ovn-util: Add solicited node addresses to ipv6_netaddr.

Every IPv6 host has a link-local solicited node multicast address for
neighbor discovery.  This commit defines the solicited node address for
each IPv6 address added to a logical switch or router port.

Signed-off-by: Justin Pettit <jpettit@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>

ovn/lib/ovn-util.c

@@ -53,9 +53,12 @@ add_ipv6_netaddr(struct lport_addresses *laddrs, struct in6_addr addr,
     na->mask = ipv6_create_mask(plen);
     na->network = ipv6_addr_bitand(&addr, &na->mask);
     na->plen = plen;
+    in6_addr_solicited_node(&na->sn_addr, &addr);
 
     na->addr_s = xmalloc(INET6_ADDRSTRLEN);
     inet_ntop(AF_INET6, &addr, na->addr_s, INET6_ADDRSTRLEN);
+    na->sn_addr_s = xmalloc(INET6_ADDRSTRLEN);
+    inet_ntop(AF_INET6, &na->sn_addr, na->sn_addr_s, INET6_ADDRSTRLEN);
     na->network_s = xmalloc(INET6_ADDRSTRLEN);
     inet_ntop(AF_INET6, &na->network, na->network_s, INET6_ADDRSTRLEN);
 }
@@ -189,6 +192,7 @@ destroy_lport_addresses(struct lport_addresses *laddrs)
 
     for (int i = 0; i < laddrs->n_ipv6_addrs; i++) {
         free(laddrs->ipv6_addrs[i].addr_s);
+        free(laddrs->ipv6_addrs[i].sn_addr_s);
         free(laddrs->ipv6_addrs[i].network_s);
     }
     free(laddrs->ipv6_addrs);

ovn/lib/ovn-util.h

@@ -34,10 +34,12 @@ struct ipv4_netaddr {
 struct ipv6_netaddr {
     struct in6_addr addr;     /* fc00::1 */
     struct in6_addr mask;     /* ffff:ffff:ffff:ffff:: */
+    struct in6_addr sn_addr;  /* ff02:1:ff00::1 */
     struct in6_addr network;  /* fc00:: */
     unsigned int plen;        /* CIDR Prefix: 64 */
 
     char *addr_s;             /* "fc00::1" */
+    char *sn_addr_s;          /* "ff02:1:ff00::1" */
     char *network_s;          /* "fc00::" */
 };