From 03a32b6e1e364bccf6d181057ba876162685c44d Mon Sep 17 00:00:00 2001
From: Junichi Uekawa <dancerj@gmail.com>
Date: Wed, 8 Oct 2008 04:08:56 +0000
Subject: [PATCH] add sanity checking in filenames and paths.

Check files exist, and check paths are specified absolute.
I am relying on paths starting from '/' when they are absolute.

daemon() will chdir to /, and that means giving relative paths to this
program will give unexpected (to the user) results.
---
 lsyncd.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/lsyncd.c b/lsyncd.c
index 71fe59c..ea2ff47 100644
--- a/lsyncd.c
+++ b/lsyncd.c
@@ -800,6 +800,35 @@ bool scan_homes()
 	return true;
 }
 
+/**
+ * Utility function to check file exists. Print out error message and die.
+ *
+ * @param filename  filename to check
+ */
+void check_file_exists(const char* filename)
+{
+	struct stat st;
+	if (-1==stat(filename, &st)) {
+		printlogf(LOG_ERROR, "File [%s] does not exist\n", filename);
+		exit (-1);
+	}
+}
+
+
+/**
+ * Utility function to check given path is absolute path.
+ *
+ * @param filename  filename to check
+ */
+void check_absolute_path(const char* filename)
+{
+	if (filename[0] != '/') {
+		printlogf(LOG_ERROR, "Filename [%s] is not an absolute path\n", filename);
+		exit (-1);
+	}
+}
+
+
 /**
  * Prints the help text and exits 0.
  *
@@ -907,6 +936,7 @@ bool parse_options(int argc, char **argv)
 		}
 	}
 
+
 	if (optind + 2 != argc) {
 		printf("Error: please specify SOURCE and TARGET (see --help)\n");
 		exit(-1);
@@ -922,6 +952,15 @@ bool parse_options(int argc, char **argv)
 	}
 
 	printlogf(LOG_NORMAL, "syncing %s -> %s\n", option_source, option_target);
+
+	/* sanity checking here */
+	if (exclude_file) {
+		check_absolute_path(exclude_file);
+		check_file_exists(exclude_file);
+	}
+	if (pidfile) {
+		check_absolute_path(pidfile);
+	}
 	return true;
 }