sendrecv: make them two pairs of send/recv to properly deal with FTPS

FTP(S) use two connections that can be set to different recv and
send functions independently, so by introducing recv+send pairs
in the same manner we already have sockets/connections we can
work with FTPS fine.

This commit fixes the FTPS regression introduced in change d64bd82.

lib/gtls.c

@@ -633,8 +633,8 @@ gtls_connect_step3(struct connectdata *conn,
   infof(data, "\t MAC: %s\n", ptr);
 
   conn->ssl[sockindex].state = ssl_connection_complete;
-  conn->recv = gtls_recv;
+  conn->recv[sockindex] = gtls_recv;
-  conn->send = gtls_send;
+  conn->send[sockindex] = gtls_send;
 
   {
     /* we always unconditionally get the session id here, as even if we

lib/nss.c

@@ -1339,8 +1339,8 @@ CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
   }
 
   connssl->state = ssl_connection_complete;
-  conn->recv = nss_recv;
+  conn->recv[sockindex] = nss_recv;
-  conn->send = nss_send;
+  conn->send[sockindex] = nss_send;
 
   display_conn_info(conn, connssl->handle);
 

lib/polarssl.c

@@ -302,8 +302,8 @@ Curl_polarssl_connect(struct connectdata *conn,
   }
 
   conn->ssl[sockindex].state = ssl_connection_complete;
-  conn->recv = polarssl_recv;
+  conn->recv[sockindex] = polarssl_recv;
-  conn->send = polarssl_send;
+  conn->send[sockindex] = polarssl_send;
 
   /* Save the current session data for possible re-use */
   {

lib/qssl.c

@@ -268,8 +268,8 @@ CURLcode Curl_qsossl_connect(struct connectdata * conn, int sockindex)
   }
   if (rc == CURLE_OK) {
     connssl->state = ssl_connection_complete;
-    conn->recv = qsossl_recv;
+    conn->recv[sockindex] = qsossl_recv;
-    conn->send = qsossl_send;
+    conn->send[sockindex] = qsossl_send;
   }
 
   return rc;

lib/security.c

@@ -466,8 +466,10 @@ Curl_sec_login(struct connectdata *conn)
     conn->mech = *m;
     conn->sec_complete = 1;
     if (conn->data_prot != prot_clear) {
-      conn->recv = sec_read;
+      conn->recv[FIRSTSOCKET] = sec_read;
-      conn->send = _sec_send;
+      conn->send[FIRSTSOCKET] = _sec_send;
+      conn->recv[SECONDARYSOCKET] = sec_read;
+      conn->send[SECONDARYSOCKET] = _sec_send;
     }
     conn->command_prot = prot_safe;
     /* Set the requested protection level */

lib/sendf.c

@@ -251,7 +251,7 @@ CURLcode Curl_write(struct connectdata *conn,
   CURLcode curlcode = CURLE_OK;
   int num = (sockfd == conn->sock[SECONDARYSOCKET]);
 
-  bytes_written = conn->send(conn, num, mem, len, &curlcode);
+  bytes_written = conn->send[num](conn, num, mem, len, &curlcode);
 
   *written = bytes_written;
   if(-1 != bytes_written)
@@ -576,7 +576,7 @@ CURLcode Curl_read(struct connectdata *conn, /* connection data */
     buffertofill = buf;
   }
 
-  nread = conn->recv(conn, num, buffertofill, bytesfromsocket, &curlcode);
+  nread = conn->recv[num](conn, num, buffertofill, bytesfromsocket, &curlcode);
   if(nread == -1)
     return curlcode;
 

lib/ssh.c

@@ -2493,11 +2493,11 @@ static CURLcode ssh_connect(struct connectdata *conn, bool *done)
     return result;
 
   if(conn->protocol & PROT_SCP) {
-    conn->recv = scp_recv;
+    conn->recv[FIRSTSOCKET] = scp_recv;
-    conn->send = scp_send;
+    conn->send[FIRSTSOCKET] = scp_send;
   } else {
-    conn->recv = sftp_recv;
+    conn->recv[FIRSTSOCKET] = sftp_recv;
-    conn->send = sftp_send;
+    conn->send[FIRSTSOCKET] = sftp_send;
   }
   ssh = &conn->proto.sshc;
 

lib/ssluse.c

@@ -2440,8 +2440,8 @@ ossl_connect_common(struct connectdata *conn,
 
   if(ssl_connect_done==connssl->connecting_state) {
     connssl->state = ssl_connection_complete;
-    conn->recv = ossl_recv;
+    conn->recv[sockindex] = ossl_recv;
-    conn->send = ossl_send;
+    conn->send[sockindex] = ossl_send;
     *done = TRUE;
   }
   else

lib/url.c

@@ -4754,8 +4754,10 @@ static CURLcode create_conn(struct SessionHandle *data,
     return result;
   }
 
-  conn->recv = Curl_recv_plain;
+  conn->recv[FIRSTSOCKET] = Curl_recv_plain;
-  conn->send = Curl_send_plain;
+  conn->send[FIRSTSOCKET] = Curl_send_plain;
+  conn->recv[SECONDARYSOCKET] = Curl_recv_plain;
+  conn->send[SECONDARYSOCKET] = Curl_send_plain;
 
   /***********************************************************************
    * file: is a special case in that it doesn't need a network connection

lib/urldata.h

@@ -760,8 +760,8 @@ struct connectdata {
   curl_socket_t sock[2]; /* two sockets, the second is used for the data
                             transfer when doing FTP */
 
-  Curl_recv *recv;
+  Curl_recv *recv[2];
-  Curl_send *send;
+  Curl_send *send[2];
 
   struct ssl_connect_data ssl[2]; /* this is for ssl-stuff */
   struct ssl_config_data ssl_config;