darwinssl: Fix bug where packets were sometimes transmitted twice

There was a bug where, if SSLWrite() returned errSSLWouldBlock but did
succeed in transmitting at least something, then we'd incorrectly
resend the packet. Now we never take errSSLWouldBlock as a sign that
nothing was transferred to/from the server.

Bug: http://curl.haxx.se/mail/lib-2013-01/0295.html
Reported by: Bruno de Carvalho

diff --git a/lib/curl_darwinssl.c b/lib/curl_darwinssl.c
index e8fa2758beea5423be59e7b57bfef049caf09959..827c876e0e4b1e4e249368734757ce8b86f08f07 100644 (file)
--- a/lib/curl_darwinssl.c
+++ b/lib/curl_darwinssl.c
@@ -5,8 +5,8 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 2012, Nick Zitzmann, <nickzman@gmail.com>.
- * Copyright (C) 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2012-2013, Nick Zitzmann, <nickzman@gmail.com>.
+ * Copyright (C) 2012-2013, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -1383,12 +1383,14 @@ static ssize_t darwinssl_send(struct connectdata *conn,
 {
   /*struct SessionHandle *data = conn->data;*/
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
-  size_t processed;
+  size_t processed = 0UL;
   OSStatus err = SSLWrite(connssl->ssl_ctx, mem, len, &processed);
 
   if(err != noErr) {
     switch (err) {
-      case errSSLWouldBlock:  /* we're not done yet; keep sending */
+      case errSSLWouldBlock:  /* return how much we sent (if anything) */
+        if(processed)
+          return (ssize_t)processed;
         *curlcode = CURLE_AGAIN;
         return -1;
         break;
@@ -1411,12 +1413,14 @@ static ssize_t darwinssl_recv(struct connectdata *conn,
 {
   /*struct SessionHandle *data = conn->data;*/
   struct ssl_connect_data *connssl = &conn->ssl[num];
-  size_t processed;
+  size_t processed = 0UL;
   OSStatus err = SSLRead(connssl->ssl_ctx, buf, buffersize, &processed);
 
   if(err != noErr) {
     switch (err) {
-      case errSSLWouldBlock:  /* we're not done yet; keep reading */
+      case errSSLWouldBlock:  /* return how much we read (if anything) */
+        if(processed)
+          return (ssize_t)processed;
         *curlcode = CURLE_AGAIN;
         return -1;
         break;