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

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/list.h>
  31 #include <linux/inet.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  47               "Alex Aizman <itn780@yahoo.com>");
  48 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  49 MODULE_LICENSE("GPL");
  50 MODULE_VERSION("0:4.445");
  51 /* #define DEBUG_TCP */
  52 #define DEBUG_ASSERT
  53
  54 #ifdef DEBUG_TCP
  55 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
  56 #else
  57 #define debug_tcp(fmt...)
  58 #endif
  59
  60 #ifndef DEBUG_ASSERT
  61 #ifdef BUG_ON
  62 #undef BUG_ON
  63 #endif
  64 #define BUG_ON(expr)
  65 #endif
  66
  67 static unsigned int iscsi_max_lun = 512;
  68 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  69
  70 /* global data */
  71 static kmem_cache_t *taskcache;
  72
  73 static inline void
  74 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  75 {
  76         ibuf->sg.page = virt_to_page(vbuf);
  77         ibuf->sg.offset = offset_in_page(vbuf);
  78         ibuf->sg.length = size;
  79         ibuf->sent = 0;
  80         ibuf->use_sendmsg = 1;
  81 }
  82
  83 static inline void
  84 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  85 {
  86         ibuf->sg.page = sg->page;
  87         ibuf->sg.offset = sg->offset;
  88         ibuf->sg.length = sg->length;
  89         /*
  90          * Fastpath: sg element fits into single page
  91          */
  92         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
  93                 ibuf->use_sendmsg = 0;
  94         else
  95                 ibuf->use_sendmsg = 1;
  96         ibuf->sent = 0;
  97 }
  98
  99 static inline int
 100 iscsi_buf_left(struct iscsi_buf *ibuf)
 101 {
 102         int rc;
 103
 104         rc = ibuf->sg.length - ibuf->sent;
 105         BUG_ON(rc < 0);
 106         return rc;
 107 }
 108
 109 static inline void
 110 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 111                  u8* crc)
 112 {
 113         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 114
 115         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 116         buf->sg.length += sizeof(uint32_t);
 117 }
 118
 119 static inline int
 120 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 121 {
 122         struct sk_buff *skb = tcp_conn->in.skb;
 123
 124         tcp_conn->in.zero_copy_hdr = 0;
 125
 126         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 127             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 128                 /*
 129                  * Zero-copy PDU Header: using connection context
 130                  * to store header pointer.
 131                  */
 132                 if (skb_shinfo(skb)->frag_list == NULL &&
 133                     !skb_shinfo(skb)->nr_frags) {
 134                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 135                                 ((char*)skb->data + tcp_conn->in.offset);
 136                         tcp_conn->in.zero_copy_hdr = 1;
 137                 } else {
 138                         /* ignoring return code since we checked
 139                          * in.copy before */
 140                         skb_copy_bits(skb, tcp_conn->in.offset,
 141                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 142                         tcp_conn->in.hdr = &tcp_conn->hdr;
 143                 }
 144                 tcp_conn->in.offset += tcp_conn->hdr_size;
 145                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 146         } else {
 147                 int hdr_remains;
 148                 int copylen;
 149
 150                 /*
 151                  * PDU header scattered across SKB's,
 152                  * copying it... This'll happen quite rarely.
 153                  */
 154
 155                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 156                         tcp_conn->in.hdr_offset = 0;
 157
 158                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 159                 BUG_ON(hdr_remains <= 0);
 160
 161                 copylen = min(tcp_conn->in.copy, hdr_remains);
 162                 skb_copy_bits(skb, tcp_conn->in.offset,
 163                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 164                         copylen);
 165
 166                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 167                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 168                        tcp_conn->in.offset, tcp_conn->in.copy);
 169
 170                 tcp_conn->in.offset += copylen;
 171                 tcp_conn->in.copy -= copylen;
 172                 if (copylen < hdr_remains)  {
 173                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 174                         tcp_conn->in.hdr_offset += copylen;
 175                         return -EAGAIN;
 176                 }
 177                 tcp_conn->in.hdr = &tcp_conn->hdr;
 178                 tcp_conn->discontiguous_hdr_cnt++;
 179                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 180         }
 181
 182         return 0;
 183 }
 184
 185 /*
 186  * must be called with session lock
 187  */
 188 static void
 189 __iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 190 {
 191         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 192         struct scsi_cmnd *sc;
 193
 194         sc = ctask->sc;
 195         if (unlikely(!sc))
 196                 return;
 197
 198         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 199                 struct iscsi_data_task *dtask, *n;
 200
 201                 /* WRITE: cleanup Data-Out's if any */
 202                 list_for_each_entry_safe(dtask, n, &tcp_ctask->dataqueue,
 203                                          item) {
 204                         list_del(&dtask->item);
 205                         mempool_free(dtask, tcp_ctask->datapool);
 206                 }
 207         }
 208         tcp_ctask->xmstate = XMSTATE_IDLE;
 209         tcp_ctask->r2t = NULL;
 210 }
 211
 212 /**
 213  * iscsi_data_rsp - SCSI Data-In Response processing
 214  * @conn: iscsi connection
 215  * @ctask: scsi command task
 216  **/
 217 static int
 218 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 219 {
 220         int rc;
 221         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 222         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 223         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 224         struct iscsi_session *session = conn->session;
 225         int datasn = be32_to_cpu(rhdr->datasn);
 226
 227         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 228         if (rc)
 229                 return rc;
 230         /*
 231          * setup Data-In byte counter (gets decremented..)
 232          */
 233         ctask->data_count = tcp_conn->in.datalen;
 234
 235         if (tcp_conn->in.datalen == 0)
 236                 return 0;
 237
 238         if (ctask->datasn != datasn)
 239                 return ISCSI_ERR_DATASN;
 240
 241         ctask->datasn++;
 242
 243         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 244         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 245                 return ISCSI_ERR_DATA_OFFSET;
 246
 247         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 248                 struct scsi_cmnd *sc = ctask->sc;
 249
 250                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 251                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 252                         int res_count = be32_to_cpu(rhdr->residual_count);
 253
 254                         if (res_count > 0 &&
 255                             res_count <= sc->request_bufflen) {
 256                                 sc->resid = res_count;
 257                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 258                         } else
 259                                 sc->result = (DID_BAD_TARGET << 16) |
 260                                         rhdr->cmd_status;
 261                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 262                         sc->resid = be32_to_cpu(rhdr->residual_count);
 263                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 264                 } else
 265                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 266         }
 267
 268         conn->datain_pdus_cnt++;
 269         return 0;
 270 }
 271
 272 /**
 273  * iscsi_solicit_data_init - initialize first Data-Out
 274  * @conn: iscsi connection
 275  * @ctask: scsi command task
 276  * @r2t: R2T info
 277  *
 278  * Notes:
 279  *      Initialize first Data-Out within this R2T sequence and finds
 280  *      proper data_offset within this SCSI command.
 281  *
 282  *      This function is called with connection lock taken.
 283  **/
 284 static void
 285 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 286                         struct iscsi_r2t_info *r2t)
 287 {
 288         struct iscsi_data *hdr;
 289         struct iscsi_data_task *dtask;
 290         struct scsi_cmnd *sc = ctask->sc;
 291         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 292
 293         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
 294         BUG_ON(!dtask);
 295         INIT_LIST_HEAD(&dtask->item);
 296         hdr = &dtask->hdr;
 297         memset(hdr, 0, sizeof(struct iscsi_data));
 298         hdr->ttt = r2t->ttt;
 299         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 300         r2t->solicit_datasn++;
 301         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 302         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 303         hdr->itt = ctask->hdr->itt;
 304         hdr->exp_statsn = r2t->exp_statsn;
 305         hdr->offset = cpu_to_be32(r2t->data_offset);
 306         if (r2t->data_length > conn->max_xmit_dlength) {
 307                 hton24(hdr->dlength, conn->max_xmit_dlength);
 308                 r2t->data_count = conn->max_xmit_dlength;
 309                 hdr->flags = 0;
 310         } else {
 311                 hton24(hdr->dlength, r2t->data_length);
 312                 r2t->data_count = r2t->data_length;
 313                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 314         }
 315         conn->dataout_pdus_cnt++;
 316
 317         r2t->sent = 0;
 318
 319         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
 320                            sizeof(struct iscsi_hdr));
 321
 322         r2t->dtask = dtask;
 323
 324         if (sc->use_sg) {
 325                 int i, sg_count = 0;
 326                 struct scatterlist *sg = sc->request_buffer;
 327
 328                 r2t->sg = NULL;
 329                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 330                         /* FIXME: prefetch ? */
 331                         if (sg_count + sg->length > r2t->data_offset) {
 332                                 int page_offset;
 333
 334                                 /* sg page found! */
 335
 336                                 /* offset within this page */
 337                                 page_offset = r2t->data_offset - sg_count;
 338
 339                                 /* fill in this buffer */
 340                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 341                                 r2t->sendbuf.sg.offset += page_offset;
 342                                 r2t->sendbuf.sg.length -= page_offset;
 343
 344                                 /* xmit logic will continue with next one */
 345                                 r2t->sg = sg + 1;
 346                                 break;
 347                         }
 348                         sg_count += sg->length;
 349                 }
 350                 BUG_ON(r2t->sg == NULL);
 351         } else
 352                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 353                             (char*)sc->request_buffer + r2t->data_offset,
 354                             r2t->data_count);
 355
 356         list_add(&dtask->item, &tcp_ctask->dataqueue);
 357 }
 358
 359 /**
 360  * iscsi_r2t_rsp - iSCSI R2T Response processing
 361  * @conn: iscsi connection
 362  * @ctask: scsi command task
 363  **/
 364 static int
 365 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 366 {
 367         struct iscsi_r2t_info *r2t;
 368         struct iscsi_session *session = conn->session;
 369         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 370         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 371         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 372         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 373         int rc;
 374
 375         if (tcp_conn->in.datalen)
 376                 return ISCSI_ERR_DATALEN;
 377
 378         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 379                 return ISCSI_ERR_R2TSN;
 380
 381         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 382         if (rc)
 383                 return rc;
 384
 385         /* FIXME: use R2TSN to detect missing R2T */
 386
 387         /* fill-in new R2T associated with the task */
 388         spin_lock(&session->lock);
 389         if (!ctask->sc || ctask->mtask ||
 390              session->state != ISCSI_STATE_LOGGED_IN) {
 391                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 392                        "recovery...\n", ctask->itt);
 393                 spin_unlock(&session->lock);
 394                 return 0;
 395         }
 396         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 397         BUG_ON(!rc);
 398
 399         r2t->exp_statsn = rhdr->statsn;
 400         r2t->data_length = be32_to_cpu(rhdr->data_length);
 401         if (r2t->data_length == 0 ||
 402             r2t->data_length > session->max_burst) {
 403                 spin_unlock(&session->lock);
 404                 return ISCSI_ERR_DATALEN;
 405         }
 406
 407         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 408         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 409                 spin_unlock(&session->lock);
 410                 return ISCSI_ERR_DATALEN;
 411         }
 412
 413         r2t->ttt = rhdr->ttt; /* no flip */
 414         r2t->solicit_datasn = 0;
 415
 416         iscsi_solicit_data_init(conn, ctask, r2t);
 417
 418         tcp_ctask->exp_r2tsn = r2tsn + 1;
 419         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 420         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 421         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 422
 423         scsi_queue_work(session->host, &conn->xmitwork);
 424         conn->r2t_pdus_cnt++;
 425         spin_unlock(&session->lock);
 426
 427         return 0;
 428 }
 429
 430 static int
 431 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 432 {
 433         int rc = 0, opcode, ahslen;
 434         struct iscsi_hdr *hdr;
 435         struct iscsi_session *session = conn->session;
 436         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 437         uint32_t cdgst, rdgst = 0, itt;
 438
 439         hdr = tcp_conn->in.hdr;
 440
 441         /* verify PDU length */
 442         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 443         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 444                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 445                        tcp_conn->in.datalen, conn->max_recv_dlength);
 446                 return ISCSI_ERR_DATALEN;
 447         }
 448         tcp_conn->data_copied = 0;
 449
 450         /* read AHS */
 451         ahslen = hdr->hlength << 2;
 452         tcp_conn->in.offset += ahslen;
 453         tcp_conn->in.copy -= ahslen;
 454         if (tcp_conn->in.copy < 0) {
 455                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 456                        "%d bytes\n", ahslen);
 457                 return ISCSI_ERR_AHSLEN;
 458         }
 459
 460         /* calculate read padding */
 461         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 462         if (tcp_conn->in.padding) {
 463                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 464                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 465         }
 466
 467         if (conn->hdrdgst_en) {
 468                 struct scatterlist sg;
 469
 470                 sg_init_one(&sg, (u8 *)hdr,
 471                             sizeof(struct iscsi_hdr) + ahslen);
 472                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 473                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 474                                      ahslen);
 475                 if (cdgst != rdgst) {
 476                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 477                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 478                         return ISCSI_ERR_HDR_DGST;
 479                 }
 480         }
 481
 482         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 483         /* verify itt (itt encoding: age+cid+itt) */
 484         rc = iscsi_verify_itt(conn, hdr, &itt);
 485         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 486                 tcp_conn->in.datalen = 0; /* force drop */
 487                 return 0;
 488         } else if (rc)
 489                 return rc;
 490
 491         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 492                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 493                   ahslen, tcp_conn->in.datalen);
 494
 495         switch(opcode) {
 496         case ISCSI_OP_SCSI_DATA_IN:
 497                 tcp_conn->in.ctask = session->cmds[itt];
 498                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 499                 /* fall through */
 500         case ISCSI_OP_SCSI_CMD_RSP:
 501                 tcp_conn->in.ctask = session->cmds[itt];
 502                 if (tcp_conn->in.datalen)
 503                         goto copy_hdr;
 504
 505                 spin_lock(&session->lock);
 506                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 507                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 508                 spin_unlock(&session->lock);
 509                 break;
 510         case ISCSI_OP_R2T:
 511                 tcp_conn->in.ctask = session->cmds[itt];
 512                 if (ahslen)
 513                         rc = ISCSI_ERR_AHSLEN;
 514                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 515                                                                 DMA_TO_DEVICE)
 516                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 517                 else
 518                         rc = ISCSI_ERR_PROTO;
 519                 break;
 520         case ISCSI_OP_LOGIN_RSP:
 521         case ISCSI_OP_TEXT_RSP:
 522         case ISCSI_OP_LOGOUT_RSP:
 523         case ISCSI_OP_NOOP_IN:
 524         case ISCSI_OP_REJECT:
 525         case ISCSI_OP_ASYNC_EVENT:
 526                 if (tcp_conn->in.datalen)
 527                         goto copy_hdr;
 528         /* fall through */
 529         case ISCSI_OP_SCSI_TMFUNC_RSP:
 530                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 531                 break;
 532         default:
 533                 rc = ISCSI_ERR_BAD_OPCODE;
 534                 break;
 535         }
 536
 537         return rc;
 538
 539 copy_hdr:
 540         /*
 541          * if we did zero copy for the header but we will need multiple
 542          * skbs to complete the command then we have to copy the header
 543          * for later use
 544          */
 545         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
 546            (tcp_conn->in.datalen + tcp_conn->in.padding +
 547             (conn->datadgst_en ? 4 : 0))) {
 548                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 549                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 550                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 551                        sizeof(struct iscsi_hdr));
 552                 tcp_conn->in.hdr = &tcp_conn->hdr;
 553                 tcp_conn->in.zero_copy_hdr = 0;
 554         }
 555         return 0;
 556 }
 557
 558 /**
 559  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 560  * @conn: iscsi tcp connection
 561  * @ctask: scsi command task
 562  * @buf: buffer to copy to
 563  * @buf_size: size of buffer
 564  * @offset: offset within the buffer
 565  *
 566  * Notes:
 567  *      The function calls skb_copy_bits() and updates per-connection and
 568  *      per-cmd byte counters.
 569  *
 570  *      Read counters (in bytes):
 571  *
 572  *      conn->in.offset         offset within in progress SKB
 573  *      conn->in.copy           left to copy from in progress SKB
 574  *                              including padding
 575  *      conn->in.copied         copied already from in progress SKB
 576  *      conn->data_copied       copied already from in progress buffer
 577  *      ctask->sent             total bytes sent up to the MidLayer
 578  *      ctask->data_count       left to copy from in progress Data-In
 579  *      buf_left                left to copy from in progress buffer
 580  **/
 581 static inline int
 582 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 583                 void *buf, int buf_size, int offset)
 584 {
 585         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 586         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 587         int size = min(tcp_conn->in.copy, buf_left);
 588         int rc;
 589
 590         size = min(size, ctask->data_count);
 591
 592         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 593                size, tcp_conn->in.offset, tcp_conn->in.copied);
 594
 595         BUG_ON(size <= 0);
 596         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 597
 598         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 599                            (char*)buf + (offset + tcp_conn->data_copied), size);
 600         /* must fit into skb->len */
 601         BUG_ON(rc);
 602
 603         tcp_conn->in.offset += size;
 604         tcp_conn->in.copy -= size;
 605         tcp_conn->in.copied += size;
 606         tcp_conn->data_copied += size;
 607         tcp_ctask->sent += size;
 608         ctask->data_count -= size;
 609
 610         BUG_ON(tcp_conn->in.copy < 0);
 611         BUG_ON(ctask->data_count < 0);
 612
 613         if (buf_size != (tcp_conn->data_copied + offset)) {
 614                 if (!ctask->data_count) {
 615                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 616                         /* done with this PDU */
 617                         return buf_size - tcp_conn->data_copied;
 618                 }
 619                 return -EAGAIN;
 620         }
 621
 622         /* done with this buffer or with both - PDU and buffer */
 623         tcp_conn->data_copied = 0;
 624         return 0;
 625 }
 626
 627 /**
 628  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 629  * @conn: iscsi tcp connection
 630  *
 631  * Notes:
 632  *      The function calls skb_copy_bits() and updates per-connection
 633  *      byte counters.
 634  **/
 635 static inline int
 636 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 637 {
 638         void *buf = tcp_conn->data;
 639         int buf_size = tcp_conn->in.datalen;
 640         int buf_left = buf_size - tcp_conn->data_copied;
 641         int size = min(tcp_conn->in.copy, buf_left);
 642         int rc;
 643
 644         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 645                size, tcp_conn->in.offset, tcp_conn->data_copied);
 646         BUG_ON(size <= 0);
 647
 648         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 649                            (char*)buf + tcp_conn->data_copied, size);
 650         BUG_ON(rc);
 651
 652         tcp_conn->in.offset += size;
 653         tcp_conn->in.copy -= size;
 654         tcp_conn->in.copied += size;
 655         tcp_conn->data_copied += size;
 656
 657         if (buf_size != tcp_conn->data_copied)
 658                 return -EAGAIN;
 659
 660         return 0;
 661 }
 662
 663 static inline void
 664 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 665                          struct scatterlist *sg, int offset, int length)
 666 {
 667         struct scatterlist temp;
 668
 669         memcpy(&temp, sg, sizeof(struct scatterlist));
 670         temp.offset = offset;
 671         temp.length = length;
 672         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 673 }
 674
 675 static void
 676 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 677 {
 678         struct scatterlist tmp;
 679
 680         sg_init_one(&tmp, buf, len);
 681         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 682 }
 683
 684 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 685 {
 686         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 687         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 688         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 689         struct scsi_cmnd *sc = ctask->sc;
 690         struct scatterlist *sg;
 691         int i, offset, rc = 0;
 692
 693         BUG_ON((void*)ctask != sc->SCp.ptr);
 694
 695         /*
 696          * copying Data-In into the Scsi_Cmnd
 697          */
 698         if (!sc->use_sg) {
 699                 i = ctask->data_count;
 700                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 701                                       sc->request_bufflen,
 702                                       tcp_ctask->data_offset);
 703                 if (rc == -EAGAIN)
 704                         return rc;
 705                 if (conn->datadgst_en)
 706                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 707                                                  i);
 708                 rc = 0;
 709                 goto done;
 710         }
 711
 712         offset = tcp_ctask->data_offset;
 713         sg = sc->request_buffer;
 714
 715         if (tcp_ctask->data_offset)
 716                 for (i = 0; i < tcp_ctask->sg_count; i++)
 717                         offset -= sg[i].length;
 718         /* we've passed through partial sg*/
 719         if (offset < 0)
 720                 offset = 0;
 721
 722         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 723                 char *dest;
 724
 725                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 726                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 727                                       sg[i].length, offset);
 728                 kunmap_atomic(dest, KM_SOFTIRQ0);
 729                 if (rc == -EAGAIN)
 730                         /* continue with the next SKB/PDU */
 731                         return rc;
 732                 if (!rc) {
 733                         if (conn->datadgst_en) {
 734                                 if (!offset)
 735                                         crypto_digest_update(
 736                                                         tcp_conn->data_rx_tfm,
 737                                                         &sg[i], 1);
 738                                 else
 739                                         partial_sg_digest_update(tcp_conn,
 740                                                         &sg[i],
 741                                                         sg[i].offset + offset,
 742                                                         sg[i].length - offset);
 743                         }
 744                         offset = 0;
 745                         tcp_ctask->sg_count++;
 746                 }
 747
 748                 if (!ctask->data_count) {
 749                         if (rc && conn->datadgst_en)
 750                                 /*
 751                                  * data-in is complete, but buffer not...
 752                                  */
 753                                 partial_sg_digest_update(tcp_conn, &sg[i],
 754                                                 sg[i].offset, sg[i].length-rc);
 755                         rc = 0;
 756                         break;
 757                 }
 758
 759                 if (!tcp_conn->in.copy)
 760                         return -EAGAIN;
 761         }
 762         BUG_ON(ctask->data_count);
 763
 764 done:
 765         /* check for non-exceptional status */
 766         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 767                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 768                            (long)sc, sc->result, ctask->itt);
 769                 spin_lock(&conn->session->lock);
 770                 __iscsi_ctask_cleanup(conn, ctask);
 771                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 772                 spin_unlock(&conn->session->lock);
 773         }
 774
 775         return rc;
 776 }
 777
 778 static int
 779 iscsi_data_recv(struct iscsi_conn *conn)
 780 {
 781         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 782         int rc = 0, opcode;
 783
 784         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 785         switch (opcode) {
 786         case ISCSI_OP_SCSI_DATA_IN:
 787                 rc = iscsi_scsi_data_in(conn);
 788                 break;
 789         case ISCSI_OP_SCSI_CMD_RSP:
 790                 spin_lock(&conn->session->lock);
 791                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 792                 spin_unlock(&conn->session->lock);
 793         case ISCSI_OP_TEXT_RSP:
 794         case ISCSI_OP_LOGIN_RSP:
 795         case ISCSI_OP_NOOP_IN:
 796         case ISCSI_OP_ASYNC_EVENT:
 797         case ISCSI_OP_REJECT:
 798                 /*
 799                  * Collect data segment to the connection's data
 800                  * placeholder
 801                  */
 802                 if (iscsi_tcp_copy(tcp_conn)) {
 803                         rc = -EAGAIN;
 804                         goto exit;
 805                 }
 806
 807                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 808                                         tcp_conn->in.datalen);
 809                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 810                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 811                                                 tcp_conn->in.datalen);
 812                 break;
 813         default:
 814                 BUG_ON(1);
 815         }
 816 exit:
 817         return rc;
 818 }
 819
 820 /**
 821  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 822  * @rd_desc: read descriptor
 823  * @skb: socket buffer
 824  * @offset: offset in skb
 825  * @len: skb->len - offset
 826  **/
 827 static int
 828 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 829                 unsigned int offset, size_t len)
 830 {
 831         int rc;
 832         struct iscsi_conn *conn = rd_desc->arg.data;
 833         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 834         int processed;
 835         char pad[ISCSI_PAD_LEN];
 836         struct scatterlist sg;
 837
 838         /*
 839          * Save current SKB and its offset in the corresponding
 840          * connection context.
 841          */
 842         tcp_conn->in.copy = skb->len - offset;
 843         tcp_conn->in.offset = offset;
 844         tcp_conn->in.skb = skb;
 845         tcp_conn->in.len = tcp_conn->in.copy;
 846         BUG_ON(tcp_conn->in.copy <= 0);
 847         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 848
 849 more:
 850         tcp_conn->in.copied = 0;
 851         rc = 0;
 852
 853         if (unlikely(conn->suspend_rx)) {
 854                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 855                 return 0;
 856         }
 857
 858         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 859             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 860                 rc = iscsi_hdr_extract(tcp_conn);
 861                 if (rc) {
 862                        if (rc == -EAGAIN)
 863                                 goto nomore;
 864                        else {
 865                                 iscsi_conn_failure(conn, rc);
 866                                 return 0;
 867                        }
 868                 }
 869
 870                 /*
 871                  * Verify and process incoming PDU header.
 872                  */
 873                 rc = iscsi_tcp_hdr_recv(conn);
 874                 if (!rc && tcp_conn->in.datalen) {
 875                         if (conn->datadgst_en) {
 876                                 BUG_ON(!tcp_conn->data_rx_tfm);
 877                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 878                         }
 879                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 880                 } else if (rc) {
 881                         iscsi_conn_failure(conn, rc);
 882                         return 0;
 883                 }
 884         }
 885
 886         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 887                 uint32_t recv_digest;
 888
 889                 debug_tcp("extra data_recv offset %d copy %d\n",
 890                           tcp_conn->in.offset, tcp_conn->in.copy);
 891                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 892                                 &recv_digest, 4);
 893                 tcp_conn->in.offset += 4;
 894                 tcp_conn->in.copy -= 4;
 895                 if (recv_digest != tcp_conn->in.datadgst) {
 896                         debug_tcp("iscsi_tcp: data digest error!"
 897                                   "0x%x != 0x%x\n", recv_digest,
 898                                   tcp_conn->in.datadgst);
 899                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 900                         return 0;
 901                 } else {
 902                         debug_tcp("iscsi_tcp: data digest match!"
 903                                   "0x%x == 0x%x\n", recv_digest,
 904                                   tcp_conn->in.datadgst);
 905                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 906                 }
 907         }
 908
 909         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 910            tcp_conn->in.copy) {
 911
 912                 debug_tcp("data_recv offset %d copy %d\n",
 913                        tcp_conn->in.offset, tcp_conn->in.copy);
 914
 915                 rc = iscsi_data_recv(conn);
 916                 if (rc) {
 917                         if (rc == -EAGAIN)
 918                                 goto again;
 919                         iscsi_conn_failure(conn, rc);
 920                         return 0;
 921                 }
 922                 tcp_conn->in.copy -= tcp_conn->in.padding;
 923                 tcp_conn->in.offset += tcp_conn->in.padding;
 924                 if (conn->datadgst_en) {
 925                         if (tcp_conn->in.padding) {
 926                                 debug_tcp("padding -> %d\n",
 927                                           tcp_conn->in.padding);
 928                                 memset(pad, 0, tcp_conn->in.padding);
 929                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 930                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 931                                                      &sg, 1);
 932                         }
 933                         crypto_digest_final(tcp_conn->data_rx_tfm,
 934                                             (u8 *) & tcp_conn->in.datadgst);
 935                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 936                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 937                 } else
 938                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 939         }
 940
 941         debug_tcp("f, processed %d from out of %d padding %d\n",
 942                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 943         BUG_ON(tcp_conn->in.offset - offset > len);
 944
 945         if (tcp_conn->in.offset - offset != len) {
 946                 debug_tcp("continue to process %d bytes\n",
 947                        (int)len - (tcp_conn->in.offset - offset));
 948                 goto more;
 949         }
 950
 951 nomore:
 952         processed = tcp_conn->in.offset - offset;
 953         BUG_ON(processed == 0);
 954         return processed;
 955
 956 again:
 957         processed = tcp_conn->in.offset - offset;
 958         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 959                   processed, (int)len, (int)rd_desc->count);
 960         BUG_ON(processed == 0);
 961         BUG_ON(processed > len);
 962
 963         conn->rxdata_octets += processed;
 964         return processed;
 965 }
 966
 967 static void
 968 iscsi_tcp_data_ready(struct sock *sk, int flag)
 969 {
 970         struct iscsi_conn *conn = sk->sk_user_data;
 971         read_descriptor_t rd_desc;
 972
 973         read_lock(&sk->sk_callback_lock);
 974
 975         /*
 976          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 977          * We set count to 1 because we want the network layer to
 978          * hand us all the skbs that are available. iscsi_tcp_data_recv
 979          * handled pdus that cross buffers or pdus that still need data.
 980          */
 981         rd_desc.arg.data = conn;
 982         rd_desc.count = 1;
 983         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 984
 985         read_unlock(&sk->sk_callback_lock);
 986 }
 987
 988 static void
 989 iscsi_tcp_state_change(struct sock *sk)
 990 {
 991         struct iscsi_tcp_conn *tcp_conn;
 992         struct iscsi_conn *conn;
 993         struct iscsi_session *session;
 994         void (*old_state_change)(struct sock *);
 995
 996         read_lock(&sk->sk_callback_lock);
 997
 998         conn = (struct iscsi_conn*)sk->sk_user_data;
 999         session = conn->session;
1000
1001         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1002              sk->sk_state == TCP_CLOSE) &&
1003             !atomic_read(&sk->sk_rmem_alloc)) {
1004                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1005                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1006         }
1007
1008         tcp_conn = conn->dd_data;
1009         old_state_change = tcp_conn->old_state_change;
1010
1011         read_unlock(&sk->sk_callback_lock);
1012
1013         old_state_change(sk);
1014 }
1015
1016 /**
1017  * iscsi_write_space - Called when more output buffer space is available
1018  * @sk: socket space is available for
1019  **/
1020 static void
1021 iscsi_write_space(struct sock *sk)
1022 {
1023         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1024         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1025
1026         tcp_conn->old_write_space(sk);
1027         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1028         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1029         scsi_queue_work(conn->session->host, &conn->xmitwork);
1030 }
1031
1032 static void
1033 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1034 {
1035         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1036         struct sock *sk = tcp_conn->sock->sk;
1037
1038         /* assign new callbacks */
1039         write_lock_bh(&sk->sk_callback_lock);
1040         sk->sk_user_data = conn;
1041         tcp_conn->old_data_ready = sk->sk_data_ready;
1042         tcp_conn->old_state_change = sk->sk_state_change;
1043         tcp_conn->old_write_space = sk->sk_write_space;
1044         sk->sk_data_ready = iscsi_tcp_data_ready;
1045         sk->sk_state_change = iscsi_tcp_state_change;
1046         sk->sk_write_space = iscsi_write_space;
1047         write_unlock_bh(&sk->sk_callback_lock);
1048 }
1049
1050 static void
1051 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1052 {
1053         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1054         struct sock *sk = tcp_conn->sock->sk;
1055
1056         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1057         write_lock_bh(&sk->sk_callback_lock);
1058         sk->sk_user_data    = NULL;
1059         sk->sk_data_ready   = tcp_conn->old_data_ready;
1060         sk->sk_state_change = tcp_conn->old_state_change;
1061         sk->sk_write_space  = tcp_conn->old_write_space;
1062         sk->sk_no_check  = 0;
1063         write_unlock_bh(&sk->sk_callback_lock);
1064 }
1065
1066 /**
1067  * iscsi_send - generic send routine
1068  * @sk: kernel's socket
1069  * @buf: buffer to write from
1070  * @size: actual size to write
1071  * @flags: socket's flags
1072  */
1073 static inline int
1074 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1075 {
1076         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1077         struct socket *sk = tcp_conn->sock;
1078         int offset = buf->sg.offset + buf->sent;
1079
1080         /*
1081          * if we got use_sg=0 or are sending something we kmallocd
1082          * then we did not have to do kmap (kmap returns page_address)
1083          *
1084          * if we got use_sg > 0, but had to drop down, we do not
1085          * set clustering so this should only happen for that
1086          * slab case.
1087          */
1088         if (buf->use_sendmsg)
1089                 return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1090         else
1091                 return tcp_conn->sendpage(sk, buf->sg.page, offset, size,
1092                                           flags);
1093 }
1094
1095 /**
1096  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1097  * @conn: iscsi connection
1098  * @buf: buffer to write from
1099  * @datalen: lenght of data to be sent after the header
1100  *
1101  * Notes:
1102  *      (Tx, Fast Path)
1103  **/
1104 static inline int
1105 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1106 {
1107         struct iscsi_tcp_conn *tcp_conn;
1108         int flags = 0; /* MSG_DONTWAIT; */
1109         int res, size;
1110
1111         size = buf->sg.length - buf->sent;
1112         BUG_ON(buf->sent + size > buf->sg.length);
1113         if (buf->sent + size != buf->sg.length || datalen)
1114                 flags |= MSG_MORE;
1115
1116         res = iscsi_send(conn, buf, size, flags);
1117         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1118         if (res >= 0) {
1119                 conn->txdata_octets += res;
1120                 buf->sent += res;
1121                 if (size != res)
1122                         return -EAGAIN;
1123                 return 0;
1124         } else if (res == -EAGAIN) {
1125                 tcp_conn = conn->dd_data;
1126                 tcp_conn->sendpage_failures_cnt++;
1127                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1128         } else if (res == -EPIPE)
1129                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1130
1131         return res;
1132 }
1133
1134 /**
1135  * iscsi_sendpage - send one page of iSCSI Data-Out.
1136  * @conn: iscsi connection
1137  * @buf: buffer to write from
1138  * @count: remaining data
1139  * @sent: number of bytes sent
1140  *
1141  * Notes:
1142  *      (Tx, Fast Path)
1143  **/
1144 static inline int
1145 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1146                int *count, int *sent)
1147 {
1148         struct iscsi_tcp_conn *tcp_conn;
1149         int flags = 0; /* MSG_DONTWAIT; */
1150         int res, size;
1151
1152         size = buf->sg.length - buf->sent;
1153         BUG_ON(buf->sent + size > buf->sg.length);
1154         if (size > *count)
1155                 size = *count;
1156         if (buf->sent + size != buf->sg.length || *count != size)
1157                 flags |= MSG_MORE;
1158
1159         res = iscsi_send(conn, buf, size, flags);
1160         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1161                   size, buf->sent, *count, *sent, res);
1162         if (res >= 0) {
1163                 conn->txdata_octets += res;
1164                 buf->sent += res;
1165                 *count -= res;
1166                 *sent += res;
1167                 if (size != res)
1168                         return -EAGAIN;
1169                 return 0;
1170         } else if (res == -EAGAIN) {
1171                 tcp_conn = conn->dd_data;
1172                 tcp_conn->sendpage_failures_cnt++;
1173                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1174         } else if (res == -EPIPE)
1175                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1176
1177         return res;
1178 }
1179
1180 static inline void
1181 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1182                       struct iscsi_cmd_task *ctask)
1183 {
1184         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1185
1186         BUG_ON(!tcp_conn->data_tx_tfm);
1187         crypto_digest_init(tcp_conn->data_tx_tfm);
1188         tcp_ctask->digest_count = 4;
1189 }
1190
1191 static int
1192 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1193                         struct iscsi_buf *buf, uint32_t *digest, int final)
1194 {
1195         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1196         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1197         int rc = 0;
1198         int sent = 0;
1199
1200         if (final)
1201                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1202
1203         iscsi_buf_init_iov(buf, (char*)digest, 4);
1204         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1205         if (rc) {
1206                 tcp_ctask->datadigest = *digest;
1207                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1208         } else
1209                 tcp_ctask->digest_count = 4;
1210         return rc;
1211 }
1212
1213 /**
1214  * iscsi_solicit_data_cont - initialize next Data-Out
1215  * @conn: iscsi connection
1216  * @ctask: scsi command task
1217  * @r2t: R2T info
1218  * @left: bytes left to transfer
1219  *
1220  * Notes:
1221  *      Initialize next Data-Out within this R2T sequence and continue
1222  *      to process next Scatter-Gather element(if any) of this SCSI command.
1223  *
1224  *      Called under connection lock.
1225  **/
1226 static void
1227 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1228                         struct iscsi_r2t_info *r2t, int left)
1229 {
1230         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1231         struct iscsi_data *hdr;
1232         struct iscsi_data_task *dtask;
1233         struct scsi_cmnd *sc = ctask->sc;
1234         int new_offset;
1235
1236         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
1237         BUG_ON(!dtask);
1238         INIT_LIST_HEAD(&dtask->item);
1239         hdr = &dtask->hdr;
1240         memset(hdr, 0, sizeof(struct iscsi_data));
1241         hdr->ttt = r2t->ttt;
1242         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1243         r2t->solicit_datasn++;
1244         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1245         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1246         hdr->itt = ctask->hdr->itt;
1247         hdr->exp_statsn = r2t->exp_statsn;
1248         new_offset = r2t->data_offset + r2t->sent;
1249         hdr->offset = cpu_to_be32(new_offset);
1250         if (left > conn->max_xmit_dlength) {
1251                 hton24(hdr->dlength, conn->max_xmit_dlength);
1252                 r2t->data_count = conn->max_xmit_dlength;
1253         } else {
1254                 hton24(hdr->dlength, left);
1255                 r2t->data_count = left;
1256                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1257         }
1258         conn->dataout_pdus_cnt++;
1259
1260         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1261                            sizeof(struct iscsi_hdr));
1262
1263         r2t->dtask = dtask;
1264
1265         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1266                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1267                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1268                 r2t->sg += 1;
1269         } else
1270                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1271                             (char*)sc->request_buffer + new_offset,
1272                             r2t->data_count);
1273
1274         list_add(&dtask->item, &tcp_ctask->dataqueue);
1275 }
1276
1277 static void
1278 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1279 {
1280         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1281         struct iscsi_data_task *dtask;
1282
1283         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
1284         BUG_ON(!dtask);
1285         INIT_LIST_HEAD(&dtask->item);
1286
1287         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1288                                       tcp_ctask->r2t_data_count);
1289         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1290                            sizeof(struct iscsi_hdr));
1291
1292         list_add(&dtask->item, &tcp_ctask->dataqueue);
1293         tcp_ctask->dtask = dtask;
1294 }
1295
1296 /**
1297  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1298  * @conn: iscsi connection
1299  * @ctask: scsi command task
1300  * @sc: scsi command
1301  **/
1302 static void
1303 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1304 {
1305         struct scsi_cmnd *sc = ctask->sc;
1306         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1307
1308         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1309
1310         tcp_ctask->sent = 0;
1311         tcp_ctask->sg_count = 0;
1312
1313         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1314                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1315                 tcp_ctask->exp_r2tsn = 0;
1316                 BUG_ON(ctask->total_length == 0);
1317
1318                 if (sc->use_sg) {
1319                         struct scatterlist *sg = sc->request_buffer;
1320
1321                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1322                                           &sg[tcp_ctask->sg_count++]);
1323                         tcp_ctask->sg = sg;
1324                         tcp_ctask->bad_sg = sg + sc->use_sg;
1325                 } else
1326                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1327                                            sc->request_buffer,
1328                                            sc->request_bufflen);
1329
1330                 if (ctask->imm_count)
1331                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1332
1333                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1334                 if (tcp_ctask->pad_count) {
1335                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1336                                                         tcp_ctask->pad_count;
1337                         debug_scsi("write padding %d bytes\n",
1338                                    tcp_ctask->pad_count);
1339                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1340                 }
1341
1342                 if (ctask->unsol_count)
1343                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1344                                                 XMSTATE_UNS_INIT;
1345                 tcp_ctask->r2t_data_count = ctask->total_length -
1346                                     ctask->imm_count -
1347                                     ctask->unsol_count;
1348
1349                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1350                            "r2t_data %d]\n",
1351                            ctask->itt, ctask->total_length, ctask->imm_count,
1352                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1353         } else
1354                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1355
1356         iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1357                             sizeof(struct iscsi_hdr));
1358 }
1359
1360 /**
1361  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1362  * @conn: iscsi connection
1363  * @mtask: task management task
1364  *
1365  * Notes:
1366  *      The function can return -EAGAIN in which case caller must
1367  *      call it again later, or recover. '0' return code means successful
1368  *      xmit.
1369  *
1370  *      Management xmit state machine consists of two states:
1371  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1372  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1373  **/
1374 static int
1375 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1376 {
1377         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1378
1379         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1380                 conn->id, tcp_mtask->xmstate, mtask->itt);
1381
1382         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1383                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1384                 if (mtask->data_count)
1385                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1386                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1387                     conn->stop_stage != STOP_CONN_RECOVER &&
1388                     conn->hdrdgst_en)
1389                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1390                                         (u8*)tcp_mtask->hdrext);
1391                 if (iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1392                                   mtask->data_count)) {
1393                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1394                         if (mtask->data_count)
1395                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1396                         return -EAGAIN;
1397                 }
1398         }
1399
1400         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1401                 BUG_ON(!mtask->data_count);
1402                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1403                 /* FIXME: implement.
1404                  * Virtual buffer could be spreaded across multiple pages...
1405                  */
1406                 do {
1407                         if (iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1408                                    &mtask->data_count, &tcp_mtask->sent)) {
1409                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1410                                 return -EAGAIN;
1411                         }
1412                 } while (mtask->data_count);
1413         }
1414
1415         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1416         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1417                 struct iscsi_session *session = conn->session;
1418
1419                 spin_lock_bh(&session->lock);
1420                 list_del(&conn->mtask->running);
1421                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1422                             sizeof(void*));
1423                 spin_unlock_bh(&session->lock);
1424         }
1425         return 0;
1426 }
1427
1428 static inline int
1429 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1430                      struct iscsi_tcp_cmd_task *tcp_ctask)
1431 {
1432         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1433         if (conn->hdrdgst_en)
1434                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1435                                  (u8*)tcp_ctask->hdrext);
1436         if (!iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0)) {
1437                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1438                 return 0; /* wait for Data-In */
1439         }
1440         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1441         return -EAGAIN;
1442 }
1443
1444 static inline int
1445 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1446                      struct iscsi_cmd_task *ctask)
1447 {
1448         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1449
1450         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1451         if (conn->hdrdgst_en)
1452                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1453                                  (u8*)tcp_ctask->hdrext);
1454         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count)) {
1455                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1456                 return -EAGAIN;
1457         }
1458         return 0;
1459 }
1460
1461 static inline int
1462 handle_xmstate_data_digest(struct iscsi_conn *conn,
1463                            struct iscsi_cmd_task *ctask)
1464 {
1465         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1466
1467         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1468         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1469         if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1470                                     &tcp_ctask->datadigest, 0)) {
1471                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1472                 debug_tcp("resent data digest 0x%x fail!\n",
1473                           tcp_ctask->datadigest);
1474                 return -EAGAIN;
1475         }
1476         return 0;
1477 }
1478
1479 static inline int
1480 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1481 {
1482         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1483         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1484
1485         BUG_ON(!ctask->imm_count);
1486         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1487
1488         if (conn->datadgst_en) {
1489                 iscsi_data_digest_init(tcp_conn, ctask);
1490                 tcp_ctask->immdigest = 0;
1491         }
1492
1493         for (;;) {
1494                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &ctask->imm_count,
1495                                    &tcp_ctask->sent)) {
1496                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1497                         if (conn->datadgst_en) {
1498                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1499                                                 (u8*)&tcp_ctask->immdigest);
1500                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1501                                           tcp_ctask->datadigest);
1502                         }
1503                         return -EAGAIN;
1504                 }
1505                 if (conn->datadgst_en)
1506                         crypto_digest_update(tcp_conn->data_tx_tfm,
1507                                              &tcp_ctask->sendbuf.sg, 1);
1508
1509                 if (!ctask->imm_count)
1510                         break;
1511                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1512                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1513         }
1514
1515         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1516                 if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1517                                             &tcp_ctask->immdigest, 1)) {
1518                         debug_tcp("sending imm digest 0x%x fail!\n",
1519                                   tcp_ctask->immdigest);
1520                         return -EAGAIN;
1521                 }
1522                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1523         }
1524
1525         return 0;
1526 }
1527
1528 static inline int
1529 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1530 {
1531         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1532         struct iscsi_data_task *dtask;
1533
1534         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1535         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1536                 iscsi_unsolicit_data_init(conn, ctask);
1537                 BUG_ON(!tcp_ctask->dtask);
1538                 dtask = tcp_ctask->dtask;
1539                 if (conn->hdrdgst_en)
1540                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1541                                         (u8*)dtask->hdrext);
1542                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1543         }
1544         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count)) {
1545                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1546                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1547                 return -EAGAIN;
1548         }
1549
1550         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1551                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1552         return 0;
1553 }
1554
1555 static inline int
1556 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1557 {
1558         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1559         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1560         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1561
1562         BUG_ON(!ctask->data_count);
1563         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1564
1565         if (conn->datadgst_en) {
1566                 iscsi_data_digest_init(tcp_conn, ctask);
1567                 dtask->digest = 0;
1568         }
1569
1570         for (;;) {
1571                 int start = tcp_ctask->sent;
1572
1573                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1574                                    &ctask->data_count, &tcp_ctask->sent)) {
1575                         ctask->unsol_count -= tcp_ctask->sent - start;
1576                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1577                         /* will continue with this ctask later.. */
1578                         if (conn->datadgst_en) {
1579                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1580                                                 (u8 *)&dtask->digest);
1581                                 debug_tcp("tx uns data fail 0x%x\n",
1582                                           dtask->digest);
1583                         }
1584                         return -EAGAIN;
1585                 }
1586
1587                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1588                 ctask->unsol_count -= tcp_ctask->sent - start;
1589
1590                 /*
1591                  * XXX:we may run here with un-initial sendbuf.
1592                  * so pass it
1593                  */
1594                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1595                         crypto_digest_update(tcp_conn->data_tx_tfm,
1596                                              &tcp_ctask->sendbuf.sg, 1);
1597
1598                 if (!ctask->data_count)
1599                         break;
1600                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1601                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1602         }
1603         BUG_ON(ctask->unsol_count < 0);
1604
1605         /*
1606          * Done with the Data-Out. Next, check if we need
1607          * to send another unsolicited Data-Out.
1608          */
1609         if (ctask->unsol_count) {
1610                 if (conn->datadgst_en) {
1611                         if (iscsi_digest_final_send(conn, ctask,
1612                                                     &dtask->digestbuf,
1613                                                     &dtask->digest, 1)) {
1614                                 debug_tcp("send uns digest 0x%x fail\n",
1615                                           dtask->digest);
1616                                 return -EAGAIN;
1617                         }
1618                         debug_tcp("sending uns digest 0x%x, more uns\n",
1619                                   dtask->digest);
1620                 }
1621                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1622                 return 1;
1623         }
1624
1625         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1626                 if (iscsi_digest_final_send(conn, ctask,
1627                                             &dtask->digestbuf,
1628                                             &dtask->digest, 1)) {
1629                         debug_tcp("send last uns digest 0x%x fail\n",
1630                                    dtask->digest);
1631                         return -EAGAIN;
1632                 }
1633                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1634         }
1635
1636         return 0;
1637 }
1638
1639 static inline int
1640 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1641 {
1642         struct iscsi_session *session = conn->session;
1643         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1644         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1645         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1646         struct iscsi_data_task *dtask = r2t->dtask;
1647         int left;
1648
1649         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1650         tcp_ctask->dtask = dtask;
1651
1652         if (conn->datadgst_en) {
1653                 iscsi_data_digest_init(tcp_conn, ctask);
1654                 dtask->digest = 0;
1655         }
1656 solicit_again:
1657         /*
1658          * send Data-Out whitnin this R2T sequence.
1659          */
1660         if (!r2t->data_count)
1661                 goto data_out_done;
1662
1663         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1664                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1665                 /* will continue with this ctask later.. */
1666                 if (conn->datadgst_en) {
1667                         crypto_digest_final(tcp_conn->data_tx_tfm,
1668                                           (u8 *)&dtask->digest);
1669                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1670                 }
1671                 return -EAGAIN;
1672         }
1673
1674         BUG_ON(r2t->data_count < 0);
1675         if (conn->datadgst_en)
1676                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1677                                      1);
1678
1679         if (r2t->data_count) {
1680                 BUG_ON(ctask->sc->use_sg == 0);
1681                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1682                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1683                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1684                         r2t->sg += 1;
1685                 }
1686                 goto solicit_again;
1687         }
1688
1689 data_out_done:
1690         /*
1691          * Done with this Data-Out. Next, check if we have
1692          * to send another Data-Out for this R2T.
1693          */
1694         BUG_ON(r2t->data_length - r2t->sent < 0);
1695         left = r2t->data_length - r2t->sent;
1696         if (left) {
1697                 if (conn->datadgst_en) {
1698                         if (iscsi_digest_final_send(conn, ctask,
1699                                                     &dtask->digestbuf,
1700                                                     &dtask->digest, 1)) {
1701                                 debug_tcp("send r2t data digest 0x%x"
1702                                           "fail\n", dtask->digest);
1703                                 return -EAGAIN;
1704                         }
1705                         debug_tcp("r2t data send digest 0x%x\n",
1706                                   dtask->digest);
1707                 }
1708                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1709                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1710                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1711                 return 1;
1712         }
1713
1714         /*
1715          * Done with this R2T. Check if there are more
1716          * outstanding R2Ts ready to be processed.
1717          */
1718         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1719         if (conn->datadgst_en) {
1720                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1721                                             &dtask->digest, 1)) {
1722                         debug_tcp("send last r2t data digest 0x%x"
1723                                   "fail\n", dtask->digest);
1724                         return -EAGAIN;
1725                 }
1726                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1727         }
1728
1729         tcp_ctask->r2t_data_count -= r2t->data_length;
1730         tcp_ctask->r2t = NULL;
1731         spin_lock_bh(&session->lock);
1732         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1733         spin_unlock_bh(&session->lock);
1734         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1735                 tcp_ctask->r2t = r2t;
1736                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1737                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1738                 return 1;
1739         }
1740
1741         return 0;
1742 }
1743
1744 static inline int
1745 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1746 {
1747         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1748         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1749         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1750         int sent;
1751
1752         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1753         iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1754                             tcp_ctask->pad_count);
1755         if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1756                            &sent)) {
1757                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1758                 return -EAGAIN;
1759         }
1760
1761         if (conn->datadgst_en) {
1762                 crypto_digest_update(tcp_conn->data_tx_tfm,
1763                                      &tcp_ctask->sendbuf.sg, 1);
1764                 /* imm data? */
1765                 if (!dtask) {
1766                         if (iscsi_digest_final_send(conn, ctask,
1767                                                     &tcp_ctask->immbuf,
1768                                                     &tcp_ctask->immdigest, 1)) {
1769                                 debug_tcp("send padding digest 0x%x"
1770                                           "fail!\n", tcp_ctask->immdigest);
1771                                 return -EAGAIN;
1772                         }
1773                         debug_tcp("done with padding, digest 0x%x\n",
1774                                   tcp_ctask->datadigest);
1775                 } else {
1776                         if (iscsi_digest_final_send(conn, ctask,
1777                                                     &dtask->digestbuf,
1778                                                     &dtask->digest, 1)) {
1779                                 debug_tcp("send padding digest 0x%x"
1780                                           "fail\n", dtask->digest);
1781                                 return -EAGAIN;
1782                         }
1783                         debug_tcp("done with padding, digest 0x%x\n",
1784                                   dtask->digest);
1785                 }
1786         }
1787
1788         return 0;
1789 }
1790
1791 static int
1792 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1793 {
1794         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1795         int rc = 0;
1796
1797         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1798                 conn->id, tcp_ctask->xmstate, ctask->itt);
1799
1800         /*
1801          * serialize with TMF AbortTask
1802          */
1803         if (ctask->mtask)
1804                 return rc;
1805
1806         if (tcp_ctask->xmstate & XMSTATE_R_HDR) {
1807                 rc = handle_xmstate_r_hdr(conn, tcp_ctask);
1808                 return rc;
1809         }
1810
1811         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1812                 rc = handle_xmstate_w_hdr(conn, ctask);
1813                 if (rc)
1814                         return rc;
1815         }
1816
1817         /* XXX: for data digest xmit recover */
1818         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1819                 rc = handle_xmstate_data_digest(conn, ctask);
1820                 if (rc)
1821                         return rc;
1822         }
1823
1824         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1825                 rc = handle_xmstate_imm_data(conn, ctask);
1826                 if (rc)
1827                         return rc;
1828         }
1829
1830         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1831                 BUG_ON(!ctask->unsol_count);
1832                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1833 unsolicit_head_again:
1834                 rc = handle_xmstate_uns_hdr(conn, ctask);
1835                 if (rc)
1836                         return rc;
1837         }
1838
1839         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1840                 rc = handle_xmstate_uns_data(conn, ctask);
1841                 if (rc == 1)
1842                         goto unsolicit_head_again;
1843                 else if (rc)
1844                         return rc;
1845                 goto done;
1846         }
1847
1848         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1849                 struct iscsi_r2t_info *r2t;
1850
1851                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1852                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1853                 if (!tcp_ctask->r2t)
1854                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1855                                     sizeof(void*));
1856 solicit_head_again:
1857                 r2t = tcp_ctask->r2t;
1858                 if (conn->hdrdgst_en)
1859                         iscsi_hdr_digest(conn, &r2t->headbuf,
1860                                         (u8*)r2t->dtask->hdrext);
1861                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
1862                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1863                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1864                         return -EAGAIN;
1865                 }
1866
1867                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1868                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1869                         r2t->sent);
1870         }
1871
1872         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1873                 rc = handle_xmstate_sol_data(conn, ctask);
1874                 if (rc == 1)
1875                         goto solicit_head_again;
1876                 if (rc)
1877                         return rc;
1878         }
1879
1880 done:
1881         /*
1882          * Last thing to check is whether we need to send write
1883          * padding. Note that we check for xmstate equality, not just the bit.
1884          */
1885         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1886                 rc = handle_xmstate_w_pad(conn, ctask);
1887
1888         return rc;
1889 }
1890
1891 static struct iscsi_cls_conn *
1892 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1893 {
1894         struct iscsi_conn *conn;
1895         struct iscsi_cls_conn *cls_conn;
1896         struct iscsi_tcp_conn *tcp_conn;
1897
1898         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1899         if (!cls_conn)
1900                 return NULL;
1901         conn = cls_conn->dd_data;
1902         /*
1903          * due to strange issues with iser these are not set
1904          * in iscsi_conn_setup
1905          */
1906         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1907
1908         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1909         if (!tcp_conn)
1910                 goto tcp_conn_alloc_fail;
1911
1912         conn->dd_data = tcp_conn;
1913         tcp_conn->iscsi_conn = conn;
1914         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1915         /* initial operational parameters */
1916         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1917         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1918
1919         /* allocate initial PDU receive place holder */
1920         if (tcp_conn->data_size <= PAGE_SIZE)
1921                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1922         else
1923                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1924                                         get_order(tcp_conn->data_size));
1925         if (!tcp_conn->data)
1926                 goto max_recv_dlenght_alloc_fail;
1927
1928         return cls_conn;
1929
1930 max_recv_dlenght_alloc_fail:
1931         kfree(tcp_conn);
1932 tcp_conn_alloc_fail:
1933         iscsi_conn_teardown(cls_conn);
1934         return NULL;
1935 }
1936
1937 static void
1938 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1939 {
1940         struct iscsi_conn *conn = cls_conn->dd_data;
1941         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1942         int digest = 0;
1943
1944         if (conn->hdrdgst_en || conn->datadgst_en)
1945                 digest = 1;
1946
1947         iscsi_conn_teardown(cls_conn);
1948
1949         /* now free tcp_conn */
1950         if (digest) {
1951                 if (tcp_conn->tx_tfm)
1952                         crypto_free_tfm(tcp_conn->tx_tfm);
1953                 if (tcp_conn->rx_tfm)
1954                         crypto_free_tfm(tcp_conn->rx_tfm);
1955                 if (tcp_conn->data_tx_tfm)
1956                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1957                 if (tcp_conn->data_rx_tfm)
1958                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1959         }
1960
1961         /* free conn->data, size = MaxRecvDataSegmentLength */
1962         if (tcp_conn->data_size <= PAGE_SIZE)
1963                 kfree(tcp_conn->data);
1964         else
1965                 free_pages((unsigned long)tcp_conn->data,
1966                            get_order(tcp_conn->data_size));
1967         kfree(tcp_conn);
1968 }
1969
1970 static int
1971 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1972                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1973                     int is_leading)
1974 {
1975         struct iscsi_conn *conn = cls_conn->dd_data;
1976         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1977         struct sock *sk;
1978         struct socket *sock;
1979         int err;
1980
1981         /* lookup for existing socket */
1982         sock = sockfd_lookup((int)transport_eph, &err);
1983         if (!sock) {
1984                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1985                 return -EEXIST;
1986         }
1987
1988         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1989         if (err)
1990                 return err;
1991
1992         if (conn->stop_stage != STOP_CONN_SUSPEND) {
1993                 /* bind iSCSI connection and socket */
1994                 tcp_conn->sock = sock;
1995
1996                 /* setup Socket parameters */
1997                 sk = sock->sk;
1998                 sk->sk_reuse = 1;
1999                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2000                 sk->sk_allocation = GFP_ATOMIC;
2001
2002                 /* FIXME: disable Nagle's algorithm */
2003
2004                 /*
2005                  * Intercept TCP callbacks for sendfile like receive
2006                  * processing.
2007                  */
2008                 conn->recv_lock = &sk->sk_callback_lock;
2009                 iscsi_conn_set_callbacks(conn);
2010                 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2011                 /*
2012                  * set receive state machine into initial state
2013                  */
2014                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2015         }
2016
2017         return 0;
2018 }
2019
2020 static void
2021 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2022 {
2023         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2024         struct iscsi_r2t_info *r2t;
2025
2026         /* flush ctask's r2t queues */
2027         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
2028                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
2029                             sizeof(void*));
2030
2031         __iscsi_ctask_cleanup(conn, ctask);
2032 }
2033
2034 static void
2035 iscsi_tcp_suspend_conn_rx(struct iscsi_conn *conn)
2036 {
2037         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2038         struct sock *sk;
2039
2040         if (!tcp_conn->sock)
2041                 return;
2042
2043         sk = tcp_conn->sock->sk;
2044         write_lock_bh(&sk->sk_callback_lock);
2045         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2046         write_unlock_bh(&sk->sk_callback_lock);
2047 }
2048
2049 static void
2050 iscsi_tcp_terminate_conn(struct iscsi_conn *conn)
2051 {
2052         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2053
2054         if (!tcp_conn->sock)
2055                 return;
2056
2057         sock_hold(tcp_conn->sock->sk);
2058         iscsi_conn_restore_callbacks(conn);
2059         sock_put(tcp_conn->sock->sk);
2060
2061         sock_release(tcp_conn->sock);
2062         tcp_conn->sock = NULL;
2063         conn->recv_lock = NULL;
2064 }
2065
2066 /* called with host lock */
2067 static void
2068 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2069                     char *data, uint32_t data_size)
2070 {
2071         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2072
2073         iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2074                            sizeof(struct iscsi_hdr));
2075         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2076
2077         if (mtask->data_count)
2078                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2079                                     mtask->data_count);
2080 }
2081
2082 static int
2083 iscsi_r2tpool_alloc(struct iscsi_session *session)
2084 {
2085         int i;
2086         int cmd_i;
2087
2088         /*
2089          * initialize per-task: R2T pool and xmit queue
2090          */
2091         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2092                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2093                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2094
2095                 /*
2096                  * pre-allocated x4 as much r2ts to handle race when
2097                  * target acks DataOut faster than we data_xmit() queues
2098                  * could replenish r2tqueue.
2099                  */
2100
2101                 /* R2T pool */
2102                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2103                                     (void***)&tcp_ctask->r2ts,
2104                                     sizeof(struct iscsi_r2t_info))) {
2105                         goto r2t_alloc_fail;
2106                 }
2107
2108                 /* R2T xmit queue */
2109                 tcp_ctask->r2tqueue = kfifo_alloc(
2110                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2111                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2112                         iscsi_pool_free(&tcp_ctask->r2tpool,
2113                                         (void**)tcp_ctask->r2ts);
2114                         goto r2t_alloc_fail;
2115                 }
2116
2117                 /*
2118                  * number of
2119                  * Data-Out PDU's within R2T-sequence can be quite big;
2120                  * using mempool
2121                  */
2122                 tcp_ctask->datapool = mempool_create_slab_pool(ISCSI_DTASK_DEFAULT_MAX,
2123                                                                taskcache);
2124                 if (tcp_ctask->datapool == NULL) {
2125                         kfifo_free(tcp_ctask->r2tqueue);
2126                         iscsi_pool_free(&tcp_ctask->r2tpool,
2127                                         (void**)tcp_ctask->r2ts);
2128                         goto r2t_alloc_fail;
2129                 }
2130                 INIT_LIST_HEAD(&tcp_ctask->dataqueue);
2131         }
2132
2133         return 0;
2134
2135 r2t_alloc_fail:
2136         for (i = 0; i < cmd_i; i++) {
2137                 struct iscsi_cmd_task *ctask = session->cmds[i];
2138                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2139
2140                 mempool_destroy(tcp_ctask->datapool);
2141                 kfifo_free(tcp_ctask->r2tqueue);
2142                 iscsi_pool_free(&tcp_ctask->r2tpool,
2143                                 (void**)tcp_ctask->r2ts);
2144         }
2145         return -ENOMEM;
2146 }
2147
2148 static void
2149 iscsi_r2tpool_free(struct iscsi_session *session)
2150 {
2151         int i;
2152
2153         for (i = 0; i < session->cmds_max; i++) {
2154                 struct iscsi_cmd_task *ctask = session->cmds[i];
2155                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2156
2157                 mempool_destroy(tcp_ctask->datapool);
2158                 kfifo_free(tcp_ctask->r2tqueue);
2159                 iscsi_pool_free(&tcp_ctask->r2tpool,
2160                                 (void**)tcp_ctask->r2ts);
2161         }
2162 }
2163
2164 static int
2165 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2166                      uint32_t value)
2167 {
2168         struct iscsi_conn *conn = cls_conn->dd_data;
2169         struct iscsi_session *session = conn->session;
2170         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2171
2172         switch(param) {
2173         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2174                 char *saveptr = tcp_conn->data;
2175                 gfp_t flags = GFP_KERNEL;
2176
2177                 if (tcp_conn->data_size >= value) {
2178                         conn->max_recv_dlength = value;
2179                         break;
2180                 }
2181
2182                 spin_lock_bh(&session->lock);
2183                 if (conn->stop_stage == STOP_CONN_RECOVER)
2184                         flags = GFP_ATOMIC;
2185                 spin_unlock_bh(&session->lock);
2186
2187                 if (value <= PAGE_SIZE)
2188                         tcp_conn->data = kmalloc(value, flags);
2189                 else
2190                         tcp_conn->data = (void*)__get_free_pages(flags,
2191                                                              get_order(value));
2192                 if (tcp_conn->data == NULL) {
2193                         tcp_conn->data = saveptr;
2194                         return -ENOMEM;
2195                 }
2196                 if (tcp_conn->data_size <= PAGE_SIZE)
2197                         kfree(saveptr);
2198                 else
2199                         free_pages((unsigned long)saveptr,
2200                                    get_order(tcp_conn->data_size));
2201                 conn->max_recv_dlength = value;
2202                 tcp_conn->data_size = value;
2203                 }
2204                 break;
2205         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2206                 conn->max_xmit_dlength =  value;
2207                 break;
2208         case ISCSI_PARAM_HDRDGST_EN:
2209                 conn->hdrdgst_en = value;
2210                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2211                 if (conn->hdrdgst_en) {
2212                         tcp_conn->hdr_size += sizeof(__u32);
2213                         if (!tcp_conn->tx_tfm)
2214                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2215                                                                     0);
2216                         if (!tcp_conn->tx_tfm)
2217                                 return -ENOMEM;
2218                         if (!tcp_conn->rx_tfm)
2219                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2220                                                                     0);
2221                         if (!tcp_conn->rx_tfm) {
2222                                 crypto_free_tfm(tcp_conn->tx_tfm);
2223                                 return -ENOMEM;
2224                         }
2225                 } else {
2226                         if (tcp_conn->tx_tfm)
2227                                 crypto_free_tfm(tcp_conn->tx_tfm);
2228                         if (tcp_conn->rx_tfm)
2229                                 crypto_free_tfm(tcp_conn->rx_tfm);
2230                 }
2231                 break;
2232         case ISCSI_PARAM_DATADGST_EN:
2233                 conn->datadgst_en = value;
2234                 if (conn->datadgst_en) {
2235                         if (!tcp_conn->data_tx_tfm)
2236                                 tcp_conn->data_tx_tfm =
2237                                     crypto_alloc_tfm("crc32c", 0);
2238                         if (!tcp_conn->data_tx_tfm)
2239                                 return -ENOMEM;
2240                         if (!tcp_conn->data_rx_tfm)
2241                                 tcp_conn->data_rx_tfm =
2242                                     crypto_alloc_tfm("crc32c", 0);
2243                         if (!tcp_conn->data_rx_tfm) {
2244                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2245                                 return -ENOMEM;
2246                         }
2247                 } else {
2248                         if (tcp_conn->data_tx_tfm)
2249                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2250                         if (tcp_conn->data_rx_tfm)
2251                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2252                 }
2253                 tcp_conn->sendpage = conn->datadgst_en ?
2254                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2255                 break;
2256         case ISCSI_PARAM_INITIAL_R2T_EN:
2257                 session->initial_r2t_en = value;
2258                 break;
2259         case ISCSI_PARAM_MAX_R2T:
2260                 if (session->max_r2t == roundup_pow_of_two(value))
2261                         break;
2262                 iscsi_r2tpool_free(session);
2263                 session->max_r2t = value;
2264                 if (session->max_r2t & (session->max_r2t - 1))
2265                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2266                 if (iscsi_r2tpool_alloc(session))
2267                         return -ENOMEM;
2268                 break;
2269         case ISCSI_PARAM_IMM_DATA_EN:
2270                 session->imm_data_en = value;
2271                 break;
2272         case ISCSI_PARAM_FIRST_BURST:
2273                 session->first_burst = value;
2274                 break;
2275         case ISCSI_PARAM_MAX_BURST:
2276                 session->max_burst = value;
2277                 break;
2278         case ISCSI_PARAM_PDU_INORDER_EN:
2279                 session->pdu_inorder_en = value;
2280                 break;
2281         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2282                 session->dataseq_inorder_en = value;
2283                 break;
2284         case ISCSI_PARAM_ERL:
2285                 session->erl = value;
2286                 break;
2287         case ISCSI_PARAM_IFMARKER_EN:
2288                 BUG_ON(value);
2289                 session->ifmarker_en = value;
2290                 break;
2291         case ISCSI_PARAM_OFMARKER_EN:
2292                 BUG_ON(value);
2293                 session->ofmarker_en = value;
2294                 break;
2295         case ISCSI_PARAM_EXP_STATSN:
2296                 conn->exp_statsn = value;
2297                 break;
2298         default:
2299                 break;
2300         }
2301
2302         return 0;
2303 }
2304
2305 static int
2306 iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2307                         enum iscsi_param param, uint32_t *value)
2308 {
2309         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2310         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2311
2312         switch(param) {
2313         case ISCSI_PARAM_INITIAL_R2T_EN:
2314                 *value = session->initial_r2t_en;
2315                 break;
2316         case ISCSI_PARAM_MAX_R2T:
2317                 *value = session->max_r2t;
2318                 break;
2319         case ISCSI_PARAM_IMM_DATA_EN:
2320                 *value = session->imm_data_en;
2321                 break;
2322         case ISCSI_PARAM_FIRST_BURST:
2323                 *value = session->first_burst;
2324                 break;
2325         case ISCSI_PARAM_MAX_BURST:
2326                 *value = session->max_burst;
2327                 break;
2328         case ISCSI_PARAM_PDU_INORDER_EN:
2329                 *value = session->pdu_inorder_en;
2330                 break;
2331         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2332                 *value = session->dataseq_inorder_en;
2333                 break;
2334         case ISCSI_PARAM_ERL:
2335                 *value = session->erl;
2336                 break;
2337         case ISCSI_PARAM_IFMARKER_EN:
2338                 *value = session->ifmarker_en;
2339                 break;
2340         case ISCSI_PARAM_OFMARKER_EN:
2341                 *value = session->ofmarker_en;
2342                 break;
2343         default:
2344                 return -EINVAL;
2345         }
2346
2347         return 0;
2348 }
2349
2350 static int
2351 iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2352                      enum iscsi_param param, uint32_t *value)
2353 {
2354         struct iscsi_conn *conn = cls_conn->dd_data;
2355         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2356         struct inet_sock *inet;
2357
2358         switch(param) {
2359         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2360                 *value = conn->max_recv_dlength;
2361                 break;
2362         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2363                 *value = conn->max_xmit_dlength;
2364                 break;
2365         case ISCSI_PARAM_HDRDGST_EN:
2366                 *value = conn->hdrdgst_en;
2367                 break;
2368         case ISCSI_PARAM_DATADGST_EN:
2369                 *value = conn->datadgst_en;
2370                 break;
2371         case ISCSI_PARAM_CONN_PORT:
2372                 mutex_lock(&conn->xmitmutex);
2373                 if (!tcp_conn->sock) {
2374                         mutex_unlock(&conn->xmitmutex);
2375                         return -EINVAL;
2376                 }
2377
2378                 inet = inet_sk(tcp_conn->sock->sk);
2379                 *value = be16_to_cpu(inet->dport);
2380                 mutex_unlock(&conn->xmitmutex);
2381         case ISCSI_PARAM_EXP_STATSN:
2382                 *value = conn->exp_statsn;
2383                 break;
2384         default:
2385                 return -EINVAL;
2386         }
2387
2388         return 0;
2389 }
2390
2391 static int
2392 iscsi_conn_get_str_param(struct iscsi_cls_conn *cls_conn,
2393                          enum iscsi_param param, char *buf)
2394 {
2395         struct iscsi_conn *conn = cls_conn->dd_data;
2396         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2397         struct sock *sk;
2398         struct inet_sock *inet;
2399         struct ipv6_pinfo *np;
2400         int len = 0;
2401
2402         switch (param) {
2403         case ISCSI_PARAM_CONN_ADDRESS:
2404                 mutex_lock(&conn->xmitmutex);
2405                 if (!tcp_conn->sock) {
2406                         mutex_unlock(&conn->xmitmutex);
2407                         return -EINVAL;
2408                 }
2409
2410                 sk = tcp_conn->sock->sk;
2411                 if (sk->sk_family == PF_INET) {
2412                         inet = inet_sk(sk);
2413                         len = sprintf(buf, "%u.%u.%u.%u\n",
2414                                       NIPQUAD(inet->daddr));
2415                 } else {
2416                         np = inet6_sk(sk);
2417                         len = sprintf(buf,
2418                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2419                                 NIP6(np->daddr));
2420                 }
2421                 mutex_unlock(&conn->xmitmutex);
2422                 break;
2423         default:
2424                 return -EINVAL;
2425         }
2426
2427         return len;
2428 }
2429
2430 static void
2431 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2432 {
2433         struct iscsi_conn *conn = cls_conn->dd_data;
2434         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2435
2436         stats->txdata_octets = conn->txdata_octets;
2437         stats->rxdata_octets = conn->rxdata_octets;
2438         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2439         stats->dataout_pdus = conn->dataout_pdus_cnt;
2440         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2441         stats->datain_pdus = conn->datain_pdus_cnt;
2442         stats->r2t_pdus = conn->r2t_pdus_cnt;
2443         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2444         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2445         stats->custom_length = 3;
2446         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2447         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2448         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2449         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2450         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2451         stats->custom[2].value = conn->eh_abort_cnt;
2452 }
2453
2454 static struct iscsi_cls_session *
2455 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2456                          struct scsi_transport_template *scsit,
2457                          uint32_t initial_cmdsn, uint32_t *hostno)
2458 {
2459         struct iscsi_cls_session *cls_session;
2460         struct iscsi_session *session;
2461         uint32_t hn;
2462         int cmd_i;
2463
2464         cls_session = iscsi_session_setup(iscsit, scsit,
2465                                          sizeof(struct iscsi_tcp_cmd_task),
2466                                          sizeof(struct iscsi_tcp_mgmt_task),
2467                                          initial_cmdsn, &hn);
2468         if (!cls_session)
2469                 return NULL;
2470         *hostno = hn;
2471
2472         session = class_to_transport_session(cls_session);
2473         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2474                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2475                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2476
2477                 ctask->hdr = &tcp_ctask->hdr;
2478         }
2479
2480         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2481                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2482                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2483
2484                 mtask->hdr = &tcp_mtask->hdr;
2485         }
2486
2487         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2488                 goto r2tpool_alloc_fail;
2489
2490         return cls_session;
2491
2492 r2tpool_alloc_fail:
2493         iscsi_session_teardown(cls_session);
2494         return NULL;
2495 }
2496
2497 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2498 {
2499         struct iscsi_session *session = class_to_transport_session(cls_session);
2500         struct iscsi_data_task *dtask, *n;
2501         int cmd_i;
2502
2503         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2504                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2505                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2506
2507                 list_for_each_entry_safe(dtask, n, &tcp_ctask->dataqueue,
2508                                          item) {
2509                         list_del(&dtask->item);
2510                         mempool_free(dtask, tcp_ctask->datapool);
2511                 }
2512         }
2513
2514         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2515         iscsi_session_teardown(cls_session);
2516 }
2517
2518 static struct scsi_host_template iscsi_sht = {
2519         .name                   = "iSCSI Initiator over TCP/IP, v."
2520                                   ISCSI_VERSION_STR,
2521         .queuecommand           = iscsi_queuecommand,
2522         .change_queue_depth     = iscsi_change_queue_depth,
2523         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2524         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2525         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2526         .eh_abort_handler       = iscsi_eh_abort,
2527         .eh_host_reset_handler  = iscsi_eh_host_reset,
2528         .use_clustering         = DISABLE_CLUSTERING,
2529         .proc_name              = "iscsi_tcp",
2530         .this_id                = -1,
2531 };
2532
2533 static struct iscsi_transport iscsi_tcp_transport = {
2534         .owner                  = THIS_MODULE,
2535         .name                   = "tcp",
2536         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2537                                   | CAP_DATADGST,
2538         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2539                                   ISCSI_MAX_XMIT_DLENGTH |
2540                                   ISCSI_HDRDGST_EN |
2541                                   ISCSI_DATADGST_EN |
2542                                   ISCSI_INITIAL_R2T_EN |
2543                                   ISCSI_MAX_R2T |
2544                                   ISCSI_IMM_DATA_EN |
2545                                   ISCSI_FIRST_BURST |
2546                                   ISCSI_MAX_BURST |
2547                                   ISCSI_PDU_INORDER_EN |
2548                                   ISCSI_DATASEQ_INORDER_EN |
2549                                   ISCSI_ERL |
2550                                   ISCSI_CONN_PORT |
2551                                   ISCSI_CONN_ADDRESS |
2552                                   ISCSI_EXP_STATSN,
2553         .host_template          = &iscsi_sht,
2554         .conndata_size          = sizeof(struct iscsi_conn),
2555         .max_conn               = 1,
2556         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2557         /* session management */
2558         .create_session         = iscsi_tcp_session_create,
2559         .destroy_session        = iscsi_tcp_session_destroy,
2560         /* connection management */
2561         .create_conn            = iscsi_tcp_conn_create,
2562         .bind_conn              = iscsi_tcp_conn_bind,
2563         .destroy_conn           = iscsi_tcp_conn_destroy,
2564         .set_param              = iscsi_conn_set_param,
2565         .get_conn_param         = iscsi_conn_get_param,
2566         .get_conn_str_param     = iscsi_conn_get_str_param,
2567         .get_session_param      = iscsi_session_get_param,
2568         .start_conn             = iscsi_conn_start,
2569         .stop_conn              = iscsi_conn_stop,
2570         /* these are called as part of conn recovery */
2571         .suspend_conn_recv      = iscsi_tcp_suspend_conn_rx,
2572         .terminate_conn         = iscsi_tcp_terminate_conn,
2573         /* IO */
2574         .send_pdu               = iscsi_conn_send_pdu,
2575         .get_stats              = iscsi_conn_get_stats,
2576         .init_cmd_task          = iscsi_tcp_cmd_init,
2577         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2578         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2579         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2580         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2581         /* recovery */
2582         .session_recovery_timedout = iscsi_session_recovery_timedout,
2583 };
2584
2585 static int __init
2586 iscsi_tcp_init(void)
2587 {
2588         if (iscsi_max_lun < 1) {
2589                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2590                        iscsi_max_lun);
2591                 return -EINVAL;
2592         }
2593         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2594
2595         taskcache = kmem_cache_create("iscsi_taskcache",
2596                         sizeof(struct iscsi_data_task), 0,
2597                         SLAB_HWCACHE_ALIGN, NULL, NULL);
2598         if (!taskcache)
2599                 return -ENOMEM;
2600
2601         if (!iscsi_register_transport(&iscsi_tcp_transport))
2602                 kmem_cache_destroy(taskcache);
2603
2604         return 0;
2605 }
2606
2607 static void __exit
2608 iscsi_tcp_exit(void)
2609 {
2610         iscsi_unregister_transport(&iscsi_tcp_transport);
2611         kmem_cache_destroy(taskcache);
2612 }
2613
2614 module_init(iscsi_tcp_init);
2615 module_exit(iscsi_tcp_exit);