drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/list.h>
  31 #include <linux/inet.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 #define ISCSI_TCP_VERSION "1.0-595"
  47
  48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION(ISCSI_TCP_VERSION);
  53 /* #define DEBUG_TCP */
  54 #define DEBUG_ASSERT
  55
  56 #ifdef DEBUG_TCP
  57 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  58 #else
  59 #define debug_tcp(fmt...)
  60 #endif
  61
  62 #ifndef DEBUG_ASSERT
  63 #ifdef BUG_ON
  64 #undef BUG_ON
  65 #endif
  66 #define BUG_ON(expr)
  67 #endif
  68
  69 static unsigned int iscsi_max_lun = 512;
  70 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  71
  72 static inline void
  73 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  74 {
  75         ibuf->sg.page = virt_to_page(vbuf);
  76         ibuf->sg.offset = offset_in_page(vbuf);
  77         ibuf->sg.length = size;
  78         ibuf->sent = 0;
  79         ibuf->use_sendmsg = 1;
  80 }
  81
  82 static inline void
  83 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  84 {
  85         ibuf->sg.page = sg->page;
  86         ibuf->sg.offset = sg->offset;
  87         ibuf->sg.length = sg->length;
  88         /*
  89          * Fastpath: sg element fits into single page
  90          */
  91         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  92                 ibuf->use_sendmsg = 0;
  93         else
  94                 ibuf->use_sendmsg = 1;
  95         ibuf->sent = 0;
  96 }
  97
  98 static inline int
  99 iscsi_buf_left(struct iscsi_buf *ibuf)
 100 {
 101         int rc;
 102
 103         rc = ibuf->sg.length - ibuf->sent;
 104         BUG_ON(rc < 0);
 105         return rc;
 106 }
 107
 108 static inline void
 109 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 110                  u8* crc)
 111 {
 112         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 113
 114         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 115         buf->sg.length += sizeof(uint32_t);
 116 }
 117
 118 static inline int
 119 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 120 {
 121         struct sk_buff *skb = tcp_conn->in.skb;
 122
 123         tcp_conn->in.zero_copy_hdr = 0;
 124
 125         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 126             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 127                 /*
 128                  * Zero-copy PDU Header: using connection context
 129                  * to store header pointer.
 130                  */
 131                 if (skb_shinfo(skb)->frag_list == NULL &&
 132                     !skb_shinfo(skb)->nr_frags) {
 133                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 134                                 ((char*)skb->data + tcp_conn->in.offset);
 135                         tcp_conn->in.zero_copy_hdr = 1;
 136                 } else {
 137                         /* ignoring return code since we checked
 138                          * in.copy before */
 139                         skb_copy_bits(skb, tcp_conn->in.offset,
 140                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 141                         tcp_conn->in.hdr = &tcp_conn->hdr;
 142                 }
 143                 tcp_conn->in.offset += tcp_conn->hdr_size;
 144                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 145         } else {
 146                 int hdr_remains;
 147                 int copylen;
 148
 149                 /*
 150                  * PDU header scattered across SKB's,
 151                  * copying it... This'll happen quite rarely.
 152                  */
 153
 154                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 155                         tcp_conn->in.hdr_offset = 0;
 156
 157                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 158                 BUG_ON(hdr_remains <= 0);
 159
 160                 copylen = min(tcp_conn->in.copy, hdr_remains);
 161                 skb_copy_bits(skb, tcp_conn->in.offset,
 162                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 163                         copylen);
 164
 165                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 166                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 167                        tcp_conn->in.offset, tcp_conn->in.copy);
 168
 169                 tcp_conn->in.offset += copylen;
 170                 tcp_conn->in.copy -= copylen;
 171                 if (copylen < hdr_remains)  {
 172                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 173                         tcp_conn->in.hdr_offset += copylen;
 174                         return -EAGAIN;
 175                 }
 176                 tcp_conn->in.hdr = &tcp_conn->hdr;
 177                 tcp_conn->discontiguous_hdr_cnt++;
 178                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 179         }
 180
 181         return 0;
 182 }
 183
 184 /*
 185  * must be called with session lock
 186  */
 187 static void
 188 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 191         struct iscsi_r2t_info *r2t;
 192         struct scsi_cmnd *sc;
 193
 194         /* flush ctask's r2t queues */
 195         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
 196                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
 197                             sizeof(void*));
 198                 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
 199         }
 200
 201         sc = ctask->sc;
 202         if (unlikely(!sc))
 203                 return;
 204
 205         tcp_ctask->xmstate = XMSTATE_IDLE;
 206         tcp_ctask->r2t = NULL;
 207 }
 208
 209 /**
 210  * iscsi_data_rsp - SCSI Data-In Response processing
 211  * @conn: iscsi connection
 212  * @ctask: scsi command task
 213  **/
 214 static int
 215 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 216 {
 217         int rc;
 218         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 219         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 220         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 221         struct iscsi_session *session = conn->session;
 222         int datasn = be32_to_cpu(rhdr->datasn);
 223
 224         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 225         if (rc)
 226                 return rc;
 227         /*
 228          * setup Data-In byte counter (gets decremented..)
 229          */
 230         ctask->data_count = tcp_conn->in.datalen;
 231
 232         if (tcp_conn->in.datalen == 0)
 233                 return 0;
 234
 235         if (ctask->datasn != datasn)
 236                 return ISCSI_ERR_DATASN;
 237
 238         ctask->datasn++;
 239
 240         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 241         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 242                 return ISCSI_ERR_DATA_OFFSET;
 243
 244         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 245                 struct scsi_cmnd *sc = ctask->sc;
 246
 247                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 248                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 249                         int res_count = be32_to_cpu(rhdr->residual_count);
 250
 251                         if (res_count > 0 &&
 252                             res_count <= sc->request_bufflen) {
 253                                 sc->resid = res_count;
 254                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 255                         } else
 256                                 sc->result = (DID_BAD_TARGET << 16) |
 257                                         rhdr->cmd_status;
 258                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 259                         sc->resid = be32_to_cpu(rhdr->residual_count);
 260                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 261                 } else
 262                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 263         }
 264
 265         conn->datain_pdus_cnt++;
 266         return 0;
 267 }
 268
 269 /**
 270  * iscsi_solicit_data_init - initialize first Data-Out
 271  * @conn: iscsi connection
 272  * @ctask: scsi command task
 273  * @r2t: R2T info
 274  *
 275  * Notes:
 276  *      Initialize first Data-Out within this R2T sequence and finds
 277  *      proper data_offset within this SCSI command.
 278  *
 279  *      This function is called with connection lock taken.
 280  **/
 281 static void
 282 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 283                         struct iscsi_r2t_info *r2t)
 284 {
 285         struct iscsi_data *hdr;
 286         struct scsi_cmnd *sc = ctask->sc;
 287         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 288
 289         hdr = &r2t->dtask.hdr;
 290         memset(hdr, 0, sizeof(struct iscsi_data));
 291         hdr->ttt = r2t->ttt;
 292         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 293         r2t->solicit_datasn++;
 294         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 295         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 296         hdr->itt = ctask->hdr->itt;
 297         hdr->exp_statsn = r2t->exp_statsn;
 298         hdr->offset = cpu_to_be32(r2t->data_offset);
 299         if (r2t->data_length > conn->max_xmit_dlength) {
 300                 hton24(hdr->dlength, conn->max_xmit_dlength);
 301                 r2t->data_count = conn->max_xmit_dlength;
 302                 hdr->flags = 0;
 303         } else {
 304                 hton24(hdr->dlength, r2t->data_length);
 305                 r2t->data_count = r2t->data_length;
 306                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 307         }
 308         conn->dataout_pdus_cnt++;
 309
 310         r2t->sent = 0;
 311
 312         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 313                            sizeof(struct iscsi_hdr));
 314
 315         if (sc->use_sg) {
 316                 int i, sg_count = 0;
 317                 struct scatterlist *sg = sc->request_buffer;
 318
 319                 r2t->sg = NULL;
 320                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 321                         /* FIXME: prefetch ? */
 322                         if (sg_count + sg->length > r2t->data_offset) {
 323                                 int page_offset;
 324
 325                                 /* sg page found! */
 326
 327                                 /* offset within this page */
 328                                 page_offset = r2t->data_offset - sg_count;
 329
 330                                 /* fill in this buffer */
 331                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 332                                 r2t->sendbuf.sg.offset += page_offset;
 333                                 r2t->sendbuf.sg.length -= page_offset;
 334
 335                                 /* xmit logic will continue with next one */
 336                                 r2t->sg = sg + 1;
 337                                 break;
 338                         }
 339                         sg_count += sg->length;
 340                 }
 341                 BUG_ON(r2t->sg == NULL);
 342         } else
 343                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 344                             (char*)sc->request_buffer + r2t->data_offset,
 345                             r2t->data_count);
 346 }
 347
 348 /**
 349  * iscsi_r2t_rsp - iSCSI R2T Response processing
 350  * @conn: iscsi connection
 351  * @ctask: scsi command task
 352  **/
 353 static int
 354 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 355 {
 356         struct iscsi_r2t_info *r2t;
 357         struct iscsi_session *session = conn->session;
 358         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 359         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 360         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 361         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 362         int rc;
 363
 364         if (tcp_conn->in.datalen)
 365                 return ISCSI_ERR_DATALEN;
 366
 367         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 368                 return ISCSI_ERR_R2TSN;
 369
 370         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 371         if (rc)
 372                 return rc;
 373
 374         /* FIXME: use R2TSN to detect missing R2T */
 375
 376         /* fill-in new R2T associated with the task */
 377         spin_lock(&session->lock);
 378         if (!ctask->sc || ctask->mtask ||
 379              session->state != ISCSI_STATE_LOGGED_IN) {
 380                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 381                        "recovery...\n", ctask->itt);
 382                 spin_unlock(&session->lock);
 383                 return 0;
 384         }
 385
 386         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 387         BUG_ON(!rc);
 388
 389         r2t->exp_statsn = rhdr->statsn;
 390         r2t->data_length = be32_to_cpu(rhdr->data_length);
 391         if (r2t->data_length == 0 ||
 392             r2t->data_length > session->max_burst) {
 393                 spin_unlock(&session->lock);
 394                 return ISCSI_ERR_DATALEN;
 395         }
 396
 397         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 398         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 399                 spin_unlock(&session->lock);
 400                 return ISCSI_ERR_DATALEN;
 401         }
 402
 403         r2t->ttt = rhdr->ttt; /* no flip */
 404         r2t->solicit_datasn = 0;
 405
 406         iscsi_solicit_data_init(conn, ctask, r2t);
 407
 408         tcp_ctask->exp_r2tsn = r2tsn + 1;
 409         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 410         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 411         list_move_tail(&ctask->running, &conn->xmitqueue);
 412
 413         scsi_queue_work(session->host, &conn->xmitwork);
 414         conn->r2t_pdus_cnt++;
 415         spin_unlock(&session->lock);
 416
 417         return 0;
 418 }
 419
 420 static int
 421 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 422 {
 423         int rc = 0, opcode, ahslen;
 424         struct iscsi_hdr *hdr;
 425         struct iscsi_session *session = conn->session;
 426         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 427         uint32_t cdgst, rdgst = 0, itt;
 428
 429         hdr = tcp_conn->in.hdr;
 430
 431         /* verify PDU length */
 432         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 433         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 434                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 435                        tcp_conn->in.datalen, conn->max_recv_dlength);
 436                 return ISCSI_ERR_DATALEN;
 437         }
 438         tcp_conn->data_copied = 0;
 439
 440         /* read AHS */
 441         ahslen = hdr->hlength << 2;
 442         tcp_conn->in.offset += ahslen;
 443         tcp_conn->in.copy -= ahslen;
 444         if (tcp_conn->in.copy < 0) {
 445                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 446                        "%d bytes\n", ahslen);
 447                 return ISCSI_ERR_AHSLEN;
 448         }
 449
 450         /* calculate read padding */
 451         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 452         if (tcp_conn->in.padding) {
 453                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 454                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 455         }
 456
 457         if (conn->hdrdgst_en) {
 458                 struct scatterlist sg;
 459
 460                 sg_init_one(&sg, (u8 *)hdr,
 461                             sizeof(struct iscsi_hdr) + ahslen);
 462                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 463                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 464                                      ahslen);
 465                 if (cdgst != rdgst) {
 466                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 467                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 468                         return ISCSI_ERR_HDR_DGST;
 469                 }
 470         }
 471
 472         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 473         /* verify itt (itt encoding: age+cid+itt) */
 474         rc = iscsi_verify_itt(conn, hdr, &itt);
 475         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 476                 tcp_conn->in.datalen = 0; /* force drop */
 477                 return 0;
 478         } else if (rc)
 479                 return rc;
 480
 481         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 482                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 483                   ahslen, tcp_conn->in.datalen);
 484
 485         switch(opcode) {
 486         case ISCSI_OP_SCSI_DATA_IN:
 487                 tcp_conn->in.ctask = session->cmds[itt];
 488                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 489                 if (rc)
 490                         return rc;
 491                 /* fall through */
 492         case ISCSI_OP_SCSI_CMD_RSP:
 493                 tcp_conn->in.ctask = session->cmds[itt];
 494                 if (tcp_conn->in.datalen)
 495                         goto copy_hdr;
 496
 497                 spin_lock(&session->lock);
 498                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 499                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 500                 spin_unlock(&session->lock);
 501                 break;
 502         case ISCSI_OP_R2T:
 503                 tcp_conn->in.ctask = session->cmds[itt];
 504                 if (ahslen)
 505                         rc = ISCSI_ERR_AHSLEN;
 506                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 507                                                                 DMA_TO_DEVICE)
 508                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 509                 else
 510                         rc = ISCSI_ERR_PROTO;
 511                 break;
 512         case ISCSI_OP_LOGIN_RSP:
 513         case ISCSI_OP_TEXT_RSP:
 514         case ISCSI_OP_LOGOUT_RSP:
 515         case ISCSI_OP_NOOP_IN:
 516         case ISCSI_OP_REJECT:
 517         case ISCSI_OP_ASYNC_EVENT:
 518                 if (tcp_conn->in.datalen)
 519                         goto copy_hdr;
 520         /* fall through */
 521         case ISCSI_OP_SCSI_TMFUNC_RSP:
 522                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 523                 break;
 524         default:
 525                 rc = ISCSI_ERR_BAD_OPCODE;
 526                 break;
 527         }
 528
 529         return rc;
 530
 531 copy_hdr:
 532         /*
 533          * if we did zero copy for the header but we will need multiple
 534          * skbs to complete the command then we have to copy the header
 535          * for later use
 536          */
 537         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
 538            (tcp_conn->in.datalen + tcp_conn->in.padding +
 539             (conn->datadgst_en ? 4 : 0))) {
 540                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 541                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 542                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 543                        sizeof(struct iscsi_hdr));
 544                 tcp_conn->in.hdr = &tcp_conn->hdr;
 545                 tcp_conn->in.zero_copy_hdr = 0;
 546         }
 547         return 0;
 548 }
 549
 550 /**
 551  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 552  * @conn: iscsi tcp connection
 553  * @ctask: scsi command task
 554  * @buf: buffer to copy to
 555  * @buf_size: size of buffer
 556  * @offset: offset within the buffer
 557  *
 558  * Notes:
 559  *      The function calls skb_copy_bits() and updates per-connection and
 560  *      per-cmd byte counters.
 561  *
 562  *      Read counters (in bytes):
 563  *
 564  *      conn->in.offset         offset within in progress SKB
 565  *      conn->in.copy           left to copy from in progress SKB
 566  *                              including padding
 567  *      conn->in.copied         copied already from in progress SKB
 568  *      conn->data_copied       copied already from in progress buffer
 569  *      ctask->sent             total bytes sent up to the MidLayer
 570  *      ctask->data_count       left to copy from in progress Data-In
 571  *      buf_left                left to copy from in progress buffer
 572  **/
 573 static inline int
 574 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 575                 void *buf, int buf_size, int offset)
 576 {
 577         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 578         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 579         int size = min(tcp_conn->in.copy, buf_left);
 580         int rc;
 581
 582         size = min(size, ctask->data_count);
 583
 584         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 585                size, tcp_conn->in.offset, tcp_conn->in.copied);
 586
 587         BUG_ON(size <= 0);
 588         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 589
 590         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 591                            (char*)buf + (offset + tcp_conn->data_copied), size);
 592         /* must fit into skb->len */
 593         BUG_ON(rc);
 594
 595         tcp_conn->in.offset += size;
 596         tcp_conn->in.copy -= size;
 597         tcp_conn->in.copied += size;
 598         tcp_conn->data_copied += size;
 599         tcp_ctask->sent += size;
 600         ctask->data_count -= size;
 601
 602         BUG_ON(tcp_conn->in.copy < 0);
 603         BUG_ON(ctask->data_count < 0);
 604
 605         if (buf_size != (tcp_conn->data_copied + offset)) {
 606                 if (!ctask->data_count) {
 607                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 608                         /* done with this PDU */
 609                         return buf_size - tcp_conn->data_copied;
 610                 }
 611                 return -EAGAIN;
 612         }
 613
 614         /* done with this buffer or with both - PDU and buffer */
 615         tcp_conn->data_copied = 0;
 616         return 0;
 617 }
 618
 619 /**
 620  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 621  * @conn: iscsi tcp connection
 622  *
 623  * Notes:
 624  *      The function calls skb_copy_bits() and updates per-connection
 625  *      byte counters.
 626  **/
 627 static inline int
 628 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 629 {
 630         void *buf = tcp_conn->data;
 631         int buf_size = tcp_conn->in.datalen;
 632         int buf_left = buf_size - tcp_conn->data_copied;
 633         int size = min(tcp_conn->in.copy, buf_left);
 634         int rc;
 635
 636         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 637                size, tcp_conn->in.offset, tcp_conn->data_copied);
 638         BUG_ON(size <= 0);
 639
 640         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 641                            (char*)buf + tcp_conn->data_copied, size);
 642         BUG_ON(rc);
 643
 644         tcp_conn->in.offset += size;
 645         tcp_conn->in.copy -= size;
 646         tcp_conn->in.copied += size;
 647         tcp_conn->data_copied += size;
 648
 649         if (buf_size != tcp_conn->data_copied)
 650                 return -EAGAIN;
 651
 652         return 0;
 653 }
 654
 655 static inline void
 656 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 657                          struct scatterlist *sg, int offset, int length)
 658 {
 659         struct scatterlist temp;
 660
 661         memcpy(&temp, sg, sizeof(struct scatterlist));
 662         temp.offset = offset;
 663         temp.length = length;
 664         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 665 }
 666
 667 static void
 668 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 669 {
 670         struct scatterlist tmp;
 671
 672         sg_init_one(&tmp, buf, len);
 673         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 674 }
 675
 676 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 677 {
 678         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 679         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 680         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 681         struct scsi_cmnd *sc = ctask->sc;
 682         struct scatterlist *sg;
 683         int i, offset, rc = 0;
 684
 685         BUG_ON((void*)ctask != sc->SCp.ptr);
 686
 687         /*
 688          * copying Data-In into the Scsi_Cmnd
 689          */
 690         if (!sc->use_sg) {
 691                 i = ctask->data_count;
 692                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 693                                       sc->request_bufflen,
 694                                       tcp_ctask->data_offset);
 695                 if (rc == -EAGAIN)
 696                         return rc;
 697                 if (conn->datadgst_en)
 698                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 699                                                  i);
 700                 rc = 0;
 701                 goto done;
 702         }
 703
 704         offset = tcp_ctask->data_offset;
 705         sg = sc->request_buffer;
 706
 707         if (tcp_ctask->data_offset)
 708                 for (i = 0; i < tcp_ctask->sg_count; i++)
 709                         offset -= sg[i].length;
 710         /* we've passed through partial sg*/
 711         if (offset < 0)
 712                 offset = 0;
 713
 714         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 715                 char *dest;
 716
 717                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 718                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 719                                       sg[i].length, offset);
 720                 kunmap_atomic(dest, KM_SOFTIRQ0);
 721                 if (rc == -EAGAIN)
 722                         /* continue with the next SKB/PDU */
 723                         return rc;
 724                 if (!rc) {
 725                         if (conn->datadgst_en) {
 726                                 if (!offset)
 727                                         crypto_digest_update(
 728                                                         tcp_conn->data_rx_tfm,
 729                                                         &sg[i], 1);
 730                                 else
 731                                         partial_sg_digest_update(tcp_conn,
 732                                                         &sg[i],
 733                                                         sg[i].offset + offset,
 734                                                         sg[i].length - offset);
 735                         }
 736                         offset = 0;
 737                         tcp_ctask->sg_count++;
 738                 }
 739
 740                 if (!ctask->data_count) {
 741                         if (rc && conn->datadgst_en)
 742                                 /*
 743                                  * data-in is complete, but buffer not...
 744                                  */
 745                                 partial_sg_digest_update(tcp_conn, &sg[i],
 746                                                 sg[i].offset, sg[i].length-rc);
 747                         rc = 0;
 748                         break;
 749                 }
 750
 751                 if (!tcp_conn->in.copy)
 752                         return -EAGAIN;
 753         }
 754         BUG_ON(ctask->data_count);
 755
 756 done:
 757         /* check for non-exceptional status */
 758         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 759                 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
 760                            (long)sc, sc->result, ctask->itt,
 761                            tcp_conn->in.hdr->flags);
 762                 spin_lock(&conn->session->lock);
 763                 iscsi_tcp_cleanup_ctask(conn, ctask);
 764                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 765                 spin_unlock(&conn->session->lock);
 766         }
 767
 768         return rc;
 769 }
 770
 771 static int
 772 iscsi_data_recv(struct iscsi_conn *conn)
 773 {
 774         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 775         int rc = 0, opcode;
 776
 777         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 778         switch (opcode) {
 779         case ISCSI_OP_SCSI_DATA_IN:
 780                 rc = iscsi_scsi_data_in(conn);
 781                 break;
 782         case ISCSI_OP_SCSI_CMD_RSP:
 783                 spin_lock(&conn->session->lock);
 784                 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
 785                 spin_unlock(&conn->session->lock);
 786         case ISCSI_OP_TEXT_RSP:
 787         case ISCSI_OP_LOGIN_RSP:
 788         case ISCSI_OP_NOOP_IN:
 789         case ISCSI_OP_ASYNC_EVENT:
 790         case ISCSI_OP_REJECT:
 791                 /*
 792                  * Collect data segment to the connection's data
 793                  * placeholder
 794                  */
 795                 if (iscsi_tcp_copy(tcp_conn)) {
 796                         rc = -EAGAIN;
 797                         goto exit;
 798                 }
 799
 800                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 801                                         tcp_conn->in.datalen);
 802                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 803                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 804                                                 tcp_conn->in.datalen);
 805                 break;
 806         default:
 807                 BUG_ON(1);
 808         }
 809 exit:
 810         return rc;
 811 }
 812
 813 /**
 814  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 815  * @rd_desc: read descriptor
 816  * @skb: socket buffer
 817  * @offset: offset in skb
 818  * @len: skb->len - offset
 819  **/
 820 static int
 821 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 822                 unsigned int offset, size_t len)
 823 {
 824         int rc;
 825         struct iscsi_conn *conn = rd_desc->arg.data;
 826         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 827         int processed;
 828         char pad[ISCSI_PAD_LEN];
 829         struct scatterlist sg;
 830
 831         /*
 832          * Save current SKB and its offset in the corresponding
 833          * connection context.
 834          */
 835         tcp_conn->in.copy = skb->len - offset;
 836         tcp_conn->in.offset = offset;
 837         tcp_conn->in.skb = skb;
 838         tcp_conn->in.len = tcp_conn->in.copy;
 839         BUG_ON(tcp_conn->in.copy <= 0);
 840         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 841
 842 more:
 843         tcp_conn->in.copied = 0;
 844         rc = 0;
 845
 846         if (unlikely(conn->suspend_rx)) {
 847                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 848                 return 0;
 849         }
 850
 851         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 852             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 853                 rc = iscsi_hdr_extract(tcp_conn);
 854                 if (rc) {
 855                        if (rc == -EAGAIN)
 856                                 goto nomore;
 857                        else {
 858                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 859                                 return 0;
 860                        }
 861                 }
 862
 863                 /*
 864                  * Verify and process incoming PDU header.
 865                  */
 866                 rc = iscsi_tcp_hdr_recv(conn);
 867                 if (!rc && tcp_conn->in.datalen) {
 868                         if (conn->datadgst_en) {
 869                                 BUG_ON(!tcp_conn->data_rx_tfm);
 870                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 871                         }
 872                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 873                 } else if (rc) {
 874                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 875                         return 0;
 876                 }
 877         }
 878
 879         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 880                 uint32_t recv_digest;
 881
 882                 debug_tcp("extra data_recv offset %d copy %d\n",
 883                           tcp_conn->in.offset, tcp_conn->in.copy);
 884                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 885                                 &recv_digest, 4);
 886                 tcp_conn->in.offset += 4;
 887                 tcp_conn->in.copy -= 4;
 888                 if (recv_digest != tcp_conn->in.datadgst) {
 889                         debug_tcp("iscsi_tcp: data digest error!"
 890                                   "0x%x != 0x%x\n", recv_digest,
 891                                   tcp_conn->in.datadgst);
 892                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 893                         return 0;
 894                 } else {
 895                         debug_tcp("iscsi_tcp: data digest match!"
 896                                   "0x%x == 0x%x\n", recv_digest,
 897                                   tcp_conn->in.datadgst);
 898                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 899                 }
 900         }
 901
 902         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 903            tcp_conn->in.copy) {
 904
 905                 debug_tcp("data_recv offset %d copy %d\n",
 906                        tcp_conn->in.offset, tcp_conn->in.copy);
 907
 908                 rc = iscsi_data_recv(conn);
 909                 if (rc) {
 910                         if (rc == -EAGAIN)
 911                                 goto again;
 912                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 913                         return 0;
 914                 }
 915                 tcp_conn->in.copy -= tcp_conn->in.padding;
 916                 tcp_conn->in.offset += tcp_conn->in.padding;
 917                 if (conn->datadgst_en) {
 918                         if (tcp_conn->in.padding) {
 919                                 debug_tcp("padding -> %d\n",
 920                                           tcp_conn->in.padding);
 921                                 memset(pad, 0, tcp_conn->in.padding);
 922                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 923                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 924                                                      &sg, 1);
 925                         }
 926                         crypto_digest_final(tcp_conn->data_rx_tfm,
 927                                             (u8 *) & tcp_conn->in.datadgst);
 928                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 929                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 930                 } else
 931                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 932         }
 933
 934         debug_tcp("f, processed %d from out of %d padding %d\n",
 935                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 936         BUG_ON(tcp_conn->in.offset - offset > len);
 937
 938         if (tcp_conn->in.offset - offset != len) {
 939                 debug_tcp("continue to process %d bytes\n",
 940                        (int)len - (tcp_conn->in.offset - offset));
 941                 goto more;
 942         }
 943
 944 nomore:
 945         processed = tcp_conn->in.offset - offset;
 946         BUG_ON(processed == 0);
 947         return processed;
 948
 949 again:
 950         processed = tcp_conn->in.offset - offset;
 951         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 952                   processed, (int)len, (int)rd_desc->count);
 953         BUG_ON(processed == 0);
 954         BUG_ON(processed > len);
 955
 956         conn->rxdata_octets += processed;
 957         return processed;
 958 }
 959
 960 static void
 961 iscsi_tcp_data_ready(struct sock *sk, int flag)
 962 {
 963         struct iscsi_conn *conn = sk->sk_user_data;
 964         read_descriptor_t rd_desc;
 965
 966         read_lock(&sk->sk_callback_lock);
 967
 968         /*
 969          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 970          * We set count to 1 because we want the network layer to
 971          * hand us all the skbs that are available. iscsi_tcp_data_recv
 972          * handled pdus that cross buffers or pdus that still need data.
 973          */
 974         rd_desc.arg.data = conn;
 975         rd_desc.count = 1;
 976         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 977
 978         read_unlock(&sk->sk_callback_lock);
 979 }
 980
 981 static void
 982 iscsi_tcp_state_change(struct sock *sk)
 983 {
 984         struct iscsi_tcp_conn *tcp_conn;
 985         struct iscsi_conn *conn;
 986         struct iscsi_session *session;
 987         void (*old_state_change)(struct sock *);
 988
 989         read_lock(&sk->sk_callback_lock);
 990
 991         conn = (struct iscsi_conn*)sk->sk_user_data;
 992         session = conn->session;
 993
 994         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 995              sk->sk_state == TCP_CLOSE) &&
 996             !atomic_read(&sk->sk_rmem_alloc)) {
 997                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 998                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 999         }
1000
1001         tcp_conn = conn->dd_data;
1002         old_state_change = tcp_conn->old_state_change;
1003
1004         read_unlock(&sk->sk_callback_lock);
1005
1006         old_state_change(sk);
1007 }
1008
1009 /**
1010  * iscsi_write_space - Called when more output buffer space is available
1011  * @sk: socket space is available for
1012  **/
1013 static void
1014 iscsi_write_space(struct sock *sk)
1015 {
1016         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1017         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1018
1019         tcp_conn->old_write_space(sk);
1020         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1021         scsi_queue_work(conn->session->host, &conn->xmitwork);
1022 }
1023
1024 static void
1025 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1026 {
1027         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1028         struct sock *sk = tcp_conn->sock->sk;
1029
1030         /* assign new callbacks */
1031         write_lock_bh(&sk->sk_callback_lock);
1032         sk->sk_user_data = conn;
1033         tcp_conn->old_data_ready = sk->sk_data_ready;
1034         tcp_conn->old_state_change = sk->sk_state_change;
1035         tcp_conn->old_write_space = sk->sk_write_space;
1036         sk->sk_data_ready = iscsi_tcp_data_ready;
1037         sk->sk_state_change = iscsi_tcp_state_change;
1038         sk->sk_write_space = iscsi_write_space;
1039         write_unlock_bh(&sk->sk_callback_lock);
1040 }
1041
1042 static void
1043 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1044 {
1045         struct sock *sk = tcp_conn->sock->sk;
1046
1047         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1048         write_lock_bh(&sk->sk_callback_lock);
1049         sk->sk_user_data    = NULL;
1050         sk->sk_data_ready   = tcp_conn->old_data_ready;
1051         sk->sk_state_change = tcp_conn->old_state_change;
1052         sk->sk_write_space  = tcp_conn->old_write_space;
1053         sk->sk_no_check  = 0;
1054         write_unlock_bh(&sk->sk_callback_lock);
1055 }
1056
1057 /**
1058  * iscsi_send - generic send routine
1059  * @sk: kernel's socket
1060  * @buf: buffer to write from
1061  * @size: actual size to write
1062  * @flags: socket's flags
1063  */
1064 static inline int
1065 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1066 {
1067         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1068         struct socket *sk = tcp_conn->sock;
1069         int offset = buf->sg.offset + buf->sent, res;
1070
1071         /*
1072          * if we got use_sg=0 or are sending something we kmallocd
1073          * then we did not have to do kmap (kmap returns page_address)
1074          *
1075          * if we got use_sg > 0, but had to drop down, we do not
1076          * set clustering so this should only happen for that
1077          * slab case.
1078          */
1079         if (buf->use_sendmsg)
1080                 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1081         else
1082                 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1083
1084         if (res >= 0) {
1085                 conn->txdata_octets += res;
1086                 buf->sent += res;
1087                 return res;
1088         }
1089
1090         tcp_conn->sendpage_failures_cnt++;
1091         if (res == -EAGAIN)
1092                 res = -ENOBUFS;
1093         else
1094                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1095         return res;
1096 }
1097
1098 /**
1099  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1100  * @conn: iscsi connection
1101  * @buf: buffer to write from
1102  * @datalen: lenght of data to be sent after the header
1103  *
1104  * Notes:
1105  *      (Tx, Fast Path)
1106  **/
1107 static inline int
1108 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1109 {
1110         int flags = 0; /* MSG_DONTWAIT; */
1111         int res, size;
1112
1113         size = buf->sg.length - buf->sent;
1114         BUG_ON(buf->sent + size > buf->sg.length);
1115         if (buf->sent + size != buf->sg.length || datalen)
1116                 flags |= MSG_MORE;
1117
1118         res = iscsi_send(conn, buf, size, flags);
1119         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1120         if (res >= 0) {
1121                 if (size != res)
1122                         return -EAGAIN;
1123                 return 0;
1124         }
1125
1126         return res;
1127 }
1128
1129 /**
1130  * iscsi_sendpage - send one page of iSCSI Data-Out.
1131  * @conn: iscsi connection
1132  * @buf: buffer to write from
1133  * @count: remaining data
1134  * @sent: number of bytes sent
1135  *
1136  * Notes:
1137  *      (Tx, Fast Path)
1138  **/
1139 static inline int
1140 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1141                int *count, int *sent)
1142 {
1143         int flags = 0; /* MSG_DONTWAIT; */
1144         int res, size;
1145
1146         size = buf->sg.length - buf->sent;
1147         BUG_ON(buf->sent + size > buf->sg.length);
1148         if (size > *count)
1149                 size = *count;
1150         if (buf->sent + size != buf->sg.length || *count != size)
1151                 flags |= MSG_MORE;
1152
1153         res = iscsi_send(conn, buf, size, flags);
1154         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1155                   size, buf->sent, *count, *sent, res);
1156         if (res >= 0) {
1157                 *count -= res;
1158                 *sent += res;
1159                 if (size != res)
1160                         return -EAGAIN;
1161                 return 0;
1162         }
1163
1164         return res;
1165 }
1166
1167 static inline void
1168 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1169                       struct iscsi_cmd_task *ctask)
1170 {
1171         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1172
1173         BUG_ON(!tcp_conn->data_tx_tfm);
1174         crypto_digest_init(tcp_conn->data_tx_tfm);
1175         tcp_ctask->digest_count = 4;
1176 }
1177
1178 static int
1179 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1180                         struct iscsi_buf *buf, uint32_t *digest, int final)
1181 {
1182         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1183         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1184         int rc = 0;
1185         int sent = 0;
1186
1187         if (final)
1188                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1189
1190         iscsi_buf_init_iov(buf, (char*)digest, 4);
1191         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1192         if (rc) {
1193                 tcp_ctask->datadigest = *digest;
1194                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1195         } else
1196                 tcp_ctask->digest_count = 4;
1197         return rc;
1198 }
1199
1200 /**
1201  * iscsi_solicit_data_cont - initialize next Data-Out
1202  * @conn: iscsi connection
1203  * @ctask: scsi command task
1204  * @r2t: R2T info
1205  * @left: bytes left to transfer
1206  *
1207  * Notes:
1208  *      Initialize next Data-Out within this R2T sequence and continue
1209  *      to process next Scatter-Gather element(if any) of this SCSI command.
1210  *
1211  *      Called under connection lock.
1212  **/
1213 static void
1214 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1215                         struct iscsi_r2t_info *r2t, int left)
1216 {
1217         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1218         struct iscsi_data *hdr;
1219         struct scsi_cmnd *sc = ctask->sc;
1220         int new_offset;
1221
1222         hdr = &r2t->dtask.hdr;
1223         memset(hdr, 0, sizeof(struct iscsi_data));
1224         hdr->ttt = r2t->ttt;
1225         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1226         r2t->solicit_datasn++;
1227         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1228         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1229         hdr->itt = ctask->hdr->itt;
1230         hdr->exp_statsn = r2t->exp_statsn;
1231         new_offset = r2t->data_offset + r2t->sent;
1232         hdr->offset = cpu_to_be32(new_offset);
1233         if (left > conn->max_xmit_dlength) {
1234                 hton24(hdr->dlength, conn->max_xmit_dlength);
1235                 r2t->data_count = conn->max_xmit_dlength;
1236         } else {
1237                 hton24(hdr->dlength, left);
1238                 r2t->data_count = left;
1239                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1240         }
1241         conn->dataout_pdus_cnt++;
1242
1243         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1244                            sizeof(struct iscsi_hdr));
1245
1246         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1247                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1248                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1249                 r2t->sg += 1;
1250         } else
1251                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1252                             (char*)sc->request_buffer + new_offset,
1253                             r2t->data_count);
1254 }
1255
1256 static void
1257 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1258 {
1259         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1260         struct iscsi_data_task *dtask;
1261
1262         dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1263         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1264                                       tcp_ctask->r2t_data_count);
1265         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1266                            sizeof(struct iscsi_hdr));
1267 }
1268
1269 /**
1270  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1271  * @conn: iscsi connection
1272  * @ctask: scsi command task
1273  * @sc: scsi command
1274  **/
1275 static void
1276 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1277 {
1278         struct scsi_cmnd *sc = ctask->sc;
1279         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1280
1281         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1282
1283         tcp_ctask->sent = 0;
1284         tcp_ctask->sg_count = 0;
1285
1286         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1287                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1288                 tcp_ctask->exp_r2tsn = 0;
1289                 BUG_ON(ctask->total_length == 0);
1290
1291                 if (sc->use_sg) {
1292                         struct scatterlist *sg = sc->request_buffer;
1293
1294                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1295                                           &sg[tcp_ctask->sg_count++]);
1296                         tcp_ctask->sg = sg;
1297                         tcp_ctask->bad_sg = sg + sc->use_sg;
1298                 } else
1299                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1300                                            sc->request_buffer,
1301                                            sc->request_bufflen);
1302
1303                 if (ctask->imm_count)
1304                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1305
1306                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1307                 if (tcp_ctask->pad_count) {
1308                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1309                                                         tcp_ctask->pad_count;
1310                         debug_scsi("write padding %d bytes\n",
1311                                    tcp_ctask->pad_count);
1312                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1313                 }
1314
1315                 if (ctask->unsol_count)
1316                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1317                                                 XMSTATE_UNS_INIT;
1318                 tcp_ctask->r2t_data_count = ctask->total_length -
1319                                     ctask->imm_count -
1320                                     ctask->unsol_count;
1321
1322                 debug_scsi("cmd [itt 0x%x total %d imm %d imm_data %d "
1323                            "r2t_data %d]\n",
1324                            ctask->itt, ctask->total_length, ctask->imm_count,
1325                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1326         } else
1327                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1328
1329         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1330                             sizeof(struct iscsi_hdr));
1331 }
1332
1333 /**
1334  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1335  * @conn: iscsi connection
1336  * @mtask: task management task
1337  *
1338  * Notes:
1339  *      The function can return -EAGAIN in which case caller must
1340  *      call it again later, or recover. '0' return code means successful
1341  *      xmit.
1342  *
1343  *      Management xmit state machine consists of two states:
1344  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1345  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1346  **/
1347 static int
1348 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1349 {
1350         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1351         int rc;
1352
1353         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1354                 conn->id, tcp_mtask->xmstate, mtask->itt);
1355
1356         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1357                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1358                 if (mtask->data_count)
1359                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1360                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1361                     conn->stop_stage != STOP_CONN_RECOVER &&
1362                     conn->hdrdgst_en)
1363                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1364                                         (u8*)tcp_mtask->hdrext);
1365                 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1366                                    mtask->data_count);
1367                 if (rc) {
1368                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1369                         if (mtask->data_count)
1370                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1371                         return rc;
1372                 }
1373         }
1374
1375         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1376                 BUG_ON(!mtask->data_count);
1377                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1378                 /* FIXME: implement.
1379                  * Virtual buffer could be spreaded across multiple pages...
1380                  */
1381                 do {
1382                         int rc;
1383
1384                         rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1385                                         &mtask->data_count, &tcp_mtask->sent);
1386                         if (rc) {
1387                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1388                                 return rc;
1389                         }
1390                 } while (mtask->data_count);
1391         }
1392
1393         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1394         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1395                 struct iscsi_session *session = conn->session;
1396
1397                 spin_lock_bh(&session->lock);
1398                 list_del(&conn->mtask->running);
1399                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1400                             sizeof(void*));
1401                 spin_unlock_bh(&session->lock);
1402         }
1403         return 0;
1404 }
1405
1406 static inline int
1407 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1408                      struct iscsi_tcp_cmd_task *tcp_ctask)
1409 {
1410         int rc;
1411
1412         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1413         if (conn->hdrdgst_en)
1414                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1415                                  (u8*)tcp_ctask->hdrext);
1416         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1417         if (!rc) {
1418                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1419                 return 0; /* wait for Data-In */
1420         }
1421         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1422         return rc;
1423 }
1424
1425 static inline int
1426 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1427                      struct iscsi_cmd_task *ctask)
1428 {
1429         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1430         int rc;
1431
1432         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1433         if (conn->hdrdgst_en)
1434                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1435                                  (u8*)tcp_ctask->hdrext);
1436         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1437         if (rc)
1438                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1439         return rc;
1440 }
1441
1442 static inline int
1443 handle_xmstate_data_digest(struct iscsi_conn *conn,
1444                            struct iscsi_cmd_task *ctask)
1445 {
1446         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1447         int rc;
1448
1449         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1450         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1451         rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1452                                     &tcp_ctask->datadigest, 0);
1453         if (rc) {
1454                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1455                 debug_tcp("resent data digest 0x%x fail!\n",
1456                           tcp_ctask->datadigest);
1457         }
1458
1459         return rc;
1460 }
1461
1462 static inline int
1463 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1464 {
1465         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1466         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1467         int rc;
1468
1469         BUG_ON(!ctask->imm_count);
1470         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1471
1472         if (conn->datadgst_en) {
1473                 iscsi_data_digest_init(tcp_conn, ctask);
1474                 tcp_ctask->immdigest = 0;
1475         }
1476
1477         for (;;) {
1478                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1479                                    &ctask->imm_count, &tcp_ctask->sent);
1480                 if (rc) {
1481                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1482                         if (conn->datadgst_en) {
1483                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1484                                                 (u8*)&tcp_ctask->immdigest);
1485                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1486                                           tcp_ctask->datadigest);
1487                         }
1488                         return rc;
1489                 }
1490                 if (conn->datadgst_en)
1491                         crypto_digest_update(tcp_conn->data_tx_tfm,
1492                                              &tcp_ctask->sendbuf.sg, 1);
1493
1494                 if (!ctask->imm_count)
1495                         break;
1496                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1497                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1498         }
1499
1500         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1501                 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1502                                             &tcp_ctask->immdigest, 1);
1503                 if (rc) {
1504                         debug_tcp("sending imm digest 0x%x fail!\n",
1505                                   tcp_ctask->immdigest);
1506                         return rc;
1507                 }
1508                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1509         }
1510
1511         return 0;
1512 }
1513
1514 static inline int
1515 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1516 {
1517         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1518         struct iscsi_data_task *dtask;
1519         int rc;
1520
1521         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1522         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1523                 iscsi_unsolicit_data_init(conn, ctask);
1524                 dtask = tcp_ctask->dtask;
1525                 if (conn->hdrdgst_en)
1526                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1527                                         (u8*)dtask->hdrext);
1528                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1529         }
1530
1531         rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1532         if (rc) {
1533                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1534                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1535                 return rc;
1536         }
1537
1538         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1539                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1540         return 0;
1541 }
1542
1543 static inline int
1544 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1545 {
1546         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1547         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1548         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1549         int rc;
1550
1551         BUG_ON(!ctask->data_count);
1552         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1553
1554         if (conn->datadgst_en) {
1555                 iscsi_data_digest_init(tcp_conn, ctask);
1556                 dtask->digest = 0;
1557         }
1558
1559         for (;;) {
1560                 int start = tcp_ctask->sent;
1561
1562                 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1563                                    &ctask->data_count, &tcp_ctask->sent);
1564                 if (rc) {
1565                         ctask->unsol_count -= tcp_ctask->sent - start;
1566                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1567                         /* will continue with this ctask later.. */
1568                         if (conn->datadgst_en) {
1569                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1570                                                 (u8 *)&dtask->digest);
1571                                 debug_tcp("tx uns data fail 0x%x\n",
1572                                           dtask->digest);
1573                         }
1574                         return rc;
1575                 }
1576
1577                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1578                 ctask->unsol_count -= tcp_ctask->sent - start;
1579
1580                 /*
1581                  * XXX:we may run here with un-initial sendbuf.
1582                  * so pass it
1583                  */
1584                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1585                         crypto_digest_update(tcp_conn->data_tx_tfm,
1586                                              &tcp_ctask->sendbuf.sg, 1);
1587
1588                 if (!ctask->data_count)
1589                         break;
1590                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1591                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1592         }
1593         BUG_ON(ctask->unsol_count < 0);
1594
1595         /*
1596          * Done with the Data-Out. Next, check if we need
1597          * to send another unsolicited Data-Out.
1598          */
1599         if (ctask->unsol_count) {
1600                 if (conn->datadgst_en) {
1601                         rc = iscsi_digest_final_send(conn, ctask,
1602                                                     &dtask->digestbuf,
1603                                                     &dtask->digest, 1);
1604                         if (rc) {
1605                                 debug_tcp("send uns digest 0x%x fail\n",
1606                                           dtask->digest);
1607                                 return rc;
1608                         }
1609                         debug_tcp("sending uns digest 0x%x, more uns\n",
1610                                   dtask->digest);
1611                 }
1612                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1613                 return 1;
1614         }
1615
1616         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1617                 rc = iscsi_digest_final_send(conn, ctask,
1618                                             &dtask->digestbuf,
1619                                             &dtask->digest, 1);
1620                 if (rc) {
1621                         debug_tcp("send last uns digest 0x%x fail\n",
1622                                    dtask->digest);
1623                         return rc;
1624                 }
1625                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1626         }
1627
1628         return 0;
1629 }
1630
1631 static inline int
1632 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1633 {
1634         struct iscsi_session *session = conn->session;
1635         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1636         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1637         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1638         struct iscsi_data_task *dtask = &r2t->dtask;
1639         int left, rc;
1640
1641         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1642         tcp_ctask->dtask = dtask;
1643
1644         if (conn->datadgst_en) {
1645                 iscsi_data_digest_init(tcp_conn, ctask);
1646                 dtask->digest = 0;
1647         }
1648 solicit_again:
1649         /*
1650          * send Data-Out within this R2T sequence.
1651          */
1652         if (!r2t->data_count)
1653                 goto data_out_done;
1654
1655         rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
1656         if (rc) {
1657                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1658                 /* will continue with this ctask later.. */
1659                 if (conn->datadgst_en) {
1660                         crypto_digest_final(tcp_conn->data_tx_tfm,
1661                                           (u8 *)&dtask->digest);
1662                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1663                 }
1664                 return rc;
1665         }
1666
1667         BUG_ON(r2t->data_count < 0);
1668         if (conn->datadgst_en)
1669                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1670                                      1);
1671
1672         if (r2t->data_count) {
1673                 BUG_ON(ctask->sc->use_sg == 0);
1674                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1675                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1676                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1677                         r2t->sg += 1;
1678                 }
1679                 goto solicit_again;
1680         }
1681
1682 data_out_done:
1683         /*
1684          * Done with this Data-Out. Next, check if we have
1685          * to send another Data-Out for this R2T.
1686          */
1687         BUG_ON(r2t->data_length - r2t->sent < 0);
1688         left = r2t->data_length - r2t->sent;
1689         if (left) {
1690                 if (conn->datadgst_en) {
1691                         rc = iscsi_digest_final_send(conn, ctask,
1692                                                     &dtask->digestbuf,
1693                                                     &dtask->digest, 1);
1694                         if (rc) {
1695                                 debug_tcp("send r2t data digest 0x%x"
1696                                           "fail\n", dtask->digest);
1697                                 return rc;
1698                         }
1699                         debug_tcp("r2t data send digest 0x%x\n",
1700                                   dtask->digest);
1701                 }
1702                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1703                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1704                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1705                 return 1;
1706         }
1707
1708         /*
1709          * Done with this R2T. Check if there are more
1710          * outstanding R2Ts ready to be processed.
1711          */
1712         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1713         if (conn->datadgst_en) {
1714                 rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1715                                             &dtask->digest, 1);
1716                 if (rc) {
1717                         debug_tcp("send last r2t data digest 0x%x"
1718                                   "fail\n", dtask->digest);
1719                         return rc;
1720                 }
1721                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1722         }
1723
1724         tcp_ctask->r2t_data_count -= r2t->data_length;
1725         tcp_ctask->r2t = NULL;
1726         spin_lock_bh(&session->lock);
1727         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1728         spin_unlock_bh(&session->lock);
1729         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1730                 tcp_ctask->r2t = r2t;
1731                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1732                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1733                 return 1;
1734         }
1735
1736         return 0;
1737 }
1738
1739 static inline int
1740 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1741 {
1742         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1743         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1744         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1745         int sent = 0, rc;
1746
1747         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1748         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1749                             tcp_ctask->pad_count);
1750         rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1751                            &sent);
1752         if (rc) {
1753                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1754                 return rc;
1755         }
1756
1757         if (conn->datadgst_en) {
1758                 crypto_digest_update(tcp_conn->data_tx_tfm,
1759                                      &tcp_ctask->sendbuf.sg, 1);
1760                 /* imm data? */
1761                 if (!dtask) {
1762                         rc = iscsi_digest_final_send(conn, ctask,
1763                                                     &tcp_ctask->immbuf,
1764                                                     &tcp_ctask->immdigest, 1);
1765                         if (rc) {
1766                                 debug_tcp("send padding digest 0x%x"
1767                                           "fail!\n", tcp_ctask->immdigest);
1768                                 return rc;
1769                         }
1770                         debug_tcp("done with padding, digest 0x%x\n",
1771                                   tcp_ctask->datadigest);
1772                 } else {
1773                         rc = iscsi_digest_final_send(conn, ctask,
1774                                                     &dtask->digestbuf,
1775                                                     &dtask->digest, 1);
1776                         if (rc) {
1777                                 debug_tcp("send padding digest 0x%x"
1778                                           "fail\n", dtask->digest);
1779                                 return rc;
1780                         }
1781                         debug_tcp("done with padding, digest 0x%x\n",
1782                                   dtask->digest);
1783                 }
1784         }
1785
1786         return 0;
1787 }
1788
1789 static int
1790 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1791 {
1792         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1793         int rc = 0;
1794
1795         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1796                 conn->id, tcp_ctask->xmstate, ctask->itt);
1797
1798         /*
1799          * serialize with TMF AbortTask
1800          */
1801         if (ctask->mtask)
1802                 return rc;
1803
1804         if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1805                 return handle_xmstate_r_hdr(conn, tcp_ctask);
1806
1807         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1808                 rc = handle_xmstate_w_hdr(conn, ctask);
1809                 if (rc)
1810                         return rc;
1811         }
1812
1813         /* XXX: for data digest xmit recover */
1814         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1815                 rc = handle_xmstate_data_digest(conn, ctask);
1816                 if (rc)
1817                         return rc;
1818         }
1819
1820         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1821                 rc = handle_xmstate_imm_data(conn, ctask);
1822                 if (rc)
1823                         return rc;
1824         }
1825
1826         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1827                 BUG_ON(!ctask->unsol_count);
1828                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1829 unsolicit_head_again:
1830                 rc = handle_xmstate_uns_hdr(conn, ctask);
1831                 if (rc)
1832                         return rc;
1833         }
1834
1835         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1836                 rc = handle_xmstate_uns_data(conn, ctask);
1837                 if (rc == 1)
1838                         goto unsolicit_head_again;
1839                 else if (rc)
1840                         return rc;
1841                 goto done;
1842         }
1843
1844         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1845                 struct iscsi_r2t_info *r2t;
1846
1847                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1848                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1849                 if (!tcp_ctask->r2t)
1850                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1851                                     sizeof(void*));
1852 solicit_head_again:
1853                 r2t = tcp_ctask->r2t;
1854                 if (conn->hdrdgst_en)
1855                         iscsi_hdr_digest(conn, &r2t->headbuf,
1856                                         (u8*)r2t->dtask.hdrext);
1857                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1858                 if (rc) {
1859                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1860                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1861                         return rc;
1862                 }
1863
1864                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1865                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1866                         r2t->sent);
1867         }
1868
1869         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1870                 rc = handle_xmstate_sol_data(conn, ctask);
1871                 if (rc == 1)
1872                         goto solicit_head_again;
1873                 if (rc)
1874                         return rc;
1875         }
1876
1877 done:
1878         /*
1879          * Last thing to check is whether we need to send write
1880          * padding. Note that we check for xmstate equality, not just the bit.
1881          */
1882         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1883                 rc = handle_xmstate_w_pad(conn, ctask);
1884
1885         return rc;
1886 }
1887
1888 static struct iscsi_cls_conn *
1889 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1890 {
1891         struct iscsi_conn *conn;
1892         struct iscsi_cls_conn *cls_conn;
1893         struct iscsi_tcp_conn *tcp_conn;
1894
1895         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1896         if (!cls_conn)
1897                 return NULL;
1898         conn = cls_conn->dd_data;
1899         /*
1900          * due to strange issues with iser these are not set
1901          * in iscsi_conn_setup
1902          */
1903         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1904
1905         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1906         if (!tcp_conn)
1907                 goto tcp_conn_alloc_fail;
1908
1909         conn->dd_data = tcp_conn;
1910         tcp_conn->iscsi_conn = conn;
1911         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1912         /* initial operational parameters */
1913         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1914         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1915
1916         /* allocate initial PDU receive place holder */
1917         if (tcp_conn->data_size <= PAGE_SIZE)
1918                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1919         else
1920                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1921                                         get_order(tcp_conn->data_size));
1922         if (!tcp_conn->data)
1923                 goto max_recv_dlenght_alloc_fail;
1924
1925         return cls_conn;
1926
1927 max_recv_dlenght_alloc_fail:
1928         kfree(tcp_conn);
1929 tcp_conn_alloc_fail:
1930         iscsi_conn_teardown(cls_conn);
1931         return NULL;
1932 }
1933
1934 static void
1935 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1936 {
1937         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1938
1939         if (!tcp_conn->sock)
1940                 return;
1941
1942         sock_hold(tcp_conn->sock->sk);
1943         iscsi_conn_restore_callbacks(tcp_conn);
1944         sock_put(tcp_conn->sock->sk);
1945
1946         sock_release(tcp_conn->sock);
1947         tcp_conn->sock = NULL;
1948         conn->recv_lock = NULL;
1949 }
1950
1951 static void
1952 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1953 {
1954         struct iscsi_conn *conn = cls_conn->dd_data;
1955         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1956         int digest = 0;
1957
1958         if (conn->hdrdgst_en || conn->datadgst_en)
1959                 digest = 1;
1960
1961         iscsi_tcp_release_conn(conn);
1962         iscsi_conn_teardown(cls_conn);
1963
1964         /* now free tcp_conn */
1965         if (digest) {
1966                 if (tcp_conn->tx_tfm)
1967                         crypto_free_tfm(tcp_conn->tx_tfm);
1968                 if (tcp_conn->rx_tfm)
1969                         crypto_free_tfm(tcp_conn->rx_tfm);
1970                 if (tcp_conn->data_tx_tfm)
1971                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1972                 if (tcp_conn->data_rx_tfm)
1973                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1974         }
1975
1976         /* free conn->data, size = MaxRecvDataSegmentLength */
1977         if (tcp_conn->data_size <= PAGE_SIZE)
1978                 kfree(tcp_conn->data);
1979         else
1980                 free_pages((unsigned long)tcp_conn->data,
1981                            get_order(tcp_conn->data_size));
1982         kfree(tcp_conn);
1983 }
1984
1985 static void
1986 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1987 {
1988         struct iscsi_conn *conn = cls_conn->dd_data;
1989
1990         iscsi_conn_stop(cls_conn, flag);
1991         iscsi_tcp_release_conn(conn);
1992 }
1993
1994 static int
1995 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1996                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1997                     int is_leading)
1998 {
1999         struct iscsi_conn *conn = cls_conn->dd_data;
2000         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2001         struct sock *sk;
2002         struct socket *sock;
2003         int err;
2004
2005         /* lookup for existing socket */
2006         sock = sockfd_lookup((int)transport_eph, &err);
2007         if (!sock) {
2008                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2009                 return -EEXIST;
2010         }
2011
2012         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
2013         if (err)
2014                 return err;
2015
2016         /* bind iSCSI connection and socket */
2017         tcp_conn->sock = sock;
2018
2019         /* setup Socket parameters */
2020         sk = sock->sk;
2021         sk->sk_reuse = 1;
2022         sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2023         sk->sk_allocation = GFP_ATOMIC;
2024
2025         /* FIXME: disable Nagle's algorithm */
2026
2027         /*
2028          * Intercept TCP callbacks for sendfile like receive
2029          * processing.
2030          */
2031         conn->recv_lock = &sk->sk_callback_lock;
2032         iscsi_conn_set_callbacks(conn);
2033         tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2034         /*
2035          * set receive state machine into initial state
2036          */
2037         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2038
2039         return 0;
2040 }
2041
2042 /* called with host lock */
2043 static void
2044 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2045                     char *data, uint32_t data_size)
2046 {
2047         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2048
2049         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2050                            sizeof(struct iscsi_hdr));
2051         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2052         tcp_mtask->sent = 0;
2053
2054         if (mtask->data_count)
2055                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2056                                     mtask->data_count);
2057 }
2058
2059 static int
2060 iscsi_r2tpool_alloc(struct iscsi_session *session)
2061 {
2062         int i;
2063         int cmd_i;
2064
2065         /*
2066          * initialize per-task: R2T pool and xmit queue
2067          */
2068         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2069                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2070                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2071
2072                 /*
2073                  * pre-allocated x4 as much r2ts to handle race when
2074                  * target acks DataOut faster than we data_xmit() queues
2075                  * could replenish r2tqueue.
2076                  */
2077
2078                 /* R2T pool */
2079                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2080                                     (void***)&tcp_ctask->r2ts,
2081                                     sizeof(struct iscsi_r2t_info))) {
2082                         goto r2t_alloc_fail;
2083                 }
2084
2085                 /* R2T xmit queue */
2086                 tcp_ctask->r2tqueue = kfifo_alloc(
2087                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2088                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2089                         iscsi_pool_free(&tcp_ctask->r2tpool,
2090                                         (void**)tcp_ctask->r2ts);
2091                         goto r2t_alloc_fail;
2092                 }
2093         }
2094
2095         return 0;
2096
2097 r2t_alloc_fail:
2098         for (i = 0; i < cmd_i; i++) {
2099                 struct iscsi_cmd_task *ctask = session->cmds[i];
2100                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2101
2102                 kfifo_free(tcp_ctask->r2tqueue);
2103                 iscsi_pool_free(&tcp_ctask->r2tpool,
2104                                 (void**)tcp_ctask->r2ts);
2105         }
2106         return -ENOMEM;
2107 }
2108
2109 static void
2110 iscsi_r2tpool_free(struct iscsi_session *session)
2111 {
2112         int i;
2113
2114         for (i = 0; i < session->cmds_max; i++) {
2115                 struct iscsi_cmd_task *ctask = session->cmds[i];
2116                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2117
2118                 kfifo_free(tcp_ctask->r2tqueue);
2119                 iscsi_pool_free(&tcp_ctask->r2tpool,
2120                                 (void**)tcp_ctask->r2ts);
2121         }
2122 }
2123
2124 static int
2125 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2126                      char *buf, int buflen)
2127 {
2128         struct iscsi_conn *conn = cls_conn->dd_data;
2129         struct iscsi_session *session = conn->session;
2130         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2131         int value;
2132
2133         switch(param) {
2134         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2135                 char *saveptr = tcp_conn->data;
2136                 gfp_t flags = GFP_KERNEL;
2137
2138                 sscanf(buf, "%d", &value);
2139                 if (tcp_conn->data_size >= value) {
2140                         iscsi_set_param(cls_conn, param, buf, buflen);
2141                         break;
2142                 }
2143
2144                 spin_lock_bh(&session->lock);
2145                 if (conn->stop_stage == STOP_CONN_RECOVER)
2146                         flags = GFP_ATOMIC;
2147                 spin_unlock_bh(&session->lock);
2148
2149                 if (value <= PAGE_SIZE)
2150                         tcp_conn->data = kmalloc(value, flags);
2151                 else
2152                         tcp_conn->data = (void*)__get_free_pages(flags,
2153                                                              get_order(value));
2154                 if (tcp_conn->data == NULL) {
2155                         tcp_conn->data = saveptr;
2156                         return -ENOMEM;
2157                 }
2158                 if (tcp_conn->data_size <= PAGE_SIZE)
2159                         kfree(saveptr);
2160                 else
2161                         free_pages((unsigned long)saveptr,
2162                                    get_order(tcp_conn->data_size));
2163                 iscsi_set_param(cls_conn, param, buf, buflen);
2164                 tcp_conn->data_size = value;
2165                 break;
2166                 }
2167         case ISCSI_PARAM_HDRDGST_EN:
2168                 iscsi_set_param(cls_conn, param, buf, buflen);
2169                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2170                 if (conn->hdrdgst_en) {
2171                         tcp_conn->hdr_size += sizeof(__u32);
2172                         if (!tcp_conn->tx_tfm)
2173                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2174                                                                     0);
2175                         if (!tcp_conn->tx_tfm)
2176                                 return -ENOMEM;
2177                         if (!tcp_conn->rx_tfm)
2178                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2179                                                                     0);
2180                         if (!tcp_conn->rx_tfm) {
2181                                 crypto_free_tfm(tcp_conn->tx_tfm);
2182                                 return -ENOMEM;
2183                         }
2184                 } else {
2185                         if (tcp_conn->tx_tfm)
2186                                 crypto_free_tfm(tcp_conn->tx_tfm);
2187                         if (tcp_conn->rx_tfm)
2188                                 crypto_free_tfm(tcp_conn->rx_tfm);
2189                 }
2190                 break;
2191         case ISCSI_PARAM_DATADGST_EN:
2192                 iscsi_set_param(cls_conn, param, buf, buflen);
2193                 if (conn->datadgst_en) {
2194                         if (!tcp_conn->data_tx_tfm)
2195                                 tcp_conn->data_tx_tfm =
2196                                     crypto_alloc_tfm("crc32c", 0);
2197                         if (!tcp_conn->data_tx_tfm)
2198                                 return -ENOMEM;
2199                         if (!tcp_conn->data_rx_tfm)
2200                                 tcp_conn->data_rx_tfm =
2201                                     crypto_alloc_tfm("crc32c", 0);
2202                         if (!tcp_conn->data_rx_tfm) {
2203                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2204                                 return -ENOMEM;
2205                         }
2206                 } else {
2207                         if (tcp_conn->data_tx_tfm)
2208                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2209                         if (tcp_conn->data_rx_tfm)
2210                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2211                 }
2212                 tcp_conn->sendpage = conn->datadgst_en ?
2213                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2214                 break;
2215         case ISCSI_PARAM_MAX_R2T:
2216                 sscanf(buf, "%d", &value);
2217                 if (session->max_r2t == roundup_pow_of_two(value))
2218                         break;
2219                 iscsi_r2tpool_free(session);
2220                 iscsi_set_param(cls_conn, param, buf, buflen);
2221                 if (session->max_r2t & (session->max_r2t - 1))
2222                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2223                 if (iscsi_r2tpool_alloc(session))
2224                         return -ENOMEM;
2225                 break;
2226         default:
2227                 return iscsi_set_param(cls_conn, param, buf, buflen);
2228         }
2229
2230         return 0;
2231 }
2232
2233 static int
2234 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2235                          enum iscsi_param param, char *buf)
2236 {
2237         struct iscsi_conn *conn = cls_conn->dd_data;
2238         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2239         struct inet_sock *inet;
2240         struct ipv6_pinfo *np;
2241         struct sock *sk;
2242         int len;
2243
2244         switch(param) {
2245         case ISCSI_PARAM_CONN_PORT:
2246                 mutex_lock(&conn->xmitmutex);
2247                 if (!tcp_conn->sock) {
2248                         mutex_unlock(&conn->xmitmutex);
2249                         return -EINVAL;
2250                 }
2251
2252                 inet = inet_sk(tcp_conn->sock->sk);
2253                 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2254                 mutex_unlock(&conn->xmitmutex);
2255                 break;
2256         case ISCSI_PARAM_CONN_ADDRESS:
2257                 mutex_lock(&conn->xmitmutex);
2258                 if (!tcp_conn->sock) {
2259                         mutex_unlock(&conn->xmitmutex);
2260                         return -EINVAL;
2261                 }
2262
2263                 sk = tcp_conn->sock->sk;
2264                 if (sk->sk_family == PF_INET) {
2265                         inet = inet_sk(sk);
2266                         len = sprintf(buf, "%u.%u.%u.%u\n",
2267                                       NIPQUAD(inet->daddr));
2268                 } else {
2269                         np = inet6_sk(sk);
2270                         len = sprintf(buf,
2271                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2272                                 NIP6(np->daddr));
2273                 }
2274                 mutex_unlock(&conn->xmitmutex);
2275                 break;
2276         default:
2277                 return iscsi_conn_get_param(cls_conn, param, buf);
2278         }
2279
2280         return len;
2281 }
2282
2283 static void
2284 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2285 {
2286         struct iscsi_conn *conn = cls_conn->dd_data;
2287         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2288
2289         stats->txdata_octets = conn->txdata_octets;
2290         stats->rxdata_octets = conn->rxdata_octets;
2291         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2292         stats->dataout_pdus = conn->dataout_pdus_cnt;
2293         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2294         stats->datain_pdus = conn->datain_pdus_cnt;
2295         stats->r2t_pdus = conn->r2t_pdus_cnt;
2296         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2297         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2298         stats->custom_length = 3;
2299         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2300         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2301         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2302         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2303         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2304         stats->custom[2].value = conn->eh_abort_cnt;
2305 }
2306
2307 static struct iscsi_cls_session *
2308 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2309                          struct scsi_transport_template *scsit,
2310                          uint32_t initial_cmdsn, uint32_t *hostno)
2311 {
2312         struct iscsi_cls_session *cls_session;
2313         struct iscsi_session *session;
2314         uint32_t hn;
2315         int cmd_i;
2316
2317         cls_session = iscsi_session_setup(iscsit, scsit,
2318                                          sizeof(struct iscsi_tcp_cmd_task),
2319                                          sizeof(struct iscsi_tcp_mgmt_task),
2320                                          initial_cmdsn, &hn);
2321         if (!cls_session)
2322                 return NULL;
2323         *hostno = hn;
2324
2325         session = class_to_transport_session(cls_session);
2326         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2327                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2328                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2329
2330                 ctask->hdr = &tcp_ctask->hdr;
2331         }
2332
2333         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2334                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2335                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2336
2337                 mtask->hdr = &tcp_mtask->hdr;
2338         }
2339
2340         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2341                 goto r2tpool_alloc_fail;
2342
2343         return cls_session;
2344
2345 r2tpool_alloc_fail:
2346         iscsi_session_teardown(cls_session);
2347         return NULL;
2348 }
2349
2350 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2351 {
2352         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2353         iscsi_session_teardown(cls_session);
2354 }
2355
2356 static struct scsi_host_template iscsi_sht = {
2357         .name                   = "iSCSI Initiator over TCP/IP, v"
2358                                   ISCSI_TCP_VERSION,
2359         .queuecommand           = iscsi_queuecommand,
2360         .change_queue_depth     = iscsi_change_queue_depth,
2361         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2362         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2363         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2364         .eh_abort_handler       = iscsi_eh_abort,
2365         .eh_host_reset_handler  = iscsi_eh_host_reset,
2366         .use_clustering         = DISABLE_CLUSTERING,
2367         .proc_name              = "iscsi_tcp",
2368         .this_id                = -1,
2369 };
2370
2371 static struct iscsi_transport iscsi_tcp_transport = {
2372         .owner                  = THIS_MODULE,
2373         .name                   = "tcp",
2374         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2375                                   | CAP_DATADGST,
2376         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2377                                   ISCSI_MAX_XMIT_DLENGTH |
2378                                   ISCSI_HDRDGST_EN |
2379                                   ISCSI_DATADGST_EN |
2380                                   ISCSI_INITIAL_R2T_EN |
2381                                   ISCSI_MAX_R2T |
2382                                   ISCSI_IMM_DATA_EN |
2383                                   ISCSI_FIRST_BURST |
2384                                   ISCSI_MAX_BURST |
2385                                   ISCSI_PDU_INORDER_EN |
2386                                   ISCSI_DATASEQ_INORDER_EN |
2387                                   ISCSI_ERL |
2388                                   ISCSI_CONN_PORT |
2389                                   ISCSI_CONN_ADDRESS |
2390                                   ISCSI_EXP_STATSN |
2391                                   ISCSI_PERSISTENT_PORT |
2392                                   ISCSI_PERSISTENT_ADDRESS |
2393                                   ISCSI_TARGET_NAME |
2394                                   ISCSI_TPGT,
2395         .host_template          = &iscsi_sht,
2396         .conndata_size          = sizeof(struct iscsi_conn),
2397         .max_conn               = 1,
2398         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2399         /* session management */
2400         .create_session         = iscsi_tcp_session_create,
2401         .destroy_session        = iscsi_tcp_session_destroy,
2402         /* connection management */
2403         .create_conn            = iscsi_tcp_conn_create,
2404         .bind_conn              = iscsi_tcp_conn_bind,
2405         .destroy_conn           = iscsi_tcp_conn_destroy,
2406         .set_param              = iscsi_conn_set_param,
2407         .get_conn_param         = iscsi_tcp_conn_get_param,
2408         .get_session_param      = iscsi_session_get_param,
2409         .start_conn             = iscsi_conn_start,
2410         .stop_conn              = iscsi_tcp_conn_stop,
2411         /* IO */
2412         .send_pdu               = iscsi_conn_send_pdu,
2413         .get_stats              = iscsi_conn_get_stats,
2414         .init_cmd_task          = iscsi_tcp_cmd_init,
2415         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2416         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2417         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2418         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2419         /* recovery */
2420         .session_recovery_timedout = iscsi_session_recovery_timedout,
2421 };
2422
2423 static int __init
2424 iscsi_tcp_init(void)
2425 {
2426         if (iscsi_max_lun < 1) {
2427                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2428                        iscsi_max_lun);
2429                 return -EINVAL;
2430         }
2431         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2432
2433         if (!iscsi_register_transport(&iscsi_tcp_transport))
2434                 return -ENODEV;
2435
2436         return 0;
2437 }
2438
2439 static void __exit
2440 iscsi_tcp_exit(void)
2441 {
2442         iscsi_unregister_transport(&iscsi_tcp_transport);
2443 }
2444
2445 module_init(iscsi_tcp_init);
2446 module_exit(iscsi_tcp_exit);