if.c

很好的一个嵌入式linux平台下的bootloader

		for (; cp3 < cplim; cp3++)
			if ((*cp++ ^ *cp2++) & *cp3)
				break;
		if (cp3 == cplim)
			return (ifa);
	}
	return (ifa_maybe);
}

#include "route.h"
/*
 * Default action when installing a route with a Link Level gateway.
 * Lookup an appropriate real ifa to point to.
 * This should be moved to /sys/net/link.c eventually.
 */
link_rtrequest(cmd, rt, sa)
register struct rtentry *rt;
struct sockaddr *sa;
{
	register struct ifaddr *ifa;
	struct sockaddr *dst;
	struct ifnet *ifp, *oldifnet = ifnet;

	if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
	    ((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
		return;
	if (ifa = ifaof_ifpforaddr(dst, ifp)) {
		rt->rt_ifa = ifa;
		if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
			ifa->ifa_rtrequest(cmd, rt, sa);
	}
}

/*
 * Mark an interface down and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
if_down(ifp)
	register struct ifnet *ifp;
{
	register struct ifaddr *ifa;

	ifp->if_flags &= ~IFF_UP;
	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
		pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
	if_qflush(&ifp->if_snd);
}

/*
 * Flush an interface queue.
 */
if_qflush(ifq)
	register struct ifqueue *ifq;
{
	register struct mbuf *m, *n;

	n = ifq->ifq_head;
	while (m = n) {
		n = m->m_act;
		m_freem(m);
	}
	ifq->ifq_head = 0;
	ifq->ifq_tail = 0;
	ifq->ifq_len = 0;
}

/*
 * Handle interface watchdog timer routines.  Called
 * from softclock, we decrement timers (if set) and
 * call the appropriate interface routine on expiration.
 */
if_slowtimo()
{
	register struct ifnet *ifp;
	int s = splimp();

	for (ifp = ifnet; ifp; ifp = ifp->if_next) {
		if (ifp->if_timer == 0 || --ifp->if_timer)
			continue;
		if (ifp->if_watchdog)
			(*ifp->if_watchdog)(ifp->if_unit);
	}
	splx(s);
	timeout(if_slowtimo, (caddr_t)0, hz / IFNET_SLOWHZ);
}

/*
 * Map interface name to
 * interface structure pointer.
 */
struct ifnet *
ifunit(name)
	register char *name;
{
	register char *cp;
	register struct ifnet *ifp;
	int unit;
	unsigned len;
	char *ep, c;

	for (cp = name; cp < name + IFNAMSIZ && *cp; cp++)
		if (*cp >= '0' && *cp <= '9')
			break;
	if (*cp == '\0' || cp == name + IFNAMSIZ)
		return ((struct ifnet *)0);
	/*
	 * Save first char of unit, and pointer to it,
	 * so we can put a null there to avoid matching
	 * initial substrings of interface names.
	 */
	len = cp - name + 1;
	c = *cp;
	ep = cp;
	for (unit = 0; *cp >= '0' && *cp <= '9'; )
		unit = unit * 10 + *cp++ - '0';
	*ep = 0;
	for (ifp = ifnet; ifp; ifp = ifp->if_next) {
		if (bcmp(ifp->if_name, name, len))
			continue;
		if (unit == ifp->if_unit)
			break;
	}
	*ep = c;
	return (ifp);
}

/*
 * Interface ioctls.
 */
ifioctl(so, cmd, data, p)
	struct socket *so;
	int cmd;
	caddr_t data;
	struct proc *p;
{
	register struct ifnet *ifp;
	register struct ifreq *ifr;
	int error;

	switch (cmd) {

	case SIOCGIFCONF:
	case OSIOCGIFCONF:
		return (ifconf(cmd, data));

#if defined(INET) && NETHER > 0
	case SIOCSARP:
	case SIOCDARP:
		if (error = suser(p->p_ucred, &p->p_acflag))
			return (error);
		/* FALL THROUGH */
	case SIOCGARP:
	case OSIOCGARP:
		return (arpioctl(cmd, data));
#endif
	}
	ifr = (struct ifreq *)data;
	ifp = ifunit(ifr->ifr_name);
	if (ifp == 0)
		return (ENXIO);
	switch (cmd) {

	case SIOCGIFFLAGS:
		ifr->ifr_flags = ifp->if_flags;
		break;

	case SIOCGIFMETRIC:
		ifr->ifr_metric = ifp->if_metric;
		break;

	case SIOCSIFFLAGS:
		if (error = suser(p->p_ucred, &p->p_acflag))
			return (error);
		if (ifp->if_flags & IFF_UP && (ifr->ifr_flags & IFF_UP) == 0) {
			int s = splimp();
			if_down(ifp);
			splx(s);
		}
		ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
			(ifr->ifr_flags &~ IFF_CANTCHANGE);
		if (ifp->if_ioctl)
			(void) (*ifp->if_ioctl)(ifp, cmd, data);
		break;

	case SIOCSIFMETRIC:
		if (error = suser(p->p_ucred, &p->p_acflag))
			return (error);
		ifp->if_metric = ifr->ifr_metric;
		break;

	default:
		if (so->so_proto == 0)
			return (EOPNOTSUPP);
#ifndef COMPAT_43
		return ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
			cmd, data, ifp));
#else
	    {
		int ocmd = cmd;

		switch (cmd) {

		case SIOCSIFDSTADDR:
		case SIOCSIFADDR:
		case SIOCSIFBRDADDR:
		case SIOCSIFNETMASK:
#if BYTE_ORDER != BIG_ENDIAN
			if (ifr->ifr_addr.sa_family == 0 &&
			    ifr->ifr_addr.sa_len < 16) {
				ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
				ifr->ifr_addr.sa_len = 16;
			}
#else
			if (ifr->ifr_addr.sa_len == 0)
				ifr->ifr_addr.sa_len = 16;
#endif
			break;

		case OSIOCGIFADDR:
			cmd = SIOCGIFADDR;
			break;

		case OSIOCGIFDSTADDR:
			cmd = SIOCGIFDSTADDR;
			break;

		case OSIOCGIFBRDADDR:
			cmd = SIOCGIFBRDADDR;
			break;

		case OSIOCGIFNETMASK:
			cmd = SIOCGIFNETMASK;
		}
		error =  ((*so->so_proto->pr_usrreq)(so, PRU_CONTROL,
							    cmd, data, ifp));
		switch (ocmd) {

		case OSIOCGIFADDR:
		case OSIOCGIFDSTADDR:
		case OSIOCGIFBRDADDR:
		case OSIOCGIFNETMASK:
			*(u_short *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;
		}
		return (error);

	    }
#endif
	}
	return (0);
}

/*
 * Return interface configuration
 * of system.  List may be used
 * in later ioctl's (above) to get
 * other information.
 */
/*ARGSUSED*/
ifconf(cmd, data)
	int cmd;
	caddr_t data;
{
	register struct ifconf *ifc = (struct ifconf *)data;
	register struct ifnet *ifp = ifnet;
	register struct ifaddr *ifa;
	register char *cp, *ep;
	struct ifreq ifr, *ifrp;
	int space = ifc->ifc_len, error = 0;

	ifrp = ifc->ifc_req;
	ep = ifr.ifr_name + sizeof (ifr.ifr_name) - 2;
	for (; space > sizeof (ifr) && ifp; ifp = ifp->if_next) {
		bcopy(ifp->if_name, ifr.ifr_name, sizeof (ifr.ifr_name) - 2);
		for (cp = ifr.ifr_name; cp < ep && *cp; cp++)
			;
		*cp++ = '0' + ifp->if_unit; *cp = '\0';
		if ((ifa = ifp->if_addrlist) == 0) {
			bzero((caddr_t)&ifr.ifr_addr, sizeof(ifr.ifr_addr));
			error = copyout((caddr_t)&ifr, (caddr_t)ifrp, sizeof (ifr));
			if (error)
				break;
			space -= sizeof (ifr), ifrp++;
		} else 
		    for ( ; space > sizeof (ifr) && ifa; ifa = ifa->ifa_next) {
			register struct sockaddr *sa = ifa->ifa_addr;
#ifdef COMPAT_43
			if (cmd == OSIOCGIFCONF) {
				struct osockaddr *osa =
					 (struct osockaddr *)&ifr.ifr_addr;
				ifr.ifr_addr = *sa;
				osa->sa_family = sa->sa_family;
				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
						sizeof (ifr));
				ifrp++;
			} else
#endif
			if (sa->sa_len <= sizeof(*sa)) {
				ifr.ifr_addr = *sa;
				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
						sizeof (ifr));
				ifrp++;
			} else {
				space -= sa->sa_len - sizeof(*sa);
				if (space < sizeof (ifr))
					break;
				error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
						sizeof (ifr.ifr_name));
				if (error == 0)
				    error = copyout((caddr_t)sa,
				      (caddr_t)&ifrp->ifr_addr, sa->sa_len);
				ifrp = (struct ifreq *)
					(sa->sa_len + (caddr_t)&ifrp->ifr_addr);
			}
			if (error)
				break;
			space -= sizeof (ifr);
		}
	}
	ifc->ifc_len -= space;
	return (error);
}

static char *
sprint_d(n, buf, buflen)
	u_int n;
	char *buf;
	int buflen;
{
	register char *cp = buf + buflen - 1;

	*cp = 0;
	do {
		cp--;
		*cp = "0123456789"[n % 10];
		n /= 10;
	} while (n != 0);
	return (cp);
}