tar-1.29HEADtar-1.29master

1 files changed, 164 insertions, 0 deletions

diff --git a/lib/paxnames.c b/lib/paxnames.c
new file mode 100644
index 0000000..5766d4c
--- /dev/null
+++ b/lib/paxnames.c
@@ -0,0 +1,164 @@
+/* This file is part of GNU paxutils
+   Copyright (C) 2005, 2007, 2010 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 the
+   Free Software Foundation; either version 3, or (at your option) any later
+   version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+   Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation, Inc.,
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <system.h>
+#include <hash.h>
+#include <paxlib.h>
+
+
+/* Hash tables of strings.  */
+
+/* Calculate the hash of a string.  */
+static size_t
+hash_string_hasher (void const *name, size_t n_buckets)
+{
+  return hash_string (name, n_buckets);
+}
+
+/* Compare two strings for equality.  */
+static bool
+hash_string_compare (void const *name1, void const *name2)
+{
+  return strcmp (name1, name2) == 0;
+}
+
+/* Return zero if TABLE contains a LEN-character long prefix of STRING,
+   otherwise, insert a newly allocated copy of this prefix to TABLE and
+   return 1.  If RETURN_PREFIX is not NULL, point it to the allocated
+   copy. */
+static bool
+hash_string_insert_prefix (Hash_table **table, char const *string, size_t len,
+			   const char **return_prefix)
+{
+  Hash_table *t = *table;
+  char *s;
+  char *e;
+
+  if (len)
+    {
+      s = xmalloc (len + 1);
+      memcpy (s, string, len);
+      s[len] = 0;
+    }
+  else
+    s = xstrdup (string);
+
+  if (! ((t
+	  || (*table = t = hash_initialize (0, 0, hash_string_hasher,
+					    hash_string_compare, 0)))
+	 && (e = hash_insert (t, s))))
+    xalloc_die ();
+
+  if (e == s)
+    {
+      if (return_prefix)
+	*return_prefix = s;
+      return 1;
+    }
+  else
+    {
+      free (s);
+      return 0;
+    }
+}
+
+
+static Hash_table *prefix_table[2];
+
+/* Return true if file names of some members in the archive were stripped off
+   their leading components. We could have used
+        return prefix_table[0] || prefix_table[1]
+   but the following seems to be safer: */
+bool
+removed_prefixes_p (void)
+{
+  return (prefix_table[0] && hash_get_n_entries (prefix_table[0]) != 0)
+         || (prefix_table[1] && hash_get_n_entries (prefix_table[1]) != 0);
+}
+
+/* Return a safer suffix of FILE_NAME, or "." if it has no safer
+   suffix.  Check for fully specified file names and other atrocities.
+   Warn the user if we do not return NAME.  If LINK_TARGET is 1,
+   FILE_NAME is the target of a hard link, not a member name.
+   If ABSOLUTE_NAMES is 0, strip filesystem prefix from the file name. */
+
+char *
+safer_name_suffix (char const *file_name, bool link_target,
+		   bool absolute_names)
+{
+  char const *p;
+
+  if (absolute_names)
+    p = file_name;
+  else
+    {
+      /* Skip file system prefixes, leading file name components that contain
+	 "..", and leading slashes.  */
+
+      size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (file_name);
+
+      for (p = file_name + prefix_len; *p; )
+	{
+          if (p[0] == '.' && p[1] == '.' && (ISSLASH (p[2]) || !p[2]))
+	    prefix_len = p + 2 - file_name;
+
+	  do
+	    {
+	      char c = *p++;
+	      if (ISSLASH (c))
+		break;
+	    }
+	  while (*p);
+	}
+
+      for (p = file_name + prefix_len; ISSLASH (*p); p++)
+	continue;
+      prefix_len = p - file_name;
+
+      if (prefix_len)
+	{
+	  const char *prefix;
+	  if (hash_string_insert_prefix (&prefix_table[link_target], file_name,
+					 prefix_len, &prefix))
+	    {
+	      static char const *const diagnostic[] =
+	      {
+		N_("Removing leading `%s' from member names"),
+		N_("Removing leading `%s' from hard link targets")
+	      };
+	      WARN ((0, 0, _(diagnostic[link_target]), prefix));
+	    }
+	}
+    }
+
+  if (! *p)
+    {
+      if (p == file_name)
+	{
+	  static char const *const diagnostic[] =
+	  {
+	    N_("Substituting `.' for empty member name"),
+	    N_("Substituting `.' for empty hard link target")
+	  };
+	  WARN ((0, 0, "%s", _(diagnostic[link_target])));
+	}
+
+      p = ".";
+    }
+
+  return (char *) p;
+}