Merge tag 'spi-fix-v5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
[linux-2.6-microblaze.git] / net / ipv6 / ipcomp6.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
4  *
5  * Copyright (C)2003 USAGI/WIDE Project
6  *
7  * Author       Mitsuru KANDA  <mk@linux-ipv6.org>
8  */
9 /*
10  * [Memo]
11  *
12  * Outbound:
13  *  The compression of IP datagram MUST be done before AH/ESP processing,
14  *  fragmentation, and the addition of Hop-by-Hop/Routing header.
15  *
16  * Inbound:
17  *  The decompression of IP datagram MUST be done after the reassembly,
18  *  AH/ESP processing.
19  */
20
21 #define pr_fmt(fmt) "IPv6: " fmt
22
23 #include <linux/module.h>
24 #include <net/ip.h>
25 #include <net/xfrm.h>
26 #include <net/ipcomp.h>
27 #include <linux/crypto.h>
28 #include <linux/err.h>
29 #include <linux/pfkeyv2.h>
30 #include <linux/random.h>
31 #include <linux/percpu.h>
32 #include <linux/smp.h>
33 #include <linux/list.h>
34 #include <linux/vmalloc.h>
35 #include <linux/rtnetlink.h>
36 #include <net/ip6_route.h>
37 #include <net/icmp.h>
38 #include <net/ipv6.h>
39 #include <net/protocol.h>
40 #include <linux/ipv6.h>
41 #include <linux/icmpv6.h>
42 #include <linux/mutex.h>
43
44 static int ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
45                                 u8 type, u8 code, int offset, __be32 info)
46 {
47         struct net *net = dev_net(skb->dev);
48         __be32 spi;
49         const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
50         struct ip_comp_hdr *ipcomph =
51                 (struct ip_comp_hdr *)(skb->data + offset);
52         struct xfrm_state *x;
53
54         if (type != ICMPV6_PKT_TOOBIG &&
55             type != NDISC_REDIRECT)
56                 return 0;
57
58         spi = htonl(ntohs(ipcomph->cpi));
59         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
60                               spi, IPPROTO_COMP, AF_INET6);
61         if (!x)
62                 return 0;
63
64         if (type == NDISC_REDIRECT)
65                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
66                              sock_net_uid(net, NULL));
67         else
68                 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
69         xfrm_state_put(x);
70
71         return 0;
72 }
73
74 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
75 {
76         struct net *net = xs_net(x);
77         struct xfrm_state *t = NULL;
78
79         t = xfrm_state_alloc(net);
80         if (!t)
81                 goto out;
82
83         t->id.proto = IPPROTO_IPV6;
84         t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
85         if (!t->id.spi)
86                 goto error;
87
88         memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
89         memcpy(&t->sel, &x->sel, sizeof(t->sel));
90         t->props.family = AF_INET6;
91         t->props.mode = x->props.mode;
92         memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
93         memcpy(&t->mark, &x->mark, sizeof(t->mark));
94         t->if_id = x->if_id;
95
96         if (xfrm_init_state(t))
97                 goto error;
98
99         atomic_set(&t->tunnel_users, 1);
100
101 out:
102         return t;
103
104 error:
105         t->km.state = XFRM_STATE_DEAD;
106         xfrm_state_put(t);
107         t = NULL;
108         goto out;
109 }
110
111 static int ipcomp6_tunnel_attach(struct xfrm_state *x)
112 {
113         struct net *net = xs_net(x);
114         int err = 0;
115         struct xfrm_state *t = NULL;
116         __be32 spi;
117         u32 mark = x->mark.m & x->mark.v;
118
119         spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
120         if (spi)
121                 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
122                                               spi, IPPROTO_IPV6, AF_INET6);
123         if (!t) {
124                 t = ipcomp6_tunnel_create(x);
125                 if (!t) {
126                         err = -EINVAL;
127                         goto out;
128                 }
129                 xfrm_state_insert(t);
130                 xfrm_state_hold(t);
131         }
132         x->tunnel = t;
133         atomic_inc(&t->tunnel_users);
134
135 out:
136         return err;
137 }
138
139 static int ipcomp6_init_state(struct xfrm_state *x)
140 {
141         int err = -EINVAL;
142
143         x->props.header_len = 0;
144         switch (x->props.mode) {
145         case XFRM_MODE_TRANSPORT:
146                 break;
147         case XFRM_MODE_TUNNEL:
148                 x->props.header_len += sizeof(struct ipv6hdr);
149                 break;
150         default:
151                 goto out;
152         }
153
154         err = ipcomp_init_state(x);
155         if (err)
156                 goto out;
157
158         if (x->props.mode == XFRM_MODE_TUNNEL) {
159                 err = ipcomp6_tunnel_attach(x);
160                 if (err)
161                         goto out;
162         }
163
164         err = 0;
165 out:
166         return err;
167 }
168
169 static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
170 {
171         return 0;
172 }
173
174 static const struct xfrm_type ipcomp6_type = {
175         .description    = "IPCOMP6",
176         .owner          = THIS_MODULE,
177         .proto          = IPPROTO_COMP,
178         .init_state     = ipcomp6_init_state,
179         .destructor     = ipcomp_destroy,
180         .input          = ipcomp_input,
181         .output         = ipcomp_output,
182         .hdr_offset     = xfrm6_find_1stfragopt,
183 };
184
185 static struct xfrm6_protocol ipcomp6_protocol = {
186         .handler        = xfrm6_rcv,
187         .input_handler  = xfrm_input,
188         .cb_handler     = ipcomp6_rcv_cb,
189         .err_handler    = ipcomp6_err,
190         .priority       = 0,
191 };
192
193 static int __init ipcomp6_init(void)
194 {
195         if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
196                 pr_info("%s: can't add xfrm type\n", __func__);
197                 return -EAGAIN;
198         }
199         if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
200                 pr_info("%s: can't add protocol\n", __func__);
201                 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
202                 return -EAGAIN;
203         }
204         return 0;
205 }
206
207 static void __exit ipcomp6_fini(void)
208 {
209         if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
210                 pr_info("%s: can't remove protocol\n", __func__);
211         xfrm_unregister_type(&ipcomp6_type, AF_INET6);
212 }
213
214 module_init(ipcomp6_init);
215 module_exit(ipcomp6_fini);
216 MODULE_LICENSE("GPL");
217 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
218 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
219
220 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);