if.c

eCos操作系统源码

//==========================================================================
//
//      src/sys/net/if.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) 1980, 1986, 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.
 *
 *	@(#)if.c	8.3 (Berkeley) 1/4/94
 * $FreeBSD: src/sys/net/if.c,v 1.85.2.9 2001/07/24 19:10:17 brooks Exp $
 */

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

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

#if defined(INET) || defined(INET6)
/*XXX*/
#include <netinet/in.h>
#include <netinet/in_var.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet6/in6_ifattach.h>
#endif
#endif

/*
 * System initialization
 */

static int ifconf __P((u_long, caddr_t));
static void ifinit __P((void *));
static void if_qflush __P((struct ifqueue *));
static void if_slowtimo __P((void *));
static void link_rtrequest __P((int, struct rtentry *, struct sockaddr *));
static int  if_rtdel __P((struct radix_node *, void *));

SYSINIT(interfaces, SI_SUB_PROTO_IF, SI_ORDER_FIRST, ifinit, NULL)

int	ifqmaxlen = IFQ_MAXLEN;
struct	ifnethead ifnet;	/* depend on static init XXX */

#ifdef INET6
/*
 * XXX: declare here to avoid to include many inet6 related files..
 * should be more generalized?
 */
extern void	nd6_setmtu __P((struct ifnet *));
#endif

struct if_clone *if_clone_lookup __P((const char *, int *));
int if_clone_list __P((struct if_clonereq *));

LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
int if_cloners_count;

/*
 * Network interface utility routines.
 *
 * Routines with ifa_ifwith* names take sockaddr *'s as
 * parameters.
 */
/* ARGSUSED*/
void
ifinit(dummy)
	void *dummy;
{
#ifdef DEBUG_IFINIT
	struct ifnet *ifp;
	int s;

	s = splimp();
	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
            log(LOG_INIT, "IFP: %p, next: %p\n", ifp, ifp->if_link.tqe_next);
        }
	splx(s);
#endif
	if_slowtimo(0);
}

int if_index = 0;
struct ifaddr **ifnet_addrs;
struct ifnet **ifindex2ifnet = NULL;

char *
_sa(struct ifaddr *ifa)
{
    struct sockaddr *sa = ifa->ifa_addr;
    static char _unknown[128];

    switch (sa->sa_family) {
    case AF_INET:
        return inet_ntoa((struct in_addr)((struct sockaddr_in *)(ifa->ifa_addr))->sin_addr);
#ifdef INET6
    case AF_INET6:
        diag_sprintf(_unknown, "%s/%d", ip6_sprintf(IFA_IN6(ifa)), 
                     in6_mask2len(&((struct in6_ifaddr *)ifa)->ia_prefixmask.sin6_addr, NULL));
        return _unknown;
#endif
    case AF_LINK:
        diag_sprintf(_unknown, "<<%p>>", sa);
        return _unknown;
    default:
        diag_sprintf(_unknown, "[%d]", sa->sa_family);
        return _unknown;
    }
}

void
_show_ifp(struct ifnet *ifp)
{
    log_(LOG_ADDR) {
        struct ifaddr *ifa;
        diag_printf("IFP: %p (%s%d)\n", ifp, ifp->if_name, ifp->if_unit);
        TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
            diag_printf("IFA: %p - %s\n", ifa, _sa(ifa));
        }
    }
}

/*
 * Attach an interface to the
 * list of "active" interfaces.
 */
void
if_attach(ifp)
	struct ifnet *ifp;
{
	unsigned socksize, ifasize;
	int namelen, masklen;
	char workbuf[64];
	register struct sockaddr_dl *sdl;
	register struct ifaddr *ifa;
	static int if_indexlim = 8;
	static int inited;

	if (!inited) {
		TAILQ_INIT(&ifnet);
		inited = 1;
	}

        if (ifp->if_snd.ifq_maxlen == 0) {
            ifp->if_snd.ifq_maxlen = ifqmaxlen;
        }

	TAILQ_INSERT_TAIL(&ifnet, ifp, if_link);
	ifp->if_index = ++if_index;
	/*
	 * XXX -
	 * The old code would work if the interface passed a pre-existing
	 * chain of ifaddrs to this code.  We don't trust our callers to
	 * properly initialize the tailq, however, so we no longer allow
	 * this unlikely case.
	 */
	TAILQ_INIT(&ifp->if_addrhead);        
        log_(LOG_ADDR) {
            diag_printf("%s.%d - After initialize list %p\n",   
                        __FUNCTION__, __LINE__,                         
                        &ifp->if_addrlist);                             
            _show_ifp(ifp);                                     
        }
	TAILQ_INIT(&ifp->if_prefixhead);
	LIST_INIT(&ifp->if_multiaddrs);
	getmicrotime(&ifp->if_lastchange);
	if (ifnet_addrs == 0 || if_index >= if_indexlim) {
		unsigned n = (if_indexlim <<= 1) * sizeof(ifa);
		caddr_t q = malloc(n, M_IFADDR, M_WAITOK);
		bzero(q, n);
		if (ifnet_addrs) {
			bcopy((caddr_t)ifnet_addrs, (caddr_t)q, n/2);
			free((caddr_t)ifnet_addrs, M_IFADDR);
		}
		ifnet_addrs = (struct ifaddr **)q;

		/* grow ifindex2ifnet */
		n = if_indexlim * sizeof(struct ifnet *);
		q = malloc(n, M_IFADDR, M_WAITOK);
		bzero(q, n);
		if (ifindex2ifnet) {
			bcopy((caddr_t)ifindex2ifnet, q, n/2);
			free((caddr_t)ifindex2ifnet, M_IFADDR);
		}
		ifindex2ifnet = (struct ifnet **)q;
	}

	ifindex2ifnet[if_index] = ifp;

	/*
	 * create a Link Level name for this device
	 */
	namelen = snprintf(workbuf, sizeof(workbuf),
	    "%s%d", ifp->if_name, ifp->if_unit);
#define _offsetof(t, m) ((int)((caddr_t)&((t *)0)->m))
	masklen = _offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
	socksize = masklen + ifp->if_addrlen;
#define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
	if (socksize < sizeof(*sdl))
		socksize = sizeof(*sdl);
	socksize = ROUNDUP(socksize);
	ifasize = sizeof(*ifa) + 2 * socksize;
	ifa = (struct ifaddr *)malloc(ifasize, M_IFADDR, M_WAITOK);
	if (ifa) {
		bzero((caddr_t)ifa, ifasize);
		sdl = (struct sockaddr_dl *)(ifa + 1);
		sdl->sdl_len = socksize;
		sdl->sdl_family = AF_LINK;
		bcopy(workbuf, sdl->sdl_data, namelen);
		sdl->sdl_nlen = namelen;
		sdl->sdl_index = ifp->if_index;
		sdl->sdl_type = ifp->if_type;
		ifnet_addrs[if_index - 1] = ifa;
		ifa->ifa_ifp = ifp;
		ifa->ifa_rtrequest = link_rtrequest;
		ifa->ifa_addr = (struct sockaddr *)sdl;
		sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
		ifa->ifa_netmask = (struct sockaddr *)sdl;
		sdl->sdl_len = masklen;
		while (namelen != 0)
			sdl->sdl_data[--namelen] = 0xff;
		TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
                log_(LOG_ADDR) {
                    diag_printf("%s.%d - After inserting %p into list %p\n", 
                                __FUNCTION__, __LINE__,
                                ifa, &ifp->if_addrlist);
                    _show_ifp(ifp);
                }
	}
#ifdef ALTQ
	ifp->if_snd.altq_type = 0;
	ifp->if_snd.altq_disc = NULL;
	ifp->if_snd.altq_flags &= ALTQF_CANTCHANGE;
	ifp->if_snd.altq_tbr  = NULL;
	ifp->if_snd.altq_ifp  = ifp;
#endif
}

/*
 * Detach an interface, removing it from the
 * list of "active" interfaces.
 */
void
if_detach(ifp)
	struct ifnet *ifp;
{
	struct ifaddr *ifa;
	struct radix_node_head	*rnh;
	int s;
	int i;

	/*
	 * Remove routes and flush queues.
	 */
	s = splnet();
	if_down(ifp);
#ifdef ALTQ
	if (ALTQ_IS_ENABLED(&ifp->if_snd))
		altq_disable(&ifp->if_snd);
	if (ALTQ_IS_ATTACHED(&ifp->if_snd))
		altq_detach(&ifp->if_snd);
#endif

	/*
	 * Remove address from ifnet_addrs[] and maybe decrement if_index.
	 * Clean up all addresses.
	 */
	ifnet_addrs[ifp->if_index - 1] = 0;
	while (if_index > 0 && ifnet_addrs[if_index - 1] == 0)
		if_index--;

	for (ifa = TAILQ_FIRST(&ifp->if_addrhead); ifa;
	     ifa = TAILQ_FIRST(&ifp->if_addrhead)) {
#ifdef INET
		/* XXX: Ugly!! ad hoc just for INET */
		if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
			struct ifaliasreq ifr;

			bzero(&ifr, sizeof(ifr));
			ifr.ifra_addr = *ifa->ifa_addr;
			if (ifa->ifa_dstaddr)
				ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
			if (in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr, ifp,
			    NULL) == 0)
				continue;
		}
#endif /* INET */
#ifdef INET6
		if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6) {
			in6_purgeaddr(ifa);
			/* ifp_addrhead is already updated */
			continue;
		}
#endif /* INET6 */
		TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
		IFAFREE(ifa);
	}

#ifdef INET6
	/*
	 * Remove all IPv6 kernel structs related to ifp.  This should be done
	 * before removing routing entries below, since IPv6 interface direct
	 * routes are expected to be removed by the IPv6-specific kernel API.
	 * Otherwise, the kernel will detect some inconsistency and bark it.
	 */
	in6_ifdetach(ifp);
#endif

	/*
	 * Delete all remaining routes using this interface
	 * Unfortuneatly the only way to do this is to slog through
	 * the entire routing table looking for routes which point
	 * to this interface...oh well...
	 */
	for (i = 1; i <= AF_MAX; i++) {
		if ((rnh = rt_tables[i]) == NULL)
			continue;
		(void) rnh->rnh_walktree(rnh, if_rtdel, ifp);
	}

	TAILQ_REMOVE(&ifnet, ifp, if_link);
	splx(s);
}

/*
 * Delete Routes for a Network Interface
 * 
 * Called for each routing entry via the rnh->rnh_walktree() call above
 * to delete all route entries referencing a detaching network interface.
 *
 * Arguments:
 *	rn	pointer to node in the routing table
 *	arg	argument passed to rnh->rnh_walktree() - detaching interface
 *
 * Returns:
 *	0	successful
 *	errno	failed - reason indicated
 *
 */
static int
if_rtdel(rn, arg)
	struct radix_node	*rn;
	void			*arg;
{
	struct rtentry	*rt = (struct rtentry *)rn;
	struct ifnet	*ifp = arg;
	int		err;

	if (rt->rt_ifp == ifp) {

		/*
		 * Protect (sorta) against walktree recursion problems
		 * with cloned routes
		 */
		if ((rt->rt_flags & RTF_UP) == 0)
			return (0);

		err = rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
				rt_mask(rt), rt->rt_flags,
				(struct rtentry **) NULL);
		if (err) {
			log(LOG_WARNING, "if_rtdel: error %d\n", err);
		}
	}

	return (0);
}

/*
 * Create a clone network interface.
 */
int
if_clone_create(name, len)
	char *name;
	int len;
{
	struct if_clone *ifc;
	char *dp;
	int wildcard;
	int unit;
	int err;

	ifc = if_clone_lookup(name, &unit);
	if (ifc == NULL)
		return (EINVAL);

	if (ifunit(name) != NULL)
		return (EEXIST);

	wildcard = (unit < 0);

	err = (*ifc->ifc_create)(ifc, &unit);
	if (err != 0)
		return (err);

	/* In the wildcard case, we need to update the name. */
	if (wildcard) {
		for (dp = name; *dp != '\0'; dp++);
		if (snprintf(dp, len - (dp-name), "%d", unit) >
		    len - (dp-name) - 1) {
			/*
			 * This can only be a programmer error and
			 * there's no straightforward way to recover if
			 * it happens.
			 */
			panic("if_clone_create(): interface name too long");
		}
			
	}

	return (0);
}

/*
 * Destroy a clone network interface.
 */
int
if_clone_destroy(name)
	const char *name;
{
	struct if_clone *ifc;
	struct ifnet *ifp;

	ifc = if_clone_lookup(name, NULL);
	if (ifc == NULL)
		return (EINVAL);

	ifp = ifunit(name);
	if (ifp == NULL)
		return (ENXIO);

	if (ifc->ifc_destroy == NULL)
		return (EOPNOTSUPP);

	(*ifc->ifc_destroy)(ifp);
	return (0);
}

/*
 * Look up a network interface cloner.
 */
struct if_clone *
if_clone_lookup(name, unitp)
	const char *name;
	int *unitp;
{
	struct if_clone *ifc;
	const char *cp;
	int i;

	for (ifc = LIST_FIRST(&if_cloners); ifc != NULL;) {
		for (cp = name, i = 0; i < ifc->ifc_namelen; i++, cp++) {
			if (ifc->ifc_name[i] != *cp)
				goto next_ifc;
		}
		goto found_name;
 next_ifc:
		ifc = LIST_NEXT(ifc, ifc_list);
	}

	/* No match. */
	return ((struct if_clone *)NULL);

 found_name:
	if (*cp == '\0') {
		i = -1;
	} else {
		for (i = 0; *cp != '\0'; cp++) {
			if (*cp < '0' || *cp > '9') {
				/* Bogus unit number. */
				return (NULL);
			}
			i = (i * 10) + (*cp - '0');
		}
	}

	if (unitp != NULL)
		*unitp = i;
	return (ifc);
}

/*
 * Register a network interface cloner.
 */
void
if_clone_attach(ifc)
	struct if_clone *ifc;
{

	LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
	if_cloners_count++;
}

/*
 * Unregister a network interface cloner.
 */
void
if_clone_detach(ifc)
	struct if_clone *ifc;
{

	LIST_REMOVE(ifc, ifc_list);
	if_cloners_count--;
}

/*
 * Provide list of interface cloners to userspace.
 */
int
if_clone_list(ifcr)
	struct if_clonereq *ifcr;
{
	char outbuf[IFNAMSIZ], *dst;
	struct if_clone *ifc;
	int count, error = 0;

	ifcr->ifcr_total = if_cloners_count;
	if ((dst = ifcr->ifcr_buffer) == NULL) {
		/* Just asking how many there are. */
		return (0);
	}

	if (ifcr->ifcr_count < 0)
		return (EINVAL);