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