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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
30static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
31 [MPLS_IPTUNNEL_DST] = { .len = sizeof(u32) },
32 [MPLS_IPTUNNEL_TTL] = { .type = NLA_U8 },
33};
34
35static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en)
36{
37
38 return en->labels * sizeof(struct mpls_shim_hdr);
39}
40
41static int mpls_xmit(struct sk_buff *skb)
42{
43 struct mpls_iptunnel_encap *tun_encap_info;
44 struct mpls_shim_hdr *hdr;
45 struct net_device *out_dev;
46 unsigned int hh_len;
47 unsigned int new_header_size;
48 unsigned int mtu;
49 struct dst_entry *dst = skb_dst(skb);
50 struct rtable *rt = NULL;
51 struct rt6_info *rt6 = NULL;
52 struct mpls_dev *out_mdev;
53 struct net *net;
54 int err = 0;
55 bool bos;
56 int i;
57 unsigned int ttl;
58
59
60 out_dev = dst->dev;
61 net = dev_net(out_dev);
62
63 skb_orphan(skb);
64
65 if (!mpls_output_possible(out_dev) ||
66 !dst->lwtstate || skb_warn_if_lro(skb))
67 goto drop;
68
69 skb_forward_csum(skb);
70
71 tun_encap_info = mpls_lwtunnel_encap(dst->lwtstate);
72
73
74
75
76
77
78
79
80
81
82
83 if (dst->ops->family == AF_INET) {
84 if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DISABLED)
85 ttl = tun_encap_info->default_ttl;
86 else if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
87 !net->mpls.ip_ttl_propagate)
88 ttl = net->mpls.default_ttl;
89 else
90 ttl = ip_hdr(skb)->ttl;
91 rt = (struct rtable *)dst;
92 } else if (dst->ops->family == AF_INET6) {
93 if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DISABLED)
94 ttl = tun_encap_info->default_ttl;
95 else if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
96 !net->mpls.ip_ttl_propagate)
97 ttl = net->mpls.default_ttl;
98 else
99 ttl = ipv6_hdr(skb)->hop_limit;
100 rt6 = (struct rt6_info *)dst;
101 } else {
102 goto drop;
103 }
104
105
106 new_header_size = mpls_encap_size(tun_encap_info);
107 mtu = mpls_dev_mtu(out_dev);
108 if (mpls_pkt_too_big(skb, mtu - new_header_size))
109 goto drop;
110
111 hh_len = LL_RESERVED_SPACE(out_dev);
112 if (!out_dev->header_ops)
113 hh_len = 0;
114
115
116 if (skb_cow(skb, hh_len + new_header_size))
117 goto drop;
118
119 skb_set_inner_protocol(skb, skb->protocol);
120 skb_reset_inner_network_header(skb);
121
122 skb_push(skb, new_header_size);
123
124 skb_reset_network_header(skb);
125
126 skb->dev = out_dev;
127 skb->protocol = htons(ETH_P_MPLS_UC);
128
129
130 hdr = mpls_hdr(skb);
131 bos = true;
132 for (i = tun_encap_info->labels - 1; i >= 0; i--) {
133 hdr[i] = mpls_entry_encode(tun_encap_info->label[i],
134 ttl, 0, bos);
135 bos = false;
136 }
137
138 mpls_stats_inc_outucastpkts(out_dev, skb);
139
140 if (rt)
141 err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway,
142 skb);
143 else if (rt6) {
144 if (ipv6_addr_v4mapped(&rt6->rt6i_gateway)) {
145
146 err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt6->rt6i_gateway.s6_addr32[3],
147 skb);
148 } else
149 err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
150 skb);
151 }
152 if (err)
153 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
154 __func__, err);
155
156 return LWTUNNEL_XMIT_DONE;
157
158drop:
159 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
160 if (out_mdev)
161 MPLS_INC_STATS(out_mdev, tx_errors);
162 kfree_skb(skb);
163 return -EINVAL;
164}
165
166static int mpls_build_state(struct nlattr *nla,
167 unsigned int family, const void *cfg,
168 struct lwtunnel_state **ts,
169 struct netlink_ext_ack *extack)
170{
171 struct mpls_iptunnel_encap *tun_encap_info;
172 struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
173 struct lwtunnel_state *newts;
174 u8 n_labels;
175 int ret;
176
177 ret = nla_parse_nested_deprecated(tb, MPLS_IPTUNNEL_MAX, nla,
178 mpls_iptunnel_policy, extack);
179 if (ret < 0)
180 return ret;
181
182 if (!tb[MPLS_IPTUNNEL_DST]) {
183 NL_SET_ERR_MSG(extack, "MPLS_IPTUNNEL_DST attribute is missing");
184 return -EINVAL;
185 }
186
187
188 if (nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
189 &n_labels, NULL, extack))
190 return -EINVAL;
191
192 newts = lwtunnel_state_alloc(sizeof(*tun_encap_info) +
193 n_labels * sizeof(u32));
194 if (!newts)
195 return -ENOMEM;
196
197 tun_encap_info = mpls_lwtunnel_encap(newts);
198 ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], n_labels,
199 &tun_encap_info->labels, tun_encap_info->label,
200 extack);
201 if (ret)
202 goto errout;
203
204 tun_encap_info->ttl_propagate = MPLS_TTL_PROP_DEFAULT;
205
206 if (tb[MPLS_IPTUNNEL_TTL]) {
207 tun_encap_info->default_ttl = nla_get_u8(tb[MPLS_IPTUNNEL_TTL]);
208
209 tun_encap_info->ttl_propagate = tun_encap_info->default_ttl ?
210 MPLS_TTL_PROP_DISABLED :
211 MPLS_TTL_PROP_ENABLED;
212 }
213
214 newts->type = LWTUNNEL_ENCAP_MPLS;
215 newts->flags |= LWTUNNEL_STATE_XMIT_REDIRECT;
216 newts->headroom = mpls_encap_size(tun_encap_info);
217
218 *ts = newts;
219
220 return 0;
221
222errout:
223 kfree(newts);
224 *ts = NULL;
225
226 return ret;
227}
228
229static int mpls_fill_encap_info(struct sk_buff *skb,
230 struct lwtunnel_state *lwtstate)
231{
232 struct mpls_iptunnel_encap *tun_encap_info;
233
234 tun_encap_info = mpls_lwtunnel_encap(lwtstate);
235
236 if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels,
237 tun_encap_info->label))
238 goto nla_put_failure;
239
240 if (tun_encap_info->ttl_propagate != MPLS_TTL_PROP_DEFAULT &&
241 nla_put_u8(skb, MPLS_IPTUNNEL_TTL, tun_encap_info->default_ttl))
242 goto nla_put_failure;
243
244 return 0;
245
246nla_put_failure:
247 return -EMSGSIZE;
248}
249
250static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate)
251{
252 struct mpls_iptunnel_encap *tun_encap_info;
253 int nlsize;
254
255 tun_encap_info = mpls_lwtunnel_encap(lwtstate);
256
257 nlsize = nla_total_size(tun_encap_info->labels * 4);
258
259 if (tun_encap_info->ttl_propagate != MPLS_TTL_PROP_DEFAULT)
260 nlsize += nla_total_size(1);
261
262 return nlsize;
263}
264
265static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
266{
267 struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a);
268 struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b);
269 int l;
270
271 if (a_hdr->labels != b_hdr->labels ||
272 a_hdr->ttl_propagate != b_hdr->ttl_propagate ||
273 a_hdr->default_ttl != b_hdr->default_ttl)
274 return 1;
275
276 for (l = 0; l < a_hdr->labels; l++)
277 if (a_hdr->label[l] != b_hdr->label[l])
278 return 1;
279 return 0;
280}
281
282static const struct lwtunnel_encap_ops mpls_iptun_ops = {
283 .build_state = mpls_build_state,
284 .xmit = mpls_xmit,
285 .fill_encap = mpls_fill_encap_info,
286 .get_encap_size = mpls_encap_nlsize,
287 .cmp_encap = mpls_encap_cmp,
288 .owner = THIS_MODULE,
289};
290
291static int __init mpls_iptunnel_init(void)
292{
293 return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
294}
295module_init(mpls_iptunnel_init);
296
297static void __exit mpls_iptunnel_exit(void)
298{
299 lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
300}
301module_exit(mpls_iptunnel_exit);
302
303MODULE_ALIAS_RTNL_LWT(MPLS);
304MODULE_SOFTDEP("post: mpls_gso");
305MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
306MODULE_LICENSE("GPL v2");
307