nd6.c

eCos操作系统源码

//==========================================================================
//
//      src/sys/netinet6/nd6.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####
//==========================================================================

/*	$KAME: nd6.c,v 1.221 2001/12/18 02:23:45 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

/*
 * XXX
 * KAME 970409 note:
 * BSD/OS version heavily modifies this code, related to llinfo.
 * Since we don't have BSD/OS version of net/route.c in our hand,
 * I left the code mostly as it was in 970310.  -- itojun
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/queue.h>
#include <sys/sysctl.h>

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

#include <netinet/in.h>
#ifndef __NetBSD__
#include <netinet/if_ether.h>
#ifdef __bsdi__
#include <net/if_fddi.h>
#endif
#ifdef __OpenBSD__
#include <netinet/ip_ipsp.h>
#endif
#else /* __NetBSD__ */
#include <net/if_ether.h>
#include <netinet/if_inarp.h>
#include <net/if_fddi.h>
#endif /* __NetBSD__ */
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>

#if defined(__NetBSD__)
extern struct ifnet loif[NLOOP];
#endif

#define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
#define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */

#define SIN6(s) ((struct sockaddr_in6 *)s)
#define SDL(s) ((struct sockaddr_dl *)s)

/* timer values */
int	nd6_prune	= 1;	/* walk list every 1 seconds */
int	nd6_delay	= 5;	/* delay first probe time 5 second */
int	nd6_umaxtries	= 3;	/* maximum unicast query */
int	nd6_mmaxtries	= 3;	/* maximum multicast query */
int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */

/* preventing too many loops in ND option parsing */
int nd6_maxndopt = 10;	/* max # of ND options allowed */

int nd6_maxnudhint = 0;	/* max # of subsequent upper layer hints */

int nd6_debug = 1;

/* for debugging? */
static int nd6_inuse, nd6_allocated;

struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
static size_t nd_ifinfo_indexlim = 8;
struct nd_ifinfo *nd_ifinfo = NULL;
struct nd_drhead nd_defrouter;
struct nd_prhead nd_prefix = { 0 };

int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
static struct sockaddr_in6 all1_sa;

static void nd6_slowtimo __P((void *));
static int regen_tmpaddr __P((struct in6_ifaddr *));
static struct llinfo_nd6 *nd6_free __P((struct rtentry *, int));

#ifdef __NetBSD__
struct callout nd6_slowtimo_ch = CALLOUT_INITIALIZER;
struct callout nd6_timer_ch = CALLOUT_INITIALIZER;
extern struct callout in6_tmpaddrtimer_ch;
#elif (defined(__FreeBSD__) && __FreeBSD__ >= 3)
struct callout nd6_slowtimo_ch;
struct callout nd6_timer_ch;
extern struct callout in6_tmpaddrtimer_ch;
#elif defined(__OpenBSD__)
struct timeout nd6_slowtimo_ch;
struct timeout nd6_timer_ch;
extern struct timeout in6_tmpaddrtimer_ch;
#endif

void
nd6_init()
{
	static int nd6_init_done = 0;
	int i;

	if (nd6_init_done) {
		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
		return;
	}

	all1_sa.sin6_family = AF_INET6;
	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
	for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
		all1_sa.sin6_addr.s6_addr[i] = 0xff;

	/* initialization of the default router list */
	TAILQ_INIT(&nd_defrouter);

	nd6_init_done = 1;

	/* start timer */
#if defined(__NetBSD__) || (defined(__FreeBSD__) && __FreeBSD__ >= 3)
	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
	    nd6_slowtimo, NULL);
#elif defined(__OpenBSD__)
	timeout_set(&nd6_slowtimo_ch, nd6_slowtimo, NULL);
	timeout_add(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz);
#else
	timeout(nd6_slowtimo, (caddr_t)0, ND6_SLOWTIMER_INTERVAL * hz);
#endif
}

void
nd6_ifattach(ifp)
	struct ifnet *ifp;
{

	/*
	 * We have some arrays that should be indexed by if_index.
	 * since if_index will grow dynamically, they should grow too.
	 */
	if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
		size_t n;
		caddr_t q;

		while (if_index >= nd_ifinfo_indexlim)
			nd_ifinfo_indexlim <<= 1;

		/* grow nd_ifinfo */
		n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
		bzero(q, n);
		if (nd_ifinfo) {
			bcopy((caddr_t)nd_ifinfo, q, n/2);
			free((caddr_t)nd_ifinfo, M_IP6NDP);
		}
		nd_ifinfo = (struct nd_ifinfo *)q;
	}

#define ND nd_ifinfo[ifp->if_index]

	/*
	 * Don't initialize if called twice.
	 * XXX: to detect this, we should choose a member that is never set
	 * before initialization of the ND structure itself.  We formaly used
	 * the linkmtu member, which was not suitable because it could be 
	 * initialized via "ifconfig mtu".
	 */
	if (ND.basereachable)
		return;

#ifdef DIAGNOSTIC
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
	if (!ifnet_byindex(ifp->if_index))
		panic("nd6_ifattach: ifnet_byindex is NULL");
#else
	if (!ifindex2ifnet[ifp->if_index])
		panic("nd6_ifattach: ifindex2ifnet is NULL");
#endif
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
	ND.linkmtu = ifnet_byindex(ifp->if_index)->if_mtu;
#else
	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
#endif
	ND.chlim = IPV6_DEFHLIM;
	ND.basereachable = REACHABLE_TIME;
	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
	ND.retrans = RETRANS_TIMER;
	ND.receivedra = 0;
	/*
	 * Note that the default value of ip6_accept_rtadv is 0, which means
	 * we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
	 * here.
	 */
	ND.flags = ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV;
	nd6_setmtu(ifp);
#undef ND
}

/*
 * Reset ND level link MTU. This function is called when the physical MTU
 * changes, which means we might have to adjust the ND level MTU.
 */
void
nd6_setmtu(ifp)
	struct ifnet *ifp;
{
#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif
	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
	u_long oldmaxmtu = ndi->maxmtu;
	u_long oldlinkmtu = ndi->linkmtu;

	switch (ifp->if_type) {
	case IFT_ARCNET:	/* XXX MTU handling needs more work */
		ndi->maxmtu = MIN(60480, ifp->if_mtu);
		break;
	case IFT_ETHER:
		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
		break;
#if defined(__FreeBSD__) || defined(__bsdi__)
	case IFT_FDDI:
#if 0 // FIXME
#if defined(__bsdi__) && _BSDI_VERSION >= 199802
		ndi->maxmtu = MIN(FDDIMTU, ifp->if_mtu);
#else
		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
#endif
#endif
		break;
#endif
#if !(defined(__bsdi__) && _BSDI_VERSION >= 199802)
	case IFT_ATM:
#if 0 // FIXME
		ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
#endif
		break;
#endif
	case IFT_IEEE1394:	/* XXX should be IEEE1394MTU(1500) */
		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
		break;
#ifdef IFT_IEEE80211
	case IFT_IEEE80211:	/* XXX should be IEEE80211MTU(1500) */
		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
		break;
#endif
	default:
		ndi->maxmtu = ifp->if_mtu;
		break;
	}

	if (oldmaxmtu != ndi->maxmtu) {
		/*
		 * If the ND level MTU is not set yet, or if the maxmtu
		 * is reset to a smaller value than the ND level MTU,
		 * also reset the ND level MTU.
		 */
		if (ndi->linkmtu == 0 ||
		    ndi->maxmtu < ndi->linkmtu) {
			ndi->linkmtu = ndi->maxmtu;
			/* also adjust in6_maxmtu if necessary. */
			if (oldlinkmtu == 0) {
				/*
				 * XXX: the case analysis is grotty, but
				 * it is not efficient to call in6_setmaxmtu()
				 * here when we are during the initialization
				 * procedure.
				 */
				if (in6_maxmtu < ndi->linkmtu)
					in6_maxmtu = ndi->linkmtu;
			} else
				in6_setmaxmtu();
		}
	}
#undef MIN
}

void
nd6_option_init(opt, icmp6len, ndopts)
	void *opt;
	int icmp6len;
	union nd_opts *ndopts;
{
	bzero(ndopts, sizeof(*ndopts));
	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
	ndopts->nd_opts_last
		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);

	if (icmp6len == 0) {
		ndopts->nd_opts_done = 1;
		ndopts->nd_opts_search = NULL;
	}
}

/*
 * Take one ND option.
 */
struct nd_opt_hdr *
nd6_option(ndopts)
	union nd_opts *ndopts;
{
	struct nd_opt_hdr *nd_opt;
	int olen;

	if (!ndopts)
		panic("ndopts == NULL in nd6_option\n");
	if (!ndopts->nd_opts_last)
		panic("uninitialized ndopts in nd6_option\n");
	if (!ndopts->nd_opts_search)
		return NULL;
	if (ndopts->nd_opts_done)
		return NULL;

	nd_opt = ndopts->nd_opts_search;

	/* make sure nd_opt_len is inside the buffer */
	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
		bzero(ndopts, sizeof(*ndopts));
		return NULL;
	}

	olen = nd_opt->nd_opt_len << 3;
	if (olen == 0) {
		/*
		 * Message validation requires that all included
		 * options have a length that is greater than zero.
		 */
		bzero(ndopts, sizeof(*ndopts));
		return NULL;
	}

	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
		/* option overruns the end of buffer, invalid */
		bzero(ndopts, sizeof(*ndopts));
		return NULL;
	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
		/* reached the end of options chain */
		ndopts->nd_opts_done = 1;
		ndopts->nd_opts_search = NULL;
	}
	return nd_opt;
}

/*
 * Parse multiple ND options.
 * This function is much easier to use, for ND routines that do not need
 * multiple options of the same type.
 */
int
nd6_options(ndopts)
	union nd_opts *ndopts;
{
	struct nd_opt_hdr *nd_opt;
	int i = 0;

	if (!ndopts)
		panic("ndopts == NULL in nd6_options\n");
	if (!ndopts->nd_opts_last)
		panic("uninitialized ndopts in nd6_options\n");
	if (!ndopts->nd_opts_search)
		return 0;

	while (1) {
		nd_opt = nd6_option(ndopts);
		if (!nd_opt && !ndopts->nd_opts_last) {
			/*
			 * Message validation requires that all included
			 * options have a length that is greater than zero.
			 */
			icmp6stat.icp6s_nd_badopt++;
			bzero(ndopts, sizeof(*ndopts));
			return -1;
		}

		if (!nd_opt)
			goto skip1;

		switch (nd_opt->nd_opt_type) {
		case ND_OPT_SOURCE_LINKADDR:
		case ND_OPT_TARGET_LINKADDR:
		case ND_OPT_MTU:
		case ND_OPT_REDIRECTED_HEADER:
		case ND_OPT_ADVINTERVAL:
		case ND_OPT_SOURCE_ADDRLIST:
		case ND_OPT_TARGET_ADDRLIST:
			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
				nd6log((LOG_INFO,
				    "duplicated ND6 option found (type=%d)\n",
				    nd_opt->nd_opt_type));
				/* XXX bark? */
			} else {
				ndopts->nd_opt_array[nd_opt->nd_opt_type]
					= nd_opt;
			}
			break;
		case ND_OPT_PREFIX_INFORMATION:
			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
				ndopts->nd_opt_array[nd_opt->nd_opt_type]
					= nd_opt;
			}
			ndopts->nd_opts_pi_end =
				(struct nd_opt_prefix_info *)nd_opt;
			break;
		case ND_OPT_HOMEAGENT_INFO:
			break;
		default:
			/*
			 * Unknown options must be silently ignored,
			 * to accomodate future extension to the protocol.
			 */
			nd6log((LOG_DEBUG,
			    "nd6_options: unsupported option %d - "
			    "option ignored\n", nd_opt->nd_opt_type));
		}

skip1:
		i++;
		if (i > nd6_maxndopt) {
			icmp6stat.icp6s_nd_toomanyopt++;
			nd6log((LOG_INFO, "too many loop in nd opt\n"));
			break;
		}

		if (ndopts->nd_opts_done)
			break;
	}

	return 0;
}

/*
 * ND6 timer routine to expire default route list and prefix list
 */
void
nd6_timer(ignored_arg)
	void	*ignored_arg;
{
	int s;
	struct llinfo_nd6 *ln;
	struct nd_defrouter *dr;
	struct nd_prefix *pr;
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
	long time_second = time.tv_sec;
#endif
	struct ifnet *ifp;