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

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/list.h>
  31 #include <linux/inet.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 #define ISCSI_TCP_VERSION "1.0-574"
  47
  48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION(ISCSI_TCP_VERSION);
  53 /* #define DEBUG_TCP */
  54 #define DEBUG_ASSERT
  55
  56 #ifdef DEBUG_TCP
  57 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  58 #else
  59 #define debug_tcp(fmt...)
  60 #endif
  61
  62 #ifndef DEBUG_ASSERT
  63 #ifdef BUG_ON
  64 #undef BUG_ON
  65 #endif
  66 #define BUG_ON(expr)
  67 #endif
  68
  69 static unsigned int iscsi_max_lun = 512;
  70 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  71
  72 static inline void
  73 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  74 {
  75         ibuf->sg.page = virt_to_page(vbuf);
  76         ibuf->sg.offset = offset_in_page(vbuf);
  77         ibuf->sg.length = size;
  78         ibuf->sent = 0;
  79         ibuf->use_sendmsg = 1;
  80 }
  81
  82 static inline void
  83 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  84 {
  85         ibuf->sg.page = sg->page;
  86         ibuf->sg.offset = sg->offset;
  87         ibuf->sg.length = sg->length;
  88         /*
  89          * Fastpath: sg element fits into single page
  90          */
  91         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  92                 ibuf->use_sendmsg = 0;
  93         else
  94                 ibuf->use_sendmsg = 1;
  95         ibuf->sent = 0;
  96 }
  97
  98 static inline int
  99 iscsi_buf_left(struct iscsi_buf *ibuf)
 100 {
 101         int rc;
 102
 103         rc = ibuf->sg.length - ibuf->sent;
 104         BUG_ON(rc < 0);
 105         return rc;
 106 }
 107
 108 static inline void
 109 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 110                  u8* crc)
 111 {
 112         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 113
 114         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 115         buf->sg.length += sizeof(uint32_t);
 116 }
 117
 118 static inline int
 119 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 120 {
 121         struct sk_buff *skb = tcp_conn->in.skb;
 122
 123         tcp_conn->in.zero_copy_hdr = 0;
 124
 125         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 126             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 127                 /*
 128                  * Zero-copy PDU Header: using connection context
 129                  * to store header pointer.
 130                  */
 131                 if (skb_shinfo(skb)->frag_list == NULL &&
 132                     !skb_shinfo(skb)->nr_frags) {
 133                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 134                                 ((char*)skb->data + tcp_conn->in.offset);
 135                         tcp_conn->in.zero_copy_hdr = 1;
 136                 } else {
 137                         /* ignoring return code since we checked
 138                          * in.copy before */
 139                         skb_copy_bits(skb, tcp_conn->in.offset,
 140                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 141                         tcp_conn->in.hdr = &tcp_conn->hdr;
 142                 }
 143                 tcp_conn->in.offset += tcp_conn->hdr_size;
 144                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 145         } else {
 146                 int hdr_remains;
 147                 int copylen;
 148
 149                 /*
 150                  * PDU header scattered across SKB's,
 151                  * copying it... This'll happen quite rarely.
 152                  */
 153
 154                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 155                         tcp_conn->in.hdr_offset = 0;
 156
 157                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 158                 BUG_ON(hdr_remains <= 0);
 159
 160                 copylen = min(tcp_conn->in.copy, hdr_remains);
 161                 skb_copy_bits(skb, tcp_conn->in.offset,
 162                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 163                         copylen);
 164
 165                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 166                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 167                        tcp_conn->in.offset, tcp_conn->in.copy);
 168
 169                 tcp_conn->in.offset += copylen;
 170                 tcp_conn->in.copy -= copylen;
 171                 if (copylen < hdr_remains)  {
 172                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 173                         tcp_conn->in.hdr_offset += copylen;
 174                         return -EAGAIN;
 175                 }
 176                 tcp_conn->in.hdr = &tcp_conn->hdr;
 177                 tcp_conn->discontiguous_hdr_cnt++;
 178                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 179         }
 180
 181         return 0;
 182 }
 183
 184 /*
 185  * must be called with session lock
 186  */
 187 static void
 188 __iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 191         struct scsi_cmnd *sc;
 192
 193         sc = ctask->sc;
 194         if (unlikely(!sc))
 195                 return;
 196
 197         tcp_ctask->xmstate = XMSTATE_IDLE;
 198         tcp_ctask->r2t = NULL;
 199 }
 200
 201 /**
 202  * iscsi_data_rsp - SCSI Data-In Response processing
 203  * @conn: iscsi connection
 204  * @ctask: scsi command task
 205  **/
 206 static int
 207 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 208 {
 209         int rc;
 210         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 211         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 212         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 213         struct iscsi_session *session = conn->session;
 214         int datasn = be32_to_cpu(rhdr->datasn);
 215
 216         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 217         if (rc)
 218                 return rc;
 219         /*
 220          * setup Data-In byte counter (gets decremented..)
 221          */
 222         ctask->data_count = tcp_conn->in.datalen;
 223
 224         if (tcp_conn->in.datalen == 0)
 225                 return 0;
 226
 227         if (ctask->datasn != datasn)
 228                 return ISCSI_ERR_DATASN;
 229
 230         ctask->datasn++;
 231
 232         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 233         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 234                 return ISCSI_ERR_DATA_OFFSET;
 235
 236         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 237                 struct scsi_cmnd *sc = ctask->sc;
 238
 239                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 240                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 241                         int res_count = be32_to_cpu(rhdr->residual_count);
 242
 243                         if (res_count > 0 &&
 244                             res_count <= sc->request_bufflen) {
 245                                 sc->resid = res_count;
 246                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 247                         } else
 248                                 sc->result = (DID_BAD_TARGET << 16) |
 249                                         rhdr->cmd_status;
 250                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 251                         sc->resid = be32_to_cpu(rhdr->residual_count);
 252                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 253                 } else
 254                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 255         }
 256
 257         conn->datain_pdus_cnt++;
 258         return 0;
 259 }
 260
 261 /**
 262  * iscsi_solicit_data_init - initialize first Data-Out
 263  * @conn: iscsi connection
 264  * @ctask: scsi command task
 265  * @r2t: R2T info
 266  *
 267  * Notes:
 268  *      Initialize first Data-Out within this R2T sequence and finds
 269  *      proper data_offset within this SCSI command.
 270  *
 271  *      This function is called with connection lock taken.
 272  **/
 273 static void
 274 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 275                         struct iscsi_r2t_info *r2t)
 276 {
 277         struct iscsi_data *hdr;
 278         struct scsi_cmnd *sc = ctask->sc;
 279         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 280
 281         hdr = &r2t->dtask.hdr;
 282         memset(hdr, 0, sizeof(struct iscsi_data));
 283         hdr->ttt = r2t->ttt;
 284         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 285         r2t->solicit_datasn++;
 286         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 287         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 288         hdr->itt = ctask->hdr->itt;
 289         hdr->exp_statsn = r2t->exp_statsn;
 290         hdr->offset = cpu_to_be32(r2t->data_offset);
 291         if (r2t->data_length > conn->max_xmit_dlength) {
 292                 hton24(hdr->dlength, conn->max_xmit_dlength);
 293                 r2t->data_count = conn->max_xmit_dlength;
 294                 hdr->flags = 0;
 295         } else {
 296                 hton24(hdr->dlength, r2t->data_length);
 297                 r2t->data_count = r2t->data_length;
 298                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 299         }
 300         conn->dataout_pdus_cnt++;
 301
 302         r2t->sent = 0;
 303
 304         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 305                            sizeof(struct iscsi_hdr));
 306
 307         if (sc->use_sg) {
 308                 int i, sg_count = 0;
 309                 struct scatterlist *sg = sc->request_buffer;
 310
 311                 r2t->sg = NULL;
 312                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 313                         /* FIXME: prefetch ? */
 314                         if (sg_count + sg->length > r2t->data_offset) {
 315                                 int page_offset;
 316
 317                                 /* sg page found! */
 318
 319                                 /* offset within this page */
 320                                 page_offset = r2t->data_offset - sg_count;
 321
 322                                 /* fill in this buffer */
 323                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 324                                 r2t->sendbuf.sg.offset += page_offset;
 325                                 r2t->sendbuf.sg.length -= page_offset;
 326
 327                                 /* xmit logic will continue with next one */
 328                                 r2t->sg = sg + 1;
 329                                 break;
 330                         }
 331                         sg_count += sg->length;
 332                 }
 333                 BUG_ON(r2t->sg == NULL);
 334         } else
 335                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 336                             (char*)sc->request_buffer + r2t->data_offset,
 337                             r2t->data_count);
 338 }
 339
 340 /**
 341  * iscsi_r2t_rsp - iSCSI R2T Response processing
 342  * @conn: iscsi connection
 343  * @ctask: scsi command task
 344  **/
 345 static int
 346 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 347 {
 348         struct iscsi_r2t_info *r2t;
 349         struct iscsi_session *session = conn->session;
 350         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 351         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 352         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 353         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 354         int rc;
 355
 356         if (tcp_conn->in.datalen)
 357                 return ISCSI_ERR_DATALEN;
 358
 359         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 360                 return ISCSI_ERR_R2TSN;
 361
 362         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 363         if (rc)
 364                 return rc;
 365
 366         /* FIXME: use R2TSN to detect missing R2T */
 367
 368         /* fill-in new R2T associated with the task */
 369         spin_lock(&session->lock);
 370         if (!ctask->sc || ctask->mtask ||
 371              session->state != ISCSI_STATE_LOGGED_IN) {
 372                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 373                        "recovery...\n", ctask->itt);
 374                 spin_unlock(&session->lock);
 375                 return 0;
 376         }
 377         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 378         BUG_ON(!rc);
 379
 380         r2t->exp_statsn = rhdr->statsn;
 381         r2t->data_length = be32_to_cpu(rhdr->data_length);
 382         if (r2t->data_length == 0 ||
 383             r2t->data_length > session->max_burst) {
 384                 spin_unlock(&session->lock);
 385                 return ISCSI_ERR_DATALEN;
 386         }
 387
 388         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 389         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 390                 spin_unlock(&session->lock);
 391                 return ISCSI_ERR_DATALEN;
 392         }
 393
 394         r2t->ttt = rhdr->ttt; /* no flip */
 395         r2t->solicit_datasn = 0;
 396
 397         iscsi_solicit_data_init(conn, ctask, r2t);
 398
 399         tcp_ctask->exp_r2tsn = r2tsn + 1;
 400         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 401         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 402         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 403
 404         scsi_queue_work(session->host, &conn->xmitwork);
 405         conn->r2t_pdus_cnt++;
 406         spin_unlock(&session->lock);
 407
 408         return 0;
 409 }
 410
 411 static int
 412 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 413 {
 414         int rc = 0, opcode, ahslen;
 415         struct iscsi_hdr *hdr;
 416         struct iscsi_session *session = conn->session;
 417         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 418         uint32_t cdgst, rdgst = 0, itt;
 419
 420         hdr = tcp_conn->in.hdr;
 421
 422         /* verify PDU length */
 423         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 424         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 425                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 426                        tcp_conn->in.datalen, conn->max_recv_dlength);
 427                 return ISCSI_ERR_DATALEN;
 428         }
 429         tcp_conn->data_copied = 0;
 430
 431         /* read AHS */
 432         ahslen = hdr->hlength << 2;
 433         tcp_conn->in.offset += ahslen;
 434         tcp_conn->in.copy -= ahslen;
 435         if (tcp_conn->in.copy < 0) {
 436                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 437                        "%d bytes\n", ahslen);
 438                 return ISCSI_ERR_AHSLEN;
 439         }
 440
 441         /* calculate read padding */
 442         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 443         if (tcp_conn->in.padding) {
 444                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 445                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 446         }
 447
 448         if (conn->hdrdgst_en) {
 449                 struct scatterlist sg;
 450
 451                 sg_init_one(&sg, (u8 *)hdr,
 452                             sizeof(struct iscsi_hdr) + ahslen);
 453                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 454                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 455                                      ahslen);
 456                 if (cdgst != rdgst) {
 457                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 458                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 459                         return ISCSI_ERR_HDR_DGST;
 460                 }
 461         }
 462
 463         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 464         /* verify itt (itt encoding: age+cid+itt) */
 465         rc = iscsi_verify_itt(conn, hdr, &itt);
 466         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 467                 tcp_conn->in.datalen = 0; /* force drop */
 468                 return 0;
 469         } else if (rc)
 470                 return rc;
 471
 472         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 473                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 474                   ahslen, tcp_conn->in.datalen);
 475
 476         switch(opcode) {
 477         case ISCSI_OP_SCSI_DATA_IN:
 478                 tcp_conn->in.ctask = session->cmds[itt];
 479                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 480                 /* fall through */
 481         case ISCSI_OP_SCSI_CMD_RSP:
 482                 tcp_conn->in.ctask = session->cmds[itt];
 483                 if (tcp_conn->in.datalen)
 484                         goto copy_hdr;
 485
 486                 spin_lock(&session->lock);
 487                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 488                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 489                 spin_unlock(&session->lock);
 490                 break;
 491         case ISCSI_OP_R2T:
 492                 tcp_conn->in.ctask = session->cmds[itt];
 493                 if (ahslen)
 494                         rc = ISCSI_ERR_AHSLEN;
 495                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 496                                                                 DMA_TO_DEVICE)
 497                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 498                 else
 499                         rc = ISCSI_ERR_PROTO;
 500                 break;
 501         case ISCSI_OP_LOGIN_RSP:
 502         case ISCSI_OP_TEXT_RSP:
 503         case ISCSI_OP_LOGOUT_RSP:
 504         case ISCSI_OP_NOOP_IN:
 505         case ISCSI_OP_REJECT:
 506         case ISCSI_OP_ASYNC_EVENT:
 507                 if (tcp_conn->in.datalen)
 508                         goto copy_hdr;
 509         /* fall through */
 510         case ISCSI_OP_SCSI_TMFUNC_RSP:
 511                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 512                 break;
 513         default:
 514                 rc = ISCSI_ERR_BAD_OPCODE;
 515                 break;
 516         }
 517
 518         return rc;
 519
 520 copy_hdr:
 521         /*
 522          * if we did zero copy for the header but we will need multiple
 523          * skbs to complete the command then we have to copy the header
 524          * for later use
 525          */
 526         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
 527            (tcp_conn->in.datalen + tcp_conn->in.padding +
 528             (conn->datadgst_en ? 4 : 0))) {
 529                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 530                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 531                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 532                        sizeof(struct iscsi_hdr));
 533                 tcp_conn->in.hdr = &tcp_conn->hdr;
 534                 tcp_conn->in.zero_copy_hdr = 0;
 535         }
 536         return 0;
 537 }
 538
 539 /**
 540  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 541  * @conn: iscsi tcp connection
 542  * @ctask: scsi command task
 543  * @buf: buffer to copy to
 544  * @buf_size: size of buffer
 545  * @offset: offset within the buffer
 546  *
 547  * Notes:
 548  *      The function calls skb_copy_bits() and updates per-connection and
 549  *      per-cmd byte counters.
 550  *
 551  *      Read counters (in bytes):
 552  *
 553  *      conn->in.offset         offset within in progress SKB
 554  *      conn->in.copy           left to copy from in progress SKB
 555  *                              including padding
 556  *      conn->in.copied         copied already from in progress SKB
 557  *      conn->data_copied       copied already from in progress buffer
 558  *      ctask->sent             total bytes sent up to the MidLayer
 559  *      ctask->data_count       left to copy from in progress Data-In
 560  *      buf_left                left to copy from in progress buffer
 561  **/
 562 static inline int
 563 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 564                 void *buf, int buf_size, int offset)
 565 {
 566         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 567         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 568         int size = min(tcp_conn->in.copy, buf_left);
 569         int rc;
 570
 571         size = min(size, ctask->data_count);
 572
 573         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 574                size, tcp_conn->in.offset, tcp_conn->in.copied);
 575
 576         BUG_ON(size <= 0);
 577         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 578
 579         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 580                            (char*)buf + (offset + tcp_conn->data_copied), size);
 581         /* must fit into skb->len */
 582         BUG_ON(rc);
 583
 584         tcp_conn->in.offset += size;
 585         tcp_conn->in.copy -= size;
 586         tcp_conn->in.copied += size;
 587         tcp_conn->data_copied += size;
 588         tcp_ctask->sent += size;
 589         ctask->data_count -= size;
 590
 591         BUG_ON(tcp_conn->in.copy < 0);
 592         BUG_ON(ctask->data_count < 0);
 593
 594         if (buf_size != (tcp_conn->data_copied + offset)) {
 595                 if (!ctask->data_count) {
 596                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 597                         /* done with this PDU */
 598                         return buf_size - tcp_conn->data_copied;
 599                 }
 600                 return -EAGAIN;
 601         }
 602
 603         /* done with this buffer or with both - PDU and buffer */
 604         tcp_conn->data_copied = 0;
 605         return 0;
 606 }
 607
 608 /**
 609  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 610  * @conn: iscsi tcp connection
 611  *
 612  * Notes:
 613  *      The function calls skb_copy_bits() and updates per-connection
 614  *      byte counters.
 615  **/
 616 static inline int
 617 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 618 {
 619         void *buf = tcp_conn->data;
 620         int buf_size = tcp_conn->in.datalen;
 621         int buf_left = buf_size - tcp_conn->data_copied;
 622         int size = min(tcp_conn->in.copy, buf_left);
 623         int rc;
 624
 625         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 626                size, tcp_conn->in.offset, tcp_conn->data_copied);
 627         BUG_ON(size <= 0);
 628
 629         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 630                            (char*)buf + tcp_conn->data_copied, size);
 631         BUG_ON(rc);
 632
 633         tcp_conn->in.offset += size;
 634         tcp_conn->in.copy -= size;
 635         tcp_conn->in.copied += size;
 636         tcp_conn->data_copied += size;
 637
 638         if (buf_size != tcp_conn->data_copied)
 639                 return -EAGAIN;
 640
 641         return 0;
 642 }
 643
 644 static inline void
 645 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 646                          struct scatterlist *sg, int offset, int length)
 647 {
 648         struct scatterlist temp;
 649
 650         memcpy(&temp, sg, sizeof(struct scatterlist));
 651         temp.offset = offset;
 652         temp.length = length;
 653         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 654 }
 655
 656 static void
 657 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 658 {
 659         struct scatterlist tmp;
 660
 661         sg_init_one(&tmp, buf, len);
 662         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 663 }
 664
 665 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 666 {
 667         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 668         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 669         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 670         struct scsi_cmnd *sc = ctask->sc;
 671         struct scatterlist *sg;
 672         int i, offset, rc = 0;
 673
 674         BUG_ON((void*)ctask != sc->SCp.ptr);
 675
 676         /*
 677          * copying Data-In into the Scsi_Cmnd
 678          */
 679         if (!sc->use_sg) {
 680                 i = ctask->data_count;
 681                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 682                                       sc->request_bufflen,
 683                                       tcp_ctask->data_offset);
 684                 if (rc == -EAGAIN)
 685                         return rc;
 686                 if (conn->datadgst_en)
 687                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 688                                                  i);
 689                 rc = 0;
 690                 goto done;
 691         }
 692
 693         offset = tcp_ctask->data_offset;
 694         sg = sc->request_buffer;
 695
 696         if (tcp_ctask->data_offset)
 697                 for (i = 0; i < tcp_ctask->sg_count; i++)
 698                         offset -= sg[i].length;
 699         /* we've passed through partial sg*/
 700         if (offset < 0)
 701                 offset = 0;
 702
 703         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 704                 char *dest;
 705
 706                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 707                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 708                                       sg[i].length, offset);
 709                 kunmap_atomic(dest, KM_SOFTIRQ0);
 710                 if (rc == -EAGAIN)
 711                         /* continue with the next SKB/PDU */
 712                         return rc;
 713                 if (!rc) {
 714                         if (conn->datadgst_en) {
 715                                 if (!offset)
 716                                         crypto_digest_update(
 717                                                         tcp_conn->data_rx_tfm,
 718                                                         &sg[i], 1);
 719                                 else
 720                                         partial_sg_digest_update(tcp_conn,
 721                                                         &sg[i],
 722                                                         sg[i].offset + offset,
 723                                                         sg[i].length - offset);
 724                         }
 725                         offset = 0;
 726                         tcp_ctask->sg_count++;
 727                 }
 728
 729                 if (!ctask->data_count) {
 730                         if (rc && conn->datadgst_en)
 731                                 /*
 732                                  * data-in is complete, but buffer not...
 733                                  */
 734                                 partial_sg_digest_update(tcp_conn, &sg[i],
 735                                                 sg[i].offset, sg[i].length-rc);
 736                         rc = 0;
 737                         break;
 738                 }
 739
 740                 if (!tcp_conn->in.copy)
 741                         return -EAGAIN;
 742         }
 743         BUG_ON(ctask->data_count);
 744
 745 done:
 746         /* check for non-exceptional status */
 747         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 748                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 749                            (long)sc, sc->result, ctask->itt);
 750                 spin_lock(&conn->session->lock);
 751                 __iscsi_ctask_cleanup(conn, ctask);
 752                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 753                 spin_unlock(&conn->session->lock);
 754         }
 755
 756         return rc;
 757 }
 758
 759 static int
 760 iscsi_data_recv(struct iscsi_conn *conn)
 761 {
 762         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 763         int rc = 0, opcode;
 764
 765         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 766         switch (opcode) {
 767         case ISCSI_OP_SCSI_DATA_IN:
 768                 rc = iscsi_scsi_data_in(conn);
 769                 break;
 770         case ISCSI_OP_SCSI_CMD_RSP:
 771                 spin_lock(&conn->session->lock);
 772                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 773                 spin_unlock(&conn->session->lock);
 774         case ISCSI_OP_TEXT_RSP:
 775         case ISCSI_OP_LOGIN_RSP:
 776         case ISCSI_OP_NOOP_IN:
 777         case ISCSI_OP_ASYNC_EVENT:
 778         case ISCSI_OP_REJECT:
 779                 /*
 780                  * Collect data segment to the connection's data
 781                  * placeholder
 782                  */
 783                 if (iscsi_tcp_copy(tcp_conn)) {
 784                         rc = -EAGAIN;
 785                         goto exit;
 786                 }
 787
 788                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 789                                         tcp_conn->in.datalen);
 790                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 791                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 792                                                 tcp_conn->in.datalen);
 793                 break;
 794         default:
 795                 BUG_ON(1);
 796         }
 797 exit:
 798         return rc;
 799 }
 800
 801 /**
 802  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 803  * @rd_desc: read descriptor
 804  * @skb: socket buffer
 805  * @offset: offset in skb
 806  * @len: skb->len - offset
 807  **/
 808 static int
 809 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 810                 unsigned int offset, size_t len)
 811 {
 812         int rc;
 813         struct iscsi_conn *conn = rd_desc->arg.data;
 814         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 815         int processed;
 816         char pad[ISCSI_PAD_LEN];
 817         struct scatterlist sg;
 818
 819         /*
 820          * Save current SKB and its offset in the corresponding
 821          * connection context.
 822          */
 823         tcp_conn->in.copy = skb->len - offset;
 824         tcp_conn->in.offset = offset;
 825         tcp_conn->in.skb = skb;
 826         tcp_conn->in.len = tcp_conn->in.copy;
 827         BUG_ON(tcp_conn->in.copy <= 0);
 828         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 829
 830 more:
 831         tcp_conn->in.copied = 0;
 832         rc = 0;
 833
 834         if (unlikely(conn->suspend_rx)) {
 835                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 836                 return 0;
 837         }
 838
 839         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 840             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 841                 rc = iscsi_hdr_extract(tcp_conn);
 842                 if (rc) {
 843                        if (rc == -EAGAIN)
 844                                 goto nomore;
 845                        else {
 846                                 iscsi_conn_failure(conn, rc);
 847                                 return 0;
 848                        }
 849                 }
 850
 851                 /*
 852                  * Verify and process incoming PDU header.
 853                  */
 854                 rc = iscsi_tcp_hdr_recv(conn);
 855                 if (!rc && tcp_conn->in.datalen) {
 856                         if (conn->datadgst_en) {
 857                                 BUG_ON(!tcp_conn->data_rx_tfm);
 858                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 859                         }
 860                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 861                 } else if (rc) {
 862                         iscsi_conn_failure(conn, rc);
 863                         return 0;
 864                 }
 865         }
 866
 867         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 868                 uint32_t recv_digest;
 869
 870                 debug_tcp("extra data_recv offset %d copy %d\n",
 871                           tcp_conn->in.offset, tcp_conn->in.copy);
 872                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 873                                 &recv_digest, 4);
 874                 tcp_conn->in.offset += 4;
 875                 tcp_conn->in.copy -= 4;
 876                 if (recv_digest != tcp_conn->in.datadgst) {
 877                         debug_tcp("iscsi_tcp: data digest error!"
 878                                   "0x%x != 0x%x\n", recv_digest,
 879                                   tcp_conn->in.datadgst);
 880                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 881                         return 0;
 882                 } else {
 883                         debug_tcp("iscsi_tcp: data digest match!"
 884                                   "0x%x == 0x%x\n", recv_digest,
 885                                   tcp_conn->in.datadgst);
 886                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 887                 }
 888         }
 889
 890         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 891            tcp_conn->in.copy) {
 892
 893                 debug_tcp("data_recv offset %d copy %d\n",
 894                        tcp_conn->in.offset, tcp_conn->in.copy);
 895
 896                 rc = iscsi_data_recv(conn);
 897                 if (rc) {
 898                         if (rc == -EAGAIN)
 899                                 goto again;
 900                         iscsi_conn_failure(conn, rc);
 901                         return 0;
 902                 }
 903                 tcp_conn->in.copy -= tcp_conn->in.padding;
 904                 tcp_conn->in.offset += tcp_conn->in.padding;
 905                 if (conn->datadgst_en) {
 906                         if (tcp_conn->in.padding) {
 907                                 debug_tcp("padding -> %d\n",
 908                                           tcp_conn->in.padding);
 909                                 memset(pad, 0, tcp_conn->in.padding);
 910                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 911                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 912                                                      &sg, 1);
 913                         }
 914                         crypto_digest_final(tcp_conn->data_rx_tfm,
 915                                             (u8 *) & tcp_conn->in.datadgst);
 916                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 917                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 918                 } else
 919                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 920         }
 921
 922         debug_tcp("f, processed %d from out of %d padding %d\n",
 923                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 924         BUG_ON(tcp_conn->in.offset - offset > len);
 925
 926         if (tcp_conn->in.offset - offset != len) {
 927                 debug_tcp("continue to process %d bytes\n",
 928                        (int)len - (tcp_conn->in.offset - offset));
 929                 goto more;
 930         }
 931
 932 nomore:
 933         processed = tcp_conn->in.offset - offset;
 934         BUG_ON(processed == 0);
 935         return processed;
 936
 937 again:
 938         processed = tcp_conn->in.offset - offset;
 939         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 940                   processed, (int)len, (int)rd_desc->count);
 941         BUG_ON(processed == 0);
 942         BUG_ON(processed > len);
 943
 944         conn->rxdata_octets += processed;
 945         return processed;
 946 }
 947
 948 static void
 949 iscsi_tcp_data_ready(struct sock *sk, int flag)
 950 {
 951         struct iscsi_conn *conn = sk->sk_user_data;
 952         read_descriptor_t rd_desc;
 953
 954         read_lock(&sk->sk_callback_lock);
 955
 956         /*
 957          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 958          * We set count to 1 because we want the network layer to
 959          * hand us all the skbs that are available. iscsi_tcp_data_recv
 960          * handled pdus that cross buffers or pdus that still need data.
 961          */
 962         rd_desc.arg.data = conn;
 963         rd_desc.count = 1;
 964         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 965
 966         read_unlock(&sk->sk_callback_lock);
 967 }
 968
 969 static void
 970 iscsi_tcp_state_change(struct sock *sk)
 971 {
 972         struct iscsi_tcp_conn *tcp_conn;
 973         struct iscsi_conn *conn;
 974         struct iscsi_session *session;
 975         void (*old_state_change)(struct sock *);
 976
 977         read_lock(&sk->sk_callback_lock);
 978
 979         conn = (struct iscsi_conn*)sk->sk_user_data;
 980         session = conn->session;
 981
 982         if ((sk->sk_state == TCP_CLOSE_WAIT ||
 983              sk->sk_state == TCP_CLOSE) &&
 984             !atomic_read(&sk->sk_rmem_alloc)) {
 985                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 986                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 987         }
 988
 989         tcp_conn = conn->dd_data;
 990         old_state_change = tcp_conn->old_state_change;
 991
 992         read_unlock(&sk->sk_callback_lock);
 993
 994         old_state_change(sk);
 995 }
 996
 997 /**
 998  * iscsi_write_space - Called when more output buffer space is available
 999  * @sk: socket space is available for
1000  **/
1001 static void
1002 iscsi_write_space(struct sock *sk)
1003 {
1004         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1005         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1006
1007         tcp_conn->old_write_space(sk);
1008         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1009         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1010         scsi_queue_work(conn->session->host, &conn->xmitwork);
1011 }
1012
1013 static void
1014 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1015 {
1016         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1017         struct sock *sk = tcp_conn->sock->sk;
1018
1019         /* assign new callbacks */
1020         write_lock_bh(&sk->sk_callback_lock);
1021         sk->sk_user_data = conn;
1022         tcp_conn->old_data_ready = sk->sk_data_ready;
1023         tcp_conn->old_state_change = sk->sk_state_change;
1024         tcp_conn->old_write_space = sk->sk_write_space;
1025         sk->sk_data_ready = iscsi_tcp_data_ready;
1026         sk->sk_state_change = iscsi_tcp_state_change;
1027         sk->sk_write_space = iscsi_write_space;
1028         write_unlock_bh(&sk->sk_callback_lock);
1029 }
1030
1031 static void
1032 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1033 {
1034         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1035         struct sock *sk = tcp_conn->sock->sk;
1036
1037         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1038         write_lock_bh(&sk->sk_callback_lock);
1039         sk->sk_user_data    = NULL;
1040         sk->sk_data_ready   = tcp_conn->old_data_ready;
1041         sk->sk_state_change = tcp_conn->old_state_change;
1042         sk->sk_write_space  = tcp_conn->old_write_space;
1043         sk->sk_no_check  = 0;
1044         write_unlock_bh(&sk->sk_callback_lock);
1045 }
1046
1047 /**
1048  * iscsi_send - generic send routine
1049  * @sk: kernel's socket
1050  * @buf: buffer to write from
1051  * @size: actual size to write
1052  * @flags: socket's flags
1053  */
1054 static inline int
1055 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1056 {
1057         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1058         struct socket *sk = tcp_conn->sock;
1059         int offset = buf->sg.offset + buf->sent;
1060
1061         /*
1062          * if we got use_sg=0 or are sending something we kmallocd
1063          * then we did not have to do kmap (kmap returns page_address)
1064          *
1065          * if we got use_sg > 0, but had to drop down, we do not
1066          * set clustering so this should only happen for that
1067          * slab case.
1068          */
1069         if (buf->use_sendmsg)
1070                 return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1071         else
1072                 return tcp_conn->sendpage(sk, buf->sg.page, offset, size,
1073                                           flags);
1074 }
1075
1076 /**
1077  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1078  * @conn: iscsi connection
1079  * @buf: buffer to write from
1080  * @datalen: lenght of data to be sent after the header
1081  *
1082  * Notes:
1083  *      (Tx, Fast Path)
1084  **/
1085 static inline int
1086 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1087 {
1088         struct iscsi_tcp_conn *tcp_conn;
1089         int flags = 0; /* MSG_DONTWAIT; */
1090         int res, size;
1091
1092         size = buf->sg.length - buf->sent;
1093         BUG_ON(buf->sent + size > buf->sg.length);
1094         if (buf->sent + size != buf->sg.length || datalen)
1095                 flags |= MSG_MORE;
1096
1097         res = iscsi_send(conn, buf, size, flags);
1098         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1099         if (res >= 0) {
1100                 conn->txdata_octets += res;
1101                 buf->sent += res;
1102                 if (size != res)
1103                         return -EAGAIN;
1104                 return 0;
1105         } else if (res == -EAGAIN) {
1106                 tcp_conn = conn->dd_data;
1107                 tcp_conn->sendpage_failures_cnt++;
1108                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1109         } else if (res == -EPIPE)
1110                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1111
1112         return res;
1113 }
1114
1115 /**
1116  * iscsi_sendpage - send one page of iSCSI Data-Out.
1117  * @conn: iscsi connection
1118  * @buf: buffer to write from
1119  * @count: remaining data
1120  * @sent: number of bytes sent
1121  *
1122  * Notes:
1123  *      (Tx, Fast Path)
1124  **/
1125 static inline int
1126 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1127                int *count, int *sent)
1128 {
1129         struct iscsi_tcp_conn *tcp_conn;
1130         int flags = 0; /* MSG_DONTWAIT; */
1131         int res, size;
1132
1133         size = buf->sg.length - buf->sent;
1134         BUG_ON(buf->sent + size > buf->sg.length);
1135         if (size > *count)
1136                 size = *count;
1137         if (buf->sent + size != buf->sg.length || *count != size)
1138                 flags |= MSG_MORE;
1139
1140         res = iscsi_send(conn, buf, size, flags);
1141         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1142                   size, buf->sent, *count, *sent, res);
1143         if (res >= 0) {
1144                 conn->txdata_octets += res;
1145                 buf->sent += res;
1146                 *count -= res;
1147                 *sent += res;
1148                 if (size != res)
1149                         return -EAGAIN;
1150                 return 0;
1151         } else if (res == -EAGAIN) {
1152                 tcp_conn = conn->dd_data;
1153                 tcp_conn->sendpage_failures_cnt++;
1154                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1155         } else if (res == -EPIPE)
1156                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1157
1158         return res;
1159 }
1160
1161 static inline void
1162 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1163                       struct iscsi_cmd_task *ctask)
1164 {
1165         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1166
1167         BUG_ON(!tcp_conn->data_tx_tfm);
1168         crypto_digest_init(tcp_conn->data_tx_tfm);
1169         tcp_ctask->digest_count = 4;
1170 }
1171
1172 static int
1173 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1174                         struct iscsi_buf *buf, uint32_t *digest, int final)
1175 {
1176         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1177         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1178         int rc = 0;
1179         int sent = 0;
1180
1181         if (final)
1182                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1183
1184         iscsi_buf_init_iov(buf, (char*)digest, 4);
1185         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1186         if (rc) {
1187                 tcp_ctask->datadigest = *digest;
1188                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1189         } else
1190                 tcp_ctask->digest_count = 4;
1191         return rc;
1192 }
1193
1194 /**
1195  * iscsi_solicit_data_cont - initialize next Data-Out
1196  * @conn: iscsi connection
1197  * @ctask: scsi command task
1198  * @r2t: R2T info
1199  * @left: bytes left to transfer
1200  *
1201  * Notes:
1202  *      Initialize next Data-Out within this R2T sequence and continue
1203  *      to process next Scatter-Gather element(if any) of this SCSI command.
1204  *
1205  *      Called under connection lock.
1206  **/
1207 static void
1208 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1209                         struct iscsi_r2t_info *r2t, int left)
1210 {
1211         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1212         struct iscsi_data *hdr;
1213         struct scsi_cmnd *sc = ctask->sc;
1214         int new_offset;
1215
1216         hdr = &r2t->dtask.hdr;
1217         memset(hdr, 0, sizeof(struct iscsi_data));
1218         hdr->ttt = r2t->ttt;
1219         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1220         r2t->solicit_datasn++;
1221         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1222         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1223         hdr->itt = ctask->hdr->itt;
1224         hdr->exp_statsn = r2t->exp_statsn;
1225         new_offset = r2t->data_offset + r2t->sent;
1226         hdr->offset = cpu_to_be32(new_offset);
1227         if (left > conn->max_xmit_dlength) {
1228                 hton24(hdr->dlength, conn->max_xmit_dlength);
1229                 r2t->data_count = conn->max_xmit_dlength;
1230         } else {
1231                 hton24(hdr->dlength, left);
1232                 r2t->data_count = left;
1233                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1234         }
1235         conn->dataout_pdus_cnt++;
1236
1237         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1238                            sizeof(struct iscsi_hdr));
1239
1240         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1241                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1242                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1243                 r2t->sg += 1;
1244         } else
1245                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1246                             (char*)sc->request_buffer + new_offset,
1247                             r2t->data_count);
1248 }
1249
1250 static void
1251 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1252 {
1253         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1254         struct iscsi_data_task *dtask;
1255
1256         dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1257         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1258                                       tcp_ctask->r2t_data_count);
1259         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1260                            sizeof(struct iscsi_hdr));
1261 }
1262
1263 /**
1264  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1265  * @conn: iscsi connection
1266  * @ctask: scsi command task
1267  * @sc: scsi command
1268  **/
1269 static void
1270 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1271 {
1272         struct scsi_cmnd *sc = ctask->sc;
1273         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1274
1275         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1276
1277         tcp_ctask->sent = 0;
1278         tcp_ctask->sg_count = 0;
1279
1280         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1281                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1282                 tcp_ctask->exp_r2tsn = 0;
1283                 BUG_ON(ctask->total_length == 0);
1284
1285                 if (sc->use_sg) {
1286                         struct scatterlist *sg = sc->request_buffer;
1287
1288                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1289                                           &sg[tcp_ctask->sg_count++]);
1290                         tcp_ctask->sg = sg;
1291                         tcp_ctask->bad_sg = sg + sc->use_sg;
1292                 } else
1293                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1294                                            sc->request_buffer,
1295                                            sc->request_bufflen);
1296
1297                 if (ctask->imm_count)
1298                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1299
1300                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1301                 if (tcp_ctask->pad_count) {
1302                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1303                                                         tcp_ctask->pad_count;
1304                         debug_scsi("write padding %d bytes\n",
1305                                    tcp_ctask->pad_count);
1306                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1307                 }
1308
1309                 if (ctask->unsol_count)
1310                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1311                                                 XMSTATE_UNS_INIT;
1312                 tcp_ctask->r2t_data_count = ctask->total_length -
1313                                     ctask->imm_count -
1314                                     ctask->unsol_count;
1315
1316                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1317                            "r2t_data %d]\n",
1318                            ctask->itt, ctask->total_length, ctask->imm_count,
1319                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1320         } else
1321                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1322
1323         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1324                             sizeof(struct iscsi_hdr));
1325 }
1326
1327 /**
1328  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1329  * @conn: iscsi connection
1330  * @mtask: task management task
1331  *
1332  * Notes:
1333  *      The function can return -EAGAIN in which case caller must
1334  *      call it again later, or recover. '0' return code means successful
1335  *      xmit.
1336  *
1337  *      Management xmit state machine consists of two states:
1338  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1339  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1340  **/
1341 static int
1342 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1343 {
1344         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1345
1346         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1347                 conn->id, tcp_mtask->xmstate, mtask->itt);
1348
1349         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1350                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1351                 if (mtask->data_count)
1352                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1353                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1354                     conn->stop_stage != STOP_CONN_RECOVER &&
1355                     conn->hdrdgst_en)
1356                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1357                                         (u8*)tcp_mtask->hdrext);
1358                 if (iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1359                                   mtask->data_count)) {
1360                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1361                         if (mtask->data_count)
1362                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1363                         return -EAGAIN;
1364                 }
1365         }
1366
1367         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1368                 BUG_ON(!mtask->data_count);
1369                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1370                 /* FIXME: implement.
1371                  * Virtual buffer could be spreaded across multiple pages...
1372                  */
1373                 do {
1374                         if (iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1375                                    &mtask->data_count, &tcp_mtask->sent)) {
1376                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1377                                 return -EAGAIN;
1378                         }
1379                 } while (mtask->data_count);
1380         }
1381
1382         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1383         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1384                 struct iscsi_session *session = conn->session;
1385
1386                 spin_lock_bh(&session->lock);
1387                 list_del(&conn->mtask->running);
1388                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1389                             sizeof(void*));
1390                 spin_unlock_bh(&session->lock);
1391         }
1392         return 0;
1393 }
1394
1395 static inline int
1396 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1397                      struct iscsi_tcp_cmd_task *tcp_ctask)
1398 {
1399         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1400         if (conn->hdrdgst_en)
1401                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1402                                  (u8*)tcp_ctask->hdrext);
1403         if (!iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0)) {
1404                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1405                 return 0; /* wait for Data-In */
1406         }
1407         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1408         return -EAGAIN;
1409 }
1410
1411 static inline int
1412 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1413                      struct iscsi_cmd_task *ctask)
1414 {
1415         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1416
1417         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1418         if (conn->hdrdgst_en)
1419                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1420                                  (u8*)tcp_ctask->hdrext);
1421         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count)) {
1422                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1423                 return -EAGAIN;
1424         }
1425         return 0;
1426 }
1427
1428 static inline int
1429 handle_xmstate_data_digest(struct iscsi_conn *conn,
1430                            struct iscsi_cmd_task *ctask)
1431 {
1432         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1433
1434         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1435         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1436         if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1437                                     &tcp_ctask->datadigest, 0)) {
1438                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1439                 debug_tcp("resent data digest 0x%x fail!\n",
1440                           tcp_ctask->datadigest);
1441                 return -EAGAIN;
1442         }
1443         return 0;
1444 }
1445
1446 static inline int
1447 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1448 {
1449         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1450         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1451
1452         BUG_ON(!ctask->imm_count);
1453         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1454
1455         if (conn->datadgst_en) {
1456                 iscsi_data_digest_init(tcp_conn, ctask);
1457                 tcp_ctask->immdigest = 0;
1458         }
1459
1460         for (;;) {
1461                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &ctask->imm_count,
1462                                    &tcp_ctask->sent)) {
1463                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1464                         if (conn->datadgst_en) {
1465                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1466                                                 (u8*)&tcp_ctask->immdigest);
1467                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1468                                           tcp_ctask->datadigest);
1469                         }
1470                         return -EAGAIN;
1471                 }
1472                 if (conn->datadgst_en)
1473                         crypto_digest_update(tcp_conn->data_tx_tfm,
1474                                              &tcp_ctask->sendbuf.sg, 1);
1475
1476                 if (!ctask->imm_count)
1477                         break;
1478                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1479                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1480         }
1481
1482         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1483                 if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1484                                             &tcp_ctask->immdigest, 1)) {
1485                         debug_tcp("sending imm digest 0x%x fail!\n",
1486                                   tcp_ctask->immdigest);
1487                         return -EAGAIN;
1488                 }
1489                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1490         }
1491
1492         return 0;
1493 }
1494
1495 static inline int
1496 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1497 {
1498         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1499         struct iscsi_data_task *dtask;
1500
1501         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1502         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1503                 iscsi_unsolicit_data_init(conn, ctask);
1504                 dtask = tcp_ctask->dtask;
1505                 if (conn->hdrdgst_en)
1506                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1507                                         (u8*)dtask->hdrext);
1508                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1509         }
1510         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count)) {
1511                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1512                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1513                 return -EAGAIN;
1514         }
1515
1516         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1517                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1518         return 0;
1519 }
1520
1521 static inline int
1522 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1523 {
1524         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1525         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1526         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1527
1528         BUG_ON(!ctask->data_count);
1529         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1530
1531         if (conn->datadgst_en) {
1532                 iscsi_data_digest_init(tcp_conn, ctask);
1533                 dtask->digest = 0;
1534         }
1535
1536         for (;;) {
1537                 int start = tcp_ctask->sent;
1538
1539                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1540                                    &ctask->data_count, &tcp_ctask->sent)) {
1541                         ctask->unsol_count -= tcp_ctask->sent - start;
1542                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1543                         /* will continue with this ctask later.. */
1544                         if (conn->datadgst_en) {
1545                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1546                                                 (u8 *)&dtask->digest);
1547                                 debug_tcp("tx uns data fail 0x%x\n",
1548                                           dtask->digest);
1549                         }
1550                         return -EAGAIN;
1551                 }
1552
1553                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1554                 ctask->unsol_count -= tcp_ctask->sent - start;
1555
1556                 /*
1557                  * XXX:we may run here with un-initial sendbuf.
1558                  * so pass it
1559                  */
1560                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1561                         crypto_digest_update(tcp_conn->data_tx_tfm,
1562                                              &tcp_ctask->sendbuf.sg, 1);
1563
1564                 if (!ctask->data_count)
1565                         break;
1566                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1567                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1568         }
1569         BUG_ON(ctask->unsol_count < 0);
1570
1571         /*
1572          * Done with the Data-Out. Next, check if we need
1573          * to send another unsolicited Data-Out.
1574          */
1575         if (ctask->unsol_count) {
1576                 if (conn->datadgst_en) {
1577                         if (iscsi_digest_final_send(conn, ctask,
1578                                                     &dtask->digestbuf,
1579                                                     &dtask->digest, 1)) {
1580                                 debug_tcp("send uns digest 0x%x fail\n",
1581                                           dtask->digest);
1582                                 return -EAGAIN;
1583                         }
1584                         debug_tcp("sending uns digest 0x%x, more uns\n",
1585                                   dtask->digest);
1586                 }
1587                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1588                 return 1;
1589         }
1590
1591         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1592                 if (iscsi_digest_final_send(conn, ctask,
1593                                             &dtask->digestbuf,
1594                                             &dtask->digest, 1)) {
1595                         debug_tcp("send last uns digest 0x%x fail\n",
1596                                    dtask->digest);
1597                         return -EAGAIN;
1598                 }
1599                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1600         }
1601
1602         return 0;
1603 }
1604
1605 static inline int
1606 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1607 {
1608         struct iscsi_session *session = conn->session;
1609         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1610         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1611         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1612         struct iscsi_data_task *dtask = &r2t->dtask;
1613         int left;
1614
1615         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1616         tcp_ctask->dtask = dtask;
1617
1618         if (conn->datadgst_en) {
1619                 iscsi_data_digest_init(tcp_conn, ctask);
1620                 dtask->digest = 0;
1621         }
1622 solicit_again:
1623         /*
1624          * send Data-Out whitnin this R2T sequence.
1625          */
1626         if (!r2t->data_count)
1627                 goto data_out_done;
1628
1629         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1630                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1631                 /* will continue with this ctask later.. */
1632                 if (conn->datadgst_en) {
1633                         crypto_digest_final(tcp_conn->data_tx_tfm,
1634                                           (u8 *)&dtask->digest);
1635                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1636                 }
1637                 return -EAGAIN;
1638         }
1639
1640         BUG_ON(r2t->data_count < 0);
1641         if (conn->datadgst_en)
1642                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1643                                      1);
1644
1645         if (r2t->data_count) {
1646                 BUG_ON(ctask->sc->use_sg == 0);
1647                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1648                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1649                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1650                         r2t->sg += 1;
1651                 }
1652                 goto solicit_again;
1653         }
1654
1655 data_out_done:
1656         /*
1657          * Done with this Data-Out. Next, check if we have
1658          * to send another Data-Out for this R2T.
1659          */
1660         BUG_ON(r2t->data_length - r2t->sent < 0);
1661         left = r2t->data_length - r2t->sent;
1662         if (left) {
1663                 if (conn->datadgst_en) {
1664                         if (iscsi_digest_final_send(conn, ctask,
1665                                                     &dtask->digestbuf,
1666                                                     &dtask->digest, 1)) {
1667                                 debug_tcp("send r2t data digest 0x%x"
1668                                           "fail\n", dtask->digest);
1669                                 return -EAGAIN;
1670                         }
1671                         debug_tcp("r2t data send digest 0x%x\n",
1672                                   dtask->digest);
1673                 }
1674                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1675                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1676                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1677                 return 1;
1678         }
1679
1680         /*
1681          * Done with this R2T. Check if there are more
1682          * outstanding R2Ts ready to be processed.
1683          */
1684         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1685         if (conn->datadgst_en) {
1686                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1687                                             &dtask->digest, 1)) {
1688                         debug_tcp("send last r2t data digest 0x%x"
1689                                   "fail\n", dtask->digest);
1690                         return -EAGAIN;
1691                 }
1692                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1693         }
1694
1695         tcp_ctask->r2t_data_count -= r2t->data_length;
1696         tcp_ctask->r2t = NULL;
1697         spin_lock_bh(&session->lock);
1698         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1699         spin_unlock_bh(&session->lock);
1700         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1701                 tcp_ctask->r2t = r2t;
1702                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1703                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1704                 return 1;
1705         }
1706
1707         return 0;
1708 }
1709
1710 static inline int
1711 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1712 {
1713         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1714         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1715         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1716         int sent;
1717
1718         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1719         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1720                             tcp_ctask->pad_count);
1721         if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1722                            &sent)) {
1723                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1724                 return -EAGAIN;
1725         }
1726
1727         if (conn->datadgst_en) {
1728                 crypto_digest_update(tcp_conn->data_tx_tfm,
1729                                      &tcp_ctask->sendbuf.sg, 1);
1730                 /* imm data? */
1731                 if (!dtask) {
1732                         if (iscsi_digest_final_send(conn, ctask,
1733                                                     &tcp_ctask->immbuf,
1734                                                     &tcp_ctask->immdigest, 1)) {
1735                                 debug_tcp("send padding digest 0x%x"
1736                                           "fail!\n", tcp_ctask->immdigest);
1737                                 return -EAGAIN;
1738                         }
1739                         debug_tcp("done with padding, digest 0x%x\n",
1740                                   tcp_ctask->datadigest);
1741                 } else {
1742                         if (iscsi_digest_final_send(conn, ctask,
1743                                                     &dtask->digestbuf,
1744                                                     &dtask->digest, 1)) {
1745                                 debug_tcp("send padding digest 0x%x"
1746                                           "fail\n", dtask->digest);
1747                                 return -EAGAIN;
1748                         }
1749                         debug_tcp("done with padding, digest 0x%x\n",
1750                                   dtask->digest);
1751                 }
1752         }
1753
1754         return 0;
1755 }
1756
1757 static int
1758 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1759 {
1760         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1761         int rc = 0;
1762
1763         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1764                 conn->id, tcp_ctask->xmstate, ctask->itt);
1765
1766         /*
1767          * serialize with TMF AbortTask
1768          */
1769         if (ctask->mtask)
1770                 return rc;
1771
1772         if (tcp_ctask->xmstate & XMSTATE_R_HDR) {
1773                 rc = handle_xmstate_r_hdr(conn, tcp_ctask);
1774                 return rc;
1775         }
1776
1777         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1778                 rc = handle_xmstate_w_hdr(conn, ctask);
1779                 if (rc)
1780                         return rc;
1781         }
1782
1783         /* XXX: for data digest xmit recover */
1784         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1785                 rc = handle_xmstate_data_digest(conn, ctask);
1786                 if (rc)
1787                         return rc;
1788         }
1789
1790         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1791                 rc = handle_xmstate_imm_data(conn, ctask);
1792                 if (rc)
1793                         return rc;
1794         }
1795
1796         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1797                 BUG_ON(!ctask->unsol_count);
1798                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1799 unsolicit_head_again:
1800                 rc = handle_xmstate_uns_hdr(conn, ctask);
1801                 if (rc)
1802                         return rc;
1803         }
1804
1805         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1806                 rc = handle_xmstate_uns_data(conn, ctask);
1807                 if (rc == 1)
1808                         goto unsolicit_head_again;
1809                 else if (rc)
1810                         return rc;
1811                 goto done;
1812         }
1813
1814         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1815                 struct iscsi_r2t_info *r2t;
1816
1817                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1818                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1819                 if (!tcp_ctask->r2t)
1820                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1821                                     sizeof(void*));
1822 solicit_head_again:
1823                 r2t = tcp_ctask->r2t;
1824                 if (conn->hdrdgst_en)
1825                         iscsi_hdr_digest(conn, &r2t->headbuf,
1826                                         (u8*)r2t->dtask.hdrext);
1827                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
1828                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1829                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1830                         return -EAGAIN;
1831                 }
1832
1833                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1834                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1835                         r2t->sent);
1836         }
1837
1838         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1839                 rc = handle_xmstate_sol_data(conn, ctask);
1840                 if (rc == 1)
1841                         goto solicit_head_again;
1842                 if (rc)
1843                         return rc;
1844         }
1845
1846 done:
1847         /*
1848          * Last thing to check is whether we need to send write
1849          * padding. Note that we check for xmstate equality, not just the bit.
1850          */
1851         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1852                 rc = handle_xmstate_w_pad(conn, ctask);
1853
1854         return rc;
1855 }
1856
1857 static struct iscsi_cls_conn *
1858 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1859 {
1860         struct iscsi_conn *conn;
1861         struct iscsi_cls_conn *cls_conn;
1862         struct iscsi_tcp_conn *tcp_conn;
1863
1864         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1865         if (!cls_conn)
1866                 return NULL;
1867         conn = cls_conn->dd_data;
1868         /*
1869          * due to strange issues with iser these are not set
1870          * in iscsi_conn_setup
1871          */
1872         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1873
1874         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1875         if (!tcp_conn)
1876                 goto tcp_conn_alloc_fail;
1877
1878         conn->dd_data = tcp_conn;
1879         tcp_conn->iscsi_conn = conn;
1880         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1881         /* initial operational parameters */
1882         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1883         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1884
1885         /* allocate initial PDU receive place holder */
1886         if (tcp_conn->data_size <= PAGE_SIZE)
1887                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1888         else
1889                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1890                                         get_order(tcp_conn->data_size));
1891         if (!tcp_conn->data)
1892                 goto max_recv_dlenght_alloc_fail;
1893
1894         return cls_conn;
1895
1896 max_recv_dlenght_alloc_fail:
1897         kfree(tcp_conn);
1898 tcp_conn_alloc_fail:
1899         iscsi_conn_teardown(cls_conn);
1900         return NULL;
1901 }
1902
1903 static void
1904 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1905 {
1906         struct iscsi_conn *conn = cls_conn->dd_data;
1907         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1908         int digest = 0;
1909
1910         if (conn->hdrdgst_en || conn->datadgst_en)
1911                 digest = 1;
1912
1913         iscsi_conn_teardown(cls_conn);
1914
1915         /* now free tcp_conn */
1916         if (digest) {
1917                 if (tcp_conn->tx_tfm)
1918                         crypto_free_tfm(tcp_conn->tx_tfm);
1919                 if (tcp_conn->rx_tfm)
1920                         crypto_free_tfm(tcp_conn->rx_tfm);
1921                 if (tcp_conn->data_tx_tfm)
1922                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1923                 if (tcp_conn->data_rx_tfm)
1924                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1925         }
1926
1927         /* free conn->data, size = MaxRecvDataSegmentLength */
1928         if (tcp_conn->data_size <= PAGE_SIZE)
1929                 kfree(tcp_conn->data);
1930         else
1931                 free_pages((unsigned long)tcp_conn->data,
1932                            get_order(tcp_conn->data_size));
1933         kfree(tcp_conn);
1934 }
1935
1936 static int
1937 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1938                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1939                     int is_leading)
1940 {
1941         struct iscsi_conn *conn = cls_conn->dd_data;
1942         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1943         struct sock *sk;
1944         struct socket *sock;
1945         int err;
1946
1947         /* lookup for existing socket */
1948         sock = sockfd_lookup((int)transport_eph, &err);
1949         if (!sock) {
1950                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1951                 return -EEXIST;
1952         }
1953
1954         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1955         if (err)
1956                 return err;
1957
1958         if (conn->stop_stage != STOP_CONN_SUSPEND) {
1959                 /* bind iSCSI connection and socket */
1960                 tcp_conn->sock = sock;
1961
1962                 /* setup Socket parameters */
1963                 sk = sock->sk;
1964                 sk->sk_reuse = 1;
1965                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
1966                 sk->sk_allocation = GFP_ATOMIC;
1967
1968                 /* FIXME: disable Nagle's algorithm */
1969
1970                 /*
1971                  * Intercept TCP callbacks for sendfile like receive
1972                  * processing.
1973                  */
1974                 conn->recv_lock = &sk->sk_callback_lock;
1975                 iscsi_conn_set_callbacks(conn);
1976                 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
1977                 /*
1978                  * set receive state machine into initial state
1979                  */
1980                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1981         }
1982
1983         return 0;
1984 }
1985
1986 static void
1987 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1988 {
1989         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1990         struct iscsi_r2t_info *r2t;
1991
1992         /* flush ctask's r2t queues */
1993         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
1994                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
1995                             sizeof(void*));
1996
1997         __iscsi_ctask_cleanup(conn, ctask);
1998 }
1999
2000 static void
2001 iscsi_tcp_suspend_conn_rx(struct iscsi_conn *conn)
2002 {
2003         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2004         struct sock *sk;
2005
2006         if (!tcp_conn->sock)
2007                 return;
2008
2009         sk = tcp_conn->sock->sk;
2010         write_lock_bh(&sk->sk_callback_lock);
2011         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2012         write_unlock_bh(&sk->sk_callback_lock);
2013 }
2014
2015 static void
2016 iscsi_tcp_terminate_conn(struct iscsi_conn *conn)
2017 {
2018         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2019
2020         if (!tcp_conn->sock)
2021                 return;
2022
2023         sock_hold(tcp_conn->sock->sk);
2024         iscsi_conn_restore_callbacks(conn);
2025         sock_put(tcp_conn->sock->sk);
2026
2027         sock_release(tcp_conn->sock);
2028         tcp_conn->sock = NULL;
2029         conn->recv_lock = NULL;
2030 }
2031
2032 /* called with host lock */
2033 static void
2034 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2035                     char *data, uint32_t data_size)
2036 {
2037         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2038
2039         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2040                            sizeof(struct iscsi_hdr));
2041         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2042
2043         if (mtask->data_count)
2044                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2045                                     mtask->data_count);
2046 }
2047
2048 static int
2049 iscsi_r2tpool_alloc(struct iscsi_session *session)
2050 {
2051         int i;
2052         int cmd_i;
2053
2054         /*
2055          * initialize per-task: R2T pool and xmit queue
2056          */
2057         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2058                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2059                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2060
2061                 /*
2062                  * pre-allocated x4 as much r2ts to handle race when
2063                  * target acks DataOut faster than we data_xmit() queues
2064                  * could replenish r2tqueue.
2065                  */
2066
2067                 /* R2T pool */
2068                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2069                                     (void***)&tcp_ctask->r2ts,
2070                                     sizeof(struct iscsi_r2t_info))) {
2071                         goto r2t_alloc_fail;
2072                 }
2073
2074                 /* R2T xmit queue */
2075                 tcp_ctask->r2tqueue = kfifo_alloc(
2076                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2077                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2078                         iscsi_pool_free(&tcp_ctask->r2tpool,
2079                                         (void**)tcp_ctask->r2ts);
2080                         goto r2t_alloc_fail;
2081                 }
2082         }
2083
2084         return 0;
2085
2086 r2t_alloc_fail:
2087         for (i = 0; i < cmd_i; i++) {
2088                 struct iscsi_cmd_task *ctask = session->cmds[i];
2089                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2090
2091                 kfifo_free(tcp_ctask->r2tqueue);
2092                 iscsi_pool_free(&tcp_ctask->r2tpool,
2093                                 (void**)tcp_ctask->r2ts);
2094         }
2095         return -ENOMEM;
2096 }
2097
2098 static void
2099 iscsi_r2tpool_free(struct iscsi_session *session)
2100 {
2101         int i;
2102
2103         for (i = 0; i < session->cmds_max; i++) {
2104                 struct iscsi_cmd_task *ctask = session->cmds[i];
2105                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2106
2107                 kfifo_free(tcp_ctask->r2tqueue);
2108                 iscsi_pool_free(&tcp_ctask->r2tpool,
2109                                 (void**)tcp_ctask->r2ts);
2110         }
2111 }
2112
2113 static int
2114 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2115                      uint32_t value)
2116 {
2117         struct iscsi_conn *conn = cls_conn->dd_data;
2118         struct iscsi_session *session = conn->session;
2119         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2120
2121         switch(param) {
2122         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2123                 char *saveptr = tcp_conn->data;
2124                 gfp_t flags = GFP_KERNEL;
2125
2126                 if (tcp_conn->data_size >= value) {
2127                         conn->max_recv_dlength = value;
2128                         break;
2129                 }
2130
2131                 spin_lock_bh(&session->lock);
2132                 if (conn->stop_stage == STOP_CONN_RECOVER)
2133                         flags = GFP_ATOMIC;
2134                 spin_unlock_bh(&session->lock);
2135
2136                 if (value <= PAGE_SIZE)
2137                         tcp_conn->data = kmalloc(value, flags);
2138                 else
2139                         tcp_conn->data = (void*)__get_free_pages(flags,
2140                                                              get_order(value));
2141                 if (tcp_conn->data == NULL) {
2142                         tcp_conn->data = saveptr;
2143                         return -ENOMEM;
2144                 }
2145                 if (tcp_conn->data_size <= PAGE_SIZE)
2146                         kfree(saveptr);
2147                 else
2148                         free_pages((unsigned long)saveptr,
2149                                    get_order(tcp_conn->data_size));
2150                 conn->max_recv_dlength = value;
2151                 tcp_conn->data_size = value;
2152                 }
2153                 break;
2154         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2155                 conn->max_xmit_dlength =  value;
2156                 break;
2157         case ISCSI_PARAM_HDRDGST_EN:
2158                 conn->hdrdgst_en = value;
2159                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2160                 if (conn->hdrdgst_en) {
2161                         tcp_conn->hdr_size += sizeof(__u32);
2162                         if (!tcp_conn->tx_tfm)
2163                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2164                                                                     0);
2165                         if (!tcp_conn->tx_tfm)
2166                                 return -ENOMEM;
2167                         if (!tcp_conn->rx_tfm)
2168                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2169                                                                     0);
2170                         if (!tcp_conn->rx_tfm) {
2171                                 crypto_free_tfm(tcp_conn->tx_tfm);
2172                                 return -ENOMEM;
2173                         }
2174                 } else {
2175                         if (tcp_conn->tx_tfm)
2176                                 crypto_free_tfm(tcp_conn->tx_tfm);
2177                         if (tcp_conn->rx_tfm)
2178                                 crypto_free_tfm(tcp_conn->rx_tfm);
2179                 }
2180                 break;
2181         case ISCSI_PARAM_DATADGST_EN:
2182                 conn->datadgst_en = value;
2183                 if (conn->datadgst_en) {
2184                         if (!tcp_conn->data_tx_tfm)
2185                                 tcp_conn->data_tx_tfm =
2186                                     crypto_alloc_tfm("crc32c", 0);
2187                         if (!tcp_conn->data_tx_tfm)
2188                                 return -ENOMEM;
2189                         if (!tcp_conn->data_rx_tfm)
2190                                 tcp_conn->data_rx_tfm =
2191                                     crypto_alloc_tfm("crc32c", 0);
2192                         if (!tcp_conn->data_rx_tfm) {
2193                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2194                                 return -ENOMEM;
2195                         }
2196                 } else {
2197                         if (tcp_conn->data_tx_tfm)
2198                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2199                         if (tcp_conn->data_rx_tfm)
2200                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2201                 }
2202                 tcp_conn->sendpage = conn->datadgst_en ?
2203                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2204                 break;
2205         case ISCSI_PARAM_INITIAL_R2T_EN:
2206                 session->initial_r2t_en = value;
2207                 break;
2208         case ISCSI_PARAM_MAX_R2T:
2209                 if (session->max_r2t == roundup_pow_of_two(value))
2210                         break;
2211                 iscsi_r2tpool_free(session);
2212                 session->max_r2t = value;
2213                 if (session->max_r2t & (session->max_r2t - 1))
2214                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2215                 if (iscsi_r2tpool_alloc(session))
2216                         return -ENOMEM;
2217                 break;
2218         case ISCSI_PARAM_IMM_DATA_EN:
2219                 session->imm_data_en = value;
2220                 break;
2221         case ISCSI_PARAM_FIRST_BURST:
2222                 session->first_burst = value;
2223                 break;
2224         case ISCSI_PARAM_MAX_BURST:
2225                 session->max_burst = value;
2226                 break;
2227         case ISCSI_PARAM_PDU_INORDER_EN:
2228                 session->pdu_inorder_en = value;
2229                 break;
2230         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2231                 session->dataseq_inorder_en = value;
2232                 break;
2233         case ISCSI_PARAM_ERL:
2234                 session->erl = value;
2235                 break;
2236         case ISCSI_PARAM_IFMARKER_EN:
2237                 BUG_ON(value);
2238                 session->ifmarker_en = value;
2239                 break;
2240         case ISCSI_PARAM_OFMARKER_EN:
2241                 BUG_ON(value);
2242                 session->ofmarker_en = value;
2243                 break;
2244         case ISCSI_PARAM_EXP_STATSN:
2245                 conn->exp_statsn = value;
2246                 break;
2247         default:
2248                 break;
2249         }
2250
2251         return 0;
2252 }
2253
2254 static int
2255 iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2256                         enum iscsi_param param, uint32_t *value)
2257 {
2258         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2259         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2260
2261         switch(param) {
2262         case ISCSI_PARAM_INITIAL_R2T_EN:
2263                 *value = session->initial_r2t_en;
2264                 break;
2265         case ISCSI_PARAM_MAX_R2T:
2266                 *value = session->max_r2t;
2267                 break;
2268         case ISCSI_PARAM_IMM_DATA_EN:
2269                 *value = session->imm_data_en;
2270                 break;
2271         case ISCSI_PARAM_FIRST_BURST:
2272                 *value = session->first_burst;
2273                 break;
2274         case ISCSI_PARAM_MAX_BURST:
2275                 *value = session->max_burst;
2276                 break;
2277         case ISCSI_PARAM_PDU_INORDER_EN:
2278                 *value = session->pdu_inorder_en;
2279                 break;
2280         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2281                 *value = session->dataseq_inorder_en;
2282                 break;
2283         case ISCSI_PARAM_ERL:
2284                 *value = session->erl;
2285                 break;
2286         case ISCSI_PARAM_IFMARKER_EN:
2287                 *value = session->ifmarker_en;
2288                 break;
2289         case ISCSI_PARAM_OFMARKER_EN:
2290                 *value = session->ofmarker_en;
2291                 break;
2292         default:
2293                 return -EINVAL;
2294         }
2295
2296         return 0;
2297 }
2298
2299 static int
2300 iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2301                      enum iscsi_param param, uint32_t *value)
2302 {
2303         struct iscsi_conn *conn = cls_conn->dd_data;
2304         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2305         struct inet_sock *inet;
2306
2307         switch(param) {
2308         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2309                 *value = conn->max_recv_dlength;
2310                 break;
2311         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2312                 *value = conn->max_xmit_dlength;
2313                 break;
2314         case ISCSI_PARAM_HDRDGST_EN:
2315                 *value = conn->hdrdgst_en;
2316                 break;
2317         case ISCSI_PARAM_DATADGST_EN:
2318                 *value = conn->datadgst_en;
2319                 break;
2320         case ISCSI_PARAM_CONN_PORT:
2321                 mutex_lock(&conn->xmitmutex);
2322                 if (!tcp_conn->sock) {
2323                         mutex_unlock(&conn->xmitmutex);
2324                         return -EINVAL;
2325                 }
2326
2327                 inet = inet_sk(tcp_conn->sock->sk);
2328                 *value = be16_to_cpu(inet->dport);
2329                 mutex_unlock(&conn->xmitmutex);
2330         case ISCSI_PARAM_EXP_STATSN:
2331                 *value = conn->exp_statsn;
2332                 break;
2333         default:
2334                 return -EINVAL;
2335         }
2336
2337         return 0;
2338 }
2339
2340 static int
2341 iscsi_conn_get_str_param(struct iscsi_cls_conn *cls_conn,
2342                          enum iscsi_param param, char *buf)
2343 {
2344         struct iscsi_conn *conn = cls_conn->dd_data;
2345         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2346         struct sock *sk;
2347         struct inet_sock *inet;
2348         struct ipv6_pinfo *np;
2349         int len = 0;
2350
2351         switch (param) {
2352         case ISCSI_PARAM_CONN_ADDRESS:
2353                 mutex_lock(&conn->xmitmutex);
2354                 if (!tcp_conn->sock) {
2355                         mutex_unlock(&conn->xmitmutex);
2356                         return -EINVAL;
2357                 }
2358
2359                 sk = tcp_conn->sock->sk;
2360                 if (sk->sk_family == PF_INET) {
2361                         inet = inet_sk(sk);
2362                         len = sprintf(buf, "%u.%u.%u.%u\n",
2363                                       NIPQUAD(inet->daddr));
2364                 } else {
2365                         np = inet6_sk(sk);
2366                         len = sprintf(buf,
2367                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2368                                 NIP6(np->daddr));
2369                 }
2370                 mutex_unlock(&conn->xmitmutex);
2371                 break;
2372         default:
2373                 return -EINVAL;
2374         }
2375
2376         return len;
2377 }
2378
2379 static void
2380 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2381 {
2382         struct iscsi_conn *conn = cls_conn->dd_data;
2383         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2384
2385         stats->txdata_octets = conn->txdata_octets;
2386         stats->rxdata_octets = conn->rxdata_octets;
2387         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2388         stats->dataout_pdus = conn->dataout_pdus_cnt;
2389         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2390         stats->datain_pdus = conn->datain_pdus_cnt;
2391         stats->r2t_pdus = conn->r2t_pdus_cnt;
2392         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2393         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2394         stats->custom_length = 3;
2395         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2396         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2397         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2398         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2399         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2400         stats->custom[2].value = conn->eh_abort_cnt;
2401 }
2402
2403 static struct iscsi_cls_session *
2404 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2405                          struct scsi_transport_template *scsit,
2406                          uint32_t initial_cmdsn, uint32_t *hostno)
2407 {
2408         struct iscsi_cls_session *cls_session;
2409         struct iscsi_session *session;
2410         uint32_t hn;
2411         int cmd_i;
2412
2413         cls_session = iscsi_session_setup(iscsit, scsit,
2414                                          sizeof(struct iscsi_tcp_cmd_task),
2415                                          sizeof(struct iscsi_tcp_mgmt_task),
2416                                          initial_cmdsn, &hn);
2417         if (!cls_session)
2418                 return NULL;
2419         *hostno = hn;
2420
2421         session = class_to_transport_session(cls_session);
2422         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2423                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2424                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2425
2426                 ctask->hdr = &tcp_ctask->hdr;
2427         }
2428
2429         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2430                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2431                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2432
2433                 mtask->hdr = &tcp_mtask->hdr;
2434         }
2435
2436         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2437                 goto r2tpool_alloc_fail;
2438
2439         return cls_session;
2440
2441 r2tpool_alloc_fail:
2442         iscsi_session_teardown(cls_session);
2443         return NULL;
2444 }
2445
2446 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2447 {
2448         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2449         iscsi_session_teardown(cls_session);
2450 }
2451
2452 static struct scsi_host_template iscsi_sht = {
2453         .name                   = "iSCSI Initiator over TCP/IP, v"
2454                                   ISCSI_TCP_VERSION,
2455         .queuecommand           = iscsi_queuecommand,
2456         .change_queue_depth     = iscsi_change_queue_depth,
2457         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2458         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2459         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2460         .eh_abort_handler       = iscsi_eh_abort,
2461         .eh_host_reset_handler  = iscsi_eh_host_reset,
2462         .use_clustering         = DISABLE_CLUSTERING,
2463         .proc_name              = "iscsi_tcp",
2464         .this_id                = -1,
2465 };
2466
2467 static struct iscsi_transport iscsi_tcp_transport = {
2468         .owner                  = THIS_MODULE,
2469         .name                   = "tcp",
2470         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2471                                   | CAP_DATADGST,
2472         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2473                                   ISCSI_MAX_XMIT_DLENGTH |
2474                                   ISCSI_HDRDGST_EN |
2475                                   ISCSI_DATADGST_EN |
2476                                   ISCSI_INITIAL_R2T_EN |
2477                                   ISCSI_MAX_R2T |
2478                                   ISCSI_IMM_DATA_EN |
2479                                   ISCSI_FIRST_BURST |
2480                                   ISCSI_MAX_BURST |
2481                                   ISCSI_PDU_INORDER_EN |
2482                                   ISCSI_DATASEQ_INORDER_EN |
2483                                   ISCSI_ERL |
2484                                   ISCSI_CONN_PORT |
2485                                   ISCSI_CONN_ADDRESS |
2486                                   ISCSI_EXP_STATSN,
2487         .host_template          = &iscsi_sht,
2488         .conndata_size          = sizeof(struct iscsi_conn),
2489         .max_conn               = 1,
2490         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2491         /* session management */
2492         .create_session         = iscsi_tcp_session_create,
2493         .destroy_session        = iscsi_tcp_session_destroy,
2494         /* connection management */
2495         .create_conn            = iscsi_tcp_conn_create,
2496         .bind_conn              = iscsi_tcp_conn_bind,
2497         .destroy_conn           = iscsi_tcp_conn_destroy,
2498         .set_param              = iscsi_conn_set_param,
2499         .get_conn_param         = iscsi_conn_get_param,
2500         .get_conn_str_param     = iscsi_conn_get_str_param,
2501         .get_session_param      = iscsi_session_get_param,
2502         .start_conn             = iscsi_conn_start,
2503         .stop_conn              = iscsi_conn_stop,
2504         /* these are called as part of conn recovery */
2505         .suspend_conn_recv      = iscsi_tcp_suspend_conn_rx,
2506         .terminate_conn         = iscsi_tcp_terminate_conn,
2507         /* IO */
2508         .send_pdu               = iscsi_conn_send_pdu,
2509         .get_stats              = iscsi_conn_get_stats,
2510         .init_cmd_task          = iscsi_tcp_cmd_init,
2511         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2512         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2513         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2514         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2515         /* recovery */
2516         .session_recovery_timedout = iscsi_session_recovery_timedout,
2517 };
2518
2519 static int __init
2520 iscsi_tcp_init(void)
2521 {
2522         if (iscsi_max_lun < 1) {
2523                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2524                        iscsi_max_lun);
2525                 return -EINVAL;
2526         }
2527         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2528
2529         if (!iscsi_register_transport(&iscsi_tcp_transport))
2530                 return -ENODEV;
2531
2532         return 0;
2533 }
2534
2535 static void __exit
2536 iscsi_tcp_exit(void)
2537 {
2538         iscsi_unregister_transport(&iscsi_tcp_transport);
2539 }
2540
2541 module_init(iscsi_tcp_init);
2542 module_exit(iscsi_tcp_exit);