imap proxy: Always send post-login capability to client.

The original code did it only when client had used CAPABILITY command. Now
it's also sent in tagged reply to login/authenticate command if the remote
server didn't already add it.

--HG--
branch : HEAD

diff --git a/src/imap-login/imap-proxy.c b/src/imap-login/imap-proxy.c
index b349587db9766c905b7184d601a8b84510133736..e959143b826660bd4c10ea84790876a8afe96634 100644 (file)
--- a/src/imap-login/imap-proxy.c
+++ b/src/imap-login/imap-proxy.c
@@ -52,27 +52,9 @@ static void get_plain_auth(struct client *client, string_t *dest)
        base64_encode(str_data(str), str_len(str), dest);
 }
 
-static void
-client_send_capability_if_needed(struct imap_client *client, string_t *str,
-                                const char *capability)
-{
-       if (!client->client_ignores_capability_resp_code || capability == NULL)
-               return;
-
-       /* reset this so that we don't re-send the CAPABILITY in case server
-          sends it multiple times */
-       client->client_ignores_capability_resp_code = FALSE;
-
-       /* client has used CAPABILITY command, so it didn't understand the
-          capabilities in the banner. send the backend's untagged CAPABILITY
-          reply and hope that the client understands it */
-       str_printfa(str, "* CAPABILITY %s\r\n", capability);
-}
-
 static void proxy_write_login(struct imap_client *client, string_t *str)
 {
-       if (client->client_ignores_capability_resp_code)
-               str_append(str, "C CAPABILITY\r\n");
+       str_append(str, "C CAPABILITY\r\n");
 
        if (client->common.proxy_master_user == NULL) {
                /* logging in normally - use LOGIN command */
@@ -136,11 +118,45 @@ static int proxy_input_banner(struct imap_client *client,
        return 0;
 }
 
+static void
+client_send_login_reply(struct imap_client *client, string_t *str,
+                       const char *line)
+{
+       const char *capability;
+       bool tagged_capability;
+
+       capability = client->proxy_backend_capability;
+       tagged_capability = strncasecmp(line, "[CAPABILITY ", 12) == 0;
+       if (tagged_capability)
+               capability = t_strcut(line + 12, ']');
+
+       if (client->client_ignores_capability_resp_code && capability != NULL) {
+               /* client has used CAPABILITY command, so it didn't understand
+                  the capabilities in the banner. send the backend's untagged
+                  CAPABILITY reply and hope that the client understands it */
+               str_printfa(str, "* CAPABILITY %s\r\n", capability);
+       }
+       str_append(str, client->cmd_tag);
+       str_append(str, " OK ");
+       if (!client->client_ignores_capability_resp_code &&
+           !tagged_capability && capability != NULL) {
+               str_printfa(str, "[CAPABILITY %s] ", capability);
+               if (*line == '[') {
+                       /* we need to send the capability.
+                          skip over this resp-code */
+                       while (*line != ']' && *line != '\0')
+                               line++;
+                       if (*line == ' ') line++;
+               }
+       }
+       str_append(str, line);
+       str_append(str, "\r\n");
+}
+
 int imap_proxy_parse_line(struct client *client, const char *line)
 {
        struct imap_client *imap_client = (struct imap_client *)client;
        struct ostream *output;
-       const char *capability;
        string_t *str;
 
        i_assert(!client->destroyed);
@@ -191,15 +207,8 @@ int imap_proxy_parse_line(struct client *client, const char *line)
                return 1;
        } else if (strncmp(line, "L OK ", 5) == 0) {
                /* Login successful. Send this line to client. */
-               capability = imap_client->proxy_backend_capability;
-               if (strncmp(line + 5, "[CAPABILITY ", 12) == 0)
-                       capability = t_strcut(line + 5 + 12, ']');
-
                str = t_str_new(128);
-               client_send_capability_if_needed(imap_client, str, capability);
-               str_append(str, imap_client->cmd_tag);
-               str_append(str, line + 1);
-               str_append(str, "\r\n");
+               client_send_login_reply(imap_client, str, line + 5);
                (void)o_stream_send(client->output,
                                    str_data(str), str_len(str));