// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <stdint.h>
#include <string.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <pthread.h>
#include <stdlib.h>
#include <setjmp.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <errno.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <net/if_arp.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

__attribute__((noreturn)) static void doexit(int status)
{
	volatile unsigned i;
	syscall(__NR_exit_group, status);
	for (i = 0;; i++) {
	}
}

__attribute__((noreturn)) static void fail(const char* msg, ...)
{
	int e = errno;
	fflush(stdout);
	va_list args;
	va_start(args, msg);
	vfprintf(stderr, msg, args);
	va_end(args);
	fprintf(stderr, " (errno %d)\n", e);
	doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* uctx)
{
	uintptr_t addr = (uintptr_t)info->si_addr;
	const uintptr_t prog_start = 1 << 20;
	const uintptr_t prog_end = 100 << 20;
	if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) {
		_longjmp(segv_env, 1);
	}
	doexit(sig);
	for (;;) {
	}
}

static void install_segv_handler()
{
	struct sigaction sa;

	memset(&sa, 0, sizeof(sa));
	sa.sa_handler = SIG_IGN;
	syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
	syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);

	memset(&sa, 0, sizeof(sa));
	sa.sa_sigaction = segv_handler;
	sa.sa_flags = SA_NODEFER | SA_SIGINFO;
	sigaction(SIGSEGV, &sa, NULL);
	sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...) { __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); if (_setjmp(segv_env) == 0) { __VA_ARGS__; } __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); }

static void use_temporary_dir()
{
	char tmpdir_template[] = "./syzkaller.XXXXXX";
	char* tmpdir = mkdtemp(tmpdir_template);
	if (!tmpdir)
		fail("failed to mkdtemp");
	if (chmod(tmpdir, 0777))
		fail("failed to chmod");
	if (chdir(tmpdir))
		fail("failed to chdir");
}

static void vsnprintf_check(char* str, size_t size, const char* format, va_list args)
{
	int rv;

	rv = vsnprintf(str, size, format, args);
	if (rv < 0)
		fail("tun: snprintf failed");
	if ((size_t)rv >= size)
		fail("tun: string '%s...' doesn't fit into buffer", str);
}

static void snprintf_check(char* str, size_t size, const char* format, ...)
{
	va_list args;

	va_start(args, format);
	vsnprintf_check(str, size, format, args);
	va_end(args);
}

#define COMMAND_MAX_LEN 128

static void execute_command(const char* format, ...)
{
	va_list args;
	char command[COMMAND_MAX_LEN];
	int rv;

	va_start(args, format);

	vsnprintf_check(command, sizeof(command), format, args);
	rv = system(command);
	if (rv != 0)
		fail("tun: command \"%s\" failed with code %d", &command[0], rv);

	va_end(args);
}

static int tunfd = -1;

#define SYZ_TUN_MAX_PACKET_SIZE 1000

#define MAX_PIDS 32
#define ADDR_MAX_LEN 32

#define LOCAL_MAC "aa:aa:aa:aa:aa:%02hx"
#define REMOTE_MAC "bb:bb:bb:bb:bb:%02hx"

#define LOCAL_IPV4 "172.20.%d.170"
#define REMOTE_IPV4 "172.20.%d.187"

#define LOCAL_IPV6 "fe80::%02hxaa"
#define REMOTE_IPV6 "fe80::%02hxbb"

static void initialize_tun(uint64_t pid)
{
	if (pid >= MAX_PIDS)
		fail("tun: no more than %d executors", MAX_PIDS);
	int id = pid;

	tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
	if (tunfd == -1)
		fail("tun: can't open /dev/net/tun");

	char iface[IFNAMSIZ];
	snprintf_check(iface, sizeof(iface), "syz%d", id);

	struct ifreq ifr;
	memset(&ifr, 0, sizeof(ifr));
	strncpy(ifr.ifr_name, iface, IFNAMSIZ);
	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
	if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0)
		fail("tun: ioctl(TUNSETIFF) failed");

	char local_mac[ADDR_MAX_LEN];
	snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id);
	char remote_mac[ADDR_MAX_LEN];
	snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id);

	char local_ipv4[ADDR_MAX_LEN];
	snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id);
	char remote_ipv4[ADDR_MAX_LEN];
	snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id);

	char local_ipv6[ADDR_MAX_LEN];
	snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id);
	char remote_ipv6[ADDR_MAX_LEN];
	snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id);

	execute_command("sysctl -w net.ipv6.conf.%s.accept_dad=0", iface);

	execute_command("sysctl -w net.ipv6.conf.%s.router_solicitations=0", iface);

	execute_command("ip link set dev %s address %s", iface, local_mac);
	execute_command("ip addr add %s/24 dev %s", local_ipv4, iface);
	execute_command("ip -6 addr add %s/120 dev %s", local_ipv6, iface);
	execute_command("ip neigh add %s lladdr %s dev %s nud permanent", remote_ipv4, remote_mac, iface);
	execute_command("ip -6 neigh add %s lladdr %s dev %s nud permanent", remote_ipv6, remote_mac, iface);
	execute_command("ip link set dev %s up", iface);
}

static void setup_tun(uint64_t pid, bool enable_tun)
{
	if (enable_tun)
		initialize_tun(pid);
}

static void loop();

static void sandbox_common()
{
	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
	setpgrp();
	setsid();

	struct rlimit rlim;
	rlim.rlim_cur = rlim.rlim_max = 128 << 20;
	setrlimit(RLIMIT_AS, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 8 << 20;
	setrlimit(RLIMIT_MEMLOCK, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 1 << 20;
	setrlimit(RLIMIT_FSIZE, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 1 << 20;
	setrlimit(RLIMIT_STACK, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 0;
	setrlimit(RLIMIT_CORE, &rlim);

	unshare(CLONE_NEWNS);
	unshare(CLONE_NEWIPC);
	unshare(CLONE_IO);
}

static int do_sandbox_none(int executor_pid, bool enable_tun)
{
	int pid = fork();
	if (pid)
		return pid;

	sandbox_common();
	setup_tun(executor_pid, enable_tun);

	loop();
	doexit(1);
}

long r[16];
void *thr(void *arg)
{
	switch ((long)arg) {
	case 0:
		r[0] = syscall(__NR_mmap, 0x20000000ul, 0xd000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul);
		break;
	case 1:
		NONFAILING(*(uint64_t*)0x20001fb0 = (uint64_t)0x0);
		NONFAILING(*(uint32_t*)0x20001fb8 = (uint32_t)0x1);
		NONFAILING(*(uint32_t*)0x20001fbc = (uint32_t)0x0);
		NONFAILING(*(uint64_t*)0x20001fc0 = (uint64_t)0x20007fcd);
		NONFAILING(*(uint64_t*)0x20001fc8 = (uint64_t)0x20005000);
		r[6] = syscall(__NR_timer_create, 0x3ul, 0x20001fb0ul, 0x20000000ul);
		break;
	case 2:
		r[7] = syscall(__NR_clock_gettime, 0x0ul, 0x20004000ul);
		if (r[7] != -1)
				NONFAILING(r[8] = *(uint64_t*)0x20004008);
		break;
	case 3:
		NONFAILING(*(uint64_t*)0x20006000 = (uint64_t)0x0);
		NONFAILING(*(uint64_t*)0x20006008 = (uint64_t)0x0);
		NONFAILING(*(uint64_t*)0x20006010 = (uint64_t)0x0);
		NONFAILING(*(uint64_t*)0x20006018 = r[8]+10000000);
		r[13] = syscall(__NR_timer_settime, 0x0ul, 0x0ul, 0x20006000ul, 0x20003fe0ul);
		break;
	case 4:
		NONFAILING(memcpy((void*)0x20006000, "\x2f\x64\x65\x76\x2f\x61\x75\x74\x6f\x66\x73\x00", 12));
		r[15] = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20006000ul, 0x8000ul, 0x0ul);
		break;
	}
	return 0;
}

void loop()
{
	long i;
	pthread_t th[10];

	syscall(SYS_write, 1, "executing program\n", strlen("executing program\n"));
	memset(r, -1, sizeof(r));
	srand(getpid());
	for (i = 0; i < 5; i++) {
		pthread_create(&th[i], 0, thr, (void*)i);
		usleep(rand()%10000);
	}
	for (i = 0; i < 5; i++) {
		pthread_create(&th[5+i], 0, thr, (void*)i);
		if (rand()%2)
			usleep(rand()%10000);
	}
	usleep(rand()%100000);
}

int main()
{
	install_segv_handler();
	use_temporary_dir();
	int pid = do_sandbox_none(0, true);
	int status = 0;
	while (waitpid(pid, &status, __WALL) != pid) {}
	return 0;
}