xfrm: Allow different selector family in temporary state
[linux-2.6.git] / net / ipv6 / xfrm6_state.c
1 /*
2  * xfrm6_state.c: based on xfrm4_state.c
3  *
4  * Authors:
5  *      Mitsuru KANDA @USAGI
6  *      Kazunori MIYAZAWA @USAGI
7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8  *              IPv6 support
9  *      YOSHIFUJI Hideaki @USAGI
10  *              Split up af-specific portion
11  *
12  */
13
14 #include <net/xfrm.h>
15 #include <linux/pfkeyv2.h>
16 #include <linux/ipsec.h>
17 #include <linux/netfilter_ipv6.h>
18 #include <net/dsfield.h>
19 #include <net/ipv6.h>
20 #include <net/addrconf.h>
21
22 static void
23 __xfrm6_init_tempsel(struct xfrm_selector *sel, struct flowi *fl)
24 {
25         /* Initialize temporary selector matching only
26          * to current session. */
27         ipv6_addr_copy((struct in6_addr *)&sel->daddr, &fl->fl6_dst);
28         ipv6_addr_copy((struct in6_addr *)&sel->saddr, &fl->fl6_src);
29         sel->dport = xfrm_flowi_dport(fl);
30         sel->dport_mask = htons(0xffff);
31         sel->sport = xfrm_flowi_sport(fl);
32         sel->sport_mask = htons(0xffff);
33         sel->family = AF_INET6;
34         sel->prefixlen_d = 128;
35         sel->prefixlen_s = 128;
36         sel->proto = fl->proto;
37         sel->ifindex = fl->oif;
38 }
39
40 static void
41 xfrm6_init_temprop(struct xfrm_state *x, struct xfrm_tmpl *tmpl,
42                    xfrm_address_t *daddr, xfrm_address_t *saddr)
43 {
44         x->id = tmpl->id;
45         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
46                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
47         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
48         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
49                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
50         x->props.mode = tmpl->mode;
51         x->props.reqid = tmpl->reqid;
52         x->props.family = AF_INET6;
53 }
54
55 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
56 static int
57 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
58 {
59         int i;
60         int class[XFRM_MAX_DEPTH];
61         int count[maxclass];
62
63         memset(count, 0, sizeof(count));
64
65         for (i = 0; i < n; i++) {
66                 int c;
67                 class[i] = c = cmp(src[i]);
68                 count[c]++;
69         }
70
71         for (i = 2; i < maxclass; i++)
72                 count[i] += count[i - 1];
73
74         for (i = 0; i < n; i++) {
75                 dst[count[class[i] - 1]++] = src[i];
76                 src[i] = NULL;
77         }
78
79         return 0;
80 }
81
82 /*
83  * Rule for xfrm_state:
84  *
85  * rule 1: select IPsec transport except AH
86  * rule 2: select MIPv6 RO or inbound trigger
87  * rule 3: select IPsec transport AH
88  * rule 4: select IPsec tunnel
89  * rule 5: others
90  */
91 static int __xfrm6_state_sort_cmp(void *p)
92 {
93         struct xfrm_state *v = p;
94
95         switch (v->props.mode) {
96         case XFRM_MODE_TRANSPORT:
97                 if (v->id.proto != IPPROTO_AH)
98                         return 1;
99                 else
100                         return 3;
101 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
102         case XFRM_MODE_ROUTEOPTIMIZATION:
103         case XFRM_MODE_IN_TRIGGER:
104                 return 2;
105 #endif
106         case XFRM_MODE_TUNNEL:
107         case XFRM_MODE_BEET:
108                 return 4;
109         }
110         return 5;
111 }
112
113 static int
114 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
115 {
116         return __xfrm6_sort((void **)dst, (void **)src, n,
117                             __xfrm6_state_sort_cmp, 6);
118 }
119
120 /*
121  * Rule for xfrm_tmpl:
122  *
123  * rule 1: select IPsec transport
124  * rule 2: select MIPv6 RO or inbound trigger
125  * rule 3: select IPsec tunnel
126  * rule 4: others
127  */
128 static int __xfrm6_tmpl_sort_cmp(void *p)
129 {
130         struct xfrm_tmpl *v = p;
131         switch (v->mode) {
132         case XFRM_MODE_TRANSPORT:
133                 return 1;
134 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
135         case XFRM_MODE_ROUTEOPTIMIZATION:
136         case XFRM_MODE_IN_TRIGGER:
137                 return 2;
138 #endif
139         case XFRM_MODE_TUNNEL:
140         case XFRM_MODE_BEET:
141                 return 3;
142         }
143         return 4;
144 }
145
146 static int
147 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
148 {
149         return __xfrm6_sort((void **)dst, (void **)src, n,
150                             __xfrm6_tmpl_sort_cmp, 5);
151 }
152
153 int xfrm6_extract_header(struct sk_buff *skb)
154 {
155         struct ipv6hdr *iph = ipv6_hdr(skb);
156
157         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
158         XFRM_MODE_SKB_CB(skb)->id = 0;
159         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
160         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
161         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
162         XFRM_MODE_SKB_CB(skb)->optlen = 0;
163         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
164                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
165
166         return 0;
167 }
168
169 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
170         .family                 = AF_INET6,
171         .proto                  = IPPROTO_IPV6,
172         .eth_proto              = htons(ETH_P_IPV6),
173         .owner                  = THIS_MODULE,
174         .init_tempsel           = __xfrm6_init_tempsel,
175         .init_temprop           = xfrm6_init_temprop,
176         .tmpl_sort              = __xfrm6_tmpl_sort,
177         .state_sort             = __xfrm6_state_sort,
178         .output                 = xfrm6_output,
179         .extract_input          = xfrm6_extract_input,
180         .extract_output         = xfrm6_extract_output,
181         .transport_finish       = xfrm6_transport_finish,
182 };
183
184 int __init xfrm6_state_init(void)
185 {
186         return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
187 }
188
189 void xfrm6_state_fini(void)
190 {
191         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
192 }
193