drivers/scsi/iscsi

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This source file includes following definitions.
iscsi_sw_tcp_recv
iscsi_sw_sk_state_check
iscsi_sw_tcp_data_ready
iscsi_sw_tcp_state_change
iscsi_sw_tcp_write_space
iscsi_sw_tcp_conn_set_callbacks
iscsi_sw_tcp_conn_restore_callbacks
iscsi_sw_tcp_xmit_segment
iscsi_sw_tcp_xmit
iscsi_sw_tcp_xmit_qlen
iscsi_sw_tcp_pdu_xmit
iscsi_sw_tcp_send_hdr_done
iscsi_sw_tcp_send_hdr_prep
iscsi_sw_tcp_send_data_prep
iscsi_sw_tcp_send_linear_data_prep
iscsi_sw_tcp_pdu_init
iscsi_sw_tcp_pdu_alloc
iscsi_sw_tcp_conn_create
iscsi_sw_tcp_release_conn
iscsi_sw_tcp_conn_destroy
iscsi_sw_tcp_conn_stop
iscsi_sw_tcp_conn_bind
iscsi_sw_tcp_conn_set_param
iscsi_sw_tcp_conn_get_param
iscsi_sw_tcp_host_get_param
iscsi_sw_tcp_conn_get_stats
iscsi_sw_tcp_session_create
iscsi_sw_tcp_session_destroy
iscsi_sw_tcp_attr_is_visible
iscsi_sw_tcp_slave_configure
iscsi_sw_tcp_init
iscsi_sw_tcp_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * iSCSI Initiator over TCP/IP Data-Path
   4  *
   5  * Copyright (C) 2004 Dmitry Yusupov
   6  * Copyright (C) 2004 Alex Aizman
   7  * Copyright (C) 2005 - 2006 Mike Christie
   8  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   9  * maintained by open-iscsi@googlegroups.com
  10  *
  11  * See the file COPYING included with this distribution for more details.
  12  *
  13  * Credits:
  14  *      Christoph Hellwig
  15  *      FUJITA Tomonori
  16  *      Arne Redlich
  17  *      Zhenyu Wang
  18  */
  19 
  20 #include <crypto/hash.h>
  21 #include <linux/types.h>
  22 #include <linux/inet.h>
  23 #include <linux/slab.h>
  24 #include <linux/sched/mm.h>
  25 #include <linux/file.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/delay.h>
  28 #include <linux/kfifo.h>
  29 #include <linux/scatterlist.h>
  30 #include <linux/module.h>
  31 #include <linux/backing-dev.h>
  32 #include <net/tcp.h>
  33 #include <scsi/scsi_cmnd.h>
  34 #include <scsi/scsi_device.h>
  35 #include <scsi/scsi_host.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_transport_iscsi.h>
  38 #include <trace/events/iscsi.h>
  39 
  40 #include "iscsi_tcp.h"
  41 
  42 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
  43               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  44               "Alex Aizman <itn780@yahoo.com>");
  45 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  46 MODULE_LICENSE("GPL");
  47 
  48 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  49 static struct scsi_host_template iscsi_sw_tcp_sht;
  50 static struct iscsi_transport iscsi_sw_tcp_transport;
  51 
  52 static unsigned int iscsi_max_lun = ~0;
  53 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  54 
  55 static int iscsi_sw_tcp_dbg;
  56 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
  57                    S_IRUGO | S_IWUSR);
  58 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
  59                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  60 
  61 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)                \
  62         do {                                                    \
  63                 if (iscsi_sw_tcp_dbg)                           \
  64                         iscsi_conn_printk(KERN_INFO, _conn,     \
  65                                              "%s " dbg_fmt,     \
  66                                              __func__, ##arg);  \
  67                 iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp,         \
  68                                 &(_conn)->cls_conn->dev,        \
  69                                 "%s " dbg_fmt, __func__, ##arg);\
  70         } while (0);
  71 
  72 
  73 /**
  74  * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  75  * @rd_desc: read descriptor
  76  * @skb: socket buffer
  77  * @offset: offset in skb
  78  * @len: skb->len - offset
  79  */
  80 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  81                              unsigned int offset, size_t len)
  82 {
  83         struct iscsi_conn *conn = rd_desc->arg.data;
  84         unsigned int consumed, total_consumed = 0;
  85         int status;
  86 
  87         ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
  88 
  89         do {
  90                 status = 0;
  91                 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  92                 offset += consumed;
  93                 total_consumed += consumed;
  94         } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  95 
  96         ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
  97                          skb->len - offset, status);
  98         return total_consumed;
  99 }
 100 
 101 /**
 102  * iscsi_sw_sk_state_check - check socket state
 103  * @sk: socket
 104  *
 105  * If the socket is in CLOSE or CLOSE_WAIT we should
 106  * not close the connection if there is still some
 107  * data pending.
 108  *
 109  * Must be called with sk_callback_lock.
 110  */
 111 static inline int iscsi_sw_sk_state_check(struct sock *sk)
 112 {
 113         struct iscsi_conn *conn = sk->sk_user_data;
 114 
 115         if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
 116             (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
 117             !atomic_read(&sk->sk_rmem_alloc)) {
 118                 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 119                 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
 120                 return -ECONNRESET;
 121         }
 122         return 0;
 123 }
 124 
 125 static void iscsi_sw_tcp_data_ready(struct sock *sk)
 126 {
 127         struct iscsi_conn *conn;
 128         struct iscsi_tcp_conn *tcp_conn;
 129         read_descriptor_t rd_desc;
 130 
 131         read_lock_bh(&sk->sk_callback_lock);
 132         conn = sk->sk_user_data;
 133         if (!conn) {
 134                 read_unlock_bh(&sk->sk_callback_lock);
 135                 return;
 136         }
 137         tcp_conn = conn->dd_data;
 138 
 139         /*
 140          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 141          * We set count to 1 because we want the network layer to
 142          * hand us all the skbs that are available. iscsi_tcp_recv
 143          * handled pdus that cross buffers or pdus that still need data.
 144          */
 145         rd_desc.arg.data = conn;
 146         rd_desc.count = 1;
 147         tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 148 
 149         iscsi_sw_sk_state_check(sk);
 150 
 151         /* If we had to (atomically) map a highmem page,
 152          * unmap it now. */
 153         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 154         read_unlock_bh(&sk->sk_callback_lock);
 155 }
 156 
 157 static void iscsi_sw_tcp_state_change(struct sock *sk)
 158 {
 159         struct iscsi_tcp_conn *tcp_conn;
 160         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 161         struct iscsi_conn *conn;
 162         void (*old_state_change)(struct sock *);
 163 
 164         read_lock_bh(&sk->sk_callback_lock);
 165         conn = sk->sk_user_data;
 166         if (!conn) {
 167                 read_unlock_bh(&sk->sk_callback_lock);
 168                 return;
 169         }
 170 
 171         iscsi_sw_sk_state_check(sk);
 172 
 173         tcp_conn = conn->dd_data;
 174         tcp_sw_conn = tcp_conn->dd_data;
 175         old_state_change = tcp_sw_conn->old_state_change;
 176 
 177         read_unlock_bh(&sk->sk_callback_lock);
 178 
 179         old_state_change(sk);
 180 }
 181 
 182 /**
 183  * iscsi_write_space - Called when more output buffer space is available
 184  * @sk: socket space is available for
 185  **/
 186 static void iscsi_sw_tcp_write_space(struct sock *sk)
 187 {
 188         struct iscsi_conn *conn;
 189         struct iscsi_tcp_conn *tcp_conn;
 190         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 191         void (*old_write_space)(struct sock *);
 192 
 193         read_lock_bh(&sk->sk_callback_lock);
 194         conn = sk->sk_user_data;
 195         if (!conn) {
 196                 read_unlock_bh(&sk->sk_callback_lock);
 197                 return;
 198         }
 199 
 200         tcp_conn = conn->dd_data;
 201         tcp_sw_conn = tcp_conn->dd_data;
 202         old_write_space = tcp_sw_conn->old_write_space;
 203         read_unlock_bh(&sk->sk_callback_lock);
 204 
 205         old_write_space(sk);
 206 
 207         ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 208         iscsi_conn_queue_work(conn);
 209 }
 210 
 211 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 212 {
 213         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 214         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 215         struct sock *sk = tcp_sw_conn->sock->sk;
 216 
 217         /* assign new callbacks */
 218         write_lock_bh(&sk->sk_callback_lock);
 219         sk->sk_user_data = conn;
 220         tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 221         tcp_sw_conn->old_state_change = sk->sk_state_change;
 222         tcp_sw_conn->old_write_space = sk->sk_write_space;
 223         sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 224         sk->sk_state_change = iscsi_sw_tcp_state_change;
 225         sk->sk_write_space = iscsi_sw_tcp_write_space;
 226         write_unlock_bh(&sk->sk_callback_lock);
 227 }
 228 
 229 static void
 230 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
 231 {
 232         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 233         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 234         struct sock *sk = tcp_sw_conn->sock->sk;
 235 
 236         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 237         write_lock_bh(&sk->sk_callback_lock);
 238         sk->sk_user_data    = NULL;
 239         sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 240         sk->sk_state_change = tcp_sw_conn->old_state_change;
 241         sk->sk_write_space  = tcp_sw_conn->old_write_space;
 242         sk->sk_no_check_tx = 0;
 243         write_unlock_bh(&sk->sk_callback_lock);
 244 }
 245 
 246 /**
 247  * iscsi_sw_tcp_xmit_segment - transmit segment
 248  * @tcp_conn: the iSCSI TCP connection
 249  * @segment: the buffer to transmnit
 250  *
 251  * This function transmits as much of the buffer as
 252  * the network layer will accept, and returns the number of
 253  * bytes transmitted.
 254  *
 255  * If CRC hashing is enabled, the function will compute the
 256  * hash as it goes. When the entire segment has been transmitted,
 257  * it will retrieve the hash value and send it as well.
 258  */
 259 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 260                                      struct iscsi_segment *segment)
 261 {
 262         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 263         struct socket *sk = tcp_sw_conn->sock;
 264         unsigned int copied = 0;
 265         int r = 0;
 266 
 267         while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 268                 struct scatterlist *sg;
 269                 unsigned int offset, copy;
 270                 int flags = 0;
 271 
 272                 r = 0;
 273                 offset = segment->copied;
 274                 copy = segment->size - offset;
 275 
 276                 if (segment->total_copied + segment->size < segment->total_size)
 277                         flags |= MSG_MORE;
 278 
 279                 /* Use sendpage if we can; else fall back to sendmsg */
 280                 if (!segment->data) {
 281                         sg = segment->sg;
 282                         offset += segment->sg_offset + sg->offset;
 283                         r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 284                                                   copy, flags);
 285                 } else {
 286                         struct msghdr msg = { .msg_flags = flags };
 287                         struct kvec iov = {
 288                                 .iov_base = segment->data + offset,
 289                                 .iov_len = copy
 290                         };
 291 
 292                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 293                 }
 294 
 295                 if (r < 0) {
 296                         iscsi_tcp_segment_unmap(segment);
 297                         return r;
 298                 }
 299                 copied += r;
 300         }
 301         return copied;
 302 }
 303 
 304 /**
 305  * iscsi_sw_tcp_xmit - TCP transmit
 306  * @conn: iscsi connection
 307  **/
 308 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 309 {
 310         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 311         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 312         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 313         unsigned int consumed = 0;
 314         int rc = 0;
 315 
 316         while (1) {
 317                 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 318                 /*
 319                  * We may not have been able to send data because the conn
 320                  * is getting stopped. libiscsi will know so propagate err
 321                  * for it to do the right thing.
 322                  */
 323                 if (rc == -EAGAIN)
 324                         return rc;
 325                 else if (rc < 0) {
 326                         rc = ISCSI_ERR_XMIT_FAILED;
 327                         goto error;
 328                 } else if (rc == 0)
 329                         break;
 330 
 331                 consumed += rc;
 332 
 333                 if (segment->total_copied >= segment->total_size) {
 334                         if (segment->done != NULL) {
 335                                 rc = segment->done(tcp_conn, segment);
 336                                 if (rc != 0)
 337                                         goto error;
 338                         }
 339                 }
 340         }
 341 
 342         ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 343 
 344         conn->txdata_octets += consumed;
 345         return consumed;
 346 
 347 error:
 348         /* Transmit error. We could initiate error recovery
 349          * here. */
 350         ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 351         iscsi_conn_failure(conn, rc);
 352         return -EIO;
 353 }
 354 
 355 /**
 356  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 357  * @conn: iscsi connection
 358  */
 359 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 360 {
 361         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 362         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 363         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 364 
 365         return segment->total_copied - segment->total_size;
 366 }
 367 
 368 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 369 {
 370         struct iscsi_conn *conn = task->conn;
 371         unsigned int noreclaim_flag;
 372         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 373         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 374         int rc = 0;
 375 
 376         if (!tcp_sw_conn->sock) {
 377                 iscsi_conn_printk(KERN_ERR, conn,
 378                                   "Transport not bound to socket!\n");
 379                 return -EINVAL;
 380         }
 381 
 382         noreclaim_flag = memalloc_noreclaim_save();
 383 
 384         while (iscsi_sw_tcp_xmit_qlen(conn)) {
 385                 rc = iscsi_sw_tcp_xmit(conn);
 386                 if (rc == 0) {
 387                         rc = -EAGAIN;
 388                         break;
 389                 }
 390                 if (rc < 0)
 391                         break;
 392                 rc = 0;
 393         }
 394 
 395         memalloc_noreclaim_restore(noreclaim_flag);
 396         return rc;
 397 }
 398 
 399 /*
 400  * This is called when we're done sending the header.
 401  * Simply copy the data_segment to the send segment, and return.
 402  */
 403 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 404                                       struct iscsi_segment *segment)
 405 {
 406         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 407 
 408         tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 409         ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 410                          "Header done. Next segment size %u total_size %u\n",
 411                          tcp_sw_conn->out.segment.size,
 412                          tcp_sw_conn->out.segment.total_size);
 413         return 0;
 414 }
 415 
 416 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 417                                        size_t hdrlen)
 418 {
 419         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 420         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 421 
 422         ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 423                          "digest enabled" : "digest disabled");
 424 
 425         /* Clear the data segment - needs to be filled in by the
 426          * caller using iscsi_tcp_send_data_prep() */
 427         memset(&tcp_sw_conn->out.data_segment, 0,
 428                sizeof(struct iscsi_segment));
 429 
 430         /* If header digest is enabled, compute the CRC and
 431          * place the digest into the same buffer. We make
 432          * sure that both iscsi_tcp_task and mtask have
 433          * sufficient room.
 434          */
 435         if (conn->hdrdgst_en) {
 436                 iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
 437                                       hdr + hdrlen);
 438                 hdrlen += ISCSI_DIGEST_SIZE;
 439         }
 440 
 441         /* Remember header pointer for later, when we need
 442          * to decide whether there's a payload to go along
 443          * with the header. */
 444         tcp_sw_conn->out.hdr = hdr;
 445 
 446         iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 447                                   iscsi_sw_tcp_send_hdr_done, NULL);
 448 }
 449 
 450 /*
 451  * Prepare the send buffer for the payload data.
 452  * Padding and checksumming will all be taken care
 453  * of by the iscsi_segment routines.
 454  */
 455 static int
 456 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 457                             unsigned int count, unsigned int offset,
 458                             unsigned int len)
 459 {
 460         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 461         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 462         struct ahash_request *tx_hash = NULL;
 463         unsigned int hdr_spec_len;
 464 
 465         ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 466                          conn->datadgst_en ?
 467                          "digest enabled" : "digest disabled");
 468 
 469         /* Make sure the datalen matches what the caller
 470            said he would send. */
 471         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 472         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 473 
 474         if (conn->datadgst_en)
 475                 tx_hash = tcp_sw_conn->tx_hash;
 476 
 477         return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 478                                      sg, count, offset, len,
 479                                      NULL, tx_hash);
 480 }
 481 
 482 static void
 483 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 484                                    size_t len)
 485 {
 486         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 487         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 488         struct ahash_request *tx_hash = NULL;
 489         unsigned int hdr_spec_len;
 490 
 491         ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 492                          "digest enabled" : "digest disabled");
 493 
 494         /* Make sure the datalen matches what the caller
 495            said he would send. */
 496         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 497         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 498 
 499         if (conn->datadgst_en)
 500                 tx_hash = tcp_sw_conn->tx_hash;
 501 
 502         iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 503                                 data, len, NULL, tx_hash);
 504 }
 505 
 506 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 507                                  unsigned int offset, unsigned int count)
 508 {
 509         struct iscsi_conn *conn = task->conn;
 510         int err = 0;
 511 
 512         iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 513 
 514         if (!count)
 515                 return 0;
 516 
 517         if (!task->sc)
 518                 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 519         else {
 520                 struct scsi_data_buffer *sdb = &task->sc->sdb;
 521 
 522                 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 523                                                   sdb->table.nents, offset,
 524                                                   count);
 525         }
 526 
 527         if (err) {
 528                 /* got invalid offset/len */
 529                 return -EIO;
 530         }
 531         return 0;
 532 }
 533 
 534 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 535 {
 536         struct iscsi_tcp_task *tcp_task = task->dd_data;
 537 
 538         task->hdr = task->dd_data + sizeof(*tcp_task);
 539         task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 540         return 0;
 541 }
 542 
 543 static struct iscsi_cls_conn *
 544 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 545                          uint32_t conn_idx)
 546 {
 547         struct iscsi_conn *conn;
 548         struct iscsi_cls_conn *cls_conn;
 549         struct iscsi_tcp_conn *tcp_conn;
 550         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 551         struct crypto_ahash *tfm;
 552 
 553         cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 554                                         conn_idx);
 555         if (!cls_conn)
 556                 return NULL;
 557         conn = cls_conn->dd_data;
 558         tcp_conn = conn->dd_data;
 559         tcp_sw_conn = tcp_conn->dd_data;
 560 
 561         tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
 562         if (IS_ERR(tfm))
 563                 goto free_conn;
 564 
 565         tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 566         if (!tcp_sw_conn->tx_hash)
 567                 goto free_tfm;
 568         ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);
 569 
 570         tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 571         if (!tcp_sw_conn->rx_hash)
 572                 goto free_tx_hash;
 573         ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);
 574 
 575         tcp_conn->rx_hash = tcp_sw_conn->rx_hash;
 576 
 577         return cls_conn;
 578 
 579 free_tx_hash:
 580         ahash_request_free(tcp_sw_conn->tx_hash);
 581 free_tfm:
 582         crypto_free_ahash(tfm);
 583 free_conn:
 584         iscsi_conn_printk(KERN_ERR, conn,
 585                           "Could not create connection due to crc32c "
 586                           "loading error. Make sure the crc32c "
 587                           "module is built as a module or into the "
 588                           "kernel\n");
 589         iscsi_tcp_conn_teardown(cls_conn);
 590         return NULL;
 591 }
 592 
 593 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 594 {
 595         struct iscsi_session *session = conn->session;
 596         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 597         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 598         struct socket *sock = tcp_sw_conn->sock;
 599 
 600         if (!sock)
 601                 return;
 602 
 603         sock_hold(sock->sk);
 604         iscsi_sw_tcp_conn_restore_callbacks(conn);
 605         sock_put(sock->sk);
 606 
 607         spin_lock_bh(&session->frwd_lock);
 608         tcp_sw_conn->sock = NULL;
 609         spin_unlock_bh(&session->frwd_lock);
 610         sockfd_put(sock);
 611 }
 612 
 613 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 614 {
 615         struct iscsi_conn *conn = cls_conn->dd_data;
 616         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 617         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 618 
 619         iscsi_sw_tcp_release_conn(conn);
 620 
 621         ahash_request_free(tcp_sw_conn->rx_hash);
 622         if (tcp_sw_conn->tx_hash) {
 623                 struct crypto_ahash *tfm;
 624 
 625                 tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
 626                 ahash_request_free(tcp_sw_conn->tx_hash);
 627                 crypto_free_ahash(tfm);
 628         }
 629 
 630         iscsi_tcp_conn_teardown(cls_conn);
 631 }
 632 
 633 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 634 {
 635         struct iscsi_conn *conn = cls_conn->dd_data;
 636         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 637         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 638         struct socket *sock = tcp_sw_conn->sock;
 639 
 640         /* userspace may have goofed up and not bound us */
 641         if (!sock)
 642                 return;
 643 
 644         sock->sk->sk_err = EIO;
 645         wake_up_interruptible(sk_sleep(sock->sk));
 646 
 647         /* stop xmit side */
 648         iscsi_suspend_tx(conn);
 649 
 650         /* stop recv side and release socket */
 651         iscsi_sw_tcp_release_conn(conn);
 652 
 653         iscsi_conn_stop(cls_conn, flag);
 654 }
 655 
 656 static int
 657 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 658                        struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 659                        int is_leading)
 660 {
 661         struct iscsi_session *session = cls_session->dd_data;
 662         struct iscsi_conn *conn = cls_conn->dd_data;
 663         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 664         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 665         struct sock *sk;
 666         struct socket *sock;
 667         int err;
 668 
 669         /* lookup for existing socket */
 670         sock = sockfd_lookup((int)transport_eph, &err);
 671         if (!sock) {
 672                 iscsi_conn_printk(KERN_ERR, conn,
 673                                   "sockfd_lookup failed %d\n", err);
 674                 return -EEXIST;
 675         }
 676 
 677         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 678         if (err)
 679                 goto free_socket;
 680 
 681         spin_lock_bh(&session->frwd_lock);
 682         /* bind iSCSI connection and socket */
 683         tcp_sw_conn->sock = sock;
 684         spin_unlock_bh(&session->frwd_lock);
 685 
 686         /* setup Socket parameters */
 687         sk = sock->sk;
 688         sk->sk_reuse = SK_CAN_REUSE;
 689         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 690         sk->sk_allocation = GFP_ATOMIC;
 691         sk_set_memalloc(sk);
 692 
 693         iscsi_sw_tcp_conn_set_callbacks(conn);
 694         tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 695         /*
 696          * set receive state machine into initial state
 697          */
 698         iscsi_tcp_hdr_recv_prep(tcp_conn);
 699         return 0;
 700 
 701 free_socket:
 702         sockfd_put(sock);
 703         return err;
 704 }
 705 
 706 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 707                                        enum iscsi_param param, char *buf,
 708                                        int buflen)
 709 {
 710         struct iscsi_conn *conn = cls_conn->dd_data;
 711         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 712         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 713 
 714         switch(param) {
 715         case ISCSI_PARAM_HDRDGST_EN:
 716                 iscsi_set_param(cls_conn, param, buf, buflen);
 717                 break;
 718         case ISCSI_PARAM_DATADGST_EN:
 719                 iscsi_set_param(cls_conn, param, buf, buflen);
 720                 tcp_sw_conn->sendpage = conn->datadgst_en ?
 721                         sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 722                 break;
 723         case ISCSI_PARAM_MAX_R2T:
 724                 return iscsi_tcp_set_max_r2t(conn, buf);
 725         default:
 726                 return iscsi_set_param(cls_conn, param, buf, buflen);
 727         }
 728 
 729         return 0;
 730 }
 731 
 732 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 733                                        enum iscsi_param param, char *buf)
 734 {
 735         struct iscsi_conn *conn = cls_conn->dd_data;
 736         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 737         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 738         struct sockaddr_in6 addr;
 739         int rc;
 740 
 741         switch(param) {
 742         case ISCSI_PARAM_CONN_PORT:
 743         case ISCSI_PARAM_CONN_ADDRESS:
 744         case ISCSI_PARAM_LOCAL_PORT:
 745                 spin_lock_bh(&conn->session->frwd_lock);
 746                 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
 747                         spin_unlock_bh(&conn->session->frwd_lock);
 748                         return -ENOTCONN;
 749                 }
 750                 if (param == ISCSI_PARAM_LOCAL_PORT)
 751                         rc = kernel_getsockname(tcp_sw_conn->sock,
 752                                                 (struct sockaddr *)&addr);
 753                 else
 754                         rc = kernel_getpeername(tcp_sw_conn->sock,
 755                                                 (struct sockaddr *)&addr);
 756                 spin_unlock_bh(&conn->session->frwd_lock);
 757                 if (rc < 0)
 758                         return rc;
 759 
 760                 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 761                                                  &addr, param, buf);
 762         default:
 763                 return iscsi_conn_get_param(cls_conn, param, buf);
 764         }
 765 
 766         return 0;
 767 }
 768 
 769 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 770                                        enum iscsi_host_param param, char *buf)
 771 {
 772         struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
 773         struct iscsi_session *session = tcp_sw_host->session;
 774         struct iscsi_conn *conn;
 775         struct iscsi_tcp_conn *tcp_conn;
 776         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 777         struct sockaddr_in6 addr;
 778         int rc;
 779 
 780         switch (param) {
 781         case ISCSI_HOST_PARAM_IPADDRESS:
 782                 if (!session)
 783                         return -ENOTCONN;
 784 
 785                 spin_lock_bh(&session->frwd_lock);
 786                 conn = session->leadconn;
 787                 if (!conn) {
 788                         spin_unlock_bh(&session->frwd_lock);
 789                         return -ENOTCONN;
 790                 }
 791                 tcp_conn = conn->dd_data;
 792 
 793                 tcp_sw_conn = tcp_conn->dd_data;
 794                 if (!tcp_sw_conn->sock) {
 795                         spin_unlock_bh(&session->frwd_lock);
 796                         return -ENOTCONN;
 797                 }
 798 
 799                 rc = kernel_getsockname(tcp_sw_conn->sock,
 800                                         (struct sockaddr *)&addr);
 801                 spin_unlock_bh(&session->frwd_lock);
 802                 if (rc < 0)
 803                         return rc;
 804 
 805                 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 806                                                  &addr,
 807                                                  (enum iscsi_param)param, buf);
 808         default:
 809                 return iscsi_host_get_param(shost, param, buf);
 810         }
 811 
 812         return 0;
 813 }
 814 
 815 static void
 816 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 817                             struct iscsi_stats *stats)
 818 {
 819         struct iscsi_conn *conn = cls_conn->dd_data;
 820         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 821         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 822 
 823         stats->custom_length = 3;
 824         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 825         stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 826         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 827         stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 828         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 829         stats->custom[2].value = conn->eh_abort_cnt;
 830 
 831         iscsi_tcp_conn_get_stats(cls_conn, stats);
 832 }
 833 
 834 static struct iscsi_cls_session *
 835 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 836                             uint16_t qdepth, uint32_t initial_cmdsn)
 837 {
 838         struct iscsi_cls_session *cls_session;
 839         struct iscsi_session *session;
 840         struct iscsi_sw_tcp_host *tcp_sw_host;
 841         struct Scsi_Host *shost;
 842 
 843         if (ep) {
 844                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 845                 return NULL;
 846         }
 847 
 848         shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
 849                                  sizeof(struct iscsi_sw_tcp_host), 1);
 850         if (!shost)
 851                 return NULL;
 852         shost->transportt = iscsi_sw_tcp_scsi_transport;
 853         shost->cmd_per_lun = qdepth;
 854         shost->max_lun = iscsi_max_lun;
 855         shost->max_id = 0;
 856         shost->max_channel = 0;
 857         shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 858 
 859         if (iscsi_host_add(shost, NULL))
 860                 goto free_host;
 861 
 862         cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 863                                           cmds_max, 0,
 864                                           sizeof(struct iscsi_tcp_task) +
 865                                           sizeof(struct iscsi_sw_tcp_hdrbuf),
 866                                           initial_cmdsn, 0);
 867         if (!cls_session)
 868                 goto remove_host;
 869         session = cls_session->dd_data;
 870         tcp_sw_host = iscsi_host_priv(shost);
 871         tcp_sw_host->session = session;
 872 
 873         shost->can_queue = session->scsi_cmds_max;
 874         if (iscsi_tcp_r2tpool_alloc(session))
 875                 goto remove_session;
 876         return cls_session;
 877 
 878 remove_session:
 879         iscsi_session_teardown(cls_session);
 880 remove_host:
 881         iscsi_host_remove(shost);
 882 free_host:
 883         iscsi_host_free(shost);
 884         return NULL;
 885 }
 886 
 887 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 888 {
 889         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 890         struct iscsi_session *session = cls_session->dd_data;
 891 
 892         if (WARN_ON_ONCE(session->leadconn))
 893                 return;
 894 
 895         iscsi_tcp_r2tpool_free(cls_session->dd_data);
 896         iscsi_session_teardown(cls_session);
 897 
 898         iscsi_host_remove(shost);
 899         iscsi_host_free(shost);
 900 }
 901 
 902 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
 903 {
 904         switch (param_type) {
 905         case ISCSI_HOST_PARAM:
 906                 switch (param) {
 907                 case ISCSI_HOST_PARAM_NETDEV_NAME:
 908                 case ISCSI_HOST_PARAM_HWADDRESS:
 909                 case ISCSI_HOST_PARAM_IPADDRESS:
 910                 case ISCSI_HOST_PARAM_INITIATOR_NAME:
 911                         return S_IRUGO;
 912                 default:
 913                         return 0;
 914                 }
 915         case ISCSI_PARAM:
 916                 switch (param) {
 917                 case ISCSI_PARAM_MAX_RECV_DLENGTH:
 918                 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
 919                 case ISCSI_PARAM_HDRDGST_EN:
 920                 case ISCSI_PARAM_DATADGST_EN:
 921                 case ISCSI_PARAM_CONN_ADDRESS:
 922                 case ISCSI_PARAM_CONN_PORT:
 923                 case ISCSI_PARAM_LOCAL_PORT:
 924                 case ISCSI_PARAM_EXP_STATSN:
 925                 case ISCSI_PARAM_PERSISTENT_ADDRESS:
 926                 case ISCSI_PARAM_PERSISTENT_PORT:
 927                 case ISCSI_PARAM_PING_TMO:
 928                 case ISCSI_PARAM_RECV_TMO:
 929                 case ISCSI_PARAM_INITIAL_R2T_EN:
 930                 case ISCSI_PARAM_MAX_R2T:
 931                 case ISCSI_PARAM_IMM_DATA_EN:
 932                 case ISCSI_PARAM_FIRST_BURST:
 933                 case ISCSI_PARAM_MAX_BURST:
 934                 case ISCSI_PARAM_PDU_INORDER_EN:
 935                 case ISCSI_PARAM_DATASEQ_INORDER_EN:
 936                 case ISCSI_PARAM_ERL:
 937                 case ISCSI_PARAM_TARGET_NAME:
 938                 case ISCSI_PARAM_TPGT:
 939                 case ISCSI_PARAM_USERNAME:
 940                 case ISCSI_PARAM_PASSWORD:
 941                 case ISCSI_PARAM_USERNAME_IN:
 942                 case ISCSI_PARAM_PASSWORD_IN:
 943                 case ISCSI_PARAM_FAST_ABORT:
 944                 case ISCSI_PARAM_ABORT_TMO:
 945                 case ISCSI_PARAM_LU_RESET_TMO:
 946                 case ISCSI_PARAM_TGT_RESET_TMO:
 947                 case ISCSI_PARAM_IFACE_NAME:
 948                 case ISCSI_PARAM_INITIATOR_NAME:
 949                         return S_IRUGO;
 950                 default:
 951                         return 0;
 952                 }
 953         }
 954 
 955         return 0;
 956 }
 957 
 958 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 959 {
 960         struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
 961         struct iscsi_session *session = tcp_sw_host->session;
 962         struct iscsi_conn *conn = session->leadconn;
 963 
 964         if (conn->datadgst_en)
 965                 sdev->request_queue->backing_dev_info->capabilities
 966                         |= BDI_CAP_STABLE_WRITES;
 967         blk_queue_dma_alignment(sdev->request_queue, 0);
 968         return 0;
 969 }
 970 
 971 static struct scsi_host_template iscsi_sw_tcp_sht = {
 972         .module                 = THIS_MODULE,
 973         .name                   = "iSCSI Initiator over TCP/IP",
 974         .queuecommand           = iscsi_queuecommand,
 975         .change_queue_depth     = scsi_change_queue_depth,
 976         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 977         .sg_tablesize           = 4096,
 978         .max_sectors            = 0xFFFF,
 979         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 980         .eh_timed_out           = iscsi_eh_cmd_timed_out,
 981         .eh_abort_handler       = iscsi_eh_abort,
 982         .eh_device_reset_handler= iscsi_eh_device_reset,
 983         .eh_target_reset_handler = iscsi_eh_recover_target,
 984         .dma_boundary           = PAGE_SIZE - 1,
 985         .slave_configure        = iscsi_sw_tcp_slave_configure,
 986         .target_alloc           = iscsi_target_alloc,
 987         .proc_name              = "iscsi_tcp",
 988         .this_id                = -1,
 989         .track_queue_depth      = 1,
 990 };
 991 
 992 static struct iscsi_transport iscsi_sw_tcp_transport = {
 993         .owner                  = THIS_MODULE,
 994         .name                   = "tcp",
 995         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 996                                   | CAP_DATADGST,
 997         /* session management */
 998         .create_session         = iscsi_sw_tcp_session_create,
 999         .destroy_session        = iscsi_sw_tcp_session_destroy,
1000         /* connection management */
1001         .create_conn            = iscsi_sw_tcp_conn_create,
1002         .bind_conn              = iscsi_sw_tcp_conn_bind,
1003         .destroy_conn           = iscsi_sw_tcp_conn_destroy,
1004         .attr_is_visible        = iscsi_sw_tcp_attr_is_visible,
1005         .set_param              = iscsi_sw_tcp_conn_set_param,
1006         .get_conn_param         = iscsi_sw_tcp_conn_get_param,
1007         .get_session_param      = iscsi_session_get_param,
1008         .start_conn             = iscsi_conn_start,
1009         .stop_conn              = iscsi_sw_tcp_conn_stop,
1010         /* iscsi host params */
1011         .get_host_param         = iscsi_sw_tcp_host_get_param,
1012         .set_host_param         = iscsi_host_set_param,
1013         /* IO */
1014         .send_pdu               = iscsi_conn_send_pdu,
1015         .get_stats              = iscsi_sw_tcp_conn_get_stats,
1016         /* iscsi task/cmd helpers */
1017         .init_task              = iscsi_tcp_task_init,
1018         .xmit_task              = iscsi_tcp_task_xmit,
1019         .cleanup_task           = iscsi_tcp_cleanup_task,
1020         /* low level pdu helpers */
1021         .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
1022         .init_pdu               = iscsi_sw_tcp_pdu_init,
1023         .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
1024         /* recovery */
1025         .session_recovery_timedout = iscsi_session_recovery_timedout,
1026 };
1027 
1028 static int __init iscsi_sw_tcp_init(void)
1029 {
1030         if (iscsi_max_lun < 1) {
1031                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1032                        iscsi_max_lun);
1033                 return -EINVAL;
1034         }
1035 
1036         iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1037                                                 &iscsi_sw_tcp_transport);
1038         if (!iscsi_sw_tcp_scsi_transport)
1039                 return -ENODEV;
1040 
1041         return 0;
1042 }
1043 
1044 static void __exit iscsi_sw_tcp_exit(void)
1045 {
1046         iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1047 }
1048 
1049 module_init(iscsi_sw_tcp_init);
1050 module_exit(iscsi_sw_tcp_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/scsi/iscsi_tcp.c

DEFINITIONS
