xref: /openbmc/linux/net/ipv6/xfrm6_state.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 struct xfrm_state_afinfo xfrm6_state_afinfo;
23 
24 static void
25 __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
26 		     struct xfrm_tmpl *tmpl,
27 		     xfrm_address_t *daddr, xfrm_address_t *saddr)
28 {
29 	/* Initialize temporary selector matching only
30 	 * to current session. */
31 	ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);
32 	ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);
33 	x->sel.dport = xfrm_flowi_dport(fl);
34 	x->sel.dport_mask = htons(0xffff);
35 	x->sel.sport = xfrm_flowi_sport(fl);
36 	x->sel.sport_mask = htons(0xffff);
37 	x->sel.prefixlen_d = 128;
38 	x->sel.prefixlen_s = 128;
39 	x->sel.proto = fl->proto;
40 	x->sel.ifindex = fl->oif;
41 	x->id = tmpl->id;
42 	if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
43 		memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
44 	memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
45 	if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
46 		memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
47 	x->props.mode = tmpl->mode;
48 	x->props.reqid = tmpl->reqid;
49 	x->props.family = AF_INET6;
50 }
51 
52 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
53 static int
54 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
55 {
56 	int i;
57 	int class[XFRM_MAX_DEPTH];
58 	int count[maxclass];
59 
60 	memset(count, 0, sizeof(count));
61 
62 	for (i = 0; i < n; i++) {
63 		int c;
64 		class[i] = c = cmp(src[i]);
65 		count[c]++;
66 	}
67 
68 	for (i = 2; i < maxclass; i++)
69 		count[i] += count[i - 1];
70 
71 	for (i = 0; i < n; i++) {
72 		dst[count[class[i] - 1]++] = src[i];
73 		src[i] = 0;
74 	}
75 
76 	return 0;
77 }
78 
79 /*
80  * Rule for xfrm_state:
81  *
82  * rule 1: select IPsec transport except AH
83  * rule 2: select MIPv6 RO or inbound trigger
84  * rule 3: select IPsec transport AH
85  * rule 4: select IPsec tunnel
86  * rule 5: others
87  */
88 static int __xfrm6_state_sort_cmp(void *p)
89 {
90 	struct xfrm_state *v = p;
91 
92 	switch (v->props.mode) {
93 	case XFRM_MODE_TRANSPORT:
94 		if (v->id.proto != IPPROTO_AH)
95 			return 1;
96 		else
97 			return 3;
98 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
99 	case XFRM_MODE_ROUTEOPTIMIZATION:
100 	case XFRM_MODE_IN_TRIGGER:
101 		return 2;
102 #endif
103 	case XFRM_MODE_TUNNEL:
104 	case XFRM_MODE_BEET:
105 		return 4;
106 	}
107 	return 5;
108 }
109 
110 static int
111 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
112 {
113 	return __xfrm6_sort((void **)dst, (void **)src, n,
114 			    __xfrm6_state_sort_cmp, 6);
115 }
116 
117 /*
118  * Rule for xfrm_tmpl:
119  *
120  * rule 1: select IPsec transport
121  * rule 2: select MIPv6 RO or inbound trigger
122  * rule 3: select IPsec tunnel
123  * rule 4: others
124  */
125 static int __xfrm6_tmpl_sort_cmp(void *p)
126 {
127 	struct xfrm_tmpl *v = p;
128 	switch (v->mode) {
129 	case XFRM_MODE_TRANSPORT:
130 		return 1;
131 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
132 	case XFRM_MODE_ROUTEOPTIMIZATION:
133 	case XFRM_MODE_IN_TRIGGER:
134 		return 2;
135 #endif
136 	case XFRM_MODE_TUNNEL:
137 	case XFRM_MODE_BEET:
138 		return 3;
139 	}
140 	return 4;
141 }
142 
143 static int
144 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
145 {
146 	return __xfrm6_sort((void **)dst, (void **)src, n,
147 			    __xfrm6_tmpl_sort_cmp, 5);
148 }
149 
150 int xfrm6_extract_header(struct sk_buff *skb)
151 {
152 	struct ipv6hdr *iph = ipv6_hdr(skb);
153 
154 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
155 	XFRM_MODE_SKB_CB(skb)->id = 0;
156 	XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
157 	XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
158 	XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
159 	XFRM_MODE_SKB_CB(skb)->optlen = 0;
160 	memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
161 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
162 
163 	return 0;
164 }
165 
166 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
167 	.family			= AF_INET6,
168 	.proto			= IPPROTO_IPV6,
169 	.eth_proto		= htons(ETH_P_IPV6),
170 	.owner			= THIS_MODULE,
171 	.init_tempsel		= __xfrm6_init_tempsel,
172 	.tmpl_sort		= __xfrm6_tmpl_sort,
173 	.state_sort		= __xfrm6_state_sort,
174 	.output			= xfrm6_output,
175 	.extract_input		= xfrm6_extract_input,
176 	.extract_output		= xfrm6_extract_output,
177 	.transport_finish	= xfrm6_transport_finish,
178 };
179 
180 int __init xfrm6_state_init(void)
181 {
182 	return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
183 }
184 
185 void xfrm6_state_fini(void)
186 {
187 	xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
188 }
189 
190