director: Preserve old mail server state when a new director connects to ring.

--HG--
branch : HEAD

diff --git a/src/director/director-connection.c b/src/director/director-connection.c
index 61f912c6cbe00d2ee0d69618857f70627be5818d..8789791c3d0ec75290aa7fc8602fc869a697700d 100644 (file)
--- a/src/director/director-connection.c
+++ b/src/director/director-connection.c
@@ -47,6 +47,7 @@ struct director_connection {
        unsigned int version_received:1;
        unsigned int me_received:1;
        unsigned int handshake_received:1;
+       unsigned int ignore_host_events:1;
 };
 
 static void director_connection_ping(struct director_connection *conn);
@@ -232,6 +233,34 @@ static bool director_cmd_director(struct director_connection *conn,
        return TRUE;
 }
 
+static bool
+director_cmd_host_hand_start(struct director_connection *conn,
+                            const char *const *args)
+{
+       const ARRAY_TYPE(mail_host) *hosts;
+       struct mail_host *const *hostp;
+       unsigned int remote_ring_completed;
+
+       if (args == NULL || str_to_uint(args[0], &remote_ring_completed) < 0) {
+               i_error("director(%s): Invalid HOST-HAND-START args",
+                       conn->name);
+               return FALSE;
+       }
+
+       if (remote_ring_completed && !conn->dir->ring_handshaked) {
+               /* clear everything we have and use only what remote sends us */
+               hosts = mail_hosts_get();
+               while (array_count(hosts) > 0) {
+                       hostp = array_idx(hosts, 0);
+                       director_remove_host(conn->dir, conn->host, *hostp);
+               }
+       } else if (!remote_ring_completed && conn->dir->ring_handshaked) {
+               /* ignore whatever remote sends */
+               conn->ignore_host_events = TRUE;
+       }
+       return TRUE;
+}
+
 static bool
 director_cmd_host(struct director_connection *conn, const char *const *args)
 {
@@ -246,6 +275,11 @@ director_cmd_host(struct director_connection *conn, const char *const *args)
                i_error("director(%s): Invalid HOST args", conn->name);
                return FALSE;
        }
+       if (conn->ignore_host_events) {
+               /* remote is sending hosts in a handshake, but it doesn't have
+                  a completed ring and we do. */
+               return TRUE;
+       }
 
        host = mail_host_lookup(&ip);
        if (host == NULL) {
@@ -363,6 +397,13 @@ director_connection_handle_handshake(struct director_connection *conn,
                return director_cmd_director(conn, args);
        if (conn->in && strcmp(cmd, "HOST") == 0 && conn->me_received)
                return director_cmd_host(conn, args);
+       if (strcmp(cmd, "HOST-HAND-START") == 0)
+               return director_cmd_host_hand_start(conn, args);
+       if (strcmp(cmd, "HOST-HAND-END") == 0) {
+               conn->ignore_host_events = TRUE;
+               return TRUE;
+       }
+
        /* only incoming connections get a USER list */
        if (conn->in && strcmp(cmd, "USER") == 0 && conn->me_received)
                return director_handshake_cmd_user(conn, args);
@@ -536,14 +577,17 @@ static void director_connection_send_directors(struct director_connection *conn,
        }
 }
 
-static void director_connection_send_hosts(string_t *str)
+static void
+director_connection_send_hosts(struct director_connection *conn, string_t *str)
 {
        struct mail_host *const *hostp;
 
+       str_printfa(str, "HOST-HAND-START\t%u\n", conn->dir->ring_handshaked);
        array_foreach(mail_hosts_get(), hostp) {
                str_printfa(str, "HOST\t%s\t%u\n",
                            net_ip2addr(&(*hostp)->ip), (*hostp)->vhost_count);
        }
+       str_printfa(str, "HOST-HAND-END\t%u\n", conn->dir->ring_handshaked);
 }
 
 static int director_connection_send_users(struct director_connection *conn)
@@ -650,7 +694,7 @@ static void director_connection_connected(struct director_connection *conn)
 
        director_connection_send_handshake(conn);
        director_connection_send_directors(conn, str);
-       director_connection_send_hosts(str);
+       director_connection_send_hosts(conn, str);
        director_connection_send(conn, str_c(str));
 
        conn->user_iter = user_directory_iter_init(dir->users);