From: David Goulet <dgoulet@efficios.com>
Date: Thu, 5 Apr 2012 15:39:59 +0000 (-0400)
Subject: Fix: make lttng expand path for trace output opt
X-Git-Tag: v2.1.0-rc1~164
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=3badf2bf32930336a4902002d840402adb6859e1

Fix: make lttng expand path for trace output opt

lttng create --output was passing the path string to the session daemon
and thus, for relative path like './mytraces', it was created in the
current directory of the session daemon.

Now lttng command line uses the realpath(3) of the --output string and
denies creation if multiple level of directory does not exist (Ex:
/tmp/foo/bar/chap, if foo/ does not exist, it is refused).

Directory creation still occurs on the session daemon side.

Reported-by: Ettore Del Negro <ettore@ettoredelnegro.me>
Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng/commands/create.c b/src/bin/lttng/commands/create.c
index b1f3e8a77..2778ef553 100644
--- a/src/bin/lttng/commands/create.c
+++ b/src/bin/lttng/commands/create.c
@@ -115,7 +115,11 @@ static int create_session()
 			goto error;
 		}
 	} else {
-		traces_path = opt_output_path;
+		traces_path = expand_full_path(opt_output_path);
+		if (traces_path == NULL) {
+			ret = CMD_ERROR;
+			goto error;
+		}
 	}
 
 	ret = lttng_create_session(session_name, traces_path);
diff --git a/src/bin/lttng/utils.c b/src/bin/lttng/utils.c
index b982bd593..8ae984836 100644
--- a/src/bin/lttng/utils.c
+++ b/src/bin/lttng/utils.c
@@ -18,12 +18,61 @@
 #define _GNU_SOURCE
 #include <stdlib.h>
 #include <ctype.h>
+#include <limits.h>
 
 #include <common/error.h>
 
 #include "conf.h"
 #include "utils.h"
 
+/*
+ * Return the realpath(3) of the path even if the last directory token does not
+ * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the
+ * /tmp/test1 does, the real path is returned. In normal time, realpath(3)
+ * fails if the end point directory does not exist.
+ */
+char *expand_full_path(const char *path)
+{
+	const char *end_path = path;
+	char *next, *cut_path, *expanded_path;
+
+	/* Find last token delimited by '/' */
+	while ((next = strpbrk(end_path + 1, "/"))) {
+		end_path = next;
+	}
+
+	/* Cut last token from original path */
+	cut_path = strndup(path, end_path - path);
+
+	expanded_path = malloc(PATH_MAX);
+	if (expanded_path == NULL) {
+		goto error;
+	}
+
+	expanded_path = realpath((char *)cut_path, expanded_path);
+	if (expanded_path == NULL) {
+		switch (errno) {
+		case ENOENT:
+			ERR("%s: No such file or directory", cut_path);
+			break;
+		default:
+			perror("realpath");
+			break;
+		}
+		goto error;
+	}
+
+	/* Add end part to expanded path */
+	strcat(expanded_path, end_path);
+
+	free(cut_path);
+	return expanded_path;
+
+error:
+	free(cut_path);
+	return NULL;
+}
+
 /*
  *  get_session_name
  *
diff --git a/src/bin/lttng/utils.h b/src/bin/lttng/utils.h
index 9c51b67e3..a430b8bdf 100644
--- a/src/bin/lttng/utils.h
+++ b/src/bin/lttng/utils.h
@@ -20,6 +20,7 @@
 
 #include <popt.h>
 
+char *expand_full_path(const char *path);
 char *get_config_file_path(void);
 char *get_session_name(void);
 int set_session_name(char *name);