drivers/target/tcm_fc/tfc_sess.c

   1 /*
   2  * Copyright (c) 2010 Cisco Systems, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 /* XXX TBD some includes may be extraneous */
  19
  20 #include <linux/module.h>
  21 #include <linux/moduleparam.h>
  22 #include <generated/utsrelease.h>
  23 #include <linux/utsname.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/kthread.h>
  27 #include <linux/types.h>
  28 #include <linux/string.h>
  29 #include <linux/configfs.h>
  30 #include <linux/ctype.h>
  31 #include <linux/hash.h>
  32 #include <linux/rcupdate.h>
  33 #include <linux/rculist.h>
  34 #include <linux/kref.h>
  35 #include <asm/unaligned.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_host.h>
  38 #include <scsi/scsi_device.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/libfc.h>
  41
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_transport.h>
  44 #include <target/target_core_fabric_ops.h>
  45 #include <target/target_core_device.h>
  46 #include <target/target_core_tpg.h>
  47 #include <target/target_core_configfs.h>
  48 #include <target/configfs_macros.h>
  49
  50 #include "tcm_fc.h"
  51
  52 static void ft_sess_delete_all(struct ft_tport *);
  53
  54 /*
  55  * Lookup or allocate target local port.
  56  * Caller holds ft_lport_lock.
  57  */
  58 static struct ft_tport *ft_tport_create(struct fc_lport *lport)
  59 {
  60         struct ft_tpg *tpg;
  61         struct ft_tport *tport;
  62         int i;
  63
  64         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
  65         if (tport && tport->tpg)
  66                 return tport;
  67
  68         tpg = ft_lport_find_tpg(lport);
  69         if (!tpg)
  70                 return NULL;
  71
  72         if (tport) {
  73                 tport->tpg = tpg;
  74                 return tport;
  75         }
  76
  77         tport = kzalloc(sizeof(*tport), GFP_KERNEL);
  78         if (!tport)
  79                 return NULL;
  80
  81         tport->lport = lport;
  82         tport->tpg = tpg;
  83         tpg->tport = tport;
  84         for (i = 0; i < FT_SESS_HASH_SIZE; i++)
  85                 INIT_HLIST_HEAD(&tport->hash[i]);
  86
  87         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
  88         return tport;
  89 }
  90
  91 /*
  92  * Free tport via RCU.
  93  */
  94 static void ft_tport_rcu_free(struct rcu_head *rcu)
  95 {
  96         struct ft_tport *tport = container_of(rcu, struct ft_tport, rcu);
  97
  98         kfree(tport);
  99 }
 100
 101 /*
 102  * Delete a target local port.
 103  * Caller holds ft_lport_lock.
 104  */
 105 static void ft_tport_delete(struct ft_tport *tport)
 106 {
 107         struct fc_lport *lport;
 108         struct ft_tpg *tpg;
 109
 110         ft_sess_delete_all(tport);
 111         lport = tport->lport;
 112         BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
 113         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);
 114
 115         tpg = tport->tpg;
 116         if (tpg) {
 117                 tpg->tport = NULL;
 118                 tport->tpg = NULL;
 119         }
 120         call_rcu(&tport->rcu, ft_tport_rcu_free);
 121 }
 122
 123 /*
 124  * Add local port.
 125  * Called thru fc_lport_iterate().
 126  */
 127 void ft_lport_add(struct fc_lport *lport, void *arg)
 128 {
 129         mutex_lock(&ft_lport_lock);
 130         ft_tport_create(lport);
 131         mutex_unlock(&ft_lport_lock);
 132 }
 133
 134 /*
 135  * Delete local port.
 136  * Called thru fc_lport_iterate().
 137  */
 138 void ft_lport_del(struct fc_lport *lport, void *arg)
 139 {
 140         struct ft_tport *tport;
 141
 142         mutex_lock(&ft_lport_lock);
 143         tport = lport->prov[FC_TYPE_FCP];
 144         if (tport)
 145                 ft_tport_delete(tport);
 146         mutex_unlock(&ft_lport_lock);
 147 }
 148
 149 /*
 150  * Notification of local port change from libfc.
 151  * Create or delete local port and associated tport.
 152  */
 153 int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
 154 {
 155         struct fc_lport *lport = arg;
 156
 157         switch (event) {
 158         case FC_LPORT_EV_ADD:
 159                 ft_lport_add(lport, NULL);
 160                 break;
 161         case FC_LPORT_EV_DEL:
 162                 ft_lport_del(lport, NULL);
 163                 break;
 164         }
 165         return NOTIFY_DONE;
 166 }
 167
 168 /*
 169  * Hash function for FC_IDs.
 170  */
 171 static u32 ft_sess_hash(u32 port_id)
 172 {
 173         return hash_32(port_id, FT_SESS_HASH_BITS);
 174 }
 175
 176 /*
 177  * Find session in local port.
 178  * Sessions and hash lists are RCU-protected.
 179  * A reference is taken which must be eventually freed.
 180  */
 181 static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 182 {
 183         struct ft_tport *tport;
 184         struct hlist_head *head;
 185         struct hlist_node *pos;
 186         struct ft_sess *sess;
 187
 188         rcu_read_lock();
 189         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
 190         if (!tport)
 191                 goto out;
 192
 193         head = &tport->hash[ft_sess_hash(port_id)];
 194         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 195                 if (sess->port_id == port_id) {
 196                         kref_get(&sess->kref);
 197                         rcu_read_unlock();
 198                         pr_debug("port_id %x found %p\n", port_id, sess);
 199                         return sess;
 200                 }
 201         }
 202 out:
 203         rcu_read_unlock();
 204         pr_debug("port_id %x not found\n", port_id);
 205         return NULL;
 206 }
 207
 208 /*
 209  * Allocate session and enter it in the hash for the local port.
 210  * Caller holds ft_lport_lock.
 211  */
 212 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 213                                       struct ft_node_acl *acl)
 214 {
 215         struct ft_sess *sess;
 216         struct hlist_head *head;
 217         struct hlist_node *pos;
 218
 219         head = &tport->hash[ft_sess_hash(port_id)];
 220         hlist_for_each_entry_rcu(sess, pos, head, hash)
 221                 if (sess->port_id == port_id)
 222                         return sess;
 223
 224         sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 225         if (!sess)
 226                 return NULL;
 227
 228         sess->se_sess = transport_init_session();
 229         if (IS_ERR(sess->se_sess)) {
 230                 kfree(sess);
 231                 return NULL;
 232         }
 233         sess->se_sess->se_node_acl = &acl->se_node_acl;
 234         sess->tport = tport;
 235         sess->port_id = port_id;
 236         kref_init(&sess->kref); /* ref for table entry */
 237         hlist_add_head_rcu(&sess->hash, head);
 238         tport->sess_count++;
 239
 240         pr_debug("port_id %x sess %p\n", port_id, sess);
 241
 242         transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
 243                                    sess->se_sess, sess);
 244         return sess;
 245 }
 246
 247 /*
 248  * Unhash the session.
 249  * Caller holds ft_lport_lock.
 250  */
 251 static void ft_sess_unhash(struct ft_sess *sess)
 252 {
 253         struct ft_tport *tport = sess->tport;
 254
 255         hlist_del_rcu(&sess->hash);
 256         BUG_ON(!tport->sess_count);
 257         tport->sess_count--;
 258         sess->port_id = -1;
 259         sess->params = 0;
 260 }
 261
 262 /*
 263  * Delete session from hash.
 264  * Caller holds ft_lport_lock.
 265  */
 266 static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
 267 {
 268         struct hlist_head *head;
 269         struct hlist_node *pos;
 270         struct ft_sess *sess;
 271
 272         head = &tport->hash[ft_sess_hash(port_id)];
 273         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 274                 if (sess->port_id == port_id) {
 275                         ft_sess_unhash(sess);
 276                         return sess;
 277                 }
 278         }
 279         return NULL;
 280 }
 281
 282 /*
 283  * Delete all sessions from tport.
 284  * Caller holds ft_lport_lock.
 285  */
 286 static void ft_sess_delete_all(struct ft_tport *tport)
 287 {
 288         struct hlist_head *head;
 289         struct hlist_node *pos;
 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, pos, head, hash) {
 295                         ft_sess_unhash(sess);
 296                         transport_deregister_session_configfs(sess->se_sess);
 297                         ft_sess_put(sess);      /* release from table */
 298                 }
 299         }
 300 }
 301
 302 /*
 303  * TCM ops for sessions.
 304  */
 305
 306 /*
 307  * Determine whether session is allowed to be shutdown in the current context.
 308  * Returns non-zero if the session should be shutdown.
 309  */
 310 int ft_sess_shutdown(struct se_session *se_sess)
 311 {
 312         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 313
 314         pr_debug("port_id %x\n", sess->port_id);
 315         return 1;
 316 }
 317
 318 /*
 319  * Remove session and send PRLO.
 320  * This is called when the ACL is being deleted or queue depth is changing.
 321  */
 322 void ft_sess_close(struct se_session *se_sess)
 323 {
 324         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 325         struct fc_lport *lport;
 326         u32 port_id;
 327
 328         mutex_lock(&ft_lport_lock);
 329         lport = sess->tport->lport;
 330         port_id = sess->port_id;
 331         if (port_id == -1) {
 332                 mutex_unlock(&ft_lport_lock);
 333                 return;
 334         }
 335         pr_debug("port_id %x\n", port_id);
 336         ft_sess_unhash(sess);
 337         mutex_unlock(&ft_lport_lock);
 338         transport_deregister_session_configfs(se_sess);
 339         ft_sess_put(sess);
 340         /* XXX Send LOGO or PRLO */
 341         synchronize_rcu();              /* let transport deregister happen */
 342 }
 343
 344 void ft_sess_stop(struct se_session *se_sess, int sess_sleep, int conn_sleep)
 345 {
 346         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 347
 348         pr_debug("port_id %x\n", sess->port_id);
 349 }
 350
 351 int ft_sess_logged_in(struct se_session *se_sess)
 352 {
 353         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 354
 355         return sess->port_id != -1;
 356 }
 357
 358 u32 ft_sess_get_index(struct se_session *se_sess)
 359 {
 360         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 361
 362         return sess->port_id;   /* XXX TBD probably not what is needed */
 363 }
 364
 365 u32 ft_sess_get_port_name(struct se_session *se_sess,
 366                           unsigned char *buf, u32 len)
 367 {
 368         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 369
 370         return ft_format_wwn(buf, len, sess->port_name);
 371 }
 372
 373 void ft_sess_set_erl0(struct se_session *se_sess)
 374 {
 375         /* XXX TBD called when out of memory */
 376 }
 377
 378 /*
 379  * libfc ops involving sessions.
 380  */
 381
 382 static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
 383                           const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 384 {
 385         struct ft_tport *tport;
 386         struct ft_sess *sess;
 387         struct ft_node_acl *acl;
 388         u32 fcp_parm;
 389
 390         tport = ft_tport_create(rdata->local_port);
 391         if (!tport)
 392                 return 0;       /* not a target for this local port */
 393
 394         acl = ft_acl_get(tport->tpg, rdata);
 395         if (!acl)
 396                 return 0;
 397
 398         if (!rspp)
 399                 goto fill;
 400
 401         if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
 402                 return FC_SPP_RESP_NO_PA;
 403
 404         /*
 405          * If both target and initiator bits are off, the SPP is invalid.
 406          */
 407         fcp_parm = ntohl(rspp->spp_params);
 408         if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
 409                 return FC_SPP_RESP_INVL;
 410
 411         /*
 412          * Create session (image pair) only if requested by
 413          * EST_IMG_PAIR flag and if the requestor is an initiator.
 414          */
 415         if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
 416                 spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
 417                 if (!(fcp_parm & FCP_SPPF_INIT_FCN))
 418                         return FC_SPP_RESP_CONF;
 419                 sess = ft_sess_create(tport, rdata->ids.port_id, acl);
 420                 if (!sess)
 421                         return FC_SPP_RESP_RES;
 422                 if (!sess->params)
 423                         rdata->prli_count++;
 424                 sess->params = fcp_parm;
 425                 sess->port_name = rdata->ids.port_name;
 426                 sess->max_frame = rdata->maxframe_size;
 427
 428                 /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 429         }
 430
 431         /*
 432          * OR in our service parameters with other provider (initiator), if any.
 433          * TBD XXX - indicate RETRY capability?
 434          */
 435 fill:
 436         fcp_parm = ntohl(spp->spp_params);
 437         spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
 438         return FC_SPP_RESP_ACK;
 439 }
 440
 441 /**
 442  * tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
 443  * @rdata: remote port private
 444  * @spp_len: service parameter page length
 445  * @rspp: received service parameter page (NULL for outgoing PRLI)
 446  * @spp: response service parameter page
 447  *
 448  * Returns spp response code.
 449  */
 450 static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
 451                    const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 452 {
 453         int ret;
 454
 455         mutex_lock(&ft_lport_lock);
 456         ret = ft_prli_locked(rdata, spp_len, rspp, spp);
 457         mutex_unlock(&ft_lport_lock);
 458         pr_debug("port_id %x flags %x ret %x\n",
 459                rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
 460         return ret;
 461 }
 462
 463 static void ft_sess_rcu_free(struct rcu_head *rcu)
 464 {
 465         struct ft_sess *sess = container_of(rcu, struct ft_sess, rcu);
 466
 467         transport_deregister_session(sess->se_sess);
 468         kfree(sess);
 469 }
 470
 471 static void ft_sess_free(struct kref *kref)
 472 {
 473         struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
 474
 475         call_rcu(&sess->rcu, ft_sess_rcu_free);
 476 }
 477
 478 void ft_sess_put(struct ft_sess *sess)
 479 {
 480         int sess_held = atomic_read(&sess->kref.refcount);
 481
 482         BUG_ON(!sess_held);
 483         kref_put(&sess->kref, ft_sess_free);
 484 }
 485
 486 static void ft_prlo(struct fc_rport_priv *rdata)
 487 {
 488         struct ft_sess *sess;
 489         struct ft_tport *tport;
 490
 491         mutex_lock(&ft_lport_lock);
 492         tport = rcu_dereference(rdata->local_port->prov[FC_TYPE_FCP]);
 493         if (!tport) {
 494                 mutex_unlock(&ft_lport_lock);
 495                 return;
 496         }
 497         sess = ft_sess_delete(tport, rdata->ids.port_id);
 498         if (!sess) {
 499                 mutex_unlock(&ft_lport_lock);
 500                 return;
 501         }
 502         mutex_unlock(&ft_lport_lock);
 503         transport_deregister_session_configfs(sess->se_sess);
 504         ft_sess_put(sess);              /* release from table */
 505         rdata->prli_count--;
 506         /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 507 }
 508
 509 /*
 510  * Handle incoming FCP request.
 511  * Caller has verified that the frame is type FCP.
 512  */
 513 static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
 514 {
 515         struct ft_sess *sess;
 516         u32 sid = fc_frame_sid(fp);
 517
 518         pr_debug("sid %x\n", sid);
 519
 520         sess = ft_sess_get(lport, sid);
 521         if (!sess) {
 522                 pr_debug("sid %x sess lookup failed\n", sid);
 523                 /* TBD XXX - if FCP_CMND, send PRLO */
 524                 fc_frame_free(fp);
 525                 return;
 526         }
 527         ft_recv_req(sess, fp);  /* must do ft_sess_put() */
 528 }
 529
 530 /*
 531  * Provider ops for libfc.
 532  */
 533 struct fc4_prov ft_prov = {
 534         .prli = ft_prli,
 535         .prlo = ft_prlo,
 536         .recv = ft_recv,
 537         .module = THIS_MODULE,
 538 };