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