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/***
This file is part of PulseAudio.
Copyright 2004-2006 Lennart Poettering
Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 2.1 of the License,
or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <pulsecore/i18n.h>
#include <pulsecore/macro.h>
#include <pulsecore/log.h>
#ifdef HAVE_SYS_CAPABILITY_H
#include <sys/capability.h>
#endif
#include "caps.h"
/* Glibc <= 2.2 has broken unistd.h */
#if defined(__linux__) && (__GLIBC__ <= 2 && __GLIBC_MINOR__ <= 2)
int setresgid(gid_t r, gid_t e, gid_t s);
int setresuid(uid_t r, uid_t e, uid_t s);
#endif
/* Drop root rights when called SUID root */
void pa_drop_root(void) {
#ifdef HAVE_GETUID
uid_t uid;
gid_t gid;
pa_log_debug("Cleaning up privileges.");
uid = getuid();
gid = getgid();
#if defined(HAVE_SETRESUID)
pa_assert_se(setresuid(uid, uid, uid) >= 0);
pa_assert_se(setresgid(gid, gid, gid) >= 0);
#elif defined(HAVE_SETREUID)
pa_assert_se(setreuid(uid, uid) >= 0);
pa_assert_se(setregid(gid, gid) >= 0);
#else
pa_assert_se(setuid(uid) >= 0);
pa_assert_se(seteuid(uid) >= 0);
pa_assert_se(setgid(gid) >= 0);
pa_assert_se(setegid(gid) >= 0);
#endif
pa_assert_se(getuid() == uid);
pa_assert_se(geteuid() == uid);
pa_assert_se(getgid() == gid);
pa_assert_se(getegid() == gid);
if (uid != 0)
pa_drop_caps();
#endif
}
void pa_drop_caps(void) {
#ifdef HAVE_SYS_CAPABILITY_H
#if defined(__linux__)
cap_t caps;
pa_assert_se(caps = cap_init());
pa_assert_se(cap_clear(caps) == 0);
pa_assert_se(cap_set_proc(caps) == 0);
pa_assert_se(cap_free(caps) == 0);
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
/* FreeBSD doesn't have this functionality, even though sys/capability.h is
* available. See https://bugs.freedesktop.org/show_bug.cgi?id=72580 */
pa_log_warn("FreeBSD cannot drop extra capabilities, implementation needed.");
#else
#error "Don't know how to do capabilities on your system. Please send a patch."
#endif /* __linux__ */
#else /* HAVE_SYS_CAPABILITY_H */
pa_log_warn("Normally all extra capabilities would be dropped now, but "
"that's impossible because PulseAudio was built without "
"capabilities support.");
#endif
}
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