2 * IPV6 GSO/GRO offload support
3 * Linux INET implementation
5 * Copyright (C) 2016 secunet Security Networks AG
6 * Author: Steffen Klassert <steffen.klassert@secunet.com>
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.
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>
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>
31 #include <linux/icmpv6.h>
33 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
35 int off = sizeof(struct ipv6hdr);
36 struct ipv6_opt_hdr *exthdr;
38 if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
39 return offsetof(struct ipv6hdr, nexthdr);
42 exthdr = (void *)ipv6_hdr + off;
43 if (exthdr->nexthdr == NEXTHDR_ESP)
46 off += ipv6_optlen(exthdr);
52 static struct sk_buff **esp6_gro_receive(struct sk_buff **head,
55 int offset = skb_gro_offset(skb);
56 struct xfrm_offload *xo;
63 if (!pskb_pull(skb, offset))
66 if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
69 xo = xfrm_offload(skb);
70 if (!xo || !(xo->flags & CRYPTO_DONE)) {
71 err = secpath_set(skb);
75 if (skb->sp->len == XFRM_MAX_DEPTH)
78 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
79 (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
80 spi, IPPROTO_ESP, AF_INET6);
84 skb->sp->xvec[skb->sp->len++] = x;
87 xo = xfrm_offload(skb);
94 xo->flags |= XFRM_GRO;
96 nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
100 IP6CB(skb)->nhoff = nhoff;
101 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
102 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
103 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
104 XFRM_SPI_SKB_CB(skb)->seq = seq;
106 /* We don't need to handle errors from xfrm_input, it does all
107 * the error handling and frees the resources on error. */
108 xfrm_input(skb, IPPROTO_ESP, spi, -2);
110 return ERR_PTR(-EINPROGRESS);
112 skb_push(skb, offset);
113 NAPI_GRO_CB(skb)->same_flow = 0;
114 NAPI_GRO_CB(skb)->flush = 1;
119 static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
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;
126 skb_push(skb, -skb_network_offset(skb));
128 if (x->outer_mode->encap == XFRM_MODE_TRANSPORT) {
131 ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, &frag);
134 esph = ip_esp_hdr(skb);
135 *skb_mac_header(skb) = IPPROTO_ESP;
137 esph->spi = x->id.spi;
138 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
143 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
144 netdev_features_t features)
148 struct sk_buff *skb2;
149 struct xfrm_state *x;
150 struct ip_esp_hdr *esph;
151 struct crypto_aead *aead;
152 struct sk_buff *segs = ERR_PTR(-EINVAL);
153 netdev_features_t esp_features = features;
154 struct xfrm_offload *xo = xfrm_offload(skb);
159 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
164 x = skb->sp->xvec[skb->sp->len - 1];
166 esph = ip_esp_hdr(skb);
168 if (esph->spi != x->id.spi)
171 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
174 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
176 skb->encap_hdr_csum = 1;
178 if (!(features & NETIF_F_HW_ESP))
179 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
181 segs = x->outer_mode->gso_segment(x, skb, esp_features);
182 if (IS_ERR_OR_NULL(segs))
185 __skb_pull(skb, skb->data - skb_mac_header(skb));
189 struct sk_buff *nskb = skb2->next;
191 xo = xfrm_offload(skb2);
192 xo->flags |= XFRM_GSO_SEGMENT;
194 xo->seq.hi = xfrm_replay_seqhi(x, seq);
196 if(!(features & NETIF_F_HW_ESP))
197 xo->flags |= CRYPTO_FALLBACK;
199 x->outer_mode->xmit(x, skb2);
201 err = x->type_offload->xmit(x, skb2, esp_features);
203 kfree_skb_list(segs);
207 if (!skb_is_gso(skb2))
210 seq += skb_shinfo(skb2)->gso_segs;
212 skb_push(skb2, skb2->mac_len);
220 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
222 struct crypto_aead *aead = x->data;
223 struct xfrm_offload *xo = xfrm_offload(skb);
225 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
228 if (!(xo->flags & CRYPTO_DONE))
229 skb->ip_summed = CHECKSUM_NONE;
231 return esp6_input_done2(skb, 0);
234 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
239 struct xfrm_offload *xo;
240 struct ip_esp_hdr *esph;
241 struct crypto_aead *aead;
243 bool hw_offload = true;
247 xo = xfrm_offload(skb);
252 if (!(features & NETIF_F_HW_ESP) || !x->xso.offload_handle ||
253 (x->xso.dev != skb->dev)) {
254 xo->flags |= CRYPTO_FALLBACK;
258 esp.proto = xo->proto;
260 /* skb is pure payload to encrypt */
263 alen = crypto_aead_authsize(aead);
266 /* XXX: Add support for tfc padding here. */
268 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
269 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
270 esp.plen = esp.clen - skb->len - esp.tfclen;
271 esp.tailen = esp.tfclen + esp.plen + alen;
273 if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
274 esp.nfrags = esp6_output_head(x, skb, &esp);
279 esph = ip_esp_hdr(skb);
280 esph->spi = x->id.spi;
282 skb_push(skb, -skb_network_offset(skb));
284 if (xo->flags & XFRM_GSO_SEGMENT) {
285 esph->seq_no = htonl(xo->seq.low);
289 len = skb->len - sizeof(struct ipv6hdr);
290 if (len > IPV6_MAXPLEN)
293 ipv6_hdr(skb)->payload_len = htons(len);
299 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
301 err = esp6_output_tail(x, skb, &esp);
307 if (skb_needs_linearize(skb, skb->dev->features) &&
308 __skb_linearize(skb))
313 static const struct net_offload esp6_offload = {
315 .gro_receive = esp6_gro_receive,
316 .gso_segment = esp6_gso_segment,
320 static const struct xfrm_type_offload esp6_type_offload = {
321 .description = "ESP6 OFFLOAD",
322 .owner = THIS_MODULE,
323 .proto = IPPROTO_ESP,
324 .input_tail = esp6_input_tail,
326 .encap = esp6_gso_encap,
329 static int __init esp6_offload_init(void)
331 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
332 pr_info("%s: can't add xfrm type offload\n", __func__);
336 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
339 static void __exit esp6_offload_exit(void)
341 if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
342 pr_info("%s: can't remove xfrm type offload\n", __func__);
344 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
347 module_init(esp6_offload_init);
348 module_exit(esp6_offload_exit);
349 MODULE_LICENSE("GPL");
350 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
351 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);