Richard Atterer fixed libcurl's way of dealing with the EPSV

response. Previously, libcurl would re-resolve the host name with the new
port number and attempt to connect to that, while it should use the IP from
the control channel. This bug made it hard to EPSV from an FTP server with
multiple IP addresses!

1 files changed, 8 insertions, 9 deletions

diff --git a/lib/ftp.c b/lib/ftp.c
index 47cb361aa..cc667acdb 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -1519,8 +1519,8 @@ CURLcode ftp_use_pasv(struct connectdata *conn,
 
   /* newhost must be able to hold a full IP-style address in ASCII, which
      in the IPv6 case means 5*8-1 = 39 letters */
-  char newhost[48];
-  char *newhostp=NULL;
+#define NEWHOST_BUFSIZE 48
+  char newhost[NEWHOST_BUFSIZE];
 
 #ifdef PF_INET6
   if(!conn->bits.ftp_use_epsv &&
@@ -1584,7 +1584,6 @@ CURLcode ftp_use_pasv(struct connectdata *conn,
 
     snprintf(newhost, sizeof(newhost),
              "%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
-    newhostp = newhost;
     newport = (port[0]<<8) + port[1];
   }
   else if (229 == results[modeoff]) {
@@ -1613,8 +1612,8 @@ CURLcode ftp_use_pasv(struct connectdata *conn,
         if(ptr) {
           newport = num;
 
-          /* we should use the same host we already are connected to */
-          newhostp = conn->host.name;
+          /* We must use the same IP we are already connected to */
+          Curl_printable_address(conn->ip_addr, newhost, NEWHOST_BUFSIZE);
         }
       }
       else
@@ -1646,12 +1645,12 @@ CURLcode ftp_use_pasv(struct connectdata *conn,
   }
   else {
     /* normal, direct, ftp connection */
-    rc = Curl_resolv(conn, newhostp, newport, &addr);
+    rc = Curl_resolv(conn, newhost, newport, &addr);
     if(rc == CURLRESOLV_PENDING)
       rc = Curl_wait_for_resolv(conn, &addr);
 
     if(!addr) {
-      failf(data, "Can't resolve new host %s:%d", newhostp, newport);
+      failf(data, "Can't resolve new host %s:%d", newhost, newport);
       return CURLE_FTP_CANT_GET_HOST;
     }
     connectport = newport; /* we connect to the remote port */
@@ -1676,13 +1675,13 @@ CURLcode ftp_use_pasv(struct connectdata *conn,
 
   if(data->set.verbose)
     /* this just dumps information about this second connection */
-    ftp_pasv_verbose(conn, conninfo, newhostp, connectport);
+    ftp_pasv_verbose(conn, conninfo, newhost, connectport);
 
 #ifndef CURL_DISABLE_HTTP
   if(conn->bits.tunnel_proxy) {
     /* We want "seamless" FTP operations through HTTP proxy tunnel */
     result = Curl_ConnectHTTPProxyTunnel(conn, SECONDARYSOCKET,
-                                         newhostp, newport);
+                                         newhost, newport);
     if(CURLE_OK != result)
       return result;
   }