diff options
Diffstat (limited to 'src/daemon/caps.c')
-rw-r--r-- | src/daemon/caps.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/src/daemon/caps.c b/src/daemon/caps.c new file mode 100644 index 00000000..8d429459 --- /dev/null +++ b/src/daemon/caps.c @@ -0,0 +1,131 @@ +/* $Id$ */ + +/*** + This file is part of polypaudio. + + polypaudio 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 of the License, + or (at your option) any later version. + + polypaudio 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 polypaudio; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. +***/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <assert.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> + +#ifdef HAVE_SYS_CAPABILITY_H +#include <sys/capability.h> +#endif + +#include <polypcore/log.h> +#include "caps.h" + +#ifdef HAVE_GETUID + +/* Drop root rights when called SUID root */ +void pa_drop_root(void) { + uid_t uid = getuid(); + + if (uid == 0 || geteuid() != 0) + return; + + pa_log_info(__FILE__": dropping root rights.\n"); + +#if defined(HAVE_SETRESUID) + setresuid(uid, uid, uid); +#elif defined(HAVE_SETREUID) + setreuid(uid, uid); +#else + setuid(uid); + seteuid(uid); +#endif +} + +#else + +void pa_drop_root(void) { +} + +#endif + +#ifdef HAVE_SYS_CAPABILITY_H + +/* Limit capabilities set to CAPSYS_NICE */ +int pa_limit_caps(void) { + int r = -1; + cap_t caps; + cap_value_t nice_cap = CAP_SYS_NICE; + + caps = cap_init(); + assert(caps); + + cap_clear(caps); + + cap_set_flag(caps, CAP_EFFECTIVE, 1, &nice_cap, CAP_SET); + cap_set_flag(caps, CAP_PERMITTED, 1, &nice_cap, CAP_SET); + + if (cap_set_proc(caps) < 0) + goto fail; + + pa_log_info(__FILE__": dropped capabilities successfully.\n"); + + r = 0; + +fail: + cap_free (caps); + + return r; +} + +/* Drop all capabilities, effectively becoming a normal user */ +int pa_drop_caps(void) { + cap_t caps; + int r = -1; + + caps = cap_init(); + assert(caps); + + cap_clear(caps); + + if (cap_set_proc(caps) < 0) { + pa_log(__FILE__": failed to drop capabilities: %s\n", strerror(errno)); + goto fail; + } + + r = 0; + +fail: + cap_free (caps); + + return r; +} + +#else + +/* NOOPs in case capabilities are not available. */ +int pa_limit_caps(void) { + return 0; +} + +int pa_drop_caps(void) { + pa_drop_root(); + return 0; +} + +#endif + |