1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * __Userspace__ version of /usr/src/sys/kern/kern_mbuf.c 34 * We are initializing two zones for Mbufs and Clusters. 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 /* #include <sys/param.h> This defines MSIZE 256 */ 41 #if !defined(SCTP_SIMPLE_ALLOCATOR) 42 #include "umem.h" 43 #endif 44 #include "user_mbuf.h" 45 #include "user_environment.h" 46 #include "user_atomic.h" 47 #include "netinet/sctp_pcb.h" 48 49 #define KIPC_MAX_LINKHDR 4 /* int: max length of link header (see sys/sysclt.h) */ 50 #define KIPC_MAX_PROTOHDR 5 /* int: max length of network header (see sys/sysclt.h)*/ 51 int max_linkhdr = KIPC_MAX_LINKHDR; 52 int max_protohdr = KIPC_MAX_PROTOHDR; /* Size of largest protocol layer header. */ 53 54 /* 55 * Zones from which we allocate. 56 */ 57 sctp_zone_t zone_mbuf; 58 sctp_zone_t zone_clust; 59 sctp_zone_t zone_ext_refcnt; 60 61 /* __Userspace__ clust_mb_args will be passed as callback data to mb_ctor_clust 62 * and mb_dtor_clust. 63 * Note: I had to use struct clust_args as an encapsulation for an mbuf pointer. 64 * struct mbuf * clust_mb_args; does not work. 65 */ 66 struct clust_args clust_mb_args; 67 68 69 /* __Userspace__ 70 * Local prototypes. 71 */ 72 static int mb_ctor_mbuf(void *, void *, int); 73 static int mb_ctor_clust(void *, void *, int); 74 static void mb_dtor_mbuf(void *, void *); 75 static void mb_dtor_clust(void *, void *); 76 77 78 /***************** Functions taken from user_mbuf.h *************/ 79 80 static int mbuf_constructor_dup(struct mbuf *m, int pkthdr, short type) 81 { 82 int flags = pkthdr; 83 if (type == MT_NOINIT) 84 return (0); 85 86 m->m_next = NULL; 87 m->m_nextpkt = NULL; 88 m->m_len = 0; 89 m->m_flags = flags; 90 m->m_type = type; 91 if (flags & M_PKTHDR) { 92 m->m_data = m->m_pktdat; 93 m->m_pkthdr.rcvif = NULL; 94 m->m_pkthdr.len = 0; 95 m->m_pkthdr.header = NULL; 96 m->m_pkthdr.csum_flags = 0; 97 m->m_pkthdr.csum_data = 0; 98 m->m_pkthdr.tso_segsz = 0; 99 m->m_pkthdr.ether_vtag = 0; 100 SLIST_INIT(&m->m_pkthdr.tags); 101 } else 102 m->m_data = m->m_dat; 103 104 return (0); 105 } 106 107 /* __Userspace__ */ 108 struct mbuf * 109 m_get(int how, short type) 110 { 111 struct mbuf *mret; 112 #if defined(SCTP_SIMPLE_ALLOCATOR) 113 struct mb_args mbuf_mb_args; 114 115 /* The following setter function is not yet being enclosed within 116 * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested 117 * mb_dtor_mbuf. See comment there 118 */ 119 mbuf_mb_args.flags = 0; 120 mbuf_mb_args.type = type; 121 #endif 122 /* Mbuf master zone, zone_mbuf, has already been 123 * created in mbuf_initialize() */ 124 mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf); 125 #if defined(SCTP_SIMPLE_ALLOCATOR) 126 mb_ctor_mbuf(mret, &mbuf_mb_args, 0); 127 #endif 128 /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/ 129 130 /* There are cases when an object available in the current CPU's 131 * loaded magazine and in those cases the object's constructor is not applied. 132 * If that is the case, then we are duplicating constructor initialization here, 133 * so that the mbuf is properly constructed before returning it. 134 */ 135 if (mret) { 136 #if USING_MBUF_CONSTRUCTOR 137 if (! (mret->m_type == type) ) { 138 mbuf_constructor_dup(mret, 0, type); 139 } 140 #else 141 mbuf_constructor_dup(mret, 0, type); 142 #endif 143 144 } 145 return mret; 146 } 147 148 149 /* __Userspace__ */ 150 struct mbuf * 151 m_gethdr(int how, short type) 152 { 153 struct mbuf *mret; 154 #if defined(SCTP_SIMPLE_ALLOCATOR) 155 struct mb_args mbuf_mb_args; 156 157 /* The following setter function is not yet being enclosed within 158 * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested 159 * mb_dtor_mbuf. See comment there 160 */ 161 mbuf_mb_args.flags = M_PKTHDR; 162 mbuf_mb_args.type = type; 163 #endif 164 mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf); 165 #if defined(SCTP_SIMPLE_ALLOCATOR) 166 mb_ctor_mbuf(mret, &mbuf_mb_args, 0); 167 #endif 168 /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/ 169 /* There are cases when an object available in the current CPU's 170 * loaded magazine and in those cases the object's constructor is not applied. 171 * If that is the case, then we are duplicating constructor initialization here, 172 * so that the mbuf is properly constructed before returning it. 173 */ 174 if (mret) { 175 #if USING_MBUF_CONSTRUCTOR 176 if (! ((mret->m_flags & M_PKTHDR) && (mret->m_type == type)) ) { 177 mbuf_constructor_dup(mret, M_PKTHDR, type); 178 } 179 #else 180 mbuf_constructor_dup(mret, M_PKTHDR, type); 181 #endif 182 } 183 return mret; 184 } 185 186 /* __Userspace__ */ 187 struct mbuf * 188 m_free(struct mbuf *m) 189 { 190 191 struct mbuf *n = m->m_next; 192 193 if (m->m_flags & M_EXT) 194 mb_free_ext(m); 195 else if ((m->m_flags & M_NOFREE) == 0) { 196 #if defined(SCTP_SIMPLE_ALLOCATOR) 197 mb_dtor_mbuf(m, NULL); 198 #endif 199 SCTP_ZONE_FREE(zone_mbuf, m); 200 } 201 /*umem_cache_free(zone_mbuf, m);*/ 202 return (n); 203 } 204 205 206 static void 207 clust_constructor_dup(caddr_t m_clust, struct mbuf* m) 208 { 209 u_int *refcnt; 210 int type, size; 211 212 if (m == NULL) { 213 return; 214 } 215 /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */ 216 type = EXT_CLUSTER; 217 size = MCLBYTES; 218 219 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 220 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 221 #if !defined(SCTP_SIMPLE_ALLOCATOR) 222 if (refcnt == NULL) { 223 umem_reap(); 224 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 225 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 226 } 227 #endif 228 *refcnt = 1; 229 m->m_ext.ext_buf = (caddr_t)m_clust; 230 m->m_data = m->m_ext.ext_buf; 231 m->m_flags |= M_EXT; 232 m->m_ext.ext_free = NULL; 233 m->m_ext.ext_args = NULL; 234 m->m_ext.ext_size = size; 235 m->m_ext.ext_type = type; 236 m->m_ext.ref_cnt = refcnt; 237 return; 238 } 239 240 241 /* __Userspace__ */ 242 void 243 m_clget(struct mbuf *m, int how) 244 { 245 caddr_t mclust_ret; 246 #if defined(SCTP_SIMPLE_ALLOCATOR) 247 struct clust_args clust_mb_args_l; 248 #endif 249 if (m->m_flags & M_EXT) { 250 SCTPDBG(SCTP_DEBUG_USR, "%s: %p mbuf already has cluster\n", __func__, (void *)m); 251 } 252 m->m_ext.ext_buf = (char *)NULL; 253 #if defined(SCTP_SIMPLE_ALLOCATOR) 254 clust_mb_args_l.parent_mbuf = m; 255 #endif 256 mclust_ret = SCTP_ZONE_GET(zone_clust, char); 257 #if defined(SCTP_SIMPLE_ALLOCATOR) 258 mb_ctor_clust(mclust_ret, &clust_mb_args_l, 0); 259 #endif 260 /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/ 261 /* 262 On a cluster allocation failure, call umem_reap() and retry. 263 */ 264 265 if (mclust_ret == NULL) { 266 #if !defined(SCTP_SIMPLE_ALLOCATOR) 267 /* mclust_ret = SCTP_ZONE_GET(zone_clust, char); 268 mb_ctor_clust(mclust_ret, &clust_mb_args, 0); 269 #else*/ 270 umem_reap(); 271 mclust_ret = SCTP_ZONE_GET(zone_clust, char); 272 #endif 273 /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/ 274 /* if (NULL == mclust_ret) { */ 275 SCTPDBG(SCTP_DEBUG_USR, "Memory allocation failure in %s\n", __func__); 276 /* } */ 277 } 278 279 #if USING_MBUF_CONSTRUCTOR 280 if ((m->m_ext.ext_buf == NULL)) { 281 clust_constructor_dup(mclust_ret, m); 282 } 283 #else 284 clust_constructor_dup(mclust_ret, m); 285 #endif 286 } 287 288 struct mbuf * 289 m_getm2(struct mbuf *m, int len, int how, short type, int flags, int allonebuf) 290 { 291 struct mbuf *mb, *nm = NULL, *mtail = NULL; 292 int size, mbuf_threshold, space_needed = len; 293 294 KASSERT(len >= 0, ("%s: len is < 0", __func__)); 295 296 /* Validate flags. */ 297 flags &= (M_PKTHDR | M_EOR); 298 299 /* Packet header mbuf must be first in chain. */ 300 if ((flags & M_PKTHDR) && m != NULL) { 301 flags &= ~M_PKTHDR; 302 } 303 304 if (allonebuf == 0) 305 mbuf_threshold = SCTP_BASE_SYSCTL(sctp_mbuf_threshold_count); 306 else 307 mbuf_threshold = 1; 308 309 /* Loop and append maximum sized mbufs to the chain tail. */ 310 while (len > 0) { 311 if ((!allonebuf && len >= MCLBYTES) || (len > (int)(((mbuf_threshold - 1) * MLEN) + MHLEN))) { 312 mb = m_gethdr(how, type); 313 MCLGET(mb, how); 314 size = MCLBYTES; 315 /* SCTP_BUF_LEN(mb) = MCLBYTES; */ 316 } else if (flags & M_PKTHDR) { 317 mb = m_gethdr(how, type); 318 if (len < MHLEN) { 319 size = len; 320 } else { 321 size = MHLEN; 322 } 323 } else { 324 mb = m_get(how, type); 325 if (len < MLEN) { 326 size = len; 327 } else { 328 size = MLEN; 329 } 330 } 331 332 /* Fail the whole operation if one mbuf can't be allocated. */ 333 if (mb == NULL) { 334 if (nm != NULL) 335 m_freem(nm); 336 return (NULL); 337 } 338 339 if (allonebuf != 0 && size < space_needed) { 340 m_freem(mb); 341 return (NULL); 342 } 343 344 /* Book keeping. */ 345 len -= size; 346 if (mtail != NULL) 347 mtail->m_next = mb; 348 else 349 nm = mb; 350 mtail = mb; 351 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */ 352 } 353 if (flags & M_EOR) { 354 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */ 355 } 356 357 /* If mbuf was supplied, append new chain to the end of it. */ 358 if (m != NULL) { 359 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next); 360 mtail->m_next = nm; 361 mtail->m_flags &= ~M_EOR; 362 } else { 363 m = nm; 364 } 365 366 return (m); 367 } 368 369 /* 370 * Copy the contents of uio into a properly sized mbuf chain. 371 */ 372 struct mbuf * 373 m_uiotombuf(struct uio *uio, int how, int len, int align, int flags) 374 { 375 struct mbuf *m, *mb; 376 int error, length; 377 ssize_t total; 378 int progress = 0; 379 380 /* 381 * len can be zero or an arbitrary large value bound by 382 * the total data supplied by the uio. 383 */ 384 if (len > 0) 385 total = min(uio->uio_resid, len); 386 else 387 total = uio->uio_resid; 388 /* 389 * The smallest unit returned by m_getm2() is a single mbuf 390 * with pkthdr. We can't align past it. 391 */ 392 if (align >= MHLEN) 393 return (NULL); 394 /* 395 * Give us the full allocation or nothing. 396 * If len is zero return the smallest empty mbuf. 397 */ 398 m = m_getm2(NULL, (int)max(total + align, 1), how, MT_DATA, flags, 0); 399 if (m == NULL) 400 return (NULL); 401 m->m_data += align; 402 403 /* Fill all mbufs with uio data and update header information. */ 404 for (mb = m; mb != NULL; mb = mb->m_next) { 405 length = (int)min(M_TRAILINGSPACE(mb), total - progress); 406 error = uiomove(mtod(mb, void *), length, uio); 407 if (error) { 408 m_freem(m); 409 return (NULL); 410 } 411 412 mb->m_len = length; 413 progress += length; 414 if (flags & M_PKTHDR) 415 m->m_pkthdr.len += length; 416 } 417 KASSERT(progress == total, ("%s: progress != total", __func__)); 418 419 return (m); 420 } 421 422 u_int 423 m_length(struct mbuf *m0, struct mbuf **last) 424 { 425 struct mbuf *m; 426 u_int len; 427 428 len = 0; 429 for (m = m0; m != NULL; m = m->m_next) { 430 len += m->m_len; 431 if (m->m_next == NULL) 432 break; 433 } 434 if (last != NULL) 435 *last = m; 436 return (len); 437 } 438 439 struct mbuf * 440 m_last(struct mbuf *m) 441 { 442 while (m->m_next) { 443 m = m->m_next; 444 } 445 return (m); 446 } 447 448 /* 449 * Unlink a tag from the list of tags associated with an mbuf. 450 */ 451 static __inline void 452 m_tag_unlink(struct mbuf *m, struct m_tag *t) 453 { 454 455 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 456 } 457 458 /* 459 * Reclaim resources associated with a tag. 460 */ 461 static __inline void 462 m_tag_free(struct m_tag *t) 463 { 464 465 (*t->m_tag_free)(t); 466 } 467 468 /* 469 * Set up the contents of a tag. Note that this does not fill in the free 470 * method; the caller is expected to do that. 471 * 472 * XXX probably should be called m_tag_init, but that was already taken. 473 */ 474 static __inline void 475 m_tag_setup(struct m_tag *t, uint32_t cookie, int type, int len) 476 { 477 478 t->m_tag_id = type; 479 t->m_tag_len = len; 480 t->m_tag_cookie = cookie; 481 } 482 483 /************ End functions from user_mbuf.h ******************/ 484 485 486 487 /************ End functions to substitute umem_cache_alloc and umem_cache_free **************/ 488 489 void 490 mbuf_initialize(void *dummy) 491 { 492 493 /* 494 * __Userspace__Configure UMA zones for Mbufs and Clusters. 495 * (TODO: m_getcl() - using packet secondary zone). 496 * There is no provision for trash_init and trash_fini in umem. 497 * 498 */ 499 /* zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, 500 mb_ctor_mbuf, mb_dtor_mbuf, NULL, 501 &mbuf_mb_args, 502 NULL, 0); 503 zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, NULL, NULL, NULL, NULL, NULL, 0);*/ 504 #if defined(SCTP_SIMPLE_ALLOCATOR) 505 SCTP_ZONE_INIT(zone_mbuf, MBUF_MEM_NAME, MSIZE, 0); 506 #else 507 zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, 508 mb_ctor_mbuf, mb_dtor_mbuf, NULL, 509 NUULL, 510 NULL, 0); 511 #endif 512 /*zone_ext_refcnt = umem_cache_create(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0, 513 NULL, NULL, NULL, 514 NULL, 515 NULL, 0);*/ 516 SCTP_ZONE_INIT(zone_ext_refcnt, MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0); 517 518 /*zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, 519 mb_ctor_clust, mb_dtor_clust, NULL, 520 &clust_mb_args, 521 NULL, 0); 522 zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, NULL, NULL, NULL, NULL, NULL,0);*/ 523 #if defined(SCTP_SIMPLE_ALLOCATOR) 524 SCTP_ZONE_INIT(zone_clust, MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0); 525 #else 526 zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, 527 mb_ctor_clust, mb_dtor_clust, NULL, 528 &clust_mb_args, 529 NULL, 0); 530 #endif 531 532 /* uma_prealloc() goes here... */ 533 534 /* __Userspace__ Add umem_reap here for low memory situation? 535 * 536 */ 537 538 } 539 540 541 542 /* 543 * __Userspace__ 544 * 545 * Constructor for Mbuf master zone. We have a different constructor 546 * for allocating the cluster. 547 * 548 * The 'arg' pointer points to a mb_args structure which 549 * contains call-specific information required to support the 550 * mbuf allocation API. See user_mbuf.h. 551 * 552 * The flgs parameter below can be UMEM_DEFAULT or UMEM_NOFAIL depending on what 553 * was passed when umem_cache_alloc was called. 554 * TODO: Use UMEM_NOFAIL in umem_cache_alloc and also define a failure handler 555 * and call umem_nofail_callback(my_failure_handler) in the stack initialization routines 556 * The advantage of using UMEM_NOFAIL is that we don't have to check if umem_cache_alloc 557 * was successful or not. The failure handler would take care of it, if we use the UMEM_NOFAIL 558 * flag. 559 * 560 * NOTE Ref: http://docs.sun.com/app/docs/doc/819-2243/6n4i099p2?l=en&a=view&q=umem_zalloc) 561 * The umem_nofail_callback() function sets the **process-wide** UMEM_NOFAIL callback. 562 * It also mentions that umem_nofail_callback is Evolving. 563 * 564 */ 565 static int 566 mb_ctor_mbuf(void *mem, void *arg, int flgs) 567 { 568 #if USING_MBUF_CONSTRUCTOR 569 struct mbuf *m; 570 struct mb_args *args; 571 572 int flags; 573 short type; 574 575 m = (struct mbuf *)mem; 576 args = (struct mb_args *)arg; 577 flags = args->flags; 578 type = args->type; 579 580 /* 581 * The mbuf is initialized later. 582 * 583 */ 584 if (type == MT_NOINIT) 585 return (0); 586 587 m->m_next = NULL; 588 m->m_nextpkt = NULL; 589 m->m_len = 0; 590 m->m_flags = flags; 591 m->m_type = type; 592 if (flags & M_PKTHDR) { 593 m->m_data = m->m_pktdat; 594 m->m_pkthdr.rcvif = NULL; 595 m->m_pkthdr.len = 0; 596 m->m_pkthdr.header = NULL; 597 m->m_pkthdr.csum_flags = 0; 598 m->m_pkthdr.csum_data = 0; 599 m->m_pkthdr.tso_segsz = 0; 600 m->m_pkthdr.ether_vtag = 0; 601 SLIST_INIT(&m->m_pkthdr.tags); 602 } else 603 m->m_data = m->m_dat; 604 #endif 605 return (0); 606 } 607 608 609 /* 610 * __Userspace__ 611 * The Mbuf master zone destructor. 612 * This would be called in response to umem_cache_destroy 613 * TODO: Recheck if this is what we want to do in this destructor. 614 * (Note: the number of times mb_dtor_mbuf is called is equal to the 615 * number of individual mbufs allocated from zone_mbuf. 616 */ 617 static void 618 mb_dtor_mbuf(void *mem, void *arg) 619 { 620 struct mbuf *m; 621 622 m = (struct mbuf *)mem; 623 if ((m->m_flags & M_PKTHDR) != 0) { 624 m_tag_delete_chain(m, NULL); 625 } 626 } 627 628 629 /* __Userspace__ 630 * The Cluster zone constructor. 631 * 632 * Here the 'arg' pointer points to the Mbuf which we 633 * are configuring cluster storage for. If 'arg' is 634 * empty we allocate just the cluster without setting 635 * the mbuf to it. See mbuf.h. 636 */ 637 static int 638 mb_ctor_clust(void *mem, void *arg, int flgs) 639 { 640 641 #if USING_MBUF_CONSTRUCTOR 642 struct mbuf *m; 643 struct clust_args * cla; 644 u_int *refcnt; 645 int type, size; 646 sctp_zone_t zone; 647 648 /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */ 649 type = EXT_CLUSTER; 650 zone = zone_clust; 651 size = MCLBYTES; 652 653 cla = (struct clust_args *)arg; 654 m = cla->parent_mbuf; 655 656 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 657 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 658 *refcnt = 1; 659 660 if (m != NULL) { 661 m->m_ext.ext_buf = (caddr_t)mem; 662 m->m_data = m->m_ext.ext_buf; 663 m->m_flags |= M_EXT; 664 m->m_ext.ext_free = NULL; 665 m->m_ext.ext_args = NULL; 666 m->m_ext.ext_size = size; 667 m->m_ext.ext_type = type; 668 m->m_ext.ref_cnt = refcnt; 669 } 670 #endif 671 return (0); 672 } 673 674 /* __Userspace__ */ 675 static void 676 mb_dtor_clust(void *mem, void *arg) 677 { 678 679 /* mem is of type caddr_t. In sys/types.h we have typedef char * caddr_t; */ 680 /* mb_dtor_clust is called at time of umem_cache_destroy() (the number of times 681 * mb_dtor_clust is called is equal to the number of individual mbufs allocated 682 * from zone_clust. Similarly for mb_dtor_mbuf). 683 * At this point the following: 684 * struct mbuf *m; 685 * m = (struct mbuf *)arg; 686 * assert (*(m->m_ext.ref_cnt) == 0); is not meaningful since m->m_ext.ref_cnt = NULL; 687 * has been done in mb_free_ext(). 688 */ 689 690 } 691 692 693 694 695 /* Unlink and free a packet tag. */ 696 void 697 m_tag_delete(struct mbuf *m, struct m_tag *t) 698 { 699 KASSERT(m && t, ("m_tag_delete: null argument, m %p t %p", (void *)m, (void *)t)); 700 m_tag_unlink(m, t); 701 m_tag_free(t); 702 } 703 704 705 /* Unlink and free a packet tag chain, starting from given tag. */ 706 void 707 m_tag_delete_chain(struct mbuf *m, struct m_tag *t) 708 { 709 710 struct m_tag *p, *q; 711 712 KASSERT(m, ("m_tag_delete_chain: null mbuf")); 713 if (t != NULL) 714 p = t; 715 else 716 p = SLIST_FIRST(&m->m_pkthdr.tags); 717 if (p == NULL) 718 return; 719 while ((q = SLIST_NEXT(p, m_tag_link)) != NULL) 720 m_tag_delete(m, q); 721 m_tag_delete(m, p); 722 } 723 724 #if 0 725 static void 726 sctp_print_mbuf_chain(struct mbuf *m) 727 { 728 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "Printing mbuf chain %p.\n", (void *)m); 729 for(; m; m=m->m_next) { 730 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%p: m_len = %ld, m_type = %x, m_next = %p.\n", (void *)m, m->m_len, m->m_type, (void *)m->m_next); 731 if (m->m_flags & M_EXT) 732 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%p: extend_size = %d, extend_buffer = %p, ref_cnt = %d.\n", (void *)m, m->m_ext.ext_size, (void *)m->m_ext.ext_buf, *(m->m_ext.ref_cnt)); 733 } 734 } 735 #endif 736 737 /* 738 * Free an entire chain of mbufs and associated external buffers, if 739 * applicable. 740 */ 741 void 742 m_freem(struct mbuf *mb) 743 { 744 while (mb != NULL) 745 mb = m_free(mb); 746 } 747 748 /* 749 * __Userspace__ 750 * clean mbufs with M_EXT storage attached to them 751 * if the reference count hits 1. 752 */ 753 void 754 mb_free_ext(struct mbuf *m) 755 { 756 757 int skipmbuf; 758 759 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 760 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 761 762 /* 763 * check if the header is embedded in the cluster 764 */ 765 skipmbuf = (m->m_flags & M_NOFREE); 766 767 /* Free the external attached storage if this 768 * mbuf is the only reference to it. 769 *__Userspace__ TODO: jumbo frames 770 * 771 */ 772 /* NOTE: We had the same code that SCTP_DECREMENT_AND_CHECK_REFCOUNT 773 reduces to here before but the IPHONE malloc commit had changed 774 this to compare to 0 instead of 1 (see next line). Why? 775 . .. this caused a huge memory leak in Linux. 776 */ 777 #ifdef IPHONE 778 if (atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 0) 779 #else 780 if (SCTP_DECREMENT_AND_CHECK_REFCOUNT(m->m_ext.ref_cnt)) 781 #endif 782 { 783 if (m->m_ext.ext_type == EXT_CLUSTER){ 784 #if defined(SCTP_SIMPLE_ALLOCATOR) 785 mb_dtor_clust(m->m_ext.ext_buf, &clust_mb_args); 786 #endif 787 SCTP_ZONE_FREE(zone_clust, m->m_ext.ext_buf); 788 SCTP_ZONE_FREE(zone_ext_refcnt, (u_int*)m->m_ext.ref_cnt); 789 m->m_ext.ref_cnt = NULL; 790 } 791 } 792 793 if (skipmbuf) 794 return; 795 796 797 /* __Userspace__ Also freeing the storage for ref_cnt 798 * Free this mbuf back to the mbuf zone with all m_ext 799 * information purged. 800 */ 801 m->m_ext.ext_buf = NULL; 802 m->m_ext.ext_free = NULL; 803 m->m_ext.ext_args = NULL; 804 m->m_ext.ref_cnt = NULL; 805 m->m_ext.ext_size = 0; 806 m->m_ext.ext_type = 0; 807 m->m_flags &= ~M_EXT; 808 #if defined(SCTP_SIMPLE_ALLOCATOR) 809 mb_dtor_mbuf(m, NULL); 810 #endif 811 SCTP_ZONE_FREE(zone_mbuf, m); 812 813 /*umem_cache_free(zone_mbuf, m);*/ 814 } 815 816 /* 817 * "Move" mbuf pkthdr from "from" to "to". 818 * "from" must have M_PKTHDR set, and "to" must be empty. 819 */ 820 void 821 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 822 { 823 824 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 825 if ((to->m_flags & M_EXT) == 0) 826 to->m_data = to->m_pktdat; 827 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 828 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 829 from->m_flags &= ~M_PKTHDR; 830 } 831 832 833 /* 834 * Rearange an mbuf chain so that len bytes are contiguous 835 * and in the data area of an mbuf (so that mtod and dtom 836 * will work for a structure of size len). Returns the resulting 837 * mbuf chain on success, frees it and returns null on failure. 838 * If there is room, it will add up to max_protohdr-len extra bytes to the 839 * contiguous region in an attempt to avoid being called next time. 840 */ 841 struct mbuf * 842 m_pullup(struct mbuf *n, int len) 843 { 844 struct mbuf *m; 845 int count; 846 int space; 847 848 /* 849 * If first mbuf has no cluster, and has room for len bytes 850 * without shifting current data, pullup into it, 851 * otherwise allocate a new mbuf to prepend to the chain. 852 */ 853 if ((n->m_flags & M_EXT) == 0 && 854 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 855 if (n->m_len >= len) 856 return (n); 857 m = n; 858 n = n->m_next; 859 len -= m->m_len; 860 } else { 861 if (len > MHLEN) 862 goto bad; 863 MGET(m, M_NOWAIT, n->m_type); 864 if (m == NULL) 865 goto bad; 866 m->m_len = 0; 867 if (n->m_flags & M_PKTHDR) 868 M_MOVE_PKTHDR(m, n); 869 } 870 space = (int)(&m->m_dat[MLEN] - (m->m_data + m->m_len)); 871 do { 872 count = min(min(max(len, max_protohdr), space), n->m_len); 873 memcpy(mtod(m, caddr_t) + m->m_len,mtod(n, caddr_t), (u_int)count); 874 len -= count; 875 m->m_len += count; 876 n->m_len -= count; 877 space -= count; 878 if (n->m_len) 879 n->m_data += count; 880 else 881 n = m_free(n); 882 } while (len > 0 && n); 883 if (len > 0) { 884 (void) m_free(m); 885 goto bad; 886 } 887 m->m_next = n; 888 return (m); 889 bad: 890 m_freem(n); 891 return (NULL); 892 } 893 894 895 static struct mbuf * 896 m_dup1(struct mbuf *m, int off, int len, int wait) 897 { 898 struct mbuf *n = NULL; 899 int copyhdr; 900 901 if (len > MCLBYTES) 902 return NULL; 903 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) 904 copyhdr = 1; 905 else 906 copyhdr = 0; 907 if (len >= MINCLSIZE) { 908 if (copyhdr == 1) { 909 m_clget(n, wait); /* TODO: include code for copying the header */ 910 m_dup_pkthdr(n, m, wait); 911 } else 912 m_clget(n, wait); 913 } else { 914 if (copyhdr == 1) 915 n = m_gethdr(wait, m->m_type); 916 else 917 n = m_get(wait, m->m_type); 918 } 919 if (!n) 920 return NULL; /* ENOBUFS */ 921 922 if (copyhdr && !m_dup_pkthdr(n, m, wait)) { 923 m_free(n); 924 return NULL; 925 } 926 m_copydata(m, off, len, mtod(n, caddr_t)); 927 n->m_len = len; 928 return n; 929 } 930 931 932 /* Taken from sys/kern/uipc_mbuf2.c */ 933 struct mbuf * 934 m_pulldown(struct mbuf *m, int off, int len, int *offp) 935 { 936 struct mbuf *n, *o; 937 int hlen, tlen, olen; 938 int writable; 939 940 /* check invalid arguments. */ 941 KASSERT(m, ("m == NULL in m_pulldown()")); 942 if (len > MCLBYTES) { 943 m_freem(m); 944 return NULL; /* impossible */ 945 } 946 947 #ifdef PULLDOWN_DEBUG 948 { 949 struct mbuf *t; 950 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "before:"); 951 for (t = m; t; t = t->m_next) 952 SCTP_DEBUG_USR(SCTP_DEBUG_USR, " %d", t->m_len); 953 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "\n"); 954 } 955 #endif 956 n = m; 957 while (n != NULL && off > 0) { 958 if (n->m_len > off) 959 break; 960 off -= n->m_len; 961 n = n->m_next; 962 } 963 /* be sure to point non-empty mbuf */ 964 while (n != NULL && n->m_len == 0) 965 n = n->m_next; 966 if (!n) { 967 m_freem(m); 968 return NULL; /* mbuf chain too short */ 969 } 970 971 writable = 0; 972 if ((n->m_flags & M_EXT) == 0 || 973 (n->m_ext.ext_type == EXT_CLUSTER && M_WRITABLE(n))) 974 writable = 1; 975 976 /* 977 * the target data is on <n, off>. 978 * if we got enough data on the mbuf "n", we're done. 979 */ 980 if ((off == 0 || offp) && len <= n->m_len - off && writable) 981 goto ok; 982 983 /* 984 * when len <= n->m_len - off and off != 0, it is a special case. 985 * len bytes from <n, off> sits in single mbuf, but the caller does 986 * not like the starting position (off). 987 * chop the current mbuf into two pieces, set off to 0. 988 */ 989 if (len <= n->m_len - off) { 990 o = m_dup1(n, off, n->m_len - off, M_NOWAIT); 991 if (o == NULL) { 992 m_freem(m); 993 return NULL; /* ENOBUFS */ 994 } 995 n->m_len = off; 996 o->m_next = n->m_next; 997 n->m_next = o; 998 n = n->m_next; 999 off = 0; 1000 goto ok; 1001 } 1002 /* 1003 * we need to take hlen from <n, off> and tlen from <n->m_next, 0>, 1004 * and construct contiguous mbuf with m_len == len. 1005 * note that hlen + tlen == len, and tlen > 0. 1006 */ 1007 hlen = n->m_len - off; 1008 tlen = len - hlen; 1009 1010 /* 1011 * ensure that we have enough trailing data on mbuf chain. 1012 * if not, we can do nothing about the chain. 1013 */ 1014 olen = 0; 1015 for (o = n->m_next; o != NULL; o = o->m_next) 1016 olen += o->m_len; 1017 if (hlen + olen < len) { 1018 m_freem(m); 1019 return NULL; /* mbuf chain too short */ 1020 } 1021 1022 /* 1023 * easy cases first. 1024 * we need to use m_copydata() to get data from <n->m_next, 0>. 1025 */ 1026 if ((off == 0 || offp) && (M_TRAILINGSPACE(n) >= tlen) && writable) { 1027 m_copydata(n->m_next, 0, tlen, mtod(n, caddr_t) + n->m_len); 1028 n->m_len += tlen; 1029 m_adj(n->m_next, tlen); 1030 goto ok; 1031 } 1032 1033 if ((off == 0 || offp) && (M_LEADINGSPACE(n->m_next) >= hlen) && writable) { 1034 n->m_next->m_data -= hlen; 1035 n->m_next->m_len += hlen; 1036 memcpy( mtod(n->m_next, caddr_t), mtod(n, caddr_t) + off,hlen); 1037 n->m_len -= hlen; 1038 n = n->m_next; 1039 off = 0; 1040 goto ok; 1041 } 1042 1043 /* 1044 * now, we need to do the hard way. don't m_copy as there's no room 1045 * on both end. 1046 */ 1047 if (len > MLEN) 1048 m_clget(o, M_NOWAIT); 1049 /* o = m_getcl(M_NOWAIT, m->m_type, 0);*/ 1050 else 1051 o = m_get(M_NOWAIT, m->m_type); 1052 if (!o) { 1053 m_freem(m); 1054 return NULL; /* ENOBUFS */ 1055 } 1056 /* get hlen from <n, off> into <o, 0> */ 1057 o->m_len = hlen; 1058 memcpy(mtod(o, caddr_t), mtod(n, caddr_t) + off, hlen); 1059 n->m_len -= hlen; 1060 /* get tlen from <n->m_next, 0> into <o, hlen> */ 1061 m_copydata(n->m_next, 0, tlen, mtod(o, caddr_t) + o->m_len); 1062 o->m_len += tlen; 1063 m_adj(n->m_next, tlen); 1064 o->m_next = n->m_next; 1065 n->m_next = o; 1066 n = o; 1067 off = 0; 1068 ok: 1069 #ifdef PULLDOWN_DEBUG 1070 { 1071 struct mbuf *t; 1072 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "after:"); 1073 for (t = m; t; t = t->m_next) 1074 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%c%d", t == n ? '*' : ' ', t->m_len); 1075 SCTP_DEBUG_USR(SCTP_DEBUG_USR, " (off=%d)\n", off); 1076 } 1077 #endif 1078 if (offp) 1079 *offp = off; 1080 return n; 1081 } 1082 1083 /* 1084 * Attach the the cluster from *m to *n, set up m_ext in *n 1085 * and bump the refcount of the cluster. 1086 */ 1087 static void 1088 mb_dupcl(struct mbuf *n, struct mbuf *m) 1089 { 1090 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 1091 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 1092 KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__)); 1093 1094 if (*(m->m_ext.ref_cnt) == 1) 1095 *(m->m_ext.ref_cnt) += 1; 1096 else 1097 atomic_add_int(m->m_ext.ref_cnt, 1); 1098 n->m_ext.ext_buf = m->m_ext.ext_buf; 1099 n->m_ext.ext_free = m->m_ext.ext_free; 1100 n->m_ext.ext_args = m->m_ext.ext_args; 1101 n->m_ext.ext_size = m->m_ext.ext_size; 1102 n->m_ext.ref_cnt = m->m_ext.ref_cnt; 1103 n->m_ext.ext_type = m->m_ext.ext_type; 1104 n->m_flags |= M_EXT; 1105 } 1106 1107 1108 /* 1109 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 1110 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 1111 * The wait parameter is a choice of M_TRYWAIT/M_NOWAIT from caller. 1112 * Note that the copy is read-only, because clusters are not copied, 1113 * only their reference counts are incremented. 1114 */ 1115 1116 struct mbuf * 1117 m_copym(struct mbuf *m, int off0, int len, int wait) 1118 { 1119 struct mbuf *n, **np; 1120 int off = off0; 1121 struct mbuf *top; 1122 int copyhdr = 0; 1123 1124 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 1125 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 1126 KASSERT(m != NULL, ("m_copym, m is NULL")); 1127 1128 #if !defined(INVARIANTS) 1129 if (m == NULL) { 1130 return (NULL); 1131 } 1132 #endif 1133 if (off == 0 && m->m_flags & M_PKTHDR) 1134 copyhdr = 1; 1135 while (off > 0) { 1136 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 1137 if (off < m->m_len) 1138 break; 1139 off -= m->m_len; 1140 m = m->m_next; 1141 } 1142 np = ⊤ 1143 top = 0; 1144 while (len > 0) { 1145 if (m == NULL) { 1146 KASSERT(len == M_COPYALL, ("m_copym, length > size of mbuf chain")); 1147 break; 1148 } 1149 if (copyhdr) 1150 MGETHDR(n, wait, m->m_type); 1151 else 1152 MGET(n, wait, m->m_type); 1153 *np = n; 1154 if (n == NULL) 1155 goto nospace; 1156 if (copyhdr) { 1157 if (!m_dup_pkthdr(n, m, wait)) 1158 goto nospace; 1159 if (len == M_COPYALL) 1160 n->m_pkthdr.len -= off0; 1161 else 1162 n->m_pkthdr.len = len; 1163 copyhdr = 0; 1164 } 1165 n->m_len = min(len, m->m_len - off); 1166 if (m->m_flags & M_EXT) { 1167 n->m_data = m->m_data + off; 1168 mb_dupcl(n, m); 1169 } else 1170 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, (u_int)n->m_len); 1171 if (len != M_COPYALL) 1172 len -= n->m_len; 1173 off = 0; 1174 m = m->m_next; 1175 np = &n->m_next; 1176 } 1177 1178 return (top); 1179 nospace: 1180 m_freem(top); 1181 return (NULL); 1182 } 1183 1184 1185 int 1186 m_tag_copy_chain(struct mbuf *to, struct mbuf *from, int how) 1187 { 1188 struct m_tag *p, *t, *tprev = NULL; 1189 1190 KASSERT(to && from, ("m_tag_copy_chain: null argument, to %p from %p", (void *)to, (void *)from)); 1191 m_tag_delete_chain(to, NULL); 1192 SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) { 1193 t = m_tag_copy(p, how); 1194 if (t == NULL) { 1195 m_tag_delete_chain(to, NULL); 1196 return 0; 1197 } 1198 if (tprev == NULL) 1199 SLIST_INSERT_HEAD(&to->m_pkthdr.tags, t, m_tag_link); 1200 else 1201 SLIST_INSERT_AFTER(tprev, t, m_tag_link); 1202 tprev = t; 1203 } 1204 return 1; 1205 } 1206 1207 /* 1208 * Duplicate "from"'s mbuf pkthdr in "to". 1209 * "from" must have M_PKTHDR set, and "to" must be empty. 1210 * In particular, this does a deep copy of the packet tags. 1211 */ 1212 int 1213 m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 1214 { 1215 1216 KASSERT(to, ("m_dup_pkthdr: to is NULL")); 1217 KASSERT(from, ("m_dup_pkthdr: from is NULL")); 1218 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 1219 if ((to->m_flags & M_EXT) == 0) 1220 to->m_data = to->m_pktdat; 1221 to->m_pkthdr = from->m_pkthdr; 1222 SLIST_INIT(&to->m_pkthdr.tags); 1223 return (m_tag_copy_chain(to, from, MBTOM(how))); 1224 } 1225 1226 /* Copy a single tag. */ 1227 struct m_tag * 1228 m_tag_copy(struct m_tag *t, int how) 1229 { 1230 struct m_tag *p; 1231 1232 KASSERT(t, ("m_tag_copy: null tag")); 1233 p = m_tag_alloc(t->m_tag_cookie, t->m_tag_id, t->m_tag_len, how); 1234 if (p == NULL) 1235 return (NULL); 1236 memcpy(p + 1, t + 1, t->m_tag_len); /* Copy the data */ 1237 return p; 1238 } 1239 1240 /* Get a packet tag structure along with specified data following. */ 1241 struct m_tag * 1242 m_tag_alloc(uint32_t cookie, int type, int len, int wait) 1243 { 1244 struct m_tag *t; 1245 1246 if (len < 0) 1247 return NULL; 1248 t = malloc(len + sizeof(struct m_tag)); 1249 if (t == NULL) 1250 return NULL; 1251 m_tag_setup(t, cookie, type, len); 1252 t->m_tag_free = m_tag_free_default; 1253 return t; 1254 } 1255 1256 /* Free a packet tag. */ 1257 void 1258 m_tag_free_default(struct m_tag *t) 1259 { 1260 free(t); 1261 } 1262 1263 /* 1264 * Copy data from a buffer back into the indicated mbuf chain, 1265 * starting "off" bytes from the beginning, extending the mbuf 1266 * chain if necessary. 1267 */ 1268 void 1269 m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) 1270 { 1271 int mlen; 1272 struct mbuf *m = m0, *n; 1273 int totlen = 0; 1274 1275 if (m0 == NULL) 1276 return; 1277 while (off > (mlen = m->m_len)) { 1278 off -= mlen; 1279 totlen += mlen; 1280 if (m->m_next == NULL) { 1281 n = m_get(M_NOWAIT, m->m_type); 1282 if (n == NULL) 1283 goto out; 1284 memset(mtod(n, caddr_t), 0, MLEN); 1285 n->m_len = min(MLEN, len + off); 1286 m->m_next = n; 1287 } 1288 m = m->m_next; 1289 } 1290 while (len > 0) { 1291 mlen = min (m->m_len - off, len); 1292 memcpy(off + mtod(m, caddr_t), cp, (u_int)mlen); 1293 cp += mlen; 1294 len -= mlen; 1295 mlen += off; 1296 off = 0; 1297 totlen += mlen; 1298 if (len == 0) 1299 break; 1300 if (m->m_next == NULL) { 1301 n = m_get(M_NOWAIT, m->m_type); 1302 if (n == NULL) 1303 break; 1304 n->m_len = min(MLEN, len); 1305 m->m_next = n; 1306 } 1307 m = m->m_next; 1308 } 1309 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1310 m->m_pkthdr.len = totlen; 1311 } 1312 1313 1314 /* 1315 * Lesser-used path for M_PREPEND: 1316 * allocate new mbuf to prepend to chain, 1317 * copy junk along. 1318 */ 1319 struct mbuf * 1320 m_prepend(struct mbuf *m, int len, int how) 1321 { 1322 struct mbuf *mn; 1323 1324 if (m->m_flags & M_PKTHDR) 1325 MGETHDR(mn, how, m->m_type); 1326 else 1327 MGET(mn, how, m->m_type); 1328 if (mn == NULL) { 1329 m_freem(m); 1330 return (NULL); 1331 } 1332 if (m->m_flags & M_PKTHDR) 1333 M_MOVE_PKTHDR(mn, m); 1334 mn->m_next = m; 1335 m = mn; 1336 if (m->m_flags & M_PKTHDR) { 1337 if (len < MHLEN) 1338 MH_ALIGN(m, len); 1339 } else { 1340 if (len < MLEN) 1341 M_ALIGN(m, len); 1342 } 1343 m->m_len = len; 1344 return (m); 1345 } 1346 1347 /* 1348 * Copy data from an mbuf chain starting "off" bytes from the beginning, 1349 * continuing for "len" bytes, into the indicated buffer. 1350 */ 1351 void 1352 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 1353 { 1354 u_int count; 1355 1356 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 1357 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 1358 while (off > 0) { 1359 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 1360 if (off < m->m_len) 1361 break; 1362 off -= m->m_len; 1363 m = m->m_next; 1364 } 1365 while (len > 0) { 1366 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 1367 count = min(m->m_len - off, len); 1368 memcpy(cp, mtod(m, caddr_t) + off, count); 1369 len -= count; 1370 cp += count; 1371 off = 0; 1372 m = m->m_next; 1373 } 1374 } 1375 1376 1377 /* 1378 * Concatenate mbuf chain n to m. 1379 * Both chains must be of the same type (e.g. MT_DATA). 1380 * Any m_pkthdr is not updated. 1381 */ 1382 void 1383 m_cat(struct mbuf *m, struct mbuf *n) 1384 { 1385 while (m->m_next) 1386 m = m->m_next; 1387 while (n) { 1388 if (m->m_flags & M_EXT || 1389 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 1390 /* just join the two chains */ 1391 m->m_next = n; 1392 return; 1393 } 1394 /* splat the data from one into the other */ 1395 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), (u_int)n->m_len); 1396 m->m_len += n->m_len; 1397 n = m_free(n); 1398 } 1399 } 1400 1401 1402 void 1403 m_adj(struct mbuf *mp, int req_len) 1404 { 1405 int len = req_len; 1406 struct mbuf *m; 1407 int count; 1408 1409 if ((m = mp) == NULL) 1410 return; 1411 if (len >= 0) { 1412 /* 1413 * Trim from head. 1414 */ 1415 while (m != NULL && len > 0) { 1416 if (m->m_len <= len) { 1417 len -= m->m_len; 1418 m->m_len = 0; 1419 m = m->m_next; 1420 } else { 1421 m->m_len -= len; 1422 m->m_data += len; 1423 len = 0; 1424 } 1425 } 1426 m = mp; 1427 if (mp->m_flags & M_PKTHDR) 1428 m->m_pkthdr.len -= (req_len - len); 1429 } else { 1430 /* 1431 * Trim from tail. Scan the mbuf chain, 1432 * calculating its length and finding the last mbuf. 1433 * If the adjustment only affects this mbuf, then just 1434 * adjust and return. Otherwise, rescan and truncate 1435 * after the remaining size. 1436 */ 1437 len = -len; 1438 count = 0; 1439 for (;;) { 1440 count += m->m_len; 1441 if (m->m_next == (struct mbuf *)0) 1442 break; 1443 m = m->m_next; 1444 } 1445 if (m->m_len >= len) { 1446 m->m_len -= len; 1447 if (mp->m_flags & M_PKTHDR) 1448 mp->m_pkthdr.len -= len; 1449 return; 1450 } 1451 count -= len; 1452 if (count < 0) 1453 count = 0; 1454 /* 1455 * Correct length for chain is "count". 1456 * Find the mbuf with last data, adjust its length, 1457 * and toss data from remaining mbufs on chain. 1458 */ 1459 m = mp; 1460 if (m->m_flags & M_PKTHDR) 1461 m->m_pkthdr.len = count; 1462 for (; m; m = m->m_next) { 1463 if (m->m_len >= count) { 1464 m->m_len = count; 1465 if (m->m_next != NULL) { 1466 m_freem(m->m_next); 1467 m->m_next = NULL; 1468 } 1469 break; 1470 } 1471 count -= m->m_len; 1472 } 1473 } 1474 } 1475 1476 1477 /* m_split is used within sctp_handle_cookie_echo. */ 1478 1479 /* 1480 * Partition an mbuf chain in two pieces, returning the tail -- 1481 * all but the first len0 bytes. In case of failure, it returns NULL and 1482 * attempts to restore the chain to its original state. 1483 * 1484 * Note that the resulting mbufs might be read-only, because the new 1485 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1486 * the "breaking point" happens to lie within a cluster mbuf. Use the 1487 * M_WRITABLE() macro to check for this case. 1488 */ 1489 struct mbuf * 1490 m_split(struct mbuf *m0, int len0, int wait) 1491 { 1492 struct mbuf *m, *n; 1493 u_int len = len0, remain; 1494 1495 /* MBUF_CHECKSLEEP(wait); */ 1496 for (m = m0; m && (int)len > m->m_len; m = m->m_next) 1497 len -= m->m_len; 1498 if (m == NULL) 1499 return (NULL); 1500 remain = m->m_len - len; 1501 if (m0->m_flags & M_PKTHDR) { 1502 MGETHDR(n, wait, m0->m_type); 1503 if (n == NULL) 1504 return (NULL); 1505 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1506 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1507 m0->m_pkthdr.len = len0; 1508 if (m->m_flags & M_EXT) 1509 goto extpacket; 1510 if (remain > MHLEN) { 1511 /* m can't be the lead packet */ 1512 MH_ALIGN(n, 0); 1513 n->m_next = m_split(m, len, wait); 1514 if (n->m_next == NULL) { 1515 (void) m_free(n); 1516 return (NULL); 1517 } else { 1518 n->m_len = 0; 1519 return (n); 1520 } 1521 } else 1522 MH_ALIGN(n, remain); 1523 } else if (remain == 0) { 1524 n = m->m_next; 1525 m->m_next = NULL; 1526 return (n); 1527 } else { 1528 MGET(n, wait, m->m_type); 1529 if (n == NULL) 1530 return (NULL); 1531 M_ALIGN(n, remain); 1532 } 1533 extpacket: 1534 if (m->m_flags & M_EXT) { 1535 n->m_data = m->m_data + len; 1536 mb_dupcl(n, m); 1537 } else { 1538 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + len, remain); 1539 } 1540 n->m_len = remain; 1541 m->m_len = len; 1542 n->m_next = m->m_next; 1543 m->m_next = NULL; 1544 return (n); 1545 } 1546 1547 1548 1549 1550 int 1551 pack_send_buffer(caddr_t buffer, struct mbuf* mb){ 1552 1553 int count_to_copy; 1554 int total_count_copied = 0; 1555 int offset = 0; 1556 1557 do { 1558 count_to_copy = mb->m_len; 1559 memcpy(buffer+offset, mtod(mb, caddr_t), count_to_copy); 1560 offset += count_to_copy; 1561 total_count_copied += count_to_copy; 1562 mb = mb->m_next; 1563 } while(mb); 1564 1565 return (total_count_copied); 1566 } 1567