/*
 * Copyright (c) 2014 The FreeBSD Foundation.
 * Copyright (C) 2005 David Xu <davidxu@freebsd.org>.
 * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>.
 * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
 * All rights reserved.
 * 
 * Portions of this software were developed by Konstantin Belousov
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice(s), this list of conditions and the following disclaimer as
 *    the first lines of this file unmodified other than the possible
 *    addition of one or more copyright notices.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice(s), this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include "namespace.h"
#include <sys/param.h>
#include <sys/exterrvar.h>
#include <sys/mman.h>
#include <sys/select.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <aio.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <pthread.h>
#include "un-namespace.h"

#include "libc_private.h"
#include "thr_private.h"

static int
__thr_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_accept(s, addr, addrlen);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   If thread is canceled, no socket is created.
 */
static int
__thr_accept4(int s, struct sockaddr *addr, socklen_t *addrlen, int flags)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_accept4(s, addr, addrlen, flags);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

static int
__thr_aio_suspend(const struct aiocb * const iocbs[], int niocb, const struct
    timespec *timeout)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_aio_suspend(iocbs, niocb, timeout);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   According to manual of close(), the file descriptor is always deleted.
 *   Here, thread is only canceled after the system call, so the file
 *   descriptor is always deleted despite whether the thread is canceled
 *   or not.
 */
static int
__thr_close(int fd)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter2(curthread, 0);
        ret = __sys_close(fd);
        _thr_cancel_leave(curthread, 1);
        
        return (ret);
}

/*
 * Cancellation behavior:
 *   If the thread is canceled, connection is not made.
 */
static int
__thr_connect(int fd, const struct sockaddr *name, socklen_t namelen)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_connect(fd, name, namelen);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   According to specification, only F_SETLKW is a cancellation point.
 *   Thread is only canceled at start, or canceled if the system call
 *   is failure, this means the function does not generate side effect
 *   if it is canceled.
 */
static int
__thr_fcntl(int fd, int cmd, __intptr_t arg)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        if (cmd == F_OSETLKW || cmd == F_SETLKW) {
                _thr_cancel_enter(curthread);
                ret = __sys_fcntl(fd, cmd, arg);
                _thr_cancel_leave(curthread, ret == -1);
        } else {
                ret = __sys_fcntl(fd, cmd, arg);
        }

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled after system call.
 */
static int
__thr_fsync(int fd)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter2(curthread, 0);
        ret = __sys_fsync(fd);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

static int
__thr_fdatasync(int fd)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter2(curthread, 0);
        ret = __sys_fdatasync(fd);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled after system call.
 */
static int
__thr_msync(void *addr, size_t len, int flags)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter2(curthread, 0);
        ret = __sys_msync(addr, len, flags);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

static int
__thr_clock_nanosleep(clockid_t clock_id, int flags,
    const struct timespec *time_to_sleep, struct timespec *time_remaining)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_clock_nanosleep(clock_id, flags, time_to_sleep,
            time_remaining);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

static int
__thr_nanosleep(const struct timespec *time_to_sleep,
    struct timespec *time_remaining)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_nanosleep(time_to_sleep, time_remaining);
        _thr_cancel_leave(curthread, 1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   If the thread is canceled, file is not opened.
 */
static int
__thr_openat(int fd, const char *path, int flags, int mode)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_openat(fd, path, flags, mode);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns something,
 *   the thread is not canceled.
 */
static int
__thr_poll(struct pollfd *fds, unsigned int nfds, int timeout)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_poll(fds, nfds, timeout);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns something,
 *   the thread is not canceled.
 */
static int
__thr_ppoll(struct pollfd pfd[], nfds_t nfds, const struct timespec *
    timeout, const sigset_t *newsigmask)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_ppoll(pfd, nfds, timeout, newsigmask);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns something,
 *   the thread is not canceled.
 */
static int
__thr_pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds, 
        const struct timespec *timo, const sigset_t *mask)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_pselect(count, rfds, wfds, efds, timo, mask);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

static int
__thr_kevent(int kq, const struct kevent *changelist, int nchanges,
    struct kevent *eventlist, int nevents, const struct timespec *timeout)
{
        struct pthread *curthread;
        int ret;

        if (nevents == 0) {
                /*
                 * No blocking, do not make the call cancellable.
                 */
                return (__sys_kevent(kq, changelist, nchanges, eventlist,
                    nevents, timeout));
        }
        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_kevent(kq, changelist, nchanges, eventlist, nevents,
            timeout);
        _thr_cancel_leave(curthread, ret == -1 && nchanges == 0);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call got some data, 
 *   the thread is not canceled.
 */
static ssize_t
__thr_read(int fd, void *buf, size_t nbytes)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_read(fd, buf, nbytes);
        _thr_cancel_leave(curthread, ret == -1);

        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call got some data, 
 *   the thread is not canceled.
 */
static ssize_t
__thr_readv(int fd, const struct iovec *iov, int iovcnt)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_readv(fd, iov, iovcnt);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call got some data, 
 *   the thread is not canceled.
 */
static ssize_t
__thr_recvfrom(int s, void *b, size_t l, int f, struct sockaddr *from,
    socklen_t *fl)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_recvfrom(s, b, l, f, from, fl);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call got some data, 
 *   the thread is not canceled.
 */
static ssize_t
__thr_recvmsg(int s, struct msghdr *m, int f)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_recvmsg(s, m, f);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns something,
 *   the thread is not canceled.
 */
static int 
__thr_select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
        struct timeval *timeout)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_select(numfds, readfds, writefds, exceptfds, timeout);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call sent
 *   data, the thread is not canceled.
 */
static ssize_t
__thr_sendmsg(int s, const struct msghdr *m, int f)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_sendmsg(s, m, f);
        _thr_cancel_leave(curthread, ret <= 0);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call sent some
 *   data, the thread is not canceled.
 */
static ssize_t
__thr_sendto(int s, const void *m, size_t l, int f, const struct sockaddr *t,
    socklen_t tl)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_sendto(s, m, l, f, t, tl);
        _thr_cancel_leave(curthread, ret <= 0);
        return (ret);
}

static int
__thr_system(const char *string)
{
        struct pthread *curthread;
        int ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __libc_system(string);
        _thr_cancel_leave(curthread, 1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   If thread is canceled, the system call is not completed,
 *   this means not all bytes were drained.
 */
static int
__thr_tcdrain(int fd)
{
        struct pthread *curthread;
        int ret;
        
        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __libc_tcdrain(fd);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns
 *   a child pid, the thread is not canceled.
 */
static pid_t
__thr_wait4(pid_t pid, int *status, int options, struct rusage *rusage)
{
        struct pthread *curthread;
        pid_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_wait4(pid, status, options, rusage);
        _thr_cancel_leave(curthread, ret <= 0);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the system call returns
 *   a child pid, the thread is not canceled.
 */
static pid_t
__thr_wait6(idtype_t idtype, id_t id, int *status, int options,
    struct __wrusage *ru, siginfo_t *infop)
{
        struct pthread *curthread;
        pid_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_wait6(idtype, id, status, options, ru, infop);
        _thr_cancel_leave(curthread, ret <= 0);
        return (ret);
}

static pid_t
__thr_pdwait(int fd, int *status, int options, struct __wrusage *ru,
    siginfo_t *infop)
{
        struct pthread *curthread;
        pid_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_pdwait(fd, status, options, ru, infop);
        _thr_cancel_leave(curthread, ret == -1);
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the thread wrote some data,
 *   it is not canceled.
 */
static ssize_t
__thr_write(int fd, const void *buf, size_t nbytes)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_write(fd, buf, nbytes);
        _thr_cancel_leave(curthread, (ret <= 0));
        return (ret);
}

/*
 * Cancellation behavior:
 *   Thread may be canceled at start, but if the thread wrote some data,
 *   it is not canceled.
 */
static ssize_t
__thr_writev(int fd, const struct iovec *iov, int iovcnt)
{
        struct pthread *curthread;
        ssize_t ret;

        curthread = _get_curthread();
        _thr_cancel_enter(curthread);
        ret = __sys_writev(fd, iov, iovcnt);
        _thr_cancel_leave(curthread, (ret <= 0));
        return (ret);
}

static int
__thr_uexterr_gettext(char *buf, size_t bufsz)
{
        struct pthread *curthread;

        curthread = _get_curthread();
        return (__uexterr_format(&curthread->uexterr, buf, bufsz));
}

void
__thr_interpose_libc(void)
{

        __set_error_selector(__error_threaded);
#define SLOT(name)                                      \
        *(__libc_interposing_slot(INTERPOS_##name)) =   \
            (interpos_func_t)__thr_##name;
        SLOT(system);
        SLOT(tcdrain);
        SLOT(spinlock);
        SLOT(spinunlock);
        SLOT(map_stacks_exec);
#undef SLOT

#define SLOT(name)                                      \
        *(__libc_interposing_slot(INTERPOS_##name)) =   \
            (interpos_func_t)__thr_##name;
        SLOT(accept);
        SLOT(accept4);
        SLOT(aio_suspend);
        SLOT(close);
        SLOT(connect);
        SLOT(fcntl);
        SLOT(fsync);
        SLOT(fork);
        SLOT(msync);
        SLOT(nanosleep);
        SLOT(openat);
        SLOT(poll);
        SLOT(pselect);
        SLOT(read);
        SLOT(readv);
        SLOT(recvfrom);
        SLOT(recvmsg);
        SLOT(select);
        SLOT(sendmsg);
        SLOT(sendto);
        SLOT(setcontext);
        SLOT(sigaction);
        SLOT(sigprocmask);
        SLOT(sigsuspend);
        SLOT(sigwait);
        SLOT(sigtimedwait);
        SLOT(sigwaitinfo);
        SLOT(swapcontext);
        SLOT(wait4);
        SLOT(write);
        SLOT(writev);
        SLOT(kevent);
        SLOT(wait6);
        SLOT(ppoll);
        SLOT(fdatasync);
        SLOT(clock_nanosleep);
        SLOT(pdfork);
        SLOT(uexterr_gettext);
        SLOT(pdwait);
#undef SLOT
        *(__libc_interposing_slot(
            INTERPOS__pthread_mutex_init_calloc_cb)) =
            (interpos_func_t)_pthread_mutex_init_calloc_cb;
}