]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - net/ipv4/ipcomp.c
xfrm: fix freed block size calculation in xfrm_policy_fini()
[~shefty/rdma-dev.git] / net / ipv4 / ipcomp.c
1 /*
2  * IP Payload Compression Protocol (IPComp) - RFC3173.
3  *
4  * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  * Todo:
12  *   - Tunable compression parameters.
13  *   - Compression stats.
14  *   - Adaptive compression.
15  */
16 #include <linux/module.h>
17 #include <linux/err.h>
18 #include <linux/rtnetlink.h>
19 #include <net/ip.h>
20 #include <net/xfrm.h>
21 #include <net/icmp.h>
22 #include <net/ipcomp.h>
23 #include <net/protocol.h>
24 #include <net/sock.h>
25
26 static void ipcomp4_err(struct sk_buff *skb, u32 info)
27 {
28         struct net *net = dev_net(skb->dev);
29         __be32 spi;
30         const struct iphdr *iph = (const struct iphdr *)skb->data;
31         struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
32         struct xfrm_state *x;
33
34         switch (icmp_hdr(skb)->type) {
35         case ICMP_DEST_UNREACH:
36                 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
37                         return;
38         case ICMP_REDIRECT:
39                 break;
40         default:
41                 return;
42         }
43
44         spi = htonl(ntohs(ipch->cpi));
45         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
46                               spi, IPPROTO_COMP, AF_INET);
47         if (!x)
48                 return;
49
50         if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
51                 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
52         else
53                 ipv4_redirect(skb, net, 0, 0, IPPROTO_COMP, 0);
54         xfrm_state_put(x);
55 }
56
57 /* We always hold one tunnel user reference to indicate a tunnel */
58 static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
59 {
60         struct net *net = xs_net(x);
61         struct xfrm_state *t;
62
63         t = xfrm_state_alloc(net);
64         if (t == NULL)
65                 goto out;
66
67         t->id.proto = IPPROTO_IPIP;
68         t->id.spi = x->props.saddr.a4;
69         t->id.daddr.a4 = x->id.daddr.a4;
70         memcpy(&t->sel, &x->sel, sizeof(t->sel));
71         t->props.family = AF_INET;
72         t->props.mode = x->props.mode;
73         t->props.saddr.a4 = x->props.saddr.a4;
74         t->props.flags = x->props.flags;
75         memcpy(&t->mark, &x->mark, sizeof(t->mark));
76
77         if (xfrm_init_state(t))
78                 goto error;
79
80         atomic_set(&t->tunnel_users, 1);
81 out:
82         return t;
83
84 error:
85         t->km.state = XFRM_STATE_DEAD;
86         xfrm_state_put(t);
87         t = NULL;
88         goto out;
89 }
90
91 /*
92  * Must be protected by xfrm_cfg_mutex.  State and tunnel user references are
93  * always incremented on success.
94  */
95 static int ipcomp_tunnel_attach(struct xfrm_state *x)
96 {
97         struct net *net = xs_net(x);
98         int err = 0;
99         struct xfrm_state *t;
100         u32 mark = x->mark.v & x->mark.m;
101
102         t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4,
103                               x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
104         if (!t) {
105                 t = ipcomp_tunnel_create(x);
106                 if (!t) {
107                         err = -EINVAL;
108                         goto out;
109                 }
110                 xfrm_state_insert(t);
111                 xfrm_state_hold(t);
112         }
113         x->tunnel = t;
114         atomic_inc(&t->tunnel_users);
115 out:
116         return err;
117 }
118
119 static int ipcomp4_init_state(struct xfrm_state *x)
120 {
121         int err = -EINVAL;
122
123         x->props.header_len = 0;
124         switch (x->props.mode) {
125         case XFRM_MODE_TRANSPORT:
126                 break;
127         case XFRM_MODE_TUNNEL:
128                 x->props.header_len += sizeof(struct iphdr);
129                 break;
130         default:
131                 goto out;
132         }
133
134         err = ipcomp_init_state(x);
135         if (err)
136                 goto out;
137
138         if (x->props.mode == XFRM_MODE_TUNNEL) {
139                 err = ipcomp_tunnel_attach(x);
140                 if (err)
141                         goto out;
142         }
143
144         err = 0;
145 out:
146         return err;
147 }
148
149 static const struct xfrm_type ipcomp_type = {
150         .description    = "IPCOMP4",
151         .owner          = THIS_MODULE,
152         .proto          = IPPROTO_COMP,
153         .init_state     = ipcomp4_init_state,
154         .destructor     = ipcomp_destroy,
155         .input          = ipcomp_input,
156         .output         = ipcomp_output
157 };
158
159 static const struct net_protocol ipcomp4_protocol = {
160         .handler        =       xfrm4_rcv,
161         .err_handler    =       ipcomp4_err,
162         .no_policy      =       1,
163 };
164
165 static int __init ipcomp4_init(void)
166 {
167         if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
168                 pr_info("%s: can't add xfrm type\n", __func__);
169                 return -EAGAIN;
170         }
171         if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
172                 pr_info("%s: can't add protocol\n", __func__);
173                 xfrm_unregister_type(&ipcomp_type, AF_INET);
174                 return -EAGAIN;
175         }
176         return 0;
177 }
178
179 static void __exit ipcomp4_fini(void)
180 {
181         if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
182                 pr_info("%s: can't remove protocol\n", __func__);
183         if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
184                 pr_info("%s: can't remove xfrm type\n", __func__);
185 }
186
187 module_init(ipcomp4_init);
188 module_exit(ipcomp4_fini);
189
190 MODULE_LICENSE("GPL");
191 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
192 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
193
194 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);