drm/amdgpu/vg20:Restruct uvd to support multiple uvds
[muen/linux.git] / net / xfrm / xfrm_output.c
1 /*
2  * xfrm_output.c - Common IPsec encapsulation code.
3  *
4  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
5  *
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.
10  */
11
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>
19 #include <net/dst.h>
20 #include <net/xfrm.h>
21
22 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
23
24 static int xfrm_skb_check_space(struct sk_buff *skb)
25 {
26         struct dst_entry *dst = skb_dst(skb);
27         int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
28                 - skb_headroom(skb);
29         int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
30
31         if (nhead <= 0) {
32                 if (ntail <= 0)
33                         return 0;
34                 nhead = 0;
35         } else if (ntail < 0)
36                 ntail = 0;
37
38         return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
39 }
40
41 /* Children define the path of the packet through the
42  * Linux networking.  Thus, destinations are stackable.
43  */
44
45 static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
46 {
47         struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
48
49         skb_dst_drop(skb);
50         return child;
51 }
52
53 static int xfrm_output_one(struct sk_buff *skb, int err)
54 {
55         struct dst_entry *dst = skb_dst(skb);
56         struct xfrm_state *x = dst->xfrm;
57         struct net *net = xs_net(x);
58
59         if (err <= 0)
60                 goto resume;
61
62         do {
63                 err = xfrm_skb_check_space(skb);
64                 if (err) {
65                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
66                         goto error_nolock;
67                 }
68
69                 if (x->props.output_mark)
70                         skb->mark = x->props.output_mark;
71
72                 err = x->outer_mode->output(x, skb);
73                 if (err) {
74                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
75                         goto error_nolock;
76                 }
77
78                 spin_lock_bh(&x->lock);
79
80                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
81                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
82                         err = -EINVAL;
83                         goto error;
84                 }
85
86                 err = xfrm_state_check_expire(x);
87                 if (err) {
88                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
89                         goto error;
90                 }
91
92                 err = x->repl->overflow(x, skb);
93                 if (err) {
94                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
95                         goto error;
96                 }
97
98                 x->curlft.bytes += skb->len;
99                 x->curlft.packets++;
100
101                 spin_unlock_bh(&x->lock);
102
103                 skb_dst_force(skb);
104
105                 if (xfrm_offload(skb)) {
106                         x->type_offload->encap(x, skb);
107                 } else {
108                         /* Inner headers are invalid now. */
109                         skb->encapsulation = 0;
110
111                         err = x->type->output(x, skb);
112                         if (err == -EINPROGRESS)
113                                 goto out;
114                 }
115
116 resume:
117                 if (err) {
118                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
119                         goto error_nolock;
120                 }
121
122                 dst = skb_dst_pop(skb);
123                 if (!dst) {
124                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
125                         err = -EHOSTUNREACH;
126                         goto error_nolock;
127                 }
128                 skb_dst_set(skb, dst);
129                 x = dst->xfrm;
130         } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
131
132         return 0;
133
134 error:
135         spin_unlock_bh(&x->lock);
136 error_nolock:
137         kfree_skb(skb);
138 out:
139         return err;
140 }
141
142 int xfrm_output_resume(struct sk_buff *skb, int err)
143 {
144         struct net *net = xs_net(skb_dst(skb)->xfrm);
145
146         while (likely((err = xfrm_output_one(skb, err)) == 0)) {
147                 nf_reset(skb);
148
149                 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
150                 if (unlikely(err != 1))
151                         goto out;
152
153                 if (!skb_dst(skb)->xfrm)
154                         return dst_output(net, skb->sk, skb);
155
156                 err = nf_hook(skb_dst(skb)->ops->family,
157                               NF_INET_POST_ROUTING, net, skb->sk, skb,
158                               NULL, skb_dst(skb)->dev, xfrm_output2);
159                 if (unlikely(err != 1))
160                         goto out;
161         }
162
163         if (err == -EINPROGRESS)
164                 err = 0;
165
166 out:
167         return err;
168 }
169 EXPORT_SYMBOL_GPL(xfrm_output_resume);
170
171 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
172 {
173         return xfrm_output_resume(skb, 1);
174 }
175
176 static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
177 {
178         struct sk_buff *segs;
179
180         BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
181         BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
182         segs = skb_gso_segment(skb, 0);
183         kfree_skb(skb);
184         if (IS_ERR(segs))
185                 return PTR_ERR(segs);
186         if (segs == NULL)
187                 return -EINVAL;
188
189         do {
190                 struct sk_buff *nskb = segs->next;
191                 int err;
192
193                 segs->next = NULL;
194                 err = xfrm_output2(net, sk, segs);
195
196                 if (unlikely(err)) {
197                         kfree_skb_list(nskb);
198                         return err;
199                 }
200
201                 segs = nskb;
202         } while (segs);
203
204         return 0;
205 }
206
207 int xfrm_output(struct sock *sk, struct sk_buff *skb)
208 {
209         struct net *net = dev_net(skb_dst(skb)->dev);
210         struct xfrm_state *x = skb_dst(skb)->xfrm;
211         int err;
212
213         secpath_reset(skb);
214
215         if (xfrm_dev_offload_ok(skb, x)) {
216                 struct sec_path *sp;
217
218                 sp = secpath_dup(skb->sp);
219                 if (!sp) {
220                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
221                         kfree_skb(skb);
222                         return -ENOMEM;
223                 }
224                 if (skb->sp)
225                         secpath_put(skb->sp);
226                 skb->sp = sp;
227                 skb->encapsulation = 1;
228
229                 sp->olen++;
230                 sp->xvec[skb->sp->len++] = x;
231                 xfrm_state_hold(x);
232
233                 if (skb_is_gso(skb)) {
234                         skb_shinfo(skb)->gso_type |= SKB_GSO_ESP;
235
236                         return xfrm_output2(net, sk, skb);
237                 }
238
239                 if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)
240                         goto out;
241         }
242
243         if (skb_is_gso(skb))
244                 return xfrm_output_gso(net, sk, skb);
245
246         if (skb->ip_summed == CHECKSUM_PARTIAL) {
247                 err = skb_checksum_help(skb);
248                 if (err) {
249                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
250                         kfree_skb(skb);
251                         return err;
252                 }
253         }
254
255 out:
256         return xfrm_output2(net, sk, skb);
257 }
258 EXPORT_SYMBOL_GPL(xfrm_output);
259
260 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
261 {
262         struct xfrm_mode *inner_mode;
263         if (x->sel.family == AF_UNSPEC)
264                 inner_mode = xfrm_ip2inner_mode(x,
265                                 xfrm_af2proto(skb_dst(skb)->ops->family));
266         else
267                 inner_mode = x->inner_mode;
268
269         if (inner_mode == NULL)
270                 return -EAFNOSUPPORT;
271         return inner_mode->afinfo->extract_output(x, skb);
272 }
273 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
274
275 void xfrm_local_error(struct sk_buff *skb, int mtu)
276 {
277         unsigned int proto;
278         struct xfrm_state_afinfo *afinfo;
279
280         if (skb->protocol == htons(ETH_P_IP))
281                 proto = AF_INET;
282         else if (skb->protocol == htons(ETH_P_IPV6))
283                 proto = AF_INET6;
284         else
285                 return;
286
287         afinfo = xfrm_state_get_afinfo(proto);
288         if (afinfo) {
289                 afinfo->local_error(skb, mtu);
290                 rcu_read_unlock();
291         }
292 }
293 EXPORT_SYMBOL_GPL(xfrm_local_error);