1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2013 Nicira, Inc.
4 */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/skbuff.h>
11 #include <linux/netdevice.h>
12 #include <linux/in.h>
13 #include <linux/if_arp.h>
14 #include <linux/init.h>
15 #include <linux/in6.h>
16 #include <linux/inetdevice.h>
17 #include <linux/netfilter_ipv4.h>
18 #include <linux/etherdevice.h>
19 #include <linux/if_ether.h>
20 #include <linux/if_vlan.h>
21 #include <linux/static_key.h>
22
23 #include <net/ip.h>
24 #include <net/icmp.h>
25 #include <net/protocol.h>
26 #include <net/ip_tunnels.h>
27 #include <net/ip6_tunnel.h>
28 #include <net/arp.h>
29 #include <net/checksum.h>
30 #include <net/dsfield.h>
31 #include <net/inet_ecn.h>
32 #include <net/xfrm.h>
33 #include <net/net_namespace.h>
34 #include <net/netns/generic.h>
35 #include <net/rtnetlink.h>
36 #include <net/dst_metadata.h>
37
38 const struct ip_tunnel_encap_ops __rcu *
39 iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
40 EXPORT_SYMBOL(iptun_encaps);
41
42 const struct ip6_tnl_encap_ops __rcu *
43 ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
44 EXPORT_SYMBOL(ip6tun_encaps);
45
iptunnel_xmit(struct sock * sk,struct rtable * rt,struct sk_buff * skb,__be32 src,__be32 dst,__u8 proto,__u8 tos,__u8 ttl,__be16 df,bool xnet)46 void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
47 __be32 src, __be32 dst, __u8 proto,
48 __u8 tos, __u8 ttl, __be16 df, bool xnet)
49 {
50 int pkt_len = skb->len - skb_inner_network_offset(skb);
51 struct net *net = dev_net(rt->dst.dev);
52 struct net_device *dev = skb->dev;
53 struct iphdr *iph;
54 int err;
55
56 skb_scrub_packet(skb, xnet);
57
58 skb_clear_hash_if_not_l4(skb);
59 skb_dst_set(skb, &rt->dst);
60 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
61
62 /* Push down and install the IP header. */
63 skb_push(skb, sizeof(struct iphdr));
64 skb_reset_network_header(skb);
65
66 iph = ip_hdr(skb);
67
68 iph->version = 4;
69 iph->ihl = sizeof(struct iphdr) >> 2;
70 iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df;
71 iph->protocol = proto;
72 iph->tos = tos;
73 iph->daddr = dst;
74 iph->saddr = src;
75 iph->ttl = ttl;
76 __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
77
78 err = ip_local_out(net, sk, skb);
79
80 if (dev) {
81 if (unlikely(net_xmit_eval(err)))
82 pkt_len = 0;
83 iptunnel_xmit_stats(dev, pkt_len);
84 }
85 }
86 EXPORT_SYMBOL_GPL(iptunnel_xmit);
87
__iptunnel_pull_header(struct sk_buff * skb,int hdr_len,__be16 inner_proto,bool raw_proto,bool xnet)88 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
89 __be16 inner_proto, bool raw_proto, bool xnet)
90 {
91 if (unlikely(!pskb_may_pull(skb, hdr_len)))
92 return -ENOMEM;
93
94 skb_pull_rcsum(skb, hdr_len);
95
96 if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
97 struct ethhdr *eh;
98
99 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
100 return -ENOMEM;
101
102 eh = (struct ethhdr *)skb->data;
103 if (likely(eth_proto_is_802_3(eh->h_proto)))
104 skb->protocol = eh->h_proto;
105 else
106 skb->protocol = htons(ETH_P_802_2);
107
108 } else {
109 skb->protocol = inner_proto;
110 }
111
112 skb_clear_hash_if_not_l4(skb);
113 __vlan_hwaccel_clear_tag(skb);
114 skb_set_queue_mapping(skb, 0);
115 skb_scrub_packet(skb, xnet);
116
117 return iptunnel_pull_offloads(skb);
118 }
119 EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
120
iptunnel_metadata_reply(struct metadata_dst * md,gfp_t flags)121 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
122 gfp_t flags)
123 {
124 struct metadata_dst *res;
125 struct ip_tunnel_info *dst, *src;
126
127 if (!md || md->type != METADATA_IP_TUNNEL ||
128 md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
129
130 return NULL;
131
132 res = metadata_dst_alloc(0, METADATA_IP_TUNNEL, flags);
133 if (!res)
134 return NULL;
135
136 dst = &res->u.tun_info;
137 src = &md->u.tun_info;
138 dst->key.tun_id = src->key.tun_id;
139 if (src->mode & IP_TUNNEL_INFO_IPV6)
140 memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
141 sizeof(struct in6_addr));
142 else
143 dst->key.u.ipv4.dst = src->key.u.ipv4.src;
144 dst->key.tun_flags = src->key.tun_flags;
145 dst->mode = src->mode | IP_TUNNEL_INFO_TX;
146
147 return res;
148 }
149 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
150
iptunnel_handle_offloads(struct sk_buff * skb,int gso_type_mask)151 int iptunnel_handle_offloads(struct sk_buff *skb,
152 int gso_type_mask)
153 {
154 int err;
155
156 if (likely(!skb->encapsulation)) {
157 skb_reset_inner_headers(skb);
158 skb->encapsulation = 1;
159 }
160
161 if (skb_is_gso(skb)) {
162 err = skb_header_unclone(skb, GFP_ATOMIC);
163 if (unlikely(err))
164 return err;
165 skb_shinfo(skb)->gso_type |= gso_type_mask;
166 return 0;
167 }
168
169 if (skb->ip_summed != CHECKSUM_PARTIAL) {
170 skb->ip_summed = CHECKSUM_NONE;
171 /* We clear encapsulation here to prevent badly-written
172 * drivers potentially deciding to offload an inner checksum
173 * if we set CHECKSUM_PARTIAL on the outer header.
174 * This should go away when the drivers are all fixed.
175 */
176 skb->encapsulation = 0;
177 }
178
179 return 0;
180 }
181 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
182
183 /* Often modified stats are per cpu, other are shared (netdev->stats) */
ip_tunnel_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * tot)184 void ip_tunnel_get_stats64(struct net_device *dev,
185 struct rtnl_link_stats64 *tot)
186 {
187 int i;
188
189 netdev_stats_to_stats64(tot, &dev->stats);
190
191 for_each_possible_cpu(i) {
192 const struct pcpu_sw_netstats *tstats =
193 per_cpu_ptr(dev->tstats, i);
194 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
195 unsigned int start;
196
197 do {
198 start = u64_stats_fetch_begin_irq(&tstats->syncp);
199 rx_packets = tstats->rx_packets;
200 tx_packets = tstats->tx_packets;
201 rx_bytes = tstats->rx_bytes;
202 tx_bytes = tstats->tx_bytes;
203 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
204
205 tot->rx_packets += rx_packets;
206 tot->tx_packets += tx_packets;
207 tot->rx_bytes += rx_bytes;
208 tot->tx_bytes += tx_bytes;
209 }
210 }
211 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
212
213 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
214 [LWTUNNEL_IP_ID] = { .type = NLA_U64 },
215 [LWTUNNEL_IP_DST] = { .type = NLA_U32 },
216 [LWTUNNEL_IP_SRC] = { .type = NLA_U32 },
217 [LWTUNNEL_IP_TTL] = { .type = NLA_U8 },
218 [LWTUNNEL_IP_TOS] = { .type = NLA_U8 },
219 [LWTUNNEL_IP_FLAGS] = { .type = NLA_U16 },
220 };
221
ip_tun_build_state(struct nlattr * attr,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)222 static int ip_tun_build_state(struct nlattr *attr,
223 unsigned int family, const void *cfg,
224 struct lwtunnel_state **ts,
225 struct netlink_ext_ack *extack)
226 {
227 struct ip_tunnel_info *tun_info;
228 struct lwtunnel_state *new_state;
229 struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
230 int err;
231
232 err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
233 ip_tun_policy, extack);
234 if (err < 0)
235 return err;
236
237 new_state = lwtunnel_state_alloc(sizeof(*tun_info));
238 if (!new_state)
239 return -ENOMEM;
240
241 new_state->type = LWTUNNEL_ENCAP_IP;
242
243 tun_info = lwt_tun_info(new_state);
244
245 #ifdef CONFIG_DST_CACHE
246 err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
247 if (err) {
248 lwtstate_free(new_state);
249 return err;
250 }
251 #endif
252
253 if (tb[LWTUNNEL_IP_ID])
254 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
255
256 if (tb[LWTUNNEL_IP_DST])
257 tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
258
259 if (tb[LWTUNNEL_IP_SRC])
260 tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
261
262 if (tb[LWTUNNEL_IP_TTL])
263 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
264
265 if (tb[LWTUNNEL_IP_TOS])
266 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
267
268 if (tb[LWTUNNEL_IP_FLAGS])
269 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP_FLAGS]);
270
271 tun_info->mode = IP_TUNNEL_INFO_TX;
272 tun_info->options_len = 0;
273
274 *ts = new_state;
275
276 return 0;
277 }
278
ip_tun_destroy_state(struct lwtunnel_state * lwtstate)279 static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
280 {
281 #ifdef CONFIG_DST_CACHE
282 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
283
284 dst_cache_destroy(&tun_info->dst_cache);
285 #endif
286 }
287
ip_tun_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)288 static int ip_tun_fill_encap_info(struct sk_buff *skb,
289 struct lwtunnel_state *lwtstate)
290 {
291 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
292
293 if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
294 LWTUNNEL_IP_PAD) ||
295 nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
296 nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
297 nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
298 nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
299 nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags))
300 return -ENOMEM;
301
302 return 0;
303 }
304
ip_tun_encap_nlsize(struct lwtunnel_state * lwtstate)305 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
306 {
307 return nla_total_size_64bit(8) /* LWTUNNEL_IP_ID */
308 + nla_total_size(4) /* LWTUNNEL_IP_DST */
309 + nla_total_size(4) /* LWTUNNEL_IP_SRC */
310 + nla_total_size(1) /* LWTUNNEL_IP_TOS */
311 + nla_total_size(1) /* LWTUNNEL_IP_TTL */
312 + nla_total_size(2); /* LWTUNNEL_IP_FLAGS */
313 }
314
ip_tun_cmp_encap(struct lwtunnel_state * a,struct lwtunnel_state * b)315 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
316 {
317 return memcmp(lwt_tun_info(a), lwt_tun_info(b),
318 sizeof(struct ip_tunnel_info));
319 }
320
321 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
322 .build_state = ip_tun_build_state,
323 .destroy_state = ip_tun_destroy_state,
324 .fill_encap = ip_tun_fill_encap_info,
325 .get_encap_size = ip_tun_encap_nlsize,
326 .cmp_encap = ip_tun_cmp_encap,
327 .owner = THIS_MODULE,
328 };
329
330 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
331 [LWTUNNEL_IP6_ID] = { .type = NLA_U64 },
332 [LWTUNNEL_IP6_DST] = { .len = sizeof(struct in6_addr) },
333 [LWTUNNEL_IP6_SRC] = { .len = sizeof(struct in6_addr) },
334 [LWTUNNEL_IP6_HOPLIMIT] = { .type = NLA_U8 },
335 [LWTUNNEL_IP6_TC] = { .type = NLA_U8 },
336 [LWTUNNEL_IP6_FLAGS] = { .type = NLA_U16 },
337 };
338
ip6_tun_build_state(struct nlattr * attr,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)339 static int ip6_tun_build_state(struct nlattr *attr,
340 unsigned int family, const void *cfg,
341 struct lwtunnel_state **ts,
342 struct netlink_ext_ack *extack)
343 {
344 struct ip_tunnel_info *tun_info;
345 struct lwtunnel_state *new_state;
346 struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
347 int err;
348
349 err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
350 ip6_tun_policy, extack);
351 if (err < 0)
352 return err;
353
354 new_state = lwtunnel_state_alloc(sizeof(*tun_info));
355 if (!new_state)
356 return -ENOMEM;
357
358 new_state->type = LWTUNNEL_ENCAP_IP6;
359
360 tun_info = lwt_tun_info(new_state);
361
362 if (tb[LWTUNNEL_IP6_ID])
363 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
364
365 if (tb[LWTUNNEL_IP6_DST])
366 tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
367
368 if (tb[LWTUNNEL_IP6_SRC])
369 tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
370
371 if (tb[LWTUNNEL_IP6_HOPLIMIT])
372 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
373
374 if (tb[LWTUNNEL_IP6_TC])
375 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
376
377 if (tb[LWTUNNEL_IP6_FLAGS])
378 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]);
379
380 tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
381 tun_info->options_len = 0;
382
383 *ts = new_state;
384
385 return 0;
386 }
387
ip6_tun_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)388 static int ip6_tun_fill_encap_info(struct sk_buff *skb,
389 struct lwtunnel_state *lwtstate)
390 {
391 struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
392
393 if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
394 LWTUNNEL_IP6_PAD) ||
395 nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
396 nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
397 nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
398 nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
399 nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags))
400 return -ENOMEM;
401
402 return 0;
403 }
404
ip6_tun_encap_nlsize(struct lwtunnel_state * lwtstate)405 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
406 {
407 return nla_total_size_64bit(8) /* LWTUNNEL_IP6_ID */
408 + nla_total_size(16) /* LWTUNNEL_IP6_DST */
409 + nla_total_size(16) /* LWTUNNEL_IP6_SRC */
410 + nla_total_size(1) /* LWTUNNEL_IP6_HOPLIMIT */
411 + nla_total_size(1) /* LWTUNNEL_IP6_TC */
412 + nla_total_size(2); /* LWTUNNEL_IP6_FLAGS */
413 }
414
415 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
416 .build_state = ip6_tun_build_state,
417 .fill_encap = ip6_tun_fill_encap_info,
418 .get_encap_size = ip6_tun_encap_nlsize,
419 .cmp_encap = ip_tun_cmp_encap,
420 .owner = THIS_MODULE,
421 };
422
ip_tunnel_core_init(void)423 void __init ip_tunnel_core_init(void)
424 {
425 /* If you land here, make sure whether increasing ip_tunnel_info's
426 * options_len is a reasonable choice with its usage in front ends
427 * (f.e., it's part of flow keys, etc).
428 */
429 BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
430
431 lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
432 lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
433 }
434
435 DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
436 EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
437
ip_tunnel_need_metadata(void)438 void ip_tunnel_need_metadata(void)
439 {
440 static_branch_inc(&ip_tunnel_metadata_cnt);
441 }
442 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
443
ip_tunnel_unneed_metadata(void)444 void ip_tunnel_unneed_metadata(void)
445 {
446 static_branch_dec(&ip_tunnel_metadata_cnt);
447 }
448 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
449