summaryrefslogtreecommitdiff
path: root/lib/paxnames.c
blob: 3ca8bfaa7f96ce5c85b957705bdad0420108643f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/* 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;
}