Fix: relayd: fail to create session when trace chunk is not found
[lttng-tools.git] / src / bin / lttng-relayd / session.c
index 28e75f1dc1804c3f3e3740bca3a7a4e3e9fd9548..1a1cadfdfa1ba3829efe46f217b014fa4983e511 100644 (file)
 
 #define _LGPL_SOURCE
 #include <common/common.h>
-#include <common/compat/uuid.h>
+#include <common/uuid.h>
+#include <common/time.h>
+#include <common/utils.h>
+#include <common/uuid.h>
+#include <common/compat/path.h>
 #include <urcu/rculist.h>
 
-#include "lttng-relayd.h"
+#include <sys/stat.h>
+
 #include "ctf-trace.h"
+#include "lttng-relayd.h"
 #include "session.h"
-#include "stream.h"
 #include "sessiond-trace-chunks.h"
+#include "stream.h"
+#include <common/defaults.h>
+#include "utils.h"
 
 /* Global session id used in the session creation. */
 static uint64_t last_relay_session_id;
 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
 
+static int init_session_output_path_group_by_host(struct relay_session *session)
+{
+       /*
+        * session_directory:
+        *
+        * if base_path is \0'
+        *   hostname/session_name
+        * else
+        *   hostname/base_path
+        */
+       char *session_directory = NULL;
+       int ret = 0;
+
+       if (session->output_path[0] != '\0') {
+               goto end;
+       }
+       /*
+        * If base path is set, it overrides the session name for the
+        * session relative base path. No timestamp is appended if the
+        * base path is overridden.
+        *
+        * If the session name already contains the creation time (e.g.
+        * auto-<timestamp>, don't append yet another timestamp after
+        * the session name in the generated path.
+        *
+        * Otherwise, generate the path with session_name-<timestamp>.
+        */
+       if (session->base_path[0] != '\0') {
+               ret = asprintf(&session_directory, "%s/%s", session->hostname,
+                               session->base_path);
+       } else if (session->session_name_contains_creation_time) {
+               ret = asprintf(&session_directory, "%s/%s", session->hostname,
+                               session->session_name);
+       } else {
+               char session_creation_datetime[DATETIME_STR_LEN];
+
+               ret = time_to_datetime_str(
+                               LTTNG_OPTIONAL_GET(session->creation_time),
+                               session_creation_datetime,
+                               sizeof(session_creation_datetime));
+               if (ret) {
+                       ERR("Failed to format session creation timestamp while initializing session output directory handle");
+                       ret = -1;
+                       goto end;
+               }
+
+               ret = asprintf(&session_directory, "%s/%s-%s",
+                               session->hostname, session->session_name,
+                               session_creation_datetime);
+       }
+       if (ret < 0) {
+               PERROR("Failed to format session directory name");
+               goto end;
+       }
+
+       if (strlen(session_directory) >= LTTNG_PATH_MAX) {
+               ERR("Session output directory exceeds maximal length");
+               ret = -1;
+               goto end;
+       }
+       strcpy(session->output_path, session_directory);
+       ret = 0;
+
+end:
+       free(session_directory);
+       return ret;
+}
+
+static int init_session_output_path_group_by_session(
+               struct relay_session *session)
+{
+       /*
+        * session_directory:
+        *
+        *   session_name/hostname-creation_time/base_path
+        *
+        * For session name including the datetime, use it as the complete name
+        * since. Do not perform modification on it since the datetime is an
+        * integral part of the name and how a user identify a session.
+        */
+       int ret = 0;
+       char *session_directory = NULL;
+       char creation_datetime[DATETIME_STR_LEN];
+
+       if (session->output_path[0] != '\0') {
+               /* output_path as been generated already */
+               goto end;
+       }
+
+       ret = time_to_datetime_str(LTTNG_OPTIONAL_GET(session->creation_time),
+                       creation_datetime, sizeof(creation_datetime));
+       if (ret) {
+               ERR("Failed to format session creation timestamp while initializing session output directory handle");
+               ret = -1;
+               goto end;
+       }
+
+       ret = asprintf(&session_directory, "%s/%s-%s%s%s",
+                       session->session_name, session->hostname,
+                       creation_datetime,
+                       session->base_path[0] != '\0' ? "/" : "",
+                       session->base_path);
+       if (ret < 0) {
+               PERROR("Failed to format session directory name");
+               goto end;
+       }
+
+       if (strlen(session_directory) >= LTTNG_PATH_MAX) {
+               ERR("Session output directory exceeds maximal length");
+               ret = -1;
+               goto end;
+       }
+
+       strcpy(session->output_path, session_directory);
+       ret = 0;
+
+end:
+       free(session_directory);
+       return ret;
+}
+
+static int init_session_output_path(struct relay_session *session)
+{
+       int ret;
+
+       switch (opt_group_output_by) {
+       case RELAYD_GROUP_OUTPUT_BY_HOST:
+               ret = init_session_output_path_group_by_host(session);
+               break;
+       case RELAYD_GROUP_OUTPUT_BY_SESSION:
+               ret = init_session_output_path_group_by_session(session);
+               break;
+       case RELAYD_GROUP_OUTPUT_BY_UNKNOWN:
+       default:
+               abort();
+               break;
+       }
+
+       return ret;
+}
+
 static int session_set_anonymous_chunk(struct relay_session *session)
 {
        int ret = 0;
        struct lttng_trace_chunk *chunk = NULL;
        enum lttng_trace_chunk_status status;
-       struct lttng_directory_handle output_directory;
+       struct lttng_directory_handle *output_directory;
 
-       ret = lttng_directory_handle_init(&output_directory, opt_output_path);
-       if (ret) {
+       output_directory = session_create_output_directory_handle(session);
+       if (!output_directory) {
                goto end;
        }
 
@@ -55,26 +204,58 @@ static int session_set_anonymous_chunk(struct relay_session *session)
                goto end;
        }
 
-       status = lttng_trace_chunk_set_as_owner(chunk, &output_directory);
+       status = lttng_trace_chunk_set_as_owner(chunk, output_directory);
        if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                ret = -1;
                goto end;
        }
+       output_directory = NULL;
        session->current_trace_chunk = chunk;
        chunk = NULL;
 end:
        lttng_trace_chunk_put(chunk);
-       lttng_directory_handle_fini(&output_directory);
+       lttng_directory_handle_put(output_directory);
        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.
  *
  * Return allocated session or else NULL.
  */
 struct relay_session *session_create(const char *session_name,
-               const char *hostname,
+               const char *hostname, const char *base_path,
                uint32_t live_timer,
                bool snapshot,
                const lttng_uuid sessiond_uuid,
@@ -82,10 +263,29 @@ struct relay_session *session_create(const char *session_name,
                const uint64_t *current_chunk_id,
                const time_t *creation_time,
                uint32_t major,
-               uint32_t minor)
+               uint32_t minor,
+               bool session_name_contains_creation_time)
 {
        int ret;
-       struct relay_session *session;
+       struct relay_session *session = NULL;
+
+       assert(session_name);
+       assert(hostname);
+       assert(base_path);
+
+       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, "../")) {
+               ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
+                               base_path);
+               goto error;
+       }
 
        session = zmalloc(sizeof(*session));
        if (!session) {
@@ -102,6 +302,17 @@ struct relay_session *session_create(const char *session_name,
                WARN("Hostname exceeds maximal allowed length");
                goto error;
        }
+       if (lttng_strncpy(session->base_path, base_path,
+                       sizeof(session->base_path))) {
+               WARN("Base path exceeds maximal allowed length");
+               goto error;
+       }
+       if (creation_time) {
+               LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
+       }
+       session->session_name_contains_creation_time =
+                       session_name_contains_creation_time;
+
        session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
        if (!session->ctf_traces_ht) {
                goto error;
@@ -127,6 +338,14 @@ struct relay_session *session_create(const char *session_name,
                LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
        }
 
+       if (major == 2 && minor >= 11) {
+               /* Only applies for 2.11+ peers using trace chunks. */
+               ret = init_session_output_path(session);
+               if (ret) {
+                       goto error;
+               }
+       }
+
        ret = sessiond_trace_chunk_registry_session_created(
                        sessiond_trace_chunk_registry, sessiond_uuid);
        if (ret) {
@@ -141,12 +360,13 @@ struct relay_session *session_create(const char *session_name,
                                        session->id_sessiond.value,
                                        *current_chunk_id);
                if (!session->current_trace_chunk) {
-                       char uuid_str[UUID_STR_LEN];
+                       char uuid_str[LTTNG_UUID_STR_LEN];
 
                        lttng_uuid_to_str(sessiond_uuid, uuid_str);
                        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) {
                /*
@@ -161,9 +381,6 @@ struct relay_session *session_create(const char *session_name,
        }
 
        lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
-       if (creation_time) {
-               LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
-       }
        return session;
 
 error:
@@ -253,7 +470,7 @@ static void destroy_session(struct relay_session *session)
        call_rcu(&session->rcu_node, rcu_destroy_session);
 }
 
-void session_release(struct urcu_ref *ref)
+static void session_release(struct urcu_ref *ref)
 {
        struct relay_session *session =
                        caa_container_of(ref, struct relay_session, ref);
@@ -263,6 +480,9 @@ void session_release(struct urcu_ref *ref)
 
 void session_put(struct relay_session *session)
 {
+       if (!session) {
+               return;
+       }
        rcu_read_lock();
        urcu_ref_put(&session->ref, session_release);
        rcu_read_unlock();
@@ -342,3 +562,35 @@ void print_sessions(void)
        }
        rcu_read_unlock();
 }
+
+struct lttng_directory_handle *session_create_output_directory_handle(
+               struct relay_session *session)
+{
+       int ret;
+       /*
+        * relayd_output_path/session_directory
+        * e.g. /home/user/lttng-traces/hostname/session_name
+        */
+       char *full_session_path = NULL;
+       struct lttng_directory_handle *handle = NULL;
+
+       pthread_mutex_lock(&session->lock);
+       full_session_path = create_output_path(session->output_path);
+       if (!full_session_path) {
+               goto end;
+       }
+
+       ret = utils_mkdir_recursive(
+                       full_session_path, S_IRWXU | S_IRWXG, -1, -1);
+       if (ret) {
+               ERR("Failed to create session output path \"%s\"",
+                               full_session_path);
+               goto end;
+       }
+
+       handle = lttng_directory_handle_create(full_session_path);
+end:
+       pthread_mutex_unlock(&session->lock);
+       free(full_session_path);
+       return handle;
+}
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