			    imsg.hdr.type);
@@ -1261,7 +1290,6 @@ gen_addr(struct slaacd_iface *iface, struct radv_prefix *prefix, struct
 {
 	SHA2_CTX ctx;
 	struct in6_addr	iid;
-	int dad_counter = 0; /* XXX not used */
 	int i;
 	u_int8_t digest[SHA512_DIGEST_LENGTH];
 
@@ -1293,7 +1321,8 @@ gen_addr(struct slaacd_iface *iface, struct radv_prefix *prefix, struct
 		    sizeof(prefix->prefix));
 		SHA512Update(&ctx, &iface->hw_address,
 		    sizeof(iface->hw_address));
-		SHA512Update(&ctx, &dad_counter, sizeof(dad_counter));
+		SHA512Update(&ctx, &prefix->dad_counter,
+		    sizeof(prefix->dad_counter));
 		SHA512Update(&ctx, addr_proposal->soiikey,
 		    sizeof(addr_proposal->soiikey));
 		SHA512Final(digest, &ctx);
@@ -1601,13 +1630,16 @@ void update_iface_ra(struct slaacd_iface *iface, struct radv *ra)
 	struct address_proposal	*addr_proposal;
 	struct dfr_proposal	*dfr_proposal, *tmp;
 	uint32_t		 remaining_lifetime;
-	int			 found, found_privacy;
+	int			 found, found_privacy, duplicate_found;
 	const char		*hbuf;
 
 	if ((old_ra = find_ra(iface, &ra->from)) == NULL)
 		LIST_INSERT_HEAD(&iface->radvs, ra, entries);
 	else {
 		LIST_REPLACE(old_ra, ra, entries);
+
+		merge_dad_couters(old_ra, ra);
+
 		free_ra(old_ra);
 	}
 	if (ra->router_lifetime == 0) {
@@ -1674,6 +1706,8 @@ void update_iface_ra(struct slaacd_iface *iface, struct radv *ra)
 				continue;
 			found = 0;
 			found_privacy = 0;
+			duplicate_found = 0;
+
 			LIST_FOREACH(addr_proposal, &iface->addr_proposals,
 			    entries) {
 				if (prefix->prefix_len ==
@@ -1699,7 +1733,9 @@ void update_iface_ra(struct slaacd_iface *iface, struct radv *ra)
 					 * expires
 					 */
 					if (addr_proposal->state !=
-					    PROPOSAL_NEARLY_EXPIRED)
+					    PROPOSAL_NEARLY_EXPIRED &&
+					    addr_proposal->state !=
+					    PROPOSAL_DUPLICATED)
 						found_privacy = 1;
 
 					if (!iface->autoconfprivacy)
@@ -1715,6 +1751,12 @@ void update_iface_ra(struct slaacd_iface *iface, struct radv *ra)
 					continue;
 				}
 
+				if (addr_proposal->state ==
+				    PROPOSAL_DUPLICATED) {
+					duplicate_found = 1;
+					continue;
+				}
+
 				found = 1;
 
 				remaining_lifetime =
@@ -1751,6 +1793,12 @@ void update_iface_ra(struct slaacd_iface *iface, struct radv *ra)
 				}
 			}
 
+			if (!found && duplicate_found && iface->soii) {
+				prefix->dad_counter++;
+				log_debug("%s dad_counter: %d",
+				     __func__, prefix->dad_counter);
+			}
+
 			if (!found &&
 			    (iface->soii || prefix->prefix_len <= 64))
 				/* new proposal */
@@ -2117,6 +2165,13 @@ address_proposal_timeout(int fd, short events, void *arg)
 		log_debug("%s: scheduling new timeout in %llds.%06ld",
 		    __func__, tv.tv_sec, tv.tv_usec);
 		break;
+	case PROPOSAL_DUPLICATED:
+		engine_imsg_compose_frontend(IMSG_CTL_SEND_SOLICITATION,
+		    0, &addr_proposal->if_index,
+		    sizeof(addr_proposal->if_index));
+		log_debug("%s: address duplicated",
+		    __func__);
+		break;
 	default:
 		log_debug("%s: unhandled state: %s", __func__,
 		    proposal_state_name[addr_proposal->state]);
@@ -2304,32 +2359,19 @@ find_dfr_proposal_by_gw(struct slaacd_iface *iface, struct sockaddr_in6
 }
 
 
-/* XXX currently unused */
-void
-find_prefix(struct slaacd_iface *iface, struct address_proposal *addr_proposal,
-    struct radv **result_ra, struct radv_prefix **result_prefix)
+struct radv_prefix *
+find_prefix(struct radv *ra, struct radv_prefix *prefix)
 {
-	struct radv		*ra;
-	struct radv_prefix	*prefix;
-	uint32_t		 lifetime, max_lifetime = 0;
+	struct radv_prefix	*result;
 
-	*result_ra = NULL;
-	*result_prefix = NULL;
 
-	LIST_FOREACH(ra, &iface->radvs, entries) {
-		LIST_FOREACH(prefix, &ra->prefixes, entries) {
-			if (memcmp(&prefix->prefix, &addr_proposal->prefix,
-			    sizeof(addr_proposal->prefix)) != 0)
-				continue;
-			lifetime = real_lifetime(&ra->uptime,
-			    prefix->vltime);
-			if (lifetime > max_lifetime) {
-				max_lifetime = lifetime;
-				*result_ra = ra;
-				*result_prefix = prefix;
-			}
-		}
+	LIST_FOREACH(result, &ra->prefixes, entries) {
+		if (memcmp(&result->prefix, &prefix->prefix,
+		    sizeof(prefix->prefix)) == 0 && result->prefix_len ==
+		    prefix->prefix_len)
+			return (result);
 	}
+	return (NULL);
 }
 
 uint32_t
@@ -2350,3 +2392,17 @@ real_lifetime(struct timespec *received_uptime, uint32_t ltime)
 
 	return (remaining);
 }
+
+void
+merge_dad_couters(struct radv *old_ra, struct radv *new_ra)
+{
+
+	struct radv_prefix	*old_prefix, *new_prefix;
+
+	LIST_FOREACH(old_prefix, &old_ra->prefixes, entries) {
+		if (!old_prefix->dad_counter)
+			continue;
+		if ((new_prefix = find_prefix(new_ra, old_prefix)) != NULL)
+			new_prefix->dad_counter = old_prefix->dad_counter;
+	}
+}
diff --git a/sbin/slaacd/frontend.c b/sbin/slaacd/frontend.c
index 96d69b8b661..cdbe7d11b5b 100644
--- a/sbin/slaacd/frontend.c
+++ b/sbin/slaacd/frontend.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: frontend.c,v 1.20 2018/06/06 14:08:28 florian Exp $	*/
+/*	$OpenBSD: frontend.c,v 1.21 2018/07/23 06:14:14 florian Exp $	*/
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -73,6 +73,7 @@ void		 get_lladdr(char *, struct ether_addr *, struct sockaddr_in6 *);
 void		 send_solicitation(uint32_t);
 #ifndef	SMALL
 void		 update_autoconf_addresses(uint32_t, char*);
+const char	*flags_to_str(int);
 #endif	/* SMALL */
 
 struct imsgev			*iev_main;
@@ -592,6 +593,31 @@ update_autoconf_addresses(uint32_t if_index, char* if_name)
 	}
 	freeifaddrs(ifap);
 }
+
+const char*
+flags_to_str(int flags)
+{
+	static char	buf[sizeof(" anycast tentative duplicated detached "
+			    "deprecated autoconf autoconfprivacy")];
+
+	buf[0] = '\0';
+	if (flags & IN6_IFF_ANYCAST)
+		(void)strlcat(buf, " anycast", sizeof(buf));
+	if (flags & IN6_IFF_TENTATIVE)
+		(void)strlcat(buf, " tentative", sizeof(buf));
+	if (flags & IN6_IFF_DUPLICATED)
+		(void)strlcat(buf, " duplicated", sizeof(buf));
+	if (flags & IN6_IFF_DETACHED)
+		(void)strlcat(buf, " detached", sizeof(buf));
+	if (flags & IN6_IFF_DEPRECATED)
+		(void)strlcat(buf, " deprecated", sizeof(buf));
+	if (flags & IN6_IFF_AUTOCONF)
+		(void)strlcat(buf, " autoconf", sizeof(buf));
+	if (flags & IN6_IFF_PRIVACY)
+		(void)strlcat(buf, " autoconfprivacy", sizeof(buf));
+
+	return (buf);
+}
 #endif	/* SMALL */
 
 void
@@ -673,7 +699,10 @@ handle_route_message(struct rt_msghdr *rtm, struct sockaddr **rti_info)
 	struct imsg_proposal_ack	 proposal_ack;
 	struct imsg_del_addr		 del_addr;
 	struct imsg_del_route		 del_route;
+	struct imsg_dup_addr		 dup_addr;
 	struct sockaddr_rtlabel		*rl;
+	struct sockaddr_in6		*sin6;
+	struct in6_ifreq		 ifr6;
 	struct in6_addr			*in6;
 	int64_t				 id, pid;
 	int				 xflags, if_index;
@@ -728,6 +757,42 @@ handle_route_message(struct rt_msghdr *rtm, struct sockaddr **rti_info)
 			    ifm->ifm_index);
 		}
 		break;
+	case RTM_CHGADDRATTR:
+		ifm = (struct if_msghdr *)rtm;
+		if_name = if_indextoname(ifm->ifm_index, ifnamebuf);
+		if (rtm->rtm_addrs & RTA_IFA && rti_info[RTAX_IFA]->sa_family
+		    == AF_INET6) {
+			sin6 = (struct sockaddr_in6 *) rti_info[RTAX_IFA];
+
+			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
+				break;
+
+			memset(&ifr6, 0, sizeof(ifr6));
+			(void) strlcpy(ifr6.ifr_name, if_name,
+			    sizeof(ifr6.ifr_name));
+			memcpy(&ifr6.ifr_addr, sin6, sizeof(ifr6.ifr_addr));
+
+			if (ioctl(ioctlsock, SIOCGIFAFLAG_IN6, (caddr_t)&ifr6)
+			    < 0) {
+				log_warn("SIOCGIFAFLAG_IN6");
+				break;
+			}
+
+#ifndef	SMALL
+			log_debug("RTM_CHGADDRATTR: %s -%s",
+			    sin6_to_str(sin6),
+			    flags_to_str(ifr6.ifr_ifru.ifru_flags6));
+#endif	/* SMALL */
+
+			if (ifr6.ifr_ifru.ifru_flags6 & IN6_IFF_DUPLICATED) {
+				dup_addr.if_index = ifm->ifm_index;
+				dup_addr.addr = *sin6;
+				frontend_imsg_compose_engine(IMSG_DUP_ADDRESS,
+				    0, 0, &dup_addr, sizeof(dup_addr));
+			}
+
+		}
+		break;
 	case RTM_DELETE:
 		ifm = (struct if_msghdr *)rtm;
 		if ((rtm->rtm_addrs & (RTA_DST | RTA_GATEWAY | RTA_LABEL)) !=
diff --git a/sbin/slaacd/slaacd.c b/sbin/slaacd/slaacd.c
index 6778659fa10..633864bf566 100644
--- a/sbin/slaacd/slaacd.c
+++ b/sbin/slaacd/slaacd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: slaacd.c,v 1.25 2018/07/09 07:41:15 florian Exp $	*/
+/*	$OpenBSD: slaacd.c,v 1.26 2018/07/23 06:14:14 florian Exp $	*/
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -275,7 +275,7 @@ main(int argc, char *argv[])
 
 	rtfilter = ROUTE_FILTER(RTM_IFINFO) | ROUTE_FILTER(RTM_NEWADDR) |
 	    ROUTE_FILTER(RTM_DELADDR) | ROUTE_FILTER(RTM_PROPOSAL) |
-	    ROUTE_FILTER(RTM_DELETE);
+	    ROUTE_FILTER(RTM_DELETE) | ROUTE_FILTER(RTM_CHGADDRATTR);
 	if (setsockopt(frontend_routesock, PF_ROUTE, ROUTE_MSGFILTER,
 	    &rtfilter, sizeof(rtfilter)) < 0)
 		fatal("setsockopt(ROUTE_MSGFILTER)");
diff --git a/sbin/slaacd/slaacd.h b/sbin/slaacd/slaacd.h
index 910be91e687..1659c564abf 100644
--- a/sbin/slaacd/slaacd.h
+++ b/sbin/slaacd/slaacd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: slaacd.h,v 1.17 2018/07/09 07:41:15 florian Exp $	*/
+/*	$OpenBSD: slaacd.h,v 1.18 2018/07/23 06:14:14 florian Exp $	*/
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -74,6 +74,7 @@ enum imsg_type {
 	IMSG_FAKE_ACK,
 	IMSG_CONFIGURE_DFR,
 	IMSG_WITHDRAW_DFR,
+	IMSG_DUP_ADDRESS,
 };
 
 enum {
@@ -202,6 +203,11 @@ struct imsg_ra {
 	uint8_t			packet[1500];
 };
 
+struct imsg_dup_addr {
+	uint32_t		if_index;
+	struct sockaddr_in6	addr;
+};
+
 /* slaacd.c */
 void		imsg_event_add(struct imsgev *);
 int		imsg_compose_event(struct imsgev *, uint16_t, uint32_t, pid_t,