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 <linux/version.h>
  23 #include <generated/utsrelease.h>
  24 #include <linux/utsname.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/kthread.h>
  28 #include <linux/types.h>
  29 #include <linux/string.h>
  30 #include <linux/configfs.h>
  31 #include <linux/ctype.h>
  32 #include <linux/hash.h>
  33 #include <linux/rcupdate.h>
  34 #include <linux/rculist.h>
  35 #include <linux/kref.h>
  36 #include <asm/unaligned.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_cmnd.h>
  41 #include <scsi/libfc.h>
  42
  43 #include <target/target_core_base.h>
  44 #include <target/target_core_transport.h>
  45 #include <target/target_core_fabric_ops.h>
  46 #include <target/target_core_device.h>
  47 #include <target/target_core_tpg.h>
  48 #include <target/target_core_configfs.h>
  49 #include <target/configfs_macros.h>
  50
  51 #include "tcm_fc.h"
  52
  53 static void ft_sess_delete_all(struct ft_tport *);
  54
  55 /*
  56  * Lookup or allocate target local port.
  57  * Caller holds ft_lport_lock.
  58  */
  59 static struct ft_tport *ft_tport_create(struct fc_lport *lport)
  60 {
  61         struct ft_tpg *tpg;
  62         struct ft_tport *tport;
  63         int i;
  64
  65         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
  66         if (tport && tport->tpg)
  67                 return tport;
  68
  69         tpg = ft_lport_find_tpg(lport);
  70         if (!tpg)
  71                 return NULL;
  72
  73         if (tport) {
  74                 tport->tpg = tpg;
  75                 return tport;
  76         }
  77
  78         tport = kzalloc(sizeof(*tport), GFP_KERNEL);
  79         if (!tport)
  80                 return NULL;
  81
  82         tport->lport = lport;
  83         tport->tpg = tpg;
  84         tpg->tport = tport;
  85         for (i = 0; i < FT_SESS_HASH_SIZE; i++)
  86                 INIT_HLIST_HEAD(&tport->hash[i]);
  87
  88         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
  89         return tport;
  90 }
  91
  92 /*
  93  * Free tport via RCU.
  94  */
  95 static void ft_tport_rcu_free(struct rcu_head *rcu)
  96 {
  97         struct ft_tport *tport = container_of(rcu, struct ft_tport, rcu);
  98
  99         kfree(tport);
 100 }
 101
 102 /*
 103  * Delete a target local port.
 104  * Caller holds ft_lport_lock.
 105  */
 106 static void ft_tport_delete(struct ft_tport *tport)
 107 {
 108         struct fc_lport *lport;
 109         struct ft_tpg *tpg;
 110
 111         ft_sess_delete_all(tport);
 112         lport = tport->lport;
 113         BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
 114         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);
 115
 116         tpg = tport->tpg;
 117         if (tpg) {
 118                 tpg->tport = NULL;
 119                 tport->tpg = NULL;
 120         }
 121         call_rcu(&tport->rcu, ft_tport_rcu_free);
 122 }
 123
 124 /*
 125  * Add local port.
 126  * Called thru fc_lport_iterate().
 127  */
 128 void ft_lport_add(struct fc_lport *lport, void *arg)
 129 {
 130         mutex_lock(&ft_lport_lock);
 131         ft_tport_create(lport);
 132         mutex_unlock(&ft_lport_lock);
 133 }
 134
 135 /*
 136  * Delete local port.
 137  * Called thru fc_lport_iterate().
 138  */
 139 void ft_lport_del(struct fc_lport *lport, void *arg)
 140 {
 141         struct ft_tport *tport;
 142
 143         mutex_lock(&ft_lport_lock);
 144         tport = lport->prov[FC_TYPE_FCP];
 145         if (tport)
 146                 ft_tport_delete(tport);
 147         mutex_unlock(&ft_lport_lock);
 148 }
 149
 150 /*
 151  * Notification of local port change from libfc.
 152  * Create or delete local port and associated tport.
 153  */
 154 int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
 155 {
 156         struct fc_lport *lport = arg;
 157
 158         switch (event) {
 159         case FC_LPORT_EV_ADD:
 160                 ft_lport_add(lport, NULL);
 161                 break;
 162         case FC_LPORT_EV_DEL:
 163                 ft_lport_del(lport, NULL);
 164                 break;
 165         }
 166         return NOTIFY_DONE;
 167 }
 168
 169 /*
 170  * Hash function for FC_IDs.
 171  */
 172 static u32 ft_sess_hash(u32 port_id)
 173 {
 174         return hash_32(port_id, FT_SESS_HASH_BITS);
 175 }
 176
 177 /*
 178  * Find session in local port.
 179  * Sessions and hash lists are RCU-protected.
 180  * A reference is taken which must be eventually freed.
 181  */
 182 static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 183 {
 184         struct ft_tport *tport;
 185         struct hlist_head *head;
 186         struct hlist_node *pos;
 187         struct ft_sess *sess;
 188
 189         rcu_read_lock();
 190         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
 191         if (!tport)
 192                 goto out;
 193
 194         head = &tport->hash[ft_sess_hash(port_id)];
 195         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 196                 if (sess->port_id == port_id) {
 197                         kref_get(&sess->kref);
 198                         rcu_read_unlock();
 199                         pr_debug("port_id %x found %p\n", port_id, sess);
 200                         return sess;
 201                 }
 202         }
 203 out:
 204         rcu_read_unlock();
 205         pr_debug("port_id %x not found\n", port_id);
 206         return NULL;
 207 }
 208
 209 /*
 210  * Allocate session and enter it in the hash for the local port.
 211  * Caller holds ft_lport_lock.
 212  */
 213 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 214                                       struct ft_node_acl *acl)
 215 {
 216         struct ft_sess *sess;
 217         struct hlist_head *head;
 218         struct hlist_node *pos;
 219
 220         head = &tport->hash[ft_sess_hash(port_id)];
 221         hlist_for_each_entry_rcu(sess, pos, head, hash)
 222                 if (sess->port_id == port_id)
 223                         return sess;
 224
 225         sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 226         if (!sess)
 227                 return NULL;
 228
 229         sess->se_sess = transport_init_session();
 230         if (IS_ERR(sess->se_sess)) {
 231                 kfree(sess);
 232                 return NULL;
 233         }
 234         sess->se_sess->se_node_acl = &acl->se_node_acl;
 235         sess->tport = tport;
 236         sess->port_id = port_id;
 237         kref_init(&sess->kref); /* ref for table entry */
 238         hlist_add_head_rcu(&sess->hash, head);
 239         tport->sess_count++;
 240
 241         pr_debug("port_id %x sess %p\n", port_id, sess);
 242
 243         transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
 244                                    sess->se_sess, sess);
 245         return sess;
 246 }
 247
 248 /*
 249  * Unhash the session.
 250  * Caller holds ft_lport_lock.
 251  */
 252 static void ft_sess_unhash(struct ft_sess *sess)
 253 {
 254         struct ft_tport *tport = sess->tport;
 255
 256         hlist_del_rcu(&sess->hash);
 257         BUG_ON(!tport->sess_count);
 258         tport->sess_count--;
 259         sess->port_id = -1;
 260         sess->params = 0;
 261 }
 262
 263 /*
 264  * Delete session from hash.
 265  * Caller holds ft_lport_lock.
 266  */
 267 static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
 268 {
 269         struct hlist_head *head;
 270         struct hlist_node *pos;
 271         struct ft_sess *sess;
 272
 273         head = &tport->hash[ft_sess_hash(port_id)];
 274         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 275                 if (sess->port_id == port_id) {
 276                         ft_sess_unhash(sess);
 277                         return sess;
 278                 }
 279         }
 280         return NULL;
 281 }
 282
 283 /*
 284  * Delete all sessions from tport.
 285  * Caller holds ft_lport_lock.
 286  */
 287 static void ft_sess_delete_all(struct ft_tport *tport)
 288 {
 289         struct hlist_head *head;
 290         struct hlist_node *pos;
 291         struct ft_sess *sess;
 292
 293         for (head = tport->hash;
 294              head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
 295                 hlist_for_each_entry_rcu(sess, pos, head, hash) {
 296                         ft_sess_unhash(sess);
 297                         transport_deregister_session_configfs(sess->se_sess);
 298                         ft_sess_put(sess);      /* release from table */
 299                 }
 300         }
 301 }
 302
 303 /*
 304  * TCM ops for sessions.
 305  */
 306
 307 /*
 308  * Determine whether session is allowed to be shutdown in the current context.
 309  * Returns non-zero if the session should be shutdown.
 310  */
 311 int ft_sess_shutdown(struct se_session *se_sess)
 312 {
 313         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 314
 315         pr_debug("port_id %x\n", sess->port_id);
 316         return 1;
 317 }
 318
 319 /*
 320  * Remove session and send PRLO.
 321  * This is called when the ACL is being deleted or queue depth is changing.
 322  */
 323 void ft_sess_close(struct se_session *se_sess)
 324 {
 325         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 326         struct fc_lport *lport;
 327         u32 port_id;
 328
 329         mutex_lock(&ft_lport_lock);
 330         lport = sess->tport->lport;
 331         port_id = sess->port_id;
 332         if (port_id == -1) {
 333                 mutex_unlock(&ft_lport_lock);
 334                 return;
 335         }
 336         pr_debug("port_id %x\n", port_id);
 337         ft_sess_unhash(sess);
 338         mutex_unlock(&ft_lport_lock);
 339         transport_deregister_session_configfs(se_sess);
 340         ft_sess_put(sess);
 341         /* XXX Send LOGO or PRLO */
 342         synchronize_rcu();              /* let transport deregister happen */
 343 }
 344
 345 void ft_sess_stop(struct se_session *se_sess, int sess_sleep, int conn_sleep)
 346 {
 347         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 348
 349         pr_debug("port_id %x\n", sess->port_id);
 350 }
 351
 352 int ft_sess_logged_in(struct se_session *se_sess)
 353 {
 354         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 355
 356         return sess->port_id != -1;
 357 }
 358
 359 u32 ft_sess_get_index(struct se_session *se_sess)
 360 {
 361         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 362
 363         return sess->port_id;   /* XXX TBD probably not what is needed */
 364 }
 365
 366 u32 ft_sess_get_port_name(struct se_session *se_sess,
 367                           unsigned char *buf, u32 len)
 368 {
 369         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 370
 371         return ft_format_wwn(buf, len, sess->port_name);
 372 }
 373
 374 void ft_sess_set_erl0(struct se_session *se_sess)
 375 {
 376         /* XXX TBD called when out of memory */
 377 }
 378
 379 /*
 380  * libfc ops involving sessions.
 381  */
 382
 383 static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
 384                           const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 385 {
 386         struct ft_tport *tport;
 387         struct ft_sess *sess;
 388         struct ft_node_acl *acl;
 389         u32 fcp_parm;
 390
 391         tport = ft_tport_create(rdata->local_port);
 392         if (!tport)
 393                 return 0;       /* not a target for this local port */
 394
 395         acl = ft_acl_get(tport->tpg, rdata);
 396         if (!acl)
 397                 return 0;
 398
 399         if (!rspp)
 400                 goto fill;
 401
 402         if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
 403                 return FC_SPP_RESP_NO_PA;
 404
 405         /*
 406          * If both target and initiator bits are off, the SPP is invalid.
 407          */
 408         fcp_parm = ntohl(rspp->spp_params);
 409         if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
 410                 return FC_SPP_RESP_INVL;
 411
 412         /*
 413          * Create session (image pair) only if requested by
 414          * EST_IMG_PAIR flag and if the requestor is an initiator.
 415          */
 416         if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
 417                 spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
 418                 if (!(fcp_parm & FCP_SPPF_INIT_FCN))
 419                         return FC_SPP_RESP_CONF;
 420                 sess = ft_sess_create(tport, rdata->ids.port_id, acl);
 421                 if (!sess)
 422                         return FC_SPP_RESP_RES;
 423                 if (!sess->params)
 424                         rdata->prli_count++;
 425                 sess->params = fcp_parm;
 426                 sess->port_name = rdata->ids.port_name;
 427                 sess->max_frame = rdata->maxframe_size;
 428
 429                 /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 430         }
 431
 432         /*
 433          * OR in our service parameters with other provider (initiator), if any.
 434          * TBD XXX - indicate RETRY capability?
 435          */
 436 fill:
 437         fcp_parm = ntohl(spp->spp_params);
 438         spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
 439         return FC_SPP_RESP_ACK;
 440 }
 441
 442 /**
 443  * tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
 444  * @rdata: remote port private
 445  * @spp_len: service parameter page length
 446  * @rspp: received service parameter page (NULL for outgoing PRLI)
 447  * @spp: response service parameter page
 448  *
 449  * Returns spp response code.
 450  */
 451 static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
 452                    const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 453 {
 454         int ret;
 455
 456         mutex_lock(&ft_lport_lock);
 457         ret = ft_prli_locked(rdata, spp_len, rspp, spp);
 458         mutex_unlock(&ft_lport_lock);
 459         pr_debug("port_id %x flags %x ret %x\n",
 460                rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
 461         return ret;
 462 }
 463
 464 static void ft_sess_rcu_free(struct rcu_head *rcu)
 465 {
 466         struct ft_sess *sess = container_of(rcu, struct ft_sess, rcu);
 467
 468         transport_deregister_session(sess->se_sess);
 469         kfree(sess);
 470 }
 471
 472 static void ft_sess_free(struct kref *kref)
 473 {
 474         struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
 475
 476         call_rcu(&sess->rcu, ft_sess_rcu_free);
 477 }
 478
 479 void ft_sess_put(struct ft_sess *sess)
 480 {
 481         int sess_held = atomic_read(&sess->kref.refcount);
 482
 483         BUG_ON(!sess_held);
 484         kref_put(&sess->kref, ft_sess_free);
 485 }
 486
 487 static void ft_prlo(struct fc_rport_priv *rdata)
 488 {
 489         struct ft_sess *sess;
 490         struct ft_tport *tport;
 491
 492         mutex_lock(&ft_lport_lock);
 493         tport = rcu_dereference(rdata->local_port->prov[FC_TYPE_FCP]);
 494         if (!tport) {
 495                 mutex_unlock(&ft_lport_lock);
 496                 return;
 497         }
 498         sess = ft_sess_delete(tport, rdata->ids.port_id);
 499         if (!sess) {
 500                 mutex_unlock(&ft_lport_lock);
 501                 return;
 502         }
 503         mutex_unlock(&ft_lport_lock);
 504         transport_deregister_session_configfs(sess->se_sess);
 505         ft_sess_put(sess);              /* release from table */
 506         rdata->prli_count--;
 507         /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 508 }
 509
 510 /*
 511  * Handle incoming FCP request.
 512  * Caller has verified that the frame is type FCP.
 513  */
 514 static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
 515 {
 516         struct ft_sess *sess;
 517         u32 sid = fc_frame_sid(fp);
 518
 519         pr_debug("sid %x\n", sid);
 520
 521         sess = ft_sess_get(lport, sid);
 522         if (!sess) {
 523                 pr_debug("sid %x sess lookup failed\n", sid);
 524                 /* TBD XXX - if FCP_CMND, send PRLO */
 525                 fc_frame_free(fp);
 526                 return;
 527         }
 528         ft_recv_req(sess, fp);  /* must do ft_sess_put() */
 529 }
 530
 531 /*
 532  * Provider ops for libfc.
 533  */
 534 struct fc4_prov ft_prov = {
 535         .prli = ft_prli,
 536         .prlo = ft_prlo,
 537         .recv = ft_recv,
 538         .module = THIS_MODULE,
 539 };