Commit 397fc9e5 authored by Roopa Prabhu's avatar Roopa Prabhu Committed by David S. Miller
Browse files

mpls: route get support 



This patch adds RTM_GETROUTE doit handler for mpls routes.

Input:
RTA_DST - input label
RTA_NEWDST - labels in packet for multipath selection

By default the getroute handler returns matched
nexthop label, via and oif

With RTM_F_FIB_MATCH flag, full matched route is
returned.

example (with patched iproute2):
$ip -f mpls route show
101
        nexthop as to 102/103 via inet 172.16.2.2 dev virt1-2
        nexthop as to 302/303 via inet 172.16.12.2 dev virt1-12
201
        nexthop as to 202/203 via inet6 2001:db8:2::2 dev virt1-2
        nexthop as to 402/403 via inet6 2001:db8:12::2 dev virt1-12

$ip -f mpls route get 103
RTNETLINK answers: Network is unreachable

$ip -f mpls route get 101
101 as to 102/103 via inet 172.16.2.2 dev virt1-2

$ip -f mpls route get as to 302/303 101
101 as to 302/303 via inet 172.16.12.2 dev virt1-12

$ip -f mpls route get fibmatch 103
RTNETLINK answers: Network is unreachable

$ip -f mpls route get fibmatch 101
101
        nexthop as to 102/103 via inet 172.16.2.2 dev virt1-2
        nexthop as to 302/303 via inet 172.16.12.2 dev virt1-12

Signed-off-by: default avatarRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7597b266

net/mpls/af_mpls.c

+162 −1
Original line number Diff line number Diff line
@@ -2071,6 +2071,166 @@ errout: 
		rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);

}



static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,

			 struct netlink_ext_ack *extack)

{

	struct net *net = sock_net(in_skb->sk);

	u32 portid = NETLINK_CB(in_skb).portid;

	struct nlattr *tb[RTA_MAX + 1];

	u32 labels[MAX_NEW_LABELS];

	struct mpls_shim_hdr *hdr;

	unsigned int hdr_size = 0;

	struct net_device *dev;

	struct mpls_route *rt;

	struct rtmsg *rtm, *r;

	struct nlmsghdr *nlh;

	struct sk_buff *skb;

	struct mpls_nh *nh;

	int err = -EINVAL;

	u32 in_label;

	u8 n_labels;



	err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,

			  rtm_ipv4_policy, extack);

	if (err < 0)

		goto errout;



	rtm = nlmsg_data(in_nlh);



	if (tb[RTA_DST]) {

		u8 label_count;



		if (nla_get_labels(tb[RTA_DST], 1, &label_count,

				   &in_label, extack))

			goto errout;



		if (in_label < MPLS_LABEL_FIRST_UNRESERVED)

			goto errout;

	}



	rt = mpls_route_input_rcu(net, in_label);

	if (!rt) {

		err = -ENETUNREACH;

		goto errout;

	}



	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {

		skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);

		if (!skb) {

			err = -ENOBUFS;

			goto errout;

		}



		err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,

				      RTM_NEWROUTE, in_label, rt, 0);

		if (err < 0) {

			/* -EMSGSIZE implies BUG in lfib_nlmsg_size */

			WARN_ON(err == -EMSGSIZE);

			goto errout_free;

		}



		return rtnl_unicast(skb, net, portid);

	}



	if (tb[RTA_NEWDST]) {

		if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,

				   labels, extack) != 0) {

			err = -EINVAL;

			goto errout;

		}



		hdr_size = n_labels * sizeof(struct mpls_shim_hdr);

	}



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb) {

		err = -ENOBUFS;

		goto errout;

	}



	skb->protocol = htons(ETH_P_MPLS_UC);



	if (hdr_size) {

		bool bos;

		int i;



		if (skb_cow(skb, hdr_size)) {

			err = -ENOBUFS;

			goto errout_free;

		}



		skb_reserve(skb, hdr_size);

		skb_push(skb, hdr_size);

		skb_reset_network_header(skb);



		/* Push new labels */

		hdr = mpls_hdr(skb);

		bos = true;

		for (i = n_labels - 1; i >= 0; i--) {

			hdr[i] = mpls_entry_encode(labels[i],

						   1, 0, bos);

			bos = false;

		}

	}



	nh = mpls_select_multipath(rt, skb);

	if (!nh) {

		err = -ENETUNREACH;

		goto errout_free;

	}



	if (hdr_size) {

		skb_pull(skb, hdr_size);

		skb_reset_network_header(skb);

	}



	nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,

			RTM_NEWROUTE, sizeof(*r), 0);

	if (!nlh) {

		err = -EMSGSIZE;

		goto errout_free;

	}



	r = nlmsg_data(nlh);

	r->rtm_family	 = AF_MPLS;

	r->rtm_dst_len	= 20;

	r->rtm_src_len	= 0;

	r->rtm_table	= RT_TABLE_MAIN;

	r->rtm_type	= RTN_UNICAST;

	r->rtm_scope	= RT_SCOPE_UNIVERSE;

	r->rtm_protocol = rt->rt_protocol;

	r->rtm_flags	= 0;



	if (nla_put_labels(skb, RTA_DST, 1, &in_label))

		goto nla_put_failure;



	if (nh->nh_labels &&

	    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,

			   nh->nh_label))

		goto nla_put_failure;



	if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&

	    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),

			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;



	nlmsg_end(skb, nlh);



	err = rtnl_unicast(skb, net, portid);

errout:

	return err;



nla_put_failure:

	nlmsg_cancel(skb, nlh);

	err = -EMSGSIZE;

errout_free:

	kfree_skb(skb);

	return err;

}



static int resize_platform_label_table(struct net *net, size_t limit)

{

	size_t size = sizeof(struct mpls_route *) * limit;
@@ -2317,7 +2477,8 @@ static int __init mpls_init(void) 


	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);

	rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes,

		      NULL);

	rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,

		      mpls_netconf_dump_devconf, NULL);

	err = 0;

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