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authorEric W. Biederman <ebiederm@xmission.com>2015-03-03 19:13:56 -0600
committerDavid S. Miller <davem@davemloft.net>2015-03-04 00:26:06 -0500
commit03c0566542f4c7a45ce3193f27cbf5700b506c18 (patch)
tree97389268330933037ffe3cd5e4184f4c6b870359 /net/mpls
parent966bae3349da22bb6286f6f3874c279177b8633f (diff)
downloadlinux-stericsson-03c0566542f4c7a45ce3193f27cbf5700b506c18.tar.gz
mpls: Netlink commands to add, remove, and dump routes
This change adds two new netlink routing attributes: RTA_VIA and RTA_NEWDST. RTA_VIA specifies the specifies the next machine to send a packet to like RTA_GATEWAY. RTA_VIA differs from RTA_GATEWAY in that it includes the address family of the address of the next machine to send a packet to. Currently the MPLS code supports addresses in AF_INET, AF_INET6 and AF_PACKET. For AF_INET and AF_INET6 the destination mac address is acquired from the neighbour table. For AF_PACKET the destination mac_address is specified in the netlink configuration. I think raw destination mac address support with the family AF_PACKET will prove useful. There is MPLS-TP which is defined to operate on machines that do not support internet packets of any flavor. Further seem to be corner cases where it can be useful. At this point I don't care much either way. RTA_NEWDST specifies the destination address to forward the packet with. MPLS typically changes it's destination address at every hop. For a swap operation RTA_NEWDST is specified with a length of one label. For a push operation RTA_NEWDST is specified with two or more labels. For a pop operation RTA_NEWDST is not specified or equivalently an emtpy RTAN_NEWDST is specified. Those new netlink attributes are used to implement handling of rt-netlink RTM_NEWROUTE, RTM_DELROUTE, and RTM_GETROUTE messages, to maintain the MPLS label table. rtm_to_route_config parses a netlink RTM_NEWROUTE or RTM_DELROUTE message, verify no unhandled attributes or unhandled values are present and sets up the data structures for mpls_route_add and mpls_route_del. I did my best to match up with the existing conventions with the caveats that MPLS addresses are all destination-specific-addresses, and so don't properly have a scope. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mpls')
-rw-r--r--net/mpls/af_mpls.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 2d6612a10e30..b4d7cec398d2 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -212,6 +212,11 @@ static struct packet_type mpls_packet_type __read_mostly = {
.func = mpls_forward,
};
+const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
+ [RTA_DST] = { .type = NLA_U32 },
+ [RTA_OIF] = { .type = NLA_U32 },
+};
+
struct mpls_route_config {
u32 rc_protocol;
u32 rc_ifindex;
@@ -410,6 +415,22 @@ static struct notifier_block mpls_dev_notifier = {
.notifier_call = mpls_dev_notify,
};
+static int nla_put_via(struct sk_buff *skb,
+ u16 family, const void *addr, int alen)
+{
+ struct nlattr *nla;
+ struct rtvia *via;
+
+ nla = nla_reserve(skb, RTA_VIA, alen + 2);
+ if (!nla)
+ return -EMSGSIZE;
+
+ via = nla_data(nla);
+ via->rtvia_family = family;
+ memcpy(via->rtvia_addr, addr, alen);
+ return 0;
+}
+
int nla_put_labels(struct sk_buff *skb, int attrtype,
u8 labels, const u32 label[])
{
@@ -467,6 +488,210 @@ int nla_get_labels(const struct nlattr *nla,
return 0;
}
+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:
+ {
+ u32 label_count;
+ if (nla_get_labels(nla, 1, &label_count,
+ &cfg->rc_label))
+ goto errout;
+
+ /* The first 16 labels are reserved, and may not be set */
+ if (cfg->rc_label < 16)
+ goto errout;
+
+ break;
+ }
+ case RTA_VIA:
+ {
+ struct rtvia *via = nla_data(nla);
+ cfg->rc_via_family = via->rtvia_family;
+ cfg->rc_via_alen = nla_len(nla) - 2;
+ if (cfg->rc_via_alen > MAX_VIA_ALEN)
+ goto errout;
+
+ /* Validate the address family */
+ switch(cfg->rc_via_family) {
+ case AF_PACKET:
+ break;
+ case AF_INET:
+ if (cfg->rc_via_alen != 4)
+ goto errout;
+ break;
+ case AF_INET6:
+ if (cfg->rc_via_alen != 16)
+ goto errout;
+ break;
+ default:
+ /* Unsupported address family */
+ goto errout;
+ }
+
+ memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
+ 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)
+{
+ 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 (rt->rt_labels &&
+ nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
+ goto nla_put_failure;
+ if (nla_put_via(skb, rt->rt_via_family, rt->rt_via, rt->rt_via_alen))
+ goto nla_put_failure;
+ if (rt->rt_dev && nla_put_u32(skb, RTA_OIF, rt->rt_dev->ifindex))
+ goto nla_put_failure;
+ if (nla_put_labels(skb, RTA_DST, 1, &label))
+ goto nla_put_failure;
+
+ 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);
+ unsigned int index;
+
+ ASSERT_RTNL();
+
+ index = cb->args[0];
+ if (index < 16)
+ index = 16;
+
+ for (; index < net->mpls.platform_labels; index++) {
+ struct mpls_route *rt;
+ rt = net->mpls.platform_label[index];
+ 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;
+}
+
static int resize_platform_label_table(struct net *net, size_t limit)
{
size_t size = sizeof(struct mpls_route *) * limit;
@@ -662,6 +887,9 @@ static int __init mpls_init(void)
dev_add_pack(&mpls_packet_type);
+ 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);
err = 0;
out:
return err;
@@ -674,6 +902,7 @@ module_init(mpls_init);
static void __exit mpls_exit(void)
{
+ rtnl_unregister_all(PF_MPLS);
dev_remove_pack(&mpls_packet_type);
unregister_netdevice_notifier(&mpls_dev_notifier);
unregister_pernet_subsys(&mpls_net_ops);