relay/remote: check that remote API is exactly the same version as local one upon connection

src/plugins/relay/api/remote/relay-remote-event.c

@@ -33,6 +33,7 @@
 #include "../../../weechat-plugin.h"
 #include "../../relay.h"
 #include "../../relay-auth.h"
+#include "../../relay-config.h"
 #include "../../relay-http.h"
 #include "../../relay-raw.h"
 #include "../../relay-remote.h"
@@ -804,6 +805,7 @@ RELAY_REMOTE_EVENT_CALLBACK(version)
 {
     cJSON *json_obj;
     const char *weechat_version, *weechat_version_git, *relay_api_version;
+    char *weechat_version_local, request[1024];
 
     if (!event->json)
         return WEECHAT_RC_OK;
@@ -819,6 +821,40 @@ RELAY_REMOTE_EVENT_CALLBACK(version)
                     weechat_version_git,
                     relay_api_version);
 
+    if (!event->remote->version_ok)
+    {
+        /* check version: the remote API must be exactly the same as local API */
+        if (strcmp (relay_api_version, RELAY_API_VERSION_STR) != 0)
+        {
+                weechat_version_local = weechat_info_get ("version", NULL);
+                weechat_printf (
+                    NULL,
+                    _("%sremote[%s]: API version mismatch: "
+                      "remote API is %s (WeeChat %s), "
+                      "local API %s (WeeChat %s)"),
+                    weechat_prefix ("error"),
+                    event->remote->name,
+                    relay_api_version,
+                    weechat_version,
+                    RELAY_API_VERSION_STR,
+                    weechat_version_local);
+                free (weechat_version_local);
+                relay_remote_network_disconnect (event->remote);
+                return WEECHAT_RC_OK;
+        }
+
+        event->remote->version_ok = 1;
+        snprintf (request, sizeof (request),
+                  "{\"request\": \"GET /api/buffers?"
+                  "lines=-%d"
+                  "&nicks=true"
+                  "&colors=weechat"
+                  "\"}",
+                  weechat_config_integer (relay_config_api_remote_get_lines));
+        relay_remote_network_send (event->remote, RELAY_MSG_STANDARD,
+                                   request, strlen (request));
+    }
+
     return WEECHAT_RC_OK;
 }
 

src/plugins/relay/api/remote/relay-remote-network.c

@@ -34,7 +34,6 @@
 #include "../../../weechat-plugin.h"
 #include "../../relay.h"
 #include "../../relay-auth.h"
-#include "../../relay-config.h"
 #include "../../relay-http.h"
 #include "../../relay-raw.h"
 #include "../../relay-remote.h"
@@ -105,6 +104,7 @@ relay_remote_network_close_connection (struct t_relay_remote *remote)
         remote->sock = -1;
     }
     relay_websocket_deflate_reinit (remote->ws_deflate);
+    remote->version_ok = 0;
     remote->synced = 0;
     if (remote->partial_ws_frame)
     {
@@ -383,12 +383,6 @@ relay_remote_network_recv_text (struct t_relay_remote *remote,
                   "{\"request\": \"GET /api/version\"}");
         relay_remote_network_send (remote, RELAY_MSG_STANDARD,
                                    request, strlen (request));
-        snprintf (request, sizeof (request),
-                  "{\"request\": \"GET /api/buffers?"
-                  "lines=-%d&nicks=true&colors=weechat\"}",
-                  weechat_config_integer (relay_config_api_remote_get_lines));
-        relay_remote_network_send (remote, RELAY_MSG_STANDARD,
-                                   request, strlen (request));
     }
     else
     {

src/plugins/relay/relay-remote.c

@@ -340,6 +340,7 @@ relay_remote_alloc (const char *name)
     new_remote->hook_fd = NULL;
     new_remote->gnutls_sess = NULL;
     new_remote->ws_deflate = relay_websocket_deflate_alloc ();
+    new_remote->version_ok = 0;
     new_remote->synced = 0;
     new_remote->partial_ws_frame = NULL;
     new_remote->partial_ws_frame_size = 0;
@@ -577,6 +578,7 @@ relay_remote_new_with_infolist (struct t_infolist *infolist)
             }
         }
     }
+    new_remote->version_ok = weechat_infolist_integer (infolist, "version_ok");
     new_remote->synced = weechat_infolist_integer (infolist, "synced");
     ptr_ws_frame = weechat_infolist_buffer (infolist, "partial_ws_frame", &ws_frame_size);
     if (ptr_ws_frame && (ws_frame_size > 0))
@@ -941,6 +943,8 @@ relay_remote_add_to_infolist (struct t_infolist *infolist,
             free (dict);
         }
     }
+    if (!weechat_infolist_new_var_integer (ptr_item, "version_ok", remote->version_ok))
+        return 0;
     if (!weechat_infolist_new_var_integer (ptr_item, "synced", remote->synced))
         return 0;
 
@@ -992,6 +996,7 @@ relay_remote_print_log ()
         weechat_log_printf ("  hook_fd . . . . . . . . : 0x%lx", ptr_remote->hook_fd);
         weechat_log_printf ("  gnutls_sess . . . . . . : 0x%lx", ptr_remote->gnutls_sess);
         relay_websocket_deflate_print_log (ptr_remote->ws_deflate, "");
+        weechat_log_printf ("  version_ok. . . . . . . : %d", ptr_remote->version_ok);
         weechat_log_printf ("  synced. . . . . . . . . : %d", ptr_remote->synced);
         weechat_log_printf ("  partial_ws_frame. . . . : %p (%d bytes)",
                             ptr_remote->partial_ws_frame,

src/plugins/relay/relay-remote.h

@@ -57,6 +57,7 @@ struct t_relay_remote
     struct t_hook *hook_fd;            /* hook for socket                   */
     gnutls_session_t gnutls_sess;      /* gnutls session (only if TLS used) */
     struct t_relay_websocket_deflate *ws_deflate; /* websocket deflate data */
+    int version_ok;                    /* remote API version is OK?         */
     int synced;                        /* 1 if synced with remote           */
     char *partial_ws_frame;            /* part. binary websocket frame recv */
     int partial_ws_frame_size;         /* size of partial websocket frame   */