xref: /openbmc/linux/net/ipv6/esp6_offload.c (revision f7c35abe)
1 /*
2  * IPV6 GSO/GRO offload support
3  * Linux INET implementation
4  *
5  * Copyright (C) 2016 secunet Security Networks AG
6  * Author: Steffen Klassert <steffen.klassert@secunet.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * ESP GRO support
13  */
14 
15 #include <linux/skbuff.h>
16 #include <linux/init.h>
17 #include <net/protocol.h>
18 #include <crypto/aead.h>
19 #include <crypto/authenc.h>
20 #include <linux/err.h>
21 #include <linux/module.h>
22 #include <net/ip.h>
23 #include <net/xfrm.h>
24 #include <net/esp.h>
25 #include <linux/scatterlist.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <net/ip6_route.h>
30 #include <net/ipv6.h>
31 #include <linux/icmpv6.h>
32 
33 static struct sk_buff **esp6_gro_receive(struct sk_buff **head,
34 					 struct sk_buff *skb)
35 {
36 	int offset = skb_gro_offset(skb);
37 	struct xfrm_offload *xo;
38 	struct xfrm_state *x;
39 	__be32 seq;
40 	__be32 spi;
41 	int err;
42 
43 	skb_pull(skb, offset);
44 
45 	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
46 		goto out;
47 
48 	err = secpath_set(skb);
49 	if (err)
50 		goto out;
51 
52 	if (skb->sp->len == XFRM_MAX_DEPTH)
53 		goto out;
54 
55 	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
56 			      (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
57 			      spi, IPPROTO_ESP, AF_INET6);
58 	if (!x)
59 		goto out;
60 
61 	skb->sp->xvec[skb->sp->len++] = x;
62 	skb->sp->olen++;
63 
64 	xo = xfrm_offload(skb);
65 	if (!xo) {
66 		xfrm_state_put(x);
67 		goto out;
68 	}
69 	xo->flags |= XFRM_GRO;
70 
71 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
72 	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
73 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
74 	XFRM_SPI_SKB_CB(skb)->seq = seq;
75 
76 	/* We don't need to handle errors from xfrm_input, it does all
77 	 * the error handling and frees the resources on error. */
78 	xfrm_input(skb, IPPROTO_ESP, spi, -2);
79 
80 	return ERR_PTR(-EINPROGRESS);
81 out:
82 	skb_push(skb, offset);
83 	NAPI_GRO_CB(skb)->same_flow = 0;
84 	NAPI_GRO_CB(skb)->flush = 1;
85 
86 	return NULL;
87 }
88 
89 static const struct net_offload esp6_offload = {
90 	.callbacks = {
91 		.gro_receive = esp6_gro_receive,
92 	},
93 };
94 
95 static int __init esp6_offload_init(void)
96 {
97 	return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
98 }
99 
100 static void __exit esp6_offload_exit(void)
101 {
102 	inet6_del_offload(&esp6_offload, IPPROTO_ESP);
103 }
104 
105 module_init(esp6_offload_init);
106 module_exit(esp6_offload_exit);
107 MODULE_LICENSE("GPL");
108 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
109