From: Roopa Prabhu <ro...@cumulusnetworks.com>
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 <ro...@cumulusnetworks.com>
---
net/mpls/af_mpls.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 161 insertions(+), 1 deletion(-)
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 554daf3..4b6ff85 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2110,6 +2110,166 @@ 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;
@@ -2356,7 +2516,7 @@ 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,
+ 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);
--
1.9.1
