Truncate exclusion names to have a terminal '\0'

[lttng-tools.git] / src / bin / lttng-sessiond / agent.c

diff --git a/src/bin/lttng-sessiond/agent.c b/src/bin/lttng-sessiond/agent.c
index a4b1b34344bea6f4527df623190187a33d0efe19..f6f2f772e08af693c26268e10b0dfda5bed08d09 100644 (file)
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -15,7 +15,6 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <assert.h>
 #include <urcu/uatomic.h>
@@ -127,6 +126,12 @@ static int ht_match_event(struct cds_lfht_node *node,
                goto no_match;
        }
 
+       /* Filter expression */
+       if (strncmp(event->filter_expression, key->filter_expression,
+                       strlen(event->filter_expression)) != 0) {
+               goto no_match;
+       }
+
        return 1;
 
 no_match:
@@ -149,6 +154,7 @@ static void add_unique_agent_event(struct lttng_ht *ht,
        key.name = event->name;
        key.loglevel_value = event->loglevel_value;
        key.loglevel_type = event->loglevel_type;
+       key.filter_expression = event->filter_expression;
 
        node_ptr = cds_lfht_add_unique(ht->ht,
                        ht->hash_fct(event->node.key, lttng_ht_seed),
@@ -361,7 +367,9 @@ error:
 static int enable_event(struct agent_app *app, struct agent_event *event)
 {
        int ret;
+       char *bytes_to_send;
        uint64_t data_size;
+       size_t filter_expression_length;
        uint32_t reply_ret_code;
        struct lttcomm_agent_enable msg;
        struct lttcomm_agent_generic_reply reply;
@@ -373,7 +381,16 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
        DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name,
                        app->pid, app->sock->fd);
 
-       data_size = sizeof(msg);
+       /*
+        * Calculate the payload's size, which is the fixed-size struct followed
+        * by the variable-length filter expression (+1 for the ending \0).
+        */
+       if (!event->filter_expression) {
+               filter_expression_length = 0;
+       } else {
+               filter_expression_length = strlen(event->filter_expression) + 1;
+       }
+       data_size = sizeof(msg) + filter_expression_length;
 
        ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
        if (ret < 0) {
@@ -381,10 +398,25 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
        }
 
        memset(&msg, 0, sizeof(msg));
-       msg.loglevel_value = event->loglevel_value;
-       msg.loglevel_type = event->loglevel_type;
+       msg.loglevel_value = htobe32(event->loglevel_value);
+       msg.loglevel_type = htobe32(event->loglevel_type);
        strncpy(msg.name, event->name, sizeof(msg.name));
-       ret = send_payload(app->sock, &msg, sizeof(msg));
+       msg.filter_expression_length = htobe32(filter_expression_length);
+
+       bytes_to_send = zmalloc(data_size);
+       if (!bytes_to_send) {
+               ret = LTTNG_ERR_NOMEM;
+               goto error;
+       }
+
+       memcpy(bytes_to_send, &msg, sizeof(msg));
+       if (filter_expression_length > 0) {
+               memcpy(bytes_to_send + sizeof(msg), event->filter_expression,
+                               filter_expression_length);
+       }
+
+       ret = send_payload(app->sock, bytes_to_send, data_size);
+       free(bytes_to_send);
        if (ret < 0) {
                goto error_io;
        }
@@ -834,8 +866,10 @@ struct agent_event *agent_create_event(const char *name,
 {
        struct agent_event *event = NULL;
 
-       DBG3("Agent create new event with name %s, loglevel type %d and loglevel value %d",
-               name, loglevel_type, loglevel_value);
+       DBG3("Agent create new event with name %s, loglevel type %d, \
+                       loglevel value %d and filter %s",
+                       name, loglevel_type, loglevel_value,
+                       filter_expression ? filter_expression : "NULL");
 
        if (!name) {
                ERR("Failed to create agent event; no name provided.");
@@ -918,7 +952,7 @@ void agent_event_next_duplicate(const char *name,
 }
 
 /*
- * Find a agent event in the given agent using name and loglevel.
+ * Find a agent event in the given agent using name, loglevel and filter.
  *
  * RCU read side lock MUST be acquired. It must be kept for as long as
  * the returned agent_event is used.
@@ -927,7 +961,7 @@ void agent_event_next_duplicate(const char *name,
  */
 struct agent_event *agent_find_event(const char *name,
                enum lttng_loglevel_type loglevel_type, int loglevel_value,
-               struct agent *agt)
+               char *filter_expression, struct agent *agt)
 {
        struct lttng_ht_node_str *node;
        struct lttng_ht_iter iter;
@@ -942,6 +976,7 @@ struct agent_event *agent_find_event(const char *name,
        key.name = name;
        key.loglevel_value = loglevel_value;
        key.loglevel_type = loglevel_type;
+       key.filter_expression = filter_expression;
 
        cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
                        ht_match_event, &key, &iter.iter);