SAFE public projects git trees. - safe/jmp/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 #undef DEBUG_TCP
  52
  53 #ifdef DEBUG_TCP
  54 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  55 #else
  56 #define debug_tcp(fmt...)
  57 #endif
  58
  59 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  60 static struct scsi_host_template iscsi_sw_tcp_sht;
  61 static struct iscsi_transport iscsi_sw_tcp_transport;
  62
  63 static unsigned int iscsi_max_lun = 512;
  64 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  65
  66 /**
  67  * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  68  * @rd_desc: read descriptor
  69  * @skb: socket buffer
  70  * @offset: offset in skb
  71  * @len: skb->len - offset
  72  */
  73 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  74                              unsigned int offset, size_t len)
  75 {
  76         struct iscsi_conn *conn = rd_desc->arg.data;
  77         unsigned int consumed, total_consumed = 0;
  78         int status;
  79
  80         debug_tcp("in %d bytes\n", skb->len - offset);
  81
  82         do {
  83                 status = 0;
  84                 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  85                 offset += consumed;
  86                 total_consumed += consumed;
  87         } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  88
  89         debug_tcp("read %d bytes status %d\n", skb->len - offset, status);
  90         return total_consumed;
  91 }
  92
  93 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
  94 {
  95         struct iscsi_conn *conn = sk->sk_user_data;
  96         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
  97         read_descriptor_t rd_desc;
  98
  99         read_lock(&sk->sk_callback_lock);
 100
 101         /*
 102          * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 103          * We set count to 1 because we want the network layer to
 104          * hand us all the skbs that are available. iscsi_tcp_recv
 105          * handled pdus that cross buffers or pdus that still need data.
 106          */
 107         rd_desc.arg.data = conn;
 108         rd_desc.count = 1;
 109         tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 110
 111         read_unlock(&sk->sk_callback_lock);
 112
 113         /* If we had to (atomically) map a highmem page,
 114          * unmap it now. */
 115         iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 116 }
 117
 118 static void iscsi_sw_tcp_state_change(struct sock *sk)
 119 {
 120         struct iscsi_tcp_conn *tcp_conn;
 121         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 122         struct iscsi_conn *conn;
 123         struct iscsi_session *session;
 124         void (*old_state_change)(struct sock *);
 125
 126         read_lock(&sk->sk_callback_lock);
 127
 128         conn = (struct iscsi_conn*)sk->sk_user_data;
 129         session = conn->session;
 130
 131         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 132              sk->sk_state == TCP_CLOSE) &&
 133             !atomic_read(&sk->sk_rmem_alloc)) {
 134                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 135                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 136         }
 137
 138         tcp_conn = conn->dd_data;
 139         tcp_sw_conn = tcp_conn->dd_data;
 140         old_state_change = tcp_sw_conn->old_state_change;
 141
 142         read_unlock(&sk->sk_callback_lock);
 143
 144         old_state_change(sk);
 145 }
 146
 147 /**
 148  * iscsi_write_space - Called when more output buffer space is available
 149  * @sk: socket space is available for
 150  **/
 151 static void iscsi_sw_tcp_write_space(struct sock *sk)
 152 {
 153         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 154         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 155         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 156
 157         tcp_sw_conn->old_write_space(sk);
 158         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
 159         scsi_queue_work(conn->session->host, &conn->xmitwork);
 160 }
 161
 162 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 163 {
 164         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 165         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 166         struct sock *sk = tcp_sw_conn->sock->sk;
 167
 168         /* assign new callbacks */
 169         write_lock_bh(&sk->sk_callback_lock);
 170         sk->sk_user_data = conn;
 171         tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 172         tcp_sw_conn->old_state_change = sk->sk_state_change;
 173         tcp_sw_conn->old_write_space = sk->sk_write_space;
 174         sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 175         sk->sk_state_change = iscsi_sw_tcp_state_change;
 176         sk->sk_write_space = iscsi_sw_tcp_write_space;
 177         write_unlock_bh(&sk->sk_callback_lock);
 178 }
 179
 180 static void
 181 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn)
 182 {
 183         struct sock *sk = tcp_sw_conn->sock->sk;
 184
 185         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 186         write_lock_bh(&sk->sk_callback_lock);
 187         sk->sk_user_data    = NULL;
 188         sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 189         sk->sk_state_change = tcp_sw_conn->old_state_change;
 190         sk->sk_write_space  = tcp_sw_conn->old_write_space;
 191         sk->sk_no_check  = 0;
 192         write_unlock_bh(&sk->sk_callback_lock);
 193 }
 194
 195 /**
 196  * iscsi_sw_tcp_xmit_segment - transmit segment
 197  * @tcp_conn: the iSCSI TCP connection
 198  * @segment: the buffer to transmnit
 199  *
 200  * This function transmits as much of the buffer as
 201  * the network layer will accept, and returns the number of
 202  * bytes transmitted.
 203  *
 204  * If CRC hashing is enabled, the function will compute the
 205  * hash as it goes. When the entire segment has been transmitted,
 206  * it will retrieve the hash value and send it as well.
 207  */
 208 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 209                                      struct iscsi_segment *segment)
 210 {
 211         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 212         struct socket *sk = tcp_sw_conn->sock;
 213         unsigned int copied = 0;
 214         int r = 0;
 215
 216         while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 217                 struct scatterlist *sg;
 218                 unsigned int offset, copy;
 219                 int flags = 0;
 220
 221                 r = 0;
 222                 offset = segment->copied;
 223                 copy = segment->size - offset;
 224
 225                 if (segment->total_copied + segment->size < segment->total_size)
 226                         flags |= MSG_MORE;
 227
 228                 /* Use sendpage if we can; else fall back to sendmsg */
 229                 if (!segment->data) {
 230                         sg = segment->sg;
 231                         offset += segment->sg_offset + sg->offset;
 232                         r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 233                                                   copy, flags);
 234                 } else {
 235                         struct msghdr msg = { .msg_flags = flags };
 236                         struct kvec iov = {
 237                                 .iov_base = segment->data + offset,
 238                                 .iov_len = copy
 239                         };
 240
 241                         r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 242                 }
 243
 244                 if (r < 0) {
 245                         iscsi_tcp_segment_unmap(segment);
 246                         if (copied || r == -EAGAIN)
 247                                 break;
 248                         return r;
 249                 }
 250                 copied += r;
 251         }
 252         return copied;
 253 }
 254
 255 /**
 256  * iscsi_sw_tcp_xmit - TCP transmit
 257  **/
 258 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 259 {
 260         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 261         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 262         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 263         unsigned int consumed = 0;
 264         int rc = 0;
 265
 266         while (1) {
 267                 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 268                 if (rc < 0) {
 269                         rc = ISCSI_ERR_XMIT_FAILED;
 270                         goto error;
 271                 }
 272                 if (rc == 0)
 273                         break;
 274
 275                 consumed += rc;
 276
 277                 if (segment->total_copied >= segment->total_size) {
 278                         if (segment->done != NULL) {
 279                                 rc = segment->done(tcp_conn, segment);
 280                                 if (rc != 0)
 281                                         goto error;
 282                         }
 283                 }
 284         }
 285
 286         debug_tcp("xmit %d bytes\n", consumed);
 287
 288         conn->txdata_octets += consumed;
 289         return consumed;
 290
 291 error:
 292         /* Transmit error. We could initiate error recovery
 293          * here. */
 294         debug_tcp("Error sending PDU, errno=%d\n", rc);
 295         iscsi_conn_failure(conn, rc);
 296         return -EIO;
 297 }
 298
 299 /**
 300  * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 301  */
 302 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 303 {
 304         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 305         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 306         struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 307
 308         return segment->total_copied - segment->total_size;
 309 }
 310
 311 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 312 {
 313         struct iscsi_conn *conn = task->conn;
 314         int rc;
 315
 316         while (iscsi_sw_tcp_xmit_qlen(conn)) {
 317                 rc = iscsi_sw_tcp_xmit(conn);
 318                 if (rc == 0)
 319                         return -EAGAIN;
 320                 if (rc < 0)
 321                         return rc;
 322         }
 323
 324         return 0;
 325 }
 326
 327 /*
 328  * This is called when we're done sending the header.
 329  * Simply copy the data_segment to the send segment, and return.
 330  */
 331 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 332                                       struct iscsi_segment *segment)
 333 {
 334         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 335
 336         tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 337         debug_tcp("Header done. Next segment size %u total_size %u\n",
 338                   tcp_sw_conn->out.segment.size,
 339                   tcp_sw_conn->out.segment.total_size);
 340         return 0;
 341 }
 342
 343 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 344                                        size_t hdrlen)
 345 {
 346         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 347         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 348
 349         debug_tcp("%s(%p%s)\n", __func__, tcp_conn,
 350                         conn->hdrdgst_en? ", digest enabled" : "");
 351
 352         /* Clear the data segment - needs to be filled in by the
 353          * caller using iscsi_tcp_send_data_prep() */
 354         memset(&tcp_sw_conn->out.data_segment, 0,
 355                sizeof(struct iscsi_segment));
 356
 357         /* If header digest is enabled, compute the CRC and
 358          * place the digest into the same buffer. We make
 359          * sure that both iscsi_tcp_task and mtask have
 360          * sufficient room.
 361          */
 362         if (conn->hdrdgst_en) {
 363                 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 364                                       hdr + hdrlen);
 365                 hdrlen += ISCSI_DIGEST_SIZE;
 366         }
 367
 368         /* Remember header pointer for later, when we need
 369          * to decide whether there's a payload to go along
 370          * with the header. */
 371         tcp_sw_conn->out.hdr = hdr;
 372
 373         iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 374                                   iscsi_sw_tcp_send_hdr_done, NULL);
 375 }
 376
 377 /*
 378  * Prepare the send buffer for the payload data.
 379  * Padding and checksumming will all be taken care
 380  * of by the iscsi_segment routines.
 381  */
 382 static int
 383 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 384                             unsigned int count, unsigned int offset,
 385                             unsigned int len)
 386 {
 387         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 388         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 389         struct hash_desc *tx_hash = NULL;
 390         unsigned int hdr_spec_len;
 391
 392         debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __func__,
 393                         tcp_conn, offset, len,
 394                         conn->datadgst_en? ", digest enabled" : "");
 395
 396         /* Make sure the datalen matches what the caller
 397            said he would send. */
 398         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 399         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 400
 401         if (conn->datadgst_en)
 402                 tx_hash = &tcp_sw_conn->tx_hash;
 403
 404         return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 405                                      sg, count, offset, len,
 406                                      NULL, tx_hash);
 407 }
 408
 409 static void
 410 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 411                                    size_t len)
 412 {
 413         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 414         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 415         struct hash_desc *tx_hash = NULL;
 416         unsigned int hdr_spec_len;
 417
 418         debug_tcp("%s(%p, datalen=%d%s)\n", __func__, tcp_conn, len,
 419                   conn->datadgst_en? ", digest enabled" : "");
 420
 421         /* Make sure the datalen matches what the caller
 422            said he would send. */
 423         hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 424         WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 425
 426         if (conn->datadgst_en)
 427                 tx_hash = &tcp_sw_conn->tx_hash;
 428
 429         iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 430                                 data, len, NULL, tx_hash);
 431 }
 432
 433 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 434                                  unsigned int offset, unsigned int count)
 435 {
 436         struct iscsi_conn *conn = task->conn;
 437         int err = 0;
 438
 439         iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 440
 441         if (!count)
 442                 return 0;
 443
 444         if (!task->sc)
 445                 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 446         else {
 447                 struct scsi_data_buffer *sdb = scsi_out(task->sc);
 448
 449                 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 450                                                   sdb->table.nents, offset,
 451                                                   count);
 452         }
 453
 454         if (err) {
 455                 iscsi_conn_failure(conn, err);
 456                 return -EIO;
 457         }
 458         return 0;
 459 }
 460
 461 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 462 {
 463         struct iscsi_tcp_task *tcp_task = task->dd_data;
 464
 465         task->hdr = task->dd_data + sizeof(*tcp_task);
 466         task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 467         return 0;
 468 }
 469
 470 static struct iscsi_cls_conn *
 471 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 472                          uint32_t conn_idx)
 473 {
 474         struct iscsi_conn *conn;
 475         struct iscsi_cls_conn *cls_conn;
 476         struct iscsi_tcp_conn *tcp_conn;
 477         struct iscsi_sw_tcp_conn *tcp_sw_conn;
 478
 479         cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 480                                         conn_idx);
 481         if (!cls_conn)
 482                 return NULL;
 483         conn = cls_conn->dd_data;
 484         tcp_conn = conn->dd_data;
 485         tcp_sw_conn = tcp_conn->dd_data;
 486
 487         tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 488                                                      CRYPTO_ALG_ASYNC);
 489         tcp_sw_conn->tx_hash.flags = 0;
 490         if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 491                 goto free_conn;
 492
 493         tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 494                                                      CRYPTO_ALG_ASYNC);
 495         tcp_sw_conn->rx_hash.flags = 0;
 496         if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 497                 goto free_tx_tfm;
 498         tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 499
 500         return cls_conn;
 501
 502 free_tx_tfm:
 503         crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 504 free_conn:
 505         iscsi_conn_printk(KERN_ERR, conn,
 506                           "Could not create connection due to crc32c "
 507                           "loading error. Make sure the crc32c "
 508                           "module is built as a module or into the "
 509                           "kernel\n");
 510         iscsi_tcp_conn_teardown(cls_conn);
 511         return NULL;
 512 }
 513
 514 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 515 {
 516         struct iscsi_session *session = conn->session;
 517         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 518         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 519         struct socket *sock = tcp_sw_conn->sock;
 520
 521         if (!sock)
 522                 return;
 523
 524         sock_hold(sock->sk);
 525         iscsi_sw_tcp_conn_restore_callbacks(tcp_sw_conn);
 526         sock_put(sock->sk);
 527
 528         spin_lock_bh(&session->lock);
 529         tcp_sw_conn->sock = NULL;
 530         spin_unlock_bh(&session->lock);
 531         sockfd_put(sock);
 532 }
 533
 534 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 535 {
 536         struct iscsi_conn *conn = cls_conn->dd_data;
 537         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 538         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 539
 540         iscsi_sw_tcp_release_conn(conn);
 541
 542         if (tcp_sw_conn->tx_hash.tfm)
 543                 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 544         if (tcp_sw_conn->rx_hash.tfm)
 545                 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 546
 547         iscsi_tcp_conn_teardown(cls_conn);
 548 }
 549
 550 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 551 {
 552         struct iscsi_conn *conn = cls_conn->dd_data;
 553         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 554         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 555
 556         /* userspace may have goofed up and not bound us */
 557         if (!tcp_sw_conn->sock)
 558                 return;
 559         /*
 560          * Make sure our recv side is stopped.
 561          * Older tools called conn stop before ep_disconnect
 562          * so IO could still be coming in.
 563          */
 564         write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 565         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 566         write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 567
 568         iscsi_conn_stop(cls_conn, flag);
 569         iscsi_sw_tcp_release_conn(conn);
 570 }
 571
 572 static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
 573                                  char *buf, int *port,
 574                                  int (*getname)(struct socket *,
 575                                                 struct sockaddr *,
 576                                                 int *addrlen))
 577 {
 578         struct sockaddr_storage *addr;
 579         struct sockaddr_in6 *sin6;
 580         struct sockaddr_in *sin;
 581         int rc = 0, len;
 582
 583         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
 584         if (!addr)
 585                 return -ENOMEM;
 586
 587         if (getname(sock, (struct sockaddr *) addr, &len)) {
 588                 rc = -ENODEV;
 589                 goto free_addr;
 590         }
 591
 592         switch (addr->ss_family) {
 593         case AF_INET:
 594                 sin = (struct sockaddr_in *)addr;
 595                 spin_lock_bh(&conn->session->lock);
 596                 sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
 597                 *port = be16_to_cpu(sin->sin_port);
 598                 spin_unlock_bh(&conn->session->lock);
 599                 break;
 600         case AF_INET6:
 601                 sin6 = (struct sockaddr_in6 *)addr;
 602                 spin_lock_bh(&conn->session->lock);
 603                 sprintf(buf, "%pI6", &sin6->sin6_addr);
 604                 *port = be16_to_cpu(sin6->sin6_port);
 605                 spin_unlock_bh(&conn->session->lock);
 606                 break;
 607         }
 608 free_addr:
 609         kfree(addr);
 610         return rc;
 611 }
 612
 613 static int
 614 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 615                        struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 616                        int is_leading)
 617 {
 618         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 619         struct iscsi_host *ihost = shost_priv(shost);
 620         struct iscsi_conn *conn = cls_conn->dd_data;
 621         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 622         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 623         struct sock *sk;
 624         struct socket *sock;
 625         int err;
 626
 627         /* lookup for existing socket */
 628         sock = sockfd_lookup((int)transport_eph, &err);
 629         if (!sock) {
 630                 iscsi_conn_printk(KERN_ERR, conn,
 631                                   "sockfd_lookup failed %d\n", err);
 632                 return -EEXIST;
 633         }
 634         /*
 635          * copy these values now because if we drop the session
 636          * userspace may still want to query the values since we will
 637          * be using them for the reconnect
 638          */
 639         err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
 640                                     &conn->portal_port, kernel_getpeername);
 641         if (err)
 642                 goto free_socket;
 643
 644         err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
 645                                     &ihost->local_port, kernel_getsockname);
 646         if (err)
 647                 goto free_socket;
 648
 649         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 650         if (err)
 651                 goto free_socket;
 652
 653         /* bind iSCSI connection and socket */
 654         tcp_sw_conn->sock = sock;
 655
 656         /* setup Socket parameters */
 657         sk = sock->sk;
 658         sk->sk_reuse = 1;
 659         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 660         sk->sk_allocation = GFP_ATOMIC;
 661
 662         iscsi_sw_tcp_conn_set_callbacks(conn);
 663         tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 664         /*
 665          * set receive state machine into initial state
 666          */
 667         iscsi_tcp_hdr_recv_prep(tcp_conn);
 668         return 0;
 669
 670 free_socket:
 671         sockfd_put(sock);
 672         return err;
 673 }
 674
 675 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 676                                        enum iscsi_param param, char *buf,
 677                                        int buflen)
 678 {
 679         struct iscsi_conn *conn = cls_conn->dd_data;
 680         struct iscsi_session *session = conn->session;
 681         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 682         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 683         int value;
 684
 685         switch(param) {
 686         case ISCSI_PARAM_HDRDGST_EN:
 687                 iscsi_set_param(cls_conn, param, buf, buflen);
 688                 break;
 689         case ISCSI_PARAM_DATADGST_EN:
 690                 iscsi_set_param(cls_conn, param, buf, buflen);
 691                 tcp_sw_conn->sendpage = conn->datadgst_en ?
 692                         sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 693                 break;
 694         case ISCSI_PARAM_MAX_R2T:
 695                 sscanf(buf, "%d", &value);
 696                 if (value <= 0 || !is_power_of_2(value))
 697                         return -EINVAL;
 698                 if (session->max_r2t == value)
 699                         break;
 700                 iscsi_tcp_r2tpool_free(session);
 701                 iscsi_set_param(cls_conn, param, buf, buflen);
 702                 if (iscsi_tcp_r2tpool_alloc(session))
 703                         return -ENOMEM;
 704                 break;
 705         default:
 706                 return iscsi_set_param(cls_conn, param, buf, buflen);
 707         }
 708
 709         return 0;
 710 }
 711
 712 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 713                                        enum iscsi_param param, char *buf)
 714 {
 715         struct iscsi_conn *conn = cls_conn->dd_data;
 716         int len;
 717
 718         switch(param) {
 719         case ISCSI_PARAM_CONN_PORT:
 720                 spin_lock_bh(&conn->session->lock);
 721                 len = sprintf(buf, "%hu\n", conn->portal_port);
 722                 spin_unlock_bh(&conn->session->lock);
 723                 break;
 724         case ISCSI_PARAM_CONN_ADDRESS:
 725                 spin_lock_bh(&conn->session->lock);
 726                 len = sprintf(buf, "%s\n", conn->portal_address);
 727                 spin_unlock_bh(&conn->session->lock);
 728                 break;
 729         default:
 730                 return iscsi_conn_get_param(cls_conn, param, buf);
 731         }
 732
 733         return len;
 734 }
 735
 736 static void
 737 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 738                             struct iscsi_stats *stats)
 739 {
 740         struct iscsi_conn *conn = cls_conn->dd_data;
 741         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 742         struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 743
 744         stats->custom_length = 3;
 745         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 746         stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 747         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 748         stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 749         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 750         stats->custom[2].value = conn->eh_abort_cnt;
 751
 752         iscsi_tcp_conn_get_stats(cls_conn, stats);
 753 }
 754
 755 static struct iscsi_cls_session *
 756 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 757                             uint16_t qdepth, uint32_t initial_cmdsn,
 758                             uint32_t *hostno)
 759 {
 760         struct iscsi_cls_session *cls_session;
 761         struct iscsi_session *session;
 762         struct Scsi_Host *shost;
 763
 764         if (ep) {
 765                 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 766                 return NULL;
 767         }
 768
 769         shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 0, qdepth);
 770         if (!shost)
 771                 return NULL;
 772         shost->transportt = iscsi_sw_tcp_scsi_transport;
 773         shost->max_lun = iscsi_max_lun;
 774         shost->max_id = 0;
 775         shost->max_channel = 0;
 776         shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 777
 778         if (iscsi_host_add(shost, NULL))
 779                 goto free_host;
 780         *hostno = shost->host_no;
 781
 782         cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 783                                           cmds_max,
 784                                           sizeof(struct iscsi_tcp_task) +
 785                                           sizeof(struct iscsi_sw_tcp_hdrbuf),
 786                                           initial_cmdsn, 0);
 787         if (!cls_session)
 788                 goto remove_host;
 789         session = cls_session->dd_data;
 790
 791         shost->can_queue = session->scsi_cmds_max;
 792         if (iscsi_tcp_r2tpool_alloc(session))
 793                 goto remove_session;
 794         return cls_session;
 795
 796 remove_session:
 797         iscsi_session_teardown(cls_session);
 798 remove_host:
 799         iscsi_host_remove(shost);
 800 free_host:
 801         iscsi_host_free(shost);
 802         return NULL;
 803 }
 804
 805 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 806 {
 807         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 808
 809         iscsi_tcp_r2tpool_free(cls_session->dd_data);
 810         iscsi_session_teardown(cls_session);
 811
 812         iscsi_host_remove(shost);
 813         iscsi_host_free(shost);
 814 }
 815
 816 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 817 {
 818         set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 819         return 0;
 820 }
 821
 822 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 823 {
 824         blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 825         blk_queue_dma_alignment(sdev->request_queue, 0);
 826         return 0;
 827 }
 828
 829 static struct scsi_host_template iscsi_sw_tcp_sht = {
 830         .module                 = THIS_MODULE,
 831         .name                   = "iSCSI Initiator over TCP/IP",
 832         .queuecommand           = iscsi_queuecommand,
 833         .change_queue_depth     = iscsi_change_queue_depth,
 834         .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 835         .sg_tablesize           = 4096,
 836         .max_sectors            = 0xFFFF,
 837         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 838         .eh_abort_handler       = iscsi_eh_abort,
 839         .eh_device_reset_handler= iscsi_eh_device_reset,
 840         .eh_target_reset_handler= iscsi_eh_target_reset,
 841         .use_clustering         = DISABLE_CLUSTERING,
 842         .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 843         .slave_configure        = iscsi_sw_tcp_slave_configure,
 844         .proc_name              = "iscsi_tcp",
 845         .this_id                = -1,
 846 };
 847
 848 static struct iscsi_transport iscsi_sw_tcp_transport = {
 849         .owner                  = THIS_MODULE,
 850         .name                   = "tcp",
 851         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 852                                   | CAP_DATADGST,
 853         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 854                                   ISCSI_MAX_XMIT_DLENGTH |
 855                                   ISCSI_HDRDGST_EN |
 856                                   ISCSI_DATADGST_EN |
 857                                   ISCSI_INITIAL_R2T_EN |
 858                                   ISCSI_MAX_R2T |
 859                                   ISCSI_IMM_DATA_EN |
 860                                   ISCSI_FIRST_BURST |
 861                                   ISCSI_MAX_BURST |
 862                                   ISCSI_PDU_INORDER_EN |
 863                                   ISCSI_DATASEQ_INORDER_EN |
 864                                   ISCSI_ERL |
 865                                   ISCSI_CONN_PORT |
 866                                   ISCSI_CONN_ADDRESS |
 867                                   ISCSI_EXP_STATSN |
 868                                   ISCSI_PERSISTENT_PORT |
 869                                   ISCSI_PERSISTENT_ADDRESS |
 870                                   ISCSI_TARGET_NAME | ISCSI_TPGT |
 871                                   ISCSI_USERNAME | ISCSI_PASSWORD |
 872                                   ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
 873                                   ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
 874                                   ISCSI_LU_RESET_TMO |
 875                                   ISCSI_PING_TMO | ISCSI_RECV_TMO |
 876                                   ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
 877         .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
 878                                   ISCSI_HOST_INITIATOR_NAME |
 879                                   ISCSI_HOST_NETDEV_NAME,
 880         /* session management */
 881         .create_session         = iscsi_sw_tcp_session_create,
 882         .destroy_session        = iscsi_sw_tcp_session_destroy,
 883         /* connection management */
 884         .create_conn            = iscsi_sw_tcp_conn_create,
 885         .bind_conn              = iscsi_sw_tcp_conn_bind,
 886         .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 887         .set_param              = iscsi_sw_tcp_conn_set_param,
 888         .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 889         .get_session_param      = iscsi_session_get_param,
 890         .start_conn             = iscsi_conn_start,
 891         .stop_conn              = iscsi_sw_tcp_conn_stop,
 892         /* iscsi host params */
 893         .get_host_param         = iscsi_host_get_param,
 894         .set_host_param         = iscsi_host_set_param,
 895         /* IO */
 896         .send_pdu               = iscsi_conn_send_pdu,
 897         .get_stats              = iscsi_sw_tcp_conn_get_stats,
 898         /* iscsi task/cmd helpers */
 899         .init_task              = iscsi_tcp_task_init,
 900         .xmit_task              = iscsi_tcp_task_xmit,
 901         .cleanup_task           = iscsi_tcp_cleanup_task,
 902         /* low level pdu helpers */
 903         .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 904         .init_pdu               = iscsi_sw_tcp_pdu_init,
 905         .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 906         /* recovery */
 907         .session_recovery_timedout = iscsi_session_recovery_timedout,
 908 };
 909
 910 static int __init iscsi_sw_tcp_init(void)
 911 {
 912         if (iscsi_max_lun < 1) {
 913                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 914                        iscsi_max_lun);
 915                 return -EINVAL;
 916         }
 917
 918         iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 919                                                 &iscsi_sw_tcp_transport);
 920         if (!iscsi_sw_tcp_scsi_transport)
 921                 return -ENODEV;
 922
 923         return 0;
 924 }
 925
 926 static void __exit iscsi_sw_tcp_exit(void)
 927 {
 928         iscsi_unregister_transport(&iscsi_sw_tcp_transport);
 929 }
 930
 931 module_init(iscsi_sw_tcp_init);
 932 module_exit(iscsi_sw_tcp_exit);