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1da177e4 LT |
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 <linux/in_route.h> | |
30 | #include <asm/atomic.h> | |
31 | #include <asm/uaccess.h> | |
32 | #include <net/neighbour.h> | |
33 | #include <net/dst.h> | |
34 | #include <net/flow.h> | |
35 | #include <net/dn.h> | |
36 | #include <net/dn_fib.h> | |
37 | #include <net/dn_neigh.h> | |
38 | #include <net/dn_dev.h> | |
39 | ||
40 | struct dn_fib_rule | |
41 | { | |
42 | struct dn_fib_rule *r_next; | |
43 | atomic_t r_clntref; | |
44 | u32 r_preference; | |
45 | unsigned char r_table; | |
46 | unsigned char r_action; | |
47 | unsigned char r_dst_len; | |
48 | unsigned char r_src_len; | |
49 | dn_address r_src; | |
50 | dn_address r_srcmask; | |
51 | dn_address r_dst; | |
52 | dn_address r_dstmask; | |
53 | dn_address r_srcmap; | |
54 | u8 r_flags; | |
55 | #ifdef CONFIG_DECNET_ROUTE_FWMARK | |
56 | u32 r_fwmark; | |
57 | #endif | |
58 | int r_ifindex; | |
59 | char r_ifname[IFNAMSIZ]; | |
60 | int r_dead; | |
61 | }; | |
62 | ||
63 | static struct dn_fib_rule default_rule = { | |
64 | .r_clntref = ATOMIC_INIT(2), | |
65 | .r_preference = 0x7fff, | |
66 | .r_table = RT_TABLE_MAIN, | |
67 | .r_action = RTN_UNICAST | |
68 | }; | |
69 | ||
70 | static struct dn_fib_rule *dn_fib_rules = &default_rule; | |
71 | static DEFINE_RWLOCK(dn_fib_rules_lock); | |
72 | ||
73 | ||
74 | int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) | |
75 | { | |
76 | struct rtattr **rta = arg; | |
77 | struct rtmsg *rtm = NLMSG_DATA(nlh); | |
78 | struct dn_fib_rule *r, **rp; | |
79 | int err = -ESRCH; | |
80 | ||
81 | for(rp=&dn_fib_rules; (r=*rp) != NULL; rp = &r->r_next) { | |
82 | if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) && | |
83 | rtm->rtm_src_len == r->r_src_len && | |
84 | rtm->rtm_dst_len == r->r_dst_len && | |
85 | (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) && | |
86 | #ifdef CONFIG_DECNET_ROUTE_FWMARK | |
87 | (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) && | |
88 | #endif | |
89 | (!rtm->rtm_type || rtm->rtm_type == r->r_action) && | |
90 | (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) && | |
91 | (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) && | |
92 | (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) { | |
93 | ||
94 | err = -EPERM; | |
95 | if (r == &default_rule) | |
96 | break; | |
97 | ||
98 | write_lock_bh(&dn_fib_rules_lock); | |
99 | *rp = r->r_next; | |
100 | r->r_dead = 1; | |
101 | write_unlock_bh(&dn_fib_rules_lock); | |
102 | dn_fib_rule_put(r); | |
103 | err = 0; | |
104 | break; | |
105 | } | |
106 | } | |
107 | ||
108 | return err; | |
109 | } | |
110 | ||
111 | void dn_fib_rule_put(struct dn_fib_rule *r) | |
112 | { | |
113 | if (atomic_dec_and_test(&r->r_clntref)) { | |
114 | if (r->r_dead) | |
115 | kfree(r); | |
116 | else | |
117 | printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n"); | |
118 | } | |
119 | } | |
120 | ||
121 | ||
122 | int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) | |
123 | { | |
124 | struct rtattr **rta = arg; | |
125 | struct rtmsg *rtm = NLMSG_DATA(nlh); | |
126 | struct dn_fib_rule *r, *new_r, **rp; | |
127 | unsigned char table_id; | |
128 | ||
129 | if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16) | |
130 | return -EINVAL; | |
131 | ||
132 | if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ) | |
133 | return -EINVAL; | |
134 | ||
135 | if (rtm->rtm_type == RTN_NAT) | |
136 | return -EINVAL; | |
137 | ||
138 | table_id = rtm->rtm_table; | |
139 | if (table_id == RT_TABLE_UNSPEC) { | |
140 | struct dn_fib_table *tb; | |
141 | if (rtm->rtm_type == RTN_UNICAST) { | |
142 | if ((tb = dn_fib_empty_table()) == NULL) | |
143 | return -ENOBUFS; | |
144 | table_id = tb->n; | |
145 | } | |
146 | } | |
147 | ||
148 | new_r = kmalloc(sizeof(*new_r), GFP_KERNEL); | |
149 | if (!new_r) | |
150 | return -ENOMEM; | |
151 | memset(new_r, 0, sizeof(*new_r)); | |
152 | if (rta[RTA_SRC-1]) | |
153 | memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2); | |
154 | if (rta[RTA_DST-1]) | |
155 | memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2); | |
156 | if (rta[RTA_GATEWAY-1]) | |
157 | memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2); | |
158 | new_r->r_src_len = rtm->rtm_src_len; | |
159 | new_r->r_dst_len = rtm->rtm_dst_len; | |
160 | new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len); | |
161 | new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len); | |
162 | #ifdef CONFIG_DECNET_ROUTE_FWMARK | |
163 | if (rta[RTA_PROTOINFO-1]) | |
164 | memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4); | |
165 | #endif | |
166 | new_r->r_action = rtm->rtm_type; | |
167 | new_r->r_flags = rtm->rtm_flags; | |
168 | if (rta[RTA_PRIORITY-1]) | |
169 | memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4); | |
170 | new_r->r_table = table_id; | |
171 | if (rta[RTA_IIF-1]) { | |
172 | struct net_device *dev; | |
173 | rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ); | |
174 | new_r->r_ifindex = -1; | |
175 | dev = dev_get_by_name(new_r->r_ifname); | |
176 | if (dev) { | |
177 | new_r->r_ifindex = dev->ifindex; | |
178 | dev_put(dev); | |
179 | } | |
180 | } | |
181 | ||
182 | rp = &dn_fib_rules; | |
183 | if (!new_r->r_preference) { | |
184 | r = dn_fib_rules; | |
185 | if (r && (r = r->r_next) != NULL) { | |
186 | rp = &dn_fib_rules->r_next; | |
187 | if (r->r_preference) | |
188 | new_r->r_preference = r->r_preference - 1; | |
189 | } | |
190 | } | |
191 | ||
192 | while((r=*rp) != NULL) { | |
193 | if (r->r_preference > new_r->r_preference) | |
194 | break; | |
195 | rp = &r->r_next; | |
196 | } | |
197 | ||
198 | new_r->r_next = r; | |
199 | atomic_inc(&new_r->r_clntref); | |
200 | write_lock_bh(&dn_fib_rules_lock); | |
201 | *rp = new_r; | |
202 | write_unlock_bh(&dn_fib_rules_lock); | |
203 | return 0; | |
204 | } | |
205 | ||
206 | ||
207 | int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res) | |
208 | { | |
209 | struct dn_fib_rule *r, *policy; | |
210 | struct dn_fib_table *tb; | |
211 | dn_address saddr = flp->fld_src; | |
212 | dn_address daddr = flp->fld_dst; | |
213 | int err; | |
214 | ||
215 | read_lock(&dn_fib_rules_lock); | |
216 | for(r = dn_fib_rules; r; r = r->r_next) { | |
217 | if (((saddr^r->r_src) & r->r_srcmask) || | |
218 | ((daddr^r->r_dst) & r->r_dstmask) || | |
219 | #ifdef CONFIG_DECNET_ROUTE_FWMARK | |
220 | (r->r_fwmark && r->r_fwmark != flp->fld_fwmark) || | |
221 | #endif | |
222 | (r->r_ifindex && r->r_ifindex != flp->iif)) | |
223 | continue; | |
224 | ||
225 | switch(r->r_action) { | |
226 | case RTN_UNICAST: | |
227 | case RTN_NAT: | |
228 | policy = r; | |
229 | break; | |
230 | case RTN_UNREACHABLE: | |
231 | read_unlock(&dn_fib_rules_lock); | |
232 | return -ENETUNREACH; | |
233 | default: | |
234 | case RTN_BLACKHOLE: | |
235 | read_unlock(&dn_fib_rules_lock); | |
236 | return -EINVAL; | |
237 | case RTN_PROHIBIT: | |
238 | read_unlock(&dn_fib_rules_lock); | |
239 | return -EACCES; | |
240 | } | |
241 | ||
242 | if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL) | |
243 | continue; | |
244 | err = tb->lookup(tb, flp, res); | |
245 | if (err == 0) { | |
246 | res->r = policy; | |
247 | if (policy) | |
248 | atomic_inc(&policy->r_clntref); | |
249 | read_unlock(&dn_fib_rules_lock); | |
250 | return 0; | |
251 | } | |
252 | if (err < 0 && err != -EAGAIN) { | |
253 | read_unlock(&dn_fib_rules_lock); | |
254 | return err; | |
255 | } | |
256 | } | |
257 | ||
258 | read_unlock(&dn_fib_rules_lock); | |
259 | return -ESRCH; | |
260 | } | |
261 | ||
262 | unsigned dnet_addr_type(__u16 addr) | |
263 | { | |
264 | struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } }; | |
265 | struct dn_fib_res res; | |
266 | unsigned ret = RTN_UNICAST; | |
267 | struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL]; | |
268 | ||
269 | res.r = NULL; | |
270 | ||
271 | if (tb) { | |
272 | if (!tb->lookup(tb, &fl, &res)) { | |
273 | ret = res.type; | |
274 | dn_fib_res_put(&res); | |
275 | } | |
276 | } | |
277 | return ret; | |
278 | } | |
279 | ||
280 | __u16 dn_fib_rules_policy(__u16 saddr, struct dn_fib_res *res, unsigned *flags) | |
281 | { | |
282 | struct dn_fib_rule *r = res->r; | |
283 | ||
284 | if (r->r_action == RTN_NAT) { | |
285 | int addrtype = dnet_addr_type(r->r_srcmap); | |
286 | ||
287 | if (addrtype == RTN_NAT) { | |
288 | saddr = (saddr&~r->r_srcmask)|r->r_srcmap; | |
289 | *flags |= RTCF_SNAT; | |
290 | } else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) { | |
291 | saddr = r->r_srcmap; | |
292 | *flags |= RTCF_MASQ; | |
293 | } | |
294 | } | |
295 | return saddr; | |
296 | } | |
297 | ||
298 | static void dn_fib_rules_detach(struct net_device *dev) | |
299 | { | |
300 | struct dn_fib_rule *r; | |
301 | ||
302 | for(r = dn_fib_rules; r; r = r->r_next) { | |
303 | if (r->r_ifindex == dev->ifindex) { | |
304 | write_lock_bh(&dn_fib_rules_lock); | |
305 | r->r_ifindex = -1; | |
306 | write_unlock_bh(&dn_fib_rules_lock); | |
307 | } | |
308 | } | |
309 | } | |
310 | ||
311 | static void dn_fib_rules_attach(struct net_device *dev) | |
312 | { | |
313 | struct dn_fib_rule *r; | |
314 | ||
315 | for(r = dn_fib_rules; r; r = r->r_next) { | |
316 | if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) { | |
317 | write_lock_bh(&dn_fib_rules_lock); | |
318 | r->r_ifindex = dev->ifindex; | |
319 | write_unlock_bh(&dn_fib_rules_lock); | |
320 | } | |
321 | } | |
322 | } | |
323 | ||
324 | static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr) | |
325 | { | |
326 | struct net_device *dev = ptr; | |
327 | ||
328 | switch(event) { | |
329 | case NETDEV_UNREGISTER: | |
330 | dn_fib_rules_detach(dev); | |
331 | dn_fib_sync_down(0, dev, 1); | |
332 | case NETDEV_REGISTER: | |
333 | dn_fib_rules_attach(dev); | |
334 | dn_fib_sync_up(dev); | |
335 | } | |
336 | ||
337 | return NOTIFY_DONE; | |
338 | } | |
339 | ||
340 | ||
341 | static struct notifier_block dn_fib_rules_notifier = { | |
342 | .notifier_call = dn_fib_rules_event, | |
343 | }; | |
344 | ||
345 | static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r, struct netlink_callback *cb) | |
346 | { | |
347 | struct rtmsg *rtm; | |
348 | struct nlmsghdr *nlh; | |
349 | unsigned char *b = skb->tail; | |
350 | ||
351 | ||
352 | nlh = NLMSG_PUT(skb, NETLINK_CREDS(cb->skb)->pid, cb->nlh->nlmsg_seq, RTM_NEWRULE, sizeof(*rtm)); | |
353 | rtm = NLMSG_DATA(nlh); | |
354 | rtm->rtm_family = AF_DECnet; | |
355 | rtm->rtm_dst_len = r->r_dst_len; | |
356 | rtm->rtm_src_len = r->r_src_len; | |
357 | rtm->rtm_tos = 0; | |
358 | #ifdef CONFIG_DECNET_ROUTE_FWMARK | |
359 | if (r->r_fwmark) | |
360 | RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark); | |
361 | #endif | |
362 | rtm->rtm_table = r->r_table; | |
363 | rtm->rtm_protocol = 0; | |
364 | rtm->rtm_scope = 0; | |
365 | rtm->rtm_type = r->r_action; | |
366 | rtm->rtm_flags = r->r_flags; | |
367 | ||
368 | if (r->r_dst_len) | |
369 | RTA_PUT(skb, RTA_DST, 2, &r->r_dst); | |
370 | if (r->r_src_len) | |
371 | RTA_PUT(skb, RTA_SRC, 2, &r->r_src); | |
372 | if (r->r_ifname[0]) | |
373 | RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname); | |
374 | if (r->r_preference) | |
375 | RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference); | |
376 | if (r->r_srcmap) | |
377 | RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap); | |
378 | nlh->nlmsg_len = skb->tail - b; | |
379 | return skb->len; | |
380 | ||
381 | nlmsg_failure: | |
382 | rtattr_failure: | |
383 | skb_trim(skb, b - skb->data); | |
384 | return -1; | |
385 | } | |
386 | ||
387 | int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb) | |
388 | { | |
389 | int idx; | |
390 | int s_idx = cb->args[0]; | |
391 | struct dn_fib_rule *r; | |
392 | ||
393 | read_lock(&dn_fib_rules_lock); | |
394 | for(r = dn_fib_rules, idx = 0; r; r = r->r_next, idx++) { | |
395 | if (idx < s_idx) | |
396 | continue; | |
397 | if (dn_fib_fill_rule(skb, r, cb) < 0) | |
398 | break; | |
399 | } | |
400 | read_unlock(&dn_fib_rules_lock); | |
401 | cb->args[0] = idx; | |
402 | ||
403 | return skb->len; | |
404 | } | |
405 | ||
406 | void __init dn_fib_rules_init(void) | |
407 | { | |
408 | register_netdevice_notifier(&dn_fib_rules_notifier); | |
409 | } | |
410 | ||
411 | void __exit dn_fib_rules_cleanup(void) | |
412 | { | |
413 | unregister_netdevice_notifier(&dn_fib_rules_notifier); | |
414 | } | |
415 | ||
416 |