Alexey Simak filed bug report #1600447

(http://curl.haxx.se/bug/view.cgi?id=1600447) in which he noted that active
FTP connections don't work with the multi interface. The problem is here that
the multi interface state machine has a state during which it can wait for the
data connection to connect, but the active connection is not done in the same
step in the sequence as the passive one is so it doesn't quite work for
active. The active FTP code still use a blocking function to allow the remote
server to connect.

The fix (work-around is a better word) for this problem is to set the
boolean prematurely that the data connection is completed, so that the "wait
for connect" phase ends at once.

3 files changed, 31 insertions, 5 deletions

diff --git a/CHANGES b/CHANGES
index 0da422072..399fca226 100644
--- a/CHANGES
+++ b/CHANGES
@@ -7,6 +7,22 @@
                                   Changelog
 
 Daniel (5 December 2006)
+- Alexey Simak filed bug report #1600447
+  (http://curl.haxx.se/bug/view.cgi?id=1600447) in which he noted that active
+  FTP connections don't work with the multi interface. The problem is here
+  that the multi interface state machine has a state during which it can wait
+  for the data connection to connect, but the active connection is not done in
+  the same step in the sequence as the passive one is so it doesn't quite work
+  for active. The active FTP code still use a blocking function to allow the
+  remote server to connect.
+
+  The fix (work-around is a better word) for this problem is to set the
+  boolean prematurely that the data connection is completed, so that the "wait
+  for connect" phase ends at once.
+
+  The proper fix, left for the future, is of course to make the active FTP
+  case to act in a non-blocking way too.
+
 - Matt Witherspoon fixed a problem case when the CPU load went to 100% when a
   HTTP upload was disconnected:
 
diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 28cf5837f..2db25e372 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -26,7 +26,8 @@ This release includes the following bugfixes:
  o HTTP responses on persistent connections without Content-Length nor chunked
    encoding are now considered to be without response body
  o Content-Range: header parsing improved
- o CPU 100% load when upload connection broke
+ o CPU 100% load when HTTP upload connection broke
+ o active FTP didn't work with multi interface
 
 Other curl-related news:
 
@@ -44,6 +45,6 @@ advice from friends like these:
 
  James Housley, Olaf Stueben, Yang Tse, Gisle Vanem, Bradford Bruce,
  Ciprian Badescu, Dmitriy Sergeyev, Nir Soffer, Venkat Akella, Toon Verwaest,
- Matt Witherspoon
+ Matt Witherspoon, Alexey Simak
 
         Thanks! (and sorry if I forgot to mention someone)
diff --git a/lib/ftp.c b/lib/ftp.c
index e3d14a2ba..4e4dd5346 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -573,7 +573,7 @@ CURLcode Curl_GetFTPResponse(ssize_t *nreadp, /* return number of bytes read */
 
             /* output debug output if that is requested */
             if(data->set.verbose)
-              Curl_debug(data, CURLINFO_HEADER_IN, 
+              Curl_debug(data, CURLINFO_HEADER_IN,
                          line_start, (size_t)perline, conn);
 
             /*
@@ -1168,6 +1168,15 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
 
 #endif /* end of ipv4-specific code */
 
+  /* this tcpconnect assignment below is a hackish work-around to make the
+     multi interface with active FTP work - as it will not wait for a
+     (passive) connect in Curl_is_connected().
+
+     The *proper* fix is to make sure that the active connection from the
+     server is done in a non-blocking way. Currently, it is still BLOCKING.
+  */
+  conn->bits.tcpconnect = TRUE;
+
   state(conn, FTP_PORT);
   return result;
 }
@@ -3433,7 +3442,7 @@ CURLcode Curl_nbftpsendf(struct connectdata *conn,
     return res;
 
   if(conn->data->set.verbose)
-    Curl_debug(conn->data, CURLINFO_HEADER_OUT, 
+    Curl_debug(conn->data, CURLINFO_HEADER_OUT,
                sptr, (size_t)bytes_written, conn);
 
   if(bytes_written != (ssize_t)write_len) {
@@ -3491,7 +3500,7 @@ CURLcode Curl_ftpsendf(struct connectdata *conn,
       break;
 
     if(conn->data->set.verbose)
-      Curl_debug(conn->data, CURLINFO_HEADER_OUT, 
+      Curl_debug(conn->data, CURLINFO_HEADER_OUT,
                  sptr, (size_t)bytes_written, conn);
 
     if(bytes_written != (ssize_t)write_len) {