route.c

来自「eCos操作系统源码」· C语言 代码 · 共 1,078 行 · 第 1/2 页

		if (flags & RTF_HOST) 
			ifa = ifa_ifwithdstaddr(dst);
		if (ifa == NULL)
			ifa = ifa_ifwithaddr(gateway);
	} else {
		/*
		 * If we are adding a route to a remote net
		 * or host, the gateway may still be on the
		 * other end of a pt to pt link.
		 */
		ifa = ifa_ifwithdstaddr(gateway);
	}
	if (ifa == NULL)
		ifa = ifa_ifwithnet(gateway);
	if (ifa == NULL) {
		struct rtentry *rt = rtalloc1(gateway, 0);
		if (rt == NULL)
			return (NULL);
		rt->rt_refcnt--;
		/* The gateway must be local if the same address family. */
		if (!(flags & RTF_TUNNEL) && (rt->rt_flags & RTF_GATEWAY) && 
		    rt_key(rt)->sa_family == dst->sa_family)
			return (0);
		if ((ifa = rt->rt_ifa) == NULL)
			return (NULL);
	}
	if (ifa->ifa_addr->sa_family != dst->sa_family) {
		struct ifaddr *oifa = ifa;
		ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
		if (ifa == NULL)
			ifa = oifa;
	}
	return (ifa);
}

#define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))

const char *
_rt_cmd(int req)
{
    switch (req)
    {
    case RTM_DELETE:
        return "DELETE";
    case RTM_RESOLVE:
        return "RESOLVE";
    case RTM_ADD:
        return "ADD";
    default:
        return "???";
    }
}

int
rtrequest(req, dst, gateway, netmask, flags, ret_nrt)
	int req, flags;
	struct sockaddr *dst, *gateway, *netmask;
	struct rtentry **ret_nrt;
{
	int s = splsoftnet(); int error = 0;
	register struct rtentry *rt;
	register struct radix_node *rn;
	register struct radix_node_head *rnh;
	struct ifaddr *ifa;
	struct sockaddr *ndst;
#define senderr(x) { error = x ; goto bad; }

	if ((rnh = rt_tables[dst->sa_family]) == 0)
		senderr(EAFNOSUPPORT);
	if (flags & RTF_HOST)
		netmask = 0;
	switch (req) {
	case RTM_DELETE:
		if ((rn = rnh->rnh_deladdr(dst, netmask, rnh)) == NULL)
			senderr(ESRCH);
		if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
			panic ("rtrequest delete");
		rt = (struct rtentry *)rn;
		rt->rt_flags &= ~RTF_UP;
		if (rt->rt_gwroute) {
		    if (rt != rt->rt_gwroute)
			RTFREE( rt->rt_gwroute ); // Free it up as normal
		    else
			rt->rt_refcnt--; // Just dec the refcount - freeing
					 // it here would be premature
		    rt->rt_gwroute = NULL;
		}
		if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
			ifa->ifa_rtrequest(RTM_DELETE, rt, SA(NULL));
		rttrash++;
		if (ret_nrt)
			*ret_nrt = rt;
		else if (rt->rt_refcnt <= 0) {
			rt->rt_refcnt++;
			rtfree(rt);
		}
		break;

	case RTM_RESOLVE:
		if (ret_nrt == NULL || (rt = *ret_nrt) == NULL)
			senderr(EINVAL);
		ifa = rt->rt_ifa;
		flags = rt->rt_flags & ~RTF_CLONING;
		gateway = rt->rt_gateway;
		if ((netmask = rt->rt_genmask) == NULL)
			flags |= RTF_HOST;
		goto makeroute;

	case RTM_ADD:
		if ((ifa = ifa_ifwithroute(flags, dst, gateway)) == NULL)
			senderr(ENETUNREACH);

		/* The interface found in the previous statement may
		 * be overridden later by rt_setif.  See the code
		 * for case RTM_ADD in rtsock.c:route_output.
		 */
	makeroute:
		R_Malloc(rt, struct rtentry *, sizeof(*rt));
		if (rt == NULL)
			senderr(ENOBUFS);
		Bzero(rt, sizeof(*rt));
		rt->rt_flags = RTF_UP | flags;
		LIST_INIT(&rt->rt_timer);
		if (rt_setgate(rt, dst, gateway)) {
			Free(rt);
			senderr(ENOBUFS);
		}
		ndst = rt_key(rt);
		if (netmask) {
			rt_maskedcopy(dst, ndst, netmask);
		} else
			Bcopy(dst, ndst, dst->sa_len);
if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU)) { /* XXX */
  rt->rt_rmx.rmx_mtu = ifa->ifa_ifp->if_mtu;
}
		rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask,
					rnh, rt->rt_nodes);
		if (rn == NULL) {
			if (rt->rt_gwroute)
				rtfree(rt->rt_gwroute);
			Free(rt_key(rt));
			Free(rt);
			senderr(EEXIST);
		}
		ifa->ifa_refcnt++;
		rt->rt_ifa = ifa;
		rt->rt_ifp = ifa->ifa_ifp;
		if (req == RTM_RESOLVE) {
			/*
			 * Copy both metrics and a back pointer to the cloned
			 * route's parent.
			 */
			rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
			rt->rt_parent = *ret_nrt;	 /* Back ptr. to parent. */
		}
		if (ifa->ifa_rtrequest)
			ifa->ifa_rtrequest(req, rt, SA(ret_nrt ? *ret_nrt : NULL));
		if (ret_nrt) {
			*ret_nrt = rt;
			rt->rt_refcnt++;
		}
#ifdef INET6
		/* If we have a v4_in_v4 or a v4_in_v6 tunnel route
		 * then do some tunnel state (e.g. security state)
		 * initialization.
		 *
		 * Since IPV6 packets flow down this path, we don't
		 * want it using ipv4_tunnelsetup(rt) (since they
		 * have their own ipv6_tunnel_parent/child()
		 * routines which are called ipv6_rtrequest().)
		 *
		 * Thus, we check to see if the packet is to a v4
		 * destination.
		 */
		if (dst->sa_family == AF_INET && (rt->rt_flags & RTF_TUNNEL))
			ipv4_tunnelsetup(rt);
#endif /* INET6 */
		break;
	}
bad:
	splx(s);
	return (error);
}

/*
 * Set up any tunnel states (e.g. security) information
 * for v4_in_v4 or v4_in_v6 tunnel routes.
 */
void
ipv4_tunnelsetup(rt)
	register struct rtentry *rt;
{
	/* XXX */
}

int
rt_setgate(rt0, dst, gate)
	struct rtentry *rt0;
	struct sockaddr *dst, *gate;
{
	caddr_t new, old;
	int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len);
	register struct rtentry *rt = rt0;

	if (rt->rt_gateway == NULL || glen > ROUNDUP(rt->rt_gateway->sa_len)) {
		old = (caddr_t)rt_key(rt);
		R_Malloc(new, caddr_t, dlen + glen);
		if (new == NULL)
			return 1;
		rt->rt_nodes->rn_key = new;
	} else {
		new = rt->rt_nodes->rn_key;
		old = NULL;
	}
	Bcopy(gate, (rt->rt_gateway = (struct sockaddr *)(new + dlen)), glen);
	if (old) {
		Bcopy(dst, new, dlen);
		Free(old);
	}
	if (rt->rt_gwroute != NULL) {
		rt = rt->rt_gwroute;
		RTFREE(rt);
		rt = rt0;
		rt->rt_gwroute = NULL;
	}
	if (rt->rt_flags & RTF_GATEWAY) {
		rt->rt_gwroute = rtalloc1(gate, 1);
	}
	return 0;
}

void
rt_maskedcopy(src, dst, netmask)
	struct sockaddr *src, *dst, *netmask;
{
	register u_char *cp1 = (u_char *)src;
	register u_char *cp2 = (u_char *)dst;
	register u_char *cp3 = (u_char *)netmask;
	u_char *cplim = cp2 + *cp3;
	u_char *cplim2 = cp2 + *cp1;

	*cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
	cp3 += 2;
	if (cplim > cplim2)
		cplim = cplim2;
	while (cp2 < cplim)
		*cp2++ = *cp1++ & *cp3++;
	if (cp2 < cplim2)
		bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
}

/*
 * Set up a routing table entry, normally
 * for an interface.
 */
int
rtinit(ifa, cmd, flags)
	register struct ifaddr *ifa;
	int cmd, flags;
{
	register struct rtentry *rt;
	register struct sockaddr *dst;
	register struct sockaddr *deldst;
	struct mbuf *m = NULL;
	struct rtentry *nrt = NULL;
	int error;

	dst = flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr;
	if (cmd == RTM_DELETE) {
		if ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
			m = m_get(M_DONTWAIT, MT_SONAME);
			if (m == NULL)
				return(ENOBUFS);
			deldst = mtod(m, struct sockaddr *);
			rt_maskedcopy(dst, deldst, ifa->ifa_netmask);
			dst = deldst;
		}
		if ((rt = rtalloc1(dst, 0)) != NULL) {
			rt->rt_refcnt--;
			if (rt->rt_ifa != ifa) {
				if (m != NULL)
					(void) m_free(m);
				return (flags & RTF_HOST ? EHOSTUNREACH
							: ENETUNREACH);
			}
		}
	}
	error = rtrequest(cmd, dst, ifa->ifa_addr, ifa->ifa_netmask,
			flags | ifa->ifa_flags, &nrt);
	if (m != NULL)
		(void) m_free(m);
	if (cmd == RTM_DELETE && error == 0 && (rt = nrt) != NULL) {
		rt_newaddrmsg(cmd, ifa, error, nrt);
		if (rt->rt_refcnt <= 0) {
			rt->rt_refcnt++;
			rtfree(rt);
		}
	}
	if (cmd == RTM_ADD && error == 0 && (rt = nrt) != NULL) {
		rt->rt_refcnt--;
#ifdef INET6
		/* Initialize Path MTU for IPv6 interface route */
		if (ifa->ifa_addr->sa_family == AF_INET6 &&
		    !rt->rt_rmx.rmx_mtu)
			rt->rt_rmx.rmx_mtu = ifa->ifa_ifp->if_mtu;
#endif /* INET6 */
		if (rt->rt_ifa != ifa) {
#ifdef __ECOS
			diag_printf("rtinit: wrong ifa (%x) was (%x)\n",
			       ifa, rt->rt_ifa);
#else
			printf("rtinit: wrong ifa (%x) was (%x)\n",
			       ifa, rt->rt_ifa);
#endif
			if (rt->rt_ifa->ifa_rtrequest)
				rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt,
				    SA(NULL));
			IFAFREE(rt->rt_ifa);
			rt->rt_ifa = ifa;
			rt->rt_ifp = ifa->ifa_ifp;
			rt->rt_rmx.rmx_mtu = ifa->ifa_ifp->if_mtu;	/*XXX*/
			ifa->ifa_refcnt++;
			if (ifa->ifa_rtrequest)
				ifa->ifa_rtrequest(RTM_ADD, rt, SA(NULL));
		}
		rt_newaddrmsg(cmd, ifa, error, nrt);
	}
	return (error);
}

/*
 * Route timer routines.  These routes allow functions to be called
 * for various routes at any time.  This is useful in supporting
 * path MTU discovery and redirect route deletion.
 *
 * This is similar to some BSDI internal functions, but it provides
 * for multiple queues for efficiency's sake...
 */

LIST_HEAD(, rttimer_queue) rttimer_queue_head;
static int rt_init_done = 0;

#define RTTIMER_CALLOUT(r)	{				\
	if (r->rtt_func != NULL) {				\
		(*r->rtt_func)(r->rtt_rt, r);			\
	} else {						\
		rtrequest((int) RTM_DELETE,			\
			  (struct sockaddr *)rt_key(r->rtt_rt),	\
			  0, 0, 0, 0);				\
	}							\
}

/* 
 * Some subtle order problems with domain initialization mean that
 * we cannot count on this being run from rt_init before various
 * protocol initializations are done.  Therefore, we make sure
 * that this is run when the first queue is added...
 */

void	 
rt_timer_init()
{
#ifndef __ECOS
	assert(rt_init_done == 0);
#endif

#if 0
	pool_init(&rttimer_pool, sizeof(struct rttimer), 0, 0, 0, "rttmrpl",
	    0, NULL, NULL, M_RTABLE);
#endif

	LIST_INIT(&rttimer_queue_head);
	timeout(rt_timer_timer, NULL, hz);  /* every second */
	rt_init_done = 1;
}

struct rttimer_queue *
rt_timer_queue_create(timeout)
	u_int	timeout;
{
	struct rttimer_queue *rtq;

	if (rt_init_done == 0)
		rt_timer_init();

	R_Malloc(rtq, struct rttimer_queue *, sizeof *rtq);
	if (rtq == NULL)
		return (NULL);		

	rtq->rtq_timeout = timeout;
	TAILQ_INIT(&rtq->rtq_head);
	LIST_INSERT_HEAD(&rttimer_queue_head, rtq, rtq_link);

	return (rtq);
}

void
rt_timer_queue_change(rtq, timeout)
	struct rttimer_queue *rtq;
	long timeout;
{

	rtq->rtq_timeout = timeout;
}


void
rt_timer_queue_destroy(rtq, destroy)
	struct rttimer_queue *rtq;
	int destroy;
{
	struct rttimer *r;

	while ((r = TAILQ_FIRST(&rtq->rtq_head)) != NULL) {
		LIST_REMOVE(r, rtt_link);
		TAILQ_REMOVE(&rtq->rtq_head, r, rtt_next);
		if (destroy)
			RTTIMER_CALLOUT(r);
#if 0
		pool_put(&rttimer_pool, r);
#else
		free(r, M_RTABLE);
#endif
	}

	LIST_REMOVE(rtq, rtq_link);

	/*
	 * Caller is responsible for freeing the rttimer_queue structure.
	 */
}

void     
rt_timer_remove_all(rt)
	struct rtentry *rt;
{
	struct rttimer *r;

	while ((r = LIST_FIRST(&rt->rt_timer)) != NULL) {
		LIST_REMOVE(r, rtt_link);
		TAILQ_REMOVE(&r->rtt_queue->rtq_head, r, rtt_next);
#if 0
		pool_put(&rttimer_pool, r);
#else
		free(r, M_RTABLE);
#endif
	}
}

int      
rt_timer_add(rt, func, queue)
	struct rtentry *rt;
	void(*func) __P((struct rtentry *, struct rttimer *));
	struct rttimer_queue *queue;
{
	struct rttimer *r;
	long current_time;
	int s;

	s = splclock();
#ifdef __ECOS
        get_mono_time();
#endif
	current_time = mono_time.tv_sec;
	splx(s);

	/*
	 * If there's already a timer with this action, destroy it before
	 * we add a new one.
	 */
	for (r = LIST_FIRST(&rt->rt_timer); r != NULL;
	     r = LIST_NEXT(r, rtt_link)) {
		if (r->rtt_func == func) {
			LIST_REMOVE(r, rtt_link);
			TAILQ_REMOVE(&r->rtt_queue->rtq_head, r, rtt_next);
#if 0
			pool_put(&rttimer_pool, r);
#else
			free(r, M_RTABLE);
#endif
			break;  /* only one per list, so we can quit... */
		}
	}

#if 0
	r = pool_get(&rttimer_pool, PR_NOWAIT);
#else
	r = (struct rttimer *)malloc(sizeof(*r), M_RTABLE, M_NOWAIT);
#endif
	if (r == NULL)
		return (ENOBUFS);

	r->rtt_rt = rt;
	r->rtt_time = current_time;
	r->rtt_func = func;
	r->rtt_queue = queue;
	LIST_INSERT_HEAD(&rt->rt_timer, r, rtt_link);
	TAILQ_INSERT_TAIL(&queue->rtq_head, r, rtt_next);
	
	return (0);
}

/* ARGSUSED */
void
rt_timer_timer(arg)
	void *arg;
{
	struct rttimer_queue *rtq;
	struct rttimer *r;
	long current_time;
	int s;

	s = splclock();
#ifdef __ECOS
        get_mono_time();
#endif
	current_time = mono_time.tv_sec;
	splx(s);

	s = splsoftnet();
	for (rtq = LIST_FIRST(&rttimer_queue_head); rtq != NULL; 
	     rtq = LIST_NEXT(rtq, rtq_link)) {
		while ((r = TAILQ_FIRST(&rtq->rtq_head)) != NULL &&
		    (r->rtt_time + rtq->rtq_timeout) < current_time) {
			LIST_REMOVE(r, rtt_link);
			TAILQ_REMOVE(&rtq->rtq_head, r, rtt_next);
			RTTIMER_CALLOUT(r);
#if 0
			pool_put(&rttimer_pool, r);
#else
			free(r, M_RTABLE);
#endif
		}
	}
	splx(s);

	timeout(rt_timer_timer, NULL, hz);  /* every second */
}