[evolution-ews] I#42 - Check also DNS SRV _autodiscover._tcp during autodiscover

[Milan Crha <mcrha src gnome org>]

commit 5888a106ad94728d4e7c8b65984c2a73fa549079
Author: Milan Crha <mcrha redhat com>
Date:   Mon Jun 3 10:51:09 2019 +0200

    I#42 - Check also DNS SRV _autodiscover._tcp during autodiscover
    
    Closes https://gitlab.gnome.org/GNOME/evolution-ews/issues/42

 src/server/e-ews-connection.c | 97 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 90 insertions(+), 7 deletions(-)
---
diff --git a/src/server/e-ews-connection.c b/src/server/e-ews-connection.c
index df626eb0..6847d6af 100644
--- a/src/server/e-ews-connection.c
+++ b/src/server/e-ews-connection.c
@@ -2956,7 +2956,7 @@ e_ews_autodiscover_ws_xml (const gchar *email_address)
 struct _autodiscover_data {
        EEwsConnection *cnc;
        xmlOutputBuffer *buf;
-       SoupMessage *msgs[5];
+       SoupMessage *msgs[6];
 
        GCancellable *cancellable;
        gulong cancel_id;
@@ -3034,11 +3034,11 @@ autodiscover_response_cb (SoupSession *session,
 
        ad = g_simple_async_result_get_op_res_gpointer (simple);
 
-       for (idx = 0; idx < 5; idx++) {
+       for (idx = 0; idx < 6; idx++) {
                if (ad->msgs[idx] == msg)
                        break;
        }
-       if (idx == 5) {
+       if (idx == 6 || (idx == 5 && !ad->msgs[5])) {
                /* We already got removed (cancelled). Do nothing */
                goto unref;
        }
@@ -3141,7 +3141,7 @@ autodiscover_response_cb (SoupSession *session,
        }
 
        /* We have a good response; cancel all the others */
-       for (idx = 0; idx < 5; idx++) {
+       for (idx = 0; idx < 6; idx++) {
                if (ad->msgs[idx]) {
                        SoupMessage *m = ad->msgs[idx];
                        ad->msgs[idx] = NULL;
@@ -3165,7 +3165,7 @@ autodiscover_response_cb (SoupSession *session,
        goto exit;
 
  failed:
-       for (idx = 0; idx < 5; idx++) {
+       for (idx = 0; idx < 6; idx++) {
                if (ad->msgs[idx]) {
                        /* There's another request outstanding.
                         * Hope that it has better luck. */
@@ -3268,6 +3268,67 @@ e_ews_get_msg_for_url (EEwsConnection *cnc,
        return msg;
 }
 
+static void
+autodiscover_srv_record_resolved_cb (GObject *source,
+                                    GAsyncResult *result,
+                                    gpointer user_data)
+{
+       GList *targets, *link;
+       GSimpleAsyncResult *simple = user_data;
+       struct _autodiscover_data *ad;
+       gchar *new_uri = NULL;
+       gboolean success;
+
+       ad = g_simple_async_result_get_op_res_gpointer (simple);
+
+       g_return_if_fail (ad != NULL);
+
+       targets = g_resolver_lookup_service_finish (G_RESOLVER (source), result, NULL);
+
+       success = ad->msgs[5] && targets;
+
+       for (link = targets; link && success; link = g_list_next (link)) {
+               GSrvTarget *target = link->data;
+               const gchar *hostname;
+
+               hostname = g_srv_target_get_hostname (target);
+
+               switch (g_srv_target_get_port (target)) {
+               case 80:
+                       link = NULL;
+                       new_uri = g_strdup_printf ("http://%s/autodiscover/autodiscover.xml";, hostname);
+                       break;
+               case 443:
+                       link = NULL;
+                       new_uri = g_strdup_printf ("https://%s/autodiscover/autodiscover.xml";, hostname);
+                       break;
+               }
+       }
+
+       g_list_free_full (targets, (GDestroyNotify) g_srv_target_free);
+
+       if (new_uri && success) {
+               SoupURI *suri;
+
+               suri = soup_uri_new (new_uri);
+               if (suri) {
+                       soup_message_set_uri (ad->msgs[5], suri);
+                       /* The autodiscover_response_cb will free the 'simple' */
+                       ews_connection_schedule_queue_message (ad->cnc, ad->msgs[5], 
autodiscover_response_cb, simple);
+                       soup_uri_free (suri);
+               } else {
+                       success = FALSE;
+               }
+       } else {
+               success = FALSE;
+       }
+
+       if (!success) {
+               /* The callback also frees the 'simple' */
+               autodiscover_response_cb (NULL, ad->msgs[5], simple);
+       }
+}
+
 gboolean
 e_ews_autodiscover_ws_url_sync (ESource *source,
                                CamelEwsSettings *settings,
@@ -3319,6 +3380,7 @@ e_ews_autodiscover_ws_url (ESource *source,
        EEwsConnection *cnc;
        SoupURI *soup_uri = NULL;
        gboolean use_secure = TRUE;
+       gboolean is_outlook = FALSE;
        const gchar *host_url;
        GError *error = NULL;
 
@@ -3365,15 +3427,18 @@ e_ews_autodiscover_ws_url (ESource *source,
                url1 = g_strdup_printf ("http%s://%s/autodiscover/autodiscover.xml", use_secure ? "s" : "", 
host);
                url2 = g_strdup_printf ("http%s://autodiscover.%s/autodiscover/autodiscover.xml", use_secure 
? "s" : "", host);
 
+               is_outlook = host && g_ascii_strcasecmp (host, "outlook.office365.com") == 0;
+
                /* outlook.office365.com has its autodiscovery at outlook.com */
-               if (host && g_ascii_strcasecmp (host, "outlook.office365.com") == 0 &&
-                   domain && g_ascii_strcasecmp (domain, "outlook.com") != 0) {
+               if (is_outlook && g_ascii_strcasecmp (domain, "outlook.com") != 0) {
                        url5 = "https://outlook.com/autodiscover/autodiscover.xml";;
                }
 
                soup_uri_free (soup_uri);
        }
 
+       is_outlook = is_outlook || g_ascii_strcasecmp (domain, "outlook.com") == 0;
+
        url3 = g_strdup_printf ("http%s://%s/autodiscover/autodiscover.xml", use_secure ? "s" : "", domain);
        url4 = g_strdup_printf ("http%s://autodiscover.%s/autodiscover/autodiscover.xml", use_secure ? "s" : 
"", domain);
 
@@ -3411,6 +3476,24 @@ e_ews_autodiscover_ws_url (ESource *source,
        ad->msgs[3] = e_ews_get_msg_for_url (cnc, settings, url4, buf, NULL);
        ad->msgs[4] = e_ews_get_msg_for_url (cnc, settings, url5, buf, NULL);
 
+       if (!is_outlook && *domain && (ad->msgs[0] || ad->msgs[1] || ad->msgs[2] || ad->msgs[3] || 
ad->msgs[4])) {
+               gchar *tmp;
+
+               tmp = g_strdup_printf ("http%s://%s/", use_secure ? "s" : "", domain);
+
+               /* Fake SoupMessage, for the autodiscovery with SRV record help */
+               ad->msgs[5] = e_ews_get_msg_for_url (cnc, settings, tmp, buf, NULL);
+
+               if (ad->msgs[5]) {
+                       g_resolver_lookup_service_async (g_resolver_get_default (), "autodiscover", "tcp", 
domain, ad->cancellable,
+                               autodiscover_srv_record_resolved_cb, g_object_ref (simple));
+               }
+
+               g_free (tmp);
+       } else {
+               ad->msgs[5] = NULL;
+       }
+
        /* These have to be submitted only after they're both set in ad->msgs[]
         * or there will be races with fast completion */
        if (ad->msgs[0] != NULL)