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#include "sandbox.h"
static struct timespec start_timespec = { 0 };
static noreturn void finish(enum poe_exit_reason reason, int status, const char *fmt, ...)
{
if (!start_timespec.tv_sec && !start_timespec.tv_nsec)
bug("start_timespec not set?");
struct timespec end_timespec;
if (clock_gettime(CLOCK_MONOTONIC, &end_timespec))
bug("clock_gettime failed");
int elapsed = (end_timespec.tv_sec - start_timespec.tv_sec) * 1000 +
(end_timespec.tv_nsec - start_timespec.tv_nsec) / 1000 / 1000;
int xx[] = { reason, status, elapsed };
fwrite(xx, sizeof(int), sizeof(xx) / sizeof(int), stderr);
if (fmt) {
va_list args;
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
}
exit(0);
}
static void handle_stdout(int fd, int orig_fd)
{
assert(PIPE_BUF % 4 == 0);
uint32_t buf[PIPE_BUF / 4 + 2];
ssize_t n = read(fd, (char *)(buf + 2), PIPE_BUF);
if (n < 0)
bug("read from stdout/err pipe");
buf[0] = (uint32_t)orig_fd;
buf[1] = (uint32_t)n;
if (write(STDOUT_FILENO, buf, n + 8) < 0)
bug("write to stdout failed");
}
static void handle_signal(pid_t mpid, struct signalfd_siginfo *si)
{
if (si->ssi_signo == SIGINT || si->ssi_signo == SIGTERM ||
si->ssi_signo == SIGHUP)
finish(POE_TIMEDOUT, -1, "Supervisor terminated");
if (si->ssi_signo != SIGCHLD)
bug("unknown signal %d", si->ssi_signo);
int status;
pid_t spid;
while ((spid = waitpid(-mpid, &status, WNOHANG | __WALL)) > 0) {
if (spid == mpid && WIFEXITED(status)) {
finish(POE_SUCCESS, WEXITSTATUS(status), NULL);
} else if (spid == mpid && WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
finish(POE_SIGNALED, -1, "Program terminated with signal %d (%s)", sig, strsignal(sig));
} else if (WIFSTOPPED(status)) {
switch (status >> 16 & 0xff) {
case PTRACE_EVENT_SECCOMP:
errno = 0;
int syscalln = ptrace(PTRACE_PEEKUSER, spid, sizeof(long) * ORIG_RAX);
if (errno)
bug("ptrace(PTRACE_PEEKUSER) failed");
char *name = poe_seccomp_syscall_resolve(syscalln);
finish(POE_SIGNALED, -1, "System call %s is blocked", name);
break;
case PTRACE_EVENT_CLONE:
case PTRACE_EVENT_FORK:
case PTRACE_EVENT_VFORK:
ptrace(PTRACE_CONT, spid, 0, 0);
break;
default:
ptrace(PTRACE_CONT, spid, 0, WSTOPSIG(status));
break;
}
}
}
if (spid < 0) {
if (errno == ECHILD)
bug("child dies too early (before raising SIGSTOP)");
else
bug("waitpid failed");
}
}
int main(int argc, char *argv[])
{
if (argc < 5)
die("usage: runner basedir overlaydir sourcefile cmdl..");
struct playground *pg = poe_playground_init(argv[1], argv[2]);
if (!pg)
die("playground init failed");
if (poe_playground_init_command_line(pg, argv + 4, argv[3]))
die("copy program failed");
int stdout_fd[2], stderr_fd[2], child_fd[2];
if (pipe2(stdout_fd, O_DIRECT))
bug("pipe2 failed");
if (pipe2(stderr_fd, O_DIRECT))
bug("pipe2 failed");
if (pipe2(child_fd, O_DIRECT | O_CLOEXEC))
bug("pipe2 failed");
// init cgroup: create root hierarchy and setup controllers
if (poe_cgroup_init())
die("failed to init cgroup");
// TODO: CLONE_NEWUSER
pid_t pid = (pid_t)syscall(SYS_clone, SIGCHLD | CLONE_NEWIPC | CLONE_NEWNS | CLONE_NEWPID | CLONE_NEWUTS | CLONE_NEWNET, 0);
if (pid < 0)
bug("clone failed");
if (!pid) {
poe_child_do(pg, stdout_fd, stderr_fd, child_fd);
bug("unreachable");
}
if (close(stdout_fd[1]) || close(stderr_fd[1]) || close(child_fd[1]))
bug("close child write pipe failed");
int epoll_fd = epoll_create1(0);
if (epoll_fd < 0)
bug("epoll_create1 failed");
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGCHLD);
sigaddset(&mask, SIGINT);
sigaddset(&mask, SIGTERM);
sigaddset(&mask, SIGHUP);
sigprocmask(SIG_BLOCK, &mask, NULL);
int signal_fd = signalfd(-1, &mask, 0);
if (signal_fd < 0)
bug("signalfd failed");
int timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
if (timer_fd < 0)
bug("timerfd_create failed");
if (timerfd_settime(timer_fd, 0, &(struct itimerspec) { .it_value.tv_sec = POE_TIME_LIMIT }, NULL))
bug("timerfd_settime failed");
#define ADD(_fd__) do if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, _fd__, &(struct epoll_event) { .data.fd = _fd__, .events = EPOLLRDHUP|EPOLLIN })) \
bug("EPOLL_CTL_ADD failed"); while (0)
ADD(signal_fd);
ADD(timer_fd);
ADD(child_fd[0]);
ADD(stdout_fd[0]);
ADD(stderr_fd[0]);
if (ptrace(PTRACE_SEIZE, pid, NULL,
PTRACE_O_TRACECLONE |
PTRACE_O_TRACEFORK |
PTRACE_O_TRACESECCOMP |
PTRACE_O_TRACEVFORK))
bug("ptrace failed");
if (poe_cgroup_add(pid))
die("failed cgroup add");
while (true) {
struct epoll_event events[10];
int n = epoll_wait(epoll_fd, events, sizeof(events) / sizeof(events[0]), -1);
if (n < 0)
bug("epoll_wait failed");
for (int i = 0; i < n; i++) {
struct epoll_event *ev = &events[i];
if (ev->events & EPOLLIN) {
if (ev->data.fd == stdout_fd[0]) {
handle_stdout(ev->data.fd, STDOUT_FILENO);
} else if (ev->data.fd == stderr_fd[0]) {
handle_stdout(ev->data.fd, STDERR_FILENO);
} else if (ev->data.fd == signal_fd) {
struct signalfd_siginfo si;
if (sizeof(si) != read(signal_fd, &si, sizeof(si)))
die("partial read signalfd");
handle_signal(pid, &si);
} else if (ev->data.fd == timer_fd) {
finish(POE_TIMEDOUT, -1, NULL);
} else if (ev->data.fd == child_fd[0]) {
char buf[PIPE_BUF];
ssize_t nx = read(child_fd[0], buf, sizeof(buf));
if (nx > 0) // TODO
die("child err: %s", strndupa(buf, nx));
}
}
if (ev->events & EPOLLERR || ev->events & EPOLLHUP || ev->events & EPOLLRDHUP) {
// fd closed
close(ev->data.fd);
if (ev->data.fd == child_fd[0])
// exec succeeded
if (clock_gettime(CLOCK_MONOTONIC, &start_timespec))
bug("clock_gettime failed");
}
}
}
bug("unreachable");
}
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