lib/util/util_paths.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    Copyright (c) 2020      Andreas Schneider <asn@samba.org>
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "dynconfig/dynconfig.h"
  27 #include "lib/util/util_paths.h"
  28 #include "system/passwd.h"
  29
  30 /**
  31  * @brief Returns an absolute path to a file in the Samba modules directory.
  32  *
  33  * @param name File to find, relative to MODULESDIR.
  34  *
  35  * @retval Pointer to a string containing the full path.
  36  **/
  37
  38 char *modules_path(TALLOC_CTX *mem_ctx, const char *name)
  39 {
  40         return talloc_asprintf(mem_ctx, "%s/%s", get_dyn_MODULESDIR(), name);
  41 }
  42
  43 /**
  44  * @brief Returns an absolute path to a file in the Samba data directory.
  45  *
  46  * @param name File to find, relative to CODEPAGEDIR.
  47  *
  48  * @retval Pointer to a talloc'ed string containing the full path.
  49  **/
  50
  51 char *data_path(TALLOC_CTX *mem_ctx, const char *name)
  52 {
  53         return talloc_asprintf(mem_ctx, "%s/%s", get_dyn_CODEPAGEDIR(), name);
  54 }
  55
  56 /**
  57  * @brief Returns the platform specific shared library extension.
  58  *
  59  * @retval Pointer to a const char * containing the extension.
  60  **/
  61
  62 const char *shlib_ext(void)
  63 {
  64         return get_dyn_SHLIBEXT();
  65 }
  66
  67 static char *get_user_home_dir(TALLOC_CTX *mem_ctx)
  68 {
  69         struct passwd pwd = {0};
  70         struct passwd *pwdbuf = NULL;
  71         char *buf = NULL;
  72         char *out = NULL;
  73         long int initlen;
  74         size_t len;
  75         int rc;
  76
  77         initlen = sysconf(_SC_GETPW_R_SIZE_MAX);
  78         if (initlen == -1) {
  79                 len = 1024;
  80         } else {
  81                 len = (size_t)initlen;
  82         }
  83         buf = talloc_size(mem_ctx, len);
  84         if (buf == NULL) {
  85                 return NULL;
  86         }
  87
  88         rc = getpwuid_r(getuid(), &pwd, buf, len, &pwdbuf);
  89         while (rc == ERANGE) {
  90                 size_t newlen = 2 * len;
  91                 if (newlen < len) {
  92                         /* Overflow */
  93                         goto done;
  94                 }
  95                 len = newlen;
  96                 buf = talloc_realloc_size(mem_ctx, buf, len);
  97                 if (buf == NULL) {
  98                         goto done;
  99                 }
 100                 rc = getpwuid_r(getuid(), &pwd, buf, len, &pwdbuf);
 101         }
 102         if (rc != 0 || pwdbuf == NULL ) {
 103                 const char *szPath = getenv("HOME");
 104                 if (szPath == NULL) {
 105                         goto done;
 106                 }
 107                 len = strnlen(szPath, PATH_MAX);
 108                 if (len >= PATH_MAX) {
 109                         goto done;
 110                 }
 111                 out = talloc_strdup(mem_ctx, szPath);
 112                 goto done;
 113         }
 114
 115         out = talloc_strdup(mem_ctx, pwd.pw_dir);
 116 done:
 117         TALLOC_FREE(buf);
 118         return out;
 119 }
 120
 121 char *path_expand_tilde(TALLOC_CTX *mem_ctx, const char *d)
 122 {
 123         char *h = NULL, *r = NULL;
 124         const char *p = NULL;
 125         struct stat sb = {0};
 126         int rc;
 127
 128         if (d[0] != '~') {
 129                 return talloc_strdup(mem_ctx, d);
 130         }
 131         d++;
 132
 133         /* handle ~user/path */
 134         p = strchr(d, '/');
 135         if (p != NULL && p > d) {
 136                 struct passwd *pw;
 137                 size_t s = p - d;
 138                 char u[128];
 139
 140                 if (s >= sizeof(u)) {
 141                         return NULL;
 142                 }
 143                 memcpy(u, d, s);
 144                 u[s] = '\0';
 145
 146                 pw = getpwnam(u);
 147                 if (pw == NULL) {
 148                         return NULL;
 149                 }
 150                 h = talloc_strdup(mem_ctx, pw->pw_dir);
 151         } else {
 152                 p = d;
 153                 h = get_user_home_dir(mem_ctx);
 154         }
 155         if (h == NULL) {
 156                 return NULL;
 157         }
 158
 159         rc = stat(h, &sb);
 160         if (rc != 0) {
 161                 TALLOC_FREE(h);
 162                 return NULL;
 163         }
 164
 165         r = talloc_asprintf(mem_ctx, "%s%s", h, p);
 166         TALLOC_FREE(h);
 167
 168         return r;
 169 }