login-common: Optimize kicking proxy connections by username

Track proxy connections by username in a hash table. Kicking only needs to
do a hash lookup from there to find the user's all sessions. Only detached
proxies are tracked this way. It's likely not worth the trouble to track
non-detached pending proxies in this way, since normally there shouldn't be
many of them.

diff --git a/src/login-common/login-proxy.c b/src/login-common/login-proxy.c
index dc8f3c1ccdbb3245ebb0b6ca9cc4bf9c319d5058..03147cbb4a28ac84a3bf347ba427d480b293fdb2 100644 (file)
--- a/src/login-common/login-proxy.c
+++ b/src/login-common/login-proxy.c
@@ -10,6 +10,7 @@
 #include "iostream-ssl.h"
 #include "llist.h"
 #include "array.h"
+#include "hash.h"
 #include "str.h"
 #include "strescape.h"
 #include "time-util.h"
@@ -49,6 +50,9 @@ struct login_proxy_redirect {
 
 struct login_proxy {
        struct login_proxy *prev, *next;
+       /* Linked list of the proxies with the same virtual_user within
+          login_proxies_hash. This is set only after the proxy is detached. */
+       struct login_proxy *user_prev, *user_next;
 
        struct client *client;
        struct event *event;
@@ -90,6 +94,7 @@ struct login_proxy {
 
 static struct login_proxy_state *proxy_state;
 static struct login_proxy *login_proxies = NULL;
+static HASH_TABLE(char *, struct login_proxy *) login_proxies_hash;
 static struct login_proxy *login_proxies_pending = NULL;
 static struct login_proxy *login_proxies_disconnecting = NULL;
 static unsigned int detached_login_proxies_count = 0;
@@ -487,6 +492,48 @@ static void login_proxy_disconnect(struct login_proxy *proxy)
        proxy->connected = FALSE;
 }
 
+static void login_proxy_detached_link(struct login_proxy *proxy)
+{
+       struct login_proxy *first_proxy;
+       char *user;
+
+       if (!hash_table_lookup_full(login_proxies_hash,
+                                   proxy->client->virtual_user,
+                                   &user, &first_proxy)) {
+               user = i_strdup(proxy->client->virtual_user);
+               hash_table_insert(login_proxies_hash, user, proxy);
+       } else {
+               DLLIST_PREPEND_FULL(&first_proxy, proxy, user_prev, user_next);
+               hash_table_update(login_proxies_hash, user, proxy);
+       }
+
+       DLLIST_PREPEND(&login_proxies, proxy);
+       detached_login_proxies_count++;
+}
+
+static void login_proxy_detached_unlink(struct login_proxy *proxy)
+{
+       struct login_proxy *first_proxy;
+       char *user;
+
+       i_assert(detached_login_proxies_count > 0);
+       detached_login_proxies_count--;
+
+       DLLIST_REMOVE(&login_proxies, proxy);
+
+       if (!hash_table_lookup_full(login_proxies_hash,
+                                   proxy->client->virtual_user,
+                                   &user, &first_proxy))
+               i_unreached();
+       DLLIST_REMOVE_FULL(&first_proxy, proxy, user_prev, user_next);
+       if (first_proxy != NULL)
+               hash_table_update(login_proxies_hash, user, first_proxy);
+       else {
+               hash_table_remove(login_proxies_hash, user);
+               i_free(user);
+       }
+}
+
 static void login_proxy_free_final(struct login_proxy *proxy)
 {
        i_assert(proxy->server_ssl_iostream == NULL);
@@ -600,7 +647,7 @@ login_proxy_free_full(struct login_proxy **_proxy, const char *log_msg,
        if (proxy->detached) {
                /* detached proxy */
                i_assert(log_msg != NULL || proxy->client->destroyed);
-               DLLIST_REMOVE(&login_proxies, proxy);
+               login_proxy_detached_unlink(proxy);
 
                if ((flags & LOGIN_PROXY_FREE_FLAG_DELAYED) != 0)
                        delay_ms = login_proxy_delay_disconnect(proxy);
@@ -612,8 +659,6 @@ login_proxy_free_full(struct login_proxy **_proxy, const char *log_msg,
                               "%s - disconnecting client in %ums",
                               log_msg, delay_ms);
                }
-               i_assert(detached_login_proxies_count > 0);
-               detached_login_proxies_count--;
 
                struct master_service_anvil_session anvil_session = {
                        .username = client->virtual_user,
@@ -939,8 +984,7 @@ void login_proxy_detach(struct login_proxy *proxy)
                proxy->anvil_connect_sent = TRUE;
 
        DLLIST_REMOVE(&login_proxies_pending, proxy);
-       DLLIST_PREPEND(&login_proxies, proxy);
-       detached_login_proxies_count++;
+       login_proxy_detached_link(proxy);
 
        client->login_proxy = NULL;
 }
@@ -1029,35 +1073,20 @@ void login_proxy_kill_idle(void)
        }
 }
 
-static bool
-want_kick_user(struct login_proxy *proxy, const char *const *userp,
-              unsigned int key_idx ATTR_UNUSED)
-{
-       return strcmp(proxy->client->virtual_user, *userp) == 0;
-}
-
-static bool
-want_kick_user_session(struct login_proxy *proxy, const char *const *args,
-                      unsigned int key_idx ATTR_UNUSED)
-{
-       return strcmp(proxy->client->virtual_user, args[0]) == 0 &&
-               guid_128_cmp(proxy->anvil_conn_guid, (const uint8_t *)args[1]) == 0;
-}
-
-static unsigned int
-login_proxy_kick(const char *const *args,
-                bool (*want_kick)(struct login_proxy *, const char *const *,
-                                  unsigned int), unsigned int key_idx)
+unsigned int
+login_proxy_kick_user_connection(const char *user, const guid_128_t conn_guid)
 {
        struct login_proxy *proxy, *next;
        unsigned int count = 0;
+       bool match_conn_guid = conn_guid != NULL &&
+               !guid_128_is_empty(conn_guid);
 
-       i_assert(args[0] != NULL);
+       proxy = hash_table_lookup(login_proxies_hash, user);
+       for (; proxy != NULL; proxy = next) T_BEGIN {
+               next = proxy->user_next;
 
-       for (proxy = login_proxies; proxy != NULL; proxy = next) T_BEGIN {
-               next = proxy->next;
-
-               if (want_kick(proxy, args, key_idx)) {
+               if (!match_conn_guid ||
+                   guid_128_cmp(proxy->anvil_conn_guid, conn_guid) == 0) {
                        login_proxy_free_full(&proxy,
                                LOGIN_PROXY_KILL_PREFIX KILLED_BY_ADMIN_REASON,
                                KILLED_BY_ADMIN_REASON,
@@ -1069,7 +1098,9 @@ login_proxy_kick(const char *const *args,
        for (proxy = login_proxies_pending; proxy != NULL; proxy = next) T_BEGIN {
                next = proxy->next;
 
-               if (want_kick(proxy, args, key_idx)) {
+               if (strcmp(proxy->client->virtual_user, user) == 0 &&
+                   (!match_conn_guid ||
+                    guid_128_cmp(proxy->anvil_conn_guid, conn_guid) == 0)) {
                        client_disconnect(proxy->client,
                                LOGIN_PROXY_KILL_PREFIX KILLED_BY_ADMIN_REASON,
                                FALSE);
@@ -1080,18 +1111,6 @@ login_proxy_kick(const char *const *args,
        return count;
 }
 
-unsigned int
-login_proxy_kick_user_connection(const char *user, const guid_128_t conn_guid)
-{
-       if (conn_guid == NULL || guid_128_is_empty(conn_guid))
-               return login_proxy_kick(&user, want_kick_user, 0);
-
-       const char *const args[] = {
-               user, (const char *)conn_guid
-       };
-       return login_proxy_kick(args, want_kick_user_session, 0);
-}
-
 unsigned int login_proxies_get_detached_count(void)
 {
        return detached_login_proxies_count;
@@ -1105,6 +1124,8 @@ struct client *login_proxies_get_first_detached_client(void)
 void login_proxy_init(const char *proxy_notify_pipe_path)
 {
        proxy_state = login_proxy_state_init(proxy_notify_pipe_path);
+       hash_table_create(&login_proxies_hash, default_pool, 0,
+                         str_hash, strcmp);
 }
 
 void login_proxy_deinit(void)
@@ -1122,5 +1143,8 @@ void login_proxy_deinit(void)
 
        while (login_proxies_disconnecting != NULL)
                login_proxy_free_final(login_proxies_disconnecting);
+
+       i_assert(hash_table_count(login_proxies_hash) == 0);
+       hash_table_destroy(&login_proxies_hash);
        login_proxy_state_deinit(&proxy_state);
 }