Merge git://git.kernel.org/pub/scm/linux/kernel/git/perex/alsa
[linux-2.6] / net / ipv4 / fib_rules.c
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>
36 #include <linux/inetdevice.h>
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>
43
44 #include <net/ip.h>
45 #include <net/protocol.h>
46 #include <net/route.h>
47 #include <net/tcp.h>
48 #include <net/sock.h>
49 #include <net/ip_fib.h>
50
51 #define FRprintk(a...)
52
53 struct fib_rule
54 {
55         struct fib_rule *r_next;
56         atomic_t        r_clntref;
57         u32             r_preference;
58         unsigned char   r_table;
59         unsigned char   r_action;
60         unsigned char   r_dst_len;
61         unsigned char   r_src_len;
62         u32             r_src;
63         u32             r_srcmask;
64         u32             r_dst;
65         u32             r_dstmask;
66         u32             r_srcmap;
67         u8              r_flags;
68         u8              r_tos;
69 #ifdef CONFIG_IP_ROUTE_FWMARK
70         u32             r_fwmark;
71 #endif
72         int             r_ifindex;
73 #ifdef CONFIG_NET_CLS_ROUTE
74         __u32           r_tclassid;
75 #endif
76         char            r_ifname[IFNAMSIZ];
77         int             r_dead;
78 };
79
80 static struct fib_rule default_rule = {
81         .r_clntref =    ATOMIC_INIT(2),
82         .r_preference = 0x7FFF,
83         .r_table =      RT_TABLE_DEFAULT,
84         .r_action =     RTN_UNICAST,
85 };
86
87 static struct fib_rule main_rule = {
88         .r_next =       &default_rule,
89         .r_clntref =    ATOMIC_INIT(2),
90         .r_preference = 0x7FFE,
91         .r_table =      RT_TABLE_MAIN,
92         .r_action =     RTN_UNICAST,
93 };
94
95 static struct fib_rule local_rule = {
96         .r_next =       &main_rule,
97         .r_clntref =    ATOMIC_INIT(2),
98         .r_table =      RT_TABLE_LOCAL,
99         .r_action =     RTN_UNICAST,
100 };
101
102 static struct fib_rule *fib_rules = &local_rule;
103 static DEFINE_RWLOCK(fib_rules_lock);
104
105 int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
106 {
107         struct rtattr **rta = arg;
108         struct rtmsg *rtm = NLMSG_DATA(nlh);
109         struct fib_rule *r, **rp;
110         int err = -ESRCH;
111
112         for (rp=&fib_rules; (r=*rp) != NULL; rp=&r->r_next) {
113                 if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&
114                     rtm->rtm_src_len == r->r_src_len &&
115                     rtm->rtm_dst_len == r->r_dst_len &&
116                     (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&
117                     rtm->rtm_tos == r->r_tos &&
118 #ifdef CONFIG_IP_ROUTE_FWMARK
119                     (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
120 #endif
121                     (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
122                     (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
123                     (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
124                     (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
125                         err = -EPERM;
126                         if (r == &local_rule)
127                                 break;
128
129                         write_lock_bh(&fib_rules_lock);
130                         *rp = r->r_next;
131                         r->r_dead = 1;
132                         write_unlock_bh(&fib_rules_lock);
133                         fib_rule_put(r);
134                         err = 0;
135                         break;
136                 }
137         }
138         return err;
139 }
140
141 /* Allocate new unique table id */
142
143 static struct fib_table *fib_empty_table(void)
144 {
145         int id;
146
147         for (id = 1; id <= RT_TABLE_MAX; id++)
148                 if (fib_tables[id] == NULL)
149                         return __fib_new_table(id);
150         return NULL;
151 }
152
153 void fib_rule_put(struct fib_rule *r)
154 {
155         if (atomic_dec_and_test(&r->r_clntref)) {
156                 if (r->r_dead)
157                         kfree(r);
158                 else
159                         printk("Freeing alive rule %p\n", r);
160         }
161 }
162
163 int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
164 {
165         struct rtattr **rta = arg;
166         struct rtmsg *rtm = NLMSG_DATA(nlh);
167         struct fib_rule *r, *new_r, **rp;
168         unsigned char table_id;
169
170         if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 ||
171             (rtm->rtm_tos & ~IPTOS_TOS_MASK))
172                 return -EINVAL;
173
174         if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
175                 return -EINVAL;
176
177         table_id = rtm->rtm_table;
178         if (table_id == RT_TABLE_UNSPEC) {
179                 struct fib_table *table;
180                 if (rtm->rtm_type == RTN_UNICAST) {
181                         if ((table = fib_empty_table()) == NULL)
182                                 return -ENOBUFS;
183                         table_id = table->tb_id;
184                 }
185         }
186
187         new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
188         if (!new_r)
189                 return -ENOMEM;
190         memset(new_r, 0, sizeof(*new_r));
191         if (rta[RTA_SRC-1])
192                 memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);
193         if (rta[RTA_DST-1])
194                 memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);
195         if (rta[RTA_GATEWAY-1])
196                 memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);
197         new_r->r_src_len = rtm->rtm_src_len;
198         new_r->r_dst_len = rtm->rtm_dst_len;
199         new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);
200         new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);
201         new_r->r_tos = rtm->rtm_tos;
202 #ifdef CONFIG_IP_ROUTE_FWMARK
203         if (rta[RTA_PROTOINFO-1])
204                 memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
205 #endif
206         new_r->r_action = rtm->rtm_type;
207         new_r->r_flags = rtm->rtm_flags;
208         if (rta[RTA_PRIORITY-1])
209                 memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
210         new_r->r_table = table_id;
211         if (rta[RTA_IIF-1]) {
212                 struct net_device *dev;
213                 rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
214                 new_r->r_ifindex = -1;
215                 dev = __dev_get_by_name(new_r->r_ifname);
216                 if (dev)
217                         new_r->r_ifindex = dev->ifindex;
218         }
219 #ifdef CONFIG_NET_CLS_ROUTE
220         if (rta[RTA_FLOW-1])
221                 memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);
222 #endif
223
224         rp = &fib_rules;
225         if (!new_r->r_preference) {
226                 r = fib_rules;
227                 if (r && (r = r->r_next) != NULL) {
228                         rp = &fib_rules->r_next;
229                         if (r->r_preference)
230                                 new_r->r_preference = r->r_preference - 1;
231                 }
232         }
233
234         while ( (r = *rp) != NULL ) {
235                 if (r->r_preference > new_r->r_preference)
236                         break;
237                 rp = &r->r_next;
238         }
239
240         new_r->r_next = r;
241         atomic_inc(&new_r->r_clntref);
242         write_lock_bh(&fib_rules_lock);
243         *rp = new_r;
244         write_unlock_bh(&fib_rules_lock);
245         return 0;
246 }
247
248 #ifdef CONFIG_NET_CLS_ROUTE
249 u32 fib_rules_tclass(struct fib_result *res)
250 {
251         if (res->r)
252                 return res->r->r_tclassid;
253         return 0;
254 }
255 #endif
256
257
258 static void fib_rules_detach(struct net_device *dev)
259 {
260         struct fib_rule *r;
261
262         for (r=fib_rules; r; r=r->r_next) {
263                 if (r->r_ifindex == dev->ifindex) {
264                         write_lock_bh(&fib_rules_lock);
265                         r->r_ifindex = -1;
266                         write_unlock_bh(&fib_rules_lock);
267                 }
268         }
269 }
270
271 static void fib_rules_attach(struct net_device *dev)
272 {
273         struct fib_rule *r;
274
275         for (r=fib_rules; r; r=r->r_next) {
276                 if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
277                         write_lock_bh(&fib_rules_lock);
278                         r->r_ifindex = dev->ifindex;
279                         write_unlock_bh(&fib_rules_lock);
280                 }
281         }
282 }
283
284 int fib_lookup(const struct flowi *flp, struct fib_result *res)
285 {
286         int err;
287         struct fib_rule *r, *policy;
288         struct fib_table *tb;
289
290         u32 daddr = flp->fl4_dst;
291         u32 saddr = flp->fl4_src;
292
293 FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",
294         NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));
295         read_lock(&fib_rules_lock);
296         for (r = fib_rules; r; r=r->r_next) {
297                 if (((saddr^r->r_src) & r->r_srcmask) ||
298                     ((daddr^r->r_dst) & r->r_dstmask) ||
299                     (r->r_tos && r->r_tos != flp->fl4_tos) ||
300 #ifdef CONFIG_IP_ROUTE_FWMARK
301                     (r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) ||
302 #endif
303                     (r->r_ifindex && r->r_ifindex != flp->iif))
304                         continue;
305
306 FRprintk("tb %d r %d ", r->r_table, r->r_action);
307                 switch (r->r_action) {
308                 case RTN_UNICAST:
309                         policy = r;
310                         break;
311                 case RTN_UNREACHABLE:
312                         read_unlock(&fib_rules_lock);
313                         return -ENETUNREACH;
314                 default:
315                 case RTN_BLACKHOLE:
316                         read_unlock(&fib_rules_lock);
317                         return -EINVAL;
318                 case RTN_PROHIBIT:
319                         read_unlock(&fib_rules_lock);
320                         return -EACCES;
321                 }
322
323                 if ((tb = fib_get_table(r->r_table)) == NULL)
324                         continue;
325                 err = tb->tb_lookup(tb, flp, res);
326                 if (err == 0) {
327                         res->r = policy;
328                         if (policy)
329                                 atomic_inc(&policy->r_clntref);
330                         read_unlock(&fib_rules_lock);
331                         return 0;
332                 }
333                 if (err < 0 && err != -EAGAIN) {
334                         read_unlock(&fib_rules_lock);
335                         return err;
336                 }
337         }
338 FRprintk("FAILURE\n");
339         read_unlock(&fib_rules_lock);
340         return -ENETUNREACH;
341 }
342
343 void fib_select_default(const struct flowi *flp, struct fib_result *res)
344 {
345         if (res->r && res->r->r_action == RTN_UNICAST &&
346             FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
347                 struct fib_table *tb;
348                 if ((tb = fib_get_table(res->r->r_table)) != NULL)
349                         tb->tb_select_default(tb, flp, res);
350         }
351 }
352
353 static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
354 {
355         struct net_device *dev = ptr;
356
357         if (event == NETDEV_UNREGISTER)
358                 fib_rules_detach(dev);
359         else if (event == NETDEV_REGISTER)
360                 fib_rules_attach(dev);
361         return NOTIFY_DONE;
362 }
363
364
365 static struct notifier_block fib_rules_notifier = {
366         .notifier_call =fib_rules_event,
367 };
368
369 static __inline__ int inet_fill_rule(struct sk_buff *skb,
370                                      struct fib_rule *r,
371                                      struct netlink_callback *cb,
372                                      unsigned int flags)
373 {
374         struct rtmsg *rtm;
375         struct nlmsghdr  *nlh;
376         unsigned char    *b = skb->tail;
377
378         nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
379         rtm = NLMSG_DATA(nlh);
380         rtm->rtm_family = AF_INET;
381         rtm->rtm_dst_len = r->r_dst_len;
382         rtm->rtm_src_len = r->r_src_len;
383         rtm->rtm_tos = r->r_tos;
384 #ifdef CONFIG_IP_ROUTE_FWMARK
385         if (r->r_fwmark)
386                 RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
387 #endif
388         rtm->rtm_table = r->r_table;
389         rtm->rtm_protocol = 0;
390         rtm->rtm_scope = 0;
391         rtm->rtm_type = r->r_action;
392         rtm->rtm_flags = r->r_flags;
393
394         if (r->r_dst_len)
395                 RTA_PUT(skb, RTA_DST, 4, &r->r_dst);
396         if (r->r_src_len)
397                 RTA_PUT(skb, RTA_SRC, 4, &r->r_src);
398         if (r->r_ifname[0])
399                 RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
400         if (r->r_preference)
401                 RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
402         if (r->r_srcmap)
403                 RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);
404 #ifdef CONFIG_NET_CLS_ROUTE
405         if (r->r_tclassid)
406                 RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);
407 #endif
408         nlh->nlmsg_len = skb->tail - b;
409         return skb->len;
410
411 nlmsg_failure:
412 rtattr_failure:
413         skb_trim(skb, b - skb->data);
414         return -1;
415 }
416
417 int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
418 {
419         int idx;
420         int s_idx = cb->args[0];
421         struct fib_rule *r;
422
423         read_lock(&fib_rules_lock);
424         for (r=fib_rules, idx=0; r; r = r->r_next, idx++) {
425                 if (idx < s_idx)
426                         continue;
427                 if (inet_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
428                         break;
429         }
430         read_unlock(&fib_rules_lock);
431         cb->args[0] = idx;
432
433         return skb->len;
434 }
435
436 void __init fib_rules_init(void)
437 {
438         register_netdevice_notifier(&fib_rules_notifier);
439 }