sys/dev/iscsi/icl.c

   1 /*-
   2  * Copyright (c) 2012 The FreeBSD Foundation
   3  * All rights reserved.
   4  *
   5  * This software was developed by Edward Tomasz Napierala under sponsorship
   6  * from the FreeBSD Foundation.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30
  31 /*
  32  * iSCSI Common Layer.  It's used by both the initiator and target to send
  33  * and receive iSCSI PDUs.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 #include <sys/param.h>
  40 #include <sys/capsicum.h>
  41 #include <sys/condvar.h>
  42 #include <sys/conf.h>
  43 #include <sys/file.h>
  44 #include <sys/kernel.h>
  45 #include <sys/kthread.h>
  46 #include <sys/lock.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/mutex.h>
  49 #include <sys/module.h>
  50 #include <sys/protosw.h>
  51 #include <sys/socket.h>
  52 #include <sys/socketvar.h>
  53 #include <sys/sysctl.h>
  54 #include <sys/systm.h>
  55 #include <sys/sx.h>
  56 #include <sys/uio.h>
  57 #include <vm/uma.h>
  58 #include <netinet/in.h>
  59 #include <netinet/tcp.h>
  60
  61 #include <dev/iscsi/icl.h>
  62 #include <dev/iscsi/iscsi_proto.h>
  63
  64 SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD, 0, "iSCSI Common Layer");
  65 static int debug = 1;
  66 SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
  67     &debug, 0, "Enable debug messages");
  68 static int coalesce = 1;
  69 SYSCTL_INT(_kern_icl, OID_AUTO, coalesce, CTLFLAG_RWTUN,
  70     &coalesce, 0, "Try to coalesce PDUs before sending");
  71 static int partial_receive_len = 128 * 1024;
  72 SYSCTL_INT(_kern_icl, OID_AUTO, partial_receive_len, CTLFLAG_RWTUN,
  73     &partial_receive_len, 0, "Minimum read size for partially received "
  74     "data segment");
  75 static int sendspace = 1048576;
  76 SYSCTL_INT(_kern_icl, OID_AUTO, sendspace, CTLFLAG_RWTUN,
  77     &sendspace, 0, "Default send socket buffer size");
  78 static int recvspace = 1048576;
  79 SYSCTL_INT(_kern_icl, OID_AUTO, recvspace, CTLFLAG_RWTUN,
  80     &recvspace, 0, "Default receive socket buffer size");
  81
  82 static uma_zone_t icl_conn_zone;
  83 static uma_zone_t icl_pdu_zone;
  84
  85 static volatile u_int   icl_ncons;
  86
  87 #define ICL_DEBUG(X, ...)                                               \
  88         do {                                                            \
  89                 if (debug > 1)                                          \
  90                         printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
  91         } while (0)
  92
  93 #define ICL_WARN(X, ...)                                                \
  94         do {                                                            \
  95                 if (debug > 0) {                                        \
  96                         printf("WARNING: %s: " X "\n",                  \
  97                             __func__, ## __VA_ARGS__);                  \
  98                 }                                                       \
  99         } while (0)
 100
 101 #define ICL_CONN_LOCK(X)                mtx_lock(X->ic_lock)
 102 #define ICL_CONN_UNLOCK(X)              mtx_unlock(X->ic_lock)
 103 #define ICL_CONN_LOCK_ASSERT(X)         mtx_assert(X->ic_lock, MA_OWNED)
 104 #define ICL_CONN_LOCK_ASSERT_NOT(X)     mtx_assert(X->ic_lock, MA_NOTOWNED)
 105
 106 STAILQ_HEAD(icl_pdu_stailq, icl_pdu);
 107
 108 static void
 109 icl_conn_fail(struct icl_conn *ic)
 110 {
 111         if (ic->ic_socket == NULL)
 112                 return;
 113
 114         /*
 115          * XXX
 116          */
 117         ic->ic_socket->so_error = EDOOFUS;
 118         (ic->ic_error)(ic);
 119 }
 120
 121 static struct mbuf *
 122 icl_conn_receive(struct icl_conn *ic, size_t len)
 123 {
 124         struct uio uio;
 125         struct socket *so;
 126         struct mbuf *m;
 127         int error, flags;
 128
 129         so = ic->ic_socket;
 130
 131         memset(&uio, 0, sizeof(uio));
 132         uio.uio_resid = len;
 133
 134         flags = MSG_DONTWAIT;
 135         error = soreceive(so, NULL, &uio, &m, NULL, &flags);
 136         if (error != 0) {
 137                 ICL_DEBUG("soreceive error %d", error);
 138                 return (NULL);
 139         }
 140         if (uio.uio_resid != 0) {
 141                 m_freem(m);
 142                 ICL_DEBUG("short read");
 143                 return (NULL);
 144         }
 145
 146         return (m);
 147 }
 148
 149 static struct icl_pdu *
 150 icl_pdu_new_empty(struct icl_conn *ic, int flags)
 151 {
 152         struct icl_pdu *ip;
 153
 154 #ifdef DIAGNOSTIC
 155         refcount_acquire(&ic->ic_outstanding_pdus);
 156 #endif
 157         ip = uma_zalloc(icl_pdu_zone, flags | M_ZERO);
 158         if (ip == NULL) {
 159                 ICL_WARN("failed to allocate %zd bytes", sizeof(*ip));
 160 #ifdef DIAGNOSTIC
 161                 refcount_release(&ic->ic_outstanding_pdus);
 162 #endif
 163                 return (NULL);
 164         }
 165
 166         ip->ip_conn = ic;
 167
 168         return (ip);
 169 }
 170
 171 void
 172 icl_pdu_free(struct icl_pdu *ip)
 173 {
 174         struct icl_conn *ic;
 175
 176         ic = ip->ip_conn;
 177
 178         m_freem(ip->ip_bhs_mbuf);
 179         m_freem(ip->ip_ahs_mbuf);
 180         m_freem(ip->ip_data_mbuf);
 181         uma_zfree(icl_pdu_zone, ip);
 182 #ifdef DIAGNOSTIC
 183         refcount_release(&ic->ic_outstanding_pdus);
 184 #endif
 185 }
 186
 187 /*
 188  * Allocate icl_pdu with empty BHS to fill up by the caller.
 189  */
 190 struct icl_pdu *
 191 icl_pdu_new(struct icl_conn *ic, int flags)
 192 {
 193         struct icl_pdu *ip;
 194
 195         ip = icl_pdu_new_empty(ic, flags);
 196         if (ip == NULL)
 197                 return (NULL);
 198
 199         ip->ip_bhs_mbuf = m_getm2(NULL, sizeof(struct iscsi_bhs),
 200             flags, MT_DATA, M_PKTHDR);
 201         if (ip->ip_bhs_mbuf == NULL) {
 202                 ICL_WARN("failed to allocate %zd bytes", sizeof(*ip));
 203                 icl_pdu_free(ip);
 204                 return (NULL);
 205         }
 206         ip->ip_bhs = mtod(ip->ip_bhs_mbuf, struct iscsi_bhs *);
 207         memset(ip->ip_bhs, 0, sizeof(struct iscsi_bhs));
 208         ip->ip_bhs_mbuf->m_len = sizeof(struct iscsi_bhs);
 209
 210         return (ip);
 211 }
 212
 213 static int
 214 icl_pdu_ahs_length(const struct icl_pdu *request)
 215 {
 216
 217         return (request->ip_bhs->bhs_total_ahs_len * 4);
 218 }
 219
 220 size_t
 221 icl_pdu_data_segment_length(const struct icl_pdu *request)
 222 {
 223         uint32_t len = 0;
 224
 225         len += request->ip_bhs->bhs_data_segment_len[0];
 226         len <<= 8;
 227         len += request->ip_bhs->bhs_data_segment_len[1];
 228         len <<= 8;
 229         len += request->ip_bhs->bhs_data_segment_len[2];
 230
 231         return (len);
 232 }
 233
 234 static void
 235 icl_pdu_set_data_segment_length(struct icl_pdu *response, uint32_t len)
 236 {
 237
 238         response->ip_bhs->bhs_data_segment_len[2] = len;
 239         response->ip_bhs->bhs_data_segment_len[1] = len >> 8;
 240         response->ip_bhs->bhs_data_segment_len[0] = len >> 16;
 241 }
 242
 243 static size_t
 244 icl_pdu_padding(const struct icl_pdu *ip)
 245 {
 246
 247         if ((ip->ip_data_len % 4) != 0)
 248                 return (4 - (ip->ip_data_len % 4));
 249
 250         return (0);
 251 }
 252
 253 static size_t
 254 icl_pdu_size(const struct icl_pdu *response)
 255 {
 256         size_t len;
 257
 258         KASSERT(response->ip_ahs_len == 0, ("responding with AHS"));
 259
 260         len = sizeof(struct iscsi_bhs) + response->ip_data_len +
 261             icl_pdu_padding(response);
 262         if (response->ip_conn->ic_header_crc32c)
 263                 len += ISCSI_HEADER_DIGEST_SIZE;
 264         if (response->ip_data_len != 0 && response->ip_conn->ic_data_crc32c)
 265                 len += ISCSI_DATA_DIGEST_SIZE;
 266
 267         return (len);
 268 }
 269
 270 static int
 271 icl_pdu_receive_bhs(struct icl_pdu *request, size_t *availablep)
 272 {
 273         struct mbuf *m;
 274
 275         m = icl_conn_receive(request->ip_conn, sizeof(struct iscsi_bhs));
 276         if (m == NULL) {
 277                 ICL_DEBUG("failed to receive BHS");
 278                 return (-1);
 279         }
 280
 281         request->ip_bhs_mbuf = m_pullup(m, sizeof(struct iscsi_bhs));
 282         if (request->ip_bhs_mbuf == NULL) {
 283                 ICL_WARN("m_pullup failed");
 284                 return (-1);
 285         }
 286         request->ip_bhs = mtod(request->ip_bhs_mbuf, struct iscsi_bhs *);
 287
 288         /*
 289          * XXX: For architectures with strict alignment requirements
 290          *      we may need to allocate ip_bhs and copy the data into it.
 291          *      For some reason, though, not doing this doesn't seem
 292          *      to cause problems; tested on sparc64.
 293          */
 294
 295         *availablep -= sizeof(struct iscsi_bhs);
 296         return (0);
 297 }
 298
 299 static int
 300 icl_pdu_receive_ahs(struct icl_pdu *request, size_t *availablep)
 301 {
 302
 303         request->ip_ahs_len = icl_pdu_ahs_length(request);
 304         if (request->ip_ahs_len == 0)
 305                 return (0);
 306
 307         request->ip_ahs_mbuf = icl_conn_receive(request->ip_conn,
 308             request->ip_ahs_len);
 309         if (request->ip_ahs_mbuf == NULL) {
 310                 ICL_DEBUG("failed to receive AHS");
 311                 return (-1);
 312         }
 313
 314         *availablep -= request->ip_ahs_len;
 315         return (0);
 316 }
 317
 318 static uint32_t
 319 icl_mbuf_to_crc32c(const struct mbuf *m0)
 320 {
 321         uint32_t digest = 0xffffffff;
 322         const struct mbuf *m;
 323
 324         for (m = m0; m != NULL; m = m->m_next)
 325                 digest = calculate_crc32c(digest,
 326                     mtod(m, const void *), m->m_len);
 327
 328         digest = digest ^ 0xffffffff;
 329
 330         return (digest);
 331 }
 332
 333 static int
 334 icl_pdu_check_header_digest(struct icl_pdu *request, size_t *availablep)
 335 {
 336         struct mbuf *m;
 337         uint32_t received_digest, valid_digest;
 338
 339         if (request->ip_conn->ic_header_crc32c == false)
 340                 return (0);
 341
 342         m = icl_conn_receive(request->ip_conn, ISCSI_HEADER_DIGEST_SIZE);
 343         if (m == NULL) {
 344                 ICL_DEBUG("failed to receive header digest");
 345                 return (-1);
 346         }
 347
 348         CTASSERT(sizeof(received_digest) == ISCSI_HEADER_DIGEST_SIZE);
 349         m_copydata(m, 0, ISCSI_HEADER_DIGEST_SIZE, (void *)&received_digest);
 350         m_freem(m);
 351
 352         *availablep -= ISCSI_HEADER_DIGEST_SIZE;
 353
 354         /*
 355          * XXX: Handle AHS.
 356          */
 357         valid_digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf);
 358         if (received_digest != valid_digest) {
 359                 ICL_WARN("header digest check failed; got 0x%x, "
 360                     "should be 0x%x", received_digest, valid_digest);
 361                 return (-1);
 362         }
 363
 364         return (0);
 365 }
 366
 367 /*
 368  * Return the number of bytes that should be waiting in the receive socket
 369  * before icl_pdu_receive_data_segment() gets called.
 370  */
 371 static size_t
 372 icl_pdu_data_segment_receive_len(const struct icl_pdu *request)
 373 {
 374         size_t len;
 375
 376         len = icl_pdu_data_segment_length(request);
 377         if (len == 0)
 378                 return (0);
 379
 380         /*
 381          * Account for the parts of data segment already read from
 382          * the socket buffer.
 383          */
 384         KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len"));
 385         len -= request->ip_data_len;
 386
 387         /*
 388          * Don't always wait for the full data segment to be delivered
 389          * to the socket; this might badly affect performance due to
 390          * TCP window scaling.
 391          */
 392         if (len > partial_receive_len) {
 393 #if 0
 394                 ICL_DEBUG("need %zd bytes of data, limiting to %zd",
 395                     len, partial_receive_len));
 396 #endif
 397                 len = partial_receive_len;
 398
 399                 return (len);
 400         }
 401
 402         /*
 403          * Account for padding.  Note that due to the way code is written,
 404          * the icl_pdu_receive_data_segment() must always receive padding
 405          * along with the last part of data segment, because it would be
 406          * impossible to tell whether we've already received the full data
 407          * segment including padding, or without it.
 408          */
 409         if ((len % 4) != 0)
 410                 len += 4 - (len % 4);
 411
 412 #if 0
 413         ICL_DEBUG("need %zd bytes of data", len));
 414 #endif
 415
 416         return (len);
 417 }
 418
 419 static int
 420 icl_pdu_receive_data_segment(struct icl_pdu *request,
 421     size_t *availablep, bool *more_neededp)
 422 {
 423         struct icl_conn *ic;
 424         size_t len, padding = 0;
 425         struct mbuf *m;
 426
 427         ic = request->ip_conn;
 428
 429         *more_neededp = false;
 430         ic->ic_receive_len = 0;
 431
 432         len = icl_pdu_data_segment_length(request);
 433         if (len == 0)
 434                 return (0);
 435
 436         if ((len % 4) != 0)
 437                 padding = 4 - (len % 4);
 438
 439         /*
 440          * Account for already received parts of data segment.
 441          */
 442         KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len"));
 443         len -= request->ip_data_len;
 444
 445         if (len + padding > *availablep) {
 446                 /*
 447                  * Not enough data in the socket buffer.  Receive as much
 448                  * as we can.  Don't receive padding, since, obviously, it's
 449                  * not the end of data segment yet.
 450                  */
 451 #if 0
 452                 ICL_DEBUG("limited from %zd to %zd",
 453                     len + padding, *availablep - padding));
 454 #endif
 455                 len = *availablep - padding;
 456                 *more_neededp = true;
 457                 padding = 0;
 458         }
 459
 460         /*
 461          * Must not try to receive padding without at least one byte
 462          * of actual data segment.
 463          */
 464         if (len > 0) {
 465                 m = icl_conn_receive(request->ip_conn, len + padding);
 466                 if (m == NULL) {
 467                         ICL_DEBUG("failed to receive data segment");
 468                         return (-1);
 469                 }
 470
 471                 if (request->ip_data_mbuf == NULL)
 472                         request->ip_data_mbuf = m;
 473                 else
 474                         m_cat(request->ip_data_mbuf, m);
 475
 476                 request->ip_data_len += len;
 477                 *availablep -= len + padding;
 478         } else
 479                 ICL_DEBUG("len 0");
 480
 481         if (*more_neededp)
 482                 ic->ic_receive_len =
 483                     icl_pdu_data_segment_receive_len(request);
 484
 485         return (0);
 486 }
 487
 488 static int
 489 icl_pdu_check_data_digest(struct icl_pdu *request, size_t *availablep)
 490 {
 491         struct mbuf *m;
 492         uint32_t received_digest, valid_digest;
 493
 494         if (request->ip_conn->ic_data_crc32c == false)
 495                 return (0);
 496
 497         if (request->ip_data_len == 0)
 498                 return (0);
 499
 500         m = icl_conn_receive(request->ip_conn, ISCSI_DATA_DIGEST_SIZE);
 501         if (m == NULL) {
 502                 ICL_DEBUG("failed to receive data digest");
 503                 return (-1);
 504         }
 505
 506         CTASSERT(sizeof(received_digest) == ISCSI_DATA_DIGEST_SIZE);
 507         m_copydata(m, 0, ISCSI_DATA_DIGEST_SIZE, (void *)&received_digest);
 508         m_freem(m);
 509
 510         *availablep -= ISCSI_DATA_DIGEST_SIZE;
 511
 512         /*
 513          * Note that ip_data_mbuf also contains padding; since digest
 514          * calculation is supposed to include that, we iterate over
 515          * the entire ip_data_mbuf chain, not just ip_data_len bytes of it.
 516          */
 517         valid_digest = icl_mbuf_to_crc32c(request->ip_data_mbuf);
 518         if (received_digest != valid_digest) {
 519                 ICL_WARN("data digest check failed; got 0x%x, "
 520                     "should be 0x%x", received_digest, valid_digest);
 521                 return (-1);
 522         }
 523
 524         return (0);
 525 }
 526
 527 /*
 528  * Somewhat contrary to the name, this attempts to receive only one
 529  * "part" of PDU at a time; call it repeatedly until it returns non-NULL.
 530  */
 531 static struct icl_pdu *
 532 icl_conn_receive_pdu(struct icl_conn *ic, size_t *availablep)
 533 {
 534         struct icl_pdu *request;
 535         struct socket *so;
 536         size_t len;
 537         int error;
 538         bool more_needed;
 539
 540         so = ic->ic_socket;
 541
 542         if (ic->ic_receive_state == ICL_CONN_STATE_BHS) {
 543                 KASSERT(ic->ic_receive_pdu == NULL,
 544                     ("ic->ic_receive_pdu != NULL"));
 545                 request = icl_pdu_new_empty(ic, M_NOWAIT);
 546                 if (request == NULL) {
 547                         ICL_DEBUG("failed to allocate PDU; "
 548                             "dropping connection");
 549                         icl_conn_fail(ic);
 550                         return (NULL);
 551                 }
 552                 ic->ic_receive_pdu = request;
 553         } else {
 554                 KASSERT(ic->ic_receive_pdu != NULL,
 555                     ("ic->ic_receive_pdu == NULL"));
 556                 request = ic->ic_receive_pdu;
 557         }
 558
 559         if (*availablep < ic->ic_receive_len) {
 560 #if 0
 561                 ICL_DEBUG("not enough data; need %zd, "
 562                     "have %zd", ic->ic_receive_len, *availablep);
 563 #endif
 564                 return (NULL);
 565         }
 566
 567         switch (ic->ic_receive_state) {
 568         case ICL_CONN_STATE_BHS:
 569                 //ICL_DEBUG("receiving BHS");
 570                 error = icl_pdu_receive_bhs(request, availablep);
 571                 if (error != 0) {
 572                         ICL_DEBUG("failed to receive BHS; "
 573                             "dropping connection");
 574                         break;
 575                 }
 576
 577                 /*
 578                  * We don't enforce any limit for AHS length;
 579                  * its length is stored in 8 bit field.
 580                  */
 581
 582                 len = icl_pdu_data_segment_length(request);
 583                 if (len > ic->ic_max_data_segment_length) {
 584                         ICL_WARN("received data segment "
 585                             "length %zd is larger than negotiated "
 586                             "MaxDataSegmentLength %zd; "
 587                             "dropping connection",
 588                             len, ic->ic_max_data_segment_length);
 589                         error = EINVAL;
 590                         break;
 591                 }
 592
 593                 ic->ic_receive_state = ICL_CONN_STATE_AHS;
 594                 ic->ic_receive_len = icl_pdu_ahs_length(request);
 595                 break;
 596
 597         case ICL_CONN_STATE_AHS:
 598                 //ICL_DEBUG("receiving AHS");
 599                 error = icl_pdu_receive_ahs(request, availablep);
 600                 if (error != 0) {
 601                         ICL_DEBUG("failed to receive AHS; "
 602                             "dropping connection");
 603                         break;
 604                 }
 605                 ic->ic_receive_state = ICL_CONN_STATE_HEADER_DIGEST;
 606                 if (ic->ic_header_crc32c == false)
 607                         ic->ic_receive_len = 0;
 608                 else
 609                         ic->ic_receive_len = ISCSI_HEADER_DIGEST_SIZE;
 610                 break;
 611
 612         case ICL_CONN_STATE_HEADER_DIGEST:
 613                 //ICL_DEBUG("receiving header digest");
 614                 error = icl_pdu_check_header_digest(request, availablep);
 615                 if (error != 0) {
 616                         ICL_DEBUG("header digest failed; "
 617                             "dropping connection");
 618                         break;
 619                 }
 620
 621                 ic->ic_receive_state = ICL_CONN_STATE_DATA;
 622                 ic->ic_receive_len =
 623                     icl_pdu_data_segment_receive_len(request);
 624                 break;
 625
 626         case ICL_CONN_STATE_DATA:
 627                 //ICL_DEBUG("receiving data segment");
 628                 error = icl_pdu_receive_data_segment(request, availablep,
 629                     &more_needed);
 630                 if (error != 0) {
 631                         ICL_DEBUG("failed to receive data segment;"
 632                             "dropping connection");
 633                         break;
 634                 }
 635
 636                 if (more_needed)
 637                         break;
 638
 639                 ic->ic_receive_state = ICL_CONN_STATE_DATA_DIGEST;
 640                 if (request->ip_data_len == 0 || ic->ic_data_crc32c == false)
 641                         ic->ic_receive_len = 0;
 642                 else
 643                         ic->ic_receive_len = ISCSI_DATA_DIGEST_SIZE;
 644                 break;
 645
 646         case ICL_CONN_STATE_DATA_DIGEST:
 647                 //ICL_DEBUG("receiving data digest");
 648                 error = icl_pdu_check_data_digest(request, availablep);
 649                 if (error != 0) {
 650                         ICL_DEBUG("data digest failed; "
 651                             "dropping connection");
 652                         break;
 653                 }
 654
 655                 /*
 656                  * We've received complete PDU; reset the receive state machine
 657                  * and return the PDU.
 658                  */
 659                 ic->ic_receive_state = ICL_CONN_STATE_BHS;
 660                 ic->ic_receive_len = sizeof(struct iscsi_bhs);
 661                 ic->ic_receive_pdu = NULL;
 662                 return (request);
 663
 664         default:
 665                 panic("invalid ic_receive_state %d\n", ic->ic_receive_state);
 666         }
 667
 668         if (error != 0) {
 669                 /*
 670                  * Don't free the PDU; it's pointed to by ic->ic_receive_pdu
 671                  * and will get freed in icl_conn_close().
 672                  */
 673                 icl_conn_fail(ic);
 674         }
 675
 676         return (NULL);
 677 }
 678
 679 static void
 680 icl_conn_receive_pdus(struct icl_conn *ic, size_t available)
 681 {
 682         struct icl_pdu *response;
 683         struct socket *so;
 684
 685         so = ic->ic_socket;
 686
 687         /*
 688          * This can never happen; we're careful to only mess with ic->ic_socket
 689          * pointer when the send/receive threads are not running.
 690          */
 691         KASSERT(so != NULL, ("NULL socket"));
 692
 693         for (;;) {
 694                 if (ic->ic_disconnecting)
 695                         return;
 696
 697                 if (so->so_error != 0) {
 698                         ICL_DEBUG("connection error %d; "
 699                             "dropping connection", so->so_error);
 700                         icl_conn_fail(ic);
 701                         return;
 702                 }
 703
 704                 /*
 705                  * Loop until we have a complete PDU or there is not enough
 706                  * data in the socket buffer.
 707                  */
 708                 if (available < ic->ic_receive_len) {
 709 #if 0
 710                         ICL_DEBUG("not enough data; have %zd, "
 711                             "need %zd", available,
 712                             ic->ic_receive_len);
 713 #endif
 714                         return;
 715                 }
 716
 717                 response = icl_conn_receive_pdu(ic, &available);
 718                 if (response == NULL)
 719                         continue;
 720
 721                 if (response->ip_ahs_len > 0) {
 722                         ICL_WARN("received PDU with unsupported "
 723                             "AHS; opcode 0x%x; dropping connection",
 724                             response->ip_bhs->bhs_opcode);
 725                         icl_pdu_free(response);
 726                         icl_conn_fail(ic);
 727                         return;
 728                 }
 729
 730                 (ic->ic_receive)(response);
 731         }
 732 }
 733
 734 static void
 735 icl_receive_thread(void *arg)
 736 {
 737         struct icl_conn *ic;
 738         size_t available;
 739         struct socket *so;
 740
 741         ic = arg;
 742         so = ic->ic_socket;
 743
 744         ICL_CONN_LOCK(ic);
 745         ic->ic_receive_running = true;
 746         ICL_CONN_UNLOCK(ic);
 747
 748         for (;;) {
 749                 if (ic->ic_disconnecting) {
 750                         //ICL_DEBUG("terminating");
 751                         break;
 752                 }
 753
 754                 /*
 755                  * Set the low watermark, to be checked by
 756                  * soreadable() in icl_soupcall_receive()
 757                  * to avoid unneccessary wakeups until there
 758                  * is enough data received to read the PDU.
 759                  */
 760                 SOCKBUF_LOCK(&so->so_rcv);
 761                 available = sbavail(&so->so_rcv);
 762                 if (available < ic->ic_receive_len) {
 763                         so->so_rcv.sb_lowat = ic->ic_receive_len;
 764                         cv_wait(&ic->ic_receive_cv, &so->so_rcv.sb_mtx);
 765                 } else
 766                         so->so_rcv.sb_lowat = so->so_rcv.sb_hiwat + 1;
 767                 SOCKBUF_UNLOCK(&so->so_rcv);
 768
 769                 icl_conn_receive_pdus(ic, available);
 770         }
 771
 772         ICL_CONN_LOCK(ic);
 773         ic->ic_receive_running = false;
 774         cv_signal(&ic->ic_send_cv);
 775         ICL_CONN_UNLOCK(ic);
 776         kthread_exit();
 777 }
 778
 779 static int
 780 icl_soupcall_receive(struct socket *so, void *arg, int waitflag)
 781 {
 782         struct icl_conn *ic;
 783
 784         if (!soreadable(so))
 785                 return (SU_OK);
 786
 787         ic = arg;
 788         cv_signal(&ic->ic_receive_cv);
 789         return (SU_OK);
 790 }
 791
 792 static int
 793 icl_pdu_finalize(struct icl_pdu *request)
 794 {
 795         size_t padding, pdu_len;
 796         uint32_t digest, zero = 0;
 797         int ok;
 798         struct icl_conn *ic;
 799
 800         ic = request->ip_conn;
 801
 802         icl_pdu_set_data_segment_length(request, request->ip_data_len);
 803
 804         pdu_len = icl_pdu_size(request);
 805
 806         if (ic->ic_header_crc32c) {
 807                 digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf);
 808                 ok = m_append(request->ip_bhs_mbuf, sizeof(digest),
 809                     (void *)&digest);
 810                 if (ok != 1) {
 811                         ICL_WARN("failed to append header digest");
 812                         return (1);
 813                 }
 814         }
 815
 816         if (request->ip_data_len != 0) {
 817                 padding = icl_pdu_padding(request);
 818                 if (padding > 0) {
 819                         ok = m_append(request->ip_data_mbuf, padding,
 820                             (void *)&zero);
 821                         if (ok != 1) {
 822                                 ICL_WARN("failed to append padding");
 823                                 return (1);
 824                         }
 825                 }
 826
 827                 if (ic->ic_data_crc32c) {
 828                         digest = icl_mbuf_to_crc32c(request->ip_data_mbuf);
 829
 830                         ok = m_append(request->ip_data_mbuf, sizeof(digest),
 831                             (void *)&digest);
 832                         if (ok != 1) {
 833                                 ICL_WARN("failed to append data digest");
 834                                 return (1);
 835                         }
 836                 }
 837
 838                 m_cat(request->ip_bhs_mbuf, request->ip_data_mbuf);
 839                 request->ip_data_mbuf = NULL;
 840         }
 841
 842         request->ip_bhs_mbuf->m_pkthdr.len = pdu_len;
 843
 844         return (0);
 845 }
 846
 847 static void
 848 icl_conn_send_pdus(struct icl_conn *ic, struct icl_pdu_stailq *queue)
 849 {
 850         struct icl_pdu *request, *request2;
 851         struct socket *so;
 852         size_t available, size, size2;
 853         int coalesced, error;
 854
 855         ICL_CONN_LOCK_ASSERT_NOT(ic);
 856
 857         so = ic->ic_socket;
 858
 859         SOCKBUF_LOCK(&so->so_snd);
 860         /*
 861          * Check how much space do we have for transmit.  We can't just
 862          * call sosend() and retry when we get EWOULDBLOCK or EMSGSIZE,
 863          * as it always frees the mbuf chain passed to it, even in case
 864          * of error.
 865          */
 866         available = sbspace(&so->so_snd);
 867
 868         /*
 869          * Notify the socket upcall that we don't need wakeups
 870          * for the time being.
 871          */
 872         so->so_snd.sb_lowat = so->so_snd.sb_hiwat + 1;
 873         SOCKBUF_UNLOCK(&so->so_snd);
 874
 875         while (!STAILQ_EMPTY(queue)) {
 876                 request = STAILQ_FIRST(queue);
 877                 size = icl_pdu_size(request);
 878                 if (available < size) {
 879
 880                         /*
 881                          * Set the low watermark, to be checked by
 882                          * sowriteable() in icl_soupcall_send()
 883                          * to avoid unneccessary wakeups until there
 884                          * is enough space for the PDU to fit.
 885                          */
 886                         SOCKBUF_LOCK(&so->so_snd);
 887                         available = sbspace(&so->so_snd);
 888                         if (available < size) {
 889 #if 1
 890                                 ICL_DEBUG("no space to send; "
 891                                     "have %zd, need %zd",
 892                                     available, size);
 893 #endif
 894                                 so->so_snd.sb_lowat = size;
 895                                 SOCKBUF_UNLOCK(&so->so_snd);
 896                                 return;
 897                         }
 898                         SOCKBUF_UNLOCK(&so->so_snd);
 899                 }
 900                 STAILQ_REMOVE_HEAD(queue, ip_next);
 901                 error = icl_pdu_finalize(request);
 902                 if (error != 0) {
 903                         ICL_DEBUG("failed to finalize PDU; "
 904                             "dropping connection");
 905                         icl_conn_fail(ic);
 906                         icl_pdu_free(request);
 907                         return;
 908                 }
 909                 if (coalesce) {
 910                         coalesced = 1;
 911                         for (;;) {
 912                                 request2 = STAILQ_FIRST(queue);
 913                                 if (request2 == NULL)
 914                                         break;
 915                                 size2 = icl_pdu_size(request2);
 916                                 if (available < size + size2)
 917                                         break;
 918                                 STAILQ_REMOVE_HEAD(queue, ip_next);
 919                                 error = icl_pdu_finalize(request2);
 920                                 if (error != 0) {
 921                                         ICL_DEBUG("failed to finalize PDU; "
 922                                             "dropping connection");
 923                                         icl_conn_fail(ic);
 924                                         icl_pdu_free(request);
 925                                         icl_pdu_free(request2);
 926                                         return;
 927                                 }
 928                                 m_cat(request->ip_bhs_mbuf, request2->ip_bhs_mbuf);
 929                                 request2->ip_bhs_mbuf = NULL;
 930                                 request->ip_bhs_mbuf->m_pkthdr.len += size2;
 931                                 size += size2;
 932                                 STAILQ_REMOVE_AFTER(queue, request, ip_next);
 933                                 icl_pdu_free(request2);
 934                                 coalesced++;
 935                         }
 936 #if 0
 937                         if (coalesced > 1) {
 938                                 ICL_DEBUG("coalesced %d PDUs into %zd bytes",
 939                                     coalesced, size);
 940                         }
 941 #endif
 942                 }
 943                 available -= size;
 944                 error = sosend(so, NULL, NULL, request->ip_bhs_mbuf,
 945                     NULL, MSG_DONTWAIT, curthread);
 946                 request->ip_bhs_mbuf = NULL; /* Sosend consumes the mbuf. */
 947                 if (error != 0) {
 948                         ICL_DEBUG("failed to send PDU, error %d; "
 949                             "dropping connection", error);
 950                         icl_conn_fail(ic);
 951                         icl_pdu_free(request);
 952                         return;
 953                 }
 954                 icl_pdu_free(request);
 955         }
 956 }
 957
 958 static void
 959 icl_send_thread(void *arg)
 960 {
 961         struct icl_conn *ic;
 962         struct icl_pdu_stailq queue;
 963
 964         ic = arg;
 965
 966         STAILQ_INIT(&queue);
 967
 968         ICL_CONN_LOCK(ic);
 969         ic->ic_send_running = true;
 970
 971         for (;;) {
 972                 for (;;) {
 973                         /*
 974                          * If the local queue is empty, populate it from
 975                          * the main one.  This way the icl_conn_send_pdus()
 976                          * can go through all the queued PDUs without holding
 977                          * any locks.
 978                          */
 979                         if (STAILQ_EMPTY(&queue))
 980                                 STAILQ_SWAP(&ic->ic_to_send, &queue, icl_pdu);
 981
 982                         ic->ic_check_send_space = false;
 983                         ICL_CONN_UNLOCK(ic);
 984                         icl_conn_send_pdus(ic, &queue);
 985                         ICL_CONN_LOCK(ic);
 986
 987                         /*
 988                          * The icl_soupcall_send() was called since the last
 989                          * call to sbspace(); go around;
 990                          */
 991                         if (ic->ic_check_send_space)
 992                                 continue;
 993
 994                         /*
 995                          * Local queue is empty, but we still have PDUs
 996                          * in the main one; go around.
 997                          */
 998                         if (STAILQ_EMPTY(&queue) &&
 999                             !STAILQ_EMPTY(&ic->ic_to_send))
1000                                 continue;
1001
1002                         /*
1003                          * There might be some stuff in the local queue,
1004                          * which didn't get sent due to not having enough send
1005                          * space.  Wait for socket upcall.
1006                          */
1007                         break;
1008                 }
1009
1010                 if (ic->ic_disconnecting) {
1011                         //ICL_DEBUG("terminating");
1012                         break;
1013                 }
1014
1015                 cv_wait(&ic->ic_send_cv, ic->ic_lock);
1016         }
1017
1018         /*
1019          * We're exiting; move PDUs back to the main queue, so they can
1020          * get freed properly.  At this point ordering doesn't matter.
1021          */
1022         STAILQ_CONCAT(&ic->ic_to_send, &queue);
1023
1024         ic->ic_send_running = false;
1025         cv_signal(&ic->ic_send_cv);
1026         ICL_CONN_UNLOCK(ic);
1027         kthread_exit();
1028 }
1029
1030 static int
1031 icl_soupcall_send(struct socket *so, void *arg, int waitflag)
1032 {
1033         struct icl_conn *ic;
1034
1035         if (!sowriteable(so))
1036                 return (SU_OK);
1037
1038         ic = arg;
1039
1040         ICL_CONN_LOCK(ic);
1041         ic->ic_check_send_space = true;
1042         ICL_CONN_UNLOCK(ic);
1043
1044         cv_signal(&ic->ic_send_cv);
1045
1046         return (SU_OK);
1047 }
1048
1049 int
1050 icl_pdu_append_data(struct icl_pdu *request, const void *addr, size_t len,
1051     int flags)
1052 {
1053         struct mbuf *mb, *newmb;
1054         size_t copylen, off = 0;
1055
1056         KASSERT(len > 0, ("len == 0"));
1057
1058         newmb = m_getm2(NULL, len, flags, MT_DATA, M_PKTHDR);
1059         if (newmb == NULL) {
1060                 ICL_WARN("failed to allocate mbuf for %zd bytes", len);
1061                 return (ENOMEM);
1062         }
1063
1064         for (mb = newmb; mb != NULL; mb = mb->m_next) {
1065                 copylen = min(M_TRAILINGSPACE(mb), len - off);
1066                 memcpy(mtod(mb, char *), (const char *)addr + off, copylen);
1067                 mb->m_len = copylen;
1068                 off += copylen;
1069         }
1070         KASSERT(off == len, ("%s: off != len", __func__));
1071
1072         if (request->ip_data_mbuf == NULL) {
1073                 request->ip_data_mbuf = newmb;
1074                 request->ip_data_len = len;
1075         } else {
1076                 m_cat(request->ip_data_mbuf, newmb);
1077                 request->ip_data_len += len;
1078         }
1079
1080         return (0);
1081 }
1082
1083 void
1084 icl_pdu_get_data(struct icl_pdu *ip, size_t off, void *addr, size_t len)
1085 {
1086
1087         m_copydata(ip->ip_data_mbuf, off, len, addr);
1088 }
1089
1090 void
1091 icl_pdu_queue(struct icl_pdu *ip)
1092 {
1093         struct icl_conn *ic;
1094
1095         ic = ip->ip_conn;
1096
1097         ICL_CONN_LOCK_ASSERT(ic);
1098
1099         if (ic->ic_disconnecting || ic->ic_socket == NULL) {
1100                 ICL_DEBUG("icl_pdu_queue on closed connection");
1101                 icl_pdu_free(ip);
1102                 return;
1103         }
1104
1105         if (!STAILQ_EMPTY(&ic->ic_to_send)) {
1106                 STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
1107                 /*
1108                  * If the queue is not empty, someone else had already
1109                  * signaled the send thread; no need to do that again,
1110                  * just return.
1111                  */
1112                 return;
1113         }
1114
1115         STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
1116         cv_signal(&ic->ic_send_cv);
1117 }
1118
1119 struct icl_conn *
1120 icl_conn_new(const char *name, struct mtx *lock)
1121 {
1122         struct icl_conn *ic;
1123
1124         refcount_acquire(&icl_ncons);
1125
1126         ic = uma_zalloc(icl_conn_zone, M_WAITOK | M_ZERO);
1127
1128         STAILQ_INIT(&ic->ic_to_send);
1129         ic->ic_lock = lock;
1130         cv_init(&ic->ic_send_cv, "icl_tx");
1131         cv_init(&ic->ic_receive_cv, "icl_rx");
1132 #ifdef DIAGNOSTIC
1133         refcount_init(&ic->ic_outstanding_pdus, 0);
1134 #endif
1135         ic->ic_max_data_segment_length = ICL_MAX_DATA_SEGMENT_LENGTH;
1136         ic->ic_name = name;
1137
1138         return (ic);
1139 }
1140
1141 void
1142 icl_conn_free(struct icl_conn *ic)
1143 {
1144
1145         cv_destroy(&ic->ic_send_cv);
1146         cv_destroy(&ic->ic_receive_cv);
1147         uma_zfree(icl_conn_zone, ic);
1148         refcount_release(&icl_ncons);
1149 }
1150
1151 static int
1152 icl_conn_start(struct icl_conn *ic)
1153 {
1154         size_t minspace;
1155         struct sockopt opt;
1156         int error, one = 1;
1157
1158         ICL_CONN_LOCK(ic);
1159
1160         /*
1161          * XXX: Ugly hack.
1162          */
1163         if (ic->ic_socket == NULL) {
1164                 ICL_CONN_UNLOCK(ic);
1165                 return (EINVAL);
1166         }
1167
1168         ic->ic_receive_state = ICL_CONN_STATE_BHS;
1169         ic->ic_receive_len = sizeof(struct iscsi_bhs);
1170         ic->ic_disconnecting = false;
1171
1172         ICL_CONN_UNLOCK(ic);
1173
1174         /*
1175          * For sendspace, this is required because the current code cannot
1176          * send a PDU in pieces; thus, the minimum buffer size is equal
1177          * to the maximum PDU size.  "+4" is to account for possible padding.
1178          *
1179          * What we should actually do here is to use autoscaling, but set
1180          * some minimal buffer size to "minspace".  I don't know a way to do
1181          * that, though.
1182          */
1183         minspace = sizeof(struct iscsi_bhs) + ic->ic_max_data_segment_length +
1184             ISCSI_HEADER_DIGEST_SIZE + ISCSI_DATA_DIGEST_SIZE + 4;
1185         if (sendspace < minspace) {
1186                 ICL_WARN("kern.icl.sendspace too low; must be at least %zd",
1187                     minspace);
1188                 sendspace = minspace;
1189         }
1190         if (recvspace < minspace) {
1191                 ICL_WARN("kern.icl.recvspace too low; must be at least %zd",
1192                     minspace);
1193                 recvspace = minspace;
1194         }
1195
1196         error = soreserve(ic->ic_socket, sendspace, recvspace);
1197         if (error != 0) {
1198                 ICL_WARN("soreserve failed with error %d", error);
1199                 icl_conn_close(ic);
1200                 return (error);
1201         }
1202         ic->ic_socket->so_snd.sb_flags |= SB_AUTOSIZE;
1203         ic->ic_socket->so_rcv.sb_flags |= SB_AUTOSIZE;
1204
1205         /*
1206          * Disable Nagle.
1207          */
1208         bzero(&opt, sizeof(opt));
1209         opt.sopt_dir = SOPT_SET;
1210         opt.sopt_level = IPPROTO_TCP;
1211         opt.sopt_name = TCP_NODELAY;
1212         opt.sopt_val = &one;
1213         opt.sopt_valsize = sizeof(one);
1214         error = sosetopt(ic->ic_socket, &opt);
1215         if (error != 0) {
1216                 ICL_WARN("disabling TCP_NODELAY failed with error %d", error);
1217                 icl_conn_close(ic);
1218                 return (error);
1219         }
1220
1221         /*
1222          * Start threads.
1223          */
1224         error = kthread_add(icl_send_thread, ic, NULL, NULL, 0, 0, "%stx",
1225             ic->ic_name);
1226         if (error != 0) {
1227                 ICL_WARN("kthread_add(9) failed with error %d", error);
1228                 icl_conn_close(ic);
1229                 return (error);
1230         }
1231
1232         error = kthread_add(icl_receive_thread, ic, NULL, NULL, 0, 0, "%srx",
1233             ic->ic_name);
1234         if (error != 0) {
1235                 ICL_WARN("kthread_add(9) failed with error %d", error);
1236                 icl_conn_close(ic);
1237                 return (error);
1238         }
1239
1240         /*
1241          * Register socket upcall, to get notified about incoming PDUs
1242          * and free space to send outgoing ones.
1243          */
1244         SOCKBUF_LOCK(&ic->ic_socket->so_snd);
1245         soupcall_set(ic->ic_socket, SO_SND, icl_soupcall_send, ic);
1246         SOCKBUF_UNLOCK(&ic->ic_socket->so_snd);
1247         SOCKBUF_LOCK(&ic->ic_socket->so_rcv);
1248         soupcall_set(ic->ic_socket, SO_RCV, icl_soupcall_receive, ic);
1249         SOCKBUF_UNLOCK(&ic->ic_socket->so_rcv);
1250
1251         return (0);
1252 }
1253
1254 int
1255 icl_conn_handoff(struct icl_conn *ic, int fd)
1256 {
1257         struct file *fp;
1258         struct socket *so;
1259         cap_rights_t rights;
1260         int error;
1261
1262         ICL_CONN_LOCK_ASSERT_NOT(ic);
1263
1264         /*
1265          * Steal the socket from userland.
1266          */
1267         error = fget(curthread, fd,
1268             cap_rights_init(&rights, CAP_SOCK_CLIENT), &fp);
1269         if (error != 0)
1270                 return (error);
1271         if (fp->f_type != DTYPE_SOCKET) {
1272                 fdrop(fp, curthread);
1273                 return (EINVAL);
1274         }
1275         so = fp->f_data;
1276         if (so->so_type != SOCK_STREAM) {
1277                 fdrop(fp, curthread);
1278                 return (EINVAL);
1279         }
1280
1281         ICL_CONN_LOCK(ic);
1282
1283         if (ic->ic_socket != NULL) {
1284                 ICL_CONN_UNLOCK(ic);
1285                 fdrop(fp, curthread);
1286                 return (EBUSY);
1287         }
1288
1289         ic->ic_socket = fp->f_data;
1290         fp->f_ops = &badfileops;
1291         fp->f_data = NULL;
1292         fdrop(fp, curthread);
1293         ICL_CONN_UNLOCK(ic);
1294
1295         error = icl_conn_start(ic);
1296
1297         return (error);
1298 }
1299
1300 void
1301 icl_conn_close(struct icl_conn *ic)
1302 {
1303         struct icl_pdu *pdu;
1304
1305         ICL_CONN_LOCK_ASSERT_NOT(ic);
1306
1307         ICL_CONN_LOCK(ic);
1308         if (ic->ic_socket == NULL) {
1309                 ICL_CONN_UNLOCK(ic);
1310                 return;
1311         }
1312
1313         /*
1314          * Deregister socket upcalls.
1315          */
1316         ICL_CONN_UNLOCK(ic);
1317         SOCKBUF_LOCK(&ic->ic_socket->so_snd);
1318         if (ic->ic_socket->so_snd.sb_upcall != NULL)
1319                 soupcall_clear(ic->ic_socket, SO_SND);
1320         SOCKBUF_UNLOCK(&ic->ic_socket->so_snd);
1321         SOCKBUF_LOCK(&ic->ic_socket->so_rcv);
1322         if (ic->ic_socket->so_rcv.sb_upcall != NULL)
1323                 soupcall_clear(ic->ic_socket, SO_RCV);
1324         SOCKBUF_UNLOCK(&ic->ic_socket->so_rcv);
1325         ICL_CONN_LOCK(ic);
1326
1327         ic->ic_disconnecting = true;
1328
1329         /*
1330          * Wake up the threads, so they can properly terminate.
1331          */
1332         while (ic->ic_receive_running || ic->ic_send_running) {
1333                 //ICL_DEBUG("waiting for send/receive threads to terminate");
1334                 cv_signal(&ic->ic_receive_cv);
1335                 cv_signal(&ic->ic_send_cv);
1336                 cv_wait(&ic->ic_send_cv, ic->ic_lock);
1337         }
1338         //ICL_DEBUG("send/receive threads terminated");
1339
1340         ICL_CONN_UNLOCK(ic);
1341         soclose(ic->ic_socket);
1342         ICL_CONN_LOCK(ic);
1343         ic->ic_socket = NULL;
1344
1345         if (ic->ic_receive_pdu != NULL) {
1346                 //ICL_DEBUG("freeing partially received PDU");
1347                 icl_pdu_free(ic->ic_receive_pdu);
1348                 ic->ic_receive_pdu = NULL;
1349         }
1350
1351         /*
1352          * Remove any outstanding PDUs from the send queue.
1353          */
1354         while (!STAILQ_EMPTY(&ic->ic_to_send)) {
1355                 pdu = STAILQ_FIRST(&ic->ic_to_send);
1356                 STAILQ_REMOVE_HEAD(&ic->ic_to_send, ip_next);
1357                 icl_pdu_free(pdu);
1358         }
1359
1360         KASSERT(STAILQ_EMPTY(&ic->ic_to_send),
1361             ("destroying session with non-empty send queue"));
1362 #ifdef DIAGNOSTIC
1363         KASSERT(ic->ic_outstanding_pdus == 0,
1364             ("destroying session with %d outstanding PDUs",
1365              ic->ic_outstanding_pdus));
1366 #endif
1367         ICL_CONN_UNLOCK(ic);
1368 }
1369
1370 bool
1371 icl_conn_connected(struct icl_conn *ic)
1372 {
1373         ICL_CONN_LOCK_ASSERT_NOT(ic);
1374
1375         ICL_CONN_LOCK(ic);
1376         if (ic->ic_socket == NULL) {
1377                 ICL_CONN_UNLOCK(ic);
1378                 return (false);
1379         }
1380         if (ic->ic_socket->so_error != 0) {
1381                 ICL_CONN_UNLOCK(ic);
1382                 return (false);
1383         }
1384         ICL_CONN_UNLOCK(ic);
1385         return (true);
1386 }
1387
1388 #ifdef ICL_KERNEL_PROXY
1389 int
1390 icl_conn_handoff_sock(struct icl_conn *ic, struct socket *so)
1391 {
1392         int error;
1393
1394         ICL_CONN_LOCK_ASSERT_NOT(ic);
1395
1396         if (so->so_type != SOCK_STREAM)
1397                 return (EINVAL);
1398
1399         ICL_CONN_LOCK(ic);
1400         if (ic->ic_socket != NULL) {
1401                 ICL_CONN_UNLOCK(ic);
1402                 return (EBUSY);
1403         }
1404         ic->ic_socket = so;
1405         ICL_CONN_UNLOCK(ic);
1406
1407         error = icl_conn_start(ic);
1408
1409         return (error);
1410 }
1411 #endif /* ICL_KERNEL_PROXY */
1412
1413 static int
1414 icl_unload(void)
1415 {
1416
1417         if (icl_ncons != 0)
1418                 return (EBUSY);
1419
1420         uma_zdestroy(icl_conn_zone);
1421         uma_zdestroy(icl_pdu_zone);
1422
1423         return (0);
1424 }
1425
1426 static void
1427 icl_load(void)
1428 {
1429
1430         icl_conn_zone = uma_zcreate("icl_conn",
1431             sizeof(struct icl_conn), NULL, NULL, NULL, NULL,
1432             UMA_ALIGN_PTR, 0);
1433         icl_pdu_zone = uma_zcreate("icl_pdu",
1434             sizeof(struct icl_pdu), NULL, NULL, NULL, NULL,
1435             UMA_ALIGN_PTR, 0);
1436
1437         refcount_init(&icl_ncons, 0);
1438 }
1439
1440 static int
1441 icl_modevent(module_t mod, int what, void *arg)
1442 {
1443
1444         switch (what) {
1445         case MOD_LOAD:
1446                 icl_load();
1447                 return (0);
1448         case MOD_UNLOAD:
1449                 return (icl_unload());
1450         default:
1451                 return (EINVAL);
1452         }
1453 }
1454
1455 moduledata_t icl_data = {
1456         "icl",
1457         icl_modevent,
1458         0
1459 };
1460
1461 DECLARE_MODULE(icl, icl_data, SI_SUB_DRIVERS, SI_ORDER_FIRST);
1462 MODULE_VERSION(icl, 1);