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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#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->data - skb_network_header(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 skb_mac_header_rebuild(skb);
62 skb_reset_transport_header(skb);
63 return 0;
64 }
65
66 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
67 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
68 xfrm6_transport_finish2);
69 return 0;
70}
71
72static int __xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull)
73{
74 struct udp_sock *up = udp_sk(sk);
75 struct udphdr *uh;
76 struct ipv6hdr *ip6h;
77 int len;
78 int ip6hlen = sizeof(struct ipv6hdr);
79 __u8 *udpdata;
80 __be32 *udpdata32;
81 u16 encap_type;
82
83 encap_type = READ_ONCE(up->encap_type);
84 /* if this is not encapsulated socket, then just return now */
85 if (!encap_type)
86 return 1;
87
88 /* If this is a paged skb, make sure we pull up
89 * whatever data we need to look at. */
90 len = skb->len - sizeof(struct udphdr);
91 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
92 return 1;
93
94 /* Now we can get the pointers */
95 uh = udp_hdr(skb);
96 udpdata = (__u8 *)uh + sizeof(struct udphdr);
97 udpdata32 = (__be32 *)udpdata;
98
99 switch (encap_type) {
100 default:
101 case UDP_ENCAP_ESPINUDP:
102 /* Check if this is a keepalive packet. If so, eat it. */
103 if (len == 1 && udpdata[0] == 0xff) {
104 return -EINVAL;
105 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
106 /* ESP Packet without Non-ESP header */
107 len = sizeof(struct udphdr);
108 } else
109 /* Must be an IKE packet.. pass it through */
110 return 1;
111 break;
112 case UDP_ENCAP_ESPINUDP_NON_IKE:
113 /* Check if this is a keepalive packet. If so, eat it. */
114 if (len == 1 && udpdata[0] == 0xff) {
115 return -EINVAL;
116 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
117 udpdata32[0] == 0 && udpdata32[1] == 0) {
118
119 /* ESP Packet with Non-IKE marker */
120 len = sizeof(struct udphdr) + 2 * sizeof(u32);
121 } else
122 /* Must be an IKE packet.. pass it through */
123 return 1;
124 break;
125 }
126
127 /* At this point we are sure that this is an ESPinUDP packet,
128 * so we need to remove 'len' bytes from the packet (the UDP
129 * header and optional ESP marker bytes) and then modify the
130 * protocol to ESP, and then call into the transform receiver.
131 */
132 if (skb_unclone(skb, GFP_ATOMIC))
133 return -EINVAL;
134
135 /* Now we can update and verify the packet length... */
136 ip6h = ipv6_hdr(skb);
137 ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
138 if (skb->len < ip6hlen + len) {
139 /* packet is too small!?! */
140 return -EINVAL;
141 }
142
143 /* pull the data buffer up to the ESP header and set the
144 * transport header to point to ESP. Keep UDP on the stack
145 * for later.
146 */
147 if (pull) {
148 __skb_pull(skb, len);
149 skb_reset_transport_header(skb);
150 } else {
151 skb_set_transport_header(skb, len);
152 }
153
154 /* process ESP */
155 return 0;
156}
157
158/* If it's a keepalive packet, then just eat it.
159 * If it's an encapsulated packet, then pass it to the
160 * IPsec xfrm input.
161 * Returns 0 if skb passed to xfrm or was dropped.
162 * Returns >0 if skb should be passed to UDP.
163 * Returns <0 if skb should be resubmitted (-ret is protocol)
164 */
165int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
166{
167 int ret;
168
169 if (skb->protocol == htons(ETH_P_IP))
170 return xfrm4_udp_encap_rcv(sk, skb);
171
172 ret = __xfrm6_udp_encap_rcv(sk, skb, true);
173 if (!ret)
174 return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0,
175 udp_sk(sk)->encap_type);
176
177 if (ret < 0) {
178 kfree_skb(skb);
179 return 0;
180 }
181
182 return ret;
183}
184
185struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
186 struct sk_buff *skb)
187{
188 int offset = skb_gro_offset(skb);
189 const struct net_offload *ops;
190 struct sk_buff *pp = NULL;
191 int ret;
192
193 if (skb->protocol == htons(ETH_P_IP))
194 return xfrm4_gro_udp_encap_rcv(sk, head, skb);
195
196 offset = offset - sizeof(struct udphdr);
197
198 if (!pskb_pull(skb, offset))
199 return NULL;
200
201 rcu_read_lock();
202 ops = rcu_dereference(inet6_offloads[IPPROTO_ESP]);
203 if (!ops || !ops->callbacks.gro_receive)
204 goto out;
205
206 ret = __xfrm6_udp_encap_rcv(sk, skb, false);
207 if (ret)
208 goto out;
209
210 skb_push(skb, offset);
211 NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
212
213 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
214 rcu_read_unlock();
215
216 return pp;
217
218out:
219 rcu_read_unlock();
220 skb_push(skb, offset);
221 NAPI_GRO_CB(skb)->same_flow = 0;
222 NAPI_GRO_CB(skb)->flush = 1;
223
224 return NULL;
225}
226
227int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
228{
229 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
230 0, t);
231}
232EXPORT_SYMBOL(xfrm6_rcv_tnl);
233
234int xfrm6_rcv(struct sk_buff *skb)
235{
236 return xfrm6_rcv_tnl(skb, NULL);
237}
238EXPORT_SYMBOL(xfrm6_rcv);
239int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
240 xfrm_address_t *saddr, u8 proto)
241{
242 struct net *net = dev_net(skb->dev);
243 struct xfrm_state *x = NULL;
244 struct sec_path *sp;
245 int i = 0;
246
247 sp = secpath_set(skb);
248 if (!sp) {
249 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
250 goto drop;
251 }
252
253 if (1 + sp->len == XFRM_MAX_DEPTH) {
254 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
255 goto drop;
256 }
257
258 for (i = 0; i < 3; i++) {
259 xfrm_address_t *dst, *src;
260
261 switch (i) {
262 case 0:
263 dst = daddr;
264 src = saddr;
265 break;
266 case 1:
267 /* lookup state with wild-card source address */
268 dst = daddr;
269 src = (xfrm_address_t *)&in6addr_any;
270 break;
271 default:
272 /* lookup state with wild-card addresses */
273 dst = (xfrm_address_t *)&in6addr_any;
274 src = (xfrm_address_t *)&in6addr_any;
275 break;
276 }
277
278 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
279 if (!x)
280 continue;
281
282 spin_lock(&x->lock);
283
284 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
285 likely(x->km.state == XFRM_STATE_VALID) &&
286 !xfrm_state_check_expire(x)) {
287 spin_unlock(&x->lock);
288 if (x->type->input(x, skb) > 0) {
289 /* found a valid state */
290 break;
291 }
292 } else
293 spin_unlock(&x->lock);
294
295 xfrm_state_put(x);
296 x = NULL;
297 }
298
299 if (!x) {
300 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
301 xfrm_audit_state_notfound_simple(skb, AF_INET6);
302 goto drop;
303 }
304
305 sp->xvec[sp->len++] = x;
306
307 spin_lock(&x->lock);
308
309 x->curlft.bytes += skb->len;
310 x->curlft.packets++;
311
312 spin_unlock(&x->lock);
313
314 return 1;
315
316drop:
317 return -1;
318}
319EXPORT_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 }
117
118 /* At this point we are sure that this is an ESPinUDP packet,
119 * so we need to remove 'len' bytes from the packet (the UDP
120 * header and optional ESP marker bytes) and then modify the
121 * protocol to ESP, and then call into the transform receiver.
122 */
123 if (skb_unclone(skb, GFP_ATOMIC))
124 return -EINVAL;
125
126 /* Now we can update and verify the packet length... */
127 ip6h = ipv6_hdr(skb);
128 ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
129 if (skb->len < ip6hlen + len) {
130 /* packet is too small!?! */
131 return -EINVAL;
132 }
133
134 /* pull the data buffer up to the ESP header and set the
135 * transport header to point to ESP. Keep UDP on the stack
136 * for later.
137 */
138 if (pull) {
139 __skb_pull(skb, len);
140 skb_reset_transport_header(skb);
141 } else {
142 skb_set_transport_header(skb, len);
143 }
144
145 /* process ESP */
146 return 0;
147}
148
149/* If it's a keepalive packet, then just eat it.
150 * If it's an encapsulated packet, then pass it to the
151 * IPsec xfrm input.
152 * Returns 0 if skb passed to xfrm or was dropped.
153 * Returns >0 if skb should be passed to UDP.
154 * Returns <0 if skb should be resubmitted (-ret is protocol)
155 */
156int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
157{
158 int ret;
159
160 if (skb->protocol == htons(ETH_P_IP))
161 return xfrm4_udp_encap_rcv(sk, skb);
162
163 ret = __xfrm6_udp_encap_rcv(sk, skb, true);
164 if (!ret)
165 return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0,
166 udp_sk(sk)->encap_type);
167
168 if (ret < 0) {
169 kfree_skb(skb);
170 return 0;
171 }
172
173 return ret;
174}
175
176struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
177 struct sk_buff *skb)
178{
179 int offset = skb_gro_offset(skb);
180 const struct net_offload *ops;
181 struct sk_buff *pp = NULL;
182 int ret;
183
184 if (skb->protocol == htons(ETH_P_IP))
185 return xfrm4_gro_udp_encap_rcv(sk, head, skb);
186
187 offset = offset - sizeof(struct udphdr);
188
189 if (!pskb_pull(skb, offset))
190 return NULL;
191
192 rcu_read_lock();
193 ops = rcu_dereference(inet6_offloads[IPPROTO_ESP]);
194 if (!ops || !ops->callbacks.gro_receive)
195 goto out;
196
197 ret = __xfrm6_udp_encap_rcv(sk, skb, false);
198 if (ret)
199 goto out;
200
201 skb_push(skb, offset);
202 NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
203
204 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
205 rcu_read_unlock();
206
207 return pp;
208
209out:
210 rcu_read_unlock();
211 skb_push(skb, offset);
212 NAPI_GRO_CB(skb)->same_flow = 0;
213 NAPI_GRO_CB(skb)->flush = 1;
214
215 return NULL;
216}
217
218int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
219{
220 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
221 0, t);
222}
223EXPORT_SYMBOL(xfrm6_rcv_tnl);
224
225int xfrm6_rcv(struct sk_buff *skb)
226{
227 return xfrm6_rcv_tnl(skb, NULL);
228}
229EXPORT_SYMBOL(xfrm6_rcv);
230int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
231 xfrm_address_t *saddr, u8 proto)
232{
233 struct net *net = dev_net(skb->dev);
234 struct xfrm_state *x = NULL;
235 struct sec_path *sp;
236 int i = 0;
237
238 sp = secpath_set(skb);
239 if (!sp) {
240 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
241 goto drop;
242 }
243
244 if (1 + sp->len == XFRM_MAX_DEPTH) {
245 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
246 goto drop;
247 }
248
249 for (i = 0; i < 3; i++) {
250 xfrm_address_t *dst, *src;
251
252 switch (i) {
253 case 0:
254 dst = daddr;
255 src = saddr;
256 break;
257 case 1:
258 /* lookup state with wild-card source address */
259 dst = daddr;
260 src = (xfrm_address_t *)&in6addr_any;
261 break;
262 default:
263 /* lookup state with wild-card addresses */
264 dst = (xfrm_address_t *)&in6addr_any;
265 src = (xfrm_address_t *)&in6addr_any;
266 break;
267 }
268
269 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
270 if (!x)
271 continue;
272
273 if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) {
274 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR);
275 xfrm_state_put(x);
276 x = NULL;
277 continue;
278 }
279
280 spin_lock(&x->lock);
281
282 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
283 likely(x->km.state == XFRM_STATE_VALID) &&
284 !xfrm_state_check_expire(x)) {
285 spin_unlock(&x->lock);
286 if (x->type->input(x, skb) > 0) {
287 /* found a valid state */
288 break;
289 }
290 } else
291 spin_unlock(&x->lock);
292
293 xfrm_state_put(x);
294 x = NULL;
295 }
296
297 if (!x) {
298 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
299 xfrm_audit_state_notfound_simple(skb, AF_INET6);
300 goto drop;
301 }
302
303 sp->xvec[sp->len++] = x;
304
305 spin_lock(&x->lock);
306
307 x->curlft.bytes += skb->len;
308 x->curlft.packets++;
309
310 spin_unlock(&x->lock);
311
312 return 1;
313
314drop:
315 return -1;
316}
317EXPORT_SYMBOL(xfrm6_input_addr);