Commit | Line | Data |
---|---|---|
e905a9ed | 1 | /* |
1da177e4 LT |
2 | * xfrm4_policy.c |
3 | * | |
4 | * Changes: | |
5 | * Kazunori MIYAZAWA @USAGI | |
6 | * YOSHIFUJI Hideaki @USAGI | |
7 | * Split up af-specific portion | |
e905a9ed | 8 | * |
1da177e4 LT |
9 | */ |
10 | ||
66cdb3ca HX |
11 | #include <linux/err.h> |
12 | #include <linux/kernel.h> | |
aabc9761 | 13 | #include <linux/inetdevice.h> |
cc9ff19d | 14 | #include <linux/if_tunnel.h> |
45ff5a3f | 15 | #include <net/dst.h> |
1da177e4 LT |
16 | #include <net/xfrm.h> |
17 | #include <net/ip.h> | |
18 | ||
1da177e4 LT |
19 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo; |
20 | ||
8f01cb08 DM |
21 | static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4, |
22 | int tos, | |
23 | const xfrm_address_t *saddr, | |
24 | const xfrm_address_t *daddr) | |
1da177e4 | 25 | { |
66cdb3ca | 26 | struct rtable *rt; |
a1e59abf | 27 | |
8f01cb08 DM |
28 | memset(fl4, 0, sizeof(*fl4)); |
29 | fl4->daddr = daddr->a4; | |
30 | fl4->flowi4_tos = tos; | |
66cdb3ca | 31 | if (saddr) |
8f01cb08 | 32 | fl4->saddr = saddr->a4; |
66cdb3ca | 33 | |
8f01cb08 | 34 | rt = __ip_route_output_key(net, fl4); |
b23dd4fe DM |
35 | if (!IS_ERR(rt)) |
36 | return &rt->dst; | |
37 | ||
38 | return ERR_CAST(rt); | |
66cdb3ca HX |
39 | } |
40 | ||
8f01cb08 DM |
41 | static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, |
42 | const xfrm_address_t *saddr, | |
43 | const xfrm_address_t *daddr) | |
44 | { | |
45 | struct flowi4 fl4; | |
46 | ||
47 | return __xfrm4_dst_lookup(net, &fl4, tos, saddr, daddr); | |
48 | } | |
49 | ||
fbda33b2 AD |
50 | static int xfrm4_get_saddr(struct net *net, |
51 | xfrm_address_t *saddr, xfrm_address_t *daddr) | |
66cdb3ca HX |
52 | { |
53 | struct dst_entry *dst; | |
8f01cb08 | 54 | struct flowi4 fl4; |
66cdb3ca | 55 | |
8f01cb08 | 56 | dst = __xfrm4_dst_lookup(net, &fl4, 0, NULL, daddr); |
66cdb3ca HX |
57 | if (IS_ERR(dst)) |
58 | return -EHOSTUNREACH; | |
59 | ||
8f01cb08 | 60 | saddr->a4 = fl4.saddr; |
66cdb3ca HX |
61 | dst_release(dst); |
62 | return 0; | |
a1e59abf PM |
63 | } |
64 | ||
05d84025 | 65 | static int xfrm4_get_tos(const struct flowi *fl) |
1da177e4 | 66 | { |
7e1dc7b6 | 67 | return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */ |
25ee3286 | 68 | } |
1da177e4 | 69 | |
a1b05140 MN |
70 | static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst, |
71 | int nfheader_len) | |
72 | { | |
73 | return 0; | |
74 | } | |
75 | ||
87c1e12b | 76 | static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, |
0c7b3eef | 77 | const struct flowi *fl) |
25ee3286 HX |
78 | { |
79 | struct rtable *rt = (struct rtable *)xdst->route; | |
7e1dc7b6 | 80 | const struct flowi4 *fl4 = &fl->u.ip4; |
1da177e4 | 81 | |
b7323396 | 82 | xdst->u.rt.rt_iif = fl4->flowi4_iif; |
1da177e4 | 83 | |
25ee3286 HX |
84 | xdst->u.dst.dev = dev; |
85 | dev_hold(dev); | |
43372262 | 86 | |
25ee3286 HX |
87 | /* Sheit... I remember I did this right. Apparently, |
88 | * it was magically lost, so this code needs audit */ | |
9917e1e8 | 89 | xdst->u.rt.rt_is_input = rt->rt_is_input; |
25ee3286 HX |
90 | xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | |
91 | RTCF_LOCAL); | |
92 | xdst->u.rt.rt_type = rt->rt_type; | |
25ee3286 | 93 | xdst->u.rt.rt_gateway = rt->rt_gateway; |
155e8336 | 94 | xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; |
5943634f | 95 | xdst->u.rt.rt_pmtu = rt->rt_pmtu; |
caacf05e | 96 | INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); |
1da177e4 | 97 | |
1da177e4 | 98 | return 0; |
1da177e4 LT |
99 | } |
100 | ||
101 | static void | |
d5422efe | 102 | _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) |
1da177e4 | 103 | { |
b71d1d42 | 104 | const struct iphdr *iph = ip_hdr(skb); |
d56f90a7 | 105 | u8 *xprth = skb_network_header(skb) + iph->ihl * 4; |
7e1dc7b6 | 106 | struct flowi4 *fl4 = &fl->u.ip4; |
84502b5e SK |
107 | int oif = 0; |
108 | ||
109 | if (skb_dst(skb)) | |
110 | oif = skb_dst(skb)->dev->ifindex; | |
1da177e4 | 111 | |
7e1dc7b6 DM |
112 | memset(fl4, 0, sizeof(struct flowi4)); |
113 | fl4->flowi4_mark = skb->mark; | |
84502b5e | 114 | fl4->flowi4_oif = reverse ? skb->skb_iif : oif; |
44b451f1 | 115 | |
56f8a75c | 116 | if (!ip_is_fragment(iph)) { |
1da177e4 LT |
117 | switch (iph->protocol) { |
118 | case IPPROTO_UDP: | |
ba4e58ec | 119 | case IPPROTO_UDPLITE: |
1da177e4 LT |
120 | case IPPROTO_TCP: |
121 | case IPPROTO_SCTP: | |
9e999993 | 122 | case IPPROTO_DCCP: |
c615c9f3 WY |
123 | if (xprth + 4 < skb->data || |
124 | pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
8c689a6e | 125 | __be16 *ports = (__be16 *)xprth; |
1da177e4 | 126 | |
9cce96df DM |
127 | fl4->fl4_sport = ports[!!reverse]; |
128 | fl4->fl4_dport = ports[!reverse]; | |
1da177e4 LT |
129 | } |
130 | break; | |
131 | ||
132 | case IPPROTO_ICMP: | |
133 | if (pskb_may_pull(skb, xprth + 2 - skb->data)) { | |
134 | u8 *icmp = xprth; | |
135 | ||
9cce96df DM |
136 | fl4->fl4_icmp_type = icmp[0]; |
137 | fl4->fl4_icmp_code = icmp[1]; | |
1da177e4 LT |
138 | } |
139 | break; | |
140 | ||
141 | case IPPROTO_ESP: | |
142 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 143 | __be32 *ehdr = (__be32 *)xprth; |
1da177e4 | 144 | |
9cce96df | 145 | fl4->fl4_ipsec_spi = ehdr[0]; |
1da177e4 LT |
146 | } |
147 | break; | |
148 | ||
149 | case IPPROTO_AH: | |
150 | if (pskb_may_pull(skb, xprth + 8 - skb->data)) { | |
5e73ea1a | 151 | __be32 *ah_hdr = (__be32 *)xprth; |
1da177e4 | 152 | |
9cce96df | 153 | fl4->fl4_ipsec_spi = ah_hdr[1]; |
1da177e4 LT |
154 | } |
155 | break; | |
156 | ||
157 | case IPPROTO_COMP: | |
158 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 159 | __be16 *ipcomp_hdr = (__be16 *)xprth; |
1da177e4 | 160 | |
9cce96df | 161 | fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); |
1da177e4 LT |
162 | } |
163 | break; | |
cc9ff19d TT |
164 | |
165 | case IPPROTO_GRE: | |
166 | if (pskb_may_pull(skb, xprth + 12 - skb->data)) { | |
167 | __be16 *greflags = (__be16 *)xprth; | |
168 | __be32 *gre_hdr = (__be32 *)xprth; | |
169 | ||
170 | if (greflags[0] & GRE_KEY) { | |
171 | if (greflags[0] & GRE_CSUM) | |
172 | gre_hdr++; | |
9cce96df | 173 | fl4->fl4_gre_key = gre_hdr[1]; |
cc9ff19d TT |
174 | } |
175 | } | |
176 | break; | |
177 | ||
1da177e4 | 178 | default: |
9cce96df | 179 | fl4->fl4_ipsec_spi = 0; |
1da177e4 | 180 | break; |
3ff50b79 | 181 | } |
1da177e4 | 182 | } |
7e1dc7b6 DM |
183 | fl4->flowi4_proto = iph->protocol; |
184 | fl4->daddr = reverse ? iph->saddr : iph->daddr; | |
185 | fl4->saddr = reverse ? iph->daddr : iph->saddr; | |
186 | fl4->flowi4_tos = iph->tos; | |
1da177e4 LT |
187 | } |
188 | ||
569d3645 | 189 | static inline int xfrm4_garbage_collect(struct dst_ops *ops) |
1da177e4 | 190 | { |
d7c7544c AD |
191 | struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops); |
192 | ||
193 | xfrm4_policy_afinfo.garbage_collect(net); | |
fc66f95c | 194 | return (dst_entries_get_slow(ops) > ops->gc_thresh * 2); |
1da177e4 LT |
195 | } |
196 | ||
6700c270 DM |
197 | static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, |
198 | struct sk_buff *skb, u32 mtu) | |
1da177e4 LT |
199 | { |
200 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
201 | struct dst_entry *path = xdst->route; | |
202 | ||
6700c270 | 203 | path->ops->update_pmtu(path, sk, skb, mtu); |
1da177e4 LT |
204 | } |
205 | ||
6700c270 DM |
206 | static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, |
207 | struct sk_buff *skb) | |
55be7a9c DM |
208 | { |
209 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
210 | struct dst_entry *path = xdst->route; | |
211 | ||
6700c270 | 212 | path->ops->redirect(path, sk, skb); |
55be7a9c DM |
213 | } |
214 | ||
aabc9761 HX |
215 | static void xfrm4_dst_destroy(struct dst_entry *dst) |
216 | { | |
217 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
218 | ||
62fa8a84 DM |
219 | dst_destroy_metrics_generic(dst); |
220 | ||
aabc9761 HX |
221 | xfrm_dst_destroy(xdst); |
222 | } | |
223 | ||
224 | static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
225 | int unregister) | |
226 | { | |
aabc9761 HX |
227 | if (!unregister) |
228 | return; | |
229 | ||
aabc9761 HX |
230 | xfrm_dst_ifdown(dst, dev); |
231 | } | |
232 | ||
1da177e4 LT |
233 | static struct dst_ops xfrm4_dst_ops = { |
234 | .family = AF_INET, | |
1da177e4 LT |
235 | .gc = xfrm4_garbage_collect, |
236 | .update_pmtu = xfrm4_update_pmtu, | |
55be7a9c | 237 | .redirect = xfrm4_redirect, |
62fa8a84 | 238 | .cow_metrics = dst_cow_metrics_generic, |
aabc9761 HX |
239 | .destroy = xfrm4_dst_destroy, |
240 | .ifdown = xfrm4_dst_ifdown, | |
862b82c6 | 241 | .local_out = __ip_local_out, |
eeb1b733 | 242 | .gc_thresh = 32768, |
1da177e4 LT |
243 | }; |
244 | ||
245 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { | |
246 | .family = AF_INET, | |
1da177e4 LT |
247 | .dst_ops = &xfrm4_dst_ops, |
248 | .dst_lookup = xfrm4_dst_lookup, | |
a1e59abf | 249 | .get_saddr = xfrm4_get_saddr, |
1da177e4 | 250 | .decode_session = _decode_session4, |
25ee3286 | 251 | .get_tos = xfrm4_get_tos, |
a1b05140 | 252 | .init_path = xfrm4_init_path, |
25ee3286 | 253 | .fill_dst = xfrm4_fill_dst, |
2774c131 | 254 | .blackhole_route = ipv4_blackhole_route, |
1da177e4 LT |
255 | }; |
256 | ||
f816700a | 257 | #ifdef CONFIG_SYSCTL |
a44a4a00 NH |
258 | static struct ctl_table xfrm4_policy_table[] = { |
259 | { | |
a44a4a00 | 260 | .procname = "xfrm4_gc_thresh", |
d7c7544c | 261 | .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, |
a44a4a00 NH |
262 | .maxlen = sizeof(int), |
263 | .mode = 0644, | |
264 | .proc_handler = proc_dointvec, | |
265 | }, | |
266 | { } | |
267 | }; | |
268 | ||
8d068875 MK |
269 | static int __net_init xfrm4_net_init(struct net *net) |
270 | { | |
271 | struct ctl_table *table; | |
272 | struct ctl_table_header *hdr; | |
273 | ||
274 | table = xfrm4_policy_table; | |
275 | if (!net_eq(net, &init_net)) { | |
276 | table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); | |
277 | if (!table) | |
278 | goto err_alloc; | |
279 | ||
280 | table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; | |
281 | } | |
282 | ||
283 | hdr = register_net_sysctl(net, "net/ipv4", table); | |
284 | if (!hdr) | |
285 | goto err_reg; | |
286 | ||
287 | net->ipv4.xfrm4_hdr = hdr; | |
288 | return 0; | |
289 | ||
290 | err_reg: | |
291 | if (!net_eq(net, &init_net)) | |
292 | kfree(table); | |
293 | err_alloc: | |
294 | return -ENOMEM; | |
295 | } | |
296 | ||
297 | static void __net_exit xfrm4_net_exit(struct net *net) | |
298 | { | |
299 | struct ctl_table *table; | |
300 | ||
51456b29 | 301 | if (!net->ipv4.xfrm4_hdr) |
8d068875 MK |
302 | return; |
303 | ||
304 | table = net->ipv4.xfrm4_hdr->ctl_table_arg; | |
305 | unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); | |
306 | if (!net_eq(net, &init_net)) | |
307 | kfree(table); | |
308 | } | |
309 | ||
310 | static struct pernet_operations __net_initdata xfrm4_net_ops = { | |
311 | .init = xfrm4_net_init, | |
312 | .exit = xfrm4_net_exit, | |
313 | }; | |
f816700a | 314 | #endif |
a44a4a00 | 315 | |
1da177e4 LT |
316 | static void __init xfrm4_policy_init(void) |
317 | { | |
318 | xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); | |
319 | } | |
320 | ||
703fb94e | 321 | void __init xfrm4_init(void) |
1da177e4 | 322 | { |
fc66f95c | 323 | dst_entries_init(&xfrm4_dst_ops); |
d7c7544c AD |
324 | |
325 | xfrm4_state_init(); | |
326 | xfrm4_policy_init(); | |
2f32b51b | 327 | xfrm4_protocol_init(); |
f816700a | 328 | #ifdef CONFIG_SYSCTL |
8d068875 | 329 | register_pernet_subsys(&xfrm4_net_ops); |
f816700a | 330 | #endif |
1da177e4 LT |
331 | } |
332 |