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#define _GNU_SOURCE
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sched.h>
#include <unistd.h>
#include <signal.h>
#include <limits.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <linux/audit.h>
#include <linux/filter.h>
#include <linux/seccomp.h>
#include <sys/mman.h>
#include <sys/un.h>
#include <sys/socket.h>
#include "testutil.h"
#include "common.h"
#include "filter.h"
struct seccomp_notif req;
int notifyfd;
struct args_target *at;
int pipefd[2];
pid_t pid;
char path[PATH_MAX] = "/tmp/test-seitan";
uint16_t tmp_data[TMP_DATA_SIZE];
int install_notification_filter(struct args_target *at)
{
/* filter a single syscall for the tests */
struct sock_filter filter[] = {
BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
(offsetof(struct seccomp_data, arch))),
BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, SEITAN_AUDIT_ARCH, 0, 3),
BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
(offsetof(struct seccomp_data, nr))),
BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, at->nr, 0, 1),
BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_USER_NOTIF),
BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ALLOW),
};
return install_filter(
filter, (unsigned short)(sizeof(filter) / sizeof(filter[0])));
}
int target()
{
int buf = 0;
if (at->install_filter(at) < 0) {
return -1;
}
at->ret = syscall(at->nr, at->args[0], at->args[1], at->args[2],
at->args[3], at->args[4], at->args[5]);
at->err = errno;
if (at->open_path) {
if ((at->fd = open(path, O_CREAT | O_RDONLY)) < 0) {
perror("open");
return -1;
}
}
if (at->check_fd)
read(pipefd[0], &buf, 1);
close(pipefd[0]);
write(pipefd[1], &buf, 1);
close(pipefd[1]);
exit(0);
}
pid_t do_clone(int (*fn)(void *), void *arg)
{
char stack[STACK_SIZE];
pid_t child;
int flags = SIGCHLD;
child = clone(fn, stack + sizeof(stack), flags, arg);
if (child == -1) {
perror("clone");
return -1;
}
return child;
}
int create_test_fd()
{
return open("/tmp", O_RDWR | O_TMPFILE);
}
int get_fd_notifier(pid_t pid)
{
char path[PATH_MAX + 1];
int pidfd, notifier;
int fd = -1;
snprintf(path, sizeof(path), "/proc/%d/fd", pid);
while (fd < 0) {
sleep(2);
fd = find_fd_seccomp_notifier(path);
}
ck_assert_int_ge(fd, 0);
pidfd = syscall(SYS_pidfd_open, pid, 0);
ck_assert_msg(pidfd >= 0, strerror(errno));
sleep(1);
notifier = syscall(SYS_pidfd_getfd, pidfd, fd, 0);
ck_assert_msg(notifier >= 0, strerror(errno));
return notifier;
}
void target_exit()
{
int status;
waitpid(-1, &status, WUNTRACED | WNOHANG);
if (WEXITSTATUS(status) != 0) {
fprintf(stderr, "target process exited with an error\n");
exit(-1);
}
}
void check_target_fd(int pid, int fd)
{
int buf = 0;
ck_assert(has_fd(pid, fd));
write(pipefd[1], &buf, 1);
close(pipefd[1]);
}
bool has_fd(int pid, int fd)
{
char path[PATH_MAX + 1];
snprintf(path, sizeof(path), "/proc/%d/fd/%d", pid, fd);
return access(path, F_OK) == 0;
}
void check_target_result(long ret, int err, bool ignore_ret)
{
int buf;
read(pipefd[0], &buf, 1);
if (!ignore_ret)
ck_assert_msg(at->ret == ret,
"expect return value %ld to be equal to %ld",
at->ret, ret);
ck_assert_int_eq(at->err, err);
ck_assert_int_eq(close(pipefd[0]), 0);
}
void continue_target()
{
struct seccomp_notif_resp resp;
int ret;
ret = ioctl(notifyfd, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id);
ck_assert_msg(ret == 0, strerror(errno));
resp.id = req.id;
resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
resp.error = 0;
resp.val = 0;
ret = ioctl(notifyfd, SECCOMP_IOCTL_NOTIF_SEND, &resp);
ck_assert_msg(ret == 0, strerror(errno));
}
void mock_syscall_target()
{
struct seccomp_notif_resp resp;
int ret;
ret = ioctl(notifyfd, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id);
ck_assert_msg(ret == 0, strerror(errno));
resp.id = req.id;
resp.flags = 0;
resp.error = 0;
resp.val = 0;
ret = ioctl(notifyfd, SECCOMP_IOCTL_NOTIF_SEND, &resp);
ck_assert_msg(ret == 0, strerror(errno));
}
void set_args_no_check(struct args_target *at)
{
for (unsigned int i = 0; i < 6; i++)
at->cmp[i] = NO_CHECK;
}
void setup()
{
int ret;
signal(SIGCHLD, target_exit);
ck_assert_int_ne(pipe(pipefd), -1);
if (at->target == NULL)
at->target = target;
pid = do_clone(at->target, NULL);
ck_assert_int_ge(pid, 0);
/* Use write pipe to sync the target for checking the existance of the fd */
if (!at->check_fd)
ck_assert_int_ne(close(pipefd[1]), -1);
notifyfd = get_fd_notifier(pid);
memset(&req, 0, sizeof(req));
ret = ioctl(notifyfd, SECCOMP_IOCTL_NOTIF_RECV, &req);
ck_assert_msg(ret == 0, strerror(errno));
ck_assert_msg((req.data).nr == at->nr, "filter syscall nr: %d",
(req.data).nr);
}
void teardown()
{
if (at != NULL)
munmap(at, sizeof(struct args_target));
}
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