iscsi_utils.c revision 1.16
1 /* $NetBSD: iscsi_utils.c,v 1.16 2016/06/05 05:41:53 mlelstv Exp $ */ 2 3 /*- 4 * Copyright (c) 2004,2005,2006,2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Wasabi Systems, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include "iscsi_globals.h" 32 33 #include <sys/systm.h> 34 #include <sys/buf.h> 35 #include <sys/socketvar.h> 36 #include <sys/bswap.h> 37 #include <sys/atomic.h> 38 39 40 #ifdef ISCSI_DEBUG 41 42 /* debug helper routine */ 43 void 44 iscsi_hexdump(void *buff, int len) 45 { 46 uint8_t *bp = (uint8_t *) buff; 47 int i; 48 49 while (len > 0) { 50 for (i = min(16, len); i > 0; i--) 51 printf("%02x ", *bp++); 52 printf("\n"); 53 len -= 16; 54 } 55 } 56 57 #endif 58 59 /***************************************************************************** 60 * Digest functions 61 *****************************************************************************/ 62 63 /***************************************************************** 64 * 65 * CRC LOOKUP TABLE 66 * ================ 67 * The following CRC lookup table was generated automagically 68 * by the Rocksoft^tm Model CRC Algorithm Table Generation 69 * Program V1.0 using the following model parameters: 70 * 71 * Width : 4 bytes. 72 * Poly : 0x1EDC6F41L 73 * Reverse : TRUE. 74 * 75 * For more information on the Rocksoft^tm Model CRC Algorithm, 76 * see the document titled "A Painless Guide to CRC Error 77 * Detection Algorithms" by Ross Williams 78 * (ross (at) guest.adelaide.edu.au.). This document is likely to be 79 * in the FTP archive "ftp.adelaide.edu.au/pub/rocksoft". 80 * 81 *****************************************************************/ 82 83 STATIC uint32_t crc_table[256] = { 84 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L, 85 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL, 86 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL, 87 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L, 88 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL, 89 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L, 90 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L, 91 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL, 92 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL, 93 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L, 94 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L, 95 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL, 96 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L, 97 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL, 98 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL, 99 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L, 100 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L, 101 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L, 102 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L, 103 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L, 104 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L, 105 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L, 106 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L, 107 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L, 108 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L, 109 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L, 110 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L, 111 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L, 112 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L, 113 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L, 114 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L, 115 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L, 116 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL, 117 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L, 118 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L, 119 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL, 120 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L, 121 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL, 122 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL, 123 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L, 124 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L, 125 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL, 126 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL, 127 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L, 128 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL, 129 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L, 130 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L, 131 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL, 132 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L, 133 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL, 134 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL, 135 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L, 136 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL, 137 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L, 138 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L, 139 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL, 140 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL, 141 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L, 142 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L, 143 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL, 144 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L, 145 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL, 146 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL, 147 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L 148 }; 149 150 151 /* 152 * gen_digest: 153 * Generate an iSCSI CRC32C digest over the given data. 154 * 155 * Parameters: 156 * buff The data 157 * len The length of the data in bytes 158 * 159 * Returns: The digest in network byte order 160 */ 161 162 uint32_t 163 gen_digest(void *buff, int len) 164 { 165 uint8_t *bp = (uint8_t *) buff; 166 uint32_t crc = 0xffffffff; 167 168 while (len--) { 169 crc = ((crc >> 8) & 0x00ffffff) ^ crc_table[(crc ^ *bp++) & 0xff]; 170 } 171 return htonl(bswap32(crc ^ 0xffffffff)); 172 } 173 174 175 /* 176 * gen_digest_2: 177 * Generate an iSCSI CRC32C digest over the given data, which is split over 178 * two buffers. 179 * 180 * Parameters: 181 * buf1, buf2 The data 182 * len1, len2 The length of the data in bytes 183 * 184 * Returns: The digest in network byte order 185 */ 186 187 uint32_t 188 gen_digest_2(void *buf1, int len1, void *buf2, int len2) 189 { 190 uint8_t *bp = (uint8_t *) buf1; 191 uint32_t crc = 0xffffffff; 192 193 while (len1--) { 194 crc = ((crc >> 8) & 0x00ffffff) ^ crc_table[(crc ^ *bp++) & 0xff]; 195 } 196 bp = (uint8_t *) buf2; 197 while (len2--) { 198 crc = ((crc >> 8) & 0x00ffffff) ^ crc_table[(crc ^ *bp++) & 0xff]; 199 } 200 return htonl(bswap32(crc ^ 0xffffffff)); 201 } 202 203 /***************************************************************************** 204 * CCB management functions 205 *****************************************************************************/ 206 207 /* 208 * get_ccb: 209 * Get a CCB for the SCSI operation, waiting if none is available. 210 * 211 * Parameter: 212 * sess The session containing this CCB 213 * waitok Whether waiting for a CCB is OK 214 * 215 * Returns: The CCB. 216 */ 217 218 ccb_t * 219 get_ccb(connection_t *conn, bool waitok) 220 { 221 ccb_t *ccb; 222 session_t *sess = conn->session; 223 224 mutex_enter(&sess->lock); 225 do { 226 ccb = TAILQ_FIRST(&sess->ccb_pool); 227 DEB(100, ("get_ccb: ccb = %p, waitok = %d\n", ccb, waitok)); 228 229 if (ccb != NULL) { 230 TAILQ_REMOVE(&sess->ccb_pool, ccb, chain); 231 } else { 232 if (!waitok || conn->terminating) { 233 mutex_exit(&sess->lock); 234 return NULL; 235 } 236 cv_wait(&sess->ccb_cv, &sess->lock); 237 } 238 } while (ccb == NULL); 239 mutex_exit(&sess->lock); 240 241 ccb->flags = 0; 242 ccb->timedout = TOUT_NONE; 243 ccb->xs = NULL; 244 ccb->temp_data = NULL; 245 ccb->text_data = NULL; 246 ccb->status = ISCSI_STATUS_SUCCESS; 247 ccb->ITT = (ccb->ITT & 0xffffff); 248 ccb->disp = CCBDISP_NOWAIT; 249 ccb->connection = conn; 250 ccb->num_timeouts = 0; 251 atomic_inc_uint(&conn->usecount); 252 253 DEBC(conn, 15, ( 254 "get_ccb: ccb = %p, usecount = %d\n", 255 ccb, conn->usecount)); 256 257 return ccb; 258 } 259 260 /* 261 * free_ccb: 262 * Put a CCB back onto the free list. 263 * 264 * Parameter: The CCB. 265 */ 266 267 void 268 free_ccb(ccb_t *ccb) 269 { 270 session_t *sess = ccb->session; 271 pdu_t *pdu; 272 273 DEBC(ccb->connection, 15, ( 274 "free_ccb: ccb = %p, usecount = %d\n", 275 ccb, ccb->connection->usecount-1)); 276 277 KASSERT((ccb->flags & CCBF_THROTTLING) == 0); 278 KASSERT((ccb->flags & CCBF_WAITQUEUE) == 0); 279 280 atomic_dec_uint(&ccb->connection->usecount); 281 ccb->connection = NULL; 282 283 if (ccb->disp > CCBDISP_NOWAIT) { 284 DEBOUT(("Freeing CCB with disp %d\n",ccb->disp)); 285 } 286 287 ccb->disp = CCBDISP_UNUSED; 288 289 /* free temporary data */ 290 if (ccb->temp_data != NULL) { 291 free(ccb->temp_data, M_TEMP); 292 } 293 if (ccb->text_data != NULL) { 294 free(ccb->text_data, M_TEMP); 295 } 296 /* free PDU waiting for ACK */ 297 if ((pdu = ccb->pdu_waiting) != NULL) { 298 ccb->pdu_waiting = NULL; 299 free_pdu(pdu); 300 } 301 302 mutex_enter(&sess->lock); 303 TAILQ_INSERT_TAIL(&sess->ccb_pool, ccb, chain); 304 mutex_exit(&sess->lock); 305 306 cv_broadcast(&sess->ccb_cv); 307 } 308 309 /* 310 * create_ccbs 311 * "Create" the pool of CCBs. This doesn't actually create the CCBs 312 * (they are allocated with the session structure), but it links them 313 * into the free-list. 314 * 315 * Parameter: The session owning the CCBs. 316 */ 317 318 void 319 create_ccbs(session_t *sess) 320 { 321 int i; 322 ccb_t *ccb; 323 int sid = sess->id << 8; 324 325 /* Note: CCBs are initialized to 0 with connection structure */ 326 327 for (i = 0, ccb = sess->ccb; i < CCBS_PER_SESSION; i++, ccb++) { 328 ccb->ITT = i | sid; 329 ccb->session = sess; 330 331 callout_init(&ccb->timeout, CALLOUT_MPSAFE); 332 callout_setfunc(&ccb->timeout, ccb_timeout_co, ccb); 333 334 DEB(9, ("Create_ccbs: ccb %p itt %x\n", ccb, ccb->ITT)); 335 TAILQ_INSERT_HEAD(&sess->ccb_pool, ccb, chain); 336 } 337 } 338 339 /* 340 * suspend_ccb: 341 * Put CCB on wait queue 342 */ 343 void 344 suspend_ccb(ccb_t *ccb, bool yes) 345 { 346 connection_t *conn; 347 348 conn = ccb->connection; 349 if (yes) { 350 KASSERT((ccb->flags & CCBF_THROTTLING) == 0); 351 KASSERT((ccb->flags & CCBF_WAITQUEUE) == 0); 352 TAILQ_INSERT_TAIL(&conn->ccbs_waiting, ccb, chain); 353 ccb->flags |= CCBF_WAITQUEUE; 354 } else if (ccb->flags & CCBF_WAITQUEUE) { 355 KASSERT((ccb->flags & CCBF_THROTTLING) == 0); 356 TAILQ_REMOVE(&conn->ccbs_waiting, ccb, chain); 357 ccb->flags &= ~CCBF_WAITQUEUE; 358 } 359 } 360 361 /* 362 * throttle_ccb: 363 * Put CCB on throttling queue 364 */ 365 void 366 throttle_ccb(ccb_t *ccb, bool yes) 367 { 368 session_t *sess; 369 370 KASSERT(mutex_owned(&sess->lock)); 371 372 sess = ccb->session; 373 if (yes) { 374 KASSERT((ccb->flags & CCBF_THROTTLING) == 0); 375 KASSERT((ccb->flags & CCBF_WAITQUEUE) == 0); 376 TAILQ_INSERT_TAIL(&sess->ccbs_throttled, ccb, chain); 377 ccb->flags |= CCBF_THROTTLING; 378 } else if (ccb->flags & CCBF_THROTTLING) { 379 KASSERT((ccb->flags & CCBF_WAITQUEUE) == 0); 380 TAILQ_REMOVE(&sess->ccbs_throttled, ccb, chain); 381 ccb->flags &= ~CCBF_THROTTLING; 382 } 383 } 384 385 386 /* 387 * wake_ccb: 388 * Wake up (or dispose of) a CCB. Depending on the CCB's disposition, 389 * either wake up the requesting thread, signal SCSIPI that we're done, 390 * or just free the CCB for CCBDISP_FREE. 391 * 392 * Parameter: The CCB to handle and the new status of the CCB 393 */ 394 395 void 396 wake_ccb(ccb_t *ccb, uint32_t status) 397 { 398 ccb_disp_t disp; 399 connection_t *conn; 400 401 conn = ccb->connection; 402 403 #ifdef ISCSI_DEBUG 404 DEBC(conn, 9, ("CCB done, ccb = %p, disp = %d\n", 405 ccb, ccb->disp)); 406 #endif 407 408 ccb_timeout_stop(ccb); 409 410 mutex_enter(&conn->lock); 411 disp = ccb->disp; 412 if (disp <= CCBDISP_NOWAIT || 413 (disp == CCBDISP_DEFER && conn->state <= ST_WINDING_DOWN)) { 414 mutex_exit(&conn->lock); 415 return; 416 } 417 418 suspend_ccb(ccb, FALSE); 419 throttle_ccb(ccb, FALSE); 420 421 /* change the disposition so nobody tries this again */ 422 ccb->disp = CCBDISP_BUSY; 423 ccb->status = status; 424 mutex_exit(&conn->lock); 425 426 switch (disp) { 427 case CCBDISP_FREE: 428 free_ccb(ccb); 429 break; 430 431 case CCBDISP_WAIT: 432 cv_broadcast(&conn->ccb_cv); 433 break; 434 435 case CCBDISP_SCSIPI: 436 iscsi_done(ccb); 437 free_ccb(ccb); 438 break; 439 440 case CCBDISP_DEFER: 441 break; 442 443 default: 444 DEBC(conn, 1, ("CCB done, ccb = %p, invalid disposition %d", ccb, disp)); 445 free_ccb(ccb); 446 break; 447 } 448 } 449 450 /***************************************************************************** 451 * PDU management functions 452 *****************************************************************************/ 453 454 /* 455 * get_pdu: 456 * Get a PDU for the SCSI operation. 457 * 458 * Parameter: 459 * conn The connection this PDU should be associated with 460 * waitok OK to wait for PDU if TRUE 461 * 462 * Returns: The PDU or NULL if none is available and waitok is FALSE. 463 */ 464 465 pdu_t * 466 get_pdu(connection_t *conn, bool waitok) 467 { 468 pdu_t *pdu; 469 470 mutex_enter(&conn->lock); 471 do { 472 pdu = TAILQ_FIRST(&conn->pdu_pool); 473 if (pdu != NULL) 474 TAILQ_REMOVE(&conn->pdu_pool, pdu, chain); 475 476 DEB(100, ("get_pdu_c: pdu = %p, waitok = %d\n", pdu, waitok)); 477 478 if (pdu == NULL) { 479 if (!waitok || conn->terminating) { 480 mutex_exit(&conn->lock); 481 return NULL; 482 } 483 cv_wait(&conn->conn_cv, &conn->lock); 484 } 485 } while (pdu == NULL); 486 mutex_exit(&conn->lock); 487 488 memset(pdu, 0, sizeof(pdu_t)); 489 pdu->connection = conn; 490 pdu->disp = PDUDISP_FREE; 491 492 return pdu; 493 } 494 495 /* 496 * free_pdu: 497 * Put a PDU back onto the free list. 498 * 499 * Parameter: The PDU. 500 */ 501 502 void 503 free_pdu(pdu_t *pdu) 504 { 505 connection_t *conn = pdu->connection; 506 pdu_disp_t pdisp; 507 508 KASSERT((pdu->flags & PDUF_INQUEUE) == 0); 509 510 if (PDUDISP_UNUSED == (pdisp = pdu->disp)) 511 return; 512 pdu->disp = PDUDISP_UNUSED; 513 514 /* free temporary data in this PDU */ 515 if (pdu->temp_data) 516 free(pdu->temp_data, M_TEMP); 517 518 mutex_enter(&conn->lock); 519 TAILQ_INSERT_TAIL(&conn->pdu_pool, pdu, chain); 520 mutex_exit(&conn->lock); 521 522 cv_broadcast(&conn->conn_cv); 523 } 524 525 /* 526 * create_pdus 527 * "Create" the pool of PDUs. This doesn't actually create the PDUs 528 * (they are allocated with the connection structure), but it links them 529 * into the free-list. 530 * 531 * Parameter: The connection owning the PDUs. 532 */ 533 534 void 535 create_pdus(connection_t *conn) 536 { 537 int i; 538 pdu_t *pdu; 539 540 /* Note: PDUs are initialized to 0 with connection structure */ 541 542 for (i = 0, pdu = conn->pdu; i < PDUS_PER_CONNECTION; i++, pdu++) { 543 TAILQ_INSERT_HEAD(&conn->pdu_pool, pdu, chain); 544 } 545 } 546 547 548 /***************************************************************************** 549 * Serial Number management functions 550 *****************************************************************************/ 551 552 /* 553 * init_sernum: 554 * Initialize serial number buffer variables. 555 * 556 * Parameter: 557 * buff The serial number buffer. 558 */ 559 560 void 561 init_sernum(sernum_buffer_t *buff) 562 { 563 564 buff->bottom = 0; 565 buff->top = 0; 566 buff->next_sn = 0; 567 buff->ExpSN = 0; 568 } 569 570 571 /* 572 * add_sernum: 573 * Add a received serial number to the buffer. 574 * If the serial number is smaller than the expected one, it is ignored. 575 * If it is larger, all missing serial numbers are added as well. 576 * 577 * Parameter: 578 * buff The serial number buffer. 579 * num The received serial number 580 * 581 * Returns: 582 * 0 if the received block is a duplicate 583 * 1 if the number is the expected one 584 * >1 if the numer is > the expected value, in this case the 585 * return value is the number of unacknowledged blocks 586 * <0 if the buffer is full (i.e. an excessive number of blocks 587 * is unacknowledged) 588 */ 589 590 int 591 add_sernum(sernum_buffer_t *buff, uint32_t num) 592 { 593 int i, t, b; 594 uint32_t n; 595 int32_t diff; 596 597 /* 598 * next_sn is the next expected SN, so normally diff should be 1. 599 */ 600 n = buff->next_sn; 601 diff = (num - n) + 1; 602 603 if (diff <= 0) { 604 return 0; /* ignore if SN is smaller than expected (dup or retransmit) */ 605 } 606 607 buff->next_sn = num + 1; 608 t = buff->top; 609 b = buff->bottom; 610 611 for (i = 0; i < diff; i++) { 612 buff->sernum[t] = n++; 613 buff->ack[t] = false; 614 t = (t + 1) % SERNUM_BUFFER_LENGTH; 615 if (t == b) { 616 DEB(1, ("AddSernum: Buffer Full! num %d, diff %d\n", num, diff)); 617 return -1; 618 } 619 } 620 621 buff->top = t; 622 DEB(11, ("AddSernum bottom %d [%d], top %d, num %u, diff %d\n", 623 b, buff->sernum[b], buff->top, num, diff)); 624 625 return diff; 626 } 627 628 629 /* 630 * ack_sernum: 631 * Mark a received serial number as acknowledged. This does not necessarily 632 * change the associated ExpSN if there are lower serial numbers in the 633 * buffer. 634 * 635 * Parameter: 636 * buff The serial number buffer. 637 * num The serial number to acknowledge. 638 * 639 * Returns: The value of ExpSN. 640 */ 641 642 uint32_t 643 ack_sernum(sernum_buffer_t *buff, uint32_t num) 644 { 645 int b = buff->bottom; 646 int t = buff->top; 647 648 /* shortcut for most likely case */ 649 if (t == (b + 1) && num == buff->sernum[b]) { 650 /* buffer is now empty, reset top */ 651 buff->top = b; 652 } else if (b != t) { 653 for (; b != t; b = (b + 1) % SERNUM_BUFFER_LENGTH) { 654 if (!sn_a_lt_b(buff->sernum[b], num)) 655 break; 656 } 657 if (num == buff->sernum[b]) { 658 if (b == buff->bottom) 659 buff->bottom = (b + 1) % SERNUM_BUFFER_LENGTH; 660 else 661 buff->ack[b] = true; 662 } 663 664 for (b = buff->bottom, num = buff->sernum[b] - 1; 665 b != t && buff->ack[b]; b = (b + 1) % SERNUM_BUFFER_LENGTH) { 666 num = buff->sernum[b]; 667 } 668 } 669 670 if (!sn_a_lt_b(num, buff->ExpSN)) 671 buff->ExpSN = num + 1; 672 673 DEB(11, ("AckSernum bottom %d, top %d, num %d ExpSN %d\n", 674 buff->bottom, buff->top, num, buff->ExpSN)); 675 676 return buff->ExpSN; 677 } 678 679 /* 680 * next_sernum: 681 * Return the current command serial number of the session 682 * and optionally increment it for the next query 683 */ 684 uint32_t 685 get_sernum(session_t *sess, bool bump) 686 { 687 uint32_t sn; 688 689 KASSERT(mutex_owned(&sess->lock)); 690 691 sn = sess->CmdSN; 692 if (bump) 693 atomic_inc_32(&sess->CmdSN); 694 return sn; 695 } 696 697 /* 698 * sernum_in_window: 699 * Check wether serial number is in send window 700 * 701 */ 702 int 703 sernum_in_window(session_t *sess) 704 { 705 706 KASSERT(mutex_owned(&sess->lock)); 707 return sn_a_le_b(sess->CmdSN, sess->MaxCmdSN); 708 } 709 710
Indexes created Tue Sep 30 20:09:53 GMT 2025