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/list.h>
  31 #include <linux/inet.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 <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.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("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  47               "Alex Aizman <itn780@yahoo.com>");
  48 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  49 MODULE_LICENSE("GPL");
  50 /* #define DEBUG_TCP */
  51 #define DEBUG_ASSERT
  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 #ifndef DEBUG_ASSERT
  60 #ifdef BUG_ON
  61 #undef BUG_ON
  62 #endif
  63 #define BUG_ON(expr)
  64 #endif
  65
  66 static unsigned int iscsi_max_lun = 512;
  67 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  68
  69 static inline void
  70 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  71 {
  72         ibuf->sg.page = virt_to_page(vbuf);
  73         ibuf->sg.offset = offset_in_page(vbuf);
  74         ibuf->sg.length = size;
  75         ibuf->sent = 0;
  76         ibuf->use_sendmsg = 1;
  77 }
  78
  79 static inline void
  80 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  81 {
  82         ibuf->sg.page = sg->page;
  83         ibuf->sg.offset = sg->offset;
  84         ibuf->sg.length = sg->length;
  85         /*
  86          * Fastpath: sg element fits into single page
  87          */
  88         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  89                 ibuf->use_sendmsg = 0;
  90         else
  91                 ibuf->use_sendmsg = 1;
  92         ibuf->sent = 0;
  93 }
  94
  95 static inline int
  96 iscsi_buf_left(struct iscsi_buf *ibuf)
  97 {
  98         int rc;
  99
 100         rc = ibuf->sg.length - ibuf->sent;
 101         BUG_ON(rc < 0);
 102         return rc;
 103 }
 104
 105 static inline void
 106 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 107                  u8* crc)
 108 {
 109         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 110
 111         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 112         buf->sg.length += sizeof(uint32_t);
 113 }
 114
 115 static inline int
 116 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 117 {
 118         struct sk_buff *skb = tcp_conn->in.skb;
 119
 120         tcp_conn->in.zero_copy_hdr = 0;
 121
 122         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 123             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 124                 /*
 125                  * Zero-copy PDU Header: using connection context
 126                  * to store header pointer.
 127                  */
 128                 if (skb_shinfo(skb)->frag_list == NULL &&
 129                     !skb_shinfo(skb)->nr_frags) {
 130                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 131                                 ((char*)skb->data + tcp_conn->in.offset);
 132                         tcp_conn->in.zero_copy_hdr = 1;
 133                 } else {
 134                         /* ignoring return code since we checked
 135                          * in.copy before */
 136                         skb_copy_bits(skb, tcp_conn->in.offset,
 137                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 138                         tcp_conn->in.hdr = &tcp_conn->hdr;
 139                 }
 140                 tcp_conn->in.offset += tcp_conn->hdr_size;
 141                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 142         } else {
 143                 int hdr_remains;
 144                 int copylen;
 145
 146                 /*
 147                  * PDU header scattered across SKB's,
 148                  * copying it... This'll happen quite rarely.
 149                  */
 150
 151                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 152                         tcp_conn->in.hdr_offset = 0;
 153
 154                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 155                 BUG_ON(hdr_remains <= 0);
 156
 157                 copylen = min(tcp_conn->in.copy, hdr_remains);
 158                 skb_copy_bits(skb, tcp_conn->in.offset,
 159                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 160                         copylen);
 161
 162                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 163                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 164                        tcp_conn->in.offset, tcp_conn->in.copy);
 165
 166                 tcp_conn->in.offset += copylen;
 167                 tcp_conn->in.copy -= copylen;
 168                 if (copylen < hdr_remains)  {
 169                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 170                         tcp_conn->in.hdr_offset += copylen;
 171                         return -EAGAIN;
 172                 }
 173                 tcp_conn->in.hdr = &tcp_conn->hdr;
 174                 tcp_conn->discontiguous_hdr_cnt++;
 175                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 176         }
 177
 178         return 0;
 179 }
 180
 181 /*
 182  * must be called with session lock
 183  */
 184 static void
 185 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 186 {
 187         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 188         struct iscsi_r2t_info *r2t;
 189         struct scsi_cmnd *sc;
 190
 191         /* flush ctask's r2t queues */
 192         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
 193                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
 194                             sizeof(void*));
 195                 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
 196         }
 197
 198         sc = ctask->sc;
 199         if (unlikely(!sc))
 200                 return;
 201
 202         tcp_ctask->xmstate = XMSTATE_IDLE;
 203         tcp_ctask->r2t = NULL;
 204 }
 205
 206 /**
 207  * iscsi_data_rsp - SCSI Data-In Response processing
 208  * @conn: iscsi connection
 209  * @ctask: scsi command task
 210  **/
 211 static int
 212 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 213 {
 214         int rc;
 215         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 216         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 217         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 218         struct iscsi_session *session = conn->session;
 219         int datasn = be32_to_cpu(rhdr->datasn);
 220
 221         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 222         if (rc)
 223                 return rc;
 224         /*
 225          * setup Data-In byte counter (gets decremented..)
 226          */
 227         ctask->data_count = tcp_conn->in.datalen;
 228
 229         if (tcp_conn->in.datalen == 0)
 230                 return 0;
 231
 232         if (ctask->datasn != datasn)
 233                 return ISCSI_ERR_DATASN;
 234
 235         ctask->datasn++;
 236
 237         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 238         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 239                 return ISCSI_ERR_DATA_OFFSET;
 240
 241         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 242                 struct scsi_cmnd *sc = ctask->sc;
 243
 244                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 245                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 246                         int res_count = be32_to_cpu(rhdr->residual_count);
 247
 248                         if (res_count > 0 &&
 249                             res_count <= sc->request_bufflen) {
 250                                 sc->resid = res_count;
 251                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 252                         } else
 253                                 sc->result = (DID_BAD_TARGET << 16) |
 254                                         rhdr->cmd_status;
 255                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 256                         sc->resid = be32_to_cpu(rhdr->residual_count);
 257                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 258                 } else
 259                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 260         }
 261
 262         conn->datain_pdus_cnt++;
 263         return 0;
 264 }
 265
 266 /**
 267  * iscsi_solicit_data_init - initialize first Data-Out
 268  * @conn: iscsi connection
 269  * @ctask: scsi command task
 270  * @r2t: R2T info
 271  *
 272  * Notes:
 273  *      Initialize first Data-Out within this R2T sequence and finds
 274  *      proper data_offset within this SCSI command.
 275  *
 276  *      This function is called with connection lock taken.
 277  **/
 278 static void
 279 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 280                         struct iscsi_r2t_info *r2t)
 281 {
 282         struct iscsi_data *hdr;
 283         struct scsi_cmnd *sc = ctask->sc;
 284         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 285
 286         hdr = &r2t->dtask.hdr;
 287         memset(hdr, 0, sizeof(struct iscsi_data));
 288         hdr->ttt = r2t->ttt;
 289         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 290         r2t->solicit_datasn++;
 291         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 292         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 293         hdr->itt = ctask->hdr->itt;
 294         hdr->exp_statsn = r2t->exp_statsn;
 295         hdr->offset = cpu_to_be32(r2t->data_offset);
 296         if (r2t->data_length > conn->max_xmit_dlength) {
 297                 hton24(hdr->dlength, conn->max_xmit_dlength);
 298                 r2t->data_count = conn->max_xmit_dlength;
 299                 hdr->flags = 0;
 300         } else {
 301                 hton24(hdr->dlength, r2t->data_length);
 302                 r2t->data_count = r2t->data_length;
 303                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 304         }
 305         conn->dataout_pdus_cnt++;
 306
 307         r2t->sent = 0;
 308
 309         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 310                            sizeof(struct iscsi_hdr));
 311
 312         if (sc->use_sg) {
 313                 int i, sg_count = 0;
 314                 struct scatterlist *sg = sc->request_buffer;
 315
 316                 r2t->sg = NULL;
 317                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 318                         /* FIXME: prefetch ? */
 319                         if (sg_count + sg->length > r2t->data_offset) {
 320                                 int page_offset;
 321
 322                                 /* sg page found! */
 323
 324                                 /* offset within this page */
 325                                 page_offset = r2t->data_offset - sg_count;
 326
 327                                 /* fill in this buffer */
 328                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 329                                 r2t->sendbuf.sg.offset += page_offset;
 330                                 r2t->sendbuf.sg.length -= page_offset;
 331
 332                                 /* xmit logic will continue with next one */
 333                                 r2t->sg = sg + 1;
 334                                 break;
 335                         }
 336                         sg_count += sg->length;
 337                 }
 338                 BUG_ON(r2t->sg == NULL);
 339         } else
 340                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 341                             (char*)sc->request_buffer + r2t->data_offset,
 342                             r2t->data_count);
 343 }
 344
 345 /**
 346  * iscsi_r2t_rsp - iSCSI R2T Response processing
 347  * @conn: iscsi connection
 348  * @ctask: scsi command task
 349  **/
 350 static int
 351 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 352 {
 353         struct iscsi_r2t_info *r2t;
 354         struct iscsi_session *session = conn->session;
 355         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 356         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 357         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 358         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 359         int rc;
 360
 361         if (tcp_conn->in.datalen)
 362                 return ISCSI_ERR_DATALEN;
 363
 364         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 365                 return ISCSI_ERR_R2TSN;
 366
 367         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 368         if (rc)
 369                 return rc;
 370
 371         /* FIXME: use R2TSN to detect missing R2T */
 372
 373         /* fill-in new R2T associated with the task */
 374         spin_lock(&session->lock);
 375         if (!ctask->sc || ctask->mtask ||
 376              session->state != ISCSI_STATE_LOGGED_IN) {
 377                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 378                        "recovery...\n", ctask->itt);
 379                 spin_unlock(&session->lock);
 380                 return 0;
 381         }
 382
 383         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 384         BUG_ON(!rc);
 385
 386         r2t->exp_statsn = rhdr->statsn;
 387         r2t->data_length = be32_to_cpu(rhdr->data_length);
 388         if (r2t->data_length == 0 ||
 389             r2t->data_length > session->max_burst) {
 390                 spin_unlock(&session->lock);
 391                 return ISCSI_ERR_DATALEN;
 392         }
 393
 394         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 395         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 396                 spin_unlock(&session->lock);
 397                 return ISCSI_ERR_DATALEN;
 398         }
 399
 400         r2t->ttt = rhdr->ttt; /* no flip */
 401         r2t->solicit_datasn = 0;
 402
 403         iscsi_solicit_data_init(conn, ctask, r2t);
 404
 405         tcp_ctask->exp_r2tsn = r2tsn + 1;
 406         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 407         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 408         list_move_tail(&ctask->running, &conn->xmitqueue);
 409
 410         scsi_queue_work(session->host, &conn->xmitwork);
 411         conn->r2t_pdus_cnt++;
 412         spin_unlock(&session->lock);
 413
 414         return 0;
 415 }
 416
 417 static int
 418 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 419 {
 420         int rc = 0, opcode, ahslen;
 421         struct iscsi_hdr *hdr;
 422         struct iscsi_session *session = conn->session;
 423         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 424         uint32_t cdgst, rdgst = 0, itt;
 425
 426         hdr = tcp_conn->in.hdr;
 427
 428         /* verify PDU length */
 429         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 430         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 431                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 432                        tcp_conn->in.datalen, conn->max_recv_dlength);
 433                 return ISCSI_ERR_DATALEN;
 434         }
 435         tcp_conn->data_copied = 0;
 436
 437         /* read AHS */
 438         ahslen = hdr->hlength << 2;
 439         tcp_conn->in.offset += ahslen;
 440         tcp_conn->in.copy -= ahslen;
 441         if (tcp_conn->in.copy < 0) {
 442                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 443                        "%d bytes\n", ahslen);
 444                 return ISCSI_ERR_AHSLEN;
 445         }
 446
 447         /* calculate read padding */
 448         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 449         if (tcp_conn->in.padding) {
 450                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 451                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 452         }
 453
 454         if (conn->hdrdgst_en) {
 455                 struct scatterlist sg;
 456
 457                 sg_init_one(&sg, (u8 *)hdr,
 458                             sizeof(struct iscsi_hdr) + ahslen);
 459                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 460                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 461                                      ahslen);
 462                 if (cdgst != rdgst) {
 463                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 464                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 465                         return ISCSI_ERR_HDR_DGST;
 466                 }
 467         }
 468
 469         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 470         /* verify itt (itt encoding: age+cid+itt) */
 471         rc = iscsi_verify_itt(conn, hdr, &itt);
 472         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 473                 tcp_conn->in.datalen = 0; /* force drop */
 474                 return 0;
 475         } else if (rc)
 476                 return rc;
 477
 478         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 479                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 480                   ahslen, tcp_conn->in.datalen);
 481
 482         switch(opcode) {
 483         case ISCSI_OP_SCSI_DATA_IN:
 484                 tcp_conn->in.ctask = session->cmds[itt];
 485                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 486                 if (rc)
 487                         return rc;
 488                 /* fall through */
 489         case ISCSI_OP_SCSI_CMD_RSP:
 490                 tcp_conn->in.ctask = session->cmds[itt];
 491                 if (tcp_conn->in.datalen)
 492                         goto copy_hdr;
 493
 494                 spin_lock(&session->lock);
 495                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 496                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 497                 spin_unlock(&session->lock);
 498                 break;
 499         case ISCSI_OP_R2T:
 500                 tcp_conn->in.ctask = session->cmds[itt];
 501                 if (ahslen)
 502                         rc = ISCSI_ERR_AHSLEN;
 503                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 504                                                                 DMA_TO_DEVICE)
 505                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 506                 else
 507                         rc = ISCSI_ERR_PROTO;
 508                 break;
 509         case ISCSI_OP_LOGIN_RSP:
 510         case ISCSI_OP_TEXT_RSP:
 511         case ISCSI_OP_REJECT:
 512         case ISCSI_OP_ASYNC_EVENT:
 513                 /*
 514                  * It is possible that we could get a PDU with a buffer larger
 515                  * than 8K, but there are no targets that currently do this.
 516                  * For now we fail until we find a vendor that needs it
 517                  */
 518                 if (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH <
 519                     tcp_conn->in.datalen) {
 520                         printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
 521                               "but conn buffer is only %u (opcode %0x)\n",
 522                               tcp_conn->in.datalen,
 523                               DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, opcode);
 524                         rc = ISCSI_ERR_PROTO;
 525                         break;
 526                 }
 527
 528                 if (tcp_conn->in.datalen)
 529                         goto copy_hdr;
 530         /* fall through */
 531         case ISCSI_OP_LOGOUT_RSP:
 532         case ISCSI_OP_NOOP_IN:
 533         case ISCSI_OP_SCSI_TMFUNC_RSP:
 534                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 535                 break;
 536         default:
 537                 rc = ISCSI_ERR_BAD_OPCODE;
 538                 break;
 539         }
 540
 541         return rc;
 542
 543 copy_hdr:
 544         /*
 545          * if we did zero copy for the header but we will need multiple
 546          * skbs to complete the command then we have to copy the header
 547          * for later use
 548          */
 549         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
 550            (tcp_conn->in.datalen + tcp_conn->in.padding +
 551             (conn->datadgst_en ? 4 : 0))) {
 552                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 553                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 554                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 555                        sizeof(struct iscsi_hdr));
 556                 tcp_conn->in.hdr = &tcp_conn->hdr;
 557                 tcp_conn->in.zero_copy_hdr = 0;
 558         }
 559         return 0;
 560 }
 561
 562 /**
 563  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 564  * @conn: iscsi tcp connection
 565  * @ctask: scsi command task
 566  * @buf: buffer to copy to
 567  * @buf_size: size of buffer
 568  * @offset: offset within the buffer
 569  *
 570  * Notes:
 571  *      The function calls skb_copy_bits() and updates per-connection and
 572  *      per-cmd byte counters.
 573  *
 574  *      Read counters (in bytes):
 575  *
 576  *      conn->in.offset         offset within in progress SKB
 577  *      conn->in.copy           left to copy from in progress SKB
 578  *                              including padding
 579  *      conn->in.copied         copied already from in progress SKB
 580  *      conn->data_copied       copied already from in progress buffer
 581  *      ctask->sent             total bytes sent up to the MidLayer
 582  *      ctask->data_count       left to copy from in progress Data-In
 583  *      buf_left                left to copy from in progress buffer
 584  **/
 585 static inline int
 586 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 587                 void *buf, int buf_size, int offset)
 588 {
 589         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 590         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 591         int size = min(tcp_conn->in.copy, buf_left);
 592         int rc;
 593
 594         size = min(size, ctask->data_count);
 595
 596         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 597                size, tcp_conn->in.offset, tcp_conn->in.copied);
 598
 599         BUG_ON(size <= 0);
 600         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 601
 602         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 603                            (char*)buf + (offset + tcp_conn->data_copied), size);
 604         /* must fit into skb->len */
 605         BUG_ON(rc);
 606
 607         tcp_conn->in.offset += size;
 608         tcp_conn->in.copy -= size;
 609         tcp_conn->in.copied += size;
 610         tcp_conn->data_copied += size;
 611         tcp_ctask->sent += size;
 612         ctask->data_count -= size;
 613
 614         BUG_ON(tcp_conn->in.copy < 0);
 615         BUG_ON(ctask->data_count < 0);
 616
 617         if (buf_size != (tcp_conn->data_copied + offset)) {
 618                 if (!ctask->data_count) {
 619                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 620                         /* done with this PDU */
 621                         return buf_size - tcp_conn->data_copied;
 622                 }
 623                 return -EAGAIN;
 624         }
 625
 626         /* done with this buffer or with both - PDU and buffer */
 627         tcp_conn->data_copied = 0;
 628         return 0;
 629 }
 630
 631 /**
 632  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 633  * @conn: iscsi tcp connection
 634  *
 635  * Notes:
 636  *      The function calls skb_copy_bits() and updates per-connection
 637  *      byte counters.
 638  **/
 639 static inline int
 640 iscsi_tcp_copy(struct iscsi_conn *conn)
 641 {
 642         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 643         int buf_size = tcp_conn->in.datalen;
 644         int buf_left = buf_size - tcp_conn->data_copied;
 645         int size = min(tcp_conn->in.copy, buf_left);
 646         int rc;
 647
 648         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 649                size, tcp_conn->in.offset, tcp_conn->data_copied);
 650         BUG_ON(size <= 0);
 651
 652         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 653                            (char*)conn->data + tcp_conn->data_copied, size);
 654         BUG_ON(rc);
 655
 656         tcp_conn->in.offset += size;
 657         tcp_conn->in.copy -= size;
 658         tcp_conn->in.copied += size;
 659         tcp_conn->data_copied += size;
 660
 661         if (buf_size != tcp_conn->data_copied)
 662                 return -EAGAIN;
 663
 664         return 0;
 665 }
 666
 667 static inline void
 668 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 669                          struct scatterlist *sg, int offset, int length)
 670 {
 671         struct scatterlist temp;
 672
 673         memcpy(&temp, sg, sizeof(struct scatterlist));
 674         temp.offset = offset;
 675         temp.length = length;
 676         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 677 }
 678
 679 static void
 680 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 681 {
 682         struct scatterlist tmp;
 683
 684         sg_init_one(&tmp, buf, len);
 685         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 686 }
 687
 688 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 689 {
 690         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 691         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 692         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 693         struct scsi_cmnd *sc = ctask->sc;
 694         struct scatterlist *sg;
 695         int i, offset, rc = 0;
 696
 697         BUG_ON((void*)ctask != sc->SCp.ptr);
 698
 699         /*
 700          * copying Data-In into the Scsi_Cmnd
 701          */
 702         if (!sc->use_sg) {
 703                 i = ctask->data_count;
 704                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 705                                       sc->request_bufflen,
 706                                       tcp_ctask->data_offset);
 707                 if (rc == -EAGAIN)
 708                         return rc;
 709                 if (conn->datadgst_en)
 710                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 711                                                  i);
 712                 rc = 0;
 713                 goto done;
 714         }
 715
 716         offset = tcp_ctask->data_offset;
 717         sg = sc->request_buffer;
 718
 719         if (tcp_ctask->data_offset)
 720                 for (i = 0; i < tcp_ctask->sg_count; i++)
 721                         offset -= sg[i].length;
 722         /* we've passed through partial sg*/
 723         if (offset < 0)
 724                 offset = 0;
 725
 726         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 727                 char *dest;
 728
 729                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 730                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 731                                       sg[i].length, offset);
 732                 kunmap_atomic(dest, KM_SOFTIRQ0);
 733                 if (rc == -EAGAIN)
 734                         /* continue with the next SKB/PDU */
 735                         return rc;
 736                 if (!rc) {
 737                         if (conn->datadgst_en) {
 738                                 if (!offset)
 739                                         crypto_digest_update(
 740                                                         tcp_conn->data_rx_tfm,
 741                                                         &sg[i], 1);
 742                                 else
 743                                         partial_sg_digest_update(tcp_conn,
 744                                                         &sg[i],
 745                                                         sg[i].offset + offset,
 746                                                         sg[i].length - offset);
 747                         }
 748                         offset = 0;
 749                         tcp_ctask->sg_count++;
 750                 }
 751
 752                 if (!ctask->data_count) {
 753                         if (rc && conn->datadgst_en)
 754                                 /*
 755                                  * data-in is complete, but buffer not...
 756                                  */
 757                                 partial_sg_digest_update(tcp_conn, &sg[i],
 758                                                 sg[i].offset, sg[i].length-rc);
 759                         rc = 0;
 760                         break;
 761                 }
 762
 763                 if (!tcp_conn->in.copy)
 764                         return -EAGAIN;
 765         }
 766         BUG_ON(ctask->data_count);
 767
 768 done:
 769         /* check for non-exceptional status */
 770         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 771                 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
 772                            (long)sc, sc->result, ctask->itt,
 773                            tcp_conn->in.hdr->flags);
 774                 spin_lock(&conn->session->lock);
 775                 iscsi_tcp_cleanup_ctask(conn, ctask);
 776                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 777                 spin_unlock(&conn->session->lock);
 778         }
 779
 780         return rc;
 781 }
 782
 783 static int
 784 iscsi_data_recv(struct iscsi_conn *conn)
 785 {
 786         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 787         int rc = 0, opcode;
 788
 789         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 790         switch (opcode) {
 791         case ISCSI_OP_SCSI_DATA_IN:
 792                 rc = iscsi_scsi_data_in(conn);
 793                 break;
 794         case ISCSI_OP_SCSI_CMD_RSP:
 795                 spin_lock(&conn->session->lock);
 796                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 797                 spin_unlock(&conn->session->lock);
 798         case ISCSI_OP_TEXT_RSP:
 799         case ISCSI_OP_LOGIN_RSP:
 800         case ISCSI_OP_ASYNC_EVENT:
 801         case ISCSI_OP_REJECT:
 802                 /*
 803                  * Collect data segment to the connection's data
 804                  * placeholder
 805                  */
 806                 if (iscsi_tcp_copy(conn)) {
 807                         rc = -EAGAIN;
 808                         goto exit;
 809                 }
 810
 811                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
 812                                         tcp_conn->in.datalen);
 813                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 814                         iscsi_recv_digest_update(tcp_conn, conn->data,
 815                                                 tcp_conn->in.datalen);
 816                 break;
 817         default:
 818                 BUG_ON(1);
 819         }
 820 exit:
 821         return rc;
 822 }
 823
 824 /**
 825  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 826  * @rd_desc: read descriptor
 827  * @skb: socket buffer
 828  * @offset: offset in skb
 829  * @len: skb->len - offset
 830  **/
 831 static int
 832 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 833                 unsigned int offset, size_t len)
 834 {
 835         int rc;
 836         struct iscsi_conn *conn = rd_desc->arg.data;
 837         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 838         int processed;
 839         char pad[ISCSI_PAD_LEN];
 840         struct scatterlist sg;
 841
 842         /*
 843          * Save current SKB and its offset in the corresponding
 844          * connection context.
 845          */
 846         tcp_conn->in.copy = skb->len - offset;
 847         tcp_conn->in.offset = offset;
 848         tcp_conn->in.skb = skb;
 849         tcp_conn->in.len = tcp_conn->in.copy;
 850         BUG_ON(tcp_conn->in.copy <= 0);
 851         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 852
 853 more:
 854         tcp_conn->in.copied = 0;
 855         rc = 0;
 856
 857         if (unlikely(conn->suspend_rx)) {
 858                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 859                 return 0;
 860         }
 861
 862         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 863             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 864                 rc = iscsi_hdr_extract(tcp_conn);
 865                 if (rc) {
 866                        if (rc == -EAGAIN)
 867                                 goto nomore;
 868                        else {
 869                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 870                                 return 0;
 871                        }
 872                 }
 873
 874                 /*
 875                  * Verify and process incoming PDU header.
 876                  */
 877                 rc = iscsi_tcp_hdr_recv(conn);
 878                 if (!rc && tcp_conn->in.datalen) {
 879                         if (conn->datadgst_en) {
 880                                 BUG_ON(!tcp_conn->data_rx_tfm);
 881                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 882                         }
 883                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 884                 } else if (rc) {
 885                         iscsi_conn_failure(conn, rc);
 886                         return 0;
 887                 }
 888         }
 889
 890         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 891                 uint32_t recv_digest;
 892
 893                 debug_tcp("extra data_recv offset %d copy %d\n",
 894                           tcp_conn->in.offset, tcp_conn->in.copy);
 895                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 896                                 &recv_digest, 4);
 897                 tcp_conn->in.offset += 4;
 898                 tcp_conn->in.copy -= 4;
 899                 if (recv_digest != tcp_conn->in.datadgst) {
 900                         debug_tcp("iscsi_tcp: data digest error!"
 901                                   "0x%x != 0x%x\n", recv_digest,
 902                                   tcp_conn->in.datadgst);
 903                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 904                         return 0;
 905                 } else {
 906                         debug_tcp("iscsi_tcp: data digest match!"
 907                                   "0x%x == 0x%x\n", recv_digest,
 908                                   tcp_conn->in.datadgst);
 909                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 910                 }
 911         }
 912
 913         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 914            tcp_conn->in.copy) {
 915
 916                 debug_tcp("data_recv offset %d copy %d\n",
 917                        tcp_conn->in.offset, tcp_conn->in.copy);
 918
 919                 rc = iscsi_data_recv(conn);
 920                 if (rc) {
 921                         if (rc == -EAGAIN)
 922                                 goto again;
 923                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 924                         return 0;
 925                 }
 926                 tcp_conn->in.copy -= tcp_conn->in.padding;
 927                 tcp_conn->in.offset += tcp_conn->in.padding;
 928                 if (conn->datadgst_en) {
 929                         if (tcp_conn->in.padding) {
 930                                 debug_tcp("padding -> %d\n",
 931                                           tcp_conn->in.padding);
 932                                 memset(pad, 0, tcp_conn->in.padding);
 933                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 934                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 935                                                      &sg, 1);
 936                         }
 937                         crypto_digest_final(tcp_conn->data_rx_tfm,
 938                                             (u8 *) & tcp_conn->in.datadgst);
 939                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 940                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 941                 } else
 942                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 943         }
 944
 945         debug_tcp("f, processed %d from out of %d padding %d\n",
 946                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 947         BUG_ON(tcp_conn->in.offset - offset > len);
 948
 949         if (tcp_conn->in.offset - offset != len) {
 950                 debug_tcp("continue to process %d bytes\n",
 951                        (int)len - (tcp_conn->in.offset - offset));
 952                 goto more;
 953         }
 954
 955 nomore:
 956         processed = tcp_conn->in.offset - offset;
 957         BUG_ON(processed == 0);
 958         return processed;
 959
 960 again:
 961         processed = tcp_conn->in.offset - offset;
 962         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 963                   processed, (int)len, (int)rd_desc->count);
 964         BUG_ON(processed == 0);
 965         BUG_ON(processed > len);
 966
 967         conn->rxdata_octets += processed;
 968         return processed;
 969 }
 970
 971 static void
 972 iscsi_tcp_data_ready(struct sock *sk, int flag)
 973 {
 974         struct iscsi_conn *conn = sk->sk_user_data;
 975         read_descriptor_t rd_desc;
 976
 977         read_lock(&sk->sk_callback_lock);
 978
 979         /*
 980          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 981          * We set count to 1 because we want the network layer to
 982          * hand us all the skbs that are available. iscsi_tcp_data_recv
 983          * handled pdus that cross buffers or pdus that still need data.
 984          */
 985         rd_desc.arg.data = conn;
 986         rd_desc.count = 1;
 987         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 988
 989         read_unlock(&sk->sk_callback_lock);
 990 }
 991
 992 static void
 993 iscsi_tcp_state_change(struct sock *sk)
 994 {
 995         struct iscsi_tcp_conn *tcp_conn;
 996         struct iscsi_conn *conn;
 997         struct iscsi_session *session;
 998         void (*old_state_change)(struct sock *);
 999
1000         read_lock(&sk->sk_callback_lock);
1001
1002         conn = (struct iscsi_conn*)sk->sk_user_data;
1003         session = conn->session;
1004
1005         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1006              sk->sk_state == TCP_CLOSE) &&
1007             !atomic_read(&sk->sk_rmem_alloc)) {
1008                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1009                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1010         }
1011
1012         tcp_conn = conn->dd_data;
1013         old_state_change = tcp_conn->old_state_change;
1014
1015         read_unlock(&sk->sk_callback_lock);
1016
1017         old_state_change(sk);
1018 }
1019
1020 /**
1021  * iscsi_write_space - Called when more output buffer space is available
1022  * @sk: socket space is available for
1023  **/
1024 static void
1025 iscsi_write_space(struct sock *sk)
1026 {
1027         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1028         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1029
1030         tcp_conn->old_write_space(sk);
1031         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1032         scsi_queue_work(conn->session->host, &conn->xmitwork);
1033 }
1034
1035 static void
1036 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1037 {
1038         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1039         struct sock *sk = tcp_conn->sock->sk;
1040
1041         /* assign new callbacks */
1042         write_lock_bh(&sk->sk_callback_lock);
1043         sk->sk_user_data = conn;
1044         tcp_conn->old_data_ready = sk->sk_data_ready;
1045         tcp_conn->old_state_change = sk->sk_state_change;
1046         tcp_conn->old_write_space = sk->sk_write_space;
1047         sk->sk_data_ready = iscsi_tcp_data_ready;
1048         sk->sk_state_change = iscsi_tcp_state_change;
1049         sk->sk_write_space = iscsi_write_space;
1050         write_unlock_bh(&sk->sk_callback_lock);
1051 }
1052
1053 static void
1054 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1055 {
1056         struct sock *sk = tcp_conn->sock->sk;
1057
1058         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1059         write_lock_bh(&sk->sk_callback_lock);
1060         sk->sk_user_data    = NULL;
1061         sk->sk_data_ready   = tcp_conn->old_data_ready;
1062         sk->sk_state_change = tcp_conn->old_state_change;
1063         sk->sk_write_space  = tcp_conn->old_write_space;
1064         sk->sk_no_check  = 0;
1065         write_unlock_bh(&sk->sk_callback_lock);
1066 }
1067
1068 /**
1069  * iscsi_send - generic send routine
1070  * @sk: kernel's socket
1071  * @buf: buffer to write from
1072  * @size: actual size to write
1073  * @flags: socket's flags
1074  */
1075 static inline int
1076 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1077 {
1078         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1079         struct socket *sk = tcp_conn->sock;
1080         int offset = buf->sg.offset + buf->sent, res;
1081
1082         /*
1083          * if we got use_sg=0 or are sending something we kmallocd
1084          * then we did not have to do kmap (kmap returns page_address)
1085          *
1086          * if we got use_sg > 0, but had to drop down, we do not
1087          * set clustering so this should only happen for that
1088          * slab case.
1089          */
1090         if (buf->use_sendmsg)
1091                 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1092         else
1093                 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1094
1095         if (res >= 0) {
1096                 conn->txdata_octets += res;
1097                 buf->sent += res;
1098                 return res;
1099         }
1100
1101         tcp_conn->sendpage_failures_cnt++;
1102         if (res == -EAGAIN)
1103                 res = -ENOBUFS;
1104         else
1105                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1106         return res;
1107 }
1108
1109 /**
1110  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1111  * @conn: iscsi connection
1112  * @buf: buffer to write from
1113  * @datalen: lenght of data to be sent after the header
1114  *
1115  * Notes:
1116  *      (Tx, Fast Path)
1117  **/
1118 static inline int
1119 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1120 {
1121         int flags = 0; /* MSG_DONTWAIT; */
1122         int res, size;
1123
1124         size = buf->sg.length - buf->sent;
1125         BUG_ON(buf->sent + size > buf->sg.length);
1126         if (buf->sent + size != buf->sg.length || datalen)
1127                 flags |= MSG_MORE;
1128
1129         res = iscsi_send(conn, buf, size, flags);
1130         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1131         if (res >= 0) {
1132                 if (size != res)
1133                         return -EAGAIN;
1134                 return 0;
1135         }
1136
1137         return res;
1138 }
1139
1140 /**
1141  * iscsi_sendpage - send one page of iSCSI Data-Out.
1142  * @conn: iscsi connection
1143  * @buf: buffer to write from
1144  * @count: remaining data
1145  * @sent: number of bytes sent
1146  *
1147  * Notes:
1148  *      (Tx, Fast Path)
1149  **/
1150 static inline int
1151 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1152                int *count, int *sent)
1153 {
1154         int flags = 0; /* MSG_DONTWAIT; */
1155         int res, size;
1156
1157         size = buf->sg.length - buf->sent;
1158         BUG_ON(buf->sent + size > buf->sg.length);
1159         if (size > *count)
1160                 size = *count;
1161         if (buf->sent + size != buf->sg.length || *count != size)
1162                 flags |= MSG_MORE;
1163
1164         res = iscsi_send(conn, buf, size, flags);
1165         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1166                   size, buf->sent, *count, *sent, res);
1167         if (res >= 0) {
1168                 *count -= res;
1169                 *sent += res;
1170                 if (size != res)
1171                         return -EAGAIN;
1172                 return 0;
1173         }
1174
1175         return res;
1176 }
1177
1178 static inline void
1179 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1180                       struct iscsi_cmd_task *ctask)
1181 {
1182         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1183
1184         BUG_ON(!tcp_conn->data_tx_tfm);
1185         crypto_digest_init(tcp_conn->data_tx_tfm);
1186         tcp_ctask->digest_count = 4;
1187 }
1188
1189 static int
1190 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1191                         struct iscsi_buf *buf, uint32_t *digest, int final)
1192 {
1193         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1194         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1195         int rc = 0;
1196         int sent = 0;
1197
1198         if (final)
1199                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1200
1201         iscsi_buf_init_iov(buf, (char*)digest, 4);
1202         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1203         if (rc) {
1204                 tcp_ctask->datadigest = *digest;
1205                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1206         } else
1207                 tcp_ctask->digest_count = 4;
1208         return rc;
1209 }
1210
1211 /**
1212  * iscsi_solicit_data_cont - initialize next Data-Out
1213  * @conn: iscsi connection
1214  * @ctask: scsi command task
1215  * @r2t: R2T info
1216  * @left: bytes left to transfer
1217  *
1218  * Notes:
1219  *      Initialize next Data-Out within this R2T sequence and continue
1220  *      to process next Scatter-Gather element(if any) of this SCSI command.
1221  *
1222  *      Called under connection lock.
1223  **/
1224 static void
1225 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1226                         struct iscsi_r2t_info *r2t, int left)
1227 {
1228         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1229         struct iscsi_data *hdr;
1230         struct scsi_cmnd *sc = ctask->sc;
1231         int new_offset;
1232
1233         hdr = &r2t->dtask.hdr;
1234         memset(hdr, 0, sizeof(struct iscsi_data));
1235         hdr->ttt = r2t->ttt;
1236         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1237         r2t->solicit_datasn++;
1238         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1239         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1240         hdr->itt = ctask->hdr->itt;
1241         hdr->exp_statsn = r2t->exp_statsn;
1242         new_offset = r2t->data_offset + r2t->sent;
1243         hdr->offset = cpu_to_be32(new_offset);
1244         if (left > conn->max_xmit_dlength) {
1245                 hton24(hdr->dlength, conn->max_xmit_dlength);
1246                 r2t->data_count = conn->max_xmit_dlength;
1247         } else {
1248                 hton24(hdr->dlength, left);
1249                 r2t->data_count = left;
1250                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1251         }
1252         conn->dataout_pdus_cnt++;
1253
1254         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1255                            sizeof(struct iscsi_hdr));
1256
1257         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1258                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1259                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1260                 r2t->sg += 1;
1261         } else
1262                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1263                             (char*)sc->request_buffer + new_offset,
1264                             r2t->data_count);
1265 }
1266
1267 /**
1268  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1269  * @conn: iscsi connection
1270  * @ctask: scsi command task
1271  * @sc: scsi command
1272  **/
1273 static void
1274 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1275 {
1276         struct scsi_cmnd *sc = ctask->sc;
1277         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1278
1279         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1280
1281         tcp_ctask->sent = 0;
1282         tcp_ctask->sg_count = 0;
1283
1284         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1285                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1286                 tcp_ctask->exp_r2tsn = 0;
1287                 BUG_ON(ctask->total_length == 0);
1288
1289                 if (sc->use_sg) {
1290                         struct scatterlist *sg = sc->request_buffer;
1291
1292                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1293                                           &sg[tcp_ctask->sg_count++]);
1294                         tcp_ctask->sg = sg;
1295                         tcp_ctask->bad_sg = sg + sc->use_sg;
1296                 } else
1297                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1298                                            sc->request_buffer,
1299                                            sc->request_bufflen);
1300
1301                 if (ctask->imm_count)
1302                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1303
1304                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1305                 if (tcp_ctask->pad_count) {
1306                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1307                                                         tcp_ctask->pad_count;
1308                         debug_scsi("write padding %d bytes\n",
1309                                    tcp_ctask->pad_count);
1310                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1311                 }
1312
1313                 if (ctask->unsol_count)
1314                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1315                                                 XMSTATE_UNS_INIT;
1316
1317                 debug_scsi("cmd [itt 0x%x total %d imm_data %d "
1318                            "unsol count %d, unsol offset %d]\n",
1319                            ctask->itt, ctask->total_length, ctask->imm_count,
1320                            ctask->unsol_count, ctask->unsol_offset);
1321         } else
1322                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1323
1324         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1325                             sizeof(struct iscsi_hdr));
1326 }
1327
1328 /**
1329  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1330  * @conn: iscsi connection
1331  * @mtask: task management task
1332  *
1333  * Notes:
1334  *      The function can return -EAGAIN in which case caller must
1335  *      call it again later, or recover. '0' return code means successful
1336  *      xmit.
1337  *
1338  *      Management xmit state machine consists of two states:
1339  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1340  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1341  **/
1342 static int
1343 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1344 {
1345         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1346         int rc;
1347
1348         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1349                 conn->id, tcp_mtask->xmstate, mtask->itt);
1350
1351         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1352                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1353                 if (mtask->data_count)
1354                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1355                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1356                     conn->stop_stage != STOP_CONN_RECOVER &&
1357                     conn->hdrdgst_en)
1358                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1359                                         (u8*)tcp_mtask->hdrext);
1360                 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1361                                    mtask->data_count);
1362                 if (rc) {
1363                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1364                         if (mtask->data_count)
1365                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1366                         return rc;
1367                 }
1368         }
1369
1370         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1371                 BUG_ON(!mtask->data_count);
1372                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1373                 /* FIXME: implement.
1374                  * Virtual buffer could be spreaded across multiple pages...
1375                  */
1376                 do {
1377                         int rc;
1378
1379                         rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1380                                         &mtask->data_count, &tcp_mtask->sent);
1381                         if (rc) {
1382                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1383                                 return rc;
1384                         }
1385                 } while (mtask->data_count);
1386         }
1387
1388         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1389         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1390                 struct iscsi_session *session = conn->session;
1391
1392                 spin_lock_bh(&session->lock);
1393                 list_del(&conn->mtask->running);
1394                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1395                             sizeof(void*));
1396                 spin_unlock_bh(&session->lock);
1397         }
1398         return 0;
1399 }
1400
1401 static inline int
1402 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1403                      struct iscsi_tcp_cmd_task *tcp_ctask)
1404 {
1405         int rc;
1406
1407         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1408         if (conn->hdrdgst_en)
1409                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1410                                  (u8*)tcp_ctask->hdrext);
1411         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1412         if (!rc) {
1413                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1414                 return 0; /* wait for Data-In */
1415         }
1416         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1417         return rc;
1418 }
1419
1420 static inline int
1421 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1422                      struct iscsi_cmd_task *ctask)
1423 {
1424         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1425         int rc;
1426
1427         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1428         if (conn->hdrdgst_en)
1429                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1430                                  (u8*)tcp_ctask->hdrext);
1431         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1432         if (rc)
1433                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1434         return rc;
1435 }
1436
1437 static inline int
1438 handle_xmstate_data_digest(struct iscsi_conn *conn,
1439                            struct iscsi_cmd_task *ctask)
1440 {
1441         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1442         int rc;
1443
1444         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1445         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1446         rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1447                                     &tcp_ctask->datadigest, 0);
1448         if (rc) {
1449                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1450                 debug_tcp("resent data digest 0x%x fail!\n",
1451                           tcp_ctask->datadigest);
1452         }
1453
1454         return rc;
1455 }
1456
1457 static inline int
1458 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1459 {
1460         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1461         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1462         int rc;
1463
1464         BUG_ON(!ctask->imm_count);
1465         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1466
1467         if (conn->datadgst_en) {
1468                 iscsi_data_digest_init(tcp_conn, ctask);
1469                 tcp_ctask->immdigest = 0;
1470         }
1471
1472         for (;;) {
1473                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1474                                    &ctask->imm_count, &tcp_ctask->sent);
1475                 if (rc) {
1476                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1477                         if (conn->datadgst_en) {
1478                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1479                                                 (u8*)&tcp_ctask->immdigest);
1480                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1481                                           tcp_ctask->datadigest);
1482                         }
1483                         return rc;
1484                 }
1485                 if (conn->datadgst_en)
1486                         crypto_digest_update(tcp_conn->data_tx_tfm,
1487                                              &tcp_ctask->sendbuf.sg, 1);
1488
1489                 if (!ctask->imm_count)
1490                         break;
1491                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1492                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1493         }
1494
1495         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1496                 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1497                                             &tcp_ctask->immdigest, 1);
1498                 if (rc) {
1499                         debug_tcp("sending imm digest 0x%x fail!\n",
1500                                   tcp_ctask->immdigest);
1501                         return rc;
1502                 }
1503                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1504         }
1505
1506         return 0;
1507 }
1508
1509 static inline int
1510 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1511 {
1512         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1513         struct iscsi_data_task *dtask;
1514         int rc;
1515
1516         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1517         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1518                 dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1519                 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr);
1520                 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1521                                    sizeof(struct iscsi_hdr));
1522                 if (conn->hdrdgst_en)
1523                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1524                                         (u8*)dtask->hdrext);
1525                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1526         }
1527
1528         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1529         if (rc) {
1530                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1531                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1532                 return rc;
1533         }
1534
1535         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1536                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1537         return 0;
1538 }
1539
1540 static inline int
1541 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1542 {
1543         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1544         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1545         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1546         int rc;
1547
1548         BUG_ON(!ctask->data_count);
1549         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1550
1551         if (conn->datadgst_en) {
1552                 iscsi_data_digest_init(tcp_conn, ctask);
1553                 dtask->digest = 0;
1554         }
1555
1556         for (;;) {
1557                 int start = tcp_ctask->sent;
1558
1559                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1560                                    &ctask->data_count, &tcp_ctask->sent);
1561                 if (rc) {
1562                         ctask->unsol_count -= tcp_ctask->sent - start;
1563                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1564                         /* will continue with this ctask later.. */
1565                         if (conn->datadgst_en) {
1566                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1567                                                 (u8 *)&dtask->digest);
1568                                 debug_tcp("tx uns data fail 0x%x\n",
1569                                           dtask->digest);
1570                         }
1571                         return rc;
1572                 }
1573
1574                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1575                 ctask->unsol_count -= tcp_ctask->sent - start;
1576
1577                 /*
1578                  * XXX:we may run here with un-initial sendbuf.
1579                  * so pass it
1580                  */
1581                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1582                         crypto_digest_update(tcp_conn->data_tx_tfm,
1583                                              &tcp_ctask->sendbuf.sg, 1);
1584
1585                 if (!ctask->data_count)
1586                         break;
1587                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1588                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1589         }
1590         BUG_ON(ctask->unsol_count < 0);
1591
1592         /*
1593          * Done with the Data-Out. Next, check if we need
1594          * to send another unsolicited Data-Out.
1595          */
1596         if (ctask->unsol_count) {
1597                 if (conn->datadgst_en) {
1598                         rc = iscsi_digest_final_send(conn, ctask,
1599                                                     &dtask->digestbuf,
1600                                                     &dtask->digest, 1);
1601                         if (rc) {
1602                                 debug_tcp("send uns digest 0x%x fail\n",
1603                                           dtask->digest);
1604                                 return rc;
1605                         }
1606                         debug_tcp("sending uns digest 0x%x, more uns\n",
1607                                   dtask->digest);
1608                 }
1609                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1610                 return 1;
1611         }
1612
1613         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1614                 rc = iscsi_digest_final_send(conn, ctask,
1615                                             &dtask->digestbuf,
1616                                             &dtask->digest, 1);
1617                 if (rc) {
1618                         debug_tcp("send last uns digest 0x%x fail\n",
1619                                    dtask->digest);
1620                         return rc;
1621                 }
1622                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1623         }
1624
1625         return 0;
1626 }
1627
1628 static inline int
1629 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1630 {
1631         struct iscsi_session *session = conn->session;
1632         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1633         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1634         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1635         struct iscsi_data_task *dtask = &r2t->dtask;
1636         int left, rc;
1637
1638         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1639         tcp_ctask->dtask = dtask;
1640
1641         if (conn->datadgst_en) {
1642                 iscsi_data_digest_init(tcp_conn, ctask);
1643                 dtask->digest = 0;
1644         }
1645 solicit_again:
1646         /*
1647          * send Data-Out within this R2T sequence.
1648          */
1649         if (!r2t->data_count)
1650                 goto data_out_done;
1651
1652         rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
1653         if (rc) {
1654                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1655                 /* will continue with this ctask later.. */
1656                 if (conn->datadgst_en) {
1657                         crypto_digest_final(tcp_conn->data_tx_tfm,
1658                                           (u8 *)&dtask->digest);
1659                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1660                 }
1661                 return rc;
1662         }
1663
1664         BUG_ON(r2t->data_count < 0);
1665         if (conn->datadgst_en)
1666                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1667                                      1);
1668
1669         if (r2t->data_count) {
1670                 BUG_ON(ctask->sc->use_sg == 0);
1671                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1672                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1673                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1674                         r2t->sg += 1;
1675                 }
1676                 goto solicit_again;
1677         }
1678
1679 data_out_done:
1680         /*
1681          * Done with this Data-Out. Next, check if we have
1682          * to send another Data-Out for this R2T.
1683          */
1684         BUG_ON(r2t->data_length - r2t->sent < 0);
1685         left = r2t->data_length - r2t->sent;
1686         if (left) {
1687                 if (conn->datadgst_en) {
1688                         rc = iscsi_digest_final_send(conn, ctask,
1689                                                     &dtask->digestbuf,
1690                                                     &dtask->digest, 1);
1691                         if (rc) {
1692                                 debug_tcp("send r2t data digest 0x%x"
1693                                           "fail\n", dtask->digest);
1694                                 return rc;
1695                         }
1696                         debug_tcp("r2t data send digest 0x%x\n",
1697                                   dtask->digest);
1698                 }
1699                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1700                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1701                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1702                 return 1;
1703         }
1704
1705         /*
1706          * Done with this R2T. Check if there are more
1707          * outstanding R2Ts ready to be processed.
1708          */
1709         if (conn->datadgst_en) {
1710                 rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1711                                             &dtask->digest, 1);
1712                 if (rc) {
1713                         debug_tcp("send last r2t data digest 0x%x"
1714                                   "fail\n", dtask->digest);
1715                         return rc;
1716                 }
1717                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1718         }
1719
1720         tcp_ctask->r2t = NULL;
1721         spin_lock_bh(&session->lock);
1722         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1723         spin_unlock_bh(&session->lock);
1724         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1725                 tcp_ctask->r2t = r2t;
1726                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1727                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1728                 return 1;
1729         }
1730
1731         return 0;
1732 }
1733
1734 static inline int
1735 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1736 {
1737         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1738         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1739         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1740         int sent = 0, rc;
1741
1742         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1743         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1744                             tcp_ctask->pad_count);
1745         rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1746                            &sent);
1747         if (rc) {
1748                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1749                 return rc;
1750         }
1751
1752         if (conn->datadgst_en) {
1753                 crypto_digest_update(tcp_conn->data_tx_tfm,
1754                                      &tcp_ctask->sendbuf.sg, 1);
1755                 /* imm data? */
1756                 if (!dtask) {
1757                         rc = iscsi_digest_final_send(conn, ctask,
1758                                                     &tcp_ctask->immbuf,
1759                                                     &tcp_ctask->immdigest, 1);
1760                         if (rc) {
1761                                 debug_tcp("send padding digest 0x%x"
1762                                           "fail!\n", tcp_ctask->immdigest);
1763                                 return rc;
1764                         }
1765                         debug_tcp("done with padding, digest 0x%x\n",
1766                                   tcp_ctask->datadigest);
1767                 } else {
1768                         rc = iscsi_digest_final_send(conn, ctask,
1769                                                     &dtask->digestbuf,
1770                                                     &dtask->digest, 1);
1771                         if (rc) {
1772                                 debug_tcp("send padding digest 0x%x"
1773                                           "fail\n", dtask->digest);
1774                                 return rc;
1775                         }
1776                         debug_tcp("done with padding, digest 0x%x\n",
1777                                   dtask->digest);
1778                 }
1779         }
1780
1781         return 0;
1782 }
1783
1784 static int
1785 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1786 {
1787         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1788         int rc = 0;
1789
1790         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1791                 conn->id, tcp_ctask->xmstate, ctask->itt);
1792
1793         /*
1794          * serialize with TMF AbortTask
1795          */
1796         if (ctask->mtask)
1797                 return rc;
1798
1799         if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1800                 return handle_xmstate_r_hdr(conn, tcp_ctask);
1801
1802         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1803                 rc = handle_xmstate_w_hdr(conn, ctask);
1804                 if (rc)
1805                         return rc;
1806         }
1807
1808         /* XXX: for data digest xmit recover */
1809         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1810                 rc = handle_xmstate_data_digest(conn, ctask);
1811                 if (rc)
1812                         return rc;
1813         }
1814
1815         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1816                 rc = handle_xmstate_imm_data(conn, ctask);
1817                 if (rc)
1818                         return rc;
1819         }
1820
1821         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1822                 BUG_ON(!ctask->unsol_count);
1823                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1824 unsolicit_head_again:
1825                 rc = handle_xmstate_uns_hdr(conn, ctask);
1826                 if (rc)
1827                         return rc;
1828         }
1829
1830         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1831                 rc = handle_xmstate_uns_data(conn, ctask);
1832                 if (rc == 1)
1833                         goto unsolicit_head_again;
1834                 else if (rc)
1835                         return rc;
1836                 goto done;
1837         }
1838
1839         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1840                 struct iscsi_r2t_info *r2t;
1841
1842                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1843                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1844                 if (!tcp_ctask->r2t)
1845                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1846                                     sizeof(void*));
1847 solicit_head_again:
1848                 r2t = tcp_ctask->r2t;
1849                 if (conn->hdrdgst_en)
1850                         iscsi_hdr_digest(conn, &r2t->headbuf,
1851                                         (u8*)r2t->dtask.hdrext);
1852                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1853                 if (rc) {
1854                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1855                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1856                         return rc;
1857                 }
1858
1859                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1860                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1861                         r2t->sent);
1862         }
1863
1864         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1865                 rc = handle_xmstate_sol_data(conn, ctask);
1866                 if (rc == 1)
1867                         goto solicit_head_again;
1868                 if (rc)
1869                         return rc;
1870         }
1871
1872 done:
1873         /*
1874          * Last thing to check is whether we need to send write
1875          * padding. Note that we check for xmstate equality, not just the bit.
1876          */
1877         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1878                 rc = handle_xmstate_w_pad(conn, ctask);
1879
1880         return rc;
1881 }
1882
1883 static struct iscsi_cls_conn *
1884 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1885 {
1886         struct iscsi_conn *conn;
1887         struct iscsi_cls_conn *cls_conn;
1888         struct iscsi_tcp_conn *tcp_conn;
1889
1890         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1891         if (!cls_conn)
1892                 return NULL;
1893         conn = cls_conn->dd_data;
1894         /*
1895          * due to strange issues with iser these are not set
1896          * in iscsi_conn_setup
1897          */
1898         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1899
1900         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1901         if (!tcp_conn)
1902                 goto tcp_conn_alloc_fail;
1903
1904         conn->dd_data = tcp_conn;
1905         tcp_conn->iscsi_conn = conn;
1906         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1907         /* initial operational parameters */
1908         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1909
1910         return cls_conn;
1911
1912 tcp_conn_alloc_fail:
1913         iscsi_conn_teardown(cls_conn);
1914         return NULL;
1915 }
1916
1917 static void
1918 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1919 {
1920         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1921
1922         if (!tcp_conn->sock)
1923                 return;
1924
1925         sock_hold(tcp_conn->sock->sk);
1926         iscsi_conn_restore_callbacks(tcp_conn);
1927         sock_put(tcp_conn->sock->sk);
1928
1929         sock_release(tcp_conn->sock);
1930         tcp_conn->sock = NULL;
1931         conn->recv_lock = NULL;
1932 }
1933
1934 static void
1935 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1936 {
1937         struct iscsi_conn *conn = cls_conn->dd_data;
1938         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1939         int digest = 0;
1940
1941         if (conn->hdrdgst_en || conn->datadgst_en)
1942                 digest = 1;
1943
1944         iscsi_tcp_release_conn(conn);
1945         iscsi_conn_teardown(cls_conn);
1946
1947         /* now free tcp_conn */
1948         if (digest) {
1949                 if (tcp_conn->tx_tfm)
1950                         crypto_free_tfm(tcp_conn->tx_tfm);
1951                 if (tcp_conn->rx_tfm)
1952                         crypto_free_tfm(tcp_conn->rx_tfm);
1953                 if (tcp_conn->data_tx_tfm)
1954                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1955                 if (tcp_conn->data_rx_tfm)
1956                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1957         }
1958
1959         kfree(tcp_conn);
1960 }
1961
1962 static void
1963 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1964 {
1965         struct iscsi_conn *conn = cls_conn->dd_data;
1966
1967         iscsi_conn_stop(cls_conn, flag);
1968         iscsi_tcp_release_conn(conn);
1969 }
1970
1971 static int
1972 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1973                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1974                     int is_leading)
1975 {
1976         struct iscsi_conn *conn = cls_conn->dd_data;
1977         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1978         struct sock *sk;
1979         struct socket *sock;
1980         int err;
1981
1982         /* lookup for existing socket */
1983         sock = sockfd_lookup((int)transport_eph, &err);
1984         if (!sock) {
1985                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1986                 return -EEXIST;
1987         }
1988
1989         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1990         if (err)
1991                 return err;
1992
1993         /* bind iSCSI connection and socket */
1994         tcp_conn->sock = sock;
1995
1996         /* setup Socket parameters */
1997         sk = sock->sk;
1998         sk->sk_reuse = 1;
1999         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2000         sk->sk_allocation = GFP_ATOMIC;
2001
2002         /* FIXME: disable Nagle's algorithm */
2003
2004         /*
2005          * Intercept TCP callbacks for sendfile like receive
2006          * processing.
2007          */
2008         conn->recv_lock = &sk->sk_callback_lock;
2009         iscsi_conn_set_callbacks(conn);
2010         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2011         /*
2012          * set receive state machine into initial state
2013          */
2014         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2015
2016         return 0;
2017 }
2018
2019 /* called with host lock */
2020 static void
2021 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2022                     char *data, uint32_t data_size)
2023 {
2024         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2025
2026         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2027                            sizeof(struct iscsi_hdr));
2028         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2029         tcp_mtask->sent = 0;
2030
2031         if (mtask->data_count)
2032                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2033                                     mtask->data_count);
2034 }
2035
2036 static int
2037 iscsi_r2tpool_alloc(struct iscsi_session *session)
2038 {
2039         int i;
2040         int cmd_i;
2041
2042         /*
2043          * initialize per-task: R2T pool and xmit queue
2044          */
2045         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2046                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2047                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2048
2049                 /*
2050                  * pre-allocated x4 as much r2ts to handle race when
2051                  * target acks DataOut faster than we data_xmit() queues
2052                  * could replenish r2tqueue.
2053                  */
2054
2055                 /* R2T pool */
2056                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2057                                     (void***)&tcp_ctask->r2ts,
2058                                     sizeof(struct iscsi_r2t_info))) {
2059                         goto r2t_alloc_fail;
2060                 }
2061
2062                 /* R2T xmit queue */
2063                 tcp_ctask->r2tqueue = kfifo_alloc(
2064                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2065                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2066                         iscsi_pool_free(&tcp_ctask->r2tpool,
2067                                         (void**)tcp_ctask->r2ts);
2068                         goto r2t_alloc_fail;
2069                 }
2070         }
2071
2072         return 0;
2073
2074 r2t_alloc_fail:
2075         for (i = 0; i < cmd_i; i++) {
2076                 struct iscsi_cmd_task *ctask = session->cmds[i];
2077                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2078
2079                 kfifo_free(tcp_ctask->r2tqueue);
2080                 iscsi_pool_free(&tcp_ctask->r2tpool,
2081                                 (void**)tcp_ctask->r2ts);
2082         }
2083         return -ENOMEM;
2084 }
2085
2086 static void
2087 iscsi_r2tpool_free(struct iscsi_session *session)
2088 {
2089         int i;
2090
2091         for (i = 0; i < session->cmds_max; i++) {
2092                 struct iscsi_cmd_task *ctask = session->cmds[i];
2093                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2094
2095                 kfifo_free(tcp_ctask->r2tqueue);
2096                 iscsi_pool_free(&tcp_ctask->r2tpool,
2097                                 (void**)tcp_ctask->r2ts);
2098         }
2099 }
2100
2101 static int
2102 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2103                      char *buf, int buflen)
2104 {
2105         struct iscsi_conn *conn = cls_conn->dd_data;
2106         struct iscsi_session *session = conn->session;
2107         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2108         int value;
2109
2110         switch(param) {
2111         case ISCSI_PARAM_HDRDGST_EN:
2112                 iscsi_set_param(cls_conn, param, buf, buflen);
2113                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2114                 if (conn->hdrdgst_en) {
2115                         tcp_conn->hdr_size += sizeof(__u32);
2116                         if (!tcp_conn->tx_tfm)
2117                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2118                                                                     0);
2119                         if (!tcp_conn->tx_tfm)
2120                                 return -ENOMEM;
2121                         if (!tcp_conn->rx_tfm)
2122                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2123                                                                     0);
2124                         if (!tcp_conn->rx_tfm) {
2125                                 crypto_free_tfm(tcp_conn->tx_tfm);
2126                                 return -ENOMEM;
2127                         }
2128                 } else {
2129                         if (tcp_conn->tx_tfm)
2130                                 crypto_free_tfm(tcp_conn->tx_tfm);
2131                         if (tcp_conn->rx_tfm)
2132                                 crypto_free_tfm(tcp_conn->rx_tfm);
2133                 }
2134                 break;
2135         case ISCSI_PARAM_DATADGST_EN:
2136                 iscsi_set_param(cls_conn, param, buf, buflen);
2137                 if (conn->datadgst_en) {
2138                         if (!tcp_conn->data_tx_tfm)
2139                                 tcp_conn->data_tx_tfm =
2140                                     crypto_alloc_tfm("crc32c", 0);
2141                         if (!tcp_conn->data_tx_tfm)
2142                                 return -ENOMEM;
2143                         if (!tcp_conn->data_rx_tfm)
2144                                 tcp_conn->data_rx_tfm =
2145                                     crypto_alloc_tfm("crc32c", 0);
2146                         if (!tcp_conn->data_rx_tfm) {
2147                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2148                                 return -ENOMEM;
2149                         }
2150                 } else {
2151                         if (tcp_conn->data_tx_tfm)
2152                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2153                         if (tcp_conn->data_rx_tfm)
2154                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2155                 }
2156                 tcp_conn->sendpage = conn->datadgst_en ?
2157                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2158                 break;
2159         case ISCSI_PARAM_MAX_R2T:
2160                 sscanf(buf, "%d", &value);
2161                 if (session->max_r2t == roundup_pow_of_two(value))
2162                         break;
2163                 iscsi_r2tpool_free(session);
2164                 iscsi_set_param(cls_conn, param, buf, buflen);
2165                 if (session->max_r2t & (session->max_r2t - 1))
2166                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2167                 if (iscsi_r2tpool_alloc(session))
2168                         return -ENOMEM;
2169                 break;
2170         default:
2171                 return iscsi_set_param(cls_conn, param, buf, buflen);
2172         }
2173
2174         return 0;
2175 }
2176
2177 static int
2178 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2179                          enum iscsi_param param, char *buf)
2180 {
2181         struct iscsi_conn *conn = cls_conn->dd_data;
2182         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2183         struct inet_sock *inet;
2184         struct ipv6_pinfo *np;
2185         struct sock *sk;
2186         int len;
2187
2188         switch(param) {
2189         case ISCSI_PARAM_CONN_PORT:
2190                 mutex_lock(&conn->xmitmutex);
2191                 if (!tcp_conn->sock) {
2192                         mutex_unlock(&conn->xmitmutex);
2193                         return -EINVAL;
2194                 }
2195
2196                 inet = inet_sk(tcp_conn->sock->sk);
2197                 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2198                 mutex_unlock(&conn->xmitmutex);
2199                 break;
2200         case ISCSI_PARAM_CONN_ADDRESS:
2201                 mutex_lock(&conn->xmitmutex);
2202                 if (!tcp_conn->sock) {
2203                         mutex_unlock(&conn->xmitmutex);
2204                         return -EINVAL;
2205                 }
2206
2207                 sk = tcp_conn->sock->sk;
2208                 if (sk->sk_family == PF_INET) {
2209                         inet = inet_sk(sk);
2210                         len = sprintf(buf, "%u.%u.%u.%u\n",
2211                                       NIPQUAD(inet->daddr));
2212                 } else {
2213                         np = inet6_sk(sk);
2214                         len = sprintf(buf,
2215                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2216                                 NIP6(np->daddr));
2217                 }
2218                 mutex_unlock(&conn->xmitmutex);
2219                 break;
2220         default:
2221                 return iscsi_conn_get_param(cls_conn, param, buf);
2222         }
2223
2224         return len;
2225 }
2226
2227 static void
2228 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2229 {
2230         struct iscsi_conn *conn = cls_conn->dd_data;
2231         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2232
2233         stats->txdata_octets = conn->txdata_octets;
2234         stats->rxdata_octets = conn->rxdata_octets;
2235         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2236         stats->dataout_pdus = conn->dataout_pdus_cnt;
2237         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2238         stats->datain_pdus = conn->datain_pdus_cnt;
2239         stats->r2t_pdus = conn->r2t_pdus_cnt;
2240         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2241         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2242         stats->custom_length = 3;
2243         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2244         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2245         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2246         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2247         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2248         stats->custom[2].value = conn->eh_abort_cnt;
2249 }
2250
2251 static struct iscsi_cls_session *
2252 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2253                          struct scsi_transport_template *scsit,
2254                          uint32_t initial_cmdsn, uint32_t *hostno)
2255 {
2256         struct iscsi_cls_session *cls_session;
2257         struct iscsi_session *session;
2258         uint32_t hn;
2259         int cmd_i;
2260
2261         cls_session = iscsi_session_setup(iscsit, scsit,
2262                                          sizeof(struct iscsi_tcp_cmd_task),
2263                                          sizeof(struct iscsi_tcp_mgmt_task),
2264                                          initial_cmdsn, &hn);
2265         if (!cls_session)
2266                 return NULL;
2267         *hostno = hn;
2268
2269         session = class_to_transport_session(cls_session);
2270         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2271                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2272                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2273
2274                 ctask->hdr = &tcp_ctask->hdr;
2275         }
2276
2277         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2278                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2279                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2280
2281                 mtask->hdr = &tcp_mtask->hdr;
2282         }
2283
2284         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2285                 goto r2tpool_alloc_fail;
2286
2287         return cls_session;
2288
2289 r2tpool_alloc_fail:
2290         iscsi_session_teardown(cls_session);
2291         return NULL;
2292 }
2293
2294 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2295 {
2296         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2297         iscsi_session_teardown(cls_session);
2298 }
2299
2300 static struct scsi_host_template iscsi_sht = {
2301         .name                   = "iSCSI Initiator over TCP/IP",
2302         .queuecommand           = iscsi_queuecommand,
2303         .change_queue_depth     = iscsi_change_queue_depth,
2304         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2305         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2306         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2307         .eh_abort_handler       = iscsi_eh_abort,
2308         .eh_host_reset_handler  = iscsi_eh_host_reset,
2309         .use_clustering         = DISABLE_CLUSTERING,
2310         .proc_name              = "iscsi_tcp",
2311         .this_id                = -1,
2312 };
2313
2314 static struct iscsi_transport iscsi_tcp_transport = {
2315         .owner                  = THIS_MODULE,
2316         .name                   = "tcp",
2317         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2318                                   | CAP_DATADGST,
2319         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2320                                   ISCSI_MAX_XMIT_DLENGTH |
2321                                   ISCSI_HDRDGST_EN |
2322                                   ISCSI_DATADGST_EN |
2323                                   ISCSI_INITIAL_R2T_EN |
2324                                   ISCSI_MAX_R2T |
2325                                   ISCSI_IMM_DATA_EN |
2326                                   ISCSI_FIRST_BURST |
2327                                   ISCSI_MAX_BURST |
2328                                   ISCSI_PDU_INORDER_EN |
2329                                   ISCSI_DATASEQ_INORDER_EN |
2330                                   ISCSI_ERL |
2331                                   ISCSI_CONN_PORT |
2332                                   ISCSI_CONN_ADDRESS |
2333                                   ISCSI_EXP_STATSN |
2334                                   ISCSI_PERSISTENT_PORT |
2335                                   ISCSI_PERSISTENT_ADDRESS |
2336                                   ISCSI_TARGET_NAME |
2337                                   ISCSI_TPGT,
2338         .host_template          = &iscsi_sht,
2339         .conndata_size          = sizeof(struct iscsi_conn),
2340         .max_conn               = 1,
2341         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2342         /* session management */
2343         .create_session         = iscsi_tcp_session_create,
2344         .destroy_session        = iscsi_tcp_session_destroy,
2345         /* connection management */
2346         .create_conn            = iscsi_tcp_conn_create,
2347         .bind_conn              = iscsi_tcp_conn_bind,
2348         .destroy_conn           = iscsi_tcp_conn_destroy,
2349         .set_param              = iscsi_conn_set_param,
2350         .get_conn_param         = iscsi_tcp_conn_get_param,
2351         .get_session_param      = iscsi_session_get_param,
2352         .start_conn             = iscsi_conn_start,
2353         .stop_conn              = iscsi_tcp_conn_stop,
2354         /* IO */
2355         .send_pdu               = iscsi_conn_send_pdu,
2356         .get_stats              = iscsi_conn_get_stats,
2357         .init_cmd_task          = iscsi_tcp_cmd_init,
2358         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2359         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2360         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2361         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2362         /* recovery */
2363         .session_recovery_timedout = iscsi_session_recovery_timedout,
2364 };
2365
2366 static int __init
2367 iscsi_tcp_init(void)
2368 {
2369         if (iscsi_max_lun < 1) {
2370                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2371                        iscsi_max_lun);
2372                 return -EINVAL;
2373         }
2374         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2375
2376         if (!iscsi_register_transport(&iscsi_tcp_transport))
2377                 return -ENODEV;
2378
2379         return 0;
2380 }
2381
2382 static void __exit
2383 iscsi_tcp_exit(void)
2384 {
2385         iscsi_unregister_transport(&iscsi_tcp_transport);
2386 }
2387
2388 module_init(iscsi_tcp_init);
2389 module_exit(iscsi_tcp_exit);