summaryrefslogtreecommitdiffstats
path: root/net/ipv6/xfrm6_policy.c
blob: da87428681cccc9d955fdc80ee6f8bd4998356dd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
/*
 * xfrm6_policy.c: based on xfrm4_policy.c
 *
 * Authors:
 *	Mitsuru KANDA @USAGI
 * 	Kazunori MIYAZAWA @USAGI
 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 * 		IPv6 support
 * 	YOSHIFUJI Hideaki
 * 		Split up af-specific portion
 *
 */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <net/addrconf.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
#include <net/mip6.h>
#endif

static struct xfrm_policy_afinfo xfrm6_policy_afinfo;

static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos,
					  xfrm_address_t *saddr,
					  xfrm_address_t *daddr)
{
	struct flowi fl = {};
	struct dst_entry *dst;
	int err;

	memcpy(&fl.fl6_dst, daddr, sizeof(fl.fl6_dst));
	if (saddr)
		memcpy(&fl.fl6_src, saddr, sizeof(fl.fl6_src));

	dst = ip6_route_output(net, NULL, &fl);

	err = dst->error;
	if (dst->error) {
		dst_release(dst);
		dst = ERR_PTR(err);
	}

	return dst;
}

static int xfrm6_get_saddr(struct net *net,
			   xfrm_address_t *saddr, xfrm_address_t *daddr)
{
	struct dst_entry *dst;
	struct net_device *dev;

	dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
	if (IS_ERR(dst))
		return -EHOSTUNREACH;

	dev = ip6_dst_idev(dst)->dev;
	ipv6_dev_get_saddr(dev_net(dev), dev,
			   (struct in6_addr *)&daddr->a6, 0,
			   (struct in6_addr *)&saddr->a6);
	dst_release(dst);
	return 0;
}

static int xfrm6_get_tos(struct flowi *fl)
{
	return 0;
}

static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
			   int nfheader_len)
{
	if (dst->ops->family == AF_INET6) {
		struct rt6_info *rt = (struct rt6_info*)dst;
		if (rt->rt6i_node)
			path->path_cookie = rt->rt6i_node->fn_sernum;
	}

	path->u.rt6.rt6i_nfheader_len = nfheader_len;

	return 0;
}

static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
			  struct flowi *fl)
{
	struct rt6_info *rt = (struct rt6_info*)xdst->route;

	xdst->u.dst.dev = dev;
	dev_hold(dev);

	xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
	if (!xdst->u.rt6.rt6i_idev)
		return -ENODEV;

	xdst->u.rt6.rt6i_peer = rt->rt6i_peer;
	if (rt->rt6i_peer)
		atomic_inc(&rt->rt6i_peer->refcnt);

	/* Sheit... I remember I did this right. Apparently,
	 * it was magically lost, so this code needs audit */
	xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
						   RTF_LOCAL);
	xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
	xdst->u.rt6.rt6i_node = rt->rt6i_node;
	if (rt->rt6i_node)
		xdst->route_cookie = rt->rt6i_node->fn_sernum;
	xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
	xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
	xdst->u.rt6.rt6i_src = rt->rt6i_src;

	return 0;
}

static inline void
_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
{
	int onlyproto = 0;
	u16 offset = skb_network_header_len(skb);
	struct ipv6hdr *hdr = ipv6_hdr(skb);
	struct ipv6_opt_hdr *exthdr;
	const unsigned char *nh = skb_network_header(skb);
	u8 nexthdr = nh[IP6CB(skb)->nhoff];

	memset(fl, 0, sizeof(struct flowi));
	fl->mark = skb->mark;

	ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr);
	ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr);

	while (nh + offset + 1 < skb->data ||
	       pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
		nh = skb_network_header(skb);
		exthdr = (struct ipv6_opt_hdr *)(nh + offset);

		switch (nexthdr) {
		case NEXTHDR_FRAGMENT:
			onlyproto = 1;
		case NEXTHDR_ROUTING:
		case NEXTHDR_HOP:
		case NEXTHDR_DEST:
			offset += ipv6_optlen(exthdr);
			nexthdr = exthdr->nexthdr;
			exthdr = (struct ipv6_opt_hdr *)(nh + offset);
			break;

		case IPPROTO_UDP:
		case IPPROTO_UDPLITE:
		case IPPROTO_TCP:
		case IPPROTO_SCTP:
		case IPPROTO_DCCP:
			if (!onlyproto && (nh + offset + 4 < skb->data ||
			     pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
				__be16 *ports = (__be16 *)exthdr;

				fl->fl_ip_sport = ports[!!reverse];
				fl->fl_ip_dport = ports[!reverse];
			}
			fl->proto = nexthdr;
			return;

		case IPPROTO_ICMPV6:
			if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
				u8 *icmp = (u8 *)exthdr;

				fl->fl_icmp_type = icmp[0];
				fl->fl_icmp_code = icmp[1];
			}
			fl->proto = nexthdr;
			return;

#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
		case IPPROTO_MH:
			if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
				struct ip6_mh *mh;
				mh = (struct ip6_mh *)exthdr;

				fl->fl_mh_type = mh->ip6mh_type;
			}
			fl->proto = nexthdr;
			return;
#endif

		/* XXX Why are there these headers? */
		case IPPROTO_AH:
		case IPPROTO_ESP:
		case IPPROTO_COMP:
		default:
			fl->fl_ipsec_spi = 0;
			fl->proto = nexthdr;
			return;
		}
	}
}

static inline int xfrm6_garbage_collect(struct dst_ops *ops)
{
	struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);

	xfrm6_policy_afinfo.garbage_collect(net);
	return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
}

static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
{
	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
	struct dst_entry *path = xdst->route;

	path->ops->update_pmtu(path, mtu);
}

static void xfrm6_dst_destroy(struct dst_entry *dst)
{
	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;

	if (likely(xdst->u.rt6.rt6i_idev))
		in6_dev_put(xdst->u.rt6.rt6i_idev);
	if (likely(xdst->u.rt6.rt6i_peer))
		inet_putpeer(xdst->u.rt6.rt6i_peer);
	xfrm_dst_destroy(xdst);
}

static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
			     int unregister)
{
	struct xfrm_dst *xdst;

	if (!unregister)
		return;

	xdst = (struct xfrm_dst *)dst;
	if (xdst->u.rt6.rt6i_idev->dev == dev) {
		struct inet6_dev *loopback_idev =
			in6_dev_get(dev_net(dev)->loopback_dev);
		BUG_ON(!loopback_idev);

		do {
			in6_dev_put(xdst->u.rt6.rt6i_idev);
			xdst->u.rt6.rt6i_idev = loopback_idev;
			in6_dev_hold(loopback_idev);
			xdst = (struct xfrm_dst *)xdst->u.dst.child;
		} while (xdst->u.dst.xfrm);

		__in6_dev_put(loopback_idev);
	}

	xfrm_dst_ifdown(dst, dev);
}

static struct dst_ops xfrm6_dst_ops = {
	.family =		AF_INET6,
	.protocol =		cpu_to_be16(ETH_P_IPV6),
	.gc =			xfrm6_garbage_collect,
	.update_pmtu =		xfrm6_update_pmtu,
	.destroy =		xfrm6_dst_destroy,
	.ifdown =		xfrm6_dst_ifdown,
	.local_out =		__ip6_local_out,
	.gc_thresh =		1024,
};

static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
	.family =		AF_INET6,
	.dst_ops =		&xfrm6_dst_ops,
	.dst_lookup =		xfrm6_dst_lookup,
	.get_saddr = 		xfrm6_get_saddr,
	.decode_session =	_decode_session6,
	.get_tos =		xfrm6_get_tos,
	.init_path =		xfrm6_init_path,
	.fill_dst =		xfrm6_fill_dst,
};

static int __init xfrm6_policy_init(void)
{
	return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
}

static void xfrm6_policy_fini(void)
{
	xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
}

#ifdef CONFIG_SYSCTL
static struct ctl_table xfrm6_policy_table[] = {
	{
		.procname       = "xfrm6_gc_thresh",
		.data	   	= &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
		.maxlen	 	= sizeof(int),
		.mode	   	= 0644,
		.proc_handler   = proc_dointvec,
	},
	{ }
};

static struct ctl_table_header *sysctl_hdr;
#endif

int __init xfrm6_init(void)
{
	int ret;
	unsigned int gc_thresh;

	/*
	 * We need a good default value for the xfrm6 gc threshold.
	 * In ipv4 we set it to the route hash table size * 8, which
	 * is half the size of the maximaum route cache for ipv4.  It
	 * would be good to do the same thing for v6, except the table is
	 * constructed differently here.  Here each table for a net namespace
	 * can have FIB_TABLE_HASHSZ entries, so lets go with the same
	 * computation that we used for ipv4 here.  Also, lets keep the initial
	 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults
	 * to that as a minimum as well
	 */
	gc_thresh = FIB6_TABLE_HASHSZ * 8;
	xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
	dst_entries_init(&xfrm6_dst_ops);

	ret = xfrm6_policy_init();
	if (ret) {
		dst_entries_destroy(&xfrm6_dst_ops);
		goto out;
	}
	ret = xfrm6_state_init();
	if (ret)
		goto out_policy;

#ifdef CONFIG_SYSCTL
	sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path,
						xfrm6_policy_table);
#endif
out:
	return ret;
out_policy:
	xfrm6_policy_fini();
	goto out;
}

void xfrm6_fini(void)
{
#ifdef CONFIG_SYSCTL
	if (sysctl_hdr)
		unregister_net_sysctl_table(sysctl_hdr);
#endif
	//xfrm6_input_fini();
	xfrm6_policy_fini();
	xfrm6_state_fini();
	dst_entries_destroy(&xfrm6_dst_ops);
}