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

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/list.h>
  31 #include <linux/inet.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  47               "Alex Aizman <itn780@yahoo.com>");
  48 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  49 MODULE_LICENSE("GPL");
  50 MODULE_VERSION("0:4.445");
  51 /* #define DEBUG_TCP */
  52 #define DEBUG_ASSERT
  53
  54 #ifdef DEBUG_TCP
  55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  56 #else
  57 #define debug_tcp(fmt...)
  58 #endif
  59
  60 #ifndef DEBUG_ASSERT
  61 #ifdef BUG_ON
  62 #undef BUG_ON
  63 #endif
  64 #define BUG_ON(expr)
  65 #endif
  66
  67 static unsigned int iscsi_max_lun = 512;
  68 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  69
  70 static inline void
  71 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  72 {
  73         ibuf->sg.page = virt_to_page(vbuf);
  74         ibuf->sg.offset = offset_in_page(vbuf);
  75         ibuf->sg.length = size;
  76         ibuf->sent = 0;
  77         ibuf->use_sendmsg = 1;
  78 }
  79
  80 static inline void
  81 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  82 {
  83         ibuf->sg.page = sg->page;
  84         ibuf->sg.offset = sg->offset;
  85         ibuf->sg.length = sg->length;
  86         /*
  87          * Fastpath: sg element fits into single page
  88          */
  89         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  90                 ibuf->use_sendmsg = 0;
  91         else
  92                 ibuf->use_sendmsg = 1;
  93         ibuf->sent = 0;
  94 }
  95
  96 static inline int
  97 iscsi_buf_left(struct iscsi_buf *ibuf)
  98 {
  99         int rc;
 100
 101         rc = ibuf->sg.length - ibuf->sent;
 102         BUG_ON(rc < 0);
 103         return rc;
 104 }
 105
 106 static inline void
 107 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 108                  u8* crc)
 109 {
 110         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 111
 112         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 113         buf->sg.length += sizeof(uint32_t);
 114 }
 115
 116 static inline int
 117 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 118 {
 119         struct sk_buff *skb = tcp_conn->in.skb;
 120
 121         tcp_conn->in.zero_copy_hdr = 0;
 122
 123         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 124             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 125                 /*
 126                  * Zero-copy PDU Header: using connection context
 127                  * to store header pointer.
 128                  */
 129                 if (skb_shinfo(skb)->frag_list == NULL &&
 130                     !skb_shinfo(skb)->nr_frags) {
 131                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 132                                 ((char*)skb->data + tcp_conn->in.offset);
 133                         tcp_conn->in.zero_copy_hdr = 1;
 134                 } else {
 135                         /* ignoring return code since we checked
 136                          * in.copy before */
 137                         skb_copy_bits(skb, tcp_conn->in.offset,
 138                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 139                         tcp_conn->in.hdr = &tcp_conn->hdr;
 140                 }
 141                 tcp_conn->in.offset += tcp_conn->hdr_size;
 142                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 143         } else {
 144                 int hdr_remains;
 145                 int copylen;
 146
 147                 /*
 148                  * PDU header scattered across SKB's,
 149                  * copying it... This'll happen quite rarely.
 150                  */
 151
 152                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 153                         tcp_conn->in.hdr_offset = 0;
 154
 155                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 156                 BUG_ON(hdr_remains <= 0);
 157
 158                 copylen = min(tcp_conn->in.copy, hdr_remains);
 159                 skb_copy_bits(skb, tcp_conn->in.offset,
 160                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 161                         copylen);
 162
 163                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 164                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 165                        tcp_conn->in.offset, tcp_conn->in.copy);
 166
 167                 tcp_conn->in.offset += copylen;
 168                 tcp_conn->in.copy -= copylen;
 169                 if (copylen < hdr_remains)  {
 170                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 171                         tcp_conn->in.hdr_offset += copylen;
 172                         return -EAGAIN;
 173                 }
 174                 tcp_conn->in.hdr = &tcp_conn->hdr;
 175                 tcp_conn->discontiguous_hdr_cnt++;
 176                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 177         }
 178
 179         return 0;
 180 }
 181
 182 /*
 183  * must be called with session lock
 184  */
 185 static void
 186 __iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 187 {
 188         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 189         struct scsi_cmnd *sc;
 190
 191         sc = ctask->sc;
 192         if (unlikely(!sc))
 193                 return;
 194
 195         tcp_ctask->xmstate = XMSTATE_IDLE;
 196         tcp_ctask->r2t = NULL;
 197 }
 198
 199 /**
 200  * iscsi_data_rsp - SCSI Data-In Response processing
 201  * @conn: iscsi connection
 202  * @ctask: scsi command task
 203  **/
 204 static int
 205 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 206 {
 207         int rc;
 208         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 209         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 210         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 211         struct iscsi_session *session = conn->session;
 212         int datasn = be32_to_cpu(rhdr->datasn);
 213
 214         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 215         if (rc)
 216                 return rc;
 217         /*
 218          * setup Data-In byte counter (gets decremented..)
 219          */
 220         ctask->data_count = tcp_conn->in.datalen;
 221
 222         if (tcp_conn->in.datalen == 0)
 223                 return 0;
 224
 225         if (ctask->datasn != datasn)
 226                 return ISCSI_ERR_DATASN;
 227
 228         ctask->datasn++;
 229
 230         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 231         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 232                 return ISCSI_ERR_DATA_OFFSET;
 233
 234         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 235                 struct scsi_cmnd *sc = ctask->sc;
 236
 237                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 238                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 239                         int res_count = be32_to_cpu(rhdr->residual_count);
 240
 241                         if (res_count > 0 &&
 242                             res_count <= sc->request_bufflen) {
 243                                 sc->resid = res_count;
 244                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 245                         } else
 246                                 sc->result = (DID_BAD_TARGET << 16) |
 247                                         rhdr->cmd_status;
 248                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 249                         sc->resid = be32_to_cpu(rhdr->residual_count);
 250                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 251                 } else
 252                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 253         }
 254
 255         conn->datain_pdus_cnt++;
 256         return 0;
 257 }
 258
 259 /**
 260  * iscsi_solicit_data_init - initialize first Data-Out
 261  * @conn: iscsi connection
 262  * @ctask: scsi command task
 263  * @r2t: R2T info
 264  *
 265  * Notes:
 266  *      Initialize first Data-Out within this R2T sequence and finds
 267  *      proper data_offset within this SCSI command.
 268  *
 269  *      This function is called with connection lock taken.
 270  **/
 271 static void
 272 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 273                         struct iscsi_r2t_info *r2t)
 274 {
 275         struct iscsi_data *hdr;
 276         struct scsi_cmnd *sc = ctask->sc;
 277         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 278
 279         hdr = &r2t->dtask.hdr;
 280         memset(hdr, 0, sizeof(struct iscsi_data));
 281         hdr->ttt = r2t->ttt;
 282         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 283         r2t->solicit_datasn++;
 284         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 285         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 286         hdr->itt = ctask->hdr->itt;
 287         hdr->exp_statsn = r2t->exp_statsn;
 288         hdr->offset = cpu_to_be32(r2t->data_offset);
 289         if (r2t->data_length > conn->max_xmit_dlength) {
 290                 hton24(hdr->dlength, conn->max_xmit_dlength);
 291                 r2t->data_count = conn->max_xmit_dlength;
 292                 hdr->flags = 0;
 293         } else {
 294                 hton24(hdr->dlength, r2t->data_length);
 295                 r2t->data_count = r2t->data_length;
 296                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 297         }
 298         conn->dataout_pdus_cnt++;
 299
 300         r2t->sent = 0;
 301
 302         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 303                            sizeof(struct iscsi_hdr));
 304
 305         if (sc->use_sg) {
 306                 int i, sg_count = 0;
 307                 struct scatterlist *sg = sc->request_buffer;
 308
 309                 r2t->sg = NULL;
 310                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 311                         /* FIXME: prefetch ? */
 312                         if (sg_count + sg->length > r2t->data_offset) {
 313                                 int page_offset;
 314
 315                                 /* sg page found! */
 316
 317                                 /* offset within this page */
 318                                 page_offset = r2t->data_offset - sg_count;
 319
 320                                 /* fill in this buffer */
 321                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 322                                 r2t->sendbuf.sg.offset += page_offset;
 323                                 r2t->sendbuf.sg.length -= page_offset;
 324
 325                                 /* xmit logic will continue with next one */
 326                                 r2t->sg = sg + 1;
 327                                 break;
 328                         }
 329                         sg_count += sg->length;
 330                 }
 331                 BUG_ON(r2t->sg == NULL);
 332         } else
 333                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 334                             (char*)sc->request_buffer + r2t->data_offset,
 335                             r2t->data_count);
 336 }
 337
 338 /**
 339  * iscsi_r2t_rsp - iSCSI R2T Response processing
 340  * @conn: iscsi connection
 341  * @ctask: scsi command task
 342  **/
 343 static int
 344 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 345 {
 346         struct iscsi_r2t_info *r2t;
 347         struct iscsi_session *session = conn->session;
 348         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 349         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 350         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 351         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 352         int rc;
 353
 354         if (tcp_conn->in.datalen)
 355                 return ISCSI_ERR_DATALEN;
 356
 357         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 358                 return ISCSI_ERR_R2TSN;
 359
 360         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 361         if (rc)
 362                 return rc;
 363
 364         /* FIXME: use R2TSN to detect missing R2T */
 365
 366         /* fill-in new R2T associated with the task */
 367         spin_lock(&session->lock);
 368         if (!ctask->sc || ctask->mtask ||
 369              session->state != ISCSI_STATE_LOGGED_IN) {
 370                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 371                        "recovery...\n", ctask->itt);
 372                 spin_unlock(&session->lock);
 373                 return 0;
 374         }
 375         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 376         BUG_ON(!rc);
 377
 378         r2t->exp_statsn = rhdr->statsn;
 379         r2t->data_length = be32_to_cpu(rhdr->data_length);
 380         if (r2t->data_length == 0 ||
 381             r2t->data_length > session->max_burst) {
 382                 spin_unlock(&session->lock);
 383                 return ISCSI_ERR_DATALEN;
 384         }
 385
 386         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 387         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 388                 spin_unlock(&session->lock);
 389                 return ISCSI_ERR_DATALEN;
 390         }
 391
 392         r2t->ttt = rhdr->ttt; /* no flip */
 393         r2t->solicit_datasn = 0;
 394
 395         iscsi_solicit_data_init(conn, ctask, r2t);
 396
 397         tcp_ctask->exp_r2tsn = r2tsn + 1;
 398         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 399         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 400         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 401
 402         scsi_queue_work(session->host, &conn->xmitwork);
 403         conn->r2t_pdus_cnt++;
 404         spin_unlock(&session->lock);
 405
 406         return 0;
 407 }
 408
 409 static int
 410 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 411 {
 412         int rc = 0, opcode, ahslen;
 413         struct iscsi_hdr *hdr;
 414         struct iscsi_session *session = conn->session;
 415         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 416         uint32_t cdgst, rdgst = 0, itt;
 417
 418         hdr = tcp_conn->in.hdr;
 419
 420         /* verify PDU length */
 421         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 422         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 423                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 424                        tcp_conn->in.datalen, conn->max_recv_dlength);
 425                 return ISCSI_ERR_DATALEN;
 426         }
 427         tcp_conn->data_copied = 0;
 428
 429         /* read AHS */
 430         ahslen = hdr->hlength << 2;
 431         tcp_conn->in.offset += ahslen;
 432         tcp_conn->in.copy -= ahslen;
 433         if (tcp_conn->in.copy < 0) {
 434                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 435                        "%d bytes\n", ahslen);
 436                 return ISCSI_ERR_AHSLEN;
 437         }
 438
 439         /* calculate read padding */
 440         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 441         if (tcp_conn->in.padding) {
 442                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 443                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 444         }
 445
 446         if (conn->hdrdgst_en) {
 447                 struct scatterlist sg;
 448
 449                 sg_init_one(&sg, (u8 *)hdr,
 450                             sizeof(struct iscsi_hdr) + ahslen);
 451                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 452                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 453                                      ahslen);
 454                 if (cdgst != rdgst) {
 455                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 456                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 457                         return ISCSI_ERR_HDR_DGST;
 458                 }
 459         }
 460
 461         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 462         /* verify itt (itt encoding: age+cid+itt) */
 463         rc = iscsi_verify_itt(conn, hdr, &itt);
 464         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 465                 tcp_conn->in.datalen = 0; /* force drop */
 466                 return 0;
 467         } else if (rc)
 468                 return rc;
 469
 470         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 471                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 472                   ahslen, tcp_conn->in.datalen);
 473
 474         switch(opcode) {
 475         case ISCSI_OP_SCSI_DATA_IN:
 476                 tcp_conn->in.ctask = session->cmds[itt];
 477                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 478                 /* fall through */
 479         case ISCSI_OP_SCSI_CMD_RSP:
 480                 tcp_conn->in.ctask = session->cmds[itt];
 481                 if (tcp_conn->in.datalen)
 482                         goto copy_hdr;
 483
 484                 spin_lock(&session->lock);
 485                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 486                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 487                 spin_unlock(&session->lock);
 488                 break;
 489         case ISCSI_OP_R2T:
 490                 tcp_conn->in.ctask = session->cmds[itt];
 491                 if (ahslen)
 492                         rc = ISCSI_ERR_AHSLEN;
 493                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 494                                                                 DMA_TO_DEVICE)
 495                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 496                 else
 497                         rc = ISCSI_ERR_PROTO;
 498                 break;
 499         case ISCSI_OP_LOGIN_RSP:
 500         case ISCSI_OP_TEXT_RSP:
 501         case ISCSI_OP_LOGOUT_RSP:
 502         case ISCSI_OP_NOOP_IN:
 503         case ISCSI_OP_REJECT:
 504         case ISCSI_OP_ASYNC_EVENT:
 505                 if (tcp_conn->in.datalen)
 506                         goto copy_hdr;
 507         /* fall through */
 508         case ISCSI_OP_SCSI_TMFUNC_RSP:
 509                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 510                 break;
 511         default:
 512                 rc = ISCSI_ERR_BAD_OPCODE;
 513                 break;
 514         }
 515
 516         return rc;
 517
 518 copy_hdr:
 519         /*
 520          * if we did zero copy for the header but we will need multiple
 521          * skbs to complete the command then we have to copy the header
 522          * for later use
 523          */
 524         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
 525            (tcp_conn->in.datalen + tcp_conn->in.padding +
 526             (conn->datadgst_en ? 4 : 0))) {
 527                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 528                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 529                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 530                        sizeof(struct iscsi_hdr));
 531                 tcp_conn->in.hdr = &tcp_conn->hdr;
 532                 tcp_conn->in.zero_copy_hdr = 0;
 533         }
 534         return 0;
 535 }
 536
 537 /**
 538  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 539  * @conn: iscsi tcp connection
 540  * @ctask: scsi command task
 541  * @buf: buffer to copy to
 542  * @buf_size: size of buffer
 543  * @offset: offset within the buffer
 544  *
 545  * Notes:
 546  *      The function calls skb_copy_bits() and updates per-connection and
 547  *      per-cmd byte counters.
 548  *
 549  *      Read counters (in bytes):
 550  *
 551  *      conn->in.offset         offset within in progress SKB
 552  *      conn->in.copy           left to copy from in progress SKB
 553  *                              including padding
 554  *      conn->in.copied         copied already from in progress SKB
 555  *      conn->data_copied       copied already from in progress buffer
 556  *      ctask->sent             total bytes sent up to the MidLayer
 557  *      ctask->data_count       left to copy from in progress Data-In
 558  *      buf_left                left to copy from in progress buffer
 559  **/
 560 static inline int
 561 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 562                 void *buf, int buf_size, int offset)
 563 {
 564         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 565         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 566         int size = min(tcp_conn->in.copy, buf_left);
 567         int rc;
 568
 569         size = min(size, ctask->data_count);
 570
 571         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 572                size, tcp_conn->in.offset, tcp_conn->in.copied);
 573
 574         BUG_ON(size <= 0);
 575         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 576
 577         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 578                            (char*)buf + (offset + tcp_conn->data_copied), size);
 579         /* must fit into skb->len */
 580         BUG_ON(rc);
 581
 582         tcp_conn->in.offset += size;
 583         tcp_conn->in.copy -= size;
 584         tcp_conn->in.copied += size;
 585         tcp_conn->data_copied += size;
 586         tcp_ctask->sent += size;
 587         ctask->data_count -= size;
 588
 589         BUG_ON(tcp_conn->in.copy < 0);
 590         BUG_ON(ctask->data_count < 0);
 591
 592         if (buf_size != (tcp_conn->data_copied + offset)) {
 593                 if (!ctask->data_count) {
 594                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 595                         /* done with this PDU */
 596                         return buf_size - tcp_conn->data_copied;
 597                 }
 598                 return -EAGAIN;
 599         }
 600
 601         /* done with this buffer or with both - PDU and buffer */
 602         tcp_conn->data_copied = 0;
 603         return 0;
 604 }
 605
 606 /**
 607  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 608  * @conn: iscsi tcp connection
 609  *
 610  * Notes:
 611  *      The function calls skb_copy_bits() and updates per-connection
 612  *      byte counters.
 613  **/
 614 static inline int
 615 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 616 {
 617         void *buf = tcp_conn->data;
 618         int buf_size = tcp_conn->in.datalen;
 619         int buf_left = buf_size - tcp_conn->data_copied;
 620         int size = min(tcp_conn->in.copy, buf_left);
 621         int rc;
 622
 623         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 624                size, tcp_conn->in.offset, tcp_conn->data_copied);
 625         BUG_ON(size <= 0);
 626
 627         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 628                            (char*)buf + tcp_conn->data_copied, size);
 629         BUG_ON(rc);
 630
 631         tcp_conn->in.offset += size;
 632         tcp_conn->in.copy -= size;
 633         tcp_conn->in.copied += size;
 634         tcp_conn->data_copied += size;
 635
 636         if (buf_size != tcp_conn->data_copied)
 637                 return -EAGAIN;
 638
 639         return 0;
 640 }
 641
 642 static inline void
 643 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 644                          struct scatterlist *sg, int offset, int length)
 645 {
 646         struct scatterlist temp;
 647
 648         memcpy(&temp, sg, sizeof(struct scatterlist));
 649         temp.offset = offset;
 650         temp.length = length;
 651         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 652 }
 653
 654 static void
 655 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 656 {
 657         struct scatterlist tmp;
 658
 659         sg_init_one(&tmp, buf, len);
 660         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 661 }
 662
 663 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 664 {
 665         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 666         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 667         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 668         struct scsi_cmnd *sc = ctask->sc;
 669         struct scatterlist *sg;
 670         int i, offset, rc = 0;
 671
 672         BUG_ON((void*)ctask != sc->SCp.ptr);
 673
 674         /*
 675          * copying Data-In into the Scsi_Cmnd
 676          */
 677         if (!sc->use_sg) {
 678                 i = ctask->data_count;
 679                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 680                                       sc->request_bufflen,
 681                                       tcp_ctask->data_offset);
 682                 if (rc == -EAGAIN)
 683                         return rc;
 684                 if (conn->datadgst_en)
 685                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 686                                                  i);
 687                 rc = 0;
 688                 goto done;
 689         }
 690
 691         offset = tcp_ctask->data_offset;
 692         sg = sc->request_buffer;
 693
 694         if (tcp_ctask->data_offset)
 695                 for (i = 0; i < tcp_ctask->sg_count; i++)
 696                         offset -= sg[i].length;
 697         /* we've passed through partial sg*/
 698         if (offset < 0)
 699                 offset = 0;
 700
 701         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 702                 char *dest;
 703
 704                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 705                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 706                                       sg[i].length, offset);
 707                 kunmap_atomic(dest, KM_SOFTIRQ0);
 708                 if (rc == -EAGAIN)
 709                         /* continue with the next SKB/PDU */
 710                         return rc;
 711                 if (!rc) {
 712                         if (conn->datadgst_en) {
 713                                 if (!offset)
 714                                         crypto_digest_update(
 715                                                         tcp_conn->data_rx_tfm,
 716                                                         &sg[i], 1);
 717                                 else
 718                                         partial_sg_digest_update(tcp_conn,
 719                                                         &sg[i],
 720                                                         sg[i].offset + offset,
 721                                                         sg[i].length - offset);
 722                         }
 723                         offset = 0;
 724                         tcp_ctask->sg_count++;
 725                 }
 726
 727                 if (!ctask->data_count) {
 728                         if (rc && conn->datadgst_en)
 729                                 /*
 730                                  * data-in is complete, but buffer not...
 731                                  */
 732                                 partial_sg_digest_update(tcp_conn, &sg[i],
 733                                                 sg[i].offset, sg[i].length-rc);
 734                         rc = 0;
 735                         break;
 736                 }
 737
 738                 if (!tcp_conn->in.copy)
 739                         return -EAGAIN;
 740         }
 741         BUG_ON(ctask->data_count);
 742
 743 done:
 744         /* check for non-exceptional status */
 745         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 746                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 747                            (long)sc, sc->result, ctask->itt);
 748                 spin_lock(&conn->session->lock);
 749                 __iscsi_ctask_cleanup(conn, ctask);
 750                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 751                 spin_unlock(&conn->session->lock);
 752         }
 753
 754         return rc;
 755 }
 756
 757 static int
 758 iscsi_data_recv(struct iscsi_conn *conn)
 759 {
 760         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 761         int rc = 0, opcode;
 762
 763         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 764         switch (opcode) {
 765         case ISCSI_OP_SCSI_DATA_IN:
 766                 rc = iscsi_scsi_data_in(conn);
 767                 break;
 768         case ISCSI_OP_SCSI_CMD_RSP:
 769                 spin_lock(&conn->session->lock);
 770                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 771                 spin_unlock(&conn->session->lock);
 772         case ISCSI_OP_TEXT_RSP:
 773         case ISCSI_OP_LOGIN_RSP:
 774         case ISCSI_OP_NOOP_IN:
 775         case ISCSI_OP_ASYNC_EVENT:
 776         case ISCSI_OP_REJECT:
 777                 /*
 778                  * Collect data segment to the connection's data
 779                  * placeholder
 780                  */
 781                 if (iscsi_tcp_copy(tcp_conn)) {
 782                         rc = -EAGAIN;
 783                         goto exit;
 784                 }
 785
 786                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 787                                         tcp_conn->in.datalen);
 788                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 789                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 790                                                 tcp_conn->in.datalen);
 791                 break;
 792         default:
 793                 BUG_ON(1);
 794         }
 795 exit:
 796         return rc;
 797 }
 798
 799 /**
 800  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 801  * @rd_desc: read descriptor
 802  * @skb: socket buffer
 803  * @offset: offset in skb
 804  * @len: skb->len - offset
 805  **/
 806 static int
 807 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 808                 unsigned int offset, size_t len)
 809 {
 810         int rc;
 811         struct iscsi_conn *conn = rd_desc->arg.data;
 812         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 813         int processed;
 814         char pad[ISCSI_PAD_LEN];
 815         struct scatterlist sg;
 816
 817         /*
 818          * Save current SKB and its offset in the corresponding
 819          * connection context.
 820          */
 821         tcp_conn->in.copy = skb->len - offset;
 822         tcp_conn->in.offset = offset;
 823         tcp_conn->in.skb = skb;
 824         tcp_conn->in.len = tcp_conn->in.copy;
 825         BUG_ON(tcp_conn->in.copy <= 0);
 826         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 827
 828 more:
 829         tcp_conn->in.copied = 0;
 830         rc = 0;
 831
 832         if (unlikely(conn->suspend_rx)) {
 833                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 834                 return 0;
 835         }
 836
 837         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 838             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 839                 rc = iscsi_hdr_extract(tcp_conn);
 840                 if (rc) {
 841                        if (rc == -EAGAIN)
 842                                 goto nomore;
 843                        else {
 844                                 iscsi_conn_failure(conn, rc);
 845                                 return 0;
 846                        }
 847                 }
 848
 849                 /*
 850                  * Verify and process incoming PDU header.
 851                  */
 852                 rc = iscsi_tcp_hdr_recv(conn);
 853                 if (!rc && tcp_conn->in.datalen) {
 854                         if (conn->datadgst_en) {
 855                                 BUG_ON(!tcp_conn->data_rx_tfm);
 856                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 857                         }
 858                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 859                 } else if (rc) {
 860                         iscsi_conn_failure(conn, rc);
 861                         return 0;
 862                 }
 863         }
 864
 865         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 866                 uint32_t recv_digest;
 867
 868                 debug_tcp("extra data_recv offset %d copy %d\n",
 869                           tcp_conn->in.offset, tcp_conn->in.copy);
 870                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 871                                 &recv_digest, 4);
 872                 tcp_conn->in.offset += 4;
 873                 tcp_conn->in.copy -= 4;
 874                 if (recv_digest != tcp_conn->in.datadgst) {
 875                         debug_tcp("iscsi_tcp: data digest error!"
 876                                   "0x%x != 0x%x\n", recv_digest,
 877                                   tcp_conn->in.datadgst);
 878                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 879                         return 0;
 880                 } else {
 881                         debug_tcp("iscsi_tcp: data digest match!"
 882                                   "0x%x == 0x%x\n", recv_digest,
 883                                   tcp_conn->in.datadgst);
 884                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 885                 }
 886         }
 887
 888         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 889            tcp_conn->in.copy) {
 890
 891                 debug_tcp("data_recv offset %d copy %d\n",
 892                        tcp_conn->in.offset, tcp_conn->in.copy);
 893
 894                 rc = iscsi_data_recv(conn);
 895                 if (rc) {
 896                         if (rc == -EAGAIN)
 897                                 goto again;
 898                         iscsi_conn_failure(conn, rc);
 899                         return 0;
 900                 }
 901                 tcp_conn->in.copy -= tcp_conn->in.padding;
 902                 tcp_conn->in.offset += tcp_conn->in.padding;
 903                 if (conn->datadgst_en) {
 904                         if (tcp_conn->in.padding) {
 905                                 debug_tcp("padding -> %d\n",
 906                                           tcp_conn->in.padding);
 907                                 memset(pad, 0, tcp_conn->in.padding);
 908                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 909                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 910                                                      &sg, 1);
 911                         }
 912                         crypto_digest_final(tcp_conn->data_rx_tfm,
 913                                             (u8 *) & tcp_conn->in.datadgst);
 914                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 915                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 916                 } else
 917                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 918         }
 919
 920         debug_tcp("f, processed %d from out of %d padding %d\n",
 921                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 922         BUG_ON(tcp_conn->in.offset - offset > len);
 923
 924         if (tcp_conn->in.offset - offset != len) {
 925                 debug_tcp("continue to process %d bytes\n",
 926                        (int)len - (tcp_conn->in.offset - offset));
 927                 goto more;
 928         }
 929
 930 nomore:
 931         processed = tcp_conn->in.offset - offset;
 932         BUG_ON(processed == 0);
 933         return processed;
 934
 935 again:
 936         processed = tcp_conn->in.offset - offset;
 937         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 938                   processed, (int)len, (int)rd_desc->count);
 939         BUG_ON(processed == 0);
 940         BUG_ON(processed > len);
 941
 942         conn->rxdata_octets += processed;
 943         return processed;
 944 }
 945
 946 static void
 947 iscsi_tcp_data_ready(struct sock *sk, int flag)
 948 {
 949         struct iscsi_conn *conn = sk->sk_user_data;
 950         read_descriptor_t rd_desc;
 951
 952         read_lock(&sk->sk_callback_lock);
 953
 954         /*
 955          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 956          * We set count to 1 because we want the network layer to
 957          * hand us all the skbs that are available. iscsi_tcp_data_recv
 958          * handled pdus that cross buffers or pdus that still need data.
 959          */
 960         rd_desc.arg.data = conn;
 961         rd_desc.count = 1;
 962         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 963
 964         read_unlock(&sk->sk_callback_lock);
 965 }
 966
 967 static void
 968 iscsi_tcp_state_change(struct sock *sk)
 969 {
 970         struct iscsi_tcp_conn *tcp_conn;
 971         struct iscsi_conn *conn;
 972         struct iscsi_session *session;
 973         void (*old_state_change)(struct sock *);
 974
 975         read_lock(&sk->sk_callback_lock);
 976
 977         conn = (struct iscsi_conn*)sk->sk_user_data;
 978         session = conn->session;
 979
 980         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 981              sk->sk_state == TCP_CLOSE) &&
 982             !atomic_read(&sk->sk_rmem_alloc)) {
 983                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 984                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 985         }
 986
 987         tcp_conn = conn->dd_data;
 988         old_state_change = tcp_conn->old_state_change;
 989
 990         read_unlock(&sk->sk_callback_lock);
 991
 992         old_state_change(sk);
 993 }
 994
 995 /**
 996  * iscsi_write_space - Called when more output buffer space is available
 997  * @sk: socket space is available for
 998  **/
 999 static void
1000 iscsi_write_space(struct sock *sk)
1001 {
1002         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1003         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1004
1005         tcp_conn->old_write_space(sk);
1006         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1007         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1008         scsi_queue_work(conn->session->host, &conn->xmitwork);
1009 }
1010
1011 static void
1012 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1013 {
1014         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1015         struct sock *sk = tcp_conn->sock->sk;
1016
1017         /* assign new callbacks */
1018         write_lock_bh(&sk->sk_callback_lock);
1019         sk->sk_user_data = conn;
1020         tcp_conn->old_data_ready = sk->sk_data_ready;
1021         tcp_conn->old_state_change = sk->sk_state_change;
1022         tcp_conn->old_write_space = sk->sk_write_space;
1023         sk->sk_data_ready = iscsi_tcp_data_ready;
1024         sk->sk_state_change = iscsi_tcp_state_change;
1025         sk->sk_write_space = iscsi_write_space;
1026         write_unlock_bh(&sk->sk_callback_lock);
1027 }
1028
1029 static void
1030 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1031 {
1032         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1033         struct sock *sk = tcp_conn->sock->sk;
1034
1035         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1036         write_lock_bh(&sk->sk_callback_lock);
1037         sk->sk_user_data    = NULL;
1038         sk->sk_data_ready   = tcp_conn->old_data_ready;
1039         sk->sk_state_change = tcp_conn->old_state_change;
1040         sk->sk_write_space  = tcp_conn->old_write_space;
1041         sk->sk_no_check  = 0;
1042         write_unlock_bh(&sk->sk_callback_lock);
1043 }
1044
1045 /**
1046  * iscsi_send - generic send routine
1047  * @sk: kernel's socket
1048  * @buf: buffer to write from
1049  * @size: actual size to write
1050  * @flags: socket's flags
1051  */
1052 static inline int
1053 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1054 {
1055         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1056         struct socket *sk = tcp_conn->sock;
1057         int offset = buf->sg.offset + buf->sent;
1058
1059         /*
1060          * if we got use_sg=0 or are sending something we kmallocd
1061          * then we did not have to do kmap (kmap returns page_address)
1062          *
1063          * if we got use_sg > 0, but had to drop down, we do not
1064          * set clustering so this should only happen for that
1065          * slab case.
1066          */
1067         if (buf->use_sendmsg)
1068                 return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1069         else
1070                 return tcp_conn->sendpage(sk, buf->sg.page, offset, size,
1071                                           flags);
1072 }
1073
1074 /**
1075  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1076  * @conn: iscsi connection
1077  * @buf: buffer to write from
1078  * @datalen: lenght of data to be sent after the header
1079  *
1080  * Notes:
1081  *      (Tx, Fast Path)
1082  **/
1083 static inline int
1084 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1085 {
1086         struct iscsi_tcp_conn *tcp_conn;
1087         int flags = 0; /* MSG_DONTWAIT; */
1088         int res, size;
1089
1090         size = buf->sg.length - buf->sent;
1091         BUG_ON(buf->sent + size > buf->sg.length);
1092         if (buf->sent + size != buf->sg.length || datalen)
1093                 flags |= MSG_MORE;
1094
1095         res = iscsi_send(conn, buf, size, flags);
1096         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1097         if (res >= 0) {
1098                 conn->txdata_octets += res;
1099                 buf->sent += res;
1100                 if (size != res)
1101                         return -EAGAIN;
1102                 return 0;
1103         } else if (res == -EAGAIN) {
1104                 tcp_conn = conn->dd_data;
1105                 tcp_conn->sendpage_failures_cnt++;
1106                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1107         } else if (res == -EPIPE)
1108                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1109
1110         return res;
1111 }
1112
1113 /**
1114  * iscsi_sendpage - send one page of iSCSI Data-Out.
1115  * @conn: iscsi connection
1116  * @buf: buffer to write from
1117  * @count: remaining data
1118  * @sent: number of bytes sent
1119  *
1120  * Notes:
1121  *      (Tx, Fast Path)
1122  **/
1123 static inline int
1124 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1125                int *count, int *sent)
1126 {
1127         struct iscsi_tcp_conn *tcp_conn;
1128         int flags = 0; /* MSG_DONTWAIT; */
1129         int res, size;
1130
1131         size = buf->sg.length - buf->sent;
1132         BUG_ON(buf->sent + size > buf->sg.length);
1133         if (size > *count)
1134                 size = *count;
1135         if (buf->sent + size != buf->sg.length || *count != size)
1136                 flags |= MSG_MORE;
1137
1138         res = iscsi_send(conn, buf, size, flags);
1139         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1140                   size, buf->sent, *count, *sent, res);
1141         if (res >= 0) {
1142                 conn->txdata_octets += res;
1143                 buf->sent += res;
1144                 *count -= res;
1145                 *sent += res;
1146                 if (size != res)
1147                         return -EAGAIN;
1148                 return 0;
1149         } else if (res == -EAGAIN) {
1150                 tcp_conn = conn->dd_data;
1151                 tcp_conn->sendpage_failures_cnt++;
1152                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1153         } else if (res == -EPIPE)
1154                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1155
1156         return res;
1157 }
1158
1159 static inline void
1160 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1161                       struct iscsi_cmd_task *ctask)
1162 {
1163         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1164
1165         BUG_ON(!tcp_conn->data_tx_tfm);
1166         crypto_digest_init(tcp_conn->data_tx_tfm);
1167         tcp_ctask->digest_count = 4;
1168 }
1169
1170 static int
1171 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1172                         struct iscsi_buf *buf, uint32_t *digest, int final)
1173 {
1174         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1175         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1176         int rc = 0;
1177         int sent = 0;
1178
1179         if (final)
1180                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1181
1182         iscsi_buf_init_iov(buf, (char*)digest, 4);
1183         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1184         if (rc) {
1185                 tcp_ctask->datadigest = *digest;
1186                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1187         } else
1188                 tcp_ctask->digest_count = 4;
1189         return rc;
1190 }
1191
1192 /**
1193  * iscsi_solicit_data_cont - initialize next Data-Out
1194  * @conn: iscsi connection
1195  * @ctask: scsi command task
1196  * @r2t: R2T info
1197  * @left: bytes left to transfer
1198  *
1199  * Notes:
1200  *      Initialize next Data-Out within this R2T sequence and continue
1201  *      to process next Scatter-Gather element(if any) of this SCSI command.
1202  *
1203  *      Called under connection lock.
1204  **/
1205 static void
1206 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1207                         struct iscsi_r2t_info *r2t, int left)
1208 {
1209         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1210         struct iscsi_data *hdr;
1211         struct scsi_cmnd *sc = ctask->sc;
1212         int new_offset;
1213
1214         hdr = &r2t->dtask.hdr;
1215         memset(hdr, 0, sizeof(struct iscsi_data));
1216         hdr->ttt = r2t->ttt;
1217         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1218         r2t->solicit_datasn++;
1219         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1220         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1221         hdr->itt = ctask->hdr->itt;
1222         hdr->exp_statsn = r2t->exp_statsn;
1223         new_offset = r2t->data_offset + r2t->sent;
1224         hdr->offset = cpu_to_be32(new_offset);
1225         if (left > conn->max_xmit_dlength) {
1226                 hton24(hdr->dlength, conn->max_xmit_dlength);
1227                 r2t->data_count = conn->max_xmit_dlength;
1228         } else {
1229                 hton24(hdr->dlength, left);
1230                 r2t->data_count = left;
1231                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1232         }
1233         conn->dataout_pdus_cnt++;
1234
1235         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1236                            sizeof(struct iscsi_hdr));
1237
1238         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1239                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1240                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1241                 r2t->sg += 1;
1242         } else
1243                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1244                             (char*)sc->request_buffer + new_offset,
1245                             r2t->data_count);
1246 }
1247
1248 static void
1249 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1250 {
1251         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1252         struct iscsi_data_task *dtask;
1253
1254         dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1255         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1256                                       tcp_ctask->r2t_data_count);
1257         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1258                            sizeof(struct iscsi_hdr));
1259 }
1260
1261 /**
1262  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1263  * @conn: iscsi connection
1264  * @ctask: scsi command task
1265  * @sc: scsi command
1266  **/
1267 static void
1268 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1269 {
1270         struct scsi_cmnd *sc = ctask->sc;
1271         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1272
1273         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1274
1275         tcp_ctask->sent = 0;
1276         tcp_ctask->sg_count = 0;
1277
1278         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1279                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1280                 tcp_ctask->exp_r2tsn = 0;
1281                 BUG_ON(ctask->total_length == 0);
1282
1283                 if (sc->use_sg) {
1284                         struct scatterlist *sg = sc->request_buffer;
1285
1286                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1287                                           &sg[tcp_ctask->sg_count++]);
1288                         tcp_ctask->sg = sg;
1289                         tcp_ctask->bad_sg = sg + sc->use_sg;
1290                 } else
1291                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1292                                            sc->request_buffer,
1293                                            sc->request_bufflen);
1294
1295                 if (ctask->imm_count)
1296                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1297
1298                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1299                 if (tcp_ctask->pad_count) {
1300                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1301                                                         tcp_ctask->pad_count;
1302                         debug_scsi("write padding %d bytes\n",
1303                                    tcp_ctask->pad_count);
1304                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1305                 }
1306
1307                 if (ctask->unsol_count)
1308                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1309                                                 XMSTATE_UNS_INIT;
1310                 tcp_ctask->r2t_data_count = ctask->total_length -
1311                                     ctask->imm_count -
1312                                     ctask->unsol_count;
1313
1314                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1315                            "r2t_data %d]\n",
1316                            ctask->itt, ctask->total_length, ctask->imm_count,
1317                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1318         } else
1319                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1320
1321         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1322                             sizeof(struct iscsi_hdr));
1323 }
1324
1325 /**
1326  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1327  * @conn: iscsi connection
1328  * @mtask: task management task
1329  *
1330  * Notes:
1331  *      The function can return -EAGAIN in which case caller must
1332  *      call it again later, or recover. '0' return code means successful
1333  *      xmit.
1334  *
1335  *      Management xmit state machine consists of two states:
1336  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1337  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1338  **/
1339 static int
1340 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1341 {
1342         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1343
1344         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1345                 conn->id, tcp_mtask->xmstate, mtask->itt);
1346
1347         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1348                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1349                 if (mtask->data_count)
1350                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1351                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1352                     conn->stop_stage != STOP_CONN_RECOVER &&
1353                     conn->hdrdgst_en)
1354                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1355                                         (u8*)tcp_mtask->hdrext);
1356                 if (iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1357                                   mtask->data_count)) {
1358                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1359                         if (mtask->data_count)
1360                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1361                         return -EAGAIN;
1362                 }
1363         }
1364
1365         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1366                 BUG_ON(!mtask->data_count);
1367                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1368                 /* FIXME: implement.
1369                  * Virtual buffer could be spreaded across multiple pages...
1370                  */
1371                 do {
1372                         if (iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1373                                    &mtask->data_count, &tcp_mtask->sent)) {
1374                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1375                                 return -EAGAIN;
1376                         }
1377                 } while (mtask->data_count);
1378         }
1379
1380         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1381         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1382                 struct iscsi_session *session = conn->session;
1383
1384                 spin_lock_bh(&session->lock);
1385                 list_del(&conn->mtask->running);
1386                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1387                             sizeof(void*));
1388                 spin_unlock_bh(&session->lock);
1389         }
1390         return 0;
1391 }
1392
1393 static inline int
1394 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1395                      struct iscsi_tcp_cmd_task *tcp_ctask)
1396 {
1397         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1398         if (conn->hdrdgst_en)
1399                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1400                                  (u8*)tcp_ctask->hdrext);
1401         if (!iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0)) {
1402                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1403                 return 0; /* wait for Data-In */
1404         }
1405         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1406         return -EAGAIN;
1407 }
1408
1409 static inline int
1410 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1411                      struct iscsi_cmd_task *ctask)
1412 {
1413         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1414
1415         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1416         if (conn->hdrdgst_en)
1417                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1418                                  (u8*)tcp_ctask->hdrext);
1419         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count)) {
1420                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1421                 return -EAGAIN;
1422         }
1423         return 0;
1424 }
1425
1426 static inline int
1427 handle_xmstate_data_digest(struct iscsi_conn *conn,
1428                            struct iscsi_cmd_task *ctask)
1429 {
1430         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1431
1432         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1433         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1434         if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1435                                     &tcp_ctask->datadigest, 0)) {
1436                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1437                 debug_tcp("resent data digest 0x%x fail!\n",
1438                           tcp_ctask->datadigest);
1439                 return -EAGAIN;
1440         }
1441         return 0;
1442 }
1443
1444 static inline int
1445 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1446 {
1447         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1448         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1449
1450         BUG_ON(!ctask->imm_count);
1451         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1452
1453         if (conn->datadgst_en) {
1454                 iscsi_data_digest_init(tcp_conn, ctask);
1455                 tcp_ctask->immdigest = 0;
1456         }
1457
1458         for (;;) {
1459                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &ctask->imm_count,
1460                                    &tcp_ctask->sent)) {
1461                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1462                         if (conn->datadgst_en) {
1463                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1464                                                 (u8*)&tcp_ctask->immdigest);
1465                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1466                                           tcp_ctask->datadigest);
1467                         }
1468                         return -EAGAIN;
1469                 }
1470                 if (conn->datadgst_en)
1471                         crypto_digest_update(tcp_conn->data_tx_tfm,
1472                                              &tcp_ctask->sendbuf.sg, 1);
1473
1474                 if (!ctask->imm_count)
1475                         break;
1476                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1477                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1478         }
1479
1480         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1481                 if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1482                                             &tcp_ctask->immdigest, 1)) {
1483                         debug_tcp("sending imm digest 0x%x fail!\n",
1484                                   tcp_ctask->immdigest);
1485                         return -EAGAIN;
1486                 }
1487                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1488         }
1489
1490         return 0;
1491 }
1492
1493 static inline int
1494 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1495 {
1496         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1497         struct iscsi_data_task *dtask;
1498
1499         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1500         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1501                 iscsi_unsolicit_data_init(conn, ctask);
1502                 dtask = tcp_ctask->dtask;
1503                 if (conn->hdrdgst_en)
1504                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1505                                         (u8*)dtask->hdrext);
1506                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1507         }
1508         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count)) {
1509                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1510                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1511                 return -EAGAIN;
1512         }
1513
1514         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1515                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1516         return 0;
1517 }
1518
1519 static inline int
1520 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1521 {
1522         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1523         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1524         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1525
1526         BUG_ON(!ctask->data_count);
1527         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1528
1529         if (conn->datadgst_en) {
1530                 iscsi_data_digest_init(tcp_conn, ctask);
1531                 dtask->digest = 0;
1532         }
1533
1534         for (;;) {
1535                 int start = tcp_ctask->sent;
1536
1537                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1538                                    &ctask->data_count, &tcp_ctask->sent)) {
1539                         ctask->unsol_count -= tcp_ctask->sent - start;
1540                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1541                         /* will continue with this ctask later.. */
1542                         if (conn->datadgst_en) {
1543                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1544                                                 (u8 *)&dtask->digest);
1545                                 debug_tcp("tx uns data fail 0x%x\n",
1546                                           dtask->digest);
1547                         }
1548                         return -EAGAIN;
1549                 }
1550
1551                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1552                 ctask->unsol_count -= tcp_ctask->sent - start;
1553
1554                 /*
1555                  * XXX:we may run here with un-initial sendbuf.
1556                  * so pass it
1557                  */
1558                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1559                         crypto_digest_update(tcp_conn->data_tx_tfm,
1560                                              &tcp_ctask->sendbuf.sg, 1);
1561
1562                 if (!ctask->data_count)
1563                         break;
1564                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1565                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1566         }
1567         BUG_ON(ctask->unsol_count < 0);
1568
1569         /*
1570          * Done with the Data-Out. Next, check if we need
1571          * to send another unsolicited Data-Out.
1572          */
1573         if (ctask->unsol_count) {
1574                 if (conn->datadgst_en) {
1575                         if (iscsi_digest_final_send(conn, ctask,
1576                                                     &dtask->digestbuf,
1577                                                     &dtask->digest, 1)) {
1578                                 debug_tcp("send uns digest 0x%x fail\n",
1579                                           dtask->digest);
1580                                 return -EAGAIN;
1581                         }
1582                         debug_tcp("sending uns digest 0x%x, more uns\n",
1583                                   dtask->digest);
1584                 }
1585                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1586                 return 1;
1587         }
1588
1589         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1590                 if (iscsi_digest_final_send(conn, ctask,
1591                                             &dtask->digestbuf,
1592                                             &dtask->digest, 1)) {
1593                         debug_tcp("send last uns digest 0x%x fail\n",
1594                                    dtask->digest);
1595                         return -EAGAIN;
1596                 }
1597                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1598         }
1599
1600         return 0;
1601 }
1602
1603 static inline int
1604 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1605 {
1606         struct iscsi_session *session = conn->session;
1607         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1608         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1609         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1610         struct iscsi_data_task *dtask = &r2t->dtask;
1611         int left;
1612
1613         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1614         tcp_ctask->dtask = dtask;
1615
1616         if (conn->datadgst_en) {
1617                 iscsi_data_digest_init(tcp_conn, ctask);
1618                 dtask->digest = 0;
1619         }
1620 solicit_again:
1621         /*
1622          * send Data-Out whitnin this R2T sequence.
1623          */
1624         if (!r2t->data_count)
1625                 goto data_out_done;
1626
1627         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1628                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1629                 /* will continue with this ctask later.. */
1630                 if (conn->datadgst_en) {
1631                         crypto_digest_final(tcp_conn->data_tx_tfm,
1632                                           (u8 *)&dtask->digest);
1633                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1634                 }
1635                 return -EAGAIN;
1636         }
1637
1638         BUG_ON(r2t->data_count < 0);
1639         if (conn->datadgst_en)
1640                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1641                                      1);
1642
1643         if (r2t->data_count) {
1644                 BUG_ON(ctask->sc->use_sg == 0);
1645                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1646                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1647                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1648                         r2t->sg += 1;
1649                 }
1650                 goto solicit_again;
1651         }
1652
1653 data_out_done:
1654         /*
1655          * Done with this Data-Out. Next, check if we have
1656          * to send another Data-Out for this R2T.
1657          */
1658         BUG_ON(r2t->data_length - r2t->sent < 0);
1659         left = r2t->data_length - r2t->sent;
1660         if (left) {
1661                 if (conn->datadgst_en) {
1662                         if (iscsi_digest_final_send(conn, ctask,
1663                                                     &dtask->digestbuf,
1664                                                     &dtask->digest, 1)) {
1665                                 debug_tcp("send r2t data digest 0x%x"
1666                                           "fail\n", dtask->digest);
1667                                 return -EAGAIN;
1668                         }
1669                         debug_tcp("r2t data send digest 0x%x\n",
1670                                   dtask->digest);
1671                 }
1672                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1673                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1674                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1675                 return 1;
1676         }
1677
1678         /*
1679          * Done with this R2T. Check if there are more
1680          * outstanding R2Ts ready to be processed.
1681          */
1682         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1683         if (conn->datadgst_en) {
1684                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1685                                             &dtask->digest, 1)) {
1686                         debug_tcp("send last r2t data digest 0x%x"
1687                                   "fail\n", dtask->digest);
1688                         return -EAGAIN;
1689                 }
1690                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1691         }
1692
1693         tcp_ctask->r2t_data_count -= r2t->data_length;
1694         tcp_ctask->r2t = NULL;
1695         spin_lock_bh(&session->lock);
1696         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1697         spin_unlock_bh(&session->lock);
1698         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1699                 tcp_ctask->r2t = r2t;
1700                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1701                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1702                 return 1;
1703         }
1704
1705         return 0;
1706 }
1707
1708 static inline int
1709 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1710 {
1711         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1712         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1713         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1714         int sent;
1715
1716         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1717         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1718                             tcp_ctask->pad_count);
1719         if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1720                            &sent)) {
1721                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1722                 return -EAGAIN;
1723         }
1724
1725         if (conn->datadgst_en) {
1726                 crypto_digest_update(tcp_conn->data_tx_tfm,
1727                                      &tcp_ctask->sendbuf.sg, 1);
1728                 /* imm data? */
1729                 if (!dtask) {
1730                         if (iscsi_digest_final_send(conn, ctask,
1731                                                     &tcp_ctask->immbuf,
1732                                                     &tcp_ctask->immdigest, 1)) {
1733                                 debug_tcp("send padding digest 0x%x"
1734                                           "fail!\n", tcp_ctask->immdigest);
1735                                 return -EAGAIN;
1736                         }
1737                         debug_tcp("done with padding, digest 0x%x\n",
1738                                   tcp_ctask->datadigest);
1739                 } else {
1740                         if (iscsi_digest_final_send(conn, ctask,
1741                                                     &dtask->digestbuf,
1742                                                     &dtask->digest, 1)) {
1743                                 debug_tcp("send padding digest 0x%x"
1744                                           "fail\n", dtask->digest);
1745                                 return -EAGAIN;
1746                         }
1747                         debug_tcp("done with padding, digest 0x%x\n",
1748                                   dtask->digest);
1749                 }
1750         }
1751
1752         return 0;
1753 }
1754
1755 static int
1756 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1757 {
1758         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1759         int rc = 0;
1760
1761         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1762                 conn->id, tcp_ctask->xmstate, ctask->itt);
1763
1764         /*
1765          * serialize with TMF AbortTask
1766          */
1767         if (ctask->mtask)
1768                 return rc;
1769
1770         if (tcp_ctask->xmstate & XMSTATE_R_HDR) {
1771                 rc = handle_xmstate_r_hdr(conn, tcp_ctask);
1772                 return rc;
1773         }
1774
1775         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1776                 rc = handle_xmstate_w_hdr(conn, ctask);
1777                 if (rc)
1778                         return rc;
1779         }
1780
1781         /* XXX: for data digest xmit recover */
1782         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1783                 rc = handle_xmstate_data_digest(conn, ctask);
1784                 if (rc)
1785                         return rc;
1786         }
1787
1788         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1789                 rc = handle_xmstate_imm_data(conn, ctask);
1790                 if (rc)
1791                         return rc;
1792         }
1793
1794         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1795                 BUG_ON(!ctask->unsol_count);
1796                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1797 unsolicit_head_again:
1798                 rc = handle_xmstate_uns_hdr(conn, ctask);
1799                 if (rc)
1800                         return rc;
1801         }
1802
1803         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1804                 rc = handle_xmstate_uns_data(conn, ctask);
1805                 if (rc == 1)
1806                         goto unsolicit_head_again;
1807                 else if (rc)
1808                         return rc;
1809                 goto done;
1810         }
1811
1812         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1813                 struct iscsi_r2t_info *r2t;
1814
1815                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1816                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1817                 if (!tcp_ctask->r2t)
1818                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1819                                     sizeof(void*));
1820 solicit_head_again:
1821                 r2t = tcp_ctask->r2t;
1822                 if (conn->hdrdgst_en)
1823                         iscsi_hdr_digest(conn, &r2t->headbuf,
1824                                         (u8*)r2t->dtask.hdrext);
1825                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
1826                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1827                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1828                         return -EAGAIN;
1829                 }
1830
1831                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1832                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1833                         r2t->sent);
1834         }
1835
1836         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1837                 rc = handle_xmstate_sol_data(conn, ctask);
1838                 if (rc == 1)
1839                         goto solicit_head_again;
1840                 if (rc)
1841                         return rc;
1842         }
1843
1844 done:
1845         /*
1846          * Last thing to check is whether we need to send write
1847          * padding. Note that we check for xmstate equality, not just the bit.
1848          */
1849         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1850                 rc = handle_xmstate_w_pad(conn, ctask);
1851
1852         return rc;
1853 }
1854
1855 static struct iscsi_cls_conn *
1856 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1857 {
1858         struct iscsi_conn *conn;
1859         struct iscsi_cls_conn *cls_conn;
1860         struct iscsi_tcp_conn *tcp_conn;
1861
1862         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1863         if (!cls_conn)
1864                 return NULL;
1865         conn = cls_conn->dd_data;
1866         /*
1867          * due to strange issues with iser these are not set
1868          * in iscsi_conn_setup
1869          */
1870         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1871
1872         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1873         if (!tcp_conn)
1874                 goto tcp_conn_alloc_fail;
1875
1876         conn->dd_data = tcp_conn;
1877         tcp_conn->iscsi_conn = conn;
1878         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1879         /* initial operational parameters */
1880         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1881         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1882
1883         /* allocate initial PDU receive place holder */
1884         if (tcp_conn->data_size <= PAGE_SIZE)
1885                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1886         else
1887                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1888                                         get_order(tcp_conn->data_size));
1889         if (!tcp_conn->data)
1890                 goto max_recv_dlenght_alloc_fail;
1891
1892         return cls_conn;
1893
1894 max_recv_dlenght_alloc_fail:
1895         kfree(tcp_conn);
1896 tcp_conn_alloc_fail:
1897         iscsi_conn_teardown(cls_conn);
1898         return NULL;
1899 }
1900
1901 static void
1902 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1903 {
1904         struct iscsi_conn *conn = cls_conn->dd_data;
1905         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1906         int digest = 0;
1907
1908         if (conn->hdrdgst_en || conn->datadgst_en)
1909                 digest = 1;
1910
1911         iscsi_conn_teardown(cls_conn);
1912
1913         /* now free tcp_conn */
1914         if (digest) {
1915                 if (tcp_conn->tx_tfm)
1916                         crypto_free_tfm(tcp_conn->tx_tfm);
1917                 if (tcp_conn->rx_tfm)
1918                         crypto_free_tfm(tcp_conn->rx_tfm);
1919                 if (tcp_conn->data_tx_tfm)
1920                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1921                 if (tcp_conn->data_rx_tfm)
1922                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1923         }
1924
1925         /* free conn->data, size = MaxRecvDataSegmentLength */
1926         if (tcp_conn->data_size <= PAGE_SIZE)
1927                 kfree(tcp_conn->data);
1928         else
1929                 free_pages((unsigned long)tcp_conn->data,
1930                            get_order(tcp_conn->data_size));
1931         kfree(tcp_conn);
1932 }
1933
1934 static int
1935 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1936                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1937                     int is_leading)
1938 {
1939         struct iscsi_conn *conn = cls_conn->dd_data;
1940         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1941         struct sock *sk;
1942         struct socket *sock;
1943         int err;
1944
1945         /* lookup for existing socket */
1946         sock = sockfd_lookup((int)transport_eph, &err);
1947         if (!sock) {
1948                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1949                 return -EEXIST;
1950         }
1951
1952         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1953         if (err)
1954                 return err;
1955
1956         if (conn->stop_stage != STOP_CONN_SUSPEND) {
1957                 /* bind iSCSI connection and socket */
1958                 tcp_conn->sock = sock;
1959
1960                 /* setup Socket parameters */
1961                 sk = sock->sk;
1962                 sk->sk_reuse = 1;
1963                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1964                 sk->sk_allocation = GFP_ATOMIC;
1965
1966                 /* FIXME: disable Nagle's algorithm */
1967
1968                 /*
1969                  * Intercept TCP callbacks for sendfile like receive
1970                  * processing.
1971                  */
1972                 conn->recv_lock = &sk->sk_callback_lock;
1973                 iscsi_conn_set_callbacks(conn);
1974                 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1975                 /*
1976                  * set receive state machine into initial state
1977                  */
1978                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1979         }
1980
1981         return 0;
1982 }
1983
1984 static void
1985 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1986 {
1987         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1988         struct iscsi_r2t_info *r2t;
1989
1990         /* flush ctask's r2t queues */
1991         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
1992                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1993                             sizeof(void*));
1994
1995         __iscsi_ctask_cleanup(conn, ctask);
1996 }
1997
1998 static void
1999 iscsi_tcp_suspend_conn_rx(struct iscsi_conn *conn)
2000 {
2001         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2002         struct sock *sk;
2003
2004         if (!tcp_conn->sock)
2005                 return;
2006
2007         sk = tcp_conn->sock->sk;
2008         write_lock_bh(&sk->sk_callback_lock);
2009         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2010         write_unlock_bh(&sk->sk_callback_lock);
2011 }
2012
2013 static void
2014 iscsi_tcp_terminate_conn(struct iscsi_conn *conn)
2015 {
2016         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2017
2018         if (!tcp_conn->sock)
2019                 return;
2020
2021         sock_hold(tcp_conn->sock->sk);
2022         iscsi_conn_restore_callbacks(conn);
2023         sock_put(tcp_conn->sock->sk);
2024
2025         sock_release(tcp_conn->sock);
2026         tcp_conn->sock = NULL;
2027         conn->recv_lock = NULL;
2028 }
2029
2030 /* called with host lock */
2031 static void
2032 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2033                     char *data, uint32_t data_size)
2034 {
2035         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2036
2037         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2038                            sizeof(struct iscsi_hdr));
2039         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2040
2041         if (mtask->data_count)
2042                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2043                                     mtask->data_count);
2044 }
2045
2046 static int
2047 iscsi_r2tpool_alloc(struct iscsi_session *session)
2048 {
2049         int i;
2050         int cmd_i;
2051
2052         /*
2053          * initialize per-task: R2T pool and xmit queue
2054          */
2055         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2056                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2057                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2058
2059                 /*
2060                  * pre-allocated x4 as much r2ts to handle race when
2061                  * target acks DataOut faster than we data_xmit() queues
2062                  * could replenish r2tqueue.
2063                  */
2064
2065                 /* R2T pool */
2066                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2067                                     (void***)&tcp_ctask->r2ts,
2068                                     sizeof(struct iscsi_r2t_info))) {
2069                         goto r2t_alloc_fail;
2070                 }
2071
2072                 /* R2T xmit queue */
2073                 tcp_ctask->r2tqueue = kfifo_alloc(
2074                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2075                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2076                         iscsi_pool_free(&tcp_ctask->r2tpool,
2077                                         (void**)tcp_ctask->r2ts);
2078                         goto r2t_alloc_fail;
2079                 }
2080         }
2081
2082         return 0;
2083
2084 r2t_alloc_fail:
2085         for (i = 0; i < cmd_i; i++) {
2086                 struct iscsi_cmd_task *ctask = session->cmds[i];
2087                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2088
2089                 kfifo_free(tcp_ctask->r2tqueue);
2090                 iscsi_pool_free(&tcp_ctask->r2tpool,
2091                                 (void**)tcp_ctask->r2ts);
2092         }
2093         return -ENOMEM;
2094 }
2095
2096 static void
2097 iscsi_r2tpool_free(struct iscsi_session *session)
2098 {
2099         int i;
2100
2101         for (i = 0; i < session->cmds_max; i++) {
2102                 struct iscsi_cmd_task *ctask = session->cmds[i];
2103                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2104
2105                 kfifo_free(tcp_ctask->r2tqueue);
2106                 iscsi_pool_free(&tcp_ctask->r2tpool,
2107                                 (void**)tcp_ctask->r2ts);
2108         }
2109 }
2110
2111 static int
2112 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2113                      uint32_t value)
2114 {
2115         struct iscsi_conn *conn = cls_conn->dd_data;
2116         struct iscsi_session *session = conn->session;
2117         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2118
2119         switch(param) {
2120         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2121                 char *saveptr = tcp_conn->data;
2122                 gfp_t flags = GFP_KERNEL;
2123
2124                 if (tcp_conn->data_size >= value) {
2125                         conn->max_recv_dlength = value;
2126                         break;
2127                 }
2128
2129                 spin_lock_bh(&session->lock);
2130                 if (conn->stop_stage == STOP_CONN_RECOVER)
2131                         flags = GFP_ATOMIC;
2132                 spin_unlock_bh(&session->lock);
2133
2134                 if (value <= PAGE_SIZE)
2135                         tcp_conn->data = kmalloc(value, flags);
2136                 else
2137                         tcp_conn->data = (void*)__get_free_pages(flags,
2138                                                              get_order(value));
2139                 if (tcp_conn->data == NULL) {
2140                         tcp_conn->data = saveptr;
2141                         return -ENOMEM;
2142                 }
2143                 if (tcp_conn->data_size <= PAGE_SIZE)
2144                         kfree(saveptr);
2145                 else
2146                         free_pages((unsigned long)saveptr,
2147                                    get_order(tcp_conn->data_size));
2148                 conn->max_recv_dlength = value;
2149                 tcp_conn->data_size = value;
2150                 }
2151                 break;
2152         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2153                 conn->max_xmit_dlength =  value;
2154                 break;
2155         case ISCSI_PARAM_HDRDGST_EN:
2156                 conn->hdrdgst_en = value;
2157                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2158                 if (conn->hdrdgst_en) {
2159                         tcp_conn->hdr_size += sizeof(__u32);
2160                         if (!tcp_conn->tx_tfm)
2161                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2162                                                                     0);
2163                         if (!tcp_conn->tx_tfm)
2164                                 return -ENOMEM;
2165                         if (!tcp_conn->rx_tfm)
2166                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2167                                                                     0);
2168                         if (!tcp_conn->rx_tfm) {
2169                                 crypto_free_tfm(tcp_conn->tx_tfm);
2170                                 return -ENOMEM;
2171                         }
2172                 } else {
2173                         if (tcp_conn->tx_tfm)
2174                                 crypto_free_tfm(tcp_conn->tx_tfm);
2175                         if (tcp_conn->rx_tfm)
2176                                 crypto_free_tfm(tcp_conn->rx_tfm);
2177                 }
2178                 break;
2179         case ISCSI_PARAM_DATADGST_EN:
2180                 conn->datadgst_en = value;
2181                 if (conn->datadgst_en) {
2182                         if (!tcp_conn->data_tx_tfm)
2183                                 tcp_conn->data_tx_tfm =
2184                                     crypto_alloc_tfm("crc32c", 0);
2185                         if (!tcp_conn->data_tx_tfm)
2186                                 return -ENOMEM;
2187                         if (!tcp_conn->data_rx_tfm)
2188                                 tcp_conn->data_rx_tfm =
2189                                     crypto_alloc_tfm("crc32c", 0);
2190                         if (!tcp_conn->data_rx_tfm) {
2191                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2192                                 return -ENOMEM;
2193                         }
2194                 } else {
2195                         if (tcp_conn->data_tx_tfm)
2196                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2197                         if (tcp_conn->data_rx_tfm)
2198                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2199                 }
2200                 tcp_conn->sendpage = conn->datadgst_en ?
2201                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2202                 break;
2203         case ISCSI_PARAM_INITIAL_R2T_EN:
2204                 session->initial_r2t_en = value;
2205                 break;
2206         case ISCSI_PARAM_MAX_R2T:
2207                 if (session->max_r2t == roundup_pow_of_two(value))
2208                         break;
2209                 iscsi_r2tpool_free(session);
2210                 session->max_r2t = value;
2211                 if (session->max_r2t & (session->max_r2t - 1))
2212                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2213                 if (iscsi_r2tpool_alloc(session))
2214                         return -ENOMEM;
2215                 break;
2216         case ISCSI_PARAM_IMM_DATA_EN:
2217                 session->imm_data_en = value;
2218                 break;
2219         case ISCSI_PARAM_FIRST_BURST:
2220                 session->first_burst = value;
2221                 break;
2222         case ISCSI_PARAM_MAX_BURST:
2223                 session->max_burst = value;
2224                 break;
2225         case ISCSI_PARAM_PDU_INORDER_EN:
2226                 session->pdu_inorder_en = value;
2227                 break;
2228         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2229                 session->dataseq_inorder_en = value;
2230                 break;
2231         case ISCSI_PARAM_ERL:
2232                 session->erl = value;
2233                 break;
2234         case ISCSI_PARAM_IFMARKER_EN:
2235                 BUG_ON(value);
2236                 session->ifmarker_en = value;
2237                 break;
2238         case ISCSI_PARAM_OFMARKER_EN:
2239                 BUG_ON(value);
2240                 session->ofmarker_en = value;
2241                 break;
2242         case ISCSI_PARAM_EXP_STATSN:
2243                 conn->exp_statsn = value;
2244                 break;
2245         default:
2246                 break;
2247         }
2248
2249         return 0;
2250 }
2251
2252 static int
2253 iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2254                         enum iscsi_param param, uint32_t *value)
2255 {
2256         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2257         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2258
2259         switch(param) {
2260         case ISCSI_PARAM_INITIAL_R2T_EN:
2261                 *value = session->initial_r2t_en;
2262                 break;
2263         case ISCSI_PARAM_MAX_R2T:
2264                 *value = session->max_r2t;
2265                 break;
2266         case ISCSI_PARAM_IMM_DATA_EN:
2267                 *value = session->imm_data_en;
2268                 break;
2269         case ISCSI_PARAM_FIRST_BURST:
2270                 *value = session->first_burst;
2271                 break;
2272         case ISCSI_PARAM_MAX_BURST:
2273                 *value = session->max_burst;
2274                 break;
2275         case ISCSI_PARAM_PDU_INORDER_EN:
2276                 *value = session->pdu_inorder_en;
2277                 break;
2278         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2279                 *value = session->dataseq_inorder_en;
2280                 break;
2281         case ISCSI_PARAM_ERL:
2282                 *value = session->erl;
2283                 break;
2284         case ISCSI_PARAM_IFMARKER_EN:
2285                 *value = session->ifmarker_en;
2286                 break;
2287         case ISCSI_PARAM_OFMARKER_EN:
2288                 *value = session->ofmarker_en;
2289                 break;
2290         default:
2291                 return -EINVAL;
2292         }
2293
2294         return 0;
2295 }
2296
2297 static int
2298 iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2299                      enum iscsi_param param, uint32_t *value)
2300 {
2301         struct iscsi_conn *conn = cls_conn->dd_data;
2302         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2303         struct inet_sock *inet;
2304
2305         switch(param) {
2306         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2307                 *value = conn->max_recv_dlength;
2308                 break;
2309         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2310                 *value = conn->max_xmit_dlength;
2311                 break;
2312         case ISCSI_PARAM_HDRDGST_EN:
2313                 *value = conn->hdrdgst_en;
2314                 break;
2315         case ISCSI_PARAM_DATADGST_EN:
2316                 *value = conn->datadgst_en;
2317                 break;
2318         case ISCSI_PARAM_CONN_PORT:
2319                 mutex_lock(&conn->xmitmutex);
2320                 if (!tcp_conn->sock) {
2321                         mutex_unlock(&conn->xmitmutex);
2322                         return -EINVAL;
2323                 }
2324
2325                 inet = inet_sk(tcp_conn->sock->sk);
2326                 *value = be16_to_cpu(inet->dport);
2327                 mutex_unlock(&conn->xmitmutex);
2328         case ISCSI_PARAM_EXP_STATSN:
2329                 *value = conn->exp_statsn;
2330                 break;
2331         default:
2332                 return -EINVAL;
2333         }
2334
2335         return 0;
2336 }
2337
2338 static int
2339 iscsi_conn_get_str_param(struct iscsi_cls_conn *cls_conn,
2340                          enum iscsi_param param, char *buf)
2341 {
2342         struct iscsi_conn *conn = cls_conn->dd_data;
2343         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2344         struct sock *sk;
2345         struct inet_sock *inet;
2346         struct ipv6_pinfo *np;
2347         int len = 0;
2348
2349         switch (param) {
2350         case ISCSI_PARAM_CONN_ADDRESS:
2351                 mutex_lock(&conn->xmitmutex);
2352                 if (!tcp_conn->sock) {
2353                         mutex_unlock(&conn->xmitmutex);
2354                         return -EINVAL;
2355                 }
2356
2357                 sk = tcp_conn->sock->sk;
2358                 if (sk->sk_family == PF_INET) {
2359                         inet = inet_sk(sk);
2360                         len = sprintf(buf, "%u.%u.%u.%u\n",
2361                                       NIPQUAD(inet->daddr));
2362                 } else {
2363                         np = inet6_sk(sk);
2364                         len = sprintf(buf,
2365                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2366                                 NIP6(np->daddr));
2367                 }
2368                 mutex_unlock(&conn->xmitmutex);
2369                 break;
2370         default:
2371                 return -EINVAL;
2372         }
2373
2374         return len;
2375 }
2376
2377 static void
2378 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2379 {
2380         struct iscsi_conn *conn = cls_conn->dd_data;
2381         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2382
2383         stats->txdata_octets = conn->txdata_octets;
2384         stats->rxdata_octets = conn->rxdata_octets;
2385         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2386         stats->dataout_pdus = conn->dataout_pdus_cnt;
2387         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2388         stats->datain_pdus = conn->datain_pdus_cnt;
2389         stats->r2t_pdus = conn->r2t_pdus_cnt;
2390         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2391         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2392         stats->custom_length = 3;
2393         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2394         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2395         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2396         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2397         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2398         stats->custom[2].value = conn->eh_abort_cnt;
2399 }
2400
2401 static struct iscsi_cls_session *
2402 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2403                          struct scsi_transport_template *scsit,
2404                          uint32_t initial_cmdsn, uint32_t *hostno)
2405 {
2406         struct iscsi_cls_session *cls_session;
2407         struct iscsi_session *session;
2408         uint32_t hn;
2409         int cmd_i;
2410
2411         cls_session = iscsi_session_setup(iscsit, scsit,
2412                                          sizeof(struct iscsi_tcp_cmd_task),
2413                                          sizeof(struct iscsi_tcp_mgmt_task),
2414                                          initial_cmdsn, &hn);
2415         if (!cls_session)
2416                 return NULL;
2417         *hostno = hn;
2418
2419         session = class_to_transport_session(cls_session);
2420         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2421                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2422                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2423
2424                 ctask->hdr = &tcp_ctask->hdr;
2425         }
2426
2427         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2428                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2429                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2430
2431                 mtask->hdr = &tcp_mtask->hdr;
2432         }
2433
2434         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2435                 goto r2tpool_alloc_fail;
2436
2437         return cls_session;
2438
2439 r2tpool_alloc_fail:
2440         iscsi_session_teardown(cls_session);
2441         return NULL;
2442 }
2443
2444 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2445 {
2446         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2447         iscsi_session_teardown(cls_session);
2448 }
2449
2450 static struct scsi_host_template iscsi_sht = {
2451         .name                   = "iSCSI Initiator over TCP/IP, v."
2452                                   ISCSI_VERSION_STR,
2453         .queuecommand           = iscsi_queuecommand,
2454         .change_queue_depth     = iscsi_change_queue_depth,
2455         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2456         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2457         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2458         .eh_abort_handler       = iscsi_eh_abort,
2459         .eh_host_reset_handler  = iscsi_eh_host_reset,
2460         .use_clustering         = DISABLE_CLUSTERING,
2461         .proc_name              = "iscsi_tcp",
2462         .this_id                = -1,
2463 };
2464
2465 static struct iscsi_transport iscsi_tcp_transport = {
2466         .owner                  = THIS_MODULE,
2467         .name                   = "tcp",
2468         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2469                                   | CAP_DATADGST,
2470         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2471                                   ISCSI_MAX_XMIT_DLENGTH |
2472                                   ISCSI_HDRDGST_EN |
2473                                   ISCSI_DATADGST_EN |
2474                                   ISCSI_INITIAL_R2T_EN |
2475                                   ISCSI_MAX_R2T |
2476                                   ISCSI_IMM_DATA_EN |
2477                                   ISCSI_FIRST_BURST |
2478                                   ISCSI_MAX_BURST |
2479                                   ISCSI_PDU_INORDER_EN |
2480                                   ISCSI_DATASEQ_INORDER_EN |
2481                                   ISCSI_ERL |
2482                                   ISCSI_CONN_PORT |
2483                                   ISCSI_CONN_ADDRESS |
2484                                   ISCSI_EXP_STATSN,
2485         .host_template          = &iscsi_sht,
2486         .conndata_size          = sizeof(struct iscsi_conn),
2487         .max_conn               = 1,
2488         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2489         /* session management */
2490         .create_session         = iscsi_tcp_session_create,
2491         .destroy_session        = iscsi_tcp_session_destroy,
2492         /* connection management */
2493         .create_conn            = iscsi_tcp_conn_create,
2494         .bind_conn              = iscsi_tcp_conn_bind,
2495         .destroy_conn           = iscsi_tcp_conn_destroy,
2496         .set_param              = iscsi_conn_set_param,
2497         .get_conn_param         = iscsi_conn_get_param,
2498         .get_conn_str_param     = iscsi_conn_get_str_param,
2499         .get_session_param      = iscsi_session_get_param,
2500         .start_conn             = iscsi_conn_start,
2501         .stop_conn              = iscsi_conn_stop,
2502         /* these are called as part of conn recovery */
2503         .suspend_conn_recv      = iscsi_tcp_suspend_conn_rx,
2504         .terminate_conn         = iscsi_tcp_terminate_conn,
2505         /* IO */
2506         .send_pdu               = iscsi_conn_send_pdu,
2507         .get_stats              = iscsi_conn_get_stats,
2508         .init_cmd_task          = iscsi_tcp_cmd_init,
2509         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2510         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2511         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2512         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2513         /* recovery */
2514         .session_recovery_timedout = iscsi_session_recovery_timedout,
2515 };
2516
2517 static int __init
2518 iscsi_tcp_init(void)
2519 {
2520         if (iscsi_max_lun < 1) {
2521                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2522                        iscsi_max_lun);
2523                 return -EINVAL;
2524         }
2525         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2526
2527         if (!iscsi_register_transport(&iscsi_tcp_transport))
2528                 return -ENODEV;
2529
2530         return 0;
2531 }
2532
2533 static void __exit
2534 iscsi_tcp_exit(void)
2535 {
2536         iscsi_unregister_transport(&iscsi_tcp_transport);
2537 }
2538
2539 module_init(iscsi_tcp_init);
2540 module_exit(iscsi_tcp_exit);