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