xref: /linux/net/ipv6/xfrm6_state.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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, const struct flowi *fl)
24 {
25 	const struct flowi6 *fl6 = &fl->u.ip6;
26 
27 	/* Initialize temporary selector matching only
28 	 * to current session. */
29 	ipv6_addr_copy((struct in6_addr *)&sel->daddr, &fl6->daddr);
30 	ipv6_addr_copy((struct in6_addr *)&sel->saddr, &fl6->saddr);
31 	sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
32 	sel->dport_mask = htons(0xffff);
33 	sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
34 	sel->sport_mask = htons(0xffff);
35 	sel->family = AF_INET6;
36 	sel->prefixlen_d = 128;
37 	sel->prefixlen_s = 128;
38 	sel->proto = fl6->flowi6_proto;
39 	sel->ifindex = fl6->flowi6_oif;
40 }
41 
42 static void
43 xfrm6_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
44 		   const xfrm_address_t *daddr, const xfrm_address_t *saddr)
45 {
46 	x->id = tmpl->id;
47 	if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
48 		memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
49 	memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
50 	if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
51 		memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
52 	x->props.mode = tmpl->mode;
53 	x->props.reqid = tmpl->reqid;
54 	x->props.family = AF_INET6;
55 }
56 
57 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
58 static int
59 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
60 {
61 	int i;
62 	int class[XFRM_MAX_DEPTH];
63 	int count[maxclass];
64 
65 	memset(count, 0, sizeof(count));
66 
67 	for (i = 0; i < n; i++) {
68 		int c;
69 		class[i] = c = cmp(src[i]);
70 		count[c]++;
71 	}
72 
73 	for (i = 2; i < maxclass; i++)
74 		count[i] += count[i - 1];
75 
76 	for (i = 0; i < n; i++) {
77 		dst[count[class[i] - 1]++] = src[i];
78 		src[i] = NULL;
79 	}
80 
81 	return 0;
82 }
83 
84 /*
85  * Rule for xfrm_state:
86  *
87  * rule 1: select IPsec transport except AH
88  * rule 2: select MIPv6 RO or inbound trigger
89  * rule 3: select IPsec transport AH
90  * rule 4: select IPsec tunnel
91  * rule 5: others
92  */
93 static int __xfrm6_state_sort_cmp(void *p)
94 {
95 	struct xfrm_state *v = p;
96 
97 	switch (v->props.mode) {
98 	case XFRM_MODE_TRANSPORT:
99 		if (v->id.proto != IPPROTO_AH)
100 			return 1;
101 		else
102 			return 3;
103 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
104 	case XFRM_MODE_ROUTEOPTIMIZATION:
105 	case XFRM_MODE_IN_TRIGGER:
106 		return 2;
107 #endif
108 	case XFRM_MODE_TUNNEL:
109 	case XFRM_MODE_BEET:
110 		return 4;
111 	}
112 	return 5;
113 }
114 
115 static int
116 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
117 {
118 	return __xfrm6_sort((void **)dst, (void **)src, n,
119 			    __xfrm6_state_sort_cmp, 6);
120 }
121 
122 /*
123  * Rule for xfrm_tmpl:
124  *
125  * rule 1: select IPsec transport
126  * rule 2: select MIPv6 RO or inbound trigger
127  * rule 3: select IPsec tunnel
128  * rule 4: others
129  */
130 static int __xfrm6_tmpl_sort_cmp(void *p)
131 {
132 	struct xfrm_tmpl *v = p;
133 	switch (v->mode) {
134 	case XFRM_MODE_TRANSPORT:
135 		return 1;
136 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
137 	case XFRM_MODE_ROUTEOPTIMIZATION:
138 	case XFRM_MODE_IN_TRIGGER:
139 		return 2;
140 #endif
141 	case XFRM_MODE_TUNNEL:
142 	case XFRM_MODE_BEET:
143 		return 3;
144 	}
145 	return 4;
146 }
147 
148 static int
149 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
150 {
151 	return __xfrm6_sort((void **)dst, (void **)src, n,
152 			    __xfrm6_tmpl_sort_cmp, 5);
153 }
154 
155 int xfrm6_extract_header(struct sk_buff *skb)
156 {
157 	struct ipv6hdr *iph = ipv6_hdr(skb);
158 
159 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
160 	XFRM_MODE_SKB_CB(skb)->id = 0;
161 	XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
162 	XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
163 	XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
164 	XFRM_MODE_SKB_CB(skb)->optlen = 0;
165 	memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
166 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
167 
168 	return 0;
169 }
170 
171 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
172 	.family			= AF_INET6,
173 	.proto			= IPPROTO_IPV6,
174 	.eth_proto		= htons(ETH_P_IPV6),
175 	.owner			= THIS_MODULE,
176 	.init_tempsel		= __xfrm6_init_tempsel,
177 	.init_temprop		= xfrm6_init_temprop,
178 	.tmpl_sort		= __xfrm6_tmpl_sort,
179 	.state_sort		= __xfrm6_state_sort,
180 	.output			= xfrm6_output,
181 	.output_finish		= xfrm6_output_finish,
182 	.extract_input		= xfrm6_extract_input,
183 	.extract_output		= xfrm6_extract_output,
184 	.transport_finish	= xfrm6_transport_finish,
185 };
186 
187 int __init xfrm6_state_init(void)
188 {
189 	return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
190 }
191 
192 void xfrm6_state_fini(void)
193 {
194 	xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
195 }
196 
197