From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Wed, 16 May 2018 22:24:01 +0000 (-0400)
Subject: Backport: Add --working-directory options to lttng-relayd
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=763755801af9465a7936b1a4cbb613123781f740

Backport: Add --working-directory options to lttng-relayd

Base version

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
---

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 43498017d..7f0b413bc 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -83,7 +83,7 @@ enum relay_connection_status {
 };
 
 /* command line options */
-char *opt_output_path;
+char *opt_output_path, *opt_working_directory;
 static int opt_daemon, opt_background;
 
 /*
@@ -169,6 +169,7 @@ static struct option long_options[] = {
 	{ "verbose", 0, 0, 'v', },
 	{ "config", 1, 0, 'f' },
 	{ "version", 0, 0, 'V' },
+	{ "working-directory", 1, 0, 'w', },
 	{ NULL, 0, 0, 0, },
 };
 
@@ -279,6 +280,20 @@ static int set_option(int opt, const char *arg, const char *optname)
 			}
 		}
 		break;
+	case 'w':
+		if (lttng_is_setuid_setgid()) {
+			WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
+				"-w, --working-directory");
+		} else {
+			ret = asprintf(&opt_working_directory, "%s", arg);
+			if (ret < 0) {
+				ret = -errno;
+				PERROR("asprintf working_directory");
+				goto end;
+			}
+		}
+		break;
+
 	case 'v':
 		/* Verbose level can increase using multiple -v */
 		if (arg) {
@@ -3191,6 +3206,15 @@ int main(int argc, char **argv)
 		}
 	}
 
+
+	if (opt_working_directory) {
+		ret = utils_change_working_dir(opt_working_directory);
+		if (ret) {
+			ERR("Changing working directory");
+			goto exit_options;
+		}
+	}
+
 	/* Initialize thread health monitoring */
 	health_relayd = health_app_create(NR_HEALTH_RELAYD_TYPES);
 	if (!health_relayd) {
diff --git a/src/common/utils.c b/src/common/utils.c
index 25d510854..d8a78091a 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -1452,3 +1452,33 @@ int utils_show_man_page(int section, const char *page_name)
 		section_string, page_name, NULL);
 	return ret;
 }
+
+LTTNG_HIDDEN
+int utils_change_working_dir(const char *path)
+{
+	int ret;
+
+	assert(path);
+
+	ret = chdir(path);
+	if (ret) {
+		PERROR("Failed to change working directory: %s", path);
+		goto end;
+	}
+
+	/* Check for write access */
+	if (access(path, W_OK)) {
+		if (errno == EACCES) {
+			/*
+			 * Do not treat this as an error since the permission
+			 * might change in the lifetime of the process
+			 */
+			DBG("Working directory is not writable: %s", path);
+		} else {
+			PERROR("access");
+		}
+	}
+
+end:
+	return ret;
+}
diff --git a/src/common/utils.h b/src/common/utils.h
index 0daf5b98d..4c7884b76 100644
--- a/src/common/utils.h
+++ b/src/common/utils.h
@@ -61,5 +61,6 @@ int utils_create_lock_file(const char *filepath);
 int utils_recursive_rmdir(const char *path);
 int utils_truncate_stream_file(int fd, off_t length);
 int utils_show_man_page(int section, const char *page_name);
+int utils_change_working_dir(const char *path);
 
 #endif /* _COMMON_UTILS_H */