summaryrefslogtreecommitdiffstats
path: root/net/ipv6/ila/ila_lwt.c
blob: 13b5e85fe0d56471ab792b1e75801def3800ee9c (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
#include <linux/errno.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/types.h>
#include <net/checksum.h>
#include <net/dst_cache.h>
#include <net/ip.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/lwtunnel.h>
#include <net/protocol.h>
#include <uapi/linux/ila.h>
#include "ila.h"

struct ila_lwt {
	struct ila_params p;
	struct dst_cache dst_cache;
	u32 connected : 1;
};

static inline struct ila_lwt *ila_lwt_lwtunnel(
	struct lwtunnel_state *lwt)
{
	return (struct ila_lwt *)lwt->data;
}

static inline struct ila_params *ila_params_lwtunnel(
	struct lwtunnel_state *lwt)
{
	return &ila_lwt_lwtunnel(lwt)->p;
}

static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *orig_dst = skb_dst(skb);
	struct rt6_info *rt = (struct rt6_info *)orig_dst;
	struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate);
	struct dst_entry *dst;
	int err = -EINVAL;

	if (skb->protocol != htons(ETH_P_IPV6))
		goto drop;

	ila_update_ipv6_locator(skb, ila_params_lwtunnel(orig_dst->lwtstate),
				true);

	if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
		/* Already have a next hop address in route, no need for
		 * dest cache route.
		 */
		return orig_dst->lwtstate->orig_output(net, sk, skb);
	}

	dst = dst_cache_get(&ilwt->dst_cache);
	if (unlikely(!dst)) {
		struct ipv6hdr *ip6h = ipv6_hdr(skb);
		struct flowi6 fl6;

		/* Lookup a route for the new destination. Take into
		 * account that the base route may already have a gateway.
		 */

		memset(&fl6, 0, sizeof(fl6));
		fl6.flowi6_oif = orig_dst->dev->ifindex;
		fl6.flowi6_iif = LOOPBACK_IFINDEX;
		fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst,
					 &ip6h->daddr);

		dst = ip6_route_output(net, NULL, &fl6);
		if (dst->error) {
			err = -EHOSTUNREACH;
			dst_release(dst);
			goto drop;
		}

		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
		if (IS_ERR(dst)) {
			err = PTR_ERR(dst);
			goto drop;
		}

		if (ilwt->connected)
			dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr);
	}

	skb_dst_set(skb, dst);
	return dst_output(net, sk, skb);

drop:
	kfree_skb(skb);
	return -EINVAL;
}

static int ila_input(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);

	if (skb->protocol != htons(ETH_P_IPV6))
		goto drop;

	ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), false);

	return dst->lwtstate->orig_input(skb);

drop:
	kfree_skb(skb);
	return -EINVAL;
}

static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
};

static int ila_build_state(struct net_device *dev, struct nlattr *nla,
			   unsigned int family, const void *cfg,
			   struct lwtunnel_state **ts)
{
	struct ila_lwt *ilwt;
	struct ila_params *p;
	struct nlattr *tb[ILA_ATTR_MAX + 1];
	struct lwtunnel_state *newts;
	const struct fib6_config *cfg6 = cfg;
	struct ila_addr *iaddr;
	int ret;

	if (family != AF_INET6)
		return -EINVAL;

	if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
		/* Need to have full locator and at least type field
		 * included in destination
		 */
		return -EINVAL;
	}

	iaddr = (struct ila_addr *)&cfg6->fc_dst;

	if (!ila_addr_is_ila(iaddr) || ila_csum_neutral_set(iaddr->ident)) {
		/* Don't allow translation for a non-ILA address or checksum
		 * neutral flag to be set.
		 */
		return -EINVAL;
	}

	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla,
			       ila_nl_policy);
	if (ret < 0)
		return ret;

	if (!tb[ILA_ATTR_LOCATOR])
		return -EINVAL;

	newts = lwtunnel_state_alloc(sizeof(*ilwt));
	if (!newts)
		return -ENOMEM;

	ilwt = ila_lwt_lwtunnel(newts);
	ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC);
	if (ret) {
		kfree(newts);
		return ret;
	}

	p = ila_params_lwtunnel(newts);

	p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);

	/* Precompute checksum difference for translation since we
	 * know both the old locator and the new one.
	 */
	p->locator_match = iaddr->loc;
	p->csum_diff = compute_csum_diff8(
		(__be32 *)&p->locator_match, (__be32 *)&p->locator);

	if (tb[ILA_ATTR_CSUM_MODE])
		p->csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);

	ila_init_saved_csum(p);

	newts->type = LWTUNNEL_ENCAP_ILA;
	newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
			LWTUNNEL_STATE_INPUT_REDIRECT;

	if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr))
		ilwt->connected = 1;

	*ts = newts;

	return 0;
}

static void ila_destroy_state(struct lwtunnel_state *lwt)
{
	dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache);
}

static int ila_fill_encap_info(struct sk_buff *skb,
			       struct lwtunnel_state *lwtstate)
{
	struct ila_params *p = ila_params_lwtunnel(lwtstate);

	if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
			      ILA_ATTR_PAD))
		goto nla_put_failure;
	if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
{
	return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_CSUM_MODE */
	       0;
}

static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
	struct ila_params *a_p = ila_params_lwtunnel(a);
	struct ila_params *b_p = ila_params_lwtunnel(b);

	return (a_p->locator.v64 != b_p->locator.v64);
}

static const struct lwtunnel_encap_ops ila_encap_ops = {
	.build_state = ila_build_state,
	.destroy_state = ila_destroy_state,
	.output = ila_output,
	.input = ila_input,
	.fill_encap = ila_fill_encap_info,
	.get_encap_size = ila_encap_nlsize,
	.cmp_encap = ila_encap_cmp,
	.owner = THIS_MODULE,
};

int ila_lwt_init(void)
{
	return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
}

void ila_lwt_fini(void)
{
	lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
}
OpenPOWER on IntegriCloud