1 // SPDX-License-Identifier: GPL-2.0-only
3 * IPV6 GSO/GRO offload support
4 * Linux INET implementation
6 * Copyright (C) 2016 secunet Security Networks AG
7 * Author: Steffen Klassert <steffen.klassert@secunet.com>
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>
23 #include <linux/scatterlist.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 #include <net/ip6_route.h>
29 #include <linux/icmpv6.h>
31 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
33 int off = sizeof(struct ipv6hdr);
34 struct ipv6_opt_hdr *exthdr;
36 if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
37 return offsetof(struct ipv6hdr, nexthdr);
40 exthdr = (void *)ipv6_hdr + off;
41 if (exthdr->nexthdr == NEXTHDR_ESP)
44 off += ipv6_optlen(exthdr);
50 static struct sk_buff *esp6_gro_receive(struct list_head *head,
53 int offset = skb_gro_offset(skb);
54 struct xfrm_offload *xo;
60 if (!pskb_pull(skb, offset))
63 if (xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq) != 0)
66 xo = xfrm_offload(skb);
67 if (!xo || !(xo->flags & CRYPTO_DONE)) {
68 struct sec_path *sp = secpath_set(skb);
73 if (sp->len == XFRM_MAX_DEPTH)
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);
82 skb->mark = xfrm_smark_get(skb->mark, x);
84 sp->xvec[sp->len++] = x;
87 xo = xfrm_offload(skb);
92 xo->flags |= XFRM_GRO;
94 nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
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;
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);
108 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 *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
145 netdev_features_t features)
147 __be16 type = x->inner_mode.family == AF_INET ? htons(ETH_P_IP)
150 return skb_eth_gso_segment(skb, features, type);
153 static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
155 netdev_features_t features)
157 const struct net_offload *ops;
158 struct sk_buff *segs = ERR_PTR(-EINVAL);
159 struct xfrm_offload *xo = xfrm_offload(skb);
161 skb->transport_header += x->props.header_len;
162 ops = rcu_dereference(inet6_offloads[xo->proto]);
163 if (likely(ops && ops->callbacks.gso_segment))
164 segs = ops->callbacks.gso_segment(skb, features);
169 static struct sk_buff *xfrm6_beet_gso_segment(struct xfrm_state *x,
171 netdev_features_t features)
173 struct xfrm_offload *xo = xfrm_offload(skb);
174 struct sk_buff *segs = ERR_PTR(-EINVAL);
175 const struct net_offload *ops;
176 u8 proto = xo->proto;
178 skb->transport_header += x->props.header_len;
180 if (x->sel.family != AF_INET6) {
181 skb->transport_header -=
182 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
184 if (proto == IPPROTO_BEETPH) {
185 struct ip_beet_phdr *ph =
186 (struct ip_beet_phdr *)skb->data;
188 skb->transport_header += ph->hdrlen * 8;
191 skb->transport_header -= IPV4_BEET_PHMAXLEN;
194 if (proto == IPPROTO_TCP)
195 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
199 skb->transport_header +=
200 ipv6_skip_exthdr(skb, 0, &proto, &frag);
203 if (proto == IPPROTO_IPIP)
204 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
206 __skb_pull(skb, skb_transport_offset(skb));
207 ops = rcu_dereference(inet6_offloads[proto]);
208 if (likely(ops && ops->callbacks.gso_segment))
209 segs = ops->callbacks.gso_segment(skb, features);
214 static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
216 netdev_features_t features)
218 switch (x->outer_mode.encap) {
219 case XFRM_MODE_TUNNEL:
220 return xfrm6_tunnel_gso_segment(x, skb, features);
221 case XFRM_MODE_TRANSPORT:
222 return xfrm6_transport_gso_segment(x, skb, features);
224 return xfrm6_beet_gso_segment(x, skb, features);
227 return ERR_PTR(-EOPNOTSUPP);
230 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
231 netdev_features_t features)
233 struct xfrm_state *x;
234 struct ip_esp_hdr *esph;
235 struct crypto_aead *aead;
236 netdev_features_t esp_features = features;
237 struct xfrm_offload *xo = xfrm_offload(skb);
241 return ERR_PTR(-EINVAL);
243 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
244 return ERR_PTR(-EINVAL);
246 sp = skb_sec_path(skb);
247 x = sp->xvec[sp->len - 1];
249 esph = ip_esp_hdr(skb);
251 if (esph->spi != x->id.spi)
252 return ERR_PTR(-EINVAL);
254 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
255 return ERR_PTR(-EINVAL);
257 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
259 skb->encap_hdr_csum = 1;
261 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
262 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK |
264 else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
265 esp_features = features & ~(NETIF_F_CSUM_MASK |
268 xo->flags |= XFRM_GSO_SEGMENT;
270 return xfrm6_outer_mode_gso_segment(x, skb, esp_features);
273 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
275 struct crypto_aead *aead = x->data;
276 struct xfrm_offload *xo = xfrm_offload(skb);
278 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
281 if (!(xo->flags & CRYPTO_DONE))
282 skb->ip_summed = CHECKSUM_NONE;
284 return esp6_input_done2(skb, 0);
287 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
293 struct xfrm_offload *xo;
294 struct crypto_aead *aead;
296 bool hw_offload = true;
301 xo = xfrm_offload(skb);
306 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
307 xo->flags |= CRYPTO_FALLBACK;
311 esp.proto = xo->proto;
313 /* skb is pure payload to encrypt */
316 alen = crypto_aead_authsize(aead);
319 /* XXX: Add support for tfc padding here. */
321 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
322 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
323 esp.plen = esp.clen - skb->len - esp.tfclen;
324 esp.tailen = esp.tfclen + esp.plen + alen;
326 if (!hw_offload || !skb_is_gso(skb)) {
327 esp.nfrags = esp6_output_head(x, skb, &esp);
334 esp.esph = ip_esp_hdr(skb);
335 esp.esph->spi = x->id.spi;
337 skb_push(skb, -skb_network_offset(skb));
339 if (xo->flags & XFRM_GSO_SEGMENT) {
340 esp.esph->seq_no = htonl(seq);
342 if (!skb_is_gso(skb))
345 xo->seq.low += skb_shinfo(skb)->gso_segs;
348 if (xo->seq.low < seq)
351 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
353 len = skb->len - sizeof(struct ipv6hdr);
354 if (len > IPV6_MAXPLEN)
357 ipv6_hdr(skb)->payload_len = htons(len);
360 if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
363 xo = xfrm_offload(skb);
367 xo->flags |= XFRM_XMIT;
371 err = esp6_output_tail(x, skb, &esp);
380 static const struct net_offload esp6_offload = {
382 .gro_receive = esp6_gro_receive,
383 .gso_segment = esp6_gso_segment,
387 static const struct xfrm_type_offload esp6_type_offload = {
388 .owner = THIS_MODULE,
389 .proto = IPPROTO_ESP,
390 .input_tail = esp6_input_tail,
392 .encap = esp6_gso_encap,
395 static int __init esp6_offload_init(void)
397 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
398 pr_info("%s: can't add xfrm type offload\n", __func__);
402 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
405 static void __exit esp6_offload_exit(void)
407 xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6);
408 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
411 module_init(esp6_offload_init);
412 module_exit(esp6_offload_exit);
413 MODULE_LICENSE("GPL");
414 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
415 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);
416 MODULE_DESCRIPTION("IPV6 GSO/GRO offload support");