JSON-RPC: add log.subscribe and log.unsubscribe

https://www.unrealircd.org/docs/JSON-RPC:Log

doc/RELEASE-NOTES.md

@@ -58,6 +58,11 @@ You can help us by testing this release and reporting any issues at https://bugs
     and [User](https://www.unrealircd.org/docs/JSON-RPC:User#Structure_of_a_client_object)
     response object will be. Especially useful if you don't need all the
     details in the list calls.
+  * New JSON-RPC methods
+    [`log.subscribe`](https://www.unrealircd.org/docs/JSON-RPC:Log#log.subscribe) and
+    [`log.unsubscribe`](https://www.unrealircd.org/docs/JSON-RPC:Log#log.unsubscribe)
+    to allow real-time streaming of
+    [JSON log events](https://www.unrealircd.org/docs/JSON_logging).
   * New JSON-RPC method
     [`rpc.set_issuer`](https://www.unrealircd.org/docs/JSON-RPC:Rpc#rpc.set_issuer)
     to indiciate who is actually issuing the requests. The admin panel uses this

doc/conf/modules.default.conf

@@ -249,6 +249,7 @@ loadmodule "rpc/server_ban";
 loadmodule "rpc/server_ban_exception";
 loadmodule "rpc/name_ban";
 loadmodule "rpc/spamfilter";
+loadmodule "rpc/log";
 
 /*** Other ***/
 // These are modules that don't fit in any of the previous sections

include/h.h

@@ -1268,7 +1268,7 @@ extern const char *log_type_valtostring(LogType v);
 #endif
 extern void do_unreal_log(LogLevel loglevel, const char *subsystem, const char *event_id, Client *client, const char *msg, ...) __attribute__((format(printf,5,0)));
 extern void do_unreal_log_raw(LogLevel loglevel, const char *subsystem, const char *event_id, Client *client, const char *msg, ...);
-extern void do_unreal_log_internal_from_remote(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, const char *json_serialized, Client *from_server);
+extern void do_unreal_log_internal_from_remote(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, json_t *json, const char *json_serialized, Client *from_server);
 extern LogData *log_data_string(const char *key, const char *str);
 extern LogData *log_data_char(const char *key, const char c);
 extern LogData *log_data_integer(const char *key, int64_t integer);
@@ -1291,6 +1291,9 @@ extern const char *log_level_valtostring(LogLevel loglevel);
 extern LogLevel log_level_stringtoval(const char *str);
 extern int valid_event_id(const char *s);
 extern int valid_subsystem(const char *s);
+extern LogSource *add_log_source(const char *str);
+extern void free_log_sources(LogSource *l);
+extern int log_sources_match(LogSource *logsource, LogLevel loglevel, const char *subsystem, const char *event_id, int matched_already);
 extern const char *timestamp_iso8601_now(void);
 extern const char *timestamp_iso8601(time_t v);
 extern int is_valid_snomask(char c);

include/modules.h

@@ -1839,11 +1839,12 @@ int hooktype_tkl_del(Client *client, TKL *tkl);
  * @param subsystem		Subsystem (eg "operoverride")
  * @param event_id		Event ID (eg "SAJOIN_COMMAND")
  * @param msg			Message(s) in text form
- * @param json_serialized	The associated JSON text
+ * @param json			The JSON log entry
+ * @param json_serialized	The serialized JSON log entry (as a string)
  * @param timebuf		The [xxxx] time buffer, for convenience
  * @return The return value is ignored (use return 0)
  */
-int hooktype_log(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, const char *json_serialized, const char *timebuf);
+int hooktype_log(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, json_t *json, const char *json_serialized, const char *timebuf);
 
 /** Called when a local user matches a spamfilter (function prototype for HOOKTYPE_LOCAL_SPAMFILTER).
  * @param client		The client

include/struct.h

@@ -1443,6 +1443,7 @@ struct RPCClient {
 	char *rpc_user; /**< Name of the rpc-user block after authentication, NULL during pre-auth */
 	char *issuer; /**< Optional name of the issuer, set by rpc.set_issuer(), eg logged in user on admin panel, can be NULL */
 	json_t *rehash_request; /**< If a REHASH (request) is currently running, otherwise NULL */
+	LogSource *log_sources; /**< Subscribed to which log sources */
 };
 
 struct MessageTag {

src/list.c

@@ -147,6 +147,19 @@ Client *make_client(Client *from, Client *servr)
 	return client;
 }
 
+/** Free the client->rpc struct.
+ * NOTE: if you want to fully free the entire client, call free_client()
+ */
+void free_client_rpc(Client *client)
+{
+	safe_free(client->rpc->rpc_user);
+	safe_free(client->rpc->issuer);
+	if (client->rpc->rehash_request)
+		json_decref(client->rpc->rehash_request);
+	free_log_sources(client->rpc->log_sources);
+	safe_free(client->rpc);
+}
+
 void free_client(Client *client)
 {
 	if (!list_empty(&client->client_node))
@@ -191,15 +204,10 @@ void free_client(Client *client)
 			del_from_id_hash_table(client->id, client);
 		}
 	}
+
 	if (client->rpc)
-	{
-		safe_free(client->rpc->rpc_user);
-		safe_free(client->rpc->issuer);
-		if (client->rpc->rehash_request)
-			json_decref(client->rpc->rehash_request);
-		safe_free(client->rpc);
-	}
-	
+		free_client_rpc(client);
+
 	safe_free(client->ip);
 
 	mp_pool_release(client);

src/log.c

@@ -880,7 +880,7 @@ literal:
 }
 
 /** Do the actual writing to log files */
-void do_unreal_log_disk(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, const char *json_serialized, Client *from_server)
+void do_unreal_log_disk(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, json_t *json, const char *json_serialized, Client *from_server)
 {
 	static time_t last_log_file_warning = 0;
 	Log *l;
@@ -893,7 +893,7 @@ void do_unreal_log_disk(LogLevel loglevel, const char *subsystem, const char *ev
 
 	snprintf(timebuf, sizeof(timebuf), "[%s] ", myctime(TStime()));
 
-	RunHook(HOOKTYPE_LOG, loglevel, subsystem, event_id, msg, json_serialized, timebuf);
+	RunHook(HOOKTYPE_LOG, loglevel, subsystem, event_id, msg, json, json_serialized, timebuf);
 
 	if (!loop.forked && (loglevel > ULOG_DEBUG))
 	{
@@ -1535,7 +1535,7 @@ void do_unreal_log_internal(LogLevel loglevel, const char *subsystem, const char
 
 	/* Now call all the loggers: */
 
-	do_unreal_log_disk(loglevel, subsystem, event_id, mmsg, json_serialized, from_server);
+	do_unreal_log_disk(loglevel, subsystem, event_id, mmsg, j, json_serialized, from_server);
 
 	if ((loop.rehashing == 2) || !strcmp(subsystem, "config"))
 		do_unreal_log_control(loglevel, subsystem, event_id, mmsg, j, json_serialized, from_server);
@@ -1572,14 +1572,14 @@ void do_unreal_log_internal(LogLevel loglevel, const char *subsystem, const char
 }
 
 void do_unreal_log_internal_from_remote(LogLevel loglevel, const char *subsystem, const char *event_id,
-                                        MultiLine *msg, const char *json_serialized, Client *from_server)
+                                        MultiLine *msg, json_t *json, const char *json_serialized, Client *from_server)
 {
 	if (unreal_log_recursion_trap)
 		return;
 	unreal_log_recursion_trap = 1;
 
 	/* Call the disk loggers */
-	do_unreal_log_disk(loglevel, subsystem, event_id, msg, json_serialized, from_server);
+	do_unreal_log_disk(loglevel, subsystem, event_id, msg, json, json_serialized, from_server);
 
 	/* And to IRC */
 	do_unreal_log_opers(loglevel, subsystem, event_id, msg, json_serialized, from_server);

src/modules/rpc/Makefile.in

@@ -32,7 +32,9 @@ INCLUDES = ../../include/channel.h \
 	../../include/version.h ../../include/whowas.h
 
 R_MODULES= \
-	rpc.so stats.so user.so server.so channel.so server_ban.so server_ban_exception.so name_ban.so spamfilter.so
+	rpc.so stats.so user.so server.so channel.so server_ban.so \
+	server_ban_exception.so name_ban.so spamfilter.so \
+	log.so
 
 MODULES=$(R_MODULES)
 MODULEFLAGS=@MODULEFLAGS@

src/modules/rpc/log.c

@@ -0,0 +1,136 @@
+/* log.* RPC calls
+ * (C) Copyright 2023-.. Bram Matthys (Syzop) and the UnrealIRCd team
+ * License: GPLv2 or later
+ */
+
+#include "unrealircd.h"
+
+ModuleHeader MOD_HEADER
+= {
+	"rpc/log",
+	"1.0.0",
+	"log.* RPC calls",
+	"UnrealIRCd Team",
+	"unrealircd-6",
+};
+
+/* Forward declarations */
+void rpc_log_hook_subscribe(Client *client, json_t *request, json_t *params);
+void rpc_log_hook_unsubscribe(Client *client, json_t *request, json_t *params);
+int rpc_log_hook(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, json_t *json, const char *json_serialized, const char *timebuf);
+
+MOD_INIT()
+{
+	RPCHandlerInfo r;
+
+	MARK_AS_OFFICIAL_MODULE(modinfo);
+
+	memset(&r, 0, sizeof(r));
+	r.method = "log.subscribe";
+	r.loglevel = ULOG_DEBUG;
+	r.call = rpc_log_hook_subscribe;
+	if (!RPCHandlerAdd(modinfo->handle, &r))
+	{
+		config_error("[rpc/log] Could not register RPC handler");
+		return MOD_FAILED;
+	}
+
+	memset(&r, 0, sizeof(r));
+	r.method = "log.unsubscribe";
+	r.loglevel = ULOG_DEBUG;
+	r.call = rpc_log_hook_unsubscribe;
+	if (!RPCHandlerAdd(modinfo->handle, &r))
+	{
+		config_error("[rpc/log] Could not register RPC handler");
+		return MOD_FAILED;
+	}
+
+	HookAdd(modinfo->handle, HOOKTYPE_LOG, 0, rpc_log_hook);
+
+	return MOD_SUCCESS;
+}
+
+MOD_LOAD()
+{
+	return MOD_SUCCESS;
+}
+
+MOD_UNLOAD()
+{
+	return MOD_SUCCESS;
+}
+
+void rpc_log_hook_subscribe(Client *client, json_t *request, json_t *params)
+{
+	json_t *result;
+	json_t *sources;
+	size_t index;
+	json_t *value;
+	const char *str;
+	LogSource *s;
+
+	sources = json_object_get(params, "sources");
+	if (!sources || !json_is_array(sources))
+	{
+		rpc_error_fmt(client, request, JSON_RPC_ERROR_INVALID_PARAMS, "Missing parameter: '%s'", "sources");
+		return;
+	}
+
+	/* Erase the old subscriptions first */
+	free_log_sources(client->rpc->log_sources);
+	client->rpc->log_sources = NULL;
+
+	/* Add subscriptions... */
+	json_array_foreach(sources, index, value)
+	{
+		str = json_get_value(value);
+		if (!str)
+			continue;
+
+		s = add_log_source(str);
+		AddListItem(s, client->rpc->log_sources);
+	}
+
+	result = json_boolean(1);
+
+	rpc_response(client, request, result);
+	json_decref(result);
+}
+
+/** log.unsubscribe: unsubscribe from all log messages */
+void rpc_log_hook_unsubscribe(Client *client, json_t *request, json_t *params)
+{
+	json_t *result;
+
+	free_log_sources(client->rpc->log_sources);
+	client->rpc->log_sources = NULL;
+	result = json_boolean(1);
+	rpc_response(client, request, result);
+	json_decref(result);
+}
+
+int rpc_log_hook(LogLevel loglevel, const char *subsystem, const char *event_id, MultiLine *msg, json_t *json, const char *json_serialized, const char *timebuf)
+{
+	Client *client;
+	json_t *request = NULL;
+
+	list_for_each_entry(client, &unknown_list, lclient_node)
+	{
+		if (IsRPC(client) && client->rpc->log_sources &&
+		    log_sources_match(client->rpc->log_sources, loglevel, subsystem, event_id, 0))
+		{
+			if (request == NULL)
+			{
+				/* Lazy initalization */
+				request = json_object();
+				json_object_set_new(request, "method", json_string_unreal("log.event"));
+			}
+			rpc_response(client, request, json);
+		}
+	}
+
+	if (request)
+		json_decref(request);
+
+	return 0;
+}

src/modules/slog.c

@@ -157,7 +157,7 @@ CMD_FUNC(cmd_slog)
 	json_serialized = json_dumps(j, JSON_COMPACT);
 
 	if (json_serialized)
-		do_unreal_log_internal_from_remote(loglevel, subsystem, event_id, mmsg, json_serialized, client);
+		do_unreal_log_internal_from_remote(loglevel, subsystem, event_id, mmsg, j, json_serialized, client);
 
 	/* Broadcast to the other servers */
 	sendto_server(client, 0, 0, recv_mtags, ":%s SLOG %s %s %s :%s",