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> | |
4ec3b28c | 18 | #include <net/vrf.h> |
1da177e4 | 19 | |
1da177e4 LT |
20 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo; |
21 | ||
8f01cb08 | 22 | static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4, |
42a7b32b | 23 | int tos, int oif, |
8f01cb08 DM |
24 | const xfrm_address_t *saddr, |
25 | const xfrm_address_t *daddr) | |
1da177e4 | 26 | { |
66cdb3ca | 27 | struct rtable *rt; |
a1e59abf | 28 | |
8f01cb08 DM |
29 | memset(fl4, 0, sizeof(*fl4)); |
30 | fl4->daddr = daddr->a4; | |
31 | fl4->flowi4_tos = tos; | |
42a7b32b | 32 | fl4->flowi4_oif = oif; |
66cdb3ca | 33 | if (saddr) |
8f01cb08 | 34 | fl4->saddr = saddr->a4; |
66cdb3ca | 35 | |
8f01cb08 | 36 | rt = __ip_route_output_key(net, fl4); |
b23dd4fe DM |
37 | if (!IS_ERR(rt)) |
38 | return &rt->dst; | |
39 | ||
40 | return ERR_CAST(rt); | |
66cdb3ca HX |
41 | } |
42 | ||
42a7b32b | 43 | static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, int oif, |
8f01cb08 DM |
44 | const xfrm_address_t *saddr, |
45 | const xfrm_address_t *daddr) | |
46 | { | |
47 | struct flowi4 fl4; | |
48 | ||
42a7b32b | 49 | return __xfrm4_dst_lookup(net, &fl4, tos, oif, saddr, daddr); |
8f01cb08 DM |
50 | } |
51 | ||
42a7b32b | 52 | static int xfrm4_get_saddr(struct net *net, int oif, |
fbda33b2 | 53 | xfrm_address_t *saddr, xfrm_address_t *daddr) |
66cdb3ca HX |
54 | { |
55 | struct dst_entry *dst; | |
8f01cb08 | 56 | struct flowi4 fl4; |
66cdb3ca | 57 | |
42a7b32b | 58 | dst = __xfrm4_dst_lookup(net, &fl4, 0, oif, NULL, daddr); |
66cdb3ca HX |
59 | if (IS_ERR(dst)) |
60 | return -EHOSTUNREACH; | |
61 | ||
8f01cb08 | 62 | saddr->a4 = fl4.saddr; |
66cdb3ca HX |
63 | dst_release(dst); |
64 | return 0; | |
a1e59abf PM |
65 | } |
66 | ||
05d84025 | 67 | static int xfrm4_get_tos(const struct flowi *fl) |
1da177e4 | 68 | { |
7e1dc7b6 | 69 | return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */ |
25ee3286 | 70 | } |
1da177e4 | 71 | |
a1b05140 MN |
72 | static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst, |
73 | int nfheader_len) | |
74 | { | |
75 | return 0; | |
76 | } | |
77 | ||
87c1e12b | 78 | static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, |
0c7b3eef | 79 | const struct flowi *fl) |
25ee3286 HX |
80 | { |
81 | struct rtable *rt = (struct rtable *)xdst->route; | |
7e1dc7b6 | 82 | const struct flowi4 *fl4 = &fl->u.ip4; |
1da177e4 | 83 | |
b7323396 | 84 | xdst->u.rt.rt_iif = fl4->flowi4_iif; |
1da177e4 | 85 | |
25ee3286 HX |
86 | xdst->u.dst.dev = dev; |
87 | dev_hold(dev); | |
43372262 | 88 | |
25ee3286 HX |
89 | /* Sheit... I remember I did this right. Apparently, |
90 | * it was magically lost, so this code needs audit */ | |
9917e1e8 | 91 | xdst->u.rt.rt_is_input = rt->rt_is_input; |
25ee3286 HX |
92 | xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | |
93 | RTCF_LOCAL); | |
94 | xdst->u.rt.rt_type = rt->rt_type; | |
25ee3286 | 95 | xdst->u.rt.rt_gateway = rt->rt_gateway; |
155e8336 | 96 | xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; |
5943634f | 97 | xdst->u.rt.rt_pmtu = rt->rt_pmtu; |
caacf05e | 98 | INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); |
1da177e4 | 99 | |
1da177e4 | 100 | return 0; |
1da177e4 LT |
101 | } |
102 | ||
103 | static void | |
d5422efe | 104 | _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) |
1da177e4 | 105 | { |
b71d1d42 | 106 | const struct iphdr *iph = ip_hdr(skb); |
d56f90a7 | 107 | u8 *xprth = skb_network_header(skb) + iph->ihl * 4; |
7e1dc7b6 | 108 | struct flowi4 *fl4 = &fl->u.ip4; |
84502b5e SK |
109 | int oif = 0; |
110 | ||
4ec3b28c DA |
111 | if (skb_dst(skb)) { |
112 | oif = vrf_master_ifindex(skb_dst(skb)->dev) ? | |
113 | : skb_dst(skb)->dev->ifindex; | |
114 | } | |
1da177e4 | 115 | |
7e1dc7b6 DM |
116 | memset(fl4, 0, sizeof(struct flowi4)); |
117 | fl4->flowi4_mark = skb->mark; | |
84502b5e | 118 | fl4->flowi4_oif = reverse ? skb->skb_iif : oif; |
44b451f1 | 119 | |
56f8a75c | 120 | if (!ip_is_fragment(iph)) { |
1da177e4 LT |
121 | switch (iph->protocol) { |
122 | case IPPROTO_UDP: | |
ba4e58ec | 123 | case IPPROTO_UDPLITE: |
1da177e4 LT |
124 | case IPPROTO_TCP: |
125 | case IPPROTO_SCTP: | |
9e999993 | 126 | case IPPROTO_DCCP: |
c615c9f3 WY |
127 | if (xprth + 4 < skb->data || |
128 | pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
8c689a6e | 129 | __be16 *ports = (__be16 *)xprth; |
1da177e4 | 130 | |
9cce96df DM |
131 | fl4->fl4_sport = ports[!!reverse]; |
132 | fl4->fl4_dport = ports[!reverse]; | |
1da177e4 LT |
133 | } |
134 | break; | |
135 | ||
136 | case IPPROTO_ICMP: | |
137 | if (pskb_may_pull(skb, xprth + 2 - skb->data)) { | |
138 | u8 *icmp = xprth; | |
139 | ||
9cce96df DM |
140 | fl4->fl4_icmp_type = icmp[0]; |
141 | fl4->fl4_icmp_code = icmp[1]; | |
1da177e4 LT |
142 | } |
143 | break; | |
144 | ||
145 | case IPPROTO_ESP: | |
146 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 147 | __be32 *ehdr = (__be32 *)xprth; |
1da177e4 | 148 | |
9cce96df | 149 | fl4->fl4_ipsec_spi = ehdr[0]; |
1da177e4 LT |
150 | } |
151 | break; | |
152 | ||
153 | case IPPROTO_AH: | |
154 | if (pskb_may_pull(skb, xprth + 8 - skb->data)) { | |
5e73ea1a | 155 | __be32 *ah_hdr = (__be32 *)xprth; |
1da177e4 | 156 | |
9cce96df | 157 | fl4->fl4_ipsec_spi = ah_hdr[1]; |
1da177e4 LT |
158 | } |
159 | break; | |
160 | ||
161 | case IPPROTO_COMP: | |
162 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 163 | __be16 *ipcomp_hdr = (__be16 *)xprth; |
1da177e4 | 164 | |
9cce96df | 165 | fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); |
1da177e4 LT |
166 | } |
167 | break; | |
cc9ff19d TT |
168 | |
169 | case IPPROTO_GRE: | |
170 | if (pskb_may_pull(skb, xprth + 12 - skb->data)) { | |
171 | __be16 *greflags = (__be16 *)xprth; | |
172 | __be32 *gre_hdr = (__be32 *)xprth; | |
173 | ||
174 | if (greflags[0] & GRE_KEY) { | |
175 | if (greflags[0] & GRE_CSUM) | |
176 | gre_hdr++; | |
9cce96df | 177 | fl4->fl4_gre_key = gre_hdr[1]; |
cc9ff19d TT |
178 | } |
179 | } | |
180 | break; | |
181 | ||
1da177e4 | 182 | default: |
9cce96df | 183 | fl4->fl4_ipsec_spi = 0; |
1da177e4 | 184 | break; |
3ff50b79 | 185 | } |
1da177e4 | 186 | } |
7e1dc7b6 DM |
187 | fl4->flowi4_proto = iph->protocol; |
188 | fl4->daddr = reverse ? iph->saddr : iph->daddr; | |
189 | fl4->saddr = reverse ? iph->daddr : iph->saddr; | |
190 | fl4->flowi4_tos = iph->tos; | |
1da177e4 LT |
191 | } |
192 | ||
569d3645 | 193 | static inline int xfrm4_garbage_collect(struct dst_ops *ops) |
1da177e4 | 194 | { |
d7c7544c AD |
195 | struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops); |
196 | ||
197 | xfrm4_policy_afinfo.garbage_collect(net); | |
fc66f95c | 198 | return (dst_entries_get_slow(ops) > ops->gc_thresh * 2); |
1da177e4 LT |
199 | } |
200 | ||
6700c270 DM |
201 | static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, |
202 | struct sk_buff *skb, u32 mtu) | |
1da177e4 LT |
203 | { |
204 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
205 | struct dst_entry *path = xdst->route; | |
206 | ||
6700c270 | 207 | path->ops->update_pmtu(path, sk, skb, mtu); |
1da177e4 LT |
208 | } |
209 | ||
6700c270 DM |
210 | static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, |
211 | struct sk_buff *skb) | |
55be7a9c DM |
212 | { |
213 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
214 | struct dst_entry *path = xdst->route; | |
215 | ||
6700c270 | 216 | path->ops->redirect(path, sk, skb); |
55be7a9c DM |
217 | } |
218 | ||
aabc9761 HX |
219 | static void xfrm4_dst_destroy(struct dst_entry *dst) |
220 | { | |
221 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
222 | ||
62fa8a84 DM |
223 | dst_destroy_metrics_generic(dst); |
224 | ||
aabc9761 HX |
225 | xfrm_dst_destroy(xdst); |
226 | } | |
227 | ||
228 | static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
229 | int unregister) | |
230 | { | |
aabc9761 HX |
231 | if (!unregister) |
232 | return; | |
233 | ||
aabc9761 HX |
234 | xfrm_dst_ifdown(dst, dev); |
235 | } | |
236 | ||
1da177e4 LT |
237 | static struct dst_ops xfrm4_dst_ops = { |
238 | .family = AF_INET, | |
1da177e4 LT |
239 | .gc = xfrm4_garbage_collect, |
240 | .update_pmtu = xfrm4_update_pmtu, | |
55be7a9c | 241 | .redirect = xfrm4_redirect, |
62fa8a84 | 242 | .cow_metrics = dst_cow_metrics_generic, |
aabc9761 HX |
243 | .destroy = xfrm4_dst_destroy, |
244 | .ifdown = xfrm4_dst_ifdown, | |
862b82c6 | 245 | .local_out = __ip_local_out, |
eeb1b733 | 246 | .gc_thresh = 32768, |
1da177e4 LT |
247 | }; |
248 | ||
249 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { | |
250 | .family = AF_INET, | |
1da177e4 LT |
251 | .dst_ops = &xfrm4_dst_ops, |
252 | .dst_lookup = xfrm4_dst_lookup, | |
a1e59abf | 253 | .get_saddr = xfrm4_get_saddr, |
1da177e4 | 254 | .decode_session = _decode_session4, |
25ee3286 | 255 | .get_tos = xfrm4_get_tos, |
a1b05140 | 256 | .init_path = xfrm4_init_path, |
25ee3286 | 257 | .fill_dst = xfrm4_fill_dst, |
2774c131 | 258 | .blackhole_route = ipv4_blackhole_route, |
1da177e4 LT |
259 | }; |
260 | ||
f816700a | 261 | #ifdef CONFIG_SYSCTL |
a44a4a00 NH |
262 | static struct ctl_table xfrm4_policy_table[] = { |
263 | { | |
a44a4a00 | 264 | .procname = "xfrm4_gc_thresh", |
d7c7544c | 265 | .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, |
a44a4a00 NH |
266 | .maxlen = sizeof(int), |
267 | .mode = 0644, | |
268 | .proc_handler = proc_dointvec, | |
269 | }, | |
270 | { } | |
271 | }; | |
272 | ||
8d068875 MK |
273 | static int __net_init xfrm4_net_init(struct net *net) |
274 | { | |
275 | struct ctl_table *table; | |
276 | struct ctl_table_header *hdr; | |
277 | ||
278 | table = xfrm4_policy_table; | |
279 | if (!net_eq(net, &init_net)) { | |
280 | table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); | |
281 | if (!table) | |
282 | goto err_alloc; | |
283 | ||
284 | table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; | |
285 | } | |
286 | ||
287 | hdr = register_net_sysctl(net, "net/ipv4", table); | |
288 | if (!hdr) | |
289 | goto err_reg; | |
290 | ||
291 | net->ipv4.xfrm4_hdr = hdr; | |
292 | return 0; | |
293 | ||
294 | err_reg: | |
295 | if (!net_eq(net, &init_net)) | |
296 | kfree(table); | |
297 | err_alloc: | |
298 | return -ENOMEM; | |
299 | } | |
300 | ||
301 | static void __net_exit xfrm4_net_exit(struct net *net) | |
302 | { | |
303 | struct ctl_table *table; | |
304 | ||
51456b29 | 305 | if (!net->ipv4.xfrm4_hdr) |
8d068875 MK |
306 | return; |
307 | ||
308 | table = net->ipv4.xfrm4_hdr->ctl_table_arg; | |
309 | unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); | |
310 | if (!net_eq(net, &init_net)) | |
311 | kfree(table); | |
312 | } | |
313 | ||
314 | static struct pernet_operations __net_initdata xfrm4_net_ops = { | |
315 | .init = xfrm4_net_init, | |
316 | .exit = xfrm4_net_exit, | |
317 | }; | |
f816700a | 318 | #endif |
a44a4a00 | 319 | |
1da177e4 LT |
320 | static void __init xfrm4_policy_init(void) |
321 | { | |
322 | xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); | |
323 | } | |
324 | ||
703fb94e | 325 | void __init xfrm4_init(void) |
1da177e4 | 326 | { |
fc66f95c | 327 | dst_entries_init(&xfrm4_dst_ops); |
d7c7544c AD |
328 | |
329 | xfrm4_state_init(); | |
330 | xfrm4_policy_init(); | |
2f32b51b | 331 | xfrm4_protocol_init(); |
f816700a | 332 | #ifdef CONFIG_SYSCTL |
8d068875 | 333 | register_pernet_subsys(&xfrm4_net_ops); |
f816700a | 334 | #endif |
1da177e4 LT |
335 | } |
336 |