//==========================================================================
//
//      src/sys/kern/sockio.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

//==========================================================================
//
//      sys/kern/sockio.c
//
//     Socket interface to Fileio subsystem
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD or other sources,
// and are covered by the appropriate copyright disclaimers included herein.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    nickg
// Contributors: nickg, gthomas
// Date:         2000-06-06
// Purpose:      
// Description:  File I/O operations for network sockets.  Ruthelessly
//               cribbed from the BSD sources and adapted to eCos.
//
//####DESCRIPTIONEND####
//
//==========================================================================

/*
 * Copyright (c) 1982, 1986, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * sendfile(2) and related extensions:
 * Copyright (c) 1998, David Greenman. 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)uipc_syscalls.c	8.4 (Berkeley) 2/21/94
 * $FreeBSD: src/sys/kern/uipc_syscalls.c,v 1.65.2.9 2001/07/31 10:49:39 dwmalone Exp $
 */
//==========================================================================

#include <pkgconf/net.h>
#include <pkgconf/io_fileio.h>

#include <sys/types.h>

#include <cyg/io/file.h>

#include <cyg/fileio/fileio.h>
#include <cyg/fileio/sockio.h>

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/route.h>

//==========================================================================
// Forward definitions

static int     bsd_init  (cyg_nstab_entry *nste);
static int     bsd_socket(cyg_nstab_entry *nste, int domain, int type,
                          int protocol, cyg_file *file);

static int bsd_bind      (cyg_file *fp, const sockaddr *sa, socklen_t len);
static int bsd_connect   (cyg_file *fp, const sockaddr *sa, socklen_t len);
static int bsd_accept    (cyg_file *fp, cyg_file *new_fp,
                          struct sockaddr *name, socklen_t *anamelen);
static int bsd_listen    (cyg_file *fp, int len);
static int bsd_getname   (cyg_file *fp, sockaddr *sa, socklen_t *len, int peer);
static int bsd_shutdown  (cyg_file *fp, int flags);
static int bsd_getsockopt(cyg_file *fp, int level, int optname,
                          void *optval, socklen_t *optlen);
static int bsd_setsockopt(cyg_file *fp, int level, int optname,
                          const void *optval, socklen_t optlen);
static int bsd_sendmsg   (cyg_file *fp, const struct msghdr *m,
                          int flags, ssize_t *retsize);
static int bsd_recvmsg   (cyg_file *fp, struct msghdr *m,
                          socklen_t *namelen, ssize_t *retsize);


// File operations
static int bsd_read      (struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio);
static int bsd_write     (struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio);
static int bsd_lseek     (struct CYG_FILE_TAG *fp, off_t *pos, int whence);
static int bsd_ioctl     (struct CYG_FILE_TAG *fp, CYG_ADDRWORD com,
                                CYG_ADDRWORD data);
static int bsd_select    (struct CYG_FILE_TAG *fp, int which, CYG_ADDRWORD info);
static int bsd_fsync     (struct CYG_FILE_TAG *fp, int mode);        
static int bsd_close     (struct CYG_FILE_TAG *fp);
static int bsd_fstat     (struct CYG_FILE_TAG *fp, struct stat *buf);
static int bsd_getinfo   (struct CYG_FILE_TAG *fp, int key, void *buf, int len);
static int bsd_setinfo   (struct CYG_FILE_TAG *fp, int key, void *buf, int len);

static int bsd_recvit    (cyg_file *fp, struct msghdr *mp, 
                          socklen_t *namelenp, ssize_t *retsize);
static int bsd_sendit    (cyg_file *fp, const struct msghdr *mp, 
                          int flags, ssize_t *retsize);

static int getsockaddr   (struct sockaddr **namp, caddr_t uaddr, size_t len);

//==========================================================================
// Table entrys

NSTAB_ENTRY( bsd_nste, 0,
             "bsd_tcpip",
             "",
             0,
             bsd_init,
             bsd_socket);

struct cyg_sock_ops bsd_sockops =
{
    bsd_bind,
    bsd_connect,
    bsd_accept,
    bsd_listen,
    bsd_getname,
    bsd_shutdown,
    bsd_getsockopt,
    bsd_setsockopt,
    bsd_sendmsg,
    bsd_recvmsg
};

cyg_fileops bsd_sock_fileops =
{
    bsd_read,
    bsd_write,
    bsd_lseek,
    bsd_ioctl,
    bsd_select,
    bsd_fsync,
    bsd_close,
    bsd_fstat,
    bsd_getinfo,
    bsd_setinfo    
};

//==========================================================================
// NStab functions



// -------------------------------------------------------------------------

static int     
bsd_init(cyg_nstab_entry *nste)
{
    // Initialization already handled via constructor
    
    return ENOERR;
}

// -------------------------------------------------------------------------

static int     
bsd_socket(cyg_nstab_entry *nste, int domain, int type,
           int protocol, cyg_file *file)
{
    int error = 0;
    struct socket *so;

    error = socreate(domain, &so, type, protocol, (struct proc *)&proc0);

    if( error == ENOERR)
    {

        cyg_selinit(&so->so_rcv.sb_sel);
        cyg_selinit(&so->so_snd.sb_sel);
        
        file->f_flag   |= CYG_FREAD|CYG_FWRITE;
        file->f_type    = CYG_FILE_TYPE_SOCKET;
        file->f_ops     = &bsd_sock_fileops;
        file->f_offset  = 0;
        file->f_data    = (CYG_ADDRWORD)so;
        file->f_xops    = (CYG_ADDRWORD)&bsd_sockops;
    }
    
    return error;
}


//==========================================================================
// Sockops functions

// -------------------------------------------------------------------------

static int 
bsd_bind(cyg_file *fp, const sockaddr *sa, socklen_t len)
{
    int error;

    error = sobind((struct socket *)fp->f_data, (sockaddr *)sa, 0);
    return error;
}

// -------------------------------------------------------------------------

static int 
bsd_connect(cyg_file *fp, const sockaddr *sa, socklen_t len)
{
    struct socket *so;
    int error, s;

    so = (struct socket *)fp->f_data;

    if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING))
        return (EALREADY);

    error = soconnect(so, (struct sockaddr *)sa, 0);
    if (error)
        goto bad;

    if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
        return (EINPROGRESS);
    }

    s = splsoftnet();
    while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
        error = tsleep((caddr_t)&so->so_timeo, PSOCK | PCATCH,
                       "netcon", 0);
        if (error)
            break;
    }

    if (error == 0) {
        error = so->so_error;
        so->so_error = 0;
    }

    splx(s);

bad:
    so->so_state &= ~SS_ISCONNECTING;

    return error;
}

// -------------------------------------------------------------------------

static int 
bsd_accept(cyg_file *fp, cyg_file *new_fp,
           struct sockaddr *name, socklen_t *anamelen)
{
    socklen_t namelen = 0;
    int error = 0, s;
    struct socket *head, *so;
    struct sockaddr *sa;

    if( anamelen != NULL)
        namelen = *anamelen;

    s = splsoftnet();
    head = (struct socket *)fp->f_data;

    if ((head->so_options & SO_ACCEPTCONN) == 0) {
        splx(s);
        return (EINVAL);
    }

    if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->so_comp)) {
        splx(s);
        return (EWOULDBLOCK);
    }

    while (TAILQ_EMPTY(&head->so_comp) && head->so_error == 0) {
        if (head->so_state & SS_CANTRCVMORE) {
            head->so_error = ECONNABORTED;
            break;
        }
        error = tsleep((caddr_t)&head->so_timeo, PSOCK | PCATCH,
                       "netcon", 0);
        if (error) {
            splx(s);
            return (error);
        }
    }

    if (head->so_error) {
        error = head->so_error;
        head->so_error = 0;
        splx(s);
        return (error);
    }

    /*
     * At this point we know that there is at least one connection
     * ready to be accepted. Remove it from the queue prior to
     * allocating the file descriptor for it since falloc() may
     * block allowing another process to accept the connection
     * instead.
     */
    so = TAILQ_FIRST(&head->so_comp);
    TAILQ_REMOVE(&head->so_comp, so, so_list);
    head->so_qlen--;

#if 0 // FIXME
    fflag = lfp->f_flag;
    error = falloc(p, &nfp, &fd);
    if (error) {
        /*
         * Probably ran out of file descriptors. Put the
         * unaccepted connection back onto the queue and
         * do another wakeup so some other process might
         * have a chance at it.
         */
        TAILQ_INSERT_HEAD(&head->so_comp, so, so_list);
        head->so_qlen++;
        wakeup_one(&head->so_timeo);
        splx(s);
        goto done;
    }
    fhold(nfp);
    p->p_retval[0] = fd;

    /* connection has been removed from the listen queue */
    KNOTE(&head->so_rcv.sb_sel.si_note, 0);
#endif

    so->so_state &= ~SS_COMP;
    so->so_head = NULL;

    cyg_selinit(&so->so_rcv.sb_sel);
    cyg_selinit(&so->so_snd.sb_sel);
    
    new_fp->f_type      = DTYPE_SOCKET;
    new_fp->f_flag     |= FREAD|FWRITE;
    new_fp->f_offset    = 0;
    new_fp->f_ops       = &bsd_sock_fileops;
    new_fp->f_data      = (CYG_ADDRWORD)so;
    new_fp->f_xops      = (CYG_ADDRWORD)&bsd_sockops;
    
    sa = 0;
    error = soaccept(so, &sa);
    if (error) {
        /*
         * return a namelen of zero for older code which might
         * ignore the return value from accept.
         */	
        if (name != NULL) {
            *anamelen = 0;
        }
        goto noconnection;
    }
    if (sa == NULL) {
        namelen = 0;
        if (name)
            goto gotnoname;
        splx(s);
        error = 0;
        goto done;
    }
    if (name) {
        if (namelen > sa->sa_len)
            namelen = sa->sa_len;
#ifdef COMPAT_OLDSOCK
        if (compat)
            ((struct osockaddr *)sa)->sa_family = sa->sa_family;
#endif
        error = copyout(sa, (caddr_t)name, namelen);
        if (!error)
gotnoname:
        *anamelen = namelen;
    }
noconnection:

#if 0 // FIXME
	/*
	 * close the new descriptor, assuming someone hasn't ripped it
	 * out from under us.
	 */
	if (error) {
		if (fdp->fd_ofiles[fd] == nfp) {
			fdp->fd_ofiles[fd] = NULL;
			fdrop(nfp, p);
		}
	}
	splx(s);

	/*
	 * Release explicitly held references before returning.
	 */
done:
	if (nfp != NULL)
		fdrop(nfp, p);
	fdrop(lfp, p);
	return (error);
    m_freem(nam);
#else
 done:
    splx(s);
    if (sa)
        FREE(sa, M_SONAME);
#endif
    
    return (error);
}

// -------------------------------------------------------------------------

static int 
bsd_listen(cyg_file *fp, int backlog)
{
    return (solisten((struct socket *)fp->f_data, backlog, 0));
}

// -------------------------------------------------------------------------

static int 
bsd_getname(cyg_file *fp, sockaddr *asa, socklen_t *alen, int peer)
{
    struct socket *so;
    socklen_t len = 0;
    int error;
    sockaddr *sa;
    
    if( alen != NULL)
        len = *alen;
        
    so = (struct socket *)fp->f_data;
    sa = 0;
    if (peer) {
        // getpeername()
	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
            return (ENOTCONN);
	}
	error = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so, &sa);
    } else {
        // getsockname()
	error = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, &sa);
    }
    if (error)
        goto bad;
    if (sa == 0) {
        len = 0;
        goto gotnothing;
    }
    len = min(len, sa->sa_len);
#ifdef COMPAT_OLDSOCK
    if (compat)
        ((struct osockaddr *)sa)->sa_family = sa->sa_family;
#endif
    error = copyout(sa, (caddr_t)asa, (u_int)len);
 gotnothing:
    *alen = len;
 bad:
    if (sa)
        FREE(sa, M_SONAME);
    return (error);
}

// -------------------------------------------------------------------------

static int 
bsd_shutdown(cyg_file *fp, int how)
{
    return (soshutdown((struct socket *)fp->f_data, how));
}

// -------------------------------------------------------------------------

static int 
bsd_getsockopt(cyg_file *fp, int level, int optname,
               void *optval, socklen_t *optlen)
{
    socklen_t valsize = 0;
    int error;
    struct sockopt opt;

    if( optval != NULL && optlen != NULL)
        valsize = *optlen;
    
    opt.sopt_dir = SOPT_GET;
    opt.sopt_level = level;
    opt.sopt_name = optname;
    opt.sopt_val = optval;
    opt.sopt_valsize = valsize;
    opt.sopt_p = 0;

    error = sogetopt((struct socket *)fp->f_data, &opt);
    if (error == 0) {
        *optlen = opt.sopt_valsize;
    }
    return (error);
}

// -------------------------------------------------------------------------

static int 
bsd_setsockopt(cyg_file *fp, int level, int optname,
               const void *optval, socklen_t optlen)
{
    struct sockopt opt;

    opt.sopt_dir = SOPT_SET;
    opt.sopt_level = level;
    opt.sopt_name = optname;
    opt.sopt_val = (void *)optval;
    opt.sopt_valsize = optlen;
    opt.sopt_p = 0;
    
    return sosetopt((struct socket *)fp->f_data, &opt);
}

// -------------------------------------------------------------------------

static int 
bsd_sendmsg(cyg_file *fp, const struct msghdr *m, int flags, ssize_t *retsize)
{
    return bsd_sendit(fp, m, flags, retsize);
}

// -------------------------------------------------------------------------

static int 
bsd_recvmsg(cyg_file *fp, struct msghdr *m, socklen_t *namelen, ssize_t *retsize)
{
    return bsd_recvit(fp, m, namelen, retsize);
}

//==========================================================================
// File system call functions

// -------------------------------------------------------------------------

static int 
bsd_read(struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio)
{
    return (soreceive((struct socket *)fp->f_data, (struct sockaddr **)0,
                      uio, (struct mbuf **)0, (struct mbuf **)0, (int *)0));
}

// -------------------------------------------------------------------------

static int 
bsd_write(struct CYG_FILE_TAG *fp, struct CYG_UIO_TAG *uio)
{
    return (sosend((struct socket *)fp->f_data, (struct sockaddr *)0,
                   uio, (struct mbuf *)0, (struct mbuf *)0, 0, 0));
}

// -------------------------------------------------------------------------

static int 
bsd_lseek(struct CYG_FILE_TAG *fp, off_t *pos, int whence)
{
    return ESPIPE;
}

// -------------------------------------------------------------------------

static int 
bsd_ioctl(struct CYG_FILE_TAG *fp, CYG_ADDRWORD cmd, CYG_ADDRWORD data)
{
    struct socket *so = (struct socket *)fp->f_data;
    void *p = 0;

    switch (cmd) {

    case FIONBIO:
        if (*(int *)data)
            so->so_state |= SS_NBIO;
        else
            so->so_state &= ~SS_NBIO;
        return (0);

    case FIOASYNC:
        if (*(int *)data) {
            so->so_state |= SS_ASYNC;
            so->so_rcv.sb_flags |= SB_ASYNC;
            so->so_snd.sb_flags |= SB_ASYNC;
        } else {
            so->so_state &= ~SS_ASYNC;
            so->so_rcv.sb_flags &= ~SB_ASYNC;
            so->so_snd.sb_flags &= ~SB_ASYNC;
        }
        return (0);

    case FIONREAD:
        *(int *)data = so->so_rcv.sb_cc;
        return (0);

    case SIOCATMARK:
        *(int *)data = (so->so_state&SS_RCVATMARK) != 0;
        return (0);
    }
    /*
     * Interface/routing/protocol specific ioctls:
     * interface and routing ioctls should have a
     * different entry since a socket's unnecessary
     */
    if (IOCGROUP(cmd) == 'i')
        return (ifioctl(so, (u_long)cmd, (caddr_t)data, p));
    if (IOCGROUP(cmd) == 'r')
        return (rtioctl((u_long)cmd, (caddr_t)data, p));
    return ((*so->so_proto->pr_usrreqs->pru_control)(so, cmd, (caddr_t)data, 0, 0));
}

#if 0  // DEBUG support
static int 
bsd_ioctl(struct CYG_FILE_TAG *fp, CYG_ADDRWORD cmd, CYG_ADDRWORD data)
{
    int res = _bsd_ioctl(fp, cmd, data);
    diag_printf("ioctl(%x,%x) = %x\n", cmd, data, res);
    return res;
}
#endif

// -------------------------------------------------------------------------

static int 
bsd_select(struct CYG_FILE_TAG *fp, int which, CYG_ADDRWORD info)
{
    register struct socket *so = (struct socket *)fp->f_data;
    register int s = splsoftnet();

    switch (which) {

    case FREAD:
        if (soreadable(so)) {
            splx(s);
            return (1);
        }
        cyg_selrecord(info, &so->so_rcv.sb_sel);
        so->so_rcv.sb_flags |= SB_SEL;
        break;

    case FWRITE:
        if (sowriteable(so)) {
            splx(s);
            return (1);
        }
        cyg_selrecord(info, &so->so_snd.sb_sel);
        so->so_snd.sb_flags |= SB_SEL;
        break;

    case 0:
        if (so->so_oobmark || (so->so_state & SS_RCVATMARK)) {
            splx(s);
            return (1);
        }
        cyg_selrecord(info, &so->so_rcv.sb_sel);
        so->so_rcv.sb_flags |= SB_SEL;
        break;
    }
    splx(s);
    
    return ENOERR;
}

// -------------------------------------------------------------------------

static int 
bsd_fsync(struct CYG_FILE_TAG *fp, int mode)
{
    // FIXME: call some sort of flush IOCTL?
    return 0;
}

// -------------------------------------------------------------------------

static int 
bsd_close(struct CYG_FILE_TAG *fp)
{
    int error = 0;

    if (fp->f_data)
        error = soclose((struct socket *)fp->f_data);
    fp->f_data = 0;
    return (error);
}

// -------------------------------------------------------------------------

static int 
bsd_fstat(struct CYG_FILE_TAG *fp, struct stat *buf)
{
    register struct socket *so = (struct socket *)fp->f_data;

    bzero((caddr_t)buf, sizeof (*buf));

    // Mark socket as a fifo for now. We need to add socket types to
    // sys/stat.h.
    buf->st_mode = __stat_mode_FIFO;
    
    return ((*so->so_proto->pr_usrreqs->pru_sense)(so, buf));
}

// -------------------------------------------------------------------------

static int 
bsd_getinfo(struct CYG_FILE_TAG *fp, int key, void *buf, int len)
{
    return ENOSYS;
}

// -------------------------------------------------------------------------

static int 
bsd_setinfo(struct CYG_FILE_TAG *fp, int key, void *buf, int len)
{
    return ENOSYS;
}


#if 0
//==========================================================================
// Select support

// -------------------------------------------------------------------------
// This function is called by the lower layers to record the
// fact that a particular 'select' event is being requested.
//

void        
selrecord(void *selector, struct selinfo *info)
{
    // Unused by this implementation
}

// -------------------------------------------------------------------------
// This function is called to indicate that a 'select' event
// may have occurred.
//

void    
selwakeup(struct selinfo *info)
{
    cyg_selwakeup( info);
}
#endif

//==========================================================================
// Misc support functions

int
sockargs(mp, buf, buflen, type)
	struct mbuf **mp;
	caddr_t buf;
	int buflen;
	int type;
{
	register struct sockaddr *sa;
	register struct mbuf *m;
	int error;

	if (buflen > MLEN) {
#ifdef COMPAT_OLDSOCK
		if (type == MT_SONAME && buflen <= 112)
			buflen = MLEN;		/* unix domain compat. hack */
		else
#endif
		return (EINVAL);
	}
	m = m_get(M_WAIT, type);
	if (m == NULL)
		return (ENOBUFS);
	m->m_len = buflen;
	error = copyin(buf, mtod(m, caddr_t), buflen);
	if (error) {
		(void) m_free(m);
		return (error);
	}
	*mp = m;
	if (type == MT_SONAME) {
		sa = mtod(m, struct sockaddr *);

#if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
			sa->sa_family = sa->sa_len;
#endif
		sa->sa_len = buflen;
	}
	return (0);
}


// -------------------------------------------------------------------------
// bsd_recvit()
// Support for message reception. This is a lightly edited version of the
// recvit() function is uipc_syscalls.c.

static int
bsd_recvit(cyg_file *fp, struct msghdr *mp, socklen_t *namelenp, ssize_t *retsize)
{
    struct uio auio;
    struct iovec *iov;
    int i;
    size_t len;
    int error;
    struct mbuf *m, *control = 0;
    caddr_t ctlbuf;
    struct socket *so;
    struct sockaddr *fromsa = 0;

    auio.uio_iov = mp->msg_iov;
    auio.uio_iovcnt = mp->msg_iovlen;
    auio.uio_segflg = UIO_USERSPACE;
    auio.uio_rw = UIO_READ;
    auio.uio_offset = 0;			/* XXX */
    auio.uio_resid = 0;
    iov = mp->msg_iov;
    for (i = 0; i < mp->msg_iovlen; i++, iov++) {
        /* Don't allow sum > SSIZE_MAX */
        if (iov->iov_len > SSIZE_MAX ||
            (auio.uio_resid += iov->iov_len) > SSIZE_MAX)
            return (EINVAL);
    }

    len = auio.uio_resid;
    so = (struct socket *)fp->f_data;
    error = so->so_proto->pr_usrreqs->pru_soreceive(so, &fromsa, &auio,
                                                    (struct mbuf **)0, mp->msg_control ? &control : (struct mbuf **)0,
                                                    &mp->msg_flags);
    if (error) {
        if (auio.uio_resid != len && 
            (error == EINTR || error == EWOULDBLOCK))
            error = 0;
    }
    if (error)
        goto out;
    *retsize = len - auio.uio_resid;
    if (mp->msg_name) {
        len = mp->msg_namelen;
        if (len <= 0 || fromsa == 0)
            len = 0;
        else {
            /* save sa_len before it is destroyed by MSG_COMPAT */
            if (len > fromsa->sa_len)
                len = fromsa->sa_len;
#ifdef COMPAT_OLDSOCK
            if (mp->msg_flags & MSG_COMPAT)
                ((struct osockaddr *)fromsa)->sa_family =
                    fromsa->sa_family;
#endif
            error = copyout(fromsa,
			    (caddr_t)mp->msg_name, (unsigned)len);
            if (error)
                goto out;
        }
        mp->msg_namelen = len;
        if (namelenp) {
            *namelenp = len;
#ifdef COMPAT_OLDSOCK
            if (mp->msg_flags & MSG_COMPAT)
                error = 0;	/* old recvfrom didn't check */
            else
#endif
                goto out;
        }
    }
    if (mp->msg_control) {
#ifdef COMPAT_OLDSOCK
        /*
         * We assume that old recvmsg calls won't receive access
         * rights and other control info, esp. as control info
         * is always optional and those options didn't exist in 4.3.
         * If we receive rights, trim the cmsghdr; anything else
         * is tossed.
         */
        if (control && mp->msg_flags & MSG_COMPAT) {
            if (mtod(control, struct cmsghdr *)->cmsg_level !=
                SOL_SOCKET ||
                mtod(control, struct cmsghdr *)->cmsg_type !=
                SCM_RIGHTS) {
                mp->msg_controllen = 0;
                goto out;
            }
            control->m_len -= sizeof (struct cmsghdr);
            control->m_data += sizeof (struct cmsghdr);
        }
#endif
        len = mp->msg_controllen;
        m = control;
        mp->msg_controllen = 0;
        ctlbuf = (caddr_t) mp->msg_control;

        while (m && len > 0) {
            unsigned int tocopy;

            if (len >= m->m_len) 
                tocopy = m->m_len;
            else {
                mp->msg_flags |= MSG_CTRUNC;
                tocopy = len;
            }
		
            if ((error = copyout((caddr_t)mtod(m, caddr_t),
                                 ctlbuf, tocopy)) != 0)
                goto out;

            ctlbuf += tocopy;
            len -= tocopy;
            m = m->m_next;
        }
        mp->msg_controllen = ctlbuf - (caddr_t)mp->msg_control;
    }
 out:
    if (fromsa)
        FREE(fromsa, M_SONAME);
    if (control)
        m_freem(control);
    return (error);
}

// -------------------------------------------------------------------------
// sendit()
// Support for message transmission. This is a lightly edited version of the
// synonymous function is uipc_syscalls.c.

static int
bsd_sendit(cyg_file *fp, const struct msghdr *mp, int flags, ssize_t *retsize)
{
    struct uio auio;
    register struct iovec *iov;
    register int i;
    struct mbuf *control;
    struct sockaddr *to;
    int len, error;
    struct socket *so;
	
    auio.uio_iov = mp->msg_iov;
    auio.uio_iovcnt = mp->msg_iovlen;
    auio.uio_segflg = UIO_USERSPACE;
    auio.uio_rw = UIO_WRITE;
    auio.uio_offset = 0;			/* XXX */
    auio.uio_resid = 0;
    iov = mp->msg_iov;
    for (i = 0; i < mp->msg_iovlen; i++, iov++) {
        /* Don't allow sum > SSIZE_MAX */
        if (iov->iov_len > SSIZE_MAX ||
            (auio.uio_resid += iov->iov_len) > SSIZE_MAX)
            return (EINVAL);
    }
    if (mp->msg_name) {
        error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
        if (error) {
            return (error);
        }
    } else {
        to = 0;
    }
    if (mp->msg_control) {
        if (mp->msg_controllen < sizeof(struct cmsghdr)
#ifdef COMPAT_OLDSOCK
            && mp->msg_flags != MSG_COMPAT
#endif
            ) {
            error = EINVAL;
            goto bad;
        }
        error = sockargs(&control, mp->msg_control,
                         mp->msg_controllen, MT_CONTROL);
        if (error)
            goto bad;
#ifdef COMPAT_OLDSOCK
        if (mp->msg_flags == MSG_COMPAT) {
            register struct cmsghdr *cm;

            M_PREPEND(control, sizeof(*cm), M_WAIT);
            if (control == 0) {
                error = ENOBUFS;
                goto bad;
            } else {
                cm = mtod(control, struct cmsghdr *);
                cm->cmsg_len = control->m_len;
                cm->cmsg_level = SOL_SOCKET;
                cm->cmsg_type = SCM_RIGHTS;
            }
        }
#endif
    } else
        control = 0;

    len = auio.uio_resid;
    so = (struct socket *)fp->f_data;
    error = so->so_proto->pr_usrreqs->pru_sosend(so, to, &auio, 0, control,
                                                 flags, 0);
    if (error) {
        if (auio.uio_resid != len && (error == EINTR || error == EWOULDBLOCK))
            error = 0;
    }
    if (error == 0)
        *retsize = len - auio.uio_resid;
 bad:
    if (to)
        FREE(to, M_SONAME);
    return (error);
}

static int
getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len)
{
	struct sockaddr *sa;
	int error;

	if (len > SOCK_MAXADDRLEN)
		return ENAMETOOLONG;
	MALLOC(sa, struct sockaddr *, len, M_SONAME, M_WAITOK);
	error = copyin(uaddr, sa, len);
	if (error) {
		FREE(sa, M_SONAME);
	} else {
#if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
			sa->sa_family = sa->sa_len;
#endif
		sa->sa_len = len;
		*namp = sa;
	}
	return error;
}

//==========================================================================
// End of sockio.c
