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>
24 #include <linux/scatterlist.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <net/ip6_route.h>
30 #include <linux/icmpv6.h>
32 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
34 int off = sizeof(struct ipv6hdr);
35 struct ipv6_opt_hdr *exthdr;
38 if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP ||
39 ipv6_hdr->nexthdr == NEXTHDR_UDP))
40 return offsetof(struct ipv6hdr, nexthdr);
43 exthdr = (void *)ipv6_hdr + off;
44 if (exthdr->nexthdr == NEXTHDR_ESP)
47 off += ipv6_optlen(exthdr);
53 static struct sk_buff *esp6_gro_receive(struct list_head *head,
56 int offset = skb_gro_offset(skb);
57 struct xfrm_offload *xo;
64 if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
65 encap_type = UDP_ENCAP_ESPINUDP;
67 if (!pskb_pull(skb, offset))
70 if (xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq) != 0)
73 xo = xfrm_offload(skb);
74 if (!xo || !(xo->flags & CRYPTO_DONE)) {
75 struct sec_path *sp = secpath_set(skb);
80 if (sp->len == XFRM_MAX_DEPTH)
83 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
84 (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
85 spi, IPPROTO_ESP, AF_INET6);
89 skb->mark = xfrm_smark_get(skb->mark, x);
91 sp->xvec[sp->len++] = x;
94 xo = xfrm_offload(skb);
99 xo->flags |= XFRM_GRO;
101 nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
105 IP6CB(skb)->nhoff = nhoff;
106 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
107 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
108 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
109 XFRM_SPI_SKB_CB(skb)->seq = seq;
111 /* We don't need to handle errors from xfrm_input, it does all
112 * the error handling and frees the resources on error. */
113 xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
115 return ERR_PTR(-EINPROGRESS);
119 skb_push(skb, offset);
120 NAPI_GRO_CB(skb)->same_flow = 0;
121 NAPI_GRO_CB(skb)->flush = 1;
126 static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
128 struct ip_esp_hdr *esph;
129 struct ipv6hdr *iph = ipv6_hdr(skb);
130 struct xfrm_offload *xo = xfrm_offload(skb);
131 u8 proto = iph->nexthdr;
133 skb_push(skb, -skb_network_offset(skb));
135 if (x->outer_mode.encap == XFRM_MODE_TRANSPORT) {
138 ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, &frag);
141 esph = ip_esp_hdr(skb);
142 *skb_mac_header(skb) = IPPROTO_ESP;
144 esph->spi = x->id.spi;
145 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
150 static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
152 netdev_features_t features)
154 __be16 type = x->inner_mode.family == AF_INET ? htons(ETH_P_IP)
157 return skb_eth_gso_segment(skb, features, type);
160 static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
162 netdev_features_t features)
164 const struct net_offload *ops;
165 struct sk_buff *segs = ERR_PTR(-EINVAL);
166 struct xfrm_offload *xo = xfrm_offload(skb);
168 skb->transport_header += x->props.header_len;
169 ops = rcu_dereference(inet6_offloads[xo->proto]);
170 if (likely(ops && ops->callbacks.gso_segment))
171 segs = ops->callbacks.gso_segment(skb, features);
176 static struct sk_buff *xfrm6_beet_gso_segment(struct xfrm_state *x,
178 netdev_features_t features)
180 struct xfrm_offload *xo = xfrm_offload(skb);
181 struct sk_buff *segs = ERR_PTR(-EINVAL);
182 const struct net_offload *ops;
183 u8 proto = xo->proto;
185 skb->transport_header += x->props.header_len;
187 if (x->sel.family != AF_INET6) {
188 skb->transport_header -=
189 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
191 if (proto == IPPROTO_BEETPH) {
192 struct ip_beet_phdr *ph =
193 (struct ip_beet_phdr *)skb->data;
195 skb->transport_header += ph->hdrlen * 8;
198 skb->transport_header -= IPV4_BEET_PHMAXLEN;
201 if (proto == IPPROTO_TCP)
202 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
206 skb->transport_header +=
207 ipv6_skip_exthdr(skb, 0, &proto, &frag);
210 if (proto == IPPROTO_IPIP)
211 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
213 __skb_pull(skb, skb_transport_offset(skb));
214 ops = rcu_dereference(inet6_offloads[proto]);
215 if (likely(ops && ops->callbacks.gso_segment))
216 segs = ops->callbacks.gso_segment(skb, features);
221 static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
223 netdev_features_t features)
225 switch (x->outer_mode.encap) {
226 case XFRM_MODE_TUNNEL:
227 return xfrm6_tunnel_gso_segment(x, skb, features);
228 case XFRM_MODE_TRANSPORT:
229 return xfrm6_transport_gso_segment(x, skb, features);
231 return xfrm6_beet_gso_segment(x, skb, features);
234 return ERR_PTR(-EOPNOTSUPP);
237 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
238 netdev_features_t features)
240 struct xfrm_state *x;
241 struct ip_esp_hdr *esph;
242 struct crypto_aead *aead;
243 netdev_features_t esp_features = features;
244 struct xfrm_offload *xo = xfrm_offload(skb);
248 return ERR_PTR(-EINVAL);
250 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
251 return ERR_PTR(-EINVAL);
253 sp = skb_sec_path(skb);
254 x = sp->xvec[sp->len - 1];
256 esph = ip_esp_hdr(skb);
258 if (esph->spi != x->id.spi)
259 return ERR_PTR(-EINVAL);
261 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
262 return ERR_PTR(-EINVAL);
264 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
266 skb->encap_hdr_csum = 1;
268 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
269 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK |
271 else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
272 esp_features = features & ~(NETIF_F_CSUM_MASK |
275 xo->flags |= XFRM_GSO_SEGMENT;
277 return xfrm6_outer_mode_gso_segment(x, skb, esp_features);
280 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
282 struct crypto_aead *aead = x->data;
283 struct xfrm_offload *xo = xfrm_offload(skb);
285 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
288 if (!(xo->flags & CRYPTO_DONE))
289 skb->ip_summed = CHECKSUM_NONE;
291 return esp6_input_done2(skb, 0);
294 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
300 struct xfrm_offload *xo;
301 struct crypto_aead *aead;
303 bool hw_offload = true;
308 xo = xfrm_offload(skb);
313 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
314 xo->flags |= CRYPTO_FALLBACK;
318 esp.proto = xo->proto;
320 /* skb is pure payload to encrypt */
323 alen = crypto_aead_authsize(aead);
326 /* XXX: Add support for tfc padding here. */
328 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
329 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
330 esp.plen = esp.clen - skb->len - esp.tfclen;
331 esp.tailen = esp.tfclen + esp.plen + alen;
333 if (!hw_offload || !skb_is_gso(skb)) {
334 esp.nfrags = esp6_output_head(x, skb, &esp);
341 esp.esph = ip_esp_hdr(skb);
342 esp.esph->spi = x->id.spi;
344 skb_push(skb, -skb_network_offset(skb));
346 if (xo->flags & XFRM_GSO_SEGMENT) {
347 esp.esph->seq_no = htonl(seq);
349 if (!skb_is_gso(skb))
352 xo->seq.low += skb_shinfo(skb)->gso_segs;
355 if (xo->seq.low < seq)
358 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
360 len = skb->len - sizeof(struct ipv6hdr);
361 if (len > IPV6_MAXPLEN)
364 ipv6_hdr(skb)->payload_len = htons(len);
367 if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
370 xo = xfrm_offload(skb);
374 xo->flags |= XFRM_XMIT;
378 err = esp6_output_tail(x, skb, &esp);
384 if (skb_needs_linearize(skb, skb->dev->features) &&
385 __skb_linearize(skb))
390 static const struct net_offload esp6_offload = {
392 .gro_receive = esp6_gro_receive,
393 .gso_segment = esp6_gso_segment,
397 static const struct xfrm_type_offload esp6_type_offload = {
398 .owner = THIS_MODULE,
399 .proto = IPPROTO_ESP,
400 .input_tail = esp6_input_tail,
402 .encap = esp6_gso_encap,
405 static int __init esp6_offload_init(void)
407 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
408 pr_info("%s: can't add xfrm type offload\n", __func__);
412 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
415 static void __exit esp6_offload_exit(void)
417 xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6);
418 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
421 module_init(esp6_offload_init);
422 module_exit(esp6_offload_exit);
423 MODULE_LICENSE("GPL");
424 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
425 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);
426 MODULE_DESCRIPTION("IPV6 GSO/GRO offload support");