1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2010 Cisco Systems, Inc.
4 */
5
6 /* XXX TBD some includes may be extraneous */
7
8 #include <linux/module.h>
9 #include <linux/moduleparam.h>
10 #include <linux/utsname.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/kthread.h>
14 #include <linux/types.h>
15 #include <linux/string.h>
16 #include <linux/configfs.h>
17 #include <linux/ctype.h>
18 #include <linux/hash.h>
19 #include <linux/rcupdate.h>
20 #include <linux/rculist.h>
21 #include <linux/kref.h>
22 #include <asm/unaligned.h>
23 #include <scsi/libfc.h>
24
25 #include <target/target_core_base.h>
26 #include <target/target_core_fabric.h>
27
28 #include "tcm_fc.h"
29
30 #define TFC_SESS_DBG(lport, fmt, args...) \
31 pr_debug("host%u: rport %6.6x: " fmt, \
32 (lport)->host->host_no, \
33 (lport)->port_id, ##args )
34
35 static void ft_sess_delete_all(struct ft_tport *);
36
37 /*
38 * Lookup or allocate target local port.
39 * Caller holds ft_lport_lock.
40 */
ft_tport_get(struct fc_lport * lport)41 static struct ft_tport *ft_tport_get(struct fc_lport *lport)
42 {
43 struct ft_tpg *tpg;
44 struct ft_tport *tport;
45 int i;
46
47 tport = rcu_dereference_protected(lport->prov[FC_TYPE_FCP],
48 lockdep_is_held(&ft_lport_lock));
49 if (tport && tport->tpg)
50 return tport;
51
52 tpg = ft_lport_find_tpg(lport);
53 if (!tpg)
54 return NULL;
55
56 if (tport) {
57 tport->tpg = tpg;
58 tpg->tport = tport;
59 return tport;
60 }
61
62 tport = kzalloc(sizeof(*tport), GFP_KERNEL);
63 if (!tport)
64 return NULL;
65
66 tport->lport = lport;
67 tport->tpg = tpg;
68 tpg->tport = tport;
69 for (i = 0; i < FT_SESS_HASH_SIZE; i++)
70 INIT_HLIST_HEAD(&tport->hash[i]);
71
72 rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
73 return tport;
74 }
75
76 /*
77 * Delete a target local port.
78 * Caller holds ft_lport_lock.
79 */
ft_tport_delete(struct ft_tport * tport)80 static void ft_tport_delete(struct ft_tport *tport)
81 {
82 struct fc_lport *lport;
83 struct ft_tpg *tpg;
84
85 ft_sess_delete_all(tport);
86 lport = tport->lport;
87 lport->service_params &= ~FCP_SPPF_TARG_FCN;
88 BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
89 RCU_INIT_POINTER(lport->prov[FC_TYPE_FCP], NULL);
90
91 tpg = tport->tpg;
92 if (tpg) {
93 tpg->tport = NULL;
94 tport->tpg = NULL;
95 }
96 kfree_rcu(tport, rcu);
97 }
98
99 /*
100 * Add local port.
101 * Called thru fc_lport_iterate().
102 */
ft_lport_add(struct fc_lport * lport,void * arg)103 void ft_lport_add(struct fc_lport *lport, void *arg)
104 {
105 mutex_lock(&ft_lport_lock);
106 ft_tport_get(lport);
107 lport->service_params |= FCP_SPPF_TARG_FCN;
108 mutex_unlock(&ft_lport_lock);
109 }
110
111 /*
112 * Delete local port.
113 * Called thru fc_lport_iterate().
114 */
ft_lport_del(struct fc_lport * lport,void * arg)115 void ft_lport_del(struct fc_lport *lport, void *arg)
116 {
117 struct ft_tport *tport;
118
119 mutex_lock(&ft_lport_lock);
120 tport = lport->prov[FC_TYPE_FCP];
121 if (tport)
122 ft_tport_delete(tport);
123 mutex_unlock(&ft_lport_lock);
124 }
125
126 /*
127 * Notification of local port change from libfc.
128 * Create or delete local port and associated tport.
129 */
ft_lport_notify(struct notifier_block * nb,unsigned long event,void * arg)130 int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
131 {
132 struct fc_lport *lport = arg;
133
134 switch (event) {
135 case FC_LPORT_EV_ADD:
136 ft_lport_add(lport, NULL);
137 break;
138 case FC_LPORT_EV_DEL:
139 ft_lport_del(lport, NULL);
140 break;
141 }
142 return NOTIFY_DONE;
143 }
144
145 /*
146 * Hash function for FC_IDs.
147 */
ft_sess_hash(u32 port_id)148 static u32 ft_sess_hash(u32 port_id)
149 {
150 return hash_32(port_id, FT_SESS_HASH_BITS);
151 }
152
153 /*
154 * Find session in local port.
155 * Sessions and hash lists are RCU-protected.
156 * A reference is taken which must be eventually freed.
157 */
ft_sess_get(struct fc_lport * lport,u32 port_id)158 static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
159 {
160 struct ft_tport *tport;
161 struct hlist_head *head;
162 struct ft_sess *sess;
163 char *reason = "no session created";
164
165 rcu_read_lock();
166 tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
167 if (!tport) {
168 reason = "not an FCP port";
169 goto out;
170 }
171
172 head = &tport->hash[ft_sess_hash(port_id)];
173 hlist_for_each_entry_rcu(sess, head, hash) {
174 if (sess->port_id == port_id) {
175 kref_get(&sess->kref);
176 rcu_read_unlock();
177 TFC_SESS_DBG(lport, "port_id %x found %p\n",
178 port_id, sess);
179 return sess;
180 }
181 }
182 out:
183 rcu_read_unlock();
184 TFC_SESS_DBG(lport, "port_id %x not found, %s\n",
185 port_id, reason);
186 return NULL;
187 }
188
ft_sess_alloc_cb(struct se_portal_group * se_tpg,struct se_session * se_sess,void * p)189 static int ft_sess_alloc_cb(struct se_portal_group *se_tpg,
190 struct se_session *se_sess, void *p)
191 {
192 struct ft_sess *sess = p;
193 struct ft_tport *tport = sess->tport;
194 struct hlist_head *head = &tport->hash[ft_sess_hash(sess->port_id)];
195
196 TFC_SESS_DBG(tport->lport, "port_id %x sess %p\n", sess->port_id, sess);
197 hlist_add_head_rcu(&sess->hash, head);
198 tport->sess_count++;
199
200 return 0;
201 }
202
203 /*
204 * Allocate session and enter it in the hash for the local port.
205 * Caller holds ft_lport_lock.
206 */
ft_sess_create(struct ft_tport * tport,u32 port_id,struct fc_rport_priv * rdata)207 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
208 struct fc_rport_priv *rdata)
209 {
210 struct se_portal_group *se_tpg = &tport->tpg->se_tpg;
211 struct ft_sess *sess;
212 struct hlist_head *head;
213 unsigned char initiatorname[TRANSPORT_IQN_LEN];
214
215 ft_format_wwn(&initiatorname[0], TRANSPORT_IQN_LEN, rdata->ids.port_name);
216
217 head = &tport->hash[ft_sess_hash(port_id)];
218 hlist_for_each_entry_rcu(sess, head, hash)
219 if (sess->port_id == port_id)
220 return sess;
221
222 sess = kzalloc(sizeof(*sess), GFP_KERNEL);
223 if (!sess)
224 return ERR_PTR(-ENOMEM);
225
226 kref_init(&sess->kref); /* ref for table entry */
227 sess->tport = tport;
228 sess->port_id = port_id;
229
230 sess->se_sess = target_setup_session(se_tpg, TCM_FC_DEFAULT_TAGS,
231 sizeof(struct ft_cmd),
232 TARGET_PROT_NORMAL, &initiatorname[0],
233 sess, ft_sess_alloc_cb);
234 if (IS_ERR(sess->se_sess)) {
235 int rc = PTR_ERR(sess->se_sess);
236 kfree(sess);
237 sess = ERR_PTR(rc);
238 }
239 return sess;
240 }
241
242 /*
243 * Unhash the session.
244 * Caller holds ft_lport_lock.
245 */
ft_sess_unhash(struct ft_sess * sess)246 static void ft_sess_unhash(struct ft_sess *sess)
247 {
248 struct ft_tport *tport = sess->tport;
249
250 hlist_del_rcu(&sess->hash);
251 BUG_ON(!tport->sess_count);
252 tport->sess_count--;
253 sess->port_id = -1;
254 sess->params = 0;
255 }
256
257 /*
258 * Delete session from hash.
259 * Caller holds ft_lport_lock.
260 */
ft_sess_delete(struct ft_tport * tport,u32 port_id)261 static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
262 {
263 struct hlist_head *head;
264 struct ft_sess *sess;
265
266 head = &tport->hash[ft_sess_hash(port_id)];
267 hlist_for_each_entry_rcu(sess, head, hash) {
268 if (sess->port_id == port_id) {
269 ft_sess_unhash(sess);
270 return sess;
271 }
272 }
273 return NULL;
274 }
275
ft_close_sess(struct ft_sess * sess)276 static void ft_close_sess(struct ft_sess *sess)
277 {
278 target_stop_session(sess->se_sess);
279 target_wait_for_sess_cmds(sess->se_sess);
280 ft_sess_put(sess);
281 }
282
283 /*
284 * Delete all sessions from tport.
285 * Caller holds ft_lport_lock.
286 */
ft_sess_delete_all(struct ft_tport * tport)287 static void ft_sess_delete_all(struct ft_tport *tport)
288 {
289 struct hlist_head *head;
290 struct ft_sess *sess;
291
292 for (head = tport->hash;
293 head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
294 hlist_for_each_entry_rcu(sess, head, hash) {
295 ft_sess_unhash(sess);
296 ft_close_sess(sess); /* release from table */
297 }
298 }
299 }
300
301 /*
302 * TCM ops for sessions.
303 */
304
305 /*
306 * Remove session and send PRLO.
307 * This is called when the ACL is being deleted or queue depth is changing.
308 */
ft_sess_close(struct se_session * se_sess)309 void ft_sess_close(struct se_session *se_sess)
310 {
311 struct ft_sess *sess = se_sess->fabric_sess_ptr;
312 u32 port_id;
313
314 mutex_lock(&ft_lport_lock);
315 port_id = sess->port_id;
316 if (port_id == -1) {
317 mutex_unlock(&ft_lport_lock);
318 return;
319 }
320 TFC_SESS_DBG(sess->tport->lport, "port_id %x close session\n", port_id);
321 ft_sess_unhash(sess);
322 mutex_unlock(&ft_lport_lock);
323 ft_close_sess(sess);
324 /* XXX Send LOGO or PRLO */
325 synchronize_rcu(); /* let transport deregister happen */
326 }
327
ft_sess_get_index(struct se_session * se_sess)328 u32 ft_sess_get_index(struct se_session *se_sess)
329 {
330 struct ft_sess *sess = se_sess->fabric_sess_ptr;
331
332 return sess->port_id; /* XXX TBD probably not what is needed */
333 }
334
ft_sess_get_port_name(struct se_session * se_sess,unsigned char * buf,u32 len)335 u32 ft_sess_get_port_name(struct se_session *se_sess,
336 unsigned char *buf, u32 len)
337 {
338 struct ft_sess *sess = se_sess->fabric_sess_ptr;
339
340 return ft_format_wwn(buf, len, sess->port_name);
341 }
342
343 /*
344 * libfc ops involving sessions.
345 */
346
ft_prli_locked(struct fc_rport_priv * rdata,u32 spp_len,const struct fc_els_spp * rspp,struct fc_els_spp * spp)347 static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
348 const struct fc_els_spp *rspp, struct fc_els_spp *spp)
349 {
350 struct ft_tport *tport;
351 struct ft_sess *sess;
352 u32 fcp_parm;
353
354 tport = ft_tport_get(rdata->local_port);
355 if (!tport)
356 goto not_target; /* not a target for this local port */
357
358 if (!rspp)
359 goto fill;
360
361 if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
362 return FC_SPP_RESP_NO_PA;
363
364 /*
365 * If both target and initiator bits are off, the SPP is invalid.
366 */
367 fcp_parm = ntohl(rspp->spp_params);
368 if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
369 return FC_SPP_RESP_INVL;
370
371 /*
372 * Create session (image pair) only if requested by
373 * EST_IMG_PAIR flag and if the requestor is an initiator.
374 */
375 if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
376 spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
377 if (!(fcp_parm & FCP_SPPF_INIT_FCN))
378 return FC_SPP_RESP_CONF;
379 sess = ft_sess_create(tport, rdata->ids.port_id, rdata);
380 if (IS_ERR(sess)) {
381 if (PTR_ERR(sess) == -EACCES) {
382 spp->spp_flags &= ~FC_SPP_EST_IMG_PAIR;
383 return FC_SPP_RESP_CONF;
384 } else
385 return FC_SPP_RESP_RES;
386 }
387 if (!sess->params)
388 rdata->prli_count++;
389 sess->params = fcp_parm;
390 sess->port_name = rdata->ids.port_name;
391 sess->max_frame = rdata->maxframe_size;
392
393 /* XXX TBD - clearing actions. unit attn, see 4.10 */
394 }
395
396 /*
397 * OR in our service parameters with other provider (initiator), if any.
398 */
399 fill:
400 fcp_parm = ntohl(spp->spp_params);
401 fcp_parm &= ~FCP_SPPF_RETRY;
402 spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
403 return FC_SPP_RESP_ACK;
404
405 not_target:
406 fcp_parm = ntohl(spp->spp_params);
407 fcp_parm &= ~FCP_SPPF_TARG_FCN;
408 spp->spp_params = htonl(fcp_parm);
409 return 0;
410 }
411
412 /**
413 * ft_prli() - Handle incoming or outgoing PRLI for the FCP target
414 * @rdata: remote port private
415 * @spp_len: service parameter page length
416 * @rspp: received service parameter page (NULL for outgoing PRLI)
417 * @spp: response service parameter page
418 *
419 * Returns spp response code.
420 */
ft_prli(struct fc_rport_priv * rdata,u32 spp_len,const struct fc_els_spp * rspp,struct fc_els_spp * spp)421 static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
422 const struct fc_els_spp *rspp, struct fc_els_spp *spp)
423 {
424 int ret;
425
426 mutex_lock(&ft_lport_lock);
427 ret = ft_prli_locked(rdata, spp_len, rspp, spp);
428 mutex_unlock(&ft_lport_lock);
429 TFC_SESS_DBG(rdata->local_port, "port_id %x flags %x ret %x\n",
430 rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
431 return ret;
432 }
433
ft_sess_free(struct kref * kref)434 static void ft_sess_free(struct kref *kref)
435 {
436 struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
437
438 target_remove_session(sess->se_sess);
439 kfree_rcu(sess, rcu);
440 }
441
ft_sess_put(struct ft_sess * sess)442 void ft_sess_put(struct ft_sess *sess)
443 {
444 int sess_held = kref_read(&sess->kref);
445
446 BUG_ON(!sess_held);
447 kref_put(&sess->kref, ft_sess_free);
448 }
449
ft_prlo(struct fc_rport_priv * rdata)450 static void ft_prlo(struct fc_rport_priv *rdata)
451 {
452 struct ft_sess *sess;
453 struct ft_tport *tport;
454
455 mutex_lock(&ft_lport_lock);
456 tport = rcu_dereference_protected(rdata->local_port->prov[FC_TYPE_FCP],
457 lockdep_is_held(&ft_lport_lock));
458
459 if (!tport) {
460 mutex_unlock(&ft_lport_lock);
461 return;
462 }
463 sess = ft_sess_delete(tport, rdata->ids.port_id);
464 if (!sess) {
465 mutex_unlock(&ft_lport_lock);
466 return;
467 }
468 mutex_unlock(&ft_lport_lock);
469 ft_close_sess(sess); /* release from table */
470 rdata->prli_count--;
471 /* XXX TBD - clearing actions. unit attn, see 4.10 */
472 }
473
474 /*
475 * Handle incoming FCP request.
476 * Caller has verified that the frame is type FCP.
477 */
ft_recv(struct fc_lport * lport,struct fc_frame * fp)478 static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
479 {
480 struct ft_sess *sess;
481 u32 sid = fc_frame_sid(fp);
482
483 TFC_SESS_DBG(lport, "recv sid %x\n", sid);
484
485 sess = ft_sess_get(lport, sid);
486 if (!sess) {
487 TFC_SESS_DBG(lport, "sid %x sess lookup failed\n", sid);
488 /* TBD XXX - if FCP_CMND, send PRLO */
489 fc_frame_free(fp);
490 return;
491 }
492 ft_recv_req(sess, fp); /* must do ft_sess_put() */
493 }
494
495 /*
496 * Provider ops for libfc.
497 */
498 struct fc4_prov ft_prov = {
499 .prli = ft_prli,
500 .prlo = ft_prlo,
501 .recv = ft_recv,
502 .module = THIS_MODULE,
503 };
504