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/*
* Copyright (C) 2014-2023 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_optimize.h"
#include "../include/syscall.h"
int arg_seccomp_error_action = SECCOMP_RET_ERRNO | EPERM; // error action: errno, log or kill
static const char *const usage_str =
"Usage:\n"
"\tfsec-optimize file - optimize seccomp filter\n";
static void usage(void) {
puts(usage_str);
}
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;
}
warn_dumpable();
char *error_action = getenv("FIREJAIL_SECCOMP_ERROR_ACTION");
if (error_action) {
if (strcmp(error_action, "kill") == 0)
arg_seccomp_error_action = SECCOMP_RET_KILL;
else if (strcmp(error_action, "log") == 0)
arg_seccomp_error_action = SECCOMP_RET_LOG;
else {
arg_seccomp_error_action = errno_find_name(error_action);
if (arg_seccomp_error_action == -1)
errExit("seccomp-error-action: unknown errno");
arg_seccomp_error_action |= SECCOMP_RET_ERRNO;
}
}
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;
close(fd);
// duplicate the filter memory and unmap the file
struct sock_filter *outfilter = duplicate(filter, entries);
if (munmap(filter, size) == -1)
perror("Error un-mmapping the file");
// optimize filter
entries = optimize(outfilter, entries);
// write the new file and free memory
fd = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0755);
if (fd == -1) {
fprintf(stderr, "Error: cannot open output file\n");
return 1;
}
size = write(fd, outfilter, entries * sizeof(struct sock_filter));
if (size != (int) (entries * sizeof(struct sock_filter))) {
fprintf(stderr, "Error: cannot write output file\n");
return 1;
}
close(fd);
free(outfilter);
return 0;
errexit:
if (fd != -1)
close(fd);
fprintf(stderr, "Error: cannot read %s\n", fname);
exit(1);
}
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