1/*- 2 * Copyright (c) 1982, 1986, 1988, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/10/sys/kern/uipc_mbuf.c 308376 2016-11-06 16:44:33Z avos $"); 34 35#include "opt_param.h" 36#include "opt_mbuf_stress_test.h" 37#include "opt_mbuf_profiling.h" 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/kernel.h> 42#include <sys/limits.h> 43#include <sys/lock.h> 44#include <sys/malloc.h> 45#include <sys/mbuf.h> 46#include <sys/sysctl.h> 47#include <sys/domain.h> 48#include <sys/protosw.h> 49#include <sys/uio.h> 50 51int max_linkhdr; 52int max_protohdr; 53int max_hdr; 54int max_datalen; 55#ifdef MBUF_STRESS_TEST 56int m_defragpackets; 57int m_defragbytes; 58int m_defraguseless; 59int m_defragfailure; 60int m_defragrandomfailures; 61#endif 62 63/* 64 * sysctl(8) exported objects 65 */ 66SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RD, 67 &max_linkhdr, 0, "Size of largest link layer header"); 68SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RD, 69 &max_protohdr, 0, "Size of largest protocol layer header"); 70SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RD, 71 &max_hdr, 0, "Size of largest link plus protocol header"); 72SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RD, 73 &max_datalen, 0, "Minimum space left in mbuf after max_hdr"); 74#ifdef MBUF_STRESS_TEST 75SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD, 76 &m_defragpackets, 0, ""); 77SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD, 78 &m_defragbytes, 0, ""); 79SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD, 80 &m_defraguseless, 0, ""); 81SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD, 82 &m_defragfailure, 0, ""); 83SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW, 84 &m_defragrandomfailures, 0, ""); 85#endif 86 87/* 88 * Ensure the correct size of various mbuf parameters. It could be off due 89 * to compiler-induced padding and alignment artifacts. 90 */ 91CTASSERT(sizeof(struct mbuf) == MSIZE); 92CTASSERT(MSIZE - offsetof(struct mbuf, m_dat) == MLEN); 93CTASSERT(MSIZE - offsetof(struct mbuf, m_pktdat) == MHLEN); 94 95/* 96 * m_get2() allocates minimum mbuf that would fit "size" argument. 97 */ 98struct mbuf * 99m_get2(int size, int how, short type, int flags) 100{ 101 struct mb_args args; 102 struct mbuf *m, *n; 103 104 args.flags = flags; 105 args.type = type; 106 107 if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0)) 108 return (uma_zalloc_arg(zone_mbuf, &args, how)); 109 if (size <= MCLBYTES) 110 return (uma_zalloc_arg(zone_pack, &args, how)); 111 112 if (size > MJUMPAGESIZE) 113 return (NULL); 114 115 m = uma_zalloc_arg(zone_mbuf, &args, how); 116 if (m == NULL) 117 return (NULL); 118 119 n = uma_zalloc_arg(zone_jumbop, m, how); 120 if (n == NULL) { 121 uma_zfree(zone_mbuf, m); 122 return (NULL); 123 } 124 125 return (m); 126} 127 128/* 129 * m_getjcl() returns an mbuf with a cluster of the specified size attached. 130 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 131 */ 132struct mbuf * 133m_getjcl(int how, short type, int flags, int size) 134{ 135 struct mb_args args; 136 struct mbuf *m, *n; 137 uma_zone_t zone; 138 139 if (size == MCLBYTES) 140 return m_getcl(how, type, flags); 141 142 args.flags = flags; 143 args.type = type; 144 145 m = uma_zalloc_arg(zone_mbuf, &args, how); 146 if (m == NULL) 147 return (NULL); 148 149 zone = m_getzone(size); 150 n = uma_zalloc_arg(zone, m, how); 151 if (n == NULL) { 152 uma_zfree(zone_mbuf, m); 153 return (NULL); 154 } 155 return (m); 156} 157 158/* 159 * Allocate a given length worth of mbufs and/or clusters (whatever fits 160 * best) and return a pointer to the top of the allocated chain. If an 161 * existing mbuf chain is provided, then we will append the new chain 162 * to the existing one but still return the top of the newly allocated 163 * chain. 164 */ 165struct mbuf * 166m_getm2(struct mbuf *m, int len, int how, short type, int flags) 167{ 168 struct mbuf *mb, *nm = NULL, *mtail = NULL; 169 170 KASSERT(len >= 0, ("%s: len is < 0", __func__)); 171 172 /* Validate flags. */ 173 flags &= (M_PKTHDR | M_EOR); 174 175 /* Packet header mbuf must be first in chain. */ 176 if ((flags & M_PKTHDR) && m != NULL) 177 flags &= ~M_PKTHDR; 178 179 /* Loop and append maximum sized mbufs to the chain tail. */ 180 while (len > 0) { 181 if (len > MCLBYTES) 182 mb = m_getjcl(how, type, (flags & M_PKTHDR), 183 MJUMPAGESIZE); 184 else if (len >= MINCLSIZE) 185 mb = m_getcl(how, type, (flags & M_PKTHDR)); 186 else if (flags & M_PKTHDR) 187 mb = m_gethdr(how, type); 188 else 189 mb = m_get(how, type); 190 191 /* Fail the whole operation if one mbuf can't be allocated. */ 192 if (mb == NULL) { 193 if (nm != NULL) 194 m_freem(nm); 195 return (NULL); 196 } 197 198 /* Book keeping. */ 199 len -= (mb->m_flags & M_EXT) ? mb->m_ext.ext_size : 200 ((mb->m_flags & M_PKTHDR) ? MHLEN : MLEN); 201 if (mtail != NULL) 202 mtail->m_next = mb; 203 else 204 nm = mb; 205 mtail = mb; 206 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */ 207 } 208 if (flags & M_EOR) 209 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */ 210 211 /* If mbuf was supplied, append new chain to the end of it. */ 212 if (m != NULL) { 213 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next) 214 ; 215 mtail->m_next = nm; 216 mtail->m_flags &= ~M_EOR; 217 } else 218 m = nm; 219 220 return (m); 221} 222 223/* 224 * Free an entire chain of mbufs and associated external buffers, if 225 * applicable. 226 */ 227void 228m_freem(struct mbuf *mb) 229{ 230 231 while (mb != NULL) 232 mb = m_free(mb); 233} 234 235/*- 236 * Configure a provided mbuf to refer to the provided external storage 237 * buffer and setup a reference count for said buffer. If the setting 238 * up of the reference count fails, the M_EXT bit will not be set. If 239 * successfull, the M_EXT bit is set in the mbuf's flags. 240 * 241 * Arguments: 242 * mb The existing mbuf to which to attach the provided buffer. 243 * buf The address of the provided external storage buffer. 244 * size The size of the provided buffer. 245 * freef A pointer to a routine that is responsible for freeing the 246 * provided external storage buffer. 247 * args A pointer to an argument structure (of any type) to be passed 248 * to the provided freef routine (may be NULL). 249 * flags Any other flags to be passed to the provided mbuf. 250 * type The type that the external storage buffer should be 251 * labeled with. 252 * 253 * Returns: 254 * Nothing. 255 */ 256int 257m_extadd(struct mbuf *mb, caddr_t buf, u_int size, 258 int (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2, 259 int flags, int type, int wait) 260{ 261 KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__)); 262 263 if (type != EXT_EXTREF) 264 mb->m_ext.ref_cnt = uma_zalloc(zone_ext_refcnt, wait); 265 266 if (mb->m_ext.ref_cnt == NULL) 267 return (ENOMEM); 268 269 *(mb->m_ext.ref_cnt) = 1; 270 mb->m_flags |= (M_EXT | flags); 271 mb->m_ext.ext_buf = buf; 272 mb->m_data = mb->m_ext.ext_buf; 273 mb->m_ext.ext_size = size; 274 mb->m_ext.ext_free = freef; 275 mb->m_ext.ext_arg1 = arg1; 276 mb->m_ext.ext_arg2 = arg2; 277 mb->m_ext.ext_type = type; 278 mb->m_ext.ext_flags = 0; 279 280 return (0); 281} 282 283/* 284 * Non-directly-exported function to clean up after mbufs with M_EXT 285 * storage attached to them if the reference count hits 1. 286 */ 287void 288mb_free_ext(struct mbuf *m) 289{ 290 int skipmbuf; 291 292 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 293 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 294 295 /* 296 * check if the header is embedded in the cluster 297 */ 298 skipmbuf = (m->m_flags & M_NOFREE); 299 300 /* Free attached storage if this mbuf is the only reference to it. */ 301 if (*(m->m_ext.ref_cnt) == 1 || 302 atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 1) { 303 switch (m->m_ext.ext_type) { 304 case EXT_PACKET: /* The packet zone is special. */ 305 if (*(m->m_ext.ref_cnt) == 0) 306 *(m->m_ext.ref_cnt) = 1; 307 uma_zfree(zone_pack, m); 308 return; /* Job done. */ 309 case EXT_CLUSTER: 310 uma_zfree(zone_clust, m->m_ext.ext_buf); 311 break; 312 case EXT_JUMBOP: 313 uma_zfree(zone_jumbop, m->m_ext.ext_buf); 314 break; 315 case EXT_JUMBO9: 316 uma_zfree(zone_jumbo9, m->m_ext.ext_buf); 317 break; 318 case EXT_JUMBO16: 319 uma_zfree(zone_jumbo16, m->m_ext.ext_buf); 320 break; 321 case EXT_SFBUF: 322 case EXT_NET_DRV: 323 case EXT_MOD_TYPE: 324 case EXT_DISPOSABLE: 325 *(m->m_ext.ref_cnt) = 0; 326 uma_zfree(zone_ext_refcnt, __DEVOLATILE(u_int *, 327 m->m_ext.ref_cnt)); 328 /* FALLTHROUGH */ 329 case EXT_EXTREF: 330 KASSERT(m->m_ext.ext_free != NULL, 331 ("%s: ext_free not set", __func__)); 332 (void)(*(m->m_ext.ext_free))(m, m->m_ext.ext_arg1, 333 m->m_ext.ext_arg2); 334 break; 335 default: 336 KASSERT(m->m_ext.ext_type == 0, 337 ("%s: unknown ext_type", __func__)); 338 } 339 } 340 if (skipmbuf) 341 return; 342 343 /* 344 * Free this mbuf back to the mbuf zone with all m_ext 345 * information purged. 346 */ 347 m->m_ext.ext_buf = NULL; 348 m->m_ext.ext_free = NULL; 349 m->m_ext.ext_arg1 = NULL; 350 m->m_ext.ext_arg2 = NULL; 351 m->m_ext.ref_cnt = NULL; 352 m->m_ext.ext_size = 0; 353 m->m_ext.ext_type = 0; 354 m->m_ext.ext_flags = 0; 355 m->m_flags &= ~M_EXT; 356 uma_zfree(zone_mbuf, m); 357} 358 359/* 360 * Attach the cluster from *m to *n, set up m_ext in *n 361 * and bump the refcount of the cluster. 362 */ 363static void 364mb_dupcl(struct mbuf *n, struct mbuf *m) 365{ 366 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 367 KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__)); 368 KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__)); 369 370 if (*(m->m_ext.ref_cnt) == 1) 371 *(m->m_ext.ref_cnt) += 1; 372 else 373 atomic_add_int(m->m_ext.ref_cnt, 1); 374 n->m_ext.ext_buf = m->m_ext.ext_buf; 375 n->m_ext.ext_free = m->m_ext.ext_free; 376 n->m_ext.ext_arg1 = m->m_ext.ext_arg1; 377 n->m_ext.ext_arg2 = m->m_ext.ext_arg2; 378 n->m_ext.ext_size = m->m_ext.ext_size; 379 n->m_ext.ref_cnt = m->m_ext.ref_cnt; 380 n->m_ext.ext_type = m->m_ext.ext_type; 381 n->m_ext.ext_flags = m->m_ext.ext_flags; 382 n->m_flags |= M_EXT; 383 n->m_flags |= m->m_flags & M_RDONLY; 384} 385 386/* 387 * Clean up mbuf (chain) from any tags and packet headers. 388 * If "all" is set then the first mbuf in the chain will be 389 * cleaned too. 390 */ 391void 392m_demote(struct mbuf *m0, int all) 393{ 394 struct mbuf *m; 395 396 for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) { 397 if (m->m_flags & M_PKTHDR) { 398 m_tag_delete_chain(m, NULL); 399 m->m_flags &= ~M_PKTHDR; 400 bzero(&m->m_pkthdr, sizeof(struct pkthdr)); 401 } 402 if (m != m0 && m->m_nextpkt != NULL) { 403 KASSERT(m->m_nextpkt == NULL, 404 ("%s: m_nextpkt not NULL", __func__)); 405 m_freem(m->m_nextpkt); 406 m->m_nextpkt = NULL; 407 } 408 m->m_flags = m->m_flags & (M_EXT|M_RDONLY|M_NOFREE); 409 } 410} 411 412/* 413 * Sanity checks on mbuf (chain) for use in KASSERT() and general 414 * debugging. 415 * Returns 0 or panics when bad and 1 on all tests passed. 416 * Sanitize, 0 to run M_SANITY_ACTION, 1 to garble things so they 417 * blow up later. 418 */ 419int 420m_sanity(struct mbuf *m0, int sanitize) 421{ 422 struct mbuf *m; 423 caddr_t a, b; 424 int pktlen = 0; 425 426#ifdef INVARIANTS 427#define M_SANITY_ACTION(s) panic("mbuf %p: " s, m) 428#else 429#define M_SANITY_ACTION(s) printf("mbuf %p: " s, m) 430#endif 431 432 for (m = m0; m != NULL; m = m->m_next) { 433 /* 434 * Basic pointer checks. If any of these fails then some 435 * unrelated kernel memory before or after us is trashed. 436 * No way to recover from that. 437 */ 438 a = ((m->m_flags & M_EXT) ? m->m_ext.ext_buf : 439 ((m->m_flags & M_PKTHDR) ? (caddr_t)(&m->m_pktdat) : 440 (caddr_t)(&m->m_dat)) ); 441 b = (caddr_t)(a + (m->m_flags & M_EXT ? m->m_ext.ext_size : 442 ((m->m_flags & M_PKTHDR) ? MHLEN : MLEN))); 443 if ((caddr_t)m->m_data < a) 444 M_SANITY_ACTION("m_data outside mbuf data range left"); 445 if ((caddr_t)m->m_data > b) 446 M_SANITY_ACTION("m_data outside mbuf data range right"); 447 if ((caddr_t)m->m_data + m->m_len > b) 448 M_SANITY_ACTION("m_data + m_len exeeds mbuf space"); 449 450 /* m->m_nextpkt may only be set on first mbuf in chain. */ 451 if (m != m0 && m->m_nextpkt != NULL) { 452 if (sanitize) { 453 m_freem(m->m_nextpkt); 454 m->m_nextpkt = (struct mbuf *)0xDEADC0DE; 455 } else 456 M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf"); 457 } 458 459 /* packet length (not mbuf length!) calculation */ 460 if (m0->m_flags & M_PKTHDR) 461 pktlen += m->m_len; 462 463 /* m_tags may only be attached to first mbuf in chain. */ 464 if (m != m0 && m->m_flags & M_PKTHDR && 465 !SLIST_EMPTY(&m->m_pkthdr.tags)) { 466 if (sanitize) { 467 m_tag_delete_chain(m, NULL); 468 /* put in 0xDEADC0DE perhaps? */ 469 } else 470 M_SANITY_ACTION("m_tags on in-chain mbuf"); 471 } 472 473 /* M_PKTHDR may only be set on first mbuf in chain */ 474 if (m != m0 && m->m_flags & M_PKTHDR) { 475 if (sanitize) { 476 bzero(&m->m_pkthdr, sizeof(m->m_pkthdr)); 477 m->m_flags &= ~M_PKTHDR; 478 /* put in 0xDEADCODE and leave hdr flag in */ 479 } else 480 M_SANITY_ACTION("M_PKTHDR on in-chain mbuf"); 481 } 482 } 483 m = m0; 484 if (pktlen && pktlen != m->m_pkthdr.len) { 485 if (sanitize) 486 m->m_pkthdr.len = 0; 487 else 488 M_SANITY_ACTION("m_pkthdr.len != mbuf chain length"); 489 } 490 return 1; 491 492#undef M_SANITY_ACTION 493} 494 495 496/* 497 * "Move" mbuf pkthdr from "from" to "to". 498 * "from" must have M_PKTHDR set, and "to" must be empty. 499 */ 500void 501m_move_pkthdr(struct mbuf *to, struct mbuf *from) 502{ 503 504#if 0 505 /* see below for why these are not enabled */ 506 M_ASSERTPKTHDR(to); 507 /* Note: with MAC, this may not be a good assertion. */ 508 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), 509 ("m_move_pkthdr: to has tags")); 510#endif 511#ifdef MAC 512 /* 513 * XXXMAC: It could be this should also occur for non-MAC? 514 */ 515 if (to->m_flags & M_PKTHDR) 516 m_tag_delete_chain(to, NULL); 517#endif 518 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 519 if ((to->m_flags & M_EXT) == 0) 520 to->m_data = to->m_pktdat; 521 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 522 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 523 from->m_flags &= ~M_PKTHDR; 524} 525 526/* 527 * Duplicate "from"'s mbuf pkthdr in "to". 528 * "from" must have M_PKTHDR set, and "to" must be empty. 529 * In particular, this does a deep copy of the packet tags. 530 */ 531int 532m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 533{ 534 535#if 0 536 /* 537 * The mbuf allocator only initializes the pkthdr 538 * when the mbuf is allocated with m_gethdr(). Many users 539 * (e.g. m_copy*, m_prepend) use m_get() and then 540 * smash the pkthdr as needed causing these 541 * assertions to trip. For now just disable them. 542 */ 543 M_ASSERTPKTHDR(to); 544 /* Note: with MAC, this may not be a good assertion. */ 545 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags")); 546#endif 547 MBUF_CHECKSLEEP(how); 548#ifdef MAC 549 if (to->m_flags & M_PKTHDR) 550 m_tag_delete_chain(to, NULL); 551#endif 552 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 553 if ((to->m_flags & M_EXT) == 0) 554 to->m_data = to->m_pktdat; 555 to->m_pkthdr = from->m_pkthdr; 556 SLIST_INIT(&to->m_pkthdr.tags); 557 return (m_tag_copy_chain(to, from, MBTOM(how))); 558} 559 560/* 561 * Lesser-used path for M_PREPEND: 562 * allocate new mbuf to prepend to chain, 563 * copy junk along. 564 */ 565struct mbuf * 566m_prepend(struct mbuf *m, int len, int how) 567{ 568 struct mbuf *mn; 569 570 if (m->m_flags & M_PKTHDR) 571 mn = m_gethdr(how, m->m_type); 572 else 573 mn = m_get(how, m->m_type); 574 if (mn == NULL) { 575 m_freem(m); 576 return (NULL); 577 } 578 if (m->m_flags & M_PKTHDR) 579 m_move_pkthdr(mn, m); 580 mn->m_next = m; 581 m = mn; 582 if(m->m_flags & M_PKTHDR) { 583 if (len < MHLEN) 584 MH_ALIGN(m, len); 585 } else { 586 if (len < MLEN) 587 M_ALIGN(m, len); 588 } 589 m->m_len = len; 590 return (m); 591} 592 593/* 594 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 595 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 596 * The wait parameter is a choice of M_WAITOK/M_NOWAIT from caller. 597 * Note that the copy is read-only, because clusters are not copied, 598 * only their reference counts are incremented. 599 */ 600struct mbuf * 601m_copym(struct mbuf *m, int off0, int len, int wait) 602{ 603 struct mbuf *n, **np; 604 int off = off0; 605 struct mbuf *top; 606 int copyhdr = 0; 607 608 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 609 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 610 MBUF_CHECKSLEEP(wait); 611 if (off == 0 && m->m_flags & M_PKTHDR) 612 copyhdr = 1; 613 while (off > 0) { 614 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 615 if (off < m->m_len) 616 break; 617 off -= m->m_len; 618 m = m->m_next; 619 } 620 np = ⊤ 621 top = 0; 622 while (len > 0) { 623 if (m == NULL) { 624 KASSERT(len == M_COPYALL, 625 ("m_copym, length > size of mbuf chain")); 626 break; 627 } 628 if (copyhdr) 629 n = m_gethdr(wait, m->m_type); 630 else 631 n = m_get(wait, m->m_type); 632 *np = n; 633 if (n == NULL) 634 goto nospace; 635 if (copyhdr) { 636 if (!m_dup_pkthdr(n, m, wait)) 637 goto nospace; 638 if (len == M_COPYALL) 639 n->m_pkthdr.len -= off0; 640 else 641 n->m_pkthdr.len = len; 642 copyhdr = 0; 643 } 644 n->m_len = min(len, m->m_len - off); 645 if (m->m_flags & M_EXT) { 646 n->m_data = m->m_data + off; 647 mb_dupcl(n, m); 648 } else 649 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 650 (u_int)n->m_len); 651 if (len != M_COPYALL) 652 len -= n->m_len; 653 off = 0; 654 m = m->m_next; 655 np = &n->m_next; 656 } 657 658 return (top); 659nospace: 660 m_freem(top); 661 return (NULL); 662} 663 664/* 665 * Returns mbuf chain with new head for the prepending case. 666 * Copies from mbuf (chain) n from off for len to mbuf (chain) m 667 * either prepending or appending the data. 668 * The resulting mbuf (chain) m is fully writeable. 669 * m is destination (is made writeable) 670 * n is source, off is offset in source, len is len from offset 671 * dir, 0 append, 1 prepend 672 * how, wait or nowait 673 */ 674 675static int 676m_bcopyxxx(void *s, void *t, u_int len) 677{ 678 bcopy(s, t, (size_t)len); 679 return 0; 680} 681 682struct mbuf * 683m_copymdata(struct mbuf *m, struct mbuf *n, int off, int len, 684 int prep, int how) 685{ 686 struct mbuf *mm, *x, *z, *prev = NULL; 687 caddr_t p; 688 int i, nlen = 0; 689 caddr_t buf[MLEN]; 690 691 KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source")); 692 KASSERT(off >= 0, ("m_copymdata, negative off %d", off)); 693 KASSERT(len >= 0, ("m_copymdata, negative len %d", len)); 694 KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep)); 695 696 mm = m; 697 if (!prep) { 698 while(mm->m_next) { 699 prev = mm; 700 mm = mm->m_next; 701 } 702 } 703 for (z = n; z != NULL; z = z->m_next) 704 nlen += z->m_len; 705 if (len == M_COPYALL) 706 len = nlen - off; 707 if (off + len > nlen || len < 1) 708 return NULL; 709 710 if (!M_WRITABLE(mm)) { 711 /* XXX: Use proper m_xxx function instead. */ 712 x = m_getcl(how, MT_DATA, mm->m_flags); 713 if (x == NULL) 714 return NULL; 715 bcopy(mm->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size); 716 p = x->m_ext.ext_buf + (mm->m_data - mm->m_ext.ext_buf); 717 x->m_data = p; 718 mm->m_next = NULL; 719 if (mm != m) 720 prev->m_next = x; 721 m_free(mm); 722 mm = x; 723 } 724 725 /* 726 * Append/prepend the data. Allocating mbufs as necessary. 727 */ 728 /* Shortcut if enough free space in first/last mbuf. */ 729 if (!prep && M_TRAILINGSPACE(mm) >= len) { 730 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) + 731 mm->m_len); 732 mm->m_len += len; 733 mm->m_pkthdr.len += len; 734 return m; 735 } 736 if (prep && M_LEADINGSPACE(mm) >= len) { 737 mm->m_data = mtod(mm, caddr_t) - len; 738 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t)); 739 mm->m_len += len; 740 mm->m_pkthdr.len += len; 741 return mm; 742 } 743 744 /* Expand first/last mbuf to cluster if possible. */ 745 if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) { 746 bcopy(mm->m_data, &buf, mm->m_len); 747 m_clget(mm, how); 748 if (!(mm->m_flags & M_EXT)) 749 return NULL; 750 bcopy(&buf, mm->m_ext.ext_buf, mm->m_len); 751 mm->m_data = mm->m_ext.ext_buf; 752 } 753 if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) { 754 bcopy(mm->m_data, &buf, mm->m_len); 755 m_clget(mm, how); 756 if (!(mm->m_flags & M_EXT)) 757 return NULL; 758 bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf + 759 mm->m_ext.ext_size - mm->m_len, mm->m_len); 760 mm->m_data = (caddr_t)mm->m_ext.ext_buf + 761 mm->m_ext.ext_size - mm->m_len; 762 } 763 764 /* Append/prepend as many mbuf (clusters) as necessary to fit len. */ 765 if (!prep && len > M_TRAILINGSPACE(mm)) { 766 if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA)) 767 return NULL; 768 } 769 if (prep && len > M_LEADINGSPACE(mm)) { 770 if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA))) 771 return NULL; 772 i = 0; 773 for (x = z; x != NULL; x = x->m_next) { 774 i += x->m_flags & M_EXT ? x->m_ext.ext_size : 775 (x->m_flags & M_PKTHDR ? MHLEN : MLEN); 776 if (!x->m_next) 777 break; 778 } 779 z->m_data += i - len; 780 m_move_pkthdr(mm, z); 781 x->m_next = mm; 782 mm = z; 783 } 784 785 /* Seek to start position in source mbuf. Optimization for long chains. */ 786 while (off > 0) { 787 if (off < n->m_len) 788 break; 789 off -= n->m_len; 790 n = n->m_next; 791 } 792 793 /* Copy data into target mbuf. */ 794 z = mm; 795 while (len > 0) { 796 KASSERT(z != NULL, ("m_copymdata, falling off target edge")); 797 i = M_TRAILINGSPACE(z); 798 m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len); 799 z->m_len += i; 800 /* fixup pkthdr.len if necessary */ 801 if ((prep ? mm : m)->m_flags & M_PKTHDR) 802 (prep ? mm : m)->m_pkthdr.len += i; 803 off += i; 804 len -= i; 805 z = z->m_next; 806 } 807 return (prep ? mm : m); 808} 809 810/* 811 * Copy an entire packet, including header (which must be present). 812 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 813 * Note that the copy is read-only, because clusters are not copied, 814 * only their reference counts are incremented. 815 * Preserve alignment of the first mbuf so if the creator has left 816 * some room at the beginning (e.g. for inserting protocol headers) 817 * the copies still have the room available. 818 */ 819struct mbuf * 820m_copypacket(struct mbuf *m, int how) 821{ 822 struct mbuf *top, *n, *o; 823 824 MBUF_CHECKSLEEP(how); 825 n = m_get(how, m->m_type); 826 top = n; 827 if (n == NULL) 828 goto nospace; 829 830 if (!m_dup_pkthdr(n, m, how)) 831 goto nospace; 832 n->m_len = m->m_len; 833 if (m->m_flags & M_EXT) { 834 n->m_data = m->m_data; 835 mb_dupcl(n, m); 836 } else { 837 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 838 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 839 } 840 841 m = m->m_next; 842 while (m) { 843 o = m_get(how, m->m_type); 844 if (o == NULL) 845 goto nospace; 846 847 n->m_next = o; 848 n = n->m_next; 849 850 n->m_len = m->m_len; 851 if (m->m_flags & M_EXT) { 852 n->m_data = m->m_data; 853 mb_dupcl(n, m); 854 } else { 855 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 856 } 857 858 m = m->m_next; 859 } 860 return top; 861nospace: 862 m_freem(top); 863 return (NULL); 864} 865 866/* 867 * Copy data from an mbuf chain starting "off" bytes from the beginning, 868 * continuing for "len" bytes, into the indicated buffer. 869 */ 870void 871m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 872{ 873 u_int count; 874 875 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 876 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 877 while (off > 0) { 878 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 879 if (off < m->m_len) 880 break; 881 off -= m->m_len; 882 m = m->m_next; 883 } 884 while (len > 0) { 885 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 886 count = min(m->m_len - off, len); 887 bcopy(mtod(m, caddr_t) + off, cp, count); 888 len -= count; 889 cp += count; 890 off = 0; 891 m = m->m_next; 892 } 893} 894 895/* 896 * Copy a packet header mbuf chain into a completely new chain, including 897 * copying any mbuf clusters. Use this instead of m_copypacket() when 898 * you need a writable copy of an mbuf chain. 899 */ 900struct mbuf * 901m_dup(struct mbuf *m, int how) 902{ 903 struct mbuf **p, *top = NULL; 904 int remain, moff, nsize; 905 906 MBUF_CHECKSLEEP(how); 907 /* Sanity check */ 908 if (m == NULL) 909 return (NULL); 910 M_ASSERTPKTHDR(m); 911 912 /* While there's more data, get a new mbuf, tack it on, and fill it */ 913 remain = m->m_pkthdr.len; 914 moff = 0; 915 p = ⊤ 916 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 917 struct mbuf *n; 918 919 /* Get the next new mbuf */ 920 if (remain >= MINCLSIZE) { 921 n = m_getcl(how, m->m_type, 0); 922 nsize = MCLBYTES; 923 } else { 924 n = m_get(how, m->m_type); 925 nsize = MLEN; 926 } 927 if (n == NULL) 928 goto nospace; 929 930 if (top == NULL) { /* First one, must be PKTHDR */ 931 if (!m_dup_pkthdr(n, m, how)) { 932 m_free(n); 933 goto nospace; 934 } 935 if ((n->m_flags & M_EXT) == 0) 936 nsize = MHLEN; 937 n->m_flags &= ~M_RDONLY; 938 } 939 n->m_len = 0; 940 941 /* Link it into the new chain */ 942 *p = n; 943 p = &n->m_next; 944 945 /* Copy data from original mbuf(s) into new mbuf */ 946 while (n->m_len < nsize && m != NULL) { 947 int chunk = min(nsize - n->m_len, m->m_len - moff); 948 949 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 950 moff += chunk; 951 n->m_len += chunk; 952 remain -= chunk; 953 if (moff == m->m_len) { 954 m = m->m_next; 955 moff = 0; 956 } 957 } 958 959 /* Check correct total mbuf length */ 960 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 961 ("%s: bogus m_pkthdr.len", __func__)); 962 } 963 return (top); 964 965nospace: 966 m_freem(top); 967 return (NULL); 968} 969 970/* 971 * Concatenate mbuf chain n to m. 972 * Both chains must be of the same type (e.g. MT_DATA). 973 * Any m_pkthdr is not updated. 974 */ 975void 976m_cat(struct mbuf *m, struct mbuf *n) 977{ 978 while (m->m_next) 979 m = m->m_next; 980 while (n) { 981 if (!M_WRITABLE(m) || 982 M_TRAILINGSPACE(m) < n->m_len) { 983 /* just join the two chains */ 984 m->m_next = n; 985 return; 986 } 987 /* splat the data from one into the other */ 988 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 989 (u_int)n->m_len); 990 m->m_len += n->m_len; 991 n = m_free(n); 992 } 993} 994 995void 996m_adj(struct mbuf *mp, int req_len) 997{ 998 int len = req_len; 999 struct mbuf *m; 1000 int count; 1001 1002 if ((m = mp) == NULL) 1003 return; 1004 if (len >= 0) { 1005 /* 1006 * Trim from head. 1007 */ 1008 while (m != NULL && len > 0) { 1009 if (m->m_len <= len) { 1010 len -= m->m_len; 1011 m->m_len = 0; 1012 m = m->m_next; 1013 } else { 1014 m->m_len -= len; 1015 m->m_data += len; 1016 len = 0; 1017 } 1018 } 1019 if (mp->m_flags & M_PKTHDR) 1020 mp->m_pkthdr.len -= (req_len - len); 1021 } else { 1022 /* 1023 * Trim from tail. Scan the mbuf chain, 1024 * calculating its length and finding the last mbuf. 1025 * If the adjustment only affects this mbuf, then just 1026 * adjust and return. Otherwise, rescan and truncate 1027 * after the remaining size. 1028 */ 1029 len = -len; 1030 count = 0; 1031 for (;;) { 1032 count += m->m_len; 1033 if (m->m_next == (struct mbuf *)0) 1034 break; 1035 m = m->m_next; 1036 } 1037 if (m->m_len >= len) { 1038 m->m_len -= len; 1039 if (mp->m_flags & M_PKTHDR) 1040 mp->m_pkthdr.len -= len; 1041 return; 1042 } 1043 count -= len; 1044 if (count < 0) 1045 count = 0; 1046 /* 1047 * Correct length for chain is "count". 1048 * Find the mbuf with last data, adjust its length, 1049 * and toss data from remaining mbufs on chain. 1050 */ 1051 m = mp; 1052 if (m->m_flags & M_PKTHDR) 1053 m->m_pkthdr.len = count; 1054 for (; m; m = m->m_next) { 1055 if (m->m_len >= count) { 1056 m->m_len = count; 1057 if (m->m_next != NULL) { 1058 m_freem(m->m_next); 1059 m->m_next = NULL; 1060 } 1061 break; 1062 } 1063 count -= m->m_len; 1064 } 1065 } 1066} 1067 1068/* 1069 * Rearange an mbuf chain so that len bytes are contiguous 1070 * and in the data area of an mbuf (so that mtod will work 1071 * for a structure of size len). Returns the resulting 1072 * mbuf chain on success, frees it and returns null on failure. 1073 * If there is room, it will add up to max_protohdr-len extra bytes to the 1074 * contiguous region in an attempt to avoid being called next time. 1075 */ 1076struct mbuf * 1077m_pullup(struct mbuf *n, int len) 1078{ 1079 struct mbuf *m; 1080 int count; 1081 int space; 1082 1083 /* 1084 * If first mbuf has no cluster, and has room for len bytes 1085 * without shifting current data, pullup into it, 1086 * otherwise allocate a new mbuf to prepend to the chain. 1087 */ 1088 if ((n->m_flags & M_EXT) == 0 && 1089 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1090 if (n->m_len >= len) 1091 return (n); 1092 m = n; 1093 n = n->m_next; 1094 len -= m->m_len; 1095 } else { 1096 if (len > MHLEN) 1097 goto bad; 1098 m = m_get(M_NOWAIT, n->m_type); 1099 if (m == NULL) 1100 goto bad; 1101 if (n->m_flags & M_PKTHDR) 1102 m_move_pkthdr(m, n); 1103 } 1104 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1105 do { 1106 count = min(min(max(len, max_protohdr), space), n->m_len); 1107 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1108 (u_int)count); 1109 len -= count; 1110 m->m_len += count; 1111 n->m_len -= count; 1112 space -= count; 1113 if (n->m_len) 1114 n->m_data += count; 1115 else 1116 n = m_free(n); 1117 } while (len > 0 && n); 1118 if (len > 0) { 1119 (void) m_free(m); 1120 goto bad; 1121 } 1122 m->m_next = n; 1123 return (m); 1124bad: 1125 m_freem(n); 1126 return (NULL); 1127} 1128 1129/* 1130 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1131 * the amount of empty space before the data in the new mbuf to be specified 1132 * (in the event that the caller expects to prepend later). 1133 */ 1134int MSFail; 1135 1136struct mbuf * 1137m_copyup(struct mbuf *n, int len, int dstoff) 1138{ 1139 struct mbuf *m; 1140 int count, space; 1141 1142 if (len > (MHLEN - dstoff)) 1143 goto bad; 1144 m = m_get(M_NOWAIT, n->m_type); 1145 if (m == NULL) 1146 goto bad; 1147 if (n->m_flags & M_PKTHDR) 1148 m_move_pkthdr(m, n); 1149 m->m_data += dstoff; 1150 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1151 do { 1152 count = min(min(max(len, max_protohdr), space), n->m_len); 1153 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), 1154 (unsigned)count); 1155 len -= count; 1156 m->m_len += count; 1157 n->m_len -= count; 1158 space -= count; 1159 if (n->m_len) 1160 n->m_data += count; 1161 else 1162 n = m_free(n); 1163 } while (len > 0 && n); 1164 if (len > 0) { 1165 (void) m_free(m); 1166 goto bad; 1167 } 1168 m->m_next = n; 1169 return (m); 1170 bad: 1171 m_freem(n); 1172 MSFail++; 1173 return (NULL); 1174} 1175 1176/* 1177 * Partition an mbuf chain in two pieces, returning the tail -- 1178 * all but the first len0 bytes. In case of failure, it returns NULL and 1179 * attempts to restore the chain to its original state. 1180 * 1181 * Note that the resulting mbufs might be read-only, because the new 1182 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1183 * the "breaking point" happens to lie within a cluster mbuf. Use the 1184 * M_WRITABLE() macro to check for this case. 1185 */ 1186struct mbuf * 1187m_split(struct mbuf *m0, int len0, int wait) 1188{ 1189 struct mbuf *m, *n; 1190 u_int len = len0, remain; 1191 1192 MBUF_CHECKSLEEP(wait); 1193 for (m = m0; m && len > m->m_len; m = m->m_next) 1194 len -= m->m_len; 1195 if (m == NULL) 1196 return (NULL); 1197 remain = m->m_len - len; 1198 if (m0->m_flags & M_PKTHDR && remain == 0) { 1199 n = m_gethdr(wait, m0->m_type); 1200 if (n == NULL) 1201 return (NULL); 1202 n->m_next = m->m_next; 1203 m->m_next = NULL; 1204 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1205 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1206 m0->m_pkthdr.len = len0; 1207 return (n); 1208 } else if (m0->m_flags & M_PKTHDR) { 1209 n = m_gethdr(wait, m0->m_type); 1210 if (n == NULL) 1211 return (NULL); 1212 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1213 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1214 m0->m_pkthdr.len = len0; 1215 if (m->m_flags & M_EXT) 1216 goto extpacket; 1217 if (remain > MHLEN) { 1218 /* m can't be the lead packet */ 1219 MH_ALIGN(n, 0); 1220 n->m_next = m_split(m, len, wait); 1221 if (n->m_next == NULL) { 1222 (void) m_free(n); 1223 return (NULL); 1224 } else { 1225 n->m_len = 0; 1226 return (n); 1227 } 1228 } else 1229 MH_ALIGN(n, remain); 1230 } else if (remain == 0) { 1231 n = m->m_next; 1232 m->m_next = NULL; 1233 return (n); 1234 } else { 1235 n = m_get(wait, m->m_type); 1236 if (n == NULL) 1237 return (NULL); 1238 M_ALIGN(n, remain); 1239 } 1240extpacket: 1241 if (m->m_flags & M_EXT) { 1242 n->m_data = m->m_data + len; 1243 mb_dupcl(n, m); 1244 } else { 1245 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1246 } 1247 n->m_len = remain; 1248 m->m_len = len; 1249 n->m_next = m->m_next; 1250 m->m_next = NULL; 1251 return (n); 1252} 1253/* 1254 * Routine to copy from device local memory into mbufs. 1255 * Note that `off' argument is offset into first mbuf of target chain from 1256 * which to begin copying the data to. 1257 */ 1258struct mbuf * 1259m_devget(char *buf, int totlen, int off, struct ifnet *ifp, 1260 void (*copy)(char *from, caddr_t to, u_int len)) 1261{ 1262 struct mbuf *m; 1263 struct mbuf *top = NULL, **mp = ⊤ 1264 int len; 1265 1266 if (off < 0 || off > MHLEN) 1267 return (NULL); 1268 1269 while (totlen > 0) { 1270 if (top == NULL) { /* First one, must be PKTHDR */ 1271 if (totlen + off >= MINCLSIZE) { 1272 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 1273 len = MCLBYTES; 1274 } else { 1275 m = m_gethdr(M_NOWAIT, MT_DATA); 1276 len = MHLEN; 1277 1278 /* Place initial small packet/header at end of mbuf */ 1279 if (m && totlen + off + max_linkhdr <= MLEN) { 1280 m->m_data += max_linkhdr; 1281 len -= max_linkhdr; 1282 } 1283 } 1284 if (m == NULL) 1285 return NULL; 1286 m->m_pkthdr.rcvif = ifp; 1287 m->m_pkthdr.len = totlen; 1288 } else { 1289 if (totlen + off >= MINCLSIZE) { 1290 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1291 len = MCLBYTES; 1292 } else { 1293 m = m_get(M_NOWAIT, MT_DATA); 1294 len = MLEN; 1295 } 1296 if (m == NULL) { 1297 m_freem(top); 1298 return NULL; 1299 } 1300 } 1301 if (off) { 1302 m->m_data += off; 1303 len -= off; 1304 off = 0; 1305 } 1306 m->m_len = len = min(totlen, len); 1307 if (copy) 1308 copy(buf, mtod(m, caddr_t), (u_int)len); 1309 else 1310 bcopy(buf, mtod(m, caddr_t), (u_int)len); 1311 buf += len; 1312 *mp = m; 1313 mp = &m->m_next; 1314 totlen -= len; 1315 } 1316 return (top); 1317} 1318 1319/* 1320 * Copy data from a buffer back into the indicated mbuf chain, 1321 * starting "off" bytes from the beginning, extending the mbuf 1322 * chain if necessary. 1323 */ 1324void 1325m_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp) 1326{ 1327 int mlen; 1328 struct mbuf *m = m0, *n; 1329 int totlen = 0; 1330 1331 if (m0 == NULL) 1332 return; 1333 while (off > (mlen = m->m_len)) { 1334 off -= mlen; 1335 totlen += mlen; 1336 if (m->m_next == NULL) { 1337 n = m_get(M_NOWAIT, m->m_type); 1338 if (n == NULL) 1339 goto out; 1340 bzero(mtod(n, caddr_t), MLEN); 1341 n->m_len = min(MLEN, len + off); 1342 m->m_next = n; 1343 } 1344 m = m->m_next; 1345 } 1346 while (len > 0) { 1347 if (m->m_next == NULL && (len > m->m_len - off)) { 1348 m->m_len += min(len - (m->m_len - off), 1349 M_TRAILINGSPACE(m)); 1350 } 1351 mlen = min (m->m_len - off, len); 1352 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 1353 cp += mlen; 1354 len -= mlen; 1355 mlen += off; 1356 off = 0; 1357 totlen += mlen; 1358 if (len == 0) 1359 break; 1360 if (m->m_next == NULL) { 1361 n = m_get(M_NOWAIT, m->m_type); 1362 if (n == NULL) 1363 break; 1364 n->m_len = min(MLEN, len); 1365 m->m_next = n; 1366 } 1367 m = m->m_next; 1368 } 1369out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1370 m->m_pkthdr.len = totlen; 1371} 1372 1373/* 1374 * Append the specified data to the indicated mbuf chain, 1375 * Extend the mbuf chain if the new data does not fit in 1376 * existing space. 1377 * 1378 * Return 1 if able to complete the job; otherwise 0. 1379 */ 1380int 1381m_append(struct mbuf *m0, int len, c_caddr_t cp) 1382{ 1383 struct mbuf *m, *n; 1384 int remainder, space; 1385 1386 for (m = m0; m->m_next != NULL; m = m->m_next) 1387 ; 1388 remainder = len; 1389 space = M_TRAILINGSPACE(m); 1390 if (space > 0) { 1391 /* 1392 * Copy into available space. 1393 */ 1394 if (space > remainder) 1395 space = remainder; 1396 bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1397 m->m_len += space; 1398 cp += space, remainder -= space; 1399 } 1400 while (remainder > 0) { 1401 /* 1402 * Allocate a new mbuf; could check space 1403 * and allocate a cluster instead. 1404 */ 1405 n = m_get(M_NOWAIT, m->m_type); 1406 if (n == NULL) 1407 break; 1408 n->m_len = min(MLEN, remainder); 1409 bcopy(cp, mtod(n, caddr_t), n->m_len); 1410 cp += n->m_len, remainder -= n->m_len; 1411 m->m_next = n; 1412 m = n; 1413 } 1414 if (m0->m_flags & M_PKTHDR) 1415 m0->m_pkthdr.len += len - remainder; 1416 return (remainder == 0); 1417} 1418 1419/* 1420 * Apply function f to the data in an mbuf chain starting "off" bytes from 1421 * the beginning, continuing for "len" bytes. 1422 */ 1423int 1424m_apply(struct mbuf *m, int off, int len, 1425 int (*f)(void *, void *, u_int), void *arg) 1426{ 1427 u_int count; 1428 int rval; 1429 1430 KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1431 KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1432 while (off > 0) { 1433 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1434 if (off < m->m_len) 1435 break; 1436 off -= m->m_len; 1437 m = m->m_next; 1438 } 1439 while (len > 0) { 1440 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1441 count = min(m->m_len - off, len); 1442 rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1443 if (rval) 1444 return (rval); 1445 len -= count; 1446 off = 0; 1447 m = m->m_next; 1448 } 1449 return (0); 1450} 1451 1452/* 1453 * Return a pointer to mbuf/offset of location in mbuf chain. 1454 */ 1455struct mbuf * 1456m_getptr(struct mbuf *m, int loc, int *off) 1457{ 1458 1459 while (loc >= 0) { 1460 /* Normal end of search. */ 1461 if (m->m_len > loc) { 1462 *off = loc; 1463 return (m); 1464 } else { 1465 loc -= m->m_len; 1466 if (m->m_next == NULL) { 1467 if (loc == 0) { 1468 /* Point at the end of valid data. */ 1469 *off = m->m_len; 1470 return (m); 1471 } 1472 return (NULL); 1473 } 1474 m = m->m_next; 1475 } 1476 } 1477 return (NULL); 1478} 1479 1480void 1481m_print(const struct mbuf *m, int maxlen) 1482{ 1483 int len; 1484 int pdata; 1485 const struct mbuf *m2; 1486 1487 if (m == NULL) { 1488 printf("mbuf: %p\n", m); 1489 return; 1490 } 1491 1492 if (m->m_flags & M_PKTHDR) 1493 len = m->m_pkthdr.len; 1494 else 1495 len = -1; 1496 m2 = m; 1497 while (m2 != NULL && (len == -1 || len)) { 1498 pdata = m2->m_len; 1499 if (maxlen != -1 && pdata > maxlen) 1500 pdata = maxlen; 1501 printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len, 1502 m2->m_next, m2->m_flags, "\20\20freelist\17skipfw" 1503 "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly" 1504 "\3eor\2pkthdr\1ext", pdata ? "" : "\n"); 1505 if (pdata) 1506 printf(", %*D\n", pdata, (u_char *)m2->m_data, "-"); 1507 if (len != -1) 1508 len -= m2->m_len; 1509 m2 = m2->m_next; 1510 } 1511 if (len > 0) 1512 printf("%d bytes unaccounted for.\n", len); 1513 return; 1514} 1515 1516u_int 1517m_fixhdr(struct mbuf *m0) 1518{ 1519 u_int len; 1520 1521 len = m_length(m0, NULL); 1522 m0->m_pkthdr.len = len; 1523 return (len); 1524} 1525 1526u_int 1527m_length(struct mbuf *m0, struct mbuf **last) 1528{ 1529 struct mbuf *m; 1530 u_int len; 1531 1532 len = 0; 1533 for (m = m0; m != NULL; m = m->m_next) { 1534 len += m->m_len; 1535 if (m->m_next == NULL) 1536 break; 1537 } 1538 if (last != NULL) 1539 *last = m; 1540 return (len); 1541} 1542 1543/* 1544 * Defragment a mbuf chain, returning the shortest possible 1545 * chain of mbufs and clusters. If allocation fails and 1546 * this cannot be completed, NULL will be returned, but 1547 * the passed in chain will be unchanged. Upon success, 1548 * the original chain will be freed, and the new chain 1549 * will be returned. 1550 * 1551 * If a non-packet header is passed in, the original 1552 * mbuf (chain?) will be returned unharmed. 1553 */ 1554struct mbuf * 1555m_defrag(struct mbuf *m0, int how) 1556{ 1557 struct mbuf *m_new = NULL, *m_final = NULL; 1558 int progress = 0, length; 1559 1560 MBUF_CHECKSLEEP(how); 1561 if (!(m0->m_flags & M_PKTHDR)) 1562 return (m0); 1563 1564 m_fixhdr(m0); /* Needed sanity check */ 1565 1566#ifdef MBUF_STRESS_TEST 1567 if (m_defragrandomfailures) { 1568 int temp = arc4random() & 0xff; 1569 if (temp == 0xba) 1570 goto nospace; 1571 } 1572#endif 1573 1574 if (m0->m_pkthdr.len > MHLEN) 1575 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1576 else 1577 m_final = m_gethdr(how, MT_DATA); 1578 1579 if (m_final == NULL) 1580 goto nospace; 1581 1582 if (m_dup_pkthdr(m_final, m0, how) == 0) 1583 goto nospace; 1584 1585 m_new = m_final; 1586 1587 while (progress < m0->m_pkthdr.len) { 1588 length = m0->m_pkthdr.len - progress; 1589 if (length > MCLBYTES) 1590 length = MCLBYTES; 1591 1592 if (m_new == NULL) { 1593 if (length > MLEN) 1594 m_new = m_getcl(how, MT_DATA, 0); 1595 else 1596 m_new = m_get(how, MT_DATA); 1597 if (m_new == NULL) 1598 goto nospace; 1599 } 1600 1601 m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 1602 progress += length; 1603 m_new->m_len = length; 1604 if (m_new != m_final) 1605 m_cat(m_final, m_new); 1606 m_new = NULL; 1607 } 1608#ifdef MBUF_STRESS_TEST 1609 if (m0->m_next == NULL) 1610 m_defraguseless++; 1611#endif 1612 m_freem(m0); 1613 m0 = m_final; 1614#ifdef MBUF_STRESS_TEST 1615 m_defragpackets++; 1616 m_defragbytes += m0->m_pkthdr.len; 1617#endif 1618 return (m0); 1619nospace: 1620#ifdef MBUF_STRESS_TEST 1621 m_defragfailure++; 1622#endif 1623 if (m_final) 1624 m_freem(m_final); 1625 return (NULL); 1626} 1627 1628/* 1629 * Defragment an mbuf chain, returning at most maxfrags separate 1630 * mbufs+clusters. If this is not possible NULL is returned and 1631 * the original mbuf chain is left in it's present (potentially 1632 * modified) state. We use two techniques: collapsing consecutive 1633 * mbufs and replacing consecutive mbufs by a cluster. 1634 * 1635 * NB: this should really be named m_defrag but that name is taken 1636 */ 1637struct mbuf * 1638m_collapse(struct mbuf *m0, int how, int maxfrags) 1639{ 1640 struct mbuf *m, *n, *n2, **prev; 1641 u_int curfrags; 1642 1643 /* 1644 * Calculate the current number of frags. 1645 */ 1646 curfrags = 0; 1647 for (m = m0; m != NULL; m = m->m_next) 1648 curfrags++; 1649 /* 1650 * First, try to collapse mbufs. Note that we always collapse 1651 * towards the front so we don't need to deal with moving the 1652 * pkthdr. This may be suboptimal if the first mbuf has much 1653 * less data than the following. 1654 */ 1655 m = m0; 1656again: 1657 for (;;) { 1658 n = m->m_next; 1659 if (n == NULL) 1660 break; 1661 if (M_WRITABLE(m) && 1662 n->m_len < M_TRAILINGSPACE(m)) { 1663 bcopy(mtod(n, void *), mtod(m, char *) + m->m_len, 1664 n->m_len); 1665 m->m_len += n->m_len; 1666 m->m_next = n->m_next; 1667 m_free(n); 1668 if (--curfrags <= maxfrags) 1669 return m0; 1670 } else 1671 m = n; 1672 } 1673 KASSERT(maxfrags > 1, 1674 ("maxfrags %u, but normal collapse failed", maxfrags)); 1675 /* 1676 * Collapse consecutive mbufs to a cluster. 1677 */ 1678 prev = &m0->m_next; /* NB: not the first mbuf */ 1679 while ((n = *prev) != NULL) { 1680 if ((n2 = n->m_next) != NULL && 1681 n->m_len + n2->m_len < MCLBYTES) { 1682 m = m_getcl(how, MT_DATA, 0); 1683 if (m == NULL) 1684 goto bad; 1685 bcopy(mtod(n, void *), mtod(m, void *), n->m_len); 1686 bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len, 1687 n2->m_len); 1688 m->m_len = n->m_len + n2->m_len; 1689 m->m_next = n2->m_next; 1690 *prev = m; 1691 m_free(n); 1692 m_free(n2); 1693 if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */ 1694 return m0; 1695 /* 1696 * Still not there, try the normal collapse 1697 * again before we allocate another cluster. 1698 */ 1699 goto again; 1700 } 1701 prev = &n->m_next; 1702 } 1703 /* 1704 * No place where we can collapse to a cluster; punt. 1705 * This can occur if, for example, you request 2 frags 1706 * but the packet requires that both be clusters (we 1707 * never reallocate the first mbuf to avoid moving the 1708 * packet header). 1709 */ 1710bad: 1711 return NULL; 1712} 1713 1714#ifdef MBUF_STRESS_TEST 1715 1716/* 1717 * Fragment an mbuf chain. There's no reason you'd ever want to do 1718 * this in normal usage, but it's great for stress testing various 1719 * mbuf consumers. 1720 * 1721 * If fragmentation is not possible, the original chain will be 1722 * returned. 1723 * 1724 * Possible length values: 1725 * 0 no fragmentation will occur 1726 * > 0 each fragment will be of the specified length 1727 * -1 each fragment will be the same random value in length 1728 * -2 each fragment's length will be entirely random 1729 * (Random values range from 1 to 256) 1730 */ 1731struct mbuf * 1732m_fragment(struct mbuf *m0, int how, int length) 1733{ 1734 struct mbuf *m_new = NULL, *m_final = NULL; 1735 int progress = 0; 1736 1737 if (!(m0->m_flags & M_PKTHDR)) 1738 return (m0); 1739 1740 if ((length == 0) || (length < -2)) 1741 return (m0); 1742 1743 m_fixhdr(m0); /* Needed sanity check */ 1744 1745 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1746 1747 if (m_final == NULL) 1748 goto nospace; 1749 1750 if (m_dup_pkthdr(m_final, m0, how) == 0) 1751 goto nospace; 1752 1753 m_new = m_final; 1754 1755 if (length == -1) 1756 length = 1 + (arc4random() & 255); 1757 1758 while (progress < m0->m_pkthdr.len) { 1759 int fraglen; 1760 1761 if (length > 0) 1762 fraglen = length; 1763 else 1764 fraglen = 1 + (arc4random() & 255); 1765 if (fraglen > m0->m_pkthdr.len - progress) 1766 fraglen = m0->m_pkthdr.len - progress; 1767 1768 if (fraglen > MCLBYTES) 1769 fraglen = MCLBYTES; 1770 1771 if (m_new == NULL) { 1772 m_new = m_getcl(how, MT_DATA, 0); 1773 if (m_new == NULL) 1774 goto nospace; 1775 } 1776 1777 m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t)); 1778 progress += fraglen; 1779 m_new->m_len = fraglen; 1780 if (m_new != m_final) 1781 m_cat(m_final, m_new); 1782 m_new = NULL; 1783 } 1784 m_freem(m0); 1785 m0 = m_final; 1786 return (m0); 1787nospace: 1788 if (m_final) 1789 m_freem(m_final); 1790 /* Return the original chain on failure */ 1791 return (m0); 1792} 1793 1794#endif 1795 1796/* 1797 * Copy the contents of uio into a properly sized mbuf chain. 1798 */ 1799struct mbuf * 1800m_uiotombuf(struct uio *uio, int how, int len, int align, int flags) 1801{ 1802 struct mbuf *m, *mb; 1803 int error, length; 1804 ssize_t total; 1805 int progress = 0; 1806 1807 /* 1808 * len can be zero or an arbitrary large value bound by 1809 * the total data supplied by the uio. 1810 */ 1811 if (len > 0) 1812 total = min(uio->uio_resid, len); 1813 else 1814 total = uio->uio_resid; 1815 1816 /* 1817 * The smallest unit returned by m_getm2() is a single mbuf 1818 * with pkthdr. We can't align past it. 1819 */ 1820 if (align >= MHLEN) 1821 return (NULL); 1822 1823 /* 1824 * Give us the full allocation or nothing. 1825 * If len is zero return the smallest empty mbuf. 1826 */ 1827 m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags); 1828 if (m == NULL) 1829 return (NULL); 1830 m->m_data += align; 1831 1832 /* Fill all mbufs with uio data and update header information. */ 1833 for (mb = m; mb != NULL; mb = mb->m_next) { 1834 length = min(M_TRAILINGSPACE(mb), total - progress); 1835 1836 error = uiomove(mtod(mb, void *), length, uio); 1837 if (error) { 1838 m_freem(m); 1839 return (NULL); 1840 } 1841 1842 mb->m_len = length; 1843 progress += length; 1844 if (flags & M_PKTHDR) 1845 m->m_pkthdr.len += length; 1846 } 1847 KASSERT(progress == total, ("%s: progress != total", __func__)); 1848 1849 return (m); 1850} 1851 1852/* 1853 * Copy an mbuf chain into a uio limited by len if set. 1854 */ 1855int 1856m_mbuftouio(struct uio *uio, struct mbuf *m, int len) 1857{ 1858 int error, length, total; 1859 int progress = 0; 1860 1861 if (len > 0) 1862 total = min(uio->uio_resid, len); 1863 else 1864 total = uio->uio_resid; 1865 1866 /* Fill the uio with data from the mbufs. */ 1867 for (; m != NULL; m = m->m_next) { 1868 length = min(m->m_len, total - progress); 1869 1870 error = uiomove(mtod(m, void *), length, uio); 1871 if (error) 1872 return (error); 1873 1874 progress += length; 1875 } 1876 1877 return (0); 1878} 1879 1880/* 1881 * Set the m_data pointer of a newly-allocated mbuf 1882 * to place an object of the specified size at the 1883 * end of the mbuf, longword aligned. 1884 */ 1885void 1886m_align(struct mbuf *m, int len) 1887{ 1888#ifdef INVARIANTS 1889 const char *msg = "%s: not a virgin mbuf"; 1890#endif 1891 int adjust; 1892 1893 if (m->m_flags & M_EXT) { 1894 KASSERT(m->m_data == m->m_ext.ext_buf, (msg, __func__)); 1895 adjust = m->m_ext.ext_size - len; 1896 } else if (m->m_flags & M_PKTHDR) { 1897 KASSERT(m->m_data == m->m_pktdat, (msg, __func__)); 1898 adjust = MHLEN - len; 1899 } else { 1900 KASSERT(m->m_data == m->m_dat, (msg, __func__)); 1901 adjust = MLEN - len; 1902 } 1903 1904 m->m_data += adjust &~ (sizeof(long)-1); 1905} 1906 1907/* 1908 * Create a writable copy of the mbuf chain. While doing this 1909 * we compact the chain with a goal of producing a chain with 1910 * at most two mbufs. The second mbuf in this chain is likely 1911 * to be a cluster. The primary purpose of this work is to create 1912 * a writable packet for encryption, compression, etc. The 1913 * secondary goal is to linearize the data so the data can be 1914 * passed to crypto hardware in the most efficient manner possible. 1915 */ 1916struct mbuf * 1917m_unshare(struct mbuf *m0, int how) 1918{ 1919 struct mbuf *m, *mprev; 1920 struct mbuf *n, *mfirst, *mlast; 1921 int len, off; 1922 1923 mprev = NULL; 1924 for (m = m0; m != NULL; m = mprev->m_next) { 1925 /* 1926 * Regular mbufs are ignored unless there's a cluster 1927 * in front of it that we can use to coalesce. We do 1928 * the latter mainly so later clusters can be coalesced 1929 * also w/o having to handle them specially (i.e. convert 1930 * mbuf+cluster -> cluster). This optimization is heavily 1931 * influenced by the assumption that we're running over 1932 * Ethernet where MCLBYTES is large enough that the max 1933 * packet size will permit lots of coalescing into a 1934 * single cluster. This in turn permits efficient 1935 * crypto operations, especially when using hardware. 1936 */ 1937 if ((m->m_flags & M_EXT) == 0) { 1938 if (mprev && (mprev->m_flags & M_EXT) && 1939 m->m_len <= M_TRAILINGSPACE(mprev)) { 1940 /* XXX: this ignores mbuf types */ 1941 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1942 mtod(m, caddr_t), m->m_len); 1943 mprev->m_len += m->m_len; 1944 mprev->m_next = m->m_next; /* unlink from chain */ 1945 m_free(m); /* reclaim mbuf */ 1946#if 0 1947 newipsecstat.ips_mbcoalesced++; 1948#endif 1949 } else { 1950 mprev = m; 1951 } 1952 continue; 1953 } 1954 /* 1955 * Writable mbufs are left alone (for now). 1956 */ 1957 if (M_WRITABLE(m)) { 1958 mprev = m; 1959 continue; 1960 } 1961 1962 /* 1963 * Not writable, replace with a copy or coalesce with 1964 * the previous mbuf if possible (since we have to copy 1965 * it anyway, we try to reduce the number of mbufs and 1966 * clusters so that future work is easier). 1967 */ 1968 KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags)); 1969 /* NB: we only coalesce into a cluster or larger */ 1970 if (mprev != NULL && (mprev->m_flags & M_EXT) && 1971 m->m_len <= M_TRAILINGSPACE(mprev)) { 1972 /* XXX: this ignores mbuf types */ 1973 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1974 mtod(m, caddr_t), m->m_len); 1975 mprev->m_len += m->m_len; 1976 mprev->m_next = m->m_next; /* unlink from chain */ 1977 m_free(m); /* reclaim mbuf */ 1978#if 0 1979 newipsecstat.ips_clcoalesced++; 1980#endif 1981 continue; 1982 } 1983 1984 /* 1985 * Allocate new space to hold the copy and copy the data. 1986 * We deal with jumbo mbufs (i.e. m_len > MCLBYTES) by 1987 * splitting them into clusters. We could just malloc a 1988 * buffer and make it external but too many device drivers 1989 * don't know how to break up the non-contiguous memory when 1990 * doing DMA. 1991 */ 1992 n = m_getcl(how, m->m_type, m->m_flags & M_COPYFLAGS); 1993 if (n == NULL) { 1994 m_freem(m0); 1995 return (NULL); 1996 } 1997 if (m->m_flags & M_PKTHDR) { 1998 KASSERT(mprev == NULL, ("%s: m0 %p, m %p has M_PKTHDR", 1999 __func__, m0, m)); 2000 m_move_pkthdr(n, m); 2001 } 2002 len = m->m_len; 2003 off = 0; 2004 mfirst = n; 2005 mlast = NULL; 2006 for (;;) { 2007 int cc = min(len, MCLBYTES); 2008 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc); 2009 n->m_len = cc; 2010 if (mlast != NULL) 2011 mlast->m_next = n; 2012 mlast = n; 2013#if 0 2014 newipsecstat.ips_clcopied++; 2015#endif 2016 2017 len -= cc; 2018 if (len <= 0) 2019 break; 2020 off += cc; 2021 2022 n = m_getcl(how, m->m_type, m->m_flags & M_COPYFLAGS); 2023 if (n == NULL) { 2024 m_freem(mfirst); 2025 m_freem(m0); 2026 return (NULL); 2027 } 2028 } 2029 n->m_next = m->m_next; 2030 if (mprev == NULL) 2031 m0 = mfirst; /* new head of chain */ 2032 else 2033 mprev->m_next = mfirst; /* replace old mbuf */ 2034 m_free(m); /* release old mbuf */ 2035 mprev = mfirst; 2036 } 2037 return (m0); 2038} 2039 2040#ifdef MBUF_PROFILING 2041 2042#define MP_BUCKETS 32 /* don't just change this as things may overflow.*/ 2043struct mbufprofile { 2044 uintmax_t wasted[MP_BUCKETS]; 2045 uintmax_t used[MP_BUCKETS]; 2046 uintmax_t segments[MP_BUCKETS]; 2047} mbprof; 2048 2049#define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */ 2050#define MP_NUMLINES 6 2051#define MP_NUMSPERLINE 16 2052#define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */ 2053/* work out max space needed and add a bit of spare space too */ 2054#define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE) 2055#define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES) 2056 2057char mbprofbuf[MP_BUFSIZE]; 2058 2059void 2060m_profile(struct mbuf *m) 2061{ 2062 int segments = 0; 2063 int used = 0; 2064 int wasted = 0; 2065 2066 while (m) { 2067 segments++; 2068 used += m->m_len; 2069 if (m->m_flags & M_EXT) { 2070 wasted += MHLEN - sizeof(m->m_ext) + 2071 m->m_ext.ext_size - m->m_len; 2072 } else { 2073 if (m->m_flags & M_PKTHDR) 2074 wasted += MHLEN - m->m_len; 2075 else 2076 wasted += MLEN - m->m_len; 2077 } 2078 m = m->m_next; 2079 } 2080 /* be paranoid.. it helps */ 2081 if (segments > MP_BUCKETS - 1) 2082 segments = MP_BUCKETS - 1; 2083 if (used > 100000) 2084 used = 100000; 2085 if (wasted > 100000) 2086 wasted = 100000; 2087 /* store in the appropriate bucket */ 2088 /* don't bother locking. if it's slightly off, so what? */ 2089 mbprof.segments[segments]++; 2090 mbprof.used[fls(used)]++; 2091 mbprof.wasted[fls(wasted)]++; 2092} 2093 2094static void 2095mbprof_textify(void) 2096{ 2097 int offset; 2098 char *c; 2099 uint64_t *p; 2100 2101 2102 p = &mbprof.wasted[0]; 2103 c = mbprofbuf; 2104 offset = snprintf(c, MP_MAXLINE + 10, 2105 "wasted:\n" 2106 "%ju %ju %ju %ju %ju %ju %ju %ju " 2107 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2108 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2109 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2110#ifdef BIG_ARRAY 2111 p = &mbprof.wasted[16]; 2112 c += offset; 2113 offset = snprintf(c, MP_MAXLINE, 2114 "%ju %ju %ju %ju %ju %ju %ju %ju " 2115 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2116 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2117 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2118#endif 2119 p = &mbprof.used[0]; 2120 c += offset; 2121 offset = snprintf(c, MP_MAXLINE + 10, 2122 "used:\n" 2123 "%ju %ju %ju %ju %ju %ju %ju %ju " 2124 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2125 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2126 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2127#ifdef BIG_ARRAY 2128 p = &mbprof.used[16]; 2129 c += offset; 2130 offset = snprintf(c, MP_MAXLINE, 2131 "%ju %ju %ju %ju %ju %ju %ju %ju " 2132 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2133 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2134 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2135#endif 2136 p = &mbprof.segments[0]; 2137 c += offset; 2138 offset = snprintf(c, MP_MAXLINE + 10, 2139 "segments:\n" 2140 "%ju %ju %ju %ju %ju %ju %ju %ju " 2141 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2142 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2143 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2144#ifdef BIG_ARRAY 2145 p = &mbprof.segments[16]; 2146 c += offset; 2147 offset = snprintf(c, MP_MAXLINE, 2148 "%ju %ju %ju %ju %ju %ju %ju %ju " 2149 "%ju %ju %ju %ju %ju %ju %ju %jju", 2150 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2151 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2152#endif 2153} 2154 2155static int 2156mbprof_handler(SYSCTL_HANDLER_ARGS) 2157{ 2158 int error; 2159 2160 mbprof_textify(); 2161 error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1); 2162 return (error); 2163} 2164 2165static int 2166mbprof_clr_handler(SYSCTL_HANDLER_ARGS) 2167{ 2168 int clear, error; 2169 2170 clear = 0; 2171 error = sysctl_handle_int(oidp, &clear, 0, req); 2172 if (error || !req->newptr) 2173 return (error); 2174 2175 if (clear) { 2176 bzero(&mbprof, sizeof(mbprof)); 2177 } 2178 2179 return (error); 2180} 2181 2182 2183SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD, 2184 NULL, 0, mbprof_handler, "A", "mbuf profiling statistics"); 2185 2186SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW, 2187 NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics"); 2188#endif 2189 2190