xref: /linux/net/ipv6/xfrm6_state.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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 <linux/export.h>
19 #include <net/dsfield.h>
20 #include <net/ipv6.h>
21 #include <net/addrconf.h>
22 
23 static void
24 __xfrm6_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
25 {
26 	const struct flowi6 *fl6 = &fl->u.ip6;
27 
28 	/* Initialize temporary selector matching only
29 	 * to current session. */
30 	*(struct in6_addr *)&sel->daddr = fl6->daddr;
31 	*(struct in6_addr *)&sel->saddr = fl6->saddr;
32 	sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
33 	sel->dport_mask = htons(0xffff);
34 	sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
35 	sel->sport_mask = htons(0xffff);
36 	sel->family = AF_INET6;
37 	sel->prefixlen_d = 128;
38 	sel->prefixlen_s = 128;
39 	sel->proto = fl6->flowi6_proto;
40 	sel->ifindex = fl6->flowi6_oif;
41 }
42 
43 static void
44 xfrm6_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
45 		   const xfrm_address_t *daddr, const xfrm_address_t *saddr)
46 {
47 	x->id = tmpl->id;
48 	if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
49 		memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
50 	memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
51 	if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
52 		memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
53 	x->props.mode = tmpl->mode;
54 	x->props.reqid = tmpl->reqid;
55 	x->props.family = AF_INET6;
56 }
57 
58 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
59 static int
60 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
61 {
62 	int i;
63 	int class[XFRM_MAX_DEPTH];
64 	int count[maxclass];
65 
66 	memset(count, 0, sizeof(count));
67 
68 	for (i = 0; i < n; i++) {
69 		int c;
70 		class[i] = c = cmp(src[i]);
71 		count[c]++;
72 	}
73 
74 	for (i = 2; i < maxclass; i++)
75 		count[i] += count[i - 1];
76 
77 	for (i = 0; i < n; i++) {
78 		dst[count[class[i] - 1]++] = src[i];
79 		src[i] = NULL;
80 	}
81 
82 	return 0;
83 }
84 
85 /*
86  * Rule for xfrm_state:
87  *
88  * rule 1: select IPsec transport except AH
89  * rule 2: select MIPv6 RO or inbound trigger
90  * rule 3: select IPsec transport AH
91  * rule 4: select IPsec tunnel
92  * rule 5: others
93  */
94 static int __xfrm6_state_sort_cmp(void *p)
95 {
96 	struct xfrm_state *v = p;
97 
98 	switch (v->props.mode) {
99 	case XFRM_MODE_TRANSPORT:
100 		if (v->id.proto != IPPROTO_AH)
101 			return 1;
102 		else
103 			return 3;
104 #if IS_ENABLED(CONFIG_IPV6_MIP6)
105 	case XFRM_MODE_ROUTEOPTIMIZATION:
106 	case XFRM_MODE_IN_TRIGGER:
107 		return 2;
108 #endif
109 	case XFRM_MODE_TUNNEL:
110 	case XFRM_MODE_BEET:
111 		return 4;
112 	}
113 	return 5;
114 }
115 
116 static int
117 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
118 {
119 	return __xfrm6_sort((void **)dst, (void **)src, n,
120 			    __xfrm6_state_sort_cmp, 6);
121 }
122 
123 /*
124  * Rule for xfrm_tmpl:
125  *
126  * rule 1: select IPsec transport
127  * rule 2: select MIPv6 RO or inbound trigger
128  * rule 3: select IPsec tunnel
129  * rule 4: others
130  */
131 static int __xfrm6_tmpl_sort_cmp(void *p)
132 {
133 	struct xfrm_tmpl *v = p;
134 	switch (v->mode) {
135 	case XFRM_MODE_TRANSPORT:
136 		return 1;
137 #if IS_ENABLED(CONFIG_IPV6_MIP6)
138 	case XFRM_MODE_ROUTEOPTIMIZATION:
139 	case XFRM_MODE_IN_TRIGGER:
140 		return 2;
141 #endif
142 	case XFRM_MODE_TUNNEL:
143 	case XFRM_MODE_BEET:
144 		return 3;
145 	}
146 	return 4;
147 }
148 
149 static int
150 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
151 {
152 	return __xfrm6_sort((void **)dst, (void **)src, n,
153 			    __xfrm6_tmpl_sort_cmp, 5);
154 }
155 
156 int xfrm6_extract_header(struct sk_buff *skb)
157 {
158 	struct ipv6hdr *iph = ipv6_hdr(skb);
159 
160 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
161 	XFRM_MODE_SKB_CB(skb)->id = 0;
162 	XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
163 	XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
164 	XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
165 	XFRM_MODE_SKB_CB(skb)->optlen = 0;
166 	memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
167 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
168 
169 	return 0;
170 }
171 
172 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
173 	.family			= AF_INET6,
174 	.proto			= IPPROTO_IPV6,
175 	.eth_proto		= htons(ETH_P_IPV6),
176 	.owner			= THIS_MODULE,
177 	.init_tempsel		= __xfrm6_init_tempsel,
178 	.init_temprop		= xfrm6_init_temprop,
179 	.tmpl_sort		= __xfrm6_tmpl_sort,
180 	.state_sort		= __xfrm6_state_sort,
181 	.output			= xfrm6_output,
182 	.output_finish		= xfrm6_output_finish,
183 	.extract_input		= xfrm6_extract_input,
184 	.extract_output		= xfrm6_extract_output,
185 	.transport_finish	= xfrm6_transport_finish,
186 };
187 
188 int __init xfrm6_state_init(void)
189 {
190 	return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
191 }
192 
193 void xfrm6_state_fini(void)
194 {
195 	xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
196 }
197 
198