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("$FreeBSD$"); 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 51 int max_linkhdr; 52 int max_protohdr; 53 int max_hdr; 54 int max_datalen; 55 #ifdef MBUF_STRESS_TEST 56 int m_defragpackets; 57 int m_defragbytes; 58 int m_defraguseless; 59 int m_defragfailure; 60 int m_defragrandomfailures; 61 #endif 62 63 /* 64 * sysctl(8) exported objects 65 */ 66 SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RD, 67 &max_linkhdr, 0, "Size of largest link layer header"); 68 SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RD, 69 &max_protohdr, 0, "Size of largest protocol layer header"); 70 SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RD, 71 &max_hdr, 0, "Size of largest link plus protocol header"); 72 SYSCTL_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 75 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD, 76 &m_defragpackets, 0, ""); 77 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD, 78 &m_defragbytes, 0, ""); 79 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD, 80 &m_defraguseless, 0, ""); 81 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD, 82 &m_defragfailure, 0, ""); 83 SYSCTL_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 */ 91 CTASSERT(sizeof(struct mbuf) == MSIZE); 92 CTASSERT(MSIZE - offsetof(struct mbuf, m_dat) == MLEN); 93 CTASSERT(MSIZE - offsetof(struct mbuf, m_pktdat) == MHLEN); 94 95 /* 96 * m_get2() allocates minimum mbuf that would fit "size" argument. 97 */ 98 struct mbuf * 99 m_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 */ 132 struct mbuf * 133 m_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 */ 165 struct mbuf * 166 m_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 */ 227 void 228 m_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 */ 256 int 257 m_extadd(struct mbuf *mb, caddr_t buf, u_int size, 258 void (*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.ext_cnt = uma_zalloc(zone_ext_refcnt, wait); 265 266 if (mb->m_ext.ext_cnt == NULL) 267 return (ENOMEM); 268 269 *(mb->m_ext.ext_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 */ 287 void 288 mb_free_ext(struct mbuf *m) 289 { 290 int freembuf; 291 292 KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m)); 293 294 /* 295 * Check if the header is embedded in the cluster. 296 */ 297 freembuf = (m->m_flags & M_NOFREE) ? 0 : 1; 298 299 switch (m->m_ext.ext_type) { 300 case EXT_SFBUF: 301 sf_ext_free(m->m_ext.ext_arg1, m->m_ext.ext_arg2); 302 break; 303 default: 304 KASSERT(m->m_ext.ext_cnt != NULL, 305 ("%s: no refcounting pointer on %p", __func__, m)); 306 /* 307 * Free attached storage if this mbuf is the only 308 * reference to it. 309 */ 310 if (*(m->m_ext.ext_cnt) != 1) { 311 if (atomic_fetchadd_int(m->m_ext.ext_cnt, -1) != 1) 312 break; 313 } 314 315 switch (m->m_ext.ext_type) { 316 case EXT_PACKET: /* The packet zone is special. */ 317 if (*(m->m_ext.ext_cnt) == 0) 318 *(m->m_ext.ext_cnt) = 1; 319 uma_zfree(zone_pack, m); 320 return; /* Job done. */ 321 case EXT_CLUSTER: 322 uma_zfree(zone_clust, m->m_ext.ext_buf); 323 break; 324 case EXT_JUMBOP: 325 uma_zfree(zone_jumbop, m->m_ext.ext_buf); 326 break; 327 case EXT_JUMBO9: 328 uma_zfree(zone_jumbo9, m->m_ext.ext_buf); 329 break; 330 case EXT_JUMBO16: 331 uma_zfree(zone_jumbo16, m->m_ext.ext_buf); 332 break; 333 case EXT_NET_DRV: 334 case EXT_MOD_TYPE: 335 case EXT_DISPOSABLE: 336 *(m->m_ext.ext_cnt) = 0; 337 uma_zfree(zone_ext_refcnt, __DEVOLATILE(u_int *, 338 m->m_ext.ext_cnt)); 339 /* FALLTHROUGH */ 340 case EXT_EXTREF: 341 KASSERT(m->m_ext.ext_free != NULL, 342 ("%s: ext_free not set", __func__)); 343 (*(m->m_ext.ext_free))(m, m->m_ext.ext_arg1, 344 m->m_ext.ext_arg2); 345 break; 346 default: 347 KASSERT(m->m_ext.ext_type == 0, 348 ("%s: unknown ext_type", __func__)); 349 } 350 } 351 352 if (freembuf) 353 uma_zfree(zone_mbuf, m); 354 } 355 356 /* 357 * Attach the cluster from *m to *n, set up m_ext in *n 358 * and bump the refcount of the cluster. 359 */ 360 static void 361 mb_dupcl(struct mbuf *n, struct mbuf *m) 362 { 363 364 KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m)); 365 KASSERT(!(n->m_flags & M_EXT), ("%s: M_EXT set on %p", __func__, n)); 366 367 switch (m->m_ext.ext_type) { 368 case EXT_SFBUF: 369 sf_ext_ref(m->m_ext.ext_arg1, m->m_ext.ext_arg2); 370 break; 371 default: 372 KASSERT(m->m_ext.ext_cnt != NULL, 373 ("%s: no refcounting pointer on %p", __func__, m)); 374 if (*(m->m_ext.ext_cnt) == 1) 375 *(m->m_ext.ext_cnt) += 1; 376 else 377 atomic_add_int(m->m_ext.ext_cnt, 1); 378 } 379 380 n->m_ext = m->m_ext; 381 n->m_flags |= M_EXT; 382 n->m_flags |= m->m_flags & M_RDONLY; 383 } 384 385 /* 386 * Clean up mbuf (chain) from any tags and packet headers. 387 * If "all" is set then the first mbuf in the chain will be 388 * cleaned too. 389 */ 390 void 391 m_demote(struct mbuf *m0, int all) 392 { 393 struct mbuf *m; 394 395 for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) { 396 KASSERT(m->m_nextpkt == NULL, ("%s: m_nextpkt in m %p, m0 %p", 397 __func__, m, m0)); 398 if (m->m_flags & M_PKTHDR) { 399 m_tag_delete_chain(m, NULL); 400 m->m_flags &= ~M_PKTHDR; 401 bzero(&m->m_pkthdr, sizeof(struct pkthdr)); 402 } 403 m->m_flags = m->m_flags & (M_EXT|M_RDONLY|M_NOFREE); 404 } 405 } 406 407 /* 408 * Sanity checks on mbuf (chain) for use in KASSERT() and general 409 * debugging. 410 * Returns 0 or panics when bad and 1 on all tests passed. 411 * Sanitize, 0 to run M_SANITY_ACTION, 1 to garble things so they 412 * blow up later. 413 */ 414 int 415 m_sanity(struct mbuf *m0, int sanitize) 416 { 417 struct mbuf *m; 418 caddr_t a, b; 419 int pktlen = 0; 420 421 #ifdef INVARIANTS 422 #define M_SANITY_ACTION(s) panic("mbuf %p: " s, m) 423 #else 424 #define M_SANITY_ACTION(s) printf("mbuf %p: " s, m) 425 #endif 426 427 for (m = m0; m != NULL; m = m->m_next) { 428 /* 429 * Basic pointer checks. If any of these fails then some 430 * unrelated kernel memory before or after us is trashed. 431 * No way to recover from that. 432 */ 433 a = ((m->m_flags & M_EXT) ? m->m_ext.ext_buf : 434 ((m->m_flags & M_PKTHDR) ? (caddr_t)(&m->m_pktdat) : 435 (caddr_t)(&m->m_dat)) ); 436 b = (caddr_t)(a + (m->m_flags & M_EXT ? m->m_ext.ext_size : 437 ((m->m_flags & M_PKTHDR) ? MHLEN : MLEN))); 438 if ((caddr_t)m->m_data < a) 439 M_SANITY_ACTION("m_data outside mbuf data range left"); 440 if ((caddr_t)m->m_data > b) 441 M_SANITY_ACTION("m_data outside mbuf data range right"); 442 if ((caddr_t)m->m_data + m->m_len > b) 443 M_SANITY_ACTION("m_data + m_len exeeds mbuf space"); 444 445 /* m->m_nextpkt may only be set on first mbuf in chain. */ 446 if (m != m0 && m->m_nextpkt != NULL) { 447 if (sanitize) { 448 m_freem(m->m_nextpkt); 449 m->m_nextpkt = (struct mbuf *)0xDEADC0DE; 450 } else 451 M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf"); 452 } 453 454 /* packet length (not mbuf length!) calculation */ 455 if (m0->m_flags & M_PKTHDR) 456 pktlen += m->m_len; 457 458 /* m_tags may only be attached to first mbuf in chain. */ 459 if (m != m0 && m->m_flags & M_PKTHDR && 460 !SLIST_EMPTY(&m->m_pkthdr.tags)) { 461 if (sanitize) { 462 m_tag_delete_chain(m, NULL); 463 /* put in 0xDEADC0DE perhaps? */ 464 } else 465 M_SANITY_ACTION("m_tags on in-chain mbuf"); 466 } 467 468 /* M_PKTHDR may only be set on first mbuf in chain */ 469 if (m != m0 && m->m_flags & M_PKTHDR) { 470 if (sanitize) { 471 bzero(&m->m_pkthdr, sizeof(m->m_pkthdr)); 472 m->m_flags &= ~M_PKTHDR; 473 /* put in 0xDEADCODE and leave hdr flag in */ 474 } else 475 M_SANITY_ACTION("M_PKTHDR on in-chain mbuf"); 476 } 477 } 478 m = m0; 479 if (pktlen && pktlen != m->m_pkthdr.len) { 480 if (sanitize) 481 m->m_pkthdr.len = 0; 482 else 483 M_SANITY_ACTION("m_pkthdr.len != mbuf chain length"); 484 } 485 return 1; 486 487 #undef M_SANITY_ACTION 488 } 489 490 491 /* 492 * "Move" mbuf pkthdr from "from" to "to". 493 * "from" must have M_PKTHDR set, and "to" must be empty. 494 */ 495 void 496 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 497 { 498 499 #if 0 500 /* see below for why these are not enabled */ 501 M_ASSERTPKTHDR(to); 502 /* Note: with MAC, this may not be a good assertion. */ 503 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), 504 ("m_move_pkthdr: to has tags")); 505 #endif 506 #ifdef MAC 507 /* 508 * XXXMAC: It could be this should also occur for non-MAC? 509 */ 510 if (to->m_flags & M_PKTHDR) 511 m_tag_delete_chain(to, NULL); 512 #endif 513 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 514 if ((to->m_flags & M_EXT) == 0) 515 to->m_data = to->m_pktdat; 516 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 517 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 518 from->m_flags &= ~M_PKTHDR; 519 } 520 521 /* 522 * Duplicate "from"'s mbuf pkthdr in "to". 523 * "from" must have M_PKTHDR set, and "to" must be empty. 524 * In particular, this does a deep copy of the packet tags. 525 */ 526 int 527 m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 528 { 529 530 #if 0 531 /* 532 * The mbuf allocator only initializes the pkthdr 533 * when the mbuf is allocated with m_gethdr(). Many users 534 * (e.g. m_copy*, m_prepend) use m_get() and then 535 * smash the pkthdr as needed causing these 536 * assertions to trip. For now just disable them. 537 */ 538 M_ASSERTPKTHDR(to); 539 /* Note: with MAC, this may not be a good assertion. */ 540 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags")); 541 #endif 542 MBUF_CHECKSLEEP(how); 543 #ifdef MAC 544 if (to->m_flags & M_PKTHDR) 545 m_tag_delete_chain(to, NULL); 546 #endif 547 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 548 if ((to->m_flags & M_EXT) == 0) 549 to->m_data = to->m_pktdat; 550 to->m_pkthdr = from->m_pkthdr; 551 SLIST_INIT(&to->m_pkthdr.tags); 552 return (m_tag_copy_chain(to, from, how)); 553 } 554 555 /* 556 * Lesser-used path for M_PREPEND: 557 * allocate new mbuf to prepend to chain, 558 * copy junk along. 559 */ 560 struct mbuf * 561 m_prepend(struct mbuf *m, int len, int how) 562 { 563 struct mbuf *mn; 564 565 if (m->m_flags & M_PKTHDR) 566 mn = m_gethdr(how, m->m_type); 567 else 568 mn = m_get(how, m->m_type); 569 if (mn == NULL) { 570 m_freem(m); 571 return (NULL); 572 } 573 if (m->m_flags & M_PKTHDR) 574 m_move_pkthdr(mn, m); 575 mn->m_next = m; 576 m = mn; 577 if(m->m_flags & M_PKTHDR) { 578 if (len < MHLEN) 579 MH_ALIGN(m, len); 580 } else { 581 if (len < MLEN) 582 M_ALIGN(m, len); 583 } 584 m->m_len = len; 585 return (m); 586 } 587 588 /* 589 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 590 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 591 * The wait parameter is a choice of M_WAITOK/M_NOWAIT from caller. 592 * Note that the copy is read-only, because clusters are not copied, 593 * only their reference counts are incremented. 594 */ 595 struct mbuf * 596 m_copym(struct mbuf *m, int off0, int len, int wait) 597 { 598 struct mbuf *n, **np; 599 int off = off0; 600 struct mbuf *top; 601 int copyhdr = 0; 602 603 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 604 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 605 MBUF_CHECKSLEEP(wait); 606 if (off == 0 && m->m_flags & M_PKTHDR) 607 copyhdr = 1; 608 while (off > 0) { 609 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 610 if (off < m->m_len) 611 break; 612 off -= m->m_len; 613 m = m->m_next; 614 } 615 np = ⊤ 616 top = 0; 617 while (len > 0) { 618 if (m == NULL) { 619 KASSERT(len == M_COPYALL, 620 ("m_copym, length > size of mbuf chain")); 621 break; 622 } 623 if (copyhdr) 624 n = m_gethdr(wait, m->m_type); 625 else 626 n = m_get(wait, m->m_type); 627 *np = n; 628 if (n == NULL) 629 goto nospace; 630 if (copyhdr) { 631 if (!m_dup_pkthdr(n, m, wait)) 632 goto nospace; 633 if (len == M_COPYALL) 634 n->m_pkthdr.len -= off0; 635 else 636 n->m_pkthdr.len = len; 637 copyhdr = 0; 638 } 639 n->m_len = min(len, m->m_len - off); 640 if (m->m_flags & M_EXT) { 641 n->m_data = m->m_data + off; 642 mb_dupcl(n, m); 643 } else 644 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 645 (u_int)n->m_len); 646 if (len != M_COPYALL) 647 len -= n->m_len; 648 off = 0; 649 m = m->m_next; 650 np = &n->m_next; 651 } 652 653 return (top); 654 nospace: 655 m_freem(top); 656 return (NULL); 657 } 658 659 /* 660 * Returns mbuf chain with new head for the prepending case. 661 * Copies from mbuf (chain) n from off for len to mbuf (chain) m 662 * either prepending or appending the data. 663 * The resulting mbuf (chain) m is fully writeable. 664 * m is destination (is made writeable) 665 * n is source, off is offset in source, len is len from offset 666 * dir, 0 append, 1 prepend 667 * how, wait or nowait 668 */ 669 670 static int 671 m_bcopyxxx(void *s, void *t, u_int len) 672 { 673 bcopy(s, t, (size_t)len); 674 return 0; 675 } 676 677 struct mbuf * 678 m_copymdata(struct mbuf *m, struct mbuf *n, int off, int len, 679 int prep, int how) 680 { 681 struct mbuf *mm, *x, *z, *prev = NULL; 682 caddr_t p; 683 int i, nlen = 0; 684 caddr_t buf[MLEN]; 685 686 KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source")); 687 KASSERT(off >= 0, ("m_copymdata, negative off %d", off)); 688 KASSERT(len >= 0, ("m_copymdata, negative len %d", len)); 689 KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep)); 690 691 mm = m; 692 if (!prep) { 693 while(mm->m_next) { 694 prev = mm; 695 mm = mm->m_next; 696 } 697 } 698 for (z = n; z != NULL; z = z->m_next) 699 nlen += z->m_len; 700 if (len == M_COPYALL) 701 len = nlen - off; 702 if (off + len > nlen || len < 1) 703 return NULL; 704 705 if (!M_WRITABLE(mm)) { 706 /* XXX: Use proper m_xxx function instead. */ 707 x = m_getcl(how, MT_DATA, mm->m_flags); 708 if (x == NULL) 709 return NULL; 710 bcopy(mm->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size); 711 p = x->m_ext.ext_buf + (mm->m_data - mm->m_ext.ext_buf); 712 x->m_data = p; 713 mm->m_next = NULL; 714 if (mm != m) 715 prev->m_next = x; 716 m_free(mm); 717 mm = x; 718 } 719 720 /* 721 * Append/prepend the data. Allocating mbufs as necessary. 722 */ 723 /* Shortcut if enough free space in first/last mbuf. */ 724 if (!prep && M_TRAILINGSPACE(mm) >= len) { 725 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) + 726 mm->m_len); 727 mm->m_len += len; 728 mm->m_pkthdr.len += len; 729 return m; 730 } 731 if (prep && M_LEADINGSPACE(mm) >= len) { 732 mm->m_data = mtod(mm, caddr_t) - len; 733 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t)); 734 mm->m_len += len; 735 mm->m_pkthdr.len += len; 736 return mm; 737 } 738 739 /* Expand first/last mbuf to cluster if possible. */ 740 if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) { 741 bcopy(mm->m_data, &buf, mm->m_len); 742 m_clget(mm, how); 743 if (!(mm->m_flags & M_EXT)) 744 return NULL; 745 bcopy(&buf, mm->m_ext.ext_buf, mm->m_len); 746 mm->m_data = mm->m_ext.ext_buf; 747 } 748 if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) { 749 bcopy(mm->m_data, &buf, mm->m_len); 750 m_clget(mm, how); 751 if (!(mm->m_flags & M_EXT)) 752 return NULL; 753 bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf + 754 mm->m_ext.ext_size - mm->m_len, mm->m_len); 755 mm->m_data = (caddr_t)mm->m_ext.ext_buf + 756 mm->m_ext.ext_size - mm->m_len; 757 } 758 759 /* Append/prepend as many mbuf (clusters) as necessary to fit len. */ 760 if (!prep && len > M_TRAILINGSPACE(mm)) { 761 if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA)) 762 return NULL; 763 } 764 if (prep && len > M_LEADINGSPACE(mm)) { 765 if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA))) 766 return NULL; 767 i = 0; 768 for (x = z; x != NULL; x = x->m_next) { 769 i += x->m_flags & M_EXT ? x->m_ext.ext_size : 770 (x->m_flags & M_PKTHDR ? MHLEN : MLEN); 771 if (!x->m_next) 772 break; 773 } 774 z->m_data += i - len; 775 m_move_pkthdr(mm, z); 776 x->m_next = mm; 777 mm = z; 778 } 779 780 /* Seek to start position in source mbuf. Optimization for long chains. */ 781 while (off > 0) { 782 if (off < n->m_len) 783 break; 784 off -= n->m_len; 785 n = n->m_next; 786 } 787 788 /* Copy data into target mbuf. */ 789 z = mm; 790 while (len > 0) { 791 KASSERT(z != NULL, ("m_copymdata, falling off target edge")); 792 i = M_TRAILINGSPACE(z); 793 m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len); 794 z->m_len += i; 795 /* fixup pkthdr.len if necessary */ 796 if ((prep ? mm : m)->m_flags & M_PKTHDR) 797 (prep ? mm : m)->m_pkthdr.len += i; 798 off += i; 799 len -= i; 800 z = z->m_next; 801 } 802 return (prep ? mm : m); 803 } 804 805 /* 806 * Copy an entire packet, including header (which must be present). 807 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 808 * Note that the copy is read-only, because clusters are not copied, 809 * only their reference counts are incremented. 810 * Preserve alignment of the first mbuf so if the creator has left 811 * some room at the beginning (e.g. for inserting protocol headers) 812 * the copies still have the room available. 813 */ 814 struct mbuf * 815 m_copypacket(struct mbuf *m, int how) 816 { 817 struct mbuf *top, *n, *o; 818 819 MBUF_CHECKSLEEP(how); 820 n = m_get(how, m->m_type); 821 top = n; 822 if (n == NULL) 823 goto nospace; 824 825 if (!m_dup_pkthdr(n, m, how)) 826 goto nospace; 827 n->m_len = m->m_len; 828 if (m->m_flags & M_EXT) { 829 n->m_data = m->m_data; 830 mb_dupcl(n, m); 831 } else { 832 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 833 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 834 } 835 836 m = m->m_next; 837 while (m) { 838 o = m_get(how, m->m_type); 839 if (o == NULL) 840 goto nospace; 841 842 n->m_next = o; 843 n = n->m_next; 844 845 n->m_len = m->m_len; 846 if (m->m_flags & M_EXT) { 847 n->m_data = m->m_data; 848 mb_dupcl(n, m); 849 } else { 850 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 851 } 852 853 m = m->m_next; 854 } 855 return top; 856 nospace: 857 m_freem(top); 858 return (NULL); 859 } 860 861 /* 862 * Copy data from an mbuf chain starting "off" bytes from the beginning, 863 * continuing for "len" bytes, into the indicated buffer. 864 */ 865 void 866 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 867 { 868 u_int count; 869 870 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 871 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 872 while (off > 0) { 873 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 874 if (off < m->m_len) 875 break; 876 off -= m->m_len; 877 m = m->m_next; 878 } 879 while (len > 0) { 880 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 881 count = min(m->m_len - off, len); 882 bcopy(mtod(m, caddr_t) + off, cp, count); 883 len -= count; 884 cp += count; 885 off = 0; 886 m = m->m_next; 887 } 888 } 889 890 /* 891 * Copy a packet header mbuf chain into a completely new chain, including 892 * copying any mbuf clusters. Use this instead of m_copypacket() when 893 * you need a writable copy of an mbuf chain. 894 */ 895 struct mbuf * 896 m_dup(struct mbuf *m, int how) 897 { 898 struct mbuf **p, *top = NULL; 899 int remain, moff, nsize; 900 901 MBUF_CHECKSLEEP(how); 902 /* Sanity check */ 903 if (m == NULL) 904 return (NULL); 905 M_ASSERTPKTHDR(m); 906 907 /* While there's more data, get a new mbuf, tack it on, and fill it */ 908 remain = m->m_pkthdr.len; 909 moff = 0; 910 p = ⊤ 911 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 912 struct mbuf *n; 913 914 /* Get the next new mbuf */ 915 if (remain >= MINCLSIZE) { 916 n = m_getcl(how, m->m_type, 0); 917 nsize = MCLBYTES; 918 } else { 919 n = m_get(how, m->m_type); 920 nsize = MLEN; 921 } 922 if (n == NULL) 923 goto nospace; 924 925 if (top == NULL) { /* First one, must be PKTHDR */ 926 if (!m_dup_pkthdr(n, m, how)) { 927 m_free(n); 928 goto nospace; 929 } 930 if ((n->m_flags & M_EXT) == 0) 931 nsize = MHLEN; 932 } 933 n->m_len = 0; 934 935 /* Link it into the new chain */ 936 *p = n; 937 p = &n->m_next; 938 939 /* Copy data from original mbuf(s) into new mbuf */ 940 while (n->m_len < nsize && m != NULL) { 941 int chunk = min(nsize - n->m_len, m->m_len - moff); 942 943 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 944 moff += chunk; 945 n->m_len += chunk; 946 remain -= chunk; 947 if (moff == m->m_len) { 948 m = m->m_next; 949 moff = 0; 950 } 951 } 952 953 /* Check correct total mbuf length */ 954 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 955 ("%s: bogus m_pkthdr.len", __func__)); 956 } 957 return (top); 958 959 nospace: 960 m_freem(top); 961 return (NULL); 962 } 963 964 /* 965 * Concatenate mbuf chain n to m. 966 * Both chains must be of the same type (e.g. MT_DATA). 967 * Any m_pkthdr is not updated. 968 */ 969 void 970 m_cat(struct mbuf *m, struct mbuf *n) 971 { 972 while (m->m_next) 973 m = m->m_next; 974 while (n) { 975 if (!M_WRITABLE(m) || 976 M_TRAILINGSPACE(m) < n->m_len) { 977 /* just join the two chains */ 978 m->m_next = n; 979 return; 980 } 981 /* splat the data from one into the other */ 982 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 983 (u_int)n->m_len); 984 m->m_len += n->m_len; 985 n = m_free(n); 986 } 987 } 988 989 /* 990 * Concatenate two pkthdr mbuf chains. 991 */ 992 void 993 m_catpkt(struct mbuf *m, struct mbuf *n) 994 { 995 996 M_ASSERTPKTHDR(m); 997 M_ASSERTPKTHDR(n); 998 999 m->m_pkthdr.len += n->m_pkthdr.len; 1000 m_demote(n, 1); 1001 1002 m_cat(m, n); 1003 } 1004 1005 void 1006 m_adj(struct mbuf *mp, int req_len) 1007 { 1008 int len = req_len; 1009 struct mbuf *m; 1010 int count; 1011 1012 if ((m = mp) == NULL) 1013 return; 1014 if (len >= 0) { 1015 /* 1016 * Trim from head. 1017 */ 1018 while (m != NULL && len > 0) { 1019 if (m->m_len <= len) { 1020 len -= m->m_len; 1021 m->m_len = 0; 1022 m = m->m_next; 1023 } else { 1024 m->m_len -= len; 1025 m->m_data += len; 1026 len = 0; 1027 } 1028 } 1029 if (mp->m_flags & M_PKTHDR) 1030 mp->m_pkthdr.len -= (req_len - len); 1031 } else { 1032 /* 1033 * Trim from tail. Scan the mbuf chain, 1034 * calculating its length and finding the last mbuf. 1035 * If the adjustment only affects this mbuf, then just 1036 * adjust and return. Otherwise, rescan and truncate 1037 * after the remaining size. 1038 */ 1039 len = -len; 1040 count = 0; 1041 for (;;) { 1042 count += m->m_len; 1043 if (m->m_next == (struct mbuf *)0) 1044 break; 1045 m = m->m_next; 1046 } 1047 if (m->m_len >= len) { 1048 m->m_len -= len; 1049 if (mp->m_flags & M_PKTHDR) 1050 mp->m_pkthdr.len -= len; 1051 return; 1052 } 1053 count -= len; 1054 if (count < 0) 1055 count = 0; 1056 /* 1057 * Correct length for chain is "count". 1058 * Find the mbuf with last data, adjust its length, 1059 * and toss data from remaining mbufs on chain. 1060 */ 1061 m = mp; 1062 if (m->m_flags & M_PKTHDR) 1063 m->m_pkthdr.len = count; 1064 for (; m; m = m->m_next) { 1065 if (m->m_len >= count) { 1066 m->m_len = count; 1067 if (m->m_next != NULL) { 1068 m_freem(m->m_next); 1069 m->m_next = NULL; 1070 } 1071 break; 1072 } 1073 count -= m->m_len; 1074 } 1075 } 1076 } 1077 1078 /* 1079 * Rearange an mbuf chain so that len bytes are contiguous 1080 * and in the data area of an mbuf (so that mtod will work 1081 * for a structure of size len). Returns the resulting 1082 * mbuf chain on success, frees it and returns null on failure. 1083 * If there is room, it will add up to max_protohdr-len extra bytes to the 1084 * contiguous region in an attempt to avoid being called next time. 1085 */ 1086 struct mbuf * 1087 m_pullup(struct mbuf *n, int len) 1088 { 1089 struct mbuf *m; 1090 int count; 1091 int space; 1092 1093 /* 1094 * If first mbuf has no cluster, and has room for len bytes 1095 * without shifting current data, pullup into it, 1096 * otherwise allocate a new mbuf to prepend to the chain. 1097 */ 1098 if ((n->m_flags & M_EXT) == 0 && 1099 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1100 if (n->m_len >= len) 1101 return (n); 1102 m = n; 1103 n = n->m_next; 1104 len -= m->m_len; 1105 } else { 1106 if (len > MHLEN) 1107 goto bad; 1108 m = m_get(M_NOWAIT, n->m_type); 1109 if (m == NULL) 1110 goto bad; 1111 if (n->m_flags & M_PKTHDR) 1112 m_move_pkthdr(m, n); 1113 } 1114 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1115 do { 1116 count = min(min(max(len, max_protohdr), space), n->m_len); 1117 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1118 (u_int)count); 1119 len -= count; 1120 m->m_len += count; 1121 n->m_len -= count; 1122 space -= count; 1123 if (n->m_len) 1124 n->m_data += count; 1125 else 1126 n = m_free(n); 1127 } while (len > 0 && n); 1128 if (len > 0) { 1129 (void) m_free(m); 1130 goto bad; 1131 } 1132 m->m_next = n; 1133 return (m); 1134 bad: 1135 m_freem(n); 1136 return (NULL); 1137 } 1138 1139 /* 1140 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1141 * the amount of empty space before the data in the new mbuf to be specified 1142 * (in the event that the caller expects to prepend later). 1143 */ 1144 int MSFail; 1145 1146 struct mbuf * 1147 m_copyup(struct mbuf *n, int len, int dstoff) 1148 { 1149 struct mbuf *m; 1150 int count, space; 1151 1152 if (len > (MHLEN - dstoff)) 1153 goto bad; 1154 m = m_get(M_NOWAIT, n->m_type); 1155 if (m == NULL) 1156 goto bad; 1157 if (n->m_flags & M_PKTHDR) 1158 m_move_pkthdr(m, n); 1159 m->m_data += dstoff; 1160 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1161 do { 1162 count = min(min(max(len, max_protohdr), space), n->m_len); 1163 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), 1164 (unsigned)count); 1165 len -= count; 1166 m->m_len += count; 1167 n->m_len -= count; 1168 space -= count; 1169 if (n->m_len) 1170 n->m_data += count; 1171 else 1172 n = m_free(n); 1173 } while (len > 0 && n); 1174 if (len > 0) { 1175 (void) m_free(m); 1176 goto bad; 1177 } 1178 m->m_next = n; 1179 return (m); 1180 bad: 1181 m_freem(n); 1182 MSFail++; 1183 return (NULL); 1184 } 1185 1186 /* 1187 * Partition an mbuf chain in two pieces, returning the tail -- 1188 * all but the first len0 bytes. In case of failure, it returns NULL and 1189 * attempts to restore the chain to its original state. 1190 * 1191 * Note that the resulting mbufs might be read-only, because the new 1192 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1193 * the "breaking point" happens to lie within a cluster mbuf. Use the 1194 * M_WRITABLE() macro to check for this case. 1195 */ 1196 struct mbuf * 1197 m_split(struct mbuf *m0, int len0, int wait) 1198 { 1199 struct mbuf *m, *n; 1200 u_int len = len0, remain; 1201 1202 MBUF_CHECKSLEEP(wait); 1203 for (m = m0; m && len > m->m_len; m = m->m_next) 1204 len -= m->m_len; 1205 if (m == NULL) 1206 return (NULL); 1207 remain = m->m_len - len; 1208 if (m0->m_flags & M_PKTHDR && remain == 0) { 1209 n = m_gethdr(wait, m0->m_type); 1210 if (n == NULL) 1211 return (NULL); 1212 n->m_next = m->m_next; 1213 m->m_next = NULL; 1214 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1215 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1216 m0->m_pkthdr.len = len0; 1217 return (n); 1218 } else if (m0->m_flags & M_PKTHDR) { 1219 n = m_gethdr(wait, m0->m_type); 1220 if (n == NULL) 1221 return (NULL); 1222 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1223 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1224 m0->m_pkthdr.len = len0; 1225 if (m->m_flags & M_EXT) 1226 goto extpacket; 1227 if (remain > MHLEN) { 1228 /* m can't be the lead packet */ 1229 MH_ALIGN(n, 0); 1230 n->m_next = m_split(m, len, wait); 1231 if (n->m_next == NULL) { 1232 (void) m_free(n); 1233 return (NULL); 1234 } else { 1235 n->m_len = 0; 1236 return (n); 1237 } 1238 } else 1239 MH_ALIGN(n, remain); 1240 } else if (remain == 0) { 1241 n = m->m_next; 1242 m->m_next = NULL; 1243 return (n); 1244 } else { 1245 n = m_get(wait, m->m_type); 1246 if (n == NULL) 1247 return (NULL); 1248 M_ALIGN(n, remain); 1249 } 1250 extpacket: 1251 if (m->m_flags & M_EXT) { 1252 n->m_data = m->m_data + len; 1253 mb_dupcl(n, m); 1254 } else { 1255 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1256 } 1257 n->m_len = remain; 1258 m->m_len = len; 1259 n->m_next = m->m_next; 1260 m->m_next = NULL; 1261 return (n); 1262 } 1263 /* 1264 * Routine to copy from device local memory into mbufs. 1265 * Note that `off' argument is offset into first mbuf of target chain from 1266 * which to begin copying the data to. 1267 */ 1268 struct mbuf * 1269 m_devget(char *buf, int totlen, int off, struct ifnet *ifp, 1270 void (*copy)(char *from, caddr_t to, u_int len)) 1271 { 1272 struct mbuf *m; 1273 struct mbuf *top = NULL, **mp = ⊤ 1274 int len; 1275 1276 if (off < 0 || off > MHLEN) 1277 return (NULL); 1278 1279 while (totlen > 0) { 1280 if (top == NULL) { /* First one, must be PKTHDR */ 1281 if (totlen + off >= MINCLSIZE) { 1282 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 1283 len = MCLBYTES; 1284 } else { 1285 m = m_gethdr(M_NOWAIT, MT_DATA); 1286 len = MHLEN; 1287 1288 /* Place initial small packet/header at end of mbuf */ 1289 if (m && totlen + off + max_linkhdr <= MLEN) { 1290 m->m_data += max_linkhdr; 1291 len -= max_linkhdr; 1292 } 1293 } 1294 if (m == NULL) 1295 return NULL; 1296 m->m_pkthdr.rcvif = ifp; 1297 m->m_pkthdr.len = totlen; 1298 } else { 1299 if (totlen + off >= MINCLSIZE) { 1300 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1301 len = MCLBYTES; 1302 } else { 1303 m = m_get(M_NOWAIT, MT_DATA); 1304 len = MLEN; 1305 } 1306 if (m == NULL) { 1307 m_freem(top); 1308 return NULL; 1309 } 1310 } 1311 if (off) { 1312 m->m_data += off; 1313 len -= off; 1314 off = 0; 1315 } 1316 m->m_len = len = min(totlen, len); 1317 if (copy) 1318 copy(buf, mtod(m, caddr_t), (u_int)len); 1319 else 1320 bcopy(buf, mtod(m, caddr_t), (u_int)len); 1321 buf += len; 1322 *mp = m; 1323 mp = &m->m_next; 1324 totlen -= len; 1325 } 1326 return (top); 1327 } 1328 1329 /* 1330 * Copy data from a buffer back into the indicated mbuf chain, 1331 * starting "off" bytes from the beginning, extending the mbuf 1332 * chain if necessary. 1333 */ 1334 void 1335 m_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp) 1336 { 1337 int mlen; 1338 struct mbuf *m = m0, *n; 1339 int totlen = 0; 1340 1341 if (m0 == NULL) 1342 return; 1343 while (off > (mlen = m->m_len)) { 1344 off -= mlen; 1345 totlen += mlen; 1346 if (m->m_next == NULL) { 1347 n = m_get(M_NOWAIT, m->m_type); 1348 if (n == NULL) 1349 goto out; 1350 bzero(mtod(n, caddr_t), MLEN); 1351 n->m_len = min(MLEN, len + off); 1352 m->m_next = n; 1353 } 1354 m = m->m_next; 1355 } 1356 while (len > 0) { 1357 if (m->m_next == NULL && (len > m->m_len - off)) { 1358 m->m_len += min(len - (m->m_len - off), 1359 M_TRAILINGSPACE(m)); 1360 } 1361 mlen = min (m->m_len - off, len); 1362 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 1363 cp += mlen; 1364 len -= mlen; 1365 mlen += off; 1366 off = 0; 1367 totlen += mlen; 1368 if (len == 0) 1369 break; 1370 if (m->m_next == NULL) { 1371 n = m_get(M_NOWAIT, m->m_type); 1372 if (n == NULL) 1373 break; 1374 n->m_len = min(MLEN, len); 1375 m->m_next = n; 1376 } 1377 m = m->m_next; 1378 } 1379 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1380 m->m_pkthdr.len = totlen; 1381 } 1382 1383 /* 1384 * Append the specified data to the indicated mbuf chain, 1385 * Extend the mbuf chain if the new data does not fit in 1386 * existing space. 1387 * 1388 * Return 1 if able to complete the job; otherwise 0. 1389 */ 1390 int 1391 m_append(struct mbuf *m0, int len, c_caddr_t cp) 1392 { 1393 struct mbuf *m, *n; 1394 int remainder, space; 1395 1396 for (m = m0; m->m_next != NULL; m = m->m_next) 1397 ; 1398 remainder = len; 1399 space = M_TRAILINGSPACE(m); 1400 if (space > 0) { 1401 /* 1402 * Copy into available space. 1403 */ 1404 if (space > remainder) 1405 space = remainder; 1406 bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1407 m->m_len += space; 1408 cp += space, remainder -= space; 1409 } 1410 while (remainder > 0) { 1411 /* 1412 * Allocate a new mbuf; could check space 1413 * and allocate a cluster instead. 1414 */ 1415 n = m_get(M_NOWAIT, m->m_type); 1416 if (n == NULL) 1417 break; 1418 n->m_len = min(MLEN, remainder); 1419 bcopy(cp, mtod(n, caddr_t), n->m_len); 1420 cp += n->m_len, remainder -= n->m_len; 1421 m->m_next = n; 1422 m = n; 1423 } 1424 if (m0->m_flags & M_PKTHDR) 1425 m0->m_pkthdr.len += len - remainder; 1426 return (remainder == 0); 1427 } 1428 1429 /* 1430 * Apply function f to the data in an mbuf chain starting "off" bytes from 1431 * the beginning, continuing for "len" bytes. 1432 */ 1433 int 1434 m_apply(struct mbuf *m, int off, int len, 1435 int (*f)(void *, void *, u_int), void *arg) 1436 { 1437 u_int count; 1438 int rval; 1439 1440 KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1441 KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1442 while (off > 0) { 1443 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1444 if (off < m->m_len) 1445 break; 1446 off -= m->m_len; 1447 m = m->m_next; 1448 } 1449 while (len > 0) { 1450 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1451 count = min(m->m_len - off, len); 1452 rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1453 if (rval) 1454 return (rval); 1455 len -= count; 1456 off = 0; 1457 m = m->m_next; 1458 } 1459 return (0); 1460 } 1461 1462 /* 1463 * Return a pointer to mbuf/offset of location in mbuf chain. 1464 */ 1465 struct mbuf * 1466 m_getptr(struct mbuf *m, int loc, int *off) 1467 { 1468 1469 while (loc >= 0) { 1470 /* Normal end of search. */ 1471 if (m->m_len > loc) { 1472 *off = loc; 1473 return (m); 1474 } else { 1475 loc -= m->m_len; 1476 if (m->m_next == NULL) { 1477 if (loc == 0) { 1478 /* Point at the end of valid data. */ 1479 *off = m->m_len; 1480 return (m); 1481 } 1482 return (NULL); 1483 } 1484 m = m->m_next; 1485 } 1486 } 1487 return (NULL); 1488 } 1489 1490 void 1491 m_print(const struct mbuf *m, int maxlen) 1492 { 1493 int len; 1494 int pdata; 1495 const struct mbuf *m2; 1496 1497 if (m == NULL) { 1498 printf("mbuf: %p\n", m); 1499 return; 1500 } 1501 1502 if (m->m_flags & M_PKTHDR) 1503 len = m->m_pkthdr.len; 1504 else 1505 len = -1; 1506 m2 = m; 1507 while (m2 != NULL && (len == -1 || len)) { 1508 pdata = m2->m_len; 1509 if (maxlen != -1 && pdata > maxlen) 1510 pdata = maxlen; 1511 printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len, 1512 m2->m_next, m2->m_flags, "\20\20freelist\17skipfw" 1513 "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly" 1514 "\3eor\2pkthdr\1ext", pdata ? "" : "\n"); 1515 if (pdata) 1516 printf(", %*D\n", pdata, (u_char *)m2->m_data, "-"); 1517 if (len != -1) 1518 len -= m2->m_len; 1519 m2 = m2->m_next; 1520 } 1521 if (len > 0) 1522 printf("%d bytes unaccounted for.\n", len); 1523 return; 1524 } 1525 1526 u_int 1527 m_fixhdr(struct mbuf *m0) 1528 { 1529 u_int len; 1530 1531 len = m_length(m0, NULL); 1532 m0->m_pkthdr.len = len; 1533 return (len); 1534 } 1535 1536 u_int 1537 m_length(struct mbuf *m0, struct mbuf **last) 1538 { 1539 struct mbuf *m; 1540 u_int len; 1541 1542 len = 0; 1543 for (m = m0; m != NULL; m = m->m_next) { 1544 len += m->m_len; 1545 if (m->m_next == NULL) 1546 break; 1547 } 1548 if (last != NULL) 1549 *last = m; 1550 return (len); 1551 } 1552 1553 /* 1554 * Defragment a mbuf chain, returning the shortest possible 1555 * chain of mbufs and clusters. If allocation fails and 1556 * this cannot be completed, NULL will be returned, but 1557 * the passed in chain will be unchanged. Upon success, 1558 * the original chain will be freed, and the new chain 1559 * will be returned. 1560 * 1561 * If a non-packet header is passed in, the original 1562 * mbuf (chain?) will be returned unharmed. 1563 */ 1564 struct mbuf * 1565 m_defrag(struct mbuf *m0, int how) 1566 { 1567 struct mbuf *m_new = NULL, *m_final = NULL; 1568 int progress = 0, length; 1569 1570 MBUF_CHECKSLEEP(how); 1571 if (!(m0->m_flags & M_PKTHDR)) 1572 return (m0); 1573 1574 m_fixhdr(m0); /* Needed sanity check */ 1575 1576 #ifdef MBUF_STRESS_TEST 1577 if (m_defragrandomfailures) { 1578 int temp = arc4random() & 0xff; 1579 if (temp == 0xba) 1580 goto nospace; 1581 } 1582 #endif 1583 1584 if (m0->m_pkthdr.len > MHLEN) 1585 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1586 else 1587 m_final = m_gethdr(how, MT_DATA); 1588 1589 if (m_final == NULL) 1590 goto nospace; 1591 1592 if (m_dup_pkthdr(m_final, m0, how) == 0) 1593 goto nospace; 1594 1595 m_new = m_final; 1596 1597 while (progress < m0->m_pkthdr.len) { 1598 length = m0->m_pkthdr.len - progress; 1599 if (length > MCLBYTES) 1600 length = MCLBYTES; 1601 1602 if (m_new == NULL) { 1603 if (length > MLEN) 1604 m_new = m_getcl(how, MT_DATA, 0); 1605 else 1606 m_new = m_get(how, MT_DATA); 1607 if (m_new == NULL) 1608 goto nospace; 1609 } 1610 1611 m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 1612 progress += length; 1613 m_new->m_len = length; 1614 if (m_new != m_final) 1615 m_cat(m_final, m_new); 1616 m_new = NULL; 1617 } 1618 #ifdef MBUF_STRESS_TEST 1619 if (m0->m_next == NULL) 1620 m_defraguseless++; 1621 #endif 1622 m_freem(m0); 1623 m0 = m_final; 1624 #ifdef MBUF_STRESS_TEST 1625 m_defragpackets++; 1626 m_defragbytes += m0->m_pkthdr.len; 1627 #endif 1628 return (m0); 1629 nospace: 1630 #ifdef MBUF_STRESS_TEST 1631 m_defragfailure++; 1632 #endif 1633 if (m_final) 1634 m_freem(m_final); 1635 return (NULL); 1636 } 1637 1638 /* 1639 * Defragment an mbuf chain, returning at most maxfrags separate 1640 * mbufs+clusters. If this is not possible NULL is returned and 1641 * the original mbuf chain is left in it's present (potentially 1642 * modified) state. We use two techniques: collapsing consecutive 1643 * mbufs and replacing consecutive mbufs by a cluster. 1644 * 1645 * NB: this should really be named m_defrag but that name is taken 1646 */ 1647 struct mbuf * 1648 m_collapse(struct mbuf *m0, int how, int maxfrags) 1649 { 1650 struct mbuf *m, *n, *n2, **prev; 1651 u_int curfrags; 1652 1653 /* 1654 * Calculate the current number of frags. 1655 */ 1656 curfrags = 0; 1657 for (m = m0; m != NULL; m = m->m_next) 1658 curfrags++; 1659 /* 1660 * First, try to collapse mbufs. Note that we always collapse 1661 * towards the front so we don't need to deal with moving the 1662 * pkthdr. This may be suboptimal if the first mbuf has much 1663 * less data than the following. 1664 */ 1665 m = m0; 1666 again: 1667 for (;;) { 1668 n = m->m_next; 1669 if (n == NULL) 1670 break; 1671 if (M_WRITABLE(m) && 1672 n->m_len < M_TRAILINGSPACE(m)) { 1673 bcopy(mtod(n, void *), mtod(m, char *) + m->m_len, 1674 n->m_len); 1675 m->m_len += n->m_len; 1676 m->m_next = n->m_next; 1677 m_free(n); 1678 if (--curfrags <= maxfrags) 1679 return m0; 1680 } else 1681 m = n; 1682 } 1683 KASSERT(maxfrags > 1, 1684 ("maxfrags %u, but normal collapse failed", maxfrags)); 1685 /* 1686 * Collapse consecutive mbufs to a cluster. 1687 */ 1688 prev = &m0->m_next; /* NB: not the first mbuf */ 1689 while ((n = *prev) != NULL) { 1690 if ((n2 = n->m_next) != NULL && 1691 n->m_len + n2->m_len < MCLBYTES) { 1692 m = m_getcl(how, MT_DATA, 0); 1693 if (m == NULL) 1694 goto bad; 1695 bcopy(mtod(n, void *), mtod(m, void *), n->m_len); 1696 bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len, 1697 n2->m_len); 1698 m->m_len = n->m_len + n2->m_len; 1699 m->m_next = n2->m_next; 1700 *prev = m; 1701 m_free(n); 1702 m_free(n2); 1703 if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */ 1704 return m0; 1705 /* 1706 * Still not there, try the normal collapse 1707 * again before we allocate another cluster. 1708 */ 1709 goto again; 1710 } 1711 prev = &n->m_next; 1712 } 1713 /* 1714 * No place where we can collapse to a cluster; punt. 1715 * This can occur if, for example, you request 2 frags 1716 * but the packet requires that both be clusters (we 1717 * never reallocate the first mbuf to avoid moving the 1718 * packet header). 1719 */ 1720 bad: 1721 return NULL; 1722 } 1723 1724 #ifdef MBUF_STRESS_TEST 1725 1726 /* 1727 * Fragment an mbuf chain. There's no reason you'd ever want to do 1728 * this in normal usage, but it's great for stress testing various 1729 * mbuf consumers. 1730 * 1731 * If fragmentation is not possible, the original chain will be 1732 * returned. 1733 * 1734 * Possible length values: 1735 * 0 no fragmentation will occur 1736 * > 0 each fragment will be of the specified length 1737 * -1 each fragment will be the same random value in length 1738 * -2 each fragment's length will be entirely random 1739 * (Random values range from 1 to 256) 1740 */ 1741 struct mbuf * 1742 m_fragment(struct mbuf *m0, int how, int length) 1743 { 1744 struct mbuf *m_new = NULL, *m_final = NULL; 1745 int progress = 0; 1746 1747 if (!(m0->m_flags & M_PKTHDR)) 1748 return (m0); 1749 1750 if ((length == 0) || (length < -2)) 1751 return (m0); 1752 1753 m_fixhdr(m0); /* Needed sanity check */ 1754 1755 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1756 1757 if (m_final == NULL) 1758 goto nospace; 1759 1760 if (m_dup_pkthdr(m_final, m0, how) == 0) 1761 goto nospace; 1762 1763 m_new = m_final; 1764 1765 if (length == -1) 1766 length = 1 + (arc4random() & 255); 1767 1768 while (progress < m0->m_pkthdr.len) { 1769 int fraglen; 1770 1771 if (length > 0) 1772 fraglen = length; 1773 else 1774 fraglen = 1 + (arc4random() & 255); 1775 if (fraglen > m0->m_pkthdr.len - progress) 1776 fraglen = m0->m_pkthdr.len - progress; 1777 1778 if (fraglen > MCLBYTES) 1779 fraglen = MCLBYTES; 1780 1781 if (m_new == NULL) { 1782 m_new = m_getcl(how, MT_DATA, 0); 1783 if (m_new == NULL) 1784 goto nospace; 1785 } 1786 1787 m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t)); 1788 progress += fraglen; 1789 m_new->m_len = fraglen; 1790 if (m_new != m_final) 1791 m_cat(m_final, m_new); 1792 m_new = NULL; 1793 } 1794 m_freem(m0); 1795 m0 = m_final; 1796 return (m0); 1797 nospace: 1798 if (m_final) 1799 m_freem(m_final); 1800 /* Return the original chain on failure */ 1801 return (m0); 1802 } 1803 1804 #endif 1805 1806 /* 1807 * Copy the contents of uio into a properly sized mbuf chain. 1808 */ 1809 struct mbuf * 1810 m_uiotombuf(struct uio *uio, int how, int len, int align, int flags) 1811 { 1812 struct mbuf *m, *mb; 1813 int error, length; 1814 ssize_t total; 1815 int progress = 0; 1816 1817 /* 1818 * len can be zero or an arbitrary large value bound by 1819 * the total data supplied by the uio. 1820 */ 1821 if (len > 0) 1822 total = min(uio->uio_resid, len); 1823 else 1824 total = uio->uio_resid; 1825 1826 /* 1827 * The smallest unit returned by m_getm2() is a single mbuf 1828 * with pkthdr. We can't align past it. 1829 */ 1830 if (align >= MHLEN) 1831 return (NULL); 1832 1833 /* 1834 * Give us the full allocation or nothing. 1835 * If len is zero return the smallest empty mbuf. 1836 */ 1837 m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags); 1838 if (m == NULL) 1839 return (NULL); 1840 m->m_data += align; 1841 1842 /* Fill all mbufs with uio data and update header information. */ 1843 for (mb = m; mb != NULL; mb = mb->m_next) { 1844 length = min(M_TRAILINGSPACE(mb), total - progress); 1845 1846 error = uiomove(mtod(mb, void *), length, uio); 1847 if (error) { 1848 m_freem(m); 1849 return (NULL); 1850 } 1851 1852 mb->m_len = length; 1853 progress += length; 1854 if (flags & M_PKTHDR) 1855 m->m_pkthdr.len += length; 1856 } 1857 KASSERT(progress == total, ("%s: progress != total", __func__)); 1858 1859 return (m); 1860 } 1861 1862 /* 1863 * Copy an mbuf chain into a uio limited by len if set. 1864 */ 1865 int 1866 m_mbuftouio(struct uio *uio, struct mbuf *m, int len) 1867 { 1868 int error, length, total; 1869 int progress = 0; 1870 1871 if (len > 0) 1872 total = min(uio->uio_resid, len); 1873 else 1874 total = uio->uio_resid; 1875 1876 /* Fill the uio with data from the mbufs. */ 1877 for (; m != NULL; m = m->m_next) { 1878 length = min(m->m_len, total - progress); 1879 1880 error = uiomove(mtod(m, void *), length, uio); 1881 if (error) 1882 return (error); 1883 1884 progress += length; 1885 } 1886 1887 return (0); 1888 } 1889 1890 /* 1891 * Set the m_data pointer of a newly-allocated mbuf 1892 * to place an object of the specified size at the 1893 * end of the mbuf, longword aligned. 1894 */ 1895 void 1896 m_align(struct mbuf *m, int len) 1897 { 1898 #ifdef INVARIANTS 1899 const char *msg = "%s: not a virgin mbuf"; 1900 #endif 1901 int adjust; 1902 1903 if (m->m_flags & M_EXT) { 1904 KASSERT(m->m_data == m->m_ext.ext_buf, (msg, __func__)); 1905 adjust = m->m_ext.ext_size - len; 1906 } else if (m->m_flags & M_PKTHDR) { 1907 KASSERT(m->m_data == m->m_pktdat, (msg, __func__)); 1908 adjust = MHLEN - len; 1909 } else { 1910 KASSERT(m->m_data == m->m_dat, (msg, __func__)); 1911 adjust = MLEN - len; 1912 } 1913 1914 m->m_data += adjust &~ (sizeof(long)-1); 1915 } 1916 1917 /* 1918 * Create a writable copy of the mbuf chain. While doing this 1919 * we compact the chain with a goal of producing a chain with 1920 * at most two mbufs. The second mbuf in this chain is likely 1921 * to be a cluster. The primary purpose of this work is to create 1922 * a writable packet for encryption, compression, etc. The 1923 * secondary goal is to linearize the data so the data can be 1924 * passed to crypto hardware in the most efficient manner possible. 1925 */ 1926 struct mbuf * 1927 m_unshare(struct mbuf *m0, int how) 1928 { 1929 struct mbuf *m, *mprev; 1930 struct mbuf *n, *mfirst, *mlast; 1931 int len, off; 1932 1933 mprev = NULL; 1934 for (m = m0; m != NULL; m = mprev->m_next) { 1935 /* 1936 * Regular mbufs are ignored unless there's a cluster 1937 * in front of it that we can use to coalesce. We do 1938 * the latter mainly so later clusters can be coalesced 1939 * also w/o having to handle them specially (i.e. convert 1940 * mbuf+cluster -> cluster). This optimization is heavily 1941 * influenced by the assumption that we're running over 1942 * Ethernet where MCLBYTES is large enough that the max 1943 * packet size will permit lots of coalescing into a 1944 * single cluster. This in turn permits efficient 1945 * crypto operations, especially when using hardware. 1946 */ 1947 if ((m->m_flags & M_EXT) == 0) { 1948 if (mprev && (mprev->m_flags & M_EXT) && 1949 m->m_len <= M_TRAILINGSPACE(mprev)) { 1950 /* XXX: this ignores mbuf types */ 1951 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1952 mtod(m, caddr_t), m->m_len); 1953 mprev->m_len += m->m_len; 1954 mprev->m_next = m->m_next; /* unlink from chain */ 1955 m_free(m); /* reclaim mbuf */ 1956 #if 0 1957 newipsecstat.ips_mbcoalesced++; 1958 #endif 1959 } else { 1960 mprev = m; 1961 } 1962 continue; 1963 } 1964 /* 1965 * Writable mbufs are left alone (for now). 1966 */ 1967 if (M_WRITABLE(m)) { 1968 mprev = m; 1969 continue; 1970 } 1971 1972 /* 1973 * Not writable, replace with a copy or coalesce with 1974 * the previous mbuf if possible (since we have to copy 1975 * it anyway, we try to reduce the number of mbufs and 1976 * clusters so that future work is easier). 1977 */ 1978 KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags)); 1979 /* NB: we only coalesce into a cluster or larger */ 1980 if (mprev != NULL && (mprev->m_flags & M_EXT) && 1981 m->m_len <= M_TRAILINGSPACE(mprev)) { 1982 /* XXX: this ignores mbuf types */ 1983 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1984 mtod(m, caddr_t), m->m_len); 1985 mprev->m_len += m->m_len; 1986 mprev->m_next = m->m_next; /* unlink from chain */ 1987 m_free(m); /* reclaim mbuf */ 1988 #if 0 1989 newipsecstat.ips_clcoalesced++; 1990 #endif 1991 continue; 1992 } 1993 1994 /* 1995 * Allocate new space to hold the copy and copy the data. 1996 * We deal with jumbo mbufs (i.e. m_len > MCLBYTES) by 1997 * splitting them into clusters. We could just malloc a 1998 * buffer and make it external but too many device drivers 1999 * don't know how to break up the non-contiguous memory when 2000 * doing DMA. 2001 */ 2002 n = m_getcl(how, m->m_type, m->m_flags); 2003 if (n == NULL) { 2004 m_freem(m0); 2005 return (NULL); 2006 } 2007 len = m->m_len; 2008 off = 0; 2009 mfirst = n; 2010 mlast = NULL; 2011 for (;;) { 2012 int cc = min(len, MCLBYTES); 2013 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc); 2014 n->m_len = cc; 2015 if (mlast != NULL) 2016 mlast->m_next = n; 2017 mlast = n; 2018 #if 0 2019 newipsecstat.ips_clcopied++; 2020 #endif 2021 2022 len -= cc; 2023 if (len <= 0) 2024 break; 2025 off += cc; 2026 2027 n = m_getcl(how, m->m_type, m->m_flags); 2028 if (n == NULL) { 2029 m_freem(mfirst); 2030 m_freem(m0); 2031 return (NULL); 2032 } 2033 } 2034 n->m_next = m->m_next; 2035 if (mprev == NULL) 2036 m0 = mfirst; /* new head of chain */ 2037 else 2038 mprev->m_next = mfirst; /* replace old mbuf */ 2039 m_free(m); /* release old mbuf */ 2040 mprev = mfirst; 2041 } 2042 return (m0); 2043 } 2044 2045 #ifdef MBUF_PROFILING 2046 2047 #define MP_BUCKETS 32 /* don't just change this as things may overflow.*/ 2048 struct mbufprofile { 2049 uintmax_t wasted[MP_BUCKETS]; 2050 uintmax_t used[MP_BUCKETS]; 2051 uintmax_t segments[MP_BUCKETS]; 2052 } mbprof; 2053 2054 #define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */ 2055 #define MP_NUMLINES 6 2056 #define MP_NUMSPERLINE 16 2057 #define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */ 2058 /* work out max space needed and add a bit of spare space too */ 2059 #define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE) 2060 #define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES) 2061 2062 char mbprofbuf[MP_BUFSIZE]; 2063 2064 void 2065 m_profile(struct mbuf *m) 2066 { 2067 int segments = 0; 2068 int used = 0; 2069 int wasted = 0; 2070 2071 while (m) { 2072 segments++; 2073 used += m->m_len; 2074 if (m->m_flags & M_EXT) { 2075 wasted += MHLEN - sizeof(m->m_ext) + 2076 m->m_ext.ext_size - m->m_len; 2077 } else { 2078 if (m->m_flags & M_PKTHDR) 2079 wasted += MHLEN - m->m_len; 2080 else 2081 wasted += MLEN - m->m_len; 2082 } 2083 m = m->m_next; 2084 } 2085 /* be paranoid.. it helps */ 2086 if (segments > MP_BUCKETS - 1) 2087 segments = MP_BUCKETS - 1; 2088 if (used > 100000) 2089 used = 100000; 2090 if (wasted > 100000) 2091 wasted = 100000; 2092 /* store in the appropriate bucket */ 2093 /* don't bother locking. if it's slightly off, so what? */ 2094 mbprof.segments[segments]++; 2095 mbprof.used[fls(used)]++; 2096 mbprof.wasted[fls(wasted)]++; 2097 } 2098 2099 static void 2100 mbprof_textify(void) 2101 { 2102 int offset; 2103 char *c; 2104 uint64_t *p; 2105 2106 p = &mbprof.wasted[0]; 2107 c = mbprofbuf; 2108 offset = snprintf(c, MP_MAXLINE + 10, 2109 "wasted:\n" 2110 "%ju %ju %ju %ju %ju %ju %ju %ju " 2111 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2112 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2113 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2114 #ifdef BIG_ARRAY 2115 p = &mbprof.wasted[16]; 2116 c += offset; 2117 offset = snprintf(c, MP_MAXLINE, 2118 "%ju %ju %ju %ju %ju %ju %ju %ju " 2119 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2120 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2121 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2122 #endif 2123 p = &mbprof.used[0]; 2124 c += offset; 2125 offset = snprintf(c, MP_MAXLINE + 10, 2126 "used:\n" 2127 "%ju %ju %ju %ju %ju %ju %ju %ju " 2128 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2129 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2130 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2131 #ifdef BIG_ARRAY 2132 p = &mbprof.used[16]; 2133 c += offset; 2134 offset = snprintf(c, MP_MAXLINE, 2135 "%ju %ju %ju %ju %ju %ju %ju %ju " 2136 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2137 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2138 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2139 #endif 2140 p = &mbprof.segments[0]; 2141 c += offset; 2142 offset = snprintf(c, MP_MAXLINE + 10, 2143 "segments:\n" 2144 "%ju %ju %ju %ju %ju %ju %ju %ju " 2145 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2146 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2147 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2148 #ifdef BIG_ARRAY 2149 p = &mbprof.segments[16]; 2150 c += offset; 2151 offset = snprintf(c, MP_MAXLINE, 2152 "%ju %ju %ju %ju %ju %ju %ju %ju " 2153 "%ju %ju %ju %ju %ju %ju %ju %jju", 2154 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2155 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2156 #endif 2157 } 2158 2159 static int 2160 mbprof_handler(SYSCTL_HANDLER_ARGS) 2161 { 2162 int error; 2163 2164 mbprof_textify(); 2165 error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1); 2166 return (error); 2167 } 2168 2169 static int 2170 mbprof_clr_handler(SYSCTL_HANDLER_ARGS) 2171 { 2172 int clear, error; 2173 2174 clear = 0; 2175 error = sysctl_handle_int(oidp, &clear, 0, req); 2176 if (error || !req->newptr) 2177 return (error); 2178 2179 if (clear) { 2180 bzero(&mbprof, sizeof(mbprof)); 2181 } 2182 2183 return (error); 2184 } 2185 2186 2187 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD, 2188 NULL, 0, mbprof_handler, "A", "mbuf profiling statistics"); 2189 2190 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW, 2191 NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics"); 2192 #endif 2193 2194