in_pcb.c

eCos操作系统源码

//==========================================================================
//
//      src/sys/netinet/in_pcb.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####
//==========================================================================

/*
 * Copyright (c) 1982, 1986, 1991, 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.
 *
 *	@(#)in_pcb.c	8.4 (Berkeley) 5/24/95
 * $FreeBSD: src/sys/netinet/in_pcb.c,v 1.59.2.17 2001/08/13 16:26:17 ume Exp $
 */

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

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

#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif /* INET6 */

#ifdef IPSEC
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#endif /* IPSEC */

struct	in_addr zeroin_addr;

/*
 * These configure the range of local port addresses assigned to
 * "unspecified" outgoing connections/packets/whatever.
 */
int	ipport_lowfirstauto  = IPPORT_RESERVED - 1;	/* 1023 */
int	ipport_lowlastauto = IPPORT_RESERVEDSTART;	/* 600 */
int	ipport_firstauto = IPPORT_RESERVED;		/* 1024 */
int	ipport_lastauto  = IPPORT_USERRESERVED;		/* 5000 */
int	ipport_hifirstauto = IPPORT_HIFIRSTAUTO;	/* 49152 */
int	ipport_hilastauto  = IPPORT_HILASTAUTO;		/* 65535 */

#define RANGECHK(var, min, max) \
	if ((var) < (min)) { (var) = (min); } \
	else if ((var) > (max)) { (var) = (max); }

#ifdef CYGPKG_NET_FREEBSD_SYSCTL
static int
sysctl_net_ipport_check(SYSCTL_HANDLER_ARGS)
{
	int error = sysctl_handle_int(oidp,
		oidp->oid_arg1, oidp->oid_arg2, req);
	if (!error) {
		RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
		RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
		RANGECHK(ipport_firstauto, IPPORT_RESERVED, USHRT_MAX);
		RANGECHK(ipport_lastauto, IPPORT_RESERVED, USHRT_MAX);
		RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, USHRT_MAX);
		RANGECHK(ipport_hilastauto, IPPORT_RESERVED, USHRT_MAX);
	}
	return error;
}
#endif
#undef RANGECHK

SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0, "IP Ports");

SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast, CTLTYPE_INT|CTLFLAG_RW,
	   &ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");

/*
 * in_pcb.c: manage the Protocol Control Blocks.
 *
 * NOTE: It is assumed that most of these functions will be called at
 * splnet(). XXX - There are, unfortunately, a few exceptions to this
 * rule that should be fixed.
 */

/*
 * Allocate a PCB and associate it with the socket.
 */
int
in_pcballoc(so, pcbinfo, p)
	struct socket *so;
	struct inpcbinfo *pcbinfo;
	struct proc *p;
{
	register struct inpcb *inp;
#ifdef IPSEC
	int error;
#endif

	inp = zalloci(pcbinfo->ipi_zone);
	if (inp == NULL)
		return (ENOBUFS);
	bzero((caddr_t)inp, sizeof(*inp));
	inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
	inp->inp_pcbinfo = pcbinfo;
	inp->inp_socket = so;
#ifdef IPSEC
	error = ipsec_init_policy(so, &inp->inp_sp);
	if (error != 0) {
		zfreei(pcbinfo->ipi_zone, inp);
		return error;
	}
#endif /*IPSEC*/
#if defined(INET6)
	if (INP_SOCKAF(so) == AF_INET6 && !ip6_mapped_addr_on)
		inp->inp_flags |= IN6P_IPV6_V6ONLY;
#endif
	LIST_INSERT_HEAD(pcbinfo->listhead, inp, inp_list);
	pcbinfo->ipi_count++;
	so->so_pcb = (caddr_t)inp;
#ifdef INET6
	if (ip6_auto_flowlabel)
		inp->inp_flags |= IN6P_AUTOFLOWLABEL;
#endif
	return (0);
}

int
in_pcbbind(inp, nam, p)
	register struct inpcb *inp;
	struct sockaddr *nam;
	struct proc *p;
{
	register struct socket *so = inp->inp_socket;
	unsigned short *lastport;
	struct sockaddr_in *sin;
	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
	u_short lport = 0;
	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);

	if (TAILQ_EMPTY(&in_ifaddrhead)) /* XXX broken! */
		return (EADDRNOTAVAIL);
	if (inp->inp_lport || inp->inp_laddr.s_addr != INADDR_ANY)
		return (EINVAL);
	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
		wild = 1;
	if (nam) {
		sin = (struct sockaddr_in *)nam;
        // HACK
        if (nam->sa_len == 0) nam->sa_len = sizeof(*sin);
        // HACK
		if (nam->sa_len != sizeof (*sin))
			return (EINVAL);
#ifdef notdef
		/*
		 * We should check the family, but old programs
		 * incorrectly fail to initialize it.
		 */
		if (sin->sin_family != AF_INET)
			return (EAFNOSUPPORT);
#endif
		lport = sin->sin_port;
		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
			/*
			 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
			 * allow complete duplication of binding if
			 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
			 * and a multicast address is bound on both
			 * new and duplicated sockets.
			 */
			if (so->so_options & SO_REUSEADDR)
				reuseport = SO_REUSEADDR|SO_REUSEPORT;
		} else if (sin->sin_addr.s_addr != INADDR_ANY) {
			sin->sin_port = 0;		/* yech... */
			if (ifa_ifwithaddr((struct sockaddr *)sin) == 0)
				return (EADDRNOTAVAIL);
		}
		if (lport) {
			struct inpcb *t;

			/* GROSS */
			t = in_pcblookup_local(pcbinfo, sin->sin_addr, lport, wild);
			if (t &&
			    (reuseport & t->inp_socket->so_options) == 0) {
#if defined(INET6)
				if (ntohl(sin->sin_addr.s_addr) !=
				    INADDR_ANY ||
				    ntohl(t->inp_laddr.s_addr) !=
				    INADDR_ANY ||
				    INP_SOCKAF(so) ==
				    INP_SOCKAF(t->inp_socket))
#endif /* defined(INET6) */
				return (EADDRINUSE);
			}
		}
		inp->inp_laddr = sin->sin_addr;
	}
	if (lport == 0) {
		u_short first, last;
		int count;

		inp->inp_flags |= INP_ANONPORT;

		if (inp->inp_flags & INP_HIGHPORT) {
			first = ipport_hifirstauto;	/* sysctl */
			last  = ipport_hilastauto;
			lastport = &pcbinfo->lasthi;
		} else if (inp->inp_flags & INP_LOWPORT) {
			first = ipport_lowfirstauto;	/* 1023 */
			last  = ipport_lowlastauto;	/* 600 */
			lastport = &pcbinfo->lastlow;
		} else {
			first = ipport_firstauto;	/* sysctl */
			last  = ipport_lastauto;
			lastport = &pcbinfo->lastport;
		}
		/*
		 * Simple check to ensure all ports are not used up causing
		 * a deadlock here.
		 *
		 * We split the two cases (up and down) so that the direction
		 * is not being tested on each round of the loop.
		 */
		if (first > last) {
			/*
			 * counting down
			 */
			count = first - last;

			do {
				if (count-- < 0) {	/* completely used? */
					inp->inp_laddr.s_addr = INADDR_ANY;
					return (EADDRNOTAVAIL);
				}
				--*lastport;
				if (*lastport > first || *lastport < last)
					*lastport = first;
				lport = htons(*lastport);
			} while (in_pcblookup_local(pcbinfo,
				 inp->inp_laddr, lport, wild));
		} else {
			/*
			 * counting up
			 */
			count = last - first;

			do {
				if (count-- < 0) {	/* completely used? */
					inp->inp_laddr.s_addr = INADDR_ANY;
					return (EADDRNOTAVAIL);
				}
				++*lastport;
				if (*lastport < first || *lastport > last)
					*lastport = first;
				lport = htons(*lastport);
			} while (in_pcblookup_local(pcbinfo,
				 inp->inp_laddr, lport, wild));
		}
	}
	inp->inp_lport = lport;
	if (in_pcbinshash(inp) != 0) {
		inp->inp_laddr.s_addr = INADDR_ANY;
		inp->inp_lport = 0;
		return (EAGAIN);
	}
	return (0);
}

/*
 *   Transform old in_pcbconnect() into an inner subroutine for new
 *   in_pcbconnect(): Do some validity-checking on the remote
 *   address (in mbuf 'nam') and then determine local host address
 *   (i.e., which interface) to use to access that remote host.
 *
 *   This preserves definition of in_pcbconnect(), while supporting a
 *   slightly different version for T/TCP.  (This is more than
 *   a bit of a kludge, but cleaning up the internal interfaces would
 *   have forced minor changes in every protocol).
 */

int
in_pcbladdr(inp, nam, plocal_sin)
	register struct inpcb *inp;
	struct sockaddr *nam;
	struct sockaddr_in **plocal_sin;
{
	struct in_ifaddr *ia;
	register struct sockaddr_in *sin = (struct sockaddr_in *)nam;

	if (nam->sa_len != sizeof (*sin))
		return (EINVAL);
	if (sin->sin_family != AF_INET)
		return (EAFNOSUPPORT);
	if (sin->sin_port == 0)
		return (EADDRNOTAVAIL);
	if (!TAILQ_EMPTY(&in_ifaddrhead)) {
		/*
		 * If the destination address is INADDR_ANY,
		 * use the primary local address.
		 * If the supplied address is INADDR_BROADCAST,
		 * and the primary interface supports broadcast,
		 * choose the broadcast address for that interface.
		 */
#define	satosin(sa)	((struct sockaddr_in *)(sa))
#define sintosa(sin)	((struct sockaddr *)(sin))
#define ifatoia(ifa)	((struct in_ifaddr *)(ifa))
		if (sin->sin_addr.s_addr == INADDR_ANY)
		    sin->sin_addr = IA_SIN(TAILQ_FIRST(&in_ifaddrhead))->sin_addr;
		else if (sin->sin_addr.s_addr == (u_long)INADDR_BROADCAST &&
		  (TAILQ_FIRST(&in_ifaddrhead)->ia_ifp->if_flags & IFF_BROADCAST))
		    sin->sin_addr = satosin(&TAILQ_FIRST(&in_ifaddrhead)->ia_broadaddr)->sin_addr;
	}
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		register struct route *ro;

		ia = (struct in_ifaddr *)0;
		/*
		 * If route is known or can be allocated now,
		 * our src addr is taken from the i/f, else punt.
		 */
		ro = &inp->inp_route;
		if (ro->ro_rt &&
		    (satosin(&ro->ro_dst)->sin_addr.s_addr !=
			sin->sin_addr.s_addr ||
		    inp->inp_socket->so_options & SO_DONTROUTE)) {
			RTFREE(ro->ro_rt);
			ro->ro_rt = (struct rtentry *)0;
		}
		if ((inp->inp_socket->so_options & SO_DONTROUTE) == 0 && /*XXX*/
		    (ro->ro_rt == (struct rtentry *)0 ||
		    ro->ro_rt->rt_ifp == (struct ifnet *)0)) {
			/* No route yet, so try to acquire one */
			ro->ro_dst.sa_family = AF_INET;
			ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
			((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
				sin->sin_addr;
			rtalloc(ro);
		}
		/*
		 * If we found a route, use the address
		 * corresponding to the outgoing interface
		 * unless it is the loopback (in case a route
		 * to our address on another net goes to loopback).
		 */
		if (ro->ro_rt && !(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
			ia = ifatoia(ro->ro_rt->rt_ifa);
		if (ia == 0) {
			u_short fport = sin->sin_port;

			sin->sin_port = 0;
			ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin)));
			if (ia == 0)
				ia = ifatoia(ifa_ifwithnet(sintosa(sin)));
			sin->sin_port = fport;
			if (ia == 0)
				ia = TAILQ_FIRST(&in_ifaddrhead);
			if (ia == 0)
				return (EADDRNOTAVAIL);
		}
		/*
		 * If the destination address is multicast and an outgoing
		 * interface has been set as a multicast option, use the
		 * address of that interface as our source address.
		 */
		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) &&
		    inp->inp_moptions != NULL) {
			struct ip_moptions *imo;
			struct ifnet *ifp;

			imo = inp->inp_moptions;
			if (imo->imo_multicast_ifp != NULL) {
				ifp = imo->imo_multicast_ifp;
				TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
					if (ia->ia_ifp == ifp)
						break;
				if (ia == 0)
					return (EADDRNOTAVAIL);
			}
		}
	/*
	 * Don't do pcblookup call here; return interface in plocal_sin
	 * and exit to caller, that will do the lookup.
	 */
		*plocal_sin = &ia->ia_addr;

	}
	return(0);
}

/*
 * Outer subroutine:
 * Connect from a socket to a specified address.
 * Both address and port must be specified in argument sin.
 * If don't have a local address for this socket yet,
 * then pick one.
 */
int
in_pcbconnect(inp, nam, p)
	register struct inpcb *inp;
	struct sockaddr *nam;
	struct proc *p;
{
	struct sockaddr_in *ifaddr;
	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
	int error;

	/*
	 *   Call inner routine, to assign local interface address.
	 */
	if ((error = in_pcbladdr(inp, nam, &ifaddr)) != 0)
		return(error);

	if (in_pcblookup_hash(inp->inp_pcbinfo, sin->sin_addr, sin->sin_port,
	    inp->inp_laddr.s_addr ? inp->inp_laddr : ifaddr->sin_addr,
	    inp->inp_lport, 0, NULL) != NULL) {
		return (EADDRINUSE);
	}
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		if (inp->inp_lport == 0) {
			error = in_pcbbind(inp, (struct sockaddr *)0, p);
			if (error)
			    return (error);
		}
		inp->inp_laddr = ifaddr->sin_addr;
	}
	inp->inp_faddr = sin->sin_addr;
	inp->inp_fport = sin->sin_port;
	in_pcbrehash(inp);
#ifdef IPSEC
	if (inp->inp_socket->so_type == SOCK_STREAM)
		ipsec_pcbconn(inp->inp_sp);
#endif
	return (0);
}

void
in_pcbdisconnect(inp)
	struct inpcb *inp;
{

	inp->inp_faddr.s_addr = INADDR_ANY;
	inp->inp_fport = 0;
	in_pcbrehash(inp);
	if (inp->inp_socket->so_state & SS_NOFDREF)