liblttng-ust/getenv.h

   1 #ifndef _COMPAT_GETENV_H
   2 #define _COMPAT_GETENV_H
   3
   4 /*
   5  * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; only
  10  * version 2.1 of the License.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <sys/types.h>
  25 #include <usterr-signal-safe.h>
  26
  27 static inline
  28 int lttng_is_setuid_setgid(void)
  29 {
  30         return geteuid() != getuid() || getegid() != getgid();
  31 }
  32
  33 static inline
  34 char *lttng_secure_getenv(const char *name)
  35 {
  36         if (lttng_is_setuid_setgid()) {
  37                 ERR("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.",
  38                         name);
  39                 return NULL;
  40         }
  41         return getenv(name);
  42 }
  43
  44 #endif /* _COMPAT_GETENV_H */