treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269
[muen/linux.git] / net / ipv4 / ip_tunnel_core.c
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
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         if (unlikely(net_xmit_eval(err)))
80                 pkt_len = 0;
81         iptunnel_xmit_stats(dev, pkt_len);
82 }
83 EXPORT_SYMBOL_GPL(iptunnel_xmit);
84
85 int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
86                            __be16 inner_proto, bool raw_proto, bool xnet)
87 {
88         if (unlikely(!pskb_may_pull(skb, hdr_len)))
89                 return -ENOMEM;
90
91         skb_pull_rcsum(skb, hdr_len);
92
93         if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
94                 struct ethhdr *eh;
95
96                 if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
97                         return -ENOMEM;
98
99                 eh = (struct ethhdr *)skb->data;
100                 if (likely(eth_proto_is_802_3(eh->h_proto)))
101                         skb->protocol = eh->h_proto;
102                 else
103                         skb->protocol = htons(ETH_P_802_2);
104
105         } else {
106                 skb->protocol = inner_proto;
107         }
108
109         skb_clear_hash_if_not_l4(skb);
110         __vlan_hwaccel_clear_tag(skb);
111         skb_set_queue_mapping(skb, 0);
112         skb_scrub_packet(skb, xnet);
113
114         return iptunnel_pull_offloads(skb);
115 }
116 EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
117
118 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
119                                              gfp_t flags)
120 {
121         struct metadata_dst *res;
122         struct ip_tunnel_info *dst, *src;
123
124         if (!md || md->type != METADATA_IP_TUNNEL ||
125             md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
126
127                 return NULL;
128
129         res = metadata_dst_alloc(0, METADATA_IP_TUNNEL, flags);
130         if (!res)
131                 return NULL;
132
133         dst = &res->u.tun_info;
134         src = &md->u.tun_info;
135         dst->key.tun_id = src->key.tun_id;
136         if (src->mode & IP_TUNNEL_INFO_IPV6)
137                 memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
138                        sizeof(struct in6_addr));
139         else
140                 dst->key.u.ipv4.dst = src->key.u.ipv4.src;
141         dst->key.tun_flags = src->key.tun_flags;
142         dst->mode = src->mode | IP_TUNNEL_INFO_TX;
143
144         return res;
145 }
146 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
147
148 int iptunnel_handle_offloads(struct sk_buff *skb,
149                              int gso_type_mask)
150 {
151         int err;
152
153         if (likely(!skb->encapsulation)) {
154                 skb_reset_inner_headers(skb);
155                 skb->encapsulation = 1;
156         }
157
158         if (skb_is_gso(skb)) {
159                 err = skb_header_unclone(skb, GFP_ATOMIC);
160                 if (unlikely(err))
161                         return err;
162                 skb_shinfo(skb)->gso_type |= gso_type_mask;
163                 return 0;
164         }
165
166         if (skb->ip_summed != CHECKSUM_PARTIAL) {
167                 skb->ip_summed = CHECKSUM_NONE;
168                 /* We clear encapsulation here to prevent badly-written
169                  * drivers potentially deciding to offload an inner checksum
170                  * if we set CHECKSUM_PARTIAL on the outer header.
171                  * This should go away when the drivers are all fixed.
172                  */
173                 skb->encapsulation = 0;
174         }
175
176         return 0;
177 }
178 EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
179
180 /* Often modified stats are per cpu, other are shared (netdev->stats) */
181 void ip_tunnel_get_stats64(struct net_device *dev,
182                            struct rtnl_link_stats64 *tot)
183 {
184         int i;
185
186         netdev_stats_to_stats64(tot, &dev->stats);
187
188         for_each_possible_cpu(i) {
189                 const struct pcpu_sw_netstats *tstats =
190                                                    per_cpu_ptr(dev->tstats, i);
191                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
192                 unsigned int start;
193
194                 do {
195                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
196                         rx_packets = tstats->rx_packets;
197                         tx_packets = tstats->tx_packets;
198                         rx_bytes = tstats->rx_bytes;
199                         tx_bytes = tstats->tx_bytes;
200                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
201
202                 tot->rx_packets += rx_packets;
203                 tot->tx_packets += tx_packets;
204                 tot->rx_bytes   += rx_bytes;
205                 tot->tx_bytes   += tx_bytes;
206         }
207 }
208 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64);
209
210 static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
211         [LWTUNNEL_IP_ID]        = { .type = NLA_U64 },
212         [LWTUNNEL_IP_DST]       = { .type = NLA_U32 },
213         [LWTUNNEL_IP_SRC]       = { .type = NLA_U32 },
214         [LWTUNNEL_IP_TTL]       = { .type = NLA_U8 },
215         [LWTUNNEL_IP_TOS]       = { .type = NLA_U8 },
216         [LWTUNNEL_IP_FLAGS]     = { .type = NLA_U16 },
217 };
218
219 static int ip_tun_build_state(struct nlattr *attr,
220                               unsigned int family, const void *cfg,
221                               struct lwtunnel_state **ts,
222                               struct netlink_ext_ack *extack)
223 {
224         struct ip_tunnel_info *tun_info;
225         struct lwtunnel_state *new_state;
226         struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
227         int err;
228
229         err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
230                                           ip_tun_policy, extack);
231         if (err < 0)
232                 return err;
233
234         new_state = lwtunnel_state_alloc(sizeof(*tun_info));
235         if (!new_state)
236                 return -ENOMEM;
237
238         new_state->type = LWTUNNEL_ENCAP_IP;
239
240         tun_info = lwt_tun_info(new_state);
241
242 #ifdef CONFIG_DST_CACHE
243         err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
244         if (err) {
245                 lwtstate_free(new_state);
246                 return err;
247         }
248 #endif
249
250         if (tb[LWTUNNEL_IP_ID])
251                 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
252
253         if (tb[LWTUNNEL_IP_DST])
254                 tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
255
256         if (tb[LWTUNNEL_IP_SRC])
257                 tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
258
259         if (tb[LWTUNNEL_IP_TTL])
260                 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
261
262         if (tb[LWTUNNEL_IP_TOS])
263                 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
264
265         if (tb[LWTUNNEL_IP_FLAGS])
266                 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP_FLAGS]);
267
268         tun_info->mode = IP_TUNNEL_INFO_TX;
269         tun_info->options_len = 0;
270
271         *ts = new_state;
272
273         return 0;
274 }
275
276 static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
277 {
278 #ifdef CONFIG_DST_CACHE
279         struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
280
281         dst_cache_destroy(&tun_info->dst_cache);
282 #endif
283 }
284
285 static int ip_tun_fill_encap_info(struct sk_buff *skb,
286                                   struct lwtunnel_state *lwtstate)
287 {
288         struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
289
290         if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
291                          LWTUNNEL_IP_PAD) ||
292             nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
293             nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
294             nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
295             nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
296             nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags))
297                 return -ENOMEM;
298
299         return 0;
300 }
301
302 static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
303 {
304         return nla_total_size_64bit(8)  /* LWTUNNEL_IP_ID */
305                 + nla_total_size(4)     /* LWTUNNEL_IP_DST */
306                 + nla_total_size(4)     /* LWTUNNEL_IP_SRC */
307                 + nla_total_size(1)     /* LWTUNNEL_IP_TOS */
308                 + nla_total_size(1)     /* LWTUNNEL_IP_TTL */
309                 + nla_total_size(2);    /* LWTUNNEL_IP_FLAGS */
310 }
311
312 static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
313 {
314         return memcmp(lwt_tun_info(a), lwt_tun_info(b),
315                       sizeof(struct ip_tunnel_info));
316 }
317
318 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
319         .build_state = ip_tun_build_state,
320         .destroy_state = ip_tun_destroy_state,
321         .fill_encap = ip_tun_fill_encap_info,
322         .get_encap_size = ip_tun_encap_nlsize,
323         .cmp_encap = ip_tun_cmp_encap,
324         .owner = THIS_MODULE,
325 };
326
327 static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
328         [LWTUNNEL_IP6_ID]               = { .type = NLA_U64 },
329         [LWTUNNEL_IP6_DST]              = { .len = sizeof(struct in6_addr) },
330         [LWTUNNEL_IP6_SRC]              = { .len = sizeof(struct in6_addr) },
331         [LWTUNNEL_IP6_HOPLIMIT]         = { .type = NLA_U8 },
332         [LWTUNNEL_IP6_TC]               = { .type = NLA_U8 },
333         [LWTUNNEL_IP6_FLAGS]            = { .type = NLA_U16 },
334 };
335
336 static int ip6_tun_build_state(struct nlattr *attr,
337                                unsigned int family, const void *cfg,
338                                struct lwtunnel_state **ts,
339                                struct netlink_ext_ack *extack)
340 {
341         struct ip_tunnel_info *tun_info;
342         struct lwtunnel_state *new_state;
343         struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
344         int err;
345
346         err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
347                                           ip6_tun_policy, extack);
348         if (err < 0)
349                 return err;
350
351         new_state = lwtunnel_state_alloc(sizeof(*tun_info));
352         if (!new_state)
353                 return -ENOMEM;
354
355         new_state->type = LWTUNNEL_ENCAP_IP6;
356
357         tun_info = lwt_tun_info(new_state);
358
359         if (tb[LWTUNNEL_IP6_ID])
360                 tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
361
362         if (tb[LWTUNNEL_IP6_DST])
363                 tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
364
365         if (tb[LWTUNNEL_IP6_SRC])
366                 tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
367
368         if (tb[LWTUNNEL_IP6_HOPLIMIT])
369                 tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
370
371         if (tb[LWTUNNEL_IP6_TC])
372                 tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
373
374         if (tb[LWTUNNEL_IP6_FLAGS])
375                 tun_info->key.tun_flags = nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]);
376
377         tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
378         tun_info->options_len = 0;
379
380         *ts = new_state;
381
382         return 0;
383 }
384
385 static int ip6_tun_fill_encap_info(struct sk_buff *skb,
386                                    struct lwtunnel_state *lwtstate)
387 {
388         struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
389
390         if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
391                          LWTUNNEL_IP6_PAD) ||
392             nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
393             nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
394             nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
395             nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
396             nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags))
397                 return -ENOMEM;
398
399         return 0;
400 }
401
402 static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
403 {
404         return nla_total_size_64bit(8)  /* LWTUNNEL_IP6_ID */
405                 + nla_total_size(16)    /* LWTUNNEL_IP6_DST */
406                 + nla_total_size(16)    /* LWTUNNEL_IP6_SRC */
407                 + nla_total_size(1)     /* LWTUNNEL_IP6_HOPLIMIT */
408                 + nla_total_size(1)     /* LWTUNNEL_IP6_TC */
409                 + nla_total_size(2);    /* LWTUNNEL_IP6_FLAGS */
410 }
411
412 static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
413         .build_state = ip6_tun_build_state,
414         .fill_encap = ip6_tun_fill_encap_info,
415         .get_encap_size = ip6_tun_encap_nlsize,
416         .cmp_encap = ip_tun_cmp_encap,
417         .owner = THIS_MODULE,
418 };
419
420 void __init ip_tunnel_core_init(void)
421 {
422         /* If you land here, make sure whether increasing ip_tunnel_info's
423          * options_len is a reasonable choice with its usage in front ends
424          * (f.e., it's part of flow keys, etc).
425          */
426         BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
427
428         lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
429         lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
430 }
431
432 DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
433 EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
434
435 void ip_tunnel_need_metadata(void)
436 {
437         static_branch_inc(&ip_tunnel_metadata_cnt);
438 }
439 EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
440
441 void ip_tunnel_unneed_metadata(void)
442 {
443         static_branch_dec(&ip_tunnel_metadata_cnt);
444 }
445 EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);