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36#include <linux/mutex.h>
37#include <linux/inetdevice.h>
38#include <linux/slab.h>
39#include <linux/workqueue.h>
40#include <linux/module.h>
41#include <net/arp.h>
42#include <net/neighbour.h>
43#include <net/route.h>
44#include <net/netevent.h>
45#include <net/addrconf.h>
46#include <net/ip6_route.h>
47#include <rdma/ib_addr.h>
48
49MODULE_AUTHOR("Sean Hefty");
50MODULE_DESCRIPTION("IB Address Translation");
51MODULE_LICENSE("Dual BSD/GPL");
52
53struct addr_req {
54 struct list_head list;
55 struct sockaddr_storage src_addr;
56 struct sockaddr_storage dst_addr;
57 struct rdma_dev_addr *addr;
58 struct rdma_addr_client *client;
59 void *context;
60 void (*callback)(int status, struct sockaddr *src_addr,
61 struct rdma_dev_addr *addr, void *context);
62 unsigned long timeout;
63 int status;
64};
65
66static void process_req(struct work_struct *work);
67
68static DEFINE_MUTEX(lock);
69static LIST_HEAD(req_list);
70static DECLARE_DELAYED_WORK(work, process_req);
71static struct workqueue_struct *addr_wq;
72
73void rdma_addr_register_client(struct rdma_addr_client *client)
74{
75 atomic_set(&client->refcount, 1);
76 init_completion(&client->comp);
77}
78EXPORT_SYMBOL(rdma_addr_register_client);
79
80static inline void put_client(struct rdma_addr_client *client)
81{
82 if (atomic_dec_and_test(&client->refcount))
83 complete(&client->comp);
84}
85
86void rdma_addr_unregister_client(struct rdma_addr_client *client)
87{
88 put_client(client);
89 wait_for_completion(&client->comp);
90}
91EXPORT_SYMBOL(rdma_addr_unregister_client);
92
93int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
94 const unsigned char *dst_dev_addr)
95{
96 dev_addr->dev_type = dev->type;
97 memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
98 memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
99 if (dst_dev_addr)
100 memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
101 dev_addr->bound_dev_if = dev->ifindex;
102 return 0;
103}
104EXPORT_SYMBOL(rdma_copy_addr);
105
106int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
107{
108 struct net_device *dev;
109 int ret = -EADDRNOTAVAIL;
110
111 if (dev_addr->bound_dev_if) {
112 dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
113 if (!dev)
114 return -ENODEV;
115 ret = rdma_copy_addr(dev_addr, dev, NULL);
116 dev_put(dev);
117 return ret;
118 }
119
120 switch (addr->sa_family) {
121 case AF_INET:
122 dev = ip_dev_find(&init_net,
123 ((struct sockaddr_in *) addr)->sin_addr.s_addr);
124
125 if (!dev)
126 return ret;
127
128 ret = rdma_copy_addr(dev_addr, dev, NULL);
129 dev_put(dev);
130 break;
131
132#if IS_ENABLED(CONFIG_IPV6)
133 case AF_INET6:
134 rcu_read_lock();
135 for_each_netdev_rcu(&init_net, dev) {
136 if (ipv6_chk_addr(&init_net,
137 &((struct sockaddr_in6 *) addr)->sin6_addr,
138 dev, 1)) {
139 ret = rdma_copy_addr(dev_addr, dev, NULL);
140 break;
141 }
142 }
143 rcu_read_unlock();
144 break;
145#endif
146 }
147 return ret;
148}
149EXPORT_SYMBOL(rdma_translate_ip);
150
151static void set_timeout(unsigned long time)
152{
153 unsigned long delay;
154
155 cancel_delayed_work(&work);
156
157 delay = time - jiffies;
158 if ((long)delay <= 0)
159 delay = 1;
160
161 queue_delayed_work(addr_wq, &work, delay);
162}
163
164static void queue_req(struct addr_req *req)
165{
166 struct addr_req *temp_req;
167
168 mutex_lock(&lock);
169 list_for_each_entry_reverse(temp_req, &req_list, list) {
170 if (time_after_eq(req->timeout, temp_req->timeout))
171 break;
172 }
173
174 list_add(&req->list, &temp_req->list);
175
176 if (req_list.next == &req->list)
177 set_timeout(req->timeout);
178 mutex_unlock(&lock);
179}
180
181static int dst_fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr, void *daddr)
182{
183 struct neighbour *n;
184 int ret;
185
186 n = dst_neigh_lookup(dst, daddr);
187
188 rcu_read_lock();
189 if (!n || !(n->nud_state & NUD_VALID)) {
190 if (n)
191 neigh_event_send(n, NULL);
192 ret = -ENODATA;
193 } else {
194 ret = rdma_copy_addr(dev_addr, dst->dev, n->ha);
195 }
196 rcu_read_unlock();
197
198 if (n)
199 neigh_release(n);
200
201 return ret;
202}
203
204static int addr4_resolve(struct sockaddr_in *src_in,
205 struct sockaddr_in *dst_in,
206 struct rdma_dev_addr *addr)
207{
208 __be32 src_ip = src_in->sin_addr.s_addr;
209 __be32 dst_ip = dst_in->sin_addr.s_addr;
210 struct rtable *rt;
211 struct flowi4 fl4;
212 int ret;
213
214 memset(&fl4, 0, sizeof(fl4));
215 fl4.daddr = dst_ip;
216 fl4.saddr = src_ip;
217 fl4.flowi4_oif = addr->bound_dev_if;
218 rt = ip_route_output_key(&init_net, &fl4);
219 if (IS_ERR(rt)) {
220 ret = PTR_ERR(rt);
221 goto out;
222 }
223 src_in->sin_family = AF_INET;
224 src_in->sin_addr.s_addr = fl4.saddr;
225
226 if (rt->dst.dev->flags & IFF_LOOPBACK) {
227 ret = rdma_translate_ip((struct sockaddr *) dst_in, addr);
228 if (!ret)
229 memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
230 goto put;
231 }
232
233
234 if (rt->dst.dev->flags & IFF_NOARP) {
235 ret = rdma_copy_addr(addr, rt->dst.dev, NULL);
236 goto put;
237 }
238
239 ret = dst_fetch_ha(&rt->dst, addr, &fl4.daddr);
240put:
241 ip_rt_put(rt);
242out:
243 return ret;
244}
245
246#if IS_ENABLED(CONFIG_IPV6)
247static int addr6_resolve(struct sockaddr_in6 *src_in,
248 struct sockaddr_in6 *dst_in,
249 struct rdma_dev_addr *addr)
250{
251 struct flowi6 fl6;
252 struct dst_entry *dst;
253 int ret;
254
255 memset(&fl6, 0, sizeof fl6);
256 fl6.daddr = dst_in->sin6_addr;
257 fl6.saddr = src_in->sin6_addr;
258 fl6.flowi6_oif = addr->bound_dev_if;
259
260 dst = ip6_route_output(&init_net, NULL, &fl6);
261 if ((ret = dst->error))
262 goto put;
263
264 if (ipv6_addr_any(&fl6.saddr)) {
265 ret = ipv6_dev_get_saddr(&init_net, ip6_dst_idev(dst)->dev,
266 &fl6.daddr, 0, &fl6.saddr);
267 if (ret)
268 goto put;
269
270 src_in->sin6_family = AF_INET6;
271 src_in->sin6_addr = fl6.saddr;
272 }
273
274 if (dst->dev->flags & IFF_LOOPBACK) {
275 ret = rdma_translate_ip((struct sockaddr *) dst_in, addr);
276 if (!ret)
277 memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
278 goto put;
279 }
280
281
282 if (dst->dev->flags & IFF_NOARP) {
283 ret = rdma_copy_addr(addr, dst->dev, NULL);
284 goto put;
285 }
286
287 ret = dst_fetch_ha(dst, addr, &fl6.daddr);
288put:
289 dst_release(dst);
290 return ret;
291}
292#else
293static int addr6_resolve(struct sockaddr_in6 *src_in,
294 struct sockaddr_in6 *dst_in,
295 struct rdma_dev_addr *addr)
296{
297 return -EADDRNOTAVAIL;
298}
299#endif
300
301static int addr_resolve(struct sockaddr *src_in,
302 struct sockaddr *dst_in,
303 struct rdma_dev_addr *addr)
304{
305 if (src_in->sa_family == AF_INET) {
306 return addr4_resolve((struct sockaddr_in *) src_in,
307 (struct sockaddr_in *) dst_in, addr);
308 } else
309 return addr6_resolve((struct sockaddr_in6 *) src_in,
310 (struct sockaddr_in6 *) dst_in, addr);
311}
312
313static void process_req(struct work_struct *work)
314{
315 struct addr_req *req, *temp_req;
316 struct sockaddr *src_in, *dst_in;
317 struct list_head done_list;
318
319 INIT_LIST_HEAD(&done_list);
320
321 mutex_lock(&lock);
322 list_for_each_entry_safe(req, temp_req, &req_list, list) {
323 if (req->status == -ENODATA) {
324 src_in = (struct sockaddr *) &req->src_addr;
325 dst_in = (struct sockaddr *) &req->dst_addr;
326 req->status = addr_resolve(src_in, dst_in, req->addr);
327 if (req->status && time_after_eq(jiffies, req->timeout))
328 req->status = -ETIMEDOUT;
329 else if (req->status == -ENODATA)
330 continue;
331 }
332 list_move_tail(&req->list, &done_list);
333 }
334
335 if (!list_empty(&req_list)) {
336 req = list_entry(req_list.next, struct addr_req, list);
337 set_timeout(req->timeout);
338 }
339 mutex_unlock(&lock);
340
341 list_for_each_entry_safe(req, temp_req, &done_list, list) {
342 list_del(&req->list);
343 req->callback(req->status, (struct sockaddr *) &req->src_addr,
344 req->addr, req->context);
345 put_client(req->client);
346 kfree(req);
347 }
348}
349
350int rdma_resolve_ip(struct rdma_addr_client *client,
351 struct sockaddr *src_addr, struct sockaddr *dst_addr,
352 struct rdma_dev_addr *addr, int timeout_ms,
353 void (*callback)(int status, struct sockaddr *src_addr,
354 struct rdma_dev_addr *addr, void *context),
355 void *context)
356{
357 struct sockaddr *src_in, *dst_in;
358 struct addr_req *req;
359 int ret = 0;
360
361 req = kzalloc(sizeof *req, GFP_KERNEL);
362 if (!req)
363 return -ENOMEM;
364
365 src_in = (struct sockaddr *) &req->src_addr;
366 dst_in = (struct sockaddr *) &req->dst_addr;
367
368 if (src_addr) {
369 if (src_addr->sa_family != dst_addr->sa_family) {
370 ret = -EINVAL;
371 goto err;
372 }
373
374 memcpy(src_in, src_addr, ip_addr_size(src_addr));
375 } else {
376 src_in->sa_family = dst_addr->sa_family;
377 }
378
379 memcpy(dst_in, dst_addr, ip_addr_size(dst_addr));
380 req->addr = addr;
381 req->callback = callback;
382 req->context = context;
383 req->client = client;
384 atomic_inc(&client->refcount);
385
386 req->status = addr_resolve(src_in, dst_in, addr);
387 switch (req->status) {
388 case 0:
389 req->timeout = jiffies;
390 queue_req(req);
391 break;
392 case -ENODATA:
393 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
394 queue_req(req);
395 break;
396 default:
397 ret = req->status;
398 atomic_dec(&client->refcount);
399 goto err;
400 }
401 return ret;
402err:
403 kfree(req);
404 return ret;
405}
406EXPORT_SYMBOL(rdma_resolve_ip);
407
408void rdma_addr_cancel(struct rdma_dev_addr *addr)
409{
410 struct addr_req *req, *temp_req;
411
412 mutex_lock(&lock);
413 list_for_each_entry_safe(req, temp_req, &req_list, list) {
414 if (req->addr == addr) {
415 req->status = -ECANCELED;
416 req->timeout = jiffies;
417 list_move(&req->list, &req_list);
418 set_timeout(req->timeout);
419 break;
420 }
421 }
422 mutex_unlock(&lock);
423}
424EXPORT_SYMBOL(rdma_addr_cancel);
425
426static int netevent_callback(struct notifier_block *self, unsigned long event,
427 void *ctx)
428{
429 if (event == NETEVENT_NEIGH_UPDATE) {
430 struct neighbour *neigh = ctx;
431
432 if (neigh->nud_state & NUD_VALID) {
433 set_timeout(jiffies);
434 }
435 }
436 return 0;
437}
438
439static struct notifier_block nb = {
440 .notifier_call = netevent_callback
441};
442
443static int __init addr_init(void)
444{
445 addr_wq = create_singlethread_workqueue("ib_addr");
446 if (!addr_wq)
447 return -ENOMEM;
448
449 register_netevent_notifier(&nb);
450 return 0;
451}
452
453static void __exit addr_cleanup(void)
454{
455 unregister_netevent_notifier(&nb);
456 destroy_workqueue(addr_wq);
457}
458
459module_init(addr_init);
460module_exit(addr_cleanup);
461
