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 #define ISCSI_TCP_VERSION "1.0-595"
  47
  48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION(ISCSI_TCP_VERSION);
  53 /* #define DEBUG_TCP */
  54 #define DEBUG_ASSERT
  55
  56 #ifdef DEBUG_TCP
  57 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  58 #else
  59 #define debug_tcp(fmt...)
  60 #endif
  61
  62 #ifndef DEBUG_ASSERT
  63 #ifdef BUG_ON
  64 #undef BUG_ON
  65 #endif
  66 #define BUG_ON(expr)
  67 #endif
  68
  69 static unsigned int iscsi_max_lun = 512;
  70 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  71
  72 static inline void
  73 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  74 {
  75         ibuf->sg.page = virt_to_page(vbuf);
  76         ibuf->sg.offset = offset_in_page(vbuf);
  77         ibuf->sg.length = size;
  78         ibuf->sent = 0;
  79         ibuf->use_sendmsg = 1;
  80 }
  81
  82 static inline void
  83 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  84 {
  85         ibuf->sg.page = sg->page;
  86         ibuf->sg.offset = sg->offset;
  87         ibuf->sg.length = sg->length;
  88         /*
  89          * Fastpath: sg element fits into single page
  90          */
  91         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  92                 ibuf->use_sendmsg = 0;
  93         else
  94                 ibuf->use_sendmsg = 1;
  95         ibuf->sent = 0;
  96 }
  97
  98 static inline int
  99 iscsi_buf_left(struct iscsi_buf *ibuf)
 100 {
 101         int rc;
 102
 103         rc = ibuf->sg.length - ibuf->sent;
 104         BUG_ON(rc < 0);
 105         return rc;
 106 }
 107
 108 static inline void
 109 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 110                  u8* crc)
 111 {
 112         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 113
 114         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 115         buf->sg.length += sizeof(uint32_t);
 116 }
 117
 118 static inline int
 119 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 120 {
 121         struct sk_buff *skb = tcp_conn->in.skb;
 122
 123         tcp_conn->in.zero_copy_hdr = 0;
 124
 125         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 126             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 127                 /*
 128                  * Zero-copy PDU Header: using connection context
 129                  * to store header pointer.
 130                  */
 131                 if (skb_shinfo(skb)->frag_list == NULL &&
 132                     !skb_shinfo(skb)->nr_frags) {
 133                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 134                                 ((char*)skb->data + tcp_conn->in.offset);
 135                         tcp_conn->in.zero_copy_hdr = 1;
 136                 } else {
 137                         /* ignoring return code since we checked
 138                          * in.copy before */
 139                         skb_copy_bits(skb, tcp_conn->in.offset,
 140                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 141                         tcp_conn->in.hdr = &tcp_conn->hdr;
 142                 }
 143                 tcp_conn->in.offset += tcp_conn->hdr_size;
 144                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 145         } else {
 146                 int hdr_remains;
 147                 int copylen;
 148
 149                 /*
 150                  * PDU header scattered across SKB's,
 151                  * copying it... This'll happen quite rarely.
 152                  */
 153
 154                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 155                         tcp_conn->in.hdr_offset = 0;
 156
 157                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 158                 BUG_ON(hdr_remains <= 0);
 159
 160                 copylen = min(tcp_conn->in.copy, hdr_remains);
 161                 skb_copy_bits(skb, tcp_conn->in.offset,
 162                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 163                         copylen);
 164
 165                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 166                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 167                        tcp_conn->in.offset, tcp_conn->in.copy);
 168
 169                 tcp_conn->in.offset += copylen;
 170                 tcp_conn->in.copy -= copylen;
 171                 if (copylen < hdr_remains)  {
 172                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 173                         tcp_conn->in.hdr_offset += copylen;
 174                         return -EAGAIN;
 175                 }
 176                 tcp_conn->in.hdr = &tcp_conn->hdr;
 177                 tcp_conn->discontiguous_hdr_cnt++;
 178                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 179         }
 180
 181         return 0;
 182 }
 183
 184 /*
 185  * must be called with session lock
 186  */
 187 static void
 188 __iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 191         struct scsi_cmnd *sc;
 192
 193         sc = ctask->sc;
 194         if (unlikely(!sc))
 195                 return;
 196
 197         tcp_ctask->xmstate = XMSTATE_IDLE;
 198         tcp_ctask->r2t = NULL;
 199 }
 200
 201 /**
 202  * iscsi_data_rsp - SCSI Data-In Response processing
 203  * @conn: iscsi connection
 204  * @ctask: scsi command task
 205  **/
 206 static int
 207 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 208 {
 209         int rc;
 210         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 211         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 212         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 213         struct iscsi_session *session = conn->session;
 214         int datasn = be32_to_cpu(rhdr->datasn);
 215
 216         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 217         if (rc)
 218                 return rc;
 219         /*
 220          * setup Data-In byte counter (gets decremented..)
 221          */
 222         ctask->data_count = tcp_conn->in.datalen;
 223
 224         if (tcp_conn->in.datalen == 0)
 225                 return 0;
 226
 227         if (ctask->datasn != datasn)
 228                 return ISCSI_ERR_DATASN;
 229
 230         ctask->datasn++;
 231
 232         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 233         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 234                 return ISCSI_ERR_DATA_OFFSET;
 235
 236         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 237                 struct scsi_cmnd *sc = ctask->sc;
 238
 239                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 240                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 241                         int res_count = be32_to_cpu(rhdr->residual_count);
 242
 243                         if (res_count > 0 &&
 244                             res_count <= sc->request_bufflen) {
 245                                 sc->resid = res_count;
 246                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 247                         } else
 248                                 sc->result = (DID_BAD_TARGET << 16) |
 249                                         rhdr->cmd_status;
 250                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 251                         sc->resid = be32_to_cpu(rhdr->residual_count);
 252                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 253                 } else
 254                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 255         }
 256
 257         conn->datain_pdus_cnt++;
 258         return 0;
 259 }
 260
 261 /**
 262  * iscsi_solicit_data_init - initialize first Data-Out
 263  * @conn: iscsi connection
 264  * @ctask: scsi command task
 265  * @r2t: R2T info
 266  *
 267  * Notes:
 268  *      Initialize first Data-Out within this R2T sequence and finds
 269  *      proper data_offset within this SCSI command.
 270  *
 271  *      This function is called with connection lock taken.
 272  **/
 273 static void
 274 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 275                         struct iscsi_r2t_info *r2t)
 276 {
 277         struct iscsi_data *hdr;
 278         struct scsi_cmnd *sc = ctask->sc;
 279         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 280
 281         hdr = &r2t->dtask.hdr;
 282         memset(hdr, 0, sizeof(struct iscsi_data));
 283         hdr->ttt = r2t->ttt;
 284         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 285         r2t->solicit_datasn++;
 286         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 287         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 288         hdr->itt = ctask->hdr->itt;
 289         hdr->exp_statsn = r2t->exp_statsn;
 290         hdr->offset = cpu_to_be32(r2t->data_offset);
 291         if (r2t->data_length > conn->max_xmit_dlength) {
 292                 hton24(hdr->dlength, conn->max_xmit_dlength);
 293                 r2t->data_count = conn->max_xmit_dlength;
 294                 hdr->flags = 0;
 295         } else {
 296                 hton24(hdr->dlength, r2t->data_length);
 297                 r2t->data_count = r2t->data_length;
 298                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 299         }
 300         conn->dataout_pdus_cnt++;
 301
 302         r2t->sent = 0;
 303
 304         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 305                            sizeof(struct iscsi_hdr));
 306
 307         if (sc->use_sg) {
 308                 int i, sg_count = 0;
 309                 struct scatterlist *sg = sc->request_buffer;
 310
 311                 r2t->sg = NULL;
 312                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 313                         /* FIXME: prefetch ? */
 314                         if (sg_count + sg->length > r2t->data_offset) {
 315                                 int page_offset;
 316
 317                                 /* sg page found! */
 318
 319                                 /* offset within this page */
 320                                 page_offset = r2t->data_offset - sg_count;
 321
 322                                 /* fill in this buffer */
 323                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 324                                 r2t->sendbuf.sg.offset += page_offset;
 325                                 r2t->sendbuf.sg.length -= page_offset;
 326
 327                                 /* xmit logic will continue with next one */
 328                                 r2t->sg = sg + 1;
 329                                 break;
 330                         }
 331                         sg_count += sg->length;
 332                 }
 333                 BUG_ON(r2t->sg == NULL);
 334         } else
 335                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 336                             (char*)sc->request_buffer + r2t->data_offset,
 337                             r2t->data_count);
 338 }
 339
 340 /**
 341  * iscsi_r2t_rsp - iSCSI R2T Response processing
 342  * @conn: iscsi connection
 343  * @ctask: scsi command task
 344  **/
 345 static int
 346 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 347 {
 348         struct iscsi_r2t_info *r2t;
 349         struct iscsi_session *session = conn->session;
 350         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 351         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 352         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 353         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 354         int rc;
 355
 356         if (tcp_conn->in.datalen)
 357                 return ISCSI_ERR_DATALEN;
 358
 359         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 360                 return ISCSI_ERR_R2TSN;
 361
 362         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 363         if (rc)
 364                 return rc;
 365
 366         /* FIXME: use R2TSN to detect missing R2T */
 367
 368         /* fill-in new R2T associated with the task */
 369         spin_lock(&session->lock);
 370         if (!ctask->sc || ctask->mtask ||
 371              session->state != ISCSI_STATE_LOGGED_IN) {
 372                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 373                        "recovery...\n", ctask->itt);
 374                 spin_unlock(&session->lock);
 375                 return 0;
 376         }
 377         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 378         BUG_ON(!rc);
 379
 380         r2t->exp_statsn = rhdr->statsn;
 381         r2t->data_length = be32_to_cpu(rhdr->data_length);
 382         if (r2t->data_length == 0 ||
 383             r2t->data_length > session->max_burst) {
 384                 spin_unlock(&session->lock);
 385                 return ISCSI_ERR_DATALEN;
 386         }
 387
 388         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 389         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 390                 spin_unlock(&session->lock);
 391                 return ISCSI_ERR_DATALEN;
 392         }
 393
 394         r2t->ttt = rhdr->ttt; /* no flip */
 395         r2t->solicit_datasn = 0;
 396
 397         iscsi_solicit_data_init(conn, ctask, r2t);
 398
 399         tcp_ctask->exp_r2tsn = r2tsn + 1;
 400         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 401         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 402         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 403
 404         scsi_queue_work(session->host, &conn->xmitwork);
 405         conn->r2t_pdus_cnt++;
 406         spin_unlock(&session->lock);
 407
 408         return 0;
 409 }
 410
 411 static int
 412 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 413 {
 414         int rc = 0, opcode, ahslen;
 415         struct iscsi_hdr *hdr;
 416         struct iscsi_session *session = conn->session;
 417         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 418         uint32_t cdgst, rdgst = 0, itt;
 419
 420         hdr = tcp_conn->in.hdr;
 421
 422         /* verify PDU length */
 423         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 424         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 425                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 426                        tcp_conn->in.datalen, conn->max_recv_dlength);
 427                 return ISCSI_ERR_DATALEN;
 428         }
 429         tcp_conn->data_copied = 0;
 430
 431         /* read AHS */
 432         ahslen = hdr->hlength << 2;
 433         tcp_conn->in.offset += ahslen;
 434         tcp_conn->in.copy -= ahslen;
 435         if (tcp_conn->in.copy < 0) {
 436                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 437                        "%d bytes\n", ahslen);
 438                 return ISCSI_ERR_AHSLEN;
 439         }
 440
 441         /* calculate read padding */
 442         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 443         if (tcp_conn->in.padding) {
 444                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 445                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 446         }
 447
 448         if (conn->hdrdgst_en) {
 449                 struct scatterlist sg;
 450
 451                 sg_init_one(&sg, (u8 *)hdr,
 452                             sizeof(struct iscsi_hdr) + ahslen);
 453                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 454                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 455                                      ahslen);
 456                 if (cdgst != rdgst) {
 457                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 458                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 459                         return ISCSI_ERR_HDR_DGST;
 460                 }
 461         }
 462
 463         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 464         /* verify itt (itt encoding: age+cid+itt) */
 465         rc = iscsi_verify_itt(conn, hdr, &itt);
 466         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 467                 tcp_conn->in.datalen = 0; /* force drop */
 468                 return 0;
 469         } else if (rc)
 470                 return rc;
 471
 472         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 473                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 474                   ahslen, tcp_conn->in.datalen);
 475
 476         switch(opcode) {
 477         case ISCSI_OP_SCSI_DATA_IN:
 478                 tcp_conn->in.ctask = session->cmds[itt];
 479                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 480                 /* fall through */
 481         case ISCSI_OP_SCSI_CMD_RSP:
 482                 tcp_conn->in.ctask = session->cmds[itt];
 483                 if (tcp_conn->in.datalen)
 484                         goto copy_hdr;
 485
 486                 spin_lock(&session->lock);
 487                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 488                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 489                 spin_unlock(&session->lock);
 490                 break;
 491         case ISCSI_OP_R2T:
 492                 tcp_conn->in.ctask = session->cmds[itt];
 493                 if (ahslen)
 494                         rc = ISCSI_ERR_AHSLEN;
 495                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 496                                                                 DMA_TO_DEVICE)
 497                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 498                 else
 499                         rc = ISCSI_ERR_PROTO;
 500                 break;
 501         case ISCSI_OP_LOGIN_RSP:
 502         case ISCSI_OP_TEXT_RSP:
 503         case ISCSI_OP_LOGOUT_RSP:
 504         case ISCSI_OP_NOOP_IN:
 505         case ISCSI_OP_REJECT:
 506         case ISCSI_OP_ASYNC_EVENT:
 507                 if (tcp_conn->in.datalen)
 508                         goto copy_hdr;
 509         /* fall through */
 510         case ISCSI_OP_SCSI_TMFUNC_RSP:
 511                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 512                 break;
 513         default:
 514                 rc = ISCSI_ERR_BAD_OPCODE;
 515                 break;
 516         }
 517
 518         return rc;
 519
 520 copy_hdr:
 521         /*
 522          * if we did zero copy for the header but we will need multiple
 523          * skbs to complete the command then we have to copy the header
 524          * for later use
 525          */
 526         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
 527            (tcp_conn->in.datalen + tcp_conn->in.padding +
 528             (conn->datadgst_en ? 4 : 0))) {
 529                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 530                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 531                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 532                        sizeof(struct iscsi_hdr));
 533                 tcp_conn->in.hdr = &tcp_conn->hdr;
 534                 tcp_conn->in.zero_copy_hdr = 0;
 535         }
 536         return 0;
 537 }
 538
 539 /**
 540  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 541  * @conn: iscsi tcp connection
 542  * @ctask: scsi command task
 543  * @buf: buffer to copy to
 544  * @buf_size: size of buffer
 545  * @offset: offset within the buffer
 546  *
 547  * Notes:
 548  *      The function calls skb_copy_bits() and updates per-connection and
 549  *      per-cmd byte counters.
 550  *
 551  *      Read counters (in bytes):
 552  *
 553  *      conn->in.offset         offset within in progress SKB
 554  *      conn->in.copy           left to copy from in progress SKB
 555  *                              including padding
 556  *      conn->in.copied         copied already from in progress SKB
 557  *      conn->data_copied       copied already from in progress buffer
 558  *      ctask->sent             total bytes sent up to the MidLayer
 559  *      ctask->data_count       left to copy from in progress Data-In
 560  *      buf_left                left to copy from in progress buffer
 561  **/
 562 static inline int
 563 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 564                 void *buf, int buf_size, int offset)
 565 {
 566         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 567         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 568         int size = min(tcp_conn->in.copy, buf_left);
 569         int rc;
 570
 571         size = min(size, ctask->data_count);
 572
 573         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 574                size, tcp_conn->in.offset, tcp_conn->in.copied);
 575
 576         BUG_ON(size <= 0);
 577         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 578
 579         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 580                            (char*)buf + (offset + tcp_conn->data_copied), size);
 581         /* must fit into skb->len */
 582         BUG_ON(rc);
 583
 584         tcp_conn->in.offset += size;
 585         tcp_conn->in.copy -= size;
 586         tcp_conn->in.copied += size;
 587         tcp_conn->data_copied += size;
 588         tcp_ctask->sent += size;
 589         ctask->data_count -= size;
 590
 591         BUG_ON(tcp_conn->in.copy < 0);
 592         BUG_ON(ctask->data_count < 0);
 593
 594         if (buf_size != (tcp_conn->data_copied + offset)) {
 595                 if (!ctask->data_count) {
 596                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 597                         /* done with this PDU */
 598                         return buf_size - tcp_conn->data_copied;
 599                 }
 600                 return -EAGAIN;
 601         }
 602
 603         /* done with this buffer or with both - PDU and buffer */
 604         tcp_conn->data_copied = 0;
 605         return 0;
 606 }
 607
 608 /**
 609  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 610  * @conn: iscsi tcp connection
 611  *
 612  * Notes:
 613  *      The function calls skb_copy_bits() and updates per-connection
 614  *      byte counters.
 615  **/
 616 static inline int
 617 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 618 {
 619         void *buf = tcp_conn->data;
 620         int buf_size = tcp_conn->in.datalen;
 621         int buf_left = buf_size - tcp_conn->data_copied;
 622         int size = min(tcp_conn->in.copy, buf_left);
 623         int rc;
 624
 625         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 626                size, tcp_conn->in.offset, tcp_conn->data_copied);
 627         BUG_ON(size <= 0);
 628
 629         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 630                            (char*)buf + tcp_conn->data_copied, size);
 631         BUG_ON(rc);
 632
 633         tcp_conn->in.offset += size;
 634         tcp_conn->in.copy -= size;
 635         tcp_conn->in.copied += size;
 636         tcp_conn->data_copied += size;
 637
 638         if (buf_size != tcp_conn->data_copied)
 639                 return -EAGAIN;
 640
 641         return 0;
 642 }
 643
 644 static inline void
 645 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 646                          struct scatterlist *sg, int offset, int length)
 647 {
 648         struct scatterlist temp;
 649
 650         memcpy(&temp, sg, sizeof(struct scatterlist));
 651         temp.offset = offset;
 652         temp.length = length;
 653         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 654 }
 655
 656 static void
 657 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 658 {
 659         struct scatterlist tmp;
 660
 661         sg_init_one(&tmp, buf, len);
 662         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 663 }
 664
 665 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 666 {
 667         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 668         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 669         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 670         struct scsi_cmnd *sc = ctask->sc;
 671         struct scatterlist *sg;
 672         int i, offset, rc = 0;
 673
 674         BUG_ON((void*)ctask != sc->SCp.ptr);
 675
 676         /*
 677          * copying Data-In into the Scsi_Cmnd
 678          */
 679         if (!sc->use_sg) {
 680                 i = ctask->data_count;
 681                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 682                                       sc->request_bufflen,
 683                                       tcp_ctask->data_offset);
 684                 if (rc == -EAGAIN)
 685                         return rc;
 686                 if (conn->datadgst_en)
 687                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 688                                                  i);
 689                 rc = 0;
 690                 goto done;
 691         }
 692
 693         offset = tcp_ctask->data_offset;
 694         sg = sc->request_buffer;
 695
 696         if (tcp_ctask->data_offset)
 697                 for (i = 0; i < tcp_ctask->sg_count; i++)
 698                         offset -= sg[i].length;
 699         /* we've passed through partial sg*/
 700         if (offset < 0)
 701                 offset = 0;
 702
 703         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 704                 char *dest;
 705
 706                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 707                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 708                                       sg[i].length, offset);
 709                 kunmap_atomic(dest, KM_SOFTIRQ0);
 710                 if (rc == -EAGAIN)
 711                         /* continue with the next SKB/PDU */
 712                         return rc;
 713                 if (!rc) {
 714                         if (conn->datadgst_en) {
 715                                 if (!offset)
 716                                         crypto_digest_update(
 717                                                         tcp_conn->data_rx_tfm,
 718                                                         &sg[i], 1);
 719                                 else
 720                                         partial_sg_digest_update(tcp_conn,
 721                                                         &sg[i],
 722                                                         sg[i].offset + offset,
 723                                                         sg[i].length - offset);
 724                         }
 725                         offset = 0;
 726                         tcp_ctask->sg_count++;
 727                 }
 728
 729                 if (!ctask->data_count) {
 730                         if (rc && conn->datadgst_en)
 731                                 /*
 732                                  * data-in is complete, but buffer not...
 733                                  */
 734                                 partial_sg_digest_update(tcp_conn, &sg[i],
 735                                                 sg[i].offset, sg[i].length-rc);
 736                         rc = 0;
 737                         break;
 738                 }
 739
 740                 if (!tcp_conn->in.copy)
 741                         return -EAGAIN;
 742         }
 743         BUG_ON(ctask->data_count);
 744
 745 done:
 746         /* check for non-exceptional status */
 747         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 748                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 749                            (long)sc, sc->result, ctask->itt);
 750                 spin_lock(&conn->session->lock);
 751                 __iscsi_ctask_cleanup(conn, ctask);
 752                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 753                 spin_unlock(&conn->session->lock);
 754         }
 755
 756         return rc;
 757 }
 758
 759 static int
 760 iscsi_data_recv(struct iscsi_conn *conn)
 761 {
 762         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 763         int rc = 0, opcode;
 764
 765         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 766         switch (opcode) {
 767         case ISCSI_OP_SCSI_DATA_IN:
 768                 rc = iscsi_scsi_data_in(conn);
 769                 break;
 770         case ISCSI_OP_SCSI_CMD_RSP:
 771                 spin_lock(&conn->session->lock);
 772                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 773                 spin_unlock(&conn->session->lock);
 774         case ISCSI_OP_TEXT_RSP:
 775         case ISCSI_OP_LOGIN_RSP:
 776         case ISCSI_OP_NOOP_IN:
 777         case ISCSI_OP_ASYNC_EVENT:
 778         case ISCSI_OP_REJECT:
 779                 /*
 780                  * Collect data segment to the connection's data
 781                  * placeholder
 782                  */
 783                 if (iscsi_tcp_copy(tcp_conn)) {
 784                         rc = -EAGAIN;
 785                         goto exit;
 786                 }
 787
 788                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 789                                         tcp_conn->in.datalen);
 790                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 791                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 792                                                 tcp_conn->in.datalen);
 793                 break;
 794         default:
 795                 BUG_ON(1);
 796         }
 797 exit:
 798         return rc;
 799 }
 800
 801 /**
 802  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 803  * @rd_desc: read descriptor
 804  * @skb: socket buffer
 805  * @offset: offset in skb
 806  * @len: skb->len - offset
 807  **/
 808 static int
 809 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 810                 unsigned int offset, size_t len)
 811 {
 812         int rc;
 813         struct iscsi_conn *conn = rd_desc->arg.data;
 814         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 815         int processed;
 816         char pad[ISCSI_PAD_LEN];
 817         struct scatterlist sg;
 818
 819         /*
 820          * Save current SKB and its offset in the corresponding
 821          * connection context.
 822          */
 823         tcp_conn->in.copy = skb->len - offset;
 824         tcp_conn->in.offset = offset;
 825         tcp_conn->in.skb = skb;
 826         tcp_conn->in.len = tcp_conn->in.copy;
 827         BUG_ON(tcp_conn->in.copy <= 0);
 828         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 829
 830 more:
 831         tcp_conn->in.copied = 0;
 832         rc = 0;
 833
 834         if (unlikely(conn->suspend_rx)) {
 835                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 836                 return 0;
 837         }
 838
 839         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 840             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 841                 rc = iscsi_hdr_extract(tcp_conn);
 842                 if (rc) {
 843                        if (rc == -EAGAIN)
 844                                 goto nomore;
 845                        else {
 846                                 iscsi_conn_failure(conn, rc);
 847                                 return 0;
 848                        }
 849                 }
 850
 851                 /*
 852                  * Verify and process incoming PDU header.
 853                  */
 854                 rc = iscsi_tcp_hdr_recv(conn);
 855                 if (!rc && tcp_conn->in.datalen) {
 856                         if (conn->datadgst_en) {
 857                                 BUG_ON(!tcp_conn->data_rx_tfm);
 858                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 859                         }
 860                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 861                 } else if (rc) {
 862                         iscsi_conn_failure(conn, rc);
 863                         return 0;
 864                 }
 865         }
 866
 867         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 868                 uint32_t recv_digest;
 869
 870                 debug_tcp("extra data_recv offset %d copy %d\n",
 871                           tcp_conn->in.offset, tcp_conn->in.copy);
 872                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 873                                 &recv_digest, 4);
 874                 tcp_conn->in.offset += 4;
 875                 tcp_conn->in.copy -= 4;
 876                 if (recv_digest != tcp_conn->in.datadgst) {
 877                         debug_tcp("iscsi_tcp: data digest error!"
 878                                   "0x%x != 0x%x\n", recv_digest,
 879                                   tcp_conn->in.datadgst);
 880                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 881                         return 0;
 882                 } else {
 883                         debug_tcp("iscsi_tcp: data digest match!"
 884                                   "0x%x == 0x%x\n", recv_digest,
 885                                   tcp_conn->in.datadgst);
 886                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 887                 }
 888         }
 889
 890         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 891            tcp_conn->in.copy) {
 892
 893                 debug_tcp("data_recv offset %d copy %d\n",
 894                        tcp_conn->in.offset, tcp_conn->in.copy);
 895
 896                 rc = iscsi_data_recv(conn);
 897                 if (rc) {
 898                         if (rc == -EAGAIN)
 899                                 goto again;
 900                         iscsi_conn_failure(conn, rc);
 901                         return 0;
 902                 }
 903                 tcp_conn->in.copy -= tcp_conn->in.padding;
 904                 tcp_conn->in.offset += tcp_conn->in.padding;
 905                 if (conn->datadgst_en) {
 906                         if (tcp_conn->in.padding) {
 907                                 debug_tcp("padding -> %d\n",
 908                                           tcp_conn->in.padding);
 909                                 memset(pad, 0, tcp_conn->in.padding);
 910                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 911                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 912                                                      &sg, 1);
 913                         }
 914                         crypto_digest_final(tcp_conn->data_rx_tfm,
 915                                             (u8 *) & tcp_conn->in.datadgst);
 916                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 917                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 918                 } else
 919                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 920         }
 921
 922         debug_tcp("f, processed %d from out of %d padding %d\n",
 923                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 924         BUG_ON(tcp_conn->in.offset - offset > len);
 925
 926         if (tcp_conn->in.offset - offset != len) {
 927                 debug_tcp("continue to process %d bytes\n",
 928                        (int)len - (tcp_conn->in.offset - offset));
 929                 goto more;
 930         }
 931
 932 nomore:
 933         processed = tcp_conn->in.offset - offset;
 934         BUG_ON(processed == 0);
 935         return processed;
 936
 937 again:
 938         processed = tcp_conn->in.offset - offset;
 939         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 940                   processed, (int)len, (int)rd_desc->count);
 941         BUG_ON(processed == 0);
 942         BUG_ON(processed > len);
 943
 944         conn->rxdata_octets += processed;
 945         return processed;
 946 }
 947
 948 static void
 949 iscsi_tcp_data_ready(struct sock *sk, int flag)
 950 {
 951         struct iscsi_conn *conn = sk->sk_user_data;
 952         read_descriptor_t rd_desc;
 953
 954         read_lock(&sk->sk_callback_lock);
 955
 956         /*
 957          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 958          * We set count to 1 because we want the network layer to
 959          * hand us all the skbs that are available. iscsi_tcp_data_recv
 960          * handled pdus that cross buffers or pdus that still need data.
 961          */
 962         rd_desc.arg.data = conn;
 963         rd_desc.count = 1;
 964         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 965
 966         read_unlock(&sk->sk_callback_lock);
 967 }
 968
 969 static void
 970 iscsi_tcp_state_change(struct sock *sk)
 971 {
 972         struct iscsi_tcp_conn *tcp_conn;
 973         struct iscsi_conn *conn;
 974         struct iscsi_session *session;
 975         void (*old_state_change)(struct sock *);
 976
 977         read_lock(&sk->sk_callback_lock);
 978
 979         conn = (struct iscsi_conn*)sk->sk_user_data;
 980         session = conn->session;
 981
 982         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 983              sk->sk_state == TCP_CLOSE) &&
 984             !atomic_read(&sk->sk_rmem_alloc)) {
 985                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 986                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 987         }
 988
 989         tcp_conn = conn->dd_data;
 990         old_state_change = tcp_conn->old_state_change;
 991
 992         read_unlock(&sk->sk_callback_lock);
 993
 994         old_state_change(sk);
 995 }
 996
 997 /**
 998  * iscsi_write_space - Called when more output buffer space is available
 999  * @sk: socket space is available for
1000  **/
1001 static void
1002 iscsi_write_space(struct sock *sk)
1003 {
1004         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1005         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1006
1007         tcp_conn->old_write_space(sk);
1008         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1009         scsi_queue_work(conn->session->host, &conn->xmitwork);
1010 }
1011
1012 static void
1013 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1014 {
1015         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1016         struct sock *sk = tcp_conn->sock->sk;
1017
1018         /* assign new callbacks */
1019         write_lock_bh(&sk->sk_callback_lock);
1020         sk->sk_user_data = conn;
1021         tcp_conn->old_data_ready = sk->sk_data_ready;
1022         tcp_conn->old_state_change = sk->sk_state_change;
1023         tcp_conn->old_write_space = sk->sk_write_space;
1024         sk->sk_data_ready = iscsi_tcp_data_ready;
1025         sk->sk_state_change = iscsi_tcp_state_change;
1026         sk->sk_write_space = iscsi_write_space;
1027         write_unlock_bh(&sk->sk_callback_lock);
1028 }
1029
1030 static void
1031 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1032 {
1033         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1034         struct sock *sk = tcp_conn->sock->sk;
1035
1036         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1037         write_lock_bh(&sk->sk_callback_lock);
1038         sk->sk_user_data    = NULL;
1039         sk->sk_data_ready   = tcp_conn->old_data_ready;
1040         sk->sk_state_change = tcp_conn->old_state_change;
1041         sk->sk_write_space  = tcp_conn->old_write_space;
1042         sk->sk_no_check  = 0;
1043         write_unlock_bh(&sk->sk_callback_lock);
1044 }
1045
1046 /**
1047  * iscsi_send - generic send routine
1048  * @sk: kernel's socket
1049  * @buf: buffer to write from
1050  * @size: actual size to write
1051  * @flags: socket's flags
1052  */
1053 static inline int
1054 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1055 {
1056         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1057         struct socket *sk = tcp_conn->sock;
1058         int offset = buf->sg.offset + buf->sent, res;
1059
1060         /*
1061          * if we got use_sg=0 or are sending something we kmallocd
1062          * then we did not have to do kmap (kmap returns page_address)
1063          *
1064          * if we got use_sg > 0, but had to drop down, we do not
1065          * set clustering so this should only happen for that
1066          * slab case.
1067          */
1068         if (buf->use_sendmsg)
1069                 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1070         else
1071                 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1072
1073         if (res >= 0) {
1074                 conn->txdata_octets += res;
1075                 buf->sent += res;
1076                 return res;
1077         }
1078
1079         tcp_conn->sendpage_failures_cnt++;
1080         if (res == -EAGAIN)
1081                 res = -ENOBUFS;
1082         else
1083                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1084         return res;
1085 }
1086
1087 /**
1088  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1089  * @conn: iscsi connection
1090  * @buf: buffer to write from
1091  * @datalen: lenght of data to be sent after the header
1092  *
1093  * Notes:
1094  *      (Tx, Fast Path)
1095  **/
1096 static inline int
1097 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1098 {
1099         int flags = 0; /* MSG_DONTWAIT; */
1100         int res, size;
1101
1102         size = buf->sg.length - buf->sent;
1103         BUG_ON(buf->sent + size > buf->sg.length);
1104         if (buf->sent + size != buf->sg.length || datalen)
1105                 flags |= MSG_MORE;
1106
1107         res = iscsi_send(conn, buf, size, flags);
1108         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1109         if (res >= 0) {
1110                 if (size != res)
1111                         return -EAGAIN;
1112                 return 0;
1113         }
1114
1115         return res;
1116 }
1117
1118 /**
1119  * iscsi_sendpage - send one page of iSCSI Data-Out.
1120  * @conn: iscsi connection
1121  * @buf: buffer to write from
1122  * @count: remaining data
1123  * @sent: number of bytes sent
1124  *
1125  * Notes:
1126  *      (Tx, Fast Path)
1127  **/
1128 static inline int
1129 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1130                int *count, int *sent)
1131 {
1132         int flags = 0; /* MSG_DONTWAIT; */
1133         int res, size;
1134
1135         size = buf->sg.length - buf->sent;
1136         BUG_ON(buf->sent + size > buf->sg.length);
1137         if (size > *count)
1138                 size = *count;
1139         if (buf->sent + size != buf->sg.length || *count != size)
1140                 flags |= MSG_MORE;
1141
1142         res = iscsi_send(conn, buf, size, flags);
1143         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1144                   size, buf->sent, *count, *sent, res);
1145         if (res >= 0) {
1146                 *count -= res;
1147                 *sent += res;
1148                 if (size != res)
1149                         return -EAGAIN;
1150                 return 0;
1151         }
1152
1153         return res;
1154 }
1155
1156 static inline void
1157 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1158                       struct iscsi_cmd_task *ctask)
1159 {
1160         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1161
1162         BUG_ON(!tcp_conn->data_tx_tfm);
1163         crypto_digest_init(tcp_conn->data_tx_tfm);
1164         tcp_ctask->digest_count = 4;
1165 }
1166
1167 static int
1168 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1169                         struct iscsi_buf *buf, uint32_t *digest, int final)
1170 {
1171         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1172         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1173         int rc = 0;
1174         int sent = 0;
1175
1176         if (final)
1177                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1178
1179         iscsi_buf_init_iov(buf, (char*)digest, 4);
1180         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1181         if (rc) {
1182                 tcp_ctask->datadigest = *digest;
1183                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1184         } else
1185                 tcp_ctask->digest_count = 4;
1186         return rc;
1187 }
1188
1189 /**
1190  * iscsi_solicit_data_cont - initialize next Data-Out
1191  * @conn: iscsi connection
1192  * @ctask: scsi command task
1193  * @r2t: R2T info
1194  * @left: bytes left to transfer
1195  *
1196  * Notes:
1197  *      Initialize next Data-Out within this R2T sequence and continue
1198  *      to process next Scatter-Gather element(if any) of this SCSI command.
1199  *
1200  *      Called under connection lock.
1201  **/
1202 static void
1203 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1204                         struct iscsi_r2t_info *r2t, int left)
1205 {
1206         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1207         struct iscsi_data *hdr;
1208         struct scsi_cmnd *sc = ctask->sc;
1209         int new_offset;
1210
1211         hdr = &r2t->dtask.hdr;
1212         memset(hdr, 0, sizeof(struct iscsi_data));
1213         hdr->ttt = r2t->ttt;
1214         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1215         r2t->solicit_datasn++;
1216         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1217         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1218         hdr->itt = ctask->hdr->itt;
1219         hdr->exp_statsn = r2t->exp_statsn;
1220         new_offset = r2t->data_offset + r2t->sent;
1221         hdr->offset = cpu_to_be32(new_offset);
1222         if (left > conn->max_xmit_dlength) {
1223                 hton24(hdr->dlength, conn->max_xmit_dlength);
1224                 r2t->data_count = conn->max_xmit_dlength;
1225         } else {
1226                 hton24(hdr->dlength, left);
1227                 r2t->data_count = left;
1228                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1229         }
1230         conn->dataout_pdus_cnt++;
1231
1232         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1233                            sizeof(struct iscsi_hdr));
1234
1235         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1236                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1237                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1238                 r2t->sg += 1;
1239         } else
1240                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1241                             (char*)sc->request_buffer + new_offset,
1242                             r2t->data_count);
1243 }
1244
1245 static void
1246 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1247 {
1248         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1249         struct iscsi_data_task *dtask;
1250
1251         dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1252         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1253                                       tcp_ctask->r2t_data_count);
1254         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1255                            sizeof(struct iscsi_hdr));
1256 }
1257
1258 /**
1259  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1260  * @conn: iscsi connection
1261  * @ctask: scsi command task
1262  * @sc: scsi command
1263  **/
1264 static void
1265 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1266 {
1267         struct scsi_cmnd *sc = ctask->sc;
1268         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1269
1270         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1271
1272         tcp_ctask->sent = 0;
1273         tcp_ctask->sg_count = 0;
1274
1275         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1276                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1277                 tcp_ctask->exp_r2tsn = 0;
1278                 BUG_ON(ctask->total_length == 0);
1279
1280                 if (sc->use_sg) {
1281                         struct scatterlist *sg = sc->request_buffer;
1282
1283                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1284                                           &sg[tcp_ctask->sg_count++]);
1285                         tcp_ctask->sg = sg;
1286                         tcp_ctask->bad_sg = sg + sc->use_sg;
1287                 } else
1288                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1289                                            sc->request_buffer,
1290                                            sc->request_bufflen);
1291
1292                 if (ctask->imm_count)
1293                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1294
1295                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1296                 if (tcp_ctask->pad_count) {
1297                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1298                                                         tcp_ctask->pad_count;
1299                         debug_scsi("write padding %d bytes\n",
1300                                    tcp_ctask->pad_count);
1301                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1302                 }
1303
1304                 if (ctask->unsol_count)
1305                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1306                                                 XMSTATE_UNS_INIT;
1307                 tcp_ctask->r2t_data_count = ctask->total_length -
1308                                     ctask->imm_count -
1309                                     ctask->unsol_count;
1310
1311                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1312                            "r2t_data %d]\n",
1313                            ctask->itt, ctask->total_length, ctask->imm_count,
1314                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1315         } else
1316                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1317
1318         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1319                             sizeof(struct iscsi_hdr));
1320 }
1321
1322 /**
1323  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1324  * @conn: iscsi connection
1325  * @mtask: task management task
1326  *
1327  * Notes:
1328  *      The function can return -EAGAIN in which case caller must
1329  *      call it again later, or recover. '0' return code means successful
1330  *      xmit.
1331  *
1332  *      Management xmit state machine consists of two states:
1333  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1334  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1335  **/
1336 static int
1337 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1338 {
1339         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1340         int rc;
1341
1342         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1343                 conn->id, tcp_mtask->xmstate, mtask->itt);
1344
1345         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1346                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1347                 if (mtask->data_count)
1348                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1349                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1350                     conn->stop_stage != STOP_CONN_RECOVER &&
1351                     conn->hdrdgst_en)
1352                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1353                                         (u8*)tcp_mtask->hdrext);
1354                 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1355                                    mtask->data_count);
1356                 if (rc) {
1357                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1358                         if (mtask->data_count)
1359                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1360                         return rc;
1361                 }
1362         }
1363
1364         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1365                 BUG_ON(!mtask->data_count);
1366                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1367                 /* FIXME: implement.
1368                  * Virtual buffer could be spreaded across multiple pages...
1369                  */
1370                 do {
1371                         int rc;
1372
1373                         rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1374                                         &mtask->data_count, &tcp_mtask->sent);
1375                         if (rc) {
1376                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1377                                 return rc;
1378                         }
1379                 } while (mtask->data_count);
1380         }
1381
1382         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1383         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1384                 struct iscsi_session *session = conn->session;
1385
1386                 spin_lock_bh(&session->lock);
1387                 list_del(&conn->mtask->running);
1388                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1389                             sizeof(void*));
1390                 spin_unlock_bh(&session->lock);
1391         }
1392         return 0;
1393 }
1394
1395 static inline int
1396 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1397                      struct iscsi_tcp_cmd_task *tcp_ctask)
1398 {
1399         int rc;
1400
1401         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1402         if (conn->hdrdgst_en)
1403                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1404                                  (u8*)tcp_ctask->hdrext);
1405         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1406         if (!rc) {
1407                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1408                 return 0; /* wait for Data-In */
1409         }
1410         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1411         return rc;
1412 }
1413
1414 static inline int
1415 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1416                      struct iscsi_cmd_task *ctask)
1417 {
1418         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1419         int rc;
1420
1421         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1422         if (conn->hdrdgst_en)
1423                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1424                                  (u8*)tcp_ctask->hdrext);
1425         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1426         if (rc)
1427                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1428         return rc;
1429 }
1430
1431 static inline int
1432 handle_xmstate_data_digest(struct iscsi_conn *conn,
1433                            struct iscsi_cmd_task *ctask)
1434 {
1435         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1436         int rc;
1437
1438         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1439         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1440         rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1441                                     &tcp_ctask->datadigest, 0);
1442         if (rc) {
1443                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1444                 debug_tcp("resent data digest 0x%x fail!\n",
1445                           tcp_ctask->datadigest);
1446         }
1447
1448         return rc;
1449 }
1450
1451 static inline int
1452 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1453 {
1454         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1455         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1456         int rc;
1457
1458         BUG_ON(!ctask->imm_count);
1459         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1460
1461         if (conn->datadgst_en) {
1462                 iscsi_data_digest_init(tcp_conn, ctask);
1463                 tcp_ctask->immdigest = 0;
1464         }
1465
1466         for (;;) {
1467                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1468                                    &ctask->imm_count, &tcp_ctask->sent);
1469                 if (rc) {
1470                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1471                         if (conn->datadgst_en) {
1472                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1473                                                 (u8*)&tcp_ctask->immdigest);
1474                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1475                                           tcp_ctask->datadigest);
1476                         }
1477                         return rc;
1478                 }
1479                 if (conn->datadgst_en)
1480                         crypto_digest_update(tcp_conn->data_tx_tfm,
1481                                              &tcp_ctask->sendbuf.sg, 1);
1482
1483                 if (!ctask->imm_count)
1484                         break;
1485                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1486                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1487         }
1488
1489         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1490                 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1491                                             &tcp_ctask->immdigest, 1);
1492                 if (rc) {
1493                         debug_tcp("sending imm digest 0x%x fail!\n",
1494                                   tcp_ctask->immdigest);
1495                         return rc;
1496                 }
1497                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1498         }
1499
1500         return 0;
1501 }
1502
1503 static inline int
1504 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1505 {
1506         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1507         struct iscsi_data_task *dtask;
1508         int rc;
1509
1510         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1511         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1512                 iscsi_unsolicit_data_init(conn, ctask);
1513                 dtask = tcp_ctask->dtask;
1514                 if (conn->hdrdgst_en)
1515                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1516                                         (u8*)dtask->hdrext);
1517                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1518         }
1519
1520         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1521         if (rc) {
1522                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1523                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1524                 return rc;
1525         }
1526
1527         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1528                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1529         return 0;
1530 }
1531
1532 static inline int
1533 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1534 {
1535         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1536         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1537         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1538         int rc;
1539
1540         BUG_ON(!ctask->data_count);
1541         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1542
1543         if (conn->datadgst_en) {
1544                 iscsi_data_digest_init(tcp_conn, ctask);
1545                 dtask->digest = 0;
1546         }
1547
1548         for (;;) {
1549                 int start = tcp_ctask->sent;
1550
1551                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1552                                    &ctask->data_count, &tcp_ctask->sent);
1553                 if (rc) {
1554                         ctask->unsol_count -= tcp_ctask->sent - start;
1555                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1556                         /* will continue with this ctask later.. */
1557                         if (conn->datadgst_en) {
1558                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1559                                                 (u8 *)&dtask->digest);
1560                                 debug_tcp("tx uns data fail 0x%x\n",
1561                                           dtask->digest);
1562                         }
1563                         return rc;
1564                 }
1565
1566                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1567                 ctask->unsol_count -= tcp_ctask->sent - start;
1568
1569                 /*
1570                  * XXX:we may run here with un-initial sendbuf.
1571                  * so pass it
1572                  */
1573                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1574                         crypto_digest_update(tcp_conn->data_tx_tfm,
1575                                              &tcp_ctask->sendbuf.sg, 1);
1576
1577                 if (!ctask->data_count)
1578                         break;
1579                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1580                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1581         }
1582         BUG_ON(ctask->unsol_count < 0);
1583
1584         /*
1585          * Done with the Data-Out. Next, check if we need
1586          * to send another unsolicited Data-Out.
1587          */
1588         if (ctask->unsol_count) {
1589                 if (conn->datadgst_en) {
1590                         rc = iscsi_digest_final_send(conn, ctask,
1591                                                     &dtask->digestbuf,
1592                                                     &dtask->digest, 1);
1593                         if (rc) {
1594                                 debug_tcp("send uns digest 0x%x fail\n",
1595                                           dtask->digest);
1596                                 return rc;
1597                         }
1598                         debug_tcp("sending uns digest 0x%x, more uns\n",
1599                                   dtask->digest);
1600                 }
1601                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1602                 return 1;
1603         }
1604
1605         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1606                 rc = iscsi_digest_final_send(conn, ctask,
1607                                             &dtask->digestbuf,
1608                                             &dtask->digest, 1);
1609                 if (rc) {
1610                         debug_tcp("send last uns digest 0x%x fail\n",
1611                                    dtask->digest);
1612                         return rc;
1613                 }
1614                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1615         }
1616
1617         return 0;
1618 }
1619
1620 static inline int
1621 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1622 {
1623         struct iscsi_session *session = conn->session;
1624         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1625         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1626         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1627         struct iscsi_data_task *dtask = &r2t->dtask;
1628         int left, rc;
1629
1630         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1631         tcp_ctask->dtask = dtask;
1632
1633         if (conn->datadgst_en) {
1634                 iscsi_data_digest_init(tcp_conn, ctask);
1635                 dtask->digest = 0;
1636         }
1637 solicit_again:
1638         /*
1639          * send Data-Out whitnin this R2T sequence.
1640          */
1641         if (!r2t->data_count)
1642                 goto data_out_done;
1643
1644         rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
1645         if (rc) {
1646                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1647                 /* will continue with this ctask later.. */
1648                 if (conn->datadgst_en) {
1649                         crypto_digest_final(tcp_conn->data_tx_tfm,
1650                                           (u8 *)&dtask->digest);
1651                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1652                 }
1653                 return rc;
1654         }
1655
1656         BUG_ON(r2t->data_count < 0);
1657         if (conn->datadgst_en)
1658                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1659                                      1);
1660
1661         if (r2t->data_count) {
1662                 BUG_ON(ctask->sc->use_sg == 0);
1663                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1664                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1665                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1666                         r2t->sg += 1;
1667                 }
1668                 goto solicit_again;
1669         }
1670
1671 data_out_done:
1672         /*
1673          * Done with this Data-Out. Next, check if we have
1674          * to send another Data-Out for this R2T.
1675          */
1676         BUG_ON(r2t->data_length - r2t->sent < 0);
1677         left = r2t->data_length - r2t->sent;
1678         if (left) {
1679                 if (conn->datadgst_en) {
1680                         rc = iscsi_digest_final_send(conn, ctask,
1681                                                     &dtask->digestbuf,
1682                                                     &dtask->digest, 1);
1683                         if (rc) {
1684                                 debug_tcp("send r2t data digest 0x%x"
1685                                           "fail\n", dtask->digest);
1686                                 return rc;
1687                         }
1688                         debug_tcp("r2t data send digest 0x%x\n",
1689                                   dtask->digest);
1690                 }
1691                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1692                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1693                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1694                 return 1;
1695         }
1696
1697         /*
1698          * Done with this R2T. Check if there are more
1699          * outstanding R2Ts ready to be processed.
1700          */
1701         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1702         if (conn->datadgst_en) {
1703                 rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1704                                             &dtask->digest, 1);
1705                 if (rc) {
1706                         debug_tcp("send last r2t data digest 0x%x"
1707                                   "fail\n", dtask->digest);
1708                         return rc;
1709                 }
1710                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1711         }
1712
1713         tcp_ctask->r2t_data_count -= r2t->data_length;
1714         tcp_ctask->r2t = NULL;
1715         spin_lock_bh(&session->lock);
1716         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1717         spin_unlock_bh(&session->lock);
1718         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1719                 tcp_ctask->r2t = r2t;
1720                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1721                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1722                 return 1;
1723         }
1724
1725         return 0;
1726 }
1727
1728 static inline int
1729 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1730 {
1731         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1732         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1733         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1734         int sent, rc;
1735
1736         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1737         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1738                             tcp_ctask->pad_count);
1739         rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1740                            &sent);
1741         if (rc) {
1742                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1743                 return rc;
1744         }
1745
1746         if (conn->datadgst_en) {
1747                 crypto_digest_update(tcp_conn->data_tx_tfm,
1748                                      &tcp_ctask->sendbuf.sg, 1);
1749                 /* imm data? */
1750                 if (!dtask) {
1751                         rc = iscsi_digest_final_send(conn, ctask,
1752                                                     &tcp_ctask->immbuf,
1753                                                     &tcp_ctask->immdigest, 1);
1754                         if (rc) {
1755                                 debug_tcp("send padding digest 0x%x"
1756                                           "fail!\n", tcp_ctask->immdigest);
1757                                 return rc;
1758                         }
1759                         debug_tcp("done with padding, digest 0x%x\n",
1760                                   tcp_ctask->datadigest);
1761                 } else {
1762                         rc = iscsi_digest_final_send(conn, ctask,
1763                                                     &dtask->digestbuf,
1764                                                     &dtask->digest, 1);
1765                         if (rc) {
1766                                 debug_tcp("send padding digest 0x%x"
1767                                           "fail\n", dtask->digest);
1768                                 return rc;
1769                         }
1770                         debug_tcp("done with padding, digest 0x%x\n",
1771                                   dtask->digest);
1772                 }
1773         }
1774
1775         return 0;
1776 }
1777
1778 static int
1779 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1780 {
1781         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1782         int rc = 0;
1783
1784         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1785                 conn->id, tcp_ctask->xmstate, ctask->itt);
1786
1787         /*
1788          * serialize with TMF AbortTask
1789          */
1790         if (ctask->mtask)
1791                 return rc;
1792
1793         if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1794                 return handle_xmstate_r_hdr(conn, tcp_ctask);
1795
1796         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1797                 rc = handle_xmstate_w_hdr(conn, ctask);
1798                 if (rc)
1799                         return rc;
1800         }
1801
1802         /* XXX: for data digest xmit recover */
1803         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1804                 rc = handle_xmstate_data_digest(conn, ctask);
1805                 if (rc)
1806                         return rc;
1807         }
1808
1809         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1810                 rc = handle_xmstate_imm_data(conn, ctask);
1811                 if (rc)
1812                         return rc;
1813         }
1814
1815         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1816                 BUG_ON(!ctask->unsol_count);
1817                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1818 unsolicit_head_again:
1819                 rc = handle_xmstate_uns_hdr(conn, ctask);
1820                 if (rc)
1821                         return rc;
1822         }
1823
1824         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1825                 rc = handle_xmstate_uns_data(conn, ctask);
1826                 if (rc == 1)
1827                         goto unsolicit_head_again;
1828                 else if (rc)
1829                         return rc;
1830                 goto done;
1831         }
1832
1833         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1834                 struct iscsi_r2t_info *r2t;
1835
1836                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1837                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1838                 if (!tcp_ctask->r2t)
1839                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1840                                     sizeof(void*));
1841 solicit_head_again:
1842                 r2t = tcp_ctask->r2t;
1843                 if (conn->hdrdgst_en)
1844                         iscsi_hdr_digest(conn, &r2t->headbuf,
1845                                         (u8*)r2t->dtask.hdrext);
1846                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1847                 if (rc) {
1848                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1849                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1850                         return rc;
1851                 }
1852
1853                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1854                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1855                         r2t->sent);
1856         }
1857
1858         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1859                 rc = handle_xmstate_sol_data(conn, ctask);
1860                 if (rc == 1)
1861                         goto solicit_head_again;
1862                 if (rc)
1863                         return rc;
1864         }
1865
1866 done:
1867         /*
1868          * Last thing to check is whether we need to send write
1869          * padding. Note that we check for xmstate equality, not just the bit.
1870          */
1871         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1872                 rc = handle_xmstate_w_pad(conn, ctask);
1873
1874         return rc;
1875 }
1876
1877 static struct iscsi_cls_conn *
1878 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1879 {
1880         struct iscsi_conn *conn;
1881         struct iscsi_cls_conn *cls_conn;
1882         struct iscsi_tcp_conn *tcp_conn;
1883
1884         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1885         if (!cls_conn)
1886                 return NULL;
1887         conn = cls_conn->dd_data;
1888         /*
1889          * due to strange issues with iser these are not set
1890          * in iscsi_conn_setup
1891          */
1892         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1893
1894         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1895         if (!tcp_conn)
1896                 goto tcp_conn_alloc_fail;
1897
1898         conn->dd_data = tcp_conn;
1899         tcp_conn->iscsi_conn = conn;
1900         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1901         /* initial operational parameters */
1902         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1903         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1904
1905         /* allocate initial PDU receive place holder */
1906         if (tcp_conn->data_size <= PAGE_SIZE)
1907                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1908         else
1909                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1910                                         get_order(tcp_conn->data_size));
1911         if (!tcp_conn->data)
1912                 goto max_recv_dlenght_alloc_fail;
1913
1914         return cls_conn;
1915
1916 max_recv_dlenght_alloc_fail:
1917         kfree(tcp_conn);
1918 tcp_conn_alloc_fail:
1919         iscsi_conn_teardown(cls_conn);
1920         return NULL;
1921 }
1922
1923 static void
1924 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1925 {
1926         struct iscsi_conn *conn = cls_conn->dd_data;
1927         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1928         int digest = 0;
1929
1930         if (conn->hdrdgst_en || conn->datadgst_en)
1931                 digest = 1;
1932
1933         iscsi_conn_teardown(cls_conn);
1934
1935         /* now free tcp_conn */
1936         if (digest) {
1937                 if (tcp_conn->tx_tfm)
1938                         crypto_free_tfm(tcp_conn->tx_tfm);
1939                 if (tcp_conn->rx_tfm)
1940                         crypto_free_tfm(tcp_conn->rx_tfm);
1941                 if (tcp_conn->data_tx_tfm)
1942                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1943                 if (tcp_conn->data_rx_tfm)
1944                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1945         }
1946
1947         /* free conn->data, size = MaxRecvDataSegmentLength */
1948         if (tcp_conn->data_size <= PAGE_SIZE)
1949                 kfree(tcp_conn->data);
1950         else
1951                 free_pages((unsigned long)tcp_conn->data,
1952                            get_order(tcp_conn->data_size));
1953         kfree(tcp_conn);
1954 }
1955
1956 static int
1957 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1958                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1959                     int is_leading)
1960 {
1961         struct iscsi_conn *conn = cls_conn->dd_data;
1962         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1963         struct sock *sk;
1964         struct socket *sock;
1965         int err;
1966
1967         /* lookup for existing socket */
1968         sock = sockfd_lookup((int)transport_eph, &err);
1969         if (!sock) {
1970                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1971                 return -EEXIST;
1972         }
1973
1974         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1975         if (err)
1976                 return err;
1977
1978         /* bind iSCSI connection and socket */
1979         tcp_conn->sock = sock;
1980
1981         /* setup Socket parameters */
1982         sk = sock->sk;
1983         sk->sk_reuse = 1;
1984         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1985         sk->sk_allocation = GFP_ATOMIC;
1986
1987         /* FIXME: disable Nagle's algorithm */
1988
1989         /*
1990          * Intercept TCP callbacks for sendfile like receive
1991          * processing.
1992          */
1993         conn->recv_lock = &sk->sk_callback_lock;
1994         iscsi_conn_set_callbacks(conn);
1995         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1996         /*
1997          * set receive state machine into initial state
1998          */
1999         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2000
2001         return 0;
2002 }
2003
2004 static void
2005 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2006 {
2007         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2008         struct iscsi_r2t_info *r2t;
2009
2010         /* flush ctask's r2t queues */
2011         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
2012                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
2013                             sizeof(void*));
2014
2015         __iscsi_ctask_cleanup(conn, ctask);
2016 }
2017
2018 static void
2019 iscsi_tcp_suspend_conn_rx(struct iscsi_conn *conn)
2020 {
2021         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2022         struct sock *sk;
2023
2024         if (!tcp_conn->sock)
2025                 return;
2026
2027         sk = tcp_conn->sock->sk;
2028         write_lock_bh(&sk->sk_callback_lock);
2029         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2030         write_unlock_bh(&sk->sk_callback_lock);
2031 }
2032
2033 static void
2034 iscsi_tcp_terminate_conn(struct iscsi_conn *conn)
2035 {
2036         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2037
2038         if (!tcp_conn->sock)
2039                 return;
2040
2041         sock_hold(tcp_conn->sock->sk);
2042         iscsi_conn_restore_callbacks(conn);
2043         sock_put(tcp_conn->sock->sk);
2044
2045         sock_release(tcp_conn->sock);
2046         tcp_conn->sock = NULL;
2047         conn->recv_lock = NULL;
2048 }
2049
2050 /* called with host lock */
2051 static void
2052 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2053                     char *data, uint32_t data_size)
2054 {
2055         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2056
2057         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2058                            sizeof(struct iscsi_hdr));
2059         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2060
2061         if (mtask->data_count)
2062                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2063                                     mtask->data_count);
2064 }
2065
2066 static int
2067 iscsi_r2tpool_alloc(struct iscsi_session *session)
2068 {
2069         int i;
2070         int cmd_i;
2071
2072         /*
2073          * initialize per-task: R2T pool and xmit queue
2074          */
2075         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2076                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2077                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2078
2079                 /*
2080                  * pre-allocated x4 as much r2ts to handle race when
2081                  * target acks DataOut faster than we data_xmit() queues
2082                  * could replenish r2tqueue.
2083                  */
2084
2085                 /* R2T pool */
2086                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2087                                     (void***)&tcp_ctask->r2ts,
2088                                     sizeof(struct iscsi_r2t_info))) {
2089                         goto r2t_alloc_fail;
2090                 }
2091
2092                 /* R2T xmit queue */
2093                 tcp_ctask->r2tqueue = kfifo_alloc(
2094                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2095                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2096                         iscsi_pool_free(&tcp_ctask->r2tpool,
2097                                         (void**)tcp_ctask->r2ts);
2098                         goto r2t_alloc_fail;
2099                 }
2100         }
2101
2102         return 0;
2103
2104 r2t_alloc_fail:
2105         for (i = 0; i < cmd_i; i++) {
2106                 struct iscsi_cmd_task *ctask = session->cmds[i];
2107                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2108
2109                 kfifo_free(tcp_ctask->r2tqueue);
2110                 iscsi_pool_free(&tcp_ctask->r2tpool,
2111                                 (void**)tcp_ctask->r2ts);
2112         }
2113         return -ENOMEM;
2114 }
2115
2116 static void
2117 iscsi_r2tpool_free(struct iscsi_session *session)
2118 {
2119         int i;
2120
2121         for (i = 0; i < session->cmds_max; i++) {
2122                 struct iscsi_cmd_task *ctask = session->cmds[i];
2123                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2124
2125                 kfifo_free(tcp_ctask->r2tqueue);
2126                 iscsi_pool_free(&tcp_ctask->r2tpool,
2127                                 (void**)tcp_ctask->r2ts);
2128         }
2129 }
2130
2131 static int
2132 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2133                      char *buf, int buflen)
2134 {
2135         struct iscsi_conn *conn = cls_conn->dd_data;
2136         struct iscsi_session *session = conn->session;
2137         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2138         int value;
2139
2140         switch(param) {
2141         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2142                 char *saveptr = tcp_conn->data;
2143                 gfp_t flags = GFP_KERNEL;
2144
2145                 sscanf(buf, "%d", &value);
2146                 if (tcp_conn->data_size >= value) {
2147                         iscsi_set_param(cls_conn, param, buf, buflen);
2148                         break;
2149                 }
2150
2151                 spin_lock_bh(&session->lock);
2152                 if (conn->stop_stage == STOP_CONN_RECOVER)
2153                         flags = GFP_ATOMIC;
2154                 spin_unlock_bh(&session->lock);
2155
2156                 if (value <= PAGE_SIZE)
2157                         tcp_conn->data = kmalloc(value, flags);
2158                 else
2159                         tcp_conn->data = (void*)__get_free_pages(flags,
2160                                                              get_order(value));
2161                 if (tcp_conn->data == NULL) {
2162                         tcp_conn->data = saveptr;
2163                         return -ENOMEM;
2164                 }
2165                 if (tcp_conn->data_size <= PAGE_SIZE)
2166                         kfree(saveptr);
2167                 else
2168                         free_pages((unsigned long)saveptr,
2169                                    get_order(tcp_conn->data_size));
2170                 iscsi_set_param(cls_conn, param, buf, buflen);
2171                 tcp_conn->data_size = value;
2172                 break;
2173                 }
2174         case ISCSI_PARAM_HDRDGST_EN:
2175                 iscsi_set_param(cls_conn, param, buf, buflen);
2176                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2177                 if (conn->hdrdgst_en) {
2178                         tcp_conn->hdr_size += sizeof(__u32);
2179                         if (!tcp_conn->tx_tfm)
2180                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2181                                                                     0);
2182                         if (!tcp_conn->tx_tfm)
2183                                 return -ENOMEM;
2184                         if (!tcp_conn->rx_tfm)
2185                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2186                                                                     0);
2187                         if (!tcp_conn->rx_tfm) {
2188                                 crypto_free_tfm(tcp_conn->tx_tfm);
2189                                 return -ENOMEM;
2190                         }
2191                 } else {
2192                         if (tcp_conn->tx_tfm)
2193                                 crypto_free_tfm(tcp_conn->tx_tfm);
2194                         if (tcp_conn->rx_tfm)
2195                                 crypto_free_tfm(tcp_conn->rx_tfm);
2196                 }
2197                 break;
2198         case ISCSI_PARAM_DATADGST_EN:
2199                 iscsi_set_param(cls_conn, param, buf, buflen);
2200                 if (conn->datadgst_en) {
2201                         if (!tcp_conn->data_tx_tfm)
2202                                 tcp_conn->data_tx_tfm =
2203                                     crypto_alloc_tfm("crc32c", 0);
2204                         if (!tcp_conn->data_tx_tfm)
2205                                 return -ENOMEM;
2206                         if (!tcp_conn->data_rx_tfm)
2207                                 tcp_conn->data_rx_tfm =
2208                                     crypto_alloc_tfm("crc32c", 0);
2209                         if (!tcp_conn->data_rx_tfm) {
2210                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2211                                 return -ENOMEM;
2212                         }
2213                 } else {
2214                         if (tcp_conn->data_tx_tfm)
2215                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2216                         if (tcp_conn->data_rx_tfm)
2217                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2218                 }
2219                 tcp_conn->sendpage = conn->datadgst_en ?
2220                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2221                 break;
2222         case ISCSI_PARAM_MAX_R2T:
2223                 sscanf(buf, "%d", &value);
2224                 if (session->max_r2t == roundup_pow_of_two(value))
2225                         break;
2226                 iscsi_r2tpool_free(session);
2227                 iscsi_set_param(cls_conn, param, buf, buflen);
2228                 if (session->max_r2t & (session->max_r2t - 1))
2229                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2230                 if (iscsi_r2tpool_alloc(session))
2231                         return -ENOMEM;
2232                 break;
2233         default:
2234                 return iscsi_set_param(cls_conn, param, buf, buflen);
2235         }
2236
2237         return 0;
2238 }
2239
2240 static int
2241 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2242                          enum iscsi_param param, char *buf)
2243 {
2244         struct iscsi_conn *conn = cls_conn->dd_data;
2245         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2246         struct inet_sock *inet;
2247         struct ipv6_pinfo *np;
2248         struct sock *sk;
2249         int len;
2250
2251         switch(param) {
2252         case ISCSI_PARAM_CONN_PORT:
2253                 mutex_lock(&conn->xmitmutex);
2254                 if (!tcp_conn->sock) {
2255                         mutex_unlock(&conn->xmitmutex);
2256                         return -EINVAL;
2257                 }
2258
2259                 inet = inet_sk(tcp_conn->sock->sk);
2260                 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2261                 mutex_unlock(&conn->xmitmutex);
2262                 break;
2263         case ISCSI_PARAM_CONN_ADDRESS:
2264                 mutex_lock(&conn->xmitmutex);
2265                 if (!tcp_conn->sock) {
2266                         mutex_unlock(&conn->xmitmutex);
2267                         return -EINVAL;
2268                 }
2269
2270                 sk = tcp_conn->sock->sk;
2271                 if (sk->sk_family == PF_INET) {
2272                         inet = inet_sk(sk);
2273                         len = sprintf(buf, "%u.%u.%u.%u\n",
2274                                       NIPQUAD(inet->daddr));
2275                 } else {
2276                         np = inet6_sk(sk);
2277                         len = sprintf(buf,
2278                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2279                                 NIP6(np->daddr));
2280                 }
2281                 mutex_unlock(&conn->xmitmutex);
2282                 break;
2283         default:
2284                 return iscsi_conn_get_param(cls_conn, param, buf);
2285         }
2286
2287         return len;
2288 }
2289
2290 static void
2291 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2292 {
2293         struct iscsi_conn *conn = cls_conn->dd_data;
2294         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2295
2296         stats->txdata_octets = conn->txdata_octets;
2297         stats->rxdata_octets = conn->rxdata_octets;
2298         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2299         stats->dataout_pdus = conn->dataout_pdus_cnt;
2300         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2301         stats->datain_pdus = conn->datain_pdus_cnt;
2302         stats->r2t_pdus = conn->r2t_pdus_cnt;
2303         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2304         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2305         stats->custom_length = 3;
2306         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2307         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2308         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2309         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2310         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2311         stats->custom[2].value = conn->eh_abort_cnt;
2312 }
2313
2314 static struct iscsi_cls_session *
2315 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2316                          struct scsi_transport_template *scsit,
2317                          uint32_t initial_cmdsn, uint32_t *hostno)
2318 {
2319         struct iscsi_cls_session *cls_session;
2320         struct iscsi_session *session;
2321         uint32_t hn;
2322         int cmd_i;
2323
2324         cls_session = iscsi_session_setup(iscsit, scsit,
2325                                          sizeof(struct iscsi_tcp_cmd_task),
2326                                          sizeof(struct iscsi_tcp_mgmt_task),
2327                                          initial_cmdsn, &hn);
2328         if (!cls_session)
2329                 return NULL;
2330         *hostno = hn;
2331
2332         session = class_to_transport_session(cls_session);
2333         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2334                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2335                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2336
2337                 ctask->hdr = &tcp_ctask->hdr;
2338         }
2339
2340         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2341                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2342                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2343
2344                 mtask->hdr = &tcp_mtask->hdr;
2345         }
2346
2347         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2348                 goto r2tpool_alloc_fail;
2349
2350         return cls_session;
2351
2352 r2tpool_alloc_fail:
2353         iscsi_session_teardown(cls_session);
2354         return NULL;
2355 }
2356
2357 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2358 {
2359         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2360         iscsi_session_teardown(cls_session);
2361 }
2362
2363 static struct scsi_host_template iscsi_sht = {
2364         .name                   = "iSCSI Initiator over TCP/IP, v"
2365                                   ISCSI_TCP_VERSION,
2366         .queuecommand           = iscsi_queuecommand,
2367         .change_queue_depth     = iscsi_change_queue_depth,
2368         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2369         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2370         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2371         .eh_abort_handler       = iscsi_eh_abort,
2372         .eh_host_reset_handler  = iscsi_eh_host_reset,
2373         .use_clustering         = DISABLE_CLUSTERING,
2374         .proc_name              = "iscsi_tcp",
2375         .this_id                = -1,
2376 };
2377
2378 static struct iscsi_transport iscsi_tcp_transport = {
2379         .owner                  = THIS_MODULE,
2380         .name                   = "tcp",
2381         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2382                                   | CAP_DATADGST,
2383         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2384                                   ISCSI_MAX_XMIT_DLENGTH |
2385                                   ISCSI_HDRDGST_EN |
2386                                   ISCSI_DATADGST_EN |
2387                                   ISCSI_INITIAL_R2T_EN |
2388                                   ISCSI_MAX_R2T |
2389                                   ISCSI_IMM_DATA_EN |
2390                                   ISCSI_FIRST_BURST |
2391                                   ISCSI_MAX_BURST |
2392                                   ISCSI_PDU_INORDER_EN |
2393                                   ISCSI_DATASEQ_INORDER_EN |
2394                                   ISCSI_ERL |
2395                                   ISCSI_CONN_PORT |
2396                                   ISCSI_CONN_ADDRESS |
2397                                   ISCSI_EXP_STATSN |
2398                                   ISCSI_PERSISTENT_PORT |
2399                                   ISCSI_PERSISTENT_ADDRESS |
2400                                   ISCSI_TARGET_NAME |
2401                                   ISCSI_TPGT,
2402         .host_template          = &iscsi_sht,
2403         .conndata_size          = sizeof(struct iscsi_conn),
2404         .max_conn               = 1,
2405         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2406         /* session management */
2407         .create_session         = iscsi_tcp_session_create,
2408         .destroy_session        = iscsi_tcp_session_destroy,
2409         /* connection management */
2410         .create_conn            = iscsi_tcp_conn_create,
2411         .bind_conn              = iscsi_tcp_conn_bind,
2412         .destroy_conn           = iscsi_tcp_conn_destroy,
2413         .set_param              = iscsi_conn_set_param,
2414         .get_conn_param         = iscsi_tcp_conn_get_param,
2415         .get_session_param      = iscsi_session_get_param,
2416         .start_conn             = iscsi_conn_start,
2417         .stop_conn              = iscsi_conn_stop,
2418         /* these are called as part of conn recovery */
2419         .suspend_conn_recv      = iscsi_tcp_suspend_conn_rx,
2420         .terminate_conn         = iscsi_tcp_terminate_conn,
2421         /* IO */
2422         .send_pdu               = iscsi_conn_send_pdu,
2423         .get_stats              = iscsi_conn_get_stats,
2424         .init_cmd_task          = iscsi_tcp_cmd_init,
2425         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2426         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2427         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2428         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2429         /* recovery */
2430         .session_recovery_timedout = iscsi_session_recovery_timedout,
2431 };
2432
2433 static int __init
2434 iscsi_tcp_init(void)
2435 {
2436         if (iscsi_max_lun < 1) {
2437                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2438                        iscsi_max_lun);
2439                 return -EINVAL;
2440         }
2441         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2442
2443         if (!iscsi_register_transport(&iscsi_tcp_transport))
2444                 return -ENODEV;
2445
2446         return 0;
2447 }
2448
2449 static void __exit
2450 iscsi_tcp_exit(void)
2451 {
2452         iscsi_unregister_transport(&iscsi_tcp_transport);
2453 }
2454
2455 module_init(iscsi_tcp_init);
2456 module_exit(iscsi_tcp_exit);