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 if (top == NULL) 653 mbstat.m_mcfail++; /* XXX: No consistency. */ 654 655 return (top); 656 nospace: 657 m_freem(top); 658 mbstat.m_mcfail++; /* XXX: No consistency. */ 659 return (NULL); 660 } 661 662 /* 663 * Returns mbuf chain with new head for the prepending case. 664 * Copies from mbuf (chain) n from off for len to mbuf (chain) m 665 * either prepending or appending the data. 666 * The resulting mbuf (chain) m is fully writeable. 667 * m is destination (is made writeable) 668 * n is source, off is offset in source, len is len from offset 669 * dir, 0 append, 1 prepend 670 * how, wait or nowait 671 */ 672 673 static int 674 m_bcopyxxx(void *s, void *t, u_int len) 675 { 676 bcopy(s, t, (size_t)len); 677 return 0; 678 } 679 680 struct mbuf * 681 m_copymdata(struct mbuf *m, struct mbuf *n, int off, int len, 682 int prep, int how) 683 { 684 struct mbuf *mm, *x, *z, *prev = NULL; 685 caddr_t p; 686 int i, nlen = 0; 687 caddr_t buf[MLEN]; 688 689 KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source")); 690 KASSERT(off >= 0, ("m_copymdata, negative off %d", off)); 691 KASSERT(len >= 0, ("m_copymdata, negative len %d", len)); 692 KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep)); 693 694 mm = m; 695 if (!prep) { 696 while(mm->m_next) { 697 prev = mm; 698 mm = mm->m_next; 699 } 700 } 701 for (z = n; z != NULL; z = z->m_next) 702 nlen += z->m_len; 703 if (len == M_COPYALL) 704 len = nlen - off; 705 if (off + len > nlen || len < 1) 706 return NULL; 707 708 if (!M_WRITABLE(mm)) { 709 /* XXX: Use proper m_xxx function instead. */ 710 x = m_getcl(how, MT_DATA, mm->m_flags); 711 if (x == NULL) 712 return NULL; 713 bcopy(mm->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size); 714 p = x->m_ext.ext_buf + (mm->m_data - mm->m_ext.ext_buf); 715 x->m_data = p; 716 mm->m_next = NULL; 717 if (mm != m) 718 prev->m_next = x; 719 m_free(mm); 720 mm = x; 721 } 722 723 /* 724 * Append/prepend the data. Allocating mbufs as necessary. 725 */ 726 /* Shortcut if enough free space in first/last mbuf. */ 727 if (!prep && M_TRAILINGSPACE(mm) >= len) { 728 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) + 729 mm->m_len); 730 mm->m_len += len; 731 mm->m_pkthdr.len += len; 732 return m; 733 } 734 if (prep && M_LEADINGSPACE(mm) >= len) { 735 mm->m_data = mtod(mm, caddr_t) - len; 736 m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t)); 737 mm->m_len += len; 738 mm->m_pkthdr.len += len; 739 return mm; 740 } 741 742 /* Expand first/last mbuf to cluster if possible. */ 743 if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) { 744 bcopy(mm->m_data, &buf, mm->m_len); 745 m_clget(mm, how); 746 if (!(mm->m_flags & M_EXT)) 747 return NULL; 748 bcopy(&buf, mm->m_ext.ext_buf, mm->m_len); 749 mm->m_data = mm->m_ext.ext_buf; 750 mm->m_pkthdr.header = NULL; 751 } 752 if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) { 753 bcopy(mm->m_data, &buf, mm->m_len); 754 m_clget(mm, how); 755 if (!(mm->m_flags & M_EXT)) 756 return NULL; 757 bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf + 758 mm->m_ext.ext_size - mm->m_len, mm->m_len); 759 mm->m_data = (caddr_t)mm->m_ext.ext_buf + 760 mm->m_ext.ext_size - mm->m_len; 761 mm->m_pkthdr.header = NULL; 762 } 763 764 /* Append/prepend as many mbuf (clusters) as necessary to fit len. */ 765 if (!prep && len > M_TRAILINGSPACE(mm)) { 766 if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA)) 767 return NULL; 768 } 769 if (prep && len > M_LEADINGSPACE(mm)) { 770 if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA))) 771 return NULL; 772 i = 0; 773 for (x = z; x != NULL; x = x->m_next) { 774 i += x->m_flags & M_EXT ? x->m_ext.ext_size : 775 (x->m_flags & M_PKTHDR ? MHLEN : MLEN); 776 if (!x->m_next) 777 break; 778 } 779 z->m_data += i - len; 780 m_move_pkthdr(mm, z); 781 x->m_next = mm; 782 mm = z; 783 } 784 785 /* Seek to start position in source mbuf. Optimization for long chains. */ 786 while (off > 0) { 787 if (off < n->m_len) 788 break; 789 off -= n->m_len; 790 n = n->m_next; 791 } 792 793 /* Copy data into target mbuf. */ 794 z = mm; 795 while (len > 0) { 796 KASSERT(z != NULL, ("m_copymdata, falling off target edge")); 797 i = M_TRAILINGSPACE(z); 798 m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len); 799 z->m_len += i; 800 /* fixup pkthdr.len if necessary */ 801 if ((prep ? mm : m)->m_flags & M_PKTHDR) 802 (prep ? mm : m)->m_pkthdr.len += i; 803 off += i; 804 len -= i; 805 z = z->m_next; 806 } 807 return (prep ? mm : m); 808 } 809 810 /* 811 * Copy an entire packet, including header (which must be present). 812 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 813 * Note that the copy is read-only, because clusters are not copied, 814 * only their reference counts are incremented. 815 * Preserve alignment of the first mbuf so if the creator has left 816 * some room at the beginning (e.g. for inserting protocol headers) 817 * the copies still have the room available. 818 */ 819 struct mbuf * 820 m_copypacket(struct mbuf *m, int how) 821 { 822 struct mbuf *top, *n, *o; 823 824 MBUF_CHECKSLEEP(how); 825 n = m_get(how, m->m_type); 826 top = n; 827 if (n == NULL) 828 goto nospace; 829 830 if (!m_dup_pkthdr(n, m, how)) 831 goto nospace; 832 n->m_len = m->m_len; 833 if (m->m_flags & M_EXT) { 834 n->m_data = m->m_data; 835 mb_dupcl(n, m); 836 } else { 837 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 838 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 839 } 840 841 m = m->m_next; 842 while (m) { 843 o = m_get(how, m->m_type); 844 if (o == NULL) 845 goto nospace; 846 847 n->m_next = o; 848 n = n->m_next; 849 850 n->m_len = m->m_len; 851 if (m->m_flags & M_EXT) { 852 n->m_data = m->m_data; 853 mb_dupcl(n, m); 854 } else { 855 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 856 } 857 858 m = m->m_next; 859 } 860 return top; 861 nospace: 862 m_freem(top); 863 mbstat.m_mcfail++; /* XXX: No consistency. */ 864 return (NULL); 865 } 866 867 /* 868 * Copy data from an mbuf chain starting "off" bytes from the beginning, 869 * continuing for "len" bytes, into the indicated buffer. 870 */ 871 void 872 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 873 { 874 u_int count; 875 876 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 877 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 878 while (off > 0) { 879 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 880 if (off < m->m_len) 881 break; 882 off -= m->m_len; 883 m = m->m_next; 884 } 885 while (len > 0) { 886 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 887 count = min(m->m_len - off, len); 888 bcopy(mtod(m, caddr_t) + off, cp, count); 889 len -= count; 890 cp += count; 891 off = 0; 892 m = m->m_next; 893 } 894 } 895 896 /* 897 * Copy a packet header mbuf chain into a completely new chain, including 898 * copying any mbuf clusters. Use this instead of m_copypacket() when 899 * you need a writable copy of an mbuf chain. 900 */ 901 struct mbuf * 902 m_dup(struct mbuf *m, int how) 903 { 904 struct mbuf **p, *top = NULL; 905 int remain, moff, nsize; 906 907 MBUF_CHECKSLEEP(how); 908 /* Sanity check */ 909 if (m == NULL) 910 return (NULL); 911 M_ASSERTPKTHDR(m); 912 913 /* While there's more data, get a new mbuf, tack it on, and fill it */ 914 remain = m->m_pkthdr.len; 915 moff = 0; 916 p = ⊤ 917 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 918 struct mbuf *n; 919 920 /* Get the next new mbuf */ 921 if (remain >= MINCLSIZE) { 922 n = m_getcl(how, m->m_type, 0); 923 nsize = MCLBYTES; 924 } else { 925 n = m_get(how, m->m_type); 926 nsize = MLEN; 927 } 928 if (n == NULL) 929 goto nospace; 930 931 if (top == NULL) { /* First one, must be PKTHDR */ 932 if (!m_dup_pkthdr(n, m, how)) { 933 m_free(n); 934 goto nospace; 935 } 936 if ((n->m_flags & M_EXT) == 0) 937 nsize = MHLEN; 938 } 939 n->m_len = 0; 940 941 /* Link it into the new chain */ 942 *p = n; 943 p = &n->m_next; 944 945 /* Copy data from original mbuf(s) into new mbuf */ 946 while (n->m_len < nsize && m != NULL) { 947 int chunk = min(nsize - n->m_len, m->m_len - moff); 948 949 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 950 moff += chunk; 951 n->m_len += chunk; 952 remain -= chunk; 953 if (moff == m->m_len) { 954 m = m->m_next; 955 moff = 0; 956 } 957 } 958 959 /* Check correct total mbuf length */ 960 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 961 ("%s: bogus m_pkthdr.len", __func__)); 962 } 963 return (top); 964 965 nospace: 966 m_freem(top); 967 mbstat.m_mcfail++; /* XXX: No consistency. */ 968 return (NULL); 969 } 970 971 /* 972 * Concatenate mbuf chain n to m. 973 * Both chains must be of the same type (e.g. MT_DATA). 974 * Any m_pkthdr is not updated. 975 */ 976 void 977 m_cat(struct mbuf *m, struct mbuf *n) 978 { 979 while (m->m_next) 980 m = m->m_next; 981 while (n) { 982 if (!M_WRITABLE(m) || 983 M_TRAILINGSPACE(m) < n->m_len) { 984 /* just join the two chains */ 985 m->m_next = n; 986 return; 987 } 988 /* splat the data from one into the other */ 989 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 990 (u_int)n->m_len); 991 m->m_len += n->m_len; 992 n = m_free(n); 993 } 994 } 995 996 void 997 m_adj(struct mbuf *mp, int req_len) 998 { 999 int len = req_len; 1000 struct mbuf *m; 1001 int count; 1002 1003 if ((m = mp) == NULL) 1004 return; 1005 if (len >= 0) { 1006 /* 1007 * Trim from head. 1008 */ 1009 while (m != NULL && len > 0) { 1010 if (m->m_len <= len) { 1011 len -= m->m_len; 1012 m->m_len = 0; 1013 m = m->m_next; 1014 } else { 1015 m->m_len -= len; 1016 m->m_data += len; 1017 len = 0; 1018 } 1019 } 1020 if (mp->m_flags & M_PKTHDR) 1021 mp->m_pkthdr.len -= (req_len - len); 1022 } else { 1023 /* 1024 * Trim from tail. Scan the mbuf chain, 1025 * calculating its length and finding the last mbuf. 1026 * If the adjustment only affects this mbuf, then just 1027 * adjust and return. Otherwise, rescan and truncate 1028 * after the remaining size. 1029 */ 1030 len = -len; 1031 count = 0; 1032 for (;;) { 1033 count += m->m_len; 1034 if (m->m_next == (struct mbuf *)0) 1035 break; 1036 m = m->m_next; 1037 } 1038 if (m->m_len >= len) { 1039 m->m_len -= len; 1040 if (mp->m_flags & M_PKTHDR) 1041 mp->m_pkthdr.len -= len; 1042 return; 1043 } 1044 count -= len; 1045 if (count < 0) 1046 count = 0; 1047 /* 1048 * Correct length for chain is "count". 1049 * Find the mbuf with last data, adjust its length, 1050 * and toss data from remaining mbufs on chain. 1051 */ 1052 m = mp; 1053 if (m->m_flags & M_PKTHDR) 1054 m->m_pkthdr.len = count; 1055 for (; m; m = m->m_next) { 1056 if (m->m_len >= count) { 1057 m->m_len = count; 1058 if (m->m_next != NULL) { 1059 m_freem(m->m_next); 1060 m->m_next = NULL; 1061 } 1062 break; 1063 } 1064 count -= m->m_len; 1065 } 1066 } 1067 } 1068 1069 /* 1070 * Rearange an mbuf chain so that len bytes are contiguous 1071 * and in the data area of an mbuf (so that mtod will work 1072 * for a structure of size len). Returns the resulting 1073 * mbuf chain on success, frees it and returns null on failure. 1074 * If there is room, it will add up to max_protohdr-len extra bytes to the 1075 * contiguous region in an attempt to avoid being called next time. 1076 */ 1077 struct mbuf * 1078 m_pullup(struct mbuf *n, int len) 1079 { 1080 struct mbuf *m; 1081 int count; 1082 int space; 1083 1084 /* 1085 * If first mbuf has no cluster, and has room for len bytes 1086 * without shifting current data, pullup into it, 1087 * otherwise allocate a new mbuf to prepend to the chain. 1088 */ 1089 if ((n->m_flags & M_EXT) == 0 && 1090 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1091 if (n->m_len >= len) 1092 return (n); 1093 m = n; 1094 n = n->m_next; 1095 len -= m->m_len; 1096 } else { 1097 if (len > MHLEN) 1098 goto bad; 1099 m = m_get(M_NOWAIT, n->m_type); 1100 if (m == NULL) 1101 goto bad; 1102 if (n->m_flags & M_PKTHDR) 1103 m_move_pkthdr(m, n); 1104 } 1105 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1106 do { 1107 count = min(min(max(len, max_protohdr), space), n->m_len); 1108 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1109 (u_int)count); 1110 len -= count; 1111 m->m_len += count; 1112 n->m_len -= count; 1113 space -= count; 1114 if (n->m_len) 1115 n->m_data += count; 1116 else 1117 n = m_free(n); 1118 } while (len > 0 && n); 1119 if (len > 0) { 1120 (void) m_free(m); 1121 goto bad; 1122 } 1123 m->m_next = n; 1124 return (m); 1125 bad: 1126 m_freem(n); 1127 mbstat.m_mpfail++; /* XXX: No consistency. */ 1128 return (NULL); 1129 } 1130 1131 /* 1132 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1133 * the amount of empty space before the data in the new mbuf to be specified 1134 * (in the event that the caller expects to prepend later). 1135 */ 1136 int MSFail; 1137 1138 struct mbuf * 1139 m_copyup(struct mbuf *n, int len, int dstoff) 1140 { 1141 struct mbuf *m; 1142 int count, space; 1143 1144 if (len > (MHLEN - dstoff)) 1145 goto bad; 1146 m = m_get(M_NOWAIT, n->m_type); 1147 if (m == NULL) 1148 goto bad; 1149 if (n->m_flags & M_PKTHDR) 1150 m_move_pkthdr(m, n); 1151 m->m_data += dstoff; 1152 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1153 do { 1154 count = min(min(max(len, max_protohdr), space), n->m_len); 1155 memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), 1156 (unsigned)count); 1157 len -= count; 1158 m->m_len += count; 1159 n->m_len -= count; 1160 space -= count; 1161 if (n->m_len) 1162 n->m_data += count; 1163 else 1164 n = m_free(n); 1165 } while (len > 0 && n); 1166 if (len > 0) { 1167 (void) m_free(m); 1168 goto bad; 1169 } 1170 m->m_next = n; 1171 return (m); 1172 bad: 1173 m_freem(n); 1174 MSFail++; 1175 return (NULL); 1176 } 1177 1178 /* 1179 * Partition an mbuf chain in two pieces, returning the tail -- 1180 * all but the first len0 bytes. In case of failure, it returns NULL and 1181 * attempts to restore the chain to its original state. 1182 * 1183 * Note that the resulting mbufs might be read-only, because the new 1184 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1185 * the "breaking point" happens to lie within a cluster mbuf. Use the 1186 * M_WRITABLE() macro to check for this case. 1187 */ 1188 struct mbuf * 1189 m_split(struct mbuf *m0, int len0, int wait) 1190 { 1191 struct mbuf *m, *n; 1192 u_int len = len0, remain; 1193 1194 MBUF_CHECKSLEEP(wait); 1195 for (m = m0; m && len > m->m_len; m = m->m_next) 1196 len -= m->m_len; 1197 if (m == NULL) 1198 return (NULL); 1199 remain = m->m_len - len; 1200 if (m0->m_flags & M_PKTHDR && remain == 0) { 1201 n = m_gethdr(wait, m0->m_type); 1202 return (NULL); 1203 n->m_next = m->m_next; 1204 m->m_next = NULL; 1205 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1206 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1207 m0->m_pkthdr.len = len0; 1208 return (n); 1209 } else if (m0->m_flags & M_PKTHDR) { 1210 n = m_gethdr(wait, m0->m_type); 1211 if (n == NULL) 1212 return (NULL); 1213 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1214 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1215 m0->m_pkthdr.len = len0; 1216 if (m->m_flags & M_EXT) 1217 goto extpacket; 1218 if (remain > MHLEN) { 1219 /* m can't be the lead packet */ 1220 MH_ALIGN(n, 0); 1221 n->m_next = m_split(m, len, wait); 1222 if (n->m_next == NULL) { 1223 (void) m_free(n); 1224 return (NULL); 1225 } else { 1226 n->m_len = 0; 1227 return (n); 1228 } 1229 } else 1230 MH_ALIGN(n, remain); 1231 } else if (remain == 0) { 1232 n = m->m_next; 1233 m->m_next = NULL; 1234 return (n); 1235 } else { 1236 n = m_get(wait, m->m_type); 1237 if (n == NULL) 1238 return (NULL); 1239 M_ALIGN(n, remain); 1240 } 1241 extpacket: 1242 if (m->m_flags & M_EXT) { 1243 n->m_data = m->m_data + len; 1244 mb_dupcl(n, m); 1245 } else { 1246 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1247 } 1248 n->m_len = remain; 1249 m->m_len = len; 1250 n->m_next = m->m_next; 1251 m->m_next = NULL; 1252 return (n); 1253 } 1254 /* 1255 * Routine to copy from device local memory into mbufs. 1256 * Note that `off' argument is offset into first mbuf of target chain from 1257 * which to begin copying the data to. 1258 */ 1259 struct mbuf * 1260 m_devget(char *buf, int totlen, int off, struct ifnet *ifp, 1261 void (*copy)(char *from, caddr_t to, u_int len)) 1262 { 1263 struct mbuf *m; 1264 struct mbuf *top = NULL, **mp = ⊤ 1265 int len; 1266 1267 if (off < 0 || off > MHLEN) 1268 return (NULL); 1269 1270 while (totlen > 0) { 1271 if (top == NULL) { /* First one, must be PKTHDR */ 1272 if (totlen + off >= MINCLSIZE) { 1273 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 1274 len = MCLBYTES; 1275 } else { 1276 m = m_gethdr(M_NOWAIT, MT_DATA); 1277 len = MHLEN; 1278 1279 /* Place initial small packet/header at end of mbuf */ 1280 if (m && totlen + off + max_linkhdr <= MLEN) { 1281 m->m_data += max_linkhdr; 1282 len -= max_linkhdr; 1283 } 1284 } 1285 if (m == NULL) 1286 return NULL; 1287 m->m_pkthdr.rcvif = ifp; 1288 m->m_pkthdr.len = totlen; 1289 } else { 1290 if (totlen + off >= MINCLSIZE) { 1291 m = m_getcl(M_NOWAIT, MT_DATA, 0); 1292 len = MCLBYTES; 1293 } else { 1294 m = m_get(M_NOWAIT, MT_DATA); 1295 len = MLEN; 1296 } 1297 if (m == NULL) { 1298 m_freem(top); 1299 return NULL; 1300 } 1301 } 1302 if (off) { 1303 m->m_data += off; 1304 len -= off; 1305 off = 0; 1306 } 1307 m->m_len = len = min(totlen, len); 1308 if (copy) 1309 copy(buf, mtod(m, caddr_t), (u_int)len); 1310 else 1311 bcopy(buf, mtod(m, caddr_t), (u_int)len); 1312 buf += len; 1313 *mp = m; 1314 mp = &m->m_next; 1315 totlen -= len; 1316 } 1317 return (top); 1318 } 1319 1320 /* 1321 * Copy data from a buffer back into the indicated mbuf chain, 1322 * starting "off" bytes from the beginning, extending the mbuf 1323 * chain if necessary. 1324 */ 1325 void 1326 m_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp) 1327 { 1328 int mlen; 1329 struct mbuf *m = m0, *n; 1330 int totlen = 0; 1331 1332 if (m0 == NULL) 1333 return; 1334 while (off > (mlen = m->m_len)) { 1335 off -= mlen; 1336 totlen += mlen; 1337 if (m->m_next == NULL) { 1338 n = m_get(M_NOWAIT, m->m_type); 1339 if (n == NULL) 1340 goto out; 1341 bzero(mtod(n, caddr_t), MLEN); 1342 n->m_len = min(MLEN, len + off); 1343 m->m_next = n; 1344 } 1345 m = m->m_next; 1346 } 1347 while (len > 0) { 1348 if (m->m_next == NULL && (len > m->m_len - off)) { 1349 m->m_len += min(len - (m->m_len - off), 1350 M_TRAILINGSPACE(m)); 1351 } 1352 mlen = min (m->m_len - off, len); 1353 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 1354 cp += mlen; 1355 len -= mlen; 1356 mlen += off; 1357 off = 0; 1358 totlen += mlen; 1359 if (len == 0) 1360 break; 1361 if (m->m_next == NULL) { 1362 n = m_get(M_NOWAIT, m->m_type); 1363 if (n == NULL) 1364 break; 1365 n->m_len = min(MLEN, len); 1366 m->m_next = n; 1367 } 1368 m = m->m_next; 1369 } 1370 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1371 m->m_pkthdr.len = totlen; 1372 } 1373 1374 /* 1375 * Append the specified data to the indicated mbuf chain, 1376 * Extend the mbuf chain if the new data does not fit in 1377 * existing space. 1378 * 1379 * Return 1 if able to complete the job; otherwise 0. 1380 */ 1381 int 1382 m_append(struct mbuf *m0, int len, c_caddr_t cp) 1383 { 1384 struct mbuf *m, *n; 1385 int remainder, space; 1386 1387 for (m = m0; m->m_next != NULL; m = m->m_next) 1388 ; 1389 remainder = len; 1390 space = M_TRAILINGSPACE(m); 1391 if (space > 0) { 1392 /* 1393 * Copy into available space. 1394 */ 1395 if (space > remainder) 1396 space = remainder; 1397 bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1398 m->m_len += space; 1399 cp += space, remainder -= space; 1400 } 1401 while (remainder > 0) { 1402 /* 1403 * Allocate a new mbuf; could check space 1404 * and allocate a cluster instead. 1405 */ 1406 n = m_get(M_NOWAIT, m->m_type); 1407 if (n == NULL) 1408 break; 1409 n->m_len = min(MLEN, remainder); 1410 bcopy(cp, mtod(n, caddr_t), n->m_len); 1411 cp += n->m_len, remainder -= n->m_len; 1412 m->m_next = n; 1413 m = n; 1414 } 1415 if (m0->m_flags & M_PKTHDR) 1416 m0->m_pkthdr.len += len - remainder; 1417 return (remainder == 0); 1418 } 1419 1420 /* 1421 * Apply function f to the data in an mbuf chain starting "off" bytes from 1422 * the beginning, continuing for "len" bytes. 1423 */ 1424 int 1425 m_apply(struct mbuf *m, int off, int len, 1426 int (*f)(void *, void *, u_int), void *arg) 1427 { 1428 u_int count; 1429 int rval; 1430 1431 KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1432 KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1433 while (off > 0) { 1434 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1435 if (off < m->m_len) 1436 break; 1437 off -= m->m_len; 1438 m = m->m_next; 1439 } 1440 while (len > 0) { 1441 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1442 count = min(m->m_len - off, len); 1443 rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1444 if (rval) 1445 return (rval); 1446 len -= count; 1447 off = 0; 1448 m = m->m_next; 1449 } 1450 return (0); 1451 } 1452 1453 /* 1454 * Return a pointer to mbuf/offset of location in mbuf chain. 1455 */ 1456 struct mbuf * 1457 m_getptr(struct mbuf *m, int loc, int *off) 1458 { 1459 1460 while (loc >= 0) { 1461 /* Normal end of search. */ 1462 if (m->m_len > loc) { 1463 *off = loc; 1464 return (m); 1465 } else { 1466 loc -= m->m_len; 1467 if (m->m_next == NULL) { 1468 if (loc == 0) { 1469 /* Point at the end of valid data. */ 1470 *off = m->m_len; 1471 return (m); 1472 } 1473 return (NULL); 1474 } 1475 m = m->m_next; 1476 } 1477 } 1478 return (NULL); 1479 } 1480 1481 void 1482 m_print(const struct mbuf *m, int maxlen) 1483 { 1484 int len; 1485 int pdata; 1486 const struct mbuf *m2; 1487 1488 if (m == NULL) { 1489 printf("mbuf: %p\n", m); 1490 return; 1491 } 1492 1493 if (m->m_flags & M_PKTHDR) 1494 len = m->m_pkthdr.len; 1495 else 1496 len = -1; 1497 m2 = m; 1498 while (m2 != NULL && (len == -1 || len)) { 1499 pdata = m2->m_len; 1500 if (maxlen != -1 && pdata > maxlen) 1501 pdata = maxlen; 1502 printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len, 1503 m2->m_next, m2->m_flags, "\20\20freelist\17skipfw" 1504 "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly" 1505 "\3eor\2pkthdr\1ext", pdata ? "" : "\n"); 1506 if (pdata) 1507 printf(", %*D\n", pdata, (u_char *)m2->m_data, "-"); 1508 if (len != -1) 1509 len -= m2->m_len; 1510 m2 = m2->m_next; 1511 } 1512 if (len > 0) 1513 printf("%d bytes unaccounted for.\n", len); 1514 return; 1515 } 1516 1517 u_int 1518 m_fixhdr(struct mbuf *m0) 1519 { 1520 u_int len; 1521 1522 len = m_length(m0, NULL); 1523 m0->m_pkthdr.len = len; 1524 return (len); 1525 } 1526 1527 u_int 1528 m_length(struct mbuf *m0, struct mbuf **last) 1529 { 1530 struct mbuf *m; 1531 u_int len; 1532 1533 len = 0; 1534 for (m = m0; m != NULL; m = m->m_next) { 1535 len += m->m_len; 1536 if (m->m_next == NULL) 1537 break; 1538 } 1539 if (last != NULL) 1540 *last = m; 1541 return (len); 1542 } 1543 1544 /* 1545 * Defragment a mbuf chain, returning the shortest possible 1546 * chain of mbufs and clusters. If allocation fails and 1547 * this cannot be completed, NULL will be returned, but 1548 * the passed in chain will be unchanged. Upon success, 1549 * the original chain will be freed, and the new chain 1550 * will be returned. 1551 * 1552 * If a non-packet header is passed in, the original 1553 * mbuf (chain?) will be returned unharmed. 1554 */ 1555 struct mbuf * 1556 m_defrag(struct mbuf *m0, int how) 1557 { 1558 struct mbuf *m_new = NULL, *m_final = NULL; 1559 int progress = 0, length; 1560 1561 MBUF_CHECKSLEEP(how); 1562 if (!(m0->m_flags & M_PKTHDR)) 1563 return (m0); 1564 1565 m_fixhdr(m0); /* Needed sanity check */ 1566 1567 #ifdef MBUF_STRESS_TEST 1568 if (m_defragrandomfailures) { 1569 int temp = arc4random() & 0xff; 1570 if (temp == 0xba) 1571 goto nospace; 1572 } 1573 #endif 1574 1575 if (m0->m_pkthdr.len > MHLEN) 1576 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1577 else 1578 m_final = m_gethdr(how, MT_DATA); 1579 1580 if (m_final == NULL) 1581 goto nospace; 1582 1583 if (m_dup_pkthdr(m_final, m0, how) == 0) 1584 goto nospace; 1585 1586 m_new = m_final; 1587 1588 while (progress < m0->m_pkthdr.len) { 1589 length = m0->m_pkthdr.len - progress; 1590 if (length > MCLBYTES) 1591 length = MCLBYTES; 1592 1593 if (m_new == NULL) { 1594 if (length > MLEN) 1595 m_new = m_getcl(how, MT_DATA, 0); 1596 else 1597 m_new = m_get(how, MT_DATA); 1598 if (m_new == NULL) 1599 goto nospace; 1600 } 1601 1602 m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 1603 progress += length; 1604 m_new->m_len = length; 1605 if (m_new != m_final) 1606 m_cat(m_final, m_new); 1607 m_new = NULL; 1608 } 1609 #ifdef MBUF_STRESS_TEST 1610 if (m0->m_next == NULL) 1611 m_defraguseless++; 1612 #endif 1613 m_freem(m0); 1614 m0 = m_final; 1615 #ifdef MBUF_STRESS_TEST 1616 m_defragpackets++; 1617 m_defragbytes += m0->m_pkthdr.len; 1618 #endif 1619 return (m0); 1620 nospace: 1621 #ifdef MBUF_STRESS_TEST 1622 m_defragfailure++; 1623 #endif 1624 if (m_final) 1625 m_freem(m_final); 1626 return (NULL); 1627 } 1628 1629 /* 1630 * Defragment an mbuf chain, returning at most maxfrags separate 1631 * mbufs+clusters. If this is not possible NULL is returned and 1632 * the original mbuf chain is left in it's present (potentially 1633 * modified) state. We use two techniques: collapsing consecutive 1634 * mbufs and replacing consecutive mbufs by a cluster. 1635 * 1636 * NB: this should really be named m_defrag but that name is taken 1637 */ 1638 struct mbuf * 1639 m_collapse(struct mbuf *m0, int how, int maxfrags) 1640 { 1641 struct mbuf *m, *n, *n2, **prev; 1642 u_int curfrags; 1643 1644 /* 1645 * Calculate the current number of frags. 1646 */ 1647 curfrags = 0; 1648 for (m = m0; m != NULL; m = m->m_next) 1649 curfrags++; 1650 /* 1651 * First, try to collapse mbufs. Note that we always collapse 1652 * towards the front so we don't need to deal with moving the 1653 * pkthdr. This may be suboptimal if the first mbuf has much 1654 * less data than the following. 1655 */ 1656 m = m0; 1657 again: 1658 for (;;) { 1659 n = m->m_next; 1660 if (n == NULL) 1661 break; 1662 if (M_WRITABLE(m) && 1663 n->m_len < M_TRAILINGSPACE(m)) { 1664 bcopy(mtod(n, void *), mtod(m, char *) + m->m_len, 1665 n->m_len); 1666 m->m_len += n->m_len; 1667 m->m_next = n->m_next; 1668 m_free(n); 1669 if (--curfrags <= maxfrags) 1670 return m0; 1671 } else 1672 m = n; 1673 } 1674 KASSERT(maxfrags > 1, 1675 ("maxfrags %u, but normal collapse failed", maxfrags)); 1676 /* 1677 * Collapse consecutive mbufs to a cluster. 1678 */ 1679 prev = &m0->m_next; /* NB: not the first mbuf */ 1680 while ((n = *prev) != NULL) { 1681 if ((n2 = n->m_next) != NULL && 1682 n->m_len + n2->m_len < MCLBYTES) { 1683 m = m_getcl(how, MT_DATA, 0); 1684 if (m == NULL) 1685 goto bad; 1686 bcopy(mtod(n, void *), mtod(m, void *), n->m_len); 1687 bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len, 1688 n2->m_len); 1689 m->m_len = n->m_len + n2->m_len; 1690 m->m_next = n2->m_next; 1691 *prev = m; 1692 m_free(n); 1693 m_free(n2); 1694 if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */ 1695 return m0; 1696 /* 1697 * Still not there, try the normal collapse 1698 * again before we allocate another cluster. 1699 */ 1700 goto again; 1701 } 1702 prev = &n->m_next; 1703 } 1704 /* 1705 * No place where we can collapse to a cluster; punt. 1706 * This can occur if, for example, you request 2 frags 1707 * but the packet requires that both be clusters (we 1708 * never reallocate the first mbuf to avoid moving the 1709 * packet header). 1710 */ 1711 bad: 1712 return NULL; 1713 } 1714 1715 #ifdef MBUF_STRESS_TEST 1716 1717 /* 1718 * Fragment an mbuf chain. There's no reason you'd ever want to do 1719 * this in normal usage, but it's great for stress testing various 1720 * mbuf consumers. 1721 * 1722 * If fragmentation is not possible, the original chain will be 1723 * returned. 1724 * 1725 * Possible length values: 1726 * 0 no fragmentation will occur 1727 * > 0 each fragment will be of the specified length 1728 * -1 each fragment will be the same random value in length 1729 * -2 each fragment's length will be entirely random 1730 * (Random values range from 1 to 256) 1731 */ 1732 struct mbuf * 1733 m_fragment(struct mbuf *m0, int how, int length) 1734 { 1735 struct mbuf *m_new = NULL, *m_final = NULL; 1736 int progress = 0; 1737 1738 if (!(m0->m_flags & M_PKTHDR)) 1739 return (m0); 1740 1741 if ((length == 0) || (length < -2)) 1742 return (m0); 1743 1744 m_fixhdr(m0); /* Needed sanity check */ 1745 1746 m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1747 1748 if (m_final == NULL) 1749 goto nospace; 1750 1751 if (m_dup_pkthdr(m_final, m0, how) == 0) 1752 goto nospace; 1753 1754 m_new = m_final; 1755 1756 if (length == -1) 1757 length = 1 + (arc4random() & 255); 1758 1759 while (progress < m0->m_pkthdr.len) { 1760 int fraglen; 1761 1762 if (length > 0) 1763 fraglen = length; 1764 else 1765 fraglen = 1 + (arc4random() & 255); 1766 if (fraglen > m0->m_pkthdr.len - progress) 1767 fraglen = m0->m_pkthdr.len - progress; 1768 1769 if (fraglen > MCLBYTES) 1770 fraglen = MCLBYTES; 1771 1772 if (m_new == NULL) { 1773 m_new = m_getcl(how, MT_DATA, 0); 1774 if (m_new == NULL) 1775 goto nospace; 1776 } 1777 1778 m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t)); 1779 progress += fraglen; 1780 m_new->m_len = fraglen; 1781 if (m_new != m_final) 1782 m_cat(m_final, m_new); 1783 m_new = NULL; 1784 } 1785 m_freem(m0); 1786 m0 = m_final; 1787 return (m0); 1788 nospace: 1789 if (m_final) 1790 m_freem(m_final); 1791 /* Return the original chain on failure */ 1792 return (m0); 1793 } 1794 1795 #endif 1796 1797 /* 1798 * Copy the contents of uio into a properly sized mbuf chain. 1799 */ 1800 struct mbuf * 1801 m_uiotombuf(struct uio *uio, int how, int len, int align, int flags) 1802 { 1803 struct mbuf *m, *mb; 1804 int error, length; 1805 ssize_t total; 1806 int progress = 0; 1807 1808 /* 1809 * len can be zero or an arbitrary large value bound by 1810 * the total data supplied by the uio. 1811 */ 1812 if (len > 0) 1813 total = min(uio->uio_resid, len); 1814 else 1815 total = uio->uio_resid; 1816 1817 /* 1818 * The smallest unit returned by m_getm2() is a single mbuf 1819 * with pkthdr. We can't align past it. 1820 */ 1821 if (align >= MHLEN) 1822 return (NULL); 1823 1824 /* 1825 * Give us the full allocation or nothing. 1826 * If len is zero return the smallest empty mbuf. 1827 */ 1828 m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags); 1829 if (m == NULL) 1830 return (NULL); 1831 m->m_data += align; 1832 1833 /* Fill all mbufs with uio data and update header information. */ 1834 for (mb = m; mb != NULL; mb = mb->m_next) { 1835 length = min(M_TRAILINGSPACE(mb), total - progress); 1836 1837 error = uiomove(mtod(mb, void *), length, uio); 1838 if (error) { 1839 m_freem(m); 1840 return (NULL); 1841 } 1842 1843 mb->m_len = length; 1844 progress += length; 1845 if (flags & M_PKTHDR) 1846 m->m_pkthdr.len += length; 1847 } 1848 KASSERT(progress == total, ("%s: progress != total", __func__)); 1849 1850 return (m); 1851 } 1852 1853 /* 1854 * Copy an mbuf chain into a uio limited by len if set. 1855 */ 1856 int 1857 m_mbuftouio(struct uio *uio, struct mbuf *m, int len) 1858 { 1859 int error, length, total; 1860 int progress = 0; 1861 1862 if (len > 0) 1863 total = min(uio->uio_resid, len); 1864 else 1865 total = uio->uio_resid; 1866 1867 /* Fill the uio with data from the mbufs. */ 1868 for (; m != NULL; m = m->m_next) { 1869 length = min(m->m_len, total - progress); 1870 1871 error = uiomove(mtod(m, void *), length, uio); 1872 if (error) 1873 return (error); 1874 1875 progress += length; 1876 } 1877 1878 return (0); 1879 } 1880 1881 /* 1882 * Set the m_data pointer of a newly-allocated mbuf 1883 * to place an object of the specified size at the 1884 * end of the mbuf, longword aligned. 1885 */ 1886 void 1887 m_align(struct mbuf *m, int len) 1888 { 1889 #ifdef INVARIANTS 1890 const char *msg = "%s: not a virgin mbuf"; 1891 #endif 1892 int adjust; 1893 1894 if (m->m_flags & M_EXT) { 1895 KASSERT(m->m_data == m->m_ext.ext_buf, (msg, __func__)); 1896 adjust = m->m_ext.ext_size - len; 1897 } else if (m->m_flags & M_PKTHDR) { 1898 KASSERT(m->m_data == m->m_pktdat, (msg, __func__)); 1899 adjust = MHLEN - len; 1900 } else { 1901 KASSERT(m->m_data == m->m_dat, (msg, __func__)); 1902 adjust = MLEN - len; 1903 } 1904 1905 m->m_data += adjust &~ (sizeof(long)-1); 1906 } 1907 1908 /* 1909 * Create a writable copy of the mbuf chain. While doing this 1910 * we compact the chain with a goal of producing a chain with 1911 * at most two mbufs. The second mbuf in this chain is likely 1912 * to be a cluster. The primary purpose of this work is to create 1913 * a writable packet for encryption, compression, etc. The 1914 * secondary goal is to linearize the data so the data can be 1915 * passed to crypto hardware in the most efficient manner possible. 1916 */ 1917 struct mbuf * 1918 m_unshare(struct mbuf *m0, int how) 1919 { 1920 struct mbuf *m, *mprev; 1921 struct mbuf *n, *mfirst, *mlast; 1922 int len, off; 1923 1924 mprev = NULL; 1925 for (m = m0; m != NULL; m = mprev->m_next) { 1926 /* 1927 * Regular mbufs are ignored unless there's a cluster 1928 * in front of it that we can use to coalesce. We do 1929 * the latter mainly so later clusters can be coalesced 1930 * also w/o having to handle them specially (i.e. convert 1931 * mbuf+cluster -> cluster). This optimization is heavily 1932 * influenced by the assumption that we're running over 1933 * Ethernet where MCLBYTES is large enough that the max 1934 * packet size will permit lots of coalescing into a 1935 * single cluster. This in turn permits efficient 1936 * crypto operations, especially when using hardware. 1937 */ 1938 if ((m->m_flags & M_EXT) == 0) { 1939 if (mprev && (mprev->m_flags & M_EXT) && 1940 m->m_len <= M_TRAILINGSPACE(mprev)) { 1941 /* XXX: this ignores mbuf types */ 1942 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1943 mtod(m, caddr_t), m->m_len); 1944 mprev->m_len += m->m_len; 1945 mprev->m_next = m->m_next; /* unlink from chain */ 1946 m_free(m); /* reclaim mbuf */ 1947 #if 0 1948 newipsecstat.ips_mbcoalesced++; 1949 #endif 1950 } else { 1951 mprev = m; 1952 } 1953 continue; 1954 } 1955 /* 1956 * Writable mbufs are left alone (for now). 1957 */ 1958 if (M_WRITABLE(m)) { 1959 mprev = m; 1960 continue; 1961 } 1962 1963 /* 1964 * Not writable, replace with a copy or coalesce with 1965 * the previous mbuf if possible (since we have to copy 1966 * it anyway, we try to reduce the number of mbufs and 1967 * clusters so that future work is easier). 1968 */ 1969 KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags)); 1970 /* NB: we only coalesce into a cluster or larger */ 1971 if (mprev != NULL && (mprev->m_flags & M_EXT) && 1972 m->m_len <= M_TRAILINGSPACE(mprev)) { 1973 /* XXX: this ignores mbuf types */ 1974 memcpy(mtod(mprev, caddr_t) + mprev->m_len, 1975 mtod(m, caddr_t), m->m_len); 1976 mprev->m_len += m->m_len; 1977 mprev->m_next = m->m_next; /* unlink from chain */ 1978 m_free(m); /* reclaim mbuf */ 1979 #if 0 1980 newipsecstat.ips_clcoalesced++; 1981 #endif 1982 continue; 1983 } 1984 1985 /* 1986 * Allocate new space to hold the copy and copy the data. 1987 * We deal with jumbo mbufs (i.e. m_len > MCLBYTES) by 1988 * splitting them into clusters. We could just malloc a 1989 * buffer and make it external but too many device drivers 1990 * don't know how to break up the non-contiguous memory when 1991 * doing DMA. 1992 */ 1993 n = m_getcl(how, m->m_type, m->m_flags); 1994 if (n == NULL) { 1995 m_freem(m0); 1996 return (NULL); 1997 } 1998 len = m->m_len; 1999 off = 0; 2000 mfirst = n; 2001 mlast = NULL; 2002 for (;;) { 2003 int cc = min(len, MCLBYTES); 2004 memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc); 2005 n->m_len = cc; 2006 if (mlast != NULL) 2007 mlast->m_next = n; 2008 mlast = n; 2009 #if 0 2010 newipsecstat.ips_clcopied++; 2011 #endif 2012 2013 len -= cc; 2014 if (len <= 0) 2015 break; 2016 off += cc; 2017 2018 n = m_getcl(how, m->m_type, m->m_flags); 2019 if (n == NULL) { 2020 m_freem(mfirst); 2021 m_freem(m0); 2022 return (NULL); 2023 } 2024 } 2025 n->m_next = m->m_next; 2026 if (mprev == NULL) 2027 m0 = mfirst; /* new head of chain */ 2028 else 2029 mprev->m_next = mfirst; /* replace old mbuf */ 2030 m_free(m); /* release old mbuf */ 2031 mprev = mfirst; 2032 } 2033 return (m0); 2034 } 2035 2036 #ifdef MBUF_PROFILING 2037 2038 #define MP_BUCKETS 32 /* don't just change this as things may overflow.*/ 2039 struct mbufprofile { 2040 uintmax_t wasted[MP_BUCKETS]; 2041 uintmax_t used[MP_BUCKETS]; 2042 uintmax_t segments[MP_BUCKETS]; 2043 } mbprof; 2044 2045 #define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */ 2046 #define MP_NUMLINES 6 2047 #define MP_NUMSPERLINE 16 2048 #define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */ 2049 /* work out max space needed and add a bit of spare space too */ 2050 #define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE) 2051 #define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES) 2052 2053 char mbprofbuf[MP_BUFSIZE]; 2054 2055 void 2056 m_profile(struct mbuf *m) 2057 { 2058 int segments = 0; 2059 int used = 0; 2060 int wasted = 0; 2061 2062 while (m) { 2063 segments++; 2064 used += m->m_len; 2065 if (m->m_flags & M_EXT) { 2066 wasted += MHLEN - sizeof(m->m_ext) + 2067 m->m_ext.ext_size - m->m_len; 2068 } else { 2069 if (m->m_flags & M_PKTHDR) 2070 wasted += MHLEN - m->m_len; 2071 else 2072 wasted += MLEN - m->m_len; 2073 } 2074 m = m->m_next; 2075 } 2076 /* be paranoid.. it helps */ 2077 if (segments > MP_BUCKETS - 1) 2078 segments = MP_BUCKETS - 1; 2079 if (used > 100000) 2080 used = 100000; 2081 if (wasted > 100000) 2082 wasted = 100000; 2083 /* store in the appropriate bucket */ 2084 /* don't bother locking. if it's slightly off, so what? */ 2085 mbprof.segments[segments]++; 2086 mbprof.used[fls(used)]++; 2087 mbprof.wasted[fls(wasted)]++; 2088 } 2089 2090 static void 2091 mbprof_textify(void) 2092 { 2093 int offset; 2094 char *c; 2095 uint64_t *p; 2096 2097 2098 p = &mbprof.wasted[0]; 2099 c = mbprofbuf; 2100 offset = snprintf(c, MP_MAXLINE + 10, 2101 "wasted:\n" 2102 "%ju %ju %ju %ju %ju %ju %ju %ju " 2103 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2104 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2105 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2106 #ifdef BIG_ARRAY 2107 p = &mbprof.wasted[16]; 2108 c += offset; 2109 offset = snprintf(c, MP_MAXLINE, 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 #endif 2115 p = &mbprof.used[0]; 2116 c += offset; 2117 offset = snprintf(c, MP_MAXLINE + 10, 2118 "used:\n" 2119 "%ju %ju %ju %ju %ju %ju %ju %ju " 2120 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2121 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2122 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2123 #ifdef BIG_ARRAY 2124 p = &mbprof.used[16]; 2125 c += offset; 2126 offset = snprintf(c, MP_MAXLINE, 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 #endif 2132 p = &mbprof.segments[0]; 2133 c += offset; 2134 offset = snprintf(c, MP_MAXLINE + 10, 2135 "segments:\n" 2136 "%ju %ju %ju %ju %ju %ju %ju %ju " 2137 "%ju %ju %ju %ju %ju %ju %ju %ju\n", 2138 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], 2139 p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]); 2140 #ifdef BIG_ARRAY 2141 p = &mbprof.segments[16]; 2142 c += offset; 2143 offset = snprintf(c, MP_MAXLINE, 2144 "%ju %ju %ju %ju %ju %ju %ju %ju " 2145 "%ju %ju %ju %ju %ju %ju %ju %jju", 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 #endif 2149 } 2150 2151 static int 2152 mbprof_handler(SYSCTL_HANDLER_ARGS) 2153 { 2154 int error; 2155 2156 mbprof_textify(); 2157 error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1); 2158 return (error); 2159 } 2160 2161 static int 2162 mbprof_clr_handler(SYSCTL_HANDLER_ARGS) 2163 { 2164 int clear, error; 2165 2166 clear = 0; 2167 error = sysctl_handle_int(oidp, &clear, 0, req); 2168 if (error || !req->newptr) 2169 return (error); 2170 2171 if (clear) { 2172 bzero(&mbprof, sizeof(mbprof)); 2173 } 2174 2175 return (error); 2176 } 2177 2178 2179 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD, 2180 NULL, 0, mbprof_handler, "A", "mbuf profiling statistics"); 2181 2182 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW, 2183 NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics"); 2184 #endif 2185 2186