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/*
* Copyright (C) 2014-2020 Firejail Authors
*
* This file is part of firejail project
*
* This program 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.
*
* This program 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "fseccomp.h"
#include "../include/seccomp.h"
#include <sys/syscall.h>
void write_to_file(int fd, const void *data, size_t size) {
assert(data);
assert(size);
size_t written = 0;
while (written < size) {
int rv = write(fd, (unsigned char *) data + written, size - written);
if (rv == -1) {
fprintf(stderr, "Error fseccomp: cannot write seccomp file\n");
exit(1);
}
written += rv;
}
}
void filter_init(int fd, bool native) {
struct sock_filter filter_native[] = {
VALIDATE_ARCHITECTURE,
#if defined(__x86_64__)
EXAMINE_SYSCALL,
HANDLE_X32
#else
EXAMINE_SYSCALL
#endif
};
struct sock_filter filter_32[] = {
VALIDATE_ARCHITECTURE_32,
EXAMINE_SYSCALL
};
#if 0
{
int i;
unsigned char *ptr = (unsigned char *) &filter[0];
for (i = 0; i < sizeof(filter); i++, ptr++)
printf("%x, ", (*ptr) & 0xff);
printf("\n");
}
#endif
if (native)
write_to_file(fd, filter_native, sizeof(filter_native));
else
write_to_file(fd, filter_32, sizeof(filter_32));
}
static void write_whitelist(int fd, int syscall) {
struct sock_filter filter[] = {
WHITELIST(syscall)
};
write_to_file(fd, filter, sizeof(filter));
}
static void write_blacklist(int fd, int syscall) {
struct sock_filter filter[] = {
BLACKLIST(syscall)
};
write_to_file(fd, filter, sizeof(filter));
}
void filter_add_whitelist(int fd, int syscall, int arg, void *ptrarg, bool native) {
(void) arg;
(void) ptrarg;
(void) native;
if (syscall >= 0) {
write_whitelist(fd, syscall);
}
}
// handle seccomp list exceptions (seccomp x,y,!z)
void filter_add_whitelist_for_excluded(int fd, int syscall, int arg, void *ptrarg, bool native) {
(void) arg;
(void) ptrarg;
(void) native;
if (syscall < 0) {
write_whitelist(fd, -syscall);
}
}
void filter_add_blacklist(int fd, int syscall, int arg, void *ptrarg, bool native) {
(void) arg;
(void) ptrarg;
(void) native;
if (syscall >= 0) {
write_blacklist(fd, syscall);
}
}
// handle seccomp list exceptions (seccomp x,y,!z)
void filter_add_blacklist_for_excluded(int fd, int syscall, int arg, void *ptrarg, bool native) {
(void) arg;
(void) ptrarg;
(void) native;
if (syscall < 0) {
write_blacklist(fd, -syscall);
}
}
void filter_add_errno(int fd, int syscall, int arg, void *ptrarg, bool native) {
(void) ptrarg;
(void) native;
struct sock_filter filter[] = {
BLACKLIST_ERRNO(syscall, arg)
};
write_to_file(fd, filter, sizeof(filter));
}
void filter_end_blacklist(int fd) {
struct sock_filter filter[] = {
RETURN_ALLOW
};
write_to_file(fd, filter, sizeof(filter));
}
void filter_end_whitelist(int fd) {
struct sock_filter filter[] = {
KILL_PROCESS
};
write_to_file(fd, filter, sizeof(filter));
}
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