libports: adjust lwip's TCP_SND_BUF size

The old values were much too small and the current ones are probably to
large but the TCP send throuhgput has increased noticeable (a few MiB/s
on the Pandaboard).

Fixes #343.

libports/include/lwip/lwipopts.h

@@ -31,6 +31,9 @@
 #define LWIP_NETIF_API              1  /* Network interface API */
 #define LWIP_NETIF_LOOPBACK         1  /* Looping back to same address? */
 #define LWIP_HAVE_LOOPIF            1  /* 127.0.0.1 support ? */
+#define LWIP_STATS                  0  /* disable stating */
+#define LWIP_RCVBUF                 1  /* enable SO_RCVBUF */
+#define SO_REUSE                    1  /* enable SO_REUSE */
 
 #if LWIP_DHCP
 #define LWIP_NETIF_STATUS_CALLBACK  1  /* callback function used by DHCP init */
@@ -47,7 +50,13 @@
 #define TCPIP_MBOX_SIZE           128
 
 #define TCP_MSS                  1460
-#define TCP_SND_BUF     (2 * TCP_MSS)
+#define TCP_WND                     (32 * TCP_MSS)
+#define TCP_SND_BUF                 (128 * TCP_MSS)
+#define TCP_SND_QUEUELEN            ((32 * (TCP_SND_BUF) + (TCP_MSS - 1))/(TCP_MSS))
+
+#define RECV_BUFSIZE_DEFAULT        2147483647 /* this is actually INT_MAX, default value */
+
+#define PBUF_POOL_SIZE             32
 
 /*
  * We reduce the maximum segment lifetime from one minute to one second to

libports/lib/mk/lwip.mk

@@ -27,7 +27,7 @@ SRC_C   += etharp.c
 
 LIBS     = thread cxx alarm signal libc timed_semaphore
 
-D_OPTS   = ERRNO SO_REUSE LWIP_SO_RCVBUF RECV_BUFSIZE_DEFAULT=8192
+D_OPTS   = ERRNO
 D_OPTS  := $(addprefix -D,$(D_OPTS))
 CC_DEF  += $(D_OPTS)