2 * xfrm_output.c - Common IPsec encapsulation code.
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/netfilter.h>
16 #include <linux/skbuff.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
22 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
24 static int xfrm_skb_check_space(struct sk_buff *skb)
26 struct dst_entry *dst = skb_dst(skb);
27 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
29 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
38 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
41 /* Children define the path of the packet through the
42 * Linux networking. Thus, destinations are stackable.
45 static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
47 struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
53 static int xfrm_output_one(struct sk_buff *skb, int err)
55 struct dst_entry *dst = skb_dst(skb);
56 struct xfrm_state *x = dst->xfrm;
57 struct net *net = xs_net(x);
63 err = xfrm_skb_check_space(skb);
65 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
69 skb->mark = xfrm_smark_get(skb->mark, x);
71 err = x->outer_mode->output(x, skb);
73 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
77 spin_lock_bh(&x->lock);
79 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
80 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
85 err = xfrm_state_check_expire(x);
87 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
91 err = x->repl->overflow(x, skb);
93 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
97 x->curlft.bytes += skb->len;
100 spin_unlock_bh(&x->lock);
104 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
109 if (xfrm_offload(skb)) {
110 x->type_offload->encap(x, skb);
112 /* Inner headers are invalid now. */
113 skb->encapsulation = 0;
115 err = x->type->output(x, skb);
116 if (err == -EINPROGRESS)
122 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
126 dst = skb_dst_pop(skb);
128 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
132 skb_dst_set(skb, dst);
134 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
139 spin_unlock_bh(&x->lock);
146 int xfrm_output_resume(struct sk_buff *skb, int err)
148 struct net *net = xs_net(skb_dst(skb)->xfrm);
150 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
153 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
154 if (unlikely(err != 1))
157 if (!skb_dst(skb)->xfrm)
158 return dst_output(net, skb->sk, skb);
160 err = nf_hook(skb_dst(skb)->ops->family,
161 NF_INET_POST_ROUTING, net, skb->sk, skb,
162 NULL, skb_dst(skb)->dev, xfrm_output2);
163 if (unlikely(err != 1))
167 if (err == -EINPROGRESS)
173 EXPORT_SYMBOL_GPL(xfrm_output_resume);
175 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
177 return xfrm_output_resume(skb, 1);
180 static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
182 struct sk_buff *segs;
184 BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
185 BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
186 segs = skb_gso_segment(skb, 0);
189 return PTR_ERR(segs);
194 struct sk_buff *nskb = segs->next;
198 err = xfrm_output2(net, sk, segs);
201 kfree_skb_list(nskb);
211 int xfrm_output(struct sock *sk, struct sk_buff *skb)
213 struct net *net = dev_net(skb_dst(skb)->dev);
214 struct xfrm_state *x = skb_dst(skb)->xfrm;
219 if (xfrm_dev_offload_ok(skb, x)) {
222 sp = secpath_dup(skb->sp);
224 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
229 secpath_put(skb->sp);
231 skb->encapsulation = 1;
234 sp->xvec[skb->sp->len++] = x;
237 if (skb_is_gso(skb)) {
238 if (skb->inner_protocol)
239 return xfrm_output_gso(net, sk, skb);
241 skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
245 if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
249 return xfrm_output_gso(net, sk, skb);
252 if (skb->ip_summed == CHECKSUM_PARTIAL) {
253 err = skb_checksum_help(skb);
255 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
262 return xfrm_output2(net, sk, skb);
264 EXPORT_SYMBOL_GPL(xfrm_output);
266 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
268 struct xfrm_mode *inner_mode;
269 if (x->sel.family == AF_UNSPEC)
270 inner_mode = xfrm_ip2inner_mode(x,
271 xfrm_af2proto(skb_dst(skb)->ops->family));
273 inner_mode = x->inner_mode;
275 if (inner_mode == NULL)
276 return -EAFNOSUPPORT;
277 return inner_mode->afinfo->extract_output(x, skb);
279 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
281 void xfrm_local_error(struct sk_buff *skb, int mtu)
284 struct xfrm_state_afinfo *afinfo;
286 if (skb->protocol == htons(ETH_P_IP))
288 else if (skb->protocol == htons(ETH_P_IPV6) &&
289 skb->sk->sk_family == AF_INET6)
294 afinfo = xfrm_state_get_afinfo(proto);
296 afinfo->local_error(skb, mtu);
300 EXPORT_SYMBOL_GPL(xfrm_local_error);