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/*
* Copyright (C) 2014-2017 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 <sys/syscall.h>
typedef struct {
char *name;
int nr;
} SyscallEntry;
static SyscallEntry syslist[] = {
//
// code generated using tools/extract-syscall
//
#include "../include/syscall.h"
//
// end of generated code
//
}; // end of syslist
// return -1 if error, or syscall number
int syscall_find_name(const char *name) {
int i;
int elems = sizeof(syslist) / sizeof(syslist[0]);
for (i = 0; i < elems; i++) {
if (strcmp(name, syslist[i].name) == 0)
return syslist[i].nr;
}
return -1;
}
char *syscall_find_nr(int nr) {
int i;
int elems = sizeof(syslist) / sizeof(syslist[0]);
for (i = 0; i < elems; i++) {
if (nr == syslist[i].nr)
return syslist[i].name;
}
return "unknown";
}
void syscall_print(void) {
int i;
int elems = sizeof(syslist) / sizeof(syslist[0]);
for (i = 0; i < elems; i++) {
printf("%d\t- %s\n", syslist[i].nr, syslist[i].name);
}
printf("\n");
}
// allowed input:
// - syscall
// - syscall(error)
static void syscall_process_name(const char *name, int *syscall_nr, int *error_nr) {
assert(name);
if (strlen(name) == 0)
goto error;
*error_nr = -1;
// syntax check
char *str = strdup(name);
if (!str)
errExit("strdup");
char *syscall_name = str;
char *error_name = strchr(str, ':');
if (error_name) {
*error_name = '\0';
error_name++;
}
if (strlen(syscall_name) == 0) {
free(str);
goto error;
}
*syscall_nr = syscall_find_name(syscall_name);
if (error_name) {
*error_nr = errno_find_name(error_name);
if (*error_nr == -1)
*syscall_nr = -1;
}
free(str);
return;
error:
fprintf(stderr, "Error fseccomp: invalid syscall list entry %s\n", name);
exit(1);
}
// return 1 if error, 0 if OK
int syscall_check_list(const char *slist, void (*callback)(int fd, int syscall, int arg), int fd, int arg) {
// don't allow empty lists
if (slist == NULL || *slist == '\0') {
fprintf(stderr, "Error fseccomp: empty syscall lists are not allowed\n");
exit(1);
}
// work on a copy of the string
char *str = strdup(slist);
if (!str)
errExit("strdup");
char *ptr =strtok(str, ",");
if (ptr == NULL) {
fprintf(stderr, "Error fseccomp: empty syscall lists are not allowed\n");
exit(1);
}
while (ptr) {
int syscall_nr;
int error_nr;
syscall_process_name(ptr, &syscall_nr, &error_nr);
if (syscall_nr == -1) {
if (!arg_quiet)
fprintf(stderr, "Warning fseccomp: syscall \"%s\" not available on this platform\n", ptr);
}
else if (callback != NULL) {
if (error_nr != -1)
filter_add_errno(fd, syscall_nr, error_nr);
else
callback(fd, syscall_nr, arg);
}
ptr = strtok(NULL, ",");
}
free(str);
return 0;
}
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