Merge 'exclude' changes from tar 1.13.22.

This fixes one or two unlikely storage allocation overflow bugs,
but doesn't change user-visible behavior otherwise.

(bool): Declare, perhaps by including stdbool.h.
(<sys/types.h>): Include only if HAVE_SYS_TYPES_H.
(<stdlib.h>, <string.h>, <strings.h>, <inttypes.h>, <stdint.h>):
Include	if available.
(<xalloc.h>): Include
(SIZE_MAX): Define if <stdint.h> or <inttypes.h> doesn't.
(verify): New macro.  Use it to verify that EXCLUDE macros do not
collide with FNM macros.
(struct patopts): New struct.
(struct exclude): Use it, as exclude patterns now come with options.
(new_exclude): Support above changes.
(new_exclude, add_exclude_file):
Initial size must now be a power of two to simplify overflow checking.
(free_exclude, fnmatch_no_wildcards): New function.
(excluded_filename): No longer requires options arg, as the options
are determined by add_exclude.  Now returns bool, not int.
(excluded_filename, add_exclude):
Add support for the fancy new exclusion options.
(add_exclude, add_exclude_file): Now takes int options arg.
Check for arithmetic overflow when computing sizes.
(add_exclude_file): xrealloc might modify errno, so don't
realloc until after errno might be used.

1 files changed, 170 insertions, 34 deletions

diff --git a/lib/exclude.c b/lib/exclude.c
index 1925a398a..5a1e1ee6f 100644
--- a/lib/exclude.c
+++ b/lib/exclude.c
@@ -1,5 +1,7 @@
 /* exclude.c -- exclude file names
-   Copyright 1992, 1993, 1994, 1997, 1999, 2000 Free Software Foundation, Inc.
+
+   Copyright 1992, 1993, 1994, 1997, 1999, 2000, 2001 Free Software
+   Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,73 +24,202 @@
 # include <config.h>
 #endif
 
+#if HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+typedef enum {false = 0, true = 1} bool;
+#endif
+
 #include <errno.h>
 #ifndef errno
 extern int errno;
 #endif
+#include <stdio.h>
+#if HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#if HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+#if HAVE_STRING_H
+# include <string.h>
+#endif
+#if HAVE_STRINGS_H
+# include <strings.h>
+#endif
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#else
+# if HAVE_STDINT_H
+#  include <stdint.h>
+# endif
+#endif
+
 #include <exclude.h>
 #include <fnmatch.h>
-#include <stdio.h>
-#include <sys/types.h>
+#include <xalloc.h>
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+/* Verify a requirement at compile-time (unlike assert, which is runtime).  */
+#define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
+
+verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
+	(((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
+	  & (FNM_FILE_NAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
+	     | FNM_CASEFOLD))
+	 == 0));
 
-void *xmalloc PARAMS ((size_t));
-void *xrealloc PARAMS ((void *, size_t));
+/* An exclude pattern-options pair.  The options are fnmatch options
+   ORed with EXCLUDE_* options.  */
+
+struct patopts
+  {
+    char const *pattern;
+    int options;
+  };
 
-/* Keep track of excluded file name patterns.  */
+/* An exclude list, of pattern-options pairs.  */
 
 struct exclude
   {
-    char const **exclude;
-    int exclude_alloc;
-    int exclude_count;
+    struct patopts *exclude;
+    size_t exclude_alloc;
+    size_t exclude_count;
   };
 
+/* Return a newly allocated and empty exclude list.  */
+
 struct exclude *
 new_exclude (void)
 {
-  struct exclude *ex = (struct exclude *) xmalloc (sizeof (struct exclude));
+  struct exclude *ex = (struct exclude *) xmalloc (sizeof *ex);
   ex->exclude_count = 0;
-  ex->exclude_alloc = 64;
-  ex->exclude = (char const **) xmalloc (ex->exclude_alloc * sizeof (char *));
+  ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
+  ex->exclude = (struct patopts *) xmalloc (ex->exclude_alloc
+					    * sizeof ex->exclude[0]);
   return ex;
 }
 
-int
-excluded_filename (struct exclude const *ex, char const *f, int options)
+/* Free the storage associated with an exclude list.  */
+
+void
+free_exclude (struct exclude *ex)
 {
-  char const * const *exclude = ex->exclude;
-  int exclude_count = ex->exclude_count;
-  int i;
+  free (ex->exclude);
+  free (ex);
+}
 
-  for (i = 0;  i < exclude_count;  i++)
-    if (fnmatch (exclude[i], f, options) == 0)
-      return 1;
+/* Return zero if PATTERN matches F, obeying OPTIONS, except that
+   (unlike fnmatch) wildcards are disabled in PATTERN.  */
 
-  return 0;
+static int
+fnmatch_no_wildcards (char const *pattern, char const *f, int options)
+{
+  if (! (options & FNM_CASEFOLD))
+    return (options & FNM_LEADING_DIR ? strcasecmp : strcmp) (pattern, f);
+  else
+    {
+      size_t patlen = strlen (pattern);
+      int r = ((options & FNM_LEADING_DIR ? strncasecmp : strncmp)
+	       (pattern, f, patlen));
+      if (! r)
+	{
+	  r = f[patlen];
+	  if (r == '/' && (options & FNM_LEADING_DIR))
+	    r = 0;
+	}
+      return r;
+    }
 }
 
+/* Return true if EX excludes F.  */
+
+bool
+excluded_filename (struct exclude const *ex, char const *f)
+{
+  size_t exclude_count = ex->exclude_count;
+
+  /* If no options are given, the default is to include.  */
+  if (exclude_count == 0)
+    return 0;
+  else
+    {
+      struct patopts const *exclude = ex->exclude;
+      size_t i;
+
+      /* Otherwise, the default is the opposite of the first option.  */
+      bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
+
+      /* Scan through the options, seeing whether they change F from
+	 excluded to included or vice versa.  */
+      for (i = 0;  i < exclude_count;  i++)
+	{
+	  char const *pattern = exclude[i].pattern;
+	  int options = exclude[i].options;
+	  if (excluded == !! (options & EXCLUDE_INCLUDE))
+	    {
+	      int (*matcher) PARAMS ((char const *, char const *, int)) =
+		(options & EXCLUDE_WILDCARDS
+		 ? fnmatch
+		 : fnmatch_no_wildcards);
+	      bool matched = ((*matcher) (pattern, f, options) == 0);
+	      char const *p;
+
+	      if (! (options & EXCLUDE_ANCHORED))
+		for (p = f; *p && ! matched; p++)
+		  if (*p == '/' && p[1] != '/')
+		    matched = ((*matcher) (pattern, p + 1, options) == 0);
+
+	      excluded ^= matched;
+	    }
+	}
+
+      return excluded;
+    }
+}
+
+/* Append to EX the exclusion PATTERN with OPTIONS.  */
+
 void
-add_exclude (struct exclude *ex, char const *pattern)
+add_exclude (struct exclude *ex, char const *pattern, int options)
 {
+  struct patopts *patopts;
+
   if (ex->exclude_alloc <= ex->exclude_count)
-    ex->exclude = (char const **) xrealloc (ex->exclude,
-					    ((ex->exclude_alloc *= 2)
-					     * sizeof (char *)));
+    {
+      size_t s = 2 * ex->exclude_alloc;
+      if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
+	xalloc_die ();
+      ex->exclude_alloc = s;
+      ex->exclude = (struct patopts *) xrealloc (ex->exclude,
+						 s * sizeof ex->exclude[0]);
+    }
 
-  ex->exclude[ex->exclude_count++] = pattern;
+  patopts = &ex->exclude[ex->exclude_count++];
+  patopts->pattern = pattern;
+  patopts->options = options;
 }
 
+/* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
+   OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
+   on failure, 0 on success.  */
+
 int
-add_exclude_file (void (*add_func) PARAMS ((struct exclude *, char const *)),
-		  struct exclude *ex, char const *filename, char line_end)
+add_exclude_file (void (*add_func) PARAMS ((struct exclude *,
+					    char const *, int)),
+		  struct exclude *ex, char const *filename, int options,
+		  char line_end)
 {
-  int use_stdin = filename[0] == '-' && !filename[1];
+  bool use_stdin = filename[0] == '-' && !filename[1];
   FILE *in;
   char *buf;
   char *p;
   char const *pattern;
   char const *lim;
-  size_t buf_alloc = 1024;
+  size_t buf_alloc = (1 << 10);  /* This must be a power of two.  */
   size_t buf_count = 0;
   int c;
   int e = 0;
@@ -104,22 +235,27 @@ add_exclude_file (void (*add_func) PARAMS ((struct exclude *, char const *)),
     {
       buf[buf_count++] = c;
       if (buf_count == buf_alloc)
-	buf = xrealloc (buf, buf_alloc *= 2);
+	{
+	  buf_alloc *= 2;
+	  if (! buf_alloc)
+	    xalloc_die ();
+	  buf = xrealloc (buf, buf_alloc);
+	}
     }
 
-  buf = xrealloc (buf, buf_count + 1);
-
   if (ferror (in))
     e = errno;
 
   if (!use_stdin && fclose (in) != 0)
     e = errno;
 
+  buf = xrealloc (buf, buf_count + 1);
+
   for (pattern = p = buf, lim = buf + buf_count;  p <= lim;  p++)
     if (p < lim ? *p == line_end : buf < p && p[-1])
       {
 	*p = '\0';
-	(*add_func) (ex, pattern);
+	(*add_func) (ex, pattern, options);
 	pattern = p + 1;
       }