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