tcp_usrreq.c

嵌入式操作系统ECOS的网络开发包

//==========================================================================
//
//      sys/netinet/tcp_usrreq.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: tcp_usrreq.c,v 1.37 1999/12/08 06:50:20 itojun Exp $	*/
/*	$NetBSD: tcp_usrreq.c,v 1.20 1996/02/13 23:44:16 christos Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1988, 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.
 *
 *	@(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
 */

/*
%%% portions-copyright-nrl-95
Portions of this software are Copyright 1995-1998 by Randall Atkinson,
Ronald Lee, Daniel McDonald, Bao Phan, and Chris Winters. All Rights
Reserved. All rights under this copyright have been assigned to the US
Naval Research Laboratory (NRL). The NRL Copyright Notice and License
Agreement Version 1.1 (January 17, 1995) applies to these portions of the
software.
You should have received a copy of the license with this software. If you
didn't get a copy, you may request one from <[e-mail]>.
*/

#include <sys/param.h>
#ifndef __ECOS
#include <sys/systm.h>
#endif
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#ifndef __ECOS
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/ucred.h>

#include <vm/vm.h>
#include <sys/sysctl.h>
#endif

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

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.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>
#ifndef __ECOS
#include <dev/rndvar.h>
#endif

#ifdef IPSEC
extern int	check_ipsec_policy __P((struct inpcb *, u_int32_t));
#endif

#ifdef INET6
#include <sys/domain.h>
#endif /* INET6 */

/*
 * TCP protocol interface to socket abstraction.
 */
extern	char *tcpstates[];
extern	int tcptv_keep_init;

/* from in_pcb.c */
extern	struct baddynamicports baddynamicports;

int tcp_ident __P((void *, size_t *, void *, size_t));

#if defined(INET6) && !defined(TCP6)
int
tcp6_usrreq(so, req, m, nam, control, p)
	struct socket *so;
	int req;
	struct mbuf *m, *nam, *control;
	struct proc *p;
{
	return tcp_usrreq(so, req, m, nam, control);
}
#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;
{
	struct sockaddr_in *sin;
	register struct inpcb *inp;
	register struct tcpcb *tp = NULL;
	int s;
	int error = 0;
	int ostate;

	if (req == PRU_CONTROL) {
#ifdef INET6
		if (sotopf(so) == PF_INET6)
			return in6_control(so, (u_long)m, (caddr_t)nam,
			    (struct ifnet *)control, 0);
		else
#endif /* INET6 */
			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);
		return (EINVAL);
	}

	s = splsoftnet();
	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);
		/*
		 * The following corrects an mbuf leak under rare
		 * circumstances
		 */
		if (m && (req == PRU_SEND || req == PRU_SENDOOB))
			m_freem(m);
		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;
		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:
#ifdef INET6
		if (inp->inp_flags & INP_IPV6)
			error = in6_pcbbind(inp, nam);
		else
#endif
			error = in_pcbbind(inp, nam);
		if (error)
			break;
#ifdef INET6
		/*
		 * If we bind to an address, set up the tp->pf accordingly!
		 */
		if (inp->inp_flags & INP_IPV6) {
			/* If a PF_INET6 socket... */
			if (inp->inp_flags & INP_IPV6_MAPPED)
				tp->pf = AF_INET;
			else if ((inp->inp_flags & INP_IPV6_UNDEC) == 0)
				tp->pf = AF_INET6;
			/* else tp->pf is still 0. */
		}
		/* else socket is PF_INET, and tp->pf is PF_INET. */
#endif /* INET6 */
		break;

	/*
	 * Prepare to accept connections.
	 */
	case PRU_LISTEN:
		if (inp->inp_lport == 0) {
#ifdef INET6
			if (inp->inp_flags & INP_IPV6)
				error = in6_pcbbind(inp, NULL);
			else
#endif
				error = in_pcbbind(inp, NULL);
		}
		/* If the in_pcbbind() above is called, the tp->pf
		   should still be whatever it was before. */
		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:
		sin = mtod(nam, struct sockaddr_in *);

#ifdef INET6
		if (sin->sin_family == AF_INET6) {
			struct in6_addr *in6_addr = &mtod(nam,
			    struct sockaddr_in6 *)->sin6_addr;

			if (IN6_IS_ADDR_UNSPECIFIED(in6_addr) ||
			    IN6_IS_ADDR_MULTICAST(in6_addr) ||
			    (IN6_IS_ADDR_V4MAPPED(in6_addr) &&
			    ((in6_addr->s6_addr32[3] == INADDR_ANY) ||
			    IN_MULTICAST(in6_addr->s6_addr32[3]) ||
			    in_broadcast(sin->sin_addr, NULL)))) {
				error = EINVAL;
				break;
			}

			if (inp->inp_lport == 0) {
				error = in6_pcbbind(inp, NULL);
				if (error)
					break;
			}
			error = in6_pcbconnect(inp, nam);
		} else if (sin->sin_family == AF_INET)
#endif /* INET6 */
		{
			if ((sin->sin_addr.s_addr == INADDR_ANY) ||
			    IN_MULTICAST(sin->sin_addr.s_addr) ||
			    in_broadcast(sin->sin_addr, NULL)) {
				error = EINVAL;
				break;
			}

			/* Trying to connect to some broadcast address */
			if (in_broadcast(sin->sin_addr, NULL)) {
				error = EINVAL;
				break;
			}

			if (inp->inp_lport == 0) {
				error = in_pcbbind(inp, NULL);
				if (error)
					break;
			}
			error = in_pcbconnect(inp, nam);
		}

		if (error)
			break;

#ifdef INET6
		/*
		 * With a connection, I now know the version of IP
		 * is in use and hence can set tp->pf with authority. 
		 */
		if (inp->inp_flags & INP_IPV6) {
			if (inp->inp_flags & INP_IPV6_MAPPED)
				tp->pf = PF_INET;
			else
				tp->pf = PF_INET6;
		}
		/* else I'm a PF_INET socket, and hence tp->pf is PF_INET. */
#endif /* INET6 */

		tp->t_template = tcp_template(tp);
		if (tp->t_template == 0) {
			in_pcbdisconnect(inp);
			error = ENOBUFS;
			break;
		}

#ifdef INET6
		if ((inp->inp_flags & INP_IPV6) && (tp->pf == PF_INET)) {
			inp->inp_ip.ip_ttl = ip_defttl;
			inp->inp_ip.ip_tos = 0;
		}
#endif /* INET6 */

		so->so_state |= SS_CONNECTOUT;
		/* 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] = tcptv_keep_init;
		tp->iss = tcp_iss;
#ifdef TCP_COMPAT_42
		tcp_iss += TCP_ISSINCR/2;
#else /* TCP_COMPAT_42 */
		tcp_iss += arc4random() % TCP_ISSINCR + 1;
#endif /* !TCP_COMPAT_42 */
		tcp_sendseqinit(tp);
#if defined(TCP_SACK) || defined(TCP_NEWRENO)
		tp->snd_last = tp->snd_una;
#endif
#if defined(TCP_SACK) && defined(TCP_FACK)
		tp->snd_fack = tp->snd_una;
		tp->retran_data = 0;
		tp->snd_awnd = 0;
#endif
		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:
#ifdef INET6
		if (inp->inp_flags & INP_IPV6)
			in6_setpeeraddr(inp, nam);
		else
#endif
			in_setpeeraddr(inp, nam);
		break;

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

	/*
	 * After a receive, possibly send window update to peer.
	 */
	case PRU_RCVD:
		(void) tcp_output(tp);
		break;

	/*
	 * Do a send by putting data in output queue and updating urgent
	 * marker if URG set.  Possibly send more data.
	 */
	case PRU_SEND:
#ifdef IPSEC
		error = check_ipsec_policy(inp, 0);
		if (error)
			break;
#endif
		sbappend(&so->so_snd, m);
		error = tcp_output(tp);
		break;