net/ipv6/esp6_offload.c

   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>");