From 397fc9e5cefee0c33b86811fbddb0decb7288c52 Mon Sep 17 00:00:00 2001 From: Roopa Prabhu Date: Mon, 3 Jul 2017 15:31:21 -0700 Subject: [PATCH] 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: Roopa Prabhu Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 163 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 162 insertions(+), 1 deletion(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index b51582d92740..e17d6cd2dd45 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2071,6 +2071,166 @@ static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 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;