1 /* $NetBSD: uipc_mbuf.c,v 1.151 2013/06/28 01:23:05 matt Exp $ */ 2 3 /*- 4 * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1991, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95 62 */ 63 64 #include <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.151 2013/06/28 01:23:05 matt Exp $"); 66 67 #include "opt_mbuftrace.h" 68 #include "opt_nmbclusters.h" 69 #include "opt_ddb.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/atomic.h> 74 #include <sys/cpu.h> 75 #include <sys/proc.h> 76 #include <sys/mbuf.h> 77 #include <sys/kernel.h> 78 #include <sys/syslog.h> 79 #include <sys/domain.h> 80 #include <sys/protosw.h> 81 #include <sys/percpu.h> 82 #include <sys/pool.h> 83 #include <sys/socket.h> 84 #include <sys/sysctl.h> 85 86 #include <net/if.h> 87 88 pool_cache_t mb_cache; /* mbuf cache */ 89 pool_cache_t mcl_cache; /* mbuf cluster cache */ 90 91 struct mbstat mbstat; 92 int max_linkhdr; 93 int max_protohdr; 94 int max_hdr; 95 int max_datalen; 96 97 static int mb_ctor(void *, void *, int); 98 99 static void sysctl_kern_mbuf_setup(void); 100 101 static struct sysctllog *mbuf_sysctllog; 102 103 static struct mbuf *m_copym0(struct mbuf *, int, int, int, int); 104 static struct mbuf *m_split0(struct mbuf *, int, int, int); 105 static int m_copyback0(struct mbuf **, int, int, const void *, int, int); 106 107 /* flags for m_copyback0 */ 108 #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */ 109 #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */ 110 #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */ 111 #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */ 112 113 static const char mclpool_warnmsg[] = 114 "WARNING: mclpool limit reached; increase kern.mbuf.nmbclusters"; 115 116 MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf"); 117 118 static percpu_t *mbstat_percpu; 119 120 #ifdef MBUFTRACE 121 struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners); 122 struct mowner unknown_mowners[] = { 123 MOWNER_INIT("unknown", "free"), 124 MOWNER_INIT("unknown", "data"), 125 MOWNER_INIT("unknown", "header"), 126 MOWNER_INIT("unknown", "soname"), 127 MOWNER_INIT("unknown", "soopts"), 128 MOWNER_INIT("unknown", "ftable"), 129 MOWNER_INIT("unknown", "control"), 130 MOWNER_INIT("unknown", "oobdata"), 131 }; 132 struct mowner revoked_mowner = MOWNER_INIT("revoked", ""); 133 #endif 134 135 #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m)) 136 137 #define MCLADDREFERENCE(o, n) \ 138 do { \ 139 KASSERT(((o)->m_flags & M_EXT) != 0); \ 140 KASSERT(((n)->m_flags & M_EXT) == 0); \ 141 KASSERT((o)->m_ext.ext_refcnt >= 1); \ 142 (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \ 143 atomic_inc_uint(&(o)->m_ext.ext_refcnt); \ 144 (n)->m_ext_ref = (o)->m_ext_ref; \ 145 mowner_ref((n), (n)->m_flags); \ 146 MCLREFDEBUGN((n), __FILE__, __LINE__); \ 147 } while (/* CONSTCOND */ 0) 148 149 static int 150 nmbclusters_limit(void) 151 { 152 #if defined(PMAP_MAP_POOLPAGE) 153 /* direct mapping, doesn't use space in kmem_arena */ 154 vsize_t max_size = physmem / 4; 155 #else 156 vsize_t max_size = MIN(physmem / 4, nkmempages / 4); 157 #endif 158 159 max_size = max_size * PAGE_SIZE / MCLBYTES; 160 #ifdef NMBCLUSTERS_MAX 161 max_size = MIN(max_size, NMBCLUSTERS_MAX); 162 #endif 163 164 #ifdef NMBCLUSTERS 165 return MIN(max_size, NMBCLUSTERS); 166 #else 167 return max_size; 168 #endif 169 } 170 171 /* 172 * Initialize the mbuf allocator. 173 */ 174 void 175 mbinit(void) 176 { 177 178 CTASSERT(sizeof(struct _m_ext) <= MHLEN); 179 CTASSERT(sizeof(struct mbuf) == MSIZE); 180 181 sysctl_kern_mbuf_setup(); 182 183 mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl", 184 NULL, IPL_VM, mb_ctor, NULL, NULL); 185 KASSERT(mb_cache != NULL); 186 187 mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl", NULL, 188 IPL_VM, NULL, NULL, NULL); 189 KASSERT(mcl_cache != NULL); 190 191 pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL); 192 pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL); 193 194 /* 195 * Set an arbitrary default limit on the number of mbuf clusters. 196 */ 197 #ifdef NMBCLUSTERS 198 nmbclusters = nmbclusters_limit(); 199 #else 200 nmbclusters = MAX(1024, 201 (vsize_t)physmem * PAGE_SIZE / MCLBYTES / 16); 202 nmbclusters = MIN(nmbclusters, nmbclusters_limit()); 203 #endif 204 205 /* 206 * Set the hard limit on the mclpool to the number of 207 * mbuf clusters the kernel is to support. Log the limit 208 * reached message max once a minute. 209 */ 210 pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60); 211 212 mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu)); 213 214 /* 215 * Set a low water mark for both mbufs and clusters. This should 216 * help ensure that they can be allocated in a memory starvation 217 * situation. This is important for e.g. diskless systems which 218 * must allocate mbufs in order for the pagedaemon to clean pages. 219 */ 220 pool_cache_setlowat(mb_cache, mblowat); 221 pool_cache_setlowat(mcl_cache, mcllowat); 222 223 #ifdef MBUFTRACE 224 { 225 /* 226 * Attach the unknown mowners. 227 */ 228 int i; 229 MOWNER_ATTACH(&revoked_mowner); 230 for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]); 231 i-- > 0; ) 232 MOWNER_ATTACH(&unknown_mowners[i]); 233 } 234 #endif 235 } 236 237 /* 238 * sysctl helper routine for the kern.mbuf subtree. 239 * nmbclusters, mblowat and mcllowat need range 240 * checking and pool tweaking after being reset. 241 */ 242 static int 243 sysctl_kern_mbuf(SYSCTLFN_ARGS) 244 { 245 int error, newval; 246 struct sysctlnode node; 247 248 node = *rnode; 249 node.sysctl_data = &newval; 250 switch (rnode->sysctl_num) { 251 case MBUF_NMBCLUSTERS: 252 case MBUF_MBLOWAT: 253 case MBUF_MCLLOWAT: 254 newval = *(int*)rnode->sysctl_data; 255 break; 256 default: 257 return (EOPNOTSUPP); 258 } 259 260 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 261 if (error || newp == NULL) 262 return (error); 263 if (newval < 0) 264 return (EINVAL); 265 266 switch (node.sysctl_num) { 267 case MBUF_NMBCLUSTERS: 268 if (newval < nmbclusters) 269 return (EINVAL); 270 if (newval > nmbclusters_limit()) 271 return (EINVAL); 272 nmbclusters = newval; 273 pool_cache_sethardlimit(mcl_cache, nmbclusters, 274 mclpool_warnmsg, 60); 275 break; 276 case MBUF_MBLOWAT: 277 mblowat = newval; 278 pool_cache_setlowat(mb_cache, mblowat); 279 break; 280 case MBUF_MCLLOWAT: 281 mcllowat = newval; 282 pool_cache_setlowat(mcl_cache, mcllowat); 283 break; 284 } 285 286 return (0); 287 } 288 289 #ifdef MBUFTRACE 290 static void 291 mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 292 { 293 struct mowner_counter *mc = v1; 294 struct mowner_user *mo_user = v2; 295 int i; 296 297 for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) { 298 mo_user->mo_counter[i] += mc->mc_counter[i]; 299 } 300 } 301 302 static void 303 mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user) 304 { 305 306 memset(mo_user, 0, sizeof(*mo_user)); 307 CTASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name)); 308 CTASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr)); 309 memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name)); 310 memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr)); 311 percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user); 312 } 313 314 static int 315 sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS) 316 { 317 struct mowner *mo; 318 size_t len = 0; 319 int error = 0; 320 321 if (namelen != 0) 322 return (EINVAL); 323 if (newp != NULL) 324 return (EPERM); 325 326 LIST_FOREACH(mo, &mowners, mo_link) { 327 struct mowner_user mo_user; 328 329 mowner_convert_to_user(mo, &mo_user); 330 331 if (oldp != NULL) { 332 if (*oldlenp - len < sizeof(mo_user)) { 333 error = ENOMEM; 334 break; 335 } 336 error = copyout(&mo_user, (char *)oldp + len, 337 sizeof(mo_user)); 338 if (error) 339 break; 340 } 341 len += sizeof(mo_user); 342 } 343 344 if (error == 0) 345 *oldlenp = len; 346 347 return (error); 348 } 349 #endif /* MBUFTRACE */ 350 351 static void 352 mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 353 { 354 struct mbstat_cpu *mbsc = v1; 355 struct mbstat *mbs = v2; 356 int i; 357 358 for (i = 0; i < __arraycount(mbs->m_mtypes); i++) { 359 mbs->m_mtypes[i] += mbsc->m_mtypes[i]; 360 } 361 } 362 363 static void 364 mbstat_convert_to_user(struct mbstat *mbs) 365 { 366 367 memset(mbs, 0, sizeof(*mbs)); 368 mbs->m_drain = mbstat.m_drain; 369 percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs); 370 } 371 372 static int 373 sysctl_kern_mbuf_stats(SYSCTLFN_ARGS) 374 { 375 struct sysctlnode node; 376 struct mbstat mbs; 377 378 mbstat_convert_to_user(&mbs); 379 node = *rnode; 380 node.sysctl_data = &mbs; 381 node.sysctl_size = sizeof(mbs); 382 return sysctl_lookup(SYSCTLFN_CALL(&node)); 383 } 384 385 static void 386 sysctl_kern_mbuf_setup(void) 387 { 388 389 KASSERT(mbuf_sysctllog == NULL); 390 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 391 CTLFLAG_PERMANENT, 392 CTLTYPE_NODE, "kern", NULL, 393 NULL, 0, NULL, 0, 394 CTL_KERN, CTL_EOL); 395 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 396 CTLFLAG_PERMANENT, 397 CTLTYPE_NODE, "mbuf", 398 SYSCTL_DESCR("mbuf control variables"), 399 NULL, 0, NULL, 0, 400 CTL_KERN, KERN_MBUF, CTL_EOL); 401 402 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 403 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 404 CTLTYPE_INT, "msize", 405 SYSCTL_DESCR("mbuf base size"), 406 NULL, msize, NULL, 0, 407 CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL); 408 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 409 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 410 CTLTYPE_INT, "mclbytes", 411 SYSCTL_DESCR("mbuf cluster size"), 412 NULL, mclbytes, NULL, 0, 413 CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL); 414 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 415 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 416 CTLTYPE_INT, "nmbclusters", 417 SYSCTL_DESCR("Limit on the number of mbuf clusters"), 418 sysctl_kern_mbuf, 0, &nmbclusters, 0, 419 CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL); 420 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 421 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 422 CTLTYPE_INT, "mblowat", 423 SYSCTL_DESCR("mbuf low water mark"), 424 sysctl_kern_mbuf, 0, &mblowat, 0, 425 CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL); 426 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 427 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 428 CTLTYPE_INT, "mcllowat", 429 SYSCTL_DESCR("mbuf cluster low water mark"), 430 sysctl_kern_mbuf, 0, &mcllowat, 0, 431 CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL); 432 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 433 CTLFLAG_PERMANENT, 434 CTLTYPE_STRUCT, "stats", 435 SYSCTL_DESCR("mbuf allocation statistics"), 436 sysctl_kern_mbuf_stats, 0, NULL, 0, 437 CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL); 438 #ifdef MBUFTRACE 439 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 440 CTLFLAG_PERMANENT, 441 CTLTYPE_STRUCT, "mowners", 442 SYSCTL_DESCR("Information about mbuf owners"), 443 sysctl_kern_mbuf_mowners, 0, NULL, 0, 444 CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL); 445 #endif /* MBUFTRACE */ 446 } 447 448 static int 449 mb_ctor(void *arg, void *object, int flags) 450 { 451 struct mbuf *m = object; 452 453 #ifdef POOL_VTOPHYS 454 m->m_paddr = POOL_VTOPHYS(m); 455 #else 456 m->m_paddr = M_PADDR_INVALID; 457 #endif 458 return (0); 459 } 460 461 /* 462 * Add mbuf to the end of a chain 463 */ 464 struct mbuf * 465 m_add(struct mbuf *c, struct mbuf *m) { 466 struct mbuf *n; 467 468 if (c == NULL) 469 return m; 470 471 for (n = c; n->m_next != NULL; n = n->m_next) 472 continue; 473 n->m_next = m; 474 return c; 475 } 476 477 /* 478 * Set the m_data pointer of a newly-allocated mbuf 479 * to place an object of the specified size at the 480 * end of the mbuf, longword aligned. 481 */ 482 void 483 m_align(struct mbuf *m, int len) 484 { 485 int adjust; 486 487 if (m->m_flags & M_EXT) 488 adjust = m->m_ext.ext_size - len; 489 else if (m->m_flags & M_PKTHDR) 490 adjust = MHLEN - len; 491 else 492 adjust = MLEN - len; 493 m->m_data += adjust &~ (sizeof(long)-1); 494 } 495 496 /* 497 * Append the specified data to the indicated mbuf chain, 498 * Extend the mbuf chain if the new data does not fit in 499 * existing space. 500 * 501 * Return 1 if able to complete the job; otherwise 0. 502 */ 503 int 504 m_append(struct mbuf *m0, int len, const void *cpv) 505 { 506 struct mbuf *m, *n; 507 int remainder, space; 508 const char *cp = cpv; 509 510 for (m = m0; m->m_next != NULL; m = m->m_next) 511 continue; 512 remainder = len; 513 space = M_TRAILINGSPACE(m); 514 if (space > 0) { 515 /* 516 * Copy into available space. 517 */ 518 if (space > remainder) 519 space = remainder; 520 memmove(mtod(m, char *) + m->m_len, cp, space); 521 m->m_len += space; 522 cp = cp + space, remainder -= space; 523 } 524 while (remainder > 0) { 525 /* 526 * Allocate a new mbuf; could check space 527 * and allocate a cluster instead. 528 */ 529 n = m_get(M_DONTWAIT, m->m_type); 530 if (n == NULL) 531 break; 532 n->m_len = min(MLEN, remainder); 533 memmove(mtod(n, void *), cp, n->m_len); 534 cp += n->m_len, remainder -= n->m_len; 535 m->m_next = n; 536 m = n; 537 } 538 if (m0->m_flags & M_PKTHDR) 539 m0->m_pkthdr.len += len - remainder; 540 return (remainder == 0); 541 } 542 543 void 544 m_reclaim(void *arg, int flags) 545 { 546 struct domain *dp; 547 const struct protosw *pr; 548 struct ifnet *ifp; 549 int s; 550 551 KERNEL_LOCK(1, NULL); 552 s = splvm(); 553 DOMAIN_FOREACH(dp) { 554 for (pr = dp->dom_protosw; 555 pr < dp->dom_protoswNPROTOSW; pr++) 556 if (pr->pr_drain) 557 (*pr->pr_drain)(); 558 } 559 IFNET_FOREACH(ifp) { 560 if (ifp->if_drain) 561 (*ifp->if_drain)(ifp); 562 } 563 splx(s); 564 mbstat.m_drain++; 565 KERNEL_UNLOCK_ONE(NULL); 566 } 567 568 /* 569 * Space allocation routines. 570 * These are also available as macros 571 * for critical paths. 572 */ 573 struct mbuf * 574 m_get(int nowait, int type) 575 { 576 struct mbuf *m; 577 578 KASSERT(type != MT_FREE); 579 580 m = pool_cache_get(mb_cache, 581 nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0); 582 if (m == NULL) 583 return NULL; 584 585 mbstat_type_add(type, 1); 586 mowner_init(m, type); 587 m->m_ext_ref = m; 588 m->m_type = type; 589 m->m_next = NULL; 590 m->m_nextpkt = NULL; 591 m->m_data = m->m_dat; 592 m->m_flags = 0; 593 594 return m; 595 } 596 597 struct mbuf * 598 m_gethdr(int nowait, int type) 599 { 600 struct mbuf *m; 601 602 m = m_get(nowait, type); 603 if (m == NULL) 604 return NULL; 605 606 m->m_data = m->m_pktdat; 607 m->m_flags = M_PKTHDR; 608 m->m_pkthdr.rcvif = NULL; 609 m->m_pkthdr.csum_flags = 0; 610 m->m_pkthdr.csum_data = 0; 611 SLIST_INIT(&m->m_pkthdr.tags); 612 613 return m; 614 } 615 616 struct mbuf * 617 m_getclr(int nowait, int type) 618 { 619 struct mbuf *m; 620 621 MGET(m, nowait, type); 622 if (m == 0) 623 return (NULL); 624 memset(mtod(m, void *), 0, MLEN); 625 return (m); 626 } 627 628 void 629 m_clget(struct mbuf *m, int nowait) 630 { 631 632 MCLGET(m, nowait); 633 } 634 635 struct mbuf * 636 m_free(struct mbuf *m) 637 { 638 struct mbuf *n; 639 640 MFREE(m, n); 641 return (n); 642 } 643 644 void 645 m_freem(struct mbuf *m) 646 { 647 struct mbuf *n; 648 649 if (m == NULL) 650 return; 651 do { 652 MFREE(m, n); 653 m = n; 654 } while (m); 655 } 656 657 #ifdef MBUFTRACE 658 /* 659 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain. 660 */ 661 void 662 m_claimm(struct mbuf *m, struct mowner *mo) 663 { 664 665 for (; m != NULL; m = m->m_next) 666 MCLAIM(m, mo); 667 } 668 #endif 669 670 /* 671 * Mbuffer utility routines. 672 */ 673 674 /* 675 * Lesser-used path for M_PREPEND: 676 * allocate new mbuf to prepend to chain, 677 * copy junk along. 678 */ 679 struct mbuf * 680 m_prepend(struct mbuf *m, int len, int how) 681 { 682 struct mbuf *mn; 683 684 MGET(mn, how, m->m_type); 685 if (mn == NULL) { 686 m_freem(m); 687 return (NULL); 688 } 689 if (m->m_flags & M_PKTHDR) { 690 M_MOVE_PKTHDR(mn, m); 691 } else { 692 MCLAIM(mn, m->m_owner); 693 } 694 mn->m_next = m; 695 m = mn; 696 if (len < MHLEN) 697 MH_ALIGN(m, len); 698 m->m_len = len; 699 return (m); 700 } 701 702 /* 703 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 704 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 705 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 706 */ 707 int MCFail; 708 709 struct mbuf * 710 m_copym(struct mbuf *m, int off0, int len, int wait) 711 { 712 713 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */ 714 } 715 716 struct mbuf * 717 m_dup(struct mbuf *m, int off0, int len, int wait) 718 { 719 720 return m_copym0(m, off0, len, wait, 1); /* deep copy */ 721 } 722 723 static struct mbuf * 724 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep) 725 { 726 struct mbuf *n, **np; 727 int off = off0; 728 struct mbuf *top; 729 int copyhdr = 0; 730 731 if (off < 0 || len < 0) 732 panic("m_copym: off %d, len %d", off, len); 733 if (off == 0 && m->m_flags & M_PKTHDR) 734 copyhdr = 1; 735 while (off > 0) { 736 if (m == 0) 737 panic("m_copym: m == 0, off %d", off); 738 if (off < m->m_len) 739 break; 740 off -= m->m_len; 741 m = m->m_next; 742 } 743 np = ⊤ 744 top = 0; 745 while (len > 0) { 746 if (m == 0) { 747 if (len != M_COPYALL) 748 panic("m_copym: m == 0, len %d [!COPYALL]", 749 len); 750 break; 751 } 752 MGET(n, wait, m->m_type); 753 *np = n; 754 if (n == 0) 755 goto nospace; 756 MCLAIM(n, m->m_owner); 757 if (copyhdr) { 758 M_COPY_PKTHDR(n, m); 759 if (len == M_COPYALL) 760 n->m_pkthdr.len -= off0; 761 else 762 n->m_pkthdr.len = len; 763 copyhdr = 0; 764 } 765 n->m_len = min(len, m->m_len - off); 766 if (m->m_flags & M_EXT) { 767 if (!deep) { 768 n->m_data = m->m_data + off; 769 MCLADDREFERENCE(m, n); 770 } else { 771 /* 772 * we are unsure about the way m was allocated. 773 * copy into multiple MCLBYTES cluster mbufs. 774 */ 775 MCLGET(n, wait); 776 n->m_len = 0; 777 n->m_len = M_TRAILINGSPACE(n); 778 n->m_len = min(n->m_len, len); 779 n->m_len = min(n->m_len, m->m_len - off); 780 memcpy(mtod(n, void *), mtod(m, char *) + off, 781 (unsigned)n->m_len); 782 } 783 } else 784 memcpy(mtod(n, void *), mtod(m, char *) + off, 785 (unsigned)n->m_len); 786 if (len != M_COPYALL) 787 len -= n->m_len; 788 off += n->m_len; 789 #ifdef DIAGNOSTIC 790 if (off > m->m_len) 791 panic("m_copym0 overrun %d %d", off, m->m_len); 792 #endif 793 if (off == m->m_len) { 794 m = m->m_next; 795 off = 0; 796 } 797 np = &n->m_next; 798 } 799 if (top == 0) 800 MCFail++; 801 return (top); 802 nospace: 803 m_freem(top); 804 MCFail++; 805 return (NULL); 806 } 807 808 /* 809 * Copy an entire packet, including header (which must be present). 810 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 811 */ 812 struct mbuf * 813 m_copypacket(struct mbuf *m, int how) 814 { 815 struct mbuf *top, *n, *o; 816 817 MGET(n, how, m->m_type); 818 top = n; 819 if (!n) 820 goto nospace; 821 822 MCLAIM(n, m->m_owner); 823 M_COPY_PKTHDR(n, m); 824 n->m_len = m->m_len; 825 if (m->m_flags & M_EXT) { 826 n->m_data = m->m_data; 827 MCLADDREFERENCE(m, n); 828 } else { 829 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 830 } 831 832 m = m->m_next; 833 while (m) { 834 MGET(o, how, m->m_type); 835 if (!o) 836 goto nospace; 837 838 MCLAIM(o, m->m_owner); 839 n->m_next = o; 840 n = n->m_next; 841 842 n->m_len = m->m_len; 843 if (m->m_flags & M_EXT) { 844 n->m_data = m->m_data; 845 MCLADDREFERENCE(m, n); 846 } else { 847 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 848 } 849 850 m = m->m_next; 851 } 852 return top; 853 nospace: 854 m_freem(top); 855 MCFail++; 856 return NULL; 857 } 858 859 /* 860 * Copy data from an mbuf chain starting "off" bytes from the beginning, 861 * continuing for "len" bytes, into the indicated buffer. 862 */ 863 void 864 m_copydata(struct mbuf *m, int off, int len, void *vp) 865 { 866 unsigned count; 867 void * cp = vp; 868 struct mbuf *m0 = m; 869 int len0 = len; 870 int off0 = off; 871 void *vp0 = vp; 872 873 if (off < 0 || len < 0) 874 panic("m_copydata: off %d, len %d", off, len); 875 while (off > 0) { 876 if (m == NULL) 877 panic("m_copydata(%p,%d,%d,%p): m=NULL, off=%d (%d)", 878 m0, len0, off0, vp0, off, off0 - off); 879 if (off < m->m_len) 880 break; 881 off -= m->m_len; 882 m = m->m_next; 883 } 884 while (len > 0) { 885 if (m == NULL) 886 panic("m_copydata(%p,%d,%d,%p): " 887 "m=NULL, off=%d (%d), len=%d (%d)", 888 m0, len0, off0, vp0, 889 off, off0 - off, len, len0 - len); 890 count = min(m->m_len - off, len); 891 memcpy(cp, mtod(m, char *) + off, count); 892 len -= count; 893 cp = (char *)cp + count; 894 off = 0; 895 m = m->m_next; 896 } 897 } 898 899 /* 900 * Concatenate mbuf chain n to m. 901 * n might be copied into m (when n->m_len is small), therefore data portion of 902 * n could be copied into an mbuf of different mbuf type. 903 * Any m_pkthdr is not updated. 904 */ 905 void 906 m_cat(struct mbuf *m, struct mbuf *n) 907 { 908 909 while (m->m_next) 910 m = m->m_next; 911 while (n) { 912 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { 913 /* just join the two chains */ 914 m->m_next = n; 915 return; 916 } 917 /* splat the data from one into the other */ 918 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 919 (u_int)n->m_len); 920 m->m_len += n->m_len; 921 n = m_free(n); 922 } 923 } 924 925 void 926 m_adj(struct mbuf *mp, int req_len) 927 { 928 int len = req_len; 929 struct mbuf *m; 930 int count; 931 932 if ((m = mp) == NULL) 933 return; 934 if (len >= 0) { 935 /* 936 * Trim from head. 937 */ 938 while (m != NULL && len > 0) { 939 if (m->m_len <= len) { 940 len -= m->m_len; 941 m->m_len = 0; 942 m = m->m_next; 943 } else { 944 m->m_len -= len; 945 m->m_data += len; 946 len = 0; 947 } 948 } 949 m = mp; 950 if (mp->m_flags & M_PKTHDR) 951 m->m_pkthdr.len -= (req_len - len); 952 } else { 953 /* 954 * Trim from tail. Scan the mbuf chain, 955 * calculating its length and finding the last mbuf. 956 * If the adjustment only affects this mbuf, then just 957 * adjust and return. Otherwise, rescan and truncate 958 * after the remaining size. 959 */ 960 len = -len; 961 count = 0; 962 for (;;) { 963 count += m->m_len; 964 if (m->m_next == (struct mbuf *)0) 965 break; 966 m = m->m_next; 967 } 968 if (m->m_len >= len) { 969 m->m_len -= len; 970 if (mp->m_flags & M_PKTHDR) 971 mp->m_pkthdr.len -= len; 972 return; 973 } 974 count -= len; 975 if (count < 0) 976 count = 0; 977 /* 978 * Correct length for chain is "count". 979 * Find the mbuf with last data, adjust its length, 980 * and toss data from remaining mbufs on chain. 981 */ 982 m = mp; 983 if (m->m_flags & M_PKTHDR) 984 m->m_pkthdr.len = count; 985 for (; m; m = m->m_next) { 986 if (m->m_len >= count) { 987 m->m_len = count; 988 break; 989 } 990 count -= m->m_len; 991 } 992 if (m) 993 while (m->m_next) 994 (m = m->m_next)->m_len = 0; 995 } 996 } 997 998 /* 999 * m_ensure_contig: rearrange an mbuf chain that given length of bytes 1000 * would be contiguous and in the data area of an mbuf (therefore, mtod() 1001 * would work for a structure of given length). 1002 * 1003 * => On success, returns true and the resulting mbuf chain; false otherwise. 1004 * => The mbuf chain may change, but is always preserved valid. 1005 */ 1006 bool 1007 m_ensure_contig(struct mbuf **m0, int len) 1008 { 1009 struct mbuf *n = *m0, *m; 1010 size_t count, space; 1011 1012 /* 1013 * If first mbuf has no cluster, and has room for len bytes 1014 * without shifting current data, pullup into it, 1015 * otherwise allocate a new mbuf to prepend to the chain. 1016 */ 1017 if ((n->m_flags & M_EXT) == 0 && 1018 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1019 if (n->m_len >= len) { 1020 return true; 1021 } 1022 m = n; 1023 n = n->m_next; 1024 len -= m->m_len; 1025 } else { 1026 if (len > MHLEN) { 1027 return false; 1028 } 1029 MGET(m, M_DONTWAIT, n->m_type); 1030 if (m == NULL) { 1031 return false; 1032 } 1033 MCLAIM(m, n->m_owner); 1034 m->m_len = 0; 1035 if (n->m_flags & M_PKTHDR) { 1036 M_MOVE_PKTHDR(m, n); 1037 } 1038 } 1039 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1040 do { 1041 count = MIN(MIN(MAX(len, max_protohdr), space), n->m_len); 1042 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1043 (unsigned)count); 1044 len -= count; 1045 m->m_len += count; 1046 n->m_len -= count; 1047 space -= count; 1048 if (n->m_len) 1049 n->m_data += count; 1050 else 1051 n = m_free(n); 1052 } while (len > 0 && n); 1053 1054 m->m_next = n; 1055 *m0 = m; 1056 1057 return len <= 0; 1058 } 1059 1060 /* 1061 * m_pullup: same as m_ensure_contig(), but destroys mbuf chain on error. 1062 */ 1063 int MPFail; 1064 1065 struct mbuf * 1066 m_pullup(struct mbuf *n, int len) 1067 { 1068 struct mbuf *m = n; 1069 1070 if (!m_ensure_contig(&m, len)) { 1071 KASSERT(m != NULL); 1072 m_freem(m); 1073 MPFail++; 1074 m = NULL; 1075 } 1076 return m; 1077 } 1078 1079 /* 1080 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1081 * the amount of empty space before the data in the new mbuf to be specified 1082 * (in the event that the caller expects to prepend later). 1083 */ 1084 int MSFail; 1085 1086 struct mbuf * 1087 m_copyup(struct mbuf *n, int len, int dstoff) 1088 { 1089 struct mbuf *m; 1090 int count, space; 1091 1092 if (len > (MHLEN - dstoff)) 1093 goto bad; 1094 MGET(m, M_DONTWAIT, n->m_type); 1095 if (m == NULL) 1096 goto bad; 1097 MCLAIM(m, n->m_owner); 1098 m->m_len = 0; 1099 if (n->m_flags & M_PKTHDR) { 1100 M_MOVE_PKTHDR(m, n); 1101 } 1102 m->m_data += dstoff; 1103 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1104 do { 1105 count = min(min(max(len, max_protohdr), space), n->m_len); 1106 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1107 (unsigned)count); 1108 len -= count; 1109 m->m_len += count; 1110 n->m_len -= count; 1111 space -= count; 1112 if (n->m_len) 1113 n->m_data += count; 1114 else 1115 n = m_free(n); 1116 } while (len > 0 && n); 1117 if (len > 0) { 1118 (void) m_free(m); 1119 goto bad; 1120 } 1121 m->m_next = n; 1122 return (m); 1123 bad: 1124 m_freem(n); 1125 MSFail++; 1126 return (NULL); 1127 } 1128 1129 /* 1130 * Partition an mbuf chain in two pieces, returning the tail -- 1131 * all but the first len0 bytes. In case of failure, it returns NULL and 1132 * attempts to restore the chain to its original state. 1133 */ 1134 struct mbuf * 1135 m_split(struct mbuf *m0, int len0, int wait) 1136 { 1137 1138 return m_split0(m0, len0, wait, 1); 1139 } 1140 1141 static struct mbuf * 1142 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr) 1143 { 1144 struct mbuf *m, *n; 1145 unsigned len = len0, remain, len_save; 1146 1147 for (m = m0; m && len > m->m_len; m = m->m_next) 1148 len -= m->m_len; 1149 if (m == 0) 1150 return (NULL); 1151 remain = m->m_len - len; 1152 if (copyhdr && (m0->m_flags & M_PKTHDR)) { 1153 MGETHDR(n, wait, m0->m_type); 1154 if (n == 0) 1155 return (NULL); 1156 MCLAIM(n, m0->m_owner); 1157 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1158 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1159 len_save = m0->m_pkthdr.len; 1160 m0->m_pkthdr.len = len0; 1161 if (m->m_flags & M_EXT) 1162 goto extpacket; 1163 if (remain > MHLEN) { 1164 /* m can't be the lead packet */ 1165 MH_ALIGN(n, 0); 1166 n->m_len = 0; 1167 n->m_next = m_split(m, len, wait); 1168 if (n->m_next == 0) { 1169 (void) m_free(n); 1170 m0->m_pkthdr.len = len_save; 1171 return (NULL); 1172 } else 1173 return (n); 1174 } else 1175 MH_ALIGN(n, remain); 1176 } else if (remain == 0) { 1177 n = m->m_next; 1178 m->m_next = 0; 1179 return (n); 1180 } else { 1181 MGET(n, wait, m->m_type); 1182 if (n == 0) 1183 return (NULL); 1184 MCLAIM(n, m->m_owner); 1185 M_ALIGN(n, remain); 1186 } 1187 extpacket: 1188 if (m->m_flags & M_EXT) { 1189 n->m_data = m->m_data + len; 1190 MCLADDREFERENCE(m, n); 1191 } else { 1192 memcpy(mtod(n, void *), mtod(m, char *) + len, remain); 1193 } 1194 n->m_len = remain; 1195 m->m_len = len; 1196 n->m_next = m->m_next; 1197 m->m_next = 0; 1198 return (n); 1199 } 1200 /* 1201 * Routine to copy from device local memory into mbufs. 1202 */ 1203 struct mbuf * 1204 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, 1205 void (*copy)(const void *from, void *to, size_t len)) 1206 { 1207 struct mbuf *m; 1208 struct mbuf *top = 0, **mp = ⊤ 1209 int off = off0, len; 1210 char *cp; 1211 char *epkt; 1212 1213 cp = buf; 1214 epkt = cp + totlen; 1215 if (off) { 1216 /* 1217 * If 'off' is non-zero, packet is trailer-encapsulated, 1218 * so we have to skip the type and length fields. 1219 */ 1220 cp += off + 2 * sizeof(uint16_t); 1221 totlen -= 2 * sizeof(uint16_t); 1222 } 1223 MGETHDR(m, M_DONTWAIT, MT_DATA); 1224 if (m == 0) 1225 return (NULL); 1226 m->m_pkthdr.rcvif = ifp; 1227 m->m_pkthdr.len = totlen; 1228 m->m_len = MHLEN; 1229 1230 while (totlen > 0) { 1231 if (top) { 1232 MGET(m, M_DONTWAIT, MT_DATA); 1233 if (m == 0) { 1234 m_freem(top); 1235 return (NULL); 1236 } 1237 m->m_len = MLEN; 1238 } 1239 len = min(totlen, epkt - cp); 1240 if (len >= MINCLSIZE) { 1241 MCLGET(m, M_DONTWAIT); 1242 if ((m->m_flags & M_EXT) == 0) { 1243 m_free(m); 1244 m_freem(top); 1245 return (NULL); 1246 } 1247 m->m_len = len = min(len, MCLBYTES); 1248 } else { 1249 /* 1250 * Place initial small packet/header at end of mbuf. 1251 */ 1252 if (len < m->m_len) { 1253 if (top == 0 && len + max_linkhdr <= m->m_len) 1254 m->m_data += max_linkhdr; 1255 m->m_len = len; 1256 } else 1257 len = m->m_len; 1258 } 1259 if (copy) 1260 copy(cp, mtod(m, void *), (size_t)len); 1261 else 1262 memcpy(mtod(m, void *), cp, (size_t)len); 1263 cp += len; 1264 *mp = m; 1265 mp = &m->m_next; 1266 totlen -= len; 1267 if (cp == epkt) 1268 cp = buf; 1269 } 1270 return (top); 1271 } 1272 1273 /* 1274 * Copy data from a buffer back into the indicated mbuf chain, 1275 * starting "off" bytes from the beginning, extending the mbuf 1276 * chain if necessary. 1277 */ 1278 void 1279 m_copyback(struct mbuf *m0, int off, int len, const void *cp) 1280 { 1281 #if defined(DEBUG) 1282 struct mbuf *origm = m0; 1283 int error; 1284 #endif /* defined(DEBUG) */ 1285 1286 if (m0 == NULL) 1287 return; 1288 1289 #if defined(DEBUG) 1290 error = 1291 #endif /* defined(DEBUG) */ 1292 m_copyback0(&m0, off, len, cp, 1293 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT); 1294 1295 #if defined(DEBUG) 1296 if (error != 0 || (m0 != NULL && origm != m0)) 1297 panic("m_copyback"); 1298 #endif /* defined(DEBUG) */ 1299 } 1300 1301 struct mbuf * 1302 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how) 1303 { 1304 int error; 1305 1306 /* don't support chain expansion */ 1307 KDASSERT(off + len <= m_length(m0)); 1308 1309 error = m_copyback0(&m0, off, len, cp, 1310 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how); 1311 if (error) { 1312 /* 1313 * no way to recover from partial success. 1314 * just free the chain. 1315 */ 1316 m_freem(m0); 1317 return NULL; 1318 } 1319 return m0; 1320 } 1321 1322 /* 1323 * m_makewritable: ensure the specified range writable. 1324 */ 1325 int 1326 m_makewritable(struct mbuf **mp, int off, int len, int how) 1327 { 1328 int error; 1329 #if defined(DEBUG) 1330 struct mbuf *n; 1331 int origlen, reslen; 1332 1333 origlen = m_length(*mp); 1334 #endif /* defined(DEBUG) */ 1335 1336 #if 0 /* M_COPYALL is large enough */ 1337 if (len == M_COPYALL) 1338 len = m_length(*mp) - off; /* XXX */ 1339 #endif 1340 1341 error = m_copyback0(mp, off, len, NULL, 1342 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how); 1343 1344 #if defined(DEBUG) 1345 reslen = 0; 1346 for (n = *mp; n; n = n->m_next) 1347 reslen += n->m_len; 1348 if (origlen != reslen) 1349 panic("m_makewritable: length changed"); 1350 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len) 1351 panic("m_makewritable: inconsist"); 1352 #endif /* defined(DEBUG) */ 1353 1354 return error; 1355 } 1356 1357 /* 1358 * Copy the mbuf chain to a new mbuf chain that is as short as possible. 1359 * Return the new mbuf chain on success, NULL on failure. On success, 1360 * free the old mbuf chain. 1361 */ 1362 struct mbuf * 1363 m_defrag(struct mbuf *mold, int flags) 1364 { 1365 struct mbuf *m0, *mn, *n; 1366 size_t sz = mold->m_pkthdr.len; 1367 1368 #ifdef DIAGNOSTIC 1369 if ((mold->m_flags & M_PKTHDR) == 0) 1370 panic("m_defrag: not a mbuf chain header"); 1371 #endif 1372 1373 MGETHDR(m0, flags, MT_DATA); 1374 if (m0 == NULL) 1375 return NULL; 1376 M_COPY_PKTHDR(m0, mold); 1377 mn = m0; 1378 1379 do { 1380 if (sz > MHLEN) { 1381 MCLGET(mn, M_DONTWAIT); 1382 if ((mn->m_flags & M_EXT) == 0) { 1383 m_freem(m0); 1384 return NULL; 1385 } 1386 } 1387 1388 mn->m_len = MIN(sz, MCLBYTES); 1389 1390 m_copydata(mold, mold->m_pkthdr.len - sz, mn->m_len, 1391 mtod(mn, void *)); 1392 1393 sz -= mn->m_len; 1394 1395 if (sz > 0) { 1396 /* need more mbufs */ 1397 MGET(n, M_NOWAIT, MT_DATA); 1398 if (n == NULL) { 1399 m_freem(m0); 1400 return NULL; 1401 } 1402 1403 mn->m_next = n; 1404 mn = n; 1405 } 1406 } while (sz > 0); 1407 1408 m_freem(mold); 1409 1410 return m0; 1411 } 1412 1413 int 1414 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags, 1415 int how) 1416 { 1417 int mlen; 1418 struct mbuf *m, *n; 1419 struct mbuf **mp; 1420 int totlen = 0; 1421 const char *cp = vp; 1422 1423 KASSERT(mp0 != NULL); 1424 KASSERT(*mp0 != NULL); 1425 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL); 1426 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL); 1427 1428 /* 1429 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW, 1430 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive. 1431 */ 1432 1433 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0); 1434 1435 mp = mp0; 1436 m = *mp; 1437 while (off > (mlen = m->m_len)) { 1438 off -= mlen; 1439 totlen += mlen; 1440 if (m->m_next == NULL) { 1441 int tspace; 1442 extend: 1443 if ((flags & M_COPYBACK0_EXTEND) == 0) 1444 goto out; 1445 1446 /* 1447 * try to make some space at the end of "m". 1448 */ 1449 1450 mlen = m->m_len; 1451 if (off + len >= MINCLSIZE && 1452 (m->m_flags & M_EXT) == 0 && m->m_len == 0) { 1453 MCLGET(m, how); 1454 } 1455 tspace = M_TRAILINGSPACE(m); 1456 if (tspace > 0) { 1457 tspace = min(tspace, off + len); 1458 KASSERT(tspace > 0); 1459 memset(mtod(m, char *) + m->m_len, 0, 1460 min(off, tspace)); 1461 m->m_len += tspace; 1462 off += mlen; 1463 totlen -= mlen; 1464 continue; 1465 } 1466 1467 /* 1468 * need to allocate an mbuf. 1469 */ 1470 1471 if (off + len >= MINCLSIZE) { 1472 n = m_getcl(how, m->m_type, 0); 1473 } else { 1474 n = m_get(how, m->m_type); 1475 } 1476 if (n == NULL) { 1477 goto out; 1478 } 1479 n->m_len = 0; 1480 n->m_len = min(M_TRAILINGSPACE(n), off + len); 1481 memset(mtod(n, char *), 0, min(n->m_len, off)); 1482 m->m_next = n; 1483 } 1484 mp = &m->m_next; 1485 m = m->m_next; 1486 } 1487 while (len > 0) { 1488 mlen = m->m_len - off; 1489 if (mlen != 0 && M_READONLY(m)) { 1490 char *datap; 1491 int eatlen; 1492 1493 /* 1494 * this mbuf is read-only. 1495 * allocate a new writable mbuf and try again. 1496 */ 1497 1498 #if defined(DIAGNOSTIC) 1499 if ((flags & M_COPYBACK0_COW) == 0) 1500 panic("m_copyback0: read-only"); 1501 #endif /* defined(DIAGNOSTIC) */ 1502 1503 /* 1504 * if we're going to write into the middle of 1505 * a mbuf, split it first. 1506 */ 1507 if (off > 0) { 1508 n = m_split0(m, off, how, 0); 1509 if (n == NULL) 1510 goto enobufs; 1511 m->m_next = n; 1512 mp = &m->m_next; 1513 m = n; 1514 off = 0; 1515 continue; 1516 } 1517 1518 /* 1519 * XXX TODO coalesce into the trailingspace of 1520 * the previous mbuf when possible. 1521 */ 1522 1523 /* 1524 * allocate a new mbuf. copy packet header if needed. 1525 */ 1526 MGET(n, how, m->m_type); 1527 if (n == NULL) 1528 goto enobufs; 1529 MCLAIM(n, m->m_owner); 1530 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) { 1531 M_MOVE_PKTHDR(n, m); 1532 n->m_len = MHLEN; 1533 } else { 1534 if (len >= MINCLSIZE) 1535 MCLGET(n, M_DONTWAIT); 1536 n->m_len = 1537 (n->m_flags & M_EXT) ? MCLBYTES : MLEN; 1538 } 1539 if (n->m_len > len) 1540 n->m_len = len; 1541 1542 /* 1543 * free the region which has been overwritten. 1544 * copying data from old mbufs if requested. 1545 */ 1546 if (flags & M_COPYBACK0_PRESERVE) 1547 datap = mtod(n, char *); 1548 else 1549 datap = NULL; 1550 eatlen = n->m_len; 1551 while (m != NULL && M_READONLY(m) && 1552 n->m_type == m->m_type && eatlen > 0) { 1553 mlen = min(eatlen, m->m_len); 1554 if (datap) { 1555 m_copydata(m, 0, mlen, datap); 1556 datap += mlen; 1557 } 1558 m->m_data += mlen; 1559 m->m_len -= mlen; 1560 eatlen -= mlen; 1561 if (m->m_len == 0) 1562 *mp = m = m_free(m); 1563 } 1564 if (eatlen > 0) 1565 n->m_len -= eatlen; 1566 n->m_next = m; 1567 *mp = m = n; 1568 continue; 1569 } 1570 mlen = min(mlen, len); 1571 if (flags & M_COPYBACK0_COPYBACK) { 1572 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen); 1573 cp += mlen; 1574 } 1575 len -= mlen; 1576 mlen += off; 1577 off = 0; 1578 totlen += mlen; 1579 if (len == 0) 1580 break; 1581 if (m->m_next == NULL) { 1582 goto extend; 1583 } 1584 mp = &m->m_next; 1585 m = m->m_next; 1586 } 1587 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) { 1588 KASSERT((flags & M_COPYBACK0_EXTEND) != 0); 1589 m->m_pkthdr.len = totlen; 1590 } 1591 1592 return 0; 1593 1594 enobufs: 1595 return ENOBUFS; 1596 } 1597 1598 void 1599 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1600 { 1601 1602 KASSERT((to->m_flags & M_EXT) == 0); 1603 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL); 1604 KASSERT((from->m_flags & M_PKTHDR) != 0); 1605 1606 to->m_pkthdr = from->m_pkthdr; 1607 to->m_flags = from->m_flags & M_COPYFLAGS; 1608 to->m_data = to->m_pktdat; 1609 1610 from->m_flags &= ~M_PKTHDR; 1611 } 1612 1613 /* 1614 * Apply function f to the data in an mbuf chain starting "off" bytes from the 1615 * beginning, continuing for "len" bytes. 1616 */ 1617 int 1618 m_apply(struct mbuf *m, int off, int len, 1619 int (*f)(void *, void *, unsigned int), void *arg) 1620 { 1621 unsigned int count; 1622 int rval; 1623 1624 KASSERT(len >= 0); 1625 KASSERT(off >= 0); 1626 1627 while (off > 0) { 1628 KASSERT(m != NULL); 1629 if (off < m->m_len) 1630 break; 1631 off -= m->m_len; 1632 m = m->m_next; 1633 } 1634 while (len > 0) { 1635 KASSERT(m != NULL); 1636 count = min(m->m_len - off, len); 1637 1638 rval = (*f)(arg, mtod(m, char *) + off, count); 1639 if (rval) 1640 return (rval); 1641 1642 len -= count; 1643 off = 0; 1644 m = m->m_next; 1645 } 1646 1647 return (0); 1648 } 1649 1650 /* 1651 * Return a pointer to mbuf/offset of location in mbuf chain. 1652 */ 1653 struct mbuf * 1654 m_getptr(struct mbuf *m, int loc, int *off) 1655 { 1656 1657 while (loc >= 0) { 1658 /* Normal end of search */ 1659 if (m->m_len > loc) { 1660 *off = loc; 1661 return (m); 1662 } else { 1663 loc -= m->m_len; 1664 1665 if (m->m_next == NULL) { 1666 if (loc == 0) { 1667 /* Point at the end of valid data */ 1668 *off = m->m_len; 1669 return (m); 1670 } else 1671 return (NULL); 1672 } else 1673 m = m->m_next; 1674 } 1675 } 1676 1677 return (NULL); 1678 } 1679 1680 /* 1681 * m_ext_free: release a reference to the mbuf external storage. 1682 * 1683 * => free the mbuf m itsself as well. 1684 */ 1685 1686 void 1687 m_ext_free(struct mbuf *m) 1688 { 1689 bool embedded = MEXT_ISEMBEDDED(m); 1690 bool dofree = true; 1691 u_int refcnt; 1692 1693 KASSERT((m->m_flags & M_EXT) != 0); 1694 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref)); 1695 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0); 1696 KASSERT((m->m_flags & M_EXT_CLUSTER) == 1697 (m->m_ext_ref->m_flags & M_EXT_CLUSTER)); 1698 1699 if (__predict_true(m->m_ext.ext_refcnt == 1)) { 1700 refcnt = m->m_ext.ext_refcnt = 0; 1701 } else { 1702 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt); 1703 } 1704 if (refcnt > 0) { 1705 if (embedded) { 1706 /* 1707 * other mbuf's m_ext_ref still points to us. 1708 */ 1709 dofree = false; 1710 } else { 1711 m->m_ext_ref = m; 1712 } 1713 } else { 1714 /* 1715 * dropping the last reference 1716 */ 1717 if (!embedded) { 1718 m->m_ext.ext_refcnt++; /* XXX */ 1719 m_ext_free(m->m_ext_ref); 1720 m->m_ext_ref = m; 1721 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) { 1722 pool_cache_put_paddr((struct pool_cache *) 1723 m->m_ext.ext_arg, 1724 m->m_ext.ext_buf, m->m_ext.ext_paddr); 1725 } else if (m->m_ext.ext_free) { 1726 (*m->m_ext.ext_free)(m, 1727 m->m_ext.ext_buf, m->m_ext.ext_size, 1728 m->m_ext.ext_arg); 1729 /* 1730 * 'm' is already freed by the ext_free callback. 1731 */ 1732 dofree = false; 1733 } else { 1734 free(m->m_ext.ext_buf, m->m_ext.ext_type); 1735 } 1736 } 1737 if (dofree) { 1738 pool_cache_put(mb_cache, m); 1739 } 1740 } 1741 1742 #if defined(DDB) 1743 void 1744 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...)) 1745 { 1746 char ch; 1747 bool opt_c = false; 1748 char buf[512]; 1749 1750 while ((ch = *(modif++)) != '\0') { 1751 switch (ch) { 1752 case 'c': 1753 opt_c = true; 1754 break; 1755 } 1756 } 1757 1758 nextchain: 1759 (*pr)("MBUF %p\n", m); 1760 snprintb(buf, sizeof(buf), M_FLAGS_BITS, (u_int)m->m_flags); 1761 (*pr)(" data=%p, len=%d, type=%d, flags=%s\n", 1762 m->m_data, m->m_len, m->m_type, buf); 1763 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next, 1764 m->m_nextpkt); 1765 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n", 1766 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m), 1767 (int)M_READONLY(m)); 1768 if ((m->m_flags & M_PKTHDR) != 0) { 1769 snprintb(buf, sizeof(buf), M_CSUM_BITS, m->m_pkthdr.csum_flags); 1770 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%" 1771 PRIx32 ", segsz=%u\n", 1772 m->m_pkthdr.len, m->m_pkthdr.rcvif, 1773 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz); 1774 } 1775 if ((m->m_flags & M_EXT)) { 1776 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, " 1777 "ext_free=%p, ext_arg=%p\n", 1778 m->m_ext.ext_refcnt, 1779 m->m_ext.ext_buf, m->m_ext.ext_size, 1780 m->m_ext.ext_free, m->m_ext.ext_arg); 1781 } 1782 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) { 1783 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf; 1784 vaddr_t eva = sva + m->m_ext.ext_size; 1785 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT; 1786 int i; 1787 1788 (*pr)(" pages:"); 1789 for (i = 0; i < n; i ++) { 1790 (*pr)(" %p", m->m_ext.ext_pgs[i]); 1791 } 1792 (*pr)("\n"); 1793 } 1794 1795 if (opt_c) { 1796 m = m->m_next; 1797 if (m != NULL) { 1798 goto nextchain; 1799 } 1800 } 1801 } 1802 #endif /* defined(DDB) */ 1803 1804 void 1805 mbstat_type_add(int type, int diff) 1806 { 1807 struct mbstat_cpu *mb; 1808 int s; 1809 1810 s = splvm(); 1811 mb = percpu_getref(mbstat_percpu); 1812 mb->m_mtypes[type] += diff; 1813 percpu_putref(mbstat_percpu); 1814 splx(s); 1815 } 1816 1817 #if defined(MBUFTRACE) 1818 void 1819 mowner_attach(struct mowner *mo) 1820 { 1821 1822 KASSERT(mo->mo_counters == NULL); 1823 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter)); 1824 1825 /* XXX lock */ 1826 LIST_INSERT_HEAD(&mowners, mo, mo_link); 1827 } 1828 1829 void 1830 mowner_detach(struct mowner *mo) 1831 { 1832 1833 KASSERT(mo->mo_counters != NULL); 1834 1835 /* XXX lock */ 1836 LIST_REMOVE(mo, mo_link); 1837 1838 percpu_free(mo->mo_counters, sizeof(struct mowner_counter)); 1839 mo->mo_counters = NULL; 1840 } 1841 1842 void 1843 mowner_init(struct mbuf *m, int type) 1844 { 1845 struct mowner_counter *mc; 1846 struct mowner *mo; 1847 int s; 1848 1849 m->m_owner = mo = &unknown_mowners[type]; 1850 s = splvm(); 1851 mc = percpu_getref(mo->mo_counters); 1852 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1853 percpu_putref(mo->mo_counters); 1854 splx(s); 1855 } 1856 1857 void 1858 mowner_ref(struct mbuf *m, int flags) 1859 { 1860 struct mowner *mo = m->m_owner; 1861 struct mowner_counter *mc; 1862 int s; 1863 1864 s = splvm(); 1865 mc = percpu_getref(mo->mo_counters); 1866 if ((flags & M_EXT) != 0) 1867 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1868 if ((flags & M_CLUSTER) != 0) 1869 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1870 percpu_putref(mo->mo_counters); 1871 splx(s); 1872 } 1873 1874 void 1875 mowner_revoke(struct mbuf *m, bool all, int flags) 1876 { 1877 struct mowner *mo = m->m_owner; 1878 struct mowner_counter *mc; 1879 int s; 1880 1881 s = splvm(); 1882 mc = percpu_getref(mo->mo_counters); 1883 if ((flags & M_EXT) != 0) 1884 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++; 1885 if ((flags & M_CLUSTER) != 0) 1886 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++; 1887 if (all) 1888 mc->mc_counter[MOWNER_COUNTER_RELEASES]++; 1889 percpu_putref(mo->mo_counters); 1890 splx(s); 1891 if (all) 1892 m->m_owner = &revoked_mowner; 1893 } 1894 1895 static void 1896 mowner_claim(struct mbuf *m, struct mowner *mo) 1897 { 1898 struct mowner_counter *mc; 1899 int flags = m->m_flags; 1900 int s; 1901 1902 s = splvm(); 1903 mc = percpu_getref(mo->mo_counters); 1904 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1905 if ((flags & M_EXT) != 0) 1906 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1907 if ((flags & M_CLUSTER) != 0) 1908 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1909 percpu_putref(mo->mo_counters); 1910 splx(s); 1911 m->m_owner = mo; 1912 } 1913 1914 void 1915 m_claim(struct mbuf *m, struct mowner *mo) 1916 { 1917 1918 if (m->m_owner == mo || mo == NULL) 1919 return; 1920 1921 mowner_revoke(m, true, m->m_flags); 1922 mowner_claim(m, mo); 1923 } 1924 #endif /* defined(MBUFTRACE) */ 1925