Fix: set session should not set non-existent session

set-session does not check the existence of a session before setting
it as the current session. Fix it so that it gives error for a
non-existent session.

Fixes #885

Signed-off-by: Partha Pratim Mukherjee <ppm.floss@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng/commands/set_session.c b/src/bin/lttng/commands/set_session.c
index 4238016e40867c897299678d41097e2e497b33c6..423421deb2bdba337a2e20cae03951bc16cda605 100644 (file)
--- a/src/bin/lttng/commands/set_session.c
+++ b/src/bin/lttng/commands/set_session.c
@@ -59,11 +59,34 @@ static void usage(FILE *ofp)
 static int set_session(void)
 {
        int ret = CMD_SUCCESS;
+       int count, i;
+       unsigned int session_found = 0;
+       struct lttng_session *sessions;
 
        if (opt_session_name && strlen(opt_session_name) > NAME_MAX) {
                ERR("Session name too long. Length must be lower or equal to %d",
                        NAME_MAX);
                ret = CMD_ERROR;
+               goto end;
+       }
+
+       count = lttng_list_sessions(&sessions);
+       if (count < 0) {
+               ret = CMD_ERROR;
+               ERR("%s", lttng_strerror(count));
+               goto end;
+       }
+
+       for (i = 0; i < count; i++) {
+               if (strncmp(sessions[i].name, opt_session_name, NAME_MAX) == 0) {
+                       session_found = 1;
+                       break;
+               }
+       }
+
+       if (!session_found) {
+               ERR("Session '%s' not found", opt_session_name);
+               ret = CMD_ERROR;
                goto error;
        }
 
@@ -78,6 +101,8 @@ static int set_session(void)
        ret = CMD_SUCCESS;
 
 error:
+       free(sessions);
+end:
        return ret;
 }