blob: 098632adc9b5afa69e4b65439ee54c3fc0a8d668 [file] [log] [blame]
Thomas Gleixner2874c5f2019-05-27 08:55:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
David Lebrun6c8702c2016-11-08 14:57:41 +01002/*
3 * SR-IPv6 implementation
4 *
5 * Author:
6 * David Lebrun <david.lebrun@uclouvain.be>
David Lebrun6c8702c2016-11-08 14:57:41 +01007 */
8
9#include <linux/types.h>
10#include <linux/skbuff.h>
11#include <linux/net.h>
12#include <linux/module.h>
13#include <net/ip.h>
David Lebrun5807b222018-03-29 17:59:36 +010014#include <net/ip_tunnels.h>
David Lebrun6c8702c2016-11-08 14:57:41 +010015#include <net/lwtunnel.h>
16#include <net/netevent.h>
17#include <net/netns/generic.h>
18#include <net/ip6_fib.h>
19#include <net/route.h>
20#include <net/seg6.h>
21#include <linux/seg6.h>
22#include <linux/seg6_iptunnel.h>
23#include <net/addrconf.h>
24#include <net/ip6_route.h>
David Lebrun6c8702c2016-11-08 14:57:41 +010025#include <net/dst_cache.h>
David Lebrun9baee832016-11-08 14:59:19 +010026#ifdef CONFIG_IPV6_SEG6_HMAC
27#include <net/seg6_hmac.h>
28#endif
Ryoga Saito7a3f5b02021-08-17 08:39:37 +000029#include <linux/netfilter.h>
David Lebrun6c8702c2016-11-08 14:57:41 +010030
Ioana-Ruxandra Stăncioi88fab212020-08-03 07:33:33 +000031static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)
32{
33 int head = 0;
34
35 switch (tuninfo->mode) {
36 case SEG6_IPTUN_MODE_INLINE:
37 break;
38 case SEG6_IPTUN_MODE_ENCAP:
Andrea Mayerb07c8cd2022-07-27 20:54:05 +020039 case SEG6_IPTUN_MODE_ENCAP_RED:
Ioana-Ruxandra Stăncioi88fab212020-08-03 07:33:33 +000040 head = sizeof(struct ipv6hdr);
41 break;
42 case SEG6_IPTUN_MODE_L2ENCAP:
Andrea Mayer13f02962022-07-27 20:54:06 +020043 case SEG6_IPTUN_MODE_L2ENCAP_RED:
Ioana-Ruxandra Stăncioi88fab212020-08-03 07:33:33 +000044 return 0;
45 }
46
47 return ((tuninfo->srh->hdrlen + 1) << 3) + head;
48}
49
David Lebrun6c8702c2016-11-08 14:57:41 +010050struct seg6_lwt {
David Lebrun6c8702c2016-11-08 14:57:41 +010051 struct dst_cache cache;
Gustavo A. R. Silvab0c9a2d2020-02-28 07:36:41 -060052 struct seg6_iptunnel_encap tuninfo[];
David Lebrun6c8702c2016-11-08 14:57:41 +010053};
54
55static inline struct seg6_lwt *seg6_lwt_lwtunnel(struct lwtunnel_state *lwt)
56{
57 return (struct seg6_lwt *)lwt->data;
58}
59
60static inline struct seg6_iptunnel_encap *
61seg6_encap_lwtunnel(struct lwtunnel_state *lwt)
62{
63 return seg6_lwt_lwtunnel(lwt)->tuninfo;
64}
65
66static const struct nla_policy seg6_iptunnel_policy[SEG6_IPTUNNEL_MAX + 1] = {
67 [SEG6_IPTUNNEL_SRH] = { .type = NLA_BINARY },
68};
69
Wei Yongjunbb4005b2017-02-06 16:15:05 +000070static int nla_put_srh(struct sk_buff *skb, int attrtype,
71 struct seg6_iptunnel_encap *tuninfo)
David Lebrun6c8702c2016-11-08 14:57:41 +010072{
73 struct seg6_iptunnel_encap *data;
74 struct nlattr *nla;
75 int len;
76
77 len = SEG6_IPTUN_ENCAP_SIZE(tuninfo);
78
79 nla = nla_reserve(skb, attrtype, len);
80 if (!nla)
81 return -EMSGSIZE;
82
83 data = nla_data(nla);
84 memcpy(data, tuninfo, len);
85
86 return 0;
87}
88
89static void set_tun_src(struct net *net, struct net_device *dev,
90 struct in6_addr *daddr, struct in6_addr *saddr)
91{
92 struct seg6_pernet_data *sdata = seg6_pernet(net);
93 struct in6_addr *tun_src;
94
95 rcu_read_lock();
96
97 tun_src = rcu_dereference(sdata->tun_src);
98
99 if (!ipv6_addr_any(tun_src)) {
100 memcpy(saddr, tun_src, sizeof(struct in6_addr));
101 } else {
102 ipv6_dev_get_saddr(net, dev, daddr, IPV6_PREFER_SRC_PUBLIC,
103 saddr);
104 }
105
106 rcu_read_unlock();
107}
108
Ahmed Abdelsalamb5facfd2018-04-24 20:23:16 +0200109/* Compute flowlabel for outer IPv6 header */
110static __be32 seg6_make_flowlabel(struct net *net, struct sk_buff *skb,
111 struct ipv6hdr *inner_hdr)
112{
113 int do_flowlabel = net->ipv6.sysctl.seg6_flowlabel;
114 __be32 flowlabel = 0;
115 u32 hash;
116
117 if (do_flowlabel > 0) {
118 hash = skb_get_hash(skb);
Colin Ian King3ee593a2018-07-17 16:52:54 +0100119 hash = rol32(hash, 16);
Ahmed Abdelsalamb5facfd2018-04-24 20:23:16 +0200120 flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
121 } else if (!do_flowlabel && skb->protocol == htons(ETH_P_IPV6)) {
122 flowlabel = ip6_flowlabel(inner_hdr);
123 }
124 return flowlabel;
125}
126
David Lebrun6c8702c2016-11-08 14:57:41 +0100127/* encapsulate an IPv6 packet within an outer IPv6 header with a given SRH */
David Lebrun32d99d02017-08-25 09:56:44 +0200128int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto)
David Lebrun6c8702c2016-11-08 14:57:41 +0100129{
David Lebrun8936ef72018-03-20 14:44:56 +0000130 struct dst_entry *dst = skb_dst(skb);
131 struct net *net = dev_net(dst->dev);
David Lebrun6c8702c2016-11-08 14:57:41 +0100132 struct ipv6hdr *hdr, *inner_hdr;
133 struct ipv6_sr_hdr *isrh;
134 int hdrlen, tot_len, err;
Ahmed Abdelsalamb5facfd2018-04-24 20:23:16 +0200135 __be32 flowlabel;
David Lebrun6c8702c2016-11-08 14:57:41 +0100136
137 hdrlen = (osrh->hdrlen + 1) << 3;
138 tot_len = hdrlen + sizeof(*hdr);
139
Mathieu Xhonneuxbbb40a02018-05-25 13:29:41 +0100140 err = skb_cow_head(skb, tot_len + skb->mac_len);
David Lebrun6c8702c2016-11-08 14:57:41 +0100141 if (unlikely(err))
142 return err;
143
144 inner_hdr = ipv6_hdr(skb);
Ahmed Abdelsalam6df93462018-04-28 12:18:35 +0200145 flowlabel = seg6_make_flowlabel(net, skb, inner_hdr);
David Lebrun6c8702c2016-11-08 14:57:41 +0100146
147 skb_push(skb, tot_len);
148 skb_reset_network_header(skb);
149 skb_mac_header_rebuild(skb);
150 hdr = ipv6_hdr(skb);
151
152 /* inherit tc, flowlabel and hlim
153 * hlim will be decremented in ip6_forward() afterwards and
154 * decapsulation will overwrite inner hlim with outer hlim
155 */
David Lebrun32d99d02017-08-25 09:56:44 +0200156
157 if (skb->protocol == htons(ETH_P_IPV6)) {
158 ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),
Ahmed Abdelsalamb5facfd2018-04-24 20:23:16 +0200159 flowlabel);
David Lebrun32d99d02017-08-25 09:56:44 +0200160 hdr->hop_limit = inner_hdr->hop_limit;
161 } else {
Ahmed Abdelsalamb5facfd2018-04-24 20:23:16 +0200162 ip6_flow_hdr(hdr, 0, flowlabel);
David Lebrun32d99d02017-08-25 09:56:44 +0200163 hdr->hop_limit = ip6_dst_hoplimit(skb_dst(skb));
Yohei Kanemaruef489742019-01-29 15:52:34 +0900164
165 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
Andrea Mayerae68d9332021-12-08 20:54:09 +0100166
167 /* the control block has been erased, so we have to set the
168 * iif once again.
169 * We read the receiving interface index directly from the
170 * skb->skb_iif as it is done in the IPv4 receiving path (i.e.:
171 * ip_rcv_core(...)).
172 */
173 IP6CB(skb)->iif = skb->skb_iif;
David Lebrun32d99d02017-08-25 09:56:44 +0200174 }
175
David Lebrun6c8702c2016-11-08 14:57:41 +0100176 hdr->nexthdr = NEXTHDR_ROUTING;
177
178 isrh = (void *)hdr + sizeof(*hdr);
179 memcpy(isrh, osrh, hdrlen);
180
David Lebrun32d99d02017-08-25 09:56:44 +0200181 isrh->nexthdr = proto;
David Lebrun6c8702c2016-11-08 14:57:41 +0100182
183 hdr->daddr = isrh->segments[isrh->first_segment];
Ahmed Abdelsalama957fa12018-04-20 15:58:05 +0200184 set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
David Lebrun6c8702c2016-11-08 14:57:41 +0100185
David Lebrun9baee832016-11-08 14:59:19 +0100186#ifdef CONFIG_IPV6_SEG6_HMAC
187 if (sr_has_hmac(isrh)) {
188 err = seg6_push_hmac(net, &hdr->saddr, isrh);
189 if (unlikely(err))
190 return err;
191 }
192#endif
193
Andrea Mayerdf8386d2022-07-12 19:58:35 +0200194 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
195
David Lebrun6c8702c2016-11-08 14:57:41 +0100196 skb_postpush_rcsum(skb, hdr, tot_len);
197
198 return 0;
199}
David Lebrunb04c80d2017-08-05 12:38:25 +0200200EXPORT_SYMBOL_GPL(seg6_do_srh_encap);
David Lebrun6c8702c2016-11-08 14:57:41 +0100201
Andrea Mayerb07c8cd2022-07-27 20:54:05 +0200202/* encapsulate an IPv6 packet within an outer IPv6 header with reduced SRH */
203static int seg6_do_srh_encap_red(struct sk_buff *skb,
204 struct ipv6_sr_hdr *osrh, int proto)
205{
206 __u8 first_seg = osrh->first_segment;
207 struct dst_entry *dst = skb_dst(skb);
208 struct net *net = dev_net(dst->dev);
209 struct ipv6hdr *hdr, *inner_hdr;
210 int hdrlen = ipv6_optlen(osrh);
211 int red_tlv_offset, tlv_offset;
212 struct ipv6_sr_hdr *isrh;
213 bool skip_srh = false;
214 __be32 flowlabel;
215 int tot_len, err;
216 int red_hdrlen;
217 int tlvs_len;
218
219 if (first_seg > 0) {
220 red_hdrlen = hdrlen - sizeof(struct in6_addr);
221 } else {
222 /* NOTE: if tag/flags and/or other TLVs are introduced in the
223 * seg6_iptunnel infrastructure, they should be considered when
224 * deciding to skip the SRH.
225 */
226 skip_srh = !sr_has_hmac(osrh);
227
228 red_hdrlen = skip_srh ? 0 : hdrlen;
229 }
230
231 tot_len = red_hdrlen + sizeof(struct ipv6hdr);
232
233 err = skb_cow_head(skb, tot_len + skb->mac_len);
234 if (unlikely(err))
235 return err;
236
237 inner_hdr = ipv6_hdr(skb);
238 flowlabel = seg6_make_flowlabel(net, skb, inner_hdr);
239
240 skb_push(skb, tot_len);
241 skb_reset_network_header(skb);
242 skb_mac_header_rebuild(skb);
243 hdr = ipv6_hdr(skb);
244
245 /* based on seg6_do_srh_encap() */
246 if (skb->protocol == htons(ETH_P_IPV6)) {
247 ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),
248 flowlabel);
249 hdr->hop_limit = inner_hdr->hop_limit;
250 } else {
251 ip6_flow_hdr(hdr, 0, flowlabel);
252 hdr->hop_limit = ip6_dst_hoplimit(skb_dst(skb));
253
254 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
255 IP6CB(skb)->iif = skb->skb_iif;
256 }
257
258 /* no matter if we have to skip the SRH or not, the first segment
259 * always comes in the pushed IPv6 header.
260 */
261 hdr->daddr = osrh->segments[first_seg];
262
263 if (skip_srh) {
264 hdr->nexthdr = proto;
265
266 set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
267 goto out;
268 }
269
270 /* we cannot skip the SRH, slow path */
271
272 hdr->nexthdr = NEXTHDR_ROUTING;
273 isrh = (void *)hdr + sizeof(struct ipv6hdr);
274
275 if (unlikely(!first_seg)) {
276 /* this is a very rare case; we have only one SID but
277 * we cannot skip the SRH since we are carrying some
278 * other info.
279 */
280 memcpy(isrh, osrh, hdrlen);
281 goto srcaddr;
282 }
283
284 tlv_offset = sizeof(*osrh) + (first_seg + 1) * sizeof(struct in6_addr);
285 red_tlv_offset = tlv_offset - sizeof(struct in6_addr);
286
287 memcpy(isrh, osrh, red_tlv_offset);
288
289 tlvs_len = hdrlen - tlv_offset;
290 if (unlikely(tlvs_len > 0)) {
291 const void *s = (const void *)osrh + tlv_offset;
292 void *d = (void *)isrh + red_tlv_offset;
293
294 memcpy(d, s, tlvs_len);
295 }
296
297 --isrh->first_segment;
298 isrh->hdrlen -= 2;
299
300srcaddr:
301 isrh->nexthdr = proto;
302 set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
303
304#ifdef CONFIG_IPV6_SEG6_HMAC
305 if (unlikely(!skip_srh && sr_has_hmac(isrh))) {
306 err = seg6_push_hmac(net, &hdr->saddr, isrh);
307 if (unlikely(err))
308 return err;
309 }
310#endif
311
312out:
313 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
314
315 skb_postpush_rcsum(skb, hdr, tot_len);
316
317 return 0;
318}
319
David Lebrun6c8702c2016-11-08 14:57:41 +0100320/* insert an SRH within an IPv6 packet, just after the IPv6 header */
David Lebrunb04c80d2017-08-05 12:38:25 +0200321int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)
David Lebrun6c8702c2016-11-08 14:57:41 +0100322{
323 struct ipv6hdr *hdr, *oldhdr;
324 struct ipv6_sr_hdr *isrh;
325 int hdrlen, err;
326
327 hdrlen = (osrh->hdrlen + 1) << 3;
328
Mathieu Xhonneuxbbb40a02018-05-25 13:29:41 +0100329 err = skb_cow_head(skb, hdrlen + skb->mac_len);
David Lebrun6c8702c2016-11-08 14:57:41 +0100330 if (unlikely(err))
331 return err;
332
333 oldhdr = ipv6_hdr(skb);
334
335 skb_pull(skb, sizeof(struct ipv6hdr));
336 skb_postpull_rcsum(skb, skb_network_header(skb),
337 sizeof(struct ipv6hdr));
338
339 skb_push(skb, sizeof(struct ipv6hdr) + hdrlen);
340 skb_reset_network_header(skb);
341 skb_mac_header_rebuild(skb);
342
343 hdr = ipv6_hdr(skb);
344
345 memmove(hdr, oldhdr, sizeof(*hdr));
346
347 isrh = (void *)hdr + sizeof(*hdr);
348 memcpy(isrh, osrh, hdrlen);
349
350 isrh->nexthdr = hdr->nexthdr;
351 hdr->nexthdr = NEXTHDR_ROUTING;
352
353 isrh->segments[0] = hdr->daddr;
354 hdr->daddr = isrh->segments[isrh->first_segment];
355
David Lebrun9baee832016-11-08 14:59:19 +0100356#ifdef CONFIG_IPV6_SEG6_HMAC
357 if (sr_has_hmac(isrh)) {
358 struct net *net = dev_net(skb_dst(skb)->dev);
359
360 err = seg6_push_hmac(net, &hdr->saddr, isrh);
361 if (unlikely(err))
362 return err;
363 }
364#endif
365
Andrea Mayerdf8386d2022-07-12 19:58:35 +0200366 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
367
David Lebrun6c8702c2016-11-08 14:57:41 +0100368 skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen);
369
370 return 0;
371}
David Lebrunb04c80d2017-08-05 12:38:25 +0200372EXPORT_SYMBOL_GPL(seg6_do_srh_inline);
David Lebrun6c8702c2016-11-08 14:57:41 +0100373
374static int seg6_do_srh(struct sk_buff *skb)
375{
376 struct dst_entry *dst = skb_dst(skb);
377 struct seg6_iptunnel_encap *tinfo;
David Lebrun32d99d02017-08-25 09:56:44 +0200378 int proto, err = 0;
David Lebrun6c8702c2016-11-08 14:57:41 +0100379
380 tinfo = seg6_encap_lwtunnel(dst->lwtstate);
381
David Lebrun6c8702c2016-11-08 14:57:41 +0100382 switch (tinfo->mode) {
David Lebrun6c8702c2016-11-08 14:57:41 +0100383 case SEG6_IPTUN_MODE_INLINE:
David Lebrun32d99d02017-08-25 09:56:44 +0200384 if (skb->protocol != htons(ETH_P_IPV6))
385 return -EINVAL;
386
David Lebrun6c8702c2016-11-08 14:57:41 +0100387 err = seg6_do_srh_inline(skb, tinfo->srh);
David Lebrun32d99d02017-08-25 09:56:44 +0200388 if (err)
389 return err;
David Lebrun6c8702c2016-11-08 14:57:41 +0100390 break;
David Lebrun6c8702c2016-11-08 14:57:41 +0100391 case SEG6_IPTUN_MODE_ENCAP:
Andrea Mayerb07c8cd2022-07-27 20:54:05 +0200392 case SEG6_IPTUN_MODE_ENCAP_RED:
David Lebrun5807b222018-03-29 17:59:36 +0100393 err = iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6);
394 if (err)
395 return err;
396
David Lebrun32d99d02017-08-25 09:56:44 +0200397 if (skb->protocol == htons(ETH_P_IPV6))
398 proto = IPPROTO_IPV6;
399 else if (skb->protocol == htons(ETH_P_IP))
400 proto = IPPROTO_IPIP;
401 else
402 return -EINVAL;
403
Andrea Mayerb07c8cd2022-07-27 20:54:05 +0200404 if (tinfo->mode == SEG6_IPTUN_MODE_ENCAP)
405 err = seg6_do_srh_encap(skb, tinfo->srh, proto);
406 else
407 err = seg6_do_srh_encap_red(skb, tinfo->srh, proto);
408
David Lebrun32d99d02017-08-25 09:56:44 +0200409 if (err)
410 return err;
411
David Lebrun5807b222018-03-29 17:59:36 +0100412 skb_set_inner_transport_header(skb, skb_transport_offset(skb));
413 skb_set_inner_protocol(skb, skb->protocol);
David Lebrun32d99d02017-08-25 09:56:44 +0200414 skb->protocol = htons(ETH_P_IPV6);
David Lebrun6c8702c2016-11-08 14:57:41 +0100415 break;
David Lebrun38ee7f22017-08-25 09:56:45 +0200416 case SEG6_IPTUN_MODE_L2ENCAP:
Andrea Mayer13f02962022-07-27 20:54:06 +0200417 case SEG6_IPTUN_MODE_L2ENCAP_RED:
David Lebrun38ee7f22017-08-25 09:56:45 +0200418 if (!skb_mac_header_was_set(skb))
419 return -EINVAL;
420
421 if (pskb_expand_head(skb, skb->mac_len, 0, GFP_ATOMIC) < 0)
422 return -ENOMEM;
423
424 skb_mac_header_rebuild(skb);
425 skb_push(skb, skb->mac_len);
426
Andrea Mayer13f02962022-07-27 20:54:06 +0200427 if (tinfo->mode == SEG6_IPTUN_MODE_L2ENCAP)
428 err = seg6_do_srh_encap(skb, tinfo->srh,
429 IPPROTO_ETHERNET);
430 else
431 err = seg6_do_srh_encap_red(skb, tinfo->srh,
432 IPPROTO_ETHERNET);
433
David Lebrun38ee7f22017-08-25 09:56:45 +0200434 if (err)
435 return err;
436
437 skb->protocol = htons(ETH_P_IPV6);
438 break;
David Lebrun6c8702c2016-11-08 14:57:41 +0100439 }
440
David Lebrun6c8702c2016-11-08 14:57:41 +0100441 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000442 nf_reset_ct(skb);
David Lebrun6c8702c2016-11-08 14:57:41 +0100443
David Lebrun6c8702c2016-11-08 14:57:41 +0100444 return 0;
445}
446
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000447static int seg6_input_finish(struct net *net, struct sock *sk,
448 struct sk_buff *skb)
449{
450 return dst_input(skb);
451}
452
453static int seg6_input_core(struct net *net, struct sock *sk,
454 struct sk_buff *skb)
David Lebrun6c8702c2016-11-08 14:57:41 +0100455{
David Lebrunaf4a2202017-03-24 10:46:27 +0100456 struct dst_entry *orig_dst = skb_dst(skb);
457 struct dst_entry *dst = NULL;
458 struct seg6_lwt *slwt;
David Lebrun6c8702c2016-11-08 14:57:41 +0100459 int err;
460
461 err = seg6_do_srh(skb);
Andrea Mayer5447f972024-05-17 18:45:41 +0200462 if (unlikely(err))
463 goto drop;
David Lebrun6c8702c2016-11-08 14:57:41 +0100464
David Lebrunaf4a2202017-03-24 10:46:27 +0100465 slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
466
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000467 local_bh_disable();
David Lebrunaf4a2202017-03-24 10:46:27 +0100468 dst = dst_cache_get(&slwt->cache);
David Lebrunaf4a2202017-03-24 10:46:27 +0100469
David Lebrunaf4a2202017-03-24 10:46:27 +0100470 if (!dst) {
471 ip6_route_input(skb);
David Lebrunaf4a2202017-03-24 10:46:27 +0100472 dst = skb_dst(skb);
473 if (!dst->error) {
David Lebrunaf4a2202017-03-24 10:46:27 +0100474 dst_cache_set_ip6(&slwt->cache, dst,
475 &ipv6_hdr(skb)->saddr);
David Lebrunaf4a2202017-03-24 10:46:27 +0100476 }
David Lebrunaf4a2202017-03-24 10:46:27 +0100477 } else {
Yuya Tajimafa0583c2023-05-15 15:34:27 +0000478 skb_dst_drop(skb);
David Lebrunaf4a2202017-03-24 10:46:27 +0100479 skb_dst_set(skb, dst);
480 }
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000481 local_bh_enable();
David Lebrun6c8702c2016-11-08 14:57:41 +0100482
David Lebrunaf3b5152017-04-16 12:27:14 +0200483 err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
484 if (unlikely(err))
Andrea Mayer5447f972024-05-17 18:45:41 +0200485 goto drop;
David Lebrunaf3b5152017-04-16 12:27:14 +0200486
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000487 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
488 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
489 dev_net(skb->dev), NULL, skb, NULL,
490 skb_dst(skb)->dev, seg6_input_finish);
491
492 return seg6_input_finish(dev_net(skb->dev), NULL, skb);
Andrea Mayer5447f972024-05-17 18:45:41 +0200493drop:
494 kfree_skb(skb);
495 return err;
David Lebrun6c8702c2016-11-08 14:57:41 +0100496}
497
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000498static int seg6_input_nf(struct sk_buff *skb)
499{
500 struct net_device *dev = skb_dst(skb)->dev;
501 struct net *net = dev_net(skb->dev);
502
503 switch (skb->protocol) {
504 case htons(ETH_P_IP):
505 return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, NULL,
506 skb, NULL, dev, seg6_input_core);
507 case htons(ETH_P_IPV6):
508 return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, NULL,
509 skb, NULL, dev, seg6_input_core);
510 }
511
512 return -EINVAL;
513}
514
515static int seg6_input(struct sk_buff *skb)
516{
517 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
518 return seg6_input_nf(skb);
519
520 return seg6_input_core(dev_net(skb->dev), NULL, skb);
521}
522
523static int seg6_output_core(struct net *net, struct sock *sk,
524 struct sk_buff *skb)
David Lebrun6c8702c2016-11-08 14:57:41 +0100525{
526 struct dst_entry *orig_dst = skb_dst(skb);
527 struct dst_entry *dst = NULL;
528 struct seg6_lwt *slwt;
Colin Ian Kingbf0df732021-09-02 15:35:05 +0100529 int err;
David Lebrun6c8702c2016-11-08 14:57:41 +0100530
531 err = seg6_do_srh(skb);
532 if (unlikely(err))
533 goto drop;
534
535 slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
536
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000537 local_bh_disable();
David Lebrun6c8702c2016-11-08 14:57:41 +0100538 dst = dst_cache_get(&slwt->cache);
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000539 local_bh_enable();
David Lebrun6c8702c2016-11-08 14:57:41 +0100540
541 if (unlikely(!dst)) {
542 struct ipv6hdr *hdr = ipv6_hdr(skb);
543 struct flowi6 fl6;
544
Shmulik Ladkani1b4e5ad2018-12-07 09:50:17 +0200545 memset(&fl6, 0, sizeof(fl6));
David Lebrun6c8702c2016-11-08 14:57:41 +0100546 fl6.daddr = hdr->daddr;
547 fl6.saddr = hdr->saddr;
548 fl6.flowlabel = ip6_flowinfo(hdr);
549 fl6.flowi6_mark = skb->mark;
550 fl6.flowi6_proto = hdr->nexthdr;
551
552 dst = ip6_route_output(net, NULL, &fl6);
553 if (dst->error) {
554 err = dst->error;
555 dst_release(dst);
556 goto drop;
557 }
558
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000559 local_bh_disable();
David Lebrun6c8702c2016-11-08 14:57:41 +0100560 dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr);
Eric Dumazetc0b98ac2024-05-31 13:26:34 +0000561 local_bh_enable();
David Lebrun6c8702c2016-11-08 14:57:41 +0100562 }
563
564 skb_dst_drop(skb);
565 skb_dst_set(skb, dst);
566
David Lebrunaf3b5152017-04-16 12:27:14 +0200567 err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
568 if (unlikely(err))
569 goto drop;
570
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000571 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
572 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
573 NULL, skb_dst(skb)->dev, dst_output);
574
David Lebrun6c8702c2016-11-08 14:57:41 +0100575 return dst_output(net, sk, skb);
576drop:
577 kfree_skb(skb);
578 return err;
579}
580
Ryoga Saito7a3f5b02021-08-17 08:39:37 +0000581static int seg6_output_nf(struct net *net, struct sock *sk, struct sk_buff *skb)
582{
583 struct net_device *dev = skb_dst(skb)->dev;
584
585 switch (skb->protocol) {
586 case htons(ETH_P_IP):
587 return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
588 NULL, dev, seg6_output_core);
589 case htons(ETH_P_IPV6):
590 return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
591 NULL, dev, seg6_output_core);
592 }
593
594 return -EINVAL;
595}
596
597static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
598{
599 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
600 return seg6_output_nf(net, sk, skb);
601
602 return seg6_output_core(net, sk, skb);
603}
604
Alexander Aringfaee6762020-03-27 18:00:21 -0400605static int seg6_build_state(struct net *net, struct nlattr *nla,
David Lebrun6c8702c2016-11-08 14:57:41 +0100606 unsigned int family, const void *cfg,
David Ahern9ae28722017-05-27 16:19:28 -0600607 struct lwtunnel_state **ts,
608 struct netlink_ext_ack *extack)
David Lebrun6c8702c2016-11-08 14:57:41 +0100609{
610 struct nlattr *tb[SEG6_IPTUNNEL_MAX + 1];
611 struct seg6_iptunnel_encap *tuninfo;
612 struct lwtunnel_state *newts;
613 int tuninfo_len, min_size;
614 struct seg6_lwt *slwt;
615 int err;
616
David Lebrun32d99d02017-08-25 09:56:44 +0200617 if (family != AF_INET && family != AF_INET6)
618 return -EINVAL;
619
Johannes Berg8cb08172019-04-26 14:07:28 +0200620 err = nla_parse_nested_deprecated(tb, SEG6_IPTUNNEL_MAX, nla,
621 seg6_iptunnel_policy, extack);
David Lebrun6c8702c2016-11-08 14:57:41 +0100622
623 if (err < 0)
624 return err;
625
626 if (!tb[SEG6_IPTUNNEL_SRH])
627 return -EINVAL;
628
629 tuninfo = nla_data(tb[SEG6_IPTUNNEL_SRH]);
630 tuninfo_len = nla_len(tb[SEG6_IPTUNNEL_SRH]);
631
632 /* tuninfo must contain at least the iptunnel encap structure,
633 * the SRH and one segment
634 */
635 min_size = sizeof(*tuninfo) + sizeof(struct ipv6_sr_hdr) +
636 sizeof(struct in6_addr);
637 if (tuninfo_len < min_size)
638 return -EINVAL;
639
640 switch (tuninfo->mode) {
David Lebrun6c8702c2016-11-08 14:57:41 +0100641 case SEG6_IPTUN_MODE_INLINE:
David Lebrun32d99d02017-08-25 09:56:44 +0200642 if (family != AF_INET6)
643 return -EINVAL;
644
David Lebrun6c8702c2016-11-08 14:57:41 +0100645 break;
David Lebrun6c8702c2016-11-08 14:57:41 +0100646 case SEG6_IPTUN_MODE_ENCAP:
647 break;
David Lebrun38ee7f22017-08-25 09:56:45 +0200648 case SEG6_IPTUN_MODE_L2ENCAP:
649 break;
Andrea Mayerb07c8cd2022-07-27 20:54:05 +0200650 case SEG6_IPTUN_MODE_ENCAP_RED:
651 break;
Andrea Mayer13f02962022-07-27 20:54:06 +0200652 case SEG6_IPTUN_MODE_L2ENCAP_RED:
653 break;
David Lebrun6c8702c2016-11-08 14:57:41 +0100654 default:
655 return -EINVAL;
656 }
657
658 /* verify that SRH is consistent */
Ahmed Abdelsalambb986a52020-06-03 06:54:42 +0000659 if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo), false))
David Lebrun6c8702c2016-11-08 14:57:41 +0100660 return -EINVAL;
661
662 newts = lwtunnel_state_alloc(tuninfo_len + sizeof(*slwt));
663 if (!newts)
664 return -ENOMEM;
665
666 slwt = seg6_lwt_lwtunnel(newts);
667
David Lebrun191f86c2018-03-20 14:44:55 +0000668 err = dst_cache_init(&slwt->cache, GFP_ATOMIC);
David Lebrun6c8702c2016-11-08 14:57:41 +0100669 if (err) {
670 kfree(newts);
671 return err;
672 }
David Lebrun6c8702c2016-11-08 14:57:41 +0100673
674 memcpy(&slwt->tuninfo, tuninfo, tuninfo_len);
675
676 newts->type = LWTUNNEL_ENCAP_SEG6;
David Lebrun38ee7f22017-08-25 09:56:45 +0200677 newts->flags |= LWTUNNEL_STATE_INPUT_REDIRECT;
678
679 if (tuninfo->mode != SEG6_IPTUN_MODE_L2ENCAP)
680 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
681
David Lebrun6c8702c2016-11-08 14:57:41 +0100682 newts->headroom = seg6_lwt_headroom(tuninfo);
683
684 *ts = newts;
685
686 return 0;
687}
688
David Lebrun6c8702c2016-11-08 14:57:41 +0100689static void seg6_destroy_state(struct lwtunnel_state *lwt)
690{
691 dst_cache_destroy(&seg6_lwt_lwtunnel(lwt)->cache);
692}
David Lebrun6c8702c2016-11-08 14:57:41 +0100693
694static int seg6_fill_encap_info(struct sk_buff *skb,
695 struct lwtunnel_state *lwtstate)
696{
697 struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
698
699 if (nla_put_srh(skb, SEG6_IPTUNNEL_SRH, tuninfo))
700 return -EMSGSIZE;
701
702 return 0;
703}
704
705static int seg6_encap_nlsize(struct lwtunnel_state *lwtstate)
706{
707 struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
708
709 return nla_total_size(SEG6_IPTUN_ENCAP_SIZE(tuninfo));
710}
711
712static int seg6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
713{
714 struct seg6_iptunnel_encap *a_hdr = seg6_encap_lwtunnel(a);
715 struct seg6_iptunnel_encap *b_hdr = seg6_encap_lwtunnel(b);
716 int len = SEG6_IPTUN_ENCAP_SIZE(a_hdr);
717
718 if (len != SEG6_IPTUN_ENCAP_SIZE(b_hdr))
719 return 1;
720
721 return memcmp(a_hdr, b_hdr, len);
722}
723
724static const struct lwtunnel_encap_ops seg6_iptun_ops = {
725 .build_state = seg6_build_state,
David Lebrun6c8702c2016-11-08 14:57:41 +0100726 .destroy_state = seg6_destroy_state,
David Lebrun6c8702c2016-11-08 14:57:41 +0100727 .output = seg6_output,
728 .input = seg6_input,
729 .fill_encap = seg6_fill_encap_info,
730 .get_encap_size = seg6_encap_nlsize,
731 .cmp_encap = seg6_encap_cmp,
Robert Shearman88ff7332017-01-24 16:26:47 +0000732 .owner = THIS_MODULE,
David Lebrun6c8702c2016-11-08 14:57:41 +0100733};
734
735int __init seg6_iptunnel_init(void)
736{
737 return lwtunnel_encap_add_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
738}
739
740void seg6_iptunnel_exit(void)
741{
742 lwtunnel_encap_del_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
743}