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/target_core_base.h>
  50 #include <target/configfs_macros.h>
  51
  52 #include <scsi/libfc.h>
  53 #include "tcm_fc.h"
  54
  55 static void ft_sess_delete_all(struct ft_tport *);
  56
  57 /*
  58  * Lookup or allocate target local port.
  59  * Caller holds ft_lport_lock.
  60  */
  61 static struct ft_tport *ft_tport_create(struct fc_lport *lport)
  62 {
  63         struct ft_tpg *tpg;
  64         struct ft_tport *tport;
  65         int i;
  66
  67         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
  68         if (tport && tport->tpg)
  69                 return tport;
  70
  71         tpg = ft_lport_find_tpg(lport);
  72         if (!tpg)
  73                 return NULL;
  74
  75         if (tport) {
  76                 tport->tpg = tpg;
  77                 return tport;
  78         }
  79
  80         tport = kzalloc(sizeof(*tport), GFP_KERNEL);
  81         if (!tport)
  82                 return NULL;
  83
  84         tport->lport = lport;
  85         tport->tpg = tpg;
  86         tpg->tport = tport;
  87         for (i = 0; i < FT_SESS_HASH_SIZE; i++)
  88                 INIT_HLIST_HEAD(&tport->hash[i]);
  89
  90         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
  91         return tport;
  92 }
  93
  94 /*
  95  * Free tport via RCU.
  96  */
  97 static void ft_tport_rcu_free(struct rcu_head *rcu)
  98 {
  99         struct ft_tport *tport = container_of(rcu, struct ft_tport, rcu);
 100
 101         kfree(tport);
 102 }
 103
 104 /*
 105  * Delete a target local port.
 106  * Caller holds ft_lport_lock.
 107  */
 108 static void ft_tport_delete(struct ft_tport *tport)
 109 {
 110         struct fc_lport *lport;
 111         struct ft_tpg *tpg;
 112
 113         ft_sess_delete_all(tport);
 114         lport = tport->lport;
 115         BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
 116         rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);
 117
 118         tpg = tport->tpg;
 119         if (tpg) {
 120                 tpg->tport = NULL;
 121                 tport->tpg = NULL;
 122         }
 123         call_rcu(&tport->rcu, ft_tport_rcu_free);
 124 }
 125
 126 /*
 127  * Add local port.
 128  * Called thru fc_lport_iterate().
 129  */
 130 void ft_lport_add(struct fc_lport *lport, void *arg)
 131 {
 132         mutex_lock(&ft_lport_lock);
 133         ft_tport_create(lport);
 134         mutex_unlock(&ft_lport_lock);
 135 }
 136
 137 /*
 138  * Delete local port.
 139  * Called thru fc_lport_iterate().
 140  */
 141 void ft_lport_del(struct fc_lport *lport, void *arg)
 142 {
 143         struct ft_tport *tport;
 144
 145         mutex_lock(&ft_lport_lock);
 146         tport = lport->prov[FC_TYPE_FCP];
 147         if (tport)
 148                 ft_tport_delete(tport);
 149         mutex_unlock(&ft_lport_lock);
 150 }
 151
 152 /*
 153  * Notification of local port change from libfc.
 154  * Create or delete local port and associated tport.
 155  */
 156 int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
 157 {
 158         struct fc_lport *lport = arg;
 159
 160         switch (event) {
 161         case FC_LPORT_EV_ADD:
 162                 ft_lport_add(lport, NULL);
 163                 break;
 164         case FC_LPORT_EV_DEL:
 165                 ft_lport_del(lport, NULL);
 166                 break;
 167         }
 168         return NOTIFY_DONE;
 169 }
 170
 171 /*
 172  * Hash function for FC_IDs.
 173  */
 174 static u32 ft_sess_hash(u32 port_id)
 175 {
 176         return hash_32(port_id, FT_SESS_HASH_BITS);
 177 }
 178
 179 /*
 180  * Find session in local port.
 181  * Sessions and hash lists are RCU-protected.
 182  * A reference is taken which must be eventually freed.
 183  */
 184 static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 185 {
 186         struct ft_tport *tport;
 187         struct hlist_head *head;
 188         struct hlist_node *pos;
 189         struct ft_sess *sess;
 190
 191         rcu_read_lock();
 192         tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
 193         if (!tport)
 194                 goto out;
 195
 196         head = &tport->hash[ft_sess_hash(port_id)];
 197         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 198                 if (sess->port_id == port_id) {
 199                         kref_get(&sess->kref);
 200                         rcu_read_unlock();
 201                         FT_SESS_DBG("port_id %x found %p\n", port_id, sess);
 202                         return sess;
 203                 }
 204         }
 205 out:
 206         rcu_read_unlock();
 207         FT_SESS_DBG("port_id %x not found\n", port_id);
 208         return NULL;
 209 }
 210
 211 /*
 212  * Allocate session and enter it in the hash for the local port.
 213  * Caller holds ft_lport_lock.
 214  */
 215 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 216                                       struct ft_node_acl *acl)
 217 {
 218         struct ft_sess *sess;
 219         struct hlist_head *head;
 220         struct hlist_node *pos;
 221
 222         head = &tport->hash[ft_sess_hash(port_id)];
 223         hlist_for_each_entry_rcu(sess, pos, head, hash)
 224                 if (sess->port_id == port_id)
 225                         return sess;
 226
 227         sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 228         if (!sess)
 229                 return NULL;
 230
 231         sess->se_sess = transport_init_session();
 232         if (!sess->se_sess) {
 233                 kfree(sess);
 234                 return NULL;
 235         }
 236         sess->se_sess->se_node_acl = &acl->se_node_acl;
 237         sess->tport = tport;
 238         sess->port_id = port_id;
 239         kref_init(&sess->kref); /* ref for table entry */
 240         hlist_add_head_rcu(&sess->hash, head);
 241         tport->sess_count++;
 242
 243         FT_SESS_DBG("port_id %x sess %p\n", port_id, sess);
 244
 245         transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
 246                                    sess->se_sess, sess);
 247         return sess;
 248 }
 249
 250 /*
 251  * Unhash the session.
 252  * Caller holds ft_lport_lock.
 253  */
 254 static void ft_sess_unhash(struct ft_sess *sess)
 255 {
 256         struct ft_tport *tport = sess->tport;
 257
 258         hlist_del_rcu(&sess->hash);
 259         BUG_ON(!tport->sess_count);
 260         tport->sess_count--;
 261         sess->port_id = -1;
 262         sess->params = 0;
 263 }
 264
 265 /*
 266  * Delete session from hash.
 267  * Caller holds ft_lport_lock.
 268  */
 269 static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
 270 {
 271         struct hlist_head *head;
 272         struct hlist_node *pos;
 273         struct ft_sess *sess;
 274
 275         head = &tport->hash[ft_sess_hash(port_id)];
 276         hlist_for_each_entry_rcu(sess, pos, head, hash) {
 277                 if (sess->port_id == port_id) {
 278                         ft_sess_unhash(sess);
 279                         return sess;
 280                 }
 281         }
 282         return NULL;
 283 }
 284
 285 /*
 286  * Delete all sessions from tport.
 287  * Caller holds ft_lport_lock.
 288  */
 289 static void ft_sess_delete_all(struct ft_tport *tport)
 290 {
 291         struct hlist_head *head;
 292         struct hlist_node *pos;
 293         struct ft_sess *sess;
 294
 295         for (head = tport->hash;
 296              head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
 297                 hlist_for_each_entry_rcu(sess, pos, head, hash) {
 298                         ft_sess_unhash(sess);
 299                         transport_deregister_session_configfs(sess->se_sess);
 300                         ft_sess_put(sess);      /* release from table */
 301                 }
 302         }
 303 }
 304
 305 /*
 306  * TCM ops for sessions.
 307  */
 308
 309 /*
 310  * Determine whether session is allowed to be shutdown in the current context.
 311  * Returns non-zero if the session should be shutdown.
 312  */
 313 int ft_sess_shutdown(struct se_session *se_sess)
 314 {
 315         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 316
 317         FT_SESS_DBG("port_id %x\n", sess->port_id);
 318         return 1;
 319 }
 320
 321 /*
 322  * Remove session and send PRLO.
 323  * This is called when the ACL is being deleted or queue depth is changing.
 324  */
 325 void ft_sess_close(struct se_session *se_sess)
 326 {
 327         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 328         struct fc_lport *lport;
 329         u32 port_id;
 330
 331         mutex_lock(&ft_lport_lock);
 332         lport = sess->tport->lport;
 333         port_id = sess->port_id;
 334         if (port_id == -1) {
 335                 mutex_lock(&ft_lport_lock);
 336                 return;
 337         }
 338         FT_SESS_DBG("port_id %x\n", port_id);
 339         ft_sess_unhash(sess);
 340         mutex_unlock(&ft_lport_lock);
 341         transport_deregister_session_configfs(se_sess);
 342         ft_sess_put(sess);
 343         /* XXX Send LOGO or PRLO */
 344         synchronize_rcu();              /* let transport deregister happen */
 345 }
 346
 347 void ft_sess_stop(struct se_session *se_sess, int sess_sleep, int conn_sleep)
 348 {
 349         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 350
 351         FT_SESS_DBG("port_id %x\n", sess->port_id);
 352 }
 353
 354 int ft_sess_logged_in(struct se_session *se_sess)
 355 {
 356         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 357
 358         return sess->port_id != -1;
 359 }
 360
 361 u32 ft_sess_get_index(struct se_session *se_sess)
 362 {
 363         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 364
 365         return sess->port_id;   /* XXX TBD probably not what is needed */
 366 }
 367
 368 u32 ft_sess_get_port_name(struct se_session *se_sess,
 369                           unsigned char *buf, u32 len)
 370 {
 371         struct ft_sess *sess = se_sess->fabric_sess_ptr;
 372
 373         return ft_format_wwn(buf, len, sess->port_name);
 374 }
 375
 376 void ft_sess_set_erl0(struct se_session *se_sess)
 377 {
 378         /* XXX TBD called when out of memory */
 379 }
 380
 381 /*
 382  * libfc ops involving sessions.
 383  */
 384
 385 static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
 386                           const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 387 {
 388         struct ft_tport *tport;
 389         struct ft_sess *sess;
 390         struct ft_node_acl *acl;
 391         u32 fcp_parm;
 392
 393         tport = ft_tport_create(rdata->local_port);
 394         if (!tport)
 395                 return 0;       /* not a target for this local port */
 396
 397         acl = ft_acl_get(tport->tpg, rdata);
 398         if (!acl)
 399                 return 0;
 400
 401         if (!rspp)
 402                 goto fill;
 403
 404         if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
 405                 return FC_SPP_RESP_NO_PA;
 406
 407         /*
 408          * If both target and initiator bits are off, the SPP is invalid.
 409          */
 410         fcp_parm = ntohl(rspp->spp_params);
 411         if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
 412                 return FC_SPP_RESP_INVL;
 413
 414         /*
 415          * Create session (image pair) only if requested by
 416          * EST_IMG_PAIR flag and if the requestor is an initiator.
 417          */
 418         if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
 419                 spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
 420                 if (!(fcp_parm & FCP_SPPF_INIT_FCN))
 421                         return FC_SPP_RESP_CONF;
 422                 sess = ft_sess_create(tport, rdata->ids.port_id, acl);
 423                 if (!sess)
 424                         return FC_SPP_RESP_RES;
 425                 if (!sess->params)
 426                         rdata->prli_count++;
 427                 sess->params = fcp_parm;
 428                 sess->port_name = rdata->ids.port_name;
 429                 sess->max_frame = rdata->maxframe_size;
 430
 431                 /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 432         }
 433
 434         /*
 435          * OR in our service parameters with other provider (initiator), if any.
 436          * TBD XXX - indicate RETRY capability?
 437          */
 438 fill:
 439         fcp_parm = ntohl(spp->spp_params);
 440         spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
 441         return FC_SPP_RESP_ACK;
 442 }
 443
 444 /**
 445  * tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
 446  * @rdata: remote port private
 447  * @spp_len: service parameter page length
 448  * @rspp: received service parameter page (NULL for outgoing PRLI)
 449  * @spp: response service parameter page
 450  *
 451  * Returns spp response code.
 452  */
 453 static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
 454                    const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 455 {
 456         int ret;
 457
 458         mutex_lock(&ft_lport_lock);
 459         ret = ft_prli_locked(rdata, spp_len, rspp, spp);
 460         mutex_unlock(&ft_lport_lock);
 461         FT_SESS_DBG("port_id %x flags %x ret %x\n",
 462                rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
 463         return ret;
 464 }
 465
 466 static void ft_sess_rcu_free(struct rcu_head *rcu)
 467 {
 468         struct ft_sess *sess = container_of(rcu, struct ft_sess, rcu);
 469
 470         transport_deregister_session(sess->se_sess);
 471         kfree(sess);
 472 }
 473
 474 static void ft_sess_free(struct kref *kref)
 475 {
 476         struct ft_sess *sess = container_of(kref, struct ft_sess, kref);
 477
 478         call_rcu(&sess->rcu, ft_sess_rcu_free);
 479 }
 480
 481 void ft_sess_put(struct ft_sess *sess)
 482 {
 483         int sess_held = atomic_read(&sess->kref.refcount);
 484
 485         BUG_ON(!sess_held);
 486         kref_put(&sess->kref, ft_sess_free);
 487 }
 488
 489 static void ft_prlo(struct fc_rport_priv *rdata)
 490 {
 491         struct ft_sess *sess;
 492         struct ft_tport *tport;
 493
 494         mutex_lock(&ft_lport_lock);
 495         tport = rcu_dereference(rdata->local_port->prov[FC_TYPE_FCP]);
 496         if (!tport) {
 497                 mutex_unlock(&ft_lport_lock);
 498                 return;
 499         }
 500         sess = ft_sess_delete(tport, rdata->ids.port_id);
 501         if (!sess) {
 502                 mutex_unlock(&ft_lport_lock);
 503                 return;
 504         }
 505         mutex_unlock(&ft_lport_lock);
 506         transport_deregister_session_configfs(sess->se_sess);
 507         ft_sess_put(sess);              /* release from table */
 508         rdata->prli_count--;
 509         /* XXX TBD - clearing actions.  unit attn, see 4.10 */
 510 }
 511
 512 /*
 513  * Handle incoming FCP request.
 514  * Caller has verified that the frame is type FCP.
 515  */
 516 static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
 517 {
 518         struct ft_sess *sess;
 519         u32 sid = fc_frame_sid(fp);
 520
 521         FT_SESS_DBG("sid %x\n", sid);
 522
 523         sess = ft_sess_get(lport, sid);
 524         if (!sess) {
 525                 FT_SESS_DBG("sid %x sess lookup failed\n", sid);
 526                 /* TBD XXX - if FCP_CMND, send PRLO */
 527                 fc_frame_free(fp);
 528                 return;
 529         }
 530         ft_recv_req(sess, fp);  /* must do ft_sess_put() */
 531 }
 532
 533 /*
 534  * Provider ops for libfc.
 535  */
 536 struct fc4_prov ft_prov = {
 537         .prli = ft_prli,
 538         .prlo = ft_prlo,
 539         .recv = ft_recv,
 540         .module = THIS_MODULE,
 541 };