From e2d2b3ef21f082a034e79d0880d4b36428029a59 Mon Sep 17 00:00:00 2001
From: Michal 'vorner' Vaner <michal.vaner@nic.cz>
Date: Fri, 11 Aug 2017 12:25:36 +0200
Subject: RAdv: Buffer prefixes awhile after they disappear

Keep a cache of all the relevant prefixes we send out. When a prefix
appears, insert it into the cache. If it dies, keep it there for a
while, marked as dead.

Send out the dead prefixes with zero lifetime.
---
 proto/radv/packets.c | 53 +++++++++-------------------------------------------
 1 file changed, 9 insertions(+), 44 deletions(-)

(limited to 'proto/radv/packets.c')

diff --git a/proto/radv/packets.c b/proto/radv/packets.c
index bf051f62..088d177c 100644
--- a/proto/radv/packets.c
+++ b/proto/radv/packets.c
@@ -70,36 +70,6 @@ struct radv_opt_dnssl
   char domain[];
 };
 
-
-static struct radv_prefix_config default_prefix = {
-  .onlink = 1,
-  .autonomous = 1,
-  .valid_lifetime = DEFAULT_VALID_LIFETIME,
-  .preferred_lifetime = DEFAULT_PREFERRED_LIFETIME
-};
-
-
-static struct radv_prefix_config *
-radv_prefix_match(struct radv_iface *ifa, struct ifa *a)
-{
-  struct radv_proto *p = ifa->ra;
-  struct radv_config *cf = (struct radv_config *) (p->p.cf);
-  struct radv_prefix_config *pc;
-
-  if (a->scope <= SCOPE_LINK)
-    return NULL;
-
-  WALK_LIST(pc, ifa->cf->pref_list)
-    if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
-      return pc;
-
-  WALK_LIST(pc, cf->pref_list)
-    if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
-      return pc;
-
-  return &default_prefix;
-}
-
 static int
 radv_prepare_rdnss(struct radv_iface *ifa, list *rdnss_list, char **buf, char *bufend)
 {
@@ -236,9 +206,10 @@ radv_prepare_dnssl(struct radv_iface *ifa, list *dnssl_list, char **buf, char *b
 }
 
 static int
-radv_prepare_prefix(struct radv_iface *ifa, struct radv_prefix_config *pc,
-  struct ifa *addr, char **buf, char *bufend)
+radv_prepare_prefix(struct radv_iface *ifa, struct radv_prefix *prefix,
+		    char **buf, char *bufend)
 {
+  struct radv_prefix_config *pc = prefix->config;
   struct radv_opt_prefix *op = (void *) *buf;
 
   if (*buf + sizeof(*op) > bufend)
@@ -250,7 +221,7 @@ radv_prepare_prefix(struct radv_iface *ifa, struct radv_prefix_config *pc,
 
   op->type = OPT_PREFIX;
   op->length = 4;
-  op->pxlen = addr->pxlen;
+  op->pxlen = prefix->len;
   op->flags = (pc->onlink ? OPT_PX_ONLINK : 0) |
     (pc->autonomous ? OPT_PX_AUTONOMOUS : 0);
   op->valid_lifetime = (ifa->ra->active || !pc->valid_lifetime_sensitive) ?
@@ -258,7 +229,7 @@ radv_prepare_prefix(struct radv_iface *ifa, struct radv_prefix_config *pc,
   op->preferred_lifetime = (ifa->ra->active || !pc->preferred_lifetime_sensitive) ?
     htonl(pc->preferred_lifetime) : 0;
   op->reserved = 0;
-  op->prefix = addr->prefix;
+  op->prefix = prefix->prefix;
   ipa_hton(op->prefix);
   *buf += sizeof(*op);
 
@@ -300,16 +271,10 @@ radv_prepare_ra(struct radv_iface *ifa)
     buf += sizeof (*om);
   }
 
-  struct ifa *addr;
-  WALK_LIST(addr, ifa->iface->addrs)
+  struct radv_prefix *prefix;
+  WALK_LIST(prefix, ifa->prefixes)
   {
-    struct radv_prefix_config *pc;
-    pc = radv_prefix_match(ifa, addr);
-
-    if (!pc || pc->skip)
-      continue;
-
-    if (radv_prepare_prefix(ifa, pc, addr, &buf, bufend) < 0)
+    if (radv_prepare_prefix(ifa, prefix, &buf, bufend) < 0)
       goto done;
   }
 
@@ -419,7 +384,7 @@ radv_err_hook(sock *sk, int err)
 int
 radv_sk_open(struct radv_iface *ifa)
 {
-  sock *sk = sk_new(ifa->ra->p.pool);
+  sock *sk = sk_new(ifa->pool);
   sk->type = SK_IP;
   sk->dport = ICMPV6_PROTO;
   sk->saddr = ifa->addr->ip;
-- 
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