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 struct mbstat mbstat; 50 #define KIPC_MAX_LINKHDR 4 /* int: max length of link header (see sys/sysclt.h) */ 51 #define KIPC_MAX_PROTOHDR 5 /* int: max length of network header (see sys/sysclt.h)*/ 52 int max_linkhdr = KIPC_MAX_LINKHDR; 53 int max_protohdr = KIPC_MAX_PROTOHDR; /* Size of largest protocol layer header. */ 54 55 /* 56 * Zones from which we allocate. 57 */ 58 sctp_zone_t zone_mbuf; 59 sctp_zone_t zone_clust; 60 sctp_zone_t zone_ext_refcnt; 61 62 /* __Userspace__ clust_mb_args will be passed as callback data to mb_ctor_clust 63 * and mb_dtor_clust. 64 * Note: I had to use struct clust_args as an encapsulation for an mbuf pointer. 65 * struct mbuf * clust_mb_args; does not work. 66 */ 67 struct clust_args clust_mb_args; 68 69 70 /* __Userspace__ 71 * Local prototypes. 72 */ 73 static int mb_ctor_mbuf(void *, void *, int); 74 static int mb_ctor_clust(void *, void *, int); 75 static void mb_dtor_mbuf(void *, void *); 76 static void mb_dtor_clust(void *, void *); 77 78 79 /***************** Functions taken from user_mbuf.h *************/ 80 81 static int mbuf_constructor_dup(struct mbuf *m, int pkthdr, short type) 82 { 83 int flags = pkthdr; 84 if (type == MT_NOINIT) 85 return (0); 86 87 m->m_next = NULL; 88 m->m_nextpkt = NULL; 89 m->m_len = 0; 90 m->m_flags = flags; 91 m->m_type = type; 92 if (flags & M_PKTHDR) { 93 m->m_data = m->m_pktdat; 94 m->m_pkthdr.rcvif = NULL; 95 m->m_pkthdr.len = 0; 96 m->m_pkthdr.header = NULL; 97 m->m_pkthdr.csum_flags = 0; 98 m->m_pkthdr.csum_data = 0; 99 m->m_pkthdr.tso_segsz = 0; 100 m->m_pkthdr.ether_vtag = 0; 101 SLIST_INIT(&m->m_pkthdr.tags); 102 } else 103 m->m_data = m->m_dat; 104 105 return (0); 106 } 107 108 /* __Userspace__ */ 109 struct mbuf * 110 m_get(int how, short type) 111 { 112 struct mbuf *mret; 113 #if defined(SCTP_SIMPLE_ALLOCATOR) 114 struct mb_args mbuf_mb_args; 115 116 /* The following setter function is not yet being enclosed within 117 * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested 118 * mb_dtor_mbuf. See comment there 119 */ 120 mbuf_mb_args.flags = 0; 121 mbuf_mb_args.type = type; 122 #endif 123 /* Mbuf master zone, zone_mbuf, has already been 124 * created in mbuf_init() */ 125 mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf); 126 #if defined(SCTP_SIMPLE_ALLOCATOR) 127 mb_ctor_mbuf(mret, &mbuf_mb_args, 0); 128 #endif 129 /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/ 130 131 /* There are cases when an object available in the current CPU's 132 * loaded magazine and in those cases the object's constructor is not applied. 133 * If that is the case, then we are duplicating constructor initialization here, 134 * so that the mbuf is properly constructed before returning it. 135 */ 136 if (mret) { 137 #if USING_MBUF_CONSTRUCTOR 138 if (! (mret->m_type == type) ) { 139 mbuf_constructor_dup(mret, 0, type); 140 } 141 #else 142 mbuf_constructor_dup(mret, 0, type); 143 #endif 144 145 } 146 return mret; 147 } 148 149 150 /* __Userspace__ */ 151 struct mbuf * 152 m_gethdr(int how, short type) 153 { 154 struct mbuf *mret; 155 #if defined(SCTP_SIMPLE_ALLOCATOR) 156 struct mb_args mbuf_mb_args; 157 158 /* The following setter function is not yet being enclosed within 159 * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested 160 * mb_dtor_mbuf. See comment there 161 */ 162 mbuf_mb_args.flags = M_PKTHDR; 163 mbuf_mb_args.type = type; 164 #endif 165 mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf); 166 #if defined(SCTP_SIMPLE_ALLOCATOR) 167 mb_ctor_mbuf(mret, &mbuf_mb_args, 0); 168 #endif 169 /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/ 170 /* There are cases when an object available in the current CPU's 171 * loaded magazine and in those cases the object's constructor is not applied. 172 * If that is the case, then we are duplicating constructor initialization here, 173 * so that the mbuf is properly constructed before returning it. 174 */ 175 if (mret) { 176 #if USING_MBUF_CONSTRUCTOR 177 if (! ((mret->m_flags & M_PKTHDR) && (mret->m_type == type)) ) { 178 mbuf_constructor_dup(mret, M_PKTHDR, type); 179 } 180 #else 181 mbuf_constructor_dup(mret, M_PKTHDR, type); 182 #endif 183 } 184 return mret; 185 } 186 187 /* __Userspace__ */ 188 struct mbuf * 189 m_free(struct mbuf *m) 190 { 191 192 struct mbuf *n = m->m_next; 193 194 if (m->m_flags & M_EXT) 195 mb_free_ext(m); 196 else if ((m->m_flags & M_NOFREE) == 0) { 197 #if defined(SCTP_SIMPLE_ALLOCATOR) 198 mb_dtor_mbuf(m, NULL); 199 #endif 200 SCTP_ZONE_FREE(zone_mbuf, m); 201 } 202 /*umem_cache_free(zone_mbuf, m);*/ 203 return (n); 204 } 205 206 207 static int clust_constructor_dup(caddr_t m_clust, struct mbuf* m) 208 { 209 u_int *refcnt; 210 int type, size; 211 212 /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */ 213 type = EXT_CLUSTER; 214 size = MCLBYTES; 215 216 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 217 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 218 if (refcnt == NULL) { 219 #if !defined(SCTP_SIMPLE_ALLOCATOR) 220 umem_reap(); 221 #endif 222 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 223 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 224 } 225 *refcnt = 1; 226 if (m != NULL) { 227 m->m_ext.ext_buf = (caddr_t)m_clust; 228 m->m_data = m->m_ext.ext_buf; 229 m->m_flags |= M_EXT; 230 m->m_ext.ext_free = NULL; 231 m->m_ext.ext_args = NULL; 232 m->m_ext.ext_size = size; 233 m->m_ext.ext_type = type; 234 m->m_ext.ref_cnt = refcnt; 235 } 236 237 return (0); 238 } 239 240 241 242 /* __Userspace__ */ 243 void 244 m_clget(struct mbuf *m, int how) 245 { 246 caddr_t mclust_ret; 247 #if defined(SCTP_SIMPLE_ALLOCATOR) 248 struct clust_args clust_mb_args; 249 #endif 250 if (m->m_flags & M_EXT) { 251 SCTPDBG(SCTP_DEBUG_USR, "%s: %p mbuf already has cluster\n", __func__, (void *)m); 252 } 253 m->m_ext.ext_buf = (char *)NULL; 254 #if defined(SCTP_SIMPLE_ALLOCATOR) 255 clust_mb_args.parent_mbuf = m; 256 #endif 257 mclust_ret = SCTP_ZONE_GET(zone_clust, char); 258 #if defined(SCTP_SIMPLE_ALLOCATOR) 259 mb_ctor_clust(mclust_ret, &clust_mb_args, 0); 260 #endif 261 /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/ 262 /* 263 On a cluster allocation failure, call umem_reap() and retry. 264 */ 265 266 if (mclust_ret == NULL) { 267 #if !defined(SCTP_SIMPLE_ALLOCATOR) 268 /* mclust_ret = SCTP_ZONE_GET(zone_clust, char); 269 mb_ctor_clust(mclust_ret, &clust_mb_args, 0); 270 #else*/ 271 umem_reap(); 272 mclust_ret = SCTP_ZONE_GET(zone_clust, char); 273 #endif 274 /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/ 275 if (NULL == mclust_ret) { 276 SCTPDBG(SCTP_DEBUG_USR, "Memory allocation failure in %s\n", __func__); 277 } 278 } 279 280 #if USING_MBUF_CONSTRUCTOR 281 if ((m->m_ext.ext_buf == NULL)) { 282 clust_constructor_dup(mclust_ret, m); 283 } 284 #else 285 clust_constructor_dup(mclust_ret, m); 286 #endif 287 } 288 289 /* 290 * Unlink a tag from the list of tags associated with an mbuf. 291 */ 292 static __inline void 293 m_tag_unlink(struct mbuf *m, struct m_tag *t) 294 { 295 296 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link); 297 } 298 299 /* 300 * Reclaim resources associated with a tag. 301 */ 302 static __inline void 303 m_tag_free(struct m_tag *t) 304 { 305 306 (*t->m_tag_free)(t); 307 } 308 309 /* 310 * Set up the contents of a tag. Note that this does not fill in the free 311 * method; the caller is expected to do that. 312 * 313 * XXX probably should be called m_tag_init, but that was already taken. 314 */ 315 static __inline void 316 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len) 317 { 318 319 t->m_tag_id = type; 320 t->m_tag_len = len; 321 t->m_tag_cookie = cookie; 322 } 323 324 /************ End functions from user_mbuf.h ******************/ 325 326 327 328 /************ End functions to substitute umem_cache_alloc and umem_cache_free **************/ 329 330 /* __Userspace__ 331 * TODO: mbuf_init must be called in the initialization routines 332 * of userspace stack. 333 */ 334 void 335 mbuf_init(void *dummy) 336 { 337 338 /* 339 * __Userspace__Configure UMA zones for Mbufs and Clusters. 340 * (TODO: m_getcl() - using packet secondary zone). 341 * There is no provision for trash_init and trash_fini in umem. 342 * 343 */ 344 /* zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, 345 mb_ctor_mbuf, mb_dtor_mbuf, NULL, 346 &mbuf_mb_args, 347 NULL, 0); 348 zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, NULL, NULL, NULL, NULL, NULL, 0);*/ 349 #if defined(SCTP_SIMPLE_ALLOCATOR) 350 SCTP_ZONE_INIT(zone_mbuf, MBUF_MEM_NAME, MSIZE, 0); 351 #else 352 zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, 353 mb_ctor_mbuf, mb_dtor_mbuf, NULL, 354 NUULL, 355 NULL, 0); 356 #endif 357 /*zone_ext_refcnt = umem_cache_create(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0, 358 NULL, NULL, NULL, 359 NULL, 360 NULL, 0);*/ 361 SCTP_ZONE_INIT(zone_ext_refcnt, MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0); 362 363 /*zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, 364 mb_ctor_clust, mb_dtor_clust, NULL, 365 &clust_mb_args, 366 NULL, 0); 367 zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, NULL, NULL, NULL, NULL, NULL,0);*/ 368 #if defined(SCTP_SIMPLE_ALLOCATOR) 369 SCTP_ZONE_INIT(zone_clust, MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0); 370 #else 371 zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, 372 mb_ctor_clust, mb_dtor_clust, NULL, 373 &clust_mb_args, 374 NULL, 0); 375 #endif 376 377 /* uma_prealloc() goes here... */ 378 379 /* __Userspace__ Add umem_reap here for low memory situation? 380 * 381 */ 382 383 384 /* 385 * [Re]set counters and local statistics knobs. 386 * 387 */ 388 389 mbstat.m_mbufs = 0; 390 mbstat.m_mclusts = 0; 391 mbstat.m_drain = 0; 392 mbstat.m_msize = MSIZE; 393 mbstat.m_mclbytes = MCLBYTES; 394 mbstat.m_minclsize = MINCLSIZE; 395 mbstat.m_mlen = MLEN; 396 mbstat.m_mhlen = MHLEN; 397 mbstat.m_numtypes = MT_NTYPES; 398 399 mbstat.m_mcfail = mbstat.m_mpfail = 0; 400 mbstat.sf_iocnt = 0; 401 mbstat.sf_allocwait = mbstat.sf_allocfail = 0; 402 403 } 404 405 406 407 /* 408 * __Userspace__ 409 * 410 * Constructor for Mbuf master zone. We have a different constructor 411 * for allocating the cluster. 412 * 413 * The 'arg' pointer points to a mb_args structure which 414 * contains call-specific information required to support the 415 * mbuf allocation API. See user_mbuf.h. 416 * 417 * The flgs parameter below can be UMEM_DEFAULT or UMEM_NOFAIL depending on what 418 * was passed when umem_cache_alloc was called. 419 * TODO: Use UMEM_NOFAIL in umem_cache_alloc and also define a failure handler 420 * and call umem_nofail_callback(my_failure_handler) in the stack initialization routines 421 * The advantage of using UMEM_NOFAIL is that we don't have to check if umem_cache_alloc 422 * was successful or not. The failure handler would take care of it, if we use the UMEM_NOFAIL 423 * flag. 424 * 425 * NOTE Ref: http://docs.sun.com/app/docs/doc/819-2243/6n4i099p2?l=en&a=view&q=umem_zalloc) 426 * The umem_nofail_callback() function sets the **process-wide** UMEM_NOFAIL callback. 427 * It also mentions that umem_nofail_callback is Evolving. 428 * 429 */ 430 static int 431 mb_ctor_mbuf(void *mem, void *arg, int flgs) 432 { 433 #if USING_MBUF_CONSTRUCTOR 434 struct mbuf *m; 435 struct mb_args *args; 436 437 int flags; 438 short type; 439 440 m = (struct mbuf *)mem; 441 args = (struct mb_args *)arg; 442 flags = args->flags; 443 type = args->type; 444 445 /* 446 * The mbuf is initialized later. 447 * 448 */ 449 if (type == MT_NOINIT) 450 return (0); 451 452 m->m_next = NULL; 453 m->m_nextpkt = NULL; 454 m->m_len = 0; 455 m->m_flags = flags; 456 m->m_type = type; 457 if (flags & M_PKTHDR) { 458 m->m_data = m->m_pktdat; 459 m->m_pkthdr.rcvif = NULL; 460 m->m_pkthdr.len = 0; 461 m->m_pkthdr.header = NULL; 462 m->m_pkthdr.csum_flags = 0; 463 m->m_pkthdr.csum_data = 0; 464 m->m_pkthdr.tso_segsz = 0; 465 m->m_pkthdr.ether_vtag = 0; 466 SLIST_INIT(&m->m_pkthdr.tags); 467 } else 468 m->m_data = m->m_dat; 469 #endif 470 return (0); 471 } 472 473 474 /* 475 * __Userspace__ 476 * The Mbuf master zone destructor. 477 * This would be called in response to umem_cache_destroy 478 * TODO: Recheck if this is what we want to do in this destructor. 479 * (Note: the number of times mb_dtor_mbuf is called is equal to the 480 * number of individual mbufs allocated from zone_mbuf. 481 */ 482 static void 483 mb_dtor_mbuf(void *mem, void *arg) 484 { 485 struct mbuf *m; 486 487 m = (struct mbuf *)mem; 488 if ((m->m_flags & M_PKTHDR) != 0) { 489 m_tag_delete_chain(m, NULL); 490 } 491 } 492 493 494 /* __Userspace__ 495 * The Cluster zone constructor. 496 * 497 * Here the 'arg' pointer points to the Mbuf which we 498 * are configuring cluster storage for. If 'arg' is 499 * empty we allocate just the cluster without setting 500 * the mbuf to it. See mbuf.h. 501 */ 502 static int 503 mb_ctor_clust(void *mem, void *arg, int flgs) 504 { 505 506 #if USING_MBUF_CONSTRUCTOR 507 struct mbuf *m; 508 struct clust_args * cla; 509 u_int *refcnt; 510 int type, size; 511 sctp_zone_t zone; 512 513 /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */ 514 type = EXT_CLUSTER; 515 zone = zone_clust; 516 size = MCLBYTES; 517 518 cla = (struct clust_args *)arg; 519 m = cla->parent_mbuf; 520 521 refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int); 522 /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/ 523 *refcnt = 1; 524 525 if (m != NULL) { 526 m->m_ext.ext_buf = (caddr_t)mem; 527 m->m_data = m->m_ext.ext_buf; 528 m->m_flags |= M_EXT; 529 m->m_ext.ext_free = NULL; 530 m->m_ext.ext_args = NULL; 531 m->m_ext.ext_size = size; 532 m->m_ext.ext_type = type; 533 m->m_ext.ref_cnt = refcnt; 534 } 535 #endif 536 return (0); 537 } 538 539 /* __Userspace__ */ 540 static void 541 mb_dtor_clust(void *mem, void *arg) 542 { 543 544 /* mem is of type caddr_t. In sys/types.h we have typedef char * caddr_t; */ 545 /* mb_dtor_clust is called at time of umem_cache_destroy() (the number of times 546 * mb_dtor_clust is called is equal to the number of individual mbufs allocated 547 * from zone_clust. Similarly for mb_dtor_mbuf). 548 * At this point the following: 549 * struct mbuf *m; 550 * m = (struct mbuf *)arg; 551 * assert (*(m->m_ext.ref_cnt) == 0); is not meaningful since m->m_ext.ref_cnt = NULL; 552 * has been done in mb_free_ext(). 553 */ 554 555 } 556 557 558 559 560 /* Unlink and free a packet tag. */ 561 void 562 m_tag_delete(struct mbuf *m, struct m_tag *t) 563 { 564 KASSERT(m && t, ("m_tag_delete: null argument, m %p t %p", (void *)m, (void *)t)); 565 m_tag_unlink(m, t); 566 m_tag_free(t); 567 } 568 569 570 /* Unlink and free a packet tag chain, starting from given tag. */ 571 void 572 m_tag_delete_chain(struct mbuf *m, struct m_tag *t) 573 { 574 575 struct m_tag *p, *q; 576 577 KASSERT(m, ("m_tag_delete_chain: null mbuf")); 578 if (t != NULL) 579 p = t; 580 else 581 p = SLIST_FIRST(&m->m_pkthdr.tags); 582 if (p == NULL) 583 return; 584 while ((q = SLIST_NEXT(p, m_tag_link)) != NULL) 585 m_tag_delete(m, q); 586 m_tag_delete(m, p); 587 } 588 589 #if 0 590 static void 591 sctp_print_mbuf_chain(struct mbuf *m) 592 { 593 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "Printing mbuf chain %p.\n", (void *)m); 594 for(; m; m=m->m_next) { 595 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); 596 if (m->m_flags & M_EXT) 597 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)); 598 } 599 } 600 #endif 601 602 /* 603 * Free an entire chain of mbufs and associated external buffers, if 604 * applicable. 605 */ 606 void 607 m_freem(struct mbuf *mb) 608 { 609 while (mb != NULL) 610 mb = m_free(mb); 611 } 612 613 /* 614 * __Userspace__ 615 * clean mbufs with M_EXT storage attached to them 616 * if the reference count hits 1. 617 */ 618 void 619 mb_free_ext(struct mbuf *m) 620 { 621 622 int skipmbuf; 623 624 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 625 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 626 627 /* 628 * check if the header is embedded in the cluster 629 */ 630 skipmbuf = (m->m_flags & M_NOFREE); 631 632 /* Free the external attached storage if this 633 * mbuf is the only reference to it. 634 *__Userspace__ TODO: jumbo frames 635 * 636 */ 637 /* NOTE: We had the same code that SCTP_DECREMENT_AND_CHECK_REFCOUNT 638 reduces to here before but the IPHONE malloc commit had changed 639 this to compare to 0 instead of 1 (see next line). Why? 640 . .. this caused a huge memory leak in Linux. 641 */ 642 #ifdef IPHONE 643 if (atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 0) 644 #else 645 if (SCTP_DECREMENT_AND_CHECK_REFCOUNT(m->m_ext.ref_cnt)) 646 #endif 647 { 648 if (m->m_ext.ext_type == EXT_CLUSTER){ 649 #if defined(SCTP_SIMPLE_ALLOCATOR) 650 mb_dtor_clust(m->m_ext.ext_buf, &clust_mb_args); 651 #endif 652 SCTP_ZONE_FREE(zone_clust, m->m_ext.ext_buf); 653 SCTP_ZONE_FREE(zone_ext_refcnt, (u_int*)m->m_ext.ref_cnt); 654 m->m_ext.ref_cnt = NULL; 655 } 656 } 657 658 if (skipmbuf) 659 return; 660 661 662 /* __Userspace__ Also freeing the storage for ref_cnt 663 * Free this mbuf back to the mbuf zone with all m_ext 664 * information purged. 665 */ 666 m->m_ext.ext_buf = NULL; 667 m->m_ext.ext_free = NULL; 668 m->m_ext.ext_args = NULL; 669 m->m_ext.ref_cnt = NULL; 670 m->m_ext.ext_size = 0; 671 m->m_ext.ext_type = 0; 672 m->m_flags &= ~M_EXT; 673 #if defined(SCTP_SIMPLE_ALLOCATOR) 674 mb_dtor_mbuf(m, NULL); 675 #endif 676 SCTP_ZONE_FREE(zone_mbuf, m); 677 678 /*umem_cache_free(zone_mbuf, m);*/ 679 } 680 681 /* 682 * "Move" mbuf pkthdr from "from" to "to". 683 * "from" must have M_PKTHDR set, and "to" must be empty. 684 */ 685 void 686 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 687 { 688 689 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 690 if ((to->m_flags & M_EXT) == 0) 691 to->m_data = to->m_pktdat; 692 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 693 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 694 from->m_flags &= ~M_PKTHDR; 695 } 696 697 698 /* 699 * Rearange an mbuf chain so that len bytes are contiguous 700 * and in the data area of an mbuf (so that mtod and dtom 701 * will work for a structure of size len). Returns the resulting 702 * mbuf chain on success, frees it and returns null on failure. 703 * If there is room, it will add up to max_protohdr-len extra bytes to the 704 * contiguous region in an attempt to avoid being called next time. 705 */ 706 struct mbuf * 707 m_pullup(struct mbuf *n, int len) 708 { 709 struct mbuf *m; 710 int count; 711 int space; 712 713 /* 714 * If first mbuf has no cluster, and has room for len bytes 715 * without shifting current data, pullup into it, 716 * otherwise allocate a new mbuf to prepend to the chain. 717 */ 718 if ((n->m_flags & M_EXT) == 0 && 719 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 720 if (n->m_len >= len) 721 return (n); 722 m = n; 723 n = n->m_next; 724 len -= m->m_len; 725 } else { 726 if (len > MHLEN) 727 goto bad; 728 MGET(m, M_NOWAIT, n->m_type); 729 if (m == NULL) 730 goto bad; 731 m->m_len = 0; 732 if (n->m_flags & M_PKTHDR) 733 M_MOVE_PKTHDR(m, n); 734 } 735 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 736 do { 737 count = min(min(max(len, max_protohdr), space), n->m_len); 738 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 739 (u_int)count); 740 len -= count; 741 m->m_len += count; 742 n->m_len -= count; 743 space -= count; 744 if (n->m_len) 745 n->m_data += count; 746 else 747 n = m_free(n); 748 } while (len > 0 && n); 749 if (len > 0) { 750 (void) m_free(m); 751 goto bad; 752 } 753 m->m_next = n; 754 return (m); 755 bad: 756 m_freem(n); 757 mbstat.m_mpfail++; /* XXX: No consistency. */ 758 return (NULL); 759 } 760 761 762 static struct mbuf * 763 m_dup1(struct mbuf *m, int off, int len, int wait) 764 { 765 struct mbuf *n = NULL; 766 int copyhdr; 767 768 if (len > MCLBYTES) 769 return NULL; 770 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) 771 copyhdr = 1; 772 else 773 copyhdr = 0; 774 if (len >= MINCLSIZE) { 775 if (copyhdr == 1) { 776 m_clget(n, wait); /* TODO: include code for copying the header */ 777 m_dup_pkthdr(n, m, wait); 778 } else 779 m_clget(n, wait); 780 } else { 781 if (copyhdr == 1) 782 n = m_gethdr(wait, m->m_type); 783 else 784 n = m_get(wait, m->m_type); 785 } 786 if (!n) 787 return NULL; /* ENOBUFS */ 788 789 if (copyhdr && !m_dup_pkthdr(n, m, wait)) { 790 m_free(n); 791 return NULL; 792 } 793 m_copydata(m, off, len, mtod(n, caddr_t)); 794 n->m_len = len; 795 return n; 796 } 797 798 799 /* Taken from sys/kern/uipc_mbuf2.c */ 800 struct mbuf * 801 m_pulldown(struct mbuf *m, int off, int len, int *offp) 802 { 803 struct mbuf *n, *o; 804 int hlen, tlen, olen; 805 int writable; 806 807 /* check invalid arguments. */ 808 KASSERT(m, ("m == NULL in m_pulldown()")); 809 if (len > MCLBYTES) { 810 m_freem(m); 811 return NULL; /* impossible */ 812 } 813 814 #ifdef PULLDOWN_DEBUG 815 { 816 struct mbuf *t; 817 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "before:"); 818 for (t = m; t; t = t->m_next) 819 SCTP_DEBUG_USR(SCTP_DEBUG_USR, " %d", t->m_len); 820 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "\n"); 821 } 822 #endif 823 n = m; 824 while (n != NULL && off > 0) { 825 if (n->m_len > off) 826 break; 827 off -= n->m_len; 828 n = n->m_next; 829 } 830 /* be sure to point non-empty mbuf */ 831 while (n != NULL && n->m_len == 0) 832 n = n->m_next; 833 if (!n) { 834 m_freem(m); 835 return NULL; /* mbuf chain too short */ 836 } 837 838 writable = 0; 839 if ((n->m_flags & M_EXT) == 0 || 840 (n->m_ext.ext_type == EXT_CLUSTER && M_WRITABLE(n))) 841 writable = 1; 842 843 /* 844 * the target data is on <n, off>. 845 * if we got enough data on the mbuf "n", we're done. 846 */ 847 if ((off == 0 || offp) && len <= n->m_len - off && writable) 848 goto ok; 849 850 /* 851 * when len <= n->m_len - off and off != 0, it is a special case. 852 * len bytes from <n, off> sits in single mbuf, but the caller does 853 * not like the starting position (off). 854 * chop the current mbuf into two pieces, set off to 0. 855 */ 856 if (len <= n->m_len - off) { 857 o = m_dup1(n, off, n->m_len - off, M_NOWAIT); 858 if (o == NULL) { 859 m_freem(m); 860 return NULL; /* ENOBUFS */ 861 } 862 n->m_len = off; 863 o->m_next = n->m_next; 864 n->m_next = o; 865 n = n->m_next; 866 off = 0; 867 goto ok; 868 } 869 /* 870 * we need to take hlen from <n, off> and tlen from <n->m_next, 0>, 871 * and construct contiguous mbuf with m_len == len. 872 * note that hlen + tlen == len, and tlen > 0. 873 */ 874 hlen = n->m_len - off; 875 tlen = len - hlen; 876 877 /* 878 * ensure that we have enough trailing data on mbuf chain. 879 * if not, we can do nothing about the chain. 880 */ 881 olen = 0; 882 for (o = n->m_next; o != NULL; o = o->m_next) 883 olen += o->m_len; 884 if (hlen + olen < len) { 885 m_freem(m); 886 return NULL; /* mbuf chain too short */ 887 } 888 889 /* 890 * easy cases first. 891 * we need to use m_copydata() to get data from <n->m_next, 0>. 892 */ 893 if ((off == 0 || offp) && M_TRAILINGSPACE(n) >= tlen 894 && writable) { 895 m_copydata(n->m_next, 0, tlen, mtod(n, caddr_t) + n->m_len); 896 n->m_len += tlen; 897 m_adj(n->m_next, tlen); 898 goto ok; 899 } 900 901 if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen 902 && writable) { 903 n->m_next->m_data -= hlen; 904 n->m_next->m_len += hlen; 905 bcopy(mtod(n, caddr_t) + off, mtod(n->m_next, caddr_t), hlen); 906 n->m_len -= hlen; 907 n = n->m_next; 908 off = 0; 909 goto ok; 910 } 911 912 /* 913 * now, we need to do the hard way. don't m_copy as there's no room 914 * on both end. 915 */ 916 if (len > MLEN) 917 m_clget(o, M_NOWAIT); 918 /* o = m_getcl(M_NOWAIT, m->m_type, 0);*/ 919 else 920 o = m_get(M_NOWAIT, m->m_type); 921 if (!o) { 922 m_freem(m); 923 return NULL; /* ENOBUFS */ 924 } 925 /* get hlen from <n, off> into <o, 0> */ 926 o->m_len = hlen; 927 bcopy(mtod(n, caddr_t) + off, mtod(o, caddr_t), hlen); 928 n->m_len -= hlen; 929 /* get tlen from <n->m_next, 0> into <o, hlen> */ 930 m_copydata(n->m_next, 0, tlen, mtod(o, caddr_t) + o->m_len); 931 o->m_len += tlen; 932 m_adj(n->m_next, tlen); 933 o->m_next = n->m_next; 934 n->m_next = o; 935 n = o; 936 off = 0; 937 ok: 938 #ifdef PULLDOWN_DEBUG 939 { 940 struct mbuf *t; 941 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "after:"); 942 for (t = m; t; t = t->m_next) 943 SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%c%d", t == n ? '*' : ' ', t->m_len); 944 SCTP_DEBUG_USR(SCTP_DEBUG_USR, " (off=%d)\n", off); 945 } 946 #endif 947 if (offp) 948 *offp = off; 949 return n; 950 } 951 952 /* 953 * Attach the the cluster from *m to *n, set up m_ext in *n 954 * and bump the refcount of the cluster. 955 */ 956 static void 957 mb_dupcl(struct mbuf *n, struct mbuf *m) 958 { 959 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 960 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 961 KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__)); 962 963 if (*(m->m_ext.ref_cnt) == 1) 964 *(m->m_ext.ref_cnt) += 1; 965 else 966 atomic_add_int(m->m_ext.ref_cnt, 1); 967 n->m_ext.ext_buf = m->m_ext.ext_buf; 968 n->m_ext.ext_free = m->m_ext.ext_free; 969 n->m_ext.ext_args = m->m_ext.ext_args; 970 n->m_ext.ext_size = m->m_ext.ext_size; 971 n->m_ext.ref_cnt = m->m_ext.ref_cnt; 972 n->m_ext.ext_type = m->m_ext.ext_type; 973 n->m_flags |= M_EXT; 974 } 975 976 977 /* 978 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 979 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 980 * The wait parameter is a choice of M_TRYWAIT/M_NOWAIT from caller. 981 * Note that the copy is read-only, because clusters are not copied, 982 * only their reference counts are incremented. 983 */ 984 985 struct mbuf * 986 m_copym(struct mbuf *m, int off0, int len, int wait) 987 { 988 struct mbuf *n, **np; 989 int off = off0; 990 struct mbuf *top; 991 int copyhdr = 0; 992 993 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 994 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 995 996 if (off == 0 && m->m_flags & M_PKTHDR) 997 copyhdr = 1; 998 while (off > 0) { 999 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 1000 if (off < m->m_len) 1001 break; 1002 off -= m->m_len; 1003 m = m->m_next; 1004 } 1005 np = ⊤ 1006 top = 0; 1007 while (len > 0) { 1008 if (m == NULL) { 1009 KASSERT(len == M_COPYALL, ("m_copym, length > size of mbuf chain")); 1010 break; 1011 } 1012 if (copyhdr) 1013 MGETHDR(n, wait, m->m_type); 1014 else 1015 MGET(n, wait, m->m_type); 1016 *np = n; 1017 if (n == NULL) 1018 goto nospace; 1019 if (copyhdr) { 1020 if (!m_dup_pkthdr(n, m, wait)) 1021 goto nospace; 1022 if (len == M_COPYALL) 1023 n->m_pkthdr.len -= off0; 1024 else 1025 n->m_pkthdr.len = len; 1026 copyhdr = 0; 1027 } 1028 n->m_len = min(len, m->m_len - off); 1029 if (m->m_flags & M_EXT) { 1030 n->m_data = m->m_data + off; 1031 mb_dupcl(n, m); 1032 } else 1033 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 1034 (u_int)n->m_len); 1035 if (len != M_COPYALL) 1036 len -= n->m_len; 1037 off = 0; 1038 m = m->m_next; 1039 np = &n->m_next; 1040 } 1041 if (top == NULL) 1042 mbstat.m_mcfail++; /* XXX: No consistency. */ 1043 1044 return (top); 1045 nospace: 1046 m_freem(top); 1047 mbstat.m_mcfail++; /* XXX: No consistency. */ 1048 return (NULL); 1049 } 1050 1051 1052 int 1053 m_tag_copy_chain(struct mbuf *to, struct mbuf *from, int how) 1054 { 1055 struct m_tag *p, *t, *tprev = NULL; 1056 1057 KASSERT(to && from, ("m_tag_copy_chain: null argument, to %p from %p", (void *)to, (void *)from)); 1058 m_tag_delete_chain(to, NULL); 1059 SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) { 1060 t = m_tag_copy(p, how); 1061 if (t == NULL) { 1062 m_tag_delete_chain(to, NULL); 1063 return 0; 1064 } 1065 if (tprev == NULL) 1066 SLIST_INSERT_HEAD(&to->m_pkthdr.tags, t, m_tag_link); 1067 else 1068 SLIST_INSERT_AFTER(tprev, t, m_tag_link); 1069 tprev = t; 1070 } 1071 return 1; 1072 } 1073 1074 /* 1075 * Duplicate "from"'s mbuf pkthdr in "to". 1076 * "from" must have M_PKTHDR set, and "to" must be empty. 1077 * In particular, this does a deep copy of the packet tags. 1078 */ 1079 int 1080 m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 1081 { 1082 1083 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 1084 if ((to->m_flags & M_EXT) == 0) 1085 to->m_data = to->m_pktdat; 1086 to->m_pkthdr = from->m_pkthdr; 1087 SLIST_INIT(&to->m_pkthdr.tags); 1088 return (m_tag_copy_chain(to, from, MBTOM(how))); 1089 } 1090 1091 /* Copy a single tag. */ 1092 struct m_tag * 1093 m_tag_copy(struct m_tag *t, int how) 1094 { 1095 struct m_tag *p; 1096 1097 KASSERT(t, ("m_tag_copy: null tag")); 1098 p = m_tag_alloc(t->m_tag_cookie, t->m_tag_id, t->m_tag_len, how); 1099 if (p == NULL) 1100 return (NULL); 1101 bcopy(t + 1, p + 1, t->m_tag_len); /* Copy the data */ 1102 return p; 1103 } 1104 1105 /* Get a packet tag structure along with specified data following. */ 1106 struct m_tag * 1107 m_tag_alloc(u_int32_t cookie, int type, int len, int wait) 1108 { 1109 struct m_tag *t; 1110 1111 if (len < 0) 1112 return NULL; 1113 t = malloc(len + sizeof(struct m_tag)); 1114 if (t == NULL) 1115 return NULL; 1116 m_tag_setup(t, cookie, type, len); 1117 t->m_tag_free = m_tag_free_default; 1118 return t; 1119 } 1120 1121 /* Free a packet tag. */ 1122 void 1123 m_tag_free_default(struct m_tag *t) 1124 { 1125 free(t); 1126 } 1127 1128 /* 1129 * Copy data from a buffer back into the indicated mbuf chain, 1130 * starting "off" bytes from the beginning, extending the mbuf 1131 * chain if necessary. 1132 */ 1133 void 1134 m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) 1135 { 1136 int mlen; 1137 struct mbuf *m = m0, *n; 1138 int totlen = 0; 1139 1140 if (m0 == NULL) 1141 return; 1142 while (off > (mlen = m->m_len)) { 1143 off -= mlen; 1144 totlen += mlen; 1145 if (m->m_next == NULL) { 1146 n = m_get(M_NOWAIT, m->m_type); 1147 if (n == NULL) 1148 goto out; 1149 bzero(mtod(n, caddr_t), MLEN); 1150 n->m_len = min(MLEN, len + off); 1151 m->m_next = n; 1152 } 1153 m = m->m_next; 1154 } 1155 while (len > 0) { 1156 mlen = min (m->m_len - off, len); 1157 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 1158 cp += mlen; 1159 len -= mlen; 1160 mlen += off; 1161 off = 0; 1162 totlen += mlen; 1163 if (len == 0) 1164 break; 1165 if (m->m_next == NULL) { 1166 n = m_get(M_NOWAIT, m->m_type); 1167 if (n == NULL) 1168 break; 1169 n->m_len = min(MLEN, len); 1170 m->m_next = n; 1171 } 1172 m = m->m_next; 1173 } 1174 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1175 m->m_pkthdr.len = totlen; 1176 } 1177 1178 1179 /* 1180 * Lesser-used path for M_PREPEND: 1181 * allocate new mbuf to prepend to chain, 1182 * copy junk along. 1183 */ 1184 struct mbuf * 1185 m_prepend(struct mbuf *m, int len, int how) 1186 { 1187 struct mbuf *mn; 1188 1189 if (m->m_flags & M_PKTHDR) 1190 MGETHDR(mn, how, m->m_type); 1191 else 1192 MGET(mn, how, m->m_type); 1193 if (mn == NULL) { 1194 m_freem(m); 1195 return (NULL); 1196 } 1197 if (m->m_flags & M_PKTHDR) 1198 M_MOVE_PKTHDR(mn, m); 1199 mn->m_next = m; 1200 m = mn; 1201 if(m->m_flags & M_PKTHDR) { 1202 if (len < MHLEN) 1203 MH_ALIGN(m, len); 1204 } else { 1205 if (len < MLEN) 1206 M_ALIGN(m, len); 1207 } 1208 m->m_len = len; 1209 return (m); 1210 } 1211 1212 /* 1213 * Copy data from an mbuf chain starting "off" bytes from the beginning, 1214 * continuing for "len" bytes, into the indicated buffer. 1215 */ 1216 void 1217 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 1218 { 1219 u_int count; 1220 1221 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 1222 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 1223 while (off > 0) { 1224 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 1225 if (off < m->m_len) 1226 break; 1227 off -= m->m_len; 1228 m = m->m_next; 1229 } 1230 while (len > 0) { 1231 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 1232 count = min(m->m_len - off, len); 1233 bcopy(mtod(m, caddr_t) + off, cp, count); 1234 len -= count; 1235 cp += count; 1236 off = 0; 1237 m = m->m_next; 1238 } 1239 } 1240 1241 1242 /* 1243 * Concatenate mbuf chain n to m. 1244 * Both chains must be of the same type (e.g. MT_DATA). 1245 * Any m_pkthdr is not updated. 1246 */ 1247 void 1248 m_cat(struct mbuf *m, struct mbuf *n) 1249 { 1250 while (m->m_next) 1251 m = m->m_next; 1252 while (n) { 1253 if (m->m_flags & M_EXT || 1254 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 1255 /* just join the two chains */ 1256 m->m_next = n; 1257 return; 1258 } 1259 /* splat the data from one into the other */ 1260 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, (u_int)n->m_len); 1261 m->m_len += n->m_len; 1262 n = m_free(n); 1263 } 1264 } 1265 1266 1267 void 1268 m_adj(struct mbuf *mp, int req_len) 1269 { 1270 int len = req_len; 1271 struct mbuf *m; 1272 int count; 1273 1274 if ((m = mp) == NULL) 1275 return; 1276 if (len >= 0) { 1277 /* 1278 * Trim from head. 1279 */ 1280 while (m != NULL && len > 0) { 1281 if (m->m_len <= len) { 1282 len -= m->m_len; 1283 m->m_len = 0; 1284 m = m->m_next; 1285 } else { 1286 m->m_len -= len; 1287 m->m_data += len; 1288 len = 0; 1289 } 1290 } 1291 m = mp; 1292 if (mp->m_flags & M_PKTHDR) 1293 m->m_pkthdr.len -= (req_len - len); 1294 } else { 1295 /* 1296 * Trim from tail. Scan the mbuf chain, 1297 * calculating its length and finding the last mbuf. 1298 * If the adjustment only affects this mbuf, then just 1299 * adjust and return. Otherwise, rescan and truncate 1300 * after the remaining size. 1301 */ 1302 len = -len; 1303 count = 0; 1304 for (;;) { 1305 count += m->m_len; 1306 if (m->m_next == (struct mbuf *)0) 1307 break; 1308 m = m->m_next; 1309 } 1310 if (m->m_len >= len) { 1311 m->m_len -= len; 1312 if (mp->m_flags & M_PKTHDR) 1313 mp->m_pkthdr.len -= len; 1314 return; 1315 } 1316 count -= len; 1317 if (count < 0) 1318 count = 0; 1319 /* 1320 * Correct length for chain is "count". 1321 * Find the mbuf with last data, adjust its length, 1322 * and toss data from remaining mbufs on chain. 1323 */ 1324 m = mp; 1325 if (m->m_flags & M_PKTHDR) 1326 m->m_pkthdr.len = count; 1327 for (; m; m = m->m_next) { 1328 if (m->m_len >= count) { 1329 m->m_len = count; 1330 if (m->m_next != NULL) { 1331 m_freem(m->m_next); 1332 m->m_next = NULL; 1333 } 1334 break; 1335 } 1336 count -= m->m_len; 1337 } 1338 } 1339 } 1340 1341 1342 /* m_split is used within sctp_handle_cookie_echo. */ 1343 1344 /* 1345 * Partition an mbuf chain in two pieces, returning the tail -- 1346 * all but the first len0 bytes. In case of failure, it returns NULL and 1347 * attempts to restore the chain to its original state. 1348 * 1349 * Note that the resulting mbufs might be read-only, because the new 1350 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1351 * the "breaking point" happens to lie within a cluster mbuf. Use the 1352 * M_WRITABLE() macro to check for this case. 1353 */ 1354 struct mbuf * 1355 m_split(struct mbuf *m0, int len0, int wait) 1356 { 1357 struct mbuf *m, *n; 1358 u_int len = len0, remain; 1359 1360 /* MBUF_CHECKSLEEP(wait); */ 1361 for (m = m0; m && (int)len > m->m_len; m = m->m_next) 1362 len -= m->m_len; 1363 if (m == NULL) 1364 return (NULL); 1365 remain = m->m_len - len; 1366 if (m0->m_flags & M_PKTHDR) { 1367 MGETHDR(n, wait, m0->m_type); 1368 if (n == NULL) 1369 return (NULL); 1370 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1371 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1372 m0->m_pkthdr.len = len0; 1373 if (m->m_flags & M_EXT) 1374 goto extpacket; 1375 if (remain > MHLEN) { 1376 /* m can't be the lead packet */ 1377 MH_ALIGN(n, 0); 1378 n->m_next = m_split(m, len, wait); 1379 if (n->m_next == NULL) { 1380 (void) m_free(n); 1381 return (NULL); 1382 } else { 1383 n->m_len = 0; 1384 return (n); 1385 } 1386 } else 1387 MH_ALIGN(n, remain); 1388 } else if (remain == 0) { 1389 n = m->m_next; 1390 m->m_next = NULL; 1391 return (n); 1392 } else { 1393 MGET(n, wait, m->m_type); 1394 if (n == NULL) 1395 return (NULL); 1396 M_ALIGN(n, remain); 1397 } 1398 extpacket: 1399 if (m->m_flags & M_EXT) { 1400 n->m_data = m->m_data + len; 1401 mb_dupcl(n, m); 1402 } else { 1403 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1404 } 1405 n->m_len = remain; 1406 m->m_len = len; 1407 n->m_next = m->m_next; 1408 m->m_next = NULL; 1409 return (n); 1410 } 1411 1412 1413 1414 1415 int 1416 pack_send_buffer(caddr_t buffer, struct mbuf* mb){ 1417 1418 int count_to_copy; 1419 int total_count_copied = 0; 1420 int offset = 0; 1421 1422 do { 1423 count_to_copy = mb->m_len; 1424 bcopy(mtod(mb, caddr_t), buffer+offset, count_to_copy); 1425 offset += count_to_copy; 1426 total_count_copied += count_to_copy; 1427 mb = mb->m_next; 1428 } while(mb); 1429 1430 return (total_count_copied); 1431 } 1432
