Merge tag 'tpmdd-next-20151110' of https://github.com/jsakkine/linux-tpmdd into for...
[firefly-linux-kernel-4.4.55.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(skb_dst(skb)->child);
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                 err = x->outer_mode->output(x, skb);
70                 if (err) {
71                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
72                         goto error_nolock;
73                 }
74
75                 spin_lock_bh(&x->lock);
76
77                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
78                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
79                         err = -EINVAL;
80                         goto error;
81                 }
82
83                 err = xfrm_state_check_expire(x);
84                 if (err) {
85                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
86                         goto error;
87                 }
88
89                 err = x->repl->overflow(x, skb);
90                 if (err) {
91                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
92                         goto error;
93                 }
94
95                 x->curlft.bytes += skb->len;
96                 x->curlft.packets++;
97
98                 spin_unlock_bh(&x->lock);
99
100                 skb_dst_force(skb);
101
102                 err = x->type->output(x, skb);
103                 if (err == -EINPROGRESS)
104                         goto out;
105
106 resume:
107                 if (err) {
108                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
109                         goto error_nolock;
110                 }
111
112                 dst = skb_dst_pop(skb);
113                 if (!dst) {
114                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
115                         err = -EHOSTUNREACH;
116                         goto error_nolock;
117                 }
118                 skb_dst_set(skb, dst);
119                 x = dst->xfrm;
120         } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
121
122         return 0;
123
124 error:
125         spin_unlock_bh(&x->lock);
126 error_nolock:
127         kfree_skb(skb);
128 out:
129         return err;
130 }
131
132 int xfrm_output_resume(struct sk_buff *skb, int err)
133 {
134         struct net *net = xs_net(skb_dst(skb)->xfrm);
135
136         while (likely((err = xfrm_output_one(skb, err)) == 0)) {
137                 nf_reset(skb);
138
139                 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
140                 if (unlikely(err != 1))
141                         goto out;
142
143                 if (!skb_dst(skb)->xfrm)
144                         return dst_output(net, skb->sk, skb);
145
146                 err = nf_hook(skb_dst(skb)->ops->family,
147                               NF_INET_POST_ROUTING, net, skb->sk, skb,
148                               NULL, skb_dst(skb)->dev, xfrm_output2);
149                 if (unlikely(err != 1))
150                         goto out;
151         }
152
153         if (err == -EINPROGRESS)
154                 err = 0;
155
156 out:
157         return err;
158 }
159 EXPORT_SYMBOL_GPL(xfrm_output_resume);
160
161 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
162 {
163         return xfrm_output_resume(skb, 1);
164 }
165
166 static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
167 {
168         struct sk_buff *segs;
169
170         segs = skb_gso_segment(skb, 0);
171         kfree_skb(skb);
172         if (IS_ERR(segs))
173                 return PTR_ERR(segs);
174         if (segs == NULL)
175                 return -EINVAL;
176
177         do {
178                 struct sk_buff *nskb = segs->next;
179                 int err;
180
181                 segs->next = NULL;
182                 err = xfrm_output2(net, sk, segs);
183
184                 if (unlikely(err)) {
185                         kfree_skb_list(nskb);
186                         return err;
187                 }
188
189                 segs = nskb;
190         } while (segs);
191
192         return 0;
193 }
194
195 int xfrm_output(struct sock *sk, struct sk_buff *skb)
196 {
197         struct net *net = dev_net(skb_dst(skb)->dev);
198         int err;
199
200         if (skb_is_gso(skb))
201                 return xfrm_output_gso(net, sk, skb);
202
203         if (skb->ip_summed == CHECKSUM_PARTIAL) {
204                 err = skb_checksum_help(skb);
205                 if (err) {
206                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
207                         kfree_skb(skb);
208                         return err;
209                 }
210         }
211
212         return xfrm_output2(net, sk, skb);
213 }
214 EXPORT_SYMBOL_GPL(xfrm_output);
215
216 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
217 {
218         struct xfrm_mode *inner_mode;
219         if (x->sel.family == AF_UNSPEC)
220                 inner_mode = xfrm_ip2inner_mode(x,
221                                 xfrm_af2proto(skb_dst(skb)->ops->family));
222         else
223                 inner_mode = x->inner_mode;
224
225         if (inner_mode == NULL)
226                 return -EAFNOSUPPORT;
227         return inner_mode->afinfo->extract_output(x, skb);
228 }
229 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
230
231 void xfrm_local_error(struct sk_buff *skb, int mtu)
232 {
233         unsigned int proto;
234         struct xfrm_state_afinfo *afinfo;
235
236         if (skb->protocol == htons(ETH_P_IP))
237                 proto = AF_INET;
238         else if (skb->protocol == htons(ETH_P_IPV6))
239                 proto = AF_INET6;
240         else
241                 return;
242
243         afinfo = xfrm_state_get_afinfo(proto);
244         if (!afinfo)
245                 return;
246
247         afinfo->local_error(skb, mtu);
248         xfrm_state_put_afinfo(afinfo);
249 }
250 EXPORT_SYMBOL_GPL(xfrm_local_error);