drivers/target/tcm_fc/tfc_sess.c

   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  */
  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  */
  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  */
 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  */
 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  */
 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  */
 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  */
 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
 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  */
 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  */
 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  */
 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
 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  */
 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  */
 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
 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
 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
 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  * tcm_fcp_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  */
 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
 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
 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
 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  */
 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 };