Duane Cathey was one of our friends who reported that curl -P [IP]

(CURLOPT_FTPPORT) didn't work for ipv6-enabed curls if the IP wasn't a
"native" IP while it works fine for ipv6-disabled builds!

In the process of fixing this, I removed the support for LPRT since I can't
think of many reasons to keep doing it and asking on the mailing list didn't
reveal anyone else that could either. The code that sends EPRT and PORT is
now also a lot simpler than before (IMHO).

1 files changed, 86 insertions, 101 deletions

diff --git a/lib/ftp.c b/lib/ftp.c
index 2361c89ec..3cdcc32ef 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2005, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2006, 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
@@ -763,7 +763,11 @@ static CURLcode ftp_state_cwd(struct connectdata *conn)
   return result;
 }
 
-typedef enum { EPRT, LPRT, PORT, DONE } ftpport;
+typedef enum {
+  EPRT,
+  PORT,
+  DONE
+} ftpport;
 
 static CURLcode ftp_state_use_port(struct connectdata *conn,
                                    ftpport fcmd) /* start with this */
@@ -773,6 +777,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
   struct FTP *ftp = conn->proto.ftp;
   struct SessionHandle *data=conn->data;
   curl_socket_t portsock= CURL_SOCKET_BAD;
+  char myhost[256] = "";
 
 #ifdef ENABLE_IPV6
   /******************************************************************
@@ -783,14 +788,15 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
   socklen_t sslen;
   char hbuf[NI_MAXHOST];
   struct sockaddr *sa=(struct sockaddr *)&ss;
-  unsigned char *ap;
-  unsigned char *pp;
-  char portmsgbuf[1024], tmp[1024];
-  const char *mode[] = { "EPRT", "LPRT", "PORT", NULL };
+  char tmp[1024];
+  const char *mode[] = { "EPRT", "PORT", NULL };
   int rc;
   int error;
   char *host=NULL;
   struct Curl_dns_entry *h=NULL;
+  unsigned short port;
+
+  /* Step 1, figure out what address that is requested */
 
   if(data->set.ftpport && (strlen(data->set.ftpport) > 1)) {
     /* attempt to get the address of the given interface name */
@@ -833,6 +839,9 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
   else
     res = NULL; /* failure! */
 
+
+  /* step 2, create a socket for the requested address */
+
   portsock = CURL_SOCKET_BAD;
   error = 0;
   for (ai = res; ai; ai = ai->ai_next) {
@@ -847,35 +856,65 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
       error = Curl_ourerrno();
       continue;
     }
+    break;
+  }
+  if(!ai) {
+    failf(data, "socket failure: %s", Curl_strerror(conn, error));
+    return CURLE_FTP_PORT_FAILED;
+  }
 
-    if (bind(portsock, ai->ai_addr, ai->ai_addrlen) < 0) {
-      error = Curl_ourerrno();
+  /* step 3, bind to a suitable local address */
+
+  /* Try binding the given address. */
+  if (bind(portsock, ai->ai_addr, ai->ai_addrlen) < 0) {
+
+    /* It failed. Bind the address used for the control connection instead */
+    sslen = sizeof(ss);
+
+    if (getsockname(conn->sock[FIRSTSOCKET],
+                    (struct sockaddr *)sa, &sslen) < 0) {
+      failf(data, "getsockname() failed");
       sclose(portsock);
-      portsock = CURL_SOCKET_BAD;
-      continue;
+      return CURLE_FTP_PORT_FAILED;
     }
 
-    if (listen(portsock, 1) < 0) {
-      error = Curl_ourerrno();
+    /* set port number to zero to make bind() pick "any" */
+    if(((struct sockaddr *)sa)->sa_family == AF_INET)
+      ((struct sockaddr_in *)sa)->sin_port=0;
+    else
+      ((struct sockaddr_in6 *)sa)->sin6_port =0;
+
+    if(bind(portsock, (struct sockaddr *)sa, sslen) < 0) {
+      failf(data, "bind failed: %s", Curl_strerror(conn, Curl_ourerrno()));
       sclose(portsock);
-      portsock = CURL_SOCKET_BAD;
-      continue;
+      return CURLE_FTP_PORT_FAILED;
     }
-
-    break;
   }
 
-  if (portsock == CURL_SOCKET_BAD) {
-    failf(data, "socket failure: %s", Curl_strerror(conn,error));
+  /* get the name again after the bind() so that we can extract the
+     port number it uses now */
+  sslen = sizeof(ss);
+  if(getsockname(portsock, (struct sockaddr *)sa, &sslen)<0) {
+    failf(data, "getsockname() failed: %s",
+          Curl_strerror(conn, Curl_ourerrno()) );
     return CURLE_FTP_PORT_FAILED;
   }
 
-  sslen = sizeof(ss);
-  if (getsockname(portsock, sa, &sslen) < 0) {
-    failf(data, "getsockname(): %s", Curl_strerror(conn,Curl_ourerrno()));
+  /* step 4, listen on the socket */
+
+  if (listen(portsock, 1) < 0) {
+    error = Curl_ourerrno();
+    sclose(portsock);
+    failf(data, "socket failure: %s", Curl_strerror(conn, error));
     return CURLE_FTP_PORT_FAILED;
   }
 
+  /* step 5, send the proper FTP command */
+
+  /* get a plain printable version of the numerical address to work with
+     below */
+  Curl_printable_address(ai, myhost, sizeof(myhost));
+
 #ifdef PF_INET6
   if(!conn->bits.ftp_use_eprt && conn->bits.ipv6)
     /* EPRT is disabled but we are connected to a IPv6 host, so we ignore the
@@ -884,107 +923,58 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
 #endif
 
   for (; fcmd != DONE; fcmd++) {
-    int lprtaf, eprtaf;
-    int alen=0, plen=0;
 
     if(!conn->bits.ftp_use_eprt && (EPRT == fcmd))
       /* if disabled, goto next */
       continue;
 
-    if(!conn->bits.ftp_use_lprt && (LPRT == fcmd))
-      /* if disabled, goto next */
-      continue;
-
     switch (sa->sa_family) {
     case AF_INET:
-      ap = (unsigned char *)&((struct sockaddr_in *)&ss)->sin_addr;
-      alen = sizeof(((struct sockaddr_in *)&ss)->sin_addr);
-      pp = (unsigned char *)&((struct sockaddr_in *)&ss)->sin_port;
-      plen = sizeof(((struct sockaddr_in *)&ss)->sin_port);
-      lprtaf = 4;
-      eprtaf = 1;
+      port = ntohs(((struct sockaddr_in *)sa)->sin_port);
       break;
     case AF_INET6:
-      ap = (unsigned char *)&((struct sockaddr_in6 *)&ss)->sin6_addr;
-      alen = sizeof(((struct sockaddr_in6 *)&ss)->sin6_addr);
-      pp = (unsigned char *)&((struct sockaddr_in6 *)&ss)->sin6_port;
-      plen = sizeof(((struct sockaddr_in6 *)&ss)->sin6_port);
-      lprtaf = 6;
-      eprtaf = 2;
+      port = ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
       break;
     default:
-      ap = pp = NULL;
-      lprtaf = eprtaf = -1;
       break;
     }
 
     if (EPRT == fcmd) {
-      if (eprtaf < 0)
-        continue;
-      if (getnameinfo((struct sockaddr *)&ss, sslen,
-                      portmsgbuf, sizeof(portmsgbuf), tmp, sizeof(tmp),
-                      NIFLAGS))
-        continue;
-
-      /* do not transmit IPv6 scope identifier to the wire */
-      if (sa->sa_family == AF_INET6) {
-        char *q = strchr(portmsgbuf, '%');
-        if (q)
-          *q = '\0';
-      }
+      /*
+       * Two fine examples from RFC2428;
+       *
+       * EPRT |1|132.235.1.2|6275|
+       *
+       * EPRT |2|1080::8:800:200C:417A|5282|
+       */
 
-      result = Curl_nbftpsendf(conn, "%s |%d|%s|%s|", mode[fcmd], eprtaf,
-                               portmsgbuf, tmp);
+      result = Curl_nbftpsendf(conn, "%s |%d|%s|%d|", mode[fcmd],
+                               ai->ai_family == AF_INET?1:2,
+                               myhost, port);
       if(result)
         return result;
       break;
     }
-    else if ((LPRT == fcmd) || (PORT == fcmd)) {
-      int i;
+    else if (PORT == fcmd) {
+      char *source = myhost;
+      char *dest = tmp;
 
-      if ((LPRT == fcmd) && lprtaf < 0)
-        continue;
-      if ((PORT == fcmd) && sa->sa_family != AF_INET)
+      if ((PORT == fcmd) && ai->ai_family != AF_INET)
         continue;
 
-      portmsgbuf[0] = '\0';
-      if (LPRT == fcmd) {
-        snprintf(tmp, sizeof(tmp), "%d,%d", lprtaf, alen);
-        if (strlcat(portmsgbuf, tmp, sizeof(portmsgbuf)) >=
-            sizeof(portmsgbuf)) {
-          continue;
-        }
-      }
-
-      for (i = 0; i < alen; i++) {
-        if (portmsgbuf[0])
-          snprintf(tmp, sizeof(tmp), ",%u", ap[i]);
+      /* translate x.x.x.x to x,x,x,x */
+      while(source && *source) {
+        if(*source == '.')
+          *dest=',';
         else
-          snprintf(tmp, sizeof(tmp), "%u", ap[i]);
-
-        if (strlcat(portmsgbuf, tmp, sizeof(portmsgbuf)) >=
-            sizeof(portmsgbuf)) {
-          continue;
-        }
-      }
-
-      if (LPRT == fcmd) {
-        snprintf(tmp, sizeof(tmp), ",%d", plen);
-
-        if (strlcat(portmsgbuf, tmp, sizeof(portmsgbuf)) >= sizeof(portmsgbuf))
-          continue;
+          *dest = *source;
+        dest++;
+        source++;
       }
+      *dest = 0;
+      snprintf(dest, 20, ",%d,%d", port>>8, port&0xff);
 
-      for (i = 0; i < plen; i++) {
-        snprintf(tmp, sizeof(tmp), ",%u", pp[i]);
-
-        if (strlcat(portmsgbuf, tmp, sizeof(portmsgbuf)) >=
-            sizeof(portmsgbuf)) {
-          continue;
-        }
-      }
-
-      result = Curl_nbftpsendf(conn, "%s %s", mode[fcmd], portmsgbuf);
+      result = Curl_nbftpsendf(conn, "%s %s", mode[fcmd], tmp);
       if(result)
         return result;
       break;
@@ -1007,7 +997,6 @@ static CURLcode ftp_state_use_port(struct connectdata *conn,
    */
   struct sockaddr_in sa;
   unsigned short porttouse;
-  char myhost[256] = "";
   bool sa_filled_in = FALSE;
   Curl_addrinfo *addr = NULL;
   unsigned short ip[4];
@@ -1735,10 +1724,6 @@ static CURLcode ftp_state_port_resp(struct connectdata *conn,
       infof(data, "disabling EPRT usage\n");
       conn->bits.ftp_use_eprt = FALSE;
     }
-    else if (LPRT == fcmd) {
-      infof(data, "disabling LPRT usage\n");
-      conn->bits.ftp_use_lprt = FALSE;
-    }
     fcmd++;
 
     if(fcmd == DONE) {