1/* This file is part of GNU paxutils 2 Copyright (C) 2005 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify it 5 under the terms of the GNU General Public License as published by the 6 Free Software Foundation; either version 2, or (at your option) any later 7 version. 8 9 This program is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 12 Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with this program; if not, write to the Free Software Foundation, Inc., 16 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 17 18#include <system.h> 19#include <hash.h> 20#include <paxlib.h> 21 22 23/* Hash tables of strings. */ 24 25/* Calculate the hash of a string. */ 26static size_t 27hash_string_hasher (void const *name, size_t n_buckets) 28{ 29 return hash_string (name, n_buckets); 30} 31 32/* Compare two strings for equality. */ 33static bool 34hash_string_compare (void const *name1, void const *name2) 35{ 36 return strcmp (name1, name2) == 0; 37} 38 39/* Return zero if TABLE contains a LEN-character long prefix of STRING, 40 otherwise, insert a newly allocated copy of this prefix to TABLE and 41 return 1. If RETURN_PREFIX is not NULL, point it to the allocated 42 copy. */ 43bool 44hash_string_insert_prefix (Hash_table **table, char const *string, size_t len, 45 const char **return_prefix) 46{ 47 Hash_table *t = *table; 48 char *s; 49 char *e; 50 51 if (len) 52 { 53 s = xmalloc (len + 1); 54 memcpy (s, string, len); 55 s[len] = 0; 56 } 57 else 58 s = xstrdup (string); 59 60 if (! ((t 61 || (*table = t = hash_initialize (0, 0, hash_string_hasher, 62 hash_string_compare, 0))) 63 && (e = hash_insert (t, s)))) 64 xalloc_die (); 65 66 if (e == s) 67 { 68 if (return_prefix) 69 *return_prefix = s; 70 return 1; 71 } 72 else 73 { 74 free (s); 75 return 0; 76 } 77} 78 79/* Return zero if TABLE contains a copy of STRING; otherwise, insert a 80 copy of STRING to TABLE and return 1. */ 81bool 82hash_string_insert (Hash_table **table, char const *string) 83{ 84 return hash_string_insert_prefix (table, string, 0, NULL); 85} 86 87/* Return 1 if TABLE contains STRING. */ 88bool 89hash_string_lookup (Hash_table const *table, char const *string) 90{ 91 return table && hash_lookup (table, string); 92} 93 94 95static Hash_table *prefix_table[2]; 96 97/* Return true if file names of some members in the archive were stripped off 98 their leading components. We could have used 99 return prefix_table[0] || prefix_table[1] 100 but the following seems to be safer: */ 101bool 102removed_prefixes_p (void) 103{ 104 return (prefix_table[0] && hash_get_n_entries (prefix_table[0]) != 0) 105 || (prefix_table[1] && hash_get_n_entries (prefix_table[1]) != 0); 106} 107 108/* Return a safer suffix of FILE_NAME, or "." if it has no safer 109 suffix. Check for fully specified file names and other atrocities. 110 Warn the user if we do not return NAME. If LINK_TARGET is 1, 111 FILE_NAME is the target of a hard link, not a member name. 112 If ABSOLUTE_NAMES is 0, strip filesystem prefix from the file name. */ 113 114char * 115safer_name_suffix (char const *file_name, bool link_target, bool absolute_names) 116{ 117 char const *p; 118 119 if (absolute_names) 120 p = file_name; 121 else 122 { 123 /* Skip file system prefixes, leading file name components that contain 124 "..", and leading slashes. */ 125 126 size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (file_name); 127 128 for (p = file_name + prefix_len; *p; ) 129 { 130 if (p[0] == '.' && p[1] == '.' && (ISSLASH (p[2]) || !p[2])) 131 prefix_len = p + 2 - file_name; 132 133 do 134 { 135 char c = *p++; 136 if (ISSLASH (c)) 137 break; 138 } 139 while (*p); 140 } 141 142 for (p = file_name + prefix_len; ISSLASH (*p); p++) 143 continue; 144 prefix_len = p - file_name; 145 146 if (prefix_len) 147 { 148 const char *prefix; 149 if (hash_string_insert_prefix (&prefix_table[link_target], file_name, 150 prefix_len, &prefix)) 151 { 152 static char const *const diagnostic[] = 153 { 154 N_("Removing leading `%s' from member names"), 155 N_("Removing leading `%s' from hard link targets") 156 }; 157 WARN ((0, 0, _(diagnostic[link_target]), prefix)); 158 } 159 } 160 } 161 162 if (! *p) 163 { 164 if (p == file_name) 165 { 166 static char const *const diagnostic[] = 167 { 168 N_("Substituting `.' for empty member name"), 169 N_("Substituting `.' for empty hard link target") 170 }; 171 WARN ((0, 0, "%s", _(diagnostic[link_target]))); 172 } 173 174 p = "."; 175 } 176 177 return (char *) p; 178} 179