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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * xfrm6_input.c: based on net/ipv4/xfrm4_input.c | |
4 | * | |
5 | * Authors: | |
6 | * Mitsuru KANDA @USAGI | |
67ba4152 IM |
7 | * Kazunori MIYAZAWA @USAGI |
8 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
1da177e4 LT |
9 | * YOSHIFUJI Hideaki @USAGI |
10 | * IPv6 support | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/string.h> | |
b05e1066 PM |
15 | #include <linux/netfilter.h> |
16 | #include <linux/netfilter_ipv6.h> | |
1da177e4 LT |
17 | #include <net/ipv6.h> |
18 | #include <net/xfrm.h> | |
19 | ||
63c43787 ND |
20 | int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi, |
21 | struct ip6_tnl *t) | |
1da177e4 | 22 | { |
63c43787 | 23 | XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t; |
2fcb45b6 | 24 | XFRM_SPI_SKB_CB(skb)->family = AF_INET6; |
716062fd HX |
25 | XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); |
26 | return xfrm_input(skb, nexthdr, spi, 0); | |
27 | } | |
28 | EXPORT_SYMBOL(xfrm6_rcv_spi); | |
b05e1066 | 29 | |
acf568ee HX |
30 | static int xfrm6_transport_finish2(struct net *net, struct sock *sk, |
31 | struct sk_buff *skb) | |
32 | { | |
0146dca7 SD |
33 | if (xfrm_trans_queue(skb, ip6_rcv_finish)) { |
34 | kfree_skb(skb); | |
35 | return NET_RX_DROP; | |
36 | } | |
37 | ||
38 | return 0; | |
acf568ee HX |
39 | } |
40 | ||
716062fd HX |
41 | int xfrm6_transport_finish(struct sk_buff *skb, int async) |
42 | { | |
7785bba2 | 43 | struct xfrm_offload *xo = xfrm_offload(skb); |
e9cba694 | 44 | int nhlen = skb->data - skb_network_header(skb); |
7785bba2 | 45 | |
60d5fcfb HX |
46 | skb_network_header(skb)[IP6CB(skb)->nhoff] = |
47 | XFRM_MODE_SKB_CB(skb)->protocol; | |
48 | ||
0883ae0e HX |
49 | #ifndef CONFIG_NETFILTER |
50 | if (!async) | |
51 | return 1; | |
52 | #endif | |
53 | ||
e9cba694 | 54 | __skb_push(skb, nhlen); |
7c88e21a | 55 | ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); |
e9cba694 | 56 | skb_postpush_rcsum(skb, skb_network_header(skb), nhlen); |
b05e1066 | 57 | |
7785bba2 SK |
58 | if (xo && (xo->flags & XFRM_GRO)) { |
59 | skb_mac_header_rebuild(skb); | |
bfc0698b | 60 | skb_reset_transport_header(skb); |
0146dca7 | 61 | return 0; |
7785bba2 SK |
62 | } |
63 | ||
29a26a56 EB |
64 | NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, |
65 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
acf568ee | 66 | xfrm6_transport_finish2); |
0146dca7 SD |
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 | */ | |
77 | int 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 | ||
158 | drop: | |
159 | kfree_skb(skb); | |
160 | return 0; | |
1da177e4 LT |
161 | } |
162 | ||
63c43787 | 163 | int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t) |
1da177e4 | 164 | { |
33b5ecb8 | 165 | return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff], |
63c43787 | 166 | 0, t); |
1da177e4 | 167 | } |
63c43787 | 168 | EXPORT_SYMBOL(xfrm6_rcv_tnl); |
7159039a | 169 | |
63c43787 ND |
170 | int xfrm6_rcv(struct sk_buff *skb) |
171 | { | |
172 | return xfrm6_rcv_tnl(skb, NULL); | |
173 | } | |
174 | EXPORT_SYMBOL(xfrm6_rcv); | |
fbd9a5b4 MN |
175 | int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr, |
176 | xfrm_address_t *saddr, u8 proto) | |
177 | { | |
59c9940e | 178 | struct net *net = dev_net(skb->dev); |
1ab1457c | 179 | struct xfrm_state *x = NULL; |
0ca64da1 | 180 | struct sec_path *sp; |
fbd9a5b4 MN |
181 | int i = 0; |
182 | ||
0ca64da1 FW |
183 | sp = secpath_set(skb); |
184 | if (!sp) { | |
b0fcee82 SK |
185 | XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR); |
186 | goto drop; | |
9473e1f6 MN |
187 | } |
188 | ||
0ca64da1 | 189 | if (1 + sp->len == XFRM_MAX_DEPTH) { |
59c9940e | 190 | XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR); |
9473e1f6 MN |
191 | goto drop; |
192 | } | |
193 | ||
fbd9a5b4 MN |
194 | for (i = 0; i < 3; i++) { |
195 | xfrm_address_t *dst, *src; | |
a002c6fd | 196 | |
fbd9a5b4 MN |
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 */ | |
fbd9a5b4 | 204 | dst = daddr; |
a002c6fd | 205 | src = (xfrm_address_t *)&in6addr_any; |
fbd9a5b4 | 206 | break; |
fbd9a5b4 | 207 | default: |
1ab1457c | 208 | /* lookup state with wild-card addresses */ |
a002c6fd YH |
209 | dst = (xfrm_address_t *)&in6addr_any; |
210 | src = (xfrm_address_t *)&in6addr_any; | |
fbd9a5b4 | 211 | break; |
1ab1457c | 212 | } |
fbd9a5b4 | 213 | |
bd55775c | 214 | x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6); |
fbd9a5b4 MN |
215 | if (!x) |
216 | continue; | |
217 | ||
218 | spin_lock(&x->lock); | |
219 | ||
a002c6fd YH |
220 | if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) && |
221 | likely(x->km.state == XFRM_STATE_VALID) && | |
222 | !xfrm_state_check_expire(x)) { | |
fbd9a5b4 | 223 | spin_unlock(&x->lock); |
a002c6fd YH |
224 | if (x->type->input(x, skb) > 0) { |
225 | /* found a valid state */ | |
226 | break; | |
227 | } | |
228 | } else | |
fbd9a5b4 | 229 | spin_unlock(&x->lock); |
fbd9a5b4 | 230 | |
a002c6fd YH |
231 | xfrm_state_put(x); |
232 | x = NULL; | |
fbd9a5b4 MN |
233 | } |
234 | ||
9473e1f6 | 235 | if (!x) { |
59c9940e | 236 | XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES); |
afeb14b4 | 237 | xfrm_audit_state_notfound_simple(skb, AF_INET6); |
fbd9a5b4 | 238 | goto drop; |
fbd9a5b4 MN |
239 | } |
240 | ||
2294be0f | 241 | sp->xvec[sp->len++] = x; |
9473e1f6 MN |
242 | |
243 | spin_lock(&x->lock); | |
fbd9a5b4 | 244 | |
9473e1f6 MN |
245 | x->curlft.bytes += skb->len; |
246 | x->curlft.packets++; | |
247 | ||
248 | spin_unlock(&x->lock); | |
fbd9a5b4 MN |
249 | |
250 | return 1; | |
9473e1f6 | 251 | |
fbd9a5b4 | 252 | drop: |
fbd9a5b4 MN |
253 | return -1; |
254 | } | |
7159039a | 255 | EXPORT_SYMBOL(xfrm6_input_addr); |