aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv6/ila/ila_lwt.c
blob: 2ae3c4fd8aabc65a7206a73480b3dca4b975f7e3 (plain) (blame)
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
#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/ip.h>
#include <net/ip6_fib.h>
#include <net/lwtunnel.h>
#include <net/protocol.h>
#include <uapi/linux/ila.h>
#include "ila.h"

static inline struct ila_params *ila_params_lwtunnel(
	struct lwtunnel_state *lwstate)
{
	return (struct ila_params *)lwstate->data;
}

static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);

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

	update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));

	return dst->lwtstate->orig_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;

	update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));

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

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

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

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

	if (family != AF_INET6)
		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(encap_len);
	if (!newts)
		return -ENOMEM;

	newts->len = encap_len;
	p = ila_params_lwtunnel(newts);

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

	if (cfg6->fc_dst_len > sizeof(__be64)) {
		/* Precompute checksum difference for translation since we
		 * know both the old locator and the new one.
		 */
		p->locator_match = *(__be64 *)&cfg6->fc_dst;
		p->csum_diff = compute_csum_diff8(
			(__be32 *)&p->locator_match, (__be32 *)&p->locator);
	}

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

	*ts = newts;

	return 0;
}

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(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
{
	/* No encapsulation overhead */
	return 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 != b_p->locator);
}

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

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);
}