xref: /f-stack/lib/ff_syscall_wrapper.c (revision df6ad731)

/*
 * Copyright (c) 2010 Kip Macy. All rights reserved.
 * Copyright (C) 2017 THL A29 Limited, a Tencent company.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
 *
 * Derived in part from libplebnet's pn_syscall_wrapper.c.
 */

#include <sys/param.h>
#include <sys/limits.h>
#include <sys/uio.h>
#include <sys/proc.h>
#include <sys/syscallsubr.h>
#include <sys/module.h>
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/socketvar.h>
#include <sys/event.h>
#include <sys/kernel.h>
#include <sys/refcount.h>
#include <sys/sysctl.h>
#include <sys/pcpu.h>
#include <sys/select.h>
#include <sys/poll.h>
#include <sys/event.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <sys/ttycom.h>
#include <sys/filio.h>
#include <sys/sysproto.h>
#include <sys/fcntl.h>

#include <machine/stdarg.h>

#include "ff_api.h"
#include "ff_host_interface.h"

/* setsockopt/getsockopt define start */

#define LINUX_SOL_SOCKET      1

#define LINUX_SO_DEBUG        1
#define LINUX_SO_REUSEADDR    2
#define LINUX_SO_ERROR        4
#define LINUX_SO_DONTROUTE    5
#define LINUX_SO_BROADCAST    6
#define LINUX_SO_SNDBUF       7
#define LINUX_SO_RCVBUF       8
#define LINUX_SO_KEEPALIVE    9
#define LINUX_SO_OOBINLINE    10
#define LINUX_SO_LINGER       13
#define LINUX_SO_RCVLOWAT     18
#define LINUX_SO_SNDLOWAT     19
#define LINUX_SO_RCVTIMEO     20
#define LINUX_SO_SNDTIMEO     21
#define LINUX_SO_ACCEPTCONN   30
#define LINUX_SO_PROTOCOL     38


#define LINUX_IP_TOS        1
#define LINUX_IP_TTL        2
#define LINUX_IP_HDRINCL    3
#define LINUX_IP_OPTIONS    4

#define LINUX_IP_MULTICAST_IF       32
#define LINUX_IP_MULTICAST_TTL      33
#define LINUX_IP_MULTICAST_LOOP     34
#define LINUX_IP_ADD_MEMBERSHIP     35
#define LINUX_IP_DROP_MEMBERSHIP    36

#define LINUX_TCP_NODELAY     1
#define LINUX_TCP_MAXSEG      2
#define LINUX_TCP_KEEPIDLE    4
#define LINUX_TCP_KEEPINTVL   5
#define LINUX_TCP_KEEPCNT     6
#define LINUX_TCP_MD5SIG      14

/* setsockopt/getsockopt define end */


/* ioctl define start */

#define LINUX_TIOCEXCL    0x540C
#define LINUX_TIOCNXCL    0x540D
#define LINUX_TIOCSCTTY   0x540E
#define LINUX_TIOCGPGRP   0x540F
#define LINUX_TIOCSPGRP   0x5410
#define LINUX_TIOCOUTQ    0x5411
#define LINUX_TIOCSTI     0x5412
#define LINUX_TIOCGWINSZ  0x5413
#define LINUX_TIOCSWINSZ  0x5414
#define LINUX_TIOCMGET    0x5415
#define LINUX_TIOCMBIS    0x5416
#define LINUX_TIOCMBIC    0x5417
#define LINUX_TIOCMSET    0x5418

#define LINUX_FIONREAD    0x541B
#define LINUX_TIOCCONS    0x541D
#define LINUX_TIOCPKT     0x5420
#define LINUX_FIONBIO     0x5421
#define LINUX_TIOCNOTTY   0x5422
#define LINUX_TIOCSETD    0x5423
#define LINUX_TIOCGETD    0x5424
#define LINUX_TIOCSBRK    0x5427
#define LINUX_TIOCCBRK    0x5428
#define LINUX_TIOCGSID    0x5429

#define LINUX_FIONCLEX    0x5450
#define LINUX_FIOCLEX     0x5451
#define LINUX_FIOASYNC    0x5452

#define LINUX_TIOCPKT_DATA          0
#define LINUX_TIOCPKT_FLUSHREAD     1
#define LINUX_TIOCPKT_FLUSHWRITE    2
#define LINUX_TIOCPKT_STOP          4
#define LINUX_TIOCPKT_START         8
#define LINUX_TIOCPKT_NOSTOP        16
#define LINUX_TIOCPKT_DOSTOP        32
#define LINUX_TIOCPKT_IOCTL         64

/* ioctl define end */


extern int sendit(struct thread *td, int s, struct msghdr *mp, int flags);

static long
linux2freebsd_ioctl(unsigned long request)
{
    switch(request) {
        case LINUX_TIOCEXCL:
            return TIOCEXCL;
        case LINUX_TIOCNXCL:
            return TIOCNXCL;
        case LINUX_TIOCSCTTY:
            return TIOCSCTTY;
        case LINUX_TIOCGPGRP:
            return TIOCGPGRP;
        case LINUX_TIOCSPGRP:
            return TIOCSPGRP;
        case LINUX_TIOCOUTQ:
            return TIOCOUTQ;
        case LINUX_TIOCSTI:
            return TIOCSTI;
        case LINUX_TIOCGWINSZ:
            return TIOCGWINSZ;
        case LINUX_TIOCSWINSZ:
            return TIOCSWINSZ;
        case LINUX_TIOCMGET:
            return TIOCMGET;
        case LINUX_TIOCMBIS:
            return TIOCMBIS;
        case LINUX_TIOCMBIC:
            return TIOCMBIC;
        case LINUX_TIOCMSET:
            return TIOCMSET;
        case LINUX_FIONREAD:
            return FIONREAD;
        case LINUX_TIOCCONS:
            return TIOCCONS;
        case LINUX_TIOCPKT:
            return TIOCPKT;
        case LINUX_FIONBIO:
            return FIONBIO;
        case LINUX_TIOCNOTTY:
            return TIOCNOTTY;
        case LINUX_TIOCSETD:
            return TIOCSETD;
        case LINUX_TIOCGETD:
            return TIOCGETD;
        case LINUX_TIOCSBRK:
            return TIOCSBRK;
        case LINUX_TIOCCBRK:
            return TIOCCBRK;
        case LINUX_TIOCGSID:
            return TIOCGSID;
        case LINUX_FIONCLEX:
            return FIONCLEX;
        case LINUX_FIOCLEX:
            return FIOCLEX;
        case LINUX_FIOASYNC:
            return FIOASYNC;
        case LINUX_TIOCPKT_DATA:
            return TIOCPKT_DATA;
        case LINUX_TIOCPKT_FLUSHREAD:
            return TIOCPKT_FLUSHREAD;
        case LINUX_TIOCPKT_FLUSHWRITE:
            return TIOCPKT_FLUSHWRITE;
        case LINUX_TIOCPKT_STOP:
            return TIOCPKT_STOP;
        case LINUX_TIOCPKT_START:
            return TIOCPKT_START;
        case LINUX_TIOCPKT_NOSTOP:
            return TIOCPKT_NOSTOP;
        case LINUX_TIOCPKT_DOSTOP:
            return TIOCPKT_DOSTOP;
        case LINUX_TIOCPKT_IOCTL:
            return TIOCPKT_IOCTL;
        default:
            return request;
    }
}

static int
so_opt_convert(int optname)
{
    switch(optname) {
        case LINUX_SO_DEBUG:
            return SO_DEBUG;
        case LINUX_SO_REUSEADDR:
            return SO_REUSEADDR;
        case LINUX_SO_ERROR:
            return SO_ERROR;
        case LINUX_SO_DONTROUTE:
            return SO_DONTROUTE;
        case LINUX_SO_BROADCAST:
            return SO_BROADCAST;
        case LINUX_SO_SNDBUF:
            return SO_SNDBUF;
        case LINUX_SO_RCVBUF:
            return SO_RCVBUF;
        case LINUX_SO_KEEPALIVE:
            return SO_KEEPALIVE;
        case LINUX_SO_OOBINLINE:
            return SO_OOBINLINE;
        case LINUX_SO_LINGER:
            return SO_LINGER;
        case LINUX_SO_RCVLOWAT:
            return SO_RCVLOWAT;
        case LINUX_SO_SNDLOWAT:
            return SO_SNDLOWAT;
        case LINUX_SO_RCVTIMEO:
            return SO_RCVTIMEO;
        case LINUX_SO_SNDTIMEO:
            return SO_SNDTIMEO;
        case LINUX_SO_ACCEPTCONN:
            return SO_ACCEPTCONN;
        case LINUX_SO_PROTOCOL:
            return SO_PROTOCOL;
        default:
            return (-1);
    }
}

static int
ip_opt_convert(int optname)
{
    switch(optname) {
        case LINUX_IP_TOS:
            return IP_TOS;
        case LINUX_IP_TTL:
            return IP_TTL;
        case LINUX_IP_HDRINCL:
            return IP_HDRINCL;
        case LINUX_IP_OPTIONS:
            return IP_OPTIONS;
        case LINUX_IP_MULTICAST_IF:
            return IP_MULTICAST_IF;
        case LINUX_IP_MULTICAST_TTL:
            return IP_MULTICAST_TTL;
        case LINUX_IP_MULTICAST_LOOP:
            return IP_MULTICAST_LOOP;
        case LINUX_IP_ADD_MEMBERSHIP:
            return IP_ADD_MEMBERSHIP;
        case LINUX_IP_DROP_MEMBERSHIP:
            return IP_DROP_MEMBERSHIP;
        default:
            return (-1);
    }
}

static int
tcp_opt_convert(int optname)
{
    switch(optname) {
        case LINUX_TCP_NODELAY:
            return TCP_NODELAY;
        case LINUX_TCP_MAXSEG:
            return TCP_MAXSEG;
        case LINUX_TCP_KEEPIDLE:
            return TCP_KEEPIDLE;
        case LINUX_TCP_KEEPINTVL:
            return TCP_KEEPINTVL;
        case LINUX_TCP_KEEPCNT:
            return TCP_KEEPCNT;
        case LINUX_TCP_MD5SIG:
            return TCP_MD5SIG;
        default:
            return (-1);
    }
}

static int
linux2freebsd_opt(int level, int optname)
{
    switch(level) {
        case SOL_SOCKET:
            return so_opt_convert(optname);
        case IPPROTO_IP:
            return ip_opt_convert(optname);
        case IPPROTO_TCP:
            return tcp_opt_convert(optname);
        default:
            return (-1);
    }
}

static void
linux2freebsd_sockaddr(const struct linux_sockaddr *linux,
    socklen_t addrlen, struct sockaddr *freebsd)
{
    if (linux == NULL) {
        return;
    }

    bzero(freebsd, sizeof(struct sockaddr));
    freebsd->sa_len = addrlen;
    freebsd->sa_family = linux->sa_family;
    bcopy(linux->sa_data, freebsd->sa_data, sizeof(linux->sa_data));
}

static void
freebsd2linux_sockaddr(struct linux_sockaddr *linux,
    struct sockaddr *freebsd)
{
    if (linux == NULL) {
        return;
    }

    linux->sa_family = freebsd->sa_family;
    bcopy(freebsd->sa_data, linux->sa_data, sizeof(freebsd->sa_data));
}

int
ff_socket(int domain, int type, int protocol)
{
    int rc;
    struct socket_args sa;
    sa.domain = domain;
    sa.type = type;
    sa.protocol = protocol;
    if ((rc = sys_socket(curthread, &sa)))
        goto kern_fail;

    return curthread->td_retval[0];
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_getsockopt(int s, int level, int optname, void *optval,
    socklen_t *optlen)
{
    int rc;
    if (level == LINUX_SOL_SOCKET)
        level = SOL_SOCKET;

    optname = linux2freebsd_opt(level, optname);
    if (optname < 0) {
        rc = EINVAL;
        goto kern_fail;
    }

    if ((rc = kern_getsockopt(curthread, s, level, optname,
            optval, UIO_SYSSPACE, optlen)))
        goto kern_fail;

    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_setsockopt(int s, int level, int optname, const void *optval,
    socklen_t optlen)
{
    int rc;

    if (level == LINUX_SOL_SOCKET)
        level = SOL_SOCKET;

    optname = linux2freebsd_opt(level, optname);
    if (optname < 0) {
        rc = EINVAL;
        goto kern_fail;
    }

    if ((rc = kern_setsockopt(curthread, s, level, optname,
            __DECONST(void *, optval), UIO_SYSSPACE, optlen)))
        goto kern_fail;

    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_ioctl(int fd, unsigned long request, ...)
{
    int rc;
    va_list ap;
    caddr_t argp;

    long req = linux2freebsd_ioctl(request);
    if (req < 0) {
        rc = EINVAL;
        goto kern_fail;
    }

    va_start(ap, request);

    argp = va_arg(ap, caddr_t);
    va_end(ap);
    if ((rc = kern_ioctl(curthread, fd, req, argp)))
        goto kern_fail;

    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_close(int fd)
{
    int rc;

    if ((rc = kern_close(curthread, fd)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_read(int fd, void *buf, size_t nbytes)
{
    struct uio auio;
    struct iovec aiov;
    int rc;

    if (nbytes > INT_MAX) {
        rc = EINVAL;
        goto kern_fail;
    }

    aiov.iov_base = buf;
    aiov.iov_len = nbytes;
    auio.uio_iov = &aiov;
    auio.uio_iovcnt = 1;
    auio.uio_resid = nbytes;
    auio.uio_segflg = UIO_SYSSPACE;
    if ((rc = kern_readv(curthread, fd, &auio)))
        goto kern_fail;
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_readv(int fd, const struct iovec *iov, int iovcnt)
{
    struct uio auio;
    int rc, len, i;

    len = 0;
    for (i = 0; i < iovcnt; i++)
        len += iov[i].iov_len;
    auio.uio_iov = __DECONST(struct iovec *, iov);
    auio.uio_iovcnt = iovcnt;
    auio.uio_resid = len;
    auio.uio_segflg = UIO_SYSSPACE;

    if ((rc = kern_readv(curthread, fd, &auio)))
        goto kern_fail;
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_write(int fd, const void *buf, size_t nbytes)
{
    struct uio auio;
    struct iovec aiov;
    int rc;

    if (nbytes > INT_MAX) {
        rc = EINVAL;
        goto kern_fail;
    }

    aiov.iov_base = (void *)(uintptr_t)buf;
    aiov.iov_len = nbytes;
    auio.uio_iov = &aiov;
    auio.uio_iovcnt = 1;
    auio.uio_resid = nbytes;
    auio.uio_segflg = UIO_SYSSPACE;
    if ((rc = kern_writev(curthread, fd, &auio)))
        goto kern_fail;
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_writev(int fd, const struct iovec *iov, int iovcnt)
{
    struct uio auio;
    int i, rc, len;

    len = 0;
    for (i = 0; i < iovcnt; i++)
        len += iov[i].iov_len;
    auio.uio_iov = __DECONST(struct iovec *, iov);
    auio.uio_iovcnt = iovcnt;
    auio.uio_resid = len;
    auio.uio_segflg = UIO_SYSSPACE;
    if ((rc = kern_writev(curthread, fd, &auio)))
        goto kern_fail;
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_send(int s, const void *buf, size_t len, int flags)
{
    return (ff_sendto(s, buf, len, flags, NULL, 0));
}

ssize_t
ff_sendto(int s, const void *buf, size_t len, int flags,
         const struct linux_sockaddr *to, socklen_t tolen)
{
    struct msghdr msg;
    struct iovec aiov;
    int rc;

    struct sockaddr bsdaddr;
    struct sockaddr *pf = &bsdaddr;

    if (to) {
        linux2freebsd_sockaddr(to, tolen, pf);
    } else {
        pf = NULL;
    }

    msg.msg_name = pf;
    msg.msg_namelen = tolen;
    msg.msg_iov = &aiov;
    msg.msg_iovlen = 1;
    msg.msg_control = 0;
    aiov.iov_base = __DECONST(void *, buf);
    aiov.iov_len = len;
    if ((rc = sendit(curthread, s, &msg, flags)))
        goto kern_fail;

    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_sendmsg(int s, const struct msghdr *msg, int flags)
{
    int rc;

    if ((rc = sendit(curthread, s, __DECONST(struct msghdr *, msg), flags)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}


ssize_t
ff_recv(int s, void *buf, size_t len, int flags)
{
    return (ff_recvfrom(s, buf, len, flags, NULL, 0));
}

ssize_t
ff_recvfrom(int s, void *buf, size_t len, int flags,
    struct linux_sockaddr *from, socklen_t *fromlen)
{
    struct msghdr msg;
    struct iovec aiov;
    int rc;
    struct sockaddr bsdaddr;

    if (fromlen != NULL)
        msg.msg_namelen = *fromlen;
    else
        msg.msg_namelen = 0;

    msg.msg_name = &bsdaddr;
    msg.msg_iov = &aiov;
    msg.msg_iovlen = 1;
    aiov.iov_base = buf;
    aiov.iov_len = len;
    msg.msg_control = 0;
    msg.msg_flags = flags;
    if ((rc = kern_recvit(curthread, s, &msg, UIO_SYSSPACE, NULL)))
        goto kern_fail;
    rc = curthread->td_retval[0];
    if (fromlen != NULL)
        *fromlen = msg.msg_namelen;

    if (from)
        freebsd2linux_sockaddr(from, &bsdaddr);

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

ssize_t
ff_recvmsg(int s, struct msghdr *msg, int flags)
{
    int rc, oldflags;

    oldflags = msg->msg_flags;
    msg->msg_flags = flags;

    if ((rc = kern_recvit(curthread, s, msg, UIO_SYSSPACE, NULL))) {
        msg->msg_flags = oldflags;
        goto kern_fail;
    }
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_fcntl(int fd, int cmd, ...)
{
    int rc;
    va_list ap;
    uintptr_t argp;

    va_start(ap, cmd);

    argp = va_arg(ap, uintptr_t);
    va_end(ap);

    if ((rc = kern_fcntl(curthread, fd, cmd, argp)))
        goto kern_fail;
    rc = curthread->td_retval[0];
    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_socketpair(int domain, int type, int protocol, int *sv)
{
    int rc;
    if ((rc = kern_socketpair(curthread, domain, type, protocol, sv)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_accept(int s, struct linux_sockaddr * addr,
    socklen_t * addrlen)
{
    int rc;
    struct file *fp;
    struct sockaddr bsdaddr;
    struct sockaddr *pf = &bsdaddr;
    socklen_t socklen = sizeof(struct sockaddr);

    if ((rc = kern_accept(curthread, s, &pf, &socklen, &fp)))
        goto kern_fail;

    rc = curthread->td_retval[0];
    fdrop(fp, curthread);

    if (addr)
        freebsd2linux_sockaddr(addr, pf);

    if (addrlen)
        *addrlen = socklen;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_listen(int s, int backlog)
{
    int rc;
    struct listen_args la = {
        .s = s,
        .backlog = backlog,
    };
    if ((rc = sys_listen(curthread, &la)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_bind(int s, const struct linux_sockaddr *addr, socklen_t addrlen)
{
    int rc;
    struct sockaddr bsdaddr;
    linux2freebsd_sockaddr(addr, addrlen, &bsdaddr);

    if ((rc = kern_bindat(curthread, AT_FDCWD, s, &bsdaddr)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_connect(int s, const struct linux_sockaddr *name, socklen_t namelen)
{
    int rc;
    struct sockaddr bsdaddr;
    linux2freebsd_sockaddr(name, namelen, &bsdaddr);

    if ((rc = kern_connectat(curthread, AT_FDCWD, s, &bsdaddr)))
        goto kern_fail;
    rc = curthread->td_retval[0];
    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_getpeername(int s, struct linux_sockaddr * name,
    socklen_t *namelen)
{
    int rc;
    struct sockaddr bsdaddr;
    struct sockaddr *pf = &bsdaddr;

    if ((rc = kern_getpeername(curthread, s, &pf, namelen)))
        goto kern_fail;

    if (name)
        freebsd2linux_sockaddr(name, pf);

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_getsockname(int s, struct linux_sockaddr *name,
    socklen_t *namelen)
{
    int rc;
    struct sockaddr bsdaddr;
    struct sockaddr *pf = &bsdaddr;

    if ((rc = kern_getsockname(curthread, s, &pf, namelen)))
        goto kern_fail;

    if (name)
        freebsd2linux_sockaddr(name, pf);

    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_shutdown(int s, int how)
{
    int rc;

    struct shutdown_args sa = {
        .s = s,
        .how = how,
    };
    if ((rc = sys_shutdown(curthread, &sa)))
        goto kern_fail;

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
         const void *newp, size_t newlen)
{
    int rc;
    size_t retval;

    rc = userland_sysctl(curthread, __DECONST(int *, name), namelen, oldp, oldlenp,
        1, __DECONST(void *, newp), newlen, &retval, 0);
    if (rc)
        goto kern_fail;
    if (oldlenp)
        *oldlenp = retval;
    return (0);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
    struct timeval *timeout)

{
    int rc;

    rc = kern_select(curthread, nfds, readfds, writefds, exceptfds, timeout, 64);
    if (rc)
        goto kern_fail;
    rc = curthread->td_retval[0];

    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);

}

int
ff_poll(struct pollfd fds[], nfds_t nfds, int timeout)
{
    int rc;
    struct timespec ts;
    ts.tv_sec = 0;
    ts.tv_nsec = 0;
    if ((rc = kern_poll(curthread, fds, nfds, &ts, NULL)))
        goto kern_fail;
    rc = curthread->td_retval[0];
    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

int
ff_kqueue(void)
{
    int rc;
    if ((rc = kern_kqueue(curthread, 0, NULL)))
        goto kern_fail;

    rc = curthread->td_retval[0];
    return (rc);

kern_fail:
    ff_os_errno(rc);
    return (-1);
}

struct sys_kevent_args {
    int fd;
    const struct kevent *changelist;
    int nchanges;
    struct kevent *eventlist;
    int nevents;
    const struct timespec *timeout;
};

static int
kevent_copyout(void *arg, struct kevent *kevp, int count)
{
    struct sys_kevent_args *uap;

    uap = (struct sys_kevent_args *)arg;
    bcopy(kevp, uap->eventlist, count * sizeof *kevp);

    uap->eventlist += count;

    return (0);
}

/*
 * Copy 'count' items from the list pointed to by uap->changelist.
 */
static int
kevent_copyin(void *arg, struct kevent *kevp, int count)
{
    struct sys_kevent_args *uap;

    uap = (struct sys_kevent_args *)arg;
    bcopy(uap->changelist, kevp, count * sizeof *kevp);

    uap->changelist += count;

    return (0);
}

int
ff_kevent(int kq, const struct kevent *changelist, int nchanges,
    struct kevent *eventlist, int nevents, const struct timespec *timeout)
{
    int rc;
    struct timespec ts;
    ts.tv_sec = 0;
    ts.tv_nsec = 0;
    struct sys_kevent_args ska = {
        kq,
        changelist,
        nchanges,
        eventlist,
        nevents,
        &ts
    };
    struct kevent_copyops k_ops = {
        &ska,
        kevent_copyout,
        kevent_copyin
    };

    if ((rc = kern_kevent(curthread, kq, nchanges, nevents, &k_ops,
            &ts)))
        goto kern_fail;

    rc = curthread->td_retval[0];
    return (rc);
kern_fail:
    ff_os_errno(rc);
    return (-1);
}