Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * IPv4 Forwarding Information Base: policy rules. | |
7 | * | |
8 | * Version: $Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $ | |
9 | * | |
10 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * Fixes: | |
18 | * Rani Assaf : local_rule cannot be deleted | |
19 | * Marc Boucher : routing by fwmark | |
20 | */ | |
21 | ||
22 | #include <linux/config.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <asm/system.h> | |
25 | #include <linux/bitops.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/sched.h> | |
29 | #include <linux/mm.h> | |
30 | #include <linux/string.h> | |
31 | #include <linux/socket.h> | |
32 | #include <linux/sockios.h> | |
33 | #include <linux/errno.h> | |
34 | #include <linux/in.h> | |
35 | #include <linux/inet.h> | |
14c85021 | 36 | #include <linux/inetdevice.h> |
1da177e4 LT |
37 | #include <linux/netdevice.h> |
38 | #include <linux/if_arp.h> | |
39 | #include <linux/proc_fs.h> | |
40 | #include <linux/skbuff.h> | |
41 | #include <linux/netlink.h> | |
42 | #include <linux/init.h> | |
7b204afd RO |
43 | #include <linux/list.h> |
44 | #include <linux/rcupdate.h> | |
1da177e4 LT |
45 | |
46 | #include <net/ip.h> | |
47 | #include <net/protocol.h> | |
48 | #include <net/route.h> | |
49 | #include <net/tcp.h> | |
50 | #include <net/sock.h> | |
51 | #include <net/ip_fib.h> | |
52 | ||
53 | #define FRprintk(a...) | |
54 | ||
55 | struct fib_rule | |
56 | { | |
7b204afd | 57 | struct hlist_node hlist; |
1da177e4 LT |
58 | atomic_t r_clntref; |
59 | u32 r_preference; | |
60 | unsigned char r_table; | |
61 | unsigned char r_action; | |
62 | unsigned char r_dst_len; | |
63 | unsigned char r_src_len; | |
64 | u32 r_src; | |
65 | u32 r_srcmask; | |
66 | u32 r_dst; | |
67 | u32 r_dstmask; | |
68 | u32 r_srcmap; | |
69 | u8 r_flags; | |
70 | u8 r_tos; | |
71 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
72 | u32 r_fwmark; | |
73 | #endif | |
74 | int r_ifindex; | |
75 | #ifdef CONFIG_NET_CLS_ROUTE | |
76 | __u32 r_tclassid; | |
77 | #endif | |
78 | char r_ifname[IFNAMSIZ]; | |
79 | int r_dead; | |
7b204afd | 80 | struct rcu_head rcu; |
1da177e4 LT |
81 | }; |
82 | ||
83 | static struct fib_rule default_rule = { | |
84 | .r_clntref = ATOMIC_INIT(2), | |
85 | .r_preference = 0x7FFF, | |
86 | .r_table = RT_TABLE_DEFAULT, | |
87 | .r_action = RTN_UNICAST, | |
88 | }; | |
89 | ||
90 | static struct fib_rule main_rule = { | |
1da177e4 LT |
91 | .r_clntref = ATOMIC_INIT(2), |
92 | .r_preference = 0x7FFE, | |
93 | .r_table = RT_TABLE_MAIN, | |
94 | .r_action = RTN_UNICAST, | |
95 | }; | |
96 | ||
97 | static struct fib_rule local_rule = { | |
1da177e4 LT |
98 | .r_clntref = ATOMIC_INIT(2), |
99 | .r_table = RT_TABLE_LOCAL, | |
100 | .r_action = RTN_UNICAST, | |
101 | }; | |
102 | ||
d15150f7 | 103 | static struct hlist_head fib_rules; |
7b204afd RO |
104 | |
105 | /* writer func called from netlink -- rtnl_sem hold*/ | |
1da177e4 | 106 | |
a5cdc030 PM |
107 | static void rtmsg_rule(int, struct fib_rule *); |
108 | ||
1da177e4 LT |
109 | int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) |
110 | { | |
111 | struct rtattr **rta = arg; | |
112 | struct rtmsg *rtm = NLMSG_DATA(nlh); | |
7b204afd RO |
113 | struct fib_rule *r; |
114 | struct hlist_node *node; | |
1da177e4 LT |
115 | int err = -ESRCH; |
116 | ||
7b204afd | 117 | hlist_for_each_entry(r, node, &fib_rules, hlist) { |
1da177e4 LT |
118 | if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) && |
119 | rtm->rtm_src_len == r->r_src_len && | |
120 | rtm->rtm_dst_len == r->r_dst_len && | |
121 | (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) && | |
122 | rtm->rtm_tos == r->r_tos && | |
123 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
124 | (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) && | |
125 | #endif | |
126 | (!rtm->rtm_type || rtm->rtm_type == r->r_action) && | |
127 | (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) && | |
128 | (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) && | |
129 | (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) { | |
130 | err = -EPERM; | |
131 | if (r == &local_rule) | |
132 | break; | |
133 | ||
7b204afd | 134 | hlist_del_rcu(&r->hlist); |
1da177e4 | 135 | r->r_dead = 1; |
a5cdc030 | 136 | rtmsg_rule(RTM_DELRULE, r); |
1da177e4 LT |
137 | fib_rule_put(r); |
138 | err = 0; | |
139 | break; | |
140 | } | |
141 | } | |
142 | return err; | |
143 | } | |
144 | ||
145 | /* Allocate new unique table id */ | |
146 | ||
147 | static struct fib_table *fib_empty_table(void) | |
148 | { | |
149 | int id; | |
150 | ||
151 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
152 | if (fib_tables[id] == NULL) | |
153 | return __fib_new_table(id); | |
154 | return NULL; | |
155 | } | |
156 | ||
7b204afd RO |
157 | static inline void fib_rule_put_rcu(struct rcu_head *head) |
158 | { | |
159 | struct fib_rule *r = container_of(head, struct fib_rule, rcu); | |
160 | kfree(r); | |
161 | } | |
162 | ||
1da177e4 LT |
163 | void fib_rule_put(struct fib_rule *r) |
164 | { | |
165 | if (atomic_dec_and_test(&r->r_clntref)) { | |
166 | if (r->r_dead) | |
7b204afd | 167 | call_rcu(&r->rcu, fib_rule_put_rcu); |
1da177e4 LT |
168 | else |
169 | printk("Freeing alive rule %p\n", r); | |
170 | } | |
171 | } | |
172 | ||
7b204afd RO |
173 | /* writer func called from netlink -- rtnl_sem hold*/ |
174 | ||
1da177e4 LT |
175 | int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) |
176 | { | |
177 | struct rtattr **rta = arg; | |
178 | struct rtmsg *rtm = NLMSG_DATA(nlh); | |
7b204afd RO |
179 | struct fib_rule *r, *new_r, *last = NULL; |
180 | struct hlist_node *node = NULL; | |
1da177e4 LT |
181 | unsigned char table_id; |
182 | ||
183 | if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 || | |
184 | (rtm->rtm_tos & ~IPTOS_TOS_MASK)) | |
185 | return -EINVAL; | |
186 | ||
187 | if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ) | |
188 | return -EINVAL; | |
189 | ||
190 | table_id = rtm->rtm_table; | |
191 | if (table_id == RT_TABLE_UNSPEC) { | |
192 | struct fib_table *table; | |
193 | if (rtm->rtm_type == RTN_UNICAST) { | |
194 | if ((table = fib_empty_table()) == NULL) | |
195 | return -ENOBUFS; | |
196 | table_id = table->tb_id; | |
197 | } | |
198 | } | |
199 | ||
200 | new_r = kmalloc(sizeof(*new_r), GFP_KERNEL); | |
201 | if (!new_r) | |
202 | return -ENOMEM; | |
203 | memset(new_r, 0, sizeof(*new_r)); | |
7b204afd | 204 | |
1da177e4 LT |
205 | if (rta[RTA_SRC-1]) |
206 | memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4); | |
207 | if (rta[RTA_DST-1]) | |
208 | memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4); | |
209 | if (rta[RTA_GATEWAY-1]) | |
210 | memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4); | |
211 | new_r->r_src_len = rtm->rtm_src_len; | |
212 | new_r->r_dst_len = rtm->rtm_dst_len; | |
213 | new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len); | |
214 | new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len); | |
215 | new_r->r_tos = rtm->rtm_tos; | |
216 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
217 | if (rta[RTA_PROTOINFO-1]) | |
218 | memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4); | |
219 | #endif | |
220 | new_r->r_action = rtm->rtm_type; | |
221 | new_r->r_flags = rtm->rtm_flags; | |
222 | if (rta[RTA_PRIORITY-1]) | |
223 | memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4); | |
224 | new_r->r_table = table_id; | |
225 | if (rta[RTA_IIF-1]) { | |
226 | struct net_device *dev; | |
227 | rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ); | |
228 | new_r->r_ifindex = -1; | |
229 | dev = __dev_get_by_name(new_r->r_ifname); | |
230 | if (dev) | |
231 | new_r->r_ifindex = dev->ifindex; | |
232 | } | |
233 | #ifdef CONFIG_NET_CLS_ROUTE | |
234 | if (rta[RTA_FLOW-1]) | |
235 | memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4); | |
236 | #endif | |
7b204afd | 237 | r = container_of(fib_rules.first, struct fib_rule, hlist); |
1da177e4 | 238 | |
1da177e4 | 239 | if (!new_r->r_preference) { |
7b204afd RO |
240 | if (r && r->hlist.next != NULL) { |
241 | r = container_of(r->hlist.next, struct fib_rule, hlist); | |
1da177e4 LT |
242 | if (r->r_preference) |
243 | new_r->r_preference = r->r_preference - 1; | |
244 | } | |
245 | } | |
246 | ||
7b204afd | 247 | hlist_for_each_entry(r, node, &fib_rules, hlist) { |
1da177e4 LT |
248 | if (r->r_preference > new_r->r_preference) |
249 | break; | |
7b204afd | 250 | last = r; |
1da177e4 | 251 | } |
1da177e4 | 252 | atomic_inc(&new_r->r_clntref); |
7b204afd RO |
253 | |
254 | if (last) | |
255 | hlist_add_after_rcu(&last->hlist, &new_r->hlist); | |
256 | else | |
257 | hlist_add_before_rcu(&new_r->hlist, &r->hlist); | |
258 | ||
a5cdc030 | 259 | rtmsg_rule(RTM_NEWRULE, new_r); |
1da177e4 LT |
260 | return 0; |
261 | } | |
262 | ||
263 | #ifdef CONFIG_NET_CLS_ROUTE | |
264 | u32 fib_rules_tclass(struct fib_result *res) | |
265 | { | |
266 | if (res->r) | |
267 | return res->r->r_tclassid; | |
268 | return 0; | |
269 | } | |
270 | #endif | |
271 | ||
7b204afd | 272 | /* callers should hold rtnl semaphore */ |
1da177e4 LT |
273 | |
274 | static void fib_rules_detach(struct net_device *dev) | |
275 | { | |
7b204afd | 276 | struct hlist_node *node; |
1da177e4 LT |
277 | struct fib_rule *r; |
278 | ||
7b204afd RO |
279 | hlist_for_each_entry(r, node, &fib_rules, hlist) { |
280 | if (r->r_ifindex == dev->ifindex) | |
1da177e4 | 281 | r->r_ifindex = -1; |
7b204afd | 282 | |
1da177e4 LT |
283 | } |
284 | } | |
285 | ||
7b204afd RO |
286 | /* callers should hold rtnl semaphore */ |
287 | ||
1da177e4 LT |
288 | static void fib_rules_attach(struct net_device *dev) |
289 | { | |
7b204afd | 290 | struct hlist_node *node; |
1da177e4 LT |
291 | struct fib_rule *r; |
292 | ||
7b204afd RO |
293 | hlist_for_each_entry(r, node, &fib_rules, hlist) { |
294 | if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) | |
1da177e4 | 295 | r->r_ifindex = dev->ifindex; |
1da177e4 LT |
296 | } |
297 | } | |
298 | ||
299 | int fib_lookup(const struct flowi *flp, struct fib_result *res) | |
300 | { | |
301 | int err; | |
302 | struct fib_rule *r, *policy; | |
303 | struct fib_table *tb; | |
7b204afd | 304 | struct hlist_node *node; |
1da177e4 LT |
305 | |
306 | u32 daddr = flp->fl4_dst; | |
307 | u32 saddr = flp->fl4_src; | |
308 | ||
309 | FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ", | |
310 | NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src)); | |
7b204afd RO |
311 | |
312 | rcu_read_lock(); | |
313 | ||
314 | hlist_for_each_entry_rcu(r, node, &fib_rules, hlist) { | |
1da177e4 LT |
315 | if (((saddr^r->r_src) & r->r_srcmask) || |
316 | ((daddr^r->r_dst) & r->r_dstmask) || | |
317 | (r->r_tos && r->r_tos != flp->fl4_tos) || | |
318 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
319 | (r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) || | |
320 | #endif | |
321 | (r->r_ifindex && r->r_ifindex != flp->iif)) | |
322 | continue; | |
323 | ||
324 | FRprintk("tb %d r %d ", r->r_table, r->r_action); | |
325 | switch (r->r_action) { | |
326 | case RTN_UNICAST: | |
327 | policy = r; | |
328 | break; | |
329 | case RTN_UNREACHABLE: | |
7b204afd | 330 | rcu_read_unlock(); |
1da177e4 LT |
331 | return -ENETUNREACH; |
332 | default: | |
333 | case RTN_BLACKHOLE: | |
7b204afd | 334 | rcu_read_unlock(); |
1da177e4 LT |
335 | return -EINVAL; |
336 | case RTN_PROHIBIT: | |
7b204afd | 337 | rcu_read_unlock(); |
1da177e4 LT |
338 | return -EACCES; |
339 | } | |
340 | ||
341 | if ((tb = fib_get_table(r->r_table)) == NULL) | |
342 | continue; | |
343 | err = tb->tb_lookup(tb, flp, res); | |
344 | if (err == 0) { | |
345 | res->r = policy; | |
346 | if (policy) | |
347 | atomic_inc(&policy->r_clntref); | |
7b204afd | 348 | rcu_read_unlock(); |
1da177e4 LT |
349 | return 0; |
350 | } | |
351 | if (err < 0 && err != -EAGAIN) { | |
7b204afd | 352 | rcu_read_unlock(); |
1da177e4 LT |
353 | return err; |
354 | } | |
355 | } | |
356 | FRprintk("FAILURE\n"); | |
7b204afd | 357 | rcu_read_unlock(); |
1da177e4 LT |
358 | return -ENETUNREACH; |
359 | } | |
360 | ||
361 | void fib_select_default(const struct flowi *flp, struct fib_result *res) | |
362 | { | |
363 | if (res->r && res->r->r_action == RTN_UNICAST && | |
364 | FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) { | |
365 | struct fib_table *tb; | |
366 | if ((tb = fib_get_table(res->r->r_table)) != NULL) | |
367 | tb->tb_select_default(tb, flp, res); | |
368 | } | |
369 | } | |
370 | ||
371 | static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr) | |
372 | { | |
373 | struct net_device *dev = ptr; | |
374 | ||
375 | if (event == NETDEV_UNREGISTER) | |
376 | fib_rules_detach(dev); | |
377 | else if (event == NETDEV_REGISTER) | |
378 | fib_rules_attach(dev); | |
379 | return NOTIFY_DONE; | |
380 | } | |
381 | ||
382 | ||
383 | static struct notifier_block fib_rules_notifier = { | |
384 | .notifier_call =fib_rules_event, | |
385 | }; | |
386 | ||
387 | static __inline__ int inet_fill_rule(struct sk_buff *skb, | |
388 | struct fib_rule *r, | |
a5cdc030 | 389 | u32 pid, u32 seq, int event, |
b6544c0b | 390 | unsigned int flags) |
1da177e4 LT |
391 | { |
392 | struct rtmsg *rtm; | |
393 | struct nlmsghdr *nlh; | |
394 | unsigned char *b = skb->tail; | |
395 | ||
a5cdc030 | 396 | nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags); |
1da177e4 LT |
397 | rtm = NLMSG_DATA(nlh); |
398 | rtm->rtm_family = AF_INET; | |
399 | rtm->rtm_dst_len = r->r_dst_len; | |
400 | rtm->rtm_src_len = r->r_src_len; | |
401 | rtm->rtm_tos = r->r_tos; | |
402 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
403 | if (r->r_fwmark) | |
404 | RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark); | |
405 | #endif | |
406 | rtm->rtm_table = r->r_table; | |
407 | rtm->rtm_protocol = 0; | |
408 | rtm->rtm_scope = 0; | |
409 | rtm->rtm_type = r->r_action; | |
410 | rtm->rtm_flags = r->r_flags; | |
411 | ||
412 | if (r->r_dst_len) | |
413 | RTA_PUT(skb, RTA_DST, 4, &r->r_dst); | |
414 | if (r->r_src_len) | |
415 | RTA_PUT(skb, RTA_SRC, 4, &r->r_src); | |
416 | if (r->r_ifname[0]) | |
417 | RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname); | |
418 | if (r->r_preference) | |
419 | RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference); | |
420 | if (r->r_srcmap) | |
421 | RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap); | |
422 | #ifdef CONFIG_NET_CLS_ROUTE | |
423 | if (r->r_tclassid) | |
424 | RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid); | |
425 | #endif | |
426 | nlh->nlmsg_len = skb->tail - b; | |
427 | return skb->len; | |
428 | ||
429 | nlmsg_failure: | |
430 | rtattr_failure: | |
431 | skb_trim(skb, b - skb->data); | |
432 | return -1; | |
433 | } | |
434 | ||
7b204afd RO |
435 | /* callers should hold rtnl semaphore */ |
436 | ||
a5cdc030 PM |
437 | static void rtmsg_rule(int event, struct fib_rule *r) |
438 | { | |
439 | int size = NLMSG_SPACE(sizeof(struct rtmsg) + 128); | |
440 | struct sk_buff *skb = alloc_skb(size, GFP_KERNEL); | |
441 | ||
442 | if (!skb) | |
443 | netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, ENOBUFS); | |
444 | else if (inet_fill_rule(skb, r, 0, 0, event, 0) < 0) { | |
445 | kfree_skb(skb); | |
446 | netlink_set_err(rtnl, 0, RTNLGRP_IPV4_RULE, EINVAL); | |
447 | } else { | |
448 | netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV4_RULE, GFP_KERNEL); | |
449 | } | |
450 | } | |
451 | ||
1da177e4 LT |
452 | int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb) |
453 | { | |
7b204afd | 454 | int idx = 0; |
1da177e4 LT |
455 | int s_idx = cb->args[0]; |
456 | struct fib_rule *r; | |
7b204afd RO |
457 | struct hlist_node *node; |
458 | ||
459 | rcu_read_lock(); | |
460 | hlist_for_each_entry(r, node, &fib_rules, hlist) { | |
1da177e4 | 461 | |
1da177e4 LT |
462 | if (idx < s_idx) |
463 | continue; | |
a5cdc030 PM |
464 | if (inet_fill_rule(skb, r, NETLINK_CB(cb->skb).pid, |
465 | cb->nlh->nlmsg_seq, | |
466 | RTM_NEWRULE, NLM_F_MULTI) < 0) | |
1da177e4 | 467 | break; |
7b204afd | 468 | idx++; |
1da177e4 | 469 | } |
7b204afd | 470 | rcu_read_unlock(); |
1da177e4 LT |
471 | cb->args[0] = idx; |
472 | ||
473 | return skb->len; | |
474 | } | |
475 | ||
476 | void __init fib_rules_init(void) | |
477 | { | |
7b204afd RO |
478 | INIT_HLIST_HEAD(&fib_rules); |
479 | hlist_add_head(&local_rule.hlist, &fib_rules); | |
480 | hlist_add_after(&local_rule.hlist, &main_rule.hlist); | |
481 | hlist_add_after(&main_rule.hlist, &default_rule.hlist); | |
1da177e4 LT |
482 | register_netdevice_notifier(&fib_rules_notifier); |
483 | } |