X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fagent.c;h=ca2d4c872931632f4e5d46cb9c6b17b6b3d0d8ed;hp=d7bc1b55c698a8d4e490bb8c06df4128da1b9bb2;hb=ab21818442628467073e8d2b303f6d5d78a090f5;hpb=f8be902b22054782d4cc7b67781617030c49225e

diff --git a/src/bin/lttng-sessiond/agent.c b/src/bin/lttng-sessiond/agent.c
index d7bc1b55c..ca2d4c872 100644
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -16,6 +16,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <urcu/uatomic.h>
 
@@ -27,6 +28,44 @@
 #include "agent.h"
 #include "ust-app.h"
 #include "utils.h"
+#include "error.h"
+
+#define AGENT_RET_CODE_INDEX(code) (code - AGENT_RET_CODE_SUCCESS)
+
+/*
+ * Human readable agent return code.
+ */
+static const char *error_string_array[] = {
+	[ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_SUCCESS) ] = "Success",
+	[ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_INVALID) ] = "Invalid command",
+	[ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_UNKNOWN_NAME) ] = "Unknown logger name",
+
+	/* Last element */
+	[ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_NR) ] = "Unknown code",
+};
+
+static
+void log_reply_code(uint32_t in_reply_ret_code)
+{
+	int level = PRINT_DBG3;
+	/*
+	 * reply_ret_code and in_reply_ret_code are kept separate to have a
+	 * sanitized value (used to retrieve the human readable string) and the
+	 * original value which is logged as-is.
+	 */
+	uint32_t reply_ret_code = in_reply_ret_code;
+
+	if (reply_ret_code < AGENT_RET_CODE_SUCCESS ||
+			reply_ret_code >= AGENT_RET_CODE_NR) {
+		reply_ret_code = AGENT_RET_CODE_NR;
+		level = PRINT_ERR;
+	}
+
+	LOG(level, "Agent replied with retcode: %s (%"PRIu32")",
+			error_string_array[AGENT_RET_CODE_INDEX(
+			reply_ret_code)],
+			in_reply_ret_code);
+}
 
 /*
  * Match function for the events hash table lookup by name.
@@ -234,6 +273,7 @@ static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
 	int ret, i, len = 0, offset = 0;
 	uint32_t nb_event;
 	size_t data_size;
+	uint32_t reply_ret_code;
 	struct lttng_event *tmp_events = NULL;
 	struct lttcomm_agent_list_reply *reply = NULL;
 	struct lttcomm_agent_list_reply_hdr reply_hdr;
@@ -256,14 +296,14 @@ static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
 		goto error_io;
 	}
 
-	switch (be32toh(reply_hdr.ret_code)) {
+	reply_ret_code = be32toh(reply_hdr.ret_code);
+	log_reply_code(reply_ret_code);
+	switch (reply_ret_code) {
 	case AGENT_RET_CODE_SUCCESS:
 		data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
 		break;
 	default:
-		ERR("Agent returned an unknown code: %" PRIu32,
-				be32toh(reply_hdr.ret_code));
-		ret = LTTNG_ERR_FATAL;
+		ret = LTTNG_ERR_UNK;
 		goto error;
 	}
 
@@ -319,6 +359,7 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
 {
 	int ret;
 	uint64_t data_size;
+	uint32_t reply_ret_code;
 	struct lttcomm_agent_enable msg;
 	struct lttcomm_agent_generic_reply reply;
 
@@ -350,16 +391,16 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
 		goto error_io;
 	}
 
-	switch (be32toh(reply.ret_code)) {
+	reply_ret_code = be32toh(reply.ret_code);
+	log_reply_code(reply_ret_code);
+	switch (reply_ret_code) {
 	case AGENT_RET_CODE_SUCCESS:
 		break;
 	case AGENT_RET_CODE_UNKNOWN_NAME:
 		ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 		goto error;
 	default:
-		ERR("Agent returned an unknown code: %" PRIu32,
-				be32toh(reply.ret_code));
-		ret = LTTNG_ERR_FATAL;
+		ret = LTTNG_ERR_UNK;
 		goto error;
 	}
 
@@ -381,6 +422,7 @@ static int disable_event(struct agent_app *app, struct agent_event *event)
 {
 	int ret;
 	uint64_t data_size;
+	uint32_t reply_ret_code;
 	struct lttcomm_agent_disable msg;
 	struct lttcomm_agent_generic_reply reply;
 
@@ -410,16 +452,16 @@ static int disable_event(struct agent_app *app, struct agent_event *event)
 		goto error_io;
 	}
 
-	switch (be32toh(reply.ret_code)) {
+	reply_ret_code = be32toh(reply.ret_code);
+	log_reply_code(reply_ret_code);
+	switch (reply_ret_code) {
 	case AGENT_RET_CODE_SUCCESS:
 		break;
 	case AGENT_RET_CODE_UNKNOWN_NAME:
 		ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 		goto error;
 	default:
-		ERR("Agent returned an unknown code: %" PRIu32,
-				be32toh(reply.ret_code));
-		ret = LTTNG_ERR_FATAL;
+		ret = LTTNG_ERR_UNK;
 		goto error;
 	}
 
@@ -493,11 +535,14 @@ error:
 int agent_disable_event(struct agent_event *event,
 		enum lttng_domain_type domain)
 {
-	int ret;
+	int ret = LTTNG_OK;
 	struct agent_app *app;
 	struct lttng_ht_iter iter;
 
 	assert(event);
+	if (!event->enabled) {
+		goto end;
+	}
 
 	rcu_read_lock();
 
@@ -515,10 +560,10 @@ int agent_disable_event(struct agent_event *event,
 	}
 
 	event->enabled = 0;
-	ret = LTTNG_OK;
 
 error:
 	rcu_read_unlock();
+end:
 	return ret;
 }
 
@@ -671,14 +716,13 @@ void agent_add_app(struct agent_app *app)
 	assert(app);
 
 	DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
-
-	rcu_read_lock();
 	lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
-	rcu_read_unlock();
 }
 
 /*
  * Delete agent application from the global hash table.
+ *
+ * rcu_read_lock() must be held by the caller.
  */
 void agent_delete_app(struct agent_app *app)
 {
@@ -690,14 +734,12 @@ void agent_delete_app(struct agent_app *app)
 	DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
 
 	iter.iter.node = &app->node.node;
-	rcu_read_lock();
 	ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
-	rcu_read_unlock();
 	assert(!ret);
 }
 
 /*
- * Destroy a agent application object by detaching it from its corresponding
+ * Destroy an agent application object by detaching it from its corresponding
  * UST app if one is connected by closing the socket. Finally, perform a
  * delayed memory reclaim.
  */
@@ -747,9 +789,7 @@ void agent_add(struct agent *agt, struct lttng_ht *ht)
 
 	DBG3("Agent adding from domain %d", agt->domain);
 
-	rcu_read_lock();
 	lttng_ht_add_unique_u64(ht, &agt->node);
-	rcu_read_unlock();
 }
 
 /*
@@ -899,7 +939,7 @@ struct agent_event *agent_find_event(const char *name, int loglevel,
 	return caa_container_of(node, struct agent_event, node);
 
 error:
-	DBG3("Agent NOT found %s.", name);
+	DBG3("Agent event NOT found %s.", name);
 	return NULL;
 }
 
@@ -912,6 +952,8 @@ void agent_destroy_event(struct agent_event *event)
 {
 	assert(event);
 
+	free(event->filter);
+	free(event->filter_expression);
 	free(event);
 }
 
@@ -959,16 +1001,67 @@ void agent_destroy(struct agent *agt)
 }
 
 /*
- * Initialize agent subsystem.
+ * Allocate agent_apps_ht_by_sock.
  */
-int agent_setup(void)
+int agent_app_ht_alloc(void)
 {
+	int ret = 0;
+
 	agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 	if (!agent_apps_ht_by_sock) {
-		return -1;
+		ret = -1;
 	}
 
-	return 0;
+	return ret;
+}
+
+/*
+ * Destroy a agent application by socket.
+ */
+void agent_destroy_app_by_sock(int sock)
+{
+	struct agent_app *app;
+
+	assert(sock >= 0);
+
+	/*
+	 * Not finding an application is a very important error that should NEVER
+	 * happen. The hash table deletion is ONLY done through this call when the
+	 * main sessiond thread is torn down.
+	 */
+	rcu_read_lock();
+	app = agent_find_app_by_sock(sock);
+	assert(app);
+
+	/* RCU read side lock is assumed to be held by this function. */
+	agent_delete_app(app);
+
+	/* The application is freed in a RCU call but the socket is closed here. */
+	agent_destroy_app(app);
+	rcu_read_unlock();
+}
+
+/*
+ * Clean-up the agent app hash table and destroy it.
+ */
+void agent_app_ht_clean(void)
+{
+	struct lttng_ht_node_ulong *node;
+	struct lttng_ht_iter iter;
+
+	if (!agent_apps_ht_by_sock) {
+		return;
+	}
+	rcu_read_lock();
+	cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
+		struct agent_app *app;
+
+		app = caa_container_of(node, struct agent_app, node);
+		agent_destroy_app_by_sock(app->sock->fd);
+	}
+	rcu_read_unlock();
+
+	lttng_ht_destroy(agent_apps_ht_by_sock);
 }
 
 /*