fix a kmap leak in virtio_console
[linux/fpc-iii.git] / net / ipv4 / xfrm4_mode_tunnel.c
blob31b18152528fe4dbf9e500ae0c9a2a1a5a3a2adf
1 /*
2 * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
4 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
5 */
7 #include <linux/gfp.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/stringify.h>
13 #include <net/dst.h>
14 #include <net/inet_ecn.h>
15 #include <net/ip.h>
16 #include <net/xfrm.h>
18 /* Informational hook. The decap is still done here. */
19 static struct xfrm_tunnel_notifier __rcu *rcv_notify_handlers __read_mostly;
20 static DEFINE_MUTEX(xfrm4_mode_tunnel_input_mutex);
22 int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler)
24 struct xfrm_tunnel_notifier __rcu **pprev;
25 struct xfrm_tunnel_notifier *t;
26 int ret = -EEXIST;
27 int priority = handler->priority;
29 mutex_lock(&xfrm4_mode_tunnel_input_mutex);
31 for (pprev = &rcv_notify_handlers;
32 (t = rcu_dereference_protected(*pprev,
33 lockdep_is_held(&xfrm4_mode_tunnel_input_mutex))) != NULL;
34 pprev = &t->next) {
35 if (t->priority > priority)
36 break;
37 if (t->priority == priority)
38 goto err;
42 handler->next = *pprev;
43 rcu_assign_pointer(*pprev, handler);
45 ret = 0;
47 err:
48 mutex_unlock(&xfrm4_mode_tunnel_input_mutex);
49 return ret;
51 EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_register);
53 int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler)
55 struct xfrm_tunnel_notifier __rcu **pprev;
56 struct xfrm_tunnel_notifier *t;
57 int ret = -ENOENT;
59 mutex_lock(&xfrm4_mode_tunnel_input_mutex);
60 for (pprev = &rcv_notify_handlers;
61 (t = rcu_dereference_protected(*pprev,
62 lockdep_is_held(&xfrm4_mode_tunnel_input_mutex))) != NULL;
63 pprev = &t->next) {
64 if (t == handler) {
65 *pprev = handler->next;
66 ret = 0;
67 break;
70 mutex_unlock(&xfrm4_mode_tunnel_input_mutex);
71 synchronize_net();
73 return ret;
75 EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_deregister);
77 static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
79 struct iphdr *inner_iph = ipip_hdr(skb);
81 if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
82 IP_ECN_set_ce(inner_iph);
85 /* Add encapsulation header.
87 * The top IP header will be constructed per RFC 2401.
89 static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
91 struct dst_entry *dst = skb_dst(skb);
92 struct iphdr *top_iph;
93 int flags;
95 skb_set_network_header(skb, -x->props.header_len);
96 skb->mac_header = skb->network_header +
97 offsetof(struct iphdr, protocol);
98 skb->transport_header = skb->network_header + sizeof(*top_iph);
99 top_iph = ip_hdr(skb);
101 top_iph->ihl = 5;
102 top_iph->version = 4;
104 top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
106 /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
107 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
108 top_iph->tos = 0;
109 else
110 top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
111 top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
112 XFRM_MODE_SKB_CB(skb)->tos);
114 flags = x->props.flags;
115 if (flags & XFRM_STATE_NOECN)
116 IP_ECN_clear(top_iph);
118 top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
119 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
120 ip_select_ident(skb, dst->child, NULL);
122 top_iph->ttl = ip4_dst_hoplimit(dst->child);
124 top_iph->saddr = x->props.saddr.a4;
125 top_iph->daddr = x->id.daddr.a4;
127 return 0;
130 #define for_each_input_rcu(head, handler) \
131 for (handler = rcu_dereference(head); \
132 handler != NULL; \
133 handler = rcu_dereference(handler->next))
135 static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
137 struct xfrm_tunnel_notifier *handler;
138 int err = -EINVAL;
140 if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
141 goto out;
143 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
144 goto out;
146 for_each_input_rcu(rcv_notify_handlers, handler)
147 handler->handler(skb);
149 err = skb_unclone(skb, GFP_ATOMIC);
150 if (err)
151 goto out;
153 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
154 ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
155 if (!(x->props.flags & XFRM_STATE_NOECN))
156 ipip_ecn_decapsulate(skb);
158 skb_reset_network_header(skb);
159 skb_mac_header_rebuild(skb);
161 err = 0;
163 out:
164 return err;
167 static struct xfrm_mode xfrm4_tunnel_mode = {
168 .input2 = xfrm4_mode_tunnel_input,
169 .input = xfrm_prepare_input,
170 .output2 = xfrm4_mode_tunnel_output,
171 .output = xfrm4_prepare_output,
172 .owner = THIS_MODULE,
173 .encap = XFRM_MODE_TUNNEL,
174 .flags = XFRM_MODE_FLAG_TUNNEL,
177 static int __init xfrm4_mode_tunnel_init(void)
179 return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
182 static void __exit xfrm4_mode_tunnel_exit(void)
184 int err;
186 err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
187 BUG_ON(err);
190 module_init(xfrm4_mode_tunnel_init);
191 module_exit(xfrm4_mode_tunnel_exit);
192 MODULE_LICENSE("GPL");
193 MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);