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//==========================================================================

//

//      sys/kern/uipc_socket.c

//

//     

//

//==========================================================================

//####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):    gthomas

// Contributors: gthomas

// Date:         2000-01-10

// Purpose:      

// Description:  

//              

//

//####DESCRIPTIONEND####

//

//==========================================================================

/*      $OpenBSD: uipc_socket.c,v 1.27 1999/10/14 08:18:49 cmetz Exp $  */

/*      $NetBSD: uipc_socket.c,v 1.21 1996/02/04 02:17:52 christos Exp $        */

/*

 * Copyright (c) 1982, 1986, 1988, 1990, 1993

 *      The Regents of the University of California.  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_socket.c       8.3 (Berkeley) 4/15/94

 */

#include <sys/param.h>

#ifdef __ECOS

#include <cyg/io/file.h>

#else

#include <sys/systm.h>

#include <sys/proc.h>

#include <sys/file.h>

#endif

#include <sys/malloc.h>

#include <sys/mbuf.h>

#include <sys/domain.h>

#include <sys/kernel.h>

#include <sys/protosw.h>

#include <sys/socket.h>

#include <sys/socketvar.h>

#ifndef __ECOS

#include <sys/signalvar.h>

#include <sys/resourcevar.h>

#endif

#ifndef SOMINCONN

#define SOMINCONN 80

#endif /* SOMINCONN */

int     somaxconn = SOMAXCONN;

int     sominconn = SOMINCONN;

/*

 * Socket operation routines.

 * These routines are called by the routines in

 * sys_socket.c or from a system process, and

 * implement the semantics of socket operations by

 * switching out to the protocol specific routines.

 */

/*ARGSUSED*/

int

socreate(dom, aso, type, proto)

        int dom;

        struct socket **aso;

        register int type;

        int proto;

{

#ifndef __ECOS

        struct proc *p = curproc;               /* XXX */

#endif

        register struct protosw *prp;

        register struct socket *so;

        register int error;

        if (proto)

                prp = pffindproto(dom, proto, type);

        else

                prp = pffindtype(dom, type);

        if (prp == 0 || prp->pr_usrreq == 0)

                return (EPROTONOSUPPORT);

        if (prp->pr_type != type)

                return (EPROTOTYPE);

        MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_WAIT);

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

        so->so_type = type;

#ifdef __ECOS

        so->so_state = SS_PRIV;

        so->so_ruid = 0;  // FIXME

        so->so_euid = 0;  // FIXME

#else

        if (p->p_ucred->cr_uid == 0)

                so->so_state = SS_PRIV;

        so->so_ruid = p->p_cred->p_ruid;

        so->so_euid = p->p_ucred->cr_uid;

#endif

        so->so_proto = prp;

        error =

            (*prp->pr_usrreq)(so, PRU_ATTACH, NULL, (struct mbuf *)(long)proto,

                              NULL);

        if (error) {

                so->so_state |= SS_NOFDREF;

                sofree(so);

                return (error);

        }

#ifdef COMPAT_SUNOS

        {

                extern struct emul emul_sunos;

                if (p->p_emul == &emul_sunos && type == SOCK_DGRAM)

                        so->so_options |= SO_BROADCAST;

        }

#endif

        *aso = so;

        return (0);

}

int

sobind(so, nam)

        struct socket *so;

        struct mbuf *nam;

{

        int s = splsoftnet();

        int error;

        error = (*so->so_proto->pr_usrreq)(so, PRU_BIND, NULL, nam, NULL);

        splx(s);

        return (error);

}

int

solisten(so, backlog)

        register struct socket *so;

        int backlog;

{

        int s = splsoftnet(), error;

        error = (*so->so_proto->pr_usrreq)(so, PRU_LISTEN, NULL, NULL, NULL);

        if (error) {

                splx(s);

                return (error);

        }

        if (so->so_q == 0)

                so->so_options |= SO_ACCEPTCONN;

        if (backlog < 0 || backlog > somaxconn)

                backlog = somaxconn;

        if (backlog < sominconn)

                backlog = sominconn;

        so->so_qlimit = backlog;

        splx(s);

        return (0);

}

void

sofree(so)

        register struct socket *so;

{

        if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)

                return;

        if (so->so_head) {

                /*

                 * We must not decommission a socket that's on the accept(2)

                 * queue.  If we do, then accept(2) may hang after select(2)

                 * indicated that the listening socket was ready.

                 */

                if (!soqremque(so, 0))

                        return;

        }

        sbrelease(&so->so_snd);

        sorflush(so);

        FREE(so, M_SOCKET);

}

/*

 * Close a socket on last file table reference removal.

 * Initiate disconnect if connected.

 * Free socket when disconnect complete.

 */

int

soclose(so)

        register struct socket *so;

{

        struct socket *so2;

        int s = splsoftnet();           /* conservative */

        int error = 0;

        if (so->so_options & SO_ACCEPTCONN) {

                while ((so2 = so->so_q0) != NULL) {

                        (void) soqremque(so2, 0);

                        (void) soabort(so2);

                }

                while ((so2 = so->so_q) != NULL) {

                        (void) soqremque(so2, 1);

                        (void) soabort(so2);

                }

        }

        if (so->so_pcb == 0)

                goto discard;

        if (so->so_state & SS_ISCONNECTED) {

                if ((so->so_state & SS_ISDISCONNECTING) == 0) {

                        error = sodisconnect(so);

                        if (error)

                                goto drop;

                }

                if (so->so_options & SO_LINGER) {

                        if ((so->so_state & SS_ISDISCONNECTING) &&

                            (so->so_state & SS_NBIO))

                                goto drop;

                        while (so->so_state & SS_ISCONNECTED) {

                                error = tsleep((caddr_t)&so->so_timeo,

                                    PSOCK | PCATCH, netcls,

                                    so->so_linger * hz);

                                if (error)

                                        break;

                        }

                }

        }

drop:

        if (so->so_pcb) {

                int error2 = (*so->so_proto->pr_usrreq)(so, PRU_DETACH, NULL,

                                                        NULL, NULL);

                if (error == 0)

                        error = error2;

        }

discard:

        if (so->so_state & SS_NOFDREF)

                panic("soclose: NOFDREF");

        so->so_state |= SS_NOFDREF;

        sofree(so);

        splx(s);

        return (error);

}

/*

 * Must be called at splsoftnet...

 */

int

soabort(so)

        struct socket *so;

{

        return (*so->so_proto->pr_usrreq)(so, PRU_ABORT, NULL, NULL, NULL);

}

int

soaccept(so, nam)

        register struct socket *so;

        struct mbuf *nam;

{

        int s = splsoftnet();

        int error = 0;

        if ((so->so_state & SS_NOFDREF) == 0)

                panic("soaccept: !NOFDREF");

        so->so_state &= ~SS_NOFDREF;

        if ((so->so_state & SS_ISDISCONNECTED) == 0)

                error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT, NULL,

                    nam, NULL);

        splx(s);

        return (error);

}

int

soconnect(so, nam)

        register struct socket *so;

        struct mbuf *nam;

{

        int s;

        int error;

        if (so->so_options & SO_ACCEPTCONN)

                return (EOPNOTSUPP);

        s = splsoftnet();

        /*

         * If protocol is connection-based, can only connect once.

         * Otherwise, if connected, try to disconnect first.

         * This allows user to disconnect by connecting to, e.g.,

         * a null address.

         */

        if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&

            ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||

            (error = sodisconnect(so))))

                error = EISCONN;

        else

                error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,

                                                   NULL, nam, NULL);

        splx(s);

        return (error);

}

int

soconnect2(so1, so2)

        register struct socket *so1;

        struct socket *so2;

{

        int s = splsoftnet();

        int error;

        error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2, NULL,

                                            (struct mbuf *)so2, NULL);

        splx(s);

        return (error);

}

int

sodisconnect(so)

        register struct socket *so;

{

        int s = splsoftnet();

        int error;

        if ((so->so_state & SS_ISCONNECTED) == 0) {

                error = ENOTCONN;

                goto bad;

        }

        if (so->so_state & SS_ISDISCONNECTING) {

                error = EALREADY;

                goto bad;

        }

        error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT, NULL, NULL,

                                           NULL);

bad:

        splx(s);

        return (error);

}

#define SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)

/*

 * Send on a socket.

 * If send must go all at once and message is larger than

 * send buffering, then hard error.

 * Lock against other senders.

 * If must go all at once and not enough room now, then

 * inform user that this would block and do nothing.

 * Otherwise, if nonblocking, send as much as possible.

 * The data to be sent is described by "uio" if nonzero,

 * otherwise by the mbuf chain "top" (which must be null

 * if uio is not).  Data provided in mbuf chain must be small

 * enough to send all at once.

 *

 * Returns nonzero on error, timeout or signal; callers

 * must check for short counts if EINTR/ERESTART are returned.

 * Data and control buffers are freed on return.

 */

int

sosend(so, addr, uio, top, control, flags)

        register struct socket *so;

        struct mbuf *addr;

        struct uio *uio;

        struct mbuf *top;

        struct mbuf *control;

        int flags;

{

#ifndef __ECOS

        struct proc *p = curproc;               /* XXX */

#endif

        struct mbuf **mp;

        register struct mbuf *m;

        register long space, len;

        register quad_t resid;

        int clen = 0, error, s, dontroute, mlen;

        int atomic = sosendallatonce(so) || top;

        if (uio)

                resid = uio->uio_resid;

        else

                resid = top->m_pkthdr.len;

        /*

         * In theory resid should be unsigned (since uio->uio_resid is).

         * However, space must be signed, as it might be less than 0

         * if we over-committed, and we must use a signed comparison

         * of space and resid.  On the other hand, a negative resid

         * causes us to loop sending 0-length segments to the protocol.

         * MSG_EOR on a SOCK_STREAM socket is also invalid.

         */

        if (resid < 0 ||

            (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {

                error = EINVAL;

                goto out;

        }

        dontroute =

            (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&

            (so->so_proto->pr_flags & PR_ATOMIC);

#ifndef __ECOS

        p->p_stats->p_ru.ru_msgsnd++;

#endif

        if (control)

                clen = control->m_len;

#define snderr(errno)   { error = errno; splx(s); goto release; }

restart:

        if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)

                goto out;

        do {

                s = splsoftnet();

                if (so->so_state & SS_CANTSENDMORE)

                        snderr(EPIPE);

                if (so->so_error)

                        snderr(so->so_error);

                if ((so->so_state & SS_ISCONNECTED) == 0) {

                        if (so->so_proto->pr_flags & PR_CONNREQUIRED) {

                                if ((so->so_state & SS_ISCONFIRMING) == 0 &&

                                    !(resid == 0 && clen != 0))

                                        snderr(ENOTCONN);

                        } else if (addr == 0)

                                snderr(EDESTADDRREQ);

                }

                space = sbspace(&so->so_snd);

                if (flags & MSG_OOB)

                        space += 1024;

                if ((atomic && resid > so->so_snd.sb_hiwat) ||

                    clen > so->so_snd.sb_hiwat)

                        snderr(EMSGSIZE);

                if (space < resid + clen && uio &&

                    (atomic || space < so->so_snd.sb_lowat || space < clen)) {

                        if (so->so_state & SS_NBIO)

                                snderr(EWOULDBLOCK);

                        sbunlock(&so->so_snd);

                        error = sbwait(&so->so_snd);

                        splx(s);

                        if (error)

                                goto out;

                        goto restart;

                }

                splx(s);

                mp = ⊤

                space -= clen;

                do {

                    if (uio == NULL) {

                        /*

                         * Data is prepackaged in "top".

                         */

                        resid = 0;

                        if (flags & MSG_EOR)

                                top->m_flags |= M_EOR;

                    } else do {

                        if (top == 0) {

                                MGETHDR(m, M_WAIT, MT_DATA);

                                mlen = MHLEN;

                                m->m_pkthdr.len = 0;

                                m->m_pkthdr.rcvif = (struct ifnet *)0;

                        } else {

                                MGET(m, M_WAIT, MT_DATA);

                                mlen = MLEN;

                        }

                        if (resid >= MINCLSIZE && space >= MCLBYTES) {

                                MCLGET(m, M_WAIT);

                                if ((m->m_flags & M_EXT) == 0)

                                        goto nopages;

                                mlen = MCLBYTES;

#ifdef  MAPPED_MBUFS

                                len = min(MCLBYTES, resid);

#else

                                if (atomic && top == 0) {

                                        len = min(MCLBYTES - max_hdr, resid);

                                        m->m_data += max_hdr;

                                } else

                                        len = min(MCLBYTES, resid);

#endif

                                space -= len;

                        } else {

nopages:

                                len = min(min(mlen, resid), space);

                                space -= len;

                                /*

                                 * For datagram protocols, leave room

                                 * for protocol headers in first mbuf.

                                 */

                                if (atomic && top == 0 && len < mlen)

                                        MH_ALIGN(m, len);

                        }

                        error = uiomove(mtod(m, caddr_t), (int)len, uio);

                        resid = uio->uio_resid;

                        m->m_len = len;

                        *mp = m;

                        top->m_pkthdr.len += len;

                        if (error)

                                goto release;

                        mp = &m->m_next;

                        if (resid <= 0) {

                                if (flags & MSG_EOR)

                                        top->m_flags |= M_EOR;

                                break;

                        }

                    } while (space > 0 && atomic);

                    if (dontroute)

                            so->so_options |= SO_DONTROUTE;

                    s = splsoftnet();                           /* XXX */

                    error = (*so->so_proto->pr_usrreq)(so, (flags & MSG_OOB) ?

                                                        PRU_SENDOOB : PRU_SEND,

                                                       top, addr, control);

                    splx(s);

                    if (dontroute)

                            so->so_options &= ~SO_DONTROUTE;

                    clen = 0;

                    control = 0;

                    top = 0;

                    mp = ⊤

                    if (error)

                        goto release;

                } while (resid && space > 0);

        } while (resid);

release:

        sbunlock(&so->so_snd);

out:

        if (top)

                m_freem(top);

        if (control)

                m_freem(control);

        return (error);

}

/*

 * Implement receive operations on a socket.

 * We depend on the way that records are added to the sockbuf

 * by sbappend*.  In particular, each record (mbufs linked through m_next)

 * must begin with an address if the protocol so specifies,

 * followed by an optional mbuf or mbufs containing ancillary data,

 * and then zero or more mbufs of data.

 * In order to avoid blocking network interrupts for the entire time here,

 * we splx() while doing the actual copy to user space.

 * Although the sockbuf is locked, new data may still be appended,

 * and thus we must maintain consistency of the sockbuf during that time.

 *

 * The caller may receive the data as a single mbuf chain by supplying

 * an mbuf **mp0 for use in returning the chain.  The uio is then used

 * only for the count in uio_resid.

 */

int

soreceive(so, paddr, uio, mp0, controlp, flagsp)

        register struct socket *so;

        struct mbuf **paddr;

        struct uio *uio;

        struct mbuf **mp0;

        struct mbuf **controlp;

        int *flagsp;

{

        register struct mbuf *m, **mp;

        register int flags, len, error, s, offset;

        struct protosw *pr = so->so_proto;

        struct mbuf *nextrecord;

        int moff, type = 0;

        size_t orig_resid = uio->uio_resid;

        int uio_error = 0;

        int resid;

        mp = mp0;

        if (paddr)

                *paddr = 0;

        if (controlp)

                *controlp = 0;

        if (flagsp)

                flags = *flagsp &~ MSG_EOR;

        else

                flags = 0;

        if (so->so_state & SS_NBIO)

                flags |= MSG_DONTWAIT;

        if (flags & MSG_OOB) {

                m = m_get(M_WAIT, MT_DATA);

                error = (*pr->pr_usrreq)(so, PRU_RCVOOB, m,

                    (struct mbuf *)(long)(flags & MSG_PEEK), NULL);

                if (error)

                        goto bad;

                do {

                        error = uiomove(mtod(m, caddr_t),

                            (int) min(uio->uio_resid, m->m_len), uio);

                        m = m_free(m);

                } while (uio->uio_resid && error == 0 && m);

bad:

                if (m)

                        m_freem(m);

                return (error);

        }

        if (mp)

                *mp = (struct mbuf *)0;

        if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)

                (*pr->pr_usrreq)(so, PRU_RCVD, NULL, NULL, NULL);

restart:

        if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)

                return (error);

        s = splsoftnet();

        m = so->so_rcv.sb_mb;

        /*

         * If we have less data than requested, block awaiting more

         * (subject to any timeout) if:

         *   1. the current count is less than the low water mark,

         *   2. MSG_WAITALL is set, and it is possible to do the entire

         *      receive operation at once if we block (resid <= hiwat), or

         *   3. MSG_DONTWAIT is not set.

         * If MSG_WAITALL is set but resid is larger than the receive buffer,

         * we have to do the receive in sections, and thus risk returning

         * a short count if a timeout or signal occurs after we start.

         */

        if (m == 0 || (((flags & MSG_DONTWAIT) == 0 &&

            so->so_rcv.sb_cc < uio->uio_resid) &&

            (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||

            ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&

            m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {

#ifdef DIAGNOSTIC

                if (m == 0 && so->so_rcv.sb_cc)

                        panic("receive 1");

#endif

                if (so->so_error) {

                        if (m)

                                goto dontblock;

                        error = so->so_error;

                        if ((flags & MSG_PEEK) == 0)

                                so->so_error = 0;

                        goto release;

                }

                if (so->so_state & SS_CANTRCVMORE) {

                        if (m)

                                goto dontblock;

                        else

                                goto release;

                }

                for (; m; m = m->m_next)

                        if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {

                                m = so->so_rcv.sb_mb;