linux/drivers/scsi/iscsi_tcp.c
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   1/*
   2 * iSCSI Initiator over TCP/IP Data-Path
   3 *
   4 * Copyright (C) 2004 Dmitry Yusupov
   5 * Copyright (C) 2004 Alex Aizman
   6 * Copyright (C) 2005 - 2006 Mike Christie
   7 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8 * maintained by open-iscsi@googlegroups.com
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published
  12 * by the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful, but
  16 * WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18 * General Public License for more details.
  19 *
  20 * See the file COPYING included with this distribution for more details.
  21 *
  22 * Credits:
  23 *      Christoph Hellwig
  24 *      FUJITA Tomonori
  25 *      Arne Redlich
  26 *      Zhenyu Wang
  27 */
  28
  29#include <linux/types.h>
  30#include <linux/inet.h>
  31#include <linux/slab.h>
  32#include <linux/file.h>
  33#include <linux/blkdev.h>
  34#include <linux/crypto.h>
  35#include <linux/delay.h>
  36#include <linux/kfifo.h>
  37#include <linux/scatterlist.h>
  38#include <net/tcp.h>
  39#include <scsi/scsi_cmnd.h>
  40#include <scsi/scsi_device.h>
  41#include <scsi/scsi_host.h>
  42#include <scsi/scsi.h>
  43#include <scsi/scsi_transport_iscsi.h>
  44
  45#include "iscsi_tcp.h"
  46
  47MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
  48              "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49              "Alex Aizman <itn780@yahoo.com>");
  50MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51MODULE_LICENSE("GPL");
  52
  53static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  54static struct scsi_host_template iscsi_sw_tcp_sht;
  55static struct iscsi_transport iscsi_sw_tcp_transport;
  56
  57static unsigned int iscsi_max_lun = 512;
  58module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  59
  60static int iscsi_sw_tcp_dbg;
  61module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
  62                   S_IRUGO | S_IWUSR);
  63MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
  64                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  65
  66#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)                \
  67        do {                                                    \
  68                if (iscsi_sw_tcp_dbg)                           \
  69                        iscsi_conn_printk(KERN_INFO, _conn,     \
  70                                             "%s " dbg_fmt,     \
  71                                             __func__, ##arg);  \
  72        } while (0);
  73
  74
  75/**
  76 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  77 * @rd_desc: read descriptor
  78 * @skb: socket buffer
  79 * @offset: offset in skb
  80 * @len: skb->len - offset
  81 */
  82static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  83                             unsigned int offset, size_t len)
  84{
  85        struct iscsi_conn *conn = rd_desc->arg.data;
  86        unsigned int consumed, total_consumed = 0;
  87        int status;
  88
  89        ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
  90
  91        do {
  92                status = 0;
  93                consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  94                offset += consumed;
  95                total_consumed += consumed;
  96        } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  97
  98        ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
  99                         skb->len - offset, status);
 100        return total_consumed;
 101}
 102
 103/**
 104 * iscsi_sw_sk_state_check - check socket state
 105 * @sk: socket
 106 *
 107 * If the socket is in CLOSE or CLOSE_WAIT we should
 108 * not close the connection if there is still some
 109 * data pending.
 110 */
 111static inline int iscsi_sw_sk_state_check(struct sock *sk)
 112{
 113        struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 114
 115        if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
 116            !atomic_read(&sk->sk_rmem_alloc)) {
 117                ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 118                iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
 119                return -ECONNRESET;
 120        }
 121        return 0;
 122}
 123
 124static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 125{
 126        struct iscsi_conn *conn = sk->sk_user_data;
 127        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 128        read_descriptor_t rd_desc;
 129
 130        read_lock(&sk->sk_callback_lock);
 131
 132        /*
 133         * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 134         * We set count to 1 because we want the network layer to
 135         * hand us all the skbs that are available. iscsi_tcp_recv
 136         * handled pdus that cross buffers or pdus that still need data.
 137         */
 138        rd_desc.arg.data = conn;
 139        rd_desc.count = 1;
 140        tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 141
 142        iscsi_sw_sk_state_check(sk);
 143
 144        read_unlock(&sk->sk_callback_lock);
 145
 146        /* If we had to (atomically) map a highmem page,
 147         * unmap it now. */
 148        iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 149}
 150
 151static void iscsi_sw_tcp_state_change(struct sock *sk)
 152{
 153        struct iscsi_tcp_conn *tcp_conn;
 154        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 155        struct iscsi_conn *conn;
 156        struct iscsi_session *session;
 157        void (*old_state_change)(struct sock *);
 158
 159        read_lock(&sk->sk_callback_lock);
 160
 161        conn = (struct iscsi_conn*)sk->sk_user_data;
 162        session = conn->session;
 163
 164        iscsi_sw_sk_state_check(sk);
 165
 166        tcp_conn = conn->dd_data;
 167        tcp_sw_conn = tcp_conn->dd_data;
 168        old_state_change = tcp_sw_conn->old_state_change;
 169
 170        read_unlock(&sk->sk_callback_lock);
 171
 172        old_state_change(sk);
 173}
 174
 175/**
 176 * iscsi_write_space - Called when more output buffer space is available
 177 * @sk: socket space is available for
 178 **/
 179static void iscsi_sw_tcp_write_space(struct sock *sk)
 180{
 181        struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
 182        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 183        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 184
 185        tcp_sw_conn->old_write_space(sk);
 186        ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 187        iscsi_conn_queue_work(conn);
 188}
 189
 190static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 191{
 192        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 193        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 194        struct sock *sk = tcp_sw_conn->sock->sk;
 195
 196        /* assign new callbacks */
 197        write_lock_bh(&sk->sk_callback_lock);
 198        sk->sk_user_data = conn;
 199        tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 200        tcp_sw_conn->old_state_change = sk->sk_state_change;
 201        tcp_sw_conn->old_write_space = sk->sk_write_space;
 202        sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 203        sk->sk_state_change = iscsi_sw_tcp_state_change;
 204        sk->sk_write_space = iscsi_sw_tcp_write_space;
 205        write_unlock_bh(&sk->sk_callback_lock);
 206}
 207
 208static void
 209iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
 210{
 211        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 212        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 213        struct sock *sk = tcp_sw_conn->sock->sk;
 214
 215        /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 216        write_lock_bh(&sk->sk_callback_lock);
 217        sk->sk_user_data    = NULL;
 218        sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 219        sk->sk_state_change = tcp_sw_conn->old_state_change;
 220        sk->sk_write_space  = tcp_sw_conn->old_write_space;
 221        sk->sk_no_check  = 0;
 222        write_unlock_bh(&sk->sk_callback_lock);
 223}
 224
 225/**
 226 * iscsi_sw_tcp_xmit_segment - transmit segment
 227 * @tcp_conn: the iSCSI TCP connection
 228 * @segment: the buffer to transmnit
 229 *
 230 * This function transmits as much of the buffer as
 231 * the network layer will accept, and returns the number of
 232 * bytes transmitted.
 233 *
 234 * If CRC hashing is enabled, the function will compute the
 235 * hash as it goes. When the entire segment has been transmitted,
 236 * it will retrieve the hash value and send it as well.
 237 */
 238static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 239                                     struct iscsi_segment *segment)
 240{
 241        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 242        struct socket *sk = tcp_sw_conn->sock;
 243        unsigned int copied = 0;
 244        int r = 0;
 245
 246        while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 247                struct scatterlist *sg;
 248                unsigned int offset, copy;
 249                int flags = 0;
 250
 251                r = 0;
 252                offset = segment->copied;
 253                copy = segment->size - offset;
 254
 255                if (segment->total_copied + segment->size < segment->total_size)
 256                        flags |= MSG_MORE;
 257
 258                /* Use sendpage if we can; else fall back to sendmsg */
 259                if (!segment->data) {
 260                        sg = segment->sg;
 261                        offset += segment->sg_offset + sg->offset;
 262                        r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 263                                                  copy, flags);
 264                } else {
 265                        struct msghdr msg = { .msg_flags = flags };
 266                        struct kvec iov = {
 267                                .iov_base = segment->data + offset,
 268                                .iov_len = copy
 269                        };
 270
 271                        r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 272                }
 273
 274                if (r < 0) {
 275                        iscsi_tcp_segment_unmap(segment);
 276                        return r;
 277                }
 278                copied += r;
 279        }
 280        return copied;
 281}
 282
 283/**
 284 * iscsi_sw_tcp_xmit - TCP transmit
 285 **/
 286static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 287{
 288        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 289        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 290        struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 291        unsigned int consumed = 0;
 292        int rc = 0;
 293
 294        while (1) {
 295                rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 296                /*
 297                 * We may not have been able to send data because the conn
 298                 * is getting stopped. libiscsi will know so propogate err
 299                 * for it to do the right thing.
 300                 */
 301                if (rc == -EAGAIN)
 302                        return rc;
 303                else if (rc < 0) {
 304                        rc = ISCSI_ERR_XMIT_FAILED;
 305                        goto error;
 306                } else if (rc == 0)
 307                        break;
 308
 309                consumed += rc;
 310
 311                if (segment->total_copied >= segment->total_size) {
 312                        if (segment->done != NULL) {
 313                                rc = segment->done(tcp_conn, segment);
 314                                if (rc != 0)
 315                                        goto error;
 316                        }
 317                }
 318        }
 319
 320        ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 321
 322        conn->txdata_octets += consumed;
 323        return consumed;
 324
 325error:
 326        /* Transmit error. We could initiate error recovery
 327         * here. */
 328        ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 329        iscsi_conn_failure(conn, rc);
 330        return -EIO;
 331}
 332
 333/**
 334 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 335 */
 336static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 337{
 338        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 339        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 340        struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 341
 342        return segment->total_copied - segment->total_size;
 343}
 344
 345static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 346{
 347        struct iscsi_conn *conn = task->conn;
 348        int rc;
 349
 350        while (iscsi_sw_tcp_xmit_qlen(conn)) {
 351                rc = iscsi_sw_tcp_xmit(conn);
 352                if (rc == 0)
 353                        return -EAGAIN;
 354                if (rc < 0)
 355                        return rc;
 356        }
 357
 358        return 0;
 359}
 360
 361/*
 362 * This is called when we're done sending the header.
 363 * Simply copy the data_segment to the send segment, and return.
 364 */
 365static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 366                                      struct iscsi_segment *segment)
 367{
 368        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 369
 370        tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 371        ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 372                         "Header done. Next segment size %u total_size %u\n",
 373                         tcp_sw_conn->out.segment.size,
 374                         tcp_sw_conn->out.segment.total_size);
 375        return 0;
 376}
 377
 378static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 379                                       size_t hdrlen)
 380{
 381        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 382        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 383
 384        ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 385                         "digest enabled" : "digest disabled");
 386
 387        /* Clear the data segment - needs to be filled in by the
 388         * caller using iscsi_tcp_send_data_prep() */
 389        memset(&tcp_sw_conn->out.data_segment, 0,
 390               sizeof(struct iscsi_segment));
 391
 392        /* If header digest is enabled, compute the CRC and
 393         * place the digest into the same buffer. We make
 394         * sure that both iscsi_tcp_task and mtask have
 395         * sufficient room.
 396         */
 397        if (conn->hdrdgst_en) {
 398                iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 399                                      hdr + hdrlen);
 400                hdrlen += ISCSI_DIGEST_SIZE;
 401        }
 402
 403        /* Remember header pointer for later, when we need
 404         * to decide whether there's a payload to go along
 405         * with the header. */
 406        tcp_sw_conn->out.hdr = hdr;
 407
 408        iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 409                                  iscsi_sw_tcp_send_hdr_done, NULL);
 410}
 411
 412/*
 413 * Prepare the send buffer for the payload data.
 414 * Padding and checksumming will all be taken care
 415 * of by the iscsi_segment routines.
 416 */
 417static int
 418iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 419                            unsigned int count, unsigned int offset,
 420                            unsigned int len)
 421{
 422        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 423        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 424        struct hash_desc *tx_hash = NULL;
 425        unsigned int hdr_spec_len;
 426
 427        ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 428                         conn->datadgst_en ?
 429                         "digest enabled" : "digest disabled");
 430
 431        /* Make sure the datalen matches what the caller
 432           said he would send. */
 433        hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 434        WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 435
 436        if (conn->datadgst_en)
 437                tx_hash = &tcp_sw_conn->tx_hash;
 438
 439        return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 440                                     sg, count, offset, len,
 441                                     NULL, tx_hash);
 442}
 443
 444static void
 445iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 446                                   size_t len)
 447{
 448        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 449        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 450        struct hash_desc *tx_hash = NULL;
 451        unsigned int hdr_spec_len;
 452
 453        ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 454                         "digest enabled" : "digest disabled");
 455
 456        /* Make sure the datalen matches what the caller
 457           said he would send. */
 458        hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 459        WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 460
 461        if (conn->datadgst_en)
 462                tx_hash = &tcp_sw_conn->tx_hash;
 463
 464        iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 465                                data, len, NULL, tx_hash);
 466}
 467
 468static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 469                                 unsigned int offset, unsigned int count)
 470{
 471        struct iscsi_conn *conn = task->conn;
 472        int err = 0;
 473
 474        iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 475
 476        if (!count)
 477                return 0;
 478
 479        if (!task->sc)
 480                iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 481        else {
 482                struct scsi_data_buffer *sdb = scsi_out(task->sc);
 483
 484                err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 485                                                  sdb->table.nents, offset,
 486                                                  count);
 487        }
 488
 489        if (err) {
 490                /* got invalid offset/len */
 491                return -EIO;
 492        }
 493        return 0;
 494}
 495
 496static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 497{
 498        struct iscsi_tcp_task *tcp_task = task->dd_data;
 499
 500        task->hdr = task->dd_data + sizeof(*tcp_task);
 501        task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 502        return 0;
 503}
 504
 505static struct iscsi_cls_conn *
 506iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 507                         uint32_t conn_idx)
 508{
 509        struct iscsi_conn *conn;
 510        struct iscsi_cls_conn *cls_conn;
 511        struct iscsi_tcp_conn *tcp_conn;
 512        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 513
 514        cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 515                                        conn_idx);
 516        if (!cls_conn)
 517                return NULL;
 518        conn = cls_conn->dd_data;
 519        tcp_conn = conn->dd_data;
 520        tcp_sw_conn = tcp_conn->dd_data;
 521
 522        tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 523                                                     CRYPTO_ALG_ASYNC);
 524        tcp_sw_conn->tx_hash.flags = 0;
 525        if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 526                goto free_conn;
 527
 528        tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 529                                                     CRYPTO_ALG_ASYNC);
 530        tcp_sw_conn->rx_hash.flags = 0;
 531        if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 532                goto free_tx_tfm;
 533        tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 534
 535        return cls_conn;
 536
 537free_tx_tfm:
 538        crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 539free_conn:
 540        iscsi_conn_printk(KERN_ERR, conn,
 541                          "Could not create connection due to crc32c "
 542                          "loading error. Make sure the crc32c "
 543                          "module is built as a module or into the "
 544                          "kernel\n");
 545        iscsi_tcp_conn_teardown(cls_conn);
 546        return NULL;
 547}
 548
 549static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 550{
 551        struct iscsi_session *session = conn->session;
 552        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 553        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 554        struct socket *sock = tcp_sw_conn->sock;
 555
 556        if (!sock)
 557                return;
 558
 559        sock_hold(sock->sk);
 560        iscsi_sw_tcp_conn_restore_callbacks(conn);
 561        sock_put(sock->sk);
 562
 563        spin_lock_bh(&session->lock);
 564        tcp_sw_conn->sock = NULL;
 565        spin_unlock_bh(&session->lock);
 566        sockfd_put(sock);
 567}
 568
 569static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 570{
 571        struct iscsi_conn *conn = cls_conn->dd_data;
 572        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 573        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 574
 575        iscsi_sw_tcp_release_conn(conn);
 576
 577        if (tcp_sw_conn->tx_hash.tfm)
 578                crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 579        if (tcp_sw_conn->rx_hash.tfm)
 580                crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 581
 582        iscsi_tcp_conn_teardown(cls_conn);
 583}
 584
 585static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 586{
 587        struct iscsi_conn *conn = cls_conn->dd_data;
 588        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 589        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 590        struct socket *sock = tcp_sw_conn->sock;
 591
 592        /* userspace may have goofed up and not bound us */
 593        if (!sock)
 594                return;
 595        /*
 596         * Make sure our recv side is stopped.
 597         * Older tools called conn stop before ep_disconnect
 598         * so IO could still be coming in.
 599         */
 600        write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 601        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 602        write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
 603
 604        sock->sk->sk_err = EIO;
 605        wake_up_interruptible(sk_sleep(sock->sk));
 606
 607        iscsi_conn_stop(cls_conn, flag);
 608        iscsi_sw_tcp_release_conn(conn);
 609}
 610
 611static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
 612                                 char *buf, int *port,
 613                                 int (*getname)(struct socket *,
 614                                                struct sockaddr *,
 615                                                int *addrlen))
 616{
 617        struct sockaddr_storage *addr;
 618        struct sockaddr_in6 *sin6;
 619        struct sockaddr_in *sin;
 620        int rc = 0, len;
 621
 622        addr = kmalloc(sizeof(*addr), GFP_KERNEL);
 623        if (!addr)
 624                return -ENOMEM;
 625
 626        if (getname(sock, (struct sockaddr *) addr, &len)) {
 627                rc = -ENODEV;
 628                goto free_addr;
 629        }
 630
 631        switch (addr->ss_family) {
 632        case AF_INET:
 633                sin = (struct sockaddr_in *)addr;
 634                spin_lock_bh(&conn->session->lock);
 635                sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
 636                *port = be16_to_cpu(sin->sin_port);
 637                spin_unlock_bh(&conn->session->lock);
 638                break;
 639        case AF_INET6:
 640                sin6 = (struct sockaddr_in6 *)addr;
 641                spin_lock_bh(&conn->session->lock);
 642                sprintf(buf, "%pI6", &sin6->sin6_addr);
 643                *port = be16_to_cpu(sin6->sin6_port);
 644                spin_unlock_bh(&conn->session->lock);
 645                break;
 646        }
 647free_addr:
 648        kfree(addr);
 649        return rc;
 650}
 651
 652static int
 653iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 654                       struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 655                       int is_leading)
 656{
 657        struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 658        struct iscsi_host *ihost = shost_priv(shost);
 659        struct iscsi_conn *conn = cls_conn->dd_data;
 660        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 661        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 662        struct sock *sk;
 663        struct socket *sock;
 664        int err;
 665
 666        /* lookup for existing socket */
 667        sock = sockfd_lookup((int)transport_eph, &err);
 668        if (!sock) {
 669                iscsi_conn_printk(KERN_ERR, conn,
 670                                  "sockfd_lookup failed %d\n", err);
 671                return -EEXIST;
 672        }
 673        /*
 674         * copy these values now because if we drop the session
 675         * userspace may still want to query the values since we will
 676         * be using them for the reconnect
 677         */
 678        err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
 679                                    &conn->portal_port, kernel_getpeername);
 680        if (err)
 681                goto free_socket;
 682
 683        err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
 684                                    &ihost->local_port, kernel_getsockname);
 685        if (err)
 686                goto free_socket;
 687
 688        err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 689        if (err)
 690                goto free_socket;
 691
 692        /* bind iSCSI connection and socket */
 693        tcp_sw_conn->sock = sock;
 694
 695        /* setup Socket parameters */
 696        sk = sock->sk;
 697        sk->sk_reuse = 1;
 698        sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 699        sk->sk_allocation = GFP_ATOMIC;
 700
 701        iscsi_sw_tcp_conn_set_callbacks(conn);
 702        tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 703        /*
 704         * set receive state machine into initial state
 705         */
 706        iscsi_tcp_hdr_recv_prep(tcp_conn);
 707        return 0;
 708
 709free_socket:
 710        sockfd_put(sock);
 711        return err;
 712}
 713
 714static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 715                                       enum iscsi_param param, char *buf,
 716                                       int buflen)
 717{
 718        struct iscsi_conn *conn = cls_conn->dd_data;
 719        struct iscsi_session *session = conn->session;
 720        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 721        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 722        int value;
 723
 724        switch(param) {
 725        case ISCSI_PARAM_HDRDGST_EN:
 726                iscsi_set_param(cls_conn, param, buf, buflen);
 727                break;
 728        case ISCSI_PARAM_DATADGST_EN:
 729                iscsi_set_param(cls_conn, param, buf, buflen);
 730                tcp_sw_conn->sendpage = conn->datadgst_en ?
 731                        sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 732                break;
 733        case ISCSI_PARAM_MAX_R2T:
 734                sscanf(buf, "%d", &value);
 735                if (value <= 0 || !is_power_of_2(value))
 736                        return -EINVAL;
 737                if (session->max_r2t == value)
 738                        break;
 739                iscsi_tcp_r2tpool_free(session);
 740                iscsi_set_param(cls_conn, param, buf, buflen);
 741                if (iscsi_tcp_r2tpool_alloc(session))
 742                        return -ENOMEM;
 743                break;
 744        default:
 745                return iscsi_set_param(cls_conn, param, buf, buflen);
 746        }
 747
 748        return 0;
 749}
 750
 751static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 752                                       enum iscsi_param param, char *buf)
 753{
 754        struct iscsi_conn *conn = cls_conn->dd_data;
 755        int len;
 756
 757        switch(param) {
 758        case ISCSI_PARAM_CONN_PORT:
 759                spin_lock_bh(&conn->session->lock);
 760                len = sprintf(buf, "%hu\n", conn->portal_port);
 761                spin_unlock_bh(&conn->session->lock);
 762                break;
 763        case ISCSI_PARAM_CONN_ADDRESS:
 764                spin_lock_bh(&conn->session->lock);
 765                len = sprintf(buf, "%s\n", conn->portal_address);
 766                spin_unlock_bh(&conn->session->lock);
 767                break;
 768        default:
 769                return iscsi_conn_get_param(cls_conn, param, buf);
 770        }
 771
 772        return len;
 773}
 774
 775static void
 776iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 777                            struct iscsi_stats *stats)
 778{
 779        struct iscsi_conn *conn = cls_conn->dd_data;
 780        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 781        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 782
 783        stats->custom_length = 3;
 784        strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 785        stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 786        strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 787        stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 788        strcpy(stats->custom[2].desc, "eh_abort_cnt");
 789        stats->custom[2].value = conn->eh_abort_cnt;
 790
 791        iscsi_tcp_conn_get_stats(cls_conn, stats);
 792}
 793
 794static struct iscsi_cls_session *
 795iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 796                            uint16_t qdepth, uint32_t initial_cmdsn)
 797{
 798        struct iscsi_cls_session *cls_session;
 799        struct iscsi_session *session;
 800        struct Scsi_Host *shost;
 801
 802        if (ep) {
 803                printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 804                return NULL;
 805        }
 806
 807        shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, 0, 1);
 808        if (!shost)
 809                return NULL;
 810        shost->transportt = iscsi_sw_tcp_scsi_transport;
 811        shost->cmd_per_lun = qdepth;
 812        shost->max_lun = iscsi_max_lun;
 813        shost->max_id = 0;
 814        shost->max_channel = 0;
 815        shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 816
 817        if (iscsi_host_add(shost, NULL))
 818                goto free_host;
 819
 820        cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 821                                          cmds_max, 0,
 822                                          sizeof(struct iscsi_tcp_task) +
 823                                          sizeof(struct iscsi_sw_tcp_hdrbuf),
 824                                          initial_cmdsn, 0);
 825        if (!cls_session)
 826                goto remove_host;
 827        session = cls_session->dd_data;
 828
 829        shost->can_queue = session->scsi_cmds_max;
 830        if (iscsi_tcp_r2tpool_alloc(session))
 831                goto remove_session;
 832        return cls_session;
 833
 834remove_session:
 835        iscsi_session_teardown(cls_session);
 836remove_host:
 837        iscsi_host_remove(shost);
 838free_host:
 839        iscsi_host_free(shost);
 840        return NULL;
 841}
 842
 843static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 844{
 845        struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 846
 847        iscsi_tcp_r2tpool_free(cls_session->dd_data);
 848        iscsi_session_teardown(cls_session);
 849
 850        iscsi_host_remove(shost);
 851        iscsi_host_free(shost);
 852}
 853
 854static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 855{
 856        set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 857        return 0;
 858}
 859
 860static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 861{
 862        blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 863        blk_queue_dma_alignment(sdev->request_queue, 0);
 864        return 0;
 865}
 866
 867static struct scsi_host_template iscsi_sw_tcp_sht = {
 868        .module                 = THIS_MODULE,
 869        .name                   = "iSCSI Initiator over TCP/IP",
 870        .queuecommand           = iscsi_queuecommand,
 871        .change_queue_depth     = iscsi_change_queue_depth,
 872        .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 873        .sg_tablesize           = 4096,
 874        .max_sectors            = 0xFFFF,
 875        .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 876        .eh_abort_handler       = iscsi_eh_abort,
 877        .eh_device_reset_handler= iscsi_eh_device_reset,
 878        .eh_target_reset_handler = iscsi_eh_recover_target,
 879        .use_clustering         = DISABLE_CLUSTERING,
 880        .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 881        .slave_configure        = iscsi_sw_tcp_slave_configure,
 882        .target_alloc           = iscsi_target_alloc,
 883        .proc_name              = "iscsi_tcp",
 884        .this_id                = -1,
 885};
 886
 887static struct iscsi_transport iscsi_sw_tcp_transport = {
 888        .owner                  = THIS_MODULE,
 889        .name                   = "tcp",
 890        .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 891                                  | CAP_DATADGST,
 892        .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 893                                  ISCSI_MAX_XMIT_DLENGTH |
 894                                  ISCSI_HDRDGST_EN |
 895                                  ISCSI_DATADGST_EN |
 896                                  ISCSI_INITIAL_R2T_EN |
 897                                  ISCSI_MAX_R2T |
 898                                  ISCSI_IMM_DATA_EN |
 899                                  ISCSI_FIRST_BURST |
 900                                  ISCSI_MAX_BURST |
 901                                  ISCSI_PDU_INORDER_EN |
 902                                  ISCSI_DATASEQ_INORDER_EN |
 903                                  ISCSI_ERL |
 904                                  ISCSI_CONN_PORT |
 905                                  ISCSI_CONN_ADDRESS |
 906                                  ISCSI_EXP_STATSN |
 907                                  ISCSI_PERSISTENT_PORT |
 908                                  ISCSI_PERSISTENT_ADDRESS |
 909                                  ISCSI_TARGET_NAME | ISCSI_TPGT |
 910                                  ISCSI_USERNAME | ISCSI_PASSWORD |
 911                                  ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
 912                                  ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
 913                                  ISCSI_LU_RESET_TMO | ISCSI_TGT_RESET_TMO |
 914                                  ISCSI_PING_TMO | ISCSI_RECV_TMO |
 915                                  ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
 916        .host_param_mask        = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
 917                                  ISCSI_HOST_INITIATOR_NAME |
 918                                  ISCSI_HOST_NETDEV_NAME,
 919        /* session management */
 920        .create_session         = iscsi_sw_tcp_session_create,
 921        .destroy_session        = iscsi_sw_tcp_session_destroy,
 922        /* connection management */
 923        .create_conn            = iscsi_sw_tcp_conn_create,
 924        .bind_conn              = iscsi_sw_tcp_conn_bind,
 925        .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 926        .set_param              = iscsi_sw_tcp_conn_set_param,
 927        .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 928        .get_session_param      = iscsi_session_get_param,
 929        .start_conn             = iscsi_conn_start,
 930        .stop_conn              = iscsi_sw_tcp_conn_stop,
 931        /* iscsi host params */
 932        .get_host_param         = iscsi_host_get_param,
 933        .set_host_param         = iscsi_host_set_param,
 934        /* IO */
 935        .send_pdu               = iscsi_conn_send_pdu,
 936        .get_stats              = iscsi_sw_tcp_conn_get_stats,
 937        /* iscsi task/cmd helpers */
 938        .init_task              = iscsi_tcp_task_init,
 939        .xmit_task              = iscsi_tcp_task_xmit,
 940        .cleanup_task           = iscsi_tcp_cleanup_task,
 941        /* low level pdu helpers */
 942        .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 943        .init_pdu               = iscsi_sw_tcp_pdu_init,
 944        .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 945        /* recovery */
 946        .session_recovery_timedout = iscsi_session_recovery_timedout,
 947};
 948
 949static int __init iscsi_sw_tcp_init(void)
 950{
 951        if (iscsi_max_lun < 1) {
 952                printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 953                       iscsi_max_lun);
 954                return -EINVAL;
 955        }
 956
 957        iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 958                                                &iscsi_sw_tcp_transport);
 959        if (!iscsi_sw_tcp_scsi_transport)
 960                return -ENODEV;
 961
 962        return 0;
 963}
 964
 965static void __exit iscsi_sw_tcp_exit(void)
 966{
 967        iscsi_unregister_transport(&iscsi_sw_tcp_transport);
 968}
 969
 970module_init(iscsi_sw_tcp_init);
 971module_exit(iscsi_sw_tcp_exit);
 972