root/net/ipv6/esp6_offload.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. esp6_nexthdr_esp_offset
  2. esp6_gro_receive
  3. esp6_gso_encap
  4. xfrm6_tunnel_gso_segment
  5. xfrm6_transport_gso_segment
  6. xfrm6_outer_mode_gso_segment
  7. esp6_gso_segment
  8. esp6_input_tail
  9. esp6_xmit
  10. esp6_offload_init
  11. esp6_offload_exit

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * IPV6 GSO/GRO offload support
   4  * Linux INET implementation
   5  *
   6  * Copyright (C) 2016 secunet Security Networks AG
   7  * Author: Steffen Klassert <steffen.klassert@secunet.com>
   8  *
   9  * ESP GRO support
  10  */
  11 
  12 #include <linux/skbuff.h>
  13 #include <linux/init.h>
  14 #include <net/protocol.h>
  15 #include <crypto/aead.h>
  16 #include <crypto/authenc.h>
  17 #include <linux/err.h>
  18 #include <linux/module.h>
  19 #include <net/ip.h>
  20 #include <net/xfrm.h>
  21 #include <net/esp.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/kernel.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26 #include <net/ip6_route.h>
  27 #include <net/ipv6.h>
  28 #include <linux/icmpv6.h>
  29 
  30 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
  31 {
  32         int off = sizeof(struct ipv6hdr);
  33         struct ipv6_opt_hdr *exthdr;
  34 
  35         if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
  36                 return offsetof(struct ipv6hdr, nexthdr);
  37 
  38         while (off < nhlen) {
  39                 exthdr = (void *)ipv6_hdr + off;
  40                 if (exthdr->nexthdr == NEXTHDR_ESP)
  41                         return off;
  42 
  43                 off += ipv6_optlen(exthdr);
  44         }
  45 
  46         return 0;
  47 }
  48 
  49 static struct sk_buff *esp6_gro_receive(struct list_head *head,
  50                                         struct sk_buff *skb)
  51 {
  52         int offset = skb_gro_offset(skb);
  53         struct xfrm_offload *xo;
  54         struct xfrm_state *x;
  55         __be32 seq;
  56         __be32 spi;
  57         int nhoff;
  58         int err;
  59 
  60         if (!pskb_pull(skb, offset))
  61                 return NULL;
  62 
  63         if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
  64                 goto out;
  65 
  66         xo = xfrm_offload(skb);
  67         if (!xo || !(xo->flags & CRYPTO_DONE)) {
  68                 struct sec_path *sp = secpath_set(skb);
  69 
  70                 if (!sp)
  71                         goto out;
  72 
  73                 if (sp->len == XFRM_MAX_DEPTH)
  74                         goto out_reset;
  75 
  76                 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
  77                                       (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
  78                                       spi, IPPROTO_ESP, AF_INET6);
  79                 if (!x)
  80                         goto out_reset;
  81 
  82                 skb->mark = xfrm_smark_get(skb->mark, x);
  83 
  84                 sp->xvec[sp->len++] = x;
  85                 sp->olen++;
  86 
  87                 xo = xfrm_offload(skb);
  88                 if (!xo)
  89                         goto out_reset;
  90         }
  91 
  92         xo->flags |= XFRM_GRO;
  93 
  94         nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
  95         if (!nhoff)
  96                 goto out;
  97 
  98         IP6CB(skb)->nhoff = nhoff;
  99         XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
 100         XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
 101         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
 102         XFRM_SPI_SKB_CB(skb)->seq = seq;
 103 
 104         /* We don't need to handle errors from xfrm_input, it does all
 105          * the error handling and frees the resources on error. */
 106         xfrm_input(skb, IPPROTO_ESP, spi, -2);
 107 
 108         return ERR_PTR(-EINPROGRESS);
 109 out_reset:
 110         secpath_reset(skb);
 111 out:
 112         skb_push(skb, offset);
 113         NAPI_GRO_CB(skb)->same_flow = 0;
 114         NAPI_GRO_CB(skb)->flush = 1;
 115 
 116         return NULL;
 117 }
 118 
 119 static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
 120 {
 121         struct ip_esp_hdr *esph;
 122         struct ipv6hdr *iph = ipv6_hdr(skb);
 123         struct xfrm_offload *xo = xfrm_offload(skb);
 124         u8 proto = iph->nexthdr;
 125 
 126         skb_push(skb, -skb_network_offset(skb));
 127 
 128         if (x->outer_mode.encap == XFRM_MODE_TRANSPORT) {
 129                 __be16 frag;
 130 
 131                 ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, &frag);
 132         }
 133 
 134         esph = ip_esp_hdr(skb);
 135         *skb_mac_header(skb) = IPPROTO_ESP;
 136 
 137         esph->spi = x->id.spi;
 138         esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 139 
 140         xo->proto = proto;
 141 }
 142 
 143 static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
 144                                                 struct sk_buff *skb,
 145                                                 netdev_features_t features)
 146 {
 147         __skb_push(skb, skb->mac_len);
 148         return skb_mac_gso_segment(skb, features);
 149 }
 150 
 151 static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
 152                                                    struct sk_buff *skb,
 153                                                    netdev_features_t features)
 154 {
 155         const struct net_offload *ops;
 156         struct sk_buff *segs = ERR_PTR(-EINVAL);
 157         struct xfrm_offload *xo = xfrm_offload(skb);
 158 
 159         skb->transport_header += x->props.header_len;
 160         ops = rcu_dereference(inet6_offloads[xo->proto]);
 161         if (likely(ops && ops->callbacks.gso_segment))
 162                 segs = ops->callbacks.gso_segment(skb, features);
 163 
 164         return segs;
 165 }
 166 
 167 static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
 168                                                     struct sk_buff *skb,
 169                                                     netdev_features_t features)
 170 {
 171         switch (x->outer_mode.encap) {
 172         case XFRM_MODE_TUNNEL:
 173                 return xfrm6_tunnel_gso_segment(x, skb, features);
 174         case XFRM_MODE_TRANSPORT:
 175                 return xfrm6_transport_gso_segment(x, skb, features);
 176         }
 177 
 178         return ERR_PTR(-EOPNOTSUPP);
 179 }
 180 
 181 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
 182                                         netdev_features_t features)
 183 {
 184         struct xfrm_state *x;
 185         struct ip_esp_hdr *esph;
 186         struct crypto_aead *aead;
 187         netdev_features_t esp_features = features;
 188         struct xfrm_offload *xo = xfrm_offload(skb);
 189         struct sec_path *sp;
 190 
 191         if (!xo)
 192                 return ERR_PTR(-EINVAL);
 193 
 194         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
 195                 return ERR_PTR(-EINVAL);
 196 
 197         sp = skb_sec_path(skb);
 198         x = sp->xvec[sp->len - 1];
 199         aead = x->data;
 200         esph = ip_esp_hdr(skb);
 201 
 202         if (esph->spi != x->id.spi)
 203                 return ERR_PTR(-EINVAL);
 204 
 205         if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
 206                 return ERR_PTR(-EINVAL);
 207 
 208         __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
 209 
 210         skb->encap_hdr_csum = 1;
 211 
 212         if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
 213                 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
 214         else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
 215                 esp_features = features & ~NETIF_F_CSUM_MASK;
 216 
 217         xo->flags |= XFRM_GSO_SEGMENT;
 218 
 219         return xfrm6_outer_mode_gso_segment(x, skb, esp_features);
 220 }
 221 
 222 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
 223 {
 224         struct crypto_aead *aead = x->data;
 225         struct xfrm_offload *xo = xfrm_offload(skb);
 226 
 227         if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
 228                 return -EINVAL;
 229 
 230         if (!(xo->flags & CRYPTO_DONE))
 231                 skb->ip_summed = CHECKSUM_NONE;
 232 
 233         return esp6_input_done2(skb, 0);
 234 }
 235 
 236 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_t features)
 237 {
 238         int len;
 239         int err;
 240         int alen;
 241         int blksize;
 242         struct xfrm_offload *xo;
 243         struct ip_esp_hdr *esph;
 244         struct crypto_aead *aead;
 245         struct esp_info esp;
 246         bool hw_offload = true;
 247         __u32 seq;
 248 
 249         esp.inplace = true;
 250 
 251         xo = xfrm_offload(skb);
 252 
 253         if (!xo)
 254                 return -EINVAL;
 255 
 256         if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
 257                 xo->flags |= CRYPTO_FALLBACK;
 258                 hw_offload = false;
 259         }
 260 
 261         esp.proto = xo->proto;
 262 
 263         /* skb is pure payload to encrypt */
 264 
 265         aead = x->data;
 266         alen = crypto_aead_authsize(aead);
 267 
 268         esp.tfclen = 0;
 269         /* XXX: Add support for tfc padding here. */
 270 
 271         blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 272         esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
 273         esp.plen = esp.clen - skb->len - esp.tfclen;
 274         esp.tailen = esp.tfclen + esp.plen + alen;
 275 
 276         if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
 277                 esp.nfrags = esp6_output_head(x, skb, &esp);
 278                 if (esp.nfrags < 0)
 279                         return esp.nfrags;
 280         }
 281 
 282         seq = xo->seq.low;
 283 
 284         esph = ip_esp_hdr(skb);
 285         esph->spi = x->id.spi;
 286 
 287         skb_push(skb, -skb_network_offset(skb));
 288 
 289         if (xo->flags & XFRM_GSO_SEGMENT) {
 290                 esph->seq_no = htonl(seq);
 291 
 292                 if (!skb_is_gso(skb))
 293                         xo->seq.low++;
 294                 else
 295                         xo->seq.low += skb_shinfo(skb)->gso_segs;
 296         }
 297 
 298         esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
 299 
 300         len = skb->len - sizeof(struct ipv6hdr);
 301         if (len > IPV6_MAXPLEN)
 302                 len = 0;
 303 
 304         ipv6_hdr(skb)->payload_len = htons(len);
 305 
 306         if (hw_offload)
 307                 return 0;
 308 
 309         err = esp6_output_tail(x, skb, &esp);
 310         if (err)
 311                 return err;
 312 
 313         secpath_reset(skb);
 314 
 315         return 0;
 316 }
 317 
 318 static const struct net_offload esp6_offload = {
 319         .callbacks = {
 320                 .gro_receive = esp6_gro_receive,
 321                 .gso_segment = esp6_gso_segment,
 322         },
 323 };
 324 
 325 static const struct xfrm_type_offload esp6_type_offload = {
 326         .description    = "ESP6 OFFLOAD",
 327         .owner          = THIS_MODULE,
 328         .proto          = IPPROTO_ESP,
 329         .input_tail     = esp6_input_tail,
 330         .xmit           = esp6_xmit,
 331         .encap          = esp6_gso_encap,
 332 };
 333 
 334 static int __init esp6_offload_init(void)
 335 {
 336         if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
 337                 pr_info("%s: can't add xfrm type offload\n", __func__);
 338                 return -EAGAIN;
 339         }
 340 
 341         return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
 342 }
 343 
 344 static void __exit esp6_offload_exit(void)
 345 {
 346         xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6);
 347         inet6_del_offload(&esp6_offload, IPPROTO_ESP);
 348 }
 349 
 350 module_init(esp6_offload_init);
 351 module_exit(esp6_offload_exit);
 352 MODULE_LICENSE("GPL");
 353 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
 354 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);

/* [<][>][^][v][top][bottom][index][help] */