From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Thu, 3 Sep 2015 19:09:00 +0000 (-0400)
Subject: Accept uid and gid parameters in utils_mkdir()/utils_mkdir_recursive()
X-Git-Tag: v2.8.0-rc1~433
X-Git-Url: http://git.lttng.org./?a=commitdiff_plain;h=d77dded285b058e4242c8a3d2233f80e725ceefc;p=lttng-tools.git

Accept uid and gid parameters in utils_mkdir()/utils_mkdir_recursive()

utils_mkdir* utils may now be use in immediate or "run_as" mode.

This is done since some of the code shared between daemons calls
run_as directly, which doesn't support negative uid/gid (which we use
to mean "run as current user").

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 8e1879f50..92d466df7 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1285,7 +1285,8 @@ int relay_add_stream(struct lttcomm_relayd_hdr *recv_hdr,
 	lttng_ht_node_init_u64(&stream->node, stream->stream_handle);
 	pthread_mutex_init(&stream->lock, NULL);
 
-	ret = utils_mkdir_recursive(stream->path_name, S_IRWXU | S_IRWXG);
+	ret = utils_mkdir_recursive(stream->path_name, S_IRWXU | S_IRWXG,
+			-1, -1);
 	if (ret < 0) {
 		ERR("relay creating output directory");
 		goto err_free_stream;
@@ -2828,7 +2829,8 @@ int main(int argc, char **argv)
 			goto exit_options;
 		}
 
-		ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG);
+		ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG,
+				-1, -1);
 		if (ret < 0) {
 			ERR("Unable to create %s", opt_output_path);
 			retval = -1;
diff --git a/src/common/runas.c b/src/common/runas.c
index 9d9091638..36be188fa 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -101,6 +101,9 @@ int use_clone(void)
 }
 #endif
 
+LTTNG_HIDDEN
+int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode);
+
 /*
  * Create recursively directory using the FULL path.
  */
@@ -114,7 +117,8 @@ int _mkdir_recursive(void *_data)
 	path = data->path;
 	mode = data->mode;
 
-	return utils_mkdir_recursive(path, mode);
+	/* Safe to call as we have transitioned to the requested uid/gid. */
+	return _utils_mkdir_recursive_unsafe(path, mode);
 }
 
 static
diff --git a/src/common/utils.c b/src/common/utils.c
index 766f224c7..db2ed8e7d 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -532,12 +532,42 @@ error:
 }
 
 /*
- * Recursively create directory using the given path and mode.
+ * Create directory using the given path and mode.
  *
  * On success, return 0 else a negative error code.
  */
 LTTNG_HIDDEN
-int utils_mkdir_recursive(const char *path, mode_t mode)
+int utils_mkdir(const char *path, mode_t mode, int uid, int gid)
+{
+	int ret;
+
+	if (uid < 0 || gid < 0) {
+		ret = mkdir(path, mode);
+	} else {
+		ret = run_as_mkdir(path, mode, uid, gid);
+	}
+	if (ret < 0) {
+		if (errno != EEXIST) {
+			PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
+					uid, gid);
+		} else {
+			ret = 0;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Internal version of mkdir_recursive. Runs as the current user.
+ * Don't call directly; use utils_mkdir_recursive().
+ *
+ * This function is ominously marked as "unsafe" since it should only
+ * be called by a caller that has transitioned to the uid and gid under which
+ * the directory creation should occur.
+ */
+LTTNG_HIDDEN
+int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode)
 {
 	char *p, tmp[PATH_MAX];
 	size_t len;
@@ -582,7 +612,7 @@ int utils_mkdir_recursive(const char *path, mode_t mode)
 	ret = mkdir(tmp, mode);
 	if (ret < 0) {
 		if (errno != EEXIST) {
-			PERROR("mkdir recursive last piece");
+			PERROR("mkdir recursive last element");
 			ret = -errno;
 		} else {
 			ret = 0;
@@ -593,8 +623,34 @@ error:
 	return ret;
 }
 
+/*
+ * Recursively create directory using the given path and mode, under the
+ * provided uid and gid.
+ *
+ * On success, return 0 else a negative error code.
+ */
+LTTNG_HIDDEN
+int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
+{
+	int ret;
+
+	if (uid < 0 || gid < 0) {
+		/* Run as current user. */
+		ret = _utils_mkdir_recursive_unsafe(path, mode);
+	} else {
+		ret = run_as_mkdir_recursive(path, mode, uid, gid);
+	}
+	if (ret < 0) {
+		PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
+				uid, gid);
+	}
+
+	return ret;
+}
+
 /*
  * Create the stream tracefile on disk.
+ * path is the output parameter. It needs to be PATH_MAX len.
  *
  * Return 0 on success or else a negative value.
  */
diff --git a/src/common/utils.h b/src/common/utils.h
index 05914cc37..e5af6fadd 100644
--- a/src/common/utils.h
+++ b/src/common/utils.h
@@ -37,7 +37,8 @@ void utils_close_pipe(int *src);
 char *utils_strdupdelim(const char *begin, const char *end);
 int utils_set_fd_cloexec(int fd);
 int utils_create_pid_file(pid_t pid, const char *filepath);
-int utils_mkdir_recursive(const char *path, mode_t mode);
+int utils_mkdir(const char *path, mode_t mode, int uid, int gid);
+int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid);
 int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size,
 		uint64_t count, int uid, int gid, char *suffix);
 int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,