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(TALLOC_CTX *mem_ctx,
  42                      const char *name,
  43                      const char *rootpath)
  44 {
  45         char *fname = NULL;
  46
  47         fname = talloc_strdup(mem_ctx, rootpath);
  48         if (!fname) {
  49                 return NULL;
  50         }
  51         trim_string(fname,"","/");
  52
  53         if (!directory_create_or_exist(fname, 0755)) {
  54                 return NULL;
  55         }
  56
  57         return talloc_asprintf_append(fname, "/%s", name);
  58 }
  59
  60 /**
  61  * @brief Returns an absolute path to a file in the Samba lock directory.
  62  *
  63  * @param name File to find, relative to LOCKDIR.
  64  *
  65  * @retval Pointer to a talloc'ed string containing the full path.
  66  **/
  67
  68 char *lock_path(TALLOC_CTX *mem_ctx, const char *name)
  69 {
  70         return xx_path(mem_ctx, name, lp_lock_directory());
  71 }
  72
  73 /**
  74  * @brief Returns an absolute path to a file in the Samba state directory.
  75  *
  76  * @param name File to find, relative to STATEDIR.
  77  *
  78  * @retval Pointer to a talloc'ed string containing the full path.
  79  **/
  80
  81 char *state_path(TALLOC_CTX *mem_ctx, const char *name)
  82 {
  83         return xx_path(mem_ctx, name, lp_state_directory());
  84 }
  85
  86 /**
  87  * @brief Returns an absolute path to a file in the Samba cache directory.
  88  *
  89  * @param name File to find, relative to CACHEDIR.
  90  *
  91  * @retval Pointer to a talloc'ed string containing the full path.
  92  **/
  93
  94 char *cache_path(TALLOC_CTX *mem_ctx, const char *name)
  95 {
  96         return xx_path(mem_ctx, name, lp_cache_directory());
  97 }
  98
  99 /**
 100  * @brief Removes any invalid path components in an absolute POSIX path.
 101  *
 102  * @param ctx Talloc context to return string.
 103  *
 104  * @param abs_path Absolute path string to process.
 105  *
 106  * @retval Pointer to a talloc'ed string containing the absolute full path.
 107  **/
 108
 109 char *canonicalize_absolute_path(TALLOC_CTX *ctx, const char *abs_path)
 110 {
 111         char *destname;
 112         char *d;
 113         const char *s = abs_path;
 114         bool start_of_name_component = true;
 115
 116         /* Allocate for strlen + '\0' + possible leading '/' */
 117         destname = (char *)talloc_size(ctx, strlen(abs_path) + 2);
 118         if (destname == NULL) {
 119                 return NULL;
 120         }
 121         d = destname;
 122
 123         *d++ = '/'; /* Always start with root. */
 124
 125         while (*s) {
 126                 if (*s == '/') {
 127                         /* Eat multiple '/' */
 128                         while (*s == '/') {
 129                                 s++;
 130                         }
 131                         if ((d > destname + 1) && (*s != '\0')) {
 132                                 *d++ = '/';
 133                         }
 134                         start_of_name_component = true;
 135                         continue;
 136                 }
 137
 138                 if (start_of_name_component) {
 139                         if ((s[0] == '.') && (s[1] == '.') &&
 140                                         (s[2] == '/' || s[2] == '\0')) {
 141                                 /* Uh oh - "/../" or "/..\0" ! */
 142
 143                                 /* Go past the .. leaving us on the / or '\0' */
 144                                 s += 2;
 145
 146                                 /* If  we just added a '/' - delete it */
 147                                 if ((d > destname) && (*(d-1) == '/')) {
 148                                         *(d-1) = '\0';
 149                                         d--;
 150                                 }
 151
 152                                 /*
 153                                  * Are we at the start ?
 154                                  * Can't go back further if so.
 155                                  */
 156                                 if (d <= destname) {
 157                                         *d++ = '/'; /* Can't delete root */
 158                                         continue;
 159                                 }
 160                                 /* Go back one level... */
 161                                 /*
 162                                  * Decrement d first as d points to
 163                                  * the *next* char to write into.
 164                                  */
 165                                 for (d--; d > destname; d--) {
 166                                         if (*d == '/') {
 167                                                 break;
 168                                         }
 169                                 }
 170
 171                                 /*
 172                                  * Are we at the start ?
 173                                  * Can't go back further if so.
 174                                  */
 175                                 if (d <= destname) {
 176                                         *d++ = '/'; /* Can't delete root */
 177                                         continue;
 178                                 }
 179
 180                                 /*
 181                                  * We're still at the start of a name
 182                                  * component, just the previous one.
 183                                  */
 184                                 continue;
 185                         } else if ((s[0] == '.') &&
 186                                         ((s[1] == '\0') || s[1] == '/')) {
 187                                 /*
 188                                  * Component of pathname can't be "." only.
 189                                  * Skip the '.' .
 190                                  */
 191                                 if (s[1] == '/') {
 192                                         s += 2;
 193                                 } else {
 194                                         s++;
 195                                 }
 196                                 continue;
 197                         }
 198                 }
 199
 200                 if (!(*s & 0x80)) {
 201                         *d++ = *s++;
 202                 } else {
 203                         size_t siz;
 204                         /* Get the size of the next MB character. */
 205                         next_codepoint(s,&siz);
 206                         switch(siz) {
 207                                 case 5:
 208                                         *d++ = *s++;
 209
 210                                         FALL_THROUGH;
 211                                 case 4:
 212                                         *d++ = *s++;
 213
 214                                         FALL_THROUGH;
 215                                 case 3:
 216                                         *d++ = *s++;
 217
 218                                         FALL_THROUGH;
 219                                 case 2:
 220                                         *d++ = *s++;
 221
 222                                         FALL_THROUGH;
 223                                 case 1:
 224                                         *d++ = *s++;
 225                                         break;
 226                                 default:
 227                                         break;
 228                         }
 229                 }
 230                 start_of_name_component = false;
 231         }
 232         *d = '\0';
 233
 234         /* And must not end in '/' */
 235         if (d > destname + 1 && (*(d-1) == '/')) {
 236                 *(d-1) = '\0';
 237         }
 238
 239         return destname;
 240 }