From d493277ea11deb725dbf654c665bf3058027658d Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Mon, 3 Aug 2015 19:31:07 +0200
Subject: [PATCH] Reject invalid filter specifications

---
 HISTORY        |  3 ++-
 Makefile.am    |  3 +++
 TODO           |  3 ---
 cmdline/elem.c | 27 +++++++++++++++++++++++++--
 4 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/HISTORY b/HISTORY
index b2f8d835..d8693d9f 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,9 +1,10 @@
 SnapRAID HISTORY
 ================
 
-8.2 2015/06
+8.2 2015/08
 ===========
  * Update 'best' RAID functions for recent Atom CPUs.
+ * Validate filters specificatinos rejecting relative paths.
 
 8.1 2015/05
 ===========
diff --git a/Makefile.am b/Makefile.am
index dba84751..7847e948 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -270,6 +270,9 @@ endif
 	echo --- Filter
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS_VERBOSE) -c $(CONF) -d disk1 check > output.log
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS_VERBOSE) -c $(CONF) -f \\*a -f a/ -f /b/a\\* check > output.log
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS_VERBOSE) -c $(CONF) --test-expect-failure -f . check > output.log
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS_VERBOSE) -c $(CONF) --test-expect-failure -f ./ check > output.log
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS_VERBOSE) -c $(CONF) --test-expect-failure -f a/a check > output.log
 	echo --- Delete some files and sync
 	rm bench/disk4/a/9*
 	rm bench/disk5/a/9*
diff --git a/TODO b/TODO
index 82c906e8..2b7d7654 100644
--- a/TODO
+++ b/TODO
@@ -5,9 +5,6 @@ This is the list of TODO items for SnapRAID.
 
 - Next
 
-* Check if filters contains "." or "..". Return an error in this case.
-Command line with -f. And also exclude/include rules.
-
 * Allow to scrub/check/verify the just synched data.
 Like an option to scrub only recent data.
 Or more simply, we can add a new option at sync that avoid
diff --git a/cmdline/elem.c b/cmdline/elem.c
index 7cb270ba..7cffbc33 100644
--- a/cmdline/elem.c
+++ b/cmdline/elem.c
@@ -46,6 +46,8 @@ struct snapraid_filter* filter_alloc_file(int direction, const char* pattern)
 	char* i;
 	char* first;
 	char* last;
+	int token_is_valid;
+	int token_is_filled;
 
 	filter = malloc_nofail(sizeof(struct snapraid_filter));
 	pathimport(filter->pattern, sizeof(filter->pattern), pattern);
@@ -54,14 +56,37 @@ struct snapraid_filter* filter_alloc_file(int direction, const char* pattern)
 	/* find first and last slash */
 	first = 0;
 	last = 0;
+	/* reject invalid tokens, like "<empty>", ".", ".." and more dots */
+	token_is_valid = 0;
+	token_is_filled = 0;
 	for (i = filter->pattern; *i; ++i) {
 		if (*i == '/') {
+			/* reject invalid tokens, but accept an empty one as first */
+			if (!token_is_valid && (first != 0 || token_is_filled)) {
+				free(filter);
+				return 0;
+			}
+			token_is_valid = 0;
+			token_is_filled = 0;
+
+			/* update slash position */
 			if (!first)
 				first = i;
 			last = i;
+		} else if (*i != '.') {
+			token_is_valid = 1;
+			token_is_filled = 1;
+		} else {
+			token_is_filled = 1;
 		}
 	}
 
+	/* reject invalid tokens, but accept an empty one as last, but not if it's the only one */
+	if (!token_is_valid && (first == 0 || token_is_filled)) {
+		free(filter);
+		return 0;
+	}
+
 	/* it's a file filter */
 	filter->is_disk = 0;
 
@@ -86,10 +111,8 @@ struct snapraid_filter* filter_alloc_file(int direction, const char* pattern)
 
 		/* a slash must be the first char, as we don't support PATH/FILE and PATH/DIR/ */
 		if (filter->pattern[0] != '/') {
-			/* LCOV_EXCL_START */
 			free(filter);
 			return 0;
-			/* LCOV_EXCL_STOP */
 		}
 	}