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/*
* Copyright (C) 2013 Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS test suite.
*
* ocserv is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* ocserv 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 General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include "utils.h"
#ifdef HAVE_LIBSECCOMP
#include <seccomp.h>
#include <errno.h>
#include <string.h>
#if defined(__linux__)
# include <sys/syscall.h>
#endif
int disable_system_calls(void)
{
int ret;
scmp_filter_ctx ctx;
/*ctx = seccomp_init(SCMP_ACT_ERRNO(EPERM));*/
ctx = seccomp_init(SCMP_ACT_TRAP);
if (ctx == NULL) {
fprintf(stderr, "could not initialize seccomp");
return -1;
}
#define ADD_SYSCALL(name, ...) \
ret = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(name), __VA_ARGS__); \
/* libseccomp returns EDOM for pseudo-syscalls due to a bug */ \
if (ret < 0 && ret != -EDOM) { \
fprintf(stderr, "could not add " #name " to seccomp filter: %s", strerror(-ret)); \
ret = -1; \
goto fail; \
}
ADD_SYSCALL(nanosleep, 0);
ADD_SYSCALL(time, 0);
ADD_SYSCALL(getpid, 0);
ADD_SYSCALL(gettimeofday, 0);
#if defined(HAVE_CLOCK_GETTIME)
ADD_SYSCALL(clock_gettime, 0);
#endif
ADD_SYSCALL(getrusage, 0);
/* recv/send for the default pull/push functions. It is unknown
* which syscall is used by libc and varies from system to system
* so we enable all */
ADD_SYSCALL(recvmsg, 0);
ADD_SYSCALL(sendmsg, 0);
ADD_SYSCALL(send, 0);
ADD_SYSCALL(recv, 0);
ADD_SYSCALL(sendto, 0);
ADD_SYSCALL(recvfrom, 0);
/* to read from /dev/urandom */
ADD_SYSCALL(read, 0);
#ifdef SYS_getrandom
ADD_SYSCALL(getrandom, 0);
#endif
/* we use it in select */
ADD_SYSCALL(sigprocmask, 0);
ADD_SYSCALL(rt_sigprocmask, 0);
/* used in to detect reading timeouts */
ADD_SYSCALL(poll, 0);
/* for memory allocation */
ADD_SYSCALL(brk, 0);
/* the following are for generic operations, not specific to
* gnutls. */
ADD_SYSCALL(close, 0);
ADD_SYSCALL(exit, 0);
ADD_SYSCALL(exit_group, 0);
/* allow returning from signal handlers */
ADD_SYSCALL(sigreturn, 0);
ADD_SYSCALL(rt_sigreturn, 0);
ret = seccomp_load(ctx);
if (ret < 0) {
fprintf(stderr, "could not load seccomp filter");
ret = -1;
goto fail;
}
ret = 0;
fail:
seccomp_release(ctx);
return ret;
}
#else
int disable_system_calls(void)
{
return 0;
}
#endif
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