X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/1d6b8f9ad296f06505b06a941df5cbe38c540e72..a41a1e87182410ec6c2eeaddb0cd961ec554c404:/util.c

diff --git a/util.c b/util.c
index 829bad6c..4f1b59ac 100644
--- a/util.c
+++ b/util.c
@@ -197,7 +197,7 @@ int create_directory_path(char *fname, int base_umask)
  *
  * Derived from GNU C's cccp.c.
  */
-static int full_write(int desc, char *ptr, size_t len)
+int full_write(int desc, char *ptr, size_t len)
 {
 	int total_written;
 
@@ -245,7 +245,7 @@ static int safe_read(int desc, char *ptr, size_t len)
 
 /** Copy a file.
  *
- * This is used in conjunction with the --temp-dir option */
+ * This is used in conjunction with the --temp-dir and --backup options */
 int copy_file(char *source, char *dest, mode_t mode)
 {
 	int ifd;
@@ -665,10 +665,10 @@ int count_dir_elements(const char *p)
 }
 
 /* Turns multiple adjacent slashes into a single slash, gets rid of "./"
- * elements, collapses ".." elements except for those at the start of
- * the string. If the resulting path would be empty, change it into a
- * ".". */
-unsigned int clean_fname(char *name)
+ * elements (but not a trailing dot dir), removes a trailing slash, and
+ * optionally collapses ".." elements (except for those at the start of the
+ * string).  If the resulting name would be empty, change it into a ".". */
+unsigned int clean_fname(char *name, BOOL collapse_dot_dot)
 {
 	char *limit = name - 1, *t = name, *f = name;
 	int anchored;
@@ -691,7 +691,8 @@ unsigned int clean_fname(char *name)
 				continue;
 			}
 			/* collapse ".." dirs */
-			if (f[1] == '.' && (f[2] == '/' || !f[2])) {
+			if (collapse_dot_dot
+			    && f[1] == '.' && (f[2] == '/' || !f[2])) {
 				char *s = t - 1;
 				if (s == name && anchored) {
 					f += 2;
@@ -703,9 +704,7 @@ unsigned int clean_fname(char *name)
 					f += 2;
 					continue;
 				}
-				*t++ = *f++;
-				*t++ = *f++;
-				limit = t;
+				limit = t + 2;
 			}
 		}
 		while (*f && (*t++ = *f++) != '/') {}
@@ -731,16 +730,20 @@ unsigned int clean_fname(char *name)
  * The rootdir string contains a value to use in place of a leading slash.
  * Specify NULL to get the default of lp_path(module_id).
  *
- * If depth is > 0, it is a count of how many '..'s to allow at the start
- * of the path.
+ * If depth is >= 0, it is a count of how many '..'s to allow at the start
+ * of the path.  Use -1 to allow unlimited depth.
  *
- * We call clean_fname() to clean up the path, but we preserve a trailing
- * slash because that is sometimes significant on command-line arguments.
- */
+ * We also clean the path in a manner similar to clean_fname() but with a
+ * few differences: 
+ *
+ * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
+ * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
+ * ALWAYS collapses ".." elements (except for those at the start of the
+ * string up to "depth" deep).  If the resulting name would be empty,
+ * change it into a ".". */
 char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 {
 	char *start, *sanp;
-	int allowdotdot = 0;
 	int rlen = 0;
 
 	if (dest != p) {
@@ -765,33 +768,25 @@ char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 	}
 
 	start = sanp = dest + rlen;
-	while (*p == '/') {
-		/* remove leading slashes */
-		p++;
-	}
 	while (*p != '\0') {
+		/* discard leading or extra slashes */
+		if (*p == '/') {
+			p++;
+			continue;
+		}
 		/* this loop iterates once per filename component in p.
 		 * both p (and sanp if the original had a slash) should
 		 * always be left pointing after a slash
 		 */
 		if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
 			/* skip "." component */
-			while (*++p == '/') {
-				/* skip following slashes */
-				;
-			}
+			p++;
 			continue;
 		}
-		allowdotdot = 0;
 		if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
 			/* ".." component followed by slash or end */
-			if (depth > 0 && sanp == start) {
-				/* allow depth levels of .. at the beginning */
-				--depth;
-				allowdotdot = 1;
-			} else {
+			if (depth <= 0 || sanp != start) {
 				p += 2;
-				while (*p == '/') p++;
 				if (sanp != start) {
 					/* back up sanp one level */
 					--sanp; /* now pointing at slash */
@@ -802,22 +797,13 @@ char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 				}
 				continue;
 			}
-		}
-		while (1) {
-			/* copy one component through next slash */
-			*sanp++ = *p++;
-			if (*p == '\0' || p[-1] == '/') {
-				while (*p == '/') {
-					/* skip multiple slashes */
-					p++;
-				}
-				break;
-			}
-		}
-		if (allowdotdot) {
+			/* allow depth levels of .. at the beginning */
+			depth--;
 			/* move the virtual beginning to leave the .. alone */
-			start = sanp;
+			start = sanp + 3;
 		}
+		/* copy one component through next slash */
+		while (*p && (*sanp++ = *p++) != '/') {}
 	}
 	if (sanp == dest) {
 		/* ended up with nothing, so put in "." component */
@@ -869,7 +855,7 @@ int push_dir(char *dir)
 		curr_dir_len += len;
 	}
 
-	curr_dir_len = clean_fname(curr_dir);
+	curr_dir_len = clean_fname(curr_dir, 1);
 
 	return 1;
 }