xref: /openbmc/linux/net/ipv6/xfrm6_state.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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_state *x, struct flowi *fl,
24 		     struct xfrm_tmpl *tmpl,
25 		     xfrm_address_t *daddr, xfrm_address_t *saddr)
26 {
27 	/* Initialize temporary selector matching only
28 	 * to current session. */
29 	ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);
30 	ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);
31 	x->sel.dport = xfrm_flowi_dport(fl);
32 	x->sel.dport_mask = htons(0xffff);
33 	x->sel.sport = xfrm_flowi_sport(fl);
34 	x->sel.sport_mask = htons(0xffff);
35 	x->sel.family = AF_INET6;
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 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
52 static int
53 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
54 {
55 	int i;
56 	int class[XFRM_MAX_DEPTH];
57 	int count[maxclass];
58 
59 	memset(count, 0, sizeof(count));
60 
61 	for (i = 0; i < n; i++) {
62 		int c;
63 		class[i] = c = cmp(src[i]);
64 		count[c]++;
65 	}
66 
67 	for (i = 2; i < maxclass; i++)
68 		count[i] += count[i - 1];
69 
70 	for (i = 0; i < n; i++) {
71 		dst[count[class[i] - 1]++] = src[i];
72 		src[i] = NULL;
73 	}
74 
75 	return 0;
76 }
77 
78 /*
79  * Rule for xfrm_state:
80  *
81  * rule 1: select IPsec transport except AH
82  * rule 2: select MIPv6 RO or inbound trigger
83  * rule 3: select IPsec transport AH
84  * rule 4: select IPsec tunnel
85  * rule 5: others
86  */
87 static int __xfrm6_state_sort_cmp(void *p)
88 {
89 	struct xfrm_state *v = p;
90 
91 	switch (v->props.mode) {
92 	case XFRM_MODE_TRANSPORT:
93 		if (v->id.proto != IPPROTO_AH)
94 			return 1;
95 		else
96 			return 3;
97 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
98 	case XFRM_MODE_ROUTEOPTIMIZATION:
99 	case XFRM_MODE_IN_TRIGGER:
100 		return 2;
101 #endif
102 	case XFRM_MODE_TUNNEL:
103 	case XFRM_MODE_BEET:
104 		return 4;
105 	}
106 	return 5;
107 }
108 
109 static int
110 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
111 {
112 	return __xfrm6_sort((void **)dst, (void **)src, n,
113 			    __xfrm6_state_sort_cmp, 6);
114 }
115 
116 /*
117  * Rule for xfrm_tmpl:
118  *
119  * rule 1: select IPsec transport
120  * rule 2: select MIPv6 RO or inbound trigger
121  * rule 3: select IPsec tunnel
122  * rule 4: others
123  */
124 static int __xfrm6_tmpl_sort_cmp(void *p)
125 {
126 	struct xfrm_tmpl *v = p;
127 	switch (v->mode) {
128 	case XFRM_MODE_TRANSPORT:
129 		return 1;
130 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
131 	case XFRM_MODE_ROUTEOPTIMIZATION:
132 	case XFRM_MODE_IN_TRIGGER:
133 		return 2;
134 #endif
135 	case XFRM_MODE_TUNNEL:
136 	case XFRM_MODE_BEET:
137 		return 3;
138 	}
139 	return 4;
140 }
141 
142 static int
143 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
144 {
145 	return __xfrm6_sort((void **)dst, (void **)src, n,
146 			    __xfrm6_tmpl_sort_cmp, 5);
147 }
148 
149 int xfrm6_extract_header(struct sk_buff *skb)
150 {
151 	struct ipv6hdr *iph = ipv6_hdr(skb);
152 
153 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
154 	XFRM_MODE_SKB_CB(skb)->id = 0;
155 	XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
156 	XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
157 	XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
158 	XFRM_MODE_SKB_CB(skb)->optlen = 0;
159 	memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
160 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
161 
162 	return 0;
163 }
164 
165 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
166 	.family			= AF_INET6,
167 	.proto			= IPPROTO_IPV6,
168 	.eth_proto		= htons(ETH_P_IPV6),
169 	.owner			= THIS_MODULE,
170 	.init_tempsel		= __xfrm6_init_tempsel,
171 	.tmpl_sort		= __xfrm6_tmpl_sort,
172 	.state_sort		= __xfrm6_state_sort,
173 	.output			= xfrm6_output,
174 	.extract_input		= xfrm6_extract_input,
175 	.extract_output		= xfrm6_extract_output,
176 	.transport_finish	= xfrm6_transport_finish,
177 };
178 
179 int __init xfrm6_state_init(void)
180 {
181 	return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
182 }
183 
184 void xfrm6_state_fini(void)
185 {
186 	xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
187 }
188 
189