| /* |
| * mpls tunnels An implementation mpls tunnels using the light weight tunnel |
| * infrastructure |
| * |
| * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| */ |
| #include <linux/types.h> |
| #include <linux/skbuff.h> |
| #include <linux/net.h> |
| #include <linux/module.h> |
| #include <linux/mpls.h> |
| #include <linux/vmalloc.h> |
| #include <net/ip.h> |
| #include <net/dst.h> |
| #include <net/lwtunnel.h> |
| #include <net/netevent.h> |
| #include <net/netns/generic.h> |
| #include <net/ip6_fib.h> |
| #include <net/route.h> |
| #include <net/mpls_iptunnel.h> |
| #include <linux/mpls_iptunnel.h> |
| #include "internal.h" |
| |
| static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = { |
| [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 }, |
| }; |
| |
| static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en) |
| { |
| /* The size of the layer 2.5 labels to be added for this route */ |
| return en->labels * sizeof(struct mpls_shim_hdr); |
| } |
| |
| static int mpls_xmit(struct sk_buff *skb) |
| { |
| struct mpls_iptunnel_encap *tun_encap_info; |
| struct mpls_shim_hdr *hdr; |
| struct net_device *out_dev; |
| unsigned int hh_len; |
| unsigned int new_header_size; |
| unsigned int mtu; |
| struct dst_entry *dst = skb_dst(skb); |
| struct rtable *rt = NULL; |
| struct rt6_info *rt6 = NULL; |
| int err = 0; |
| bool bos; |
| int i; |
| unsigned int ttl; |
| |
| /* Obtain the ttl */ |
| if (dst->ops->family == AF_INET) { |
| ttl = ip_hdr(skb)->ttl; |
| rt = (struct rtable *)dst; |
| } else if (dst->ops->family == AF_INET6) { |
| ttl = ipv6_hdr(skb)->hop_limit; |
| rt6 = (struct rt6_info *)dst; |
| } else { |
| goto drop; |
| } |
| |
| skb_orphan(skb); |
| |
| /* Find the output device */ |
| out_dev = dst->dev; |
| if (!mpls_output_possible(out_dev) || |
| !dst->lwtstate || skb_warn_if_lro(skb)) |
| goto drop; |
| |
| skb_forward_csum(skb); |
| |
| tun_encap_info = mpls_lwtunnel_encap(dst->lwtstate); |
| |
| /* Verify the destination can hold the packet */ |
| new_header_size = mpls_encap_size(tun_encap_info); |
| 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_set_inner_protocol(skb, skb->protocol); |
| skb_reset_inner_network_header(skb); |
| |
| skb_push(skb, new_header_size); |
| |
| skb_reset_network_header(skb); |
| |
| skb->dev = out_dev; |
| skb->protocol = htons(ETH_P_MPLS_UC); |
| |
| /* Push the new labels */ |
| hdr = mpls_hdr(skb); |
| bos = true; |
| for (i = tun_encap_info->labels - 1; i >= 0; i--) { |
| hdr[i] = mpls_entry_encode(tun_encap_info->label[i], |
| ttl, 0, bos); |
| bos = false; |
| } |
| |
| if (rt) |
| err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway, |
| skb); |
| else if (rt6) |
| err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway, |
| skb); |
| if (err) |
| net_dbg_ratelimited("%s: packet transmission failed: %d\n", |
| __func__, err); |
| |
| return LWTUNNEL_XMIT_DONE; |
| |
| drop: |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| static int mpls_build_state(struct net_device *dev, struct nlattr *nla, |
| unsigned int family, const void *cfg, |
| struct lwtunnel_state **ts) |
| { |
| struct mpls_iptunnel_encap *tun_encap_info; |
| struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1]; |
| struct lwtunnel_state *newts; |
| int tun_encap_info_len; |
| int ret; |
| |
| ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla, |
| mpls_iptunnel_policy); |
| if (ret < 0) |
| return ret; |
| |
| if (!tb[MPLS_IPTUNNEL_DST]) |
| return -EINVAL; |
| |
| tun_encap_info_len = sizeof(*tun_encap_info); |
| |
| newts = lwtunnel_state_alloc(tun_encap_info_len); |
| if (!newts) |
| return -ENOMEM; |
| |
| newts->len = tun_encap_info_len; |
| tun_encap_info = mpls_lwtunnel_encap(newts); |
| ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS, |
| &tun_encap_info->labels, tun_encap_info->label); |
| if (ret) |
| goto errout; |
| newts->type = LWTUNNEL_ENCAP_MPLS; |
| newts->flags |= LWTUNNEL_STATE_XMIT_REDIRECT; |
| newts->headroom = mpls_encap_size(tun_encap_info); |
| |
| *ts = newts; |
| |
| return 0; |
| |
| errout: |
| kfree(newts); |
| *ts = NULL; |
| |
| return ret; |
| } |
| |
| static int mpls_fill_encap_info(struct sk_buff *skb, |
| struct lwtunnel_state *lwtstate) |
| { |
| struct mpls_iptunnel_encap *tun_encap_info; |
| |
| tun_encap_info = mpls_lwtunnel_encap(lwtstate); |
| |
| if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels, |
| tun_encap_info->label)) |
| goto nla_put_failure; |
| |
| return 0; |
| |
| nla_put_failure: |
| return -EMSGSIZE; |
| } |
| |
| static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate) |
| { |
| struct mpls_iptunnel_encap *tun_encap_info; |
| |
| tun_encap_info = mpls_lwtunnel_encap(lwtstate); |
| |
| return nla_total_size(tun_encap_info->labels * 4); |
| } |
| |
| static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) |
| { |
| struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a); |
| struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b); |
| int l; |
| |
| if (a_hdr->labels != b_hdr->labels) |
| return 1; |
| |
| for (l = 0; l < MAX_NEW_LABELS; l++) |
| if (a_hdr->label[l] != b_hdr->label[l]) |
| return 1; |
| return 0; |
| } |
| |
| static const struct lwtunnel_encap_ops mpls_iptun_ops = { |
| .build_state = mpls_build_state, |
| .xmit = mpls_xmit, |
| .fill_encap = mpls_fill_encap_info, |
| .get_encap_size = mpls_encap_nlsize, |
| .cmp_encap = mpls_encap_cmp, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init mpls_iptunnel_init(void) |
| { |
| return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); |
| } |
| module_init(mpls_iptunnel_init); |
| |
| static void __exit mpls_iptunnel_exit(void) |
| { |
| lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); |
| } |
| module_exit(mpls_iptunnel_exit); |
| |
| MODULE_ALIAS_RTNL_LWT(MPLS); |
| MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels"); |
| MODULE_LICENSE("GPL v2"); |