rtnetlink.c

Linux Kernel 2.6.9 for OMAP1710

	}

	if (ida[IFLA_TXQLEN - 1]) {
		if (ida[IFLA_TXQLEN - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
			goto out;

		dev->tx_queue_len = *((u32 *) RTA_DATA(ida[IFLA_TXQLEN - 1]));
	}

	if (ida[IFLA_WEIGHT - 1]) {
		if (ida[IFLA_WEIGHT - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
			goto out;

		dev->weight = *((u32 *) RTA_DATA(ida[IFLA_WEIGHT - 1]));
	}

	if (ida[IFLA_IFNAME - 1]) {
		char ifname[IFNAMSIZ];

		if (ida[IFLA_IFNAME - 1]->rta_len > RTA_LENGTH(sizeof(ifname)))
			goto out;

		memset(ifname, 0, sizeof(ifname));
		memcpy(ifname, RTA_DATA(ida[IFLA_IFNAME - 1]),
			RTA_PAYLOAD(ida[IFLA_IFNAME - 1]));
		ifname[IFNAMSIZ - 1] = '\0';

		err = dev_change_name(dev, ifname);

		if (err)
			goto out;
	}

	err = 0;

out:
	if (send_addr_notify)
		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);

	dev_put(dev);
	return err;
}

static int rtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx;
	int s_idx = cb->family;

	if (s_idx == 0)
		s_idx = 1;
	for (idx=1; idx<NPROTO; idx++) {
		int type = cb->nlh->nlmsg_type-RTM_BASE;
		if (idx < s_idx || idx == PF_PACKET)
			continue;
		if (rtnetlink_links[idx] == NULL ||
		    rtnetlink_links[idx][type].dumpit == NULL)
			continue;
		if (idx > s_idx)
			memset(&cb->args[0], 0, sizeof(cb->args));
		if (rtnetlink_links[idx][type].dumpit(skb, cb))
			break;
	}
	cb->family = idx;

	return skb->len;
}

void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
{
	struct sk_buff *skb;
	int size = NLMSG_SPACE(sizeof(struct ifinfomsg) +
			       sizeof(struct rtnl_link_ifmap) +
			       sizeof(struct rtnl_link_stats) + 128);

	skb = alloc_skb(size, GFP_KERNEL);
	if (!skb)
		return;

	if (rtnetlink_fill_ifinfo(skb, dev, type, 0, 0, change) < 0) {
		kfree_skb(skb);
		return;
	}
	NETLINK_CB(skb).dst_groups = RTMGRP_LINK;
	netlink_broadcast(rtnl, skb, 0, RTMGRP_LINK, GFP_KERNEL);
}

static int rtnetlink_done(struct netlink_callback *cb)
{
	return 0;
}

/* Protected by RTNL sempahore.  */
static struct rtattr **rta_buf;
static int rtattr_max;

/* Process one rtnetlink message. */

static __inline__ int
rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
{
	struct rtnetlink_link *link;
	struct rtnetlink_link *link_tab;
	int sz_idx, kind;
	int min_len;
	int family;
	int type;
	int err;

	/* Only requests are handled by kernel now */
	if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
		return 0;

	type = nlh->nlmsg_type;

	/* A control message: ignore them */
	if (type < RTM_BASE)
		return 0;

	/* Unknown message: reply with EINVAL */
	if (type > RTM_MAX)
		goto err_inval;

	type -= RTM_BASE;

	/* All the messages must have at least 1 byte length */
	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
		return 0;

	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
	if (family >= NPROTO) {
		*errp = -EAFNOSUPPORT;
		return -1;
	}

	link_tab = rtnetlink_links[family];
	if (link_tab == NULL)
		link_tab = rtnetlink_links[PF_UNSPEC];
	link = &link_tab[type];

	sz_idx = type>>2;
	kind = type&3;

	if (kind != 2 && security_netlink_recv(skb)) {
		*errp = -EPERM;
		return -1;
	}

	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
		u32 rlen;

		if (link->dumpit == NULL)
			link = &(rtnetlink_links[PF_UNSPEC][type]);

		if (link->dumpit == NULL)
			goto err_inval;

		if ((*errp = netlink_dump_start(rtnl, skb, nlh,
						link->dumpit,
						rtnetlink_done)) != 0) {
			return -1;
		}
		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
		if (rlen > skb->len)
			rlen = skb->len;
		skb_pull(skb, rlen);
		return -1;
	}

	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));

	min_len = rtm_min[sz_idx];
	if (nlh->nlmsg_len < min_len)
		goto err_inval;

	if (nlh->nlmsg_len > min_len) {
		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);

		while (RTA_OK(attr, attrlen)) {
			unsigned flavor = attr->rta_type;
			if (flavor) {
				if (flavor > rta_max[sz_idx])
					goto err_inval;
				rta_buf[flavor-1] = attr;
			}
			attr = RTA_NEXT(attr, attrlen);
		}
	}

	if (link->doit == NULL)
		link = &(rtnetlink_links[PF_UNSPEC][type]);
	if (link->doit == NULL)
		goto err_inval;
	err = link->doit(skb, nlh, (void *)&rta_buf[0]);

	*errp = err;
	return err;

err_inval:
	*errp = -EINVAL;
	return -1;
}

/* 
 * Process one packet of messages.
 * Malformed skbs with wrong lengths of messages are discarded silently.
 */

static inline int rtnetlink_rcv_skb(struct sk_buff *skb)
{
	int err;
	struct nlmsghdr * nlh;

	while (skb->len >= NLMSG_SPACE(0)) {
		u32 rlen;

		nlh = (struct nlmsghdr *)skb->data;
		if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
			return 0;
		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
		if (rlen > skb->len)
			rlen = skb->len;
		if (rtnetlink_rcv_msg(skb, nlh, &err)) {
			/* Not error, but we must interrupt processing here:
			 *   Note, that in this case we do not pull message
			 *   from skb, it will be processed later.
			 */
			if (err == 0)
				return -1;
			netlink_ack(skb, nlh, err);
		} else if (nlh->nlmsg_flags&NLM_F_ACK)
			netlink_ack(skb, nlh, 0);
		skb_pull(skb, rlen);
	}

	return 0;
}

/*
 *  rtnetlink input queue processing routine:
 *	- try to acquire shared lock. If it is failed, defer processing.
 *	- feed skbs to rtnetlink_rcv_skb, until it refuse a message,
 *	  that will occur, when a dump started and/or acquisition of
 *	  exclusive lock failed.
 */

static void rtnetlink_rcv(struct sock *sk, int len)
{
	do {
		struct sk_buff *skb;

		if (rtnl_shlock_nowait())
			return;

		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
			if (rtnetlink_rcv_skb(skb)) {
				if (skb->len)
					skb_queue_head(&sk->sk_receive_queue,
						       skb);
				else
					kfree_skb(skb);
				break;
			}
			kfree_skb(skb);
		}

		up(&rtnl_sem);

		netdev_run_todo();
	} while (rtnl && rtnl->sk_receive_queue.qlen);
}

static struct rtnetlink_link link_rtnetlink_table[RTM_MAX-RTM_BASE+1] =
{
	[RTM_GETLINK  - RTM_BASE] = { .dumpit = rtnetlink_dump_ifinfo },
	[RTM_SETLINK  - RTM_BASE] = { .doit   = do_setlink	      },
	[RTM_GETADDR  - RTM_BASE] = { .dumpit = rtnetlink_dump_all    },
	[RTM_GETROUTE - RTM_BASE] = { .dumpit = rtnetlink_dump_all    },
	[RTM_NEWNEIGH - RTM_BASE] = { .doit   = neigh_add	      },
	[RTM_DELNEIGH - RTM_BASE] = { .doit   = neigh_delete	      },
	[RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info	      }
};

static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;
	switch (event) {
	case NETDEV_UNREGISTER:
		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
		break;
	case NETDEV_REGISTER:
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
		break;
	case NETDEV_UP:
	case NETDEV_DOWN:
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
		break;
	case NETDEV_CHANGE:
	case NETDEV_GOING_DOWN:
		break;
	default:
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
		break;
	}
	return NOTIFY_DONE;
}

static struct notifier_block rtnetlink_dev_notifier = {
	.notifier_call	= rtnetlink_event,
};

void __init rtnetlink_init(void)
{
	int i;

	rtattr_max = 0;
	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
		if (rta_max[i] > rtattr_max)
			rtattr_max = rta_max[i];
	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
	if (!rta_buf)
		panic("rtnetlink_init: cannot allocate rta_buf\n");

	rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
	if (rtnl == NULL)
		panic("rtnetlink_init: cannot initialize rtnetlink\n");
	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
	register_netdevice_notifier(&rtnetlink_dev_notifier);
	rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
	rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
}

EXPORT_SYMBOL(__rta_fill);
EXPORT_SYMBOL(rtattr_parse);
EXPORT_SYMBOL(rtnetlink_dump_ifinfo);
EXPORT_SYMBOL(rtnetlink_links);
EXPORT_SYMBOL(rtnetlink_put_metrics);
EXPORT_SYMBOL(rtnl);
EXPORT_SYMBOL(rtnl_lock);
EXPORT_SYMBOL(rtnl_sem);
EXPORT_SYMBOL(rtnl_unlock);