Fix: relayd: fail to create session when trace chunk is not found

[lttng-tools.git] / src / bin / lttng-relayd / session.c

diff --git a/src/bin/lttng-relayd/session.c b/src/bin/lttng-relayd/session.c
index df6bc102ae19d434464c636d815959ff65bbe924..1a1cadfdfa1ba3829efe46f217b014fa4983e511 100644 (file)
--- a/src/bin/lttng-relayd/session.c
+++ b/src/bin/lttng-relayd/session.c
@@ -23,6 +23,7 @@
 #include <common/time.h>
 #include <common/utils.h>
 #include <common/uuid.h>
+#include <common/compat/path.h>
 #include <urcu/rculist.h>
 
 #include <sys/stat.h>
@@ -217,6 +218,37 @@ end:
        return ret;
 }
 
+/*
+ * Check if a name is safe to use in a path.
+ *
+ * A name that is deemed "path-safe":
+ *   - Does not contains a path separator (/ or \, platform dependant),
+ *   - Does not start with a '.' (hidden file/folder),
+ *   - Is not empty.
+ */
+static bool is_name_path_safe(const char *name)
+{
+       const size_t name_len = strlen(name);
+
+       /* Not empty. */
+       if (name_len == 0) {
+               WARN("An empty name is not allowed to be used in a path");
+               return false;
+       }
+       /* Does not start with '.'. */
+       if (name[0] == '.') {
+               WARN("Name \"%s\" is not allowed to be used in a path since it starts with '.'", name);
+               return false;
+       }
+       /* Does not contain a path-separator. */
+       if (strchr(name, LTTNG_PATH_SEPARATOR)) {
+               WARN("Name \"%s\" is not allowed to be used in a path since it contains a path separator", name);
+               return false;
+       }
+
+       return true;
+}
+
 /*
  * Create a new session by assigning a new session ID.
  *
@@ -241,9 +273,12 @@ struct relay_session *session_create(const char *session_name,
        assert(hostname);
        assert(base_path);
 
-       if (strstr(session_name, ".")) {
-               ERR("Illegal character in session name: \"%s\"",
-                               session_name);
+       if (!is_name_path_safe(session_name)) {
+               ERR("Refusing to create session as the provided session name is not path-safe");
+               goto error;
+       }
+       if (!is_name_path_safe(hostname)) {
+               ERR("Refusing to create session as the provided hostname is not path-safe");
                goto error;
        }
        if (strstr(base_path, "../")) {
@@ -251,11 +286,6 @@ struct relay_session *session_create(const char *session_name,
                                base_path);
                goto error;
        }
-       if (strstr(hostname, ".")) {
-               ERR("Invalid character in hostname: \"%s\"",
-                               hostname);
-               goto error;
-       }
 
        session = zmalloc(sizeof(*session));
        if (!session) {
@@ -336,6 +366,7 @@ struct relay_session *session_create(const char *session_name,
                        ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
                                        uuid_str, *id_sessiond,
                                        *current_chunk_id);
+                       goto error;
                 }
        } else if (!id_sessiond) {
                /*