if.c

很好的一个嵌入式linux平台下的bootloader

/* $Id: if.c,v 1.3 1998/12/28 14:13:11 nigel Exp $ */
/*
 * Copyright (c) 1980, 1986 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	7.14 (Berkeley) 4/20/91
 */

#include "param.h"
#include "mbuf.h"
#include "systm.h"
#include "socket.h"
#include "socketvar.h"
#include "protosw.h"
#include "proc.h"
#include "kernel.h"
#include "ioctl.h"

#include "if.h"
#include "af.h"
#include "if_dl.h"
#include "if_types.h"

#include "ether.h"

#ifdef PROM
const int ifqmaxlen = IFQ_MAXLEN;
#else
int	ifqmaxlen = IFQ_MAXLEN;
#endif

/*
 * Network interface utility routines.
 *
 * Routines with ifa_ifwith* names take sockaddr *'s as
 * parameters.
 */

ifinit()
{
	register struct ifnet *ifp;

	for (ifp = ifnet; ifp; ifp = ifp->if_next)
		if (ifp->if_snd.ifq_maxlen == 0)
			ifp->if_snd.ifq_maxlen = ifqmaxlen;
	if_slowtimo();
}

#if defined(vax) || defined(PROM)
/*
 * Call each interface on a Unibus/PROM reset.
 */
ifubareset(uban)
	int uban;
{
	register struct ifnet *ifp;

	for (ifp = ifnet; ifp; ifp = ifp->if_next)
		if (ifp->if_reset)
			(*ifp->if_reset)(ifp->if_unit, uban);
}
#endif

int if_index;
struct ifaddr **ifnet_addrs;
static char *sprint_d();

/*
 * Attach an interface to the
 * list of "active" interfaces.
 */
if_attach(ifp)
	struct ifnet *ifp;
{
	unsigned socksize, ifasize;
	int namelen, unitlen;
	char workbuf[12], *unitname;
	register struct ifnet **p = &ifnet;
	register struct sockaddr_dl *sdl;
	register struct ifaddr *ifa;
#ifdef NO_DATA
	static int if_indexlim;
#else
	static int if_indexlim = 8;
#endif
	extern link_rtrequest();
#if NETHER > 0
	extern ether_output();
#endif

	while (*p)
		p = &((*p)->if_next);
	*p = ifp;
	ifp->if_index = ++if_index;
#ifdef NO_DATA
	if (ifnet_addrs == 0)
	  if_indexlim = 8;
#endif
	if (ifnet_addrs == 0 || if_index >= if_indexlim) {
		unsigned n = (if_indexlim <<= 1) * sizeof(ifa);
		struct ifaddr **q = (struct ifaddr **)
					malloc(n, M_IFADDR, M_WAITOK);
		if (ifnet_addrs) {
			bcopy((caddr_t)ifnet_addrs, (caddr_t)q, n/2);
			free((caddr_t)ifnet_addrs, M_IFADDR);
		}
		ifnet_addrs = q;
	}
#if NETHER > 0
	/* XXX -- Temporary fix before changing 10 ethernet drivers */
	if (ifp->if_output == ether_output) {
		ifp->if_type = IFT_ETHER;
		ifp->if_addrlen = 6;
		ifp->if_hdrlen = 14;
	}
#endif
	/*
	 * create a Link Level name for this device
	 */
	unitname = sprint_d((u_int)ifp->if_unit, workbuf, sizeof(workbuf));
	namelen = strlen(ifp->if_name);
	unitlen = strlen(unitname);
#define _offsetof(t, m) ((int)((caddr_t)&((t *)0)->m))
	socksize = _offsetof(struct sockaddr_dl, sdl_data[0]) +
			       unitlen + namelen + ifp->if_addrlen;
#define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
	socksize = ROUNDUP(socksize);
	if (socksize < sizeof(*sdl))
		socksize = sizeof(*sdl);
	ifasize = sizeof(*ifa) + 2 * socksize;
	ifa = (struct ifaddr *)malloc(ifasize, M_IFADDR, M_WAITOK);
	if (ifa == 0)
		return;
	ifnet_addrs[if_index - 1] = ifa;
	bzero((caddr_t)ifa, ifasize);
	sdl = (struct sockaddr_dl *)(ifa + 1);
	ifa->ifa_addr = (struct sockaddr *)sdl;
	ifa->ifa_ifp = ifp;
	sdl->sdl_len = socksize;
	sdl->sdl_family = AF_LINK;
	bcopy(ifp->if_name, sdl->sdl_data, namelen);
	bcopy(unitname, namelen + (caddr_t)sdl->sdl_data, unitlen);
	sdl->sdl_nlen = (namelen += unitlen);
	sdl->sdl_index = ifp->if_index;
	sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
	ifa->ifa_netmask = (struct sockaddr *)sdl;
	sdl->sdl_len = socksize - ifp->if_addrlen;
	while (namelen != 0)
		sdl->sdl_data[--namelen] = 0xff;
	ifa->ifa_next = ifp->if_addrlist;
	ifa->ifa_rtrequest = link_rtrequest;
	ifp->if_addrlist = ifa;
}


/*
 * Update the link-layer address and/or type for an existing interface.
 * We assume that ifp->if_hdrlen is correct, and that the sockaddr_dl
 * created in if_attach is large enough (i.e., if_hdrlen will not increase).
 */
void
if_newaddr(ifp, type, laddr)
	register struct ifnet *ifp;
	int type;
	caddr_t laddr;
{
	register struct ifaddr *ifa;
	register struct sockaddr_dl *sdl;

	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
		if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
		    sdl->sdl_family == AF_LINK) {
			sdl->sdl_type = type;
			sdl->sdl_alen = ifp->if_addrlen;
			bcopy(laddr, LLADDR(sdl), ifp->if_addrlen);
			break;
		}
}

/*
 * Locate an interface based on a complete address.
 */
/*ARGSUSED*/
struct ifaddr *
ifa_ifwithaddr(addr)
	register struct sockaddr *addr;
{
	register struct ifnet *ifp;
	register struct ifaddr *ifa;

#define	equal(a1, a2) \
  (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 0)
	for (ifp = ifnet; ifp; ifp = ifp->if_next)
	    for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
		if (ifa->ifa_addr->sa_family != addr->sa_family)
			continue;
		if (equal(addr, ifa->ifa_addr))
			return (ifa);
		if ((ifp->if_flags & IFF_BROADCAST) && ifa->ifa_broadaddr &&
		    equal(ifa->ifa_broadaddr, addr))
			return (ifa);
	}
	return ((struct ifaddr *)0);
}
/*
 * Locate the point to point interface with a given destination address.
 */
/*ARGSUSED*/
struct ifaddr *
ifa_ifwithdstaddr(addr)
	register struct sockaddr *addr;
{
	register struct ifnet *ifp;
	register struct ifaddr *ifa;

	for (ifp = ifnet; ifp; ifp = ifp->if_next) 
	    if (ifp->if_flags & IFF_POINTOPOINT)
		for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
			if (ifa->ifa_addr->sa_family != addr->sa_family)
				continue;
			if (equal(addr, ifa->ifa_dstaddr))
				return (ifa);
	}
	return ((struct ifaddr *)0);
}

/*
 * Find an interface on a specific network.  If many, choice
 * is first found.
 */
struct ifaddr *
ifa_ifwithnet(addr)
	struct sockaddr *addr;
{
	register struct ifnet *ifp;
	register struct ifaddr *ifa;
	u_int af = addr->sa_family;

	if (af >= AF_MAX)
		return (0);
	if (af == AF_LINK) {
	    register struct sockaddr_dl *sdl = (struct sockaddr_dl *)addr;
	    if (sdl->sdl_index && sdl->sdl_index <= if_index)
		return (ifnet_addrs[sdl->sdl_index - 1]);
	}
	for (ifp = ifnet; ifp; ifp = ifp->if_next)
	    for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
		register char *cp, *cp2, *cp3;
		register char *cplim;
		if (ifa->ifa_addr->sa_family != af || ifa->ifa_netmask == 0)
			continue;
		cp = addr->sa_data;
		cp2 = ifa->ifa_addr->sa_data;
		cp3 = ifa->ifa_netmask->sa_data;
		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
		for (; cp3 < cplim; cp3++)
			if ((*cp++ ^ *cp2++) & *cp3)
				break;
		if (cp3 == cplim)
			return (ifa);
	    }
	return ((struct ifaddr *)0);
}

/*
 * Find an interface using a specific address family
 */
struct ifaddr *
ifa_ifwithaf(af)
	register int af;
{
	register struct ifnet *ifp;
	register struct ifaddr *ifa;

	for (ifp = ifnet; ifp; ifp = ifp->if_next)
	    for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
		if (ifa->ifa_addr->sa_family == af)
			return (ifa);
	return ((struct ifaddr *)0);
}

/*
 * Find an interface address specific to an interface best matching
 * a given address.
 */
struct ifaddr *
ifaof_ifpforaddr(addr, ifp)
	struct sockaddr *addr;
	register struct ifnet *ifp;
{
	register struct ifaddr *ifa;
	register char *cp, *cp2, *cp3;
	register char *cplim;
	struct ifaddr *ifa_maybe = 0;
	u_int af = addr->sa_family;

	if (af >= AF_MAX)
		return (0);
	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
		if (ifa->ifa_addr->sa_family != af)
			continue;
		ifa_maybe = ifa;
		if (ifa->ifa_netmask == 0) {
			if (equal(addr, ifa->ifa_addr) ||
			    (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr)))
				return (ifa);
			continue;
		}
		cp = addr->sa_data;
		cp2 = ifa->ifa_addr->sa_data;
		cp3 = ifa->ifa_netmask->sa_data;
		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;