From f31d6f271fe7b1989fb335a251cfa07a22f83f57 Mon Sep 17 00:00:00 2001
From: Adam Dunkels <adam@thingsquare.com>
Date: Fri, 22 Nov 2013 15:37:21 +0100
Subject: [PATCH 1/4] Bugfix: if a SYN is received in the SYN_RCVD state we
 should not send a blank SYN, but a SYNACK in response.

---
 core/net/uip6.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/core/net/uip6.c b/core/net/uip6.c
index e79486ff1..7f51ce4e9 100644
--- a/core/net/uip6.c
+++ b/core/net/uip6.c
@@ -1833,8 +1833,12 @@ uip_process(uint8_t flag)
         UIP_TCP_BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
         UIP_TCP_BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
 
-      if(UIP_TCP_BUF->flags & TCP_SYN) {
-        goto tcp_send_synack;
+      if((UIP_TCP_BUF->flags & TCP_SYN)) {
+        if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_RCVD) {
+          goto tcp_send_synack;
+        } else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) {
+          goto tcp_send_syn;
+        }
       }
       goto tcp_send_ack;
     }

From d577d03e212daa32a7b332a5e4297daf264f9c94 Mon Sep 17 00:00:00 2001
From: Adam Dunkels <adam@thingsquare.com>
Date: Fri, 22 Nov 2013 15:38:20 +0100
Subject: [PATCH 2/4] Bugfix: correctly handle the case if uip_sappdata is
 NULL.

---
 core/net/uip6.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/core/net/uip6.c b/core/net/uip6.c
index 7f51ce4e9..f0d93688c 100644
--- a/core/net/uip6.c
+++ b/core/net/uip6.c
@@ -2320,12 +2320,23 @@ uip_send(const void *data, int len)
 {
   int copylen;
 #define MIN(a,b) ((a) < (b)? (a): (b))
-  copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN -
-                (int)((char *)uip_sappdata - (char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN]));
+
+  if(uip_sappdata != NULL) {
+    copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN -
+                  (int)((char *)uip_sappdata -
+                        (char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN]));
+  } else {
+    copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN);
+  }
   if(copylen > 0) {
     uip_slen = copylen;
     if(data != uip_sappdata) {
-      memcpy(uip_sappdata, (data), uip_slen);
+      if(uip_sappdata == NULL) {
+        memcpy((char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN],
+               (data), uip_slen);
+      } else {
+        memcpy(uip_sappdata, (data), uip_slen);
+      }
     }
   }
 }

From 61a8fa9977a0078af84ca5e41890c84a1ff5d686 Mon Sep 17 00:00:00 2001
From: Adam Dunkels <adam@thingsquare.com>
Date: Fri, 22 Nov 2013 15:44:48 +0100
Subject: [PATCH 3/4] Allow the default TTL to be configured with UIP_CONF_TTL

---
 core/net/uipopt.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/core/net/uipopt.h b/core/net/uipopt.h
index 7c9939003..ce871985f 100644
--- a/core/net/uipopt.h
+++ b/core/net/uipopt.h
@@ -144,7 +144,11 @@
  *
  * This should normally not be changed.
  */
+#ifdef UIP_CONF_TTL
+#define UIP_TTL         UIP_CONF_TTL
+#else /* UIP_CONF_TTL */
 #define UIP_TTL         64
+#endif /* UIP_CONF_TTL */
 
 /**
  * The maximum time an IP fragment should wait in the reassembly

From ea4bc3816f649175f2d2d3592dd2abd84735ac49 Mon Sep 17 00:00:00 2001
From: Adam Dunkels <adam@thingsquare.com>
Date: Fri, 22 Nov 2013 15:46:48 +0100
Subject: [PATCH 4/4] Produce an error if the UIP_TCP_MSS is too large for
 UIP_BUFSIZE

---
 core/net/uipopt.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/core/net/uipopt.h b/core/net/uipopt.h
index ce871985f..d0d3219ad 100644
--- a/core/net/uipopt.h
+++ b/core/net/uipopt.h
@@ -382,7 +382,10 @@
  * UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN.
  */
 #ifdef UIP_CONF_TCP_MSS
-#define UIP_TCP_MSS (UIP_CONF_TCP_MSS)
+#if UIP_CONF_TCP_MSS < (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN)
+#error UIP_CONF_TCP_MSS is too large for the current UIP_BUFSIZE
+#endif /* UIP_CONF_TCP_MSS < (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN) */
+#define UIP_TCP_MSS     (UIP_CONF_TCP_MSS)
 #else
 #define UIP_TCP_MSS     (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN)
 #endif