/*      $NetBSD: linux_socket.c,v 1.158 2025/06/28 18:47:36 christos Exp $      */

/*-
 * Copyright (c) 1995, 1998, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Frank van der Linden and Eric Haszlakiewicz.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Functions in multiarch:
 *      linux_sys_socketcall            : linux_socketcall.c
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_socket.c,v 1.158 2025/06/28 18:47:36 christos Exp $");

#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#endif /* defined(_KERNEL_OPT) */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/device.h>
#include <sys/protosw.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/exec.h>
#include <sys/kauth.h>
#include <sys/syscallargs.h>
#include <sys/ktrace.h>

#include <lib/libkern/libkern.h>

#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>

#include <compat/sys/socket.h>
#include <compat/sys/sockio.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_ioctl.h>
#include <compat/linux/common/linux_sched.h>
#include <compat/linux/common/linux_socket.h>
#include <compat/linux/common/linux_fcntl.h>
#if !defined(__aarch64__) && !defined(__alpha__) && !defined(__amd64__)
#include <compat/linux/common/linux_socketcall.h>
#endif
#include <compat/linux/common/linux_sockio.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>

#include <compat/linux/linux_syscallargs.h>

#ifdef DEBUG_LINUX
#define DPRINTF(a) uprintf a
#else
#define DPRINTF(a)
#endif

/*
 * The calls in this file are entered either via the linux_socketcall()
 * interface or, on the Alpha, as individual syscalls.  The
 * linux_socketcall function does any massaging of arguments so that all
 * the calls in here need not think that they are anything other
 * than a normal syscall.
 */

static int linux_to_bsd_domain(int);
static int bsd_to_linux_domain(int);
static int linux_to_bsd_type(int);
int linux_to_bsd_sopt_level(int);
int linux_to_bsd_so_sockopt(int);
int linux_to_bsd_ip_sockopt(int);
int linux_to_bsd_ipv6_sockopt(int);
int linux_to_bsd_tcp_sockopt(int);
int linux_to_bsd_udp_sockopt(int);
int linux_getifname(struct lwp *, register_t *, void *);
int linux_getifconf(struct lwp *, register_t *, void *);
int linux_getifhwaddr(struct lwp *, register_t *, u_int, void *);
static int linux_get_sa(struct lwp *, int, struct sockaddr_big *,
                const struct osockaddr *, socklen_t);
static int linux_sa_put(struct osockaddr *osa);
static int linux_to_bsd_msg_flags(int);
static int bsd_to_linux_msg_flags(int);
static void linux_to_bsd_msghdr(const struct linux_msghdr *, struct msghdr *);
static void bsd_to_linux_msghdr(const struct msghdr *, struct linux_msghdr *);

static const int linux_to_bsd_domain_[LINUX_AF_MAX] = {
        AF_UNSPEC,
        AF_UNIX,
        AF_INET,
        AF_CCITT,       /* LINUX_AF_AX25 */
        AF_IPX,
        AF_APPLETALK,
        -1,             /* LINUX_AF_NETROM */
        -1,             /* LINUX_AF_BRIDGE */
        -1,             /* LINUX_AF_ATMPVC */
        AF_CCITT,       /* LINUX_AF_X25 */
        AF_INET6,
        -1,             /* LINUX_AF_ROSE */
        AF_DECnet,
        -1,             /* LINUX_AF_NETBEUI */
        -1,             /* LINUX_AF_SECURITY */
        pseudo_AF_KEY,
        AF_ROUTE,       /* LINUX_AF_NETLINK */
        -1,             /* LINUX_AF_PACKET */
        -1,             /* LINUX_AF_ASH */
        -1,             /* LINUX_AF_ECONET */
        -1,             /* LINUX_AF_ATMSVC */
        AF_SNA,
        /* rest up to LINUX_AF_MAX-1 is not allocated */
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};

static const int bsd_to_linux_domain_[AF_MAX] = {
        LINUX_AF_UNSPEC,
        LINUX_AF_UNIX,
        LINUX_AF_INET,
        -1,             /* AF_IMPLINK */
        -1,             /* AF_PUP */
        -1,             /* AF_CHAOS */
        -1,             /* AF_NS */
        -1,             /* AF_ISO */
        -1,             /* AF_ECMA */
        -1,             /* AF_DATAKIT */
        LINUX_AF_AX25,  /* AF_CCITT */
        LINUX_AF_SNA,
        LINUX_AF_DECnet,
        -1,             /* AF_DLI */
        -1,             /* AF_LAT */
        -1,             /* AF_HYLINK */
        LINUX_AF_APPLETALK,
        LINUX_AF_NETLINK,
        -1,             /* AF_LINK */
        -1,             /* AF_XTP */
        -1,             /* AF_COIP */
        -1,             /* AF_CNT */
        -1,             /* pseudo_AF_RTIP */
        LINUX_AF_IPX,
        LINUX_AF_INET6,
        -1,             /* pseudo_AF_PIP */
        -1,             /* AF_ISDN */
        -1,             /* AF_NATM */
        -1,             /* AF_ARP */
        LINUX_pseudo_AF_KEY,
        -1,             /* pseudo_AF_HDRCMPLT */
};

static const struct {
        int bfl;
        int lfl;
} bsd_to_linux_msg_flags_[] = {
        {MSG_OOB,               LINUX_MSG_OOB},
        {MSG_PEEK,              LINUX_MSG_PEEK},
        {MSG_DONTROUTE,         LINUX_MSG_DONTROUTE},
        {MSG_EOR,               LINUX_MSG_EOR},
        {MSG_TRUNC,             LINUX_MSG_TRUNC},
        {MSG_CTRUNC,            LINUX_MSG_CTRUNC},
        {MSG_WAITALL,           LINUX_MSG_WAITALL},
        {MSG_DONTWAIT,          LINUX_MSG_DONTWAIT},
        {MSG_BCAST,             0},             /* not supported, clear */
        {MSG_MCAST,             0},             /* not supported, clear */
        {MSG_NOSIGNAL,          LINUX_MSG_NOSIGNAL},
        {-1, /* not supp */     LINUX_MSG_PROBE},
        {-1, /* not supp */     LINUX_MSG_FIN},
        {-1, /* not supp */     LINUX_MSG_SYN},
        {-1, /* not supp */     LINUX_MSG_CONFIRM},
        {-1, /* not supp */     LINUX_MSG_RST},
        {-1, /* not supp */     LINUX_MSG_ERRQUEUE},
        {-1, /* not supp */     LINUX_MSG_MORE},
};

/*
 * Convert between Linux and BSD socket domain values
 */
static int
linux_to_bsd_domain(int ldom)
{
        if (ldom < 0 || ldom >= LINUX_AF_MAX)
                return (-1);

        return linux_to_bsd_domain_[ldom];
}

/*
 * Convert between BSD and Linux socket domain values
 */
static int
bsd_to_linux_domain(int bdom)
{
        if (bdom < 0 || bdom >= AF_MAX)
                return (-1);

        return bsd_to_linux_domain_[bdom];
}

static int
linux_to_bsd_type(int ltype)
{
        int type, flags;

        /* Real types are identical between Linux and NetBSD */
        type = ltype & LINUX_SOCK_TYPE_MASK;

        /* But flags are not .. */
        flags = ltype & ~LINUX_SOCK_TYPE_MASK;
        if (flags & ~(LINUX_SOCK_CLOEXEC|LINUX_SOCK_NONBLOCK))
                return -1;

        if (flags & LINUX_SOCK_CLOEXEC)
                type |= SOCK_CLOEXEC;
        if (flags & LINUX_SOCK_NONBLOCK)
                type |= SOCK_NONBLOCK;

        return type;
}

static int
linux_to_bsd_msg_flags(int lflag)
{
        int i, lfl, bfl;
        int bflag = 0;

        if (lflag == 0)
                return (0);

        for(i = 0; i < __arraycount(bsd_to_linux_msg_flags_); i++) {
                bfl = bsd_to_linux_msg_flags_[i].bfl;
                lfl = bsd_to_linux_msg_flags_[i].lfl;

                if (lfl == 0)
                        continue;

                if (lflag & lfl) {
                        if (bfl < 0)
                                return (-1);

                        bflag |= bfl;
                }
        }

        return (bflag);
}

static int
bsd_to_linux_msg_flags(int bflag)
{
        int i, lfl, bfl;
        int lflag = 0;

        if (bflag == 0)
                return (0);

        for(i = 0; i < __arraycount(bsd_to_linux_msg_flags_); i++) {
                bfl = bsd_to_linux_msg_flags_[i].bfl;
                lfl = bsd_to_linux_msg_flags_[i].lfl;

                if (bfl <= 0)
                        continue;

                if (bflag & bfl) {
                        if (lfl < 0)
                                return (-1);

                        lflag |= lfl;
                }
        }

        return (lflag);
}

int
linux_sys_socket(struct lwp *l, const struct linux_sys_socket_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) domain;
                syscallarg(int) type;
                syscallarg(int) protocol;
        } */
        struct sys___socket30_args bsa;
        int error;


        SCARG(&bsa, protocol) = SCARG(uap, protocol);
        SCARG(&bsa, domain) = linux_to_bsd_domain(SCARG(uap, domain));
        if (SCARG(&bsa, domain) == -1)
                return EINVAL;
        SCARG(&bsa, type) = linux_to_bsd_type(SCARG(uap, type));
        if (SCARG(&bsa, type) == -1)
                return EINVAL;
        /*
         * Apparently linux uses this to talk to ISDN sockets. If we fail
         * now programs seems to handle it, but if we don't we are going
         * to fail when we bind and programs don't handle this well.
         */
        if (SCARG(&bsa, domain) == AF_ROUTE && SCARG(&bsa, type) == SOCK_RAW)
                return ENOTSUP;
        error = sys___socket30(l, &bsa, retval);

#ifdef INET6
        /*
         * Linux AF_INET6 socket has IPV6_V6ONLY setsockopt set to 0 by
         * default and some apps depend on this. So, set V6ONLY to 0
         * for Linux apps if the sysctl value is set to 1.
         */
        if (!error && ip6_v6only && SCARG(&bsa, domain) == PF_INET6) {
                struct socket *so;

                if (fd_getsock(*retval, &so) == 0) {
                        int val = 0;

                        /* ignore error */
                        (void)so_setsockopt(l, so, IPPROTO_IPV6, IPV6_V6ONLY,
                            &val, sizeof(val));

                        fd_putfile(*retval);
                }
        }
#endif

        return (error);
}

int
linux_sys_socketpair(struct lwp *l, const struct linux_sys_socketpair_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) domain;
                syscallarg(int) type;
                syscallarg(int) protocol;
                syscallarg(int *) rsv;
        } */
        struct sys_socketpair_args bsa;

        SCARG(&bsa, domain) = linux_to_bsd_domain(SCARG(uap, domain));
        if (SCARG(&bsa, domain) == -1)
                return EINVAL;
        SCARG(&bsa, type) = linux_to_bsd_type(SCARG(uap, type));
        if (SCARG(&bsa, type) == -1)
                return EINVAL;
        SCARG(&bsa, protocol) = SCARG(uap, protocol);
        SCARG(&bsa, rsv) = SCARG(uap, rsv);

        return sys_socketpair(l, &bsa, retval);
}

int
linux_sys_sendto(struct lwp *l, const struct linux_sys_sendto_args *uap, register_t *retval)
{
        /* {
                syscallarg(int)                         s;
                syscallarg(void *)                      msg;
                syscallarg(int)                         len;
                syscallarg(int)                         flags;
                syscallarg(struct osockaddr *)          to;
                syscallarg(int)                         tolen;
        } */
        struct msghdr   msg;
        struct iovec    aiov;
        struct sockaddr_big nam;
        struct mbuf *m;
        int bflags;
        int error;

        /* Translate message flags.  */
        bflags = linux_to_bsd_msg_flags(SCARG(uap, flags));
        if (bflags < 0)
                /* Some supported flag */
                return EINVAL;

        msg.msg_flags = 0;
        msg.msg_name = NULL;
        msg.msg_control = NULL;

        if (SCARG(uap, tolen)) {
                /* Read in and convert the sockaddr */
                error = linux_get_sa(l, SCARG(uap, s), &nam, SCARG(uap, to),
                    SCARG(uap, tolen));
                if (error)
                        return error;
                error = sockargs(&m, &nam, nam.sb_len, UIO_SYSSPACE, MT_SONAME);
                if (error)
                        return error;
                msg.msg_flags |= MSG_NAMEMBUF;
                msg.msg_name = m;
                msg.msg_namelen = nam.sb_len;
        }

        msg.msg_iov = &aiov;
        msg.msg_iovlen = 1;
        aiov.iov_base = __UNCONST(SCARG(uap, msg));
        aiov.iov_len = SCARG(uap, len);

        return do_sys_sendmsg(l, SCARG(uap, s), &msg, bflags, retval);
}

static void
linux_to_bsd_msghdr(const struct linux_msghdr *lmsg, struct msghdr *bmsg)
{
        memset(bmsg, 0, sizeof(*bmsg));
        bmsg->msg_name = lmsg->msg_name;
        bmsg->msg_namelen = lmsg->msg_namelen;
        bmsg->msg_iov = lmsg->msg_iov;
        bmsg->msg_iovlen = lmsg->msg_iovlen;
        bmsg->msg_control = lmsg->msg_control;
        bmsg->msg_controllen = lmsg->msg_controllen;
        bmsg->msg_flags = lmsg->msg_flags;
}

static void
bsd_to_linux_msghdr(const struct msghdr *bmsg, struct linux_msghdr *lmsg)
{
        memset(lmsg, 0, sizeof(*lmsg));
        lmsg->msg_name = bmsg->msg_name;
        lmsg->msg_namelen = bmsg->msg_namelen;
        lmsg->msg_iov = bmsg->msg_iov;
        lmsg->msg_iovlen = bmsg->msg_iovlen;
        lmsg->msg_control = bmsg->msg_control;
        lmsg->msg_controllen = bmsg->msg_controllen;
        lmsg->msg_flags = bmsg->msg_flags;
}

int
linux_sys_sendmsg(struct lwp *l, const struct linux_sys_sendmsg_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct linux_msghdr *) msg;
                syscallarg(u_int) flags;
        } */
        struct msghdr   msg;
        struct linux_msghdr lmsg;
        int             error;
        int             bflags;
        struct sockaddr_big nam;
        u_int8_t        *control;
        struct mbuf     *ctl_mbuf = NULL;

        error = copyin(SCARG(uap, msg), &lmsg, sizeof(lmsg));
        if (error)
                return error;
        linux_to_bsd_msghdr(&lmsg, &msg);

        msg.msg_flags = MSG_IOVUSRSPACE;

        /*
         * Translate message flags.
         */
        bflags = linux_to_bsd_msg_flags(SCARG(uap, flags));
        if (bflags < 0)
                /* Some supported flag */
                return EINVAL;

        if (lmsg.msg_name) {
                /* Read in and convert the sockaddr */
                error = linux_get_sa(l, SCARG(uap, s), &nam, msg.msg_name,
                    msg.msg_namelen);
                if (error)
                        return (error);
                msg.msg_name = &nam;
        }

        /*
         * Handle cmsg if there is any.
         */
        if (LINUX_CMSG_FIRSTHDR(&lmsg)) {
                struct linux_cmsghdr l_cmsg, *l_cc;
                struct cmsghdr *cmsg;
                ssize_t resid = msg.msg_controllen;
                size_t clen, cidx = 0, cspace;

                ctl_mbuf = m_get(M_WAIT, MT_CONTROL);
                clen = MLEN;
                control = mtod(ctl_mbuf, void *);

                l_cc = LINUX_CMSG_FIRSTHDR(&lmsg);
                do {
                        error = copyin(l_cc, &l_cmsg, sizeof(l_cmsg));
                        if (error)
                                goto done;

                        /*
                         * Sanity check the control message length.
                         */
                        if (l_cmsg.cmsg_len > resid
                            || l_cmsg.cmsg_len < sizeof l_cmsg) {
                                error = EINVAL;
                                goto done;
                        }

                        /*
                         * Refuse unsupported control messages, and
                         * translate fields as appropriate.
                         */
                        switch (l_cmsg.cmsg_level) {
                        case LINUX_SOL_SOCKET:
                                /* It only differs on some archs */
                                if (LINUX_SOL_SOCKET != SOL_SOCKET)
                                        l_cmsg.cmsg_level = SOL_SOCKET;

                                switch(l_cmsg.cmsg_type) {
                                case LINUX_SCM_RIGHTS:
                                        /* Linux SCM_RIGHTS is same as NetBSD */
                                        break;

                                case LINUX_SCM_CREDENTIALS:
                                        /* no native equivalent, just drop it */
                                        if (control != mtod(ctl_mbuf, void *))
                                                free(control, M_MBUF);
                                        m_free(ctl_mbuf);
                                        ctl_mbuf = NULL;
                                        msg.msg_control = NULL;
                                        msg.msg_controllen = 0;
                                        goto skipcmsg;

                                default:
                                        /* other types not supported */
                                        error = EINVAL;
                                        goto done;
                                }
                                break;
                        default:
                                /* pray and leave intact */
                                break;
                        }

                        cspace = CMSG_SPACE(l_cmsg.cmsg_len - sizeof(l_cmsg));

                        /* Check the buffer is big enough */
                        if (__predict_false(cidx + cspace > clen)) {
                                u_int8_t *nc;
                                size_t nclen;

                                nclen = cidx + cspace;
                                if (nclen >= PAGE_SIZE) {
                                        error = EINVAL;
                                        goto done;
                                }
                                nc = realloc(clen <= MLEN ? NULL : control,
                                                nclen, M_TEMP, M_WAITOK);
                                if (!nc) {
                                        error = ENOMEM;
                                        goto done;
                                }
                                if (cidx <= MLEN)
                                        /* Old buffer was in mbuf... */
                                        memcpy(nc, control, cidx);
                                control = nc;
                                clen = nclen;
                        }

                        /* Copy header */
                        cmsg = (void *)&control[cidx];
                        cmsg->cmsg_len = l_cmsg.cmsg_len + LINUX_CMSG_ALIGN_DELTA;
                        cmsg->cmsg_level = l_cmsg.cmsg_level;
                        cmsg->cmsg_type = l_cmsg.cmsg_type;

                        /* Zero area between header and data */
                        memset(cmsg + 1, 0,
                                CMSG_ALIGN(sizeof(*cmsg)) - sizeof(*cmsg));

                        /* Copyin the data */
                        error = copyin(LINUX_CMSG_DATA(l_cc),
                                CMSG_DATA(cmsg),
                                l_cmsg.cmsg_len - sizeof(l_cmsg));
                        if (error)
                                goto done;

                        resid -= LINUX_CMSG_ALIGN(l_cmsg.cmsg_len);
                        cidx += cspace;
                } while ((l_cc = LINUX_CMSG_NXTHDR(&msg, l_cc, &l_cmsg)) && resid > 0);

                /* If we allocated a buffer, attach to mbuf */
                if (cidx > MLEN) {
                        MEXTADD(ctl_mbuf, control, clen, M_MBUF, NULL, NULL);
                        ctl_mbuf->m_flags |= M_EXT_RW;
                }
                control = NULL;
                ctl_mbuf->m_len = cidx;

                msg.msg_control = ctl_mbuf;
                msg.msg_flags |= MSG_CONTROLMBUF;

                ktrkuser("mbcontrol", mtod(ctl_mbuf, void *),
                    msg.msg_controllen);
        }

skipcmsg:
        error = do_sys_sendmsg(l, SCARG(uap, s), &msg, bflags, retval);
        /* Freed internally */
        ctl_mbuf = NULL;

done:
        if (ctl_mbuf != NULL) {
                if (control != NULL && control != mtod(ctl_mbuf, void *))
                        free(control, M_MBUF);
                m_free(ctl_mbuf);
        }
        return (error);
}

int
linux_sys_recvfrom(struct lwp *l, const struct linux_sys_recvfrom_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(void *) buf;
                syscallarg(int) len;
                syscallarg(int) flags;
                syscallarg(struct osockaddr *) from;
                syscallarg(int *) fromlenaddr;
        } */
        int             error;
        struct sys_recvfrom_args bra;

        SCARG(&bra, s) = SCARG(uap, s);
        SCARG(&bra, buf) = SCARG(uap, buf);
        SCARG(&bra, len) = SCARG(uap, len);
        SCARG(&bra, flags) = SCARG(uap, flags);
        SCARG(&bra, from) = (struct sockaddr *) SCARG(uap, from);
        SCARG(&bra, fromlenaddr) = (socklen_t *)SCARG(uap, fromlenaddr);

        if ((error = sys_recvfrom(l, &bra, retval)))
                return (error);

        if (SCARG(uap, from) && (error = linux_sa_put(SCARG(uap, from))))
                return (error);

        return (0);
}

static int
linux_copyout_msg_control(struct lwp *l, struct msghdr *mp, struct mbuf *control)
{
        int dlen, error = 0;
        struct cmsghdr *cmsg;
        struct linux_cmsghdr linux_cmsg;
        struct mbuf *m;
        char *q, *q_end;

        if (mp->msg_controllen <= 0 || control == 0) {
                mp->msg_controllen = 0;
                free_control_mbuf(l, control, control);
                return 0;
        }

        ktrkuser("msgcontrol", mtod(control, void *), mp->msg_controllen);

        q = (char *)mp->msg_control;
        q_end = q + mp->msg_controllen;

        for (m = control; m != NULL; ) {
                cmsg = mtod(m, struct cmsghdr *);

                /*
                 * Fixup cmsg. We handle two things:
                 * 0. different sizeof cmsg_len.
                 * 1. different values for level/type on some archs
                 * 2. different alignment of CMSG_DATA on some archs
                 */
                memset(&linux_cmsg, 0, sizeof(linux_cmsg));
                linux_cmsg.cmsg_len = cmsg->cmsg_len - LINUX_CMSG_ALIGN_DELTA;
                linux_cmsg.cmsg_level = cmsg->cmsg_level;
                linux_cmsg.cmsg_type = cmsg->cmsg_type;

                dlen = q_end - q;
                if (linux_cmsg.cmsg_len > dlen) {
                        /* Not enough room for the parameter */
                        dlen -= sizeof linux_cmsg;
                        if (dlen <= 0)
                                /* Discard if header wont fit */
                                break;
                        mp->msg_flags |= MSG_CTRUNC;
                        if (linux_cmsg.cmsg_level == SOL_SOCKET
                            && linux_cmsg.cmsg_type == SCM_RIGHTS)
                                /* Do not truncate me ... */
                                break;
                } else
                        dlen = linux_cmsg.cmsg_len - sizeof linux_cmsg;

                switch (linux_cmsg.cmsg_level) {
                case SOL_SOCKET:
                        linux_cmsg.cmsg_level = LINUX_SOL_SOCKET;
                        switch (linux_cmsg.cmsg_type) {
                        case SCM_RIGHTS:
                                /* Linux SCM_RIGHTS is same as NetBSD */
                                break;

                        default:
                                /* other types not supported */
                                error = EINVAL;
                                goto done;
                        }
                        /* machine dependent ! */
                        break;
                default:
                        /* pray and leave intact */
                        break;
                }

                /* There can be padding between the header and data... */
                error = copyout(&linux_cmsg, q, sizeof linux_cmsg);
                if (error != 0) {
                        error = copyout(CCMSG_DATA(cmsg), q + sizeof linux_cmsg,
                            dlen);
                }
                if (error != 0) {
                        /* We must free all the SCM_RIGHTS */
                        m = control;
                        break;
                }
                m = m->m_next;
                if (m == NULL || q + LINUX_CMSG_SPACE(dlen) > q_end) {
                        q += LINUX_CMSG_LEN(dlen);
                        break;
                }
                q += LINUX_CMSG_SPACE(dlen);
        }

  done:
        free_control_mbuf(l, control, m);

        mp->msg_controllen = q - (char *)mp->msg_control;
        return error;
}

int
linux_sys_recvmsg(struct lwp *l, const struct linux_sys_recvmsg_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct linux_msghdr *) msg;
                syscallarg(u_int) flags;
        } */
        struct msghdr   msg;
        struct linux_msghdr lmsg;
        int             error;
        struct mbuf     *from, *control;

        error = copyin(SCARG(uap, msg), &lmsg, sizeof(lmsg));
        if (error)
                return (error);
        linux_to_bsd_msghdr(&lmsg, &msg);

        msg.msg_flags = linux_to_bsd_msg_flags(SCARG(uap, flags));
        if (msg.msg_flags < 0) {
                /* Some unsupported flag */
                return (EINVAL);
        }
        msg.msg_flags |= MSG_IOVUSRSPACE;

        error = do_sys_recvmsg(l, SCARG(uap, s), &msg, &from,
            msg.msg_control != NULL ? &control : NULL, retval);
        if (error != 0)
                return error;

        if (msg.msg_control != NULL)
                error = linux_copyout_msg_control(l, &msg, control);

        if (error == 0 && from != 0) {
                mtod(from, struct osockaddr *)->sa_family =
                    bsd_to_linux_domain(mtod(from, struct sockaddr *)->sa_family);
                error = copyout_sockname(msg.msg_name, &msg.msg_namelen, 0,
                        from);
        } else
                msg.msg_namelen = 0;

        if (from != NULL)
                m_free(from);

        if (error == 0) {
                msg.msg_flags = bsd_to_linux_msg_flags(msg.msg_flags);
                if (msg.msg_flags < 0)
                        /* Some flag unsupported by Linux */
                        error = EINVAL;
                else {
                        ktrkuser("msghdr", &msg, sizeof(msg));
                        bsd_to_linux_msghdr(&msg, &lmsg);
                        error = copyout(&lmsg, SCARG(uap, msg), sizeof(lmsg));
                }
        }

        return (error);
}

/*
 * Convert socket option level from Linux to NetBSD value. Only SOL_SOCKET
 * is different, the rest matches IPPROTO_* on both systems.
 */
int
linux_to_bsd_sopt_level(int llevel)
{

        switch (llevel) {
        case LINUX_SOL_SOCKET:
                return SOL_SOCKET;
        case LINUX_SOL_IP:
                return IPPROTO_IP;
#ifdef INET6
        case LINUX_SOL_IPV6:
                return IPPROTO_IPV6;
#endif
        case LINUX_SOL_TCP:
                return IPPROTO_TCP;
        case LINUX_SOL_UDP:
                return IPPROTO_UDP;
        default:
                return -1;
        }
}

/*
 * Convert Linux socket level socket option numbers to NetBSD values.
 */
int
linux_to_bsd_so_sockopt(int lopt)
{

        switch (lopt) {
        case LINUX_SO_DEBUG:
                return SO_DEBUG;
        case LINUX_SO_REUSEADDR:
                /*
                 * Linux does not implement SO_REUSEPORT, but allows reuse of
                 * a host:port pair through SO_REUSEADDR even if the address
                 * is not a multicast-address. Effectively, this means that we
                 * should use SO_REUSEPORT to allow Linux applications to not
                 * exit with EADDRINUSE
                 */
                return SO_REUSEPORT;
        case LINUX_SO_TYPE:
                return SO_TYPE;
        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_NO_CHECK:
        case LINUX_SO_PRIORITY:
                return -1;
        case LINUX_SO_LINGER:
                return SO_LINGER;
        case LINUX_SO_BSDCOMPAT:
        case LINUX_SO_PASSCRED:
        case LINUX_SO_PEERCRED:
                return -1;
        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_SECURITY_AUTHENTICATION:
        case LINUX_SO_SECURITY_ENCRYPTION_TRANSPORT:
        case LINUX_SO_SECURITY_ENCRYPTION_NETWORK:
        case LINUX_SO_BINDTODEVICE:
        case LINUX_SO_ATTACH_FILTER:
        case LINUX_SO_DETACH_FILTER:
        case LINUX_SO_PEERNAME:
                return -1;
        case LINUX_SO_TIMESTAMP:
                return SO_TIMESTAMP;
        case LINUX_SO_ACCEPTCONN:
        case LINUX_SO_PEERSEC:
        case LINUX_SO_SNDBUFFORCE:
        case LINUX_SO_RCVBUFFORCE:
        case LINUX_SO_PASSSEC:
        case LINUX_SO_TIMESTAMPNS:
        case LINUX_SO_MARK:
        case LINUX_SO_TIMESTAMPING:
        case LINUX_SO_PROTOCOL:
        case LINUX_SO_DOMAIN:
        case LINUX_SO_RXQ_OVFL:
        case LINUX_SO_WIFI_STATUS:
        case LINUX_SO_PEEK_OFF:
        case LINUX_SO_NOFCS:
        default:
                return -1;
        }
}

/*
 * Convert Linux IP level socket option number to NetBSD values.
 */
int
linux_to_bsd_ip_sockopt(int lopt)
{

        switch (lopt) {
        case LINUX_IP_TOS:
                return IP_TOS;
        case LINUX_IP_TTL:
                return IP_TTL;
        case LINUX_IP_RETOPTS:
                return IP_RETOPTS;
        case LINUX_IP_PKTINFO:
                return IP_PKTINFO;
        case LINUX_IP_RECVOPTS:
                return IP_RECVOPTS;
        case LINUX_IP_HDRINCL:
                return IP_HDRINCL;
        case LINUX_IP_MULTICAST_TTL:
                return IP_MULTICAST_TTL;
        case LINUX_IP_MULTICAST_LOOP:
                return IP_MULTICAST_LOOP;
        case LINUX_IP_MULTICAST_IF:
                return IP_MULTICAST_IF;
        case LINUX_IP_ADD_MEMBERSHIP:
                return IP_ADD_MEMBERSHIP;
        case LINUX_IP_DROP_MEMBERSHIP:
                return IP_DROP_MEMBERSHIP;
        case LINUX_IP_RECVERR:
        case LINUX_IP_FREEBIND:
                return -2;      /* ignored */
        case LINUX_IP_MULTICAST_ALL:
                return -3;      /* noprotoopt */
        default:
                return -1;
        }
}

/*
 * Convert Linux IPV6 level socket option number to NetBSD values.
 */
#ifdef INET6
int
linux_to_bsd_ipv6_sockopt(int lopt)
{

        switch (lopt) {
        case LINUX_IPV6_V6ONLY:
                return IPV6_V6ONLY;
        case LINUX_IPV6_MULTICAST_HOPS:
                return IPV6_MULTICAST_HOPS;
        case LINUX_IPV6_MULTICAST_ALL:
                return -3;      /* noprotoopt */
        default:
                return -1;
        }
}
#endif

/*
 * Convert Linux TCP level socket option number to NetBSD values.
 */
int
linux_to_bsd_tcp_sockopt(int lopt)
{

        switch (lopt) {
        case LINUX_TCP_NODELAY:
                return TCP_NODELAY;
        case LINUX_TCP_MAXSEG:
                return TCP_MAXSEG;
        default:
                return -1;
        }
}

/*
 * Convert Linux UDP level socket option number to NetBSD values.
 */
int
linux_to_bsd_udp_sockopt(int lopt)
{

        switch (lopt) {
        default:
                return -1;
        }
}

/*
 * Another reasonably straightforward function: setsockopt(2).
 * The level and option numbers are converted; the values passed
 * are not (yet) converted, the ones currently implemented don't
 * need conversion, as they are the same on both systems.
 */
int
linux_sys_setsockopt(struct lwp *l, const struct linux_sys_setsockopt_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(int) level;
                syscallarg(int) optname;
                syscallarg(void *) optval;
                syscallarg(int) optlen;
        } */
        struct sys_setsockopt_args bsa;
        int name;

        SCARG(&bsa, s) = SCARG(uap, s);
        SCARG(&bsa, level) = linux_to_bsd_sopt_level(SCARG(uap, level));
        SCARG(&bsa, val) = SCARG(uap, optval);
        SCARG(&bsa, valsize) = SCARG(uap, optlen);

        /*
         * Linux supports only SOL_SOCKET for AF_LOCAL domain sockets
         * and returns EOPNOTSUPP for other levels
         */
        if (SCARG(&bsa, level) != SOL_SOCKET) {
                struct socket *so;
                int error, family;

                /* fd_getsock() will use the descriptor for us */
                if ((error = fd_getsock(SCARG(&bsa, s), &so)) != 0)
                        return error;
                family = so->so_proto->pr_domain->dom_family;
                fd_putfile(SCARG(&bsa, s));

                if (family == AF_LOCAL)
                        return EOPNOTSUPP;
        }

        switch (SCARG(&bsa, level)) {
        case SOL_SOCKET:
                name = linux_to_bsd_so_sockopt(SCARG(uap, optname));
                break;
        case IPPROTO_IP:
                name = linux_to_bsd_ip_sockopt(SCARG(uap, optname));
                break;
#ifdef INET6
        case IPPROTO_IPV6:
                name = linux_to_bsd_ipv6_sockopt(SCARG(uap, optname));
                break;
#endif
        case IPPROTO_TCP:
                name = linux_to_bsd_tcp_sockopt(SCARG(uap, optname));
                break;
        case IPPROTO_UDP:
                name = linux_to_bsd_udp_sockopt(SCARG(uap, optname));
                break;
        default:
                return EINVAL;
        }

        switch (name) {
        case -1:
                return EINVAL;
        case -2:
                return 0;
        case -3:
                return ENOPROTOOPT;
        }
        SCARG(&bsa, name) = name;

        return sys_setsockopt(l, &bsa, retval);
}

/*
 * getsockopt(2) is very much the same as setsockopt(2) (see above)
 */
int
linux_sys_getsockopt(struct lwp *l, const struct linux_sys_getsockopt_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(int) level;
                syscallarg(int) optname;
                syscallarg(void *) optval;
                syscallarg(int *) optlen;
        } */
        struct sys_getsockopt_args bga;
        int name;

        SCARG(&bga, s) = SCARG(uap, s);
        SCARG(&bga, level) = linux_to_bsd_sopt_level(SCARG(uap, level));
        SCARG(&bga, val) = SCARG(uap, optval);
        SCARG(&bga, avalsize) = (socklen_t *)SCARG(uap, optlen);

        switch (SCARG(&bga, level)) {
        case SOL_SOCKET:
                name = linux_to_bsd_so_sockopt(SCARG(uap, optname));
                break;
        case IPPROTO_IP:
                name = linux_to_bsd_ip_sockopt(SCARG(uap, optname));
                break;
#ifdef INET6
        case IPPROTO_IPV6:
                name = linux_to_bsd_ipv6_sockopt(SCARG(uap, optname));
                break;
#endif
        case IPPROTO_TCP:
                name = linux_to_bsd_tcp_sockopt(SCARG(uap, optname));
                break;
        case IPPROTO_UDP:
                name = linux_to_bsd_udp_sockopt(SCARG(uap, optname));
                break;
        default:
                return EINVAL;
        }

        switch (name) {
        case -1:
        case -2: /* we can't ignore, since we don't know what to return */
                return EINVAL;
        case -3:
                return ENOPROTOOPT;
        }
        SCARG(&bga, name) = name;

        return sys_getsockopt(l, &bga, retval);
}

int
linux_getifname(struct lwp *l, register_t *retval, void *data)
{
        struct ifnet *ifp;
        struct linux_ifreq ifr;
        int error;
        int s;

        error = copyin(data, &ifr, sizeof(ifr));
        if (error)
                return error;

        s = pserialize_read_enter();
        ifp = if_byindex(ifr.ifr_ifru.ifru_ifindex);
        if (ifp == NULL) {
                pserialize_read_exit(s);
                return ENODEV;
        }

        strncpy(ifr.ifr_name, ifp->if_xname, sizeof(ifr.ifr_name));
        pserialize_read_exit(s);

        return copyout(&ifr, data, sizeof(ifr));
}

int
linux_getifconf(struct lwp *l, register_t *retval, void *data)
{
        struct linux_ifreq ifr, *ifrp = NULL;
        struct linux_ifconf ifc;
        struct ifnet *ifp;
        struct sockaddr *sa;
        struct osockaddr *osa;
        int space = 0, error;
        const int sz = (int)sizeof(ifr);
        bool docopy;
        int s;
        int bound;
        struct psref psref;

        error = copyin(data, &ifc, sizeof(ifc));
        if (error)
                return error;

        docopy = ifc.ifc_req != NULL;
        if (docopy) {
                if (ifc.ifc_len < 0)
                        return EINVAL;

                space = ifc.ifc_len;
                ifrp = ifc.ifc_req;
        }
        memset(&ifr, 0, sizeof(ifr));

        bound = curlwp_bind();
        s = pserialize_read_enter();
        IFNET_READER_FOREACH(ifp) {
                struct ifaddr *ifa;
                if_acquire(ifp, &psref);
                pserialize_read_exit(s);

                (void)strncpy(ifr.ifr_name, ifp->if_xname,
                    sizeof(ifr.ifr_name));
                if (ifr.ifr_name[sizeof(ifr.ifr_name) - 1] != '\0') {
                        error = ENAMETOOLONG;
                        goto release_exit;
                }

                s = pserialize_read_enter();
                IFADDR_READER_FOREACH(ifa, ifp) {
                        struct psref psref_ifa;
                        ifa_acquire(ifa, &psref_ifa);
                        pserialize_read_exit(s);

                        sa = ifa->ifa_addr;
                        if (sa->sa_family != AF_INET ||
                            sa->sa_len > sizeof(*osa))
                                goto next;
                        memcpy(&ifr.ifr_addr, sa, sa->sa_len);
                        osa = (struct osockaddr *)&ifr.ifr_addr;
                        osa->sa_family = sa->sa_family;
                        if (space >= sz) {
                                error = copyout(&ifr, ifrp, sz);
                                if (error != 0) {
                                        ifa_release(ifa, &psref_ifa);
                                        goto release_exit;
                                }
                                ifrp++;
                        }
                        space -= sz;
                next:
                        s = pserialize_read_enter();
                        ifa_release(ifa, &psref_ifa);
                }

                KASSERT(pserialize_in_read_section());
                if_release(ifp, &psref);
        }
        pserialize_read_exit(s);
        curlwp_bindx(bound);

        if (docopy)
                ifc.ifc_len -= space;
        else
                ifc.ifc_len = -space;

        return copyout(&ifc, data, sizeof(ifc));

release_exit:
        if_release(ifp, &psref);
        curlwp_bindx(bound);
        return error;
}

int
linux_getifhwaddr(struct lwp *l, register_t *retval, u_int fd,
    void *data)
{
        /* Not the full structure, just enough to map what we do here */
        struct linux_ifreq lreq;
        file_t *fp;
        struct ifaddr *ifa;
        struct ifnet *ifp;
        struct sockaddr_dl *sadl;
        int error, found;
        int index, ifnum;
        int s;

        /*
         * We can't emulate this ioctl by calling sys_ioctl() to run
         * SIOCGIFCONF, because the user buffer is not of the right
         * type to take those results.  We can't use kernel buffers to
         * receive the results, as the implementation of sys_ioctl()
         * and ifconf() [which implements SIOCGIFCONF] use
         * copyin()/copyout() which will fail on kernel addresses.
         *
         * So, we must duplicate code from sys_ioctl() and ifconf().  Ugh.
         */

        if ((fp = fd_getfile(fd)) == NULL)
                return (EBADF);

        KERNEL_LOCK(1, NULL);

        if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
                error = EBADF;
                goto out;
        }

        error = copyin(data, &lreq, sizeof(lreq));
        if (error)
                goto out;
        lreq.ifr_name[LINUX_IFNAMSIZ-1] = '\0';         /* just in case */

        /*
         * Try real interface name first, then fake "ethX"
         */
        found = 0;
        s = pserialize_read_enter();
        IFNET_READER_FOREACH(ifp) {
                if (found)
                        break;
                if (strcmp(lreq.ifr_name, ifp->if_xname))
                        /* not this interface */
                        continue;

                found=1;
                if (IFADDR_READER_EMPTY(ifp)) {
                        pserialize_read_exit(s);
                        error = ENODEV;
                        goto out;
                }
                IFADDR_READER_FOREACH(ifa, ifp) {
                        sadl = satosdl(ifa->ifa_addr);
                        /* only return ethernet addresses */
                        /* XXX what about FDDI, etc. ? */
                        if (sadl->sdl_family != AF_LINK ||
                            sadl->sdl_type != IFT_ETHER)
                                continue;
                        memcpy(&lreq.ifr_hwaddr.sa_data, CLLADDR(sadl),
                               MIN(sadl->sdl_alen,
                                   sizeof(lreq.ifr_hwaddr.sa_data)));
                        lreq.ifr_hwaddr.sa_family =
                                sadl->sdl_family;
                        pserialize_read_exit(s);

                        error = copyout(&lreq, data, sizeof(lreq));
                        goto out;
                }
        }
        pserialize_read_exit(s);

        if (strncmp(lreq.ifr_name, "eth", 3) != 0) {
                /* unknown interface, not even an "eth*" name */
                error = ENODEV;
                goto out;
        }

        for (ifnum = 0, index = 3;
             index < LINUX_IFNAMSIZ && lreq.ifr_name[index] != '\0';
             index++) {
                ifnum *= 10;
                ifnum += lreq.ifr_name[index] - '0';
        }

        error = EINVAL;                 /* in case we don't find one */
        s = pserialize_read_enter();
        IFNET_READER_FOREACH(ifp) {
                memcpy(lreq.ifr_name, ifp->if_xname,
                       MIN(LINUX_IFNAMSIZ, IFNAMSIZ));
                IFADDR_READER_FOREACH(ifa, ifp) {
                        sadl = satosdl(ifa->ifa_addr);
                        /* only return ethernet addresses */
                        /* XXX what about FDDI, etc. ? */
                        if (sadl->sdl_family != AF_LINK ||
                            sadl->sdl_type != IFT_ETHER)
                                continue;
                        if (ifnum--)
                                /* not the requested iface */
                                continue;
                        memcpy(&lreq.ifr_hwaddr.sa_data,
                               CLLADDR(sadl),
                               MIN(sadl->sdl_alen,
                                   sizeof(lreq.ifr_hwaddr.sa_data)));
                        lreq.ifr_hwaddr.sa_family =
                                sadl->sdl_family;
                        pserialize_read_exit(s);

                        error = copyout(&lreq, data, sizeof(lreq));
                        goto out;
                }
        }
        pserialize_read_exit(s);

out:
        KERNEL_UNLOCK_ONE(NULL);
        fd_putfile(fd);
        return error;
}

int
linux_ioctl_socket(struct lwp *l, const struct linux_sys_ioctl_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(u_long) com;
                syscallarg(void *) data;
        } */
        u_long com;
        int error = 0, isdev = 0, dosys = 1;
        struct sys_ioctl_args ia;
        file_t *fp;
        struct vnode *vp;
        int (*ioctlf)(file_t *, u_long, void *);
        struct ioctl_pt pt;

        if ((fp = fd_getfile(SCARG(uap, fd))) == NULL)
                return (EBADF);

        if (fp->f_type == DTYPE_VNODE) {
                vp = (struct vnode *)fp->f_data;
                isdev = vp->v_type == VCHR;
        }

        /*
         * Don't try to interpret socket ioctl calls that are done
         * on a device filedescriptor, just pass them through, to
         * emulate Linux behaviour. Use PTIOCLINUX so that the
         * device will only handle these if it's prepared to do
         * so, to avoid unexpected things from happening.
         */
        if (isdev) {
                dosys = 0;
                ioctlf = fp->f_ops->fo_ioctl;
                pt.com = SCARG(uap, com);
                pt.data = SCARG(uap, data);
                error = ioctlf(fp, PTIOCLINUX, &pt);
                /*
                 * XXX hack: if the function returns EJUSTRETURN,
                 * it has stuffed a sysctl return value in pt.data.
                 */
                if (error == EJUSTRETURN) {
                        retval[0] = (register_t)pt.data;
                        error = 0;
                }
                goto out;
        }

        com = SCARG(uap, com);
        retval[0] = 0;

        switch (com) {
        case LINUX_SIOCGIFNAME:
                error = linux_getifname(l, retval, SCARG(uap, data));
                dosys = 0;
                break;
        case LINUX_SIOCGIFCONF:
                error = linux_getifconf(l, retval, SCARG(uap, data));
                dosys = 0;
                break;
        case LINUX_SIOCGIFFLAGS:
                SCARG(&ia, com) = OSIOCGIFFLAGS;
                break;
        case LINUX_SIOCSIFFLAGS:
                SCARG(&ia, com) = OSIOCSIFFLAGS;
                break;
        case LINUX_SIOCGIFADDR:
                SCARG(&ia, com) = OOSIOCGIFADDR;
                break;
        case LINUX_SIOCGIFDSTADDR:
                SCARG(&ia, com) = OOSIOCGIFDSTADDR;
                break;
        case LINUX_SIOCGIFBRDADDR:
                SCARG(&ia, com) = OOSIOCGIFBRDADDR;
                break;
        case LINUX_SIOCGIFNETMASK:
                SCARG(&ia, com) = OOSIOCGIFNETMASK;
                break;
        case LINUX_SIOCGIFMTU:
                SCARG(&ia, com) = OSIOCGIFMTU;
                break;
        case LINUX_SIOCADDMULTI:
                SCARG(&ia, com) = OSIOCADDMULTI;
                break;
        case LINUX_SIOCDELMULTI:
                SCARG(&ia, com) = OSIOCDELMULTI;
                break;
        case LINUX_SIOCGIFHWADDR:
                error = linux_getifhwaddr(l, retval, SCARG(uap, fd),
                    SCARG(uap, data));
                dosys = 0;
                break;
        default:
                error = EINVAL;
        }

 out:
        fd_putfile(SCARG(uap, fd));

        if (error ==0 && dosys) {
                SCARG(&ia, fd) = SCARG(uap, fd);
                SCARG(&ia, data) = SCARG(uap, data);
                error = sys_ioctl(curlwp, &ia, retval);
        }

        return error;
}

int
linux_sys_connect(struct lwp *l, const struct linux_sys_connect_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(const struct sockaddr *) name;
                syscallarg(int) namelen;
        } */
        int             error;
        struct sockaddr_big sb;

        error = linux_get_sa(l, SCARG(uap, s), &sb, SCARG(uap, name),
            SCARG(uap, namelen));
        if (error)
                return (error);

        error = do_sys_connect(l, SCARG(uap, s), (struct sockaddr *)&sb);

        if (error == EISCONN) {
                struct socket *so;
                int state, prflags;

                /* fd_getsock() will use the descriptor for us */
                if (fd_getsock(SCARG(uap, s), &so) != 0)
                        return EISCONN;

                solock(so);
                state = so->so_state;
                prflags = so->so_proto->pr_flags;
                sounlock(so);
                fd_putfile(SCARG(uap, s));
                /*
                 * We should only let this call succeed once per
                 * non-blocking connect; however we don't have
                 * a convenient place to keep that state..
                 */
                if ((state & (SS_ISCONNECTED|SS_NBIO)) ==
                    (SS_ISCONNECTED|SS_NBIO) &&
                    (prflags & PR_CONNREQUIRED))
                        return 0;
        }

        return (error);
}

int
linux_sys_bind(struct lwp *l, const struct linux_sys_bind_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(const struct osockaddr *) name;
                syscallarg(int) namelen;
        } */
        int             error;
        struct sockaddr_big sb;

        error = linux_get_sa(l, SCARG(uap, s), &sb, SCARG(uap, name),
            SCARG(uap, namelen));
        if (error)
                return (error);

        return do_sys_bind(l, SCARG(uap, s), (struct sockaddr *)&sb);
}

int
linux_sys_getsockname(struct lwp *l, const struct linux_sys_getsockname_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fdes;
                syscallarg(void *) asa;
                syscallarg(int *) alen;
        } */
        int error;

        if ((error = sys_getsockname(l, (const void *)uap, retval)) != 0)
                return (error);

        if ((error = linux_sa_put((struct osockaddr *)SCARG(uap, asa))))
                return (error);

        return (0);
}

int
linux_sys_getpeername(struct lwp *l, const struct linux_sys_getpeername_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fdes;
                syscallarg(void *) asa;
                syscallarg(int *) alen;
        } */
        int error;

        if ((error = sys_getpeername(l, (const void *)uap, retval)) != 0)
                return (error);

        if ((error = linux_sa_put((struct osockaddr *)SCARG(uap, asa))))
                return (error);

        return (0);
}

/*
 * Copy the osockaddr structure pointed to by name to sb, adjust
 * family and convert to sockaddr.
 */
static int
linux_get_sa(struct lwp *l, int s, struct sockaddr_big *sb,
    const struct osockaddr *name, socklen_t namelen)
{
        int error, bdom;

        if (namelen > UCHAR_MAX ||
            namelen <= offsetof(struct sockaddr_big, sb_data))
                return EINVAL;

        error = copyin(name, sb, namelen);
        if (error)
                return error;

        bdom = linux_to_bsd_domain(sb->sb_family);
        if (bdom == -1)
                return EINVAL;

        /*
         * If the family is unspecified, use address family of the socket.
         * This avoid triggering strict family checks in netinet/in_pcb.c et.al.
         */
        if (bdom == AF_UNSPEC) {
                struct socket *so;

                /* fd_getsock() will use the descriptor for us */
                if ((error = fd_getsock(s, &so)) != 0)
                        return error;

                bdom = so->so_proto->pr_domain->dom_family;
                fd_putfile(s);
        }

        /*
         * Older Linux IPv6 code uses obsolete RFC2133 struct sockaddr_in6,
         * which lacks the scope id compared with RFC2553 one. If we detect
         * the situation, reject the address and write a message to system log.
         *
         * Still accept addresses for which the scope id is not used.
         */
        if (bdom == AF_INET6 &&
            namelen == sizeof(struct sockaddr_in6) - sizeof(uint32_t)) {
                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sb;
                if (!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr) &&
                    (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
                     IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr) ||
                     IN6_IS_ADDR_V4COMPAT(&sin6->sin6_addr) ||
                     IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
                     IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))) {
                        struct proc *p = l->l_proc;
                        int uid = l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1;

                        log(LOG_DEBUG,
                            "pid %d (%s), uid %d: obsolete pre-RFC2553 "
                            "sockaddr_in6 rejected",
                            p->p_pid, p->p_comm, uid);
                        return EINVAL;
                }
                namelen = sizeof(struct sockaddr_in6);
                sin6->sin6_scope_id = 0;
        }

        /*
         * Linux is less strict than NetBSD and permits namelen to be larger
         * than valid struct sockaddr_in*.  If this is the case, truncate
         * the value to the correct size, so that NetBSD networking does not
         * return an error.
         */
        switch (bdom) {
        case AF_INET:
                namelen = MIN(namelen, sizeof(struct sockaddr_in));
                break;
        case AF_INET6:
                namelen = MIN(namelen, sizeof(struct sockaddr_in6));
                break;
        }

        sb->sb_family = bdom;
        sb->sb_len = namelen;
        ktrkuser("mbsoname", sb, namelen);
        return 0;
}

static int
linux_sa_put(struct osockaddr *osa)
{
        struct sockaddr sa;
        struct osockaddr *kosa;
        int error, bdom, len;

        /*
         * Only read/write the sockaddr family and length part, the rest is
         * not changed.
         */
        len = sizeof(sa.sa_len) + sizeof(sa.sa_family);

        error = copyin(osa, &sa, len);
        if (error)
                return (error);

        bdom = bsd_to_linux_domain(sa.sa_family);
        if (bdom == -1)
                return (EINVAL);

        /* Note: we convert from sockaddr to osockaddr here, too */
        kosa = (struct osockaddr *) &sa;
        kosa->sa_family = bdom;
        error = copyout(kosa, osa, len);
        if (error)
                return (error);

        return (0);
}

#if !defined(__aarch64__) && !defined(__amd64__)
int
linux_sys_recv(struct lwp *l, const struct linux_sys_recv_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(void *) buf;
                syscallarg(int) len;
                syscallarg(int) flags;
        } */
        struct sys_recvfrom_args bra;


        SCARG(&bra, s) = SCARG(uap, s);
        SCARG(&bra, buf) = SCARG(uap, buf);
        SCARG(&bra, len) = (size_t) SCARG(uap, len);
        SCARG(&bra, flags) = SCARG(uap, flags);
        SCARG(&bra, from) = NULL;
        SCARG(&bra, fromlenaddr) = NULL;

        return (sys_recvfrom(l, &bra, retval));
}

int
linux_sys_send(struct lwp *l, const struct linux_sys_send_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(void *) buf;
                syscallarg(int) len;
                syscallarg(int) flags;
        } */
        struct sys_sendto_args bsa;

        SCARG(&bsa, s)          = SCARG(uap, s);
        SCARG(&bsa, buf)        = SCARG(uap, buf);
        SCARG(&bsa, len)        = SCARG(uap, len);
        SCARG(&bsa, flags)      = SCARG(uap, flags);
        SCARG(&bsa, to)         = NULL;
        SCARG(&bsa, tolen)      = 0;

        return (sys_sendto(l, &bsa, retval));
}
#endif

int
linux_sys_accept(struct lwp *l, const struct linux_sys_accept_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct osockaddr *) name;
                syscallarg(int *) anamelen;
        } */
        int error;
        struct sys_accept_args baa;

        SCARG(&baa, s)          = SCARG(uap, s);
        SCARG(&baa, name)       = (struct sockaddr *) SCARG(uap, name);
        SCARG(&baa, anamelen)   = (unsigned int *) SCARG(uap, anamelen);

        if ((error = sys_accept(l, &baa, retval)))
                return (error);

        if (SCARG(uap, name) && (error = linux_sa_put(SCARG(uap, name))))
                return (error);

        return (0);
}

int
linux_sys_accept4(struct lwp *l, const struct linux_sys_accept4_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct osockaddr *) name;
                syscallarg(int *) anamelen;
                syscallarg(int) flags;
        } */
        int error, flags;
        struct sockaddr_big name;

        if ((flags = linux_to_bsd_type(SCARG(uap, flags))) == -1)
                return EINVAL;

        name.sb_len = UCHAR_MAX;
        error = do_sys_accept(l, SCARG(uap, s), (struct sockaddr *)&name,
            retval, NULL, flags, 0);
        if (error != 0)
                return error;

        error = copyout_sockname_sb((struct sockaddr *)SCARG(uap, name),
            SCARG(uap, anamelen), MSG_LENUSRSPACE, &name);
        if (error != 0) {
                int fd = (int)*retval;
                if (fd_getfile(fd) != NULL)
                        (void)fd_close(fd);
                return error;
        }
        if (SCARG(uap, name) && (error = linux_sa_put(SCARG(uap, name))))
                return error;

        return 0;
}

int
linux_sys_sendmmsg(struct lwp *l, const struct linux_sys_sendmmsg_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct linux_mmsghdr *) msgvec;
                syscallarg(unsigned int) vlen;
                syscallarg(unsigned int) flags;
        } */
        struct linux_mmsghdr lmsg;
        struct mmsghdr bmsg;
        struct socket *so;
        file_t *fp;
        struct msghdr *msg = &bmsg.msg_hdr;
        int error, s;
        unsigned int vlen, flags, dg;

        if ((flags = linux_to_bsd_msg_flags(SCARG(uap, flags))) == -1)
                return EINVAL;

        flags = (flags & MSG_USERFLAGS) | MSG_IOVUSRSPACE;

        s = SCARG(uap, s);
        if ((error = fd_getsock1(s, &so, &fp)) != 0)
                return error;

        vlen = SCARG(uap, vlen);
        if (vlen > 1024)
                vlen = 1024;

        for (dg = 0; dg < vlen;) {
                error = copyin(SCARG(uap, msgvec) + dg, &lmsg, sizeof(lmsg));
                if (error)
                        break;
                linux_to_bsd_msghdr(&lmsg.msg_hdr, &bmsg.msg_hdr);

                msg->msg_flags = flags;

                error = do_sys_sendmsg_so(l, s, so, fp, msg, flags, retval);
                if (error)
                        break;

                ktrkuser("msghdr", msg, sizeof *msg);
                lmsg.msg_len = *retval;
                error = copyout(&lmsg, SCARG(uap, msgvec) + dg, sizeof(lmsg));
                if (error)
                        break;
                dg++;

        }

        *retval = dg;

        fd_putfile(s);

        /*
         * If we succeeded at least once, return 0.
         */
        if (dg)
                return 0;
        return error;
}

int
linux_sys_recvmmsg(struct lwp *l, const struct linux_sys_recvmmsg_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(int) s;
                syscallarg(struct linux_mmsghdr *) msgvec;
                syscallarg(unsigned int) vlen;
                syscallarg(unsigned int) flags;
                syscallarg(struct linux_timespec *) timeout;
        } */
        struct linux_mmsghdr lmsg;
        struct mmsghdr bmsg;
        struct socket *so;
        struct msghdr *msg = &bmsg.msg_hdr;
        int error, s;
        struct mbuf *from, *control;
        struct timespec ts = {0}, now;
        struct linux_timespec lts;
        unsigned int vlen, flags, dg;

        if (SCARG(uap, timeout)) {
                error = copyin(SCARG(uap, timeout), &lts, sizeof(lts));
                        return error;
                ts.tv_sec = lts.tv_sec;
                ts.tv_nsec = lts.tv_nsec;
                getnanotime(&now);
                timespecadd(&now, &ts, &ts);
        }

        s = SCARG(uap, s);
        if ((error = fd_getsock(s, &so)) != 0)
                return error;

        /*
         * If so->so_rerror holds a deferred error return it now.
         */
        if (so->so_rerror) {
                error = so->so_rerror;
                so->so_rerror = 0;
                fd_putfile(s);
                return error;
        }

        vlen = SCARG(uap, vlen);
        if (vlen > 1024)
                vlen = 1024;

        from = NULL;
        flags = (SCARG(uap, flags) & MSG_USERFLAGS) | MSG_IOVUSRSPACE;

        for (dg = 0; dg < vlen;) {
                error = copyin(SCARG(uap, msgvec) + dg, &lmsg, sizeof(lmsg));
                if (error)
                        break;
                linux_to_bsd_msghdr(&lmsg.msg_hdr, &bmsg.msg_hdr);
                msg->msg_flags = flags & ~MSG_WAITFORONE;

                if (from != NULL) {
                        m_free(from);
                        from = NULL;
                }

                error = do_sys_recvmsg_so(l, s, so, msg, &from,
                    msg->msg_control != NULL ? &control : NULL, retval);
                if (error) {
                        if (error == EAGAIN && dg > 0)
                                error = 0;
                        break;
                }

                if (msg->msg_control != NULL)
                        error = linux_copyout_msg_control(l, msg, control);
                if (error)
                        break;

                if (from != NULL) {
                        mtod(from, struct osockaddr *)->sa_family =
                            bsd_to_linux_domain(mtod(from,
                            struct sockaddr *)->sa_family);
                        error = copyout_sockname(msg->msg_name,
                            &msg->msg_namelen, 0, from);
                        if (error)
                                break;
                }


                lmsg.msg_len = *retval;
                ktrkuser("msghdr", msg, sizeof(*msg));
                bsd_to_linux_msghdr(msg, &lmsg.msg_hdr);
                error = copyout(&lmsg, SCARG(uap, msgvec) + dg, sizeof(lmsg));
                if (error)
                        break;

                dg++;
                if (msg->msg_flags & MSG_OOB)
                        break;

                if (SCARG(uap, timeout)) {
                        getnanotime(&now);
                        timespecsub(&now, &ts, &now);
                        if (now.tv_sec > 0)
                                break;
                }

                if (flags & MSG_WAITFORONE)
                        flags |= MSG_DONTWAIT;

        }

        if (from != NULL)
                m_free(from);

        *retval = dg;

        /*
         * If we succeeded at least once, return 0, hopefully so->so_rerror
         * will catch it next time.
         */
        if (error && dg > 0) {
                so->so_rerror = error;
                error = 0;
        }

        fd_putfile(s);

        return error;
}