[DCCP]: Introduce DCCP_SOCKOPT_PACKET_SIZE

So that applications can set dccp_sock->dccps_pkt_size, that in turn
is used in the CCID3 half connection init routines to set
ccid3hc[tr]x_s and use it in its rate calculations.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 4ff6ede..e22b0ee 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -672,9 +672,9 @@
 
 	memset(hctx, 0, sizeof(*hctx));
 
-	if (dp->dccps_avg_packet_size >= TFRC_MIN_PACKET_SIZE &&
-	    dp->dccps_avg_packet_size <= TFRC_MAX_PACKET_SIZE)
-		hctx->ccid3hctx_s = (u16)dp->dccps_avg_packet_size;
+	if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+	    dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+		hctx->ccid3hctx_s = dp->dccps_packet_size;
 	else
 		hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
 
@@ -1058,9 +1058,9 @@
 
 	memset(hcrx, 0, sizeof(*hcrx));
 
-	if (dp->dccps_avg_packet_size >= TFRC_MIN_PACKET_SIZE &&
-	    dp->dccps_avg_packet_size <= TFRC_MAX_PACKET_SIZE)
-		hcrx->ccid3hcrx_s = (u16)dp->dccps_avg_packet_size;
+	if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+	    dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+		hcrx->ccid3hcrx_s = dp->dccps_packet_size;
 	else
 		hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;