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