Commit | Line | Data |
---|---|---|
e3e4712e RP |
1 | /* |
2 | * mpls tunnels An implementation mpls tunnels using the light weight tunnel | |
3 | * infrastructure | |
4 | * | |
5 | * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | */ | |
13 | #include <linux/types.h> | |
14 | #include <linux/skbuff.h> | |
15 | #include <linux/net.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mpls.h> | |
18 | #include <linux/vmalloc.h> | |
19 | #include <net/ip.h> | |
20 | #include <net/dst.h> | |
21 | #include <net/lwtunnel.h> | |
22 | #include <net/netevent.h> | |
23 | #include <net/netns/generic.h> | |
24 | #include <net/ip6_fib.h> | |
25 | #include <net/route.h> | |
26 | #include <net/mpls_iptunnel.h> | |
27 | #include <linux/mpls_iptunnel.h> | |
28 | #include "internal.h" | |
29 | ||
30 | static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = { | |
31 | [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 }, | |
32 | }; | |
33 | ||
34 | static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en) | |
35 | { | |
36 | /* The size of the layer 2.5 labels to be added for this route */ | |
37 | return en->labels * sizeof(struct mpls_shim_hdr); | |
38 | } | |
39 | ||
ede2059d | 40 | int mpls_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
e3e4712e RP |
41 | { |
42 | struct mpls_iptunnel_encap *tun_encap_info; | |
43 | struct mpls_shim_hdr *hdr; | |
44 | struct net_device *out_dev; | |
45 | unsigned int hh_len; | |
46 | unsigned int new_header_size; | |
47 | unsigned int mtu; | |
48 | struct dst_entry *dst = skb_dst(skb); | |
49 | struct rtable *rt = NULL; | |
50 | struct rt6_info *rt6 = NULL; | |
e3e4712e RP |
51 | int err = 0; |
52 | bool bos; | |
53 | int i; | |
54 | unsigned int ttl; | |
55 | ||
56 | /* Obtain the ttl */ | |
57 | if (skb->protocol == htons(ETH_P_IP)) { | |
58 | ttl = ip_hdr(skb)->ttl; | |
59 | rt = (struct rtable *)dst; | |
e3e4712e RP |
60 | } else if (skb->protocol == htons(ETH_P_IPV6)) { |
61 | ttl = ipv6_hdr(skb)->hop_limit; | |
62 | rt6 = (struct rt6_info *)dst; | |
e3e4712e RP |
63 | } else { |
64 | goto drop; | |
65 | } | |
66 | ||
67 | skb_orphan(skb); | |
68 | ||
69 | /* Find the output device */ | |
de18547d | 70 | out_dev = dst->dev; |
e3e4712e | 71 | if (!mpls_output_possible(out_dev) || |
61adedf3 | 72 | !dst->lwtstate || skb_warn_if_lro(skb)) |
e3e4712e RP |
73 | goto drop; |
74 | ||
75 | skb_forward_csum(skb); | |
76 | ||
61adedf3 | 77 | tun_encap_info = mpls_lwtunnel_encap(dst->lwtstate); |
e3e4712e RP |
78 | |
79 | /* Verify the destination can hold the packet */ | |
80 | new_header_size = mpls_encap_size(tun_encap_info); | |
81 | mtu = mpls_dev_mtu(out_dev); | |
82 | if (mpls_pkt_too_big(skb, mtu - new_header_size)) | |
83 | goto drop; | |
84 | ||
85 | hh_len = LL_RESERVED_SPACE(out_dev); | |
86 | if (!out_dev->header_ops) | |
87 | hh_len = 0; | |
88 | ||
89 | /* Ensure there is enough space for the headers in the skb */ | |
90 | if (skb_cow(skb, hh_len + new_header_size)) | |
91 | goto drop; | |
92 | ||
93 | skb_push(skb, new_header_size); | |
94 | skb_reset_network_header(skb); | |
95 | ||
96 | skb->dev = out_dev; | |
97 | skb->protocol = htons(ETH_P_MPLS_UC); | |
98 | ||
99 | /* Push the new labels */ | |
100 | hdr = mpls_hdr(skb); | |
101 | bos = true; | |
102 | for (i = tun_encap_info->labels - 1; i >= 0; i--) { | |
103 | hdr[i] = mpls_entry_encode(tun_encap_info->label[i], | |
104 | ttl, 0, bos); | |
105 | bos = false; | |
106 | } | |
107 | ||
108 | if (rt) | |
109 | err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway, | |
110 | skb); | |
111 | else if (rt6) | |
112 | err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway, | |
113 | skb); | |
114 | if (err) | |
115 | net_dbg_ratelimited("%s: packet transmission failed: %d\n", | |
116 | __func__, err); | |
117 | ||
118 | return 0; | |
119 | ||
120 | drop: | |
121 | kfree_skb(skb); | |
122 | return -EINVAL; | |
123 | } | |
124 | ||
125 | static int mpls_build_state(struct net_device *dev, struct nlattr *nla, | |
127eb7cd | 126 | unsigned int family, const void *cfg, |
e3e4712e RP |
127 | struct lwtunnel_state **ts) |
128 | { | |
129 | struct mpls_iptunnel_encap *tun_encap_info; | |
130 | struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1]; | |
131 | struct lwtunnel_state *newts; | |
132 | int tun_encap_info_len; | |
133 | int ret; | |
134 | ||
135 | ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla, | |
136 | mpls_iptunnel_policy); | |
137 | if (ret < 0) | |
138 | return ret; | |
139 | ||
140 | if (!tb[MPLS_IPTUNNEL_DST]) | |
141 | return -EINVAL; | |
142 | ||
143 | tun_encap_info_len = sizeof(*tun_encap_info); | |
144 | ||
145 | newts = lwtunnel_state_alloc(tun_encap_info_len); | |
146 | if (!newts) | |
147 | return -ENOMEM; | |
148 | ||
149 | newts->len = tun_encap_info_len; | |
150 | tun_encap_info = mpls_lwtunnel_encap(newts); | |
151 | ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS, | |
152 | &tun_encap_info->labels, tun_encap_info->label); | |
153 | if (ret) | |
154 | goto errout; | |
155 | newts->type = LWTUNNEL_ENCAP_MPLS; | |
156 | newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT; | |
157 | ||
158 | *ts = newts; | |
159 | ||
160 | return 0; | |
161 | ||
162 | errout: | |
163 | kfree(newts); | |
164 | *ts = NULL; | |
165 | ||
166 | return ret; | |
167 | } | |
168 | ||
169 | static int mpls_fill_encap_info(struct sk_buff *skb, | |
170 | struct lwtunnel_state *lwtstate) | |
171 | { | |
172 | struct mpls_iptunnel_encap *tun_encap_info; | |
173 | ||
174 | tun_encap_info = mpls_lwtunnel_encap(lwtstate); | |
175 | ||
176 | if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels, | |
177 | tun_encap_info->label)) | |
178 | goto nla_put_failure; | |
179 | ||
180 | return 0; | |
181 | ||
182 | nla_put_failure: | |
183 | return -EMSGSIZE; | |
184 | } | |
185 | ||
186 | static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate) | |
187 | { | |
188 | struct mpls_iptunnel_encap *tun_encap_info; | |
189 | ||
190 | tun_encap_info = mpls_lwtunnel_encap(lwtstate); | |
191 | ||
192 | return nla_total_size(tun_encap_info->labels * 4); | |
193 | } | |
194 | ||
195 | static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) | |
196 | { | |
197 | struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a); | |
198 | struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b); | |
199 | int l; | |
200 | ||
201 | if (a_hdr->labels != b_hdr->labels) | |
202 | return 1; | |
203 | ||
204 | for (l = 0; l < MAX_NEW_LABELS; l++) | |
205 | if (a_hdr->label[l] != b_hdr->label[l]) | |
206 | return 1; | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static const struct lwtunnel_encap_ops mpls_iptun_ops = { | |
211 | .build_state = mpls_build_state, | |
212 | .output = mpls_output, | |
213 | .fill_encap = mpls_fill_encap_info, | |
214 | .get_encap_size = mpls_encap_nlsize, | |
215 | .cmp_encap = mpls_encap_cmp, | |
216 | }; | |
217 | ||
218 | static int __init mpls_iptunnel_init(void) | |
219 | { | |
220 | return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); | |
221 | } | |
222 | module_init(mpls_iptunnel_init); | |
223 | ||
224 | static void __exit mpls_iptunnel_exit(void) | |
225 | { | |
226 | lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); | |
227 | } | |
228 | module_exit(mpls_iptunnel_exit); | |
229 | ||
230 | MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels"); | |
231 | MODULE_LICENSE("GPL v2"); |