ddp.c

linux 内核源代码

	return atr ? atr->dev : NULL;
}

/* Set up a default router */
static void atrtr_set_default(struct net_device *dev)
{
	atrtr_default.dev	     = dev;
	atrtr_default.flags	     = RTF_UP;
	atrtr_default.gateway.s_net  = htons(0);
	atrtr_default.gateway.s_node = 0;
}

/*
 * Add a router. Basically make sure it looks valid and stuff the
 * entry in the list. While it uses netranges we always set them to one
 * entry to work like netatalk.
 */
static int atrtr_create(struct rtentry *r, struct net_device *devhint)
{
	struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
	struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
	struct atalk_route *rt;
	struct atalk_iface *iface, *riface;
	int retval = -EINVAL;

	/*
	 * Fixme: Raise/Lower a routing change semaphore for these
	 * operations.
	 */

	/* Validate the request */
	if (ta->sat_family != AF_APPLETALK ||
	    (!devhint && ga->sat_family != AF_APPLETALK))
		goto out;

	/* Now walk the routing table and make our decisions */
	write_lock_bh(&atalk_routes_lock);
	for (rt = atalk_routes; rt; rt = rt->next) {
		if (r->rt_flags != rt->flags)
			continue;

		if (ta->sat_addr.s_net == rt->target.s_net) {
			if (!(rt->flags & RTF_HOST))
				break;
			if (ta->sat_addr.s_node == rt->target.s_node)
				break;
		}
	}

	if (!devhint) {
		riface = NULL;

		read_lock_bh(&atalk_interfaces_lock);
		for (iface = atalk_interfaces; iface; iface = iface->next) {
			if (!riface &&
			    ntohs(ga->sat_addr.s_net) >=
					ntohs(iface->nets.nr_firstnet) &&
			    ntohs(ga->sat_addr.s_net) <=
					ntohs(iface->nets.nr_lastnet))
				riface = iface;

			if (ga->sat_addr.s_net == iface->address.s_net &&
			    ga->sat_addr.s_node == iface->address.s_node)
				riface = iface;
		}
		read_unlock_bh(&atalk_interfaces_lock);

		retval = -ENETUNREACH;
		if (!riface)
			goto out_unlock;

		devhint = riface->dev;
	}

	if (!rt) {
		rt = kzalloc(sizeof(*rt), GFP_ATOMIC);

		retval = -ENOBUFS;
		if (!rt)
			goto out_unlock;

		rt->next = atalk_routes;
		atalk_routes = rt;
	}

	/* Fill in the routing entry */
	rt->target  = ta->sat_addr;
	dev_hold(devhint);
	rt->dev     = devhint;
	rt->flags   = r->rt_flags;
	rt->gateway = ga->sat_addr;

	retval = 0;
out_unlock:
	write_unlock_bh(&atalk_routes_lock);
out:
	return retval;
}

/* Delete a route. Find it and discard it */
static int atrtr_delete(struct atalk_addr * addr)
{
	struct atalk_route **r = &atalk_routes;
	int retval = 0;
	struct atalk_route *tmp;

	write_lock_bh(&atalk_routes_lock);
	while ((tmp = *r) != NULL) {
		if (tmp->target.s_net == addr->s_net &&
		    (!(tmp->flags&RTF_GATEWAY) ||
		     tmp->target.s_node == addr->s_node)) {
			*r = tmp->next;
			dev_put(tmp->dev);
			kfree(tmp);
			goto out;
		}
		r = &tmp->next;
	}
	retval = -ENOENT;
out:
	write_unlock_bh(&atalk_routes_lock);
	return retval;
}

/*
 * Called when a device is downed. Just throw away any routes
 * via it.
 */
static void atrtr_device_down(struct net_device *dev)
{
	struct atalk_route **r = &atalk_routes;
	struct atalk_route *tmp;

	write_lock_bh(&atalk_routes_lock);
	while ((tmp = *r) != NULL) {
		if (tmp->dev == dev) {
			*r = tmp->next;
			dev_put(dev);
			kfree(tmp);
		} else
			r = &tmp->next;
	}
	write_unlock_bh(&atalk_routes_lock);

	if (atrtr_default.dev == dev)
		atrtr_set_default(NULL);
}

/* Actually down the interface */
static inline void atalk_dev_down(struct net_device *dev)
{
	atrtr_device_down(dev);	/* Remove all routes for the device */
	aarp_device_down(dev);	/* Remove AARP entries for the device */
	atif_drop_device(dev);	/* Remove the device */
}

/*
 * A device event has occurred. Watch for devices going down and
 * delete our use of them (iface and route).
 */
static int ddp_device_event(struct notifier_block *this, unsigned long event,
			    void *ptr)
{
	struct net_device *dev = ptr;

	if (dev->nd_net != &init_net)
		return NOTIFY_DONE;

	if (event == NETDEV_DOWN)
		/* Discard any use of this */
		atalk_dev_down(dev);

	return NOTIFY_DONE;
}

/* ioctl calls. Shouldn't even need touching */
/* Device configuration ioctl calls */
static int atif_ioctl(int cmd, void __user *arg)
{
	static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
	struct ifreq atreq;
	struct atalk_netrange *nr;
	struct sockaddr_at *sa;
	struct net_device *dev;
	struct atalk_iface *atif;
	int ct;
	int limit;
	struct rtentry rtdef;
	int add_route;

	if (copy_from_user(&atreq, arg, sizeof(atreq)))
		return -EFAULT;

	dev = __dev_get_by_name(&init_net, atreq.ifr_name);
	if (!dev)
		return -ENODEV;

	sa = (struct sockaddr_at *)&atreq.ifr_addr;
	atif = atalk_find_dev(dev);

	switch (cmd) {
		case SIOCSIFADDR:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (sa->sat_family != AF_APPLETALK)
				return -EINVAL;
			if (dev->type != ARPHRD_ETHER &&
			    dev->type != ARPHRD_LOOPBACK &&
			    dev->type != ARPHRD_LOCALTLK &&
			    dev->type != ARPHRD_PPP)
				return -EPROTONOSUPPORT;

			nr = (struct atalk_netrange *)&sa->sat_zero[0];
			add_route = 1;

			/*
			 * if this is a point-to-point iface, and we already
			 * have an iface for this AppleTalk address, then we
			 * should not add a route
			 */
			if ((dev->flags & IFF_POINTOPOINT) &&
			    atalk_find_interface(sa->sat_addr.s_net,
						 sa->sat_addr.s_node)) {
				printk(KERN_DEBUG "AppleTalk: point-to-point "
						  "interface added with "
						  "existing address\n");
				add_route = 0;
			}

			/*
			 * Phase 1 is fine on LocalTalk but we don't do
			 * EtherTalk phase 1. Anyone wanting to add it go ahead.
			 */
			if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
				return -EPROTONOSUPPORT;
			if (sa->sat_addr.s_node == ATADDR_BCAST ||
			    sa->sat_addr.s_node == 254)
				return -EINVAL;
			if (atif) {
				/* Already setting address */
				if (atif->status & ATIF_PROBE)
					return -EBUSY;

				atif->address.s_net  = sa->sat_addr.s_net;
				atif->address.s_node = sa->sat_addr.s_node;
				atrtr_device_down(dev);	/* Flush old routes */
			} else {
				atif = atif_add_device(dev, &sa->sat_addr);
				if (!atif)
					return -ENOMEM;
			}
			atif->nets = *nr;

			/*
			 * Check if the chosen address is used. If so we
			 * error and atalkd will try another.
			 */

			if (!(dev->flags & IFF_LOOPBACK) &&
			    !(dev->flags & IFF_POINTOPOINT) &&
			    atif_probe_device(atif) < 0) {
				atif_drop_device(dev);
				return -EADDRINUSE;
			}

			/* Hey it worked - add the direct routes */
			sa = (struct sockaddr_at *)&rtdef.rt_gateway;
			sa->sat_family = AF_APPLETALK;
			sa->sat_addr.s_net  = atif->address.s_net;
			sa->sat_addr.s_node = atif->address.s_node;
			sa = (struct sockaddr_at *)&rtdef.rt_dst;
			rtdef.rt_flags = RTF_UP;
			sa->sat_family = AF_APPLETALK;
			sa->sat_addr.s_node = ATADDR_ANYNODE;
			if (dev->flags & IFF_LOOPBACK ||
			    dev->flags & IFF_POINTOPOINT)
				rtdef.rt_flags |= RTF_HOST;

			/* Routerless initial state */
			if (nr->nr_firstnet == htons(0) &&
			    nr->nr_lastnet == htons(0xFFFE)) {
				sa->sat_addr.s_net = atif->address.s_net;
				atrtr_create(&rtdef, dev);
				atrtr_set_default(dev);
			} else {
				limit = ntohs(nr->nr_lastnet);
				if (limit - ntohs(nr->nr_firstnet) > 4096) {
					printk(KERN_WARNING "Too many routes/"
							    "iface.\n");
					return -EINVAL;
				}
				if (add_route)
					for (ct = ntohs(nr->nr_firstnet);
					     ct <= limit; ct++) {
						sa->sat_addr.s_net = htons(ct);
						atrtr_create(&rtdef, dev);
					}
			}
			dev_mc_add(dev, aarp_mcast, 6, 1);
			return 0;

		case SIOCGIFADDR:
			if (!atif)
				return -EADDRNOTAVAIL;

			sa->sat_family = AF_APPLETALK;
			sa->sat_addr = atif->address;
			break;

		case SIOCGIFBRDADDR:
			if (!atif)
				return -EADDRNOTAVAIL;

			sa->sat_family = AF_APPLETALK;
			sa->sat_addr.s_net = atif->address.s_net;
			sa->sat_addr.s_node = ATADDR_BCAST;
			break;

		case SIOCATALKDIFADDR:
		case SIOCDIFADDR:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (sa->sat_family != AF_APPLETALK)
				return -EINVAL;
			atalk_dev_down(dev);
			break;

		case SIOCSARP:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (sa->sat_family != AF_APPLETALK)
				return -EINVAL;
			if (!atif)
				return -EADDRNOTAVAIL;

			/*
			 * for now, we only support proxy AARP on ELAP;
			 * we should be able to do it for LocalTalk, too.
			 */
			if (dev->type != ARPHRD_ETHER)
				return -EPROTONOSUPPORT;

			/*
			 * atif points to the current interface on this network;
			 * we aren't concerned about its current status (at
			 * least for now), but it has all the settings about
			 * the network we're going to probe. Consequently, it
			 * must exist.
			 */
			if (!atif)
				return -EADDRNOTAVAIL;

			nr = (struct atalk_netrange *)&(atif->nets);
			/*
			 * Phase 1 is fine on Localtalk but we don't do
			 * Ethertalk phase 1. Anyone wanting to add it go ahead.
			 */
			if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
				return -EPROTONOSUPPORT;

			if (sa->sat_addr.s_node == ATADDR_BCAST ||
			    sa->sat_addr.s_node == 254)
				return -EINVAL;

			/*
			 * Check if the chosen address is used. If so we
			 * error and ATCP will try another.
			 */
			if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
				return -EADDRINUSE;

			/*
			 * We now have an address on the local network, and
			 * the AARP code will defend it for us until we take it
			 * down. We don't set up any routes right now, because
			 * ATCP will install them manually via SIOCADDRT.
			 */
			break;

		case SIOCDARP:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (sa->sat_family != AF_APPLETALK)
				return -EINVAL;
			if (!atif)
				return -EADDRNOTAVAIL;

			/* give to aarp module to remove proxy entry */
			aarp_proxy_remove(atif->dev, &(sa->sat_addr));
			return 0;
	}

	return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
}

/* Routing ioctl() calls */
static int atrtr_ioctl(unsigned int cmd, void __user *arg)
{
	struct rtentry rt;

	if (copy_from_user(&rt, arg, sizeof(rt)))
		return -EFAULT;

	switch (cmd) {
		case SIOCDELRT:
			if (rt.rt_dst.sa_family != AF_APPLETALK)
				return -EINVAL;
			return atrtr_delete(&((struct sockaddr_at *)
						&rt.rt_dst)->sat_addr);

		case SIOCADDRT: {
			struct net_device *dev = NULL;
			if (rt.rt_dev) {
				char name[IFNAMSIZ];
				if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
					return -EFAULT;
				name[IFNAMSIZ-1] = '\0';
				dev = __dev_get_by_name(&init_net, name);
				if (!dev)
					return -ENODEV;
			}
			return atrtr_create(&rt, dev);
		}
	}
	return -EINVAL;
}

/**************************************************************************\
*                                                                          *
* Handling for system calls applied via the various interfaces to an       *
* AppleTalk socket object.                                                 *
*                                                                          *
\**************************************************************************/

/*
 * Checksum: This is 'optional'. It's quite likely also a good
 * candidate for assembler hackery 8)
 */
static unsigned long atalk_sum_partial(const unsigned char *data,
				       int len, unsigned long sum)
{
	/* This ought to be unwrapped neatly. I'll trust gcc for now */
	while (len--) {
		sum += *data;
		sum <<= 1;
		if (sum & 0x10000) {
			sum++;
			sum &= 0xffff;
		}
		data++;
	}
	return sum;
}

/*  Checksum skb data --  similar to skb_checksum  */
static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
				   int len, unsigned long sum)
{
	int start = skb_headlen(skb);
	int i, copy;

	/* checksum stuff in header space */
	if ( (copy = start - offset) > 0) {
		if (copy > len)
			copy = len;
		sum = atalk_sum_partial(skb->data + offset, copy, sum);
		if ( (len -= copy) == 0)
			return sum;

		offset += copy;
	}

	/* checksum stuff in frags */
	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
		int end;

		BUG_TRAP(start <= offset + len);

		end = start + skb_shinfo(skb)->frags[i].size;
		if ((copy = end - offset) > 0) {
			u8 *vaddr;
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

			if (copy > len)
				copy = len;
			vaddr = kmap_skb_frag(frag);