1 /* $NetBSD: uipc_mbuf.c,v 1.163 2015/08/24 22:21:26 pooka 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 1.163 2015/08/24 22:21:26 pooka Exp $"); 66 67 #ifdef _KERNEL_OPT 68 #include "opt_mbuftrace.h" 69 #include "opt_nmbclusters.h" 70 #include "opt_ddb.h" 71 #endif 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/atomic.h> 76 #include <sys/cpu.h> 77 #include <sys/proc.h> 78 #include <sys/mbuf.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 #include <sys/domain.h> 82 #include <sys/protosw.h> 83 #include <sys/percpu.h> 84 #include <sys/pool.h> 85 #include <sys/socket.h> 86 #include <sys/sysctl.h> 87 88 #include <net/if.h> 89 90 pool_cache_t mb_cache; /* mbuf cache */ 91 pool_cache_t mcl_cache; /* mbuf cluster cache */ 92 93 struct mbstat mbstat; 94 int max_linkhdr; 95 int max_protohdr; 96 int max_hdr; 97 int max_datalen; 98 99 static int mb_ctor(void *, void *, int); 100 101 static void sysctl_kern_mbuf_setup(void); 102 103 static struct sysctllog *mbuf_sysctllog; 104 105 static struct mbuf *m_copym0(struct mbuf *, int, int, int, int); 106 static struct mbuf *m_split0(struct mbuf *, int, int, int); 107 static int m_copyback0(struct mbuf **, int, int, const void *, int, int); 108 109 /* flags for m_copyback0 */ 110 #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */ 111 #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */ 112 #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */ 113 #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */ 114 115 static const char mclpool_warnmsg[] = 116 "WARNING: mclpool limit reached; increase kern.mbuf.nmbclusters"; 117 118 MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf"); 119 120 static percpu_t *mbstat_percpu; 121 122 #ifdef MBUFTRACE 123 struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners); 124 struct mowner unknown_mowners[] = { 125 MOWNER_INIT("unknown", "free"), 126 MOWNER_INIT("unknown", "data"), 127 MOWNER_INIT("unknown", "header"), 128 MOWNER_INIT("unknown", "soname"), 129 MOWNER_INIT("unknown", "soopts"), 130 MOWNER_INIT("unknown", "ftable"), 131 MOWNER_INIT("unknown", "control"), 132 MOWNER_INIT("unknown", "oobdata"), 133 }; 134 struct mowner revoked_mowner = MOWNER_INIT("revoked", ""); 135 #endif 136 137 #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m)) 138 139 #define MCLADDREFERENCE(o, n) \ 140 do { \ 141 KASSERT(((o)->m_flags & M_EXT) != 0); \ 142 KASSERT(((n)->m_flags & M_EXT) == 0); \ 143 KASSERT((o)->m_ext.ext_refcnt >= 1); \ 144 (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \ 145 atomic_inc_uint(&(o)->m_ext.ext_refcnt); \ 146 (n)->m_ext_ref = (o)->m_ext_ref; \ 147 mowner_ref((n), (n)->m_flags); \ 148 MCLREFDEBUGN((n), __FILE__, __LINE__); \ 149 } while (/* CONSTCOND */ 0) 150 151 static int 152 nmbclusters_limit(void) 153 { 154 #if defined(PMAP_MAP_POOLPAGE) 155 /* direct mapping, doesn't use space in kmem_arena */ 156 vsize_t max_size = physmem / 4; 157 #else 158 vsize_t max_size = MIN(physmem / 4, nkmempages / 4); 159 #endif 160 161 max_size = max_size * PAGE_SIZE / MCLBYTES; 162 #ifdef NMBCLUSTERS_MAX 163 max_size = MIN(max_size, NMBCLUSTERS_MAX); 164 #endif 165 166 #ifdef NMBCLUSTERS 167 return MIN(max_size, NMBCLUSTERS); 168 #else 169 return max_size; 170 #endif 171 } 172 173 /* 174 * Initialize the mbuf allocator. 175 */ 176 void 177 mbinit(void) 178 { 179 180 CTASSERT(sizeof(struct _m_ext) <= MHLEN); 181 CTASSERT(sizeof(struct mbuf) == MSIZE); 182 183 sysctl_kern_mbuf_setup(); 184 185 mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl", 186 NULL, IPL_VM, mb_ctor, NULL, NULL); 187 KASSERT(mb_cache != NULL); 188 189 mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl", NULL, 190 IPL_VM, NULL, NULL, NULL); 191 KASSERT(mcl_cache != NULL); 192 193 pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL); 194 pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL); 195 196 /* 197 * Set an arbitrary default limit on the number of mbuf clusters. 198 */ 199 #ifdef NMBCLUSTERS 200 nmbclusters = nmbclusters_limit(); 201 #else 202 nmbclusters = MAX(1024, 203 (vsize_t)physmem * PAGE_SIZE / MCLBYTES / 16); 204 nmbclusters = MIN(nmbclusters, nmbclusters_limit()); 205 #endif 206 207 /* 208 * Set the hard limit on the mclpool to the number of 209 * mbuf clusters the kernel is to support. Log the limit 210 * reached message max once a minute. 211 */ 212 pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60); 213 214 mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu)); 215 216 /* 217 * Set a low water mark for both mbufs and clusters. This should 218 * help ensure that they can be allocated in a memory starvation 219 * situation. This is important for e.g. diskless systems which 220 * must allocate mbufs in order for the pagedaemon to clean pages. 221 */ 222 pool_cache_setlowat(mb_cache, mblowat); 223 pool_cache_setlowat(mcl_cache, mcllowat); 224 225 #ifdef MBUFTRACE 226 { 227 /* 228 * Attach the unknown mowners. 229 */ 230 int i; 231 MOWNER_ATTACH(&revoked_mowner); 232 for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]); 233 i-- > 0; ) 234 MOWNER_ATTACH(&unknown_mowners[i]); 235 } 236 #endif 237 } 238 239 /* 240 * sysctl helper routine for the kern.mbuf subtree. 241 * nmbclusters, mblowat and mcllowat need range 242 * checking and pool tweaking after being reset. 243 */ 244 static int 245 sysctl_kern_mbuf(SYSCTLFN_ARGS) 246 { 247 int error, newval; 248 struct sysctlnode node; 249 250 node = *rnode; 251 node.sysctl_data = &newval; 252 switch (rnode->sysctl_num) { 253 case MBUF_NMBCLUSTERS: 254 case MBUF_MBLOWAT: 255 case MBUF_MCLLOWAT: 256 newval = *(int*)rnode->sysctl_data; 257 break; 258 default: 259 return (EOPNOTSUPP); 260 } 261 262 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 263 if (error || newp == NULL) 264 return (error); 265 if (newval < 0) 266 return (EINVAL); 267 268 switch (node.sysctl_num) { 269 case MBUF_NMBCLUSTERS: 270 if (newval < nmbclusters) 271 return (EINVAL); 272 if (newval > nmbclusters_limit()) 273 return (EINVAL); 274 nmbclusters = newval; 275 pool_cache_sethardlimit(mcl_cache, nmbclusters, 276 mclpool_warnmsg, 60); 277 break; 278 case MBUF_MBLOWAT: 279 mblowat = newval; 280 pool_cache_setlowat(mb_cache, mblowat); 281 break; 282 case MBUF_MCLLOWAT: 283 mcllowat = newval; 284 pool_cache_setlowat(mcl_cache, mcllowat); 285 break; 286 } 287 288 return (0); 289 } 290 291 #ifdef MBUFTRACE 292 static void 293 mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 294 { 295 struct mowner_counter *mc = v1; 296 struct mowner_user *mo_user = v2; 297 int i; 298 299 for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) { 300 mo_user->mo_counter[i] += mc->mc_counter[i]; 301 } 302 } 303 304 static void 305 mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user) 306 { 307 308 memset(mo_user, 0, sizeof(*mo_user)); 309 CTASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name)); 310 CTASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr)); 311 memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name)); 312 memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr)); 313 percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user); 314 } 315 316 static int 317 sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS) 318 { 319 struct mowner *mo; 320 size_t len = 0; 321 int error = 0; 322 323 if (namelen != 0) 324 return (EINVAL); 325 if (newp != NULL) 326 return (EPERM); 327 328 LIST_FOREACH(mo, &mowners, mo_link) { 329 struct mowner_user mo_user; 330 331 mowner_convert_to_user(mo, &mo_user); 332 333 if (oldp != NULL) { 334 if (*oldlenp - len < sizeof(mo_user)) { 335 error = ENOMEM; 336 break; 337 } 338 error = copyout(&mo_user, (char *)oldp + len, 339 sizeof(mo_user)); 340 if (error) 341 break; 342 } 343 len += sizeof(mo_user); 344 } 345 346 if (error == 0) 347 *oldlenp = len; 348 349 return (error); 350 } 351 #endif /* MBUFTRACE */ 352 353 static void 354 mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 355 { 356 struct mbstat_cpu *mbsc = v1; 357 struct mbstat *mbs = v2; 358 int i; 359 360 for (i = 0; i < __arraycount(mbs->m_mtypes); i++) { 361 mbs->m_mtypes[i] += mbsc->m_mtypes[i]; 362 } 363 } 364 365 static void 366 mbstat_convert_to_user(struct mbstat *mbs) 367 { 368 369 memset(mbs, 0, sizeof(*mbs)); 370 mbs->m_drain = mbstat.m_drain; 371 percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs); 372 } 373 374 static int 375 sysctl_kern_mbuf_stats(SYSCTLFN_ARGS) 376 { 377 struct sysctlnode node; 378 struct mbstat mbs; 379 380 mbstat_convert_to_user(&mbs); 381 node = *rnode; 382 node.sysctl_data = &mbs; 383 node.sysctl_size = sizeof(mbs); 384 return sysctl_lookup(SYSCTLFN_CALL(&node)); 385 } 386 387 static void 388 sysctl_kern_mbuf_setup(void) 389 { 390 391 KASSERT(mbuf_sysctllog == NULL); 392 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 393 CTLFLAG_PERMANENT, 394 CTLTYPE_NODE, "mbuf", 395 SYSCTL_DESCR("mbuf control variables"), 396 NULL, 0, NULL, 0, 397 CTL_KERN, KERN_MBUF, CTL_EOL); 398 399 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 400 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 401 CTLTYPE_INT, "msize", 402 SYSCTL_DESCR("mbuf base size"), 403 NULL, msize, NULL, 0, 404 CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL); 405 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 406 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 407 CTLTYPE_INT, "mclbytes", 408 SYSCTL_DESCR("mbuf cluster size"), 409 NULL, mclbytes, NULL, 0, 410 CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL); 411 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 412 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 413 CTLTYPE_INT, "nmbclusters", 414 SYSCTL_DESCR("Limit on the number of mbuf clusters"), 415 sysctl_kern_mbuf, 0, &nmbclusters, 0, 416 CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL); 417 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 418 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 419 CTLTYPE_INT, "mblowat", 420 SYSCTL_DESCR("mbuf low water mark"), 421 sysctl_kern_mbuf, 0, &mblowat, 0, 422 CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL); 423 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 424 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 425 CTLTYPE_INT, "mcllowat", 426 SYSCTL_DESCR("mbuf cluster low water mark"), 427 sysctl_kern_mbuf, 0, &mcllowat, 0, 428 CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL); 429 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 430 CTLFLAG_PERMANENT, 431 CTLTYPE_STRUCT, "stats", 432 SYSCTL_DESCR("mbuf allocation statistics"), 433 sysctl_kern_mbuf_stats, 0, NULL, 0, 434 CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL); 435 #ifdef MBUFTRACE 436 sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, 437 CTLFLAG_PERMANENT, 438 CTLTYPE_STRUCT, "mowners", 439 SYSCTL_DESCR("Information about mbuf owners"), 440 sysctl_kern_mbuf_mowners, 0, NULL, 0, 441 CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL); 442 #endif /* MBUFTRACE */ 443 } 444 445 static int 446 mb_ctor(void *arg, void *object, int flags) 447 { 448 struct mbuf *m = object; 449 450 #ifdef POOL_VTOPHYS 451 m->m_paddr = POOL_VTOPHYS(m); 452 #else 453 m->m_paddr = M_PADDR_INVALID; 454 #endif 455 return (0); 456 } 457 458 /* 459 * Add mbuf to the end of a chain 460 */ 461 struct mbuf * 462 m_add(struct mbuf *c, struct mbuf *m) { 463 struct mbuf *n; 464 465 if (c == NULL) 466 return m; 467 468 for (n = c; n->m_next != NULL; n = n->m_next) 469 continue; 470 n->m_next = m; 471 return c; 472 } 473 474 /* 475 * Set the m_data pointer of a newly-allocated mbuf 476 * to place an object of the specified size at the 477 * end of the mbuf, longword aligned. 478 */ 479 void 480 m_align(struct mbuf *m, int len) 481 { 482 int adjust; 483 484 KASSERT(len != M_COPYALL); 485 486 if (m->m_flags & M_EXT) 487 adjust = m->m_ext.ext_size - len; 488 else if (m->m_flags & M_PKTHDR) 489 adjust = MHLEN - len; 490 else 491 adjust = MLEN - len; 492 m->m_data += adjust &~ (sizeof(long)-1); 493 } 494 495 /* 496 * Append the specified data to the indicated mbuf chain, 497 * Extend the mbuf chain if the new data does not fit in 498 * existing space. 499 * 500 * Return 1 if able to complete the job; otherwise 0. 501 */ 502 int 503 m_append(struct mbuf *m0, int len, const void *cpv) 504 { 505 struct mbuf *m, *n; 506 int remainder, space; 507 const char *cp = cpv; 508 509 KASSERT(len != M_COPYALL); 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_len = 0; 590 m->m_next = NULL; 591 m->m_nextpkt = NULL; 592 m->m_data = m->m_dat; 593 m->m_flags = 0; 594 595 return m; 596 } 597 598 struct mbuf * 599 m_gethdr(int nowait, int type) 600 { 601 struct mbuf *m; 602 603 m = m_get(nowait, type); 604 if (m == NULL) 605 return NULL; 606 607 m->m_data = m->m_pktdat; 608 m->m_flags = M_PKTHDR; 609 m->m_pkthdr.rcvif = NULL; 610 m->m_pkthdr.len = 0; 611 m->m_pkthdr.csum_flags = 0; 612 m->m_pkthdr.csum_data = 0; 613 SLIST_INIT(&m->m_pkthdr.tags); 614 615 return m; 616 } 617 618 struct mbuf * 619 m_getclr(int nowait, int type) 620 { 621 struct mbuf *m; 622 623 m = m_get(nowait, type); 624 if (m == 0) 625 return (NULL); 626 memset(mtod(m, void *), 0, MLEN); 627 return (m); 628 } 629 630 void 631 m_clget(struct mbuf *m, int nowait) 632 { 633 634 MCLGET(m, nowait); 635 } 636 637 struct mbuf * 638 m_free(struct mbuf *m) 639 { 640 struct mbuf *n; 641 642 MFREE(m, n); 643 return (n); 644 } 645 646 void 647 m_freem(struct mbuf *m) 648 { 649 struct mbuf *n; 650 651 if (m == NULL) 652 return; 653 do { 654 MFREE(m, n); 655 m = n; 656 } while (m); 657 } 658 659 #ifdef MBUFTRACE 660 /* 661 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain. 662 */ 663 void 664 m_claimm(struct mbuf *m, struct mowner *mo) 665 { 666 667 for (; m != NULL; m = m->m_next) 668 MCLAIM(m, mo); 669 } 670 #endif 671 672 /* 673 * Mbuffer utility routines. 674 */ 675 676 /* 677 * Lesser-used path for M_PREPEND: 678 * allocate new mbuf to prepend to chain, 679 * copy junk along. 680 */ 681 struct mbuf * 682 m_prepend(struct mbuf *m, int len, int how) 683 { 684 struct mbuf *mn; 685 686 KASSERT(len != M_COPYALL); 687 mn = m_get(how, m->m_type); 688 if (mn == NULL) { 689 m_freem(m); 690 return (NULL); 691 } 692 if (m->m_flags & M_PKTHDR) { 693 M_MOVE_PKTHDR(mn, m); 694 } else { 695 MCLAIM(mn, m->m_owner); 696 } 697 mn->m_next = m; 698 m = mn; 699 if (len < MHLEN) 700 MH_ALIGN(m, len); 701 m->m_len = len; 702 return (m); 703 } 704 705 /* 706 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 707 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 708 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 709 */ 710 int MCFail; 711 712 struct mbuf * 713 m_copym(struct mbuf *m, int off0, int len, int wait) 714 { 715 716 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */ 717 } 718 719 struct mbuf * 720 m_dup(struct mbuf *m, int off0, int len, int wait) 721 { 722 723 return m_copym0(m, off0, len, wait, 1); /* deep copy */ 724 } 725 726 static inline int 727 m_copylen(int len, int copylen) { 728 return len == M_COPYALL ? copylen : min(len, copylen); 729 } 730 731 static struct mbuf * 732 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep) 733 { 734 struct mbuf *n, **np; 735 int off = off0; 736 struct mbuf *top; 737 int copyhdr = 0; 738 739 if (off < 0 || (len != M_COPYALL && len < 0)) 740 panic("m_copym: off %d, len %d", off, len); 741 if (off == 0 && m->m_flags & M_PKTHDR) 742 copyhdr = 1; 743 while (off > 0) { 744 if (m == 0) 745 panic("m_copym: m == 0, off %d", off); 746 if (off < m->m_len) 747 break; 748 off -= m->m_len; 749 m = m->m_next; 750 } 751 np = ⊤ 752 top = 0; 753 while (len == M_COPYALL || len > 0) { 754 if (m == 0) { 755 if (len != M_COPYALL) 756 panic("m_copym: m == 0, len %d [!COPYALL]", 757 len); 758 break; 759 } 760 n = m_get(wait, m->m_type); 761 *np = n; 762 if (n == 0) 763 goto nospace; 764 MCLAIM(n, m->m_owner); 765 if (copyhdr) { 766 M_COPY_PKTHDR(n, m); 767 if (len == M_COPYALL) 768 n->m_pkthdr.len -= off0; 769 else 770 n->m_pkthdr.len = len; 771 copyhdr = 0; 772 } 773 n->m_len = m_copylen(len, m->m_len - off); 774 if (m->m_flags & M_EXT) { 775 if (!deep) { 776 n->m_data = m->m_data + off; 777 MCLADDREFERENCE(m, n); 778 } else { 779 /* 780 * we are unsure about the way m was allocated. 781 * copy into multiple MCLBYTES cluster mbufs. 782 * 783 * recompute m_len, it is no longer valid if MCLGET() 784 * fails to allocate a cluster. Then we try to split 785 * the source into normal sized mbufs. 786 */ 787 MCLGET(n, wait); 788 n->m_len = 0; 789 n->m_len = M_TRAILINGSPACE(n); 790 n->m_len = m_copylen(len, n->m_len); 791 n->m_len = min(n->m_len, m->m_len - off); 792 memcpy(mtod(n, void *), mtod(m, char *) + off, 793 (unsigned)n->m_len); 794 } 795 } else 796 memcpy(mtod(n, void *), mtod(m, char *) + off, 797 (unsigned)n->m_len); 798 if (len != M_COPYALL) 799 len -= n->m_len; 800 off += n->m_len; 801 #ifdef DIAGNOSTIC 802 if (off > m->m_len) 803 panic("m_copym0 overrun %d %d", off, m->m_len); 804 #endif 805 if (off == m->m_len) { 806 m = m->m_next; 807 off = 0; 808 } 809 np = &n->m_next; 810 } 811 if (top == 0) 812 MCFail++; 813 return (top); 814 nospace: 815 m_freem(top); 816 MCFail++; 817 return (NULL); 818 } 819 820 /* 821 * Copy an entire packet, including header (which must be present). 822 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 823 */ 824 struct mbuf * 825 m_copypacket(struct mbuf *m, int how) 826 { 827 struct mbuf *top, *n, *o; 828 829 n = m_get(how, m->m_type); 830 top = n; 831 if (!n) 832 goto nospace; 833 834 MCLAIM(n, m->m_owner); 835 M_COPY_PKTHDR(n, m); 836 n->m_len = m->m_len; 837 if (m->m_flags & M_EXT) { 838 n->m_data = m->m_data; 839 MCLADDREFERENCE(m, n); 840 } else { 841 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 842 } 843 844 m = m->m_next; 845 while (m) { 846 o = m_get(how, m->m_type); 847 if (!o) 848 goto nospace; 849 850 MCLAIM(o, m->m_owner); 851 n->m_next = o; 852 n = n->m_next; 853 854 n->m_len = m->m_len; 855 if (m->m_flags & M_EXT) { 856 n->m_data = m->m_data; 857 MCLADDREFERENCE(m, n); 858 } else { 859 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 860 } 861 862 m = m->m_next; 863 } 864 return top; 865 nospace: 866 m_freem(top); 867 MCFail++; 868 return NULL; 869 } 870 871 /* 872 * Copy data from an mbuf chain starting "off" bytes from the beginning, 873 * continuing for "len" bytes, into the indicated buffer. 874 */ 875 void 876 m_copydata(struct mbuf *m, int off, int len, void *vp) 877 { 878 unsigned count; 879 void * cp = vp; 880 struct mbuf *m0 = m; 881 int len0 = len; 882 int off0 = off; 883 void *vp0 = vp; 884 885 KASSERT(len != M_COPYALL); 886 if (off < 0 || len < 0) 887 panic("m_copydata: off %d, len %d", off, len); 888 while (off > 0) { 889 if (m == NULL) 890 panic("m_copydata(%p,%d,%d,%p): m=NULL, off=%d (%d)", 891 m0, len0, off0, vp0, off, off0 - off); 892 if (off < m->m_len) 893 break; 894 off -= m->m_len; 895 m = m->m_next; 896 } 897 while (len > 0) { 898 if (m == NULL) 899 panic("m_copydata(%p,%d,%d,%p): " 900 "m=NULL, off=%d (%d), len=%d (%d)", 901 m0, len0, off0, vp0, 902 off, off0 - off, len, len0 - len); 903 count = min(m->m_len - off, len); 904 memcpy(cp, mtod(m, char *) + off, count); 905 len -= count; 906 cp = (char *)cp + count; 907 off = 0; 908 m = m->m_next; 909 } 910 } 911 912 /* 913 * Concatenate mbuf chain n to m. 914 * n might be copied into m (when n->m_len is small), therefore data portion of 915 * n could be copied into an mbuf of different mbuf type. 916 * Any m_pkthdr is not updated. 917 */ 918 void 919 m_cat(struct mbuf *m, struct mbuf *n) 920 { 921 922 while (m->m_next) 923 m = m->m_next; 924 while (n) { 925 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { 926 /* just join the two chains */ 927 m->m_next = n; 928 return; 929 } 930 /* splat the data from one into the other */ 931 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 932 (u_int)n->m_len); 933 m->m_len += n->m_len; 934 n = m_free(n); 935 } 936 } 937 938 void 939 m_adj(struct mbuf *mp, int req_len) 940 { 941 int len = req_len; 942 struct mbuf *m; 943 int count; 944 945 if ((m = mp) == NULL) 946 return; 947 if (len >= 0) { 948 /* 949 * Trim from head. 950 */ 951 while (m != NULL && len > 0) { 952 if (m->m_len <= len) { 953 len -= m->m_len; 954 m->m_len = 0; 955 m = m->m_next; 956 } else { 957 m->m_len -= len; 958 m->m_data += len; 959 len = 0; 960 } 961 } 962 m = mp; 963 if (mp->m_flags & M_PKTHDR) 964 m->m_pkthdr.len -= (req_len - len); 965 } else { 966 /* 967 * Trim from tail. Scan the mbuf chain, 968 * calculating its length and finding the last mbuf. 969 * If the adjustment only affects this mbuf, then just 970 * adjust and return. Otherwise, rescan and truncate 971 * after the remaining size. 972 */ 973 len = -len; 974 count = 0; 975 for (;;) { 976 count += m->m_len; 977 if (m->m_next == (struct mbuf *)0) 978 break; 979 m = m->m_next; 980 } 981 if (m->m_len >= len) { 982 m->m_len -= len; 983 if (mp->m_flags & M_PKTHDR) 984 mp->m_pkthdr.len -= len; 985 return; 986 } 987 count -= len; 988 if (count < 0) 989 count = 0; 990 /* 991 * Correct length for chain is "count". 992 * Find the mbuf with last data, adjust its length, 993 * and toss data from remaining mbufs on chain. 994 */ 995 m = mp; 996 if (m->m_flags & M_PKTHDR) 997 m->m_pkthdr.len = count; 998 for (; m; m = m->m_next) { 999 if (m->m_len >= count) { 1000 m->m_len = count; 1001 break; 1002 } 1003 count -= m->m_len; 1004 } 1005 if (m) 1006 while (m->m_next) 1007 (m = m->m_next)->m_len = 0; 1008 } 1009 } 1010 1011 /* 1012 * m_ensure_contig: rearrange an mbuf chain that given length of bytes 1013 * would be contiguous and in the data area of an mbuf (therefore, mtod() 1014 * would work for a structure of given length). 1015 * 1016 * => On success, returns true and the resulting mbuf chain; false otherwise. 1017 * => The mbuf chain may change, but is always preserved valid. 1018 */ 1019 bool 1020 m_ensure_contig(struct mbuf **m0, int len) 1021 { 1022 struct mbuf *n = *m0, *m; 1023 size_t count, space; 1024 1025 KASSERT(len != M_COPYALL); 1026 /* 1027 * If first mbuf has no cluster, and has room for len bytes 1028 * without shifting current data, pullup into it, 1029 * otherwise allocate a new mbuf to prepend to the chain. 1030 */ 1031 if ((n->m_flags & M_EXT) == 0 && 1032 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1033 if (n->m_len >= len) { 1034 return true; 1035 } 1036 m = n; 1037 n = n->m_next; 1038 len -= m->m_len; 1039 } else { 1040 if (len > MHLEN) { 1041 return false; 1042 } 1043 m = m_get(M_DONTWAIT, n->m_type); 1044 if (m == NULL) { 1045 return false; 1046 } 1047 MCLAIM(m, n->m_owner); 1048 if (n->m_flags & M_PKTHDR) { 1049 M_MOVE_PKTHDR(m, n); 1050 } 1051 } 1052 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1053 do { 1054 count = MIN(MIN(MAX(len, max_protohdr), space), n->m_len); 1055 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1056 (unsigned)count); 1057 len -= count; 1058 m->m_len += count; 1059 n->m_len -= count; 1060 space -= count; 1061 if (n->m_len) 1062 n->m_data += count; 1063 else 1064 n = m_free(n); 1065 } while (len > 0 && n); 1066 1067 m->m_next = n; 1068 *m0 = m; 1069 1070 return len <= 0; 1071 } 1072 1073 /* 1074 * m_pullup: same as m_ensure_contig(), but destroys mbuf chain on error. 1075 */ 1076 int MPFail; 1077 1078 struct mbuf * 1079 m_pullup(struct mbuf *n, int len) 1080 { 1081 struct mbuf *m = n; 1082 1083 KASSERT(len != M_COPYALL); 1084 if (!m_ensure_contig(&m, len)) { 1085 KASSERT(m != NULL); 1086 m_freem(m); 1087 MPFail++; 1088 m = NULL; 1089 } 1090 return m; 1091 } 1092 1093 /* 1094 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1095 * the amount of empty space before the data in the new mbuf to be specified 1096 * (in the event that the caller expects to prepend later). 1097 */ 1098 int MSFail; 1099 1100 struct mbuf * 1101 m_copyup(struct mbuf *n, int len, int dstoff) 1102 { 1103 struct mbuf *m; 1104 int count, space; 1105 1106 KASSERT(len != M_COPYALL); 1107 if (len > (MHLEN - dstoff)) 1108 goto bad; 1109 m = m_get(M_DONTWAIT, n->m_type); 1110 if (m == NULL) 1111 goto bad; 1112 MCLAIM(m, n->m_owner); 1113 if (n->m_flags & M_PKTHDR) { 1114 M_MOVE_PKTHDR(m, n); 1115 } 1116 m->m_data += dstoff; 1117 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1118 do { 1119 count = min(min(max(len, max_protohdr), space), n->m_len); 1120 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1121 (unsigned)count); 1122 len -= count; 1123 m->m_len += count; 1124 n->m_len -= count; 1125 space -= count; 1126 if (n->m_len) 1127 n->m_data += count; 1128 else 1129 n = m_free(n); 1130 } while (len > 0 && n); 1131 if (len > 0) { 1132 (void) m_free(m); 1133 goto bad; 1134 } 1135 m->m_next = n; 1136 return (m); 1137 bad: 1138 m_freem(n); 1139 MSFail++; 1140 return (NULL); 1141 } 1142 1143 /* 1144 * Partition an mbuf chain in two pieces, returning the tail -- 1145 * all but the first len0 bytes. In case of failure, it returns NULL and 1146 * attempts to restore the chain to its original state. 1147 */ 1148 struct mbuf * 1149 m_split(struct mbuf *m0, int len0, int wait) 1150 { 1151 1152 return m_split0(m0, len0, wait, 1); 1153 } 1154 1155 static struct mbuf * 1156 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr) 1157 { 1158 struct mbuf *m, *n; 1159 unsigned len = len0, remain, len_save; 1160 1161 KASSERT(len0 != M_COPYALL); 1162 for (m = m0; m && len > m->m_len; m = m->m_next) 1163 len -= m->m_len; 1164 if (m == 0) 1165 return (NULL); 1166 remain = m->m_len - len; 1167 if (copyhdr && (m0->m_flags & M_PKTHDR)) { 1168 n = m_gethdr(wait, m0->m_type); 1169 if (n == NULL) 1170 return NULL; 1171 MCLAIM(n, m0->m_owner); 1172 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1173 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1174 len_save = m0->m_pkthdr.len; 1175 m0->m_pkthdr.len = len0; 1176 if (m->m_flags & M_EXT) 1177 goto extpacket; 1178 if (remain > MHLEN) { 1179 /* m can't be the lead packet */ 1180 MH_ALIGN(n, 0); 1181 n->m_len = 0; 1182 n->m_next = m_split(m, len, wait); 1183 if (n->m_next == 0) { 1184 (void) m_free(n); 1185 m0->m_pkthdr.len = len_save; 1186 return (NULL); 1187 } else 1188 return (n); 1189 } else 1190 MH_ALIGN(n, remain); 1191 } else if (remain == 0) { 1192 n = m->m_next; 1193 m->m_next = 0; 1194 return (n); 1195 } else { 1196 n = m_get(wait, m->m_type); 1197 if (n == 0) 1198 return (NULL); 1199 MCLAIM(n, m->m_owner); 1200 M_ALIGN(n, remain); 1201 } 1202 extpacket: 1203 if (m->m_flags & M_EXT) { 1204 n->m_data = m->m_data + len; 1205 MCLADDREFERENCE(m, n); 1206 } else { 1207 memcpy(mtod(n, void *), mtod(m, char *) + len, remain); 1208 } 1209 n->m_len = remain; 1210 m->m_len = len; 1211 n->m_next = m->m_next; 1212 m->m_next = 0; 1213 return (n); 1214 } 1215 /* 1216 * Routine to copy from device local memory into mbufs. 1217 */ 1218 struct mbuf * 1219 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, 1220 void (*copy)(const void *from, void *to, size_t len)) 1221 { 1222 struct mbuf *m; 1223 struct mbuf *top = 0, **mp = ⊤ 1224 int off = off0, len; 1225 char *cp; 1226 char *epkt; 1227 1228 cp = buf; 1229 epkt = cp + totlen; 1230 if (off) { 1231 /* 1232 * If 'off' is non-zero, packet is trailer-encapsulated, 1233 * so we have to skip the type and length fields. 1234 */ 1235 cp += off + 2 * sizeof(uint16_t); 1236 totlen -= 2 * sizeof(uint16_t); 1237 } 1238 m = m_gethdr(M_DONTWAIT, MT_DATA); 1239 if (m == NULL) 1240 return NULL; 1241 m->m_pkthdr.rcvif = ifp; 1242 m->m_pkthdr.len = totlen; 1243 m->m_len = MHLEN; 1244 1245 while (totlen > 0) { 1246 if (top) { 1247 m = m_get(M_DONTWAIT, MT_DATA); 1248 if (m == 0) { 1249 m_freem(top); 1250 return (NULL); 1251 } 1252 m->m_len = MLEN; 1253 } 1254 len = min(totlen, epkt - cp); 1255 if (len >= MINCLSIZE) { 1256 MCLGET(m, M_DONTWAIT); 1257 if ((m->m_flags & M_EXT) == 0) { 1258 m_free(m); 1259 m_freem(top); 1260 return (NULL); 1261 } 1262 m->m_len = len = min(len, MCLBYTES); 1263 } else { 1264 /* 1265 * Place initial small packet/header at end of mbuf. 1266 */ 1267 if (len < m->m_len) { 1268 if (top == 0 && len + max_linkhdr <= m->m_len) 1269 m->m_data += max_linkhdr; 1270 m->m_len = len; 1271 } else 1272 len = m->m_len; 1273 } 1274 if (copy) 1275 copy(cp, mtod(m, void *), (size_t)len); 1276 else 1277 memcpy(mtod(m, void *), cp, (size_t)len); 1278 cp += len; 1279 *mp = m; 1280 mp = &m->m_next; 1281 totlen -= len; 1282 if (cp == epkt) 1283 cp = buf; 1284 } 1285 return (top); 1286 } 1287 1288 /* 1289 * Copy data from a buffer back into the indicated mbuf chain, 1290 * starting "off" bytes from the beginning, extending the mbuf 1291 * chain if necessary. 1292 */ 1293 void 1294 m_copyback(struct mbuf *m0, int off, int len, const void *cp) 1295 { 1296 #if defined(DEBUG) 1297 struct mbuf *origm = m0; 1298 int error; 1299 #endif /* defined(DEBUG) */ 1300 1301 if (m0 == NULL) 1302 return; 1303 1304 #if defined(DEBUG) 1305 error = 1306 #endif /* defined(DEBUG) */ 1307 m_copyback0(&m0, off, len, cp, 1308 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT); 1309 1310 #if defined(DEBUG) 1311 if (error != 0 || (m0 != NULL && origm != m0)) 1312 panic("m_copyback"); 1313 #endif /* defined(DEBUG) */ 1314 } 1315 1316 struct mbuf * 1317 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how) 1318 { 1319 int error; 1320 1321 /* don't support chain expansion */ 1322 KASSERT(len != M_COPYALL); 1323 KDASSERT(off + len <= m_length(m0)); 1324 1325 error = m_copyback0(&m0, off, len, cp, 1326 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how); 1327 if (error) { 1328 /* 1329 * no way to recover from partial success. 1330 * just free the chain. 1331 */ 1332 m_freem(m0); 1333 return NULL; 1334 } 1335 return m0; 1336 } 1337 1338 /* 1339 * m_makewritable: ensure the specified range writable. 1340 */ 1341 int 1342 m_makewritable(struct mbuf **mp, int off, int len, int how) 1343 { 1344 int error; 1345 #if defined(DEBUG) 1346 int origlen = m_length(*mp); 1347 #endif /* defined(DEBUG) */ 1348 1349 error = m_copyback0(mp, off, len, NULL, 1350 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how); 1351 1352 #if defined(DEBUG) 1353 int reslen = 0; 1354 for (struct mbuf *n = *mp; n; n = n->m_next) 1355 reslen += n->m_len; 1356 if (origlen != reslen) 1357 panic("m_makewritable: length changed"); 1358 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len) 1359 panic("m_makewritable: inconsist"); 1360 #endif /* defined(DEBUG) */ 1361 1362 return error; 1363 } 1364 1365 /* 1366 * Copy the mbuf chain to a new mbuf chain that is as short as possible. 1367 * Return the new mbuf chain on success, NULL on failure. On success, 1368 * free the old mbuf chain. 1369 */ 1370 struct mbuf * 1371 m_defrag(struct mbuf *mold, int flags) 1372 { 1373 struct mbuf *m0, *mn, *n; 1374 size_t sz = mold->m_pkthdr.len; 1375 1376 #ifdef DIAGNOSTIC 1377 if ((mold->m_flags & M_PKTHDR) == 0) 1378 panic("m_defrag: not a mbuf chain header"); 1379 #endif 1380 1381 m0 = m_gethdr(flags, MT_DATA); 1382 if (m0 == NULL) 1383 return NULL; 1384 M_COPY_PKTHDR(m0, mold); 1385 mn = m0; 1386 1387 do { 1388 if (sz > MHLEN) { 1389 MCLGET(mn, M_DONTWAIT); 1390 if ((mn->m_flags & M_EXT) == 0) { 1391 m_freem(m0); 1392 return NULL; 1393 } 1394 } 1395 1396 mn->m_len = MIN(sz, MCLBYTES); 1397 1398 m_copydata(mold, mold->m_pkthdr.len - sz, mn->m_len, 1399 mtod(mn, void *)); 1400 1401 sz -= mn->m_len; 1402 1403 if (sz > 0) { 1404 /* need more mbufs */ 1405 n = m_get(M_NOWAIT, MT_DATA); 1406 if (n == NULL) { 1407 m_freem(m0); 1408 return NULL; 1409 } 1410 1411 mn->m_next = n; 1412 mn = n; 1413 } 1414 } while (sz > 0); 1415 1416 m_freem(mold); 1417 1418 return m0; 1419 } 1420 1421 int 1422 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags, 1423 int how) 1424 { 1425 int mlen; 1426 struct mbuf *m, *n; 1427 struct mbuf **mp; 1428 int totlen = 0; 1429 const char *cp = vp; 1430 1431 KASSERT(mp0 != NULL); 1432 KASSERT(*mp0 != NULL); 1433 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL); 1434 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL); 1435 1436 if (len == M_COPYALL) 1437 len = m_length(*mp0) - off; 1438 1439 /* 1440 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW, 1441 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive. 1442 */ 1443 1444 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0); 1445 1446 mp = mp0; 1447 m = *mp; 1448 while (off > (mlen = m->m_len)) { 1449 off -= mlen; 1450 totlen += mlen; 1451 if (m->m_next == NULL) { 1452 int tspace; 1453 extend: 1454 if ((flags & M_COPYBACK0_EXTEND) == 0) 1455 goto out; 1456 1457 /* 1458 * try to make some space at the end of "m". 1459 */ 1460 1461 mlen = m->m_len; 1462 if (off + len >= MINCLSIZE && 1463 (m->m_flags & M_EXT) == 0 && m->m_len == 0) { 1464 MCLGET(m, how); 1465 } 1466 tspace = M_TRAILINGSPACE(m); 1467 if (tspace > 0) { 1468 tspace = min(tspace, off + len); 1469 KASSERT(tspace > 0); 1470 memset(mtod(m, char *) + m->m_len, 0, 1471 min(off, tspace)); 1472 m->m_len += tspace; 1473 off += mlen; 1474 totlen -= mlen; 1475 continue; 1476 } 1477 1478 /* 1479 * need to allocate an mbuf. 1480 */ 1481 1482 if (off + len >= MINCLSIZE) { 1483 n = m_getcl(how, m->m_type, 0); 1484 } else { 1485 n = m_get(how, m->m_type); 1486 } 1487 if (n == NULL) { 1488 goto out; 1489 } 1490 n->m_len = min(M_TRAILINGSPACE(n), off + len); 1491 memset(mtod(n, char *), 0, min(n->m_len, off)); 1492 m->m_next = n; 1493 } 1494 mp = &m->m_next; 1495 m = m->m_next; 1496 } 1497 while (len > 0) { 1498 mlen = m->m_len - off; 1499 if (mlen != 0 && M_READONLY(m)) { 1500 char *datap; 1501 int eatlen; 1502 1503 /* 1504 * this mbuf is read-only. 1505 * allocate a new writable mbuf and try again. 1506 */ 1507 1508 #if defined(DIAGNOSTIC) 1509 if ((flags & M_COPYBACK0_COW) == 0) 1510 panic("m_copyback0: read-only"); 1511 #endif /* defined(DIAGNOSTIC) */ 1512 1513 /* 1514 * if we're going to write into the middle of 1515 * a mbuf, split it first. 1516 */ 1517 if (off > 0) { 1518 n = m_split0(m, off, how, 0); 1519 if (n == NULL) 1520 goto enobufs; 1521 m->m_next = n; 1522 mp = &m->m_next; 1523 m = n; 1524 off = 0; 1525 continue; 1526 } 1527 1528 /* 1529 * XXX TODO coalesce into the trailingspace of 1530 * the previous mbuf when possible. 1531 */ 1532 1533 /* 1534 * allocate a new mbuf. copy packet header if needed. 1535 */ 1536 n = m_get(how, m->m_type); 1537 if (n == NULL) 1538 goto enobufs; 1539 MCLAIM(n, m->m_owner); 1540 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) { 1541 M_MOVE_PKTHDR(n, m); 1542 n->m_len = MHLEN; 1543 } else { 1544 if (len >= MINCLSIZE) 1545 MCLGET(n, M_DONTWAIT); 1546 n->m_len = 1547 (n->m_flags & M_EXT) ? MCLBYTES : MLEN; 1548 } 1549 if (n->m_len > len) 1550 n->m_len = len; 1551 1552 /* 1553 * free the region which has been overwritten. 1554 * copying data from old mbufs if requested. 1555 */ 1556 if (flags & M_COPYBACK0_PRESERVE) 1557 datap = mtod(n, char *); 1558 else 1559 datap = NULL; 1560 eatlen = n->m_len; 1561 while (m != NULL && M_READONLY(m) && 1562 n->m_type == m->m_type && eatlen > 0) { 1563 mlen = min(eatlen, m->m_len); 1564 if (datap) { 1565 m_copydata(m, 0, mlen, datap); 1566 datap += mlen; 1567 } 1568 m->m_data += mlen; 1569 m->m_len -= mlen; 1570 eatlen -= mlen; 1571 if (m->m_len == 0) 1572 *mp = m = m_free(m); 1573 } 1574 if (eatlen > 0) 1575 n->m_len -= eatlen; 1576 n->m_next = m; 1577 *mp = m = n; 1578 continue; 1579 } 1580 mlen = min(mlen, len); 1581 if (flags & M_COPYBACK0_COPYBACK) { 1582 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen); 1583 cp += mlen; 1584 } 1585 len -= mlen; 1586 mlen += off; 1587 off = 0; 1588 totlen += mlen; 1589 if (len == 0) 1590 break; 1591 if (m->m_next == NULL) { 1592 goto extend; 1593 } 1594 mp = &m->m_next; 1595 m = m->m_next; 1596 } 1597 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) { 1598 KASSERT((flags & M_COPYBACK0_EXTEND) != 0); 1599 m->m_pkthdr.len = totlen; 1600 } 1601 1602 return 0; 1603 1604 enobufs: 1605 return ENOBUFS; 1606 } 1607 1608 void 1609 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1610 { 1611 1612 KASSERT((to->m_flags & M_EXT) == 0); 1613 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL); 1614 KASSERT((from->m_flags & M_PKTHDR) != 0); 1615 1616 to->m_pkthdr = from->m_pkthdr; 1617 to->m_flags = from->m_flags & M_COPYFLAGS; 1618 to->m_data = to->m_pktdat; 1619 1620 from->m_flags &= ~M_PKTHDR; 1621 } 1622 1623 /* 1624 * Apply function f to the data in an mbuf chain starting "off" bytes from the 1625 * beginning, continuing for "len" bytes. 1626 */ 1627 int 1628 m_apply(struct mbuf *m, int off, int len, 1629 int (*f)(void *, void *, unsigned int), void *arg) 1630 { 1631 unsigned int count; 1632 int rval; 1633 1634 KASSERT(len != M_COPYALL); 1635 KASSERT(len >= 0); 1636 KASSERT(off >= 0); 1637 1638 while (off > 0) { 1639 KASSERT(m != NULL); 1640 if (off < m->m_len) 1641 break; 1642 off -= m->m_len; 1643 m = m->m_next; 1644 } 1645 while (len > 0) { 1646 KASSERT(m != NULL); 1647 count = min(m->m_len - off, len); 1648 1649 rval = (*f)(arg, mtod(m, char *) + off, count); 1650 if (rval) 1651 return (rval); 1652 1653 len -= count; 1654 off = 0; 1655 m = m->m_next; 1656 } 1657 1658 return (0); 1659 } 1660 1661 /* 1662 * Return a pointer to mbuf/offset of location in mbuf chain. 1663 */ 1664 struct mbuf * 1665 m_getptr(struct mbuf *m, int loc, int *off) 1666 { 1667 1668 while (loc >= 0) { 1669 /* Normal end of search */ 1670 if (m->m_len > loc) { 1671 *off = loc; 1672 return (m); 1673 } else { 1674 loc -= m->m_len; 1675 1676 if (m->m_next == NULL) { 1677 if (loc == 0) { 1678 /* Point at the end of valid data */ 1679 *off = m->m_len; 1680 return (m); 1681 } else 1682 return (NULL); 1683 } else 1684 m = m->m_next; 1685 } 1686 } 1687 1688 return (NULL); 1689 } 1690 1691 /* 1692 * m_ext_free: release a reference to the mbuf external storage. 1693 * 1694 * => free the mbuf m itself as well. 1695 */ 1696 1697 void 1698 m_ext_free(struct mbuf *m) 1699 { 1700 bool embedded = MEXT_ISEMBEDDED(m); 1701 bool dofree = true; 1702 u_int refcnt; 1703 1704 KASSERT((m->m_flags & M_EXT) != 0); 1705 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref)); 1706 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0); 1707 KASSERT((m->m_flags & M_EXT_CLUSTER) == 1708 (m->m_ext_ref->m_flags & M_EXT_CLUSTER)); 1709 1710 if (__predict_true(m->m_ext.ext_refcnt == 1)) { 1711 refcnt = m->m_ext.ext_refcnt = 0; 1712 } else { 1713 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt); 1714 } 1715 if (refcnt > 0) { 1716 if (embedded) { 1717 /* 1718 * other mbuf's m_ext_ref still points to us. 1719 */ 1720 dofree = false; 1721 } else { 1722 m->m_ext_ref = m; 1723 } 1724 } else { 1725 /* 1726 * dropping the last reference 1727 */ 1728 if (!embedded) { 1729 m->m_ext.ext_refcnt++; /* XXX */ 1730 m_ext_free(m->m_ext_ref); 1731 m->m_ext_ref = m; 1732 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) { 1733 pool_cache_put_paddr((struct pool_cache *) 1734 m->m_ext.ext_arg, 1735 m->m_ext.ext_buf, m->m_ext.ext_paddr); 1736 } else if (m->m_ext.ext_free) { 1737 (*m->m_ext.ext_free)(m, 1738 m->m_ext.ext_buf, m->m_ext.ext_size, 1739 m->m_ext.ext_arg); 1740 /* 1741 * 'm' is already freed by the ext_free callback. 1742 */ 1743 dofree = false; 1744 } else { 1745 free(m->m_ext.ext_buf, m->m_ext.ext_type); 1746 } 1747 } 1748 if (dofree) { 1749 m->m_type = MT_FREE; 1750 pool_cache_put(mb_cache, m); 1751 } 1752 } 1753 1754 #if defined(DDB) 1755 void 1756 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...)) 1757 { 1758 char ch; 1759 bool opt_c = false; 1760 char buf[512]; 1761 1762 while ((ch = *(modif++)) != '\0') { 1763 switch (ch) { 1764 case 'c': 1765 opt_c = true; 1766 break; 1767 } 1768 } 1769 1770 nextchain: 1771 (*pr)("MBUF %p\n", m); 1772 snprintb(buf, sizeof(buf), M_FLAGS_BITS, (u_int)m->m_flags); 1773 (*pr)(" data=%p, len=%d, type=%d, flags=%s\n", 1774 m->m_data, m->m_len, m->m_type, buf); 1775 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next, 1776 m->m_nextpkt); 1777 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n", 1778 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m), 1779 (int)M_READONLY(m)); 1780 if ((m->m_flags & M_PKTHDR) != 0) { 1781 snprintb(buf, sizeof(buf), M_CSUM_BITS, m->m_pkthdr.csum_flags); 1782 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%" 1783 PRIx32 ", segsz=%u\n", 1784 m->m_pkthdr.len, m->m_pkthdr.rcvif, 1785 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz); 1786 } 1787 if ((m->m_flags & M_EXT)) { 1788 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, " 1789 "ext_free=%p, ext_arg=%p\n", 1790 m->m_ext.ext_refcnt, 1791 m->m_ext.ext_buf, m->m_ext.ext_size, 1792 m->m_ext.ext_free, m->m_ext.ext_arg); 1793 } 1794 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) { 1795 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf; 1796 vaddr_t eva = sva + m->m_ext.ext_size; 1797 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT; 1798 int i; 1799 1800 (*pr)(" pages:"); 1801 for (i = 0; i < n; i ++) { 1802 (*pr)(" %p", m->m_ext.ext_pgs[i]); 1803 } 1804 (*pr)("\n"); 1805 } 1806 1807 if (opt_c) { 1808 m = m->m_next; 1809 if (m != NULL) { 1810 goto nextchain; 1811 } 1812 } 1813 } 1814 #endif /* defined(DDB) */ 1815 1816 void 1817 mbstat_type_add(int type, int diff) 1818 { 1819 struct mbstat_cpu *mb; 1820 int s; 1821 1822 s = splvm(); 1823 mb = percpu_getref(mbstat_percpu); 1824 mb->m_mtypes[type] += diff; 1825 percpu_putref(mbstat_percpu); 1826 splx(s); 1827 } 1828 1829 #if defined(MBUFTRACE) 1830 void 1831 mowner_attach(struct mowner *mo) 1832 { 1833 1834 KASSERT(mo->mo_counters == NULL); 1835 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter)); 1836 1837 /* XXX lock */ 1838 LIST_INSERT_HEAD(&mowners, mo, mo_link); 1839 } 1840 1841 void 1842 mowner_detach(struct mowner *mo) 1843 { 1844 1845 KASSERT(mo->mo_counters != NULL); 1846 1847 /* XXX lock */ 1848 LIST_REMOVE(mo, mo_link); 1849 1850 percpu_free(mo->mo_counters, sizeof(struct mowner_counter)); 1851 mo->mo_counters = NULL; 1852 } 1853 1854 void 1855 mowner_init(struct mbuf *m, int type) 1856 { 1857 struct mowner_counter *mc; 1858 struct mowner *mo; 1859 int s; 1860 1861 m->m_owner = mo = &unknown_mowners[type]; 1862 s = splvm(); 1863 mc = percpu_getref(mo->mo_counters); 1864 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1865 percpu_putref(mo->mo_counters); 1866 splx(s); 1867 } 1868 1869 void 1870 mowner_ref(struct mbuf *m, int flags) 1871 { 1872 struct mowner *mo = m->m_owner; 1873 struct mowner_counter *mc; 1874 int s; 1875 1876 s = splvm(); 1877 mc = percpu_getref(mo->mo_counters); 1878 if ((flags & M_EXT) != 0) 1879 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1880 if ((flags & M_CLUSTER) != 0) 1881 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1882 percpu_putref(mo->mo_counters); 1883 splx(s); 1884 } 1885 1886 void 1887 mowner_revoke(struct mbuf *m, bool all, int flags) 1888 { 1889 struct mowner *mo = m->m_owner; 1890 struct mowner_counter *mc; 1891 int s; 1892 1893 s = splvm(); 1894 mc = percpu_getref(mo->mo_counters); 1895 if ((flags & M_EXT) != 0) 1896 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++; 1897 if ((flags & M_CLUSTER) != 0) 1898 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++; 1899 if (all) 1900 mc->mc_counter[MOWNER_COUNTER_RELEASES]++; 1901 percpu_putref(mo->mo_counters); 1902 splx(s); 1903 if (all) 1904 m->m_owner = &revoked_mowner; 1905 } 1906 1907 static void 1908 mowner_claim(struct mbuf *m, struct mowner *mo) 1909 { 1910 struct mowner_counter *mc; 1911 int flags = m->m_flags; 1912 int s; 1913 1914 s = splvm(); 1915 mc = percpu_getref(mo->mo_counters); 1916 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1917 if ((flags & M_EXT) != 0) 1918 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1919 if ((flags & M_CLUSTER) != 0) 1920 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1921 percpu_putref(mo->mo_counters); 1922 splx(s); 1923 m->m_owner = mo; 1924 } 1925 1926 void 1927 m_claim(struct mbuf *m, struct mowner *mo) 1928 { 1929 1930 if (m->m_owner == mo || mo == NULL) 1931 return; 1932 1933 mowner_revoke(m, true, m->m_flags); 1934 mowner_claim(m, mo); 1935 } 1936 #endif /* defined(MBUFTRACE) */ 1937