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/file.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <net/tcp.h>
  38 #include <scsi/scsi_cmnd.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
  47               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  48               "Alex Aizman <itn780@yahoo.com>");
  49 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  50 MODULE_LICENSE("GPL");
  51
  52 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  53 static struct scsi_host_template iscsi_sw_tcp_sht;
  54 static struct iscsi_transport iscsi_sw_tcp_transport;
  55
  56 static unsigned int iscsi_max_lun = 512;
  57 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  58
  59 static int iscsi_sw_tcp_dbg;
  60 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
  61                    S_IRUGO | S_IWUSR);
  62 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
  63                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  64
  65 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)                \
  66         do {                                                    \
  67                 if (iscsi_sw_tcp_dbg)                           \
  68                         iscsi_conn_printk(KERN_INFO, _conn,     \
  69                                              "%s " dbg_fmt,     \
  70                                              __func__, ##arg);  \
  71         } while (0);
  72
  73
  74 /**
  75  * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  76  * @rd_desc: read descriptor
  77  * @skb: socket buffer
  78  * @offset: offset in skb
  79  * @len: skb->len - offset
  80  */
  81 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  82                              unsigned int offset, size_t len)
  83 {
  84         struct iscsi_conn *conn = rd_desc->arg.data;
  85         unsigned int consumed, total_consumed = 0;
  86         int status;
  87
  88         ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
  89
  90         do {
  91                 status = 0;
  92                 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  93                 offset += consumed;
  94                 total_consumed += consumed;
  95         } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  96
  97         ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
  98                          skb->len - offset, status);
  99         return total_consumed;
 100 }
 101
 102 /**
 103  * iscsi_sw_sk_state_check - check socket state
 104  * @sk: socket
 105  *
 106  * If the socket is in CLOSE or CLOSE_WAIT we should
 107  * not close the connection if there is still some
 108  * data pending.
 109  */
 110 static inline int iscsi_sw_sk_state_check(struct sock *sk)
 111 {
 112         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 113
 114         if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
 115             !atomic_read(&sk->sk_rmem_alloc)) {
 116                 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 117                 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
 118                 return -ECONNRESET;
 119         }
 120         return 0;
 121 }
 122
 123 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 124 {
 125         struct iscsi_conn *conn = sk->sk_user_data;
 126         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 127         read_descriptor_t rd_desc;
 128
 129         read_lock(&sk->sk_callback_lock);
 130
 131         /*
 132          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 133          * We set count to 1 because we want the network layer to
 134          * hand us all the skbs that are available. iscsi_tcp_recv
 135          * handled pdus that cross buffers or pdus that still need data.
 136          */
 137         rd_desc.arg.data = conn;
 138         rd_desc.count = 1;
 139         tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 140
 141         iscsi_sw_sk_state_check(sk);
 142
 143         read_unlock(&sk->sk_callback_lock);
 144
 145         /* If we had to (atomically) map a highmem page,
 146          * unmap it now. */
 147         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 148 }
 149
 150 static void iscsi_sw_tcp_state_change(struct sock *sk)
 151 {
 152         struct iscsi_tcp_conn *tcp_conn;
 153         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 154         struct iscsi_conn *conn;
 155         struct iscsi_session *session;
 156         void (*old_state_change)(struct sock *);
 157
 158         read_lock(&sk->sk_callback_lock);
 159
 160         conn = (struct iscsi_conn*)sk->sk_user_data;
 161         session = conn->session;
 162
 163         iscsi_sw_sk_state_check(sk);
 164
 165         tcp_conn = conn->dd_data;
 166         tcp_sw_conn = tcp_conn->dd_data;
 167         old_state_change = tcp_sw_conn->old_state_change;
 168
 169         read_unlock(&sk->sk_callback_lock);
 170
 171         old_state_change(sk);
 172 }
 173
 174 /**
 175  * iscsi_write_space - Called when more output buffer space is available
 176  * @sk: socket space is available for
 177  **/
 178 static void iscsi_sw_tcp_write_space(struct sock *sk)
 179 {
 180         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 181         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 182         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 183
 184         tcp_sw_conn->old_write_space(sk);
 185         ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 186         iscsi_conn_queue_work(conn);
 187 }
 188
 189 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 190 {
 191         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 192         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 193         struct sock *sk = tcp_sw_conn->sock->sk;
 194
 195         /* assign new callbacks */
 196         write_lock_bh(&sk->sk_callback_lock);
 197         sk->sk_user_data = conn;
 198         tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 199         tcp_sw_conn->old_state_change = sk->sk_state_change;
 200         tcp_sw_conn->old_write_space = sk->sk_write_space;
 201         sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 202         sk->sk_state_change = iscsi_sw_tcp_state_change;
 203         sk->sk_write_space = iscsi_sw_tcp_write_space;
 204         write_unlock_bh(&sk->sk_callback_lock);
 205 }
 206
 207 static void
 208 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn)
 209 {
 210         struct sock *sk = tcp_sw_conn->sock->sk;
 211
 212         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 213         write_lock_bh(&sk->sk_callback_lock);
 214         sk->sk_user_data    = NULL;
 215         sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 216         sk->sk_state_change = tcp_sw_conn->old_state_change;
 217         sk->sk_write_space  = tcp_sw_conn->old_write_space;
 218         sk->sk_no_check  = 0;
 219         write_unlock_bh(&sk->sk_callback_lock);
 220 }
 221
 222 /**
 223  * iscsi_sw_tcp_xmit_segment - transmit segment
 224  * @tcp_conn: the iSCSI TCP connection
 225  * @segment: the buffer to transmnit
 226  *
 227  * This function transmits as much of the buffer as
 228  * the network layer will accept, and returns the number of
 229  * bytes transmitted.
 230  *
 231  * If CRC hashing is enabled, the function will compute the
 232  * hash as it goes. When the entire segment has been transmitted,
 233  * it will retrieve the hash value and send it as well.
 234  */
 235 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 236                                      struct iscsi_segment *segment)
 237 {
 238         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 239         struct socket *sk = tcp_sw_conn->sock;
 240         unsigned int copied = 0;
 241         int r = 0;
 242
 243         while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 244                 struct scatterlist *sg;
 245                 unsigned int offset, copy;
 246                 int flags = 0;
 247
 248                 r = 0;
 249                 offset = segment->copied;
 250                 copy = segment->size - offset;
 251
 252                 if (segment->total_copied + segment->size < segment->total_size)
 253                         flags |= MSG_MORE;
 254
 255                 /* Use sendpage if we can; else fall back to sendmsg */
 256                 if (!segment->data) {
 257                         sg = segment->sg;
 258                         offset += segment->sg_offset + sg->offset;
 259                         r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 260                                                   copy, flags);
 261                 } else {
 262                         struct msghdr msg = { .msg_flags = flags };
 263                         struct kvec iov = {
 264                                 .iov_base = segment->data + offset,
 265                                 .iov_len = copy
 266                         };
 267
 268                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 269                 }
 270
 271                 if (r < 0) {
 272                         iscsi_tcp_segment_unmap(segment);
 273                         return r;
 274                 }
 275                 copied += r;
 276         }
 277         return copied;
 278 }
 279
 280 /**
 281  * iscsi_sw_tcp_xmit - TCP transmit
 282  **/
 283 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 284 {
 285         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 286         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 287         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 288         unsigned int consumed = 0;
 289         int rc = 0;
 290
 291         while (1) {
 292                 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 293                 /*
 294                  * We may not have been able to send data because the conn
 295                  * is getting stopped. libiscsi will know so propogate err
 296                  * for it to do the right thing.
 297                  */
 298                 if (rc == -EAGAIN)
 299                         return rc;
 300                 else if (rc < 0) {
 301                         rc = ISCSI_ERR_XMIT_FAILED;
 302                         goto error;
 303                 } else if (rc == 0)
 304                         break;
 305
 306                 consumed += rc;
 307
 308                 if (segment->total_copied >= segment->total_size) {
 309                         if (segment->done != NULL) {
 310                                 rc = segment->done(tcp_conn, segment);
 311                                 if (rc != 0)
 312                                         goto error;
 313                         }
 314                 }
 315         }
 316
 317         ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 318
 319         conn->txdata_octets += consumed;
 320         return consumed;
 321
 322 error:
 323         /* Transmit error. We could initiate error recovery
 324          * here. */
 325         ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 326         iscsi_conn_failure(conn, rc);
 327         return -EIO;
 328 }
 329
 330 /**
 331  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 332  */
 333 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 334 {
 335         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 336         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 337         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 338
 339         return segment->total_copied - segment->total_size;
 340 }
 341
 342 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 343 {
 344         struct iscsi_conn *conn = task->conn;
 345         int rc;
 346
 347         while (iscsi_sw_tcp_xmit_qlen(conn)) {
 348                 rc = iscsi_sw_tcp_xmit(conn);
 349                 if (rc == 0)
 350                         return -EAGAIN;
 351                 if (rc < 0)
 352                         return rc;
 353         }
 354
 355         return 0;
 356 }
 357
 358 /*
 359  * This is called when we're done sending the header.
 360  * Simply copy the data_segment to the send segment, and return.
 361  */
 362 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 363                                       struct iscsi_segment *segment)
 364 {
 365         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 366
 367         tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 368         ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 369                          "Header done. Next segment size %u total_size %u\n",
 370                          tcp_sw_conn->out.segment.size,
 371                          tcp_sw_conn->out.segment.total_size);
 372         return 0;
 373 }
 374
 375 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 376                                        size_t hdrlen)
 377 {
 378         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 379         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 380
 381         ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 382                          "digest enabled" : "digest disabled");
 383
 384         /* Clear the data segment - needs to be filled in by the
 385          * caller using iscsi_tcp_send_data_prep() */
 386         memset(&tcp_sw_conn->out.data_segment, 0,
 387                sizeof(struct iscsi_segment));
 388
 389         /* If header digest is enabled, compute the CRC and
 390          * place the digest into the same buffer. We make
 391          * sure that both iscsi_tcp_task and mtask have
 392          * sufficient room.
 393          */
 394         if (conn->hdrdgst_en) {
 395                 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 396                                       hdr + hdrlen);
 397                 hdrlen += ISCSI_DIGEST_SIZE;
 398         }
 399
 400         /* Remember header pointer for later, when we need
 401          * to decide whether there's a payload to go along
 402          * with the header. */
 403         tcp_sw_conn->out.hdr = hdr;
 404
 405         iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 406                                   iscsi_sw_tcp_send_hdr_done, NULL);
 407 }
 408
 409 /*
 410  * Prepare the send buffer for the payload data.
 411  * Padding and checksumming will all be taken care
 412  * of by the iscsi_segment routines.
 413  */
 414 static int
 415 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 416                             unsigned int count, unsigned int offset,
 417                             unsigned int len)
 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         struct hash_desc *tx_hash = NULL;
 422         unsigned int hdr_spec_len;
 423
 424         ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 425                          conn->datadgst_en ?
 426                          "digest enabled" : "digest disabled");
 427
 428         /* Make sure the datalen matches what the caller
 429            said he would send. */
 430         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 431         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 432
 433         if (conn->datadgst_en)
 434                 tx_hash = &tcp_sw_conn->tx_hash;
 435
 436         return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 437                                      sg, count, offset, len,
 438                                      NULL, tx_hash);
 439 }
 440
 441 static void
 442 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 443                                    size_t len)
 444 {
 445         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 446         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 447         struct hash_desc *tx_hash = NULL;
 448         unsigned int hdr_spec_len;
 449
 450         ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 451                          "digest enabled" : "digest disabled");
 452
 453         /* Make sure the datalen matches what the caller
 454            said he would send. */
 455         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 456         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 457
 458         if (conn->datadgst_en)
 459                 tx_hash = &tcp_sw_conn->tx_hash;
 460
 461         iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 462                                 data, len, NULL, tx_hash);
 463 }
 464
 465 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 466                                  unsigned int offset, unsigned int count)
 467 {
 468         struct iscsi_conn *conn = task->conn;
 469         int err = 0;
 470
 471         iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 472
 473         if (!count)
 474                 return 0;
 475
 476         if (!task->sc)
 477                 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 478         else {
 479                 struct scsi_data_buffer *sdb = scsi_out(task->sc);
 480
 481                 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 482                                                   sdb->table.nents, offset,
 483                                                   count);
 484         }
 485
 486         if (err) {
 487                 /* got invalid offset/len */
 488                 return -EIO;
 489         }
 490         return 0;
 491 }
 492
 493 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 494 {
 495         struct iscsi_tcp_task *tcp_task = task->dd_data;
 496
 497         task->hdr = task->dd_data + sizeof(*tcp_task);
 498         task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 499         return 0;
 500 }
 501
 502 static struct iscsi_cls_conn *
 503 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 504                          uint32_t conn_idx)
 505 {
 506         struct iscsi_conn *conn;
 507         struct iscsi_cls_conn *cls_conn;
 508         struct iscsi_tcp_conn *tcp_conn;
 509         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 510
 511         cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 512                                         conn_idx);
 513         if (!cls_conn)
 514                 return NULL;
 515         conn = cls_conn->dd_data;
 516         tcp_conn = conn->dd_data;
 517         tcp_sw_conn = tcp_conn->dd_data;
 518
 519         tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 520                                                      CRYPTO_ALG_ASYNC);
 521         tcp_sw_conn->tx_hash.flags = 0;
 522         if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 523                 goto free_conn;
 524
 525         tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 526                                                      CRYPTO_ALG_ASYNC);
 527         tcp_sw_conn->rx_hash.flags = 0;
 528         if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 529                 goto free_tx_tfm;
 530         tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 531
 532         return cls_conn;
 533
 534 free_tx_tfm:
 535         crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 536 free_conn:
 537         iscsi_conn_printk(KERN_ERR, conn,
 538                           "Could not create connection due to crc32c "
 539                           "loading error. Make sure the crc32c "
 540                           "module is built as a module or into the "
 541                           "kernel\n");
 542         iscsi_tcp_conn_teardown(cls_conn);
 543         return NULL;
 544 }
 545
 546 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 547 {
 548         struct iscsi_session *session = conn->session;
 549         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 550         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 551         struct socket *sock = tcp_sw_conn->sock;
 552
 553         if (!sock)
 554                 return;
 555
 556         sock_hold(sock->sk);
 557         iscsi_sw_tcp_conn_restore_callbacks(tcp_sw_conn);
 558         sock_put(sock->sk);
 559
 560         spin_lock_bh(&session->lock);
 561         tcp_sw_conn->sock = NULL;
 562         spin_unlock_bh(&session->lock);
 563         sockfd_put(sock);
 564 }
 565
 566 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 567 {
 568         struct iscsi_conn *conn = cls_conn->dd_data;
 569         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 570         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 571
 572         iscsi_sw_tcp_release_conn(conn);
 573
 574         if (tcp_sw_conn->tx_hash.tfm)
 575                 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 576         if (tcp_sw_conn->rx_hash.tfm)
 577                 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 578
 579         iscsi_tcp_conn_teardown(cls_conn);
 580 }
 581
 582 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 583 {
 584         struct iscsi_conn *conn = cls_conn->dd_data;
 585         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 586         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 587         struct socket *sock = tcp_sw_conn->sock;
 588
 589         /* userspace may have goofed up and not bound us */
 590         if (!sock)
 591                 return;
 592         /*
 593          * Make sure our recv side is stopped.
 594          * Older tools called conn stop before ep_disconnect
 595          * so IO could still be coming in.
 596          */
 597         write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 598         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 599         write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 600
 601         if (sock->sk->sk_sleep && waitqueue_active(sock->sk->sk_sleep)) {
 602                 sock->sk->sk_err = EIO;
 603                 wake_up_interruptible(sock->sk->sk_sleep);
 604         }
 605
 606         iscsi_conn_stop(cls_conn, flag);
 607         iscsi_sw_tcp_release_conn(conn);
 608 }
 609
 610 static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
 611                                  char *buf, int *port,
 612                                  int (*getname)(struct socket *,
 613                                                 struct sockaddr *,
 614                                                 int *addrlen))
 615 {
 616         struct sockaddr_storage *addr;
 617         struct sockaddr_in6 *sin6;
 618         struct sockaddr_in *sin;
 619         int rc = 0, len;
 620
 621         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
 622         if (!addr)
 623                 return -ENOMEM;
 624
 625         if (getname(sock, (struct sockaddr *) addr, &len)) {
 626                 rc = -ENODEV;
 627                 goto free_addr;
 628         }
 629
 630         switch (addr->ss_family) {
 631         case AF_INET:
 632                 sin = (struct sockaddr_in *)addr;
 633                 spin_lock_bh(&conn->session->lock);
 634                 sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
 635                 *port = be16_to_cpu(sin->sin_port);
 636                 spin_unlock_bh(&conn->session->lock);
 637                 break;
 638         case AF_INET6:
 639                 sin6 = (struct sockaddr_in6 *)addr;
 640                 spin_lock_bh(&conn->session->lock);
 641                 sprintf(buf, "%pI6", &sin6->sin6_addr);
 642                 *port = be16_to_cpu(sin6->sin6_port);
 643                 spin_unlock_bh(&conn->session->lock);
 644                 break;
 645         }
 646 free_addr:
 647         kfree(addr);
 648         return rc;
 649 }
 650
 651 static int
 652 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 653                        struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 654                        int is_leading)
 655 {
 656         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 657         struct iscsi_host *ihost = shost_priv(shost);
 658         struct iscsi_conn *conn = cls_conn->dd_data;
 659         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 660         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 661         struct sock *sk;
 662         struct socket *sock;
 663         int err;
 664
 665         /* lookup for existing socket */
 666         sock = sockfd_lookup((int)transport_eph, &err);
 667         if (!sock) {
 668                 iscsi_conn_printk(KERN_ERR, conn,
 669                                   "sockfd_lookup failed %d\n", err);
 670                 return -EEXIST;
 671         }
 672         /*
 673          * copy these values now because if we drop the session
 674          * userspace may still want to query the values since we will
 675          * be using them for the reconnect
 676          */
 677         err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
 678                                     &conn->portal_port, kernel_getpeername);
 679         if (err)
 680                 goto free_socket;
 681
 682         err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
 683                                     &ihost->local_port, kernel_getsockname);
 684         if (err)
 685                 goto free_socket;
 686
 687         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 688         if (err)
 689                 goto free_socket;
 690
 691         /* bind iSCSI connection and socket */
 692         tcp_sw_conn->sock = sock;
 693
 694         /* setup Socket parameters */
 695         sk = sock->sk;
 696         sk->sk_reuse = 1;
 697         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 698         sk->sk_allocation = GFP_ATOMIC;
 699
 700         iscsi_sw_tcp_conn_set_callbacks(conn);
 701         tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 702         /*
 703          * set receive state machine into initial state
 704          */
 705         iscsi_tcp_hdr_recv_prep(tcp_conn);
 706         return 0;
 707
 708 free_socket:
 709         sockfd_put(sock);
 710         return err;
 711 }
 712
 713 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 714                                        enum iscsi_param param, char *buf,
 715                                        int buflen)
 716 {
 717         struct iscsi_conn *conn = cls_conn->dd_data;
 718         struct iscsi_session *session = conn->session;
 719         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 720         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 721         int value;
 722
 723         switch(param) {
 724         case ISCSI_PARAM_HDRDGST_EN:
 725                 iscsi_set_param(cls_conn, param, buf, buflen);
 726                 break;
 727         case ISCSI_PARAM_DATADGST_EN:
 728                 iscsi_set_param(cls_conn, param, buf, buflen);
 729                 tcp_sw_conn->sendpage = conn->datadgst_en ?
 730                         sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 731                 break;
 732         case ISCSI_PARAM_MAX_R2T:
 733                 sscanf(buf, "%d", &value);
 734                 if (value <= 0 || !is_power_of_2(value))
 735                         return -EINVAL;
 736                 if (session->max_r2t == value)
 737                         break;
 738                 iscsi_tcp_r2tpool_free(session);
 739                 iscsi_set_param(cls_conn, param, buf, buflen);
 740                 if (iscsi_tcp_r2tpool_alloc(session))
 741                         return -ENOMEM;
 742                 break;
 743         default:
 744                 return iscsi_set_param(cls_conn, param, buf, buflen);
 745         }
 746
 747         return 0;
 748 }
 749
 750 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 751                                        enum iscsi_param param, char *buf)
 752 {
 753         struct iscsi_conn *conn = cls_conn->dd_data;
 754         int len;
 755
 756         switch(param) {
 757         case ISCSI_PARAM_CONN_PORT:
 758                 spin_lock_bh(&conn->session->lock);
 759                 len = sprintf(buf, "%hu\n", conn->portal_port);
 760                 spin_unlock_bh(&conn->session->lock);
 761                 break;
 762         case ISCSI_PARAM_CONN_ADDRESS:
 763                 spin_lock_bh(&conn->session->lock);
 764                 len = sprintf(buf, "%s\n", conn->portal_address);
 765                 spin_unlock_bh(&conn->session->lock);
 766                 break;
 767         default:
 768                 return iscsi_conn_get_param(cls_conn, param, buf);
 769         }
 770
 771         return len;
 772 }
 773
 774 static void
 775 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 776                             struct iscsi_stats *stats)
 777 {
 778         struct iscsi_conn *conn = cls_conn->dd_data;
 779         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 780         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 781
 782         stats->custom_length = 3;
 783         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 784         stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 785         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 786         stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 787         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 788         stats->custom[2].value = conn->eh_abort_cnt;
 789
 790         iscsi_tcp_conn_get_stats(cls_conn, stats);
 791 }
 792
 793 static struct iscsi_cls_session *
 794 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 795                             uint16_t qdepth, uint32_t initial_cmdsn)
 796 {
 797         struct iscsi_cls_session *cls_session;
 798         struct iscsi_session *session;
 799         struct Scsi_Host *shost;
 800
 801         if (ep) {
 802                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 803                 return NULL;
 804         }
 805
 806         shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 0, 1);
 807         if (!shost)
 808                 return NULL;
 809         shost->transportt = iscsi_sw_tcp_scsi_transport;
 810         shost->cmd_per_lun = qdepth;
 811         shost->max_lun = iscsi_max_lun;
 812         shost->max_id = 0;
 813         shost->max_channel = 0;
 814         shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 815
 816         if (iscsi_host_add(shost, NULL))
 817                 goto free_host;
 818
 819         cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 820                                           cmds_max, 0,
 821                                           sizeof(struct iscsi_tcp_task) +
 822                                           sizeof(struct iscsi_sw_tcp_hdrbuf),
 823                                           initial_cmdsn, 0);
 824         if (!cls_session)
 825                 goto remove_host;
 826         session = cls_session->dd_data;
 827
 828         shost->can_queue = session->scsi_cmds_max;
 829         if (iscsi_tcp_r2tpool_alloc(session))
 830                 goto remove_session;
 831         return cls_session;
 832
 833 remove_session:
 834         iscsi_session_teardown(cls_session);
 835 remove_host:
 836         iscsi_host_remove(shost);
 837 free_host:
 838         iscsi_host_free(shost);
 839         return NULL;
 840 }
 841
 842 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 843 {
 844         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 845
 846         iscsi_tcp_r2tpool_free(cls_session->dd_data);
 847         iscsi_session_teardown(cls_session);
 848
 849         iscsi_host_remove(shost);
 850         iscsi_host_free(shost);
 851 }
 852
 853 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 854 {
 855         set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 856         return 0;
 857 }
 858
 859 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 860 {
 861         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 862         blk_queue_dma_alignment(sdev->request_queue, 0);
 863         return 0;
 864 }
 865
 866 static struct scsi_host_template iscsi_sw_tcp_sht = {
 867         .module                 = THIS_MODULE,
 868         .name                   = "iSCSI Initiator over TCP/IP",
 869         .queuecommand           = iscsi_queuecommand,
 870         .change_queue_depth     = iscsi_change_queue_depth,
 871         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 872         .sg_tablesize           = 4096,
 873         .max_sectors            = 0xFFFF,
 874         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 875         .eh_abort_handler       = iscsi_eh_abort,
 876         .eh_device_reset_handler= iscsi_eh_device_reset,
 877         .eh_target_reset_handler= iscsi_eh_target_reset,
 878         .use_clustering         = DISABLE_CLUSTERING,
 879         .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 880         .slave_configure        = iscsi_sw_tcp_slave_configure,
 881         .target_alloc           = iscsi_target_alloc,
 882         .proc_name              = "iscsi_tcp",
 883         .this_id                = -1,
 884 };
 885
 886 static struct iscsi_transport iscsi_sw_tcp_transport = {
 887         .owner                  = THIS_MODULE,
 888         .name                   = "tcp",
 889         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 890                                   | CAP_DATADGST,
 891         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 892                                   ISCSI_MAX_XMIT_DLENGTH |
 893                                   ISCSI_HDRDGST_EN |
 894                                   ISCSI_DATADGST_EN |
 895                                   ISCSI_INITIAL_R2T_EN |
 896                                   ISCSI_MAX_R2T |
 897                                   ISCSI_IMM_DATA_EN |
 898                                   ISCSI_FIRST_BURST |
 899                                   ISCSI_MAX_BURST |
 900                                   ISCSI_PDU_INORDER_EN |
 901                                   ISCSI_DATASEQ_INORDER_EN |
 902                                   ISCSI_ERL |
 903                                   ISCSI_CONN_PORT |
 904                                   ISCSI_CONN_ADDRESS |
 905                                   ISCSI_EXP_STATSN |
 906                                   ISCSI_PERSISTENT_PORT |
 907                                   ISCSI_PERSISTENT_ADDRESS |
 908                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
 909                                   ISCSI_USERNAME | ISCSI_PASSWORD |
 910                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
 911                                   ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
 912                                   ISCSI_LU_RESET_TMO | ISCSI_TGT_RESET_TMO |
 913                                   ISCSI_PING_TMO | ISCSI_RECV_TMO |
 914                                   ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
 915         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
 916                                   ISCSI_HOST_INITIATOR_NAME |
 917                                   ISCSI_HOST_NETDEV_NAME,
 918         /* session management */
 919         .create_session         = iscsi_sw_tcp_session_create,
 920         .destroy_session        = iscsi_sw_tcp_session_destroy,
 921         /* connection management */
 922         .create_conn            = iscsi_sw_tcp_conn_create,
 923         .bind_conn              = iscsi_sw_tcp_conn_bind,
 924         .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 925         .set_param              = iscsi_sw_tcp_conn_set_param,
 926         .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 927         .get_session_param      = iscsi_session_get_param,
 928         .start_conn             = iscsi_conn_start,
 929         .stop_conn              = iscsi_sw_tcp_conn_stop,
 930         /* iscsi host params */
 931         .get_host_param         = iscsi_host_get_param,
 932         .set_host_param         = iscsi_host_set_param,
 933         /* IO */
 934         .send_pdu               = iscsi_conn_send_pdu,
 935         .get_stats              = iscsi_sw_tcp_conn_get_stats,
 936         /* iscsi task/cmd helpers */
 937         .init_task              = iscsi_tcp_task_init,
 938         .xmit_task              = iscsi_tcp_task_xmit,
 939         .cleanup_task           = iscsi_tcp_cleanup_task,
 940         /* low level pdu helpers */
 941         .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 942         .init_pdu               = iscsi_sw_tcp_pdu_init,
 943         .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 944         /* recovery */
 945         .session_recovery_timedout = iscsi_session_recovery_timedout,
 946 };
 947
 948 static int __init iscsi_sw_tcp_init(void)
 949 {
 950         if (iscsi_max_lun < 1) {
 951                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 952                        iscsi_max_lun);
 953                 return -EINVAL;
 954         }
 955
 956         iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 957                                                 &iscsi_sw_tcp_transport);
 958         if (!iscsi_sw_tcp_scsi_transport)
 959                 return -ENODEV;
 960
 961         return 0;
 962 }
 963
 964 static void __exit iscsi_sw_tcp_exit(void)
 965 {
 966         iscsi_unregister_transport(&iscsi_sw_tcp_transport);
 967 }
 968
 969 module_init(iscsi_sw_tcp_init);
 970 module_exit(iscsi_sw_tcp_exit);