SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/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_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 191         struct iscsi_r2t_info *r2t;
 192         struct scsi_cmnd *sc;
 193
 194         /* flush ctask's r2t queues */
 195         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
 196                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
 197                             sizeof(void*));
 198                 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
 199         }
 200
 201         sc = ctask->sc;
 202         if (unlikely(!sc))
 203                 return;
 204
 205         tcp_ctask->xmstate = XMSTATE_IDLE;
 206         tcp_ctask->r2t = NULL;
 207 }
 208
 209 /**
 210  * iscsi_data_rsp - SCSI Data-In Response processing
 211  * @conn: iscsi connection
 212  * @ctask: scsi command task
 213  **/
 214 static int
 215 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 216 {
 217         int rc;
 218         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 219         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 220         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 221         struct iscsi_session *session = conn->session;
 222         int datasn = be32_to_cpu(rhdr->datasn);
 223
 224         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 225         if (rc)
 226                 return rc;
 227         /*
 228          * setup Data-In byte counter (gets decremented..)
 229          */
 230         ctask->data_count = tcp_conn->in.datalen;
 231
 232         if (tcp_conn->in.datalen == 0)
 233                 return 0;
 234
 235         if (ctask->datasn != datasn)
 236                 return ISCSI_ERR_DATASN;
 237
 238         ctask->datasn++;
 239
 240         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 241         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 242                 return ISCSI_ERR_DATA_OFFSET;
 243
 244         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 245                 struct scsi_cmnd *sc = ctask->sc;
 246
 247                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 248                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 249                         int res_count = be32_to_cpu(rhdr->residual_count);
 250
 251                         if (res_count > 0 &&
 252                             res_count <= sc->request_bufflen) {
 253                                 sc->resid = res_count;
 254                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 255                         } else
 256                                 sc->result = (DID_BAD_TARGET << 16) |
 257                                         rhdr->cmd_status;
 258                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 259                         sc->resid = be32_to_cpu(rhdr->residual_count);
 260                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 261                 } else
 262                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 263         }
 264
 265         conn->datain_pdus_cnt++;
 266         return 0;
 267 }
 268
 269 /**
 270  * iscsi_solicit_data_init - initialize first Data-Out
 271  * @conn: iscsi connection
 272  * @ctask: scsi command task
 273  * @r2t: R2T info
 274  *
 275  * Notes:
 276  *      Initialize first Data-Out within this R2T sequence and finds
 277  *      proper data_offset within this SCSI command.
 278  *
 279  *      This function is called with connection lock taken.
 280  **/
 281 static void
 282 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 283                         struct iscsi_r2t_info *r2t)
 284 {
 285         struct iscsi_data *hdr;
 286         struct scsi_cmnd *sc = ctask->sc;
 287         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 288
 289         hdr = &r2t->dtask.hdr;
 290         memset(hdr, 0, sizeof(struct iscsi_data));
 291         hdr->ttt = r2t->ttt;
 292         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 293         r2t->solicit_datasn++;
 294         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 295         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 296         hdr->itt = ctask->hdr->itt;
 297         hdr->exp_statsn = r2t->exp_statsn;
 298         hdr->offset = cpu_to_be32(r2t->data_offset);
 299         if (r2t->data_length > conn->max_xmit_dlength) {
 300                 hton24(hdr->dlength, conn->max_xmit_dlength);
 301                 r2t->data_count = conn->max_xmit_dlength;
 302                 hdr->flags = 0;
 303         } else {
 304                 hton24(hdr->dlength, r2t->data_length);
 305                 r2t->data_count = r2t->data_length;
 306                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 307         }
 308         conn->dataout_pdus_cnt++;
 309
 310         r2t->sent = 0;
 311
 312         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 313                            sizeof(struct iscsi_hdr));
 314
 315         if (sc->use_sg) {
 316                 int i, sg_count = 0;
 317                 struct scatterlist *sg = sc->request_buffer;
 318
 319                 r2t->sg = NULL;
 320                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 321                         /* FIXME: prefetch ? */
 322                         if (sg_count + sg->length > r2t->data_offset) {
 323                                 int page_offset;
 324
 325                                 /* sg page found! */
 326
 327                                 /* offset within this page */
 328                                 page_offset = r2t->data_offset - sg_count;
 329
 330                                 /* fill in this buffer */
 331                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 332                                 r2t->sendbuf.sg.offset += page_offset;
 333                                 r2t->sendbuf.sg.length -= page_offset;
 334
 335                                 /* xmit logic will continue with next one */
 336                                 r2t->sg = sg + 1;
 337                                 break;
 338                         }
 339                         sg_count += sg->length;
 340                 }
 341                 BUG_ON(r2t->sg == NULL);
 342         } else
 343                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 344                             (char*)sc->request_buffer + r2t->data_offset,
 345                             r2t->data_count);
 346 }
 347
 348 /**
 349  * iscsi_r2t_rsp - iSCSI R2T Response processing
 350  * @conn: iscsi connection
 351  * @ctask: scsi command task
 352  **/
 353 static int
 354 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 355 {
 356         struct iscsi_r2t_info *r2t;
 357         struct iscsi_session *session = conn->session;
 358         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 359         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 360         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 361         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 362         int rc;
 363
 364         if (tcp_conn->in.datalen)
 365                 return ISCSI_ERR_DATALEN;
 366
 367         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 368                 return ISCSI_ERR_R2TSN;
 369
 370         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 371         if (rc)
 372                 return rc;
 373
 374         /* FIXME: use R2TSN to detect missing R2T */
 375
 376         /* fill-in new R2T associated with the task */
 377         spin_lock(&session->lock);
 378         if (!ctask->sc || ctask->mtask ||
 379              session->state != ISCSI_STATE_LOGGED_IN) {
 380                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 381                        "recovery...\n", ctask->itt);
 382                 spin_unlock(&session->lock);
 383                 return 0;
 384         }
 385
 386         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 387         BUG_ON(!rc);
 388
 389         r2t->exp_statsn = rhdr->statsn;
 390         r2t->data_length = be32_to_cpu(rhdr->data_length);
 391         if (r2t->data_length == 0 ||
 392             r2t->data_length > session->max_burst) {
 393                 spin_unlock(&session->lock);
 394                 return ISCSI_ERR_DATALEN;
 395         }
 396
 397         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 398         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 399                 spin_unlock(&session->lock);
 400                 return ISCSI_ERR_DATALEN;
 401         }
 402
 403         r2t->ttt = rhdr->ttt; /* no flip */
 404         r2t->solicit_datasn = 0;
 405
 406         iscsi_solicit_data_init(conn, ctask, r2t);
 407
 408         tcp_ctask->exp_r2tsn = r2tsn + 1;
 409         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 410         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 411         list_move_tail(&ctask->running, &conn->xmitqueue);
 412
 413         scsi_queue_work(session->host, &conn->xmitwork);
 414         conn->r2t_pdus_cnt++;
 415         spin_unlock(&session->lock);
 416
 417         return 0;
 418 }
 419
 420 static int
 421 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 422 {
 423         int rc = 0, opcode, ahslen;
 424         struct iscsi_hdr *hdr;
 425         struct iscsi_session *session = conn->session;
 426         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 427         uint32_t cdgst, rdgst = 0, itt;
 428
 429         hdr = tcp_conn->in.hdr;
 430
 431         /* verify PDU length */
 432         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 433         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 434                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 435                        tcp_conn->in.datalen, conn->max_recv_dlength);
 436                 return ISCSI_ERR_DATALEN;
 437         }
 438         tcp_conn->data_copied = 0;
 439
 440         /* read AHS */
 441         ahslen = hdr->hlength << 2;
 442         tcp_conn->in.offset += ahslen;
 443         tcp_conn->in.copy -= ahslen;
 444         if (tcp_conn->in.copy < 0) {
 445                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 446                        "%d bytes\n", ahslen);
 447                 return ISCSI_ERR_AHSLEN;
 448         }
 449
 450         /* calculate read padding */
 451         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 452         if (tcp_conn->in.padding) {
 453                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 454                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 455         }
 456
 457         if (conn->hdrdgst_en) {
 458                 struct scatterlist sg;
 459
 460                 sg_init_one(&sg, (u8 *)hdr,
 461                             sizeof(struct iscsi_hdr) + ahslen);
 462                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 463                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 464                                      ahslen);
 465                 if (cdgst != rdgst) {
 466                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 467                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 468                         return ISCSI_ERR_HDR_DGST;
 469                 }
 470         }
 471
 472         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 473         /* verify itt (itt encoding: age+cid+itt) */
 474         rc = iscsi_verify_itt(conn, hdr, &itt);
 475         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 476                 tcp_conn->in.datalen = 0; /* force drop */
 477                 return 0;
 478         } else if (rc)
 479                 return rc;
 480
 481         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 482                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 483                   ahslen, tcp_conn->in.datalen);
 484
 485         switch(opcode) {
 486         case ISCSI_OP_SCSI_DATA_IN:
 487                 tcp_conn->in.ctask = session->cmds[itt];
 488                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 489                 if (rc)
 490                         return rc;
 491                 /* fall through */
 492         case ISCSI_OP_SCSI_CMD_RSP:
 493                 tcp_conn->in.ctask = session->cmds[itt];
 494                 if (tcp_conn->in.datalen)
 495                         goto copy_hdr;
 496
 497                 spin_lock(&session->lock);
 498                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 499                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 500                 spin_unlock(&session->lock);
 501                 break;
 502         case ISCSI_OP_R2T:
 503                 tcp_conn->in.ctask = session->cmds[itt];
 504                 if (ahslen)
 505                         rc = ISCSI_ERR_AHSLEN;
 506                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 507                                                                 DMA_TO_DEVICE)
 508                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 509                 else
 510                         rc = ISCSI_ERR_PROTO;
 511                 break;
 512         case ISCSI_OP_LOGIN_RSP:
 513         case ISCSI_OP_TEXT_RSP:
 514         case ISCSI_OP_REJECT:
 515         case ISCSI_OP_ASYNC_EVENT:
 516                 /*
 517                  * It is possible that we could get a PDU with a buffer larger
 518                  * than 8K, but there are no targets that currently do this.
 519                  * For now we fail until we find a vendor that needs it
 520                  */
 521                 if (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH <
 522                     tcp_conn->in.datalen) {
 523                         printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
 524                               "but conn buffer is only %u (opcode %0x)\n",
 525                               tcp_conn->in.datalen,
 526                               DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, opcode);
 527                         rc = ISCSI_ERR_PROTO;
 528                         break;
 529                 }
 530
 531                 if (tcp_conn->in.datalen)
 532                         goto copy_hdr;
 533         /* fall through */
 534         case ISCSI_OP_LOGOUT_RSP:
 535         case ISCSI_OP_NOOP_IN:
 536         case ISCSI_OP_SCSI_TMFUNC_RSP:
 537                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 538                 break;
 539         default:
 540                 rc = ISCSI_ERR_BAD_OPCODE;
 541                 break;
 542         }
 543
 544         return rc;
 545
 546 copy_hdr:
 547         /*
 548          * if we did zero copy for the header but we will need multiple
 549          * skbs to complete the command then we have to copy the header
 550          * for later use
 551          */
 552         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
 553            (tcp_conn->in.datalen + tcp_conn->in.padding +
 554             (conn->datadgst_en ? 4 : 0))) {
 555                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 556                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 557                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 558                        sizeof(struct iscsi_hdr));
 559                 tcp_conn->in.hdr = &tcp_conn->hdr;
 560                 tcp_conn->in.zero_copy_hdr = 0;
 561         }
 562         return 0;
 563 }
 564
 565 /**
 566  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 567  * @conn: iscsi tcp connection
 568  * @ctask: scsi command task
 569  * @buf: buffer to copy to
 570  * @buf_size: size of buffer
 571  * @offset: offset within the buffer
 572  *
 573  * Notes:
 574  *      The function calls skb_copy_bits() and updates per-connection and
 575  *      per-cmd byte counters.
 576  *
 577  *      Read counters (in bytes):
 578  *
 579  *      conn->in.offset         offset within in progress SKB
 580  *      conn->in.copy           left to copy from in progress SKB
 581  *                              including padding
 582  *      conn->in.copied         copied already from in progress SKB
 583  *      conn->data_copied       copied already from in progress buffer
 584  *      ctask->sent             total bytes sent up to the MidLayer
 585  *      ctask->data_count       left to copy from in progress Data-In
 586  *      buf_left                left to copy from in progress buffer
 587  **/
 588 static inline int
 589 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 590                 void *buf, int buf_size, int offset)
 591 {
 592         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 593         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 594         int size = min(tcp_conn->in.copy, buf_left);
 595         int rc;
 596
 597         size = min(size, ctask->data_count);
 598
 599         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 600                size, tcp_conn->in.offset, tcp_conn->in.copied);
 601
 602         BUG_ON(size <= 0);
 603         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 604
 605         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 606                            (char*)buf + (offset + tcp_conn->data_copied), size);
 607         /* must fit into skb->len */
 608         BUG_ON(rc);
 609
 610         tcp_conn->in.offset += size;
 611         tcp_conn->in.copy -= size;
 612         tcp_conn->in.copied += size;
 613         tcp_conn->data_copied += size;
 614         tcp_ctask->sent += size;
 615         ctask->data_count -= size;
 616
 617         BUG_ON(tcp_conn->in.copy < 0);
 618         BUG_ON(ctask->data_count < 0);
 619
 620         if (buf_size != (tcp_conn->data_copied + offset)) {
 621                 if (!ctask->data_count) {
 622                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 623                         /* done with this PDU */
 624                         return buf_size - tcp_conn->data_copied;
 625                 }
 626                 return -EAGAIN;
 627         }
 628
 629         /* done with this buffer or with both - PDU and buffer */
 630         tcp_conn->data_copied = 0;
 631         return 0;
 632 }
 633
 634 /**
 635  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 636  * @conn: iscsi tcp connection
 637  *
 638  * Notes:
 639  *      The function calls skb_copy_bits() and updates per-connection
 640  *      byte counters.
 641  **/
 642 static inline int
 643 iscsi_tcp_copy(struct iscsi_conn *conn)
 644 {
 645         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 646         int buf_size = tcp_conn->in.datalen;
 647         int buf_left = buf_size - tcp_conn->data_copied;
 648         int size = min(tcp_conn->in.copy, buf_left);
 649         int rc;
 650
 651         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 652                size, tcp_conn->in.offset, tcp_conn->data_copied);
 653         BUG_ON(size <= 0);
 654
 655         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 656                            (char*)conn->data + tcp_conn->data_copied, size);
 657         BUG_ON(rc);
 658
 659         tcp_conn->in.offset += size;
 660         tcp_conn->in.copy -= size;
 661         tcp_conn->in.copied += size;
 662         tcp_conn->data_copied += size;
 663
 664         if (buf_size != tcp_conn->data_copied)
 665                 return -EAGAIN;
 666
 667         return 0;
 668 }
 669
 670 static inline void
 671 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 672                          struct scatterlist *sg, int offset, int length)
 673 {
 674         struct scatterlist temp;
 675
 676         memcpy(&temp, sg, sizeof(struct scatterlist));
 677         temp.offset = offset;
 678         temp.length = length;
 679         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 680 }
 681
 682 static void
 683 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 684 {
 685         struct scatterlist tmp;
 686
 687         sg_init_one(&tmp, buf, len);
 688         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 689 }
 690
 691 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 692 {
 693         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 694         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 695         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 696         struct scsi_cmnd *sc = ctask->sc;
 697         struct scatterlist *sg;
 698         int i, offset, rc = 0;
 699
 700         BUG_ON((void*)ctask != sc->SCp.ptr);
 701
 702         /*
 703          * copying Data-In into the Scsi_Cmnd
 704          */
 705         if (!sc->use_sg) {
 706                 i = ctask->data_count;
 707                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 708                                       sc->request_bufflen,
 709                                       tcp_ctask->data_offset);
 710                 if (rc == -EAGAIN)
 711                         return rc;
 712                 if (conn->datadgst_en)
 713                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 714                                                  i);
 715                 rc = 0;
 716                 goto done;
 717         }
 718
 719         offset = tcp_ctask->data_offset;
 720         sg = sc->request_buffer;
 721
 722         if (tcp_ctask->data_offset)
 723                 for (i = 0; i < tcp_ctask->sg_count; i++)
 724                         offset -= sg[i].length;
 725         /* we've passed through partial sg*/
 726         if (offset < 0)
 727                 offset = 0;
 728
 729         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 730                 char *dest;
 731
 732                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 733                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 734                                       sg[i].length, offset);
 735                 kunmap_atomic(dest, KM_SOFTIRQ0);
 736                 if (rc == -EAGAIN)
 737                         /* continue with the next SKB/PDU */
 738                         return rc;
 739                 if (!rc) {
 740                         if (conn->datadgst_en) {
 741                                 if (!offset)
 742                                         crypto_digest_update(
 743                                                         tcp_conn->data_rx_tfm,
 744                                                         &sg[i], 1);
 745                                 else
 746                                         partial_sg_digest_update(tcp_conn,
 747                                                         &sg[i],
 748                                                         sg[i].offset + offset,
 749                                                         sg[i].length - offset);
 750                         }
 751                         offset = 0;
 752                         tcp_ctask->sg_count++;
 753                 }
 754
 755                 if (!ctask->data_count) {
 756                         if (rc && conn->datadgst_en)
 757                                 /*
 758                                  * data-in is complete, but buffer not...
 759                                  */
 760                                 partial_sg_digest_update(tcp_conn, &sg[i],
 761                                                 sg[i].offset, sg[i].length-rc);
 762                         rc = 0;
 763                         break;
 764                 }
 765
 766                 if (!tcp_conn->in.copy)
 767                         return -EAGAIN;
 768         }
 769         BUG_ON(ctask->data_count);
 770
 771 done:
 772         /* check for non-exceptional status */
 773         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 774                 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
 775                            (long)sc, sc->result, ctask->itt,
 776                            tcp_conn->in.hdr->flags);
 777                 spin_lock(&conn->session->lock);
 778                 iscsi_tcp_cleanup_ctask(conn, ctask);
 779                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 780                 spin_unlock(&conn->session->lock);
 781         }
 782
 783         return rc;
 784 }
 785
 786 static int
 787 iscsi_data_recv(struct iscsi_conn *conn)
 788 {
 789         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 790         int rc = 0, opcode;
 791
 792         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 793         switch (opcode) {
 794         case ISCSI_OP_SCSI_DATA_IN:
 795                 rc = iscsi_scsi_data_in(conn);
 796                 break;
 797         case ISCSI_OP_SCSI_CMD_RSP:
 798                 spin_lock(&conn->session->lock);
 799                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 800                 spin_unlock(&conn->session->lock);
 801         case ISCSI_OP_TEXT_RSP:
 802         case ISCSI_OP_LOGIN_RSP:
 803         case ISCSI_OP_ASYNC_EVENT:
 804         case ISCSI_OP_REJECT:
 805                 /*
 806                  * Collect data segment to the connection's data
 807                  * placeholder
 808                  */
 809                 if (iscsi_tcp_copy(conn)) {
 810                         rc = -EAGAIN;
 811                         goto exit;
 812                 }
 813
 814                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
 815                                         tcp_conn->in.datalen);
 816                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 817                         iscsi_recv_digest_update(tcp_conn, conn->data,
 818                                                 tcp_conn->in.datalen);
 819                 break;
 820         default:
 821                 BUG_ON(1);
 822         }
 823 exit:
 824         return rc;
 825 }
 826
 827 /**
 828  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 829  * @rd_desc: read descriptor
 830  * @skb: socket buffer
 831  * @offset: offset in skb
 832  * @len: skb->len - offset
 833  **/
 834 static int
 835 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 836                 unsigned int offset, size_t len)
 837 {
 838         int rc;
 839         struct iscsi_conn *conn = rd_desc->arg.data;
 840         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 841         int processed;
 842         char pad[ISCSI_PAD_LEN];
 843         struct scatterlist sg;
 844
 845         /*
 846          * Save current SKB and its offset in the corresponding
 847          * connection context.
 848          */
 849         tcp_conn->in.copy = skb->len - offset;
 850         tcp_conn->in.offset = offset;
 851         tcp_conn->in.skb = skb;
 852         tcp_conn->in.len = tcp_conn->in.copy;
 853         BUG_ON(tcp_conn->in.copy <= 0);
 854         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 855
 856 more:
 857         tcp_conn->in.copied = 0;
 858         rc = 0;
 859
 860         if (unlikely(conn->suspend_rx)) {
 861                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 862                 return 0;
 863         }
 864
 865         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 866             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 867                 rc = iscsi_hdr_extract(tcp_conn);
 868                 if (rc) {
 869                        if (rc == -EAGAIN)
 870                                 goto nomore;
 871                        else {
 872                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 873                                 return 0;
 874                        }
 875                 }
 876
 877                 /*
 878                  * Verify and process incoming PDU header.
 879                  */
 880                 rc = iscsi_tcp_hdr_recv(conn);
 881                 if (!rc && tcp_conn->in.datalen) {
 882                         if (conn->datadgst_en) {
 883                                 BUG_ON(!tcp_conn->data_rx_tfm);
 884                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 885                         }
 886                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 887                 } else if (rc) {
 888                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 889                         return 0;
 890                 }
 891         }
 892
 893         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 894                 uint32_t recv_digest;
 895
 896                 debug_tcp("extra data_recv offset %d copy %d\n",
 897                           tcp_conn->in.offset, tcp_conn->in.copy);
 898                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 899                                 &recv_digest, 4);
 900                 tcp_conn->in.offset += 4;
 901                 tcp_conn->in.copy -= 4;
 902                 if (recv_digest != tcp_conn->in.datadgst) {
 903                         debug_tcp("iscsi_tcp: data digest error!"
 904                                   "0x%x != 0x%x\n", recv_digest,
 905                                   tcp_conn->in.datadgst);
 906                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 907                         return 0;
 908                 } else {
 909                         debug_tcp("iscsi_tcp: data digest match!"
 910                                   "0x%x == 0x%x\n", recv_digest,
 911                                   tcp_conn->in.datadgst);
 912                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 913                 }
 914         }
 915
 916         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 917            tcp_conn->in.copy) {
 918
 919                 debug_tcp("data_recv offset %d copy %d\n",
 920                        tcp_conn->in.offset, tcp_conn->in.copy);
 921
 922                 rc = iscsi_data_recv(conn);
 923                 if (rc) {
 924                         if (rc == -EAGAIN)
 925                                 goto again;
 926                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 927                         return 0;
 928                 }
 929                 tcp_conn->in.copy -= tcp_conn->in.padding;
 930                 tcp_conn->in.offset += tcp_conn->in.padding;
 931                 if (conn->datadgst_en) {
 932                         if (tcp_conn->in.padding) {
 933                                 debug_tcp("padding -> %d\n",
 934                                           tcp_conn->in.padding);
 935                                 memset(pad, 0, tcp_conn->in.padding);
 936                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 937                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 938                                                      &sg, 1);
 939                         }
 940                         crypto_digest_final(tcp_conn->data_rx_tfm,
 941                                             (u8 *) & tcp_conn->in.datadgst);
 942                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 943                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 944                 } else
 945                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 946         }
 947
 948         debug_tcp("f, processed %d from out of %d padding %d\n",
 949                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 950         BUG_ON(tcp_conn->in.offset - offset > len);
 951
 952         if (tcp_conn->in.offset - offset != len) {
 953                 debug_tcp("continue to process %d bytes\n",
 954                        (int)len - (tcp_conn->in.offset - offset));
 955                 goto more;
 956         }
 957
 958 nomore:
 959         processed = tcp_conn->in.offset - offset;
 960         BUG_ON(processed == 0);
 961         return processed;
 962
 963 again:
 964         processed = tcp_conn->in.offset - offset;
 965         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 966                   processed, (int)len, (int)rd_desc->count);
 967         BUG_ON(processed == 0);
 968         BUG_ON(processed > len);
 969
 970         conn->rxdata_octets += processed;
 971         return processed;
 972 }
 973
 974 static void
 975 iscsi_tcp_data_ready(struct sock *sk, int flag)
 976 {
 977         struct iscsi_conn *conn = sk->sk_user_data;
 978         read_descriptor_t rd_desc;
 979
 980         read_lock(&sk->sk_callback_lock);
 981
 982         /*
 983          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 984          * We set count to 1 because we want the network layer to
 985          * hand us all the skbs that are available. iscsi_tcp_data_recv
 986          * handled pdus that cross buffers or pdus that still need data.
 987          */
 988         rd_desc.arg.data = conn;
 989         rd_desc.count = 1;
 990         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 991
 992         read_unlock(&sk->sk_callback_lock);
 993 }
 994
 995 static void
 996 iscsi_tcp_state_change(struct sock *sk)
 997 {
 998         struct iscsi_tcp_conn *tcp_conn;
 999         struct iscsi_conn *conn;
1000         struct iscsi_session *session;
1001         void (*old_state_change)(struct sock *);
1002
1003         read_lock(&sk->sk_callback_lock);
1004
1005         conn = (struct iscsi_conn*)sk->sk_user_data;
1006         session = conn->session;
1007
1008         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1009              sk->sk_state == TCP_CLOSE) &&
1010             !atomic_read(&sk->sk_rmem_alloc)) {
1011                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1012                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1013         }
1014
1015         tcp_conn = conn->dd_data;
1016         old_state_change = tcp_conn->old_state_change;
1017
1018         read_unlock(&sk->sk_callback_lock);
1019
1020         old_state_change(sk);
1021 }
1022
1023 /**
1024  * iscsi_write_space - Called when more output buffer space is available
1025  * @sk: socket space is available for
1026  **/
1027 static void
1028 iscsi_write_space(struct sock *sk)
1029 {
1030         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1031         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1032
1033         tcp_conn->old_write_space(sk);
1034         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1035         scsi_queue_work(conn->session->host, &conn->xmitwork);
1036 }
1037
1038 static void
1039 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1040 {
1041         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1042         struct sock *sk = tcp_conn->sock->sk;
1043
1044         /* assign new callbacks */
1045         write_lock_bh(&sk->sk_callback_lock);
1046         sk->sk_user_data = conn;
1047         tcp_conn->old_data_ready = sk->sk_data_ready;
1048         tcp_conn->old_state_change = sk->sk_state_change;
1049         tcp_conn->old_write_space = sk->sk_write_space;
1050         sk->sk_data_ready = iscsi_tcp_data_ready;
1051         sk->sk_state_change = iscsi_tcp_state_change;
1052         sk->sk_write_space = iscsi_write_space;
1053         write_unlock_bh(&sk->sk_callback_lock);
1054 }
1055
1056 static void
1057 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1058 {
1059         struct sock *sk = tcp_conn->sock->sk;
1060
1061         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1062         write_lock_bh(&sk->sk_callback_lock);
1063         sk->sk_user_data    = NULL;
1064         sk->sk_data_ready   = tcp_conn->old_data_ready;
1065         sk->sk_state_change = tcp_conn->old_state_change;
1066         sk->sk_write_space  = tcp_conn->old_write_space;
1067         sk->sk_no_check  = 0;
1068         write_unlock_bh(&sk->sk_callback_lock);
1069 }
1070
1071 /**
1072  * iscsi_send - generic send routine
1073  * @sk: kernel's socket
1074  * @buf: buffer to write from
1075  * @size: actual size to write
1076  * @flags: socket's flags
1077  */
1078 static inline int
1079 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1080 {
1081         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1082         struct socket *sk = tcp_conn->sock;
1083         int offset = buf->sg.offset + buf->sent, res;
1084
1085         /*
1086          * if we got use_sg=0 or are sending something we kmallocd
1087          * then we did not have to do kmap (kmap returns page_address)
1088          *
1089          * if we got use_sg > 0, but had to drop down, we do not
1090          * set clustering so this should only happen for that
1091          * slab case.
1092          */
1093         if (buf->use_sendmsg)
1094                 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1095         else
1096                 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1097
1098         if (res >= 0) {
1099                 conn->txdata_octets += res;
1100                 buf->sent += res;
1101                 return res;
1102         }
1103
1104         tcp_conn->sendpage_failures_cnt++;
1105         if (res == -EAGAIN)
1106                 res = -ENOBUFS;
1107         else
1108                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1109         return res;
1110 }
1111
1112 /**
1113  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1114  * @conn: iscsi connection
1115  * @buf: buffer to write from
1116  * @datalen: lenght of data to be sent after the header
1117  *
1118  * Notes:
1119  *      (Tx, Fast Path)
1120  **/
1121 static inline int
1122 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1123 {
1124         int flags = 0; /* MSG_DONTWAIT; */
1125         int res, size;
1126
1127         size = buf->sg.length - buf->sent;
1128         BUG_ON(buf->sent + size > buf->sg.length);
1129         if (buf->sent + size != buf->sg.length || datalen)
1130                 flags |= MSG_MORE;
1131
1132         res = iscsi_send(conn, buf, size, flags);
1133         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1134         if (res >= 0) {
1135                 if (size != res)
1136                         return -EAGAIN;
1137                 return 0;
1138         }
1139
1140         return res;
1141 }
1142
1143 /**
1144  * iscsi_sendpage - send one page of iSCSI Data-Out.
1145  * @conn: iscsi connection
1146  * @buf: buffer to write from
1147  * @count: remaining data
1148  * @sent: number of bytes sent
1149  *
1150  * Notes:
1151  *      (Tx, Fast Path)
1152  **/
1153 static inline int
1154 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1155                int *count, int *sent)
1156 {
1157         int flags = 0; /* MSG_DONTWAIT; */
1158         int res, size;
1159
1160         size = buf->sg.length - buf->sent;
1161         BUG_ON(buf->sent + size > buf->sg.length);
1162         if (size > *count)
1163                 size = *count;
1164         if (buf->sent + size != buf->sg.length || *count != size)
1165                 flags |= MSG_MORE;
1166
1167         res = iscsi_send(conn, buf, size, flags);
1168         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1169                   size, buf->sent, *count, *sent, res);
1170         if (res >= 0) {
1171                 *count -= res;
1172                 *sent += res;
1173                 if (size != res)
1174                         return -EAGAIN;
1175                 return 0;
1176         }
1177
1178         return res;
1179 }
1180
1181 static inline void
1182 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1183                       struct iscsi_cmd_task *ctask)
1184 {
1185         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1186
1187         BUG_ON(!tcp_conn->data_tx_tfm);
1188         crypto_digest_init(tcp_conn->data_tx_tfm);
1189         tcp_ctask->digest_count = 4;
1190 }
1191
1192 static int
1193 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1194                         struct iscsi_buf *buf, uint32_t *digest, int final)
1195 {
1196         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1197         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1198         int rc = 0;
1199         int sent = 0;
1200
1201         if (final)
1202                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1203
1204         iscsi_buf_init_iov(buf, (char*)digest, 4);
1205         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1206         if (rc) {
1207                 tcp_ctask->datadigest = *digest;
1208                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1209         } else
1210                 tcp_ctask->digest_count = 4;
1211         return rc;
1212 }
1213
1214 /**
1215  * iscsi_solicit_data_cont - initialize next Data-Out
1216  * @conn: iscsi connection
1217  * @ctask: scsi command task
1218  * @r2t: R2T info
1219  * @left: bytes left to transfer
1220  *
1221  * Notes:
1222  *      Initialize next Data-Out within this R2T sequence and continue
1223  *      to process next Scatter-Gather element(if any) of this SCSI command.
1224  *
1225  *      Called under connection lock.
1226  **/
1227 static void
1228 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1229                         struct iscsi_r2t_info *r2t, int left)
1230 {
1231         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1232         struct iscsi_data *hdr;
1233         struct scsi_cmnd *sc = ctask->sc;
1234         int new_offset;
1235
1236         hdr = &r2t->dtask.hdr;
1237         memset(hdr, 0, sizeof(struct iscsi_data));
1238         hdr->ttt = r2t->ttt;
1239         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1240         r2t->solicit_datasn++;
1241         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1242         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1243         hdr->itt = ctask->hdr->itt;
1244         hdr->exp_statsn = r2t->exp_statsn;
1245         new_offset = r2t->data_offset + r2t->sent;
1246         hdr->offset = cpu_to_be32(new_offset);
1247         if (left > conn->max_xmit_dlength) {
1248                 hton24(hdr->dlength, conn->max_xmit_dlength);
1249                 r2t->data_count = conn->max_xmit_dlength;
1250         } else {
1251                 hton24(hdr->dlength, left);
1252                 r2t->data_count = left;
1253                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1254         }
1255         conn->dataout_pdus_cnt++;
1256
1257         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1258                            sizeof(struct iscsi_hdr));
1259
1260         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1261                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1262                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1263                 r2t->sg += 1;
1264         } else
1265                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1266                             (char*)sc->request_buffer + new_offset,
1267                             r2t->data_count);
1268 }
1269
1270 static void
1271 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1272 {
1273         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1274         struct iscsi_data_task *dtask;
1275
1276         dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1277         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1278                                       tcp_ctask->r2t_data_count);
1279         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1280                            sizeof(struct iscsi_hdr));
1281 }
1282
1283 /**
1284  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1285  * @conn: iscsi connection
1286  * @ctask: scsi command task
1287  * @sc: scsi command
1288  **/
1289 static void
1290 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1291 {
1292         struct scsi_cmnd *sc = ctask->sc;
1293         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1294
1295         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1296
1297         tcp_ctask->sent = 0;
1298         tcp_ctask->sg_count = 0;
1299
1300         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1301                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1302                 tcp_ctask->exp_r2tsn = 0;
1303                 BUG_ON(ctask->total_length == 0);
1304
1305                 if (sc->use_sg) {
1306                         struct scatterlist *sg = sc->request_buffer;
1307
1308                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1309                                           &sg[tcp_ctask->sg_count++]);
1310                         tcp_ctask->sg = sg;
1311                         tcp_ctask->bad_sg = sg + sc->use_sg;
1312                 } else
1313                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1314                                            sc->request_buffer,
1315                                            sc->request_bufflen);
1316
1317                 if (ctask->imm_count)
1318                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1319
1320                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1321                 if (tcp_ctask->pad_count) {
1322                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1323                                                         tcp_ctask->pad_count;
1324                         debug_scsi("write padding %d bytes\n",
1325                                    tcp_ctask->pad_count);
1326                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1327                 }
1328
1329                 if (ctask->unsol_count)
1330                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1331                                                 XMSTATE_UNS_INIT;
1332                 tcp_ctask->r2t_data_count = ctask->total_length -
1333                                     ctask->imm_count -
1334                                     ctask->unsol_count;
1335
1336                 debug_scsi("cmd [itt 0x%x total %d imm %d imm_data %d "
1337                            "r2t_data %d]\n",
1338                            ctask->itt, ctask->total_length, ctask->imm_count,
1339                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1340         } else
1341                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1342
1343         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1344                             sizeof(struct iscsi_hdr));
1345 }
1346
1347 /**
1348  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1349  * @conn: iscsi connection
1350  * @mtask: task management task
1351  *
1352  * Notes:
1353  *      The function can return -EAGAIN in which case caller must
1354  *      call it again later, or recover. '0' return code means successful
1355  *      xmit.
1356  *
1357  *      Management xmit state machine consists of two states:
1358  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1359  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1360  **/
1361 static int
1362 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1363 {
1364         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1365         int rc;
1366
1367         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1368                 conn->id, tcp_mtask->xmstate, mtask->itt);
1369
1370         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1371                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1372                 if (mtask->data_count)
1373                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1374                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1375                     conn->stop_stage != STOP_CONN_RECOVER &&
1376                     conn->hdrdgst_en)
1377                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1378                                         (u8*)tcp_mtask->hdrext);
1379                 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1380                                    mtask->data_count);
1381                 if (rc) {
1382                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1383                         if (mtask->data_count)
1384                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1385                         return rc;
1386                 }
1387         }
1388
1389         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1390                 BUG_ON(!mtask->data_count);
1391                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1392                 /* FIXME: implement.
1393                  * Virtual buffer could be spreaded across multiple pages...
1394                  */
1395                 do {
1396                         int rc;
1397
1398                         rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1399                                         &mtask->data_count, &tcp_mtask->sent);
1400                         if (rc) {
1401                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1402                                 return rc;
1403                         }
1404                 } while (mtask->data_count);
1405         }
1406
1407         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1408         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1409                 struct iscsi_session *session = conn->session;
1410
1411                 spin_lock_bh(&session->lock);
1412                 list_del(&conn->mtask->running);
1413                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1414                             sizeof(void*));
1415                 spin_unlock_bh(&session->lock);
1416         }
1417         return 0;
1418 }
1419
1420 static inline int
1421 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1422                      struct iscsi_tcp_cmd_task *tcp_ctask)
1423 {
1424         int rc;
1425
1426         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1427         if (conn->hdrdgst_en)
1428                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1429                                  (u8*)tcp_ctask->hdrext);
1430         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1431         if (!rc) {
1432                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1433                 return 0; /* wait for Data-In */
1434         }
1435         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1436         return rc;
1437 }
1438
1439 static inline int
1440 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1441                      struct iscsi_cmd_task *ctask)
1442 {
1443         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1444         int rc;
1445
1446         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1447         if (conn->hdrdgst_en)
1448                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1449                                  (u8*)tcp_ctask->hdrext);
1450         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1451         if (rc)
1452                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1453         return rc;
1454 }
1455
1456 static inline int
1457 handle_xmstate_data_digest(struct iscsi_conn *conn,
1458                            struct iscsi_cmd_task *ctask)
1459 {
1460         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1461         int rc;
1462
1463         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1464         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1465         rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1466                                     &tcp_ctask->datadigest, 0);
1467         if (rc) {
1468                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1469                 debug_tcp("resent data digest 0x%x fail!\n",
1470                           tcp_ctask->datadigest);
1471         }
1472
1473         return rc;
1474 }
1475
1476 static inline int
1477 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1478 {
1479         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1480         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1481         int rc;
1482
1483         BUG_ON(!ctask->imm_count);
1484         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1485
1486         if (conn->datadgst_en) {
1487                 iscsi_data_digest_init(tcp_conn, ctask);
1488                 tcp_ctask->immdigest = 0;
1489         }
1490
1491         for (;;) {
1492                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1493                                    &ctask->imm_count, &tcp_ctask->sent);
1494                 if (rc) {
1495                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1496                         if (conn->datadgst_en) {
1497                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1498                                                 (u8*)&tcp_ctask->immdigest);
1499                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1500                                           tcp_ctask->datadigest);
1501                         }
1502                         return rc;
1503                 }
1504                 if (conn->datadgst_en)
1505                         crypto_digest_update(tcp_conn->data_tx_tfm,
1506                                              &tcp_ctask->sendbuf.sg, 1);
1507
1508                 if (!ctask->imm_count)
1509                         break;
1510                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1511                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1512         }
1513
1514         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1515                 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1516                                             &tcp_ctask->immdigest, 1);
1517                 if (rc) {
1518                         debug_tcp("sending imm digest 0x%x fail!\n",
1519                                   tcp_ctask->immdigest);
1520                         return rc;
1521                 }
1522                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1523         }
1524
1525         return 0;
1526 }
1527
1528 static inline int
1529 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1530 {
1531         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1532         struct iscsi_data_task *dtask;
1533         int rc;
1534
1535         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1536         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1537                 iscsi_unsolicit_data_init(conn, ctask);
1538                 dtask = tcp_ctask->dtask;
1539                 if (conn->hdrdgst_en)
1540                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1541                                         (u8*)dtask->hdrext);
1542                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1543         }
1544
1545         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1546         if (rc) {
1547                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1548                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1549                 return rc;
1550         }
1551
1552         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1553                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1554         return 0;
1555 }
1556
1557 static inline int
1558 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1559 {
1560         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1561         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1562         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1563         int rc;
1564
1565         BUG_ON(!ctask->data_count);
1566         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1567
1568         if (conn->datadgst_en) {
1569                 iscsi_data_digest_init(tcp_conn, ctask);
1570                 dtask->digest = 0;
1571         }
1572
1573         for (;;) {
1574                 int start = tcp_ctask->sent;
1575
1576                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1577                                    &ctask->data_count, &tcp_ctask->sent);
1578                 if (rc) {
1579                         ctask->unsol_count -= tcp_ctask->sent - start;
1580                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1581                         /* will continue with this ctask later.. */
1582                         if (conn->datadgst_en) {
1583                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1584                                                 (u8 *)&dtask->digest);
1585                                 debug_tcp("tx uns data fail 0x%x\n",
1586                                           dtask->digest);
1587                         }
1588                         return rc;
1589                 }
1590
1591                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1592                 ctask->unsol_count -= tcp_ctask->sent - start;
1593
1594                 /*
1595                  * XXX:we may run here with un-initial sendbuf.
1596                  * so pass it
1597                  */
1598                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1599                         crypto_digest_update(tcp_conn->data_tx_tfm,
1600                                              &tcp_ctask->sendbuf.sg, 1);
1601
1602                 if (!ctask->data_count)
1603                         break;
1604                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1605                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1606         }
1607         BUG_ON(ctask->unsol_count < 0);
1608
1609         /*
1610          * Done with the Data-Out. Next, check if we need
1611          * to send another unsolicited Data-Out.
1612          */
1613         if (ctask->unsol_count) {
1614                 if (conn->datadgst_en) {
1615                         rc = iscsi_digest_final_send(conn, ctask,
1616                                                     &dtask->digestbuf,
1617                                                     &dtask->digest, 1);
1618                         if (rc) {
1619                                 debug_tcp("send uns digest 0x%x fail\n",
1620                                           dtask->digest);
1621                                 return rc;
1622                         }
1623                         debug_tcp("sending uns digest 0x%x, more uns\n",
1624                                   dtask->digest);
1625                 }
1626                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1627                 return 1;
1628         }
1629
1630         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1631                 rc = iscsi_digest_final_send(conn, ctask,
1632                                             &dtask->digestbuf,
1633                                             &dtask->digest, 1);
1634                 if (rc) {
1635                         debug_tcp("send last uns digest 0x%x fail\n",
1636                                    dtask->digest);
1637                         return rc;
1638                 }
1639                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1640         }
1641
1642         return 0;
1643 }
1644
1645 static inline int
1646 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1647 {
1648         struct iscsi_session *session = conn->session;
1649         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1650         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1651         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1652         struct iscsi_data_task *dtask = &r2t->dtask;
1653         int left, rc;
1654
1655         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1656         tcp_ctask->dtask = dtask;
1657
1658         if (conn->datadgst_en) {
1659                 iscsi_data_digest_init(tcp_conn, ctask);
1660                 dtask->digest = 0;
1661         }
1662 solicit_again:
1663         /*
1664          * send Data-Out within this R2T sequence.
1665          */
1666         if (!r2t->data_count)
1667                 goto data_out_done;
1668
1669         rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
1670         if (rc) {
1671                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1672                 /* will continue with this ctask later.. */
1673                 if (conn->datadgst_en) {
1674                         crypto_digest_final(tcp_conn->data_tx_tfm,
1675                                           (u8 *)&dtask->digest);
1676                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1677                 }
1678                 return rc;
1679         }
1680
1681         BUG_ON(r2t->data_count < 0);
1682         if (conn->datadgst_en)
1683                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1684                                      1);
1685
1686         if (r2t->data_count) {
1687                 BUG_ON(ctask->sc->use_sg == 0);
1688                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1689                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1690                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1691                         r2t->sg += 1;
1692                 }
1693                 goto solicit_again;
1694         }
1695
1696 data_out_done:
1697         /*
1698          * Done with this Data-Out. Next, check if we have
1699          * to send another Data-Out for this R2T.
1700          */
1701         BUG_ON(r2t->data_length - r2t->sent < 0);
1702         left = r2t->data_length - r2t->sent;
1703         if (left) {
1704                 if (conn->datadgst_en) {
1705                         rc = iscsi_digest_final_send(conn, ctask,
1706                                                     &dtask->digestbuf,
1707                                                     &dtask->digest, 1);
1708                         if (rc) {
1709                                 debug_tcp("send r2t data digest 0x%x"
1710                                           "fail\n", dtask->digest);
1711                                 return rc;
1712                         }
1713                         debug_tcp("r2t data send digest 0x%x\n",
1714                                   dtask->digest);
1715                 }
1716                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1717                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1718                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1719                 return 1;
1720         }
1721
1722         /*
1723          * Done with this R2T. Check if there are more
1724          * outstanding R2Ts ready to be processed.
1725          */
1726         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1727         if (conn->datadgst_en) {
1728                 rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1729                                             &dtask->digest, 1);
1730                 if (rc) {
1731                         debug_tcp("send last r2t data digest 0x%x"
1732                                   "fail\n", dtask->digest);
1733                         return rc;
1734                 }
1735                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1736         }
1737
1738         tcp_ctask->r2t_data_count -= r2t->data_length;
1739         tcp_ctask->r2t = NULL;
1740         spin_lock_bh(&session->lock);
1741         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1742         spin_unlock_bh(&session->lock);
1743         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1744                 tcp_ctask->r2t = r2t;
1745                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1746                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1747                 return 1;
1748         }
1749
1750         return 0;
1751 }
1752
1753 static inline int
1754 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1755 {
1756         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1757         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1758         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1759         int sent = 0, rc;
1760
1761         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1762         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1763                             tcp_ctask->pad_count);
1764         rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1765                            &sent);
1766         if (rc) {
1767                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1768                 return rc;
1769         }
1770
1771         if (conn->datadgst_en) {
1772                 crypto_digest_update(tcp_conn->data_tx_tfm,
1773                                      &tcp_ctask->sendbuf.sg, 1);
1774                 /* imm data? */
1775                 if (!dtask) {
1776                         rc = iscsi_digest_final_send(conn, ctask,
1777                                                     &tcp_ctask->immbuf,
1778                                                     &tcp_ctask->immdigest, 1);
1779                         if (rc) {
1780                                 debug_tcp("send padding digest 0x%x"
1781                                           "fail!\n", tcp_ctask->immdigest);
1782                                 return rc;
1783                         }
1784                         debug_tcp("done with padding, digest 0x%x\n",
1785                                   tcp_ctask->datadigest);
1786                 } else {
1787                         rc = iscsi_digest_final_send(conn, ctask,
1788                                                     &dtask->digestbuf,
1789                                                     &dtask->digest, 1);
1790                         if (rc) {
1791                                 debug_tcp("send padding digest 0x%x"
1792                                           "fail\n", dtask->digest);
1793                                 return rc;
1794                         }
1795                         debug_tcp("done with padding, digest 0x%x\n",
1796                                   dtask->digest);
1797                 }
1798         }
1799
1800         return 0;
1801 }
1802
1803 static int
1804 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1805 {
1806         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1807         int rc = 0;
1808
1809         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1810                 conn->id, tcp_ctask->xmstate, ctask->itt);
1811
1812         /*
1813          * serialize with TMF AbortTask
1814          */
1815         if (ctask->mtask)
1816                 return rc;
1817
1818         if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1819                 return handle_xmstate_r_hdr(conn, tcp_ctask);
1820
1821         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1822                 rc = handle_xmstate_w_hdr(conn, ctask);
1823                 if (rc)
1824                         return rc;
1825         }
1826
1827         /* XXX: for data digest xmit recover */
1828         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1829                 rc = handle_xmstate_data_digest(conn, ctask);
1830                 if (rc)
1831                         return rc;
1832         }
1833
1834         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1835                 rc = handle_xmstate_imm_data(conn, ctask);
1836                 if (rc)
1837                         return rc;
1838         }
1839
1840         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1841                 BUG_ON(!ctask->unsol_count);
1842                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1843 unsolicit_head_again:
1844                 rc = handle_xmstate_uns_hdr(conn, ctask);
1845                 if (rc)
1846                         return rc;
1847         }
1848
1849         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1850                 rc = handle_xmstate_uns_data(conn, ctask);
1851                 if (rc == 1)
1852                         goto unsolicit_head_again;
1853                 else if (rc)
1854                         return rc;
1855                 goto done;
1856         }
1857
1858         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1859                 struct iscsi_r2t_info *r2t;
1860
1861                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1862                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1863                 if (!tcp_ctask->r2t)
1864                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1865                                     sizeof(void*));
1866 solicit_head_again:
1867                 r2t = tcp_ctask->r2t;
1868                 if (conn->hdrdgst_en)
1869                         iscsi_hdr_digest(conn, &r2t->headbuf,
1870                                         (u8*)r2t->dtask.hdrext);
1871                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1872                 if (rc) {
1873                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1874                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1875                         return rc;
1876                 }
1877
1878                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1879                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1880                         r2t->sent);
1881         }
1882
1883         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1884                 rc = handle_xmstate_sol_data(conn, ctask);
1885                 if (rc == 1)
1886                         goto solicit_head_again;
1887                 if (rc)
1888                         return rc;
1889         }
1890
1891 done:
1892         /*
1893          * Last thing to check is whether we need to send write
1894          * padding. Note that we check for xmstate equality, not just the bit.
1895          */
1896         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1897                 rc = handle_xmstate_w_pad(conn, ctask);
1898
1899         return rc;
1900 }
1901
1902 static struct iscsi_cls_conn *
1903 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1904 {
1905         struct iscsi_conn *conn;
1906         struct iscsi_cls_conn *cls_conn;
1907         struct iscsi_tcp_conn *tcp_conn;
1908
1909         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1910         if (!cls_conn)
1911                 return NULL;
1912         conn = cls_conn->dd_data;
1913         /*
1914          * due to strange issues with iser these are not set
1915          * in iscsi_conn_setup
1916          */
1917         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1918
1919         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1920         if (!tcp_conn)
1921                 goto tcp_conn_alloc_fail;
1922
1923         conn->dd_data = tcp_conn;
1924         tcp_conn->iscsi_conn = conn;
1925         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1926         /* initial operational parameters */
1927         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1928
1929         return cls_conn;
1930
1931 tcp_conn_alloc_fail:
1932         iscsi_conn_teardown(cls_conn);
1933         return NULL;
1934 }
1935
1936 static void
1937 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1938 {
1939         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1940
1941         if (!tcp_conn->sock)
1942                 return;
1943
1944         sock_hold(tcp_conn->sock->sk);
1945         iscsi_conn_restore_callbacks(tcp_conn);
1946         sock_put(tcp_conn->sock->sk);
1947
1948         sock_release(tcp_conn->sock);
1949         tcp_conn->sock = NULL;
1950         conn->recv_lock = NULL;
1951 }
1952
1953 static void
1954 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1955 {
1956         struct iscsi_conn *conn = cls_conn->dd_data;
1957         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1958         int digest = 0;
1959
1960         if (conn->hdrdgst_en || conn->datadgst_en)
1961                 digest = 1;
1962
1963         iscsi_tcp_release_conn(conn);
1964         iscsi_conn_teardown(cls_conn);
1965
1966         /* now free tcp_conn */
1967         if (digest) {
1968                 if (tcp_conn->tx_tfm)
1969                         crypto_free_tfm(tcp_conn->tx_tfm);
1970                 if (tcp_conn->rx_tfm)
1971                         crypto_free_tfm(tcp_conn->rx_tfm);
1972                 if (tcp_conn->data_tx_tfm)
1973                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1974                 if (tcp_conn->data_rx_tfm)
1975                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1976         }
1977
1978         kfree(tcp_conn);
1979 }
1980
1981 static void
1982 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1983 {
1984         struct iscsi_conn *conn = cls_conn->dd_data;
1985
1986         iscsi_conn_stop(cls_conn, flag);
1987         iscsi_tcp_release_conn(conn);
1988 }
1989
1990 static int
1991 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1992                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1993                     int is_leading)
1994 {
1995         struct iscsi_conn *conn = cls_conn->dd_data;
1996         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1997         struct sock *sk;
1998         struct socket *sock;
1999         int err;
2000
2001         /* lookup for existing socket */
2002         sock = sockfd_lookup((int)transport_eph, &err);
2003         if (!sock) {
2004                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2005                 return -EEXIST;
2006         }
2007
2008         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
2009         if (err)
2010                 return err;
2011
2012         /* bind iSCSI connection and socket */
2013         tcp_conn->sock = sock;
2014
2015         /* setup Socket parameters */
2016         sk = sock->sk;
2017         sk->sk_reuse = 1;
2018         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2019         sk->sk_allocation = GFP_ATOMIC;
2020
2021         /* FIXME: disable Nagle's algorithm */
2022
2023         /*
2024          * Intercept TCP callbacks for sendfile like receive
2025          * processing.
2026          */
2027         conn->recv_lock = &sk->sk_callback_lock;
2028         iscsi_conn_set_callbacks(conn);
2029         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2030         /*
2031          * set receive state machine into initial state
2032          */
2033         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2034
2035         return 0;
2036 }
2037
2038 /* called with host lock */
2039 static void
2040 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2041                     char *data, uint32_t data_size)
2042 {
2043         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2044
2045         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2046                            sizeof(struct iscsi_hdr));
2047         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2048         tcp_mtask->sent = 0;
2049
2050         if (mtask->data_count)
2051                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2052                                     mtask->data_count);
2053 }
2054
2055 static int
2056 iscsi_r2tpool_alloc(struct iscsi_session *session)
2057 {
2058         int i;
2059         int cmd_i;
2060
2061         /*
2062          * initialize per-task: R2T pool and xmit queue
2063          */
2064         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2065                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2066                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2067
2068                 /*
2069                  * pre-allocated x4 as much r2ts to handle race when
2070                  * target acks DataOut faster than we data_xmit() queues
2071                  * could replenish r2tqueue.
2072                  */
2073
2074                 /* R2T pool */
2075                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2076                                     (void***)&tcp_ctask->r2ts,
2077                                     sizeof(struct iscsi_r2t_info))) {
2078                         goto r2t_alloc_fail;
2079                 }
2080
2081                 /* R2T xmit queue */
2082                 tcp_ctask->r2tqueue = kfifo_alloc(
2083                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2084                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2085                         iscsi_pool_free(&tcp_ctask->r2tpool,
2086                                         (void**)tcp_ctask->r2ts);
2087                         goto r2t_alloc_fail;
2088                 }
2089         }
2090
2091         return 0;
2092
2093 r2t_alloc_fail:
2094         for (i = 0; i < cmd_i; i++) {
2095                 struct iscsi_cmd_task *ctask = session->cmds[i];
2096                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2097
2098                 kfifo_free(tcp_ctask->r2tqueue);
2099                 iscsi_pool_free(&tcp_ctask->r2tpool,
2100                                 (void**)tcp_ctask->r2ts);
2101         }
2102         return -ENOMEM;
2103 }
2104
2105 static void
2106 iscsi_r2tpool_free(struct iscsi_session *session)
2107 {
2108         int i;
2109
2110         for (i = 0; i < session->cmds_max; i++) {
2111                 struct iscsi_cmd_task *ctask = session->cmds[i];
2112                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2113
2114                 kfifo_free(tcp_ctask->r2tqueue);
2115                 iscsi_pool_free(&tcp_ctask->r2tpool,
2116                                 (void**)tcp_ctask->r2ts);
2117         }
2118 }
2119
2120 static int
2121 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2122                      char *buf, int buflen)
2123 {
2124         struct iscsi_conn *conn = cls_conn->dd_data;
2125         struct iscsi_session *session = conn->session;
2126         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2127         int value;
2128
2129         switch(param) {
2130         case ISCSI_PARAM_HDRDGST_EN:
2131                 iscsi_set_param(cls_conn, param, buf, buflen);
2132                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2133                 if (conn->hdrdgst_en) {
2134                         tcp_conn->hdr_size += sizeof(__u32);
2135                         if (!tcp_conn->tx_tfm)
2136                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2137                                                                     0);
2138                         if (!tcp_conn->tx_tfm)
2139                                 return -ENOMEM;
2140                         if (!tcp_conn->rx_tfm)
2141                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2142                                                                     0);
2143                         if (!tcp_conn->rx_tfm) {
2144                                 crypto_free_tfm(tcp_conn->tx_tfm);
2145                                 return -ENOMEM;
2146                         }
2147                 } else {
2148                         if (tcp_conn->tx_tfm)
2149                                 crypto_free_tfm(tcp_conn->tx_tfm);
2150                         if (tcp_conn->rx_tfm)
2151                                 crypto_free_tfm(tcp_conn->rx_tfm);
2152                 }
2153                 break;
2154         case ISCSI_PARAM_DATADGST_EN:
2155                 iscsi_set_param(cls_conn, param, buf, buflen);
2156                 if (conn->datadgst_en) {
2157                         if (!tcp_conn->data_tx_tfm)
2158                                 tcp_conn->data_tx_tfm =
2159                                     crypto_alloc_tfm("crc32c", 0);
2160                         if (!tcp_conn->data_tx_tfm)
2161                                 return -ENOMEM;
2162                         if (!tcp_conn->data_rx_tfm)
2163                                 tcp_conn->data_rx_tfm =
2164                                     crypto_alloc_tfm("crc32c", 0);
2165                         if (!tcp_conn->data_rx_tfm) {
2166                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2167                                 return -ENOMEM;
2168                         }
2169                 } else {
2170                         if (tcp_conn->data_tx_tfm)
2171                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2172                         if (tcp_conn->data_rx_tfm)
2173                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2174                 }
2175                 tcp_conn->sendpage = conn->datadgst_en ?
2176                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2177                 break;
2178         case ISCSI_PARAM_MAX_R2T:
2179                 sscanf(buf, "%d", &value);
2180                 if (session->max_r2t == roundup_pow_of_two(value))
2181                         break;
2182                 iscsi_r2tpool_free(session);
2183                 iscsi_set_param(cls_conn, param, buf, buflen);
2184                 if (session->max_r2t & (session->max_r2t - 1))
2185                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2186                 if (iscsi_r2tpool_alloc(session))
2187                         return -ENOMEM;
2188                 break;
2189         default:
2190                 return iscsi_set_param(cls_conn, param, buf, buflen);
2191         }
2192
2193         return 0;
2194 }
2195
2196 static int
2197 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2198                          enum iscsi_param param, char *buf)
2199 {
2200         struct iscsi_conn *conn = cls_conn->dd_data;
2201         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2202         struct inet_sock *inet;
2203         struct ipv6_pinfo *np;
2204         struct sock *sk;
2205         int len;
2206
2207         switch(param) {
2208         case ISCSI_PARAM_CONN_PORT:
2209                 mutex_lock(&conn->xmitmutex);
2210                 if (!tcp_conn->sock) {
2211                         mutex_unlock(&conn->xmitmutex);
2212                         return -EINVAL;
2213                 }
2214
2215                 inet = inet_sk(tcp_conn->sock->sk);
2216                 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2217                 mutex_unlock(&conn->xmitmutex);
2218                 break;
2219         case ISCSI_PARAM_CONN_ADDRESS:
2220                 mutex_lock(&conn->xmitmutex);
2221                 if (!tcp_conn->sock) {
2222                         mutex_unlock(&conn->xmitmutex);
2223                         return -EINVAL;
2224                 }
2225
2226                 sk = tcp_conn->sock->sk;
2227                 if (sk->sk_family == PF_INET) {
2228                         inet = inet_sk(sk);
2229                         len = sprintf(buf, "%u.%u.%u.%u\n",
2230                                       NIPQUAD(inet->daddr));
2231                 } else {
2232                         np = inet6_sk(sk);
2233                         len = sprintf(buf,
2234                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2235                                 NIP6(np->daddr));
2236                 }
2237                 mutex_unlock(&conn->xmitmutex);
2238                 break;
2239         default:
2240                 return iscsi_conn_get_param(cls_conn, param, buf);
2241         }
2242
2243         return len;
2244 }
2245
2246 static void
2247 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2248 {
2249         struct iscsi_conn *conn = cls_conn->dd_data;
2250         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2251
2252         stats->txdata_octets = conn->txdata_octets;
2253         stats->rxdata_octets = conn->rxdata_octets;
2254         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2255         stats->dataout_pdus = conn->dataout_pdus_cnt;
2256         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2257         stats->datain_pdus = conn->datain_pdus_cnt;
2258         stats->r2t_pdus = conn->r2t_pdus_cnt;
2259         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2260         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2261         stats->custom_length = 3;
2262         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2263         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2264         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2265         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2266         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2267         stats->custom[2].value = conn->eh_abort_cnt;
2268 }
2269
2270 static struct iscsi_cls_session *
2271 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2272                          struct scsi_transport_template *scsit,
2273                          uint32_t initial_cmdsn, uint32_t *hostno)
2274 {
2275         struct iscsi_cls_session *cls_session;
2276         struct iscsi_session *session;
2277         uint32_t hn;
2278         int cmd_i;
2279
2280         cls_session = iscsi_session_setup(iscsit, scsit,
2281                                          sizeof(struct iscsi_tcp_cmd_task),
2282                                          sizeof(struct iscsi_tcp_mgmt_task),
2283                                          initial_cmdsn, &hn);
2284         if (!cls_session)
2285                 return NULL;
2286         *hostno = hn;
2287
2288         session = class_to_transport_session(cls_session);
2289         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2290                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2291                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2292
2293                 ctask->hdr = &tcp_ctask->hdr;
2294         }
2295
2296         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2297                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2298                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2299
2300                 mtask->hdr = &tcp_mtask->hdr;
2301         }
2302
2303         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2304                 goto r2tpool_alloc_fail;
2305
2306         return cls_session;
2307
2308 r2tpool_alloc_fail:
2309         iscsi_session_teardown(cls_session);
2310         return NULL;
2311 }
2312
2313 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2314 {
2315         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2316         iscsi_session_teardown(cls_session);
2317 }
2318
2319 static struct scsi_host_template iscsi_sht = {
2320         .name                   = "iSCSI Initiator over TCP/IP, v"
2321                                   ISCSI_TCP_VERSION,
2322         .queuecommand           = iscsi_queuecommand,
2323         .change_queue_depth     = iscsi_change_queue_depth,
2324         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2325         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2326         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2327         .eh_abort_handler       = iscsi_eh_abort,
2328         .eh_host_reset_handler  = iscsi_eh_host_reset,
2329         .use_clustering         = DISABLE_CLUSTERING,
2330         .proc_name              = "iscsi_tcp",
2331         .this_id                = -1,
2332 };
2333
2334 static struct iscsi_transport iscsi_tcp_transport = {
2335         .owner                  = THIS_MODULE,
2336         .name                   = "tcp",
2337         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2338                                   | CAP_DATADGST,
2339         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2340                                   ISCSI_MAX_XMIT_DLENGTH |
2341                                   ISCSI_HDRDGST_EN |
2342                                   ISCSI_DATADGST_EN |
2343                                   ISCSI_INITIAL_R2T_EN |
2344                                   ISCSI_MAX_R2T |
2345                                   ISCSI_IMM_DATA_EN |
2346                                   ISCSI_FIRST_BURST |
2347                                   ISCSI_MAX_BURST |
2348                                   ISCSI_PDU_INORDER_EN |
2349                                   ISCSI_DATASEQ_INORDER_EN |
2350                                   ISCSI_ERL |
2351                                   ISCSI_CONN_PORT |
2352                                   ISCSI_CONN_ADDRESS |
2353                                   ISCSI_EXP_STATSN |
2354                                   ISCSI_PERSISTENT_PORT |
2355                                   ISCSI_PERSISTENT_ADDRESS |
2356                                   ISCSI_TARGET_NAME |
2357                                   ISCSI_TPGT,
2358         .host_template          = &iscsi_sht,
2359         .conndata_size          = sizeof(struct iscsi_conn),
2360         .max_conn               = 1,
2361         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2362         /* session management */
2363         .create_session         = iscsi_tcp_session_create,
2364         .destroy_session        = iscsi_tcp_session_destroy,
2365         /* connection management */
2366         .create_conn            = iscsi_tcp_conn_create,
2367         .bind_conn              = iscsi_tcp_conn_bind,
2368         .destroy_conn           = iscsi_tcp_conn_destroy,
2369         .set_param              = iscsi_conn_set_param,
2370         .get_conn_param         = iscsi_tcp_conn_get_param,
2371         .get_session_param      = iscsi_session_get_param,
2372         .start_conn             = iscsi_conn_start,
2373         .stop_conn              = iscsi_tcp_conn_stop,
2374         /* IO */
2375         .send_pdu               = iscsi_conn_send_pdu,
2376         .get_stats              = iscsi_conn_get_stats,
2377         .init_cmd_task          = iscsi_tcp_cmd_init,
2378         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2379         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2380         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2381         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2382         /* recovery */
2383         .session_recovery_timedout = iscsi_session_recovery_timedout,
2384 };
2385
2386 static int __init
2387 iscsi_tcp_init(void)
2388 {
2389         if (iscsi_max_lun < 1) {
2390                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2391                        iscsi_max_lun);
2392                 return -EINVAL;
2393         }
2394         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2395
2396         if (!iscsi_register_transport(&iscsi_tcp_transport))
2397                 return -ENODEV;
2398
2399         return 0;
2400 }
2401
2402 static void __exit
2403 iscsi_tcp_exit(void)
2404 {
2405         iscsi_unregister_transport(&iscsi_tcp_transport);
2406 }
2407
2408 module_init(iscsi_tcp_init);
2409 module_exit(iscsi_tcp_exit);