drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/inet.h>
  31 #include <linux/slab.h>
  32 #include <linux/file.h>
  33 #include <linux/blkdev.h>
  34 #include <linux/crypto.h>
  35 #include <linux/delay.h>
  36 #include <linux/kfifo.h>
  37 #include <linux/scatterlist.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_device.h>
  41 #include <scsi/scsi_host.h>
  42 #include <scsi/scsi.h>
  43 #include <scsi/scsi_transport_iscsi.h>
  44
  45 #include "iscsi_tcp.h"
  46
  47 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
  48               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52
  53 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  54 static struct scsi_host_template iscsi_sw_tcp_sht;
  55 static struct iscsi_transport iscsi_sw_tcp_transport;
  56
  57 static unsigned int iscsi_max_lun = 512;
  58 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  59
  60 static int iscsi_sw_tcp_dbg;
  61 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
  62                    S_IRUGO | S_IWUSR);
  63 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
  64                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  65
  66 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)                \
  67         do {                                                    \
  68                 if (iscsi_sw_tcp_dbg)                           \
  69                         iscsi_conn_printk(KERN_INFO, _conn,     \
  70                                              "%s " dbg_fmt,     \
  71                                              __func__, ##arg);  \
  72         } while (0);
  73
  74
  75 /**
  76  * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  77  * @rd_desc: read descriptor
  78  * @skb: socket buffer
  79  * @offset: offset in skb
  80  * @len: skb->len - offset
  81  */
  82 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  83                              unsigned int offset, size_t len)
  84 {
  85         struct iscsi_conn *conn = rd_desc->arg.data;
  86         unsigned int consumed, total_consumed = 0;
  87         int status;
  88
  89         ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
  90
  91         do {
  92                 status = 0;
  93                 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  94                 offset += consumed;
  95                 total_consumed += consumed;
  96         } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  97
  98         ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
  99                          skb->len - offset, status);
 100         return total_consumed;
 101 }
 102
 103 /**
 104  * iscsi_sw_sk_state_check - check socket state
 105  * @sk: socket
 106  *
 107  * If the socket is in CLOSE or CLOSE_WAIT we should
 108  * not close the connection if there is still some
 109  * data pending.
 110  */
 111 static inline int iscsi_sw_sk_state_check(struct sock *sk)
 112 {
 113         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 114
 115         if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
 116             !atomic_read(&sk->sk_rmem_alloc)) {
 117                 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 118                 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
 119                 return -ECONNRESET;
 120         }
 121         return 0;
 122 }
 123
 124 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 125 {
 126         struct iscsi_conn *conn = sk->sk_user_data;
 127         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 128         read_descriptor_t rd_desc;
 129
 130         read_lock(&sk->sk_callback_lock);
 131
 132         /*
 133          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 134          * We set count to 1 because we want the network layer to
 135          * hand us all the skbs that are available. iscsi_tcp_recv
 136          * handled pdus that cross buffers or pdus that still need data.
 137          */
 138         rd_desc.arg.data = conn;
 139         rd_desc.count = 1;
 140         tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 141
 142         iscsi_sw_sk_state_check(sk);
 143
 144         read_unlock(&sk->sk_callback_lock);
 145
 146         /* If we had to (atomically) map a highmem page,
 147          * unmap it now. */
 148         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 149 }
 150
 151 static void iscsi_sw_tcp_state_change(struct sock *sk)
 152 {
 153         struct iscsi_tcp_conn *tcp_conn;
 154         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 155         struct iscsi_conn *conn;
 156         struct iscsi_session *session;
 157         void (*old_state_change)(struct sock *);
 158
 159         read_lock(&sk->sk_callback_lock);
 160
 161         conn = (struct iscsi_conn*)sk->sk_user_data;
 162         session = conn->session;
 163
 164         iscsi_sw_sk_state_check(sk);
 165
 166         tcp_conn = conn->dd_data;
 167         tcp_sw_conn = tcp_conn->dd_data;
 168         old_state_change = tcp_sw_conn->old_state_change;
 169
 170         read_unlock(&sk->sk_callback_lock);
 171
 172         old_state_change(sk);
 173 }
 174
 175 /**
 176  * iscsi_write_space - Called when more output buffer space is available
 177  * @sk: socket space is available for
 178  **/
 179 static void iscsi_sw_tcp_write_space(struct sock *sk)
 180 {
 181         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 182         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 183         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 184
 185         tcp_sw_conn->old_write_space(sk);
 186         ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 187         iscsi_conn_queue_work(conn);
 188 }
 189
 190 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 191 {
 192         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 193         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 194         struct sock *sk = tcp_sw_conn->sock->sk;
 195
 196         /* assign new callbacks */
 197         write_lock_bh(&sk->sk_callback_lock);
 198         sk->sk_user_data = conn;
 199         tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 200         tcp_sw_conn->old_state_change = sk->sk_state_change;
 201         tcp_sw_conn->old_write_space = sk->sk_write_space;
 202         sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 203         sk->sk_state_change = iscsi_sw_tcp_state_change;
 204         sk->sk_write_space = iscsi_sw_tcp_write_space;
 205         write_unlock_bh(&sk->sk_callback_lock);
 206 }
 207
 208 static void
 209 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
 210 {
 211         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 212         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 213         struct sock *sk = tcp_sw_conn->sock->sk;
 214
 215         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 216         write_lock_bh(&sk->sk_callback_lock);
 217         sk->sk_user_data    = NULL;
 218         sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 219         sk->sk_state_change = tcp_sw_conn->old_state_change;
 220         sk->sk_write_space  = tcp_sw_conn->old_write_space;
 221         sk->sk_no_check  = 0;
 222         write_unlock_bh(&sk->sk_callback_lock);
 223 }
 224
 225 /**
 226  * iscsi_sw_tcp_xmit_segment - transmit segment
 227  * @tcp_conn: the iSCSI TCP connection
 228  * @segment: the buffer to transmnit
 229  *
 230  * This function transmits as much of the buffer as
 231  * the network layer will accept, and returns the number of
 232  * bytes transmitted.
 233  *
 234  * If CRC hashing is enabled, the function will compute the
 235  * hash as it goes. When the entire segment has been transmitted,
 236  * it will retrieve the hash value and send it as well.
 237  */
 238 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 239                                      struct iscsi_segment *segment)
 240 {
 241         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 242         struct socket *sk = tcp_sw_conn->sock;
 243         unsigned int copied = 0;
 244         int r = 0;
 245
 246         while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 247                 struct scatterlist *sg;
 248                 unsigned int offset, copy;
 249                 int flags = 0;
 250
 251                 r = 0;
 252                 offset = segment->copied;
 253                 copy = segment->size - offset;
 254
 255                 if (segment->total_copied + segment->size < segment->total_size)
 256                         flags |= MSG_MORE;
 257
 258                 /* Use sendpage if we can; else fall back to sendmsg */
 259                 if (!segment->data) {
 260                         sg = segment->sg;
 261                         offset += segment->sg_offset + sg->offset;
 262                         r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 263                                                   copy, flags);
 264                 } else {
 265                         struct msghdr msg = { .msg_flags = flags };
 266                         struct kvec iov = {
 267                                 .iov_base = segment->data + offset,
 268                                 .iov_len = copy
 269                         };
 270
 271                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 272                 }
 273
 274                 if (r < 0) {
 275                         iscsi_tcp_segment_unmap(segment);
 276                         return r;
 277                 }
 278                 copied += r;
 279         }
 280         return copied;
 281 }
 282
 283 /**
 284  * iscsi_sw_tcp_xmit - TCP transmit
 285  **/
 286 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 287 {
 288         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 289         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 290         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 291         unsigned int consumed = 0;
 292         int rc = 0;
 293
 294         while (1) {
 295                 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 296                 /*
 297                  * We may not have been able to send data because the conn
 298                  * is getting stopped. libiscsi will know so propagate err
 299                  * for it to do the right thing.
 300                  */
 301                 if (rc == -EAGAIN)
 302                         return rc;
 303                 else if (rc < 0) {
 304                         rc = ISCSI_ERR_XMIT_FAILED;
 305                         goto error;
 306                 } else if (rc == 0)
 307                         break;
 308
 309                 consumed += rc;
 310
 311                 if (segment->total_copied >= segment->total_size) {
 312                         if (segment->done != NULL) {
 313                                 rc = segment->done(tcp_conn, segment);
 314                                 if (rc != 0)
 315                                         goto error;
 316                         }
 317                 }
 318         }
 319
 320         ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 321
 322         conn->txdata_octets += consumed;
 323         return consumed;
 324
 325 error:
 326         /* Transmit error. We could initiate error recovery
 327          * here. */
 328         ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 329         iscsi_conn_failure(conn, rc);
 330         return -EIO;
 331 }
 332
 333 /**
 334  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 335  */
 336 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 337 {
 338         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 339         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 340         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 341
 342         return segment->total_copied - segment->total_size;
 343 }
 344
 345 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 346 {
 347         struct iscsi_conn *conn = task->conn;
 348         int rc;
 349
 350         while (iscsi_sw_tcp_xmit_qlen(conn)) {
 351                 rc = iscsi_sw_tcp_xmit(conn);
 352                 if (rc == 0)
 353                         return -EAGAIN;
 354                 if (rc < 0)
 355                         return rc;
 356         }
 357
 358         return 0;
 359 }
 360
 361 /*
 362  * This is called when we're done sending the header.
 363  * Simply copy the data_segment to the send segment, and return.
 364  */
 365 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 366                                       struct iscsi_segment *segment)
 367 {
 368         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 369
 370         tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 371         ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 372                          "Header done. Next segment size %u total_size %u\n",
 373                          tcp_sw_conn->out.segment.size,
 374                          tcp_sw_conn->out.segment.total_size);
 375         return 0;
 376 }
 377
 378 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 379                                        size_t hdrlen)
 380 {
 381         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 382         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 383
 384         ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 385                          "digest enabled" : "digest disabled");
 386
 387         /* Clear the data segment - needs to be filled in by the
 388          * caller using iscsi_tcp_send_data_prep() */
 389         memset(&tcp_sw_conn->out.data_segment, 0,
 390                sizeof(struct iscsi_segment));
 391
 392         /* If header digest is enabled, compute the CRC and
 393          * place the digest into the same buffer. We make
 394          * sure that both iscsi_tcp_task and mtask have
 395          * sufficient room.
 396          */
 397         if (conn->hdrdgst_en) {
 398                 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 399                                       hdr + hdrlen);
 400                 hdrlen += ISCSI_DIGEST_SIZE;
 401         }
 402
 403         /* Remember header pointer for later, when we need
 404          * to decide whether there's a payload to go along
 405          * with the header. */
 406         tcp_sw_conn->out.hdr = hdr;
 407
 408         iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 409                                   iscsi_sw_tcp_send_hdr_done, NULL);
 410 }
 411
 412 /*
 413  * Prepare the send buffer for the payload data.
 414  * Padding and checksumming will all be taken care
 415  * of by the iscsi_segment routines.
 416  */
 417 static int
 418 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 419                             unsigned int count, unsigned int offset,
 420                             unsigned int len)
 421 {
 422         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 423         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 424         struct hash_desc *tx_hash = NULL;
 425         unsigned int hdr_spec_len;
 426
 427         ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 428                          conn->datadgst_en ?
 429                          "digest enabled" : "digest disabled");
 430
 431         /* Make sure the datalen matches what the caller
 432            said he would send. */
 433         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 434         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 435
 436         if (conn->datadgst_en)
 437                 tx_hash = &tcp_sw_conn->tx_hash;
 438
 439         return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 440                                      sg, count, offset, len,
 441                                      NULL, tx_hash);
 442 }
 443
 444 static void
 445 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 446                                    size_t len)
 447 {
 448         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 449         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 450         struct hash_desc *tx_hash = NULL;
 451         unsigned int hdr_spec_len;
 452
 453         ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 454                          "digest enabled" : "digest disabled");
 455
 456         /* Make sure the datalen matches what the caller
 457            said he would send. */
 458         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 459         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 460
 461         if (conn->datadgst_en)
 462                 tx_hash = &tcp_sw_conn->tx_hash;
 463
 464         iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 465                                 data, len, NULL, tx_hash);
 466 }
 467
 468 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 469                                  unsigned int offset, unsigned int count)
 470 {
 471         struct iscsi_conn *conn = task->conn;
 472         int err = 0;
 473
 474         iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 475
 476         if (!count)
 477                 return 0;
 478
 479         if (!task->sc)
 480                 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 481         else {
 482                 struct scsi_data_buffer *sdb = scsi_out(task->sc);
 483
 484                 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 485                                                   sdb->table.nents, offset,
 486                                                   count);
 487         }
 488
 489         if (err) {
 490                 /* got invalid offset/len */
 491                 return -EIO;
 492         }
 493         return 0;
 494 }
 495
 496 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 497 {
 498         struct iscsi_tcp_task *tcp_task = task->dd_data;
 499
 500         task->hdr = task->dd_data + sizeof(*tcp_task);
 501         task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 502         return 0;
 503 }
 504
 505 static struct iscsi_cls_conn *
 506 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 507                          uint32_t conn_idx)
 508 {
 509         struct iscsi_conn *conn;
 510         struct iscsi_cls_conn *cls_conn;
 511         struct iscsi_tcp_conn *tcp_conn;
 512         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 513
 514         cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 515                                         conn_idx);
 516         if (!cls_conn)
 517                 return NULL;
 518         conn = cls_conn->dd_data;
 519         tcp_conn = conn->dd_data;
 520         tcp_sw_conn = tcp_conn->dd_data;
 521
 522         tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 523                                                      CRYPTO_ALG_ASYNC);
 524         tcp_sw_conn->tx_hash.flags = 0;
 525         if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 526                 goto free_conn;
 527
 528         tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 529                                                      CRYPTO_ALG_ASYNC);
 530         tcp_sw_conn->rx_hash.flags = 0;
 531         if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 532                 goto free_tx_tfm;
 533         tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 534
 535         return cls_conn;
 536
 537 free_tx_tfm:
 538         crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 539 free_conn:
 540         iscsi_conn_printk(KERN_ERR, conn,
 541                           "Could not create connection due to crc32c "
 542                           "loading error. Make sure the crc32c "
 543                           "module is built as a module or into the "
 544                           "kernel\n");
 545         iscsi_tcp_conn_teardown(cls_conn);
 546         return NULL;
 547 }
 548
 549 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 550 {
 551         struct iscsi_session *session = conn->session;
 552         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 553         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 554         struct socket *sock = tcp_sw_conn->sock;
 555
 556         if (!sock)
 557                 return;
 558
 559         sock_hold(sock->sk);
 560         iscsi_sw_tcp_conn_restore_callbacks(conn);
 561         sock_put(sock->sk);
 562
 563         spin_lock_bh(&session->lock);
 564         tcp_sw_conn->sock = NULL;
 565         spin_unlock_bh(&session->lock);
 566         sockfd_put(sock);
 567 }
 568
 569 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 570 {
 571         struct iscsi_conn *conn = cls_conn->dd_data;
 572         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 573         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 574
 575         iscsi_sw_tcp_release_conn(conn);
 576
 577         if (tcp_sw_conn->tx_hash.tfm)
 578                 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 579         if (tcp_sw_conn->rx_hash.tfm)
 580                 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 581
 582         iscsi_tcp_conn_teardown(cls_conn);
 583 }
 584
 585 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 586 {
 587         struct iscsi_conn *conn = cls_conn->dd_data;
 588         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 589         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 590         struct socket *sock = tcp_sw_conn->sock;
 591
 592         /* userspace may have goofed up and not bound us */
 593         if (!sock)
 594                 return;
 595         /*
 596          * Make sure our recv side is stopped.
 597          * Older tools called conn stop before ep_disconnect
 598          * so IO could still be coming in.
 599          */
 600         write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 601         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 602         write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 603
 604         sock->sk->sk_err = EIO;
 605         wake_up_interruptible(sk_sleep(sock->sk));
 606
 607         iscsi_conn_stop(cls_conn, flag);
 608         iscsi_sw_tcp_release_conn(conn);
 609 }
 610
 611 static int
 612 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 613                        struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 614                        int is_leading)
 615 {
 616         struct iscsi_session *session = cls_session->dd_data;
 617         struct iscsi_conn *conn = cls_conn->dd_data;
 618         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 619         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 620         struct sock *sk;
 621         struct socket *sock;
 622         int err;
 623
 624         /* lookup for existing socket */
 625         sock = sockfd_lookup((int)transport_eph, &err);
 626         if (!sock) {
 627                 iscsi_conn_printk(KERN_ERR, conn,
 628                                   "sockfd_lookup failed %d\n", err);
 629                 return -EEXIST;
 630         }
 631
 632         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 633         if (err)
 634                 goto free_socket;
 635
 636         spin_lock_bh(&session->lock);
 637         /* bind iSCSI connection and socket */
 638         tcp_sw_conn->sock = sock;
 639         spin_unlock_bh(&session->lock);
 640
 641         /* setup Socket parameters */
 642         sk = sock->sk;
 643         sk->sk_reuse = 1;
 644         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 645         sk->sk_allocation = GFP_ATOMIC;
 646
 647         iscsi_sw_tcp_conn_set_callbacks(conn);
 648         tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 649         /*
 650          * set receive state machine into initial state
 651          */
 652         iscsi_tcp_hdr_recv_prep(tcp_conn);
 653         return 0;
 654
 655 free_socket:
 656         sockfd_put(sock);
 657         return err;
 658 }
 659
 660 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 661                                        enum iscsi_param param, char *buf,
 662                                        int buflen)
 663 {
 664         struct iscsi_conn *conn = cls_conn->dd_data;
 665         struct iscsi_session *session = conn->session;
 666         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 667         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 668         int value;
 669
 670         switch(param) {
 671         case ISCSI_PARAM_HDRDGST_EN:
 672                 iscsi_set_param(cls_conn, param, buf, buflen);
 673                 break;
 674         case ISCSI_PARAM_DATADGST_EN:
 675                 iscsi_set_param(cls_conn, param, buf, buflen);
 676                 tcp_sw_conn->sendpage = conn->datadgst_en ?
 677                         sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 678                 break;
 679         case ISCSI_PARAM_MAX_R2T:
 680                 sscanf(buf, "%d", &value);
 681                 if (value <= 0 || !is_power_of_2(value))
 682                         return -EINVAL;
 683                 if (session->max_r2t == value)
 684                         break;
 685                 iscsi_tcp_r2tpool_free(session);
 686                 iscsi_set_param(cls_conn, param, buf, buflen);
 687                 if (iscsi_tcp_r2tpool_alloc(session))
 688                         return -ENOMEM;
 689                 break;
 690         default:
 691                 return iscsi_set_param(cls_conn, param, buf, buflen);
 692         }
 693
 694         return 0;
 695 }
 696
 697 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 698                                        enum iscsi_param param, char *buf)
 699 {
 700         struct iscsi_conn *conn = cls_conn->dd_data;
 701         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 702         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 703         struct sockaddr_in6 addr;
 704         int rc, len;
 705
 706         switch(param) {
 707         case ISCSI_PARAM_CONN_PORT:
 708         case ISCSI_PARAM_CONN_ADDRESS:
 709                 spin_lock_bh(&conn->session->lock);
 710                 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
 711                         spin_unlock_bh(&conn->session->lock);
 712                         return -ENOTCONN;
 713                 }
 714                 rc = kernel_getpeername(tcp_sw_conn->sock,
 715                                         (struct sockaddr *)&addr, &len);
 716                 spin_unlock_bh(&conn->session->lock);
 717                 if (rc)
 718                         return rc;
 719
 720                 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 721                                                  &addr, param, buf);
 722         default:
 723                 return iscsi_conn_get_param(cls_conn, param, buf);
 724         }
 725
 726         return 0;
 727 }
 728
 729 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 730                                        enum iscsi_host_param param, char *buf)
 731 {
 732         struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
 733         struct iscsi_session *session = tcp_sw_host->session;
 734         struct iscsi_conn *conn;
 735         struct iscsi_tcp_conn *tcp_conn;
 736         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 737         struct sockaddr_in6 addr;
 738         int rc, len;
 739
 740         switch (param) {
 741         case ISCSI_HOST_PARAM_IPADDRESS:
 742                 spin_lock_bh(&session->lock);
 743                 conn = session->leadconn;
 744                 if (!conn) {
 745                         spin_unlock_bh(&session->lock);
 746                         return -ENOTCONN;
 747                 }
 748                 tcp_conn = conn->dd_data;
 749
 750                 tcp_sw_conn = tcp_conn->dd_data;
 751                 if (!tcp_sw_conn->sock) {
 752                         spin_unlock_bh(&session->lock);
 753                         return -ENOTCONN;
 754                 }
 755
 756                 rc = kernel_getsockname(tcp_sw_conn->sock,
 757                                         (struct sockaddr *)&addr, &len);
 758                 spin_unlock_bh(&session->lock);
 759                 if (rc)
 760                         return rc;
 761
 762                 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 763                                                  &addr, param, buf);
 764         default:
 765                 return iscsi_host_get_param(shost, param, buf);
 766         }
 767
 768         return 0;
 769 }
 770
 771 static void
 772 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 773                             struct iscsi_stats *stats)
 774 {
 775         struct iscsi_conn *conn = cls_conn->dd_data;
 776         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 777         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 778
 779         stats->custom_length = 3;
 780         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 781         stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 782         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 783         stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 784         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 785         stats->custom[2].value = conn->eh_abort_cnt;
 786
 787         iscsi_tcp_conn_get_stats(cls_conn, stats);
 788 }
 789
 790 static struct iscsi_cls_session *
 791 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 792                             uint16_t qdepth, uint32_t initial_cmdsn)
 793 {
 794         struct iscsi_cls_session *cls_session;
 795         struct iscsi_session *session;
 796         struct iscsi_sw_tcp_host *tcp_sw_host;
 797         struct Scsi_Host *shost;
 798
 799         if (ep) {
 800                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 801                 return NULL;
 802         }
 803
 804         shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
 805                                  sizeof(struct iscsi_sw_tcp_host), 1);
 806         if (!shost)
 807                 return NULL;
 808         shost->transportt = iscsi_sw_tcp_scsi_transport;
 809         shost->cmd_per_lun = qdepth;
 810         shost->max_lun = iscsi_max_lun;
 811         shost->max_id = 0;
 812         shost->max_channel = 0;
 813         shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 814
 815         if (iscsi_host_add(shost, NULL))
 816                 goto free_host;
 817
 818         cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 819                                           cmds_max, 0,
 820                                           sizeof(struct iscsi_tcp_task) +
 821                                           sizeof(struct iscsi_sw_tcp_hdrbuf),
 822                                           initial_cmdsn, 0);
 823         if (!cls_session)
 824                 goto remove_host;
 825         session = cls_session->dd_data;
 826         tcp_sw_host = iscsi_host_priv(shost);
 827         tcp_sw_host->session = session;
 828
 829         shost->can_queue = session->scsi_cmds_max;
 830         if (iscsi_tcp_r2tpool_alloc(session))
 831                 goto remove_session;
 832         return cls_session;
 833
 834 remove_session:
 835         iscsi_session_teardown(cls_session);
 836 remove_host:
 837         iscsi_host_remove(shost);
 838 free_host:
 839         iscsi_host_free(shost);
 840         return NULL;
 841 }
 842
 843 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 844 {
 845         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 846
 847         iscsi_tcp_r2tpool_free(cls_session->dd_data);
 848         iscsi_session_teardown(cls_session);
 849
 850         iscsi_host_remove(shost);
 851         iscsi_host_free(shost);
 852 }
 853
 854 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 855 {
 856         set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 857         return 0;
 858 }
 859
 860 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 861 {
 862         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 863         blk_queue_dma_alignment(sdev->request_queue, 0);
 864         return 0;
 865 }
 866
 867 static struct scsi_host_template iscsi_sw_tcp_sht = {
 868         .module                 = THIS_MODULE,
 869         .name                   = "iSCSI Initiator over TCP/IP",
 870         .queuecommand           = iscsi_queuecommand,
 871         .change_queue_depth     = iscsi_change_queue_depth,
 872         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 873         .sg_tablesize           = 4096,
 874         .max_sectors            = 0xFFFF,
 875         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 876         .eh_abort_handler       = iscsi_eh_abort,
 877         .eh_device_reset_handler= iscsi_eh_device_reset,
 878         .eh_target_reset_handler = iscsi_eh_recover_target,
 879         .use_clustering         = DISABLE_CLUSTERING,
 880         .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 881         .slave_configure        = iscsi_sw_tcp_slave_configure,
 882         .target_alloc           = iscsi_target_alloc,
 883         .proc_name              = "iscsi_tcp",
 884         .this_id                = -1,
 885 };
 886
 887 static struct iscsi_transport iscsi_sw_tcp_transport = {
 888         .owner                  = THIS_MODULE,
 889         .name                   = "tcp",
 890         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 891                                   | CAP_DATADGST,
 892         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 893                                   ISCSI_MAX_XMIT_DLENGTH |
 894                                   ISCSI_HDRDGST_EN |
 895                                   ISCSI_DATADGST_EN |
 896                                   ISCSI_INITIAL_R2T_EN |
 897                                   ISCSI_MAX_R2T |
 898                                   ISCSI_IMM_DATA_EN |
 899                                   ISCSI_FIRST_BURST |
 900                                   ISCSI_MAX_BURST |
 901                                   ISCSI_PDU_INORDER_EN |
 902                                   ISCSI_DATASEQ_INORDER_EN |
 903                                   ISCSI_ERL |
 904                                   ISCSI_CONN_PORT |
 905                                   ISCSI_CONN_ADDRESS |
 906                                   ISCSI_EXP_STATSN |
 907                                   ISCSI_PERSISTENT_PORT |
 908                                   ISCSI_PERSISTENT_ADDRESS |
 909                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
 910                                   ISCSI_USERNAME | ISCSI_PASSWORD |
 911                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
 912                                   ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
 913                                   ISCSI_LU_RESET_TMO | ISCSI_TGT_RESET_TMO |
 914                                   ISCSI_PING_TMO | ISCSI_RECV_TMO |
 915                                   ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
 916         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
 917                                   ISCSI_HOST_INITIATOR_NAME |
 918                                   ISCSI_HOST_NETDEV_NAME,
 919         /* session management */
 920         .create_session         = iscsi_sw_tcp_session_create,
 921         .destroy_session        = iscsi_sw_tcp_session_destroy,
 922         /* connection management */
 923         .create_conn            = iscsi_sw_tcp_conn_create,
 924         .bind_conn              = iscsi_sw_tcp_conn_bind,
 925         .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 926         .set_param              = iscsi_sw_tcp_conn_set_param,
 927         .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 928         .get_session_param      = iscsi_session_get_param,
 929         .start_conn             = iscsi_conn_start,
 930         .stop_conn              = iscsi_sw_tcp_conn_stop,
 931         /* iscsi host params */
 932         .get_host_param         = iscsi_sw_tcp_host_get_param,
 933         .set_host_param         = iscsi_host_set_param,
 934         /* IO */
 935         .send_pdu               = iscsi_conn_send_pdu,
 936         .get_stats              = iscsi_sw_tcp_conn_get_stats,
 937         /* iscsi task/cmd helpers */
 938         .init_task              = iscsi_tcp_task_init,
 939         .xmit_task              = iscsi_tcp_task_xmit,
 940         .cleanup_task           = iscsi_tcp_cleanup_task,
 941         /* low level pdu helpers */
 942         .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 943         .init_pdu               = iscsi_sw_tcp_pdu_init,
 944         .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 945         /* recovery */
 946         .session_recovery_timedout = iscsi_session_recovery_timedout,
 947 };
 948
 949 static int __init iscsi_sw_tcp_init(void)
 950 {
 951         if (iscsi_max_lun < 1) {
 952                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 953                        iscsi_max_lun);
 954                 return -EINVAL;
 955         }
 956
 957         iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 958                                                 &iscsi_sw_tcp_transport);
 959         if (!iscsi_sw_tcp_scsi_transport)
 960                 return -ENODEV;
 961
 962         return 0;
 963 }
 964
 965 static void __exit iscsi_sw_tcp_exit(void)
 966 {
 967         iscsi_unregister_transport(&iscsi_sw_tcp_transport);
 968 }
 969
 970 module_init(iscsi_sw_tcp_init);
 971 module_exit(iscsi_sw_tcp_exit);