linux/drivers/scsi/iscsi_tcp.c
<<
>>
Prefs
   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 <linux/module.h>
  39#include <net/tcp.h>
  40#include <scsi/scsi_cmnd.h>
  41#include <scsi/scsi_device.h>
  42#include <scsi/scsi_host.h>
  43#include <scsi/scsi.h>
  44#include <scsi/scsi_transport_iscsi.h>
  45
  46#include "iscsi_tcp.h"
  47
  48MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
  49              "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  50              "Alex Aizman <itn780@yahoo.com>");
  51MODULE_DESCRIPTION("iSCSI/TCP data-path");
  52MODULE_LICENSE("GPL");
  53
  54static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
  55static struct scsi_host_template iscsi_sw_tcp_sht;
  56static struct iscsi_transport iscsi_sw_tcp_transport;
  57
  58static unsigned int iscsi_max_lun = ~0;
  59module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  60
  61static int iscsi_sw_tcp_dbg;
  62module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
  63                   S_IRUGO | S_IWUSR);
  64MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
  65                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  66
  67#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)                \
  68        do {                                                    \
  69                if (iscsi_sw_tcp_dbg)                           \
  70                        iscsi_conn_printk(KERN_INFO, _conn,     \
  71                                             "%s " dbg_fmt,     \
  72                                             __func__, ##arg);  \
  73        } while (0);
  74
  75
  76/**
  77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
  78 * @rd_desc: read descriptor
  79 * @skb: socket buffer
  80 * @offset: offset in skb
  81 * @len: skb->len - offset
  82 */
  83static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
  84                             unsigned int offset, size_t len)
  85{
  86        struct iscsi_conn *conn = rd_desc->arg.data;
  87        unsigned int consumed, total_consumed = 0;
  88        int status;
  89
  90        ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
  91
  92        do {
  93                status = 0;
  94                consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
  95                offset += consumed;
  96                total_consumed += consumed;
  97        } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
  98
  99        ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
 100                         skb->len - offset, status);
 101        return total_consumed;
 102}
 103
 104/**
 105 * iscsi_sw_sk_state_check - check socket state
 106 * @sk: socket
 107 *
 108 * If the socket is in CLOSE or CLOSE_WAIT we should
 109 * not close the connection if there is still some
 110 * data pending.
 111 *
 112 * Must be called with sk_callback_lock.
 113 */
 114static inline int iscsi_sw_sk_state_check(struct sock *sk)
 115{
 116        struct iscsi_conn *conn = sk->sk_user_data;
 117
 118        if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
 119            !atomic_read(&sk->sk_rmem_alloc)) {
 120                ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
 121                iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
 122                return -ECONNRESET;
 123        }
 124        return 0;
 125}
 126
 127static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 128{
 129        struct iscsi_conn *conn;
 130        struct iscsi_tcp_conn *tcp_conn;
 131        read_descriptor_t rd_desc;
 132
 133        read_lock(&sk->sk_callback_lock);
 134        conn = sk->sk_user_data;
 135        if (!conn) {
 136                read_unlock(&sk->sk_callback_lock);
 137                return;
 138        }
 139        tcp_conn = conn->dd_data;
 140
 141        /*
 142         * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
 143         * We set count to 1 because we want the network layer to
 144         * hand us all the skbs that are available. iscsi_tcp_recv
 145         * handled pdus that cross buffers or pdus that still need data.
 146         */
 147        rd_desc.arg.data = conn;
 148        rd_desc.count = 1;
 149        tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 150
 151        iscsi_sw_sk_state_check(sk);
 152
 153        /* If we had to (atomically) map a highmem page,
 154         * unmap it now. */
 155        iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
 156        read_unlock(&sk->sk_callback_lock);
 157}
 158
 159static void iscsi_sw_tcp_state_change(struct sock *sk)
 160{
 161        struct iscsi_tcp_conn *tcp_conn;
 162        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 163        struct iscsi_conn *conn;
 164        struct iscsi_session *session;
 165        void (*old_state_change)(struct sock *);
 166
 167        read_lock(&sk->sk_callback_lock);
 168        conn = sk->sk_user_data;
 169        if (!conn) {
 170                read_unlock(&sk->sk_callback_lock);
 171                return;
 172        }
 173        session = conn->session;
 174
 175        iscsi_sw_sk_state_check(sk);
 176
 177        tcp_conn = conn->dd_data;
 178        tcp_sw_conn = tcp_conn->dd_data;
 179        old_state_change = tcp_sw_conn->old_state_change;
 180
 181        read_unlock(&sk->sk_callback_lock);
 182
 183        old_state_change(sk);
 184}
 185
 186/**
 187 * iscsi_write_space - Called when more output buffer space is available
 188 * @sk: socket space is available for
 189 **/
 190static void iscsi_sw_tcp_write_space(struct sock *sk)
 191{
 192        struct iscsi_conn *conn;
 193        struct iscsi_tcp_conn *tcp_conn;
 194        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 195        void (*old_write_space)(struct sock *);
 196
 197        read_lock_bh(&sk->sk_callback_lock);
 198        conn = sk->sk_user_data;
 199        if (!conn) {
 200                read_unlock_bh(&sk->sk_callback_lock);
 201                return;
 202        }
 203
 204        tcp_conn = conn->dd_data;
 205        tcp_sw_conn = tcp_conn->dd_data;
 206        old_write_space = tcp_sw_conn->old_write_space;
 207        read_unlock_bh(&sk->sk_callback_lock);
 208
 209        old_write_space(sk);
 210
 211        ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
 212        iscsi_conn_queue_work(conn);
 213}
 214
 215static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
 216{
 217        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 218        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 219        struct sock *sk = tcp_sw_conn->sock->sk;
 220
 221        /* assign new callbacks */
 222        write_lock_bh(&sk->sk_callback_lock);
 223        sk->sk_user_data = conn;
 224        tcp_sw_conn->old_data_ready = sk->sk_data_ready;
 225        tcp_sw_conn->old_state_change = sk->sk_state_change;
 226        tcp_sw_conn->old_write_space = sk->sk_write_space;
 227        sk->sk_data_ready = iscsi_sw_tcp_data_ready;
 228        sk->sk_state_change = iscsi_sw_tcp_state_change;
 229        sk->sk_write_space = iscsi_sw_tcp_write_space;
 230        write_unlock_bh(&sk->sk_callback_lock);
 231}
 232
 233static void
 234iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
 235{
 236        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 237        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 238        struct sock *sk = tcp_sw_conn->sock->sk;
 239
 240        /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
 241        write_lock_bh(&sk->sk_callback_lock);
 242        sk->sk_user_data    = NULL;
 243        sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
 244        sk->sk_state_change = tcp_sw_conn->old_state_change;
 245        sk->sk_write_space  = tcp_sw_conn->old_write_space;
 246        sk->sk_no_check  = 0;
 247        write_unlock_bh(&sk->sk_callback_lock);
 248}
 249
 250/**
 251 * iscsi_sw_tcp_xmit_segment - transmit segment
 252 * @tcp_conn: the iSCSI TCP connection
 253 * @segment: the buffer to transmnit
 254 *
 255 * This function transmits as much of the buffer as
 256 * the network layer will accept, and returns the number of
 257 * bytes transmitted.
 258 *
 259 * If CRC hashing is enabled, the function will compute the
 260 * hash as it goes. When the entire segment has been transmitted,
 261 * it will retrieve the hash value and send it as well.
 262 */
 263static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 264                                     struct iscsi_segment *segment)
 265{
 266        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 267        struct socket *sk = tcp_sw_conn->sock;
 268        unsigned int copied = 0;
 269        int r = 0;
 270
 271        while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
 272                struct scatterlist *sg;
 273                unsigned int offset, copy;
 274                int flags = 0;
 275
 276                r = 0;
 277                offset = segment->copied;
 278                copy = segment->size - offset;
 279
 280                if (segment->total_copied + segment->size < segment->total_size)
 281                        flags |= MSG_MORE;
 282
 283                /* Use sendpage if we can; else fall back to sendmsg */
 284                if (!segment->data) {
 285                        sg = segment->sg;
 286                        offset += segment->sg_offset + sg->offset;
 287                        r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
 288                                                  copy, flags);
 289                } else {
 290                        struct msghdr msg = { .msg_flags = flags };
 291                        struct kvec iov = {
 292                                .iov_base = segment->data + offset,
 293                                .iov_len = copy
 294                        };
 295
 296                        r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
 297                }
 298
 299                if (r < 0) {
 300                        iscsi_tcp_segment_unmap(segment);
 301                        return r;
 302                }
 303                copied += r;
 304        }
 305        return copied;
 306}
 307
 308/**
 309 * iscsi_sw_tcp_xmit - TCP transmit
 310 **/
 311static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
 312{
 313        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 314        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 315        struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 316        unsigned int consumed = 0;
 317        int rc = 0;
 318
 319        while (1) {
 320                rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
 321                /*
 322                 * We may not have been able to send data because the conn
 323                 * is getting stopped. libiscsi will know so propagate err
 324                 * for it to do the right thing.
 325                 */
 326                if (rc == -EAGAIN)
 327                        return rc;
 328                else if (rc < 0) {
 329                        rc = ISCSI_ERR_XMIT_FAILED;
 330                        goto error;
 331                } else if (rc == 0)
 332                        break;
 333
 334                consumed += rc;
 335
 336                if (segment->total_copied >= segment->total_size) {
 337                        if (segment->done != NULL) {
 338                                rc = segment->done(tcp_conn, segment);
 339                                if (rc != 0)
 340                                        goto error;
 341                        }
 342                }
 343        }
 344
 345        ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
 346
 347        conn->txdata_octets += consumed;
 348        return consumed;
 349
 350error:
 351        /* Transmit error. We could initiate error recovery
 352         * here. */
 353        ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
 354        iscsi_conn_failure(conn, rc);
 355        return -EIO;
 356}
 357
 358/**
 359 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 360 */
 361static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
 362{
 363        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 364        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 365        struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
 366
 367        return segment->total_copied - segment->total_size;
 368}
 369
 370static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
 371{
 372        struct iscsi_conn *conn = task->conn;
 373        int rc;
 374
 375        while (iscsi_sw_tcp_xmit_qlen(conn)) {
 376                rc = iscsi_sw_tcp_xmit(conn);
 377                if (rc == 0)
 378                        return -EAGAIN;
 379                if (rc < 0)
 380                        return rc;
 381        }
 382
 383        return 0;
 384}
 385
 386/*
 387 * This is called when we're done sending the header.
 388 * Simply copy the data_segment to the send segment, and return.
 389 */
 390static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
 391                                      struct iscsi_segment *segment)
 392{
 393        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 394
 395        tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
 396        ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
 397                         "Header done. Next segment size %u total_size %u\n",
 398                         tcp_sw_conn->out.segment.size,
 399                         tcp_sw_conn->out.segment.total_size);
 400        return 0;
 401}
 402
 403static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
 404                                       size_t hdrlen)
 405{
 406        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 407        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 408
 409        ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
 410                         "digest enabled" : "digest disabled");
 411
 412        /* Clear the data segment - needs to be filled in by the
 413         * caller using iscsi_tcp_send_data_prep() */
 414        memset(&tcp_sw_conn->out.data_segment, 0,
 415               sizeof(struct iscsi_segment));
 416
 417        /* If header digest is enabled, compute the CRC and
 418         * place the digest into the same buffer. We make
 419         * sure that both iscsi_tcp_task and mtask have
 420         * sufficient room.
 421         */
 422        if (conn->hdrdgst_en) {
 423                iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
 424                                      hdr + hdrlen);
 425                hdrlen += ISCSI_DIGEST_SIZE;
 426        }
 427
 428        /* Remember header pointer for later, when we need
 429         * to decide whether there's a payload to go along
 430         * with the header. */
 431        tcp_sw_conn->out.hdr = hdr;
 432
 433        iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
 434                                  iscsi_sw_tcp_send_hdr_done, NULL);
 435}
 436
 437/*
 438 * Prepare the send buffer for the payload data.
 439 * Padding and checksumming will all be taken care
 440 * of by the iscsi_segment routines.
 441 */
 442static int
 443iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
 444                            unsigned int count, unsigned int offset,
 445                            unsigned int len)
 446{
 447        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 448        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 449        struct hash_desc *tx_hash = NULL;
 450        unsigned int hdr_spec_len;
 451
 452        ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
 453                         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        return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
 465                                     sg, count, offset, len,
 466                                     NULL, tx_hash);
 467}
 468
 469static void
 470iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
 471                                   size_t len)
 472{
 473        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 474        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 475        struct hash_desc *tx_hash = NULL;
 476        unsigned int hdr_spec_len;
 477
 478        ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
 479                         "digest enabled" : "digest disabled");
 480
 481        /* Make sure the datalen matches what the caller
 482           said he would send. */
 483        hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
 484        WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
 485
 486        if (conn->datadgst_en)
 487                tx_hash = &tcp_sw_conn->tx_hash;
 488
 489        iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
 490                                data, len, NULL, tx_hash);
 491}
 492
 493static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
 494                                 unsigned int offset, unsigned int count)
 495{
 496        struct iscsi_conn *conn = task->conn;
 497        int err = 0;
 498
 499        iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
 500
 501        if (!count)
 502                return 0;
 503
 504        if (!task->sc)
 505                iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 506        else {
 507                struct scsi_data_buffer *sdb = scsi_out(task->sc);
 508
 509                err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 510                                                  sdb->table.nents, offset,
 511                                                  count);
 512        }
 513
 514        if (err) {
 515                /* got invalid offset/len */
 516                return -EIO;
 517        }
 518        return 0;
 519}
 520
 521static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
 522{
 523        struct iscsi_tcp_task *tcp_task = task->dd_data;
 524
 525        task->hdr = task->dd_data + sizeof(*tcp_task);
 526        task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
 527        return 0;
 528}
 529
 530static struct iscsi_cls_conn *
 531iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
 532                         uint32_t conn_idx)
 533{
 534        struct iscsi_conn *conn;
 535        struct iscsi_cls_conn *cls_conn;
 536        struct iscsi_tcp_conn *tcp_conn;
 537        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 538
 539        cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
 540                                        conn_idx);
 541        if (!cls_conn)
 542                return NULL;
 543        conn = cls_conn->dd_data;
 544        tcp_conn = conn->dd_data;
 545        tcp_sw_conn = tcp_conn->dd_data;
 546
 547        tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 548                                                     CRYPTO_ALG_ASYNC);
 549        tcp_sw_conn->tx_hash.flags = 0;
 550        if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
 551                goto free_conn;
 552
 553        tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
 554                                                     CRYPTO_ALG_ASYNC);
 555        tcp_sw_conn->rx_hash.flags = 0;
 556        if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
 557                goto free_tx_tfm;
 558        tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
 559
 560        return cls_conn;
 561
 562free_tx_tfm:
 563        crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 564free_conn:
 565        iscsi_conn_printk(KERN_ERR, conn,
 566                          "Could not create connection due to crc32c "
 567                          "loading error. Make sure the crc32c "
 568                          "module is built as a module or into the "
 569                          "kernel\n");
 570        iscsi_tcp_conn_teardown(cls_conn);
 571        return NULL;
 572}
 573
 574static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 575{
 576        struct iscsi_session *session = conn->session;
 577        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 578        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 579        struct socket *sock = tcp_sw_conn->sock;
 580
 581        if (!sock)
 582                return;
 583
 584        sock_hold(sock->sk);
 585        iscsi_sw_tcp_conn_restore_callbacks(conn);
 586        sock_put(sock->sk);
 587
 588        spin_lock_bh(&session->lock);
 589        tcp_sw_conn->sock = NULL;
 590        spin_unlock_bh(&session->lock);
 591        sockfd_put(sock);
 592}
 593
 594static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
 595{
 596        struct iscsi_conn *conn = cls_conn->dd_data;
 597        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 598        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 599
 600        iscsi_sw_tcp_release_conn(conn);
 601
 602        if (tcp_sw_conn->tx_hash.tfm)
 603                crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
 604        if (tcp_sw_conn->rx_hash.tfm)
 605                crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
 606
 607        iscsi_tcp_conn_teardown(cls_conn);
 608}
 609
 610static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 611{
 612        struct iscsi_conn *conn = cls_conn->dd_data;
 613        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 614        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 615        struct socket *sock = tcp_sw_conn->sock;
 616
 617        /* userspace may have goofed up and not bound us */
 618        if (!sock)
 619                return;
 620
 621        sock->sk->sk_err = EIO;
 622        wake_up_interruptible(sk_sleep(sock->sk));
 623
 624        /* stop xmit side */
 625        iscsi_suspend_tx(conn);
 626
 627        /* stop recv side and release socket */
 628        iscsi_sw_tcp_release_conn(conn);
 629
 630        iscsi_conn_stop(cls_conn, flag);
 631}
 632
 633static int
 634iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 635                       struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 636                       int is_leading)
 637{
 638        struct iscsi_session *session = cls_session->dd_data;
 639        struct iscsi_conn *conn = cls_conn->dd_data;
 640        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 641        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 642        struct sock *sk;
 643        struct socket *sock;
 644        int err;
 645
 646        /* lookup for existing socket */
 647        sock = sockfd_lookup((int)transport_eph, &err);
 648        if (!sock) {
 649                iscsi_conn_printk(KERN_ERR, conn,
 650                                  "sockfd_lookup failed %d\n", err);
 651                return -EEXIST;
 652        }
 653
 654        err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 655        if (err)
 656                goto free_socket;
 657
 658        spin_lock_bh(&session->lock);
 659        /* bind iSCSI connection and socket */
 660        tcp_sw_conn->sock = sock;
 661        spin_unlock_bh(&session->lock);
 662
 663        /* setup Socket parameters */
 664        sk = sock->sk;
 665        sk->sk_reuse = SK_CAN_REUSE;
 666        sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 667        sk->sk_allocation = GFP_ATOMIC;
 668
 669        iscsi_sw_tcp_conn_set_callbacks(conn);
 670        tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
 671        /*
 672         * set receive state machine into initial state
 673         */
 674        iscsi_tcp_hdr_recv_prep(tcp_conn);
 675        return 0;
 676
 677free_socket:
 678        sockfd_put(sock);
 679        return err;
 680}
 681
 682static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 683                                       enum iscsi_param param, char *buf,
 684                                       int buflen)
 685{
 686        struct iscsi_conn *conn = cls_conn->dd_data;
 687        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 688        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 689
 690        switch(param) {
 691        case ISCSI_PARAM_HDRDGST_EN:
 692                iscsi_set_param(cls_conn, param, buf, buflen);
 693                break;
 694        case ISCSI_PARAM_DATADGST_EN:
 695                iscsi_set_param(cls_conn, param, buf, buflen);
 696                tcp_sw_conn->sendpage = conn->datadgst_en ?
 697                        sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 698                break;
 699        case ISCSI_PARAM_MAX_R2T:
 700                return iscsi_tcp_set_max_r2t(conn, buf);
 701        default:
 702                return iscsi_set_param(cls_conn, param, buf, buflen);
 703        }
 704
 705        return 0;
 706}
 707
 708static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 709                                       enum iscsi_param param, char *buf)
 710{
 711        struct iscsi_conn *conn = cls_conn->dd_data;
 712        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 713        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 714        struct sockaddr_in6 addr;
 715        int rc, len;
 716
 717        switch(param) {
 718        case ISCSI_PARAM_CONN_PORT:
 719        case ISCSI_PARAM_CONN_ADDRESS:
 720                spin_lock_bh(&conn->session->lock);
 721                if (!tcp_sw_conn || !tcp_sw_conn->sock) {
 722                        spin_unlock_bh(&conn->session->lock);
 723                        return -ENOTCONN;
 724                }
 725                rc = kernel_getpeername(tcp_sw_conn->sock,
 726                                        (struct sockaddr *)&addr, &len);
 727                spin_unlock_bh(&conn->session->lock);
 728                if (rc)
 729                        return rc;
 730
 731                return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 732                                                 &addr, param, buf);
 733        default:
 734                return iscsi_conn_get_param(cls_conn, param, buf);
 735        }
 736
 737        return 0;
 738}
 739
 740static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 741                                       enum iscsi_host_param param, char *buf)
 742{
 743        struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
 744        struct iscsi_session *session = tcp_sw_host->session;
 745        struct iscsi_conn *conn;
 746        struct iscsi_tcp_conn *tcp_conn;
 747        struct iscsi_sw_tcp_conn *tcp_sw_conn;
 748        struct sockaddr_in6 addr;
 749        int rc, len;
 750
 751        switch (param) {
 752        case ISCSI_HOST_PARAM_IPADDRESS:
 753                spin_lock_bh(&session->lock);
 754                conn = session->leadconn;
 755                if (!conn) {
 756                        spin_unlock_bh(&session->lock);
 757                        return -ENOTCONN;
 758                }
 759                tcp_conn = conn->dd_data;
 760
 761                tcp_sw_conn = tcp_conn->dd_data;
 762                if (!tcp_sw_conn->sock) {
 763                        spin_unlock_bh(&session->lock);
 764                        return -ENOTCONN;
 765                }
 766
 767                rc = kernel_getsockname(tcp_sw_conn->sock,
 768                                        (struct sockaddr *)&addr, &len);
 769                spin_unlock_bh(&session->lock);
 770                if (rc)
 771                        return rc;
 772
 773                return iscsi_conn_get_addr_param((struct sockaddr_storage *)
 774                                                 &addr, param, buf);
 775        default:
 776                return iscsi_host_get_param(shost, param, buf);
 777        }
 778
 779        return 0;
 780}
 781
 782static void
 783iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 784                            struct iscsi_stats *stats)
 785{
 786        struct iscsi_conn *conn = cls_conn->dd_data;
 787        struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 788        struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 789
 790        stats->custom_length = 3;
 791        strcpy(stats->custom[0].desc, "tx_sendpage_failures");
 792        stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
 793        strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
 794        stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
 795        strcpy(stats->custom[2].desc, "eh_abort_cnt");
 796        stats->custom[2].value = conn->eh_abort_cnt;
 797
 798        iscsi_tcp_conn_get_stats(cls_conn, stats);
 799}
 800
 801static struct iscsi_cls_session *
 802iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 803                            uint16_t qdepth, uint32_t initial_cmdsn)
 804{
 805        struct iscsi_cls_session *cls_session;
 806        struct iscsi_session *session;
 807        struct iscsi_sw_tcp_host *tcp_sw_host;
 808        struct Scsi_Host *shost;
 809
 810        if (ep) {
 811                printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
 812                return NULL;
 813        }
 814
 815        shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
 816                                 sizeof(struct iscsi_sw_tcp_host), 1);
 817        if (!shost)
 818                return NULL;
 819        shost->transportt = iscsi_sw_tcp_scsi_transport;
 820        shost->cmd_per_lun = qdepth;
 821        shost->max_lun = iscsi_max_lun;
 822        shost->max_id = 0;
 823        shost->max_channel = 0;
 824        shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 825
 826        if (iscsi_host_add(shost, NULL))
 827                goto free_host;
 828
 829        cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
 830                                          cmds_max, 0,
 831                                          sizeof(struct iscsi_tcp_task) +
 832                                          sizeof(struct iscsi_sw_tcp_hdrbuf),
 833                                          initial_cmdsn, 0);
 834        if (!cls_session)
 835                goto remove_host;
 836        session = cls_session->dd_data;
 837        tcp_sw_host = iscsi_host_priv(shost);
 838        tcp_sw_host->session = session;
 839
 840        shost->can_queue = session->scsi_cmds_max;
 841        if (iscsi_tcp_r2tpool_alloc(session))
 842                goto remove_session;
 843        return cls_session;
 844
 845remove_session:
 846        iscsi_session_teardown(cls_session);
 847remove_host:
 848        iscsi_host_remove(shost);
 849free_host:
 850        iscsi_host_free(shost);
 851        return NULL;
 852}
 853
 854static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 855{
 856        struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
 857
 858        iscsi_tcp_r2tpool_free(cls_session->dd_data);
 859        iscsi_session_teardown(cls_session);
 860
 861        iscsi_host_remove(shost);
 862        iscsi_host_free(shost);
 863}
 864
 865static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
 866{
 867        switch (param_type) {
 868        case ISCSI_HOST_PARAM:
 869                switch (param) {
 870                case ISCSI_HOST_PARAM_NETDEV_NAME:
 871                case ISCSI_HOST_PARAM_HWADDRESS:
 872                case ISCSI_HOST_PARAM_IPADDRESS:
 873                case ISCSI_HOST_PARAM_INITIATOR_NAME:
 874                        return S_IRUGO;
 875                default:
 876                        return 0;
 877                }
 878        case ISCSI_PARAM:
 879                switch (param) {
 880                case ISCSI_PARAM_MAX_RECV_DLENGTH:
 881                case ISCSI_PARAM_MAX_XMIT_DLENGTH:
 882                case ISCSI_PARAM_HDRDGST_EN:
 883                case ISCSI_PARAM_DATADGST_EN:
 884                case ISCSI_PARAM_CONN_ADDRESS:
 885                case ISCSI_PARAM_CONN_PORT:
 886                case ISCSI_PARAM_EXP_STATSN:
 887                case ISCSI_PARAM_PERSISTENT_ADDRESS:
 888                case ISCSI_PARAM_PERSISTENT_PORT:
 889                case ISCSI_PARAM_PING_TMO:
 890                case ISCSI_PARAM_RECV_TMO:
 891                case ISCSI_PARAM_INITIAL_R2T_EN:
 892                case ISCSI_PARAM_MAX_R2T:
 893                case ISCSI_PARAM_IMM_DATA_EN:
 894                case ISCSI_PARAM_FIRST_BURST:
 895                case ISCSI_PARAM_MAX_BURST:
 896                case ISCSI_PARAM_PDU_INORDER_EN:
 897                case ISCSI_PARAM_DATASEQ_INORDER_EN:
 898                case ISCSI_PARAM_ERL:
 899                case ISCSI_PARAM_TARGET_NAME:
 900                case ISCSI_PARAM_TPGT:
 901                case ISCSI_PARAM_USERNAME:
 902                case ISCSI_PARAM_PASSWORD:
 903                case ISCSI_PARAM_USERNAME_IN:
 904                case ISCSI_PARAM_PASSWORD_IN:
 905                case ISCSI_PARAM_FAST_ABORT:
 906                case ISCSI_PARAM_ABORT_TMO:
 907                case ISCSI_PARAM_LU_RESET_TMO:
 908                case ISCSI_PARAM_TGT_RESET_TMO:
 909                case ISCSI_PARAM_IFACE_NAME:
 910                case ISCSI_PARAM_INITIATOR_NAME:
 911                        return S_IRUGO;
 912                default:
 913                        return 0;
 914                }
 915        }
 916
 917        return 0;
 918}
 919
 920static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
 921{
 922        set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
 923        return 0;
 924}
 925
 926static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 927{
 928        blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
 929        blk_queue_dma_alignment(sdev->request_queue, 0);
 930        return 0;
 931}
 932
 933static struct scsi_host_template iscsi_sw_tcp_sht = {
 934        .module                 = THIS_MODULE,
 935        .name                   = "iSCSI Initiator over TCP/IP",
 936        .queuecommand           = iscsi_queuecommand,
 937        .change_queue_depth     = iscsi_change_queue_depth,
 938        .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
 939        .sg_tablesize           = 4096,
 940        .max_sectors            = 0xFFFF,
 941        .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
 942        .eh_abort_handler       = iscsi_eh_abort,
 943        .eh_device_reset_handler= iscsi_eh_device_reset,
 944        .eh_target_reset_handler = iscsi_eh_recover_target,
 945        .use_clustering         = DISABLE_CLUSTERING,
 946        .slave_alloc            = iscsi_sw_tcp_slave_alloc,
 947        .slave_configure        = iscsi_sw_tcp_slave_configure,
 948        .target_alloc           = iscsi_target_alloc,
 949        .proc_name              = "iscsi_tcp",
 950        .this_id                = -1,
 951};
 952
 953static struct iscsi_transport iscsi_sw_tcp_transport = {
 954        .owner                  = THIS_MODULE,
 955        .name                   = "tcp",
 956        .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
 957                                  | CAP_DATADGST,
 958        /* session management */
 959        .create_session         = iscsi_sw_tcp_session_create,
 960        .destroy_session        = iscsi_sw_tcp_session_destroy,
 961        /* connection management */
 962        .create_conn            = iscsi_sw_tcp_conn_create,
 963        .bind_conn              = iscsi_sw_tcp_conn_bind,
 964        .destroy_conn           = iscsi_sw_tcp_conn_destroy,
 965        .attr_is_visible        = iscsi_sw_tcp_attr_is_visible,
 966        .set_param              = iscsi_sw_tcp_conn_set_param,
 967        .get_conn_param         = iscsi_sw_tcp_conn_get_param,
 968        .get_session_param      = iscsi_session_get_param,
 969        .start_conn             = iscsi_conn_start,
 970        .stop_conn              = iscsi_sw_tcp_conn_stop,
 971        /* iscsi host params */
 972        .get_host_param         = iscsi_sw_tcp_host_get_param,
 973        .set_host_param         = iscsi_host_set_param,
 974        /* IO */
 975        .send_pdu               = iscsi_conn_send_pdu,
 976        .get_stats              = iscsi_sw_tcp_conn_get_stats,
 977        /* iscsi task/cmd helpers */
 978        .init_task              = iscsi_tcp_task_init,
 979        .xmit_task              = iscsi_tcp_task_xmit,
 980        .cleanup_task           = iscsi_tcp_cleanup_task,
 981        /* low level pdu helpers */
 982        .xmit_pdu               = iscsi_sw_tcp_pdu_xmit,
 983        .init_pdu               = iscsi_sw_tcp_pdu_init,
 984        .alloc_pdu              = iscsi_sw_tcp_pdu_alloc,
 985        /* recovery */
 986        .session_recovery_timedout = iscsi_session_recovery_timedout,
 987};
 988
 989static int __init iscsi_sw_tcp_init(void)
 990{
 991        if (iscsi_max_lun < 1) {
 992                printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
 993                       iscsi_max_lun);
 994                return -EINVAL;
 995        }
 996
 997        iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
 998                                                &iscsi_sw_tcp_transport);
 999        if (!iscsi_sw_tcp_scsi_transport)
1000                return -ENODEV;
1001
1002        return 0;
1003}
1004
1005static void __exit iscsi_sw_tcp_exit(void)
1006{
1007        iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1008}
1009
1010module_init(iscsi_sw_tcp_init);
1011module_exit(iscsi_sw_tcp_exit);
1012
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.