source3/lib/util_path.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * Samba utility functions
   4  * Copyright (C) Andrew Tridgell 1992-1998
   5  * Copyright (C) Jeremy Allison 2001-2007
   6  * Copyright (C) Simo Sorce 2001
   7  * Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   8  * Copyright (C) James Peach 2006
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 3 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 #include "replace.h"
  25 #include <talloc.h>
  26 #include "lib/util/samba_util.h"
  27 #include "lib/util_path.h"
  28
  29 struct share_params;
  30 #include "source3/param/param_proto.h"
  31
  32 /**
  33  * @brief Returns an absolute path to a file concatenating the provided
  34  * @a rootpath and @a basename
  35  *
  36  * @param name Filename, relative to @a rootpath
  37  *
  38  * @retval Pointer to a string containing the full path.
  39  **/
  40
  41 static char *xx_path(const char *name, const char *rootpath)
  42 {
  43         char *fname = NULL;
  44
  45         fname = talloc_strdup(talloc_tos(), rootpath);
  46         if (!fname) {
  47                 return NULL;
  48         }
  49         trim_string(fname,"","/");
  50
  51         if (!directory_create_or_exist(fname, 0755)) {
  52                 return NULL;
  53         }
  54
  55         return talloc_asprintf_append(fname, "/%s", name);
  56 }
  57
  58 /**
  59  * @brief Returns an absolute path to a file in the Samba lock directory.
  60  *
  61  * @param name File to find, relative to LOCKDIR.
  62  *
  63  * @retval Pointer to a talloc'ed string containing the full path.
  64  **/
  65
  66 char *lock_path(const char *name)
  67 {
  68         return xx_path(name, lp_lock_directory());
  69 }
  70
  71 /**
  72  * @brief Returns an absolute path to a file in the Samba state directory.
  73  *
  74  * @param name File to find, relative to STATEDIR.
  75  *
  76  * @retval Pointer to a talloc'ed string containing the full path.
  77  **/
  78
  79 char *state_path(const char *name)
  80 {
  81         return xx_path(name, lp_state_directory());
  82 }
  83
  84 /**
  85  * @brief Returns an absolute path to a file in the Samba cache directory.
  86  *
  87  * @param name File to find, relative to CACHEDIR.
  88  *
  89  * @retval Pointer to a talloc'ed string containing the full path.
  90  **/
  91
  92 char *cache_path(const char *name)
  93 {
  94         return xx_path(name, lp_cache_directory());
  95 }
  96
  97 /**
  98  * @brief Removes any invalid path components in an absolute POSIX path.
  99  *
 100  * @param ctx Talloc context to return string.
 101  *
 102  * @param abs_path Absolute path string to process.
 103  *
 104  * @retval Pointer to a talloc'ed string containing the absolute full path.
 105  **/
 106
 107 char *canonicalize_absolute_path(TALLOC_CTX *ctx, const char *abs_path)
 108 {
 109         char *destname;
 110         char *d;
 111         const char *s = abs_path;
 112         bool start_of_name_component = true;
 113
 114         /* Allocate for strlen + '\0' + possible leading '/' */
 115         destname = (char *)talloc_size(ctx, strlen(abs_path) + 2);
 116         if (destname == NULL) {
 117                 return NULL;
 118         }
 119         d = destname;
 120
 121         *d++ = '/'; /* Always start with root. */
 122
 123         while (*s) {
 124                 if (*s == '/') {
 125                         /* Eat multiple '/' */
 126                         while (*s == '/') {
 127                                 s++;
 128                         }
 129                         if ((d > destname + 1) && (*s != '\0')) {
 130                                 *d++ = '/';
 131                         }
 132                         start_of_name_component = true;
 133                         continue;
 134                 }
 135
 136                 if (start_of_name_component) {
 137                         if ((s[0] == '.') && (s[1] == '.') &&
 138                                         (s[2] == '/' || s[2] == '\0')) {
 139                                 /* Uh oh - "/../" or "/..\0" ! */
 140
 141                                 /* Go past the .. leaving us on the / or '\0' */
 142                                 s += 2;
 143
 144                                 /* If  we just added a '/' - delete it */
 145                                 if ((d > destname) && (*(d-1) == '/')) {
 146                                         *(d-1) = '\0';
 147                                         d--;
 148                                 }
 149
 150                                 /*
 151                                  * Are we at the start ?
 152                                  * Can't go back further if so.
 153                                  */
 154                                 if (d <= destname) {
 155                                         *d++ = '/'; /* Can't delete root */
 156                                         continue;
 157                                 }
 158                                 /* Go back one level... */
 159                                 /*
 160                                  * Decrement d first as d points to
 161                                  * the *next* char to write into.
 162                                  */
 163                                 for (d--; d > destname; d--) {
 164                                         if (*d == '/') {
 165                                                 break;
 166                                         }
 167                                 }
 168
 169                                 /*
 170                                  * Are we at the start ?
 171                                  * Can't go back further if so.
 172                                  */
 173                                 if (d <= destname) {
 174                                         *d++ = '/'; /* Can't delete root */
 175                                         continue;
 176                                 }
 177
 178                                 /*
 179                                  * We're still at the start of a name
 180                                  * component, just the previous one.
 181                                  */
 182                                 continue;
 183                         } else if ((s[0] == '.') &&
 184                                         ((s[1] == '\0') || s[1] == '/')) {
 185                                 /*
 186                                  * Component of pathname can't be "." only.
 187                                  * Skip the '.' .
 188                                  */
 189                                 if (s[1] == '/') {
 190                                         s += 2;
 191                                 } else {
 192                                         s++;
 193                                 }
 194                                 continue;
 195                         }
 196                 }
 197
 198                 if (!(*s & 0x80)) {
 199                         *d++ = *s++;
 200                 } else {
 201                         size_t siz;
 202                         /* Get the size of the next MB character. */
 203                         next_codepoint(s,&siz);
 204                         switch(siz) {
 205                                 case 5:
 206                                         *d++ = *s++;
 207                                         /*fall through*/
 208                                 case 4:
 209                                         *d++ = *s++;
 210                                         /*fall through*/
 211                                 case 3:
 212                                         *d++ = *s++;
 213                                         /*fall through*/
 214                                 case 2:
 215                                         *d++ = *s++;
 216                                         /*fall through*/
 217                                 case 1:
 218                                         *d++ = *s++;
 219                                         break;
 220                                 default:
 221                                         break;
 222                         }
 223                 }
 224                 start_of_name_component = false;
 225         }
 226         *d = '\0';
 227
 228         /* And must not end in '/' */
 229         if (d > destname + 1 && (*(d-1) == '/')) {
 230                 *(d-1) = '\0';
 231         }
 232
 233         return destname;
 234 }