Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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/string.h>
17#include <linux/net.h>
18#include <linux/socket.h>
19#include <linux/sockios.h>
20#include <linux/init.h>
21#include <linux/skbuff.h>
22#include <linux/netlink.h>
23#include <linux/rtnetlink.h>
24#include <linux/proc_fs.h>
25#include <linux/netdevice.h>
26#include <linux/timer.h>
27#include <linux/spinlock.h>
28#include <linux/in_route.h>
29#include <linux/list.h>
30#include <linux/rcupdate.h>
31#include <asm/atomic.h>
32#include <asm/uaccess.h>
33#include <net/neighbour.h>
34#include <net/dst.h>
35#include <net/flow.h>
36#include <net/dn.h>
37#include <net/dn_fib.h>
38#include <net/dn_neigh.h>
39#include <net/dn_dev.h>
40
41struct dn_fib_rule
42{
43 struct hlist_node r_hlist;
44 atomic_t r_clntref;
45 u32 r_preference;
46 unsigned char r_table;
47 unsigned char r_action;
48 unsigned char r_dst_len;
49 unsigned char r_src_len;
50 __le16 r_src;
51 __le16 r_srcmask;
52 __le16 r_dst;
53 __le16 r_dstmask;
54 __le16 r_srcmap;
55 u8 r_flags;
56#ifdef CONFIG_DECNET_ROUTE_FWMARK
57 u32 r_fwmark;
58#endif
59 int r_ifindex;
60 char r_ifname[IFNAMSIZ];
61 int r_dead;
62 struct rcu_head rcu;
63};
64
65static struct dn_fib_rule default_rule = {
66 .r_clntref = ATOMIC_INIT(2),
67 .r_preference = 0x7fff,
68 .r_table = RT_TABLE_MAIN,
69 .r_action = RTN_UNICAST
70};
71
72static struct hlist_head dn_fib_rules;
73
74int 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;
79 struct hlist_node *node;
80 int err = -ESRCH;
81
82 hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
83 if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
84 rtm->rtm_src_len == r->r_src_len &&
85 rtm->rtm_dst_len == r->r_dst_len &&
86 (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) &&
87#ifdef CONFIG_DECNET_ROUTE_FWMARK
88 (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
89#endif
90 (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
91 (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
92 (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
93 (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
94
95 err = -EPERM;
96 if (r == &default_rule)
97 break;
98
99 hlist_del_rcu(&r->r_hlist);
100 r->r_dead = 1;
101 dn_fib_rule_put(r);
102 err = 0;
103 break;
104 }
105 }
106
107 return err;
108}
109
110static inline void dn_fib_rule_put_rcu(struct rcu_head *head)
111{
112 struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu);
113 kfree(r);
114}
115
116void dn_fib_rule_put(struct dn_fib_rule *r)
117{
118 if (atomic_dec_and_test(&r->r_clntref)) {
119 if (r->r_dead)
120 call_rcu(&r->rcu, dn_fib_rule_put_rcu);
121 else
122 printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
123 }
124}
125
126
127int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
128{
129 struct rtattr **rta = arg;
130 struct rtmsg *rtm = NLMSG_DATA(nlh);
131 struct dn_fib_rule *r, *new_r, *last = NULL;
132 struct hlist_node *node = NULL;
133 unsigned char table_id;
134
135 if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
136 return -EINVAL;
137
138 if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
139 return -EINVAL;
140
141 if (rtm->rtm_type == RTN_NAT)
142 return -EINVAL;
143
144 table_id = rtm->rtm_table;
145 if (table_id == RT_TABLE_UNSPEC) {
146 struct dn_fib_table *tb;
147 if (rtm->rtm_type == RTN_UNICAST) {
148 if ((tb = dn_fib_empty_table()) == NULL)
149 return -ENOBUFS;
150 table_id = tb->n;
151 }
152 }
153
154 new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
155 if (!new_r)
156 return -ENOMEM;
157 memset(new_r, 0, sizeof(*new_r));
158
159 if (rta[RTA_SRC-1])
160 memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
161 if (rta[RTA_DST-1])
162 memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2);
163 if (rta[RTA_GATEWAY-1])
164 memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2);
165 new_r->r_src_len = rtm->rtm_src_len;
166 new_r->r_dst_len = rtm->rtm_dst_len;
167 new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len);
168 new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len);
169#ifdef CONFIG_DECNET_ROUTE_FWMARK
170 if (rta[RTA_PROTOINFO-1])
171 memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
172#endif
173 new_r->r_action = rtm->rtm_type;
174 new_r->r_flags = rtm->rtm_flags;
175 if (rta[RTA_PRIORITY-1])
176 memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
177 new_r->r_table = table_id;
178 if (rta[RTA_IIF-1]) {
179 struct net_device *dev;
180 rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
181 new_r->r_ifindex = -1;
182 dev = dev_get_by_name(new_r->r_ifname);
183 if (dev) {
184 new_r->r_ifindex = dev->ifindex;
185 dev_put(dev);
186 }
187 }
188
189 r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist);
190 if (!new_r->r_preference) {
191 if (r && r->r_hlist.next != NULL) {
192 r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist);
193 if (r->r_preference)
194 new_r->r_preference = r->r_preference - 1;
195 }
196 }
197
198 hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
199 if (r->r_preference > new_r->r_preference)
200 break;
201 last = r;
202 }
203 atomic_inc(&new_r->r_clntref);
204
205 if (last)
206 hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist);
207 else
208 hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist);
209 return 0;
210}
211
212
213int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
214{
215 struct dn_fib_rule *r, *policy;
216 struct dn_fib_table *tb;
217 __le16 saddr = flp->fld_src;
218 __le16 daddr = flp->fld_dst;
219 struct hlist_node *node;
220 int err;
221
222 rcu_read_lock();
223
224 hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) {
225 if (((saddr^r->r_src) & r->r_srcmask) ||
226 ((daddr^r->r_dst) & r->r_dstmask) ||
227#ifdef CONFIG_DECNET_ROUTE_FWMARK
228 (r->r_fwmark && r->r_fwmark != flp->fld_fwmark) ||
229#endif
230 (r->r_ifindex && r->r_ifindex != flp->iif))
231 continue;
232
233 switch(r->r_action) {
234 case RTN_UNICAST:
235 case RTN_NAT:
236 policy = r;
237 break;
238 case RTN_UNREACHABLE:
239 rcu_read_unlock();
240 return -ENETUNREACH;
241 default:
242 case RTN_BLACKHOLE:
243 rcu_read_unlock();
244 return -EINVAL;
245 case RTN_PROHIBIT:
246 rcu_read_unlock();
247 return -EACCES;
248 }
249
250 if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
251 continue;
252 err = tb->lookup(tb, flp, res);
253 if (err == 0) {
254 res->r = policy;
255 if (policy)
256 atomic_inc(&policy->r_clntref);
257 rcu_read_unlock();
258 return 0;
259 }
260 if (err < 0 && err != -EAGAIN) {
261 rcu_read_unlock();
262 return err;
263 }
264 }
265
266 rcu_read_unlock();
267 return -ESRCH;
268}
269
270unsigned dnet_addr_type(__le16 addr)
271{
272 struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
273 struct dn_fib_res res;
274 unsigned ret = RTN_UNICAST;
275 struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL];
276
277 res.r = NULL;
278
279 if (tb) {
280 if (!tb->lookup(tb, &fl, &res)) {
281 ret = res.type;
282 dn_fib_res_put(&res);
283 }
284 }
285 return ret;
286}
287
288__le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags)
289{
290 struct dn_fib_rule *r = res->r;
291
292 if (r->r_action == RTN_NAT) {
293 int addrtype = dnet_addr_type(r->r_srcmap);
294
295 if (addrtype == RTN_NAT) {
296 saddr = (saddr&~r->r_srcmask)|r->r_srcmap;
297 *flags |= RTCF_SNAT;
298 } else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) {
299 saddr = r->r_srcmap;
300 *flags |= RTCF_MASQ;
301 }
302 }
303 return saddr;
304}
305
306static void dn_fib_rules_detach(struct net_device *dev)
307{
308 struct hlist_node *node;
309 struct dn_fib_rule *r;
310
311 hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
312 if (r->r_ifindex == dev->ifindex)
313 r->r_ifindex = -1;
314 }
315}
316
317static void dn_fib_rules_attach(struct net_device *dev)
318{
319 struct hlist_node *node;
320 struct dn_fib_rule *r;
321
322 hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
323 if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
324 r->r_ifindex = dev->ifindex;
325 }
326}
327
328static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
329{
330 struct net_device *dev = ptr;
331
332 switch(event) {
333 case NETDEV_UNREGISTER:
334 dn_fib_rules_detach(dev);
335 dn_fib_sync_down(0, dev, 1);
336 case NETDEV_REGISTER:
337 dn_fib_rules_attach(dev);
338 dn_fib_sync_up(dev);
339 }
340
341 return NOTIFY_DONE;
342}
343
344
345static struct notifier_block dn_fib_rules_notifier = {
346 .notifier_call = dn_fib_rules_event,
347};
348
349static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r,
350 struct netlink_callback *cb, unsigned int flags)
351{
352 struct rtmsg *rtm;
353 struct nlmsghdr *nlh;
354 unsigned char *b = skb->tail;
355
356
357 nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
358 rtm = NLMSG_DATA(nlh);
359 rtm->rtm_family = AF_DECnet;
360 rtm->rtm_dst_len = r->r_dst_len;
361 rtm->rtm_src_len = r->r_src_len;
362 rtm->rtm_tos = 0;
363#ifdef CONFIG_DECNET_ROUTE_FWMARK
364 if (r->r_fwmark)
365 RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
366#endif
367 rtm->rtm_table = r->r_table;
368 rtm->rtm_protocol = 0;
369 rtm->rtm_scope = 0;
370 rtm->rtm_type = r->r_action;
371 rtm->rtm_flags = r->r_flags;
372
373 if (r->r_dst_len)
374 RTA_PUT(skb, RTA_DST, 2, &r->r_dst);
375 if (r->r_src_len)
376 RTA_PUT(skb, RTA_SRC, 2, &r->r_src);
377 if (r->r_ifname[0])
378 RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
379 if (r->r_preference)
380 RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
381 if (r->r_srcmap)
382 RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap);
383 nlh->nlmsg_len = skb->tail - b;
384 return skb->len;
385
386nlmsg_failure:
387rtattr_failure:
388 skb_trim(skb, b - skb->data);
389 return -1;
390}
391
392int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
393{
394 int idx = 0;
395 int s_idx = cb->args[0];
396 struct dn_fib_rule *r;
397 struct hlist_node *node;
398
399 rcu_read_lock();
400 hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
401 if (idx < s_idx)
402 continue;
403 if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
404 break;
405 idx++;
406 }
407 rcu_read_unlock();
408 cb->args[0] = idx;
409
410 return skb->len;
411}
412
413void __init dn_fib_rules_init(void)
414{
415 INIT_HLIST_HEAD(&dn_fib_rules);
416 hlist_add_head(&default_rule.r_hlist, &dn_fib_rules);
417 register_netdevice_notifier(&dn_fib_rules_notifier);
418}
419
420void __exit dn_fib_rules_cleanup(void)
421{
422 unregister_netdevice_notifier(&dn_fib_rules_notifier);
423}
424
425