ipsec: Put dumpers on the dump list

Herbert Xu came up with the idea and the original patch to make
xfrm_state dump list contain also dumpers:

As it is we go to extraordinary lengths to ensure that states
don't go away while dumpers go to sleep.  It's much easier if
we just put the dumpers themselves on the list since they can't
go away while they're going.

I've also changed the order of addition on new states to prevent
a never-ending dump.

Timo Teräs improved the patch to apply cleanly to latest tree,
modified iteration code to be more readable by using a common
struct for entries in the list, implemented the same idea for
xfrm_policy dumping and moved the af_key specific "last" entry
caching to af_key.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 5 deletions

diff --git a/net/key/af_key.c b/net/key/af_key.c
index b7f5a1c353ee..7ae641df70bd 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -58,6 +58,7 @@ struct pfkey_sock {
                         struct xfrm_policy_walk policy;
                         struct xfrm_state_walk  state;
                 } u;
+                struct sk_buff  *skb;
         } dump;
 };
 
@@ -76,6 +77,10 @@ static int pfkey_can_dump(struct sock *sk)
 static void pfkey_terminate_dump(struct pfkey_sock *pfk)
 {
         if (pfk->dump.dump) {
+                if (pfk->dump.skb) {
+                        kfree_skb(pfk->dump.skb);
+                        pfk->dump.skb = NULL;
+                }
                 pfk->dump.done(pfk);
                 pfk->dump.dump = NULL;
                 pfk->dump.done = NULL;
@@ -308,12 +313,25 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation,
 
 static int pfkey_do_dump(struct pfkey_sock *pfk)
 {
+        struct sadb_msg *hdr;
         int rc;
 
         rc = pfk->dump.dump(pfk);
         if (rc == -ENOBUFS)
                 return 0;
 
+        if (pfk->dump.skb) {
+                if (!pfkey_can_dump(&pfk->sk))
+                        return 0;
+
+                hdr = (struct sadb_msg *) pfk->dump.skb->data;
+                hdr->sadb_msg_seq = 0;
+                hdr->sadb_msg_errno = rc;
+                pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
+                                &pfk->sk);
+                pfk->dump.skb = NULL;
+        }
+
         pfkey_terminate_dump(pfk);
         return rc;
 }
@@ -1744,9 +1762,14 @@ static int dump_sa(struct xfrm_state *x, int count, void *ptr)
         out_hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
         out_hdr->sadb_msg_errno = 0;
         out_hdr->sadb_msg_reserved = 0;
-        out_hdr->sadb_msg_seq = count;
+        out_hdr->sadb_msg_seq = count + 1;
         out_hdr->sadb_msg_pid = pfk->dump.msg_pid;
-        pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, &pfk->sk);
+
+        if (pfk->dump.skb)
+                pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
+                                &pfk->sk);
+        pfk->dump.skb = out_skb;
+
         return 0;
 }
 
@@ -2245,7 +2268,7 @@ static int pfkey_spdadd(struct sock *sk, struct sk_buff *skb, struct sadb_msg *h
         return 0;
 
 out:
-        xp->dead = 1;
+        xp->walk.dead = 1;
         xfrm_policy_destroy(xp);
         return err;
 }
@@ -2583,9 +2606,14 @@ static int dump_sp(struct xfrm_policy *xp, int dir, int count, void *ptr)
         out_hdr->sadb_msg_type = SADB_X_SPDDUMP;
         out_hdr->sadb_msg_satype = SADB_SATYPE_UNSPEC;
         out_hdr->sadb_msg_errno = 0;
-        out_hdr->sadb_msg_seq = count;
+        out_hdr->sadb_msg_seq = count + 1;
         out_hdr->sadb_msg_pid = pfk->dump.msg_pid;
-        pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, &pfk->sk);
+
+        if (pfk->dump.skb)
+                pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE,
+                                &pfk->sk);
+        pfk->dump.skb = out_skb;
+
         return 0;
 }