af_mpls.c 35.7 KB
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#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
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#include <linux/sysctl.h>
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#include <linux/net.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/mpls.h>
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#include <linux/vmalloc.h>
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#include <net/ip.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/arp.h>
#include <net/ip_fib.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
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#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#endif
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#include <net/nexthop.h>
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#include "internal.h"

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/* Maximum number of labels to look ahead at when selecting a path of
 * a multipath route
 */
#define MAX_MP_SELECT_LABELS 4

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static int zero = 0;
static int label_limit = (1 << 20) - 1;

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static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
		       struct nlmsghdr *nlh, struct net *net, u32 portid,
		       unsigned int nlm_flags);

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static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
{
	struct mpls_route *rt = NULL;

	if (index < net->mpls.platform_labels) {
		struct mpls_route __rcu **platform_label =
			rcu_dereference(net->mpls.platform_label);
		rt = rcu_dereference(platform_label[index]);
	}
	return rt;
}

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static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
{
	return rcu_dereference_rtnl(dev->mpls_ptr);
}

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bool mpls_output_possible(const struct net_device *dev)
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{
	return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
}
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EXPORT_SYMBOL_GPL(mpls_output_possible);
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static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
{
	u8 *nh0_via = PTR_ALIGN((u8 *)&rt->rt_nh[rt->rt_nhn], VIA_ALEN_ALIGN);
	int nh_index = nh - rt->rt_nh;

	return nh0_via + rt->rt_max_alen * nh_index;
}

static const u8 *mpls_nh_via(const struct mpls_route *rt,
			     const struct mpls_nh *nh)
{
	return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
}

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static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
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{
	/* The size of the layer 2.5 labels to be added for this route */
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	return nh->nh_labels * sizeof(struct mpls_shim_hdr);
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}

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unsigned int mpls_dev_mtu(const struct net_device *dev)
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{
	/* The amount of data the layer 2 frame can hold */
	return dev->mtu;
}
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EXPORT_SYMBOL_GPL(mpls_dev_mtu);
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bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
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{
	if (skb->len <= mtu)
		return false;

	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
		return false;

	return true;
}
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EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
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static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
					     struct sk_buff *skb, bool bos)
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{
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	struct mpls_entry_decoded dec;
	struct mpls_shim_hdr *hdr;
	bool eli_seen = false;
	int label_index;
	int nh_index = 0;
	u32 hash = 0;

	/* No need to look further into packet if there's only
	 * one path
	 */
	if (rt->rt_nhn == 1)
		goto out;

	for (label_index = 0; label_index < MAX_MP_SELECT_LABELS && !bos;
	     label_index++) {
		if (!pskb_may_pull(skb, sizeof(*hdr) * label_index))
			break;

		/* Read and decode the current label */
		hdr = mpls_hdr(skb) + label_index;
		dec = mpls_entry_decode(hdr);

		/* RFC6790 - reserved labels MUST NOT be used as keys
		 * for the load-balancing function
		 */
		if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
			hash = jhash_1word(dec.label, hash);

			/* The entropy label follows the entropy label
			 * indicator, so this means that the entropy
			 * label was just added to the hash - no need to
			 * go any deeper either in the label stack or in the
			 * payload
			 */
			if (eli_seen)
				break;
		} else if (dec.label == MPLS_LABEL_ENTROPY) {
			eli_seen = true;
		}

		bos = dec.bos;
		if (bos && pskb_may_pull(skb, sizeof(*hdr) * label_index +
					 sizeof(struct iphdr))) {
			const struct iphdr *v4hdr;

			v4hdr = (const struct iphdr *)(mpls_hdr(skb) +
						       label_index);
			if (v4hdr->version == 4) {
				hash = jhash_3words(ntohl(v4hdr->saddr),
						    ntohl(v4hdr->daddr),
						    v4hdr->protocol, hash);
			} else if (v4hdr->version == 6 &&
				pskb_may_pull(skb, sizeof(*hdr) * label_index +
					      sizeof(struct ipv6hdr))) {
				const struct ipv6hdr *v6hdr;

				v6hdr = (const struct ipv6hdr *)(mpls_hdr(skb) +
								label_index);

				hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
				hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
				hash = jhash_1word(v6hdr->nexthdr, hash);
			}
		}
	}

	nh_index = hash % rt->rt_nhn;
out:
	return &rt->rt_nh[nh_index];
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}

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static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
			struct mpls_entry_decoded dec)
{
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	enum mpls_payload_type payload_type;
	bool success = false;
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	/* The IPv4 code below accesses through the IPv4 header
	 * checksum, which is 12 bytes into the packet.
	 * The IPv6 code below accesses through the IPv6 hop limit
	 * which is 8 bytes into the packet.
	 *
	 * For all supported cases there should always be at least 12
	 * bytes of packet data present.  The IPv4 header is 20 bytes
	 * without options and the IPv6 header is always 40 bytes
	 * long.
	 */
	if (!pskb_may_pull(skb, 12))
		return false;

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	payload_type = rt->rt_payload_type;
	if (payload_type == MPT_UNSPEC)
		payload_type = ip_hdr(skb)->version;

	switch (payload_type) {
	case MPT_IPV4: {
		struct iphdr *hdr4 = ip_hdr(skb);
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		skb->protocol = htons(ETH_P_IP);
		csum_replace2(&hdr4->check,
			      htons(hdr4->ttl << 8),
			      htons(dec.ttl << 8));
		hdr4->ttl = dec.ttl;
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		success = true;
		break;
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	}
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	case MPT_IPV6: {
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		struct ipv6hdr *hdr6 = ipv6_hdr(skb);
		skb->protocol = htons(ETH_P_IPV6);
		hdr6->hop_limit = dec.ttl;
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		success = true;
		break;
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	}
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	case MPT_UNSPEC:
		break;
	}

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	return success;
}

static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
			struct packet_type *pt, struct net_device *orig_dev)
{
	struct net *net = dev_net(dev);
	struct mpls_shim_hdr *hdr;
	struct mpls_route *rt;
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	struct mpls_nh *nh;
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	struct mpls_entry_decoded dec;
	struct net_device *out_dev;
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	struct mpls_dev *mdev;
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	unsigned int hh_len;
	unsigned int new_header_size;
	unsigned int mtu;
	int err;

	/* Careful this entire function runs inside of an rcu critical section */

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	mdev = mpls_dev_get(dev);
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	if (!mdev || !mdev->input_enabled)
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		goto drop;

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	if (skb->pkt_type != PACKET_HOST)
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		goto drop;

	if (!pskb_may_pull(skb, sizeof(*hdr)))
		goto drop;

	/* Read and decode the label */
	hdr = mpls_hdr(skb);
	dec = mpls_entry_decode(hdr);

	/* Pop the label */
	skb_pull(skb, sizeof(*hdr));
	skb_reset_network_header(skb);

	skb_orphan(skb);

	rt = mpls_route_input_rcu(net, dec.label);
	if (!rt)
		goto drop;

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	nh = mpls_select_multipath(rt, skb, dec.bos);
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	if (!nh)
		goto drop;

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	/* Find the output device */
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	out_dev = rcu_dereference(nh->nh_dev);
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	if (!mpls_output_possible(out_dev))
		goto drop;

	if (skb_warn_if_lro(skb))
		goto drop;

	skb_forward_csum(skb);

	/* Verify ttl is valid */
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	if (dec.ttl <= 1)
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		goto drop;
	dec.ttl -= 1;

	/* Verify the destination can hold the packet */
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	new_header_size = mpls_nh_header_size(nh);
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	mtu = mpls_dev_mtu(out_dev);
	if (mpls_pkt_too_big(skb, mtu - new_header_size))
		goto drop;

	hh_len = LL_RESERVED_SPACE(out_dev);
	if (!out_dev->header_ops)
		hh_len = 0;

	/* Ensure there is enough space for the headers in the skb */
	if (skb_cow(skb, hh_len + new_header_size))
		goto drop;

	skb->dev = out_dev;
	skb->protocol = htons(ETH_P_MPLS_UC);

	if (unlikely(!new_header_size && dec.bos)) {
		/* Penultimate hop popping */
		if (!mpls_egress(rt, skb, dec))
			goto drop;
	} else {
		bool bos;
		int i;
		skb_push(skb, new_header_size);
		skb_reset_network_header(skb);
		/* Push the new labels */
		hdr = mpls_hdr(skb);
		bos = dec.bos;
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		for (i = nh->nh_labels - 1; i >= 0; i--) {
			hdr[i] = mpls_entry_encode(nh->nh_label[i],
						   dec.ttl, 0, bos);
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			bos = false;
		}
	}

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	err = neigh_xmit(nh->nh_via_table, out_dev, mpls_nh_via(rt, nh), skb);
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	if (err)
		net_dbg_ratelimited("%s: packet transmission failed: %d\n",
				    __func__, err);
	return 0;

drop:
	kfree_skb(skb);
	return NET_RX_DROP;
}

static struct packet_type mpls_packet_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_MPLS_UC),
	.func = mpls_forward,
};

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static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
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	[RTA_DST]		= { .type = NLA_U32 },
	[RTA_OIF]		= { .type = NLA_U32 },
};

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struct mpls_route_config {
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	u32			rc_protocol;
	u32			rc_ifindex;
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	u8			rc_via_table;
	u8			rc_via_alen;
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	u8			rc_via[MAX_VIA_ALEN];
	u32			rc_label;
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	u8			rc_output_labels;
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	u32			rc_output_label[MAX_NEW_LABELS];
	u32			rc_nlflags;
	enum mpls_payload_type	rc_payload_type;
	struct nl_info		rc_nlinfo;
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	struct rtnexthop	*rc_mp;
	int			rc_mp_len;
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};

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static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen)
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{
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	u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN);
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	struct mpls_route *rt;

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	rt = kzalloc(ALIGN(sizeof(*rt) + num_nh * sizeof(*rt->rt_nh),
			   VIA_ALEN_ALIGN) +
		     num_nh * max_alen_aligned,
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		     GFP_KERNEL);
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	if (rt) {
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		rt->rt_nhn = num_nh;
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		rt->rt_max_alen = max_alen_aligned;
	}
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	return rt;
}

static void mpls_rt_free(struct mpls_route *rt)
{
	if (rt)
		kfree_rcu(rt, rt_rcu);
}

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static void mpls_notify_route(struct net *net, unsigned index,
			      struct mpls_route *old, struct mpls_route *new,
			      const struct nl_info *info)
{
	struct nlmsghdr *nlh = info ? info->nlh : NULL;
	unsigned portid = info ? info->portid : 0;
	int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
	struct mpls_route *rt = new ? new : old;
	unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
	/* Ignore reserved labels for now */
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	if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
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		rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
}

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static void mpls_route_update(struct net *net, unsigned index,
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			      struct mpls_route *new,
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			      const struct nl_info *info)
{
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	struct mpls_route __rcu **platform_label;
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	struct mpls_route *rt;
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	ASSERT_RTNL();

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	platform_label = rtnl_dereference(net->mpls.platform_label);
	rt = rtnl_dereference(platform_label[index]);
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	rcu_assign_pointer(platform_label[index], new);
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	mpls_notify_route(net, index, rt, new, info);
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	/* If we removed a route free it now */
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	mpls_rt_free(rt);
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}

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static unsigned find_free_label(struct net *net)
{
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	struct mpls_route __rcu **platform_label;
	size_t platform_labels;
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	unsigned index;
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	platform_label = rtnl_dereference(net->mpls.platform_label);
	platform_labels = net->mpls.platform_labels;
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	for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
	     index++) {
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		if (!rtnl_dereference(platform_label[index]))
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			return index;
	}
	return LABEL_NOT_SPECIFIED;
}

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#if IS_ENABLED(CONFIG_INET)
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static struct net_device *inet_fib_lookup_dev(struct net *net,
					      const void *addr)
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{
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	struct net_device *dev;
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	struct rtable *rt;
	struct in_addr daddr;

	memcpy(&daddr, addr, sizeof(struct in_addr));
	rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
	if (IS_ERR(rt))
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		return ERR_CAST(rt);
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	dev = rt->dst.dev;
	dev_hold(dev);

	ip_rt_put(rt);

	return dev;
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}
#else
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static struct net_device *inet_fib_lookup_dev(struct net *net,
					      const void *addr)
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{
	return ERR_PTR(-EAFNOSUPPORT);
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}
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#endif
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#if IS_ENABLED(CONFIG_IPV6)
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static struct net_device *inet6_fib_lookup_dev(struct net *net,
					       const void *addr)
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{
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	struct net_device *dev;
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	struct dst_entry *dst;
	struct flowi6 fl6;
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	int err;

	if (!ipv6_stub)
		return ERR_PTR(-EAFNOSUPPORT);
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	memset(&fl6, 0, sizeof(fl6));
	memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
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	err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
	if (err)
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		return ERR_PTR(err);
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	dev = dst->dev;
	dev_hold(dev);
	dst_release(dst);

	return dev;
}
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#else
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static struct net_device *inet6_fib_lookup_dev(struct net *net,
					       const void *addr)
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{
	return ERR_PTR(-EAFNOSUPPORT);
}
#endif
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static struct net_device *find_outdev(struct net *net,
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				      struct mpls_route *rt,
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				      struct mpls_nh *nh, int oif)
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{
	struct net_device *dev = NULL;

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	if (!oif) {
		switch (nh->nh_via_table) {
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		case NEIGH_ARP_TABLE:
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			dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
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			break;
		case NEIGH_ND_TABLE:
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			dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
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			break;
		case NEIGH_LINK_TABLE:
			break;
		}
	} else {
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		dev = dev_get_by_index(net, oif);
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	}

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	if (!dev)
		return ERR_PTR(-ENODEV);

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	/* The caller is holding rtnl anyways, so release the dev reference */
	dev_put(dev);

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	return dev;
}

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static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
			      struct mpls_nh *nh, int oif)
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{
	struct net_device *dev = NULL;
	int err = -ENODEV;

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	dev = find_outdev(net, rt, nh, oif);
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	if (IS_ERR(dev)) {
		err = PTR_ERR(dev);
		dev = NULL;
		goto errout;
	}

	/* Ensure this is a supported device */
	err = -EINVAL;
	if (!mpls_dev_get(dev))
		goto errout;

	RCU_INIT_POINTER(nh->nh_dev, dev);

	return 0;

errout:
	return err;
}

static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
				  struct mpls_route *rt)
{
	struct net *net = cfg->rc_nlinfo.nl_net;
	struct mpls_nh *nh = rt->rt_nh;
	int err;
	int i;

	if (!nh)
		return -ENOMEM;

	err = -EINVAL;
	/* Ensure only a supported number of labels are present */
	if (cfg->rc_output_labels > MAX_NEW_LABELS)
		goto errout;

	nh->nh_labels = cfg->rc_output_labels;
	for (i = 0; i < nh->nh_labels; i++)
		nh->nh_label[i] = cfg->rc_output_label[i];

	nh->nh_via_table = cfg->rc_via_table;
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	memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
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	nh->nh_via_alen = cfg->rc_via_alen;

569
	err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
R
Roopa Prabhu 已提交
570 571 572 573 574 575 576 577 578
	if (err)
		goto errout;

	return 0;

errout:
	return err;
}

579 580 581
static int mpls_nh_build(struct net *net, struct mpls_route *rt,
			 struct mpls_nh *nh, int oif,
			 struct nlattr *via, struct nlattr *newdst)
R
Roopa Prabhu 已提交
582 583 584 585 586 587 588 589 590 591 592 593 594 595
{
	int err = -ENOMEM;

	if (!nh)
		goto errout;

	if (newdst) {
		err = nla_get_labels(newdst, MAX_NEW_LABELS,
				     &nh->nh_labels, nh->nh_label);
		if (err)
			goto errout;
	}

	err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
596
			  __mpls_nh_via(rt, nh));
R
Roopa Prabhu 已提交
597 598 599
	if (err)
		goto errout;

600
	err = mpls_nh_assign_dev(net, rt, nh, oif);
R
Roopa Prabhu 已提交
601 602 603 604 605 606 607 608 609
	if (err)
		goto errout;

	return 0;

errout:
	return err;
}

610 611
static int mpls_count_nexthops(struct rtnexthop *rtnh, int len,
			       u8 cfg_via_alen, u8 *max_via_alen)
R
Roopa Prabhu 已提交
612 613 614 615
{
	int nhs = 0;
	int remaining = len;

616 617 618 619 620 621 622
	if (!rtnh) {
		*max_via_alen = cfg_via_alen;
		return 1;
	}

	*max_via_alen = 0;

R
Roopa Prabhu 已提交
623
	while (rtnh_ok(rtnh, remaining)) {
624 625 626 627 628 629 630 631 632 633 634 635 636 637 638
		struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
		int attrlen;

		attrlen = rtnh_attrlen(rtnh);
		nla = nla_find(attrs, attrlen, RTA_VIA);
		if (nla && nla_len(nla) >=
		    offsetof(struct rtvia, rtvia_addr)) {
			int via_alen = nla_len(nla) -
				offsetof(struct rtvia, rtvia_addr);

			if (via_alen <= MAX_VIA_ALEN)
				*max_via_alen = max_t(u16, *max_via_alen,
						      via_alen);
		}

R
Roopa Prabhu 已提交
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665
		nhs++;
		rtnh = rtnh_next(rtnh, &remaining);
	}

	/* leftover implies invalid nexthop configuration, discard it */
	return remaining > 0 ? 0 : nhs;
}

static int mpls_nh_build_multi(struct mpls_route_config *cfg,
			       struct mpls_route *rt)
{
	struct rtnexthop *rtnh = cfg->rc_mp;
	struct nlattr *nla_via, *nla_newdst;
	int remaining = cfg->rc_mp_len;
	int nhs = 0;
	int err = 0;

	change_nexthops(rt) {
		int attrlen;

		nla_via = NULL;
		nla_newdst = NULL;

		err = -EINVAL;
		if (!rtnh_ok(rtnh, remaining))
			goto errout;

666 667 668 669 670 671
		/* neither weighted multipath nor any flags
		 * are supported
		 */
		if (rtnh->rtnh_hops || rtnh->rtnh_flags)
			goto errout;

R
Roopa Prabhu 已提交
672 673 674 675 676 677 678 679 680 681 682
		attrlen = rtnh_attrlen(rtnh);
		if (attrlen > 0) {
			struct nlattr *attrs = rtnh_attrs(rtnh);

			nla_via = nla_find(attrs, attrlen, RTA_VIA);
			nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
		}

		if (!nla_via)
			goto errout;

683
		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
R
Roopa Prabhu 已提交
684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700
				    rtnh->rtnh_ifindex, nla_via,
				    nla_newdst);
		if (err)
			goto errout;

		rtnh = rtnh_next(rtnh, &remaining);
		nhs++;
	} endfor_nexthops(rt);

	rt->rt_nhn = nhs;

	return 0;

errout:
	return err;
}

701 702
static int mpls_route_add(struct mpls_route_config *cfg)
{
703
	struct mpls_route __rcu **platform_label;
704 705 706
	struct net *net = cfg->rc_nlinfo.nl_net;
	struct mpls_route *rt, *old;
	int err = -EINVAL;
707
	u8 max_via_alen;
R
Roopa Prabhu 已提交
708
	unsigned index;
709
	int nhs;
710 711 712 713 714 715 716 717 718

	index = cfg->rc_label;

	/* If a label was not specified during insert pick one */
	if ((index == LABEL_NOT_SPECIFIED) &&
	    (cfg->rc_nlflags & NLM_F_CREATE)) {
		index = find_free_label(net);
	}

719 720
	/* Reserved labels may not be set */
	if (index < MPLS_LABEL_FIRST_UNRESERVED)
721 722 723 724 725 726 727
		goto errout;

	/* The full 20 bit range may not be supported. */
	if (index >= net->mpls.platform_labels)
		goto errout;

	/* Append makes no sense with mpls */
728
	err = -EOPNOTSUPP;
729 730 731 732
	if (cfg->rc_nlflags & NLM_F_APPEND)
		goto errout;

	err = -EEXIST;
733 734
	platform_label = rtnl_dereference(net->mpls.platform_label);
	old = rtnl_dereference(platform_label[index]);
735 736 737 738 739 740 741 742 743 744 745
	if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
		goto errout;

	err = -EEXIST;
	if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
		goto errout;

	err = -ENOENT;
	if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
		goto errout;

746 747 748 749 750
	err = -EINVAL;
	nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
				  cfg->rc_via_alen, &max_via_alen);
	if (nhs == 0)
		goto errout;
R
Roopa Prabhu 已提交
751

752
	err = -ENOMEM;
753
	rt = mpls_rt_alloc(nhs, max_via_alen);
754 755 756 757
	if (!rt)
		goto errout;

	rt->rt_protocol = cfg->rc_protocol;
758
	rt->rt_payload_type = cfg->rc_payload_type;
759

R
Roopa Prabhu 已提交
760 761 762 763 764 765 766 767
	if (cfg->rc_mp)
		err = mpls_nh_build_multi(cfg, rt);
	else
		err = mpls_nh_build_from_cfg(cfg, rt);
	if (err)
		goto freert;

	mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
768 769 770

	return 0;

R
Roopa Prabhu 已提交
771 772
freert:
	mpls_rt_free(rt);
773 774 775 776 777 778 779 780 781 782 783 784
errout:
	return err;
}

static int mpls_route_del(struct mpls_route_config *cfg)
{
	struct net *net = cfg->rc_nlinfo.nl_net;
	unsigned index;
	int err = -EINVAL;

	index = cfg->rc_label;

785 786
	/* Reserved labels may not be removed */
	if (index < MPLS_LABEL_FIRST_UNRESERVED)
787 788 789 790 791 792
		goto errout;

	/* The full 20 bit range may not be supported */
	if (index >= net->mpls.platform_labels)
		goto errout;

R
Roopa Prabhu 已提交
793
	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
794 795 796 797 798 799

	err = 0;
errout:
	return err;
}

800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853
#define MPLS_PERDEV_SYSCTL_OFFSET(field)	\
	(&((struct mpls_dev *)0)->field)

static const struct ctl_table mpls_dev_table[] = {
	{
		.procname	= "input",
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
		.data		= MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
	},
	{ }
};

static int mpls_dev_sysctl_register(struct net_device *dev,
				    struct mpls_dev *mdev)
{
	char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
	struct ctl_table *table;
	int i;

	table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
	if (!table)
		goto out;

	/* Table data contains only offsets relative to the base of
	 * the mdev at this point, so make them absolute.
	 */
	for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
		table[i].data = (char *)mdev + (uintptr_t)table[i].data;

	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);

	mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
	if (!mdev->sysctl)
		goto free;

	return 0;

free:
	kfree(table);
out:
	return -ENOBUFS;
}

static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
{
	struct ctl_table *table;

	table = mdev->sysctl->ctl_table_arg;
	unregister_net_sysctl_table(mdev->sysctl);
	kfree(table);
}

R
Robert Shearman 已提交
854 855 856 857 858 859 860 861 862 863 864
static struct mpls_dev *mpls_add_dev(struct net_device *dev)
{
	struct mpls_dev *mdev;
	int err = -ENOMEM;

	ASSERT_RTNL();

	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	if (!mdev)
		return ERR_PTR(err);

865 866 867 868
	err = mpls_dev_sysctl_register(dev, mdev);
	if (err)
		goto free;

R
Robert Shearman 已提交
869 870 871
	rcu_assign_pointer(dev->mpls_ptr, mdev);

	return mdev;
872 873 874 875

free:
	kfree(mdev);
	return ERR_PTR(err);
R
Robert Shearman 已提交
876 877
}

E
Eric W. Biederman 已提交
878 879
static void mpls_ifdown(struct net_device *dev)
{
880
	struct mpls_route __rcu **platform_label;
E
Eric W. Biederman 已提交
881
	struct net *net = dev_net(dev);
R
Robert Shearman 已提交
882
	struct mpls_dev *mdev;
E
Eric W. Biederman 已提交
883 884
	unsigned index;

885
	platform_label = rtnl_dereference(net->mpls.platform_label);
E
Eric W. Biederman 已提交
886
	for (index = 0; index < net->mpls.platform_labels; index++) {
887
		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
E
Eric W. Biederman 已提交
888 889
		if (!rt)
			continue;
R
Roopa Prabhu 已提交
890 891 892 893 894
		for_nexthops(rt) {
			if (rtnl_dereference(nh->nh_dev) != dev)
				continue;
			nh->nh_dev = NULL;
		} endfor_nexthops(rt);
E
Eric W. Biederman 已提交
895
	}
R
Robert Shearman 已提交
896 897 898 899 900

	mdev = mpls_dev_get(dev);
	if (!mdev)
		return;

901 902
	mpls_dev_sysctl_unregister(mdev);

R
Robert Shearman 已提交
903 904
	RCU_INIT_POINTER(dev->mpls_ptr, NULL);

905
	kfree_rcu(mdev, rcu);
E
Eric W. Biederman 已提交
906 907 908 909 910 911
}

static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
			   void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
R
Robert Shearman 已提交
912
	struct mpls_dev *mdev;
E
Eric W. Biederman 已提交
913 914

	switch(event) {
R
Robert Shearman 已提交
915 916 917 918 919 920 921 922 923 924
	case NETDEV_REGISTER:
		/* For now just support ethernet devices */
		if ((dev->type == ARPHRD_ETHER) ||
		    (dev->type == ARPHRD_LOOPBACK)) {
			mdev = mpls_add_dev(dev);
			if (IS_ERR(mdev))
				return notifier_from_errno(PTR_ERR(mdev));
		}
		break;

E
Eric W. Biederman 已提交
925 926 927
	case NETDEV_UNREGISTER:
		mpls_ifdown(dev);
		break;
928 929 930 931 932 933 934 935 936 937 938
	case NETDEV_CHANGENAME:
		mdev = mpls_dev_get(dev);
		if (mdev) {
			int err;

			mpls_dev_sysctl_unregister(mdev);
			err = mpls_dev_sysctl_register(dev, mdev);
			if (err)
				return notifier_from_errno(err);
		}
		break;
E
Eric W. Biederman 已提交
939 940 941 942 943 944 945 946
	}
	return NOTIFY_OK;
}

static struct notifier_block mpls_dev_notifier = {
	.notifier_call = mpls_dev_notify,
};

947
static int nla_put_via(struct sk_buff *skb,
948
		       u8 table, const void *addr, int alen)
949
{
950 951 952
	static const int table_to_family[NEIGH_NR_TABLES + 1] = {
		AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
	};
953 954
	struct nlattr *nla;
	struct rtvia *via;
955
	int family = AF_UNSPEC;
956 957 958 959 960

	nla = nla_reserve(skb, RTA_VIA, alen + 2);
	if (!nla)
		return -EMSGSIZE;

961 962 963
	if (table <= NEIGH_NR_TABLES)
		family = table_to_family[table];

964 965 966 967 968 969
	via = nla_data(nla);
	via->rtvia_family = family;
	memcpy(via->rtvia_addr, addr, alen);
	return 0;
}

970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
int nla_put_labels(struct sk_buff *skb, int attrtype,
		   u8 labels, const u32 label[])
{
	struct nlattr *nla;
	struct mpls_shim_hdr *nla_label;
	bool bos;
	int i;
	nla = nla_reserve(skb, attrtype, labels*4);
	if (!nla)
		return -EMSGSIZE;

	nla_label = nla_data(nla);
	bos = true;
	for (i = labels - 1; i >= 0; i--) {
		nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
		bos = false;
	}

	return 0;
}
990
EXPORT_SYMBOL_GPL(nla_put_labels);
991 992

int nla_get_labels(const struct nlattr *nla,
R
Roopa Prabhu 已提交
993
		   u32 max_labels, u8 *labels, u32 label[])
994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021
{
	unsigned len = nla_len(nla);
	unsigned nla_labels;
	struct mpls_shim_hdr *nla_label;
	bool bos;
	int i;

	/* len needs to be an even multiple of 4 (the label size) */
	if (len & 3)
		return -EINVAL;

	/* Limit the number of new labels allowed */
	nla_labels = len/4;
	if (nla_labels > max_labels)
		return -EINVAL;

	nla_label = nla_data(nla);
	bos = true;
	for (i = nla_labels - 1; i >= 0; i--, bos = false) {
		struct mpls_entry_decoded dec;
		dec = mpls_entry_decode(nla_label + i);

		/* Ensure the bottom of stack flag is properly set
		 * and ttl and tc are both clear.
		 */
		if ((dec.bos != bos) || dec.ttl || dec.tc)
			return -EINVAL;

1022
		switch (dec.label) {
1023
		case MPLS_LABEL_IMPLNULL:
1024 1025 1026 1027 1028 1029 1030
			/* RFC3032: This is a label that an LSR may
			 * assign and distribute, but which never
			 * actually appears in the encapsulation.
			 */
			return -EINVAL;
		}

1031 1032 1033 1034 1035
		label[i] = dec.label;
	}
	*labels = nla_labels;
	return 0;
}
1036
EXPORT_SYMBOL_GPL(nla_get_labels);
1037

R
Roopa Prabhu 已提交
1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
int nla_get_via(const struct nlattr *nla, u8 *via_alen,
		u8 *via_table, u8 via_addr[])
{
	struct rtvia *via = nla_data(nla);
	int err = -EINVAL;
	int alen;

	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
		goto errout;
	alen = nla_len(nla) -
			offsetof(struct rtvia, rtvia_addr);
	if (alen > MAX_VIA_ALEN)
		goto errout;

	/* Validate the address family */
	switch (via->rtvia_family) {
	case AF_PACKET:
		*via_table = NEIGH_LINK_TABLE;
		break;
	case AF_INET:
		*via_table = NEIGH_ARP_TABLE;
		if (alen != 4)
			goto errout;
		break;
	case AF_INET6:
		*via_table = NEIGH_ND_TABLE;
		if (alen != 16)
			goto errout;
		break;
	default:
		/* Unsupported address family */
		goto errout;
	}

	memcpy(via_addr, via->rtvia_addr, alen);
	*via_alen = alen;
	err = 0;

errout:
	return err;
}

1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142
static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
			       struct mpls_route_config *cfg)
{
	struct rtmsg *rtm;
	struct nlattr *tb[RTA_MAX+1];
	int index;
	int err;

	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
	if (err < 0)
		goto errout;

	err = -EINVAL;
	rtm = nlmsg_data(nlh);
	memset(cfg, 0, sizeof(*cfg));

	if (rtm->rtm_family != AF_MPLS)
		goto errout;
	if (rtm->rtm_dst_len != 20)
		goto errout;
	if (rtm->rtm_src_len != 0)
		goto errout;
	if (rtm->rtm_tos != 0)
		goto errout;
	if (rtm->rtm_table != RT_TABLE_MAIN)
		goto errout;
	/* Any value is acceptable for rtm_protocol */

	/* As mpls uses destination specific addresses
	 * (or source specific address in the case of multicast)
	 * all addresses have universal scope.
	 */
	if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
		goto errout;
	if (rtm->rtm_type != RTN_UNICAST)
		goto errout;
	if (rtm->rtm_flags != 0)
		goto errout;

	cfg->rc_label		= LABEL_NOT_SPECIFIED;
	cfg->rc_protocol	= rtm->rtm_protocol;
	cfg->rc_nlflags		= nlh->nlmsg_flags;
	cfg->rc_nlinfo.portid	= NETLINK_CB(skb).portid;
	cfg->rc_nlinfo.nlh	= nlh;
	cfg->rc_nlinfo.nl_net	= sock_net(skb->sk);

	for (index = 0; index <= RTA_MAX; index++) {
		struct nlattr *nla = tb[index];
		if (!nla)
			continue;

		switch(index) {
		case RTA_OIF:
			cfg->rc_ifindex = nla_get_u32(nla);
			break;
		case RTA_NEWDST:
			if (nla_get_labels(nla, MAX_NEW_LABELS,
					   &cfg->rc_output_labels,
					   cfg->rc_output_label))
				goto errout;
			break;
		case RTA_DST:
		{
R
Roopa Prabhu 已提交
1143
			u8 label_count;
1144 1145 1146 1147
			if (nla_get_labels(nla, 1, &label_count,
					   &cfg->rc_label))
				goto errout;

1148 1149
			/* Reserved labels may not be set */
			if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED)
1150 1151 1152 1153 1154 1155
				goto errout;

			break;
		}
		case RTA_VIA:
		{
R
Roopa Prabhu 已提交
1156 1157
			if (nla_get_via(nla, &cfg->rc_via_alen,
					&cfg->rc_via_table, cfg->rc_via))
1158
				goto errout;
R
Roopa Prabhu 已提交
1159 1160 1161 1162 1163 1164
			break;
		}
		case RTA_MULTIPATH:
		{
			cfg->rc_mp = nla_data(nla);
			cfg->rc_mp_len = nla_len(nla);
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205
			break;
		}
		default:
			/* Unsupported attribute */
			goto errout;
		}
	}

	err = 0;
errout:
	return err;
}

static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	struct mpls_route_config cfg;
	int err;

	err = rtm_to_route_config(skb, nlh, &cfg);
	if (err < 0)
		return err;

	return mpls_route_del(&cfg);
}


static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	struct mpls_route_config cfg;
	int err;

	err = rtm_to_route_config(skb, nlh, &cfg);
	if (err < 0)
		return err;

	return mpls_route_add(&cfg);
}

static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
			   u32 label, struct mpls_route *rt, int flags)
{
1206
	struct net_device *dev;
1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
	struct nlmsghdr *nlh;
	struct rtmsg *rtm;

	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
	if (nlh == NULL)
		return -EMSGSIZE;

	rtm = nlmsg_data(nlh);
	rtm->rtm_family = AF_MPLS;
	rtm->rtm_dst_len = 20;
	rtm->rtm_src_len = 0;
	rtm->rtm_tos = 0;
	rtm->rtm_table = RT_TABLE_MAIN;
	rtm->rtm_protocol = rt->rt_protocol;
	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
	rtm->rtm_type = RTN_UNICAST;
	rtm->rtm_flags = 0;

	if (nla_put_labels(skb, RTA_DST, 1, &label))
		goto nla_put_failure;
R
Roopa Prabhu 已提交
1227
	if (rt->rt_nhn == 1) {
1228
		const struct mpls_nh *nh = rt->rt_nh;
R
Roopa Prabhu 已提交
1229 1230 1231 1232 1233

		if (nh->nh_labels &&
		    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
				   nh->nh_label))
			goto nla_put_failure;
1234
		if (nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
R
Roopa Prabhu 已提交
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
				nh->nh_via_alen))
			goto nla_put_failure;
		dev = rtnl_dereference(nh->nh_dev);
		if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
			goto nla_put_failure;
	} else {
		struct rtnexthop *rtnh;
		struct nlattr *mp;

		mp = nla_nest_start(skb, RTA_MULTIPATH);
		if (!mp)
			goto nla_put_failure;

		for_nexthops(rt) {
			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
			if (!rtnh)
				goto nla_put_failure;

			dev = rtnl_dereference(nh->nh_dev);
			if (dev)
				rtnh->rtnh_ifindex = dev->ifindex;
			if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
							    nh->nh_labels,
							    nh->nh_label))
				goto nla_put_failure;
			if (nla_put_via(skb, nh->nh_via_table,
1261
					mpls_nh_via(rt, nh),
R
Roopa Prabhu 已提交
1262 1263 1264 1265 1266 1267 1268 1269 1270
					nh->nh_via_alen))
				goto nla_put_failure;

			/* length of rtnetlink header + attributes */
			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
		} endfor_nexthops(rt);

		nla_nest_end(skb, mp);
	}
1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282

	nlmsg_end(skb, nlh);
	return 0;

nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net *net = sock_net(skb->sk);
1283 1284
	struct mpls_route __rcu **platform_label;
	size_t platform_labels;
1285 1286 1287 1288 1289
	unsigned int index;

	ASSERT_RTNL();

	index = cb->args[0];
1290 1291
	if (index < MPLS_LABEL_FIRST_UNRESERVED)
		index = MPLS_LABEL_FIRST_UNRESERVED;
1292

1293 1294 1295
	platform_label = rtnl_dereference(net->mpls.platform_label);
	platform_labels = net->mpls.platform_labels;
	for (; index < platform_labels; index++) {
1296
		struct mpls_route *rt;
1297
		rt = rtnl_dereference(platform_label[index]);
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310
		if (!rt)
			continue;

		if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
				    cb->nlh->nlmsg_seq, RTM_NEWROUTE,
				    index, rt, NLM_F_MULTI) < 0)
			break;
	}
	cb->args[0] = index;

	return skb->len;
}

1311 1312 1313 1314 1315
static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
{
	size_t payload =
		NLMSG_ALIGN(sizeof(struct rtmsg))
		+ nla_total_size(4);			/* RTA_DST */
R
Roopa Prabhu 已提交
1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338

	if (rt->rt_nhn == 1) {
		struct mpls_nh *nh = rt->rt_nh;

		if (nh->nh_dev)
			payload += nla_total_size(4); /* RTA_OIF */
		payload += nla_total_size(2 + nh->nh_via_alen); /* RTA_VIA */
		if (nh->nh_labels) /* RTA_NEWDST */
			payload += nla_total_size(nh->nh_labels * 4);
	} else {
		/* each nexthop is packed in an attribute */
		size_t nhsize = 0;

		for_nexthops(rt) {
			nhsize += nla_total_size(sizeof(struct rtnexthop));
			nhsize += nla_total_size(2 + nh->nh_via_alen);
			if (nh->nh_labels)
				nhsize += nla_total_size(nh->nh_labels * 4);
		} endfor_nexthops(rt);
		/* nested attribute */
		payload += nla_total_size(nhsize);
	}

1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
	return payload;
}

static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
		       struct nlmsghdr *nlh, struct net *net, u32 portid,
		       unsigned int nlm_flags)
{
	struct sk_buff *skb;
	u32 seq = nlh ? nlh->nlmsg_seq : 0;
	int err = -ENOBUFS;

	skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
	if (skb == NULL)
		goto errout;

	err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
	if (err < 0) {
		/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
		WARN_ON(err == -EMSGSIZE);
		kfree_skb(skb);
		goto errout;
	}
	rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);

	return;
errout:
	if (err < 0)
		rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
}

1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387
static int resize_platform_label_table(struct net *net, size_t limit)
{
	size_t size = sizeof(struct mpls_route *) * limit;
	size_t old_limit;
	size_t cp_size;
	struct mpls_route __rcu **labels = NULL, **old;
	struct mpls_route *rt0 = NULL, *rt2 = NULL;
	unsigned index;

	if (size) {
		labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
		if (!labels)
			labels = vzalloc(size);

		if (!labels)
			goto nolabels;
	}

	/* In case the predefined labels need to be populated */
1388
	if (limit > MPLS_LABEL_IPV4NULL) {
1389
		struct net_device *lo = net->loopback_dev;
1390
		rt0 = mpls_rt_alloc(1, lo->addr_len);
1391 1392
		if (!rt0)
			goto nort0;
R
Roopa Prabhu 已提交
1393
		RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
1394
		rt0->rt_protocol = RTPROT_KERNEL;
1395
		rt0->rt_payload_type = MPT_IPV4;
R
Roopa Prabhu 已提交
1396
		rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
1397
		rt0->rt_nh->nh_via_alen = lo->addr_len;
1398 1399
		memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
		       lo->addr_len);
1400
	}
1401
	if (limit > MPLS_LABEL_IPV6NULL) {
1402
		struct net_device *lo = net->loopback_dev;
1403
		rt2 = mpls_rt_alloc(1, lo->addr_len);
1404 1405
		if (!rt2)
			goto nort2;
R
Roopa Prabhu 已提交
1406
		RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
1407
		rt2->rt_protocol = RTPROT_KERNEL;
1408
		rt2->rt_payload_type = MPT_IPV6;
R
Roopa Prabhu 已提交
1409
		rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
1410
		rt2->rt_nh->nh_via_alen = lo->addr_len;
1411 1412
		memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
		       lo->addr_len);
1413 1414 1415 1416
	}

	rtnl_lock();
	/* Remember the original table */
1417
	old = rtnl_dereference(net->mpls.platform_label);
1418 1419 1420 1421
	old_limit = net->mpls.platform_labels;

	/* Free any labels beyond the new table */
	for (index = limit; index < old_limit; index++)
R
Roopa Prabhu 已提交
1422
		mpls_route_update(net, index, NULL, NULL);
1423 1424 1425 1426 1427 1428 1429 1430 1431

	/* Copy over the old labels */
	cp_size = size;
	if (old_limit < limit)
		cp_size = old_limit * sizeof(struct mpls_route *);

	memcpy(labels, old, cp_size);

	/* If needed set the predefined labels */
1432 1433 1434
	if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
	    (limit > MPLS_LABEL_IPV6NULL)) {
		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
1435 1436 1437
		rt2 = NULL;
	}

1438 1439 1440
	if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
	    (limit > MPLS_LABEL_IPV4NULL)) {
		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
1441 1442 1443 1444 1445
		rt0 = NULL;
	}

	/* Update the global pointers */
	net->mpls.platform_labels = limit;
1446
	rcu_assign_pointer(net->mpls.platform_label, labels);
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489

	rtnl_unlock();

	mpls_rt_free(rt2);
	mpls_rt_free(rt0);

	if (old) {
		synchronize_rcu();
		kvfree(old);
	}
	return 0;

nort2:
	mpls_rt_free(rt0);
nort0:
	kvfree(labels);
nolabels:
	return -ENOMEM;
}

static int mpls_platform_labels(struct ctl_table *table, int write,
				void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct net *net = table->data;
	int platform_labels = net->mpls.platform_labels;
	int ret;
	struct ctl_table tmp = {
		.procname	= table->procname,
		.data		= &platform_labels,
		.maxlen		= sizeof(int),
		.mode		= table->mode,
		.extra1		= &zero,
		.extra2		= &label_limit,
	};

	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);

	if (write && ret == 0)
		ret = resize_platform_label_table(net, platform_labels);

	return ret;
}

1490
static const struct ctl_table mpls_table[] = {
1491 1492 1493 1494 1495 1496 1497 1498 1499 1500
	{
		.procname	= "platform_labels",
		.data		= NULL,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= mpls_platform_labels,
	},
	{ }
};

E
Eric W. Biederman 已提交
1501 1502
static int mpls_net_init(struct net *net)
{
1503 1504
	struct ctl_table *table;

E
Eric W. Biederman 已提交
1505 1506 1507
	net->mpls.platform_labels = 0;
	net->mpls.platform_label = NULL;

1508 1509 1510 1511 1512 1513
	table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
	if (table == NULL)
		return -ENOMEM;

	table[0].data = net;
	net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
1514 1515
	if (net->mpls.ctl == NULL) {
		kfree(table);
1516
		return -ENOMEM;
1517
	}
1518

E
Eric W. Biederman 已提交
1519 1520 1521 1522 1523
	return 0;
}

static void mpls_net_exit(struct net *net)
{
1524 1525
	struct mpls_route __rcu **platform_label;
	size_t platform_labels;
1526
	struct ctl_table *table;
E
Eric W. Biederman 已提交
1527 1528
	unsigned int index;

1529 1530 1531 1532
	table = net->mpls.ctl->ctl_table_arg;
	unregister_net_sysctl_table(net->mpls.ctl);
	kfree(table);

1533 1534
	/* An rcu grace period has passed since there was a device in
	 * the network namespace (and thus the last in flight packet)
E
Eric W. Biederman 已提交
1535 1536 1537 1538 1539 1540 1541 1542
	 * left this network namespace.  This is because
	 * unregister_netdevice_many and netdev_run_todo has completed
	 * for each network device that was in this network namespace.
	 *
	 * As such no additional rcu synchronization is necessary when
	 * freeing the platform_label table.
	 */
	rtnl_lock();
1543 1544 1545 1546 1547
	platform_label = rtnl_dereference(net->mpls.platform_label);
	platform_labels = net->mpls.platform_labels;
	for (index = 0; index < platform_labels; index++) {
		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
		RCU_INIT_POINTER(platform_label[index], NULL);
E
Eric W. Biederman 已提交
1548 1549 1550 1551
		mpls_rt_free(rt);
	}
	rtnl_unlock();

1552
	kvfree(platform_label);
E
Eric W. Biederman 已提交
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
}

static struct pernet_operations mpls_net_ops = {
	.init = mpls_net_init,
	.exit = mpls_net_exit,
};

static int __init mpls_init(void)
{
	int err;

	BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);

	err = register_pernet_subsys(&mpls_net_ops);
	if (err)
		goto out;

	err = register_netdevice_notifier(&mpls_dev_notifier);
	if (err)
		goto out_unregister_pernet;

	dev_add_pack(&mpls_packet_type);

1576 1577 1578
	rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL);
	rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL);
	rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL);
E
Eric W. Biederman 已提交
1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
	err = 0;
out:
	return err;

out_unregister_pernet:
	unregister_pernet_subsys(&mpls_net_ops);
	goto out;
}
module_init(mpls_init);

static void __exit mpls_exit(void)
{
1591
	rtnl_unregister_all(PF_MPLS);
E
Eric W. Biederman 已提交
1592 1593 1594 1595 1596 1597 1598 1599 1600
	dev_remove_pack(&mpls_packet_type);
	unregister_netdevice_notifier(&mpls_dev_notifier);
	unregister_pernet_subsys(&mpls_net_ops);
}
module_exit(mpls_exit);

MODULE_DESCRIPTION("MultiProtocol Label Switching");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_NETPROTO(PF_MPLS);