[IPSEC]: Separate inner/outer mode processing on output
[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 <net/dsfield.h>
18 #include <net/ipv6.h>
19 #include <net/addrconf.h>
20
21 static struct xfrm_state_afinfo xfrm6_state_afinfo;
22
23 static void
24 __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
25                      struct xfrm_tmpl *tmpl,
26                      xfrm_address_t *daddr, xfrm_address_t *saddr)
27 {
28         /* Initialize temporary selector matching only
29          * to current session. */
30         ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);
31         ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);
32         x->sel.dport = xfrm_flowi_dport(fl);
33         x->sel.dport_mask = htons(0xffff);
34         x->sel.sport = xfrm_flowi_sport(fl);
35         x->sel.sport_mask = htons(0xffff);
36         x->sel.prefixlen_d = 128;
37         x->sel.prefixlen_s = 128;
38         x->sel.proto = fl->proto;
39         x->sel.ifindex = fl->oif;
40         x->id = tmpl->id;
41         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
42                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
43         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
44         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
45                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
46         x->props.mode = tmpl->mode;
47         x->props.reqid = tmpl->reqid;
48         x->props.family = AF_INET6;
49 }
50
51 static int
52 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
53 {
54         int i;
55         int j = 0;
56
57         /* Rule 1: select IPsec transport except AH */
58         for (i = 0; i < n; i++) {
59                 if (src[i]->props.mode == XFRM_MODE_TRANSPORT &&
60                     src[i]->id.proto != IPPROTO_AH) {
61                         dst[j++] = src[i];
62                         src[i] = NULL;
63                 }
64         }
65         if (j == n)
66                 goto end;
67
68         /* Rule 2: select MIPv6 RO or inbound trigger */
69 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
70         for (i = 0; i < n; i++) {
71                 if (src[i] &&
72                     (src[i]->props.mode == XFRM_MODE_ROUTEOPTIMIZATION ||
73                      src[i]->props.mode == XFRM_MODE_IN_TRIGGER)) {
74                         dst[j++] = src[i];
75                         src[i] = NULL;
76                 }
77         }
78         if (j == n)
79                 goto end;
80 #endif
81
82         /* Rule 3: select IPsec transport AH */
83         for (i = 0; i < n; i++) {
84                 if (src[i] &&
85                     src[i]->props.mode == XFRM_MODE_TRANSPORT &&
86                     src[i]->id.proto == IPPROTO_AH) {
87                         dst[j++] = src[i];
88                         src[i] = NULL;
89                 }
90         }
91         if (j == n)
92                 goto end;
93
94         /* Rule 4: select IPsec tunnel */
95         for (i = 0; i < n; i++) {
96                 if (src[i] &&
97                     (src[i]->props.mode == XFRM_MODE_TUNNEL ||
98                      src[i]->props.mode == XFRM_MODE_BEET)) {
99                         dst[j++] = src[i];
100                         src[i] = NULL;
101                 }
102         }
103         if (likely(j == n))
104                 goto end;
105
106         /* Final rule */
107         for (i = 0; i < n; i++) {
108                 if (src[i]) {
109                         dst[j++] = src[i];
110                         src[i] = NULL;
111                 }
112         }
113
114  end:
115         return 0;
116 }
117
118 static int
119 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
120 {
121         int i;
122         int j = 0;
123
124         /* Rule 1: select IPsec transport */
125         for (i = 0; i < n; i++) {
126                 if (src[i]->mode == XFRM_MODE_TRANSPORT) {
127                         dst[j++] = src[i];
128                         src[i] = NULL;
129                 }
130         }
131         if (j == n)
132                 goto end;
133
134         /* Rule 2: select MIPv6 RO or inbound trigger */
135 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
136         for (i = 0; i < n; i++) {
137                 if (src[i] &&
138                     (src[i]->mode == XFRM_MODE_ROUTEOPTIMIZATION ||
139                      src[i]->mode == XFRM_MODE_IN_TRIGGER)) {
140                         dst[j++] = src[i];
141                         src[i] = NULL;
142                 }
143         }
144         if (j == n)
145                 goto end;
146 #endif
147
148         /* Rule 3: select IPsec tunnel */
149         for (i = 0; i < n; i++) {
150                 if (src[i] &&
151                     (src[i]->mode == XFRM_MODE_TUNNEL ||
152                      src[i]->mode == XFRM_MODE_BEET)) {
153                         dst[j++] = src[i];
154                         src[i] = NULL;
155                 }
156         }
157         if (likely(j == n))
158                 goto end;
159
160         /* Final rule */
161         for (i = 0; i < n; i++) {
162                 if (src[i]) {
163                         dst[j++] = src[i];
164                         src[i] = NULL;
165                 }
166         }
167
168  end:
169         return 0;
170 }
171
172 int xfrm6_extract_header(struct sk_buff *skb)
173 {
174         struct ipv6hdr *iph = ipv6_hdr(skb);
175
176         XFRM_MODE_SKB_CB(skb)->id = 0;
177         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
178         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
179         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
180         XFRM_MODE_SKB_CB(skb)->protocol = iph->nexthdr;
181         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
182                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
183
184         return 0;
185 }
186
187 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
188         .family                 = AF_INET6,
189         .proto                  = IPPROTO_IPV6,
190         .owner                  = THIS_MODULE,
191         .init_tempsel           = __xfrm6_init_tempsel,
192         .tmpl_sort              = __xfrm6_tmpl_sort,
193         .state_sort             = __xfrm6_state_sort,
194         .output                 = xfrm6_output,
195         .extract_output         = xfrm6_extract_output,
196 };
197
198 void __init xfrm6_state_init(void)
199 {
200         xfrm_state_register_afinfo(&xfrm6_state_afinfo);
201 }
202
203 void xfrm6_state_fini(void)
204 {
205         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
206 }
207