Many changes in (mainly) kernel syncers.

- BSD kernel syncer is now self-conscious and can learn alien routes
- important bugfix in BSD kernel syncer (crash after protocol restart)
- many minor changes and bugfixes in kernel syncers and neighbor cache
- direct protocol does not generate host and link local routes
- min_scope check is removed, all routes have SCOPE_UNIVERSE by default
- also fixes some remaining compiler warnings

8 files changed, 219 insertions, 233 deletions

diff --git a/sysdep/bsd/krt-sock.c b/sysdep/bsd/krt-sock.c
index a527965..dac2c2e 100644
--- a/sysdep/bsd/krt-sock.c
+++ b/sysdep/bsd/krt-sock.c
@@ -33,39 +33,8 @@
 #include "lib/string.h"
 #include "lib/socket.h"
 
-#ifdef IPV6
-#define HOST_MASK 128
-#else
-#define HOST_MASK 32
-#endif
-
 int rt_sock = 0;
 
-#define CHECK_FAMILY(sa) \
-  ((((struct sockaddr *)sa)->sa_family) == BIRD_AF)
-
-static struct iface *
-krt_temp_iface_index(struct krt_proto *p, unsigned index)
-{
-  struct iface *i, *j;
-
-  WALK_LIST(i, p->scan.temp_ifs)
-    if (i->index == index)
-      return i;
-  i = mb_allocz(p->p.pool, sizeof(struct iface));
-  if (j = if_find_by_index(index))
-  {
-    strcpy(i->name, j->name);
-    i->addr = j->addr;
-  }
-  else
-    strcpy(i->name, "?");
-  i->index = index;
-  add_tail(&p->scan.temp_ifs, &i->n);
-  return i;
-}
-
-
 int
 krt_capable(rte *e)
 {
@@ -83,7 +52,7 @@ krt_capable(rte *e)
      || a->dest == RTD_UNREACHABLE
 #endif
 #ifdef RTF_BLACKHOLE
-     || a->dest == RTD_BLACKHOLE	/* FIXME Prohibited? */
+     || a->dest == RTD_BLACKHOLE
 #endif
      );
 }
@@ -96,6 +65,13 @@ krt_capable(rte *e)
           l = ROUNDUP(((struct sockaddr *)&(u))->sa_len);\
           memmove(body, &(u), l); body += l;}
 
+#define GETADDR(p, F) \
+  bzero(p, sizeof(*p));\
+  if ((addrs & (F)) && ((struct sockaddr *)body)->sa_len) {\
+    unsigned int l = ROUNDUP(((struct sockaddr *)body)->sa_len);\
+    memcpy(p, body, (l > sizeof(*p) ? sizeof(*p) : l));\
+    body += l;}
+
 static void
 krt_sock_send(int cmd, rte *e)
 {
@@ -108,7 +84,7 @@ krt_sock_send(int cmd, rte *e)
   char *body = (char *)msg.buf;
   sockaddr gate, mask, dst;
 
-  DBG("krt-sock: send %I/%d via %I", net->n.prefix, net->n.pxlen, a->gw);
+  DBG("krt-sock: send %I/%d via %I\n", net->n.prefix, net->n.pxlen, a->gw);
 
   fill_in_sockaddr(&dst, net->n.prefix, 0);
   fill_in_sockaddr(&mask, ipa_mkmask(net->n.pxlen), 0);
@@ -119,9 +95,9 @@ krt_sock_send(int cmd, rte *e)
   msg.rtm.rtm_type = cmd;
   msg.rtm.rtm_seq = msg_seq++;
   msg.rtm.rtm_addrs = RTA_DST;
-  msg.rtm.rtm_flags = RTF_UP;
+  msg.rtm.rtm_flags = RTF_UP | RTF_PROTO1;
 
-  if (net->n.pxlen == HOST_MASK)
+  if (net->n.pxlen == MAX_PREFIX_LENGTH)
   {
     msg.rtm.rtm_flags |= RTF_HOST;
   }
@@ -200,12 +176,12 @@ krt_sock_send(int cmd, rte *e)
   msg.rtm.rtm_msglen = l;
 
   if ((l = write(rt_sock, (char *)&msg, l)) < 0) {
-          log(L_ERR "KIF: error writting route to socket (%I/%d)", net->n.prefix, net->n.pxlen);
+    log(L_ERR "KIF: Error sending route %I/%d to kernel", net->n.prefix, net->n.pxlen);
   }
 }
 
 void
-krt_set_notify(struct krt_proto *p UNUSED, net *net UNUSED, rte *new, rte *old)
+krt_set_notify(struct krt_proto *p UNUSED, net *net, rte *new, rte *old)
 {
   if (old)
     {
@@ -258,68 +234,87 @@ krt_set_start(struct krt_proto *x, int first UNUSED)
     bug("krt-sock: sk_open failed");
 }
 
+#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
+
 static void
 krt_read_rt(struct ks_msg *msg, struct krt_proto *p, int scan)
 {
-  sockaddr gate, mask, dst;
   rta a;
   rte *e;
   net *net;
+  sockaddr dst, gate, mask;
   ip_addr idst, igate, imask;
   void *body = (char *)msg->buf;
   int new = (msg->rtm.rtm_type == RTM_ADD);
   int src;
+  char *errmsg = "KRT: Invalid route received";
   int flags = msg->rtm.rtm_flags;
   int addrs = msg->rtm.rtm_addrs;
-  int masklen = -1;
-
-  if (!(flags & RTF_UP))
-  {
-    DBG("Down.\n");
-    return;
-  }
 
-  if (flags & RTF_HOST)
-    masklen = HOST_MASK;
+  if (!(flags & RTF_UP) && scan)
+    SKIP("not up in scan\n");
 
-  if(!CHECK_FAMILY(body)) return;
+  if (!(flags & RTF_DONE) && !scan)
+    SKIP("not done in async\n");
 
-  if(msg->rtm.rtm_flags & RTF_LLINFO) return;	/* ARPs etc. */
+  if (flags & RTF_LLINFO)
+    SKIP("link-local\n");
 
-#define GETADDR(p, F) \
-  bzero(p, sizeof(*p));\
-  if ((addrs & (F)) && ((struct sockaddr *)body)->sa_len) {\
-    unsigned int l = ROUNDUP(((struct sockaddr *)body)->sa_len);\
-    memcpy(p, body, (l > sizeof(*p) ? sizeof(*p) : l));\
-    body += l;}
+  GETADDR(&dst, RTA_DST);
+  GETADDR(&gate, RTA_GATEWAY);
+  GETADDR(&mask, RTA_NETMASK);
 
-  GETADDR (&dst, RTA_DST);
-  GETADDR (&gate, RTA_GATEWAY);
-  GETADDR (&mask, RTA_NETMASK);
+  if (sa_family_check(&dst))
+    get_sockaddr(&dst, &idst, NULL, 0);
+  else
+    SKIP("invalid DST");
 
-  idst = IPA_NONE;
-  igate = IPA_NONE;
-  imask = IPA_NONE;
+  /* We will check later whether we have valid gateway addr */
+  if (sa_family_check(&gate))
+    get_sockaddr(&gate, &igate, NULL, 0);
+  else
+    igate = IPA_NONE;
 
-  get_sockaddr(&dst, &idst, NULL, 0);
-  if(CHECK_FAMILY(&gate)) get_sockaddr(&gate, &igate, NULL, 0);
+  /* We do not test family for RTA_NETMASK, because BSD sends us
+     some strange values, but interpreting them as IPv4/IPv6 works */
   get_sockaddr(&mask, &imask, NULL, 0);
 
-  if (masklen < 0) masklen = ipa_mklen(imask);
+  int c = ipa_classify_net(idst);
+  if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
+    SKIP("strange class/scope\n");
 
-  if (flags & (RTF_DYNAMIC | RTF_MODIFIED))
-  {
-    log(L_WARN "krt: Ignoring redirect to %I/%d via %I", idst, masklen, igate);
-    return;
-  }
+  int pxlen = (flags & RTF_HOST) ? MAX_PREFIX_LENGTH : ipa_mklen(imask);
+  if (pxlen < 0)
+    { log(L_ERR "%s (%I) - netmask %I", errmsg, idst, imask); return; }
 
-  if (masklen < 0)
-  {
-    log(L_WARN "krt: Got invalid route from kernel!");
-    return;
-  }
+  if ((flags & RTF_GATEWAY) && ipa_zero(igate))
+    { log(L_ERR "%s (%I/%d) - missing gateway", errmsg, idst, pxlen); return; }
+
+  u32 self_mask = RTF_PROTO1;
+  u32 alien_mask = RTF_STATIC | RTF_PROTO1;
+
+#ifdef RTF_PROTO2
+  alien_mask |= RTF_PROTO2;
+#endif
 
-  net = net_get(p->p.table, idst, masklen);
+#ifdef RTF_PROTO3
+  alien_mask |= RTF_PROTO3;
+#endif
+
+  if (flags & (RTF_DYNAMIC | RTF_MODIFIED))
+    src = KRT_SRC_REDIRECT;
+  else if (flags & self_mask)
+    {
+      if (!scan)
+	SKIP("echo\n");
+      src = KRT_SRC_BIRD;
+    }
+  else if (flags & alien_mask)
+    src = KRT_SRC_ALIEN;
+  else
+    src = KRT_SRC_KERNEL;
+
+  net = net_get(p->p.table, idst, pxlen);
 
   bzero(&a, sizeof(a));
 
@@ -333,56 +328,56 @@ krt_read_rt(struct ks_msg *msg, struct krt_proto *p, int scan)
   a.iface = NULL;
   a.eattrs = NULL;
 
-  a.dest = RTD_NONE;
-
-  if (flags & RTF_GATEWAY)
-  {
-    neighbor *ng = neigh_find(&p->p, &igate, 0);
-    if (ng && ng->scope)
-      a.iface = ng->iface;
-    else
-      {
-	log(L_WARN "Kernel told us to use non-neighbor %I for %I/%d", igate, net->n.prefix, net->n.pxlen);
-	return;
-      }
-
-    a.dest = RTD_ROUTER;
-    a.gw = igate;
-  }
-  else
-  {
-    a.dest = RTD_DEVICE;
-    a.gw = IPA_NONE;
-    a.iface = krt_temp_iface_index(p, msg->rtm.rtm_index);
-  }
+  /* reject/blackhole routes have also set RTF_GATEWAY,
+     we wil check them first. */
 
 #ifdef RTF_REJECT
   if(flags & RTF_REJECT) {
     a.dest = RTD_UNREACHABLE;
-    a.gw = IPA_NONE;
+    goto done;
   }
 #endif
 
 #ifdef RTF_BLACKHOLE
   if(flags & RTF_BLACKHOLE) {
     a.dest = RTD_BLACKHOLE;
-    a.gw = IPA_NONE;
+    goto done;
   }
 #endif
 
-  if (a.dest == RTD_NONE)
+  a.iface = if_find_by_index(msg->rtm.rtm_index);
+  if (!a.iface)
+    {
+      log(L_ERR "KRT: Received route %I/%d with unknown ifindex %u",
+	  net->n.prefix, net->n.pxlen, msg->rtm.rtm_index);
+      return;
+    }
+
+  if (flags & RTF_GATEWAY)
   {
-    log(L_WARN "Kernel reporting unknown route type to %I/%d", net->n.prefix, net->n.pxlen);
-    return;
-  }
+    neighbor *ng;
+    a.dest = RTD_ROUTER;
+    a.gw = igate;
 
-  src = KRT_SRC_UNKNOWN;	/* FIXME */
+    ng = neigh_find2(&p->p, &a.gw, a.iface, 0);
+    if (!ng || (ng->scope == SCOPE_HOST))
+      {
+	log(L_ERR "KRT: Received route %I/%d with strange next-hop %I",
+	    net->n.prefix, net->n.pxlen, a.gw);
+	return;
+      }
+  }
+  else
+    a.dest = RTD_DEVICE;
 
+ done:
   e = rte_get_temp(&a);
   e->net = net;
   e->u.krt.src = src;
-  //e->u.krt.proto = i->rtm_protocol;
-  //e->u.krt.type = i->rtm_type;
+
+  /* These are probably too Linux-specific */
+  e->u.krt.proto = 0;
+  e->u.krt.type = 0;
   e->u.krt.metric = 0;
 
   if (scan)
@@ -471,6 +466,10 @@ krt_read_addr(struct ks_msg *msg)
   int scope, masklen = -1;
   int new = (ifam->ifam_type == RTM_NEWADDR);
 
+  /* Strange messages with zero (invalid) ifindex appear on OpenBSD */
+  if (ifam->ifam_index == 0)
+    return;
+
   if(!(iface = if_find_by_index(ifam->ifam_index)))
   {
     log(L_ERR "KIF: Received address message for unknown interface %d", ifam->ifam_index);
@@ -486,7 +485,9 @@ krt_read_addr(struct ks_msg *msg)
   GETADDR (&null, RTA_AUTHOR);
   GETADDR (&brd, RTA_BRD);
 
-  if(!CHECK_FAMILY(&addr)) return; /* Some other family address */
+  /* Some other family address */
+  if (!sa_family_check(&addr))
+    return;
 
   get_sockaddr(&addr, &iaddr, NULL, 0);
   get_sockaddr(&mask, &imask, NULL, 0);
@@ -593,27 +594,27 @@ krt_sysctl_scan(struct proto *p, pool *pool, byte **buf, size_t *bl, int cmd)
   mib[4] = cmd;
   mib[5] = 0;
 
-  if( sysctl(mib, 6 , NULL , &needed, NULL, 0) < 0)
+  if (sysctl(mib, 6 , NULL , &needed, NULL, 0) < 0)
   {
     die("RT scan...");
   }
 
   obl = *bl;
 
-  while(needed > *bl) *bl *= 2;
-  while(needed < (*bl/2)) *bl /= 2;
+  while (needed > *bl) *bl *= 2;
+  while (needed < (*bl/2)) *bl /= 2;
 
-  if( (obl!=*bl) || !*buf)
+  if ((obl!=*bl) || !*buf)
   {
-    if(*buf) mb_free(*buf);
-    if( (*buf = mb_alloc(pool, *bl)) == NULL ) die("RT scan buf alloc");
+    if (*buf) mb_free(*buf);
+    if ((*buf = mb_alloc(pool, *bl)) == NULL) die("RT scan buf alloc");
   }
 
   on = needed;
 
-  if( sysctl(mib, 6 , *buf, &needed, NULL, 0) < 0)
+  if (sysctl(mib, 6 , *buf, &needed, NULL, 0) < 0)
   {
-    if(on != needed) return; 	/* The buffer size changed since last sysctl */
+    if (on != needed) return; 	/* The buffer size changed since last sysctl */
     die("RT scan 2");
   }
 
@@ -624,22 +625,23 @@ krt_sysctl_scan(struct proto *p, pool *pool, byte **buf, size_t *bl, int cmd)
   }
 }
 
+static byte *krt_buffer = NULL;
+static byte *kif_buffer = NULL;
+static size_t krt_buflen = 32768;
+static size_t kif_buflen = 4096;
+
 void
 krt_scan_fire(struct krt_proto *p)
 {
-  static byte *buf = NULL;
-  static size_t bl = 32768;
-  krt_sysctl_scan((struct proto *)p , p->krt_pool, &buf, &bl, NET_RT_DUMP);
+  krt_sysctl_scan((struct proto *)p, p->krt_pool, &krt_buffer, &krt_buflen, NET_RT_DUMP);
 }
 
 void
 krt_if_scan(struct kif_proto *p)
 {
-  static byte *buf = NULL;
-  static size_t bl = 4096;
   struct proto *P = (struct proto *)p;
   if_start_update();
-  krt_sysctl_scan(P, P->pool, &buf, &bl, NET_RT_IFLIST);
+  krt_sysctl_scan(P, P->pool, &kif_buffer, &kif_buflen, NET_RT_IFLIST);
   if_end_update();
 }
 
@@ -652,7 +654,9 @@ krt_set_construct(struct krt_config *c UNUSED)
 void
 krt_set_shutdown(struct krt_proto *x UNUSED, int last UNUSED)
 {
-} 
+  mb_free(krt_buffer);
+  krt_buffer = NULL;
+}
 
 void
 krt_if_io_init(void)
@@ -672,5 +676,7 @@ krt_if_start(struct kif_proto *p UNUSED)
 void
 krt_if_shutdown(struct kif_proto *p UNUSED)
 {
+  mb_free(kif_buffer);
+  kif_buffer = NULL;
 }
 
diff --git a/sysdep/cf/bsd-v6.h b/sysdep/cf/bsd-v6.h
index f3aefeb..66985ab 100644
--- a/sysdep/cf/bsd-v6.h
+++ b/sysdep/cf/bsd-v6.h
@@ -9,7 +9,7 @@
 #define IPV6
 
 #define CONFIG_AUTO_ROUTES
-#undef CONFIG_SELF_CONSCIOUS
+#define CONFIG_SELF_CONSCIOUS
 #undef CONFIG_MULTIPLE_TABLES
 
 #undef CONFIG_UNIX_IFACE
diff --git a/sysdep/cf/bsd.h b/sysdep/cf/bsd.h
index 72b2472..acd1b58 100644
--- a/sysdep/cf/bsd.h
+++ b/sysdep/cf/bsd.h
@@ -7,7 +7,7 @@
  */
 
 #define CONFIG_AUTO_ROUTES
-#undef CONFIG_SELF_CONSCIOUS
+#define CONFIG_SELF_CONSCIOUS
 #undef CONFIG_MULTIPLE_TABLES
 
 #undef CONFIG_UNIX_IFACE
diff --git a/sysdep/linux/netlink/netlink.c b/sysdep/linux/netlink/netlink.c
index f45fe15..b59b32f 100644
--- a/sysdep/linux/netlink/netlink.c
+++ b/sysdep/linux/netlink/netlink.c
@@ -52,7 +52,6 @@ struct nl_sock
 static struct nl_sock nl_scan = {.fd = -1};	/* Netlink socket for synchronous scan */
 static struct nl_sock nl_req  = {.fd = -1};	/* Netlink socket for requests */
 
-
 static void
 nl_open_sock(struct nl_sock *nl)
 {
@@ -555,23 +554,7 @@ krt_set_notify(struct krt_proto *p, net *n UNUSED, rte *new, rte *old)
     nl_send_route(p, new, 1);
 }
 
-static struct iface *
-krt_temp_iface(struct krt_proto *p, unsigned index)
-{
-  struct iface *i, *j;
-
-  WALK_LIST(i, p->scan.temp_ifs)
-    if (i->index == index)
-      return i;
-  i = mb_allocz(p->p.pool, sizeof(struct iface));
-  if (j = if_find_by_index(index))
-    strcpy(i->name, j->name);
-  else
-    strcpy(i->name, "?");
-  i->index = index;
-  add_tail(&p->scan.temp_ifs, &i->n);
-  return i;
-}
+#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
 
 static void
 nl_parse_route(struct nlmsghdr *h, int scan)
@@ -599,31 +582,7 @@ nl_parse_route(struct nlmsghdr *h, int scan)
 #endif
       (a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)))
     {
-      log(L_ERR "nl_parse_route: Malformed message received");
-      return;
-    }
-
-  p = nl_table_map[i->rtm_table];	/* Do we know this table? */
-  if (!p)
-    return;
-
-#ifdef IPV6
-  if (a[RTA_IIF])
-    {
-      DBG("KRT: Ignoring route with IIF set\n");
-      return;
-    }
-#else
-  if (i->rtm_tos != 0)			/* We don't support TOS */
-    {
-      DBG("KRT: Ignoring route with TOS %02x\n", i->rtm_tos);
-      return;
-    }
-#endif
-
-  if (scan && !new)
-    {
-      DBG("KRT: Ignoring route deletion\n");
+      log(L_ERR "KRT: Malformed message received");
       return;
     }
 
@@ -634,33 +593,57 @@ nl_parse_route(struct nlmsghdr *h, int scan)
     }
   else
     dst = IPA_NONE;
+
   if (a[RTA_OIF])
     memcpy(&oif, RTA_DATA(a[RTA_OIF]), sizeof(oif));
   else
     oif = ~0;
 
-  DBG("Got %I/%d, type=%d, oif=%d, table=%d, prid=%d, proto=%s\n", dst, i->rtm_dst_len, i->rtm_type, oif, i->rtm_table, i->rtm_protocol, p->p.name);
+  DBG("KRT: Got %I/%d, type=%d, oif=%d, table=%d, prid=%d, proto=%s\n", dst, i->rtm_dst_len, i->rtm_type, oif, i->rtm_table, i->rtm_protocol, p->p.name);
+
+  p = nl_table_map[i->rtm_table];	/* Do we know this table? */
+  if (!p)
+    SKIP("unknown table %d", i->rtm_table);
+
+#ifdef IPV6
+  if (a[RTA_IIF])
+    SKIP("IIF set\n");
+#else
+  if (i->rtm_tos != 0)			/* We don't support TOS */
+    SKIP("TOS %02x\n", i->rtm_tos);
+#endif
+
+  if (scan && !new)
+    SKIP("RTM_DELROUTE in scan\n");
+
+  int c = ipa_classify_net(dst);
+  if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
+    SKIP("strange class/scope\n");
+
+  // ignore rtm_scope, it is not a real scope
+  // if (i->rtm_scope != RT_SCOPE_UNIVERSE)
+  //   SKIP("scope %u\n", i->rtm_scope);
 
   switch (i->rtm_protocol)
     {
+    case RTPROT_UNSPEC:
+      SKIP("proto unspec\n");
+
     case RTPROT_REDIRECT:
       src = KRT_SRC_REDIRECT;
       break;
+
     case RTPROT_KERNEL:
-      DBG("Route originated in kernel, ignoring\n");
+      src = KRT_SRC_KERNEL;
       return;
+
     case RTPROT_BIRD:
-#ifdef IPV6
-    case RTPROT_BOOT:
-      /* Current Linux kernels don't remember rtm_protocol for IPv6 routes and supply RTPROT_BOOT instead */
-#endif
       if (!scan)
-	{
-	  DBG("Echo of our own route, ignoring\n");
-	  return;
-	}
+	SKIP("echo\n");
       src = KRT_SRC_BIRD;
       break;
+
+    case RTPROT_BOOT:
     default:
       src = KRT_SRC_ALIEN;
     }
@@ -679,52 +662,48 @@ nl_parse_route(struct nlmsghdr *h, int scan)
   switch (i->rtm_type)
     {
     case RTN_UNICAST:
-      if (oif == ~0U)
+      ra.iface = if_find_by_index(oif);
+      if (!ra.iface)
 	{
-	  log(L_ERR "KRT: Mysterious route with no OIF (%I/%d)", net->n.prefix, net->n.pxlen);
+	  log(L_ERR "KRT: Received route %I/%d with unknown ifindex %u",
+	      net->n.prefix, net->n.pxlen, oif);
 	  return;
 	}
+
       if (a[RTA_GATEWAY])
 	{
-	  struct iface *ifa = if_find_by_index(oif);
 	  neighbor *ng;
 	  ra.dest = RTD_ROUTER;
 	  memcpy(&ra.gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ra.gw));
 	  ipa_ntoh(ra.gw);
 
-	  if (i->rtm_flags & RTNH_F_ONLINK)
-	    {
-	      /* route with 'onlink' attribute */
-	      ra.iface = if_find_by_index(oif);
-	      if (ra.iface == NULL)
-		{
-		  log(L_WARN "Kernel told us to use unknown interface %u for %I/%d",
-		      oif, net->n.prefix, net->n.pxlen);
-		  return;
-		}
-	    }
-	  else
+	  ng = neigh_find2(&p->p, &ra.gw, ra.iface,
+			   (i->rtm_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0);
+	  if (!ng || (ng->scope == SCOPE_HOST))
 	    {
-	      ng = neigh_find2(&p->p, &ra.gw, ifa, 0);
-	      if (ng && ng->scope)
-		{
-		  if (ng->iface != ifa)
-		    log(L_WARN "KRT: Route with unexpected iface for %I/%d", net->n.prefix, net->n.pxlen);
-		  ra.iface = ng->iface;
-		}
-	      else
-		{
-		  log(L_WARN "Kernel told us to use non-neighbor %I for %I/%d", ra.gw, net->n.prefix, net->n.pxlen);
-		  return;
-		}
-
+	      log(L_ERR "KRT: Received route %I/%d with strange next-hop %I",
+		  net->n.prefix, net->n.pxlen, ra.gw);
+	      return;
 	    }
 	}
       else
 	{
 	  ra.dest = RTD_DEVICE;
-	  ra.iface = krt_temp_iface(p, oif);
+
+	  /*
+	   * In Linux IPv6, 'native' device routes have proto
+	   * RTPROT_BOOT and not RTPROT_KERNEL (which they have in
+	   * IPv4 and which is expected). We cannot distinguish
+	   * 'native' and user defined device routes, so we ignore all
+	   * such device routes and for consistency, we have the same
+	   * behavior in IPv4. Anyway, users should use RTPROT_STATIC
+	   * for their 'alien' routes.
+	   */
+
+	  if (i->rtm_protocol == RTPROT_BOOT)
+	    src = KRT_SRC_KERNEL;
 	}
+
       break;
     case RTN_BLACKHOLE:
       ra.dest = RTD_BLACKHOLE;
@@ -737,13 +716,7 @@ nl_parse_route(struct nlmsghdr *h, int scan)
       break;
     /* FIXME: What about RTN_THROW? */
     default:
-      DBG("KRT: Ignoring route with type=%d\n", i->rtm_type);
-      return;
-    }
-
-  if (i->rtm_scope != RT_SCOPE_UNIVERSE)
-    {
-      DBG("KRT: Ignoring route with scope=%d\n", i->rtm_scope);
+      SKIP("type %d\n", i->rtm_type);
       return;
     }
 
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 915baf4..02d59ab 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -663,7 +663,6 @@ get_sockaddr(struct sockaddr_in *sa, ip_addr *a, unsigned *port, int check)
 static char *
 sk_set_ttl_int(sock *s)
 {
-  int one = 1;
 #ifdef IPV6
   if (setsockopt(s->fd, SOL_IPV6, IPV6_UNICAST_HOPS, &s->ttl, sizeof(s->ttl)) < 0)
     return "IPV6_UNICAST_HOPS";
@@ -671,6 +670,7 @@ sk_set_ttl_int(sock *s)
   if (setsockopt(s->fd, SOL_IP, IP_TTL, &s->ttl, sizeof(s->ttl)) < 0)
     return "IP_TTL";
 #ifdef CONFIG_UNIX_DONTROUTE
+  int one = 1;
   if (s->ttl == 1 && setsockopt(s->fd, SOL_SOCKET, SO_DONTROUTE, &one, sizeof(one)) < 0)
     return "SO_DONTROUTE";
 #endif 
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index 6d94cad..47b9621 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -558,32 +558,30 @@ krt_got_route(struct krt_proto *p, rte *e)
   rte *old;
   net *net = e->net;
   int verdict;
-#ifdef KRT_ALLOW_LEARN
-  int src = e->u.krt.src;
-#endif
 
-#ifdef CONFIG_AUTO_ROUTES
-  if (e->attrs->dest == RTD_DEVICE)
+#ifdef KRT_ALLOW_LEARN
+  switch (e->u.krt.src)
     {
-      /* It's a device route. Probably a kernel-generated one. */
+    case KRT_SRC_KERNEL:
       verdict = KRF_IGNORE;
       goto sentenced;
-    }
-#endif
 
-#ifdef KRT_ALLOW_LEARN
-  if (src == KRT_SRC_ALIEN)
-    {
+    case KRT_SRC_REDIRECT:
+      verdict = KRF_DELETE;
+      goto sentenced;
+
+    case  KRT_SRC_ALIEN:
       if (KRT_CF->learn)
 	krt_learn_scan(p, e);
       else
 	{
-	  krt_trace_in_rl(&rl_alien_ignored, p, e, "alien route, ignored");
+	  krt_trace_in_rl(&rl_alien_ignored, p, e, "[alien] ignored");
 	  rte_free(e);
 	}
       return;
     }
 #endif
+  /* The rest is for KRT_SRC_BIRD (or KRT_SRC_UNKNOWN) */
 
   if (net->n.flags & KRF_VERDICT_MASK)
     {
@@ -605,7 +603,7 @@ krt_got_route(struct krt_proto *p, rte *e)
   else
     verdict = KRF_DELETE;
 
-sentenced:
+ sentenced:
   krt_trace_in(p, e, ((char *[]) { "?", "seen", "will be updated", "will be removed", "ignored" }) [verdict]);
   net->n.flags = (net->n.flags & ~KRF_VERDICT_MASK) | verdict;
   if (verdict == KRF_UPDATE || verdict == KRF_DELETE)
@@ -680,19 +678,24 @@ krt_prune(struct krt_proto *p)
 }
 
 void
-krt_got_route_async(struct krt_proto *p, rte *e, int new UNUSED)
+krt_got_route_async(struct krt_proto *p, rte *e, int new)
 {
   net *net = e->net;
-  int src = e->u.krt.src;
 
-  switch (src)
+  switch (e->u.krt.src)
     {
     case KRT_SRC_BIRD:
       ASSERT(0);			/* Should be filtered by the back end */
+
     case KRT_SRC_REDIRECT:
-      DBG("It's a redirect, kill him! Kill! Kill!\n");
-      krt_set_notify(p, net, NULL, e);
+      if (new)
+	{
+	  krt_trace_in(p, e, "[redirect] deleting");
+	  krt_set_notify(p, net, NULL, e);
+	}
+      /* If !new, it is probably echo of our deletion */
       break;
+
 #ifdef KRT_ALLOW_LEARN
     case KRT_SRC_ALIEN:
       if (KRT_CF->learn)
@@ -878,7 +881,6 @@ krt_init(struct proto_config *c)
 
   p->p.accept_ra_types = RA_OPTIMAL;
   p->p.rt_notify = krt_notify;
-  p->p.min_scope = SCOPE_HOST;
   return &p->p;
 }
 
diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index 607e699..1d9e144 100644
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -83,6 +83,7 @@ void krt_got_route_async(struct krt_proto *p, struct rte *e, int new);
 #define KRT_SRC_BIRD	 0	/* Our route (not passed in async mode) */
 #define KRT_SRC_REDIRECT 1	/* Redirect route, delete it */
 #define KRT_SRC_ALIEN	 2	/* Route installed by someone else */
+#define KRT_SRC_KERNEL	 3	/* Kernel routes, are ignored by krt syncer */
 
 extern struct protocol proto_unix_iface;
 
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index 1a461ee..0b179e0 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -9,6 +9,8 @@
 #ifndef _BIRD_UNIX_H_
 #define _BIRD_UNIX_H_
 
+#include <sys/socket.h>
+
 struct pool;
 
 /* main.c */
@@ -29,10 +31,12 @@ volatile int async_shutdown_flag;
 #define BIRD_PF PF_INET6
 #define BIRD_AF AF_INET6
 typedef struct sockaddr_in6 sockaddr;
+static inline int sa_family_check(sockaddr *sa) { return sa->sin6_family == AF_INET6; }
 #else
 #define BIRD_PF PF_INET
 #define BIRD_AF AF_INET
 typedef struct sockaddr_in sockaddr;
+static inline int sa_family_check(sockaddr *sa) { return sa->sin_family == AF_INET; }
 #endif
 
 #ifndef SUN_LEN