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 m->m_type = type; 670 671 mbuftrack(m); 672 673 atomic_add_long_nonlocked(&mbtypes[gd->gd_cpuid][type], 1); 674 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mbufs, 1); 675 676 } 677 678 /* 679 * Allocate an mbuf. 680 */ 681 struct mbuf * 682 m_get(int how, int type) 683 { 684 struct mbuf *m; 685 int ntries = 0; 686 int ocf = MBTOM(how); 687 688 retryonce: 689 690 m = objcache_get(mbuf_cache, ocf); 691 692 if (m == NULL) { 693 if ((how & MB_TRYWAIT) && ntries++ == 0) { 694 struct objcache *reclaimlist[] = { 695 mbufphdr_cache, 696 mbufcluster_cache, 697 mbufphdrcluster_cache 698 }; 699 const int nreclaims = __arysize(reclaimlist); 700 701 if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) 702 m_reclaim(); 703 goto retryonce; 704 } 705 ++mbstat[mycpu->gd_cpuid].m_drops; 706 return (NULL); 707 } 708 709 updatestats(m, type); 710 return (m); 711 } 712 713 struct mbuf * 714 m_gethdr(int how, int type) 715 { 716 struct mbuf *m; 717 int ocf = MBTOM(how); 718 int ntries = 0; 719 720 retryonce: 721 722 m = objcache_get(mbufphdr_cache, ocf); 723 724 if (m == NULL) { 725 if ((how & MB_TRYWAIT) && ntries++ == 0) { 726 struct objcache *reclaimlist[] = { 727 mbuf_cache, 728 mbufcluster_cache, mbufphdrcluster_cache 729 }; 730 const int nreclaims = __arysize(reclaimlist); 731 732 if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) 733 m_reclaim(); 734 goto retryonce; 735 } 736 ++mbstat[mycpu->gd_cpuid].m_drops; 737 return (NULL); 738 } 739 740 updatestats(m, type); 741 return (m); 742 } 743 744 /* 745 * Get a mbuf (not a mbuf cluster!) and zero it. 746 * Deprecated. 747 */ 748 struct mbuf * 749 m_getclr(int how, int type) 750 { 751 struct mbuf *m; 752 753 m = m_get(how, type); 754 if (m != NULL) 755 bzero(m->m_data, MLEN); 756 return (m); 757 } 758 759 /* 760 * Returns an mbuf with an attached cluster. 761 * Because many network drivers use this kind of buffers a lot, it is 762 * convenient to keep a small pool of free buffers of this kind. 763 * Even a small size such as 10 gives about 10% improvement in the 764 * forwarding rate in a bridge or router. 765 */ 766 struct mbuf * 767 m_getcl(int how, short type, int flags) 768 { 769 struct mbuf *m; 770 int ocflags = MBTOM(how); 771 int ntries = 0; 772 773 retryonce: 774 775 if (flags & M_PKTHDR) 776 m = objcache_get(mbufphdrcluster_cache, ocflags); 777 else 778 m = objcache_get(mbufcluster_cache, ocflags); 779 780 if (m == NULL) { 781 if ((how & MB_TRYWAIT) && ntries++ == 0) { 782 struct objcache *reclaimlist[1]; 783 784 if (flags & M_PKTHDR) 785 reclaimlist[0] = mbufcluster_cache; 786 else 787 reclaimlist[0] = mbufphdrcluster_cache; 788 if (!objcache_reclaimlist(reclaimlist, 1, ocflags)) 789 m_reclaim(); 790 goto retryonce; 791 } 792 ++mbstat[mycpu->gd_cpuid].m_drops; 793 return (NULL); 794 } 795 796 m->m_type = type; 797 798 mbuftrack(m); 799 800 atomic_add_long_nonlocked(&mbtypes[mycpu->gd_cpuid][type], 1); 801 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 802 return (m); 803 } 804 805 /* 806 * Allocate chain of requested length. 807 */ 808 struct mbuf * 809 m_getc(int len, int how, int type) 810 { 811 struct mbuf *n, *nfirst = NULL, **ntail = &nfirst; 812 int nsize; 813 814 while (len > 0) { 815 n = m_getl(len, how, type, 0, &nsize); 816 if (n == NULL) 817 goto failed; 818 n->m_len = 0; 819 *ntail = n; 820 ntail = &n->m_next; 821 len -= nsize; 822 } 823 return (nfirst); 824 825 failed: 826 m_freem(nfirst); 827 return (NULL); 828 } 829 830 /* 831 * Allocate len-worth of mbufs and/or mbuf clusters (whatever fits best) 832 * and return a pointer to the head of the allocated chain. If m0 is 833 * non-null, then we assume that it is a single mbuf or an mbuf chain to 834 * which we want len bytes worth of mbufs and/or clusters attached, and so 835 * if we succeed in allocating it, we will just return a pointer to m0. 836 * 837 * If we happen to fail at any point during the allocation, we will free 838 * up everything we have already allocated and return NULL. 839 * 840 * Deprecated. Use m_getc() and m_cat() instead. 841 */ 842 struct mbuf * 843 m_getm(struct mbuf *m0, int len, int type, int how) 844 { 845 struct mbuf *nfirst; 846 847 nfirst = m_getc(len, how, type); 848 849 if (m0 != NULL) { 850 m_last(m0)->m_next = nfirst; 851 return (m0); 852 } 853 854 return (nfirst); 855 } 856 857 /* 858 * Adds a cluster to a normal mbuf, M_EXT is set on success. 859 * Deprecated. Use m_getcl() instead. 860 */ 861 void 862 m_mclget(struct mbuf *m, int how) 863 { 864 struct mbcluster *mcl; 865 866 KKASSERT((m->m_flags & M_EXT) == 0); 867 mcl = objcache_get(mclmeta_cache, MBTOM(how)); 868 if (mcl != NULL) { 869 linkcluster(m, mcl); 870 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 871 1); 872 } else { 873 ++mbstat[mycpu->gd_cpuid].m_drops; 874 } 875 } 876 877 /* 878 * Updates to mbcluster must be MPSAFE. Only an entity which already has 879 * a reference to the cluster can ref it, so we are in no danger of 880 * racing an add with a subtract. But the operation must still be atomic 881 * since multiple entities may have a reference on the cluster. 882 * 883 * m_mclfree() is almost the same but it must contend with two entities 884 * freeing the cluster at the same time. 885 */ 886 static void 887 m_mclref(void *arg) 888 { 889 struct mbcluster *mcl = arg; 890 891 atomic_add_int(&mcl->mcl_refs, 1); 892 } 893 894 /* 895 * When dereferencing a cluster we have to deal with a N->0 race, where 896 * N entities free their references simultaniously. To do this we use 897 * atomic_fetchadd_int(). 898 */ 899 static void 900 m_mclfree(void *arg) 901 { 902 struct mbcluster *mcl = arg; 903 904 if (atomic_fetchadd_int(&mcl->mcl_refs, -1) == 1) 905 objcache_put(mclmeta_cache, mcl); 906 } 907 908 /* 909 * Free a single mbuf and any associated external storage. The successor, 910 * if any, is returned. 911 * 912 * We do need to check non-first mbuf for m_aux, since some of existing 913 * code does not call M_PREPEND properly. 914 * (example: call to bpf_mtap from drivers) 915 */ 916 struct mbuf * 917 m_free(struct mbuf *m) 918 { 919 struct mbuf *n; 920 struct globaldata *gd = mycpu; 921 922 KASSERT(m->m_type != MT_FREE, ("freeing free mbuf %p", m)); 923 atomic_subtract_long_nonlocked(&mbtypes[gd->gd_cpuid][m->m_type], 1); 924 925 n = m->m_next; 926 927 /* 928 * Make sure the mbuf is in constructed state before returning it 929 * to the objcache. 930 */ 931 m->m_next = NULL; 932 mbufuntrack(m); 933 #ifdef notyet 934 KKASSERT(m->m_nextpkt == NULL); 935 #else 936 if (m->m_nextpkt != NULL) { 937 static int afewtimes = 10; 938 939 if (afewtimes-- > 0) { 940 kprintf("mfree: m->m_nextpkt != NULL\n"); 941 print_backtrace(-1); 942 } 943 m->m_nextpkt = NULL; 944 } 945 #endif 946 if (m->m_flags & M_PKTHDR) { 947 m_tag_delete_chain(m); /* eliminate XXX JH */ 948 } 949 950 m->m_flags &= (M_EXT | M_EXT_CLUSTER | M_CLCACHE | M_PHCACHE); 951 952 /* 953 * Clean the M_PKTHDR state so we can return the mbuf to its original 954 * cache. This is based on the PHCACHE flag which tells us whether 955 * the mbuf was originally allocated out of a packet-header cache 956 * or a non-packet-header cache. 957 */ 958 if (m->m_flags & M_PHCACHE) { 959 m->m_flags |= M_PKTHDR; 960 m->m_pkthdr.rcvif = NULL; /* eliminate XXX JH */ 961 m->m_pkthdr.csum_flags = 0; /* eliminate XXX JH */ 962 m->m_pkthdr.fw_flags = 0; /* eliminate XXX JH */ 963 SLIST_INIT(&m->m_pkthdr.tags); 964 } 965 966 /* 967 * Handle remaining flags combinations. M_CLCACHE tells us whether 968 * the mbuf was originally allocated from a cluster cache or not, 969 * and is totally separate from whether the mbuf is currently 970 * associated with a cluster. 971 */ 972 switch(m->m_flags & (M_CLCACHE | M_EXT | M_EXT_CLUSTER)) { 973 case M_CLCACHE | M_EXT | M_EXT_CLUSTER: 974 /* 975 * mbuf+cluster cache case. The mbuf was allocated from the 976 * combined mbuf_cluster cache and can be returned to the 977 * cache if the cluster hasn't been shared. 978 */ 979 if (m_sharecount(m) == 1) { 980 /* 981 * The cluster has not been shared, we can just 982 * reset the data pointer and return the mbuf 983 * to the cluster cache. Note that the reference 984 * count is left intact (it is still associated with 985 * an mbuf). 986 */ 987 m->m_data = m->m_ext.ext_buf; 988 if (m->m_flags & M_PHCACHE) 989 objcache_put(mbufphdrcluster_cache, m); 990 else 991 objcache_put(mbufcluster_cache, m); 992 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 993 } else { 994 /* 995 * Hell. Someone else has a ref on this cluster, 996 * we have to disconnect it which means we can't 997 * put it back into the mbufcluster_cache, we 998 * have to destroy the mbuf. 999 * 1000 * Other mbuf references to the cluster will typically 1001 * be M_EXT | M_EXT_CLUSTER but without M_CLCACHE. 1002 * 1003 * XXX we could try to connect another cluster to 1004 * it. 1005 */ 1006 m->m_ext.ext_free(m->m_ext.ext_arg); 1007 m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); 1008 if (m->m_flags & M_PHCACHE) 1009 objcache_dtor(mbufphdrcluster_cache, m); 1010 else 1011 objcache_dtor(mbufcluster_cache, m); 1012 } 1013 break; 1014 case M_EXT | M_EXT_CLUSTER: 1015 /* 1016 * Normal cluster associated with an mbuf that was allocated 1017 * from the normal mbuf pool rather then the cluster pool. 1018 * The cluster has to be independantly disassociated from the 1019 * mbuf. 1020 */ 1021 if (m_sharecount(m) == 1) 1022 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_clusters, 1); 1023 /* fall through */ 1024 case M_EXT: 1025 /* 1026 * Normal cluster association case, disconnect the cluster from 1027 * the mbuf. The cluster may or may not be custom. 1028 */ 1029 m->m_ext.ext_free(m->m_ext.ext_arg); 1030 m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); 1031 /* fall through */ 1032 case 0: 1033 /* 1034 * return the mbuf to the mbuf cache. 1035 */ 1036 if (m->m_flags & M_PHCACHE) { 1037 m->m_data = m->m_pktdat; 1038 objcache_put(mbufphdr_cache, m); 1039 } else { 1040 m->m_data = m->m_dat; 1041 objcache_put(mbuf_cache, m); 1042 } 1043 atomic_subtract_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mbufs, 1); 1044 break; 1045 default: 1046 if (!panicstr) 1047 panic("bad mbuf flags %p %08x\n", m, m->m_flags); 1048 break; 1049 } 1050 return (n); 1051 } 1052 1053 void 1054 m_freem(struct mbuf *m) 1055 { 1056 while (m) 1057 m = m_free(m); 1058 } 1059 1060 /* 1061 * mbuf utility routines 1062 */ 1063 1064 /* 1065 * Lesser-used path for M_PREPEND: allocate new mbuf to prepend to chain and 1066 * copy junk along. 1067 */ 1068 struct mbuf * 1069 m_prepend(struct mbuf *m, int len, int how) 1070 { 1071 struct mbuf *mn; 1072 1073 if (m->m_flags & M_PKTHDR) 1074 mn = m_gethdr(how, m->m_type); 1075 else 1076 mn = m_get(how, m->m_type); 1077 if (mn == NULL) { 1078 m_freem(m); 1079 return (NULL); 1080 } 1081 if (m->m_flags & M_PKTHDR) 1082 M_MOVE_PKTHDR(mn, m); 1083 mn->m_next = m; 1084 m = mn; 1085 if (len < MHLEN) 1086 MH_ALIGN(m, len); 1087 m->m_len = len; 1088 return (m); 1089 } 1090 1091 /* 1092 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 1093 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 1094 * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller. 1095 * Note that the copy is read-only, because clusters are not copied, 1096 * only their reference counts are incremented. 1097 */ 1098 struct mbuf * 1099 m_copym(const struct mbuf *m, int off0, int len, int wait) 1100 { 1101 struct mbuf *n, **np; 1102 int off = off0; 1103 struct mbuf *top; 1104 int copyhdr = 0; 1105 1106 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 1107 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 1108 if (off == 0 && (m->m_flags & M_PKTHDR)) 1109 copyhdr = 1; 1110 while (off > 0) { 1111 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 1112 if (off < m->m_len) 1113 break; 1114 off -= m->m_len; 1115 m = m->m_next; 1116 } 1117 np = ⊤ 1118 top = NULL; 1119 while (len > 0) { 1120 if (m == NULL) { 1121 KASSERT(len == M_COPYALL, 1122 ("m_copym, length > size of mbuf chain")); 1123 break; 1124 } 1125 /* 1126 * Because we are sharing any cluster attachment below, 1127 * be sure to get an mbuf that does not have a cluster 1128 * associated with it. 1129 */ 1130 if (copyhdr) 1131 n = m_gethdr(wait, m->m_type); 1132 else 1133 n = m_get(wait, m->m_type); 1134 *np = n; 1135 if (n == NULL) 1136 goto nospace; 1137 if (copyhdr) { 1138 if (!m_dup_pkthdr(n, m, wait)) 1139 goto nospace; 1140 if (len == M_COPYALL) 1141 n->m_pkthdr.len -= off0; 1142 else 1143 n->m_pkthdr.len = len; 1144 copyhdr = 0; 1145 } 1146 n->m_len = min(len, m->m_len - off); 1147 if (m->m_flags & M_EXT) { 1148 KKASSERT((n->m_flags & M_EXT) == 0); 1149 n->m_data = m->m_data + off; 1150 m->m_ext.ext_ref(m->m_ext.ext_arg); 1151 n->m_ext = m->m_ext; 1152 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1153 } else { 1154 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 1155 (unsigned)n->m_len); 1156 } 1157 if (len != M_COPYALL) 1158 len -= n->m_len; 1159 off = 0; 1160 m = m->m_next; 1161 np = &n->m_next; 1162 } 1163 if (top == NULL) 1164 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1165 return (top); 1166 nospace: 1167 m_freem(top); 1168 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1169 return (NULL); 1170 } 1171 1172 /* 1173 * Copy an entire packet, including header (which must be present). 1174 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 1175 * Note that the copy is read-only, because clusters are not copied, 1176 * only their reference counts are incremented. 1177 * Preserve alignment of the first mbuf so if the creator has left 1178 * some room at the beginning (e.g. for inserting protocol headers) 1179 * the copies also have the room available. 1180 */ 1181 struct mbuf * 1182 m_copypacket(struct mbuf *m, int how) 1183 { 1184 struct mbuf *top, *n, *o; 1185 1186 n = m_gethdr(how, m->m_type); 1187 top = n; 1188 if (!n) 1189 goto nospace; 1190 1191 if (!m_dup_pkthdr(n, m, how)) 1192 goto nospace; 1193 n->m_len = m->m_len; 1194 if (m->m_flags & M_EXT) { 1195 KKASSERT((n->m_flags & M_EXT) == 0); 1196 n->m_data = m->m_data; 1197 m->m_ext.ext_ref(m->m_ext.ext_arg); 1198 n->m_ext = m->m_ext; 1199 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1200 } else { 1201 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 1202 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 1203 } 1204 1205 m = m->m_next; 1206 while (m) { 1207 o = m_get(how, m->m_type); 1208 if (!o) 1209 goto nospace; 1210 1211 n->m_next = o; 1212 n = n->m_next; 1213 1214 n->m_len = m->m_len; 1215 if (m->m_flags & M_EXT) { 1216 KKASSERT((n->m_flags & M_EXT) == 0); 1217 n->m_data = m->m_data; 1218 m->m_ext.ext_ref(m->m_ext.ext_arg); 1219 n->m_ext = m->m_ext; 1220 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1221 } else { 1222 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 1223 } 1224 1225 m = m->m_next; 1226 } 1227 return top; 1228 nospace: 1229 m_freem(top); 1230 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1231 return (NULL); 1232 } 1233 1234 /* 1235 * Copy data from an mbuf chain starting "off" bytes from the beginning, 1236 * continuing for "len" bytes, into the indicated buffer. 1237 */ 1238 void 1239 m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 1240 { 1241 unsigned count; 1242 1243 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 1244 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 1245 while (off > 0) { 1246 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 1247 if (off < m->m_len) 1248 break; 1249 off -= m->m_len; 1250 m = m->m_next; 1251 } 1252 while (len > 0) { 1253 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 1254 count = min(m->m_len - off, len); 1255 bcopy(mtod(m, caddr_t) + off, cp, count); 1256 len -= count; 1257 cp += count; 1258 off = 0; 1259 m = m->m_next; 1260 } 1261 } 1262 1263 /* 1264 * Copy a packet header mbuf chain into a completely new chain, including 1265 * copying any mbuf clusters. Use this instead of m_copypacket() when 1266 * you need a writable copy of an mbuf chain. 1267 */ 1268 struct mbuf * 1269 m_dup(struct mbuf *m, int how) 1270 { 1271 struct mbuf **p, *top = NULL; 1272 int remain, moff, nsize; 1273 1274 /* Sanity check */ 1275 if (m == NULL) 1276 return (NULL); 1277 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__)); 1278 1279 /* While there's more data, get a new mbuf, tack it on, and fill it */ 1280 remain = m->m_pkthdr.len; 1281 moff = 0; 1282 p = ⊤ 1283 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 1284 struct mbuf *n; 1285 1286 /* Get the next new mbuf */ 1287 n = m_getl(remain, how, m->m_type, top == NULL ? M_PKTHDR : 0, 1288 &nsize); 1289 if (n == NULL) 1290 goto nospace; 1291 if (top == NULL) 1292 if (!m_dup_pkthdr(n, m, how)) 1293 goto nospace0; 1294 1295 /* Link it into the new chain */ 1296 *p = n; 1297 p = &n->m_next; 1298 1299 /* Copy data from original mbuf(s) into new mbuf */ 1300 n->m_len = 0; 1301 while (n->m_len < nsize && m != NULL) { 1302 int chunk = min(nsize - n->m_len, m->m_len - moff); 1303 1304 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 1305 moff += chunk; 1306 n->m_len += chunk; 1307 remain -= chunk; 1308 if (moff == m->m_len) { 1309 m = m->m_next; 1310 moff = 0; 1311 } 1312 } 1313 1314 /* Check correct total mbuf length */ 1315 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 1316 ("%s: bogus m_pkthdr.len", __func__)); 1317 } 1318 return (top); 1319 1320 nospace: 1321 m_freem(top); 1322 nospace0: 1323 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1324 return (NULL); 1325 } 1326 1327 /* 1328 * Copy the non-packet mbuf data chain into a new set of mbufs, including 1329 * copying any mbuf clusters. This is typically used to realign a data 1330 * chain by nfs_realign(). 1331 * 1332 * The original chain is left intact. how should be MB_WAIT or MB_DONTWAIT 1333 * and NULL can be returned if MB_DONTWAIT is passed. 1334 * 1335 * Be careful to use cluster mbufs, a large mbuf chain converted to non 1336 * cluster mbufs can exhaust our supply of mbufs. 1337 */ 1338 struct mbuf * 1339 m_dup_data(struct mbuf *m, int how) 1340 { 1341 struct mbuf **p, *n, *top = NULL; 1342 int mlen, moff, chunk, gsize, nsize; 1343 1344 /* 1345 * Degenerate case 1346 */ 1347 if (m == NULL) 1348 return (NULL); 1349 1350 /* 1351 * Optimize the mbuf allocation but do not get too carried away. 1352 */ 1353 if (m->m_next || m->m_len > MLEN) 1354 gsize = MCLBYTES; 1355 else 1356 gsize = MLEN; 1357 1358 /* Chain control */ 1359 p = ⊤ 1360 n = NULL; 1361 nsize = 0; 1362 1363 /* 1364 * Scan the mbuf chain until nothing is left, the new mbuf chain 1365 * will be allocated on the fly as needed. 1366 */ 1367 while (m) { 1368 mlen = m->m_len; 1369 moff = 0; 1370 1371 while (mlen) { 1372 KKASSERT(m->m_type == MT_DATA); 1373 if (n == NULL) { 1374 n = m_getl(gsize, how, MT_DATA, 0, &nsize); 1375 n->m_len = 0; 1376 if (n == NULL) 1377 goto nospace; 1378 *p = n; 1379 p = &n->m_next; 1380 } 1381 chunk = imin(mlen, nsize); 1382 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 1383 mlen -= chunk; 1384 moff += chunk; 1385 n->m_len += chunk; 1386 nsize -= chunk; 1387 if (nsize == 0) 1388 n = NULL; 1389 } 1390 m = m->m_next; 1391 } 1392 *p = NULL; 1393 return(top); 1394 nospace: 1395 *p = NULL; 1396 m_freem(top); 1397 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1398 return (NULL); 1399 } 1400 1401 /* 1402 * Concatenate mbuf chain n to m. 1403 * Both chains must be of the same type (e.g. MT_DATA). 1404 * Any m_pkthdr is not updated. 1405 */ 1406 void 1407 m_cat(struct mbuf *m, struct mbuf *n) 1408 { 1409 m = m_last(m); 1410 while (n) { 1411 if (m->m_flags & M_EXT || 1412 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 1413 /* just join the two chains */ 1414 m->m_next = n; 1415 return; 1416 } 1417 /* splat the data from one into the other */ 1418 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1419 (u_int)n->m_len); 1420 m->m_len += n->m_len; 1421 n = m_free(n); 1422 } 1423 } 1424 1425 void 1426 m_adj(struct mbuf *mp, int req_len) 1427 { 1428 int len = req_len; 1429 struct mbuf *m; 1430 int count; 1431 1432 if ((m = mp) == NULL) 1433 return; 1434 if (len >= 0) { 1435 /* 1436 * Trim from head. 1437 */ 1438 while (m != NULL && len > 0) { 1439 if (m->m_len <= len) { 1440 len -= m->m_len; 1441 m->m_len = 0; 1442 m = m->m_next; 1443 } else { 1444 m->m_len -= len; 1445 m->m_data += len; 1446 len = 0; 1447 } 1448 } 1449 m = mp; 1450 if (mp->m_flags & M_PKTHDR) 1451 m->m_pkthdr.len -= (req_len - len); 1452 } else { 1453 /* 1454 * Trim from tail. Scan the mbuf chain, 1455 * calculating its length and finding the last mbuf. 1456 * If the adjustment only affects this mbuf, then just 1457 * adjust and return. Otherwise, rescan and truncate 1458 * after the remaining size. 1459 */ 1460 len = -len; 1461 count = 0; 1462 for (;;) { 1463 count += m->m_len; 1464 if (m->m_next == NULL) 1465 break; 1466 m = m->m_next; 1467 } 1468 if (m->m_len >= len) { 1469 m->m_len -= len; 1470 if (mp->m_flags & M_PKTHDR) 1471 mp->m_pkthdr.len -= len; 1472 return; 1473 } 1474 count -= len; 1475 if (count < 0) 1476 count = 0; 1477 /* 1478 * Correct length for chain is "count". 1479 * Find the mbuf with last data, adjust its length, 1480 * and toss data from remaining mbufs on chain. 1481 */ 1482 m = mp; 1483 if (m->m_flags & M_PKTHDR) 1484 m->m_pkthdr.len = count; 1485 for (; m; m = m->m_next) { 1486 if (m->m_len >= count) { 1487 m->m_len = count; 1488 break; 1489 } 1490 count -= m->m_len; 1491 } 1492 while (m->m_next) 1493 (m = m->m_next) ->m_len = 0; 1494 } 1495 } 1496 1497 /* 1498 * Set the m_data pointer of a newly-allocated mbuf 1499 * to place an object of the specified size at the 1500 * end of the mbuf, longword aligned. 1501 */ 1502 void 1503 m_align(struct mbuf *m, int len) 1504 { 1505 int adjust; 1506 1507 if (m->m_flags & M_EXT) 1508 adjust = m->m_ext.ext_size - len; 1509 else if (m->m_flags & M_PKTHDR) 1510 adjust = MHLEN - len; 1511 else 1512 adjust = MLEN - len; 1513 m->m_data += adjust &~ (sizeof(long)-1); 1514 } 1515 1516 /* 1517 * Rearrange an mbuf chain so that len bytes are contiguous 1518 * and in the data area of an mbuf (so that mtod will work for a structure 1519 * of size len). Returns the resulting mbuf chain on success, frees it and 1520 * returns null on failure. If there is room, it will add up to 1521 * max_protohdr-len extra bytes to the contiguous region in an attempt to 1522 * avoid being called next time. 1523 */ 1524 struct mbuf * 1525 m_pullup(struct mbuf *n, int len) 1526 { 1527 struct mbuf *m; 1528 int count; 1529 int space; 1530 1531 /* 1532 * If first mbuf has no cluster, and has room for len bytes 1533 * without shifting current data, pullup into it, 1534 * otherwise allocate a new mbuf to prepend to the chain. 1535 */ 1536 if (!(n->m_flags & M_EXT) && 1537 n->m_data + len < &n->m_dat[MLEN] && 1538 n->m_next) { 1539 if (n->m_len >= len) 1540 return (n); 1541 m = n; 1542 n = n->m_next; 1543 len -= m->m_len; 1544 } else { 1545 if (len > MHLEN) 1546 goto bad; 1547 if (n->m_flags & M_PKTHDR) 1548 m = m_gethdr(MB_DONTWAIT, n->m_type); 1549 else 1550 m = m_get(MB_DONTWAIT, n->m_type); 1551 if (m == NULL) 1552 goto bad; 1553 m->m_len = 0; 1554 if (n->m_flags & M_PKTHDR) 1555 M_MOVE_PKTHDR(m, n); 1556 } 1557 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1558 do { 1559 count = min(min(max(len, max_protohdr), space), n->m_len); 1560 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1561 (unsigned)count); 1562 len -= count; 1563 m->m_len += count; 1564 n->m_len -= count; 1565 space -= count; 1566 if (n->m_len) 1567 n->m_data += count; 1568 else 1569 n = m_free(n); 1570 } while (len > 0 && n); 1571 if (len > 0) { 1572 m_free(m); 1573 goto bad; 1574 } 1575 m->m_next = n; 1576 return (m); 1577 bad: 1578 m_freem(n); 1579 atomic_add_long_nonlocked(&mbstat[mycpu->gd_cpuid].m_mcfail, 1); 1580 return (NULL); 1581 } 1582 1583 /* 1584 * Partition an mbuf chain in two pieces, returning the tail -- 1585 * all but the first len0 bytes. In case of failure, it returns NULL and 1586 * attempts to restore the chain to its original state. 1587 * 1588 * Note that the resulting mbufs might be read-only, because the new 1589 * mbuf can end up sharing an mbuf cluster with the original mbuf if 1590 * the "breaking point" happens to lie within a cluster mbuf. Use the 1591 * M_WRITABLE() macro to check for this case. 1592 */ 1593 struct mbuf * 1594 m_split(struct mbuf *m0, int len0, int wait) 1595 { 1596 struct mbuf *m, *n; 1597 unsigned len = len0, remain; 1598 1599 for (m = m0; m && len > m->m_len; m = m->m_next) 1600 len -= m->m_len; 1601 if (m == NULL) 1602 return (NULL); 1603 remain = m->m_len - len; 1604 if (m0->m_flags & M_PKTHDR) { 1605 n = m_gethdr(wait, m0->m_type); 1606 if (n == NULL) 1607 return (NULL); 1608 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1609 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1610 m0->m_pkthdr.len = len0; 1611 if (m->m_flags & M_EXT) 1612 goto extpacket; 1613 if (remain > MHLEN) { 1614 /* m can't be the lead packet */ 1615 MH_ALIGN(n, 0); 1616 n->m_next = m_split(m, len, wait); 1617 if (n->m_next == NULL) { 1618 m_free(n); 1619 return (NULL); 1620 } else { 1621 n->m_len = 0; 1622 return (n); 1623 } 1624 } else 1625 MH_ALIGN(n, remain); 1626 } else if (remain == 0) { 1627 n = m->m_next; 1628 m->m_next = 0; 1629 return (n); 1630 } else { 1631 n = m_get(wait, m->m_type); 1632 if (n == NULL) 1633 return (NULL); 1634 M_ALIGN(n, remain); 1635 } 1636 extpacket: 1637 if (m->m_flags & M_EXT) { 1638 KKASSERT((n->m_flags & M_EXT) == 0); 1639 n->m_data = m->m_data + len; 1640 m->m_ext.ext_ref(m->m_ext.ext_arg); 1641 n->m_ext = m->m_ext; 1642 n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); 1643 } else { 1644 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 1645 } 1646 n->m_len = remain; 1647 m->m_len = len; 1648 n->m_next = m->m_next; 1649 m->m_next = 0; 1650 return (n); 1651 } 1652 1653 /* 1654 * Routine to copy from device local memory into mbufs. 1655 * Note: "offset" is ill-defined and always called as 0, so ignore it. 1656 */ 1657 struct mbuf * 1658 m_devget(char *buf, int len, int offset, struct ifnet *ifp, 1659 void (*copy)(volatile const void *from, volatile void *to, size_t length)) 1660 { 1661 struct mbuf *m, *mfirst = NULL, **mtail; 1662 int nsize, flags; 1663 1664 if (copy == NULL) 1665 copy = bcopy; 1666 mtail = &mfirst; 1667 flags = M_PKTHDR; 1668 1669 while (len > 0) { 1670 m = m_getl(len, MB_DONTWAIT, MT_DATA, flags, &nsize); 1671 if (m == NULL) { 1672 m_freem(mfirst); 1673 return (NULL); 1674 } 1675 m->m_len = min(len, nsize); 1676 1677 if (flags & M_PKTHDR) { 1678 if (len + max_linkhdr <= nsize) 1679 m->m_data += max_linkhdr; 1680 m->m_pkthdr.rcvif = ifp; 1681 m->m_pkthdr.len = len; 1682 flags = 0; 1683 } 1684 1685 copy(buf, m->m_data, (unsigned)m->m_len); 1686 buf += m->m_len; 1687 len -= m->m_len; 1688 *mtail = m; 1689 mtail = &m->m_next; 1690 } 1691 1692 return (mfirst); 1693 } 1694 1695 /* 1696 * Routine to pad mbuf to the specified length 'padto'. 1697 */ 1698 int 1699 m_devpad(struct mbuf *m, int padto) 1700 { 1701 struct mbuf *last = NULL; 1702 int padlen; 1703 1704 if (padto <= m->m_pkthdr.len) 1705 return 0; 1706 1707 padlen = padto - m->m_pkthdr.len; 1708 1709 /* if there's only the packet-header and we can pad there, use it. */ 1710 if (m->m_pkthdr.len == m->m_len && M_TRAILINGSPACE(m) >= padlen) { 1711 last = m; 1712 } else { 1713 /* 1714 * Walk packet chain to find last mbuf. We will either 1715 * pad there, or append a new mbuf and pad it 1716 */ 1717 for (last = m; last->m_next != NULL; last = last->m_next) 1718 ; /* EMPTY */ 1719 1720 /* `last' now points to last in chain. */ 1721 if (M_TRAILINGSPACE(last) < padlen) { 1722 struct mbuf *n; 1723 1724 /* Allocate new empty mbuf, pad it. Compact later. */ 1725 MGET(n, MB_DONTWAIT, MT_DATA); 1726 if (n == NULL) 1727 return ENOBUFS; 1728 n->m_len = 0; 1729 last->m_next = n; 1730 last = n; 1731 } 1732 } 1733 KKASSERT(M_TRAILINGSPACE(last) >= padlen); 1734 KKASSERT(M_WRITABLE(last)); 1735 1736 /* Now zero the pad area */ 1737 bzero(mtod(last, char *) + last->m_len, padlen); 1738 last->m_len += padlen; 1739 m->m_pkthdr.len += padlen; 1740 return 0; 1741 } 1742 1743 /* 1744 * Copy data from a buffer back into the indicated mbuf chain, 1745 * starting "off" bytes from the beginning, extending the mbuf 1746 * chain if necessary. 1747 */ 1748 void 1749 m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) 1750 { 1751 int mlen; 1752 struct mbuf *m = m0, *n; 1753 int totlen = 0; 1754 1755 if (m0 == NULL) 1756 return; 1757 while (off > (mlen = m->m_len)) { 1758 off -= mlen; 1759 totlen += mlen; 1760 if (m->m_next == NULL) { 1761 n = m_getclr(MB_DONTWAIT, m->m_type); 1762 if (n == NULL) 1763 goto out; 1764 n->m_len = min(MLEN, len + off); 1765 m->m_next = n; 1766 } 1767 m = m->m_next; 1768 } 1769 while (len > 0) { 1770 mlen = min (m->m_len - off, len); 1771 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 1772 cp += mlen; 1773 len -= mlen; 1774 mlen += off; 1775 off = 0; 1776 totlen += mlen; 1777 if (len == 0) 1778 break; 1779 if (m->m_next == NULL) { 1780 n = m_get(MB_DONTWAIT, m->m_type); 1781 if (n == NULL) 1782 break; 1783 n->m_len = min(MLEN, len); 1784 m->m_next = n; 1785 } 1786 m = m->m_next; 1787 } 1788 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 1789 m->m_pkthdr.len = totlen; 1790 } 1791 1792 /* 1793 * Append the specified data to the indicated mbuf chain, 1794 * Extend the mbuf chain if the new data does not fit in 1795 * existing space. 1796 * 1797 * Return 1 if able to complete the job; otherwise 0. 1798 */ 1799 int 1800 m_append(struct mbuf *m0, int len, c_caddr_t cp) 1801 { 1802 struct mbuf *m, *n; 1803 int remainder, space; 1804 1805 for (m = m0; m->m_next != NULL; m = m->m_next) 1806 ; 1807 remainder = len; 1808 space = M_TRAILINGSPACE(m); 1809 if (space > 0) { 1810 /* 1811 * Copy into available space. 1812 */ 1813 if (space > remainder) 1814 space = remainder; 1815 bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1816 m->m_len += space; 1817 cp += space, remainder -= space; 1818 } 1819 while (remainder > 0) { 1820 /* 1821 * Allocate a new mbuf; could check space 1822 * and allocate a cluster instead. 1823 */ 1824 n = m_get(MB_DONTWAIT, m->m_type); 1825 if (n == NULL) 1826 break; 1827 n->m_len = min(MLEN, remainder); 1828 bcopy(cp, mtod(n, caddr_t), n->m_len); 1829 cp += n->m_len, remainder -= n->m_len; 1830 m->m_next = n; 1831 m = n; 1832 } 1833 if (m0->m_flags & M_PKTHDR) 1834 m0->m_pkthdr.len += len - remainder; 1835 return (remainder == 0); 1836 } 1837 1838 /* 1839 * Apply function f to the data in an mbuf chain starting "off" bytes from 1840 * the beginning, continuing for "len" bytes. 1841 */ 1842 int 1843 m_apply(struct mbuf *m, int off, int len, 1844 int (*f)(void *, void *, u_int), void *arg) 1845 { 1846 u_int count; 1847 int rval; 1848 1849 KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1850 KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1851 while (off > 0) { 1852 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1853 if (off < m->m_len) 1854 break; 1855 off -= m->m_len; 1856 m = m->m_next; 1857 } 1858 while (len > 0) { 1859 KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1860 count = min(m->m_len - off, len); 1861 rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1862 if (rval) 1863 return (rval); 1864 len -= count; 1865 off = 0; 1866 m = m->m_next; 1867 } 1868 return (0); 1869 } 1870 1871 /* 1872 * Return a pointer to mbuf/offset of location in mbuf chain. 1873 */ 1874 struct mbuf * 1875 m_getptr(struct mbuf *m, int loc, int *off) 1876 { 1877 1878 while (loc >= 0) { 1879 /* Normal end of search. */ 1880 if (m->m_len > loc) { 1881 *off = loc; 1882 return (m); 1883 } else { 1884 loc -= m->m_len; 1885 if (m->m_next == NULL) { 1886 if (loc == 0) { 1887 /* Point at the end of valid data. */ 1888 *off = m->m_len; 1889 return (m); 1890 } 1891 return (NULL); 1892 } 1893 m = m->m_next; 1894 } 1895 } 1896 return (NULL); 1897 } 1898 1899 void 1900 m_print(const struct mbuf *m) 1901 { 1902 int len; 1903 const struct mbuf *m2; 1904 1905 len = m->m_pkthdr.len; 1906 m2 = m; 1907 while (len) { 1908 kprintf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); 1909 len -= m2->m_len; 1910 m2 = m2->m_next; 1911 } 1912 return; 1913 } 1914 1915 /* 1916 * "Move" mbuf pkthdr from "from" to "to". 1917 * "from" must have M_PKTHDR set, and "to" must be empty. 1918 */ 1919 void 1920 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1921 { 1922 KASSERT((to->m_flags & M_PKTHDR), ("m_move_pkthdr: not packet header")); 1923 1924 to->m_flags |= from->m_flags & M_COPYFLAGS; 1925 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 1926 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 1927 } 1928 1929 /* 1930 * Duplicate "from"'s mbuf pkthdr in "to". 1931 * "from" must have M_PKTHDR set, and "to" must be empty. 1932 * In particular, this does a deep copy of the packet tags. 1933 */ 1934 int 1935 m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how) 1936 { 1937 KASSERT((to->m_flags & M_PKTHDR), ("m_dup_pkthdr: not packet header")); 1938 1939 to->m_flags = (from->m_flags & M_COPYFLAGS) | 1940 (to->m_flags & ~M_COPYFLAGS); 1941 to->m_pkthdr = from->m_pkthdr; 1942 SLIST_INIT(&to->m_pkthdr.tags); 1943 return (m_tag_copy_chain(to, from, how)); 1944 } 1945 1946 /* 1947 * Defragment a mbuf chain, returning the shortest possible 1948 * chain of mbufs and clusters. If allocation fails and 1949 * this cannot be completed, NULL will be returned, but 1950 * the passed in chain will be unchanged. Upon success, 1951 * the original chain will be freed, and the new chain 1952 * will be returned. 1953 * 1954 * If a non-packet header is passed in, the original 1955 * mbuf (chain?) will be returned unharmed. 1956 * 1957 * m_defrag_nofree doesn't free the passed in mbuf. 1958 */ 1959 struct mbuf * 1960 m_defrag(struct mbuf *m0, int how) 1961 { 1962 struct mbuf *m_new; 1963 1964 if ((m_new = m_defrag_nofree(m0, how)) == NULL) 1965 return (NULL); 1966 if (m_new != m0) 1967 m_freem(m0); 1968 return (m_new); 1969 } 1970 1971 struct mbuf * 1972 m_defrag_nofree(struct mbuf *m0, int how) 1973 { 1974 struct mbuf *m_new = NULL, *m_final = NULL; 1975 int progress = 0, length, nsize; 1976 1977 if (!(m0->m_flags & M_PKTHDR)) 1978 return (m0); 1979 1980 #ifdef MBUF_STRESS_TEST 1981 if (m_defragrandomfailures) { 1982 int temp = karc4random() & 0xff; 1983 if (temp == 0xba) 1984 goto nospace; 1985 } 1986 #endif 1987 1988 m_final = m_getl(m0->m_pkthdr.len, how, MT_DATA, M_PKTHDR, &nsize); 1989 if (m_final == NULL) 1990 goto nospace; 1991 m_final->m_len = 0; /* in case m0->m_pkthdr.len is zero */ 1992 1993 if (m_dup_pkthdr(m_final, m0, how) == 0) 1994 goto nospace; 1995 1996 m_new = m_final; 1997 1998 while (progress < m0->m_pkthdr.len) { 1999 length = m0->m_pkthdr.len - progress; 2000 if (length > MCLBYTES) 2001 length = MCLBYTES; 2002 2003 if (m_new == NULL) { 2004 m_new = m_getl(length, how, MT_DATA, 0, &nsize); 2005 if (m_new == NULL) 2006 goto nospace; 2007 } 2008 2009 m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 2010 progress += length; 2011 m_new->m_len = length; 2012 if (m_new != m_final) 2013 m_cat(m_final, m_new); 2014 m_new = NULL; 2015 } 2016 if (m0->m_next == NULL) 2017 m_defraguseless++; 2018 m_defragpackets++; 2019 m_defragbytes += m_final->m_pkthdr.len; 2020 return (m_final); 2021 nospace: 2022 m_defragfailure++; 2023 if (m_new) 2024 m_free(m_new); 2025 m_freem(m_final); 2026 return (NULL); 2027 } 2028 2029 /* 2030 * Move data from uio into mbufs. 2031 */ 2032 struct mbuf * 2033 m_uiomove(struct uio *uio) 2034 { 2035 struct mbuf *m; /* current working mbuf */ 2036 struct mbuf *head = NULL; /* result mbuf chain */ 2037 struct mbuf **mp = &head; 2038 int flags = M_PKTHDR; 2039 int nsize; 2040 int error; 2041 int resid; 2042 2043 do { 2044 if (uio->uio_resid > INT_MAX) 2045 resid = INT_MAX; 2046 else 2047 resid = (int)uio->uio_resid; 2048 m = m_getl(resid, MB_WAIT, MT_DATA, flags, &nsize); 2049 if (flags) { 2050 m->m_pkthdr.len = 0; 2051 /* Leave room for protocol headers. */ 2052 if (resid < MHLEN) 2053 MH_ALIGN(m, resid); 2054 flags = 0; 2055 } 2056 m->m_len = imin(nsize, resid); 2057 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 2058 if (error) { 2059 m_free(m); 2060 goto failed; 2061 } 2062 *mp = m; 2063 mp = &m->m_next; 2064 head->m_pkthdr.len += m->m_len; 2065 } while (uio->uio_resid > 0); 2066 2067 return (head); 2068 2069 failed: 2070 m_freem(head); 2071 return (NULL); 2072 } 2073 2074 struct mbuf * 2075 m_last(struct mbuf *m) 2076 { 2077 while (m->m_next) 2078 m = m->m_next; 2079 return (m); 2080 } 2081 2082 /* 2083 * Return the number of bytes in an mbuf chain. 2084 * If lastm is not NULL, also return the last mbuf. 2085 */ 2086 u_int 2087 m_lengthm(struct mbuf *m, struct mbuf **lastm) 2088 { 2089 u_int len = 0; 2090 struct mbuf *prev = m; 2091 2092 while (m) { 2093 len += m->m_len; 2094 prev = m; 2095 m = m->m_next; 2096 } 2097 if (lastm != NULL) 2098 *lastm = prev; 2099 return (len); 2100 } 2101 2102 /* 2103 * Like m_lengthm(), except also keep track of mbuf usage. 2104 */ 2105 u_int 2106 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *pmbcnt) 2107 { 2108 u_int len = 0, mbcnt = 0; 2109 struct mbuf *prev = m; 2110 2111 while (m) { 2112 len += m->m_len; 2113 mbcnt += MSIZE; 2114 if (m->m_flags & M_EXT) 2115 mbcnt += m->m_ext.ext_size; 2116 prev = m; 2117 m = m->m_next; 2118 } 2119 if (lastm != NULL) 2120 *lastm = prev; 2121 *pmbcnt = mbcnt; 2122 return (len); 2123 } 2124