lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1341259164-7396-1-git-send-email-nhorman@tuxdriver.com>
Date:	Mon,  2 Jul 2012 15:59:24 -0400
From:	Neil Horman <nhorman@...driver.com>
To:	netdev@...r.kernel.org
Cc:	Neil Horman <nhorman@...driver.com>,
	Vlad Yasevich <vyasevich@...il.com>,
	"David S. Miller" <davem@...emloft.net>, linux-sctp@...r.kernel.org
Subject: [PATCH] sctp: refactor sctp_packet_append_chunk and clenup some memory leaks

While doing some recent work on sctp sack bundling I noted that
sctp_packet_append_chunk was pretty inefficient.  Specifially, it was called
recursively while trying to bundle auth and sack chunks.  Because of that we
call sctp_packet_bundle_sack and sctp_packet_bundle_auth a total of 4 times for
every call to sctp_packet_append_chunk, knowing that at least 3 of those calls
will do nothing.

So lets refactor sctp_packet_bundle_auth to have an outer part that does the
attempted bundling, and an inner part that just does the chunk appends.  This
saves us several calls per iteration that we just don't need.

Also, noticed that the auth and sack bundling fail to free the chunks they
allocate if the append fails, so make sure we add that in

Signed-off-by: Neil Horman <nhorman@...driver.com>
CC: Vlad Yasevich <vyasevich@...il.com>
CC: "David S. Miller" <davem@...emloft.net>
CC: linux-sctp@...r.kernel.org
---
 net/sctp/output.c |   80 +++++++++++++++++++++++++++++++++++------------------
 1 files changed, 53 insertions(+), 27 deletions(-)

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 0de6cd5..0b62f6c 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -64,6 +64,8 @@
 #include <net/sctp/checksum.h>
 
 /* Forward declarations for private helpers. */
+static sctp_xmit_t __sctp_packet_append_chunk(struct sctp_packet *packet,
+					      struct sctp_chunk *chunk);
 static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet,
 					   struct sctp_chunk *chunk);
 static void sctp_packet_append_data(struct sctp_packet *packet,
@@ -224,7 +226,10 @@ static sctp_xmit_t sctp_packet_bundle_auth(struct sctp_packet *pkt,
 	if (!auth)
 		return retval;
 
-	retval = sctp_packet_append_chunk(pkt, auth);
+	retval = __sctp_packet_append_chunk(pkt, auth);
+
+	if (retval != SCTP_XMIT_OK)
+		sctp_chunk_free(auth);
 
 	return retval;
 }
@@ -256,48 +261,31 @@ static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt,
 			asoc->a_rwnd = asoc->rwnd;
 			sack = sctp_make_sack(asoc);
 			if (sack) {
-				retval = sctp_packet_append_chunk(pkt, sack);
+				retval = __sctp_packet_append_chunk(pkt, sack);
+				if (retval != SCTP_XMIT_OK) {
+					sctp_chunk_free(sack);
+					goto out;
+				}
 				asoc->peer.sack_needed = 0;
 				if (del_timer(timer))
 					sctp_association_put(asoc);
 			}
 		}
 	}
+out:
 	return retval;
 }
 
+
 /* Append a chunk to the offered packet reporting back any inability to do
  * so.
  */
-sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
-				     struct sctp_chunk *chunk)
+static sctp_xmit_t __sctp_packet_append_chunk(struct sctp_packet *packet,
+					      struct sctp_chunk *chunk)
 {
 	sctp_xmit_t retval = SCTP_XMIT_OK;
 	__u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length));
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, packet,
-			  chunk);
-
-	/* Data chunks are special.  Before seeing what else we can
-	 * bundle into this packet, check to see if we are allowed to
-	 * send this DATA.
-	 */
-	if (sctp_chunk_is_data(chunk)) {
-		retval = sctp_packet_can_append_data(packet, chunk);
-		if (retval != SCTP_XMIT_OK)
-			goto finish;
-	}
-
-	/* Try to bundle AUTH chunk */
-	retval = sctp_packet_bundle_auth(packet, chunk);
-	if (retval != SCTP_XMIT_OK)
-		goto finish;
-
-	/* Try to bundle SACK chunk */
-	retval = sctp_packet_bundle_sack(packet, chunk);
-	if (retval != SCTP_XMIT_OK)
-		goto finish;
-
 	/* Check to see if this chunk will fit into the packet */
 	retval = sctp_packet_will_fit(packet, chunk, chunk_len);
 	if (retval != SCTP_XMIT_OK)
@@ -339,6 +327,44 @@ finish:
 	return retval;
 }
 
+/* Append a chunk to the offered packet reporting back any inability to do
+ * so.
+ */
+sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
+				     struct sctp_chunk *chunk)
+{
+	sctp_xmit_t retval = SCTP_XMIT_OK;
+	__u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length));
+
+	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, packet,
+			  chunk);
+
+	/* Data chunks are special.  Before seeing what else we can
+	 * bundle into this packet, check to see if we are allowed to
+	 * send this DATA.
+	 */
+	if (sctp_chunk_is_data(chunk)) {
+		retval = sctp_packet_can_append_data(packet, chunk);
+		if (retval != SCTP_XMIT_OK)
+			goto finish;
+	}
+
+	/* Try to bundle AUTH chunk */
+	retval = sctp_packet_bundle_auth(packet, chunk);
+	if (retval != SCTP_XMIT_OK)
+		goto finish;
+
+	/* Try to bundle SACK chunk */
+	retval = sctp_packet_bundle_sack(packet, chunk);
+	if (retval != SCTP_XMIT_OK)
+		goto finish;
+
+	retval = __sctp_packet_append_chunk(packet, chunk);
+
+finish:
+	return retval;
+}
+
 /* All packets are sent to the network through this function from
  * sctp_outq_tail().
  *
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ