code.delx.au - pulseaudio/blob - src/daemon/caps.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as published
   9   by the Free Software Foundation; either version 2.1 of the License,
  10   or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30
  31 #include <pulsecore/i18n.h>
  32 #include <pulsecore/macro.h>
  33 #include <pulsecore/log.h>
  34
  35 #ifdef HAVE_SYS_CAPABILITY_H
  36 #include <sys/capability.h>
  37 #endif
  38
  39 #include "caps.h"
  40
  41 /* Glibc <= 2.2 has broken unistd.h */
  42 #if defined(__linux__) && (__GLIBC__ <= 2 && __GLIBC_MINOR__ <= 2)
  43 int setresgid(gid_t r, gid_t e, gid_t s);
  44 int setresuid(uid_t r, uid_t e, uid_t s);
  45 #endif
  46
  47 /* Drop root rights when called SUID root */
  48 void pa_drop_root(void) {
  49
  50 #ifdef HAVE_GETUID
  51     uid_t uid;
  52     gid_t gid;
  53
  54     pa_log_debug(_("Cleaning up privileges."));
  55     uid = getuid();
  56     gid = getgid();
  57
  58 #if defined(HAVE_SETRESUID)
  59     pa_assert_se(setresuid(uid, uid, uid) >= 0);
  60     pa_assert_se(setresgid(gid, gid, gid) >= 0);
  61 #elif defined(HAVE_SETREUID)
  62     pa_assert_se(setreuid(uid, uid) >= 0);
  63     pa_assert_se(setregid(gid, gid) >= 0);
  64 #else
  65     pa_assert_se(setuid(uid) >= 0);
  66     pa_assert_se(seteuid(uid) >= 0);
  67     pa_assert_se(setgid(gid) >= 0);
  68     pa_assert_se(setegid(gid) >= 0);
  69 #endif
  70
  71     pa_assert_se(getuid() == uid);
  72     pa_assert_se(geteuid() == uid);
  73     pa_assert_se(getgid() == gid);
  74     pa_assert_se(getegid() == gid);
  75
  76     if (uid != 0)
  77         pa_drop_caps();
  78 #endif
  79 }
  80
  81 void pa_drop_caps(void) {
  82 #ifdef HAVE_SYS_CAPABILITY_H
  83 #if defined(__linux__)
  84     cap_t caps;
  85     pa_assert_se(caps = cap_init());
  86     pa_assert_se(cap_clear(caps) == 0);
  87     pa_assert_se(cap_set_proc(caps) == 0);
  88     pa_assert_se(cap_free(caps) == 0);
  89 #else
  90 #error "Don't know how to do capabilities on your system.  Please send a patch."
  91 #endif /* __linux__ */
  92 #else /* HAVE_SYS_CAPABILITY_H */
  93     pa_log_warn("Normally all extra capabilities would be dropped now, but "
  94                 "that's impossible because PulseAudio was built without "
  95                 "capabilities support.");
  96 #endif
  97 }