Diff: lwip/core/tcp_out.c

Revision:

5:dd63a1e02b1b

Parent:

0:632c9925f013

--- a/lwip/core/tcp_out.c	Fri Jul 09 14:46:47 2010 +0000
+++ b/lwip/core/tcp_out.c	Tue Jul 27 15:59:42 2010 +0000
@@ -221,6 +221,14 @@
   struct pbuf *p;
   u16_t alloc = length;
 
+#if LWIP_NETIF_TX_SINGLE_PBUF
+  LWIP_UNUSED_ARG(max_length);
+  LWIP_UNUSED_ARG(pcb);
+  LWIP_UNUSED_ARG(apiflags);
+  LWIP_UNUSED_ARG(first_seg);
+  /* always create MSS-sized pbufs */
+  alloc = TCP_MSS;
+#else /* LWIP_NETIF_TX_SINGLE_PBUF */
   if (length < max_length) {
     /* Should we allocate an oversized pbuf, or just the minimum
      * length required? If tcp_write is going to be called again
@@ -241,6 +249,7 @@
       alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
     }
   }
+#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
   p = pbuf_alloc(layer, alloc, PBUF_RAM);
   if (p == NULL) {
     return NULL;
@@ -273,6 +282,56 @@
 }
 #endif /* TCP_CHECKSUM_ON_COPY */
 
+/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
+ *
+ * @param pcb the tcp pcb to check for
+ * @param len length of data to send (checked agains snd_buf)
+ * @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
+ */
+static err_t
+tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
+{
+  /* connection is in invalid state for data transmission? */
+  if ((pcb->state != ESTABLISHED) &&
+      (pcb->state != CLOSE_WAIT) &&
+      (pcb->state != SYN_SENT) &&
+      (pcb->state != SYN_RCVD)) {
+    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
+    return ERR_CONN;
+  } else if (len == 0) {
+    return ERR_OK;
+  }
+
+  /* fail on too much data */
+  if (len > pcb->snd_buf) {
+    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
+      len, pcb->snd_buf));
+    pcb->flags |= TF_NAGLEMEMERR;
+    return ERR_MEM;
+  }
+
+  LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
+
+  /* If total number of pbufs on the unsent/unacked queues exceeds the
+   * configured maximum, return an error */
+  /* check for configured max queuelen and possible overflow */
+  if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
+    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
+      pcb->snd_queuelen, TCP_SND_QUEUELEN));
+    TCP_STATS_INC(tcp.memerr);
+    pcb->flags |= TF_NAGLEMEMERR;
+    return ERR_MEM;
+  }
+  if (pcb->snd_queuelen != 0) {
+    LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
+      pcb->unacked != NULL || pcb->unsent != NULL);
+  } else {
+    LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
+      pcb->unacked == NULL && pcb->unsent == NULL);
+  }
+  return ERR_OK;
+}
+
 /**
  * Write data for sending (but does not send it immediately).
  *
@@ -307,6 +366,7 @@
   u8_t concat_chksum_swapped = 0;
   u16_t concat_chksummed = 0;
 #endif /* TCP_CHECKSUM_ON_COPY */
+  err_t err;
 
 #if LWIP_NETIF_TX_SINGLE_PBUF
   /* Always copy to try to create single pbufs for TX */
@@ -315,50 +375,14 @@
 
   LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
     (void *)pcb, arg, len, (u16_t)apiflags));
-  /* connection is in invalid state for data transmission? */
-  if ((pcb->state != ESTABLISHED) &&
-      (pcb->state != CLOSE_WAIT) &&
-      (pcb->state != SYN_SENT) &&
-      (pcb->state != SYN_RCVD)) {
-    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
-    return ERR_CONN;
-  } else if (len == 0) {
-    return ERR_OK;
-  }
-
-  LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, arg=%p, len=%"U16_F", apiflags=%"U16_F")\n",
-    (void *)pcb, arg, len, (u16_t)apiflags));
   LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)", 
              arg != NULL, return ERR_ARG;);
 
-  /* fail on too much data */
-  if (len > pcb->snd_buf) {
-    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
-      len, pcb->snd_buf));
-    pcb->flags |= TF_NAGLEMEMERR;
-    return ERR_MEM;
+  err = tcp_write_checks(pcb, len);
+  if (err != ERR_OK) {
+    return err;
   }
-
-  LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
-
-  /* If total number of pbufs on the unsent/unacked queues exceeds the
-   * configured maximum, return an error */
   queuelen = pcb->snd_queuelen;
-  /* check for configured max queuelen and possible overflow */
-  if ((queuelen >= TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
-    LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
-      queuelen, TCP_SND_QUEUELEN));
-    TCP_STATS_INC(tcp.memerr);
-    pcb->flags |= TF_NAGLEMEMERR;
-    return ERR_MEM;
-  }
-  if (queuelen != 0) {
-    LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
-      pcb->unacked != NULL || pcb->unsent != NULL);
-  } else {
-    LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
-      pcb->unacked == NULL && pcb->unsent == NULL);
-  }
 
 #if LWIP_TCP_TIMESTAMPS
   if ((pcb->flags & TF_TIMESTAMP)) {
@@ -802,7 +826,7 @@
 tcp_build_timestamp_option(struct tcp_pcb *pcb, u32_t *opts)
 {
   /* Pad with two NOP options to make everything nicely aligned */
-  opts[0] = htonl(0x0101080A);
+  opts[0] = PP_HTONL(0x0101080A);
   opts[1] = htonl(sys_now());
   opts[2] = htonl(pcb->ts_recent);
 }
@@ -961,7 +985,12 @@
     }
 
     tcp_output_segment(seg, pcb);
+       
     snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
+    
+    LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: pcb->snd_nxt was %"U32_F" seqno=%"U32_F" len=%"U32_F" new snd_nxt=%"U32_F"\n", //DG
+                                    pcb->snd_nxt, ntohl(seg->tcphdr->seqno), TCP_TCPLEN(seg), snd_nxt));
+    
     if (TCP_SEQ_LT(pcb->snd_nxt, snd_nxt)) {
       pcb->snd_nxt = snd_nxt;
     }
@@ -1132,6 +1161,9 @@
 #endif /* TCP_CHECKSUM_ON_COPY */
 #endif /* CHECKSUM_GEN_TCP */
   TCP_STATS_INC(tcp.xmit);
+  
+  LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: Before ip_out seqno = %"U32_F"\n",
+        htonl(seg->tcphdr->seqno))); //DG
 
 #if LWIP_NETIF_HWADDRHINT
   ip_output_hinted(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
@@ -1140,6 +1172,11 @@
   ip_output(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
       IP_PROTO_TCP);
 #endif /* LWIP_NETIF_HWADDRHINT*/
+
+  LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: After ip_out seqno = %"U32_F"\n",
+        htonl(seg->tcphdr->seqno))); //DG
+
+
 }
 
 /**
@@ -1183,7 +1220,7 @@
   tcphdr->seqno = htonl(seqno);
   tcphdr->ackno = htonl(ackno);
   TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST | TCP_ACK);
-  tcphdr->wnd = htons(TCP_WND);
+  tcphdr->wnd = PP_HTONS(TCP_WND);
   tcphdr->chksum = 0;
   tcphdr->urgp = 0;