freebsd-dev/contrib/cpio/lib/paxnames.c
Peter Wemm c6acfe86c7 Merge gnu cpio 2.6 -> 2.8 changes. Unfortunately, we have massive
conflicts due to radically different approaches to security and bug fixes.
In some cases I re-started from the vendor version and reimplemented our
patches.  Fortunately, this is not enabled by default in -current.
2008-07-10 02:08:00 +00:00

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/* This file is part of GNU paxutils
Copyright (C) 2005 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 2, 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 copy of STRING; otherwise, insert a
copy of STRING to TABLE and return 1. */
bool
hash_string_insert (Hash_table **table, char const *string)
{
Hash_table *t = *table;
char *s = xstrdup (string);
char *e;
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)
return 1;
else
{
free (s);
return 0;
}
}
/* Return 1 if TABLE contains STRING. */
bool
hash_string_lookup (Hash_table const *table, char const *string)
{
return table && hash_lookup (table, string);
}
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)
{
char *prefix = alloca (prefix_len + 1);
memcpy (prefix, file_name, prefix_len);
prefix[prefix_len] = '\0';
if (hash_string_insert (&prefix_table[link_target], 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;
}