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/*
* Copyright (C) 2014-2018 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 "fsec_print.h"
static void usage(void) {
printf("Usage:\n");
printf("\tfsec-print file - disassemble seccomp filter\n");
}
int main(int argc, char **argv) {
#if 0
{
//system("cat /proc/self/status");
int i;
for (i = 0; i < argc; i++)
printf("*%s* ", argv[i]);
printf("\n");
}
#endif
if (argc != 2) {
usage();
return 1;
}
if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) {
usage();
return 0;
}
char *fname = argv[1];
// open input file
int fd = open(fname, O_RDONLY);
if (fd == -1)
goto errexit;
// calculate the number of entries
int size = lseek(fd, 0, SEEK_END);
if (size == -1) // todo: check maximum size of seccomp filter (4KB?)
goto errexit;
unsigned short entries = (unsigned short) size / (unsigned short) sizeof(struct sock_filter);
// read filter
struct sock_filter *filter = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
if (filter == MAP_FAILED)
goto errexit;
// print filter
print(filter, entries);
// free mapped memory
if (munmap(filter, size) == -1)
perror("Error un-mmapping the file");
// close file
close(fd);
return 0;
errexit:
close(fd);
fprintf(stderr, "Error: cannot read %s\n", fname);
exit(1);
}
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