2 * IPV4 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>
31 static struct sk_buff *esp4_gro_receive(struct list_head *head,
34 int offset = skb_gro_offset(skb);
35 struct xfrm_offload *xo;
41 if (!pskb_pull(skb, offset))
44 if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
47 xo = xfrm_offload(skb);
48 if (!xo || !(xo->flags & CRYPTO_DONE)) {
49 struct sec_path *sp = secpath_set(skb);
54 if (sp->len == XFRM_MAX_DEPTH)
57 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
58 (xfrm_address_t *)&ip_hdr(skb)->daddr,
59 spi, IPPROTO_ESP, AF_INET);
63 sp->xvec[sp->len++] = x;
66 xo = xfrm_offload(skb);
73 xo->flags |= XFRM_GRO;
75 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
76 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
77 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
78 XFRM_SPI_SKB_CB(skb)->seq = seq;
80 /* We don't need to handle errors from xfrm_input, it does all
81 * the error handling and frees the resources on error. */
82 xfrm_input(skb, IPPROTO_ESP, spi, -2);
84 return ERR_PTR(-EINPROGRESS);
86 skb_push(skb, offset);
87 NAPI_GRO_CB(skb)->same_flow = 0;
88 NAPI_GRO_CB(skb)->flush = 1;
93 static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
95 struct ip_esp_hdr *esph;
96 struct iphdr *iph = ip_hdr(skb);
97 struct xfrm_offload *xo = xfrm_offload(skb);
98 int proto = iph->protocol;
100 skb_push(skb, -skb_network_offset(skb));
101 esph = ip_esp_hdr(skb);
102 *skb_mac_header(skb) = IPPROTO_ESP;
104 esph->spi = x->id.spi;
105 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
110 static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x,
112 netdev_features_t features)
114 __skb_push(skb, skb->mac_len);
115 return skb_mac_gso_segment(skb, features);
118 static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
120 netdev_features_t features)
122 const struct net_offload *ops;
123 struct sk_buff *segs = ERR_PTR(-EINVAL);
124 struct xfrm_offload *xo = xfrm_offload(skb);
126 skb->transport_header += x->props.header_len;
127 ops = rcu_dereference(inet_offloads[xo->proto]);
128 if (likely(ops && ops->callbacks.gso_segment))
129 segs = ops->callbacks.gso_segment(skb, features);
134 static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x,
136 netdev_features_t features)
138 switch (x->outer_mode.encap) {
139 case XFRM_MODE_TUNNEL:
140 return xfrm4_tunnel_gso_segment(x, skb, features);
141 case XFRM_MODE_TRANSPORT:
142 return xfrm4_transport_gso_segment(x, skb, features);
145 return ERR_PTR(-EOPNOTSUPP);
148 static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
149 netdev_features_t features)
151 struct xfrm_state *x;
152 struct ip_esp_hdr *esph;
153 struct crypto_aead *aead;
154 netdev_features_t esp_features = features;
155 struct xfrm_offload *xo = xfrm_offload(skb);
159 return ERR_PTR(-EINVAL);
161 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
162 return ERR_PTR(-EINVAL);
164 sp = skb_sec_path(skb);
165 x = sp->xvec[sp->len - 1];
167 esph = ip_esp_hdr(skb);
169 if (esph->spi != x->id.spi)
170 return ERR_PTR(-EINVAL);
172 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
173 return ERR_PTR(-EINVAL);
175 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
177 skb->encap_hdr_csum = 1;
179 if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
180 !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev)
181 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
182 else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
183 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
184 esp_features = features & ~NETIF_F_CSUM_MASK;
186 xo->flags |= XFRM_GSO_SEGMENT;
188 return xfrm4_outer_mode_gso_segment(x, skb, esp_features);
191 static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb)
193 struct crypto_aead *aead = x->data;
194 struct xfrm_offload *xo = xfrm_offload(skb);
196 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
199 if (!(xo->flags & CRYPTO_DONE))
200 skb->ip_summed = CHECKSUM_NONE;
202 return esp_input_done2(skb, 0);
205 static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
210 struct xfrm_offload *xo;
211 struct ip_esp_hdr *esph;
212 struct crypto_aead *aead;
214 bool hw_offload = true;
219 xo = xfrm_offload(skb);
224 if ((!(features & NETIF_F_HW_ESP) &&
225 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) ||
226 x->xso.dev != skb->dev) {
227 xo->flags |= CRYPTO_FALLBACK;
231 esp.proto = xo->proto;
233 /* skb is pure payload to encrypt */
236 alen = crypto_aead_authsize(aead);
239 /* XXX: Add support for tfc padding here. */
241 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
242 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
243 esp.plen = esp.clen - skb->len - esp.tfclen;
244 esp.tailen = esp.tfclen + esp.plen + alen;
246 esp.esph = ip_esp_hdr(skb);
249 if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
250 esp.nfrags = esp_output_head(x, skb, &esp);
258 esph->spi = x->id.spi;
260 skb_push(skb, -skb_network_offset(skb));
262 if (xo->flags & XFRM_GSO_SEGMENT) {
263 esph->seq_no = htonl(seq);
265 if (!skb_is_gso(skb))
268 xo->seq.low += skb_shinfo(skb)->gso_segs;
271 esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
273 ip_hdr(skb)->tot_len = htons(skb->len);
274 ip_send_check(ip_hdr(skb));
279 err = esp_output_tail(x, skb, &esp);
288 static const struct net_offload esp4_offload = {
290 .gro_receive = esp4_gro_receive,
291 .gso_segment = esp4_gso_segment,
295 static const struct xfrm_type_offload esp_type_offload = {
296 .description = "ESP4 OFFLOAD",
297 .owner = THIS_MODULE,
298 .proto = IPPROTO_ESP,
299 .input_tail = esp_input_tail,
301 .encap = esp4_gso_encap,
304 static int __init esp4_offload_init(void)
306 if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
307 pr_info("%s: can't add xfrm type offload\n", __func__);
311 return inet_add_offload(&esp4_offload, IPPROTO_ESP);
314 static void __exit esp4_offload_exit(void)
316 if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
317 pr_info("%s: can't remove xfrm type offload\n", __func__);
319 inet_del_offload(&esp4_offload, IPPROTO_ESP);
322 module_init(esp4_offload_init);
323 module_exit(esp4_offload_exit);
324 MODULE_LICENSE("GPL");
325 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
326 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);