anvil: Always use a new admin-connection for KICK-USER-SIGNAL commands

Otherwise the race condition prevention doesn't work. Also it may have
attempted to send the KICK-USER-SIGNAL command to admin-client connection,
which would respond with "Unknown command".

diff --git a/src/anvil/anvil-connection.c b/src/anvil/anvil-connection.c
index 98e0fc0ec903bb45e8c0896073272157d6de903d..f97c91322a221ebb920323374a70804ed6204638 100644 (file)
--- a/src/anvil/anvil-connection.c
+++ b/src/anvil/anvil-connection.c
@@ -15,6 +15,7 @@
 #include "master-interface.h"
 #include "connect-limit.h"
 #include "penalty.h"
+#include "admin-client.h"
 #include "anvil-connection.h"
 
 #include <unistd.h>
@@ -61,6 +62,8 @@ struct anvil_cmd_kick_target {
        char *service;
        pid_t pid;
        enum kick_type kick_type;
+
+       struct admin_client *client;
 };
 
 struct anvil_cmd_kick {
@@ -77,6 +80,7 @@ static HASH_TABLE(struct anvil_connection_key *, struct anvil_connection *)
 static unsigned int anvil_global_kick_count = 0;
 static unsigned int anvil_global_cmd_counter = 0;
 static unsigned int anvil_global_connect_dump_count = 0;
+static char *anvil_base_dir;
 
 static void anvil_connection_destroy(struct connection *_conn);
 
@@ -211,6 +215,8 @@ kick_user_callback(const char *reply, const char *error,
                        target->username, target->service,
                        (long)target->pid, reply);
        }
+
+       admin_client_unref(&target->client);
        if (--kick->cmd_refcount == 0)
                kick_user_finished(kick);
        i_free(target->username);
@@ -218,6 +224,24 @@ kick_user_callback(const char *reply, const char *error,
        i_free(target);
 }
 
+static void
+kick_user_with_signal(struct anvil_cmd_kick_target *target, const char *cmd)
+{
+       /* Always create a new admin-client connection to the destination
+          process, even if one already existed. This way the process's signal
+          handler can accept() the connection and handle the kick command
+          immediately. */
+       target->client =
+               admin_client_init(anvil_base_dir, target->service, target->pid);
+       admin_client_send_cmd(target->client, cmd, kick_user_callback, target);
+       if (kill(target->pid, SIGTERM) == 0)
+               target->kick->kick_count++;
+       else if (errno != ESRCH) {
+               e_error(target->kick->conn->conn.event, "kill(%ld) failed: %m",
+                       (long)target->pid);
+       }
+}
+
 static void
 kick_user_iter(struct anvil_connection *conn, struct connect_limit_iter *iter,
               bool add_conn_guid)
@@ -277,16 +301,12 @@ kick_user_iter(struct anvil_connection *conn, struct connect_limit_iter *iter,
 
                        anvil_global_kick_count++;
                        kick->cmd_refcount++;
-                       admin_cmd_send(result.service, result.pid, str_c(cmd),
-                                      kick_user_callback, target);
-                       if (result.kick_type == KICK_TYPE_SIGNAL_WITH_SOCKET) {
-                               if (kill(result.pid, SIGTERM) == 0)
-                                       kick->kick_count++;
-                               else if (errno != ESRCH) {
-                                       e_error(conn->conn.event,
-                                               "kill(%ld) failed: %m",
-                                               (long)result.pid);
-                               }
+                       if (result.kick_type == KICK_TYPE_SIGNAL_WITH_SOCKET)
+                               kick_user_with_signal(target, str_c(cmd));
+                       else {
+                               admin_cmd_send(result.service, result.pid,
+                                              str_c(cmd),
+                                              kick_user_callback, target);
                        }
                        break;
                }
@@ -718,8 +738,9 @@ static struct connection_vfuncs anvil_connections_vfuncs = {
        .input_line = anvil_connection_input_line,
 };
 
-void anvil_connections_init(void)
+void anvil_connections_init(const char *base_dir)
 {
+       anvil_base_dir = i_strdup(base_dir);
        hash_table_create(&anvil_connections_hash, default_pool, 0,
                          anvil_connection_key_hash, anvil_connection_key_cmp);
        anvil_connections = connection_list_init(&anvil_connections_set,
@@ -732,4 +753,5 @@ void anvil_connections_deinit(void)
 
        i_assert(hash_table_count(anvil_connections_hash) == 0);
        hash_table_destroy(&anvil_connections_hash);
+       i_free(anvil_base_dir);
 }

diff --git a/src/anvil/anvil-connection.h b/src/anvil/anvil-connection.h
index ec16577b9eec70716978d36024f576aa810c6f50..0f1139a48911e60122f6a57a77978f50125ebc7e 100644 (file)
--- a/src/anvil/anvil-connection.h
+++ b/src/anvil/anvil-connection.h
@@ -21,7 +21,7 @@ void anvil_get_global_counts(unsigned int *connection_count_r,
                             unsigned int *cmd_counter_r,
                             unsigned int *connect_dump_counter_r);
 
-void anvil_connections_init(void);
+void anvil_connections_init(const char *base_dir);
 void anvil_connections_deinit(void);
 
 #endif

diff --git a/src/anvil/main.c b/src/anvil/main.c
index af8f21cca30492ca6c7a2ecd66642bff1567e816..4319f750109f1218cb54e2f5b1a36c146fe852e3 100644 (file)
--- a/src/anvil/main.c
+++ b/src/anvil/main.c
@@ -130,7 +130,7 @@ static void main_init(void)
 
        verbose_proctitle = set->verbose_proctitle;
        anvil_restarted = getenv("ANVIL_RESTARTED") != NULL;
-       anvil_connections_init();
+       anvil_connections_init(set->base_dir);
        admin_clients_init();
        admin_pool = admin_client_pool_init(set->base_dir,
                                            ANVIL_CLIENT_POOL_MAX_CONNECTIONS);