ftp: retry getpeername for FTP with TCP_FASTOPEN

In the case of TFO, the remote host name is not resolved at the
connetion time.

For FTP that has lead to missing hostname for the secondary connection.
Therefore the name resolution is done at the time, when FTP requires it.

Fixes #6252
Closes #6265
Closes #6282

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/ftp.c b/lib/ftp.c
index b18c9ef34..50e7d7dda 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -1940,6 +1940,17 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn,
 #endif
   {
     /* normal, direct, ftp connection */
+    DEBUGASSERT(ftpc->newhost);
+
+    /* postponed address resolution in case of tcp fastopen */
+    if(conn->bits.tcp_fastopen && !conn->bits.reuse && !ftpc->newhost[0]) {
+      Curl_conninfo_remote(conn, conn->sock[FIRSTSOCKET]);
+      Curl_safefree(ftpc->newhost);
+      ftpc->newhost = strdup(control_address(conn));
+      if(!ftpc->newhost)
+        return CURLE_OUT_OF_MEMORY;
+    }
+
     rc = Curl_resolv(conn, ftpc->newhost, ftpc->newport, FALSE, &addr);
     if(rc == CURLRESOLV_PENDING)
       /* BLOCKING */