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11#include <linux/err.h>
12#include <linux/kernel.h>
13#include <linux/inetdevice.h>
14#include <net/dst.h>
15#include <net/xfrm.h>
16#include <net/ip.h>
17
18static struct dst_ops xfrm4_dst_ops;
19static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
20
21static struct dst_entry *xfrm4_dst_lookup(int tos, xfrm_address_t *saddr,
22 xfrm_address_t *daddr)
23{
24 struct flowi fl = {
25 .nl_u = {
26 .ip4_u = {
27 .tos = tos,
28 .daddr = daddr->a4,
29 },
30 },
31 };
32 struct dst_entry *dst;
33 struct rtable *rt;
34 int err;
35
36 if (saddr)
37 fl.fl4_src = saddr->a4;
38
39 err = __ip_route_output_key(&init_net, &rt, &fl);
40 dst = &rt->u.dst;
41 if (err)
42 dst = ERR_PTR(err);
43 return dst;
44}
45
46static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
47{
48 struct dst_entry *dst;
49 struct rtable *rt;
50
51 dst = xfrm4_dst_lookup(0, NULL, daddr);
52 if (IS_ERR(dst))
53 return -EHOSTUNREACH;
54
55 rt = (struct rtable *)dst;
56 saddr->a4 = rt->rt_src;
57 dst_release(dst);
58 return 0;
59}
60
61static struct dst_entry *
62__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
63{
64 struct dst_entry *dst;
65
66 read_lock_bh(&policy->lock);
67 for (dst = policy->bundles; dst; dst = dst->next) {
68 struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
69 if (xdst->u.rt.fl.oif == fl->oif &&
70 xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
71 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
72 !((xdst->u.rt.fl.fl4_tos ^ fl->fl4_tos) & IPTOS_RT_MASK) &&
73 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
74 dst_clone(dst);
75 break;
76 }
77 }
78 read_unlock_bh(&policy->lock);
79 return dst;
80}
81
82static int xfrm4_get_tos(struct flowi *fl)
83{
84 return IPTOS_RT_MASK & fl->fl4_tos;
85}
86
87static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
88 int nfheader_len)
89{
90 return 0;
91}
92
93static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
94{
95 struct rtable *rt = (struct rtable *)xdst->route;
96
97 xdst->u.rt.fl = rt->fl;
98
99 xdst->u.dst.dev = dev;
100 dev_hold(dev);
101
102 xdst->u.rt.idev = in_dev_get(dev);
103 if (!xdst->u.rt.idev)
104 return -ENODEV;
105
106 xdst->u.rt.peer = rt->peer;
107 if (rt->peer)
108 atomic_inc(&rt->peer->refcnt);
109
110
111
112 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
113 RTCF_LOCAL);
114 xdst->u.rt.rt_type = rt->rt_type;
115 xdst->u.rt.rt_src = rt->rt_src;
116 xdst->u.rt.rt_dst = rt->rt_dst;
117 xdst->u.rt.rt_gateway = rt->rt_gateway;
118 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
119
120 return 0;
121}
122
123static void
124_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
125{
126 struct iphdr *iph = ip_hdr(skb);
127 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
128
129 memset(fl, 0, sizeof(struct flowi));
130 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
131 switch (iph->protocol) {
132 case IPPROTO_UDP:
133 case IPPROTO_UDPLITE:
134 case IPPROTO_TCP:
135 case IPPROTO_SCTP:
136 case IPPROTO_DCCP:
137 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
138 __be16 *ports = (__be16 *)xprth;
139
140 fl->fl_ip_sport = ports[!!reverse];
141 fl->fl_ip_dport = ports[!reverse];
142 }
143 break;
144
145 case IPPROTO_ICMP:
146 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
147 u8 *icmp = xprth;
148
149 fl->fl_icmp_type = icmp[0];
150 fl->fl_icmp_code = icmp[1];
151 }
152 break;
153
154 case IPPROTO_ESP:
155 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
156 __be32 *ehdr = (__be32 *)xprth;
157
158 fl->fl_ipsec_spi = ehdr[0];
159 }
160 break;
161
162 case IPPROTO_AH:
163 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
164 __be32 *ah_hdr = (__be32*)xprth;
165
166 fl->fl_ipsec_spi = ah_hdr[1];
167 }
168 break;
169
170 case IPPROTO_COMP:
171 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
172 __be16 *ipcomp_hdr = (__be16 *)xprth;
173
174 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
175 }
176 break;
177 default:
178 fl->fl_ipsec_spi = 0;
179 break;
180 }
181 }
182 fl->proto = iph->protocol;
183 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
184 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
185 fl->fl4_tos = iph->tos;
186}
187
188static inline int xfrm4_garbage_collect(struct dst_ops *ops)
189{
190 xfrm4_policy_afinfo.garbage_collect();
191 return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
192}
193
194static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
195{
196 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
197 struct dst_entry *path = xdst->route;
198
199 path->ops->update_pmtu(path, mtu);
200}
201
202static void xfrm4_dst_destroy(struct dst_entry *dst)
203{
204 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
205
206 if (likely(xdst->u.rt.idev))
207 in_dev_put(xdst->u.rt.idev);
208 if (likely(xdst->u.rt.peer))
209 inet_putpeer(xdst->u.rt.peer);
210 xfrm_dst_destroy(xdst);
211}
212
213static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
214 int unregister)
215{
216 struct xfrm_dst *xdst;
217
218 if (!unregister)
219 return;
220
221 xdst = (struct xfrm_dst *)dst;
222 if (xdst->u.rt.idev->dev == dev) {
223 struct in_device *loopback_idev =
224 in_dev_get(dev_net(dev)->loopback_dev);
225 BUG_ON(!loopback_idev);
226
227 do {
228 in_dev_put(xdst->u.rt.idev);
229 xdst->u.rt.idev = loopback_idev;
230 in_dev_hold(loopback_idev);
231 xdst = (struct xfrm_dst *)xdst->u.dst.child;
232 } while (xdst->u.dst.xfrm);
233
234 __in_dev_put(loopback_idev);
235 }
236
237 xfrm_dst_ifdown(dst, dev);
238}
239
240static struct dst_ops xfrm4_dst_ops = {
241 .family = AF_INET,
242 .protocol = __constant_htons(ETH_P_IP),
243 .gc = xfrm4_garbage_collect,
244 .update_pmtu = xfrm4_update_pmtu,
245 .destroy = xfrm4_dst_destroy,
246 .ifdown = xfrm4_dst_ifdown,
247 .local_out = __ip_local_out,
248 .gc_thresh = 1024,
249 .entry_size = sizeof(struct xfrm_dst),
250 .entries = ATOMIC_INIT(0),
251};
252
253static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
254 .family = AF_INET,
255 .dst_ops = &xfrm4_dst_ops,
256 .dst_lookup = xfrm4_dst_lookup,
257 .get_saddr = xfrm4_get_saddr,
258 .find_bundle = __xfrm4_find_bundle,
259 .decode_session = _decode_session4,
260 .get_tos = xfrm4_get_tos,
261 .init_path = xfrm4_init_path,
262 .fill_dst = xfrm4_fill_dst,
263};
264
265static void __init xfrm4_policy_init(void)
266{
267 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
268}
269
270static void __exit xfrm4_policy_fini(void)
271{
272 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
273}
274
275void __init xfrm4_init(void)
276{
277 xfrm4_state_init();
278 xfrm4_policy_init();
279}
280
281
