File: /usr/src/linux/net/decnet/dn_rules.c
1
2 /*
3 * DECnet An implementation of the DECnet protocol suite for the LINUX
4 * operating system. DECnet is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * DECnet Routing Forwarding Information Base (Rules)
8 *
9 * Author: Steve Whitehouse <SteveW@ACM.org>
10 * Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
11 *
12 *
13 * Changes:
14 *
15 */
16 #include <linux/config.h>
17 #include <linux/string.h>
18 #include <linux/net.h>
19 #include <linux/socket.h>
20 #include <linux/sockios.h>
21 #include <linux/init.h>
22 #include <linux/skbuff.h>
23 #include <linux/netlink.h>
24 #include <linux/rtnetlink.h>
25 #include <linux/proc_fs.h>
26 #include <linux/netdevice.h>
27 #include <linux/timer.h>
28 #include <linux/spinlock.h>
29 #include <asm/atomic.h>
30 #include <asm/uaccess.h>
31 #include <net/neighbour.h>
32 #include <net/dst.h>
33 #include <net/dn.h>
34 #include <net/dn_fib.h>
35 #include <net/dn_neigh.h>
36 #include <net/dn_dev.h>
37
38 struct dn_fib_rule
39 {
40 struct dn_fib_rule *r_next;
41 atomic_t r_clntref;
42 u32 r_preference;
43 unsigned char r_table;
44 unsigned char r_action;
45 unsigned char r_dst_len;
46 unsigned char r_src_len;
47 dn_address r_src;
48 dn_address r_srcmask;
49 dn_address r_dst;
50 dn_address r_dstmask;
51 u8 r_flags;
52 #ifdef CONFIG_DECNET_ROUTE_FWMARK
53 u32 r_fwmark;
54 #endif
55 int r_ifindex;
56 char r_ifname[IFNAMSIZ];
57 int r_dead;
58 };
59
60 static struct dn_fib_rule default_rule = {
61 r_clntref: ATOMIC_INIT(2),
62 r_preference: 0x7fff,
63 r_table: DN_DEFAULT_TABLE,
64 r_action: RTN_UNICAST
65 };
66
67 static struct dn_fib_rule *dn_fib_rules = &default_rule;
68 static rwlock_t dn_fib_rules_lock = RW_LOCK_UNLOCKED;
69
70
71 int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
72 {
73 struct rtattr **rta = arg;
74 struct rtmsg *rtm = NLMSG_DATA(nlh);
75 struct dn_fib_rule *r, **rp;
76 int err = -ESRCH;
77
78 for(rp=&dn_fib_rules; (r=*rp) != NULL; rp = &r->r_next) {
79 if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
80 rtm->rtm_src_len == r->r_src_len &&
81 rtm->rtm_dst_len == r->r_dst_len &&
82 (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) &&
83 #ifdef CONFIG_DECNET_ROUTE_FWMARK
84 (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
85 #endif
86 (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
87 (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
88 (!rta[RTA_IIF-1] || strcmp(RTA_DATA(rta[RTA_IIF-1]), r->r_ifname) == 0) &&
89 (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
90
91 err = -EPERM;
92 if (r == &default_rule)
93 break;
94
95 write_lock_bh(&dn_fib_rules_lock);
96 *rp = r->r_next;
97 r->r_dead = 1;
98 write_unlock_bh(&dn_fib_rules_lock);
99 dn_fib_rule_put(r);
100 err = 0;
101 break;
102 }
103 }
104
105 return err;
106 }
107
108 void dn_fib_rule_put(struct dn_fib_rule *r)
109 {
110 if (atomic_dec_and_test(&r->r_clntref)) {
111 if (r->r_dead)
112 kfree(r);
113 else
114 printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
115 }
116 }
117
118
119 int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
120 {
121 struct rtattr **rta = arg;
122 struct rtmsg *rtm = NLMSG_DATA(nlh);
123 struct dn_fib_rule *r, *new_r, **rp;
124 unsigned char table_id;
125
126 if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
127 return -EINVAL;
128
129 if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
130 return -EINVAL;
131
132 if (rtm->rtm_type == RTN_NAT)
133 return -EINVAL;
134
135 table_id = rtm->rtm_table;
136 if (table_id == RT_TABLE_UNSPEC) {
137 struct dn_fib_table *tb;
138 if (rtm->rtm_type == RTN_UNICAST) {
139 if ((tb = dn_fib_empty_table()) == NULL)
140 return -ENOBUFS;
141 table_id = tb->n;
142 }
143 }
144
145 new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
146 if (!new_r)
147 return -ENOMEM;
148 memset(new_r, 0, sizeof(*new_r));
149 if (rta[RTA_SRC-1])
150 memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
151 if (rta[RTA_DST-1])
152 memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2);
153 new_r->r_src_len = rtm->rtm_src_len;
154 new_r->r_dst_len = rtm->rtm_dst_len;
155 new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len);
156 new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len);
157 #ifdef CONFIG_DECNET_ROUTE_FWMARK
158 if (rta[RTA_PROTOINFO-1])
159 memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
160 #endif
161 new_r->r_action = rtm->rtm_type;
162 new_r->r_flags = rtm->rtm_flags;
163 if (rta[RTA_PRIORITY-1])
164 memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
165 new_r->r_table = table_id;
166 if (rta[RTA_IIF-1]) {
167 struct net_device *dev;
168 memcpy(new_r->r_ifname, RTA_DATA(rta[RTA_IIF-1]), IFNAMSIZ);
169 new_r->r_ifname[IFNAMSIZ-1] = 0;
170 new_r->r_ifindex = -1;
171 dev = __dev_get_by_name(new_r->r_ifname);
172 if (dev)
173 new_r->r_ifindex = dev->ifindex;
174 }
175
176 rp = &dn_fib_rules;
177 if (!new_r->r_preference) {
178 r = dn_fib_rules;
179 if (r && (r = r->r_next) != NULL) {
180 rp = &dn_fib_rules->r_next;
181 if (r->r_preference)
182 new_r->r_preference = r->r_preference - 1;
183 }
184 }
185
186 while((r=*rp) != NULL) {
187 if (r->r_preference > new_r->r_preference)
188 break;
189 rp = &r->r_next;
190 }
191
192 new_r->r_next = r;
193 atomic_inc(&new_r->r_clntref);
194 write_lock_bh(&dn_fib_rules_lock);
195 *rp = new_r;
196 write_unlock_bh(&dn_fib_rules_lock);
197 return 0;
198 }
199
200
201 int dn_fib_lookup(struct dn_fib_key *key, struct dn_fib_res *res)
202 {
203 struct dn_fib_rule *r, *policy;
204 struct dn_fib_table *tb;
205 dn_address saddr = key->src;
206 dn_address daddr = key->dst;
207 int err;
208
209 read_lock(&dn_fib_rules_lock);
210 for(r = dn_fib_rules; r; r = r->r_next) {
211 if (((saddr^r->r_src) & r->r_srcmask) ||
212 ((daddr^r->r_dst) & r->r_dstmask) ||
213 #ifdef CONFIG_DECNET_ROUTE_FWMARK
214 (r->r_fwmark && r->r_fwmark != key->fwmark) ||
215 #endif
216 (r->r_ifindex && r->r_ifindex != key->iif))
217 continue;
218
219 switch(r->r_action) {
220 case RTN_UNICAST:
221 policy = r;
222 break;
223 case RTN_UNREACHABLE:
224 read_unlock(&dn_fib_rules_lock);
225 return -ENETUNREACH;
226 default:
227 case RTN_BLACKHOLE:
228 read_unlock(&dn_fib_rules_lock);
229 return -EINVAL;
230 case RTN_PROHIBIT:
231 read_unlock(&dn_fib_rules_lock);
232 return -EACCES;
233 }
234
235 if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
236 continue;
237 err = tb->lookup(tb, key, res);
238 if (err == 0) {
239 res->r = policy;
240 if (policy)
241 atomic_inc(&policy->r_clntref);
242 read_unlock(&dn_fib_rules_lock);
243 return 0;
244 }
245 if (err < 0 && err != -EAGAIN) {
246 read_unlock(&dn_fib_rules_lock);
247 return err;
248 }
249 }
250
251 read_unlock(&dn_fib_rules_lock);
252 return -ESRCH;
253 }
254
255 static void dn_fib_rules_detach(struct net_device *dev)
256 {
257 struct dn_fib_rule *r;
258
259 for(r = dn_fib_rules; r; r = r->r_next) {
260 if (r->r_ifindex == dev->ifindex) {
261 write_lock_bh(&dn_fib_rules_lock);
262 r->r_ifindex = -1;
263 write_unlock_bh(&dn_fib_rules_lock);
264 }
265 }
266 }
267
268 static void dn_fib_rules_attach(struct net_device *dev)
269 {
270 struct dn_fib_rule *r;
271
272 for(r = dn_fib_rules; r; r = r->r_next) {
273 if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
274 write_lock_bh(&dn_fib_rules_lock);
275 r->r_ifindex = dev->ifindex;
276 write_unlock_bh(&dn_fib_rules_lock);
277 }
278 }
279 }
280
281 static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
282 {
283 struct net_device *dev = ptr;
284
285 switch(event) {
286 case NETDEV_UNREGISTER:
287 dn_fib_rules_detach(dev);
288 dn_fib_sync_down(0, dev, 1);
289 case NETDEV_REGISTER:
290 dn_fib_rules_attach(dev);
291 dn_fib_sync_up(dev);
292 }
293
294 return NOTIFY_DONE;
295 }
296
297
298 static struct notifier_block dn_fib_rules_notifier = {
299 notifier_call: dn_fib_rules_event,
300 };
301
302 #ifdef CONFIG_RTNETLINK
303
304 static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r, struct netlink_callback *cb)
305 {
306 struct rtmsg *rtm;
307 struct nlmsghdr *nlh;
308 unsigned char *b = skb->tail;
309
310
311 nlh = NLMSG_PUT(skb, NETLINK_CREDS(cb->skb)->pid, cb->nlh->nlmsg_seq, RTM_NEWRULE, sizeof(*rtm));
312 rtm = NLMSG_DATA(nlh);
313 rtm->rtm_family = AF_DECnet;
314 rtm->rtm_dst_len = r->r_dst_len;
315 rtm->rtm_src_len = r->r_src_len;
316 rtm->rtm_tos = 0;
317 #ifdef CONFIG_DECNET_ROUTE_FWMARK
318 if (r->r_fwmark)
319 RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
320 #endif
321 rtm->rtm_table = r->r_table;
322 rtm->rtm_protocol = 0;
323 rtm->rtm_scope = 0;
324 rtm->rtm_type = r->r_action;
325 rtm->rtm_flags = r->r_flags;
326
327 if (r->r_dst_len)
328 RTA_PUT(skb, RTA_DST, 2, &r->r_dst);
329 if (r->r_src_len)
330 RTA_PUT(skb, RTA_SRC, 2, &r->r_src);
331 if (r->r_ifname[0])
332 RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
333 if (r->r_preference)
334 RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
335 nlh->nlmsg_len = skb->tail - b;
336 return skb->len;
337
338 nlmsg_failure:
339 rtattr_failure:
340 skb_put(skb, b - skb->tail);
341 return -1;
342 }
343
344 int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
345 {
346 int idx;
347 int s_idx = cb->args[0];
348 struct dn_fib_rule *r;
349
350 read_lock(&dn_fib_rules_lock);
351 for(r = dn_fib_rules, idx = 0; r; r = r->r_next, idx++) {
352 if (idx < s_idx)
353 continue;
354 if (dn_fib_fill_rule(skb, r, cb) < 0)
355 break;
356 }
357 read_unlock(&dn_fib_rules_lock);
358 cb->args[0] = idx;
359
360 return skb->len;
361 }
362
363 #endif /* CONFIG_RTNETLINK */
364
365 void __init dn_fib_rules_init(void)
366 {
367 register_netdevice_notifier(&dn_fib_rules_notifier);
368 }
369
370 void __exit dn_fib_rules_cleanup(void)
371 {
372 unregister_netdevice_notifier(&dn_fib_rules_notifier);
373 }
374
375
376