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net: use the macros defined for the members of flowi
[net-next-2.6.git] / net / ipv4 / xfrm4_policy.c
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CommitLineData
1/*
2 * xfrm4_policy.c
3 *
4 * Changes:
5 * Kazunori MIYAZAWA @USAGI
6 * YOSHIFUJI Hideaki @USAGI
7 * Split up af-specific portion
8 *
9 */
10
11#include <linux/err.h>
12#include <linux/kernel.h>
13#include <linux/inetdevice.h>
14#include <linux/if_tunnel.h>
15#include <net/dst.h>
16#include <net/xfrm.h>
17#include <net/ip.h>
18
19static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
20
21static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
22 xfrm_address_t *saddr,
23 xfrm_address_t *daddr)
24{
25 struct flowi fl = {
26 .fl4_dst = daddr->a4,
27 .fl4_tos = tos,
28 };
29 struct dst_entry *dst;
30 struct rtable *rt;
31 int err;
32
33 if (saddr)
34 fl.fl4_src = saddr->a4;
35
36 err = __ip_route_output_key(net, &rt, &fl);
37 dst = &rt->dst;
38 if (err)
39 dst = ERR_PTR(err);
40 return dst;
41}
42
43static int xfrm4_get_saddr(struct net *net,
44 xfrm_address_t *saddr, xfrm_address_t *daddr)
45{
46 struct dst_entry *dst;
47 struct rtable *rt;
48
49 dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
50 if (IS_ERR(dst))
51 return -EHOSTUNREACH;
52
53 rt = (struct rtable *)dst;
54 saddr->a4 = rt->rt_src;
55 dst_release(dst);
56 return 0;
57}
58
59static int xfrm4_get_tos(struct flowi *fl)
60{
61 return IPTOS_RT_MASK & fl->fl4_tos; /* Strip ECN bits */
62}
63
64static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
65 int nfheader_len)
66{
67 return 0;
68}
69
70static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
71 struct flowi *fl)
72{
73 struct rtable *rt = (struct rtable *)xdst->route;
74
75 xdst->u.rt.fl = *fl;
76
77 xdst->u.dst.dev = dev;
78 dev_hold(dev);
79
80 xdst->u.rt.peer = rt->peer;
81 if (rt->peer)
82 atomic_inc(&rt->peer->refcnt);
83
84 /* Sheit... I remember I did this right. Apparently,
85 * it was magically lost, so this code needs audit */
86 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
87 RTCF_LOCAL);
88 xdst->u.rt.rt_type = rt->rt_type;
89 xdst->u.rt.rt_src = rt->rt_src;
90 xdst->u.rt.rt_dst = rt->rt_dst;
91 xdst->u.rt.rt_gateway = rt->rt_gateway;
92 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
93
94 return 0;
95}
96
97static void
98_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
99{
100 struct iphdr *iph = ip_hdr(skb);
101 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
102
103 memset(fl, 0, sizeof(struct flowi));
104 fl->mark = skb->mark;
105
106 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
107 switch (iph->protocol) {
108 case IPPROTO_UDP:
109 case IPPROTO_UDPLITE:
110 case IPPROTO_TCP:
111 case IPPROTO_SCTP:
112 case IPPROTO_DCCP:
113 if (xprth + 4 < skb->data ||
114 pskb_may_pull(skb, xprth + 4 - skb->data)) {
115 __be16 *ports = (__be16 *)xprth;
116
117 fl->fl_ip_sport = ports[!!reverse];
118 fl->fl_ip_dport = ports[!reverse];
119 }
120 break;
121
122 case IPPROTO_ICMP:
123 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
124 u8 *icmp = xprth;
125
126 fl->fl_icmp_type = icmp[0];
127 fl->fl_icmp_code = icmp[1];
128 }
129 break;
130
131 case IPPROTO_ESP:
132 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
133 __be32 *ehdr = (__be32 *)xprth;
134
135 fl->fl_ipsec_spi = ehdr[0];
136 }
137 break;
138
139 case IPPROTO_AH:
140 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
141 __be32 *ah_hdr = (__be32*)xprth;
142
143 fl->fl_ipsec_spi = ah_hdr[1];
144 }
145 break;
146
147 case IPPROTO_COMP:
148 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
149 __be16 *ipcomp_hdr = (__be16 *)xprth;
150
151 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
152 }
153 break;
154
155 case IPPROTO_GRE:
156 if (pskb_may_pull(skb, xprth + 12 - skb->data)) {
157 __be16 *greflags = (__be16 *)xprth;
158 __be32 *gre_hdr = (__be32 *)xprth;
159
160 if (greflags[0] & GRE_KEY) {
161 if (greflags[0] & GRE_CSUM)
162 gre_hdr++;
163 fl->fl_gre_key = gre_hdr[1];
164 }
165 }
166 break;
167
168 default:
169 fl->fl_ipsec_spi = 0;
170 break;
171 }
172 }
173 fl->proto = iph->protocol;
174 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
175 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
176 fl->fl4_tos = iph->tos;
177}
178
179static inline int xfrm4_garbage_collect(struct dst_ops *ops)
180{
181 struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
182
183 xfrm4_policy_afinfo.garbage_collect(net);
184 return (dst_entries_get_slow(ops) > ops->gc_thresh * 2);
185}
186
187static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
188{
189 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
190 struct dst_entry *path = xdst->route;
191
192 path->ops->update_pmtu(path, mtu);
193}
194
195static void xfrm4_dst_destroy(struct dst_entry *dst)
196{
197 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
198
199 if (likely(xdst->u.rt.peer))
200 inet_putpeer(xdst->u.rt.peer);
201 xfrm_dst_destroy(xdst);
202}
203
204static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
205 int unregister)
206{
207 if (!unregister)
208 return;
209
210 xfrm_dst_ifdown(dst, dev);
211}
212
213static struct dst_ops xfrm4_dst_ops = {
214 .family = AF_INET,
215 .protocol = cpu_to_be16(ETH_P_IP),
216 .gc = xfrm4_garbage_collect,
217 .update_pmtu = xfrm4_update_pmtu,
218 .destroy = xfrm4_dst_destroy,
219 .ifdown = xfrm4_dst_ifdown,
220 .local_out = __ip_local_out,
221 .gc_thresh = 1024,
222};
223
224static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
225 .family = AF_INET,
226 .dst_ops = &xfrm4_dst_ops,
227 .dst_lookup = xfrm4_dst_lookup,
228 .get_saddr = xfrm4_get_saddr,
229 .decode_session = _decode_session4,
230 .get_tos = xfrm4_get_tos,
231 .init_path = xfrm4_init_path,
232 .fill_dst = xfrm4_fill_dst,
233};
234
235#ifdef CONFIG_SYSCTL
236static struct ctl_table xfrm4_policy_table[] = {
237 {
238 .procname = "xfrm4_gc_thresh",
239 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
240 .maxlen = sizeof(int),
241 .mode = 0644,
242 .proc_handler = proc_dointvec,
243 },
244 { }
245};
246
247static struct ctl_table_header *sysctl_hdr;
248#endif
249
250static void __init xfrm4_policy_init(void)
251{
252 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
253}
254
255static void __exit xfrm4_policy_fini(void)
256{
257#ifdef CONFIG_SYSCTL
258 if (sysctl_hdr)
259 unregister_net_sysctl_table(sysctl_hdr);
260#endif
261 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
262}
263
264void __init xfrm4_init(int rt_max_size)
265{
266 /*
267 * Select a default value for the gc_thresh based on the main route
268 * table hash size. It seems to me the worst case scenario is when
269 * we have ipsec operating in transport mode, in which we create a
270 * dst_entry per socket. The xfrm gc algorithm starts trying to remove
271 * entries at gc_thresh, and prevents new allocations as 2*gc_thresh
272 * so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
273 * That will let us store an ipsec connection per route table entry,
274 * and start cleaning when were 1/2 full
275 */
276 xfrm4_dst_ops.gc_thresh = rt_max_size/2;
277 dst_entries_init(&xfrm4_dst_ops);
278
279 xfrm4_state_init();
280 xfrm4_policy_init();
281#ifdef CONFIG_SYSCTL
282 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
283 xfrm4_policy_table);
284#endif
285}
286