| /* |
| * Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "tests.h" |
| #include <stddef.h> |
| #include <unistd.h> |
| #include <stdio.h> |
| #include <errno.h> |
| #include <sys/syscall.h> |
| |
| #ifdef HAVE_PRCTL |
| # include <sys/prctl.h> |
| #endif |
| #ifdef HAVE_LINUX_SECCOMP_H |
| # include <linux/seccomp.h> |
| #endif |
| #ifdef HAVE_LINUX_FILTER_H |
| # include <linux/filter.h> |
| #endif |
| |
| #if defined HAVE_PRCTL \ |
| && defined PR_SET_NO_NEW_PRIVS \ |
| && defined PR_SET_SECCOMP \ |
| && defined SECCOMP_MODE_FILTER \ |
| && defined SECCOMP_RET_ERRNO \ |
| && defined BPF_JUMP \ |
| && defined BPF_STMT |
| |
| #define SOCK_FILTER_ALLOW_SYSCALL(nr) \ |
| BPF_JUMP(BPF_JMP | BPF_K | BPF_JEQ, __NR_ ## nr, 0, 1), \ |
| BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW) |
| |
| #define SOCK_FILTER_DENY_SYSCALL(nr, err) \ |
| BPF_JUMP(BPF_JMP | BPF_K | BPF_JEQ, __NR_ ## nr, 0, 1), \ |
| BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ERRNO | (SECCOMP_RET_DATA & (err))) |
| |
| #define SOCK_FILTER_KILL_PROCESS \ |
| BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_KILL) |
| |
| #define PRINT_ALLOW_SYSCALL(nr) \ |
| printf("BPF_JUMP(BPF_JMP | BPF_K | BPF_JEQ, %#x, 0, 0x1), " \ |
| "BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW), ", \ |
| __NR_ ## nr) |
| |
| #define PRINT_DENY_SYSCALL(nr, err) \ |
| printf("BPF_JUMP(BPF_JMP | BPF_K | BPF_JEQ, %#x, 0, 0x1), " \ |
| "BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ERRNO | %#x), ", \ |
| __NR_ ## nr, err) |
| |
| static const struct sock_filter filter[] = { |
| /* load syscall number */ |
| BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct seccomp_data, nr)), |
| |
| /* allow syscalls */ |
| SOCK_FILTER_ALLOW_SYSCALL(close), |
| SOCK_FILTER_ALLOW_SYSCALL(exit), |
| SOCK_FILTER_ALLOW_SYSCALL(exit_group), |
| |
| /* deny syscalls */ |
| SOCK_FILTER_DENY_SYSCALL(sync, EBUSY), |
| SOCK_FILTER_DENY_SYSCALL(setsid, EPERM), |
| |
| /* kill process */ |
| SOCK_FILTER_KILL_PROCESS |
| }; |
| |
| static const struct sock_fprog prog = { |
| .len = sizeof(filter) / sizeof(filter[0]), |
| .filter = (struct sock_filter *) filter, |
| }; |
| |
| int |
| main(void) |
| { |
| int fds[2]; |
| |
| puts("prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) = 0"); |
| |
| printf("prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, ["); |
| |
| printf("BPF_STMT(BPF_LD | BPF_W | BPF_ABS, %#x), ", |
| (unsigned) offsetof(struct seccomp_data, nr)); |
| |
| PRINT_ALLOW_SYSCALL(close); |
| PRINT_ALLOW_SYSCALL(exit); |
| PRINT_ALLOW_SYSCALL(exit_group); |
| |
| PRINT_DENY_SYSCALL(sync, EBUSY), |
| PRINT_DENY_SYSCALL(setsid, EPERM), |
| |
| printf("BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_KILL)"); |
| |
| puts("]) = 0"); |
| puts("+++ exited with 0 +++"); |
| |
| fflush(stdout); |
| close(0); |
| close(1); |
| |
| if (pipe(fds)) |
| perror_msg_and_fail("pipe"); |
| if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) |
| perror_msg_and_skip("PR_SET_NO_NEW_PRIVS"); |
| if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog)) |
| perror_msg_and_skip("PR_SET_SECCOMP"); |
| if (close(0) || close(1)) |
| _exit(77); |
| |
| _exit(0); |
| } |
| |
| #else |
| |
| SKIP_MAIN_UNDEFINED("HAVE_PRCTL && PR_SET_NO_NEW_PRIVS && PR_SET_SECCOMP" |
| " && SECCOMP_MODE_FILTER && SECCOMP_RET_ERRNO" |
| " && BPF_JUMP && BPF_STMT") |
| |
| #endif |