Fix: relayd: hostname check is too restrictive
[lttng-tools.git] / src / bin / lttng-relayd / session.c
index 605931d5bd82ed449143de9b6f9c6b870bb59a2b..00dfbd7d2e6e5c873b01dd66b80a7d3098198162 100644 (file)
 
 #define _LGPL_SOURCE
 #include <common/common.h>
+#include <common/uuid.h>
+#include <common/time.h>
 #include <common/utils.h>
-#include <common/compat/uuid.h>
+#include <common/uuid.h>
+#include <common/compat/path.h>
 #include <urcu/rculist.h>
 
+#include <sys/stat.h>
+
 #include "ctf-trace.h"
 #include "lttng-relayd.h"
 #include "session.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 session_set_anonymous_chunk(struct relay_session *session)
+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;
-       struct lttng_trace_chunk *chunk = NULL;
-       enum lttng_trace_chunk_status status;
-       struct lttng_directory_handle output_directory;
-       const char *base_path = opt_output_path;
-
-       if (base_path == NULL) {
-               /* No output path defined */
-               base_path = utils_get_home_dir();
-               if (base_path == NULL) {
-                       ERR("Home path not found.\n \
-                                       Please specify an output path using -o, --output PATH");
+
+       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;
        }
 
-       ret = lttng_directory_handle_init(&output_directory, base_path);
+       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;
+
+       output_directory = session_create_output_directory_handle(session);
+       if (!output_directory) {
                goto end;
        }
 
@@ -68,19 +204,51 @@ 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.
  *
@@ -101,19 +269,21 @@ struct relay_session *session_create(const char *session_name,
        int ret;
        struct relay_session *session = NULL;
 
-       if (session_name && strstr(session_name, ".")) {
-               ERR("Illegal character in session name: \"%s\"",
-                               session_name);
+       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 (base_path && strstr(base_path, "../")) {
-               ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
-                               base_path);
+       if (!is_name_path_safe(hostname)) {
+               ERR("Refusing to create session as the provided hostname is not path-safe");
                goto error;
        }
-       if (hostname && strstr(hostname, ".")) {
-               ERR("Invalid character in hostname: \"%s\"",
-                               hostname);
+       if (strstr(base_path, "../")) {
+               ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
+                               base_path);
                goto error;
        }
 
@@ -168,6 +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) {
@@ -182,7 +360,7 @@ 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,
@@ -291,7 +469,7 @@ 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);
@@ -301,6 +479,9 @@ 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();
@@ -380,3 +561,35 @@ 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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