git.oblomov.eu Git - linux-2.6/blob - 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 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 103 {
 104         struct iscsi_conn *conn = sk->sk_user_data;
 105         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 106         read_descriptor_t rd_desc;
 107
 108         read_lock(&sk->sk_callback_lock);
 109
 110         /*
 111          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 112          * We set count to 1 because we want the network layer to
 113          * hand us all the skbs that are available. iscsi_tcp_recv
 114          * handled pdus that cross buffers or pdus that still need data.
 115          */
 116         rd_desc.arg.data = conn;
 117         rd_desc.count = 1;
 118         tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 119
 120         read_unlock(&sk->sk_callback_lock);
 121
 122         /* If we had to (atomically) map a highmem page,
 123          * unmap it now. */
 124         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 125 }
 126
 127 static void iscsi_sw_tcp_state_change(struct sock *sk)
 128 {
 129         struct iscsi_tcp_conn *tcp_conn;
 130         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 131         struct iscsi_conn *conn;
 132         struct iscsi_session *session;
 133         void (*old_state_change)(struct sock *);
 134
 135         read_lock(&sk->sk_callback_lock);
 136
 137         conn = (struct iscsi_conn*)sk->sk_user_data;
 138         session = conn->session;
 139
 140         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 141              sk->sk_state == TCP_CLOSE) &&
 142             !atomic_read(&sk->sk_rmem_alloc)) {
 143                 ISCSI_SW_TCP_DBG(conn, "iscsi_tcp_state_change: "
 144                                  "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 145                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 146         }
 147
 148         tcp_conn = conn->dd_data;
 149         tcp_sw_conn = tcp_conn->dd_data;
 150         old_state_change = tcp_sw_conn->old_state_change;
 151
 152         read_unlock(&sk->sk_callback_lock);
 153
 154         old_state_change(sk);
 155 }
 156
 157 /**
 158  * iscsi_write_space - Called when more output buffer space is available
 159  * @sk: socket space is available for
 160  **/
 161 static void iscsi_sw_tcp_write_space(struct sock *sk)
 162 {
 163         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 164         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 165         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 166
 167         tcp_sw_conn->old_write_space(sk);
 168         ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 169         iscsi_conn_queue_work(conn);
 170 }
 171
 172 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 173 {
 174         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 175         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 176         struct sock *sk = tcp_sw_conn->sock->sk;
 177
 178         /* assign new callbacks */
 179         write_lock_bh(&sk->sk_callback_lock);
 180         sk->sk_user_data = conn;
 181         tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 182         tcp_sw_conn->old_state_change = sk->sk_state_change;
 183         tcp_sw_conn->old_write_space = sk->sk_write_space;
 184         sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 185         sk->sk_state_change = iscsi_sw_tcp_state_change;
 186         sk->sk_write_space = iscsi_sw_tcp_write_space;
 187         write_unlock_bh(&sk->sk_callback_lock);
 188 }
 189
 190 static void
 191 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn)
 192 {
 193         struct sock *sk = tcp_sw_conn->sock->sk;
 194
 195         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 196         write_lock_bh(&sk->sk_callback_lock);
 197         sk->sk_user_data    = NULL;
 198         sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 199         sk->sk_state_change = tcp_sw_conn->old_state_change;
 200         sk->sk_write_space  = tcp_sw_conn->old_write_space;
 201         sk->sk_no_check  = 0;
 202         write_unlock_bh(&sk->sk_callback_lock);
 203 }
 204
 205 /**
 206  * iscsi_sw_tcp_xmit_segment - transmit segment
 207  * @tcp_conn: the iSCSI TCP connection
 208  * @segment: the buffer to transmnit
 209  *
 210  * This function transmits as much of the buffer as
 211  * the network layer will accept, and returns the number of
 212  * bytes transmitted.
 213  *
 214  * If CRC hashing is enabled, the function will compute the
 215  * hash as it goes. When the entire segment has been transmitted,
 216  * it will retrieve the hash value and send it as well.
 217  */
 218 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 219                                      struct iscsi_segment *segment)
 220 {
 221         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 222         struct socket *sk = tcp_sw_conn->sock;
 223         unsigned int copied = 0;
 224         int r = 0;
 225
 226         while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 227                 struct scatterlist *sg;
 228                 unsigned int offset, copy;
 229                 int flags = 0;
 230
 231                 r = 0;
 232                 offset = segment->copied;
 233                 copy = segment->size - offset;
 234
 235                 if (segment->total_copied + segment->size < segment->total_size)
 236                         flags |= MSG_MORE;
 237
 238                 /* Use sendpage if we can; else fall back to sendmsg */
 239                 if (!segment->data) {
 240                         sg = segment->sg;
 241                         offset += segment->sg_offset + sg->offset;
 242                         r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 243                                                   copy, flags);
 244                 } else {
 245                         struct msghdr msg = { .msg_flags = flags };
 246                         struct kvec iov = {
 247                                 .iov_base = segment->data + offset,
 248                                 .iov_len = copy
 249                         };
 250
 251                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 252                 }
 253
 254                 if (r < 0) {
 255                         iscsi_tcp_segment_unmap(segment);
 256                         if (copied || r == -EAGAIN)
 257                                 break;
 258                         return r;
 259                 }
 260                 copied += r;
 261         }
 262         return copied;
 263 }
 264
 265 /**
 266  * iscsi_sw_tcp_xmit - TCP transmit
 267  **/
 268 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 269 {
 270         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 271         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 272         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 273         unsigned int consumed = 0;
 274         int rc = 0;
 275
 276         while (1) {
 277                 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 278                 if (rc < 0) {
 279                         rc = ISCSI_ERR_XMIT_FAILED;
 280                         goto error;
 281                 }
 282                 if (rc == 0)
 283                         break;
 284
 285                 consumed += rc;
 286
 287                 if (segment->total_copied >= segment->total_size) {
 288                         if (segment->done != NULL) {
 289                                 rc = segment->done(tcp_conn, segment);
 290                                 if (rc != 0)
 291                                         goto error;
 292                         }
 293                 }
 294         }
 295
 296         ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 297
 298         conn->txdata_octets += consumed;
 299         return consumed;
 300
 301 error:
 302         /* Transmit error. We could initiate error recovery
 303          * here. */
 304         ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 305         iscsi_conn_failure(conn, rc);
 306         return -EIO;
 307 }
 308
 309 /**
 310  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 311  */
 312 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 313 {
 314         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 315         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 316         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 317
 318         return segment->total_copied - segment->total_size;
 319 }
 320
 321 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 322 {
 323         struct iscsi_conn *conn = task->conn;
 324         int rc;
 325
 326         while (iscsi_sw_tcp_xmit_qlen(conn)) {
 327                 rc = iscsi_sw_tcp_xmit(conn);
 328                 if (rc == 0)
 329                         return -EAGAIN;
 330                 if (rc < 0)
 331                         return rc;
 332         }
 333
 334         return 0;
 335 }
 336
 337 /*
 338  * This is called when we're done sending the header.
 339  * Simply copy the data_segment to the send segment, and return.
 340  */
 341 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 342                                       struct iscsi_segment *segment)
 343 {
 344         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 345
 346         tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 347         ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 348                          "Header done. Next segment size %u total_size %u\n",
 349                          tcp_sw_conn->out.segment.size,
 350                          tcp_sw_conn->out.segment.total_size);
 351         return 0;
 352 }
 353
 354 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 355                                        size_t hdrlen)
 356 {
 357         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 358         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 359
 360         ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 361                          "digest enabled" : "digest disabled");
 362
 363         /* Clear the data segment - needs to be filled in by the
 364          * caller using iscsi_tcp_send_data_prep() */
 365         memset(&tcp_sw_conn->out.data_segment, 0,
 366                sizeof(struct iscsi_segment));
 367
 368         /* If header digest is enabled, compute the CRC and
 369          * place the digest into the same buffer. We make
 370          * sure that both iscsi_tcp_task and mtask have
 371          * sufficient room.
 372          */
 373         if (conn->hdrdgst_en) {
 374                 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 375                                       hdr + hdrlen);
 376                 hdrlen += ISCSI_DIGEST_SIZE;
 377         }
 378
 379         /* Remember header pointer for later, when we need
 380          * to decide whether there's a payload to go along
 381          * with the header. */
 382         tcp_sw_conn->out.hdr = hdr;
 383
 384         iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 385                                   iscsi_sw_tcp_send_hdr_done, NULL);
 386 }
 387
 388 /*
 389  * Prepare the send buffer for the payload data.
 390  * Padding and checksumming will all be taken care
 391  * of by the iscsi_segment routines.
 392  */
 393 static int
 394 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 395                             unsigned int count, unsigned int offset,
 396                             unsigned int len)
 397 {
 398         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 399         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 400         struct hash_desc *tx_hash = NULL;
 401         unsigned int hdr_spec_len;
 402
 403         ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 404                          conn->datadgst_en ?
 405                          "digest enabled" : "digest disabled");
 406
 407         /* Make sure the datalen matches what the caller
 408            said he would send. */
 409         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 410         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 411
 412         if (conn->datadgst_en)
 413                 tx_hash = &tcp_sw_conn->tx_hash;
 414
 415         return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 416                                      sg, count, offset, len,
 417                                      NULL, tx_hash);
 418 }
 419
 420 static void
 421 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 422                                    size_t len)
 423 {
 424         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 425         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 426         struct hash_desc *tx_hash = NULL;
 427         unsigned int hdr_spec_len;
 428
 429         ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 430                          "digest enabled" : "digest disabled");
 431
 432         /* Make sure the datalen matches what the caller
 433            said he would send. */
 434         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 435         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 436
 437         if (conn->datadgst_en)
 438                 tx_hash = &tcp_sw_conn->tx_hash;
 439
 440         iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 441                                 data, len, NULL, tx_hash);
 442 }
 443
 444 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 445                                  unsigned int offset, unsigned int count)
 446 {
 447         struct iscsi_conn *conn = task->conn;
 448         int err = 0;
 449
 450         iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 451
 452         if (!count)
 453                 return 0;
 454
 455         if (!task->sc)
 456                 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 457         else {
 458                 struct scsi_data_buffer *sdb = scsi_out(task->sc);
 459
 460                 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 461                                                   sdb->table.nents, offset,
 462                                                   count);
 463         }
 464
 465         if (err) {
 466                 iscsi_conn_failure(conn, err);
 467                 return -EIO;
 468         }
 469         return 0;
 470 }
 471
 472 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 473 {
 474         struct iscsi_tcp_task *tcp_task = task->dd_data;
 475
 476         task->hdr = task->dd_data + sizeof(*tcp_task);
 477         task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 478         return 0;
 479 }
 480
 481 static struct iscsi_cls_conn *
 482 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 483                          uint32_t conn_idx)
 484 {
 485         struct iscsi_conn *conn;
 486         struct iscsi_cls_conn *cls_conn;
 487         struct iscsi_tcp_conn *tcp_conn;
 488         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 489
 490         cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 491                                         conn_idx);
 492         if (!cls_conn)
 493                 return NULL;
 494         conn = cls_conn->dd_data;
 495         tcp_conn = conn->dd_data;
 496         tcp_sw_conn = tcp_conn->dd_data;
 497
 498         tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 499                                                      CRYPTO_ALG_ASYNC);
 500         tcp_sw_conn->tx_hash.flags = 0;
 501         if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 502                 goto free_conn;
 503
 504         tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 505                                                      CRYPTO_ALG_ASYNC);
 506         tcp_sw_conn->rx_hash.flags = 0;
 507         if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 508                 goto free_tx_tfm;
 509         tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 510
 511         return cls_conn;
 512
 513 free_tx_tfm:
 514         crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 515 free_conn:
 516         iscsi_conn_printk(KERN_ERR, conn,
 517                           "Could not create connection due to crc32c "
 518                           "loading error. Make sure the crc32c "
 519                           "module is built as a module or into the "
 520                           "kernel\n");
 521         iscsi_tcp_conn_teardown(cls_conn);
 522         return NULL;
 523 }
 524
 525 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 526 {
 527         struct iscsi_session *session = conn->session;
 528         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 529         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 530         struct socket *sock = tcp_sw_conn->sock;
 531
 532         if (!sock)
 533                 return;
 534
 535         sock_hold(sock->sk);
 536         iscsi_sw_tcp_conn_restore_callbacks(tcp_sw_conn);
 537         sock_put(sock->sk);
 538
 539         spin_lock_bh(&session->lock);
 540         tcp_sw_conn->sock = NULL;
 541         spin_unlock_bh(&session->lock);
 542         sockfd_put(sock);
 543 }
 544
 545 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 546 {
 547         struct iscsi_conn *conn = cls_conn->dd_data;
 548         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 549         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 550
 551         iscsi_sw_tcp_release_conn(conn);
 552
 553         if (tcp_sw_conn->tx_hash.tfm)
 554                 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 555         if (tcp_sw_conn->rx_hash.tfm)
 556                 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 557
 558         iscsi_tcp_conn_teardown(cls_conn);
 559 }
 560
 561 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 562 {
 563         struct iscsi_conn *conn = cls_conn->dd_data;
 564         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 565         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 566
 567         /* userspace may have goofed up and not bound us */
 568         if (!tcp_sw_conn->sock)
 569                 return;
 570         /*
 571          * Make sure our recv side is stopped.
 572          * Older tools called conn stop before ep_disconnect
 573          * so IO could still be coming in.
 574          */
 575         write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 576         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 577         write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 578
 579         iscsi_conn_stop(cls_conn, flag);
 580         iscsi_sw_tcp_release_conn(conn);
 581 }
 582
 583 static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
 584                                  char *buf, int *port,
 585                                  int (*getname)(struct socket *,
 586                                                 struct sockaddr *,
 587                                                 int *addrlen))
 588 {
 589         struct sockaddr_storage *addr;
 590         struct sockaddr_in6 *sin6;
 591         struct sockaddr_in *sin;
 592         int rc = 0, len;
 593
 594         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
 595         if (!addr)
 596                 return -ENOMEM;
 597
 598         if (getname(sock, (struct sockaddr *) addr, &len)) {
 599                 rc = -ENODEV;
 600                 goto free_addr;
 601         }
 602
 603         switch (addr->ss_family) {
 604         case AF_INET:
 605                 sin = (struct sockaddr_in *)addr;
 606                 spin_lock_bh(&conn->session->lock);
 607                 sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
 608                 *port = be16_to_cpu(sin->sin_port);
 609                 spin_unlock_bh(&conn->session->lock);
 610                 break;
 611         case AF_INET6:
 612                 sin6 = (struct sockaddr_in6 *)addr;
 613                 spin_lock_bh(&conn->session->lock);
 614                 sprintf(buf, "%pI6", &sin6->sin6_addr);
 615                 *port = be16_to_cpu(sin6->sin6_port);
 616                 spin_unlock_bh(&conn->session->lock);
 617                 break;
 618         }
 619 free_addr:
 620         kfree(addr);
 621         return rc;
 622 }
 623
 624 static int
 625 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 626                        struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 627                        int is_leading)
 628 {
 629         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 630         struct iscsi_host *ihost = shost_priv(shost);
 631         struct iscsi_conn *conn = cls_conn->dd_data;
 632         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 633         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 634         struct sock *sk;
 635         struct socket *sock;
 636         int err;
 637
 638         /* lookup for existing socket */
 639         sock = sockfd_lookup((int)transport_eph, &err);
 640         if (!sock) {
 641                 iscsi_conn_printk(KERN_ERR, conn,
 642                                   "sockfd_lookup failed %d\n", err);
 643                 return -EEXIST;
 644         }
 645         /*
 646          * copy these values now because if we drop the session
 647          * userspace may still want to query the values since we will
 648          * be using them for the reconnect
 649          */
 650         err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
 651                                     &conn->portal_port, kernel_getpeername);
 652         if (err)
 653                 goto free_socket;
 654
 655         err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
 656                                     &ihost->local_port, kernel_getsockname);
 657         if (err)
 658                 goto free_socket;
 659
 660         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 661         if (err)
 662                 goto free_socket;
 663
 664         /* bind iSCSI connection and socket */
 665         tcp_sw_conn->sock = sock;
 666
 667         /* setup Socket parameters */
 668         sk = sock->sk;
 669         sk->sk_reuse = 1;
 670         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 671         sk->sk_allocation = GFP_ATOMIC;
 672
 673         iscsi_sw_tcp_conn_set_callbacks(conn);
 674         tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 675         /*
 676          * set receive state machine into initial state
 677          */
 678         iscsi_tcp_hdr_recv_prep(tcp_conn);
 679         return 0;
 680
 681 free_socket:
 682         sockfd_put(sock);
 683         return err;
 684 }
 685
 686 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 687                                        enum iscsi_param param, char *buf,
 688                                        int buflen)
 689 {
 690         struct iscsi_conn *conn = cls_conn->dd_data;
 691         struct iscsi_session *session = conn->session;
 692         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 693         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 694         int value;
 695
 696         switch(param) {
 697         case ISCSI_PARAM_HDRDGST_EN:
 698                 iscsi_set_param(cls_conn, param, buf, buflen);
 699                 break;
 700         case ISCSI_PARAM_DATADGST_EN:
 701                 iscsi_set_param(cls_conn, param, buf, buflen);
 702                 tcp_sw_conn->sendpage = conn->datadgst_en ?
 703                         sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 704                 break;
 705         case ISCSI_PARAM_MAX_R2T:
 706                 sscanf(buf, "%d", &value);
 707                 if (value <= 0 || !is_power_of_2(value))
 708                         return -EINVAL;
 709                 if (session->max_r2t == value)
 710                         break;
 711                 iscsi_tcp_r2tpool_free(session);
 712                 iscsi_set_param(cls_conn, param, buf, buflen);
 713                 if (iscsi_tcp_r2tpool_alloc(session))
 714                         return -ENOMEM;
 715                 break;
 716         default:
 717                 return iscsi_set_param(cls_conn, param, buf, buflen);
 718         }
 719
 720         return 0;
 721 }
 722
 723 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 724                                        enum iscsi_param param, char *buf)
 725 {
 726         struct iscsi_conn *conn = cls_conn->dd_data;
 727         int len;
 728
 729         switch(param) {
 730         case ISCSI_PARAM_CONN_PORT:
 731                 spin_lock_bh(&conn->session->lock);
 732                 len = sprintf(buf, "%hu\n", conn->portal_port);
 733                 spin_unlock_bh(&conn->session->lock);
 734                 break;
 735         case ISCSI_PARAM_CONN_ADDRESS:
 736                 spin_lock_bh(&conn->session->lock);
 737                 len = sprintf(buf, "%s\n", conn->portal_address);
 738                 spin_unlock_bh(&conn->session->lock);
 739                 break;
 740         default:
 741                 return iscsi_conn_get_param(cls_conn, param, buf);
 742         }
 743
 744         return len;
 745 }
 746
 747 static void
 748 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 749                             struct iscsi_stats *stats)
 750 {
 751         struct iscsi_conn *conn = cls_conn->dd_data;
 752         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 753         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 754
 755         stats->custom_length = 3;
 756         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 757         stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 758         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 759         stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 760         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 761         stats->custom[2].value = conn->eh_abort_cnt;
 762
 763         iscsi_tcp_conn_get_stats(cls_conn, stats);
 764 }
 765
 766 static struct iscsi_cls_session *
 767 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 768                             uint16_t qdepth, uint32_t initial_cmdsn)
 769 {
 770         struct iscsi_cls_session *cls_session;
 771         struct iscsi_session *session;
 772         struct Scsi_Host *shost;
 773
 774         if (ep) {
 775                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 776                 return NULL;
 777         }
 778
 779         shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 0, 1);
 780         if (!shost)
 781                 return NULL;
 782         shost->transportt = iscsi_sw_tcp_scsi_transport;
 783         shost->cmd_per_lun = qdepth;
 784         shost->max_lun = iscsi_max_lun;
 785         shost->max_id = 0;
 786         shost->max_channel = 0;
 787         shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 788
 789         if (iscsi_host_add(shost, NULL))
 790                 goto free_host;
 791
 792         cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 793                                           cmds_max,
 794                                           sizeof(struct iscsi_tcp_task) +
 795                                           sizeof(struct iscsi_sw_tcp_hdrbuf),
 796                                           initial_cmdsn, 0);
 797         if (!cls_session)
 798                 goto remove_host;
 799         session = cls_session->dd_data;
 800
 801         shost->can_queue = session->scsi_cmds_max;
 802         if (iscsi_tcp_r2tpool_alloc(session))
 803                 goto remove_session;
 804         return cls_session;
 805
 806 remove_session:
 807         iscsi_session_teardown(cls_session);
 808 remove_host:
 809         iscsi_host_remove(shost);
 810 free_host:
 811         iscsi_host_free(shost);
 812         return NULL;
 813 }
 814
 815 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 816 {
 817         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 818
 819         iscsi_tcp_r2tpool_free(cls_session->dd_data);
 820         iscsi_session_teardown(cls_session);
 821
 822         iscsi_host_remove(shost);
 823         iscsi_host_free(shost);
 824 }
 825
 826 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 827 {
 828         set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 829         return 0;
 830 }
 831
 832 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 833 {
 834         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 835         blk_queue_dma_alignment(sdev->request_queue, 0);
 836         return 0;
 837 }
 838
 839 static struct scsi_host_template iscsi_sw_tcp_sht = {
 840         .module                 = THIS_MODULE,
 841         .name                   = "iSCSI Initiator over TCP/IP",
 842         .queuecommand           = iscsi_queuecommand,
 843         .change_queue_depth     = iscsi_change_queue_depth,
 844         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 845         .sg_tablesize           = 4096,
 846         .max_sectors            = 0xFFFF,
 847         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 848         .eh_abort_handler       = iscsi_eh_abort,
 849         .eh_device_reset_handler= iscsi_eh_device_reset,
 850         .eh_target_reset_handler= iscsi_eh_target_reset,
 851         .use_clustering         = DISABLE_CLUSTERING,
 852         .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 853         .slave_configure        = iscsi_sw_tcp_slave_configure,
 854         .proc_name              = "iscsi_tcp",
 855         .this_id                = -1,
 856 };
 857
 858 static struct iscsi_transport iscsi_sw_tcp_transport = {
 859         .owner                  = THIS_MODULE,
 860         .name                   = "tcp",
 861         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 862                                   | CAP_DATADGST,
 863         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 864                                   ISCSI_MAX_XMIT_DLENGTH |
 865                                   ISCSI_HDRDGST_EN |
 866                                   ISCSI_DATADGST_EN |
 867                                   ISCSI_INITIAL_R2T_EN |
 868                                   ISCSI_MAX_R2T |
 869                                   ISCSI_IMM_DATA_EN |
 870                                   ISCSI_FIRST_BURST |
 871                                   ISCSI_MAX_BURST |
 872                                   ISCSI_PDU_INORDER_EN |
 873                                   ISCSI_DATASEQ_INORDER_EN |
 874                                   ISCSI_ERL |
 875                                   ISCSI_CONN_PORT |
 876                                   ISCSI_CONN_ADDRESS |
 877                                   ISCSI_EXP_STATSN |
 878                                   ISCSI_PERSISTENT_PORT |
 879                                   ISCSI_PERSISTENT_ADDRESS |
 880                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
 881                                   ISCSI_USERNAME | ISCSI_PASSWORD |
 882                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
 883                                   ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
 884                                   ISCSI_LU_RESET_TMO |
 885                                   ISCSI_PING_TMO | ISCSI_RECV_TMO |
 886                                   ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
 887         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
 888                                   ISCSI_HOST_INITIATOR_NAME |
 889                                   ISCSI_HOST_NETDEV_NAME,
 890         /* session management */
 891         .create_session         = iscsi_sw_tcp_session_create,
 892         .destroy_session        = iscsi_sw_tcp_session_destroy,
 893         /* connection management */
 894         .create_conn            = iscsi_sw_tcp_conn_create,
 895         .bind_conn              = iscsi_sw_tcp_conn_bind,
 896         .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 897         .set_param              = iscsi_sw_tcp_conn_set_param,
 898         .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 899         .get_session_param      = iscsi_session_get_param,
 900         .start_conn             = iscsi_conn_start,
 901         .stop_conn              = iscsi_sw_tcp_conn_stop,
 902         /* iscsi host params */
 903         .get_host_param         = iscsi_host_get_param,
 904         .set_host_param         = iscsi_host_set_param,
 905         /* IO */
 906         .send_pdu               = iscsi_conn_send_pdu,
 907         .get_stats              = iscsi_sw_tcp_conn_get_stats,
 908         /* iscsi task/cmd helpers */
 909         .init_task              = iscsi_tcp_task_init,
 910         .xmit_task              = iscsi_tcp_task_xmit,
 911         .cleanup_task           = iscsi_tcp_cleanup_task,
 912         /* low level pdu helpers */
 913         .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 914         .init_pdu               = iscsi_sw_tcp_pdu_init,
 915         .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 916         /* recovery */
 917         .session_recovery_timedout = iscsi_session_recovery_timedout,
 918 };
 919
 920 static int __init iscsi_sw_tcp_init(void)
 921 {
 922         if (iscsi_max_lun < 1) {
 923                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 924                        iscsi_max_lun);
 925                 return -EINVAL;
 926         }
 927
 928         iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 929                                                 &iscsi_sw_tcp_transport);
 930         if (!iscsi_sw_tcp_scsi_transport)
 931                 return -ENODEV;
 932
 933         return 0;
 934 }
 935
 936 static void __exit iscsi_sw_tcp_exit(void)
 937 {
 938         iscsi_unregister_transport(&iscsi_sw_tcp_transport);
 939 }
 940
 941 module_init(iscsi_sw_tcp_init);
 942 module_exit(iscsi_sw_tcp_exit);