xref: /openbmc/linux/net/ipv6/xfrm6_state.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 <net/ipv6.h>
18 #include <net/addrconf.h>
19 
20 static struct xfrm_state_afinfo xfrm6_state_afinfo;
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.prefixlen_d = 128;
36 	x->sel.prefixlen_s = 128;
37 	x->sel.proto = fl->proto;
38 	x->sel.ifindex = fl->oif;
39 	x->id = tmpl->id;
40 	if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
41 		memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
42 	memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
43 	if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
44 		memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
45 	x->props.mode = tmpl->mode;
46 	x->props.reqid = tmpl->reqid;
47 	x->props.family = AF_INET6;
48 }
49 
50 static int
51 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
52 {
53 	int i;
54 	int j = 0;
55 
56 	/* Rule 1: select IPsec transport except AH */
57 	for (i = 0; i < n; i++) {
58 		if (src[i]->props.mode == XFRM_MODE_TRANSPORT &&
59 		    src[i]->id.proto != IPPROTO_AH) {
60 			dst[j++] = src[i];
61 			src[i] = NULL;
62 		}
63 	}
64 	if (j == n)
65 		goto end;
66 
67 	/* Rule 2: select MIPv6 RO or inbound trigger */
68 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
69 	for (i = 0; i < n; i++) {
70 		if (src[i] &&
71 		    (src[i]->props.mode == XFRM_MODE_ROUTEOPTIMIZATION ||
72 		     src[i]->props.mode == XFRM_MODE_IN_TRIGGER)) {
73 			dst[j++] = src[i];
74 			src[i] = NULL;
75 		}
76 	}
77 	if (j == n)
78 		goto end;
79 #endif
80 
81 	/* Rule 3: select IPsec transport AH */
82 	for (i = 0; i < n; i++) {
83 		if (src[i] &&
84 		    src[i]->props.mode == XFRM_MODE_TRANSPORT &&
85 		    src[i]->id.proto == IPPROTO_AH) {
86 			dst[j++] = src[i];
87 			src[i] = NULL;
88 		}
89 	}
90 	if (j == n)
91 		goto end;
92 
93 	/* Rule 4: select IPsec tunnel */
94 	for (i = 0; i < n; i++) {
95 		if (src[i] &&
96 		    (src[i]->props.mode == XFRM_MODE_TUNNEL ||
97 		     src[i]->props.mode == XFRM_MODE_BEET)) {
98 			dst[j++] = src[i];
99 			src[i] = NULL;
100 		}
101 	}
102 	if (likely(j == n))
103 		goto end;
104 
105 	/* Final rule */
106 	for (i = 0; i < n; i++) {
107 		if (src[i]) {
108 			dst[j++] = src[i];
109 			src[i] = NULL;
110 		}
111 	}
112 
113  end:
114 	return 0;
115 }
116 
117 static int
118 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
119 {
120 	int i;
121 	int j = 0;
122 
123 	/* Rule 1: select IPsec transport */
124 	for (i = 0; i < n; i++) {
125 		if (src[i]->mode == XFRM_MODE_TRANSPORT) {
126 			dst[j++] = src[i];
127 			src[i] = NULL;
128 		}
129 	}
130 	if (j == n)
131 		goto end;
132 
133 	/* Rule 2: select MIPv6 RO or inbound trigger */
134 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
135 	for (i = 0; i < n; i++) {
136 		if (src[i] &&
137 		    (src[i]->mode == XFRM_MODE_ROUTEOPTIMIZATION ||
138 		     src[i]->mode == XFRM_MODE_IN_TRIGGER)) {
139 			dst[j++] = src[i];
140 			src[i] = NULL;
141 		}
142 	}
143 	if (j == n)
144 		goto end;
145 #endif
146 
147 	/* Rule 3: select IPsec tunnel */
148 	for (i = 0; i < n; i++) {
149 		if (src[i] &&
150 		    (src[i]->mode == XFRM_MODE_TUNNEL ||
151 		     src[i]->mode == XFRM_MODE_BEET)) {
152 			dst[j++] = src[i];
153 			src[i] = NULL;
154 		}
155 	}
156 	if (likely(j == n))
157 		goto end;
158 
159 	/* Final rule */
160 	for (i = 0; i < n; i++) {
161 		if (src[i]) {
162 			dst[j++] = src[i];
163 			src[i] = NULL;
164 		}
165 	}
166 
167  end:
168 	return 0;
169 }
170 
171 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
172 	.family			= AF_INET6,
173 	.owner			= THIS_MODULE,
174 	.init_tempsel		= __xfrm6_init_tempsel,
175 	.tmpl_sort		= __xfrm6_tmpl_sort,
176 	.state_sort		= __xfrm6_state_sort,
177 	.output			= xfrm6_output,
178 };
179 
180 void __init xfrm6_state_init(void)
181 {
182 	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