Netlink: Improve multipath parsing errors

Function nl_parse_multipath() should handle errors internally.

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index fdf3f2db1d2c269a9283b461dea86a3041247695..1293df4d536f1d4487c848ea4173b064f63b7913 100644 (file)
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -681,7 +681,7 @@ nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af, e
 }
 
 static struct nexthop *
-nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr *ra, int af)
+nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr *n, struct rtattr *ra, int af)
 {
   struct rtattr *a[BIRD_RTA_MAX];
   struct rtnexthop *nh = RTA_DATA(ra);
@@ -695,7 +695,7 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
     {
       /* Use RTNH_OK(nh,len) ?? */
       if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
-       return NULL;
+       goto err;
 
       if (nh->rtnh_flags & RTNH_F_DEAD)
        goto next;
@@ -706,7 +706,10 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
       rv->weight = nh->rtnh_hops;
       rv->iface = if_find_by_index(nh->rtnh_ifindex);
       if (!rv->iface)
-       return NULL;
+       {
+         log(L_ERR "KRT: Received route %N with unknown ifindex %u", n, nh->rtnh_ifindex);
+         return NULL;
+       }
 
       /* Nonexistent RTNH_PAYLOAD ?? */
       nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0);
@@ -714,18 +717,18 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
         {
        case AF_INET:
          if (!nl_parse_attrs(RTNH_DATA(nh), nexthop_attr_want4, a, sizeof(a)))
-           return NULL;
+           goto err;
          break;
 
        case AF_INET6:
          if (!nl_parse_attrs(RTNH_DATA(nh), nexthop_attr_want6, a, sizeof(a)))
-           return NULL;
+           goto err;
          break;
 
 #ifdef HAVE_MPLS_KERNEL
        case AF_MPLS:
          if (!nl_parse_attrs(RTNH_DATA(nh), nexthop_attr_want_mpls, a, sizeof(a)))
-           return NULL;
+           goto err;
 
          if (a[RTA_NEWDST])
            rv->labels = rta_get_mpls(a[RTA_NEWDST], rv->label);
@@ -734,7 +737,7 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
 #endif
 
        default:
-         return NULL;
+         goto err;
        }
 
       if (a[RTA_GATEWAY])
@@ -757,14 +760,19 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
          nbr = neigh_find(&p->p, rv->gw, rv->iface,
                           (rv->flags & RNF_ONLINK) ? NEF_ONLINK : 0);
          if (!nbr || (nbr->scope == SCOPE_HOST))
-           return NULL;
+           {
+               log(L_ERR "KRT: Received route %N with strange next-hop %I", n, rv->gw);
+               return NULL;
+           }
        }
 
 #ifdef HAVE_MPLS_KERNEL
       if (a[RTA_ENCAP] && a[RTA_ENCAP_TYPE])
       {
-       if (rta_get_u16(a[RTA_ENCAP_TYPE]) != LWTUNNEL_ENCAP_MPLS) {
-         log(L_WARN "KRT: Unknown encapsulation method %d in multipath", rta_get_u16(a[RTA_ENCAP_TYPE]));
+       if (rta_get_u16(a[RTA_ENCAP_TYPE]) != LWTUNNEL_ENCAP_MPLS)
+       {
+         log(L_WARN "KRT: Received route %N with unknown encapsulation method %d",
+             n, rta_get_u16(a[RTA_ENCAP_TYPE]));
          return NULL;
        }
 
@@ -785,6 +793,10 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
     first = nexthop_sort(first);
 
   return first;
+
+err:
+  log(L_ERR "KRT: Received strange multipath route %N", n);
+  return NULL;
 }
 
 static void
@@ -1675,19 +1687,16 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 
       if (a[RTA_MULTIPATH])
         {
-         struct nexthop *nh = nl_parse_multipath(s, p, a[RTA_MULTIPATH], i->rtm_family);
+         struct nexthop *nh = nl_parse_multipath(s, p, n, a[RTA_MULTIPATH], i->rtm_family);
          if (!nh)
-           {
-             log(L_ERR "KRT: Received strange multipath route %N", net->n.addr);
-             return;
-           }
+           SKIP("strange RTA_MULTIPATH\n");
 
          nexthop_link(ra, nh);
          break;
        }
 
       if (i->rtm_flags & RTNH_F_DEAD)
-       return;
+       SKIP("ignore RTNH_F_DEAD\n");
 
       ra->nh.iface = if_find_by_index(oif);
       if (!ra->nh.iface)