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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
4 *
5 * Authors:
6 * Mitsuru KANDA @USAGI
7 * Kazunori MIYAZAWA @USAGI
8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9 * YOSHIFUJI Hideaki @USAGI
10 * IPv6 support
11 */
12
13#include <linux/module.h>
14#include <linux/string.h>
15#include <linux/netfilter.h>
16#include <linux/netfilter_ipv6.h>
17#include <net/ipv6.h>
18#include <net/xfrm.h>
19
20int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
21 struct ip6_tnl *t)
22{
23 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
24 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
25 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
26 return xfrm_input(skb, nexthdr, spi, 0);
27}
28EXPORT_SYMBOL(xfrm6_rcv_spi);
29
30static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
31 struct sk_buff *skb)
32{
33 if (xfrm_trans_queue(skb, ip6_rcv_finish)) {
34 kfree_skb(skb);
35 return NET_RX_DROP;
36 }
37
38 return 0;
39}
40
41int xfrm6_transport_finish(struct sk_buff *skb, int async)
42{
43 struct xfrm_offload *xo = xfrm_offload(skb);
44 int nhlen = skb->data - skb_network_header(skb);
45
46 skb_network_header(skb)[IP6CB(skb)->nhoff] =
47 XFRM_MODE_SKB_CB(skb)->protocol;
48
49#ifndef CONFIG_NETFILTER
50 if (!async)
51 return 1;
52#endif
53
54 __skb_push(skb, nhlen);
55 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
56 skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
57
58 if (xo && (xo->flags & XFRM_GRO)) {
59 skb_mac_header_rebuild(skb);
60 skb_reset_transport_header(skb);
61 return 0;
62 }
63
64 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
65 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
66 xfrm6_transport_finish2);
67 return 0;
68}
69
70/* If it's a keepalive packet, then just eat it.
71 * If it's an encapsulated packet, then pass it to the
72 * IPsec xfrm input.
73 * Returns 0 if skb passed to xfrm or was dropped.
74 * Returns >0 if skb should be passed to UDP.
75 * Returns <0 if skb should be resubmitted (-ret is protocol)
76 */
77int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
78{
79 struct udp_sock *up = udp_sk(sk);
80 struct udphdr *uh;
81 struct ipv6hdr *ip6h;
82 int len;
83 int ip6hlen = sizeof(struct ipv6hdr);
84
85 __u8 *udpdata;
86 __be32 *udpdata32;
87 __u16 encap_type = up->encap_type;
88
89 /* if this is not encapsulated socket, then just return now */
90 if (!encap_type)
91 return 1;
92
93 /* If this is a paged skb, make sure we pull up
94 * whatever data we need to look at. */
95 len = skb->len - sizeof(struct udphdr);
96 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
97 return 1;
98
99 /* Now we can get the pointers */
100 uh = udp_hdr(skb);
101 udpdata = (__u8 *)uh + sizeof(struct udphdr);
102 udpdata32 = (__be32 *)udpdata;
103
104 switch (encap_type) {
105 default:
106 case UDP_ENCAP_ESPINUDP:
107 /* Check if this is a keepalive packet. If so, eat it. */
108 if (len == 1 && udpdata[0] == 0xff) {
109 goto drop;
110 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
111 /* ESP Packet without Non-ESP header */
112 len = sizeof(struct udphdr);
113 } else
114 /* Must be an IKE packet.. pass it through */
115 return 1;
116 break;
117 case UDP_ENCAP_ESPINUDP_NON_IKE:
118 /* Check if this is a keepalive packet. If so, eat it. */
119 if (len == 1 && udpdata[0] == 0xff) {
120 goto drop;
121 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
122 udpdata32[0] == 0 && udpdata32[1] == 0) {
123
124 /* ESP Packet with Non-IKE marker */
125 len = sizeof(struct udphdr) + 2 * sizeof(u32);
126 } else
127 /* Must be an IKE packet.. pass it through */
128 return 1;
129 break;
130 }
131
132 /* At this point we are sure that this is an ESPinUDP packet,
133 * so we need to remove 'len' bytes from the packet (the UDP
134 * header and optional ESP marker bytes) and then modify the
135 * protocol to ESP, and then call into the transform receiver.
136 */
137 if (skb_unclone(skb, GFP_ATOMIC))
138 goto drop;
139
140 /* Now we can update and verify the packet length... */
141 ip6h = ipv6_hdr(skb);
142 ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
143 if (skb->len < ip6hlen + len) {
144 /* packet is too small!?! */
145 goto drop;
146 }
147
148 /* pull the data buffer up to the ESP header and set the
149 * transport header to point to ESP. Keep UDP on the stack
150 * for later.
151 */
152 __skb_pull(skb, len);
153 skb_reset_transport_header(skb);
154
155 /* process ESP */
156 return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
157
158drop:
159 kfree_skb(skb);
160 return 0;
161}
162
163int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
164{
165 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
166 0, t);
167}
168EXPORT_SYMBOL(xfrm6_rcv_tnl);
169
170int xfrm6_rcv(struct sk_buff *skb)
171{
172 return xfrm6_rcv_tnl(skb, NULL);
173}
174EXPORT_SYMBOL(xfrm6_rcv);
175int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
176 xfrm_address_t *saddr, u8 proto)
177{
178 struct net *net = dev_net(skb->dev);
179 struct xfrm_state *x = NULL;
180 struct sec_path *sp;
181 int i = 0;
182
183 sp = secpath_set(skb);
184 if (!sp) {
185 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
186 goto drop;
187 }
188
189 if (1 + sp->len == XFRM_MAX_DEPTH) {
190 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
191 goto drop;
192 }
193
194 for (i = 0; i < 3; i++) {
195 xfrm_address_t *dst, *src;
196
197 switch (i) {
198 case 0:
199 dst = daddr;
200 src = saddr;
201 break;
202 case 1:
203 /* lookup state with wild-card source address */
204 dst = daddr;
205 src = (xfrm_address_t *)&in6addr_any;
206 break;
207 default:
208 /* lookup state with wild-card addresses */
209 dst = (xfrm_address_t *)&in6addr_any;
210 src = (xfrm_address_t *)&in6addr_any;
211 break;
212 }
213
214 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
215 if (!x)
216 continue;
217
218 spin_lock(&x->lock);
219
220 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
221 likely(x->km.state == XFRM_STATE_VALID) &&
222 !xfrm_state_check_expire(x)) {
223 spin_unlock(&x->lock);
224 if (x->type->input(x, skb) > 0) {
225 /* found a valid state */
226 break;
227 }
228 } else
229 spin_unlock(&x->lock);
230
231 xfrm_state_put(x);
232 x = NULL;
233 }
234
235 if (!x) {
236 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
237 xfrm_audit_state_notfound_simple(skb, AF_INET6);
238 goto drop;
239 }
240
241 sp->xvec[sp->len++] = x;
242
243 spin_lock(&x->lock);
244
245 x->curlft.bytes += skb->len;
246 x->curlft.packets++;
247
248 spin_unlock(&x->lock);
249
250 return 1;
251
252drop:
253 return -1;
254}
255EXPORT_SYMBOL(xfrm6_input_addr);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
4 *
5 * Authors:
6 * Mitsuru KANDA @USAGI
7 * Kazunori MIYAZAWA @USAGI
8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9 * YOSHIFUJI Hideaki @USAGI
10 * IPv6 support
11 */
12
13#include <linux/module.h>
14#include <linux/string.h>
15#include <linux/netfilter.h>
16#include <linux/netfilter_ipv6.h>
17#include <net/ipv6.h>
18#include <net/xfrm.h>
19#include <net/protocol.h>
20#include <net/gro.h>
21
22int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
23 struct ip6_tnl *t)
24{
25 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
26 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
27 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
28 return xfrm_input(skb, nexthdr, spi, 0);
29}
30EXPORT_SYMBOL(xfrm6_rcv_spi);
31
32static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
33 struct sk_buff *skb)
34{
35 if (xfrm_trans_queue(skb, ip6_rcv_finish)) {
36 kfree_skb(skb);
37 return NET_RX_DROP;
38 }
39
40 return 0;
41}
42
43int xfrm6_transport_finish(struct sk_buff *skb, int async)
44{
45 struct xfrm_offload *xo = xfrm_offload(skb);
46 int nhlen = -skb_network_offset(skb);
47
48 skb_network_header(skb)[IP6CB(skb)->nhoff] =
49 XFRM_MODE_SKB_CB(skb)->protocol;
50
51#ifndef CONFIG_NETFILTER
52 if (!async)
53 return 1;
54#endif
55
56 __skb_push(skb, nhlen);
57 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
58 skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
59
60 if (xo && (xo->flags & XFRM_GRO)) {
61 /* The full l2 header needs to be preserved so that re-injecting the packet at l2
62 * works correctly in the presence of vlan tags.
63 */
64 skb_mac_header_rebuild_full(skb, xo->orig_mac_len);
65 skb_reset_network_header(skb);
66 skb_reset_transport_header(skb);
67 return 0;
68 }
69
70 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
71 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
72 xfrm6_transport_finish2);
73 return 0;
74}
75
76static int __xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull)
77{
78 struct udp_sock *up = udp_sk(sk);
79 struct udphdr *uh;
80 struct ipv6hdr *ip6h;
81 int len;
82 int ip6hlen = sizeof(struct ipv6hdr);
83 __u8 *udpdata;
84 __be32 *udpdata32;
85 u16 encap_type;
86
87 encap_type = READ_ONCE(up->encap_type);
88 /* if this is not encapsulated socket, then just return now */
89 if (!encap_type)
90 return 1;
91
92 /* If this is a paged skb, make sure we pull up
93 * whatever data we need to look at. */
94 len = skb->len - sizeof(struct udphdr);
95 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
96 return 1;
97
98 /* Now we can get the pointers */
99 uh = udp_hdr(skb);
100 udpdata = (__u8 *)uh + sizeof(struct udphdr);
101 udpdata32 = (__be32 *)udpdata;
102
103 switch (encap_type) {
104 default:
105 case UDP_ENCAP_ESPINUDP:
106 /* Check if this is a keepalive packet. If so, eat it. */
107 if (len == 1 && udpdata[0] == 0xff) {
108 return -EINVAL;
109 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
110 /* ESP Packet without Non-ESP header */
111 len = sizeof(struct udphdr);
112 } else
113 /* Must be an IKE packet.. pass it through */
114 return 1;
115 break;
116 case UDP_ENCAP_ESPINUDP_NON_IKE:
117 /* Check if this is a keepalive packet. If so, eat it. */
118 if (len == 1 && udpdata[0] == 0xff) {
119 return -EINVAL;
120 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
121 udpdata32[0] == 0 && udpdata32[1] == 0) {
122
123 /* ESP Packet with Non-IKE marker */
124 len = sizeof(struct udphdr) + 2 * sizeof(u32);
125 } else
126 /* Must be an IKE packet.. pass it through */
127 return 1;
128 break;
129 }
130
131 /* At this point we are sure that this is an ESPinUDP packet,
132 * so we need to remove 'len' bytes from the packet (the UDP
133 * header and optional ESP marker bytes) and then modify the
134 * protocol to ESP, and then call into the transform receiver.
135 */
136 if (skb_unclone(skb, GFP_ATOMIC))
137 return -EINVAL;
138
139 /* Now we can update and verify the packet length... */
140 ip6h = ipv6_hdr(skb);
141 ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
142 if (skb->len < ip6hlen + len) {
143 /* packet is too small!?! */
144 return -EINVAL;
145 }
146
147 /* pull the data buffer up to the ESP header and set the
148 * transport header to point to ESP. Keep UDP on the stack
149 * for later.
150 */
151 if (pull) {
152 __skb_pull(skb, len);
153 skb_reset_transport_header(skb);
154 } else {
155 skb_set_transport_header(skb, len);
156 }
157
158 /* process ESP */
159 return 0;
160}
161
162/* If it's a keepalive packet, then just eat it.
163 * If it's an encapsulated packet, then pass it to the
164 * IPsec xfrm input.
165 * Returns 0 if skb passed to xfrm or was dropped.
166 * Returns >0 if skb should be passed to UDP.
167 * Returns <0 if skb should be resubmitted (-ret is protocol)
168 */
169int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
170{
171 int ret;
172
173 if (skb->protocol == htons(ETH_P_IP))
174 return xfrm4_udp_encap_rcv(sk, skb);
175
176 ret = __xfrm6_udp_encap_rcv(sk, skb, true);
177 if (!ret)
178 return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0,
179 udp_sk(sk)->encap_type);
180
181 if (ret < 0) {
182 kfree_skb(skb);
183 return 0;
184 }
185
186 return ret;
187}
188
189struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
190 struct sk_buff *skb)
191{
192 int offset = skb_gro_offset(skb);
193 const struct net_offload *ops;
194 struct sk_buff *pp = NULL;
195 int ret;
196
197 if (skb->protocol == htons(ETH_P_IP))
198 return xfrm4_gro_udp_encap_rcv(sk, head, skb);
199
200 offset = offset - sizeof(struct udphdr);
201
202 if (!pskb_pull(skb, offset))
203 return NULL;
204
205 rcu_read_lock();
206 ops = rcu_dereference(inet6_offloads[IPPROTO_ESP]);
207 if (!ops || !ops->callbacks.gro_receive)
208 goto out;
209
210 ret = __xfrm6_udp_encap_rcv(sk, skb, false);
211 if (ret)
212 goto out;
213
214 skb_push(skb, offset);
215 NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
216
217 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
218 rcu_read_unlock();
219
220 return pp;
221
222out:
223 rcu_read_unlock();
224 skb_push(skb, offset);
225 NAPI_GRO_CB(skb)->same_flow = 0;
226 NAPI_GRO_CB(skb)->flush = 1;
227
228 return NULL;
229}
230
231int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
232{
233 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
234 0, t);
235}
236EXPORT_SYMBOL(xfrm6_rcv_tnl);
237
238int xfrm6_rcv(struct sk_buff *skb)
239{
240 return xfrm6_rcv_tnl(skb, NULL);
241}
242EXPORT_SYMBOL(xfrm6_rcv);
243int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
244 xfrm_address_t *saddr, u8 proto)
245{
246 struct net *net = dev_net(skb->dev);
247 struct xfrm_state *x = NULL;
248 struct sec_path *sp;
249 int i = 0;
250
251 sp = secpath_set(skb);
252 if (!sp) {
253 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
254 goto drop;
255 }
256
257 if (1 + sp->len == XFRM_MAX_DEPTH) {
258 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
259 goto drop;
260 }
261
262 for (i = 0; i < 3; i++) {
263 xfrm_address_t *dst, *src;
264
265 switch (i) {
266 case 0:
267 dst = daddr;
268 src = saddr;
269 break;
270 case 1:
271 /* lookup state with wild-card source address */
272 dst = daddr;
273 src = (xfrm_address_t *)&in6addr_any;
274 break;
275 default:
276 /* lookup state with wild-card addresses */
277 dst = (xfrm_address_t *)&in6addr_any;
278 src = (xfrm_address_t *)&in6addr_any;
279 break;
280 }
281
282 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
283 if (!x)
284 continue;
285
286 spin_lock(&x->lock);
287
288 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
289 likely(x->km.state == XFRM_STATE_VALID) &&
290 !xfrm_state_check_expire(x)) {
291 spin_unlock(&x->lock);
292 if (x->type->input(x, skb) > 0) {
293 /* found a valid state */
294 break;
295 }
296 } else
297 spin_unlock(&x->lock);
298
299 xfrm_state_put(x);
300 x = NULL;
301 }
302
303 if (!x) {
304 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
305 xfrm_audit_state_notfound_simple(skb, AF_INET6);
306 goto drop;
307 }
308
309 sp->xvec[sp->len++] = x;
310
311 spin_lock(&x->lock);
312
313 x->curlft.bytes += skb->len;
314 x->curlft.packets++;
315
316 spin_unlock(&x->lock);
317
318 return 1;
319
320drop:
321 return -1;
322}
323EXPORT_SYMBOL(xfrm6_input_addr);