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 list_head *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 struct sec_path *sp = secpath_set(skb);
76 if (sp->len == XFRM_MAX_DEPTH)
79 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
80 (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
81 spi, IPPROTO_ESP, AF_INET6);
85 sp->xvec[sp->len++] = x;
88 xo = xfrm_offload(skb);
95 xo->flags |= XFRM_GRO;
97 nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
101 IP6CB(skb)->nhoff = nhoff;
102 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
103 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
104 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
105 XFRM_SPI_SKB_CB(skb)->seq = seq;
107 /* We don't need to handle errors from xfrm_input, it does all
108 * the error handling and frees the resources on error. */
109 xfrm_input(skb, IPPROTO_ESP, spi, -2);
111 return ERR_PTR(-EINPROGRESS);
113 skb_push(skb, offset);
114 NAPI_GRO_CB(skb)->same_flow = 0;
115 NAPI_GRO_CB(skb)->flush = 1;
120 static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
122 struct ip_esp_hdr *esph;
123 struct ipv6hdr *iph = ipv6_hdr(skb);
124 struct xfrm_offload *xo = xfrm_offload(skb);
125 int proto = iph->nexthdr;
127 skb_push(skb, -skb_network_offset(skb));
128 esph = ip_esp_hdr(skb);
129 *skb_mac_header(skb) = IPPROTO_ESP;
131 esph->spi = x->id.spi;
132 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
137 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
138 netdev_features_t features)
140 struct xfrm_state *x;
141 struct ip_esp_hdr *esph;
142 struct crypto_aead *aead;
143 netdev_features_t esp_features = features;
144 struct xfrm_offload *xo = xfrm_offload(skb);
148 return ERR_PTR(-EINVAL);
150 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
151 return ERR_PTR(-EINVAL);
153 sp = skb_sec_path(skb);
154 x = sp->xvec[sp->len - 1];
156 esph = ip_esp_hdr(skb);
158 if (esph->spi != x->id.spi)
159 return ERR_PTR(-EINVAL);
161 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
162 return ERR_PTR(-EINVAL);
164 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
166 skb->encap_hdr_csum = 1;
168 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
169 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
170 else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
171 esp_features = features & ~NETIF_F_CSUM_MASK;
173 xo->flags |= XFRM_GSO_SEGMENT;
175 return x->outer_mode->gso_segment(x, skb, esp_features);
178 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
180 struct crypto_aead *aead = x->data;
181 struct xfrm_offload *xo = xfrm_offload(skb);
183 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
186 if (!(xo->flags & CRYPTO_DONE))
187 skb->ip_summed = CHECKSUM_NONE;
189 return esp6_input_done2(skb, 0);
192 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
198 struct xfrm_offload *xo;
199 struct ip_esp_hdr *esph;
200 struct crypto_aead *aead;
202 bool hw_offload = true;
207 xo = xfrm_offload(skb);
212 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
213 xo->flags |= CRYPTO_FALLBACK;
217 esp.proto = xo->proto;
219 /* skb is pure payload to encrypt */
222 alen = crypto_aead_authsize(aead);
225 /* XXX: Add support for tfc padding here. */
227 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
228 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
229 esp.plen = esp.clen - skb->len - esp.tfclen;
230 esp.tailen = esp.tfclen + esp.plen + alen;
232 if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
233 esp.nfrags = esp6_output_head(x, skb, &esp);
240 esph = ip_esp_hdr(skb);
241 esph->spi = x->id.spi;
243 skb_push(skb, -skb_network_offset(skb));
245 if (xo->flags & XFRM_GSO_SEGMENT) {
246 esph->seq_no = htonl(seq);
248 if (!skb_is_gso(skb))
251 xo->seq.low += skb_shinfo(skb)->gso_segs;
254 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
256 len = skb->len - sizeof(struct ipv6hdr);
257 if (len > IPV6_MAXPLEN)
260 ipv6_hdr(skb)->payload_len = htons(len);
265 err = esp6_output_tail(x, skb, &esp);
274 static const struct net_offload esp6_offload = {
276 .gro_receive = esp6_gro_receive,
277 .gso_segment = esp6_gso_segment,
281 static const struct xfrm_type_offload esp6_type_offload = {
282 .description = "ESP6 OFFLOAD",
283 .owner = THIS_MODULE,
284 .proto = IPPROTO_ESP,
285 .input_tail = esp6_input_tail,
287 .encap = esp6_gso_encap,
290 static int __init esp6_offload_init(void)
292 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
293 pr_info("%s: can't add xfrm type offload\n", __func__);
297 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
300 static void __exit esp6_offload_exit(void)
302 if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
303 pr_info("%s: can't remove xfrm type offload\n", __func__);
305 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
308 module_init(esp6_offload_init);
309 module_exit(esp6_offload_exit);
310 MODULE_LICENSE("GPL");
311 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
312 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);