Dmitry V. Levin
899220d28d
Linux socket filter uses almost the same classic BPF as seccomp filter, The only difference noticeable from strace PoV is the meaning of generic multiuse field. Transform the parser of seccomp filters to a more generic parser of classic BPF, parametrized with a method of parsing the generic multiuse field in BPF_STMT. * bpf_filter.c: New file. * bpf_filter.h: Likewise. * bpf_fprog.h: Likewise. * bpf_seccomp_filter.c: Likewise. * fetch_bpf_fprog.c: Likewise. * fetch_seccomp_fprog.c: Remove. * seccomp_fprog.h: Likewise. * Makefile.am (strace_SOURCES): Add bpf_filter.c, bpf_filter.h, bpf_fprog.h, bpf_seccomp_filter.c, and fetch_bpf_fprog.c. Remove fetch_seccomp_fprog.c and seccomp_fprog.h. * seccomp.c: Do not include linux/filter.h and xlat header files. Do not define SECCOMP_RET_ACTION. (bpf_filter, decode_bpf_code, decode_bpf_stmt, decode_bpf_jump, print_bpf_filter, print_seccomp_fprog, print_seccomp_filter): Remove. * defs.h (print_seccomp_filter): Rename to decode_seccomp_fprog. (SYS_FUNC(seccomp)): Replace print_seccomp_filter with decode_seccomp_fprog. * prctl.c (SYS_FUNC(prctl)): Likewise.
72 lines
2.4 KiB
C
72 lines
2.4 KiB
C
/*
|
|
* Decoder of seccomp filter programs.
|
|
*
|
|
* Copyright (c) 2015-2017 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 "defs.h"
|
|
|
|
#include "bpf_filter.h"
|
|
|
|
#include <linux/filter.h>
|
|
#ifdef HAVE_LINUX_SECCOMP_H
|
|
# include <linux/seccomp.h>
|
|
#endif
|
|
#ifndef SECCOMP_RET_ACTION
|
|
# define SECCOMP_RET_ACTION 0x7fff0000U
|
|
#endif
|
|
#include "xlat/seccomp_ret_action.h"
|
|
|
|
static bool
|
|
print_seccomp_filter_k(const struct bpf_filter_block *const fp)
|
|
{
|
|
if (BPF_CLASS(fp->code) == BPF_RET) {
|
|
unsigned int action = SECCOMP_RET_ACTION & fp->k;
|
|
unsigned int data = fp->k & ~action;
|
|
|
|
printxval(seccomp_ret_action, action, "SECCOMP_RET_???");
|
|
if (data)
|
|
tprintf("|%#x", data);
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void
|
|
print_seccomp_fprog(struct tcb *const tcp, const kernel_ulong_t addr,
|
|
const unsigned short len)
|
|
{
|
|
print_bpf_fprog(tcp, addr, len, print_seccomp_filter_k);
|
|
}
|
|
|
|
void
|
|
decode_seccomp_fprog(struct tcb *const tcp, const kernel_ulong_t addr)
|
|
{
|
|
decode_bpf_fprog(tcp, addr, print_seccomp_filter_k);
|
|
}
|