[SCTP] Fix SCTP sendbuffer accouting.

- Include chunk and skb sizes in sendbuffer accounting.
- 2 policies are supported. 0: per socket accouting, 1: per association
  accounting

DaveM: I've made the default per-socket.

Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 5 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 32f2249411f..0b338eca6dc 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -115,9 +115,17 @@ static inline int sctp_wspace(struct sctp_association *asoc)
 	struct sock *sk = asoc->base.sk;
 	int amt = 0;
 
-	amt = sk->sk_sndbuf - asoc->sndbuf_used;
+	if (asoc->ep->sndbuf_policy) {
+		/* make sure that no association uses more than sk_sndbuf */
+		amt = sk->sk_sndbuf - asoc->sndbuf_used;
+	} else {
+		/* do socket level accounting */
+		amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
+	}
+
 	if (amt < 0)
 		amt = 0;
+
 	return amt;
 }
 
@@ -138,12 +146,21 @@ static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
 	/* The sndbuf space is tracked per association.  */
 	sctp_association_hold(asoc);
 
+	skb_set_owner_w(chunk->skb, sk);
+
 	chunk->skb->destructor = sctp_wfree;
 	/* Save the chunk pointer in skb for sctp_wfree to use later.  */
 	*((struct sctp_chunk **)(chunk->skb->cb)) = chunk;
 
-	asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk);
-	sk->sk_wmem_queued += SCTP_DATA_SNDSIZE(chunk);
+	asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk) +
+				sizeof(struct sk_buff) +
+				sizeof(struct sctp_chunk);
+
+	sk->sk_wmem_queued += SCTP_DATA_SNDSIZE(chunk) +
+				sizeof(struct sk_buff) +
+				sizeof(struct sctp_chunk);
+
+	atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
 }
 
 /* Verify that this is a valid address. */
@@ -4422,8 +4439,17 @@ static void sctp_wfree(struct sk_buff *skb)
 	chunk = *((struct sctp_chunk **)(skb->cb));
 	asoc = chunk->asoc;
 	sk = asoc->base.sk;
-	asoc->sndbuf_used -= SCTP_DATA_SNDSIZE(chunk);
-	sk->sk_wmem_queued -= SCTP_DATA_SNDSIZE(chunk);
+	asoc->sndbuf_used -= SCTP_DATA_SNDSIZE(chunk) +
+				sizeof(struct sk_buff) +
+				sizeof(struct sctp_chunk);
+
+	sk->sk_wmem_queued -= SCTP_DATA_SNDSIZE(chunk) +
+				sizeof(struct sk_buff) +
+				sizeof(struct sctp_chunk);
+
+	atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+
+	sock_wfree(skb);
 	__sctp_write_space(asoc);
 
 	sctp_association_put(asoc);