git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 - 2006 Mike Christie
   7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * See the file COPYING included with this distribution for more details.
  21  *
  22  * Credits:
  23  *      Christoph Hellwig
  24  *      FUJITA Tomonori
  25  *      Arne Redlich
  26  *      Zhenyu Wang
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/list.h>
  31 #include <linux/inet.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/crypto.h>
  34 #include <linux/delay.h>
  35 #include <linux/kfifo.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/mutex.h>
  38 #include <net/tcp.h>
  39 #include <scsi/scsi_cmnd.h>
  40 #include <scsi/scsi_host.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_transport_iscsi.h>
  43
  44 #include "iscsi_tcp.h"
  45
  46 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_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
  75 {
  76         sg_init_one(&ibuf->sg, (u8 *)vbuf, size);
  77         ibuf->sent = 0;
  78         ibuf->use_sendmsg = 0;
  79 }
  80
  81 static inline void
  82 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  83 {
  84         ibuf->sg.page = virt_to_page(vbuf);
  85         ibuf->sg.offset = offset_in_page(vbuf);
  86         ibuf->sg.length = size;
  87         ibuf->sent = 0;
  88         ibuf->use_sendmsg = 1;
  89 }
  90
  91 static inline void
  92 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
  93 {
  94         ibuf->sg.page = sg->page;
  95         ibuf->sg.offset = sg->offset;
  96         ibuf->sg.length = sg->length;
  97         /*
  98          * Fastpath: sg element fits into single page
  99          */
 100         if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
 101                 ibuf->use_sendmsg = 0;
 102         else
 103                 ibuf->use_sendmsg = 1;
 104         ibuf->sent = 0;
 105 }
 106
 107 static inline int
 108 iscsi_buf_left(struct iscsi_buf *ibuf)
 109 {
 110         int rc;
 111
 112         rc = ibuf->sg.length - ibuf->sent;
 113         BUG_ON(rc < 0);
 114         return rc;
 115 }
 116
 117 static inline void
 118 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 119                  u8* crc)
 120 {
 121         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 122
 123         crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
 124         buf->sg.length += sizeof(uint32_t);
 125 }
 126
 127 static inline int
 128 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
 129 {
 130         struct sk_buff *skb = tcp_conn->in.skb;
 131
 132         tcp_conn->in.zero_copy_hdr = 0;
 133
 134         if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
 135             tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 136                 /*
 137                  * Zero-copy PDU Header: using connection context
 138                  * to store header pointer.
 139                  */
 140                 if (skb_shinfo(skb)->frag_list == NULL &&
 141                     !skb_shinfo(skb)->nr_frags) {
 142                         tcp_conn->in.hdr = (struct iscsi_hdr *)
 143                                 ((char*)skb->data + tcp_conn->in.offset);
 144                         tcp_conn->in.zero_copy_hdr = 1;
 145                 } else {
 146                         /* ignoring return code since we checked
 147                          * in.copy before */
 148                         skb_copy_bits(skb, tcp_conn->in.offset,
 149                                 &tcp_conn->hdr, tcp_conn->hdr_size);
 150                         tcp_conn->in.hdr = &tcp_conn->hdr;
 151                 }
 152                 tcp_conn->in.offset += tcp_conn->hdr_size;
 153                 tcp_conn->in.copy -= tcp_conn->hdr_size;
 154         } else {
 155                 int hdr_remains;
 156                 int copylen;
 157
 158                 /*
 159                  * PDU header scattered across SKB's,
 160                  * copying it... This'll happen quite rarely.
 161                  */
 162
 163                 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 164                         tcp_conn->in.hdr_offset = 0;
 165
 166                 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
 167                 BUG_ON(hdr_remains <= 0);
 168
 169                 copylen = min(tcp_conn->in.copy, hdr_remains);
 170                 skb_copy_bits(skb, tcp_conn->in.offset,
 171                         (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
 172                         copylen);
 173
 174                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 175                        "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
 176                        tcp_conn->in.offset, tcp_conn->in.copy);
 177
 178                 tcp_conn->in.offset += copylen;
 179                 tcp_conn->in.copy -= copylen;
 180                 if (copylen < hdr_remains)  {
 181                         tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 182                         tcp_conn->in.hdr_offset += copylen;
 183                         return -EAGAIN;
 184                 }
 185                 tcp_conn->in.hdr = &tcp_conn->hdr;
 186                 tcp_conn->discontiguous_hdr_cnt++;
 187                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 188         }
 189
 190         return 0;
 191 }
 192
 193 /*
 194  * must be called with session lock
 195  */
 196 static void
 197 __iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 198 {
 199         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 200         struct scsi_cmnd *sc;
 201
 202         sc = ctask->sc;
 203         if (unlikely(!sc))
 204                 return;
 205
 206         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 207                 struct iscsi_data_task *dtask, *n;
 208
 209                 /* WRITE: cleanup Data-Out's if any */
 210                 list_for_each_entry_safe(dtask, n, &tcp_ctask->dataqueue,
 211                                          item) {
 212                         list_del(&dtask->item);
 213                         mempool_free(dtask, tcp_ctask->datapool);
 214                 }
 215         }
 216         tcp_ctask->xmstate = XMSTATE_IDLE;
 217         tcp_ctask->r2t = NULL;
 218 }
 219
 220 /**
 221  * iscsi_data_rsp - SCSI Data-In Response processing
 222  * @conn: iscsi connection
 223  * @ctask: scsi command task
 224  **/
 225 static int
 226 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 227 {
 228         int rc;
 229         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 230         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 231         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
 232         struct iscsi_session *session = conn->session;
 233         int datasn = be32_to_cpu(rhdr->datasn);
 234
 235         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 236         if (rc)
 237                 return rc;
 238         /*
 239          * setup Data-In byte counter (gets decremented..)
 240          */
 241         ctask->data_count = tcp_conn->in.datalen;
 242
 243         if (tcp_conn->in.datalen == 0)
 244                 return 0;
 245
 246         if (ctask->datasn != datasn)
 247                 return ISCSI_ERR_DATASN;
 248
 249         ctask->datasn++;
 250
 251         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
 252         if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
 253                 return ISCSI_ERR_DATA_OFFSET;
 254
 255         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 256                 struct scsi_cmnd *sc = ctask->sc;
 257
 258                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 259                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 260                         int res_count = be32_to_cpu(rhdr->residual_count);
 261
 262                         if (res_count > 0 &&
 263                             res_count <= sc->request_bufflen) {
 264                                 sc->resid = res_count;
 265                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 266                         } else
 267                                 sc->result = (DID_BAD_TARGET << 16) |
 268                                         rhdr->cmd_status;
 269                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 270                         sc->resid = be32_to_cpu(rhdr->residual_count);
 271                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 272                 } else
 273                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 274         }
 275
 276         conn->datain_pdus_cnt++;
 277         return 0;
 278 }
 279
 280 /**
 281  * iscsi_solicit_data_init - initialize first Data-Out
 282  * @conn: iscsi connection
 283  * @ctask: scsi command task
 284  * @r2t: R2T info
 285  *
 286  * Notes:
 287  *      Initialize first Data-Out within this R2T sequence and finds
 288  *      proper data_offset within this SCSI command.
 289  *
 290  *      This function is called with connection lock taken.
 291  **/
 292 static void
 293 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 294                         struct iscsi_r2t_info *r2t)
 295 {
 296         struct iscsi_data *hdr;
 297         struct iscsi_data_task *dtask;
 298         struct scsi_cmnd *sc = ctask->sc;
 299         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 300
 301         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
 302         BUG_ON(!dtask);
 303         INIT_LIST_HEAD(&dtask->item);
 304         hdr = &dtask->hdr;
 305         memset(hdr, 0, sizeof(struct iscsi_data));
 306         hdr->ttt = r2t->ttt;
 307         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 308         r2t->solicit_datasn++;
 309         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 310         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 311         hdr->itt = ctask->hdr->itt;
 312         hdr->exp_statsn = r2t->exp_statsn;
 313         hdr->offset = cpu_to_be32(r2t->data_offset);
 314         if (r2t->data_length > conn->max_xmit_dlength) {
 315                 hton24(hdr->dlength, conn->max_xmit_dlength);
 316                 r2t->data_count = conn->max_xmit_dlength;
 317                 hdr->flags = 0;
 318         } else {
 319                 hton24(hdr->dlength, r2t->data_length);
 320                 r2t->data_count = r2t->data_length;
 321                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 322         }
 323         conn->dataout_pdus_cnt++;
 324
 325         r2t->sent = 0;
 326
 327         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
 328                            sizeof(struct iscsi_hdr));
 329
 330         r2t->dtask = dtask;
 331
 332         if (sc->use_sg) {
 333                 int i, sg_count = 0;
 334                 struct scatterlist *sg = sc->request_buffer;
 335
 336                 r2t->sg = NULL;
 337                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 338                         /* FIXME: prefetch ? */
 339                         if (sg_count + sg->length > r2t->data_offset) {
 340                                 int page_offset;
 341
 342                                 /* sg page found! */
 343
 344                                 /* offset within this page */
 345                                 page_offset = r2t->data_offset - sg_count;
 346
 347                                 /* fill in this buffer */
 348                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 349                                 r2t->sendbuf.sg.offset += page_offset;
 350                                 r2t->sendbuf.sg.length -= page_offset;
 351
 352                                 /* xmit logic will continue with next one */
 353                                 r2t->sg = sg + 1;
 354                                 break;
 355                         }
 356                         sg_count += sg->length;
 357                 }
 358                 BUG_ON(r2t->sg == NULL);
 359         } else
 360                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
 361                             (char*)sc->request_buffer + r2t->data_offset,
 362                             r2t->data_count);
 363
 364         list_add(&dtask->item, &tcp_ctask->dataqueue);
 365 }
 366
 367 /**
 368  * iscsi_r2t_rsp - iSCSI R2T Response processing
 369  * @conn: iscsi connection
 370  * @ctask: scsi command task
 371  **/
 372 static int
 373 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 374 {
 375         struct iscsi_r2t_info *r2t;
 376         struct iscsi_session *session = conn->session;
 377         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 378         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 379         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 380         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 381         int rc;
 382
 383         if (tcp_conn->in.datalen)
 384                 return ISCSI_ERR_DATALEN;
 385
 386         if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
 387                 return ISCSI_ERR_R2TSN;
 388
 389         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 390         if (rc)
 391                 return rc;
 392
 393         /* FIXME: use R2TSN to detect missing R2T */
 394
 395         /* fill-in new R2T associated with the task */
 396         spin_lock(&session->lock);
 397         if (!ctask->sc || ctask->mtask ||
 398              session->state != ISCSI_STATE_LOGGED_IN) {
 399                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 400                        "recovery...\n", ctask->itt);
 401                 spin_unlock(&session->lock);
 402                 return 0;
 403         }
 404         rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 405         BUG_ON(!rc);
 406
 407         r2t->exp_statsn = rhdr->statsn;
 408         r2t->data_length = be32_to_cpu(rhdr->data_length);
 409         if (r2t->data_length == 0 ||
 410             r2t->data_length > session->max_burst) {
 411                 spin_unlock(&session->lock);
 412                 return ISCSI_ERR_DATALEN;
 413         }
 414
 415         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 416         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 417                 spin_unlock(&session->lock);
 418                 return ISCSI_ERR_DATALEN;
 419         }
 420
 421         r2t->ttt = rhdr->ttt; /* no flip */
 422         r2t->solicit_datasn = 0;
 423
 424         iscsi_solicit_data_init(conn, ctask, r2t);
 425
 426         tcp_ctask->exp_r2tsn = r2tsn + 1;
 427         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
 428         __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 429         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 430
 431         scsi_queue_work(session->host, &conn->xmitwork);
 432         conn->r2t_pdus_cnt++;
 433         spin_unlock(&session->lock);
 434
 435         return 0;
 436 }
 437
 438 static int
 439 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
 440 {
 441         int rc = 0, opcode, ahslen;
 442         struct iscsi_hdr *hdr;
 443         struct iscsi_session *session = conn->session;
 444         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 445         uint32_t cdgst, rdgst = 0, itt;
 446
 447         hdr = tcp_conn->in.hdr;
 448
 449         /* verify PDU length */
 450         tcp_conn->in.datalen = ntoh24(hdr->dlength);
 451         if (tcp_conn->in.datalen > conn->max_recv_dlength) {
 452                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 453                        tcp_conn->in.datalen, conn->max_recv_dlength);
 454                 return ISCSI_ERR_DATALEN;
 455         }
 456         tcp_conn->data_copied = 0;
 457
 458         /* read AHS */
 459         ahslen = hdr->hlength << 2;
 460         tcp_conn->in.offset += ahslen;
 461         tcp_conn->in.copy -= ahslen;
 462         if (tcp_conn->in.copy < 0) {
 463                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 464                        "%d bytes\n", ahslen);
 465                 return ISCSI_ERR_AHSLEN;
 466         }
 467
 468         /* calculate read padding */
 469         tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
 470         if (tcp_conn->in.padding) {
 471                 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
 472                 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
 473         }
 474
 475         if (conn->hdrdgst_en) {
 476                 struct scatterlist sg;
 477
 478                 sg_init_one(&sg, (u8 *)hdr,
 479                             sizeof(struct iscsi_hdr) + ahslen);
 480                 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 481                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 482                                      ahslen);
 483                 if (cdgst != rdgst) {
 484                         printk(KERN_ERR "iscsi_tcp: hdrdgst error "
 485                                "recv 0x%x calc 0x%x\n", rdgst, cdgst);
 486                         return ISCSI_ERR_HDR_DGST;
 487                 }
 488         }
 489
 490         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 491         /* verify itt (itt encoding: age+cid+itt) */
 492         rc = iscsi_verify_itt(conn, hdr, &itt);
 493         if (rc == ISCSI_ERR_NO_SCSI_CMD) {
 494                 tcp_conn->in.datalen = 0; /* force drop */
 495                 return 0;
 496         } else if (rc)
 497                 return rc;
 498
 499         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 500                   opcode, tcp_conn->in.offset, tcp_conn->in.copy,
 501                   ahslen, tcp_conn->in.datalen);
 502
 503         switch(opcode) {
 504         case ISCSI_OP_SCSI_DATA_IN:
 505                 tcp_conn->in.ctask = session->cmds[itt];
 506                 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
 507                 /* fall through */
 508         case ISCSI_OP_SCSI_CMD_RSP:
 509                 tcp_conn->in.ctask = session->cmds[itt];
 510                 if (tcp_conn->in.datalen)
 511                         goto copy_hdr;
 512
 513                 spin_lock(&session->lock);
 514                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 515                 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
 516                 spin_unlock(&session->lock);
 517                 break;
 518         case ISCSI_OP_R2T:
 519                 tcp_conn->in.ctask = session->cmds[itt];
 520                 if (ahslen)
 521                         rc = ISCSI_ERR_AHSLEN;
 522                 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
 523                                                                 DMA_TO_DEVICE)
 524                         rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
 525                 else
 526                         rc = ISCSI_ERR_PROTO;
 527                 break;
 528         case ISCSI_OP_LOGIN_RSP:
 529         case ISCSI_OP_TEXT_RSP:
 530         case ISCSI_OP_LOGOUT_RSP:
 531         case ISCSI_OP_NOOP_IN:
 532         case ISCSI_OP_REJECT:
 533         case ISCSI_OP_ASYNC_EVENT:
 534                 if (tcp_conn->in.datalen)
 535                         goto copy_hdr;
 536         /* fall through */
 537         case ISCSI_OP_SCSI_TMFUNC_RSP:
 538                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
 539                 break;
 540         default:
 541                 rc = ISCSI_ERR_BAD_OPCODE;
 542                 break;
 543         }
 544
 545         return rc;
 546
 547 copy_hdr:
 548         /*
 549          * if we did zero copy for the header but we will need multiple
 550          * skbs to complete the command then we have to copy the header
 551          * for later use
 552          */
 553         if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <
 554            (tcp_conn->in.datalen + tcp_conn->in.padding +
 555             (conn->datadgst_en ? 4 : 0))) {
 556                 debug_tcp("Copying header for later use. in.copy %d in.datalen"
 557                           " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
 558                 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
 559                        sizeof(struct iscsi_hdr));
 560                 tcp_conn->in.hdr = &tcp_conn->hdr;
 561                 tcp_conn->in.zero_copy_hdr = 0;
 562         }
 563         return 0;
 564 }
 565
 566 /**
 567  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 568  * @conn: iscsi tcp connection
 569  * @ctask: scsi command task
 570  * @buf: buffer to copy to
 571  * @buf_size: size of buffer
 572  * @offset: offset within the buffer
 573  *
 574  * Notes:
 575  *      The function calls skb_copy_bits() and updates per-connection and
 576  *      per-cmd byte counters.
 577  *
 578  *      Read counters (in bytes):
 579  *
 580  *      conn->in.offset         offset within in progress SKB
 581  *      conn->in.copy           left to copy from in progress SKB
 582  *                              including padding
 583  *      conn->in.copied         copied already from in progress SKB
 584  *      conn->data_copied       copied already from in progress buffer
 585  *      ctask->sent             total bytes sent up to the MidLayer
 586  *      ctask->data_count       left to copy from in progress Data-In
 587  *      buf_left                left to copy from in progress buffer
 588  **/
 589 static inline int
 590 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 591                 void *buf, int buf_size, int offset)
 592 {
 593         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 594         int buf_left = buf_size - (tcp_conn->data_copied + offset);
 595         int size = min(tcp_conn->in.copy, buf_left);
 596         int rc;
 597
 598         size = min(size, ctask->data_count);
 599
 600         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 601                size, tcp_conn->in.offset, tcp_conn->in.copied);
 602
 603         BUG_ON(size <= 0);
 604         BUG_ON(tcp_ctask->sent + size > ctask->total_length);
 605
 606         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 607                            (char*)buf + (offset + tcp_conn->data_copied), size);
 608         /* must fit into skb->len */
 609         BUG_ON(rc);
 610
 611         tcp_conn->in.offset += size;
 612         tcp_conn->in.copy -= size;
 613         tcp_conn->in.copied += size;
 614         tcp_conn->data_copied += size;
 615         tcp_ctask->sent += size;
 616         ctask->data_count -= size;
 617
 618         BUG_ON(tcp_conn->in.copy < 0);
 619         BUG_ON(ctask->data_count < 0);
 620
 621         if (buf_size != (tcp_conn->data_copied + offset)) {
 622                 if (!ctask->data_count) {
 623                         BUG_ON(buf_size - tcp_conn->data_copied < 0);
 624                         /* done with this PDU */
 625                         return buf_size - tcp_conn->data_copied;
 626                 }
 627                 return -EAGAIN;
 628         }
 629
 630         /* done with this buffer or with both - PDU and buffer */
 631         tcp_conn->data_copied = 0;
 632         return 0;
 633 }
 634
 635 /**
 636  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 637  * @conn: iscsi tcp connection
 638  *
 639  * Notes:
 640  *      The function calls skb_copy_bits() and updates per-connection
 641  *      byte counters.
 642  **/
 643 static inline int
 644 iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
 645 {
 646         void *buf = tcp_conn->data;
 647         int buf_size = tcp_conn->in.datalen;
 648         int buf_left = buf_size - tcp_conn->data_copied;
 649         int size = min(tcp_conn->in.copy, buf_left);
 650         int rc;
 651
 652         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 653                size, tcp_conn->in.offset, tcp_conn->data_copied);
 654         BUG_ON(size <= 0);
 655
 656         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 657                            (char*)buf + tcp_conn->data_copied, size);
 658         BUG_ON(rc);
 659
 660         tcp_conn->in.offset += size;
 661         tcp_conn->in.copy -= size;
 662         tcp_conn->in.copied += size;
 663         tcp_conn->data_copied += size;
 664
 665         if (buf_size != tcp_conn->data_copied)
 666                 return -EAGAIN;
 667
 668         return 0;
 669 }
 670
 671 static inline void
 672 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
 673                          struct scatterlist *sg, int offset, int length)
 674 {
 675         struct scatterlist temp;
 676
 677         memcpy(&temp, sg, sizeof(struct scatterlist));
 678         temp.offset = offset;
 679         temp.length = length;
 680         crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
 681 }
 682
 683 static void
 684 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
 685 {
 686         struct scatterlist tmp;
 687
 688         sg_init_one(&tmp, buf, len);
 689         crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
 690 }
 691
 692 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 693 {
 694         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 695         struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
 696         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 697         struct scsi_cmnd *sc = ctask->sc;
 698         struct scatterlist *sg;
 699         int i, offset, rc = 0;
 700
 701         BUG_ON((void*)ctask != sc->SCp.ptr);
 702
 703         /*
 704          * copying Data-In into the Scsi_Cmnd
 705          */
 706         if (!sc->use_sg) {
 707                 i = ctask->data_count;
 708                 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
 709                                       sc->request_bufflen,
 710                                       tcp_ctask->data_offset);
 711                 if (rc == -EAGAIN)
 712                         return rc;
 713                 if (conn->datadgst_en)
 714                         iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
 715                                                  i);
 716                 rc = 0;
 717                 goto done;
 718         }
 719
 720         offset = tcp_ctask->data_offset;
 721         sg = sc->request_buffer;
 722
 723         if (tcp_ctask->data_offset)
 724                 for (i = 0; i < tcp_ctask->sg_count; i++)
 725                         offset -= sg[i].length;
 726         /* we've passed through partial sg*/
 727         if (offset < 0)
 728                 offset = 0;
 729
 730         for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
 731                 char *dest;
 732
 733                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 734                 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
 735                                       sg[i].length, offset);
 736                 kunmap_atomic(dest, KM_SOFTIRQ0);
 737                 if (rc == -EAGAIN)
 738                         /* continue with the next SKB/PDU */
 739                         return rc;
 740                 if (!rc) {
 741                         if (conn->datadgst_en) {
 742                                 if (!offset)
 743                                         crypto_digest_update(
 744                                                         tcp_conn->data_rx_tfm,
 745                                                         &sg[i], 1);
 746                                 else
 747                                         partial_sg_digest_update(tcp_conn,
 748                                                         &sg[i],
 749                                                         sg[i].offset + offset,
 750                                                         sg[i].length - offset);
 751                         }
 752                         offset = 0;
 753                         tcp_ctask->sg_count++;
 754                 }
 755
 756                 if (!ctask->data_count) {
 757                         if (rc && conn->datadgst_en)
 758                                 /*
 759                                  * data-in is complete, but buffer not...
 760                                  */
 761                                 partial_sg_digest_update(tcp_conn, &sg[i],
 762                                                 sg[i].offset, sg[i].length-rc);
 763                         rc = 0;
 764                         break;
 765                 }
 766
 767                 if (!tcp_conn->in.copy)
 768                         return -EAGAIN;
 769         }
 770         BUG_ON(ctask->data_count);
 771
 772 done:
 773         /* check for non-exceptional status */
 774         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 775                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 776                            (long)sc, sc->result, ctask->itt);
 777                 spin_lock(&conn->session->lock);
 778                 __iscsi_ctask_cleanup(conn, ctask);
 779                 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
 780                 spin_unlock(&conn->session->lock);
 781         }
 782
 783         return rc;
 784 }
 785
 786 static int
 787 iscsi_data_recv(struct iscsi_conn *conn)
 788 {
 789         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 790         int rc = 0, opcode;
 791
 792         opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
 793         switch (opcode) {
 794         case ISCSI_OP_SCSI_DATA_IN:
 795                 rc = iscsi_scsi_data_in(conn);
 796                 break;
 797         case ISCSI_OP_SCSI_CMD_RSP:
 798                 spin_lock(&conn->session->lock);
 799                 __iscsi_ctask_cleanup(conn, tcp_conn->in.ctask);
 800                 spin_unlock(&conn->session->lock);
 801         case ISCSI_OP_TEXT_RSP:
 802         case ISCSI_OP_LOGIN_RSP:
 803         case ISCSI_OP_NOOP_IN:
 804         case ISCSI_OP_ASYNC_EVENT:
 805         case ISCSI_OP_REJECT:
 806                 /*
 807                  * Collect data segment to the connection's data
 808                  * placeholder
 809                  */
 810                 if (iscsi_tcp_copy(tcp_conn)) {
 811                         rc = -EAGAIN;
 812                         goto exit;
 813                 }
 814
 815                 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, tcp_conn->data,
 816                                         tcp_conn->in.datalen);
 817                 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
 818                         iscsi_recv_digest_update(tcp_conn, tcp_conn->data,
 819                                                 tcp_conn->in.datalen);
 820                 break;
 821         default:
 822                 BUG_ON(1);
 823         }
 824 exit:
 825         return rc;
 826 }
 827
 828 /**
 829  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
 830  * @rd_desc: read descriptor
 831  * @skb: socket buffer
 832  * @offset: offset in skb
 833  * @len: skb->len - offset
 834  **/
 835 static int
 836 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 837                 unsigned int offset, size_t len)
 838 {
 839         int rc;
 840         struct iscsi_conn *conn = rd_desc->arg.data;
 841         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 842         int processed;
 843         char pad[ISCSI_PAD_LEN];
 844         struct scatterlist sg;
 845
 846         /*
 847          * Save current SKB and its offset in the corresponding
 848          * connection context.
 849          */
 850         tcp_conn->in.copy = skb->len - offset;
 851         tcp_conn->in.offset = offset;
 852         tcp_conn->in.skb = skb;
 853         tcp_conn->in.len = tcp_conn->in.copy;
 854         BUG_ON(tcp_conn->in.copy <= 0);
 855         debug_tcp("in %d bytes\n", tcp_conn->in.copy);
 856
 857 more:
 858         tcp_conn->in.copied = 0;
 859         rc = 0;
 860
 861         if (unlikely(conn->suspend_rx)) {
 862                 debug_tcp("conn %d Rx suspended!\n", conn->id);
 863                 return 0;
 864         }
 865
 866         if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
 867             tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
 868                 rc = iscsi_hdr_extract(tcp_conn);
 869                 if (rc) {
 870                        if (rc == -EAGAIN)
 871                                 goto nomore;
 872                        else {
 873                                 iscsi_conn_failure(conn, rc);
 874                                 return 0;
 875                        }
 876                 }
 877
 878                 /*
 879                  * Verify and process incoming PDU header.
 880                  */
 881                 rc = iscsi_tcp_hdr_recv(conn);
 882                 if (!rc && tcp_conn->in.datalen) {
 883                         if (conn->datadgst_en) {
 884                                 BUG_ON(!tcp_conn->data_rx_tfm);
 885                                 crypto_digest_init(tcp_conn->data_rx_tfm);
 886                         }
 887                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
 888                 } else if (rc) {
 889                         iscsi_conn_failure(conn, rc);
 890                         return 0;
 891                 }
 892         }
 893
 894         if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
 895                 uint32_t recv_digest;
 896
 897                 debug_tcp("extra data_recv offset %d copy %d\n",
 898                           tcp_conn->in.offset, tcp_conn->in.copy);
 899                 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
 900                                 &recv_digest, 4);
 901                 tcp_conn->in.offset += 4;
 902                 tcp_conn->in.copy -= 4;
 903                 if (recv_digest != tcp_conn->in.datadgst) {
 904                         debug_tcp("iscsi_tcp: data digest error!"
 905                                   "0x%x != 0x%x\n", recv_digest,
 906                                   tcp_conn->in.datadgst);
 907                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
 908                         return 0;
 909                 } else {
 910                         debug_tcp("iscsi_tcp: data digest match!"
 911                                   "0x%x == 0x%x\n", recv_digest,
 912                                   tcp_conn->in.datadgst);
 913                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 914                 }
 915         }
 916
 917         if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
 918            tcp_conn->in.copy) {
 919
 920                 debug_tcp("data_recv offset %d copy %d\n",
 921                        tcp_conn->in.offset, tcp_conn->in.copy);
 922
 923                 rc = iscsi_data_recv(conn);
 924                 if (rc) {
 925                         if (rc == -EAGAIN)
 926                                 goto again;
 927                         iscsi_conn_failure(conn, rc);
 928                         return 0;
 929                 }
 930                 tcp_conn->in.copy -= tcp_conn->in.padding;
 931                 tcp_conn->in.offset += tcp_conn->in.padding;
 932                 if (conn->datadgst_en) {
 933                         if (tcp_conn->in.padding) {
 934                                 debug_tcp("padding -> %d\n",
 935                                           tcp_conn->in.padding);
 936                                 memset(pad, 0, tcp_conn->in.padding);
 937                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
 938                                 crypto_digest_update(tcp_conn->data_rx_tfm,
 939                                                      &sg, 1);
 940                         }
 941                         crypto_digest_final(tcp_conn->data_rx_tfm,
 942                                             (u8 *) & tcp_conn->in.datadgst);
 943                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
 944                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
 945                 } else
 946                         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 947         }
 948
 949         debug_tcp("f, processed %d from out of %d padding %d\n",
 950                tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
 951         BUG_ON(tcp_conn->in.offset - offset > len);
 952
 953         if (tcp_conn->in.offset - offset != len) {
 954                 debug_tcp("continue to process %d bytes\n",
 955                        (int)len - (tcp_conn->in.offset - offset));
 956                 goto more;
 957         }
 958
 959 nomore:
 960         processed = tcp_conn->in.offset - offset;
 961         BUG_ON(processed == 0);
 962         return processed;
 963
 964 again:
 965         processed = tcp_conn->in.offset - offset;
 966         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
 967                   processed, (int)len, (int)rd_desc->count);
 968         BUG_ON(processed == 0);
 969         BUG_ON(processed > len);
 970
 971         conn->rxdata_octets += processed;
 972         return processed;
 973 }
 974
 975 static void
 976 iscsi_tcp_data_ready(struct sock *sk, int flag)
 977 {
 978         struct iscsi_conn *conn = sk->sk_user_data;
 979         read_descriptor_t rd_desc;
 980
 981         read_lock(&sk->sk_callback_lock);
 982
 983         /*
 984          * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
 985          * We set count to 1 because we want the network layer to
 986          * hand us all the skbs that are available. iscsi_tcp_data_recv
 987          * handled pdus that cross buffers or pdus that still need data.
 988          */
 989         rd_desc.arg.data = conn;
 990         rd_desc.count = 1;
 991         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
 992
 993         read_unlock(&sk->sk_callback_lock);
 994 }
 995
 996 static void
 997 iscsi_tcp_state_change(struct sock *sk)
 998 {
 999         struct iscsi_tcp_conn *tcp_conn;
1000         struct iscsi_conn *conn;
1001         struct iscsi_session *session;
1002         void (*old_state_change)(struct sock *);
1003
1004         read_lock(&sk->sk_callback_lock);
1005
1006         conn = (struct iscsi_conn*)sk->sk_user_data;
1007         session = conn->session;
1008
1009         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1010              sk->sk_state == TCP_CLOSE) &&
1011             !atomic_read(&sk->sk_rmem_alloc)) {
1012                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1013                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1014         }
1015
1016         tcp_conn = conn->dd_data;
1017         old_state_change = tcp_conn->old_state_change;
1018
1019         read_unlock(&sk->sk_callback_lock);
1020
1021         old_state_change(sk);
1022 }
1023
1024 /**
1025  * iscsi_write_space - Called when more output buffer space is available
1026  * @sk: socket space is available for
1027  **/
1028 static void
1029 iscsi_write_space(struct sock *sk)
1030 {
1031         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1032         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1033
1034         tcp_conn->old_write_space(sk);
1035         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1036         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1037         scsi_queue_work(conn->session->host, &conn->xmitwork);
1038 }
1039
1040 static void
1041 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1042 {
1043         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1044         struct sock *sk = tcp_conn->sock->sk;
1045
1046         /* assign new callbacks */
1047         write_lock_bh(&sk->sk_callback_lock);
1048         sk->sk_user_data = conn;
1049         tcp_conn->old_data_ready = sk->sk_data_ready;
1050         tcp_conn->old_state_change = sk->sk_state_change;
1051         tcp_conn->old_write_space = sk->sk_write_space;
1052         sk->sk_data_ready = iscsi_tcp_data_ready;
1053         sk->sk_state_change = iscsi_tcp_state_change;
1054         sk->sk_write_space = iscsi_write_space;
1055         write_unlock_bh(&sk->sk_callback_lock);
1056 }
1057
1058 static void
1059 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1060 {
1061         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1062         struct sock *sk = tcp_conn->sock->sk;
1063
1064         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1065         write_lock_bh(&sk->sk_callback_lock);
1066         sk->sk_user_data    = NULL;
1067         sk->sk_data_ready   = tcp_conn->old_data_ready;
1068         sk->sk_state_change = tcp_conn->old_state_change;
1069         sk->sk_write_space  = tcp_conn->old_write_space;
1070         sk->sk_no_check  = 0;
1071         write_unlock_bh(&sk->sk_callback_lock);
1072 }
1073
1074 /**
1075  * iscsi_send - generic send routine
1076  * @sk: kernel's socket
1077  * @buf: buffer to write from
1078  * @size: actual size to write
1079  * @flags: socket's flags
1080  */
1081 static inline int
1082 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1083 {
1084         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1085         struct socket *sk = tcp_conn->sock;
1086         int offset = buf->sg.offset + buf->sent;
1087
1088         /*
1089          * if we got use_sg=0 or are sending something we kmallocd
1090          * then we did not have to do kmap (kmap returns page_address)
1091          *
1092          * if we got use_sg > 0, but had to drop down, we do not
1093          * set clustering so this should only happen for that
1094          * slab case.
1095          */
1096         if (buf->use_sendmsg)
1097                 return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1098         else
1099                 return tcp_conn->sendpage(sk, buf->sg.page, offset, size,
1100                                           flags);
1101 }
1102
1103 /**
1104  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1105  * @conn: iscsi connection
1106  * @buf: buffer to write from
1107  * @datalen: lenght of data to be sent after the header
1108  *
1109  * Notes:
1110  *      (Tx, Fast Path)
1111  **/
1112 static inline int
1113 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1114 {
1115         struct iscsi_tcp_conn *tcp_conn;
1116         int flags = 0; /* MSG_DONTWAIT; */
1117         int res, size;
1118
1119         size = buf->sg.length - buf->sent;
1120         BUG_ON(buf->sent + size > buf->sg.length);
1121         if (buf->sent + size != buf->sg.length || datalen)
1122                 flags |= MSG_MORE;
1123
1124         res = iscsi_send(conn, buf, size, flags);
1125         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1126         if (res >= 0) {
1127                 conn->txdata_octets += res;
1128                 buf->sent += res;
1129                 if (size != res)
1130                         return -EAGAIN;
1131                 return 0;
1132         } else if (res == -EAGAIN) {
1133                 tcp_conn = conn->dd_data;
1134                 tcp_conn->sendpage_failures_cnt++;
1135                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1136         } else if (res == -EPIPE)
1137                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1138
1139         return res;
1140 }
1141
1142 /**
1143  * iscsi_sendpage - send one page of iSCSI Data-Out.
1144  * @conn: iscsi connection
1145  * @buf: buffer to write from
1146  * @count: remaining data
1147  * @sent: number of bytes sent
1148  *
1149  * Notes:
1150  *      (Tx, Fast Path)
1151  **/
1152 static inline int
1153 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1154                int *count, int *sent)
1155 {
1156         struct iscsi_tcp_conn *tcp_conn;
1157         int flags = 0; /* MSG_DONTWAIT; */
1158         int res, size;
1159
1160         size = buf->sg.length - buf->sent;
1161         BUG_ON(buf->sent + size > buf->sg.length);
1162         if (size > *count)
1163                 size = *count;
1164         if (buf->sent + size != buf->sg.length || *count != size)
1165                 flags |= MSG_MORE;
1166
1167         res = iscsi_send(conn, buf, size, flags);
1168         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1169                   size, buf->sent, *count, *sent, res);
1170         if (res >= 0) {
1171                 conn->txdata_octets += res;
1172                 buf->sent += res;
1173                 *count -= res;
1174                 *sent += res;
1175                 if (size != res)
1176                         return -EAGAIN;
1177                 return 0;
1178         } else if (res == -EAGAIN) {
1179                 tcp_conn = conn->dd_data;
1180                 tcp_conn->sendpage_failures_cnt++;
1181                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1182         } else if (res == -EPIPE)
1183                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1184
1185         return res;
1186 }
1187
1188 static inline void
1189 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1190                       struct iscsi_cmd_task *ctask)
1191 {
1192         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1193
1194         BUG_ON(!tcp_conn->data_tx_tfm);
1195         crypto_digest_init(tcp_conn->data_tx_tfm);
1196         tcp_ctask->digest_count = 4;
1197 }
1198
1199 static int
1200 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1201                         struct iscsi_buf *buf, uint32_t *digest, int final)
1202 {
1203         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1204         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1205         int rc = 0;
1206         int sent = 0;
1207
1208         if (final)
1209                 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1210
1211         iscsi_buf_init_virt(buf, (char*)digest, 4);
1212         rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1213         if (rc) {
1214                 tcp_ctask->datadigest = *digest;
1215                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1216         } else
1217                 tcp_ctask->digest_count = 4;
1218         return rc;
1219 }
1220
1221 /**
1222  * iscsi_solicit_data_cont - initialize next Data-Out
1223  * @conn: iscsi connection
1224  * @ctask: scsi command task
1225  * @r2t: R2T info
1226  * @left: bytes left to transfer
1227  *
1228  * Notes:
1229  *      Initialize next Data-Out within this R2T sequence and continue
1230  *      to process next Scatter-Gather element(if any) of this SCSI command.
1231  *
1232  *      Called under connection lock.
1233  **/
1234 static void
1235 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1236                         struct iscsi_r2t_info *r2t, int left)
1237 {
1238         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1239         struct iscsi_data *hdr;
1240         struct iscsi_data_task *dtask;
1241         struct scsi_cmnd *sc = ctask->sc;
1242         int new_offset;
1243
1244         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
1245         BUG_ON(!dtask);
1246         INIT_LIST_HEAD(&dtask->item);
1247         hdr = &dtask->hdr;
1248         memset(hdr, 0, sizeof(struct iscsi_data));
1249         hdr->ttt = r2t->ttt;
1250         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1251         r2t->solicit_datasn++;
1252         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1253         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1254         hdr->itt = ctask->hdr->itt;
1255         hdr->exp_statsn = r2t->exp_statsn;
1256         new_offset = r2t->data_offset + r2t->sent;
1257         hdr->offset = cpu_to_be32(new_offset);
1258         if (left > conn->max_xmit_dlength) {
1259                 hton24(hdr->dlength, conn->max_xmit_dlength);
1260                 r2t->data_count = conn->max_xmit_dlength;
1261         } else {
1262                 hton24(hdr->dlength, left);
1263                 r2t->data_count = left;
1264                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1265         }
1266         conn->dataout_pdus_cnt++;
1267
1268         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1269                            sizeof(struct iscsi_hdr));
1270
1271         r2t->dtask = dtask;
1272
1273         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1274                 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1275                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1276                 r2t->sg += 1;
1277         } else
1278                 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1279                             (char*)sc->request_buffer + new_offset,
1280                             r2t->data_count);
1281
1282         list_add(&dtask->item, &tcp_ctask->dataqueue);
1283 }
1284
1285 static void
1286 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1287 {
1288         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1289         struct iscsi_data_task *dtask;
1290
1291         dtask = mempool_alloc(tcp_ctask->datapool, GFP_ATOMIC);
1292         BUG_ON(!dtask);
1293         INIT_LIST_HEAD(&dtask->item);
1294
1295         iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1296                                       tcp_ctask->r2t_data_count);
1297         iscsi_buf_init_virt(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1298                            sizeof(struct iscsi_hdr));
1299
1300         list_add(&dtask->item, &tcp_ctask->dataqueue);
1301         tcp_ctask->dtask = dtask;
1302 }
1303
1304 /**
1305  * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1306  * @conn: iscsi connection
1307  * @ctask: scsi command task
1308  * @sc: scsi command
1309  **/
1310 static void
1311 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1312 {
1313         struct scsi_cmnd *sc = ctask->sc;
1314         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1315
1316         BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1317
1318         tcp_ctask->sent = 0;
1319         tcp_ctask->sg_count = 0;
1320
1321         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1322                 tcp_ctask->xmstate = XMSTATE_W_HDR;
1323                 tcp_ctask->exp_r2tsn = 0;
1324                 BUG_ON(ctask->total_length == 0);
1325
1326                 if (sc->use_sg) {
1327                         struct scatterlist *sg = sc->request_buffer;
1328
1329                         iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1330                                           &sg[tcp_ctask->sg_count++]);
1331                         tcp_ctask->sg = sg;
1332                         tcp_ctask->bad_sg = sg + sc->use_sg;
1333                 } else
1334                         iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1335                                            sc->request_buffer,
1336                                            sc->request_bufflen);
1337
1338                 if (ctask->imm_count)
1339                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1340
1341                 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1342                 if (tcp_ctask->pad_count) {
1343                         tcp_ctask->pad_count = ISCSI_PAD_LEN -
1344                                                         tcp_ctask->pad_count;
1345                         debug_scsi("write padding %d bytes\n",
1346                                    tcp_ctask->pad_count);
1347                         tcp_ctask->xmstate |= XMSTATE_W_PAD;
1348                 }
1349
1350                 if (ctask->unsol_count)
1351                         tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1352                                                 XMSTATE_UNS_INIT;
1353                 tcp_ctask->r2t_data_count = ctask->total_length -
1354                                     ctask->imm_count -
1355                                     ctask->unsol_count;
1356
1357                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1358                            "r2t_data %d]\n",
1359                            ctask->itt, ctask->total_length, ctask->imm_count,
1360                            ctask->unsol_count, tcp_ctask->r2t_data_count);
1361         } else
1362                 tcp_ctask->xmstate = XMSTATE_R_HDR;
1363
1364         iscsi_buf_init_virt(&tcp_ctask->headbuf, (char*)ctask->hdr,
1365                             sizeof(struct iscsi_hdr));
1366 }
1367
1368 /**
1369  * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1370  * @conn: iscsi connection
1371  * @mtask: task management task
1372  *
1373  * Notes:
1374  *      The function can return -EAGAIN in which case caller must
1375  *      call it again later, or recover. '0' return code means successful
1376  *      xmit.
1377  *
1378  *      Management xmit state machine consists of two states:
1379  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1380  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1381  **/
1382 static int
1383 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1384 {
1385         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1386
1387         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1388                 conn->id, tcp_mtask->xmstate, mtask->itt);
1389
1390         if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1391                 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1392                 if (mtask->data_count)
1393                         tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1394                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1395                     conn->stop_stage != STOP_CONN_RECOVER &&
1396                     conn->hdrdgst_en)
1397                         iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1398                                         (u8*)tcp_mtask->hdrext);
1399                 if (iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1400                                   mtask->data_count)) {
1401                         tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1402                         if (mtask->data_count)
1403                                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1404                         return -EAGAIN;
1405                 }
1406         }
1407
1408         if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1409                 BUG_ON(!mtask->data_count);
1410                 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1411                 /* FIXME: implement.
1412                  * Virtual buffer could be spreaded across multiple pages...
1413                  */
1414                 do {
1415                         if (iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1416                                    &mtask->data_count, &tcp_mtask->sent)) {
1417                                 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1418                                 return -EAGAIN;
1419                         }
1420                 } while (mtask->data_count);
1421         }
1422
1423         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1424         if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1425                 struct iscsi_session *session = conn->session;
1426
1427                 spin_lock_bh(&session->lock);
1428                 list_del(&conn->mtask->running);
1429                 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1430                             sizeof(void*));
1431                 spin_unlock_bh(&session->lock);
1432         }
1433         return 0;
1434 }
1435
1436 static inline int
1437 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1438                      struct iscsi_tcp_cmd_task *tcp_ctask)
1439 {
1440         tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1441         if (conn->hdrdgst_en)
1442                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1443                                  (u8*)tcp_ctask->hdrext);
1444         if (!iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0)) {
1445                 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1446                 return 0; /* wait for Data-In */
1447         }
1448         tcp_ctask->xmstate |= XMSTATE_R_HDR;
1449         return -EAGAIN;
1450 }
1451
1452 static inline int
1453 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1454                      struct iscsi_cmd_task *ctask)
1455 {
1456         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1457
1458         tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1459         if (conn->hdrdgst_en)
1460                 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1461                                  (u8*)tcp_ctask->hdrext);
1462         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count)) {
1463                 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1464                 return -EAGAIN;
1465         }
1466         return 0;
1467 }
1468
1469 static inline int
1470 handle_xmstate_data_digest(struct iscsi_conn *conn,
1471                            struct iscsi_cmd_task *ctask)
1472 {
1473         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1474
1475         tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1476         debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1477         if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1478                                     &tcp_ctask->datadigest, 0)) {
1479                 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1480                 debug_tcp("resent data digest 0x%x fail!\n",
1481                           tcp_ctask->datadigest);
1482                 return -EAGAIN;
1483         }
1484         return 0;
1485 }
1486
1487 static inline int
1488 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1489 {
1490         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1491         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1492
1493         BUG_ON(!ctask->imm_count);
1494         tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1495
1496         if (conn->datadgst_en) {
1497                 iscsi_data_digest_init(tcp_conn, ctask);
1498                 tcp_ctask->immdigest = 0;
1499         }
1500
1501         for (;;) {
1502                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &ctask->imm_count,
1503                                    &tcp_ctask->sent)) {
1504                         tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1505                         if (conn->datadgst_en) {
1506                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1507                                                 (u8*)&tcp_ctask->immdigest);
1508                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1509                                           tcp_ctask->datadigest);
1510                         }
1511                         return -EAGAIN;
1512                 }
1513                 if (conn->datadgst_en)
1514                         crypto_digest_update(tcp_conn->data_tx_tfm,
1515                                              &tcp_ctask->sendbuf.sg, 1);
1516
1517                 if (!ctask->imm_count)
1518                         break;
1519                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1520                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1521         }
1522
1523         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1524                 if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1525                                             &tcp_ctask->immdigest, 1)) {
1526                         debug_tcp("sending imm digest 0x%x fail!\n",
1527                                   tcp_ctask->immdigest);
1528                         return -EAGAIN;
1529                 }
1530                 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1531         }
1532
1533         return 0;
1534 }
1535
1536 static inline int
1537 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1538 {
1539         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1540         struct iscsi_data_task *dtask;
1541
1542         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1543         if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1544                 iscsi_unsolicit_data_init(conn, ctask);
1545                 BUG_ON(!tcp_ctask->dtask);
1546                 dtask = tcp_ctask->dtask;
1547                 if (conn->hdrdgst_en)
1548                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1549                                         (u8*)dtask->hdrext);
1550                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1551         }
1552         if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count)) {
1553                 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1554                 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1555                 return -EAGAIN;
1556         }
1557
1558         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1559                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1560         return 0;
1561 }
1562
1563 static inline int
1564 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1565 {
1566         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1567         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1568         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1569
1570         BUG_ON(!ctask->data_count);
1571         tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1572
1573         if (conn->datadgst_en) {
1574                 iscsi_data_digest_init(tcp_conn, ctask);
1575                 dtask->digest = 0;
1576         }
1577
1578         for (;;) {
1579                 int start = tcp_ctask->sent;
1580
1581                 if (iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1582                                    &ctask->data_count, &tcp_ctask->sent)) {
1583                         ctask->unsol_count -= tcp_ctask->sent - start;
1584                         tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1585                         /* will continue with this ctask later.. */
1586                         if (conn->datadgst_en) {
1587                                 crypto_digest_final(tcp_conn->data_tx_tfm,
1588                                                 (u8 *)&dtask->digest);
1589                                 debug_tcp("tx uns data fail 0x%x\n",
1590                                           dtask->digest);
1591                         }
1592                         return -EAGAIN;
1593                 }
1594
1595                 BUG_ON(tcp_ctask->sent > ctask->total_length);
1596                 ctask->unsol_count -= tcp_ctask->sent - start;
1597
1598                 /*
1599                  * XXX:we may run here with un-initial sendbuf.
1600                  * so pass it
1601                  */
1602                 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1603                         crypto_digest_update(tcp_conn->data_tx_tfm,
1604                                              &tcp_ctask->sendbuf.sg, 1);
1605
1606                 if (!ctask->data_count)
1607                         break;
1608                 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1609                                   &tcp_ctask->sg[tcp_ctask->sg_count++]);
1610         }
1611         BUG_ON(ctask->unsol_count < 0);
1612
1613         /*
1614          * Done with the Data-Out. Next, check if we need
1615          * to send another unsolicited Data-Out.
1616          */
1617         if (ctask->unsol_count) {
1618                 if (conn->datadgst_en) {
1619                         if (iscsi_digest_final_send(conn, ctask,
1620                                                     &dtask->digestbuf,
1621                                                     &dtask->digest, 1)) {
1622                                 debug_tcp("send uns digest 0x%x fail\n",
1623                                           dtask->digest);
1624                                 return -EAGAIN;
1625                         }
1626                         debug_tcp("sending uns digest 0x%x, more uns\n",
1627                                   dtask->digest);
1628                 }
1629                 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1630                 return 1;
1631         }
1632
1633         if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1634                 if (iscsi_digest_final_send(conn, ctask,
1635                                             &dtask->digestbuf,
1636                                             &dtask->digest, 1)) {
1637                         debug_tcp("send last uns digest 0x%x fail\n",
1638                                    dtask->digest);
1639                         return -EAGAIN;
1640                 }
1641                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1642         }
1643
1644         return 0;
1645 }
1646
1647 static inline int
1648 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1649 {
1650         struct iscsi_session *session = conn->session;
1651         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1652         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1653         struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1654         struct iscsi_data_task *dtask = r2t->dtask;
1655         int left;
1656
1657         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1658         tcp_ctask->dtask = dtask;
1659
1660         if (conn->datadgst_en) {
1661                 iscsi_data_digest_init(tcp_conn, ctask);
1662                 dtask->digest = 0;
1663         }
1664 solicit_again:
1665         /*
1666          * send Data-Out whitnin this R2T sequence.
1667          */
1668         if (!r2t->data_count)
1669                 goto data_out_done;
1670
1671         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1672                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1673                 /* will continue with this ctask later.. */
1674                 if (conn->datadgst_en) {
1675                         crypto_digest_final(tcp_conn->data_tx_tfm,
1676                                           (u8 *)&dtask->digest);
1677                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1678                 }
1679                 return -EAGAIN;
1680         }
1681
1682         BUG_ON(r2t->data_count < 0);
1683         if (conn->datadgst_en)
1684                 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1685                                      1);
1686
1687         if (r2t->data_count) {
1688                 BUG_ON(ctask->sc->use_sg == 0);
1689                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1690                         BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1691                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1692                         r2t->sg += 1;
1693                 }
1694                 goto solicit_again;
1695         }
1696
1697 data_out_done:
1698         /*
1699          * Done with this Data-Out. Next, check if we have
1700          * to send another Data-Out for this R2T.
1701          */
1702         BUG_ON(r2t->data_length - r2t->sent < 0);
1703         left = r2t->data_length - r2t->sent;
1704         if (left) {
1705                 if (conn->datadgst_en) {
1706                         if (iscsi_digest_final_send(conn, ctask,
1707                                                     &dtask->digestbuf,
1708                                                     &dtask->digest, 1)) {
1709                                 debug_tcp("send r2t data digest 0x%x"
1710                                           "fail\n", dtask->digest);
1711                                 return -EAGAIN;
1712                         }
1713                         debug_tcp("r2t data send digest 0x%x\n",
1714                                   dtask->digest);
1715                 }
1716                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1717                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1718                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1719                 return 1;
1720         }
1721
1722         /*
1723          * Done with this R2T. Check if there are more
1724          * outstanding R2Ts ready to be processed.
1725          */
1726         BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1727         if (conn->datadgst_en) {
1728                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1729                                             &dtask->digest, 1)) {
1730                         debug_tcp("send last r2t data digest 0x%x"
1731                                   "fail\n", dtask->digest);
1732                         return -EAGAIN;
1733                 }
1734                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1735         }
1736
1737         tcp_ctask->r2t_data_count -= r2t->data_length;
1738         tcp_ctask->r2t = NULL;
1739         spin_lock_bh(&session->lock);
1740         __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1741         spin_unlock_bh(&session->lock);
1742         if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1743                 tcp_ctask->r2t = r2t;
1744                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1745                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1746                 return 1;
1747         }
1748
1749         return 0;
1750 }
1751
1752 static inline int
1753 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1754 {
1755         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1756         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1757         struct iscsi_data_task *dtask = tcp_ctask->dtask;
1758         int sent;
1759
1760         tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1761         iscsi_buf_init_virt(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1762                             tcp_ctask->pad_count);
1763         if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1764                            &sent)) {
1765                 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1766                 return -EAGAIN;
1767         }
1768
1769         if (conn->datadgst_en) {
1770                 crypto_digest_update(tcp_conn->data_tx_tfm,
1771                                      &tcp_ctask->sendbuf.sg, 1);
1772                 /* imm data? */
1773                 if (!dtask) {
1774                         if (iscsi_digest_final_send(conn, ctask,
1775                                                     &tcp_ctask->immbuf,
1776                                                     &tcp_ctask->immdigest, 1)) {
1777                                 debug_tcp("send padding digest 0x%x"
1778                                           "fail!\n", tcp_ctask->immdigest);
1779                                 return -EAGAIN;
1780                         }
1781                         debug_tcp("done with padding, digest 0x%x\n",
1782                                   tcp_ctask->datadigest);
1783                 } else {
1784                         if (iscsi_digest_final_send(conn, ctask,
1785                                                     &dtask->digestbuf,
1786                                                     &dtask->digest, 1)) {
1787                                 debug_tcp("send padding digest 0x%x"
1788                                           "fail\n", dtask->digest);
1789                                 return -EAGAIN;
1790                         }
1791                         debug_tcp("done with padding, digest 0x%x\n",
1792                                   dtask->digest);
1793                 }
1794         }
1795
1796         return 0;
1797 }
1798
1799 static int
1800 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1801 {
1802         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1803         int rc = 0;
1804
1805         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1806                 conn->id, tcp_ctask->xmstate, ctask->itt);
1807
1808         /*
1809          * serialize with TMF AbortTask
1810          */
1811         if (ctask->mtask)
1812                 return rc;
1813
1814         if (tcp_ctask->xmstate & XMSTATE_R_HDR) {
1815                 rc = handle_xmstate_r_hdr(conn, tcp_ctask);
1816                 return rc;
1817         }
1818
1819         if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1820                 rc = handle_xmstate_w_hdr(conn, ctask);
1821                 if (rc)
1822                         return rc;
1823         }
1824
1825         /* XXX: for data digest xmit recover */
1826         if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1827                 rc = handle_xmstate_data_digest(conn, ctask);
1828                 if (rc)
1829                         return rc;
1830         }
1831
1832         if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1833                 rc = handle_xmstate_imm_data(conn, ctask);
1834                 if (rc)
1835                         return rc;
1836         }
1837
1838         if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1839                 BUG_ON(!ctask->unsol_count);
1840                 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1841 unsolicit_head_again:
1842                 rc = handle_xmstate_uns_hdr(conn, ctask);
1843                 if (rc)
1844                         return rc;
1845         }
1846
1847         if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1848                 rc = handle_xmstate_uns_data(conn, ctask);
1849                 if (rc == 1)
1850                         goto unsolicit_head_again;
1851                 else if (rc)
1852                         return rc;
1853                 goto done;
1854         }
1855
1856         if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1857                 struct iscsi_r2t_info *r2t;
1858
1859                 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1860                 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1861                 if (!tcp_ctask->r2t)
1862                         __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1863                                     sizeof(void*));
1864 solicit_head_again:
1865                 r2t = tcp_ctask->r2t;
1866                 if (conn->hdrdgst_en)
1867                         iscsi_hdr_digest(conn, &r2t->headbuf,
1868                                         (u8*)r2t->dtask->hdrext);
1869                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
1870                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1871                         tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1872                         return -EAGAIN;
1873                 }
1874
1875                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1876                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1877                         r2t->sent);
1878         }
1879
1880         if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1881                 rc = handle_xmstate_sol_data(conn, ctask);
1882                 if (rc == 1)
1883                         goto solicit_head_again;
1884                 if (rc)
1885                         return rc;
1886         }
1887
1888 done:
1889         /*
1890          * Last thing to check is whether we need to send write
1891          * padding. Note that we check for xmstate equality, not just the bit.
1892          */
1893         if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1894                 rc = handle_xmstate_w_pad(conn, ctask);
1895
1896         return rc;
1897 }
1898
1899 static struct iscsi_cls_conn *
1900 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1901 {
1902         struct iscsi_conn *conn;
1903         struct iscsi_cls_conn *cls_conn;
1904         struct iscsi_tcp_conn *tcp_conn;
1905
1906         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1907         if (!cls_conn)
1908                 return NULL;
1909         conn = cls_conn->dd_data;
1910         /*
1911          * due to strange issues with iser these are not set
1912          * in iscsi_conn_setup
1913          */
1914         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1915
1916         tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1917         if (!tcp_conn)
1918                 goto tcp_conn_alloc_fail;
1919
1920         conn->dd_data = tcp_conn;
1921         tcp_conn->iscsi_conn = conn;
1922         tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1923         /* initial operational parameters */
1924         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1925         tcp_conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1926
1927         /* allocate initial PDU receive place holder */
1928         if (tcp_conn->data_size <= PAGE_SIZE)
1929                 tcp_conn->data = kmalloc(tcp_conn->data_size, GFP_KERNEL);
1930         else
1931                 tcp_conn->data = (void*)__get_free_pages(GFP_KERNEL,
1932                                         get_order(tcp_conn->data_size));
1933         if (!tcp_conn->data)
1934                 goto max_recv_dlenght_alloc_fail;
1935
1936         return cls_conn;
1937
1938 max_recv_dlenght_alloc_fail:
1939         kfree(tcp_conn);
1940 tcp_conn_alloc_fail:
1941         iscsi_conn_teardown(cls_conn);
1942         return NULL;
1943 }
1944
1945 static void
1946 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1947 {
1948         struct iscsi_conn *conn = cls_conn->dd_data;
1949         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1950         int digest = 0;
1951
1952         if (conn->hdrdgst_en || conn->datadgst_en)
1953                 digest = 1;
1954
1955         iscsi_conn_teardown(cls_conn);
1956
1957         /* now free tcp_conn */
1958         if (digest) {
1959                 if (tcp_conn->tx_tfm)
1960                         crypto_free_tfm(tcp_conn->tx_tfm);
1961                 if (tcp_conn->rx_tfm)
1962                         crypto_free_tfm(tcp_conn->rx_tfm);
1963                 if (tcp_conn->data_tx_tfm)
1964                         crypto_free_tfm(tcp_conn->data_tx_tfm);
1965                 if (tcp_conn->data_rx_tfm)
1966                         crypto_free_tfm(tcp_conn->data_rx_tfm);
1967         }
1968
1969         /* free conn->data, size = MaxRecvDataSegmentLength */
1970         if (tcp_conn->data_size <= PAGE_SIZE)
1971                 kfree(tcp_conn->data);
1972         else
1973                 free_pages((unsigned long)tcp_conn->data,
1974                            get_order(tcp_conn->data_size));
1975         kfree(tcp_conn);
1976 }
1977
1978 static int
1979 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1980                     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1981                     int is_leading)
1982 {
1983         struct iscsi_conn *conn = cls_conn->dd_data;
1984         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1985         struct sock *sk;
1986         struct socket *sock;
1987         int err;
1988
1989         /* lookup for existing socket */
1990         sock = sockfd_lookup((int)transport_eph, &err);
1991         if (!sock) {
1992                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
1993                 return -EEXIST;
1994         }
1995
1996         err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
1997         if (err)
1998                 return err;
1999
2000         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2001                 /* bind iSCSI connection and socket */
2002                 tcp_conn->sock = sock;
2003
2004                 /* setup Socket parameters */
2005                 sk = sock->sk;
2006                 sk->sk_reuse = 1;
2007                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2008                 sk->sk_allocation = GFP_ATOMIC;
2009
2010                 /* FIXME: disable Nagle's algorithm */
2011
2012                 /*
2013                  * Intercept TCP callbacks for sendfile like receive
2014                  * processing.
2015                  */
2016                 conn->recv_lock = &sk->sk_callback_lock;
2017                 iscsi_conn_set_callbacks(conn);
2018                 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2019                 /*
2020                  * set receive state machine into initial state
2021                  */
2022                 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2023         }
2024
2025         return 0;
2026 }
2027
2028 static void
2029 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2030 {
2031         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2032         struct iscsi_r2t_info *r2t;
2033
2034         /* flush ctask's r2t queues */
2035         while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)))
2036                 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
2037                             sizeof(void*));
2038
2039         __iscsi_ctask_cleanup(conn, ctask);
2040 }
2041
2042 static void
2043 iscsi_tcp_suspend_conn_rx(struct iscsi_conn *conn)
2044 {
2045         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2046         struct sock *sk;
2047
2048         if (!tcp_conn->sock)
2049                 return;
2050
2051         sk = tcp_conn->sock->sk;
2052         write_lock_bh(&sk->sk_callback_lock);
2053         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2054         write_unlock_bh(&sk->sk_callback_lock);
2055 }
2056
2057 static void
2058 iscsi_tcp_terminate_conn(struct iscsi_conn *conn)
2059 {
2060         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2061
2062         if (!tcp_conn->sock)
2063                 return;
2064
2065         sock_hold(tcp_conn->sock->sk);
2066         iscsi_conn_restore_callbacks(conn);
2067         sock_put(tcp_conn->sock->sk);
2068
2069         sock_release(tcp_conn->sock);
2070         tcp_conn->sock = NULL;
2071         conn->recv_lock = NULL;
2072 }
2073
2074 /* called with host lock */
2075 static void
2076 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2077                     char *data, uint32_t data_size)
2078 {
2079         struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2080
2081         iscsi_buf_init_virt(&tcp_mtask->headbuf, (char*)mtask->hdr,
2082                                     sizeof(struct iscsi_hdr));
2083         tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2084
2085         if (mtask->data_count)
2086                 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2087                                     mtask->data_count);
2088 }
2089
2090 static int
2091 iscsi_r2tpool_alloc(struct iscsi_session *session)
2092 {
2093         int i;
2094         int cmd_i;
2095
2096         /*
2097          * initialize per-task: R2T pool and xmit queue
2098          */
2099         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2100                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2101                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2102
2103                 /*
2104                  * pre-allocated x4 as much r2ts to handle race when
2105                  * target acks DataOut faster than we data_xmit() queues
2106                  * could replenish r2tqueue.
2107                  */
2108
2109                 /* R2T pool */
2110                 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2111                                     (void***)&tcp_ctask->r2ts,
2112                                     sizeof(struct iscsi_r2t_info))) {
2113                         goto r2t_alloc_fail;
2114                 }
2115
2116                 /* R2T xmit queue */
2117                 tcp_ctask->r2tqueue = kfifo_alloc(
2118                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2119                 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2120                         iscsi_pool_free(&tcp_ctask->r2tpool,
2121                                         (void**)tcp_ctask->r2ts);
2122                         goto r2t_alloc_fail;
2123                 }
2124
2125                 /*
2126                  * number of
2127                  * Data-Out PDU's within R2T-sequence can be quite big;
2128                  * using mempool
2129                  */
2130                 tcp_ctask->datapool = mempool_create_slab_pool(ISCSI_DTASK_DEFAULT_MAX,
2131                                                                taskcache);
2132                 if (tcp_ctask->datapool == NULL) {
2133                         kfifo_free(tcp_ctask->r2tqueue);
2134                         iscsi_pool_free(&tcp_ctask->r2tpool,
2135                                         (void**)tcp_ctask->r2ts);
2136                         goto r2t_alloc_fail;
2137                 }
2138                 INIT_LIST_HEAD(&tcp_ctask->dataqueue);
2139         }
2140
2141         return 0;
2142
2143 r2t_alloc_fail:
2144         for (i = 0; i < cmd_i; i++) {
2145                 struct iscsi_cmd_task *ctask = session->cmds[i];
2146                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2147
2148                 mempool_destroy(tcp_ctask->datapool);
2149                 kfifo_free(tcp_ctask->r2tqueue);
2150                 iscsi_pool_free(&tcp_ctask->r2tpool,
2151                                 (void**)tcp_ctask->r2ts);
2152         }
2153         return -ENOMEM;
2154 }
2155
2156 static void
2157 iscsi_r2tpool_free(struct iscsi_session *session)
2158 {
2159         int i;
2160
2161         for (i = 0; i < session->cmds_max; i++) {
2162                 struct iscsi_cmd_task *ctask = session->cmds[i];
2163                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2164
2165                 mempool_destroy(tcp_ctask->datapool);
2166                 kfifo_free(tcp_ctask->r2tqueue);
2167                 iscsi_pool_free(&tcp_ctask->r2tpool,
2168                                 (void**)tcp_ctask->r2ts);
2169         }
2170 }
2171
2172 static int
2173 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2174                      uint32_t value)
2175 {
2176         struct iscsi_conn *conn = cls_conn->dd_data;
2177         struct iscsi_session *session = conn->session;
2178         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2179
2180         switch(param) {
2181         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
2182                 char *saveptr = tcp_conn->data;
2183                 gfp_t flags = GFP_KERNEL;
2184
2185                 if (tcp_conn->data_size >= value) {
2186                         conn->max_recv_dlength = value;
2187                         break;
2188                 }
2189
2190                 spin_lock_bh(&session->lock);
2191                 if (conn->stop_stage == STOP_CONN_RECOVER)
2192                         flags = GFP_ATOMIC;
2193                 spin_unlock_bh(&session->lock);
2194
2195                 if (value <= PAGE_SIZE)
2196                         tcp_conn->data = kmalloc(value, flags);
2197                 else
2198                         tcp_conn->data = (void*)__get_free_pages(flags,
2199                                                              get_order(value));
2200                 if (tcp_conn->data == NULL) {
2201                         tcp_conn->data = saveptr;
2202                         return -ENOMEM;
2203                 }
2204                 if (tcp_conn->data_size <= PAGE_SIZE)
2205                         kfree(saveptr);
2206                 else
2207                         free_pages((unsigned long)saveptr,
2208                                    get_order(tcp_conn->data_size));
2209                 conn->max_recv_dlength = value;
2210                 tcp_conn->data_size = value;
2211                 }
2212                 break;
2213         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2214                 conn->max_xmit_dlength =  value;
2215                 break;
2216         case ISCSI_PARAM_HDRDGST_EN:
2217                 conn->hdrdgst_en = value;
2218                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2219                 if (conn->hdrdgst_en) {
2220                         tcp_conn->hdr_size += sizeof(__u32);
2221                         if (!tcp_conn->tx_tfm)
2222                                 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2223                                                                     0);
2224                         if (!tcp_conn->tx_tfm)
2225                                 return -ENOMEM;
2226                         if (!tcp_conn->rx_tfm)
2227                                 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2228                                                                     0);
2229                         if (!tcp_conn->rx_tfm) {
2230                                 crypto_free_tfm(tcp_conn->tx_tfm);
2231                                 return -ENOMEM;
2232                         }
2233                 } else {
2234                         if (tcp_conn->tx_tfm)
2235                                 crypto_free_tfm(tcp_conn->tx_tfm);
2236                         if (tcp_conn->rx_tfm)
2237                                 crypto_free_tfm(tcp_conn->rx_tfm);
2238                 }
2239                 break;
2240         case ISCSI_PARAM_DATADGST_EN:
2241                 conn->datadgst_en = value;
2242                 if (conn->datadgst_en) {
2243                         if (!tcp_conn->data_tx_tfm)
2244                                 tcp_conn->data_tx_tfm =
2245                                     crypto_alloc_tfm("crc32c", 0);
2246                         if (!tcp_conn->data_tx_tfm)
2247                                 return -ENOMEM;
2248                         if (!tcp_conn->data_rx_tfm)
2249                                 tcp_conn->data_rx_tfm =
2250                                     crypto_alloc_tfm("crc32c", 0);
2251                         if (!tcp_conn->data_rx_tfm) {
2252                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2253                                 return -ENOMEM;
2254                         }
2255                 } else {
2256                         if (tcp_conn->data_tx_tfm)
2257                                 crypto_free_tfm(tcp_conn->data_tx_tfm);
2258                         if (tcp_conn->data_rx_tfm)
2259                                 crypto_free_tfm(tcp_conn->data_rx_tfm);
2260                 }
2261                 tcp_conn->sendpage = conn->datadgst_en ?
2262                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2263                 break;
2264         case ISCSI_PARAM_INITIAL_R2T_EN:
2265                 session->initial_r2t_en = value;
2266                 break;
2267         case ISCSI_PARAM_MAX_R2T:
2268                 if (session->max_r2t == roundup_pow_of_two(value))
2269                         break;
2270                 iscsi_r2tpool_free(session);
2271                 session->max_r2t = value;
2272                 if (session->max_r2t & (session->max_r2t - 1))
2273                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
2274                 if (iscsi_r2tpool_alloc(session))
2275                         return -ENOMEM;
2276                 break;
2277         case ISCSI_PARAM_IMM_DATA_EN:
2278                 session->imm_data_en = value;
2279                 break;
2280         case ISCSI_PARAM_FIRST_BURST:
2281                 session->first_burst = value;
2282                 break;
2283         case ISCSI_PARAM_MAX_BURST:
2284                 session->max_burst = value;
2285                 break;
2286         case ISCSI_PARAM_PDU_INORDER_EN:
2287                 session->pdu_inorder_en = value;
2288                 break;
2289         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2290                 session->dataseq_inorder_en = value;
2291                 break;
2292         case ISCSI_PARAM_ERL:
2293                 session->erl = value;
2294                 break;
2295         case ISCSI_PARAM_IFMARKER_EN:
2296                 BUG_ON(value);
2297                 session->ifmarker_en = value;
2298                 break;
2299         case ISCSI_PARAM_OFMARKER_EN:
2300                 BUG_ON(value);
2301                 session->ofmarker_en = value;
2302                 break;
2303         case ISCSI_PARAM_EXP_STATSN:
2304                 conn->exp_statsn = value;
2305                 break;
2306         default:
2307                 break;
2308         }
2309
2310         return 0;
2311 }
2312
2313 static int
2314 iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2315                         enum iscsi_param param, uint32_t *value)
2316 {
2317         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2318         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2319
2320         switch(param) {
2321         case ISCSI_PARAM_INITIAL_R2T_EN:
2322                 *value = session->initial_r2t_en;
2323                 break;
2324         case ISCSI_PARAM_MAX_R2T:
2325                 *value = session->max_r2t;
2326                 break;
2327         case ISCSI_PARAM_IMM_DATA_EN:
2328                 *value = session->imm_data_en;
2329                 break;
2330         case ISCSI_PARAM_FIRST_BURST:
2331                 *value = session->first_burst;
2332                 break;
2333         case ISCSI_PARAM_MAX_BURST:
2334                 *value = session->max_burst;
2335                 break;
2336         case ISCSI_PARAM_PDU_INORDER_EN:
2337                 *value = session->pdu_inorder_en;
2338                 break;
2339         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2340                 *value = session->dataseq_inorder_en;
2341                 break;
2342         case ISCSI_PARAM_ERL:
2343                 *value = session->erl;
2344                 break;
2345         case ISCSI_PARAM_IFMARKER_EN:
2346                 *value = session->ifmarker_en;
2347                 break;
2348         case ISCSI_PARAM_OFMARKER_EN:
2349                 *value = session->ofmarker_en;
2350                 break;
2351         default:
2352                 return -EINVAL;
2353         }
2354
2355         return 0;
2356 }
2357
2358 static int
2359 iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2360                      enum iscsi_param param, uint32_t *value)
2361 {
2362         struct iscsi_conn *conn = cls_conn->dd_data;
2363         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2364         struct inet_sock *inet;
2365
2366         switch(param) {
2367         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2368                 *value = conn->max_recv_dlength;
2369                 break;
2370         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2371                 *value = conn->max_xmit_dlength;
2372                 break;
2373         case ISCSI_PARAM_HDRDGST_EN:
2374                 *value = conn->hdrdgst_en;
2375                 break;
2376         case ISCSI_PARAM_DATADGST_EN:
2377                 *value = conn->datadgst_en;
2378                 break;
2379         case ISCSI_PARAM_CONN_PORT:
2380                 mutex_lock(&conn->xmitmutex);
2381                 if (!tcp_conn->sock) {
2382                         mutex_unlock(&conn->xmitmutex);
2383                         return -EINVAL;
2384                 }
2385
2386                 inet = inet_sk(tcp_conn->sock->sk);
2387                 *value = be16_to_cpu(inet->dport);
2388                 mutex_unlock(&conn->xmitmutex);
2389         case ISCSI_PARAM_EXP_STATSN:
2390                 *value = conn->exp_statsn;
2391                 break;
2392         default:
2393                 return -EINVAL;
2394         }
2395
2396         return 0;
2397 }
2398
2399 static int
2400 iscsi_conn_get_str_param(struct iscsi_cls_conn *cls_conn,
2401                          enum iscsi_param param, char *buf)
2402 {
2403         struct iscsi_conn *conn = cls_conn->dd_data;
2404         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2405         struct sock *sk;
2406         struct inet_sock *inet;
2407         struct ipv6_pinfo *np;
2408         int len = 0;
2409
2410         switch (param) {
2411         case ISCSI_PARAM_CONN_ADDRESS:
2412                 mutex_lock(&conn->xmitmutex);
2413                 if (!tcp_conn->sock) {
2414                         mutex_unlock(&conn->xmitmutex);
2415                         return -EINVAL;
2416                 }
2417
2418                 sk = tcp_conn->sock->sk;
2419                 if (sk->sk_family == PF_INET) {
2420                         inet = inet_sk(sk);
2421                         len = sprintf(buf, "%u.%u.%u.%u\n",
2422                                       NIPQUAD(inet->daddr));
2423                 } else {
2424                         np = inet6_sk(sk);
2425                         len = sprintf(buf,
2426                                 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2427                                 NIP6(np->daddr));
2428                 }
2429                 mutex_unlock(&conn->xmitmutex);
2430                 break;
2431         default:
2432                 return -EINVAL;
2433         }
2434
2435         return len;
2436 }
2437
2438 static void
2439 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2440 {
2441         struct iscsi_conn *conn = cls_conn->dd_data;
2442         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2443
2444         stats->txdata_octets = conn->txdata_octets;
2445         stats->rxdata_octets = conn->rxdata_octets;
2446         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2447         stats->dataout_pdus = conn->dataout_pdus_cnt;
2448         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2449         stats->datain_pdus = conn->datain_pdus_cnt;
2450         stats->r2t_pdus = conn->r2t_pdus_cnt;
2451         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2452         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2453         stats->custom_length = 3;
2454         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2455         stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2456         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2457         stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2458         strcpy(stats->custom[2].desc, "eh_abort_cnt");
2459         stats->custom[2].value = conn->eh_abort_cnt;
2460 }
2461
2462 static struct iscsi_cls_session *
2463 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2464                          struct scsi_transport_template *scsit,
2465                          uint32_t initial_cmdsn, uint32_t *hostno)
2466 {
2467         struct iscsi_cls_session *cls_session;
2468         struct iscsi_session *session;
2469         uint32_t hn;
2470         int cmd_i;
2471
2472         cls_session = iscsi_session_setup(iscsit, scsit,
2473                                          sizeof(struct iscsi_tcp_cmd_task),
2474                                          sizeof(struct iscsi_tcp_mgmt_task),
2475                                          initial_cmdsn, &hn);
2476         if (!cls_session)
2477                 return NULL;
2478         *hostno = hn;
2479
2480         session = class_to_transport_session(cls_session);
2481         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2482                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2483                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2484
2485                 ctask->hdr = &tcp_ctask->hdr;
2486         }
2487
2488         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2489                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2490                 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2491
2492                 mtask->hdr = &tcp_mtask->hdr;
2493         }
2494
2495         if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2496                 goto r2tpool_alloc_fail;
2497
2498         return cls_session;
2499
2500 r2tpool_alloc_fail:
2501         iscsi_session_teardown(cls_session);
2502         return NULL;
2503 }
2504
2505 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2506 {
2507         struct iscsi_session *session = class_to_transport_session(cls_session);
2508         struct iscsi_data_task *dtask, *n;
2509         int cmd_i;
2510
2511         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2512                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2513                 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2514
2515                 list_for_each_entry_safe(dtask, n, &tcp_ctask->dataqueue,
2516                                          item) {
2517                         list_del(&dtask->item);
2518                         mempool_free(dtask, tcp_ctask->datapool);
2519                 }
2520         }
2521
2522         iscsi_r2tpool_free(class_to_transport_session(cls_session));
2523         iscsi_session_teardown(cls_session);
2524 }
2525
2526 static struct scsi_host_template iscsi_sht = {
2527         .name                   = "iSCSI Initiator over TCP/IP, v."
2528                                   ISCSI_VERSION_STR,
2529         .queuecommand           = iscsi_queuecommand,
2530         .change_queue_depth     = iscsi_change_queue_depth,
2531         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
2532         .sg_tablesize           = ISCSI_SG_TABLESIZE,
2533         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
2534         .eh_abort_handler       = iscsi_eh_abort,
2535         .eh_host_reset_handler  = iscsi_eh_host_reset,
2536         .use_clustering         = DISABLE_CLUSTERING,
2537         .proc_name              = "iscsi_tcp",
2538         .this_id                = -1,
2539 };
2540
2541 static struct iscsi_transport iscsi_tcp_transport = {
2542         .owner                  = THIS_MODULE,
2543         .name                   = "tcp",
2544         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2545                                   | CAP_DATADGST,
2546         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
2547                                   ISCSI_MAX_XMIT_DLENGTH |
2548                                   ISCSI_HDRDGST_EN |
2549                                   ISCSI_DATADGST_EN |
2550                                   ISCSI_INITIAL_R2T_EN |
2551                                   ISCSI_MAX_R2T |
2552                                   ISCSI_IMM_DATA_EN |
2553                                   ISCSI_FIRST_BURST |
2554                                   ISCSI_MAX_BURST |
2555                                   ISCSI_PDU_INORDER_EN |
2556                                   ISCSI_DATASEQ_INORDER_EN |
2557                                   ISCSI_ERL |
2558                                   ISCSI_CONN_PORT |
2559                                   ISCSI_CONN_ADDRESS |
2560                                   ISCSI_EXP_STATSN,
2561         .host_template          = &iscsi_sht,
2562         .conndata_size          = sizeof(struct iscsi_conn),
2563         .max_conn               = 1,
2564         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
2565         /* session management */
2566         .create_session         = iscsi_tcp_session_create,
2567         .destroy_session        = iscsi_tcp_session_destroy,
2568         /* connection management */
2569         .create_conn            = iscsi_tcp_conn_create,
2570         .bind_conn              = iscsi_tcp_conn_bind,
2571         .destroy_conn           = iscsi_tcp_conn_destroy,
2572         .set_param              = iscsi_conn_set_param,
2573         .get_conn_param         = iscsi_conn_get_param,
2574         .get_conn_str_param     = iscsi_conn_get_str_param,
2575         .get_session_param      = iscsi_session_get_param,
2576         .start_conn             = iscsi_conn_start,
2577         .stop_conn              = iscsi_conn_stop,
2578         /* these are called as part of conn recovery */
2579         .suspend_conn_recv      = iscsi_tcp_suspend_conn_rx,
2580         .terminate_conn         = iscsi_tcp_terminate_conn,
2581         /* IO */
2582         .send_pdu               = iscsi_conn_send_pdu,
2583         .get_stats              = iscsi_conn_get_stats,
2584         .init_cmd_task          = iscsi_tcp_cmd_init,
2585         .init_mgmt_task         = iscsi_tcp_mgmt_init,
2586         .xmit_cmd_task          = iscsi_tcp_ctask_xmit,
2587         .xmit_mgmt_task         = iscsi_tcp_mtask_xmit,
2588         .cleanup_cmd_task       = iscsi_tcp_cleanup_ctask,
2589         /* recovery */
2590         .session_recovery_timedout = iscsi_session_recovery_timedout,
2591 };
2592
2593 static int __init
2594 iscsi_tcp_init(void)
2595 {
2596         if (iscsi_max_lun < 1) {
2597                 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2598                        iscsi_max_lun);
2599                 return -EINVAL;
2600         }
2601         iscsi_tcp_transport.max_lun = iscsi_max_lun;
2602
2603         taskcache = kmem_cache_create("iscsi_taskcache",
2604                         sizeof(struct iscsi_data_task), 0,
2605                         SLAB_HWCACHE_ALIGN, NULL, NULL);
2606         if (!taskcache)
2607                 return -ENOMEM;
2608
2609         if (!iscsi_register_transport(&iscsi_tcp_transport))
2610                 kmem_cache_destroy(taskcache);
2611
2612         return 0;
2613 }
2614
2615 static void __exit
2616 iscsi_tcp_exit(void)
2617 {
2618         iscsi_unregister_transport(&iscsi_tcp_transport);
2619         kmem_cache_destroy(taskcache);
2620 }
2621
2622 module_init(iscsi_tcp_init);
2623 module_exit(iscsi_tcp_exit);