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>
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>
28 #include <linux/icmpv6.h>
30 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
32 int off = sizeof(struct ipv6hdr);
33 struct ipv6_opt_hdr *exthdr;
35 if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
36 return offsetof(struct ipv6hdr, nexthdr);
39 exthdr = (void *)ipv6_hdr + off;
40 if (exthdr->nexthdr == NEXTHDR_ESP)
43 off += ipv6_optlen(exthdr);
49 static struct sk_buff *esp6_gro_receive(struct list_head *head,
52 int offset = skb_gro_offset(skb);
53 struct xfrm_offload *xo;
60 if (!pskb_pull(skb, offset))
63 if ((err = 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 sp->xvec[sp->len++] = x;
85 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 int proto = iph->nexthdr;
126 skb_push(skb, -skb_network_offset(skb));
127 esph = ip_esp_hdr(skb);
128 *skb_mac_header(skb) = IPPROTO_ESP;
130 esph->spi = x->id.spi;
131 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
136 static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
138 netdev_features_t features)
140 __skb_push(skb, skb->mac_len);
141 return skb_mac_gso_segment(skb, features);
144 static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
146 netdev_features_t features)
148 const struct net_offload *ops;
149 struct sk_buff *segs = ERR_PTR(-EINVAL);
150 struct xfrm_offload *xo = xfrm_offload(skb);
152 skb->transport_header += x->props.header_len;
153 ops = rcu_dereference(inet6_offloads[xo->proto]);
154 if (likely(ops && ops->callbacks.gso_segment))
155 segs = ops->callbacks.gso_segment(skb, features);
160 static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
162 netdev_features_t features)
164 switch (x->outer_mode.encap) {
165 case XFRM_MODE_TUNNEL:
166 return xfrm6_tunnel_gso_segment(x, skb, features);
167 case XFRM_MODE_TRANSPORT:
168 return xfrm6_transport_gso_segment(x, skb, features);
171 return ERR_PTR(-EOPNOTSUPP);
174 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
175 netdev_features_t features)
177 struct xfrm_state *x;
178 struct ip_esp_hdr *esph;
179 struct crypto_aead *aead;
180 netdev_features_t esp_features = features;
181 struct xfrm_offload *xo = xfrm_offload(skb);
185 return ERR_PTR(-EINVAL);
187 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
188 return ERR_PTR(-EINVAL);
190 sp = skb_sec_path(skb);
191 x = sp->xvec[sp->len - 1];
193 esph = ip_esp_hdr(skb);
195 if (esph->spi != x->id.spi)
196 return ERR_PTR(-EINVAL);
198 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
199 return ERR_PTR(-EINVAL);
201 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
203 skb->encap_hdr_csum = 1;
205 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
206 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
207 else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
208 esp_features = features & ~NETIF_F_CSUM_MASK;
210 xo->flags |= XFRM_GSO_SEGMENT;
212 return xfrm6_outer_mode_gso_segment(x, skb, esp_features);
215 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
217 struct crypto_aead *aead = x->data;
218 struct xfrm_offload *xo = xfrm_offload(skb);
220 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
223 if (!(xo->flags & CRYPTO_DONE))
224 skb->ip_summed = CHECKSUM_NONE;
226 return esp6_input_done2(skb, 0);
229 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
235 struct xfrm_offload *xo;
236 struct ip_esp_hdr *esph;
237 struct crypto_aead *aead;
239 bool hw_offload = true;
244 xo = xfrm_offload(skb);
249 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
250 xo->flags |= CRYPTO_FALLBACK;
254 esp.proto = xo->proto;
256 /* skb is pure payload to encrypt */
259 alen = crypto_aead_authsize(aead);
262 /* XXX: Add support for tfc padding here. */
264 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
265 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
266 esp.plen = esp.clen - skb->len - esp.tfclen;
267 esp.tailen = esp.tfclen + esp.plen + alen;
269 if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
270 esp.nfrags = esp6_output_head(x, skb, &esp);
277 esph = ip_esp_hdr(skb);
278 esph->spi = x->id.spi;
280 skb_push(skb, -skb_network_offset(skb));
282 if (xo->flags & XFRM_GSO_SEGMENT) {
283 esph->seq_no = htonl(seq);
285 if (!skb_is_gso(skb))
288 xo->seq.low += skb_shinfo(skb)->gso_segs;
291 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
293 len = skb->len - sizeof(struct ipv6hdr);
294 if (len > IPV6_MAXPLEN)
297 ipv6_hdr(skb)->payload_len = htons(len);
302 err = esp6_output_tail(x, skb, &esp);
311 static const struct net_offload esp6_offload = {
313 .gro_receive = esp6_gro_receive,
314 .gso_segment = esp6_gso_segment,
318 static const struct xfrm_type_offload esp6_type_offload = {
319 .description = "ESP6 OFFLOAD",
320 .owner = THIS_MODULE,
321 .proto = IPPROTO_ESP,
322 .input_tail = esp6_input_tail,
324 .encap = esp6_gso_encap,
327 static int __init esp6_offload_init(void)
329 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
330 pr_info("%s: can't add xfrm type offload\n", __func__);
334 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
337 static void __exit esp6_offload_exit(void)
339 xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6);
340 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
343 module_init(esp6_offload_init);
344 module_exit(esp6_offload_exit);
345 MODULE_LICENSE("GPL");
346 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
347 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);