[SCTP] Add sysctl parameters to update socket send/receive buffers.

include/linux/sysctl.h

@@ -578,6 +578,8 @@ enum {
 	NET_SCTP_PRESERVE_ENABLE         = 11,
 	NET_SCTP_MAX_BURST               = 12,
 	NET_SCTP_ADDIP_ENABLE		 = 13,
+	NET_SCTP_RMEM			 = 14,
+	NET_SCTP_WMEM			 = 15,
 };
 
 /* /proc/sys/net/bridge */

include/net/sctp/constants.h

@@ -323,7 +323,7 @@ typedef enum {
 #define SCTP_DEFAULT_COOKIE_LIFE_USEC	0  /* microseconds */
 
 #define SCTP_DEFAULT_MINWINDOW	1500	/* default minimum rwnd size */
-#define SCTP_DEFAULT_MAXWINDOW	32768	/* default rwnd size */
+#define SCTP_DEFAULT_MAXWINDOW	65535	/* default rwnd size */
 #define SCTP_DEFAULT_MAXSEGMENT 1500	/* MTU size, this is the limit
                                          * to which we will raise the P-MTU.
 					 */

include/net/sctp/structs.h

@@ -193,6 +193,10 @@ extern struct sctp_globals {
 	
 	/* Flag to indicate if addip is enabled. */
 	int addip_enable;
+
+	/* socket receive and send buffer sizes. */ 
+	int rmem;
+	int wmem;
 } sctp_globals;
 
 #define sctp_rto_initial		(sctp_globals.rto_initial)
@@ -221,6 +225,8 @@ extern struct sctp_globals {
 #define sctp_local_addr_list		(sctp_globals.local_addr_list)
 #define sctp_local_addr_lock		(sctp_globals.local_addr_lock)
 #define sctp_addip_enable		(sctp_globals.addip_enable)
+#define sctp_rmem			(sctp_globals.rmem)
+#define sctp_wmem			(sctp_globals.wmem)
 
 /* SCTP Socket type: UDP or TCP style. */
 typedef enum {

net/sctp/associola.c

@@ -192,7 +192,7 @@ struct sctp_association *sctp_association_init(struct sctp_association *asoc,
 	asoc->rwnd_over = 0;
 
 	/* Use my own max window until I learn something better.  */
-	asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
+	asoc->peer.rwnd = sctp_rmem;
 
 	/* Set the sndbuf size for transmit.  */
 	asoc->sndbuf_used = 0;
@@ -498,7 +498,7 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 	 * so initialize ssthresh to the default value and it will be set
 	 * later when we process the INIT.
 	 */
-	peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
+	peer->ssthresh = sctp_rmem;
 
 	peer->partial_bytes_acked = 0;
 	peer->flight_size = 0;

net/sctp/endpointola.c

@@ -148,12 +148,8 @@ struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 		sp->autoclose * HZ;
 
 	/* Set up the default send/receive buffer space.  */
-
-	/* FIXME - Should the min and max window size be configurable
-	 * sysctl parameters as opposed to be constants?
-	 */
-	sk->sk_rcvbuf = SCTP_DEFAULT_MAXWINDOW;
-	sk->sk_sndbuf = SCTP_DEFAULT_MAXWINDOW * 2;
+	sk->sk_rcvbuf = sctp_rmem;
+	sk->sk_sndbuf = sctp_wmem;
 
 	/* Use SCTP specific send buffer space queues.  */
 	sk->sk_write_space = sctp_write_space;

net/sctp/protocol.c

@@ -1049,6 +1049,10 @@ __init int sctp_init(void)
 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
 
+	/* Initialize default send & receive buffer sizes. */
+	sctp_rmem 			= SCTP_DEFAULT_MAXWINDOW;
+	sctp_wmem 			= SCTP_DEFAULT_MAXWINDOW;
+
 	/* Size and allocate the association hash table.
 	 * The methodology is similar to that of the tcp hash tables.
 	 */

net/sctp/sysctl.c

@@ -170,6 +170,22 @@ static ctl_table sctp_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec
 	},
+	{
+		.ctl_name	= NET_SCTP_RMEM,
+		.procname	= "rmem",
+		.data		= &sctp_rmem,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_SCTP_WMEM,
+		.procname	= "wmem",
+		.data		= &sctp_wmem,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
 	{ .ctl_name = 0 }
 };
 

net/sctp/ulpqueue.c

@@ -768,7 +768,7 @@ void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
 		needed = ntohs(chunk->chunk_hdr->length);
 		needed -= sizeof(sctp_data_chunk_t);
 	} else 
-		needed = SCTP_DEFAULT_MAXWINDOW;
+		needed = sctp_rmem;
 
 	freed = 0;