net: wireless: bcmdhd: Put p2p_dev_addr under DHD_P2P_DEV_ADDR_FROM_SYSFS
[linux-2.6.git] / net / ipv4 / xfrm4_mode_beet.c
1 /*
2  * xfrm4_mode_beet.c - BEET mode encapsulation for IPv4.
3  *
4  * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
5  *                    Miika Komu     <miika@iki.fi>
6  *                    Herbert Xu     <herbert@gondor.apana.org.au>
7  *                    Abhinav Pathak <abhinav.pathak@hiit.fi>
8  *                    Jeff Ahrenholz <ahrenholz@gmail.com>
9  */
10
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/stringify.h>
16 #include <net/dst.h>
17 #include <net/ip.h>
18 #include <net/xfrm.h>
19
20 static void xfrm4_beet_make_header(struct sk_buff *skb)
21 {
22         struct iphdr *iph = ip_hdr(skb);
23
24         iph->ihl = 5;
25         iph->version = 4;
26
27         iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
28         iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
29
30         iph->id = XFRM_MODE_SKB_CB(skb)->id;
31         iph->frag_off = XFRM_MODE_SKB_CB(skb)->frag_off;
32         iph->ttl = XFRM_MODE_SKB_CB(skb)->ttl;
33 }
34
35 /* Add encapsulation header.
36  *
37  * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
38  */
39 static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
40 {
41         struct ip_beet_phdr *ph;
42         struct iphdr *top_iph;
43         int hdrlen, optlen;
44
45         hdrlen = 0;
46         optlen = XFRM_MODE_SKB_CB(skb)->optlen;
47         if (unlikely(optlen))
48                 hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
49
50         skb_set_network_header(skb, -x->props.header_len -
51                                     hdrlen + (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
52         if (x->sel.family != AF_INET6)
53                 skb->network_header += IPV4_BEET_PHMAXLEN;
54         skb->mac_header = skb->network_header +
55                           offsetof(struct iphdr, protocol);
56         skb->transport_header = skb->network_header + sizeof(*top_iph);
57
58         xfrm4_beet_make_header(skb);
59
60         ph = (struct ip_beet_phdr *)
61                 __skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
62
63         top_iph = ip_hdr(skb);
64
65         if (unlikely(optlen)) {
66                 BUG_ON(optlen < 0);
67
68                 ph->padlen = 4 - (optlen & 4);
69                 ph->hdrlen = optlen / 8;
70                 ph->nexthdr = top_iph->protocol;
71                 if (ph->padlen)
72                         memset(ph + 1, IPOPT_NOP, ph->padlen);
73
74                 top_iph->protocol = IPPROTO_BEETPH;
75                 top_iph->ihl = sizeof(struct iphdr) / 4;
76         }
77
78         top_iph->saddr = x->props.saddr.a4;
79         top_iph->daddr = x->id.daddr.a4;
80
81         return 0;
82 }
83
84 static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
85 {
86         struct iphdr *iph;
87         int optlen = 0;
88         int err = -EINVAL;
89
90         if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
91                 struct ip_beet_phdr *ph;
92                 int phlen;
93
94                 if (!pskb_may_pull(skb, sizeof(*ph)))
95                         goto out;
96
97                 ph = (struct ip_beet_phdr *)skb->data;
98
99                 phlen = sizeof(*ph) + ph->padlen;
100                 optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
101                 if (optlen < 0 || optlen & 3 || optlen > 250)
102                         goto out;
103
104                 XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
105
106                 if (!pskb_may_pull(skb, phlen))
107                         goto out;
108                 __skb_pull(skb, phlen);
109         }
110
111         skb_push(skb, sizeof(*iph));
112         skb_reset_network_header(skb);
113
114         memmove(skb->data - skb->mac_len, skb_mac_header(skb),
115                 skb->mac_len);
116         skb_set_mac_header(skb, -skb->mac_len);
117
118         xfrm4_beet_make_header(skb);
119
120         iph = ip_hdr(skb);
121
122         iph->ihl += optlen / 4;
123         iph->tot_len = htons(skb->len);
124         iph->daddr = x->sel.daddr.a4;
125         iph->saddr = x->sel.saddr.a4;
126         iph->check = 0;
127         iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
128         err = 0;
129 out:
130         return err;
131 }
132
133 static struct xfrm_mode xfrm4_beet_mode = {
134         .input2 = xfrm4_beet_input,
135         .input = xfrm_prepare_input,
136         .output2 = xfrm4_beet_output,
137         .output = xfrm4_prepare_output,
138         .owner = THIS_MODULE,
139         .encap = XFRM_MODE_BEET,
140         .flags = XFRM_MODE_FLAG_TUNNEL,
141 };
142
143 static int __init xfrm4_beet_init(void)
144 {
145         return xfrm_register_mode(&xfrm4_beet_mode, AF_INET);
146 }
147
148 static void __exit xfrm4_beet_exit(void)
149 {
150         int err;
151
152         err = xfrm_unregister_mode(&xfrm4_beet_mode, AF_INET);
153         BUG_ON(err);
154 }
155
156 module_init(xfrm4_beet_init);
157 module_exit(xfrm4_beet_exit);
158 MODULE_LICENSE("GPL");
159 MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_BEET);