X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/b41c3f92738709adf79a1d77f8e7e75752bd1adf..375a4556c7a1ffb9a4e7117f33fc42ed2bc4c026:/util.c

diff --git a/util.c b/util.c
index 6e0fbaba..3c23cb7a 100644
--- a/util.c
+++ b/util.c
@@ -752,3 +752,50 @@ int unsafe_symlink(char *dest, char *src)
 	free(dest);
 	return (depth < 0);
 }
+
+/*
+ * Make path appear as if a chroot had occurred:
+ *    1. remove leading "/" (or replace with "." if at end)
+ *    2. remove leading ".." components
+ *    3. delete any other "<dir>/.." (recursively)
+ * Return a malloc'ed copy.
+ * Contributed by Dave Dykstra <dwd@bell-labs.com>
+ */
+
+char *sanitize_path(char *p)
+{
+	char *copy, *copyp;
+
+	copy = (char *) malloc(strlen(p)+1);
+	copyp = copy;
+	while (*p != '\0') {
+		if ((*p == '/') && (copyp == copy)) {
+			/* remove leading slash */
+			p++;
+		}
+		else if ((*p == '.') && (*(p+1) == '.') &&
+			    ((*(p+2) == '/') || (*(p+2) == '\0'))) {
+			/* remove .. followed by slash or end */
+			p += 2;
+			if (copyp != copy) {
+				/* backup the copy one level */
+				while ((--copyp != copy) && (*copyp == '/'))
+					/* skip trailing slashes */
+					;
+				while ((copyp != copy) && (*copyp != '/'))
+					/* skip back through slash */
+					copyp--;
+			}
+		} else {
+			/* copy one component */
+			while (1) {
+				*copyp++ = *p++;
+				if ((*p == '\0') || (*(p-1) == '/'))
+					break;
+			}
+		}
+	}
+	*copyp = '\0';
+	return(copy);
+}
+