xref: /openbmc/linux/net/ipv6/xfrm6_state.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 
194