1 files changed, 108 insertions, 27 deletions

diff --git a/net/sctp/output.c b/net/sctp/output.c
index d85543d..847639d 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -79,7 +79,10 @@ struct sctp_packet *sctp_packet_config(struct sctp_packet *packet,
 	packet->vtag = vtag;
 	packet->has_cookie_echo = 0;
 	packet->has_sack = 0;
+	packet->has_auth = 0;
+	packet->has_data = 0;
 	packet->ipfragok = 0;
+	packet->auth = NULL;
 
 	if (ecn_capable && sctp_packet_empty(packet)) {
 		chunk = sctp_get_ecne_prepend(packet->transport->asoc);
@@ -121,8 +124,11 @@ struct sctp_packet *sctp_packet_init(struct sctp_packet *packet,
 	packet->vtag = 0;
 	packet->has_cookie_echo = 0;
 	packet->has_sack = 0;
+	packet->has_auth = 0;
+	packet->has_data = 0;
 	packet->ipfragok = 0;
 	packet->malloced = 0;
+	packet->auth = NULL;
 	return packet;
 }
 
@@ -181,6 +187,39 @@ sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet,
 	return retval;
 }
 
+/* Try to bundle an auth chunk into the packet. */
+static sctp_xmit_t sctp_packet_bundle_auth(struct sctp_packet *pkt,
+					   struct sctp_chunk *chunk)
+{
+	struct sctp_association *asoc = pkt->transport->asoc;
+	struct sctp_chunk *auth;
+	sctp_xmit_t retval = SCTP_XMIT_OK;
+
+	/* if we don't have an association, we can't do authentication */
+	if (!asoc)
+		return retval;
+
+	/* See if this is an auth chunk we are bundling or if
+	 * auth is already bundled.
+	 */
+	if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->auth)
+		return retval;
+
+	/* if the peer did not request this chunk to be authenticated,
+	 * don't do it
+	 */
+	if (!chunk->auth)
+		return retval;
+
+	auth = sctp_make_auth(asoc);
+	if (!auth)
+		return retval;
+
+	retval = sctp_packet_append_chunk(pkt, auth);
+
+	return retval;
+}
+
 /* Try to bundle a SACK with the packet. */
 static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt,
 					   struct sctp_chunk *chunk)
@@ -227,12 +266,17 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __FUNCTION__, packet,
 			  chunk);
 
-	retval = sctp_packet_bundle_sack(packet, chunk);
-	psize = packet->size;
+	/* 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;
 
+	psize = packet->size;
 	pmtu  = ((packet->transport->asoc) ?
 		 (packet->transport->asoc->pathmtu) :
 		 (packet->transport->pathmtu));
@@ -241,10 +285,16 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 
 	/* Decide if we need to fragment or resubmit later. */
 	if (too_big) {
-		/* Both control chunks and data chunks with TSNs are
-		 * non-fragmentable.
+		/* It's OK to fragmet at IP level if any one of the following
+		 * is true:
+		 * 	1. The packet is empty (meaning this chunk is greater
+		 * 	   the MTU)
+		 * 	2. The chunk we are adding is a control chunk
+		 * 	3. The packet doesn't have any data in it yet and data
+		 * 	requires authentication.
 		 */
-		if (sctp_packet_empty(packet) || !sctp_chunk_is_data(chunk)) {
+		if (sctp_packet_empty(packet) || !sctp_chunk_is_data(chunk) ||
+		    (!packet->has_data && chunk->auth)) {
 			/* We no longer do re-fragmentation.
 			 * Just fragment at the IP layer, if we
 			 * actually hit this condition
@@ -266,16 +316,31 @@ append:
 	/* DATA is a special case since we must examine both rwnd and cwnd
 	 * before we send DATA.
 	 */
-	if (sctp_chunk_is_data(chunk)) {
+	switch (chunk->chunk_hdr->type) {
+	    case SCTP_CID_DATA:
 		retval = sctp_packet_append_data(packet, chunk);
 		/* Disallow SACK bundling after DATA. */
 		packet->has_sack = 1;
+		/* Disallow AUTH bundling after DATA */
+		packet->has_auth = 1;
+		/* Let it be knows that packet has DATA in it */
+		packet->has_data = 1;
 		if (SCTP_XMIT_OK != retval)
 			goto finish;
-	} else if (SCTP_CID_COOKIE_ECHO == chunk->chunk_hdr->type)
+		break;
+	    case SCTP_CID_COOKIE_ECHO:
 		packet->has_cookie_echo = 1;
-	else if (SCTP_CID_SACK == chunk->chunk_hdr->type)
+		break;
+
+	    case SCTP_CID_SACK:
 		packet->has_sack = 1;
+		break;
+
+	    case SCTP_CID_AUTH:
+		packet->has_auth = 1;
+		packet->auth = chunk;
+		break;
+	}
 
 	/* It is OK to send this chunk.  */
 	list_add_tail(&chunk->list, &packet->chunk_list);
@@ -303,6 +368,8 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	int padding;		/* How much padding do we need?  */
 	__u8 has_data = 0;
 	struct dst_entry *dst = tp->dst;
+	unsigned char *auth = NULL;	/* pointer to auth in skb data */
+	__u32 cksum_buf_len = sizeof(struct sctphdr);
 
 	SCTP_DEBUG_PRINTK("%s: packet:%p\n", __FUNCTION__, packet);
 
@@ -356,16 +423,6 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	sh->vtag     = htonl(packet->vtag);
 	sh->checksum = 0;
 
-	/* 2) Calculate the Adler-32 checksum of the whole packet,
-	 *    including the SCTP common header and all the
-	 *    chunks.
-	 *
-	 * Note: Adler-32 is no longer applicable, as has been replaced
-	 * by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
-	 */
-	if (!(dst->dev->features & NETIF_F_NO_CSUM))
-		crc32 = sctp_start_cksum((__u8 *)sh, sizeof(struct sctphdr));
-
 	/**
 	 * 6.10 Bundling
 	 *
@@ -416,14 +473,16 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 		if (padding)
 			memset(skb_put(chunk->skb, padding), 0, padding);
 
-		if (dst->dev->features & NETIF_F_NO_CSUM)
-			memcpy(skb_put(nskb, chunk->skb->len),
+		/* if this is the auth chunk that we are adding,
+		 * store pointer where it will be added and put
+		 * the auth into the packet.
+		 */
+		if (chunk == packet->auth)
+			auth = skb_tail_pointer(nskb);
+
+		cksum_buf_len += chunk->skb->len;
+		memcpy(skb_put(nskb, chunk->skb->len),
 			       chunk->skb->data, chunk->skb->len);
-		else
-			crc32 = sctp_update_copy_cksum(skb_put(nskb,
-							chunk->skb->len),
-						chunk->skb->data,
-						chunk->skb->len, crc32);
 
 		SCTP_DEBUG_PRINTK("%s %p[%s] %s 0x%x, %s %d, %s %d, %s %d\n",
 				  "*** Chunk", chunk,
@@ -445,9 +504,31 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 			sctp_chunk_free(chunk);
 	}
 
-	/* Perform final transformation on checksum. */
-	if (!(dst->dev->features & NETIF_F_NO_CSUM))
+	/* SCTP-AUTH, Section 6.2
+	 *    The sender MUST calculate the MAC as described in RFC2104 [2]
+	 *    using the hash function H as described by the MAC Identifier and
+	 *    the shared association key K based on the endpoint pair shared key
+	 *    described by the shared key identifier.  The 'data' used for the
+	 *    computation of the AUTH-chunk is given by the AUTH chunk with its
+	 *    HMAC field set to zero (as shown in Figure 6) followed by all
+	 *    chunks that are placed after the AUTH chunk in the SCTP packet.
+	 */
+	if (auth)
+		sctp_auth_calculate_hmac(asoc, nskb,
+					(struct sctp_auth_chunk *)auth,
+					GFP_ATOMIC);
+
+	/* 2) Calculate the Adler-32 checksum of the whole packet,
+	 *    including the SCTP common header and all the
+	 *    chunks.
+	 *
+	 * Note: Adler-32 is no longer applicable, as has been replaced
+	 * by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
+	 */
+	if (!(dst->dev->features & NETIF_F_NO_CSUM)) {
+		crc32 = sctp_start_cksum((__u8 *)sh, cksum_buf_len);
 		crc32 = sctp_end_cksum(crc32);
+	}
 
 	/* 3) Put the resultant value into the checksum field in the
 	 *    common header, and leave the rest of the bits unchanged.