Wait for the link-local address to become non-tentative.

Otherwise we just end up with an ugly "Can't assign requested address"
error from sendmsg(2).
OK phessler

diff --git a/sbin/slaacd/frontend.c b/sbin/slaacd/frontend.c
index 7e443d1..b518f88 100644 (file)
--- a/sbin/slaacd/frontend.c
+++ b/sbin/slaacd/frontend.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: frontend.c,v 1.61 2021/12/27 15:18:51 florian Exp $   */
+/*     $OpenBSD: frontend.c,v 1.62 2022/01/04 06:17:46 florian Exp $   */
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -75,6 +75,7 @@ struct iface {
        uint32_t                 if_index;
        int                      rdomain;
        int                      send_solicitation;
+       int                      ll_tentative;
 };
 
 __dead void     frontend_shutdown(void);
@@ -499,6 +500,7 @@ update_iface(uint32_t if_index, char* if_name)
        struct imsg_ifinfo       imsg_ifinfo;
        struct sockaddr_dl      *sdl;
        struct sockaddr_in6     *sin6;
+       struct in6_ifreq         ifr6;
        int                      flags, xflags, ifrdomain;
 
        if ((flags = get_flags(if_name)) == -1 || (xflags =
@@ -525,6 +527,7 @@ update_iface(uint32_t if_index, char* if_name)
                iface->if_index = if_index;
                iface->rdomain = ifrdomain;
                iface->icmp6ev = get_icmp6ev_by_rdomain(ifrdomain);
+               iface->ll_tentative = 1;
 
                LIST_INSERT_HEAD(&interfaces, iface, entries);
        }
@@ -571,9 +574,33 @@ update_iface(uint32_t if_index, char* if_name)
                                    sin6->sin6_addr.s6_addr[3] = 0;
                        }
 #endif
-                       if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
+                       if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
                                memcpy(&imsg_ifinfo.ll_address, sin6,
                                    sizeof(imsg_ifinfo.ll_address));
+
+                               if (!iface->ll_tentative)
+                                       break;
+
+                               memset(&ifr6, 0, sizeof(ifr6));
+                               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) == -1) {
+                                       log_warn("SIOCGIFAFLAG_IN6");
+                                       break;
+                               }
+
+                               if (!(ifr6.ifr_ifru.ifru_flags6 &
+                                   IN6_IFF_TENTATIVE)) {
+                                       iface->ll_tentative = 0;
+                                       if (iface->send_solicitation)
+                                               send_solicitation(
+                                                   iface->if_index);
+                               }
+                       }
                        break;
                default:
                        break;
@@ -877,8 +904,10 @@ handle_route_message(struct rt_msghdr *rtm, struct sockaddr **rti_info)
                    == AF_INET6) {
                        sin6 = (struct sockaddr_in6 *) rti_info[RTAX_IFA];
 
-                       if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
+                       if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
+                               update_iface(if_index, if_name);
                                break;
+                       }
 
                        memset(&ifr6, 0, sizeof(ifr6));
                        strlcpy(ifr6.ifr_name, if_name, sizeof(ifr6.ifr_name));
@@ -1080,8 +1109,13 @@ send_solicitation(uint32_t if_index)
        if (!event_initialized(&iface->icmp6ev->ev)) {
                iface->send_solicitation = 1;
                return;
+       } else if (iface->ll_tentative) {
+               iface->send_solicitation = 1;
+               return;
        }
 
+       iface->send_solicitation = 0;
+
        dst.sin6_scope_id = if_index;
 
        cm = CMSG_FIRSTHDR(&sndmhdr);
@@ -1204,9 +1238,7 @@ set_icmp6sock(int icmp6sock, int rdomain)
 
        LIST_FOREACH (iface, &interfaces, entries) {
                if (event_initialized(&iface->icmp6ev->ev) &&
-                   iface->send_solicitation) {
-                       iface->send_solicitation = 0;
+                   iface->send_solicitation)
                        send_solicitation(iface->if_index);
-               }
        }
 }