small filter changes; openat as separate function

This commit is contained in:
Cristian Toader 2013-07-30 19:09:28 +03:00
parent 8022def6f0
commit 871e5b35a8
3 changed files with 22 additions and 14 deletions

View File

@ -26,17 +26,21 @@
#if defined(USE_LIBSECCOMP)
#define _GNU_SOURCE
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <bits/signum.h>
#include <seccomp.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
sandbox_cfg_t *filter_dynamic = NULL;
static sandbox_static_cfg_t filter_static[] = {
// Example entries
{SCMP_SYS(execve), PARAM_PTR, 0, (intptr_t)("/usr/local/bin/tor"), 0},
{SCMP_SYS(rt_sigaction), PARAM_NUM, 0, (intptr_t)(SIGINT), 0},
{SCMP_SYS(rt_sigaction), PARAM_NUM, 0, (intptr_t)(SIGTERM), 0},
@ -49,19 +53,16 @@ static sandbox_static_cfg_t filter_static[] = {
#endif
{SCMP_SYS(rt_sigaction), PARAM_NUM, 0, (intptr_t)(SIGCHLD), 0},
{SCMP_SYS(time), PARAM_NUM, 0, 0, 0},
// accept4 workaround
#ifdef __NR_socketcall
{SCMP_SYS(socketcall), PARAM_NUM, 0, 18, 0}, // accept4 workaround
{SCMP_SYS(socketcall), PARAM_NUM, 0, 18, 0},
#endif
{SCMP_SYS(open), PARAM_NUM, 1, O_RDONLY | O_CLOEXEC, 0}
};
/** Variable used for storing all syscall numbers that will be allowed with the
* stage 1 general Tor sandbox.
*
* todo:
* read, write, close - rely on fd
*
*
*/
static int filter_nopar_gen[] = {
SCMP_SYS(access),
@ -72,7 +73,6 @@ static int filter_nopar_gen[] = {
SCMP_SYS(epoll_create),
SCMP_SYS(epoll_ctl),
SCMP_SYS(epoll_wait),
SCMP_SYS(execve),
SCMP_SYS(fcntl),
#ifdef __NR_fcntl64
/* Older libseccomp versions don't define PNR entries for all of these,
@ -228,23 +228,29 @@ int
sandbox_cfg_allow_open_filename(sandbox_cfg_t **cfg, char *file)
{
sandbox_cfg_t *elem = NULL;
intptr_t prot_str = (intptr_t) prot_strdup((char*) file);
elem = (sandbox_cfg_t*) malloc(sizeof(sandbox_cfg_t));
elem->syscall = SCMP_SYS(open);
elem->pindex = 0;
elem->ptype = PARAM_PTR;
elem->param = prot_str;
elem->param = (intptr_t) prot_strdup((char*) file);
elem->prot = 1;
elem->next = filter_dynamic;
filter_dynamic = elem;
// also allow openat
return 0;
}
int
sandbox_cfg_allow_openat_filename(sandbox_cfg_t **cfg, char *file)
{
sandbox_cfg_t *elem = NULL;
elem = (sandbox_cfg_t*) malloc(sizeof(sandbox_cfg_t));
elem->syscall = SCMP_SYS(openat);
elem->pindex = 1;
elem->ptype = PARAM_PTR;
elem->param = prot_str;
elem->param = (intptr_t) prot_strdup((char*) file);;
elem->prot = 1;
elem->next = filter_dynamic;
filter_dynamic = elem;

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@ -86,6 +86,7 @@ const char* sandbox_intern_string(const char *param);
sandbox_cfg_t * sandbox_cfg_new();
int sandbox_cfg_allow_open_filename(sandbox_cfg_t **cfg, char *file);
int sandbox_cfg_allow_openat_filename(sandbox_cfg_t **cfg, char *file);
int sandbox_init(sandbox_cfg_t* cfg);
#endif /* SANDBOX_H_ */

View File

@ -2644,8 +2644,9 @@ sandbox_init_filter()
{
sandbox_cfg_t *cfg = sandbox_cfg_new();
sandbox_cfg_allow_open_filename(&cfg,
sandbox_cfg_allow_openat_filename(&cfg,
get_datadir_fname("cached-status"));
sandbox_cfg_allow_open_filename(&cfg,
get_datadir_fname("cached-certs"));
sandbox_cfg_allow_open_filename(&cfg,