tcp_usrreq.c

VXWORKS源代码

/* tcp_usrreq.c - TCP interface routines */

/* Copyright 1984 - 2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
 * Copyright (c) 1982, 1986, 1988, 1993, 1995
 *	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.
 *
 *	@(#)tcp_usrreq.c	8.5 (Berkeley) 6/21/95
 */

/*
modification history
--------------------
03i,05jun02,vvv  fixed Nagle for large writes (SPR #72213)
03h,21mar02,wap  avoid making local port of TCP connection the same as
                 the foreign port (SPR #73104)
03g,12oct01,rae  merge from truestack ver 03j, base 03e
03f,14nov00,ham  remoeved tcpstates declaration(SPR 62272).
03e,26aug98,n_s  added return val check for mBufClGet in tcp_ctloutput. 
                 spr #22238.
03d,07jul97,vin  in tcp_usrreq case PRU_DETACH simplified.
03c,08mar97,vin  added changes to accomodate changes in pcb structure for
		 hash look ups.
03b,22nov96,vin  modified for cluster support, replace m_get(..) with 
		 mBufClGet(..).
03a,03mar96,vin  created from BSD4.4 stuff,integrated with 02o of tcp_usrreq.c.
*/

/*
DESCRIPTION
*/

#include "vxWorks.h"
#include "net/mbuf.h"
#include "sys/socket.h"
#include "net/socketvar.h"
#include "net/protosw.h"
#include "errno.h"
#include "sys/stat.h"

#include "net/if.h"
#include "net/route.h"

#include "netinet/in.h"
#include "netinet/in_pcb.h"
#include "netinet/in_systm.h"
#include "netinet/in_var.h"
#include "netinet/ip.h"
#include "netinet/ip_var.h"
#include "netinet/tcp.h"
#include "netinet/tcp_fsm.h"
#include "netinet/tcp_seq.h"
#include "netinet/tcp_timer.h"
#include "netinet/tcp_var.h"
#include "netinet/tcpip.h"
#include "netinet/tcp_debug.h"
#include "net/systm.h"

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET
#include "wvNetLib.h"
#endif
#endif

#ifdef VIRTUAL_STACK
#include "netinet/vsLib.h"
#else
IMPORT int tcp_keepinit;
#endif /* VIRTUAL_STACK */
IMPORT unsigned long (*pTcpRandHook)(void);

LOCAL void	tcpTraceStub ();
LOCAL void	tcpReportStub ();
VOIDFUNCPTR	tcpTraceRtn = tcpTraceStub;		/* exported */
VOIDFUNCPTR	tcpReportRtn = tcpReportStub;		/* exported */

/*
 * TCP protocol interface to socket abstraction.
 */

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET
    /* Set common fields of event identifiers for this module. */

LOCAL UCHAR wvNetModuleId = WV_NET_TCPREQ_MODULE; /* Value for tcp_usrreq.c */
LOCAL UCHAR wvNetLocalFilter = WV_NET_NONE;     /* Available event filter */

LOCAL ULONG wvNetEventId;       /* Event identifier: see wvNetLib.h */
#endif    /* INCLUDE_WVNET */
#endif

/*
 * Process a TCP user request for TCP tb.  If this is a send request
 * then m is the mbuf chain of send data.  If this is a timer expiration
 * (called from the software clock routine), then timertype tells which timer.
 */

/*ARGSUSED*/
int
tcp_usrreq(so, req, m, nam, control)
	struct socket *so;
	int req;
	struct mbuf *m, *nam, *control;
{
	register struct inpcb *inp;
	register struct tcpcb *tp = NULL;
	int s;
	int error = 0;
	int ostate;

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET    /* WV_NET_INFO event */
    WV_NET_MARKER_2 (NET_AUX_EVENT, WV_NET_INFO, 47, 8,
                     WV_NETEVENT_TCPREQ_START, so->so_fd, req)
#endif  /* INCLUDE_WVNET */
#endif

	if (req == PRU_CONTROL)
		return (in_control(so, (u_long)m, (caddr_t)nam,
			(struct ifnet *)control));
	if (control && control->m_len) {
		m_freem(control);
		if (m)
			m_freem(m);
#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET    /* WV_NET_ERROR event */
        WV_NET_MARKER_2 (NET_AUX_EVENT, WV_NET_ERROR, 38, 4,
                         WV_NETEVENT_TCPREQ_BADMEM, so->so_fd, req)
#endif  /* INCLUDE_WVNET */
#endif

		return (EINVAL);
	}

	s = splnet();
	inp = sotoinpcb(so);
	/*
	 * When a TCP is attached to a socket, then there will be
	 * a (struct inpcb) pointed at by the socket, and this
	 * structure will point at a subsidary (struct tcpcb).
	 */
	if (inp == 0 && req != PRU_ATTACH) {
		splx(s);
#if 0
		/*
		 * The following corrects an mbuf leak under rare
		 * circumstances, but has not been fully tested.
		 */
		if (m && req != PRU_SENSE)
			m_freem(m);
#else
		/* safer version of fix for mbuf leak */
		if (m && (req == PRU_SEND || req == PRU_SENDOOB))
			m_freem(m);
#endif

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET    /* WV_NET_ERROR event */
        WV_NET_MARKER_2 (NET_AUX_EVENT, WV_NET_ERROR, 39, 5,
                         WV_NETEVENT_TCPREQ_NOPCB, so->so_fd, req)
#endif  /* INCLUDE_WVNET */
#endif

		return (EINVAL);		/* XXX */
	}
	if (inp) {
		tp = intotcpcb(inp);
		/* WHAT IF TP IS 0? */
#ifdef KPROF
		tcp_acounts[tp->t_state][req]++;
#endif
		ostate = tp->t_state;
	} else
		ostate = 0;
	switch (req) {

	/*
	 * TCP attaches to socket via PRU_ATTACH, reserving space,
	 * and an internet control block.
	 */
	case PRU_ATTACH:
		if (inp) {
			error = EISCONN;
			break;
		}
		error = tcp_attach(so);
		if (error)
			break;

                /* TCP sockets use path MTU discovery by default. */

                so->so_options |= SO_USEPATHMTU;

		if ((so->so_options & SO_LINGER) && so->so_linger == 0)
			so->so_linger = TCP_LINGERTIME;
		tp = sototcpcb(so);
		break;

	/*
	 * PRU_DETACH detaches the TCP protocol from the socket.
	 * If the protocol state is non-embryonic, then can't
	 * do this directly: have to initiate a PRU_DISCONNECT,
	 * which may finish later; embryonic TCB's can just
	 * be discarded here.
	 */
	case PRU_DETACH:
            tp = tcp_disconnect(tp);
            break;

	/*
	 * Give the socket an address.
	 */
	case PRU_BIND:
		error = in_pcbbind(inp, nam);
		if (error)
			break;
		break;

	/*
	 * Prepare to accept connections.
	 */
	case PRU_LISTEN:
		if (inp->inp_lport == 0)
			error = in_pcbbind(inp, (struct mbuf *)0);
		if (error == 0)
			tp->t_state = TCPS_LISTEN;
		break;

	/*
	 * Initiate connection to peer.
	 * Create a template for use in transmissions on this connection.
	 * Enter SYN_SENT state, and mark socket as connecting.
	 * Start keep-alive timer, and seed output sequence space.
	 * Send initial segment on connection.
	 */
	case PRU_CONNECT:
		if (inp->inp_lport == 0) {
			error = in_pcbbind(inp, (struct mbuf *)0);
			if (error)
				break;

			/*
			 * Avoid case where ephemeral port for local
			 * side of connection is the same as destination
			 * port for foreign side.
			 */

			if (inp->inp_lport ==
			    (mtod (nam, struct sockaddr_in *))->sin_port)
			    {
				inp->inp_lport = 0;
				error = in_pcbbind (inp, (struct mbuf *)0);
				if (error)
					break;
			    }
		}

		error = in_pcbconnect(inp, nam);
		if (error)
			break;
		tp->t_template = tcp_template(tp);
		if (tp->t_template == 0) {
			in_pcbdisconnect(inp);
			error = ENOBUFS;
			break;
		}
		/* Compute window scaling to request.  */
		while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
		    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
			tp->request_r_scale++;
		soisconnecting(so);
		tcpstat.tcps_connattempt++;
		tp->t_state = TCPS_SYN_SENT;
               	tp->t_timer[TCPT_KEEP] = tcp_keepinit;
     		tp->iss = tcp_iss;
		tcp_iss += TCP_ISSINCR/4 + ((0x0000ffff) & (pTcpRandHook() >> 16));
		tcp_sendseqinit(tp);
		error = tcp_output(tp);
		break;

	/*
	 * Create a TCP connection between two sockets.
	 */
	case PRU_CONNECT2:
		error = EOPNOTSUPP;
		break;

	/*
	 * Initiate disconnect from peer.
	 * If connection never passed embryonic stage, just drop;
	 * else if don't need to let data drain, then can just drop anyways,
	 * else have to begin TCP shutdown process: mark socket disconnecting,
	 * drain unread data, state switch to reflect user close, and
	 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
	 * when peer sends FIN and acks ours.
	 *
	 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
	 */
	case PRU_DISCONNECT:
		tp = tcp_disconnect(tp);
		break;

	/*
	 * Accept a connection.  Essentially all the work is
	 * done at higher levels; just return the address
	 * of the peer, storing through addr.
	 */
	case PRU_ACCEPT:
		in_setpeeraddr(inp, nam);
		break;

	/*
	 * Mark the connection as being incapable of further output.
	 */
	case PRU_SHUTDOWN:
		socantsendmore(so);
		tp = tcp_usrclosed(tp);
		if (tp)
			error = tcp_output(tp);
		break;

	/*