1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved. 5 * Copyright (c) 2004 The DragonFly Project. All rights reserved. 6 * 7 * This code is derived from software contributed to The DragonFly Project 8 * by Jeffrey M. Hsu. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /* 37 * Copyright (c) 1982, 1986, 1988, 1991, 1993 38 * The Regents of the University of California. All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the University of 51 * California, Berkeley and its contributors. 52 * 4. Neither the name of the University nor the names of its contributors 53 * may be used to endorse or promote products derived from this software 54 * without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 66 * SUCH DAMAGE. 67 * 68 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 69 * $FreeBSD: src/sys/kern/uipc_mbuf.c,v 1.51.2.24 2003/04/15 06:59:29 silby Exp $ 70 * $DragonFly: src/sys/kern/uipc_mbuf.c,v 1.70 2008/11/20 14:21:01 sephe Exp $ 71 */ 72 73 #include "opt_param.h" 74 #include "opt_mbuf_stress_test.h" 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/file.h> 78 #include <sys/malloc.h> 79 #include <sys/mbuf.h> 80 #include <sys/kernel.h> 81 #include <sys/sysctl.h> 82 #include <sys/domain.h> 83 #include <sys/objcache.h> 84 #include <sys/tree.h> 85 #include <sys/protosw.h> 86 #include <sys/uio.h> 87 #include <sys/thread.h> 88 #include <sys/globaldata.h> 89 90 #include <sys/thread2.h> 91 #include <sys/spinlock2.h> 92 93 #include <machine/atomic.h> 94 #include <machine/limits.h> 95 96 #include <vm/vm.h> 97 #include <vm/vm_kern.h> 98 #include <vm/vm_extern.h> 99 100 #ifdef INVARIANTS 101 #include <machine/cpu.h> 102 #endif 103 104 /* 105 * mbuf cluster meta-data 106 */ 107 struct mbcluster { 108 int32_t mcl_refs; 109 void *mcl_data; 110 }; 111 112 /* 113 * mbuf tracking for debugging purposes 114 */ 115 #ifdef MBUF_DEBUG 116 117 static MALLOC_DEFINE(M_MTRACK, "mtrack", "mtrack"); 118 119 struct mbctrack; 120 RB_HEAD(mbuf_rb_tree, mbtrack); 121 RB_PROTOTYPE2(mbuf_rb_tree, mbtrack, rb_node, mbtrack_cmp, struct mbuf *); 122 123 struct mbtrack { 124 RB_ENTRY(mbtrack) rb_node; 125 int trackid; 126 struct mbuf *m; 127 }; 128 129 static int 130 mbtrack_cmp(struct mbtrack *mb1, struct mbtrack *mb2) 131 { 132 if (mb1->m < mb2->m) 133 return(-1); 134 if (mb1->m > mb2->m) 135 return(1); 136 return(0); 137 } 138 139 RB_GENERATE2(mbuf_rb_tree, mbtrack, rb_node, mbtrack_cmp, struct mbuf *, m); 140 141 struct mbuf_rb_tree mbuf_track_root; 142 static struct spinlock mbuf_track_spin = SPINLOCK_INITIALIZER(mbuf_track_spin); 143 144 static void 145 mbuftrack(struct mbuf *m) 146 { 147 struct mbtrack *mbt; 148 149 mbt = kmalloc(sizeof(*mbt), M_MTRACK, M_INTWAIT|M_ZERO); 150 spin_lock(&mbuf_track_spin); 151 mbt->m = m; 152 if (mbuf_rb_tree_RB_INSERT(&mbuf_track_root, mbt)) { 153 spin_unlock(&mbuf_track_spin); 154 panic("mbuftrack: mbuf %p already being tracked\n", m); 155 } 156 spin_unlock(&mbuf_track_spin); 157 } 158 159 static void 160 mbufuntrack(struct mbuf *m) 161 { 162 struct mbtrack *mbt; 163 164 spin_lock(&mbuf_track_spin); 165 mbt = mbuf_rb_tree_RB_LOOKUP(&mbuf_track_root, m); 166 if (mbt == NULL) { 167 spin_unlock(&mbuf_track_spin); 168 panic("mbufuntrack: mbuf %p was not tracked\n", m); 169 } else { 170 mbuf_rb_tree_RB_REMOVE(&mbuf_track_root, mbt); 171 spin_unlock(&mbuf_track_spin); 172 kfree(mbt, M_MTRACK); 173 } 174 } 175 176 void 177 mbuftrackid(struct mbuf *m, int trackid) 178 { 179 struct mbtrack *mbt; 180 struct mbuf *n; 181 182 spin_lock(&mbuf_track_spin); 183 while (m) { 184 n = m->m_nextpkt; 185 while (m) { 186 mbt = mbuf_rb_tree_RB_LOOKUP(&mbuf_track_root, m); 187 if (mbt == NULL) { 188 spin_unlock(&mbuf_track_spin); 189 panic("mbuftrackid: mbuf %p not tracked", m); 190 } 191 mbt->trackid = trackid; 192 m = m->m_next; 193 } 194 m = n; 195 } 196 spin_unlock(&mbuf_track_spin); 197 } 198 199 static int 200 mbuftrack_callback(struct mbtrack *mbt, void *arg) 201 { 202 struct sysctl_req *req = arg; 203 char buf[64]; 204 int error; 205 206 ksnprintf(buf, sizeof(buf), "mbuf %p track %d\n", mbt->m, mbt->trackid); 207 208 spin_unlock(&mbuf_track_spin); 209 error = SYSCTL_OUT(req, buf, strlen(buf)); 210 spin_lock(&mbuf_track_spin); 211 if (error) 212 return(-error); 213 return(0); 214 } 215 216 static int 217 mbuftrack_show(SYSCTL_HANDLER_ARGS) 218 { 219 int error; 220 221 spin_lock(&mbuf_track_spin); 222 error = mbuf_rb_tree_RB_SCAN(&mbuf_track_root, NULL, 223 mbuftrack_callback, req); 224 spin_unlock(&mbuf_track_spin); 225 return (-error); 226 } 227 SYSCTL_PROC(_kern_ipc, OID_AUTO, showmbufs, CTLFLAG_RD|CTLTYPE_STRING, 228 0, 0, mbuftrack_show, "A", "Show all in-use mbufs"); 229 230 #else 231 232 #define mbuftrack(m) 233 #define mbufuntrack(m) 234 235 #endif 236 237 static void mbinit(void *); 238 SYSINIT(mbuf, SI_BOOT2_MACHDEP, SI_ORDER_FIRST, mbinit, NULL) 239 240 static u_long mbtypes[SMP_MAXCPU][MT_NTYPES]; 241 242 static struct mbstat mbstat[SMP_MAXCPU]; 243 int max_linkhdr; 244 int max_protohdr; 245 int max_hdr; 246 int max_datalen; 247 int m_defragpackets; 248 int m_defragbytes; 249 int m_defraguseless; 250 int m_defragfailure; 251 #ifdef MBUF_STRESS_TEST 252 int m_defragrandomfailures; 253 #endif 254 255 struct objcache *mbuf_cache, *mbufphdr_cache; 256 struct objcache *mclmeta_cache; 257 struct objcache *mbufcluster_cache, *mbufphdrcluster_cache; 258 259 int nmbclusters; 260 int nmbufs; 261 262 SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, 263 &max_linkhdr, 0, "Max size of a link-level header"); 264 SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, 265 &max_protohdr, 0, "Max size of a protocol header"); 266 SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, 267 "Max size of link+protocol headers"); 268 SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, 269 &max_datalen, 0, "Max data payload size without headers"); 270 SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW, 271 &mbuf_wait, 0, "Time in ticks to sleep after failed mbuf allocations"); 272 static int do_mbstat(SYSCTL_HANDLER_ARGS); 273 274 SYSCTL_PROC(_kern_ipc, KIPC_MBSTAT, mbstat, CTLTYPE_STRUCT|CTLFLAG_RD, 275 0, 0, do_mbstat, "S,mbstat", "mbuf usage statistics"); 276 277 static int do_mbtypes(SYSCTL_HANDLER_ARGS); 278 279 SYSCTL_PROC(_kern_ipc, OID_AUTO, mbtypes, CTLTYPE_ULONG|CTLFLAG_RD, 280 0, 0, do_mbtypes, "LU", ""); 281 282 static int 283 do_mbstat(SYSCTL_HANDLER_ARGS) 284 { 285 struct mbstat mbstat_total; 286 struct mbstat *mbstat_totalp; 287 int i; 288 289 bzero(&mbstat_total, sizeof(mbstat_total)); 290 mbstat_totalp = &mbstat_total; 291 292 for (i = 0; i < ncpus; i++) 293 { 294 mbstat_total.m_mbufs += mbstat[i].m_mbufs; 295 mbstat_total.m_clusters += mbstat[i].m_clusters; 296 mbstat_total.m_spare += mbstat[i].m_spare; 297 mbstat_total.m_clfree += mbstat[i].m_clfree; 298 mbstat_total.m_drops += mbstat[i].m_drops; 299 mbstat_total.m_wait += mbstat[i].m_wait; 300 mbstat_total.m_drain += mbstat[i].m_drain; 301 mbstat_total.m_mcfail += mbstat[i].m_mcfail; 302 mbstat_total.m_mpfail += mbstat[i].m_mpfail; 303 304 } 305 /* 306 * The following fields are not cumulative fields so just 307 * get their values once. 308 */ 309 mbstat_total.m_msize = mbstat[0].m_msize; 310 mbstat_total.m_mclbytes = mbstat[0].m_mclbytes; 311 mbstat_total.m_minclsize = mbstat[0].m_minclsize; 312 mbstat_total.m_mlen = mbstat[0].m_mlen; 313 mbstat_total.m_mhlen = mbstat[0].m_mhlen; 314 315 return(sysctl_handle_opaque(oidp, mbstat_totalp, sizeof(mbstat_total), req)); 316 } 317 318 static int 319 do_mbtypes(SYSCTL_HANDLER_ARGS) 320 { 321 u_long totals[MT_NTYPES]; 322 int i, j; 323 324 for (i = 0; i < MT_NTYPES; i++) 325 totals[i] = 0; 326 327 for (i = 0; i < ncpus; i++) 328 { 329 for (j = 0; j < MT_NTYPES; j++) 330 totals[j] += mbtypes[i][j]; 331 } 332 333 return(sysctl_handle_opaque(oidp, totals, sizeof(totals), req)); 334 } 335 336 /* 337 * These are read-only because we do not currently have any code 338 * to adjust the objcache limits after the fact. The variables 339 * may only be set as boot-time tunables. 340 */ 341 SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD, 342 &nmbclusters, 0, "Maximum number of mbuf clusters available"); 343 SYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RD, &nmbufs, 0, 344 "Maximum number of mbufs available"); 345 346 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD, 347 &m_defragpackets, 0, "Number of defragment packets"); 348 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD, 349 &m_defragbytes, 0, "Number of defragment bytes"); 350 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD, 351 &m_defraguseless, 0, "Number of useless defragment mbuf chain operations"); 352 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD, 353 &m_defragfailure, 0, "Number of failed defragment mbuf chain operations"); 354 #ifdef MBUF_STRESS_TEST 355 SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW, 356 &m_defragrandomfailures, 0, ""); 357 #endif 358 359 static MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf"); 360 static MALLOC_DEFINE(M_MBUFCL, "mbufcl", "mbufcl"); 361 static MALLOC_DEFINE(M_MCLMETA, "mclmeta", "mclmeta"); 362 363 static void m_reclaim (void); 364 static void m_mclref(void *arg); 365 static void m_mclfree(void *arg); 366 367 /* 368 * NOTE: Default NMBUFS must take into account a possible DOS attack 369 * using fd passing on unix domain sockets. 370 */ 371 #ifndef NMBCLUSTERS 372 #define NMBCLUSTERS (512 + maxusers * 16) 373 #endif 374 #ifndef NMBUFS 375 #define NMBUFS (nmbclusters * 2 + maxfiles) 376 #endif 377 378 /* 379 * Perform sanity checks of tunables declared above. 380 */ 381 static void 382 tunable_mbinit(void *dummy) 383 { 384 /* 385 * This has to be done before VM init. 386 */ 387 nmbclusters = NMBCLUSTERS; 388 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters); 389 nmbufs = NMBUFS; 390 TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs); 391 /* Sanity checks */ 392 if (nmbufs < nmbclusters * 2) 393 nmbufs = nmbclusters * 2; 394 } 395 SYSINIT(tunable_mbinit, SI_BOOT1_TUNABLES, SI_ORDER_ANY, 396 tunable_mbinit, NULL); 397 398 /* "number of clusters of pages" */ 399 #define NCL_INIT 1 400 401 #define NMB_INIT 16 402 403 /* 404 * The mbuf object cache only guarantees that m_next and m_nextpkt are 405 * NULL and that m_data points to the beginning of the data area. In 406 * particular, m_len and m_pkthdr.len are uninitialized. It is the 407 * responsibility of the caller to initialize those fields before use. 408 */ 409 410 static boolean_t __inline 411 mbuf_ctor(void *obj, void *private, int ocflags) 412 { 413 struct mbuf *m = obj; 414 415 m->m_next = NULL; 416 m->m_nextpkt = NULL; 417 m->m_data = m->m_dat; 418 m->m_flags = 0; 419 420 return (TRUE); 421 } 422 423 /* 424 * Initialize the mbuf and the packet header fields. 425 */ 426 static boolean_t 427 mbufphdr_ctor(void *obj, void *private, int ocflags) 428 { 429 struct mbuf *m = obj; 430 431 m->m_next = NULL; 432 m->m_nextpkt = NULL; 433 m->m_data = m->m_pktdat; 434 m->m_flags = M_PKTHDR | M_PHCACHE; 435 436 m->m_pkthdr.rcvif = NULL; /* eliminate XXX JH */ 437 SLIST_INIT(&m->m_pkthdr.tags); 438 m->m_pkthdr.csum_flags = 0; /* eliminate XXX JH */ 439 m->m_pkthdr.fw_flags = 0; /* eliminate XXX JH */ 440 441 return (TRUE); 442 } 443 444 /* 445 * A mbcluster object consists of 2K (MCLBYTES) cluster and a refcount. 446 */ 447 static boolean_t 448 mclmeta_ctor(void *obj, void *private, int ocflags) 449 { 450 struct mbcluster *cl = obj; 451 void *buf; 452 453 if (ocflags & M_NOWAIT) 454 buf = kmalloc(MCLBYTES, M_MBUFCL, M_NOWAIT | M_ZERO); 455 else 456 buf = kmalloc(MCLBYTES, M_MBUFCL, M_INTWAIT | M_ZERO); 457 if (buf == NULL) 458 return (FALSE); 459 cl->mcl_refs = 0; 460 cl->mcl_data = buf; 461 return (TRUE); 462 } 463 464 static void 465 mclmeta_dtor(void *obj, void *private) 466 { 467 struct mbcluster *mcl = obj; 468 469 KKASSERT(mcl->mcl_refs == 0); 470 kfree(mcl->mcl_data, M_MBUFCL); 471 } 472 473 static void 474 linkcluster(struct mbuf *m, struct mbcluster *cl) 475 { 476 /* 477 * Add the cluster to the mbuf. The caller will detect that the 478 * mbuf now has an attached cluster. 479 */ 480 m->m_ext.ext_arg = cl; 481 m->m_ext.ext_buf = cl->mcl_data; 482 m->m_ext.ext_ref = m_mclref; 483 m->m_ext.ext_free = m_mclfree; 484 m->m_ext.ext_size = MCLBYTES; 485 atomic_add_int(&cl->mcl_refs, 1); 486 487 m->m_data = m->m_ext.ext_buf; 488 m->m_flags |= M_EXT | M_EXT_CLUSTER; 489 } 490 491 static boolean_t 492 mbufphdrcluster_ctor(void *obj, void *private, int ocflags) 493 { 494 struct mbuf *m = obj; 495 struct mbcluster *cl; 496 497 mbufphdr_ctor(obj, private, ocflags); 498 cl = objcache_get(mclmeta_cache, ocflags); 499 if (cl == NULL) { 500 ++mbstat[mycpu->gd_cpuid].m_drops; 501 return (FALSE); 502 } 503 m->m_flags |= M_CLCACHE; 504 linkcluster(m, cl); 505 return (TRUE); 506 } 507 508 static boolean_t 509 mbufcluster_ctor(void *obj, void *private, int ocflags) 510 { 511 struct mbuf *m = obj; 512 struct mbcluster *cl; 513 514 mbuf_ctor(obj, private, ocflags); 515 cl = objcache_get(mclmeta_cache, ocflags); 516 if (cl == NULL) { 517 ++mbstat[mycpu->gd_cpuid].m_drops; 518 return (FALSE); 519 } 520 m->m_flags |= M_CLCACHE; 521 linkcluster(m, cl); 522 return (TRUE); 523 } 524 525 /* 526 * Used for both the cluster and cluster PHDR caches. 527 * 528 * The mbuf may have lost its cluster due to sharing, deal 529 * with the situation by checking M_EXT. 530 */ 531 static void 532 mbufcluster_dtor(void *obj, void *private) 533 { 534 struct mbuf *m = obj; 535 struct mbcluster *mcl; 536 537 if (m->m_flags & M_EXT) { 538 KKASSERT((m->m_flags & M_EXT_CLUSTER) != 0); 539 mcl = m->m_ext.ext_arg; 540 KKASSERT(mcl->mcl_refs == 1); 541 mcl->mcl_refs = 0; 542 objcache_put(mclmeta_cache, mcl); 543 } 544 } 545 546 struct objcache_malloc_args mbuf_malloc_args = { MSIZE, M_MBUF }; 547 struct objcache_malloc_args mclmeta_malloc_args = 548 { sizeof(struct mbcluster), M_MCLMETA }; 549 550 /* ARGSUSED*/ 551 static void 552 mbinit(void *dummy) 553 { 554 int mb_limit, cl_limit; 555 int limit; 556 int i; 557 558 /* 559 * Initialize statistics 560 */ 561 for (i = 0; i < ncpus; i++) { 562 atomic_set_long_nonlocked(&mbstat[i].m_msize, MSIZE); 563 atomic_set_long_nonlocked(&mbstat[i].m_mclbytes, MCLBYTES); 564 atomic_set_long_nonlocked(&mbstat[i].m_minclsize, MINCLSIZE); 565 atomic_set_long_nonlocked(&mbstat[i].m_mlen, MLEN); 566 atomic_set_long_nonlocked(&mbstat[i].m_mhlen, MHLEN); 567 } 568 569 /* 570 * Create objtect caches and save cluster limits, which will 571 * be used to adjust backing kmalloc pools' limit later. 572 */ 573 574 mb_limit = cl_limit = 0; 575 576 limit = nmbufs; 577 mbuf_cache = objcache_create("mbuf", &limit, 0, 578 mbuf_ctor, NULL, NULL, 579 objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); 580 mb_limit += limit; 581 582 limit = nmbufs; 583 mbufphdr_cache = objcache_create("mbuf pkt hdr", &limit, 64, 584 mbufphdr_ctor, NULL, NULL, 585 objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); 586 mb_limit += limit; 587 588 cl_limit = nmbclusters; 589 mclmeta_cache = objcache_create("cluster mbuf", &cl_limit, 0, 590 mclmeta_ctor, mclmeta_dtor, NULL, 591 objcache_malloc_alloc, objcache_malloc_free, &mclmeta_malloc_args); 592 593 limit = nmbclusters; 594 mbufcluster_cache = objcache_create("mbuf + cluster", &limit, 0, 595 mbufcluster_ctor, mbufcluster_dtor, NULL, 596 objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); 597 mb_limit += limit; 598 599 limit = nmbclusters; 600 mbufphdrcluster_cache = objcache_create("mbuf pkt hdr + cluster", 601 &limit, 64, mbufphdrcluster_ctor, mbufcluster_dtor, NULL, 602 objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); 603 mb_limit += limit; 604 605 /* 606 * Adjust backing kmalloc pools' limit 607 * 608 * NOTE: We raise the limit by another 1/8 to take the effect 609 * of loosememuse into account. 610 */ 611 cl_limit += cl_limit / 8; 612 kmalloc_raise_limit(mclmeta_malloc_args.mtype, 613 mclmeta_malloc_args.objsize * cl_limit); 614 kmalloc_raise_limit(M_MBUFCL, MCLBYTES * cl_limit); 615 616 mb_limit += mb_limit / 8; 617 kmalloc_raise_limit(mbuf_malloc_args.mtype, 618 mbuf_malloc_args.objsize * mb_limit); 619 } 620 621 /* 622 * Return the number of references to this mbuf's data. 0 is returned 623 * if the mbuf is not M_EXT, a reference count is returned if it is 624 * M_EXT | M_EXT_CLUSTER, and 99 is returned if it is a special M_EXT. 625 */ 626 int 627 m_sharecount(struct mbuf *m) 628 { 629 switch (m->m_flags & (M_EXT | M_EXT_CLUSTER)) { 630 case 0: 631 return (0); 632 case M_EXT: 633 return (99); 634 case M_EXT | M_EXT_CLUSTER: 635 return (((struct mbcluster *)m->m_ext.ext_arg)->mcl_refs); 636 } 637 /* NOTREACHED */ 638 return (0); /* to shut up compiler */ 639 } 640 641 /* 642 * change mbuf to new type 643 */ 644 void 645 m_chtype(struct mbuf *m, int type) 646 { 647 struct globaldata *gd = mycpu; 648 649 atomic_add_long_nonlocked(&mbtypes[gd->gd_cpuid][type], 1); 650 atomic_subtract_long_nonlocked(&mbtypes[gd->gd_cpuid][m->m_type], 1); 651 atomic_set_short_nonlocked(&m->m_type, type); 652 } 653 654 static void 655 m_reclaim(void) 656 { 657 struct domain *dp; 658 struct protosw *pr; 659 660 kprintf("Debug: m_reclaim() called\n"); 661 662 SLIST_FOREACH(dp, &domains, dom_next) { 663 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) { 664 if (pr->pr_drain) 665 (*pr->pr_drain)(); 666 } 667 } 668 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_drain, 1); 669 } 670 671 static void __inline 672 updatestats(struct mbuf *m, int type) 673 { 674 struct globaldata *gd = mycpu; 675 676 m->m_type = type; 677 mbuftrack(m); 678 #ifdef MBUF_DEBUG 679 KASSERT(m->m_next == NULL, ("mbuf %p: bad m_next in get", m)); 680 KASSERT(m->m_nextpkt == NULL, ("mbuf %p: bad m_nextpkt in get", m)); 681 #endif 682 683 atomic_add_long_nonlocked(&mbtypes[gd->gd_cpuid][type], 1); 684 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mbufs, 1); 685 686 } 687 688 /* 689 * Allocate an mbuf. 690 */ 691 struct mbuf * 692 m_get(int how, int type) 693 { 694 struct mbuf *m; 695 int ntries = 0; 696 int ocf = MBTOM(how); 697 698 retryonce: 699 700 m = objcache_get(mbuf_cache, ocf); 701 702 if (m == NULL) { 703 if ((how & MB_TRYWAIT) && ntries++ == 0) { 704 struct objcache *reclaimlist[] = { 705 mbufphdr_cache, 706 mbufcluster_cache, 707 mbufphdrcluster_cache 708 }; 709 const int nreclaims = NELEM(reclaimlist); 710 711 if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) 712 m_reclaim(); 713 goto retryonce; 714 } 715 ++mbstat[mycpu->gd_cpuid].m_drops; 716 return (NULL); 717 } 718 #ifdef MBUF_DEBUG 719 KASSERT(m->m_data == m->m_dat, ("mbuf %p: bad m_data in get", m)); 720 #endif 721 m->m_len = 0; 722 723 updatestats(m, type); 724 return (m); 725 } 726 727 struct mbuf * 728 m_gethdr(int how, int type) 729 { 730 struct mbuf *m; 731 int ocf = MBTOM(how); 732 int ntries = 0; 733 734 retryonce: 735 736 m = objcache_get(mbufphdr_cache, ocf); 737 738 if (m == NULL) { 739 if ((how & MB_TRYWAIT) && ntries++ == 0) { 740 struct objcache *reclaimlist[] = { 741 mbuf_cache, 742 mbufcluster_cache, mbufphdrcluster_cache 743 }; 744 const int nreclaims = NELEM(reclaimlist); 745 746 if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) 747 m_reclaim(); 748 goto retryonce; 749 } 750 ++mbstat[mycpu->gd_cpuid].m_drops; 751 return (NULL); 752 } 753 #ifdef MBUF_DEBUG 754 KASSERT(m->m_data == m->m_pktdat, ("mbuf %p: bad m_data in get", m)); 755 #endif 756 m->m_len = 0; 757 m->m_pkthdr.len = 0; 758 759 updatestats(m, type); 760 return (m); 761 } 762 763 /* 764 * Get a mbuf (not a mbuf cluster!) and zero it. 765 * Deprecated. 766 */ 767 struct mbuf * 768 m_getclr(int how, int type) 769 { 770 struct mbuf *m; 771 772 m = m_get(how, type); 773 if (m != NULL) 774 bzero(m->m_data, MLEN); 775 return (m); 776 } 777 778 /* 779 * Returns an mbuf with an attached cluster. 780 * Because many network drivers use this kind of buffers a lot, it is 781 * convenient to keep a small pool of free buffers of this kind. 782 * Even a small size such as 10 gives about 10% improvement in the 783 * forwarding rate in a bridge or router. 784 */ 785 struct mbuf * 786 m_getcl(int how, short type, int flags) 787 { 788 struct mbuf *m; 789 int ocflags = MBTOM(how); 790 int ntries = 0; 791 792 retryonce: 793 794 if (flags & M_PKTHDR) 795 m = objcache_get(mbufphdrcluster_cache, ocflags); 796 else 797 m = objcache_get(mbufcluster_cache, ocflags); 798 799 if (m == NULL) { 800 if ((how & MB_TRYWAIT) && ntries++ == 0) { 801 struct objcache *reclaimlist[1]; 802 803 if (flags & M_PKTHDR) 804 reclaimlist[0] = mbufcluster_cache; 805 else 806 reclaimlist[0] = mbufphdrcluster_cache; 807 if (!objcache_reclaimlist(reclaimlist, 1, ocflags)) 808 m_reclaim(); 809 goto retryonce; 810 } 811 ++mbstat[mycpu->gd_cpuid].m_drops; 812 return (NULL); 813 } 814 815 #ifdef MBUF_DEBUG 816 KASSERT(m->m_data == m->m_ext.ext_buf, 817 ("mbuf %p: bad m_data in get", m)); 818 #endif 819 m->m_type = type; 820 m->m_len = 0; 821 m->m_pkthdr.len = 0; /* just do it unconditonally */ 822 823 mbuftrack(m); 824 825 atomic_add_long_nonlocked(&mbtypes[mycpu->gd_cpuid][type], 1); 826 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 827 return (m); 828 } 829 830 /* 831 * Allocate chain of requested length. 832 */ 833 struct mbuf * 834 m_getc(int len, int how, int type) 835 { 836 struct mbuf *n, *nfirst = NULL, **ntail = &nfirst; 837 int nsize; 838 839 while (len > 0) { 840 n = m_getl(len, how, type, 0, &nsize); 841 if (n == NULL) 842 goto failed; 843 n->m_len = 0; 844 *ntail = n; 845 ntail = &n->m_next; 846 len -= nsize; 847 } 848 return (nfirst); 849 850 failed: 851 m_freem(nfirst); 852 return (NULL); 853 } 854 855 /* 856 * Allocate len-worth of mbufs and/or mbuf clusters (whatever fits best) 857 * and return a pointer to the head of the allocated chain. If m0 is 858 * non-null, then we assume that it is a single mbuf or an mbuf chain to 859 * which we want len bytes worth of mbufs and/or clusters attached, and so 860 * if we succeed in allocating it, we will just return a pointer to m0. 861 * 862 * If we happen to fail at any point during the allocation, we will free 863 * up everything we have already allocated and return NULL. 864 * 865 * Deprecated. Use m_getc() and m_cat() instead. 866 */ 867 struct mbuf * 868 m_getm(struct mbuf *m0, int len, int type, int how) 869 { 870 struct mbuf *nfirst; 871 872 nfirst = m_getc(len, how, type); 873 874 if (m0 != NULL) { 875 m_last(m0)->m_next = nfirst; 876 return (m0); 877 } 878 879 return (nfirst); 880 } 881 882 /* 883 * Adds a cluster to a normal mbuf, M_EXT is set on success. 884 * Deprecated. Use m_getcl() instead. 885 */ 886 void 887 m_mclget(struct mbuf *m, int how) 888 { 889 struct mbcluster *mcl; 890 891 KKASSERT((m->m_flags & M_EXT) == 0); 892 mcl = objcache_get(mclmeta_cache, MBTOM(how)); 893 if (mcl != NULL) { 894 linkcluster(m, mcl); 895 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 896 1); 897 } else { 898 ++mbstat[mycpu->gd_cpuid].m_drops; 899 } 900 } 901 902 /* 903 * Updates to mbcluster must be MPSAFE. Only an entity which already has 904 * a reference to the cluster can ref it, so we are in no danger of 905 * racing an add with a subtract. But the operation must still be atomic 906 * since multiple entities may have a reference on the cluster. 907 * 908 * m_mclfree() is almost the same but it must contend with two entities 909 * freeing the cluster at the same time. 910 */ 911 static void 912 m_mclref(void *arg) 913 { 914 struct mbcluster *mcl = arg; 915 916 atomic_add_int(&mcl->mcl_refs, 1); 917 } 918 919 /* 920 * When dereferencing a cluster we have to deal with a N->0 race, where 921 * N entities free their references simultaniously. To do this we use 922 * atomic_fetchadd_int(). 923 */ 924 static void 925 m_mclfree(void *arg) 926 { 927 struct mbcluster *mcl = arg; 928 929 if (atomic_fetchadd_int(&mcl->mcl_refs, -1) == 1) 930 objcache_put(mclmeta_cache, mcl); 931 } 932 933 /* 934 * Free a single mbuf and any associated external storage. The successor, 935 * if any, is returned. 936 * 937 * We do need to check non-first mbuf for m_aux, since some of existing 938 * code does not call M_PREPEND properly. 939 * (example: call to bpf_mtap from drivers) 940 */ 941 942 #ifdef MBUF_DEBUG 943 944 struct mbuf * 945 _m_free(struct mbuf *m, const char *func) 946 947 #else 948 949 struct mbuf * 950 m_free(struct mbuf *m) 951 952 #endif 953 { 954 struct mbuf *n; 955 struct globaldata *gd = mycpu; 956 957 KASSERT(m->m_type != MT_FREE, ("freeing free mbuf %p", m)); 958 KASSERT(M_TRAILINGSPACE(m) >= 0, ("overflowed mbuf %p", m)); 959 atomic_subtract_long_nonlocked(&mbtypes[gd->gd_cpuid][m->m_type], 1); 960 961 n = m->m_next; 962 963 /* 964 * Make sure the mbuf is in constructed state before returning it 965 * to the objcache. 966 */ 967 m->m_next = NULL; 968 mbufuntrack(m); 969 #ifdef MBUF_DEBUG 970 m->m_hdr.mh_lastfunc = func; 971 #endif 972 #ifdef notyet 973 KKASSERT(m->m_nextpkt == NULL); 974 #else 975 if (m->m_nextpkt != NULL) { 976 static int afewtimes = 10; 977 978 if (afewtimes-- > 0) { 979 kprintf("mfree: m->m_nextpkt != NULL\n"); 980 print_backtrace(-1); 981 } 982 m->m_nextpkt = NULL; 983 } 984 #endif 985 if (m->m_flags & M_PKTHDR) { 986 m_tag_delete_chain(m); /* eliminate XXX JH */ 987 } 988 989 m->m_flags &= (M_EXT | M_EXT_CLUSTER | M_CLCACHE | M_PHCACHE); 990 991 /* 992 * Clean the M_PKTHDR state so we can return the mbuf to its original 993 * cache. This is based on the PHCACHE flag which tells us whether 994 * the mbuf was originally allocated out of a packet-header cache 995 * or a non-packet-header cache. 996 */ 997 if (m->m_flags & M_PHCACHE) { 998 m->m_flags |= M_PKTHDR; 999 m->m_pkthdr.rcvif = NULL; /* eliminate XXX JH */ 1000 m->m_pkthdr.csum_flags = 0; /* eliminate XXX JH */ 1001 m->m_pkthdr.fw_flags = 0; /* eliminate XXX JH */ 1002 SLIST_INIT(&m->m_pkthdr.tags); 1003 } 1004 1005 /* 1006 * Handle remaining flags combinations. M_CLCACHE tells us whether 1007 * the mbuf was originally allocated from a cluster cache or not, 1008 * and is totally separate from whether the mbuf is currently 1009 * associated with a cluster. 1010 */ 1011 switch(m->m_flags & (M_CLCACHE | M_EXT | M_EXT_CLUSTER)) { 1012 case M_CLCACHE | M_EXT | M_EXT_CLUSTER: 1013 /* 1014 * mbuf+cluster cache case. The mbuf was allocated from the 1015 * combined mbuf_cluster cache and can be returned to the 1016 * cache if the cluster hasn't been shared. 1017 */ 1018 if (m_sharecount(m) == 1) { 1019 /* 1020 * The cluster has not been shared, we can just 1021 * reset the data pointer and return the mbuf 1022 * to the cluster cache. Note that the reference 1023 * count is left intact (it is still associated with 1024 * an mbuf). 1025 */ 1026 m->m_data = m->m_ext.ext_buf; 1027 if (m->m_flags & M_PHCACHE) 1028 objcache_put(mbufphdrcluster_cache, m); 1029 else 1030 objcache_put(mbufcluster_cache, m); 1031 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 1032 } else { 1033 /* 1034 * Hell. Someone else has a ref on this cluster, 1035 * we have to disconnect it which means we can't 1036 * put it back into the mbufcluster_cache, we 1037 * have to destroy the mbuf. 1038 * 1039 * Other mbuf references to the cluster will typically 1040 * be M_EXT | M_EXT_CLUSTER but without M_CLCACHE. 1041 * 1042 * XXX we could try to connect another cluster to 1043 * it. 1044 */ 1045 m->m_ext.ext_free(m->m_ext.ext_arg); 1046 m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); 1047 if (m->m_flags & M_PHCACHE) 1048 objcache_dtor(mbufphdrcluster_cache, m); 1049 else 1050 objcache_dtor(mbufcluster_cache, m); 1051 } 1052 break; 1053 case M_EXT | M_EXT_CLUSTER: 1054 /* 1055 * Normal cluster associated with an mbuf that was allocated 1056 * from the normal mbuf pool rather then the cluster pool. 1057 * The cluster has to be independantly disassociated from the 1058 * mbuf. 1059 */ 1060 if (m_sharecount(m) == 1) 1061 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 1062 /* fall through */ 1063 case M_EXT: 1064 /* 1065 * Normal cluster association case, disconnect the cluster from 1066 * the mbuf. The cluster may or may not be custom. 1067 */ 1068 m->m_ext.ext_free(m->m_ext.ext_arg); 1069 m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); 1070 /* fall through */ 1071 case 0: 1072 /* 1073 * return the mbuf to the mbuf cache. 1074 */ 1075 if (m->m_flags & M_PHCACHE) { 1076 m->m_data = m->m_pktdat; 1077 objcache_put(mbufphdr_cache, m); 1078 } else { 1079 m->m_data = m->m_dat; 1080 objcache_put(mbuf_cache, m); 1081 } 1082 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mbufs, 1); 1083 break; 1084 default: 1085 if (!panicstr) 1086 panic("bad mbuf flags %p %08x\n", m, m->m_flags); 1087 break; 1088 } 1089 return (n); 1090 } 1091 1092 #ifdef MBUF_DEBUG 1093 1094 void 1095 _m_freem(struct mbuf *m, const char *func) 1096 { 1097 while (m) 1098 m = _m_free(m, func); 1099 } 1100 1101 #else 1102 1103 void 1104 m_freem(struct mbuf *m) 1105 { 1106 while (m) 1107 m = m_free(m); 1108 } 1109 1110 #endif 1111 1112 /* 1113 * mbuf utility routines 1114 */ 1115 1116 /* 1117 * Lesser-used path for M_PREPEND: allocate new mbuf to prepend to chain and 1118 * copy junk along. 1119 */ 1120 struct mbuf * 1121 m_prepend(struct mbuf *m, int len, int how) 1122 { 1123 struct mbuf *mn; 1124 1125 if (m->m_flags & M_PKTHDR) 1126 mn = m_gethdr(how, m->m_type); 1127 else 1128 mn = m_get(how, m->m_type); 1129 if (mn == NULL) { 1130 m_freem(m); 1131 return (NULL); 1132 } 1133 if (m->m_flags & M_PKTHDR) 1134 M_MOVE_PKTHDR(mn, m); 1135 mn->m_next = m; 1136 m = mn; 1137 if (len < MHLEN) 1138 MH_ALIGN(m, len); 1139 m->m_len = len; 1140 return (m); 1141 } 1142 1143 /* 1144 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 1145 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 1146 * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller. 1147 * Note that the copy is read-only, because clusters are not copied, 1148 * only their reference counts are incremented. 1149 */ 1150 struct mbuf * 1151 m_copym(const struct mbuf *m, int off0, int len, int wait) 1152 { 1153 struct mbuf *n, **np; 1154 int off = off0; 1155 struct mbuf *top; 1156 int copyhdr = 0; 1157 1158 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 1159 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 1160 if (off == 0 && (m->m_flags & M_PKTHDR)) 1161 copyhdr = 1; 1162 while (off > 0) { 1163 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 1164 if (off < m->m_len) 1165 break; 1166 off -= m->m_len; 1167 m = m->m_next; 1168 } 1169 np = ⊤ 1170 top = NULL; 1171 while (len > 0) { 1172 if (m == NULL) { 1173 KASSERT(len == M_COPYALL, 1174 ("m_copym, length > size of mbuf chain")); 1175 break; 1176 } 1177 /* 1178 * Because we are sharing any cluster attachment below, 1179 * be sure to get an mbuf that does not have a cluster 1180 * associated with it. 1181 */ 1182 if (copyhdr) 1183 n = m_gethdr(wait, m->m_type); 1184 else 1185 n = m_get(wait, m->m_type); 1186 *np = n; 1187 if (n == NULL) 1188 goto nospace; 1189 if (copyhdr) { 1190 if (!m_dup_pkthdr(n, m, wait)) 1191 goto nospace; 1192 if (len == M_COPYALL) 1193 n->m_pkthdr.len -= off0; 1194 else 1195 n->m_pkthdr.len = len; 1196 copyhdr = 0; 1197 } 1198 n->m_len = min(len, m->m_len - off); 1199 if (m->m_flags & M_EXT) { 1200 KKASSERT((n->m_flags & M_EXT) == 0); 1201 n->m_data = m->m_data + off; 1202 m->m_ext.ext_ref(m->m_ext.ext_arg); 1203 n->m_ext = m->m_ext; 1204 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1205 } else { 1206 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 1207 (unsigned)n->m_len); 1208 } 1209 if (len != M_COPYALL) 1210 len -= n->m_len; 1211 off = 0; 1212 m = m->m_next; 1213 np = &n->m_next; 1214 } 1215 if (top == NULL) 1216 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1217 return (top); 1218 nospace: 1219 m_freem(top); 1220 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1221 return (NULL); 1222 } 1223 1224 /* 1225 * Copy an entire packet, including header (which must be present). 1226 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 1227 * Note that the copy is read-only, because clusters are not copied, 1228 * only their reference counts are incremented. 1229 * Preserve alignment of the first mbuf so if the creator has left 1230 * some room at the beginning (e.g. for inserting protocol headers) 1231 * the copies also have the room available. 1232 */ 1233 struct mbuf * 1234 m_copypacket(struct mbuf *m, int how) 1235 { 1236 struct mbuf *top, *n, *o; 1237 1238 n = m_gethdr(how, m->m_type); 1239 top = n; 1240 if (!n) 1241 goto nospace; 1242 1243 if (!m_dup_pkthdr(n, m, how)) 1244 goto nospace; 1245 n->m_len = m->m_len; 1246 if (m->m_flags & M_EXT) { 1247 KKASSERT((n->m_flags & M_EXT) == 0); 1248 n->m_data = m->m_data; 1249 m->m_ext.ext_ref(m->m_ext.ext_arg); 1250 n->m_ext = m->m_ext; 1251 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1252 } else { 1253 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 1254 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 1255 } 1256 1257 m = m->m_next; 1258 while (m) { 1259 o = m_get(how, m->m_type); 1260 if (!o) 1261 goto nospace; 1262 1263 n->m_next = o; 1264 n = n->m_next; 1265 1266 n->m_len = m->m_len; 1267 if (m->m_flags & M_EXT) { 1268 KKASSERT((n->m_flags & M_EXT) == 0); 1269 n->m_data = m->m_data; 1270 m->m_ext.ext_ref(m->m_ext.ext_arg); 1271 n->m_ext = m->m_ext; 1272 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1273 } else { 1274 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 1275 } 1276 1277 m = m->m_next; 1278 } 1279 return top; 1280 nospace: 1281 m_freem(top); 1282 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1283 return (NULL); 1284 } 1285 1286 /* 1287 * Copy data from an mbuf chain starting "off" bytes from the beginning, 1288 * continuing for "len" bytes, into the indicated buffer. 1289 */ 1290 void 1291 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 1292 { 1293 unsigned count; 1294 1295 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 1296 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 1297 while (off > 0) { 1298 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 1299 if (off < m->m_len) 1300 break; 1301 off -= m->m_len; 1302 m = m->m_next; 1303 } 1304 while (len > 0) { 1305 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 1306 count = min(m->m_len - off, len); 1307 bcopy(mtod(m, caddr_t) + off, cp, count); 1308 len -= count; 1309 cp += count; 1310 off = 0; 1311 m = m->m_next; 1312 } 1313 } 1314 1315 /* 1316 * Copy a packet header mbuf chain into a completely new chain, including 1317 * copying any mbuf clusters. Use this instead of m_copypacket() when 1318 * you need a writable copy of an mbuf chain. 1319 */ 1320 struct mbuf * 1321 m_dup(struct mbuf *m, int how) 1322 { 1323 struct mbuf **p, *top = NULL; 1324 int remain, moff, nsize; 1325 1326 /* Sanity check */ 1327 if (m == NULL) 1328 return (NULL); 1329 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__)); 1330 1331 /* While there's more data, get a new mbuf, tack it on, and fill it */ 1332 remain = m->m_pkthdr.len; 1333 moff = 0; 1334 p = ⊤ 1335 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 1336 struct mbuf *n; 1337 1338 /* Get the next new mbuf */ 1339 n = m_getl(remain, how, m->m_type, top == NULL ? M_PKTHDR : 0, 1340 &nsize); 1341 if (n == NULL) 1342 goto nospace; 1343 if (top == NULL) 1344 if (!m_dup_pkthdr(n, m, how)) 1345 goto nospace0; 1346 1347 /* Link it into the new chain */ 1348 *p = n; 1349 p = &n->m_next; 1350 1351 /* Copy data from original mbuf(s) into new mbuf */ 1352 n->m_len = 0; 1353 while (n->m_len < nsize && m != NULL) { 1354 int chunk = min(nsize - n->m_len, m->m_len - moff); 1355 1356 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 1357 moff += chunk; 1358 n->m_len += chunk; 1359 remain -= chunk; 1360 if (moff == m->m_len) { 1361 m = m->m_next; 1362 moff = 0; 1363 } 1364 } 1365 1366 /* Check correct total mbuf length */ 1367 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 1368 ("%s: bogus m_pkthdr.len", __func__)); 1369 } 1370 return (top); 1371 1372 nospace: 1373 m_freem(top); 1374 nospace0: 1375 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1376 return (NULL); 1377 } 1378 1379 /* 1380 * Copy the non-packet mbuf data chain into a new set of mbufs, including 1381 * copying any mbuf clusters. This is typically used to realign a data 1382 * chain by nfs_realign(). 1383 * 1384 * The original chain is left intact. how should be MB_WAIT or MB_DONTWAIT 1385 * and NULL can be returned if MB_DONTWAIT is passed. 1386 * 1387 * Be careful to use cluster mbufs, a large mbuf chain converted to non 1388 * cluster mbufs can exhaust our supply of mbufs. 1389 */ 1390 struct mbuf * 1391 m_dup_data(struct mbuf *m, int how) 1392 { 1393 struct mbuf **p, *n, *top = NULL; 1394 int mlen, moff, chunk, gsize, nsize; 1395 1396 /* 1397 * Degenerate case 1398 */ 1399 if (m == NULL) 1400 return (NULL); 1401 1402 /* 1403 * Optimize the mbuf allocation but do not get too carried away. 1404 */ 1405 if (m->m_next || m->m_len > MLEN) 1406 gsize = MCLBYTES; 1407 else 1408 gsize = MLEN; 1409 1410 /* Chain control */ 1411 p = ⊤ 1412 n = NULL; 1413 nsize = 0; 1414 1415 /* 1416 * Scan the mbuf chain until nothing is left, the new mbuf chain 1417 * will be allocated on the fly as needed. 1418 */ 1419 while (m) { 1420 mlen = m->m_len; 1421 moff = 0; 1422 1423 while (mlen) { 1424 KKASSERT(m->m_type == MT_DATA); 1425 if (n == NULL) { 1426 n = m_getl(gsize, how, MT_DATA, 0, &nsize); 1427 n->m_len = 0; 1428 if (n == NULL) 1429 goto nospace; 1430 *p = n; 1431 p = &n->m_next; 1432 } 1433 chunk = imin(mlen, nsize); 1434 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 1435 mlen -= chunk; 1436 moff += chunk; 1437 n->m_len += chunk; 1438 nsize -= chunk; 1439 if (nsize == 0) 1440 n = NULL; 1441 } 1442 m = m->m_next; 1443 } 1444 *p = NULL; 1445 return(top); 1446 nospace: 1447 *p = NULL; 1448 m_freem(top); 1449 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1450 return (NULL); 1451 } 1452 1453 /* 1454 * Concatenate mbuf chain n to m. 1455 * Both chains must be of the same type (e.g. MT_DATA). 1456 * Any m_pkthdr is not updated. 1457 */ 1458 void 1459 m_cat(struct mbuf *m, struct mbuf *n) 1460 { 1461 m = m_last(m); 1462 while (n) { 1463 if (m->m_flags & M_EXT || 1464 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 1465 /* just join the two chains */ 1466 m->m_next = n; 1467 return; 1468 } 1469 /* splat the data from one into the other */ 1470 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1471 (u_int)n->m_len); 1472 m->m_len += n->m_len; 1473 n = m_free(n); 1474 } 1475 } 1476 1477 void 1478 m_adj(struct mbuf *mp, int req_len) 1479 { 1480 int len = req_len; 1481 struct mbuf *m; 1482 int count; 1483 1484 if ((m = mp) == NULL) 1485 return; 1486 if (len >= 0) { 1487 /* 1488 * Trim from head. 1489 */ 1490 while (m != NULL && len > 0) { 1491 if (m->m_len <= len) { 1492 len -= m->m_len; 1493 m->m_len = 0; 1494 m = m->m_next; 1495 } else { 1496 m->m_len -= len; 1497 m->m_data += len; 1498 len = 0; 1499 } 1500 } 1501 m = mp; 1502 if (mp->m_flags & M_PKTHDR) 1503 m->m_pkthdr.len -= (req_len - len); 1504 } else { 1505 /* 1506 * Trim from tail. Scan the mbuf chain, 1507 * calculating its length and finding the last mbuf. 1508 * If the adjustment only affects this mbuf, then just 1509 * adjust and return. Otherwise, rescan and truncate 1510 * after the remaining size. 1511 */ 1512 len = -len; 1513 count = 0; 1514 for (;;) { 1515 count += m->m_len; 1516 if (m->m_next == NULL) 1517 break; 1518 m = m->m_next; 1519 } 1520 if (m->m_len >= len) { 1521 m->m_len -= len; 1522 if (mp->m_flags & M_PKTHDR) 1523 mp->m_pkthdr.len -= len; 1524 return; 1525 } 1526 count -= len; 1527 if (count < 0) 1528 count = 0; 1529 /* 1530 * Correct length for chain is "count". 1531 * Find the mbuf with last data, adjust its length, 1532 * and toss data from remaining mbufs on chain. 1533 */ 1534 m = mp; 1535 if (m->m_flags & M_PKTHDR) 1536 m->m_pkthdr.len = count; 1537 for (; m; m = m->m_next) { 1538 if (m->m_len >= count) { 1539 m->m_len = count; 1540 break; 1541 } 1542 count -= m->m_len; 1543 } 1544 while (m->m_next) 1545 (m = m->m_next) ->m_len = 0; 1546 } 1547 } 1548 1549 /* 1550 * Set the m_data pointer of a newly-allocated mbuf 1551 * to place an object of the specified size at the 1552 * end of the mbuf, longword aligned. 1553 */ 1554 void 1555 m_align(struct mbuf *m, int len) 1556 { 1557 int adjust; 1558 1559 if (m->m_flags & M_EXT) 1560 adjust = m->m_ext.ext_size - len; 1561 else if (m->m_flags & M_PKTHDR) 1562 adjust = MHLEN - len; 1563 else 1564 adjust = MLEN - len; 1565 m->m_data += adjust &~ (sizeof(long)-1); 1566 } 1567 1568 /* 1569 * Rearrange an mbuf chain so that len bytes are contiguous 1570 * and in the data area of an mbuf (so that mtod will work for a structure 1571 * of size len). Returns the resulting mbuf chain on success, frees it and 1572 * returns null on failure. If there is room, it will add up to 1573 * max_protohdr-len extra bytes to the contiguous region in an attempt to 1574 * avoid being called next time. 1575 */ 1576 struct mbuf * 1577 m_pullup(struct mbuf *n, int len) 1578 { 1579 struct mbuf *m; 1580 int count; 1581 int space; 1582 1583 /* 1584 * If first mbuf has no cluster, and has room for len bytes 1585 * without shifting current data, pullup into it, 1586 * otherwise allocate a new mbuf to prepend to the chain. 1587 */ 1588 if (!(n->m_flags & M_EXT) && 1589 n->m_data + len < &n->m_dat[MLEN] && 1590 n->m_next) { 1591 if (n->m_len >= len) 1592 return (n); 1593 m = n; 1594 n = n->m_next; 1595 len -= m->m_len; 1596 } else { 1597 if (len > MHLEN) 1598 goto bad; 1599 if (n->m_flags & M_PKTHDR) 1600 m = m_gethdr(MB_DONTWAIT, n->m_type); 1601 else 1602 m = m_get(MB_DONTWAIT, n->m_type); 1603 if (m == NULL) 1604 goto bad; 1605 m->m_len = 0; 1606 if (n->m_flags & M_PKTHDR) 1607 M_MOVE_PKTHDR(m, n); 1608 } 1609 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1610 do { 1611 count = min(min(max(len, max_protohdr), space), n->m_len); 1612 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1613 (unsigned)count); 1614 len -= count; 1615 m->m_len += count; 1616 n->m_len -= count; 1617 space -= count; 1618 if (n->m_len) 1619 n->m_data += count; 1620 else 1621 n = m_free(n); 1622 } while (len > 0 && n); 1623 if (len > 0) { 1624 m_free(m); 1625 goto bad; 1626 } 1627 m->m_next = n; 1628 return (m); 1629 bad: 1630 m_freem(n); 1631 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1632 return (NULL); 1633 } 1634 1635 /* 1636 * Partition an mbuf chain in two pieces, returning the tail -- 1637 * all but the first len0 bytes. In case of failure, it returns NULL and 1638 * attempts to restore the chain to its original state. 1639 * 1640 * Note that the resulting mbufs might be read-only, because the new 1641 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1642 * the "breaking point" happens to lie within a cluster mbuf. Use the 1643 * M_WRITABLE() macro to check for this case. 1644 */ 1645 struct mbuf * 1646 m_split(struct mbuf *m0, int len0, int wait) 1647 { 1648 struct mbuf *m, *n; 1649 unsigned len = len0, remain; 1650 1651 for (m = m0; m && len > m->m_len; m = m->m_next) 1652 len -= m->m_len; 1653 if (m == NULL) 1654 return (NULL); 1655 remain = m->m_len - len; 1656 if (m0->m_flags & M_PKTHDR) { 1657 n = m_gethdr(wait, m0->m_type); 1658 if (n == NULL) 1659 return (NULL); 1660 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1661 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1662 m0->m_pkthdr.len = len0; 1663 if (m->m_flags & M_EXT) 1664 goto extpacket; 1665 if (remain > MHLEN) { 1666 /* m can't be the lead packet */ 1667 MH_ALIGN(n, 0); 1668 n->m_next = m_split(m, len, wait); 1669 if (n->m_next == NULL) { 1670 m_free(n); 1671 return (NULL); 1672 } else { 1673 n->m_len = 0; 1674 return (n); 1675 } 1676 } else 1677 MH_ALIGN(n, remain); 1678 } else if (remain == 0) { 1679 n = m->m_next; 1680 m->m_next = 0; 1681 return (n); 1682 } else { 1683 n = m_get(wait, m->m_type); 1684 if (n == NULL) 1685 return (NULL); 1686 M_ALIGN(n, remain); 1687 } 1688 extpacket: 1689 if (m->m_flags & M_EXT) { 1690 KKASSERT((n->m_flags & M_EXT) == 0); 1691 n->m_data = m->m_data + len; 1692 m->m_ext.ext_ref(m->m_ext.ext_arg); 1693 n->m_ext = m->m_ext; 1694 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1695 } else { 1696 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1697 } 1698 n->m_len = remain; 1699 m->m_len = len; 1700 n->m_next = m->m_next; 1701 m->m_next = 0; 1702 return (n); 1703 } 1704 1705 /* 1706 * Routine to copy from device local memory into mbufs. 1707 * Note: "offset" is ill-defined and always called as 0, so ignore it. 1708 */ 1709 struct mbuf * 1710 m_devget(char *buf, int len, int offset, struct ifnet *ifp, 1711 void (*copy)(volatile const void *from, volatile void *to, size_t length)) 1712 { 1713 struct mbuf *m, *mfirst = NULL, **mtail; 1714 int nsize, flags; 1715 1716 if (copy == NULL) 1717 copy = bcopy; 1718 mtail = &mfirst; 1719 flags = M_PKTHDR; 1720 1721 while (len > 0) { 1722 m = m_getl(len, MB_DONTWAIT, MT_DATA, flags, &nsize); 1723 if (m == NULL) { 1724 m_freem(mfirst); 1725 return (NULL); 1726 } 1727 m->m_len = min(len, nsize); 1728 1729 if (flags & M_PKTHDR) { 1730 if (len + max_linkhdr <= nsize) 1731 m->m_data += max_linkhdr; 1732 m->m_pkthdr.rcvif = ifp; 1733 m->m_pkthdr.len = len; 1734 flags = 0; 1735 } 1736 1737 copy(buf, m->m_data, (unsigned)m->m_len); 1738 buf += m->m_len; 1739 len -= m->m_len; 1740 *mtail = m; 1741 mtail = &m->m_next; 1742 } 1743 1744 return (mfirst); 1745 } 1746 1747 /* 1748 * Routine to pad mbuf to the specified length 'padto'. 1749 */ 1750 int 1751 m_devpad(struct mbuf *m, int padto) 1752 { 1753 struct mbuf *last = NULL; 1754 int padlen; 1755 1756 if (padto <= m->m_pkthdr.len) 1757 return 0; 1758 1759 padlen = padto - m->m_pkthdr.len; 1760 1761 /* if there's only the packet-header and we can pad there, use it. */ 1762 if (m->m_pkthdr.len == m->m_len && M_TRAILINGSPACE(m) >= padlen) { 1763 last = m; 1764 } else { 1765 /* 1766 * Walk packet chain to find last mbuf. We will either 1767 * pad there, or append a new mbuf and pad it 1768 */ 1769 for (last = m; last->m_next != NULL; last = last->m_next) 1770 ; /* EMPTY */ 1771 1772 /* `last' now points to last in chain. */ 1773 if (M_TRAILINGSPACE(last) < padlen) { 1774 struct mbuf *n; 1775 1776 /* Allocate new empty mbuf, pad it. Compact later. */ 1777 MGET(n, MB_DONTWAIT, MT_DATA); 1778 if (n == NULL) 1779 return ENOBUFS; 1780 n->m_len = 0; 1781 last->m_next = n; 1782 last = n; 1783 } 1784 } 1785 KKASSERT(M_TRAILINGSPACE(last) >= padlen); 1786 KKASSERT(M_WRITABLE(last)); 1787 1788 /* Now zero the pad area */ 1789 bzero(mtod(last, char *) + last->m_len, padlen); 1790 last->m_len += padlen; 1791 m->m_pkthdr.len += padlen; 1792 return 0; 1793 } 1794 1795 /* 1796 * Copy data from a buffer back into the indicated mbuf chain, 1797 * starting "off" bytes from the beginning, extending the mbuf 1798 * chain if necessary. 1799 */ 1800 void 1801 m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) 1802 { 1803 int mlen; 1804 struct mbuf *m = m0, *n; 1805 int totlen = 0; 1806 1807 if (m0 == NULL) 1808 return; 1809 while (off > (mlen = m->m_len)) { 1810 off -= mlen; 1811 totlen += mlen; 1812 if (m->m_next == NULL) { 1813 n = m_getclr(MB_DONTWAIT, m->m_type); 1814 if (n == NULL) 1815 goto out; 1816 n->m_len = min(MLEN, len + off); 1817 m->m_next = n; 1818 } 1819 m = m->m_next; 1820 } 1821 while (len > 0) { 1822 mlen = min (m->m_len - off, len); 1823 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 1824 cp += mlen; 1825 len -= mlen; 1826 mlen += off; 1827 off = 0; 1828 totlen += mlen; 1829 if (len == 0) 1830 break; 1831 if (m->m_next == NULL) { 1832 n = m_get(MB_DONTWAIT, m->m_type); 1833 if (n == NULL) 1834 break; 1835 n->m_len = min(MLEN, len); 1836 m->m_next = n; 1837 } 1838 m = m->m_next; 1839 } 1840 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1841 m->m_pkthdr.len = totlen; 1842 } 1843 1844 /* 1845 * Append the specified data to the indicated mbuf chain, 1846 * Extend the mbuf chain if the new data does not fit in 1847 * existing space. 1848 * 1849 * Return 1 if able to complete the job; otherwise 0. 1850 */ 1851 int 1852 m_append(struct mbuf *m0, int len, c_caddr_t cp) 1853 { 1854 struct mbuf *m, *n; 1855 int remainder, space; 1856 1857 for (m = m0; m->m_next != NULL; m = m->m_next) 1858 ; 1859 remainder = len; 1860 space = M_TRAILINGSPACE(m); 1861 if (space > 0) { 1862 /* 1863 * Copy into available space. 1864 */ 1865 if (space > remainder) 1866 space = remainder; 1867 bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1868 m->m_len += space; 1869 cp += space, remainder -= space; 1870 } 1871 while (remainder > 0) { 1872 /* 1873 * Allocate a new mbuf; could check space 1874 * and allocate a cluster instead. 1875 */ 1876 n = m_get(MB_DONTWAIT, m->m_type); 1877 if (n == NULL) 1878 break; 1879 n->m_len = min(MLEN, remainder); 1880 bcopy(cp, mtod(n, caddr_t), n->m_len); 1881 cp += n->m_len, remainder -= n->m_len; 1882 m->m_next = n; 1883 m = n; 1884 } 1885 if (m0->m_flags & M_PKTHDR) 1886 m0->m_pkthdr.len += len - remainder; 1887 return (remainder == 0); 1888 } 1889 1890 /* 1891 * Apply function f to the data in an mbuf chain starting "off" bytes from 1892 * the beginning, continuing for "len" bytes. 1893 */ 1894 int 1895 m_apply(struct mbuf *m, int off, int len, 1896 int (*f)(void *, void *, u_int), void *arg) 1897 { 1898 u_int count; 1899 int rval; 1900 1901 KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1902 KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1903 while (off > 0) { 1904 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1905 if (off < m->m_len) 1906 break; 1907 off -= m->m_len; 1908 m = m->m_next; 1909 } 1910 while (len > 0) { 1911 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1912 count = min(m->m_len - off, len); 1913 rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1914 if (rval) 1915 return (rval); 1916 len -= count; 1917 off = 0; 1918 m = m->m_next; 1919 } 1920 return (0); 1921 } 1922 1923 /* 1924 * Return a pointer to mbuf/offset of location in mbuf chain. 1925 */ 1926 struct mbuf * 1927 m_getptr(struct mbuf *m, int loc, int *off) 1928 { 1929 1930 while (loc >= 0) { 1931 /* Normal end of search. */ 1932 if (m->m_len > loc) { 1933 *off = loc; 1934 return (m); 1935 } else { 1936 loc -= m->m_len; 1937 if (m->m_next == NULL) { 1938 if (loc == 0) { 1939 /* Point at the end of valid data. */ 1940 *off = m->m_len; 1941 return (m); 1942 } 1943 return (NULL); 1944 } 1945 m = m->m_next; 1946 } 1947 } 1948 return (NULL); 1949 } 1950 1951 void 1952 m_print(const struct mbuf *m) 1953 { 1954 int len; 1955 const struct mbuf *m2; 1956 1957 len = m->m_pkthdr.len; 1958 m2 = m; 1959 while (len) { 1960 kprintf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); 1961 len -= m2->m_len; 1962 m2 = m2->m_next; 1963 } 1964 return; 1965 } 1966 1967 /* 1968 * "Move" mbuf pkthdr from "from" to "to". 1969 * "from" must have M_PKTHDR set, and "to" must be empty. 1970 */ 1971 void 1972 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1973 { 1974 KASSERT((to->m_flags & M_PKTHDR), ("m_move_pkthdr: not packet header")); 1975 1976 to->m_flags |= from->m_flags & M_COPYFLAGS; 1977 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 1978 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 1979 } 1980 1981 /* 1982 * Duplicate "from"'s mbuf pkthdr in "to". 1983 * "from" must have M_PKTHDR set, and "to" must be empty. 1984 * In particular, this does a deep copy of the packet tags. 1985 */ 1986 int 1987 m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how) 1988 { 1989 KASSERT((to->m_flags & M_PKTHDR), ("m_dup_pkthdr: not packet header")); 1990 1991 to->m_flags = (from->m_flags & M_COPYFLAGS) | 1992 (to->m_flags & ~M_COPYFLAGS); 1993 to->m_pkthdr = from->m_pkthdr; 1994 SLIST_INIT(&to->m_pkthdr.tags); 1995 return (m_tag_copy_chain(to, from, how)); 1996 } 1997 1998 /* 1999 * Defragment a mbuf chain, returning the shortest possible 2000 * chain of mbufs and clusters. If allocation fails and 2001 * this cannot be completed, NULL will be returned, but 2002 * the passed in chain will be unchanged. Upon success, 2003 * the original chain will be freed, and the new chain 2004 * will be returned. 2005 * 2006 * If a non-packet header is passed in, the original 2007 * mbuf (chain?) will be returned unharmed. 2008 * 2009 * m_defrag_nofree doesn't free the passed in mbuf. 2010 */ 2011 struct mbuf * 2012 m_defrag(struct mbuf *m0, int how) 2013 { 2014 struct mbuf *m_new; 2015 2016 if ((m_new = m_defrag_nofree(m0, how)) == NULL) 2017 return (NULL); 2018 if (m_new != m0) 2019 m_freem(m0); 2020 return (m_new); 2021 } 2022 2023 struct mbuf * 2024 m_defrag_nofree(struct mbuf *m0, int how) 2025 { 2026 struct mbuf *m_new = NULL, *m_final = NULL; 2027 int progress = 0, length, nsize; 2028 2029 if (!(m0->m_flags & M_PKTHDR)) 2030 return (m0); 2031 2032 #ifdef MBUF_STRESS_TEST 2033 if (m_defragrandomfailures) { 2034 int temp = karc4random() & 0xff; 2035 if (temp == 0xba) 2036 goto nospace; 2037 } 2038 #endif 2039 2040 m_final = m_getl(m0->m_pkthdr.len, how, MT_DATA, M_PKTHDR, &nsize); 2041 if (m_final == NULL) 2042 goto nospace; 2043 m_final->m_len = 0; /* in case m0->m_pkthdr.len is zero */ 2044 2045 if (m_dup_pkthdr(m_final, m0, how) == 0) 2046 goto nospace; 2047 2048 m_new = m_final; 2049 2050 while (progress < m0->m_pkthdr.len) { 2051 length = m0->m_pkthdr.len - progress; 2052 if (length > MCLBYTES) 2053 length = MCLBYTES; 2054 2055 if (m_new == NULL) { 2056 m_new = m_getl(length, how, MT_DATA, 0, &nsize); 2057 if (m_new == NULL) 2058 goto nospace; 2059 } 2060 2061 m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 2062 progress += length; 2063 m_new->m_len = length; 2064 if (m_new != m_final) 2065 m_cat(m_final, m_new); 2066 m_new = NULL; 2067 } 2068 if (m0->m_next == NULL) 2069 m_defraguseless++; 2070 m_defragpackets++; 2071 m_defragbytes += m_final->m_pkthdr.len; 2072 return (m_final); 2073 nospace: 2074 m_defragfailure++; 2075 if (m_new) 2076 m_free(m_new); 2077 m_freem(m_final); 2078 return (NULL); 2079 } 2080 2081 /* 2082 * Move data from uio into mbufs. 2083 */ 2084 struct mbuf * 2085 m_uiomove(struct uio *uio) 2086 { 2087 struct mbuf *m; /* current working mbuf */ 2088 struct mbuf *head = NULL; /* result mbuf chain */ 2089 struct mbuf **mp = &head; 2090 int flags = M_PKTHDR; 2091 int nsize; 2092 int error; 2093 int resid; 2094 2095 do { 2096 if (uio->uio_resid > INT_MAX) 2097 resid = INT_MAX; 2098 else 2099 resid = (int)uio->uio_resid; 2100 m = m_getl(resid, MB_WAIT, MT_DATA, flags, &nsize); 2101 if (flags) { 2102 m->m_pkthdr.len = 0; 2103 /* Leave room for protocol headers. */ 2104 if (resid < MHLEN) 2105 MH_ALIGN(m, resid); 2106 flags = 0; 2107 } 2108 m->m_len = imin(nsize, resid); 2109 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 2110 if (error) { 2111 m_free(m); 2112 goto failed; 2113 } 2114 *mp = m; 2115 mp = &m->m_next; 2116 head->m_pkthdr.len += m->m_len; 2117 } while (uio->uio_resid > 0); 2118 2119 return (head); 2120 2121 failed: 2122 m_freem(head); 2123 return (NULL); 2124 } 2125 2126 struct mbuf * 2127 m_last(struct mbuf *m) 2128 { 2129 while (m->m_next) 2130 m = m->m_next; 2131 return (m); 2132 } 2133 2134 /* 2135 * Return the number of bytes in an mbuf chain. 2136 * If lastm is not NULL, also return the last mbuf. 2137 */ 2138 u_int 2139 m_lengthm(struct mbuf *m, struct mbuf **lastm) 2140 { 2141 u_int len = 0; 2142 struct mbuf *prev = m; 2143 2144 while (m) { 2145 len += m->m_len; 2146 prev = m; 2147 m = m->m_next; 2148 } 2149 if (lastm != NULL) 2150 *lastm = prev; 2151 return (len); 2152 } 2153 2154 /* 2155 * Like m_lengthm(), except also keep track of mbuf usage. 2156 */ 2157 u_int 2158 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *pmbcnt) 2159 { 2160 u_int len = 0, mbcnt = 0; 2161 struct mbuf *prev = m; 2162 2163 while (m) { 2164 len += m->m_len; 2165 mbcnt += MSIZE; 2166 if (m->m_flags & M_EXT) 2167 mbcnt += m->m_ext.ext_size; 2168 prev = m; 2169 m = m->m_next; 2170 } 2171 if (lastm != NULL) 2172 *lastm = prev; 2173 *pmbcnt = mbcnt; 2174 return (len); 2175 } 2176