xref: /linux/net/smc/smc_pnet.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9) 
1 /*
2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
3  *
4  *  Generic netlink support functions to configure an SMC-R PNET table
5  *
6  *  Copyright IBM Corp. 2016
7  *
8  *  Author(s):  Thomas Richter <tmricht@linux.vnet.ibm.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/ctype.h>
14 #include <net/netlink.h>
15 #include <net/genetlink.h>
16 
17 #include <uapi/linux/if.h>
18 #include <uapi/linux/smc.h>
19 
20 #include <rdma/ib_verbs.h>
21 
22 #include "smc_pnet.h"
23 #include "smc_ib.h"
24 
25 #define SMC_MAX_PNET_ID_LEN	16	/* Max. length of PNET id */
26 
27 static struct nla_policy smc_pnet_policy[SMC_PNETID_MAX + 1] = {
28 	[SMC_PNETID_NAME] = {
29 		.type = NLA_NUL_STRING,
30 		.len = SMC_MAX_PNET_ID_LEN - 1
31 	},
32 	[SMC_PNETID_ETHNAME] = {
33 		.type = NLA_NUL_STRING,
34 		.len = IFNAMSIZ - 1
35 	},
36 	[SMC_PNETID_IBNAME] = {
37 		.type = NLA_NUL_STRING,
38 		.len = IB_DEVICE_NAME_MAX - 1
39 	},
40 	[SMC_PNETID_IBPORT] = { .type = NLA_U8 }
41 };
42 
43 static struct genl_family smc_pnet_nl_family;
44 
45 /**
46  * struct smc_pnettable - SMC PNET table anchor
47  * @lock: Lock for list action
48  * @pnetlist: List of PNETIDs
49  */
50 static struct smc_pnettable {
51 	rwlock_t lock;
52 	struct list_head pnetlist;
53 } smc_pnettable = {
54 	.pnetlist = LIST_HEAD_INIT(smc_pnettable.pnetlist),
55 	.lock = __RW_LOCK_UNLOCKED(smc_pnettable.lock)
56 };
57 
58 /**
59  * struct smc_pnetentry - pnet identifier name entry
60  * @list: List node.
61  * @pnet_name: Pnet identifier name
62  * @ndev: pointer to network device.
63  * @smcibdev: Pointer to IB device.
64  */
65 struct smc_pnetentry {
66 	struct list_head list;
67 	char pnet_name[SMC_MAX_PNET_ID_LEN + 1];
68 	struct net_device *ndev;
69 	struct smc_ib_device *smcibdev;
70 	u8 ib_port;
71 };
72 
73 /* Check if two RDMA device entries are identical. Use device name and port
74  * number for comparison.
75  */
76 static bool smc_pnet_same_ibname(struct smc_pnetentry *pnetelem, char *ibname,
77 				 u8 ibport)
78 {
79 	return pnetelem->ib_port == ibport &&
80 	       !strncmp(pnetelem->smcibdev->ibdev->name, ibname,
81 			sizeof(pnetelem->smcibdev->ibdev->name));
82 }
83 
84 /* Find a pnetid in the pnet table.
85  */
86 static struct smc_pnetentry *smc_pnet_find_pnetid(char *pnet_name)
87 {
88 	struct smc_pnetentry *pnetelem, *found_pnetelem = NULL;
89 
90 	read_lock(&smc_pnettable.lock);
91 	list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
92 		if (!strncmp(pnetelem->pnet_name, pnet_name,
93 			     sizeof(pnetelem->pnet_name))) {
94 			found_pnetelem = pnetelem;
95 			break;
96 		}
97 	}
98 	read_unlock(&smc_pnettable.lock);
99 	return found_pnetelem;
100 }
101 
102 /* Remove a pnetid from the pnet table.
103  */
104 static int smc_pnet_remove_by_pnetid(char *pnet_name)
105 {
106 	struct smc_pnetentry *pnetelem, *tmp_pe;
107 	int rc = -ENOENT;
108 
109 	write_lock(&smc_pnettable.lock);
110 	list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
111 				 list) {
112 		if (!strncmp(pnetelem->pnet_name, pnet_name,
113 			     sizeof(pnetelem->pnet_name))) {
114 			list_del(&pnetelem->list);
115 			dev_put(pnetelem->ndev);
116 			kfree(pnetelem);
117 			rc = 0;
118 			break;
119 		}
120 	}
121 	write_unlock(&smc_pnettable.lock);
122 	return rc;
123 }
124 
125 /* Remove a pnet entry mentioning a given network device from the pnet table.
126  */
127 static int smc_pnet_remove_by_ndev(struct net_device *ndev)
128 {
129 	struct smc_pnetentry *pnetelem, *tmp_pe;
130 	int rc = -ENOENT;
131 
132 	write_lock(&smc_pnettable.lock);
133 	list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
134 				 list) {
135 		if (pnetelem->ndev == ndev) {
136 			list_del(&pnetelem->list);
137 			dev_put(pnetelem->ndev);
138 			kfree(pnetelem);
139 			rc = 0;
140 			break;
141 		}
142 	}
143 	write_unlock(&smc_pnettable.lock);
144 	return rc;
145 }
146 
147 /* Remove a pnet entry mentioning a given ib device from the pnet table.
148  */
149 int smc_pnet_remove_by_ibdev(struct smc_ib_device *ibdev)
150 {
151 	struct smc_pnetentry *pnetelem, *tmp_pe;
152 	int rc = -ENOENT;
153 
154 	write_lock(&smc_pnettable.lock);
155 	list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
156 				 list) {
157 		if (pnetelem->smcibdev == ibdev) {
158 			list_del(&pnetelem->list);
159 			dev_put(pnetelem->ndev);
160 			kfree(pnetelem);
161 			rc = 0;
162 			break;
163 		}
164 	}
165 	write_unlock(&smc_pnettable.lock);
166 	return rc;
167 }
168 
169 /* Append a pnetid to the end of the pnet table if not already on this list.
170  */
171 static int smc_pnet_enter(struct smc_pnetentry *new_pnetelem)
172 {
173 	struct smc_pnetentry *pnetelem;
174 	int rc = -EEXIST;
175 
176 	write_lock(&smc_pnettable.lock);
177 	list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
178 		if (!strncmp(pnetelem->pnet_name, new_pnetelem->pnet_name,
179 			     sizeof(new_pnetelem->pnet_name)) ||
180 		    !strncmp(pnetelem->ndev->name, new_pnetelem->ndev->name,
181 			     sizeof(new_pnetelem->ndev->name)) ||
182 		    smc_pnet_same_ibname(pnetelem,
183 					 new_pnetelem->smcibdev->ibdev->name,
184 					 new_pnetelem->ib_port))
185 			goto found;
186 	}
187 	list_add_tail(&new_pnetelem->list, &smc_pnettable.pnetlist);
188 	rc = 0;
189 found:
190 	write_unlock(&smc_pnettable.lock);
191 	return rc;
192 }
193 
194 /* The limit for pnetid is 16 characters.
195  * Valid characters should be (single-byte character set) a-z, A-Z, 0-9.
196  * Lower case letters are converted to upper case.
197  * Interior blanks should not be used.
198  */
199 static bool smc_pnetid_valid(const char *pnet_name, char *pnetid)
200 {
201 	char *bf = skip_spaces(pnet_name);
202 	size_t len = strlen(bf);
203 	char *end = bf + len;
204 
205 	if (!len)
206 		return false;
207 	while (--end >= bf && isspace(*end))
208 		;
209 	if (end - bf >= SMC_MAX_PNET_ID_LEN)
210 		return false;
211 	while (bf <= end) {
212 		if (!isalnum(*bf))
213 			return false;
214 		*pnetid++ = islower(*bf) ? toupper(*bf) : *bf;
215 		bf++;
216 	}
217 	*pnetid = '\0';
218 	return true;
219 }
220 
221 /* Find an infiniband device by a given name. The device might not exist. */
222 struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
223 {
224 	struct smc_ib_device *ibdev;
225 
226 	spin_lock(&smc_ib_devices.lock);
227 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
228 		if (!strncmp(ibdev->ibdev->name, ib_name,
229 			     sizeof(ibdev->ibdev->name))) {
230 			goto out;
231 		}
232 	}
233 	ibdev = NULL;
234 out:
235 	spin_unlock(&smc_ib_devices.lock);
236 	return ibdev;
237 }
238 
239 /* Parse the supplied netlink attributes and fill a pnetentry structure.
240  * For ethernet and infiniband device names verify that the devices exist.
241  */
242 static int smc_pnet_fill_entry(struct net *net, struct smc_pnetentry *pnetelem,
243 			       struct nlattr *tb[])
244 {
245 	char *string, *ibname = NULL;
246 	int rc = 0;
247 
248 	memset(pnetelem, 0, sizeof(*pnetelem));
249 	INIT_LIST_HEAD(&pnetelem->list);
250 	if (tb[SMC_PNETID_NAME]) {
251 		string = (char *)nla_data(tb[SMC_PNETID_NAME]);
252 		if (!smc_pnetid_valid(string, pnetelem->pnet_name)) {
253 			rc = -EINVAL;
254 			goto error;
255 		}
256 	}
257 	if (tb[SMC_PNETID_ETHNAME]) {
258 		string = (char *)nla_data(tb[SMC_PNETID_ETHNAME]);
259 		pnetelem->ndev = dev_get_by_name(net, string);
260 		if (!pnetelem->ndev)
261 			return -ENOENT;
262 	}
263 	if (tb[SMC_PNETID_IBNAME]) {
264 		ibname = (char *)nla_data(tb[SMC_PNETID_IBNAME]);
265 		ibname = strim(ibname);
266 		pnetelem->smcibdev = smc_pnet_find_ib(ibname);
267 		if (!pnetelem->smcibdev) {
268 			rc = -ENOENT;
269 			goto error;
270 		}
271 	}
272 	if (tb[SMC_PNETID_IBPORT]) {
273 		pnetelem->ib_port = nla_get_u8(tb[SMC_PNETID_IBPORT]);
274 		if (pnetelem->ib_port > SMC_MAX_PORTS) {
275 			rc = -EINVAL;
276 			goto error;
277 		}
278 	}
279 	return 0;
280 
281 error:
282 	if (pnetelem->ndev)
283 		dev_put(pnetelem->ndev);
284 	return rc;
285 }
286 
287 /* Convert an smc_pnetentry to a netlink attribute sequence */
288 static int smc_pnet_set_nla(struct sk_buff *msg, struct smc_pnetentry *pnetelem)
289 {
290 	if (nla_put_string(msg, SMC_PNETID_NAME, pnetelem->pnet_name) ||
291 	    nla_put_string(msg, SMC_PNETID_ETHNAME, pnetelem->ndev->name) ||
292 	    nla_put_string(msg, SMC_PNETID_IBNAME,
293 			   pnetelem->smcibdev->ibdev->name) ||
294 	    nla_put_u8(msg, SMC_PNETID_IBPORT, pnetelem->ib_port))
295 		return -1;
296 	return 0;
297 }
298 
299 /* Retrieve one PNETID entry */
300 static int smc_pnet_get(struct sk_buff *skb, struct genl_info *info)
301 {
302 	struct smc_pnetentry *pnetelem;
303 	struct sk_buff *msg;
304 	void *hdr;
305 	int rc;
306 
307 	pnetelem = smc_pnet_find_pnetid(
308 				(char *)nla_data(info->attrs[SMC_PNETID_NAME]));
309 	if (!pnetelem)
310 		return -ENOENT;
311 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
312 	if (!msg)
313 		return -ENOMEM;
314 
315 	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
316 			  &smc_pnet_nl_family, 0, SMC_PNETID_GET);
317 	if (!hdr) {
318 		rc = -EMSGSIZE;
319 		goto err_out;
320 	}
321 
322 	if (smc_pnet_set_nla(msg, pnetelem)) {
323 		rc = -ENOBUFS;
324 		goto err_out;
325 	}
326 
327 	genlmsg_end(msg, hdr);
328 	return genlmsg_reply(msg, info);
329 
330 err_out:
331 	nlmsg_free(msg);
332 	return rc;
333 }
334 
335 static int smc_pnet_add(struct sk_buff *skb, struct genl_info *info)
336 {
337 	struct net *net = genl_info_net(info);
338 	struct smc_pnetentry *pnetelem;
339 	int rc;
340 
341 	pnetelem = kzalloc(sizeof(*pnetelem), GFP_KERNEL);
342 	if (!pnetelem)
343 		return -ENOMEM;
344 	rc = smc_pnet_fill_entry(net, pnetelem, info->attrs);
345 	if (!rc)
346 		rc = smc_pnet_enter(pnetelem);
347 	if (rc) {
348 		kfree(pnetelem);
349 		return rc;
350 	}
351 	rc = smc_ib_remember_port_attr(pnetelem->smcibdev, pnetelem->ib_port);
352 	if (rc)
353 		smc_pnet_remove_by_pnetid(pnetelem->pnet_name);
354 	return rc;
355 }
356 
357 static int smc_pnet_del(struct sk_buff *skb, struct genl_info *info)
358 {
359 	return smc_pnet_remove_by_pnetid(
360 				(char *)nla_data(info->attrs[SMC_PNETID_NAME]));
361 }
362 
363 static int smc_pnet_dump_start(struct netlink_callback *cb)
364 {
365 	cb->args[0] = 0;
366 	return 0;
367 }
368 
369 static int smc_pnet_dumpinfo(struct sk_buff *skb,
370 			     u32 portid, u32 seq, u32 flags,
371 			     struct smc_pnetentry *pnetelem)
372 {
373 	void *hdr;
374 
375 	hdr = genlmsg_put(skb, portid, seq, &smc_pnet_nl_family,
376 			  flags, SMC_PNETID_GET);
377 	if (!hdr)
378 		return -ENOMEM;
379 	if (smc_pnet_set_nla(skb, pnetelem) < 0) {
380 		genlmsg_cancel(skb, hdr);
381 		return -EMSGSIZE;
382 	}
383 	genlmsg_end(skb, hdr);
384 	return 0;
385 }
386 
387 static int smc_pnet_dump(struct sk_buff *skb, struct netlink_callback *cb)
388 {
389 	struct smc_pnetentry *pnetelem;
390 	int idx = 0;
391 
392 	read_lock(&smc_pnettable.lock);
393 	list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
394 		if (idx++ < cb->args[0])
395 			continue;
396 		if (smc_pnet_dumpinfo(skb, NETLINK_CB(cb->skb).portid,
397 				      cb->nlh->nlmsg_seq, NLM_F_MULTI,
398 				      pnetelem)) {
399 			--idx;
400 			break;
401 		}
402 	}
403 	cb->args[0] = idx;
404 	read_unlock(&smc_pnettable.lock);
405 	return skb->len;
406 }
407 
408 /* Remove and delete all pnetids from pnet table.
409  */
410 static int smc_pnet_flush(struct sk_buff *skb, struct genl_info *info)
411 {
412 	struct smc_pnetentry *pnetelem, *tmp_pe;
413 
414 	write_lock(&smc_pnettable.lock);
415 	list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
416 				 list) {
417 		list_del(&pnetelem->list);
418 		dev_put(pnetelem->ndev);
419 		kfree(pnetelem);
420 	}
421 	write_unlock(&smc_pnettable.lock);
422 	return 0;
423 }
424 
425 /* SMC_PNETID generic netlink operation definition */
426 static const struct genl_ops smc_pnet_ops[] = {
427 	{
428 		.cmd = SMC_PNETID_GET,
429 		.flags = GENL_ADMIN_PERM,
430 		.policy = smc_pnet_policy,
431 		.doit = smc_pnet_get,
432 		.dumpit = smc_pnet_dump,
433 		.start = smc_pnet_dump_start
434 	},
435 	{
436 		.cmd = SMC_PNETID_ADD,
437 		.flags = GENL_ADMIN_PERM,
438 		.policy = smc_pnet_policy,
439 		.doit = smc_pnet_add
440 	},
441 	{
442 		.cmd = SMC_PNETID_DEL,
443 		.flags = GENL_ADMIN_PERM,
444 		.policy = smc_pnet_policy,
445 		.doit = smc_pnet_del
446 	},
447 	{
448 		.cmd = SMC_PNETID_FLUSH,
449 		.flags = GENL_ADMIN_PERM,
450 		.policy = smc_pnet_policy,
451 		.doit = smc_pnet_flush
452 	}
453 };
454 
455 /* SMC_PNETID family definition */
456 static struct genl_family smc_pnet_nl_family = {
457 	.hdrsize = 0,
458 	.name = SMCR_GENL_FAMILY_NAME,
459 	.version = SMCR_GENL_FAMILY_VERSION,
460 	.maxattr = SMC_PNETID_MAX,
461 	.netnsok = true,
462 	.module = THIS_MODULE,
463 	.ops = smc_pnet_ops,
464 	.n_ops =  ARRAY_SIZE(smc_pnet_ops)
465 };
466 
467 static int smc_pnet_netdev_event(struct notifier_block *this,
468 				 unsigned long event, void *ptr)
469 {
470 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
471 
472 	switch (event) {
473 	case NETDEV_REBOOT:
474 	case NETDEV_UNREGISTER:
475 		smc_pnet_remove_by_ndev(event_dev);
476 	default:
477 		break;
478 	}
479 	return NOTIFY_DONE;
480 }
481 
482 static struct notifier_block smc_netdev_notifier = {
483 	.notifier_call = smc_pnet_netdev_event
484 };
485 
486 int __init smc_pnet_init(void)
487 {
488 	int rc;
489 
490 	rc = genl_register_family(&smc_pnet_nl_family);
491 	if (rc)
492 		return rc;
493 	rc = register_netdevice_notifier(&smc_netdev_notifier);
494 	if (rc)
495 		genl_unregister_family(&smc_pnet_nl_family);
496 	return rc;
497 }
498 
499 void smc_pnet_exit(void)
500 {
501 	smc_pnet_flush(NULL, NULL);
502 	unregister_netdevice_notifier(&smc_netdev_notifier);
503 	genl_unregister_family(&smc_pnet_nl_family);
504 }
505 
506 /* PNET table analysis for a given sock:
507  * determine ib_device and port belonging to used internal TCP socket
508  * ethernet interface.
509  */
510 void smc_pnet_find_roce_resource(struct sock *sk,
511 				 struct smc_ib_device **smcibdev, u8 *ibport)
512 {
513 	struct dst_entry *dst = sk_dst_get(sk);
514 	struct smc_pnetentry *pnetelem;
515 
516 	*smcibdev = NULL;
517 	*ibport = 0;
518 
519 	if (!dst)
520 		return;
521 	if (!dst->dev)
522 		goto out_rel;
523 	read_lock(&smc_pnettable.lock);
524 	list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
525 		if (dst->dev == pnetelem->ndev) {
526 			*smcibdev = pnetelem->smcibdev;
527 			*ibport = pnetelem->ib_port;
528 			break;
529 		}
530 	}
531 	read_unlock(&smc_pnettable.lock);
532 out_rel:
533 	dst_release(dst);
534 }
535