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/*
* Copyright 2017, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT
* OWNER OR CONTRIBUTORS 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 "libsyscall_intercept_hook_point.h"
#include <stddef.h>
#include <syscall.h>
#include <string.h>
static int
hook(long syscall_number,
long arg0, long arg1,
long arg2, long arg3,
long arg4, long arg5,
long *result)
{
(void) arg0;
(void) arg2;
(void) arg3;
(void) arg4;
(void) arg5;
(void) result;
if (syscall_number == SYS_write) {
const char interc[] = "intercepted_";
const char *src = interc;
/* write(fd, buf, len) */
size_t len = (size_t)arg2;
char *buf = (char *)arg1;
#ifdef EXPECT_SPURIOUS_SYSCALLS
if (strcmp(buf, "original_syscall") != 0)
return 1;
#endif
if (len > sizeof(interc)) {
while (*src != '\0')
*buf++ = *src++;
}
}
return 1;
}
static __attribute__((constructor)) void
init(void)
{
intercept_hook_point = hook;
}