--- embedaddon/bird/sysdep/linux/netlink.c	2017/08/22 12:33:54	1.1.1.1
+++ embedaddon/bird/sysdep/linux/netlink.c	2021/03/17 19:50:23	1.1.1.2
@@ -59,22 +59,26 @@
 /*
  * Structure nl_parse_state keeps state of received route processing. Ideally,
  * we could just independently parse received Netlink messages and immediately
- * propagate received routes to the rest of BIRD, but Linux kernel represents
- * and announces IPv6 ECMP routes not as one route with multiple next hops (like
- * RTA_MULTIPATH in IPv4 ECMP), but as a set of routes with the same prefix.
+ * propagate received routes to the rest of BIRD, but older Linux kernel (before
+ * version 4.11) represents and announces IPv6 ECMP routes not as one route with
+ * multiple next hops (like RTA_MULTIPATH in IPv4 ECMP), but as a sequence of
+ * routes with the same prefix. More recent kernels work as with IPv4.
  *
  * Therefore, BIRD keeps currently processed route in nl_parse_state structure
  * and postpones its propagation until we expect it to be final; i.e., when
  * non-matching route is received or when the scan ends. When another matching
  * route is received, it is merged with the already processed route to form an
  * ECMP route. Note that merging is done only for IPv6 (merge == 1), but the
- * postponing is done in both cases (for simplicity). All IPv4 routes are just
- * considered non-matching.
+ * postponing is done in both cases (for simplicity). All IPv4 routes or IPv6
+ * routes with RTA_MULTIPATH set are just considered non-matching.
  *
  * This is ignored for asynchronous notifications (every notification is handled
  * as a separate route). It is not an issue for our routes, as we ignore such
  * notifications anyways. But importing alien IPv6 ECMP routes does not work
- * properly.
+ * properly with older kernels.
+ *
+ * Whatever the kernel version is, IPv6 ECMP routes are sent as multiple routes
+ * for the same prefix.
  */
 
 struct nl_parse_state
@@ -296,6 +300,7 @@ struct nl_want_attrs {
 static struct nl_want_attrs ifla_attr_want[BIRD_IFLA_MAX] = {
   [IFLA_IFNAME]	  = { 1, 0, 0 },
   [IFLA_MTU]	  = { 1, 1, sizeof(u32) },
+  [IFLA_MASTER]	  = { 1, 1, sizeof(u32) },
   [IFLA_WIRELESS] = { 1, 0, 0 },
 };
 
@@ -320,9 +325,15 @@ static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MA
 
 #define BIRD_RTA_MAX  (RTA_TABLE+1)
 
+#ifndef IPV6
 static struct nl_want_attrs mpnh_attr_want4[BIRD_RTA_MAX] = {
   [RTA_GATEWAY]	  = { 1, 1, sizeof(ip4_addr) },
 };
+#else
+static struct nl_want_attrs mpnh_attr_want6[BIRD_RTA_MAX] = {
+  [RTA_GATEWAY]	  = { 1, 1, sizeof(ip6_addr) },
+};
+#endif
 
 #ifndef IPV6
 static struct nl_want_attrs rtm_attr_want4[BIRD_RTA_MAX] = {
@@ -345,6 +356,7 @@ static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MA
   [RTA_PRIORITY]  = { 1, 1, sizeof(u32) },
   [RTA_PREFSRC]	  = { 1, 1, sizeof(ip6_addr) },
   [RTA_METRICS]	  = { 1, 0, 0 },
+  [RTA_MULTIPATH] = { 1, 0, 0 },
   [RTA_FLOW]	  = { 1, 1, sizeof(u32) },
   [RTA_TABLE]	  = { 1, 1, sizeof(u32) },
 };
@@ -477,7 +489,7 @@ nl_add_multipath(struct nlmsghdr *h, unsigned bufsize,
 }
 
 static struct mpnh *
-nl_parse_multipath(struct krt_proto *p, struct rtattr *ra)
+nl_parse_multipath(struct krt_proto *p, struct rtattr *ra, int af)
 {
   /* Temporary buffer for multicast nexthops */
   static struct mpnh *nh_buffer;
@@ -515,10 +527,26 @@ nl_parse_multipath(struct krt_proto *p, struct rtattr 
 
       /* Nonexistent RTNH_PAYLOAD ?? */
       nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0);
-      nl_parse_attrs(RTNH_DATA(nh), mpnh_attr_want4, a, sizeof(a));
+      switch (af)
+        {
+#ifndef IPV6
+	case AF_INET:
+	  if (!nl_parse_attrs(RTNH_DATA(nh), mpnh_attr_want4, a, sizeof(a)))
+	    return NULL;
+	  break;
+#else
+	case AF_INET6:
+	  if (!nl_parse_attrs(RTNH_DATA(nh), mpnh_attr_want6, a, sizeof(a)))
+	    return NULL;
+	  break;
+#endif
+	default:
+	  return NULL;
+	}
+
       if (a[RTA_GATEWAY])
 	{
-	  memcpy(&rv->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ip_addr));
+	  memcpy(&rv->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(rv->gw));
 	  ipa_ntoh(rv->gw);
 
 	  neighbor *ng = neigh_find2(&p->p, &rv->gw, rv->iface,
@@ -591,7 +619,7 @@ nl_parse_link(struct nlmsghdr *h, int scan)
   struct iface f = {};
   struct iface *ifi;
   char *name;
-  u32 mtu;
+  u32 mtu, master = 0;
   uint fl;
 
   if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFLA_RTA(i), ifla_attr_want, a, sizeof(a)))
@@ -614,6 +642,9 @@ nl_parse_link(struct nlmsghdr *h, int scan)
   name = RTA_DATA(a[IFLA_IFNAME]);
   mtu = rta_get_u32(a[IFLA_MTU]);
 
+  if (a[IFLA_MASTER])
+    master = rta_get_u32(a[IFLA_MASTER]);
+
   ifi = if_find_by_index(i->ifi_index);
   if (!new)
     {
@@ -633,6 +664,9 @@ nl_parse_link(struct nlmsghdr *h, int scan)
       f.index = i->ifi_index;
       f.mtu = mtu;
 
+      f.master_index = master;
+      f.master = if_find_by_index(master);
+
       fl = i->ifi_flags;
       if (fl & IFF_UP)
 	f.flags |= IF_ADMIN_UP;
@@ -808,6 +842,26 @@ kif_do_scan(struct kif_proto *p UNUSED)
     else
       log(L_DEBUG "nl_scan_ifaces: Unknown packet received (type=%d)", h->nlmsg_type);
 
+  /* Re-resolve master interface for slaves */
+  struct iface *i;
+  WALK_LIST(i, iface_list)
+    if (i->master_index)
+    {
+      struct iface f = {
+	.flags = i->flags,
+	.mtu = i->mtu,
+	.index = i->index,
+	.master_index = i->master_index,
+	.master = if_find_by_index(i->master_index)
+      };
+
+      if (f.master != i->master)
+      {
+	memcpy(f.name, i->name, sizeof(f.name));
+	if_update(&f);
+      }
+    }
+
   nl_request_dump(BIRD_AF, RTM_GETADDR);
   while (h = nl_get_scan())
     if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR)
@@ -885,22 +939,25 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_l
   struct {
     struct nlmsghdr h;
     struct rtmsg r;
-    char buf[128 + KRT_METRICS_MAX*8 + nh_bufsize(a->nexthops)];
-  } r;
+    char buf[0];
+  } *r;
 
+  uint rsize = sizeof(*r) + 128 + KRT_METRICS_MAX*8 + nh_bufsize(a->nexthops);
+  r = alloca(rsize);
+
   DBG("nl_send_route(%I/%d,op=%x)\n", net->n.prefix, net->n.pxlen, op);
 
-  bzero(&r.h, sizeof(r.h));
-  bzero(&r.r, sizeof(r.r));
-  r.h.nlmsg_type = op ? RTM_NEWROUTE : RTM_DELROUTE;
-  r.h.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
-  r.h.nlmsg_flags = op | NLM_F_REQUEST | NLM_F_ACK;
+  bzero(&r->h, sizeof(r->h));
+  bzero(&r->r, sizeof(r->r));
+  r->h.nlmsg_type = op ? RTM_NEWROUTE : RTM_DELROUTE;
+  r->h.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+  r->h.nlmsg_flags = op | NLM_F_REQUEST | NLM_F_ACK;
 
-  r.r.rtm_family = BIRD_AF;
-  r.r.rtm_dst_len = net->n.pxlen;
-  r.r.rtm_protocol = RTPROT_BIRD;
-  r.r.rtm_scope = RT_SCOPE_NOWHERE;
-  nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net->n.prefix);
+  r->r.rtm_family = BIRD_AF;
+  r->r.rtm_dst_len = net->n.pxlen;
+  r->r.rtm_protocol = RTPROT_BIRD;
+  r->r.rtm_scope = RT_SCOPE_NOWHERE;
+  nl_add_attr_ipa(&r->h, rsize, RTA_DST, net->n.prefix);
 
   /*
    * Strange behavior for RTM_DELROUTE:
@@ -910,9 +967,9 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_l
    */
 
   if (krt_table_id(p) < 256)
-    r.r.rtm_table = krt_table_id(p);
+    r->r.rtm_table = krt_table_id(p);
   else
-    nl_add_attr_u32(&r.h, sizeof(r), RTA_TABLE, krt_table_id(p));
+    nl_add_attr_u32(&r->h, rsize, RTA_TABLE, krt_table_id(p));
 
   if (a->source == RTS_DUMMY)
     priority = e->u.krt.metric;
@@ -922,7 +979,7 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_l
     priority = ea->u.data;
 
   if (priority)
-    nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, priority);
+    nl_add_attr_u32(&r->h, rsize, RTA_PRIORITY, priority);
 
   /* For route delete, we do not specify remaining route attributes */
   if (op == NL_OP_DELETE)
@@ -930,15 +987,15 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_l
 
   /* Default scope is LINK for device routes, UNIVERSE otherwise */
   if (ea = ea_find(eattrs, EA_KRT_SCOPE))
-    r.r.rtm_scope = ea->u.data;
+    r->r.rtm_scope = ea->u.data;
   else
-    r.r.rtm_scope = (dest == RTD_DEVICE) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
+    r->r.rtm_scope = (dest == RTD_DEVICE) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
 
   if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
-    nl_add_attr_ipa(&r.h, sizeof(r), RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
+    nl_add_attr_ipa(&r->h, rsize, RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
 
   if (ea = ea_find(eattrs, EA_KRT_REALM))
-    nl_add_attr_u32(&r.h, sizeof(r), RTA_FLOW, ea->u.data);
+    nl_add_attr_u32(&r->h, rsize, RTA_FLOW, ea->u.data);
 
 
   u32 metrics[KRT_METRICS_MAX];
@@ -953,7 +1010,7 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_l
   }
 
   if (metrics[0])
-    nl_add_metrics(&r.h, sizeof(r), metrics, KRT_METRICS_MAX);
+    nl_add_metrics(&r->h, rsize, metrics, KRT_METRICS_MAX);
 
 
 dest:
@@ -961,26 +1018,26 @@ dest:
   switch (dest)
     {
     case RTD_ROUTER:
-      r.r.rtm_type = RTN_UNICAST;
-      nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, iface->index);
-      nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, gw);
+      r->r.rtm_type = RTN_UNICAST;
+      nl_add_attr_u32(&r->h, rsize, RTA_OIF, iface->index);
+      nl_add_attr_ipa(&r->h, rsize, RTA_GATEWAY, gw);
       break;
     case RTD_DEVICE:
-      r.r.rtm_type = RTN_UNICAST;
-      nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, iface->index);
+      r->r.rtm_type = RTN_UNICAST;
+      nl_add_attr_u32(&r->h, rsize, RTA_OIF, iface->index);
       break;
     case RTD_BLACKHOLE:
-      r.r.rtm_type = RTN_BLACKHOLE;
+      r->r.rtm_type = RTN_BLACKHOLE;
       break;
     case RTD_UNREACHABLE:
-      r.r.rtm_type = RTN_UNREACHABLE;
+      r->r.rtm_type = RTN_UNREACHABLE;
       break;
     case RTD_PROHIBIT:
-      r.r.rtm_type = RTN_PROHIBIT;
+      r->r.rtm_type = RTN_PROHIBIT;
       break;
     case RTD_MULTIPATH:
-      r.r.rtm_type = RTN_UNICAST;
-      nl_add_multipath(&r.h, sizeof(r), a->nexthops);
+      r->r.rtm_type = RTN_UNICAST;
+      nl_add_multipath(&r->h, rsize, a->nexthops);
       break;
     case RTD_NONE:
       break;
@@ -989,7 +1046,7 @@ dest:
     }
 
   /* Ignore missing for DELETE */
-  return nl_exchange(&r.h, (op == NL_OP_DELETE));
+  return nl_exchange(&r->h, (op == NL_OP_DELETE));
 }
 
 static inline int
@@ -1240,10 +1297,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsgh
     {
     case RTN_UNICAST:
 
-      if (a[RTA_MULTIPATH] && (i->rtm_family == AF_INET))
+      if (a[RTA_MULTIPATH])
 	{
 	  ra->dest = RTD_MULTIPATH;
-	  ra->nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]);
+	  ra->nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH], i->rtm_family);
 	  if (!ra->nexthops)
 	    {
 	      log(L_ERR "KRT: Received strange multipath route %I/%d",
@@ -1385,8 +1442,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsgh
 
   /*
    * Ideally, now we would send the received route to the rest of kernel code.
-   * But IPv6 ECMP routes are sent as a sequence of routes, so we postpone it
-   * and merge next hops until the end of the sequence.
+   * But IPv6 ECMP routes before 4.11 are sent as a sequence of routes, so we
+   * postpone it and merge next hops until the end of the sequence. Note that
+   * proper multipath updates are rejected by nl_mergable_route(), so it is
+   * always the first case for them.
    */
 
   if (!s->net)
@@ -1694,4 +1753,4 @@ kif_sys_start(struct kif_proto *p UNUSED)
 void
 kif_sys_shutdown(struct kif_proto *p UNUSED)
 {
-}
+}
\ No newline at end of file