text: /*
   * Copyright (c) 1982, 1986, 1988, 1990, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * Portions copyright (c) 1999, 2000
   * Intel Corporation.
   * 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, Intel Corporation, and its contributors.
   * 
   * 4. Neither the name of University, Intel Corporation, or their respective
   *    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, INTEL CORPORATION 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,
   * INTEL CORPORATION 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
   *	$Id: uipc_socket.c,v 1.1.1.1 2006/05/30 06:17:21 hhzhou Exp $
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/proc.h>		/* for proc0 declaration */
  #include <sys/fcntl.h>
  #include <sys/malloc.h>
  #include <sys/mbuf.h>
  #include <sys/domain.h>
  #include <sys/kernel.h>
  #include <sys/poll.h>
  #include <sys/protosw.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/resourcevar.h>
  #include <sys/signalvar.h>
  #include <sys/sysctl.h>
  #include <sys/uio.h>
  #include <vm/vm_zone.h>
  
  #include <machine/limits.h>
  
  struct	vm_zone *socket_zone;
  so_gen_t	so_gencnt;	/* generation count for sockets */
  
  MALLOC_DEFINE(M_SONAME, "soname", "socket name");
  MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
  
  static int somaxconn = SOMAXCONN;
  SYSCTL_INT(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLFLAG_RW, &somaxconn,
  	   0, "");
  
  #define funsetown( x )	x = NULL;
  
  /*
   * 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.
   */
  
  /*
   * Get a socket structure from our zone, and initialize it.
   * We don't implement `waitok' yet (see comments in uipc_domain.c).
   * Note that it would probably be better to allocate socket
   * and PCB at the same time, but I'm not convinced that all
   * the protocols can be easily modified to do this.
   */
  struct socket *
  soalloc(waitok)
  	int waitok;
  {
  	struct socket *so;
  
  	so = zalloci(socket_zone);
  	if (so) {
  		/* XXX race condition for reentrant kernel */
  		bzero(so, sizeof *so);
  		so->so_gencnt = ++so_gencnt;
  		so->so_zone = socket_zone;
  	}
  	return so;
  }
  
  int
  socreate(dom, aso, type, proto, p)
  	int dom;
  	struct socket **aso;
  	register int type;
  	int proto;
  	struct proc *p;
  {
  	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_usrreqs->pru_attach == 0)
  		return (EPROTONOSUPPORT);
  	if (prp->pr_type != type)
  		return (EPROTOTYPE);
  	so = soalloc(p != 0);
  	if (so == 0)
  		return (ENOBUFS);
  
  	TAILQ_INIT(&so->so_incomp);
  	TAILQ_INIT(&so->so_comp);
  	so->so_type = type;
  	if (p != 0)
  		so->so_uid = p->p_ucred->cr_uid;
  	so->so_proto = prp;
  	error = (*prp->pr_usrreqs->pru_attach)(so, proto, p);
  	if (error) {
  		so->so_state |= SS_NOFDREF;
  		sofree(so);
  		return (error);
  	}
  	*aso = so;
  	return (0);
  }
  
  int
  sobind(so, nam, p)
  	struct socket *so;
  	struct sockaddr *nam;
  	struct proc *p;
  {
  	int s = splnet();
  	int error;
  
  	error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, p);
  	splx(s);
  	return (error);
  }
  
  void
  sodealloc(so)
  	struct socket *so;
  {
  	so->so_gencnt = ++so_gencnt;
  	zfreei(so->so_zone, so);
  }
  
  int
  solisten(so, backlog, p)
  	register struct socket *so;
  	int backlog;
  	struct proc *p;
  {
  	int s, error;
  
  	s = splnet();
  	error = (*so->so_proto->pr_usrreqs->pru_listen)(so, p);
  	if (error) {
  		splx(s);
  		return (error);
  	}
  	if (so->so_comp.tqh_first == NULL)
  		so->so_options |= SO_ACCEPTCONN;
  	if (backlog < 0 || backlog > somaxconn)
  		backlog = somaxconn;
  	so->so_qlimit = backlog;
  	splx(s);
  	return (0);
  }
  
  void
  sofree(so)
  	register struct socket *so;
  {
  	struct socket *head = so->so_head;
  
  	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
  		return;
  	if (head != NULL) {
  		if (so->so_state & SS_INCOMP) {
  			TAILQ_REMOVE(&head->so_incomp, so, so_list);
  			head->so_incqlen--;
  		} else if (so->so_state & SS_COMP) {
  			TAILQ_REMOVE(&head->so_comp, so, so_list);
  		} else {
  			panic("sofree: not queued");
  		}
  		head->so_qlen--;
  		so->so_state &= ~(SS_INCOMP|SS_COMP);
  		so->so_head = NULL;
  	}
  	sbrelease(&so->so_snd);
  	sorflush(so);
  	sodealloc(so);
  }
  
  /*
   * 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;
  {
  	int s = splnet();		/* conservative */
  	int error = 0;
  
  	funsetown(so->so_sigio);
  	if (so->so_options & SO_ACCEPTCONN) {
  		struct socket *sp, *sonext;
  
  		for (sp = so->so_incomp.tqh_first; sp != NULL; sp = sonext) {
  			sonext = sp->so_list.tqe_next;
  			(void) soabort(sp);
  		}
  		for (sp = so->so_comp.tqh_first; sp != NULL; sp = sonext) {
  			sonext = sp->so_list.tqe_next;
  			(void) soabort(sp);
  		}
  	}
  	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, "soclos", so->so_linger * hz);
  				if (error)
  					break;
  			}
  		}
  	}
  drop:
  	if (so->so_pcb) {
  		int error2 = (*so->so_proto->pr_usrreqs->pru_detach)(so);
  		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 splnet...
   */
  int
  soabort(so)
  	struct socket *so;
  {
  
  	return (*so->so_proto->pr_usrreqs->pru_abort)(so);
  }
  
  int
  soaccept(so, nam)
  	register struct socket *so;
  	struct sockaddr **nam;
  {
  	int s = splnet();
  	int error;
  
  	if ((so->so_state & SS_NOFDREF) == 0)
  		panic("soaccept: !NOFDREF");
  	so->so_state &= ~SS_NOFDREF;
  	error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
  	splx(s);
  	return (error);
  }
  
  int
  soconnect(so, nam, p)
  	register struct socket *so;
  	struct sockaddr *nam;
  	struct proc *p;
  {
  	int s;
  	int error;
  
  	if (so->so_options & SO_ACCEPTCONN)
  		return (EOPNOTSUPP);
  	s = splnet();
  	/*
  	 * 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_usrreqs->pru_connect)(so, nam, p);
  	splx(s);
  	return (error);
  }
  
  int
  soconnect2(so1, so2)
  	register struct socket *so1;
  	struct socket *so2;
  {
  	int s = splnet();
  	int error;
  
  	error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
  	splx(s);
  	return (error);
  }
  
  int
  sodisconnect(so)
  	register struct socket *so;
  {
  	int s = splnet();
  	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_usrreqs->pru_disconnect)(so);
  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, p)
  	register struct socket *so;
  	struct sockaddr *addr;
  	struct uio *uio;
  	struct mbuf *top;
  	struct mbuf *control;
  	int flags;
  	struct proc *p;
  {
  	struct mbuf **mp;
  	register struct mbuf *m;
  	register long space, len, 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.
  	 * 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.
  	 *
  	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
  	 * type sockets since that's an error.
  	 */
  	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);
  	if (p)
  		p->p_stats->p_ru.ru_msgsnd++;
  	if (control)
  		clen = control->m_len;
  #define	snderr(errno)	{ error = errno; splx(s); goto release; }
  
  restart:
  	error = sblock(&so->so_snd, SBLOCKWAIT(flags));
  	if (error)
  		goto out;
  
  	do {
  		s = splnet();
  		if (so->so_state & SS_CANTSENDMORE)
  			snderr(EPIPE);
  		if (so->so_error) {
  			error = so->so_error;
  			so->so_error = 0;
  			splx(s);
  			goto release;
  		}
  		if ((so->so_state & SS_ISCONNECTED) == 0) {
  			/*
  			 * `sendto' and `sendmsg' is allowed on a connection-
  			 * based socket if it supports implied connect.
  			 * Return ENOTCONN if not connected and no address is
  			 * supplied.
  			 */
  			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
  			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
  				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
  				    !(resid == 0 && clen != 0))
  					snderr(ENOTCONN);
  			} else if (addr == 0)
  			    snderr(so->so_proto->pr_flags & PR_CONNREQUIRED ?
  				   ENOTCONN : EDESTADDRREQ);
  		}
  		space = sbspace(&so->so_snd);
  		if (flags & MSG_OOB)
  			space += 1024;
  		if ((atomic && resid > (long)so->so_snd.sb_hiwat) ||
  		    clen > (int)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 = &top;
  		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) {
  				MCLGET(m, M_WAIT);
  				if ((m->m_flags & M_EXT) == 0)
  					goto nopages;
  				mlen = MCLBYTES;
  				len = min(min(mlen, resid), space);
  			} else {
  nopages:
  				len = min(min(mlen, resid), space);
  				/*
  				 * For datagram protocols, leave room
  				 * for protocol headers in first mbuf.
  				 */
  				if (atomic && top == 0 && len < mlen)
  					MH_ALIGN(m, len);
  			}
  			space -= 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 = splnet();				/* XXX */
  		    error = (*so->so_proto->pr_usrreqs->pru_send)(so,
  			(flags & MSG_OOB) ? PRUS_OOB :
  			/*
  			 * If the user set MSG_EOF, the protocol
  			 * understands this flag and nothing left to
  			 * send then use PRU_SEND_EOF instead of PRU_SEND.
  			 */
  			((flags & MSG_EOF) &&
  			 (so->so_proto->pr_flags & PR_IMPLOPCL) &&
  			 (resid <= 0)) ?
  				PRUS_EOF :
  			/* If there is more to send set PRUS_MORETOCOME */
  			(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
  			top, addr, control, p);
  		    splx(s);
  		    if (dontroute)
  			    so->so_options &= ~SO_DONTROUTE;
  		    clen = 0;
  		    control = 0;
  		    top = 0;
  		    mp = &top;
  		    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, psa, uio, mp0, controlp, flagsp)
  	register struct socket *so;
  	struct sockaddr **psa;
  	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;
  	int orig_resid = uio->uio_resid;
  
  	mp = mp0;
  	if (psa)
  		*psa = 0;
  	if (controlp)
  		*controlp = 0;
  	if (flagsp)
  		flags = *flagsp &~ MSG_EOR;
  	else
  		flags = 0;
  	if (flags & MSG_OOB) {
  		m = m_get(M_WAIT, MT_DATA);
  		error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
  		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_usrreqs->pru_rcvd)(so, 0);
  
  restart:
  	error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
  	if (error)
  		return (error);
  
  	s = splnet();
  
  	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, or
  	 *   2. MSG_WAITALL is set, and it is possible to do the entire
  	 *	receive operation at once if we block (resid <= hiwat).
  	 *   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 < (u_long)uio->uio_resid) &&
  	    (so->so_rcv.sb_cc < (u_long)so->so_rcv.sb_lowat ||
  	    ((flags & MSG_WAITALL) && uio->uio_resid <= (int)so->so_rcv.sb_hiwat)) &&
  	    m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {
  		KASSERT(m != 0 || !so->so_rcv.sb_cc, ("receive 1"));
  		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;
  				goto dontblock;
  			}
  		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
  		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
  			error = ENOTCONN;
  			goto release;
  		}
  		if (uio->uio_resid == 0)
  			goto release;
  		if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT)) {
  			error = EWOULDBLOCK;
  			goto release;
  		}
  		
  		if ( so->so_proto->pr_domain->dom_family  == PF_ROUTE )
  			goto release;
  			
  		sbunlock(&so->so_rcv);	
  		error = sbwait(&so->so_rcv);
  		splx(s);
  		if (error)
  			return (error);
  		goto restart;
  	}
  dontblock:
  	if (uio->uio_procp)
  		uio->uio_procp->p_stats->p_ru.ru_msgrcv++;
  	nextrecord = m->m_nextpkt;
  	if (pr->pr_flags & PR_ADDR) {
  		KASSERT(m->m_type == MT_SONAME, ("receive 1a"));
  		orig_resid = 0;
  		if (psa)
  			*psa = dup_sockaddr(mtod(m, struct sockaddr *),
  					    mp0 == 0);
  		if (flags & MSG_PEEK) {
  			m = m->m_next;
  		} else {
  			sbfree(&so->so_rcv, m);
  			MFREE(m, so->so_rcv.sb_mb);
  			m = so->so_rcv.sb_mb;
  		}
  	}
  	while (m && m->m_type == MT_CONTROL && error == 0) {
  		if (flags & MSG_PEEK) {
  			if (controlp)
  				*controlp = m_copy(m, 0, m->m_len);
  			m = m->m_next;
  		} else {
  			sbfree(&so->so_rcv, m);
  			if (controlp) {
  				if (pr->pr_domain->dom_externalize &&
  				    mtod(m, struct cmsghdr *)->cmsg_type ==
  				    SCM_RIGHTS)
  				   error = (*pr->pr_domain->dom_externalize)(m);
  				*controlp = m;
  				so->so_rcv.sb_mb = m->m_next;
  				m->m_next = 0;
  				m = so->so_rcv.sb_mb;
  			} else {
  				MFREE(m, so->so_rcv.sb_mb);
  				m = so->so_rcv.sb_mb;
  			}
  		}
  		if (controlp) {
  			orig_resid = 0;
  			controlp = &(*controlp)->m_next;
  		}
  	}
  	if (m) {
  		if ((flags & MSG_PEEK) == 0)
  			m->m_nextpkt = nextrecord;
  		type = m->m_type;
  		if (type == MT_OOBDATA)
  			flags |= MSG_OOB;
  	}
  	moff = 0;
  	offset = 0;
  	while (m && uio->uio_resid > 0 && error == 0) {
  		if (m->m_type == MT_OOBDATA) {
  			if (type != MT_OOBDATA)
  				break;
  		} else if (type == MT_OOBDATA)
  			break;
  		else
  		    KASSERT(m->m_type == MT_DATA || m->m_type == MT_HEADER,
  			("receive 3"));
  		so->so_state &= ~SS_RCVATMARK;
  		len = uio->uio_resid;
  		if (so->so_oobmark && len > (int)(so->so_oobmark - offset))
  			len = so->so_oobmark - offset;
  		if (len > m->m_len - moff)
  			len = m->m_len - moff;
  		/*
  		 * If mp is set, just pass back the mbufs.
  		 * Otherwise copy them out via the uio, then free.
  		 * Sockbuf must be consistent here (points to current mbuf,
  		 * it points to next record) when we drop priority;
  		 * we must note any additions to the sockbuf when we
  		 * block interrupts again.
  		 */
  		if (mp == 0) {
  			splx(s);
  			error = uiomove(mtod(m, caddr_t) + moff, (int)len, uio);
  			s = splnet();
  			if (error)
  				goto release;
  		} else
  			uio->uio_resid -= len;
  		if (len == m->m_len - moff) {
  			if (m->m_flags & M_EOR)
  				flags |= MSG_EOR;
  			if (flags & MSG_PEEK) {
  				m = m->m_next;
  				moff = 0;
  			} else {
  				nextrecord = m->m_nextpkt;
  				sbfree(&so->so_rcv, m);
  				if (mp) {
  					*mp = m;
  					mp = &m->m_next;
  					so->so_rcv.sb_mb = m = m->m_next;
  					*mp = (struct mbuf *)0;
  				} else {
  					MFREE(m, so->so_rcv.sb_mb);
  					m = so->so_rcv.sb_mb;
  				}
  				if (m)
  					m->m_nextpkt = nextrecord;
  			}
  		} else {
  			if (flags & MSG_PEEK)
  				moff += len;
  			else {
  				if (mp)
  					*mp = m_copym(m, 0, len, M_WAIT);
  				m->m_data += len;
  				m->m_len -= len;
  				so->so_rcv.sb_cc -= len;
  			}
  		}
  		if (so->so_oobmark) {
  			if ((flags & MSG_PEEK) == 0) {
  				so->so_oobmark -= len;
  				if (so->so_oobmark == 0) {
  					so->so_state |= SS_RCVATMARK;
  					break;
  				}
  			} else {
  				offset += len;
  				if (offset == (int)so->so_oobmark)
  					break;
  			}
  		}
  		if (flags & MSG_EOR)
  			break;
  		/*
  		 * If the MSG_WAITALL flag is set (for non-atomic socket),
  		 * we must not quit until "uio->uio_resid == 0" or an error
  		 * termination.  If a signal/timeout occurs, return
  		 * with a short count but without error.
  		 * Keep sockbuf locked against other readers.
  		 */
  		while (flags & MSG_WAITALL && m == 0 && uio->uio_resid > 0 &&
  		    !sosendallatonce(so) && !nextrecord) {
  			if (so->so_error || so->so_state & SS_CANTRCVMORE)
  				break;
  			error = sbwait(&so->so_rcv);
  			if (error) {
  				sbunlock(&so->so_rcv);
  				splx(s);
  				return (0);
  			}
  			m = so->so_rcv.sb_mb;
  			if (m)
  				nextrecord = m->m_nextpkt;
  		}
  	}
  
  	if (m && pr->pr_flags & PR_ATOMIC) {
  		flags |= MSG_TRUNC;
  		if ((flags & MSG_PEEK) == 0)
  			(void) sbdroprecord(&so->so_rcv);
  	}
  	if ((flags & MSG_PEEK) == 0) {
  		if (m == 0)
  			so->so_rcv.sb_mb = nextrecord;
  		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
  			(*pr->pr_usrreqs->pru_rcvd)(so, flags);
  	}
  	if (orig_resid == uio->uio_resid && orig_resid &&
  	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
  		sbunlock(&so->so_rcv);
  		splx(s);
  		goto restart;
  	}
  
  	if (flagsp)
  		*flagsp |= flags;
  release:
  	sbunlock(&so->so_rcv);
  	splx(s);
  	return (error);
  }
  
  int
  soshutdown(so, how)
  	register struct socket *so;
  	register int how;
  {
  	register struct protosw *pr = so->so_proto;
  
  	how++;
  	if (how & FREAD)
  		sorflush(so);
  	if (how & FWRITE)
  		return ((*pr->pr_usrreqs->pru_shutdown)(so));
  	return (0);
  }
  
  void
  sorflush(so)
  	register struct socket *so;
  {
  	register struct sockbuf *sb = &so->so_rcv;
  	register struct protosw *pr = so->so_proto;
  	register int s;
  	struct sockbuf asb;
  
  	sb->sb_flags |= SB_NOINTR;
  	(void) sblock(sb, M_WAITOK);
  	s = splimp();
  	socantrcvmore(so);
  	sbunlock(sb);
  	asb = *sb;
  	bzero((caddr_t)sb, sizeof (*sb));
  	splx(s);
  	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
  		(*pr->pr_domain->dom_dispose)(asb.sb_mb);
  	sbrelease(&asb);
  }
  
  /*
   * Perhaps this routine, and sooptcopyout(), below, ought to come in
   * an additional variant to handle the case where the option value needs
   * to be some kind of integer, but not a specific size.
   * In addition to their use here, these functions are also called by the
   * protocol-level pr_ctloutput() routines.
   */
  int
  sooptcopyin(sopt, buf, len, minlen)
  	struct	sockopt *sopt;
  	void	*buf;
  	size_t	len;
  	size_t	minlen;
  {
  	size_t	valsize;
  
  	/*
  	 * If the user gives us more than we wanted, we ignore it,
  	 * but if we don't get the minimum length the caller
  	 * wants, we return EINVAL.  On success, sopt->sopt_valsize
  	 * is set to however much we actually retrieved.
  	 */
  	if ((valsize = sopt->sopt_valsize) < minlen)
  		return EINVAL;
  	if (valsize > len)
  		sopt->sopt_valsize = valsize = len;
  
  	if (sopt->sopt_p != 0)
  		return (copyin(sopt->sopt_val, buf, valsize));
  
  	bcopy(sopt->sopt_val, buf, valsize);
  	return 0;
  }
  
  int
  sosetopt(so, sopt)
  	struct socket *so;
  	struct sockopt *sopt;
  {
  	int	error, optval;
  	struct	linger l;
  	struct	timeval tv;
  	short	val;
  
  	error = 0;
  	if (sopt->sopt_level != SOL_SOCKET) {
  		if (so->so_proto && so->so_proto->pr_ctloutput)
  			return ((*so->so_proto->pr_ctloutput)
  				  (so, sopt));
  		error = ENOPROTOOPT;
  	} else {
  		switch (sopt->sopt_name) {
  		case SO_LINGER:
  			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
  			if (error)
  				goto bad;
  
  			so->so_linger = l.l_linger;
  			if (l.l_onoff)
  				so->so_options |= SO_LINGER;
  			else
  				so->so_options &= ~SO_LINGER;
  			break;
  
  		case SO_DEBUG:
  		case SO_KEEPALIVE:
  		case SO_DONTROUTE:
  		case SO_USELOOPBACK:
  		case SO_BROADCAST:
  		case SO_REUSEADDR:
  		case SO_REUSEPORT:
  		case SO_OOBINLINE:
  		case SO_TIMESTAMP:
  			error = sooptcopyin(sopt, &optval, sizeof optval,
  					    sizeof optval);
  			if (error)
  				goto bad;
  			if (optval)
  				so->so_options |= sopt->sopt_name;
  			else
  				so->so_options &= ~sopt->sopt_name;
  			break;
  
  		case SO_SNDBUF:
  		case SO_RCVBUF:
  		case SO_SNDLOWAT:
  		case SO_RCVLOWAT:
  			error = sooptcopyin(sopt, &optval, sizeof optval,
  					    sizeof optval);
  			if (error)
  				goto bad;
  
  			/*
  			 * Values < 1 make no sense for any of these
  			 * options, so disallow them.
  			 */
  			if (optval < 1) {
  				error = EINVAL;
  				goto bad;
  			}
  
  			switch (sopt->sopt_name) {
  			case SO_SNDBUF:
  			case SO_RCVBUF:
  				if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
  					      &so->so_snd : &so->so_rcv,
  					      (u_long) optval) == 0) {
  					error = ENOBUFS;
  					goto bad;
  				}
  				break;
  
  			/*
  			 * Make sure the low-water is never greater than
  			 * the high-water.
  			 */
  			case SO_SNDLOWAT:
  				so->so_snd.sb_lowat =
  				    (optval > (int)so->so_snd.sb_hiwat) ?
  				    so->so_snd.sb_hiwat : optval;
  				break;
  			case SO_RCVLOWAT:
  				so->so_rcv.sb_lowat =
  				    (optval > (int)so->so_rcv.sb_hiwat) ?
  				    so->so_rcv.sb_hiwat : optval;
  				break;
  			}
  			break;
  
  		case SO_SNDTIMEO:
  		case SO_RCVTIMEO:
  			error = sooptcopyin(sopt, &tv, sizeof tv,
  					    sizeof tv);
  			if (error)
  				goto bad;
  
  			if (tv.tv_sec > SHRT_MAX / hz - 1) {
  				error = EDOM;
  				goto bad;
  			}
  			val = (short)(tv.tv_sec * hz + tv.tv_usec / tick);
  
  			switch (sopt->sopt_name) {
  			case SO_SNDTIMEO:
  				so->so_snd.sb_timeo = val;
  				break;
  			case SO_RCVTIMEO:
  				so->so_rcv.sb_timeo = val;
  				break;
  			}
  			break;
  
  		default:
  			error = ENOPROTOOPT;
  			break;
  		}
  		if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput) {
  			(void) ((*so->so_proto->pr_ctloutput)
  				  (so, sopt));
  		}
  	}
  bad:
  	return (error);
  }
  
  /* Helper routine for getsockopt */
  int
  sooptcopyout(sopt, buf, len)
  	struct	sockopt *sopt;
  	void	*buf;
  	size_t	len;
  {
  	int	error;
  	size_t	valsize;
  
  	error = 0;
  
  	/*
  	 * Documented get behavior is that we always return a value,
  	 * possibly truncated to fit in the user's buffer.
  	 * Traditional behavior is that we always tell the user
  	 * precisely how much we copied, rather than something useful
  	 * like the total amount we had available for her.
  	 * Note that this interface is not idempotent; the entire answer must
  	 * generated ahead of time.
  	 */
  	valsize = min((int)len, (int)sopt->sopt_valsize);
  	sopt->sopt_valsize = valsize;
  	if (sopt->sopt_val != 0) {
  		if (sopt->sopt_p != 0)
  			error = copyout(buf, sopt->sopt_val, valsize);
  		else
  			bcopy(buf, sopt->sopt_val, valsize);
  	}
  	return error;
  }
  
  int
  sogetopt(so, sopt)
  	struct socket *so;
  	struct sockopt *sopt;
  {
  	int	error, optval;
  	struct	linger l;
  	struct	timeval tv;
  
  	error = 0;
  	if (sopt->sopt_level != SOL_SOCKET) {
  		if (so->so_proto && so->so_proto->pr_ctloutput) {
  			return ((*so->so_proto->pr_ctloutput)
  				  (so, sopt));
  		} else
  			return (ENOPROTOOPT);
  	} else {
  		switch (sopt->sopt_name) {
  		case SO_LINGER:
  			l.l_onoff = so->so_options & SO_LINGER;
  			l.l_linger = so->so_linger;
  			error = sooptcopyout(sopt, &l, sizeof l);
  			break;
  
  		case SO_USELOOPBACK:
  		case SO_DONTROUTE:
  		case SO_DEBUG:
  		case SO_KEEPALIVE:
  		case SO_REUSEADDR:
  		case SO_REUSEPORT:
  		case SO_BROADCAST:
  		case SO_OOBINLINE:
  		case SO_TIMESTAMP:
  			optval = so->so_options & sopt->sopt_name;
  integer:
  			error = sooptcopyout(sopt, &optval, sizeof optval);
  			break;
  
  		case SO_TYPE:
  			optval = so->so_type;
  			goto integer;
  
  		case SO_ERROR:
  			optval = so->so_error;
  			so->so_error = 0;
  			goto integer;
  
  		case SO_SNDBUF:
  			optval = so->so_snd.sb_hiwat;
  			goto integer;
  
  		case SO_RCVBUF:
  			optval = so->so_rcv.sb_hiwat;
  			goto integer;
  
  		case SO_SNDLOWAT:
  			optval = so->so_snd.sb_lowat;
  			goto integer;
  
  		case SO_RCVLOWAT:
  			optval = so->so_rcv.sb_lowat;
  			goto integer;
  
  		case SO_SNDTIMEO:
  		case SO_RCVTIMEO:
  			optval = (sopt->sopt_name == SO_SNDTIMEO ?
  				  so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
  
  			tv.tv_sec = optval / hz;
  			tv.tv_usec = (optval % hz) * tick;
  			error = sooptcopyout(sopt, &tv, sizeof tv);
  			break;			
  
  		default:
  			error = ENOPROTOOPT;
  			break;
  		}
  		return (error);
  	}
  }
  
  void
  sohasoutofband(so)
  	register struct socket *so;
  {
  	if (so->so_sigio != NULL)
  		pgsigio(so->so_sigio, SIGURG, 0);
  #ifdef _ORG_FREEBSD_
  	selwakeup(&so->so_rcv.sb_sel);
  #endif
  }
  
  int
  sopoll(struct socket *so, int events, struct ucred *cred, struct proc *p)
  {
  	int revents = 0;
  	int s = splnet();
  
  	if (events & (POLLIN | POLLRDNORM))
  		if (soreadable(so))
  			revents |= events & (POLLIN | POLLRDNORM);
  
  	if (events & (POLLOUT | POLLWRNORM))
  		if (sowriteable(so))
  			revents |= events & (POLLOUT | POLLWRNORM);
  
  	if (events & (POLLPRI | POLLRDBAND))
  		if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
  			revents |= events & (POLLPRI | POLLRDBAND);
  
  	if (revents == 0) {
  		if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
  #ifdef _ORG_FREEBSD_
  			selrecord(p, &so->so_rcv.sb_sel);
  #endif
  			so->so_rcv.sb_flags |= SB_SEL;
  		}
  
  		if (events & (POLLOUT | POLLWRNORM)) {
  #ifdef _ORG_FREEBSD_
  			selrecord(p, &so->so_snd.sb_sel);
  #endif
  			so->so_snd.sb_flags |= SB_SEL;
  		}
  	}
  
  	splx(s);
  	return (revents);
  }
  