ftp: add more conditions for connection reuse

Reported-by: Harry Sintonen
Closes #10730

lib/ftp.c

@@ -4092,6 +4092,8 @@ static CURLcode ftp_disconnect(struct Curl_easy *data,
   }
 
   freedirs(ftpc);
+  Curl_safefree(ftpc->account);
+  Curl_safefree(ftpc->alternative_to_user);
   Curl_safefree(ftpc->prevpath);
   Curl_safefree(ftpc->server_os);
   Curl_pp_disconnect(pp);
@@ -4361,11 +4363,31 @@ static CURLcode ftp_setup_connection(struct Curl_easy *data,
   char *type;
   struct FTP *ftp;
   CURLcode result = CURLE_OK;
+  struct ftp_conn *ftpc = &conn->proto.ftpc;
 
-  data->req.p.ftp = ftp = calloc(sizeof(struct FTP), 1);
+  ftp = calloc(sizeof(struct FTP), 1);
   if(!ftp)
     return CURLE_OUT_OF_MEMORY;
 
+  /* clone connection related data that is FTP specific */
+  if(data->set.str[STRING_FTP_ACCOUNT]) {
+    ftpc->account = strdup(data->set.str[STRING_FTP_ACCOUNT]);
+    if(!ftpc->account) {
+      free(ftp);
+      return CURLE_OUT_OF_MEMORY;
+    }
+  }
+  if(data->set.str[STRING_FTP_ALTERNATIVE_TO_USER]) {
+    ftpc->alternative_to_user =
+      strdup(data->set.str[STRING_FTP_ALTERNATIVE_TO_USER]);
+    if(!ftpc->alternative_to_user) {
+      Curl_safefree(ftpc->account);
+      free(ftp);
+      return CURLE_OUT_OF_MEMORY;
+    }
+  }
+  data->req.p.ftp = ftp;
+
   ftp->path = &data->state.up.path[1]; /* don't include the initial slash */
 
   /* FTP URLs support an extension like ";type=<typecode>" that
@@ -4400,7 +4422,9 @@ static CURLcode ftp_setup_connection(struct Curl_easy *data,
   /* get some initial data into the ftp struct */
   ftp->transfer = PPTRANSFER_BODY;
   ftp->downloadsize = 0;
-  conn->proto.ftpc.known_filesize = -1; /* unknown size for now */
+  ftpc->known_filesize = -1; /* unknown size for now */
+  ftpc->use_ssl = data->set.use_ssl;
+  ftpc->ccc = data->set.ftp_ccc;
 
   return result;
 }

lib/ftp.h

@@ -120,6 +120,8 @@ struct FTP {
    struct */
 struct ftp_conn {
   struct pingpong pp;
+  char *account;
+  char *alternative_to_user;
   char *entrypath; /* the PWD reply when we logged on */
   char *file;    /* url-decoded file name (or path) */
   char **dirs;   /* realloc()ed array for path components */
@@ -143,6 +145,9 @@ struct ftp_conn {
   ftpstate state; /* always use ftp.c:state() to change state! */
   ftpstate state_saved; /* transfer type saved to be reloaded after data
                            connection is established */
+  unsigned char use_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
+                              IMAP or POP3 or others! (type: curl_usessl)*/
+  unsigned char ccc;       /* ccc level for this connection */
   BIT(ftp_trying_alternative);
   BIT(dont_check);  /* Set to TRUE to prevent the final (post-transfer)
                        file size and 226/250 status check. It should still

lib/setopt.c

@@ -2369,7 +2369,7 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option, va_list param)
     arg = va_arg(param, long);
     if((arg < CURLUSESSL_NONE) || (arg >= CURLUSESSL_LAST))
       return CURLE_BAD_FUNCTION_ARGUMENT;
-    data->set.use_ssl = (curl_usessl)arg;
+    data->set.use_ssl = (unsigned char)arg;
     break;
 
   case CURLOPT_SSL_OPTIONS:

lib/url.c

@@ -1292,11 +1292,24 @@ ConnectionExists(struct Curl_easy *data,
           || ((check->httpversion >= 30) &&
            (data->state.httpwant < CURL_HTTP_VERSION_3))))
         continue;
-
-      if(get_protocol_family(needle->handler) & PROTO_FAMILY_SSH) {
+#ifdef USE_SSH
+      else if(get_protocol_family(needle->handler) & PROTO_FAMILY_SSH) {
         if(!ssh_config_matches(needle, check))
           continue;
       }
+#endif
+#ifndef CURL_DISABLE_FTP
+      else if(get_protocol_family(needle->handler) & PROTO_FAMILY_FTP) {
+        /* Also match ACCOUNT, ALTERNATIVE-TO-USER, USE_SSL and CCC options */
+        if(Curl_timestrcmp(needle->proto.ftpc.account,
+                           check->proto.ftpc.account) ||
+           Curl_timestrcmp(needle->proto.ftpc.alternative_to_user,
+                           check->proto.ftpc.alternative_to_user) ||
+           (needle->proto.ftpc.use_ssl != check->proto.ftpc.use_ssl) ||
+           (needle->proto.ftpc.ccc != check->proto.ftpc.ccc))
+          continue;
+      }
+#endif
 
       if((needle->handler->flags&PROTOPT_SSL)
 #ifndef CURL_DISABLE_PROXY

lib/urldata.h

@@ -1718,8 +1718,6 @@ struct UserDefined {
 #ifndef CURL_DISABLE_NETRC
   unsigned char use_netrc;        /* enum CURL_NETRC_OPTION values  */
 #endif
-  curl_usessl use_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
-                            IMAP or POP3 or others! */
   unsigned int new_file_perms;      /* when creating remote files */
   char *str[STRING_LAST]; /* array of strings, pointing to allocated memory */
   struct curl_blob *blobs[BLOB_LAST];
@@ -1779,6 +1777,8 @@ struct UserDefined {
   BIT(mail_rcpt_allowfails); /* allow RCPT TO command to fail for some
                                 recipients */
 #endif
+  unsigned char use_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
+                              IMAP or POP3 or others! (type: curl_usessl)*/
   unsigned char connect_only; /* make connection/request, then let
                                  application use the socket */
   BIT(is_fread_set); /* has read callback been set to non-NULL? */