1 /* $NetBSD: uipc_mbuf.c,v 1.165 2016/05/12 02:24:16 ozaki-r 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 1.165 2016/05/12 02:24:16 ozaki-r 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 /* XXX we cannot use psref in H/W interrupt */ 560 if (!cpu_intr_p()) { 561 int bound = curlwp->l_pflag & LP_BOUND; 562 curlwp->l_pflag |= LP_BOUND; 563 IFNET_READER_FOREACH(ifp) { 564 struct psref psref; 565 566 psref_acquire(&psref, &ifp->if_psref, 567 ifnet_psref_class); 568 569 if (ifp->if_drain) 570 (*ifp->if_drain)(ifp); 571 572 psref_release(&psref, &ifp->if_psref, 573 ifnet_psref_class); 574 } 575 curlwp->l_pflag ^= bound ^ LP_BOUND; 576 } 577 splx(s); 578 mbstat.m_drain++; 579 KERNEL_UNLOCK_ONE(NULL); 580 } 581 582 /* 583 * Space allocation routines. 584 * These are also available as macros 585 * for critical paths. 586 */ 587 struct mbuf * 588 m_get(int nowait, int type) 589 { 590 struct mbuf *m; 591 592 KASSERT(type != MT_FREE); 593 594 m = pool_cache_get(mb_cache, 595 nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0); 596 if (m == NULL) 597 return NULL; 598 599 mbstat_type_add(type, 1); 600 601 m_hdr_init(m, type, NULL, m->m_dat, 0); 602 603 return m; 604 } 605 606 struct mbuf * 607 m_gethdr(int nowait, int type) 608 { 609 struct mbuf *m; 610 611 m = m_get(nowait, type); 612 if (m == NULL) 613 return NULL; 614 615 m_pkthdr_init(m); 616 617 return m; 618 } 619 620 struct mbuf * 621 m_getclr(int nowait, int type) 622 { 623 struct mbuf *m; 624 625 m = m_get(nowait, type); 626 if (m == 0) 627 return (NULL); 628 memset(mtod(m, void *), 0, MLEN); 629 return (m); 630 } 631 632 void 633 m_clget(struct mbuf *m, int nowait) 634 { 635 636 MCLGET(m, nowait); 637 } 638 639 struct mbuf * 640 m_free(struct mbuf *m) 641 { 642 struct mbuf *n; 643 644 MFREE(m, n); 645 return (n); 646 } 647 648 void 649 m_freem(struct mbuf *m) 650 { 651 struct mbuf *n; 652 653 if (m == NULL) 654 return; 655 do { 656 MFREE(m, n); 657 m = n; 658 } while (m); 659 } 660 661 #ifdef MBUFTRACE 662 /* 663 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain. 664 */ 665 void 666 m_claimm(struct mbuf *m, struct mowner *mo) 667 { 668 669 for (; m != NULL; m = m->m_next) 670 MCLAIM(m, mo); 671 } 672 #endif 673 674 /* 675 * Mbuffer utility routines. 676 */ 677 678 /* 679 * Lesser-used path for M_PREPEND: 680 * allocate new mbuf to prepend to chain, 681 * copy junk along. 682 */ 683 struct mbuf * 684 m_prepend(struct mbuf *m, int len, int how) 685 { 686 struct mbuf *mn; 687 688 KASSERT(len != M_COPYALL); 689 mn = m_get(how, m->m_type); 690 if (mn == NULL) { 691 m_freem(m); 692 return (NULL); 693 } 694 if (m->m_flags & M_PKTHDR) { 695 M_MOVE_PKTHDR(mn, m); 696 } else { 697 MCLAIM(mn, m->m_owner); 698 } 699 mn->m_next = m; 700 m = mn; 701 if (len < MHLEN) 702 MH_ALIGN(m, len); 703 m->m_len = len; 704 return (m); 705 } 706 707 /* 708 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 709 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 710 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 711 */ 712 int MCFail; 713 714 struct mbuf * 715 m_copym(struct mbuf *m, int off0, int len, int wait) 716 { 717 718 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */ 719 } 720 721 struct mbuf * 722 m_dup(struct mbuf *m, int off0, int len, int wait) 723 { 724 725 return m_copym0(m, off0, len, wait, 1); /* deep copy */ 726 } 727 728 static inline int 729 m_copylen(int len, int copylen) { 730 return len == M_COPYALL ? copylen : min(len, copylen); 731 } 732 733 static struct mbuf * 734 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep) 735 { 736 struct mbuf *n, **np; 737 int off = off0; 738 struct mbuf *top; 739 int copyhdr = 0; 740 741 if (off < 0 || (len != M_COPYALL && len < 0)) 742 panic("m_copym: off %d, len %d", off, len); 743 if (off == 0 && m->m_flags & M_PKTHDR) 744 copyhdr = 1; 745 while (off > 0) { 746 if (m == 0) 747 panic("m_copym: m == 0, off %d", off); 748 if (off < m->m_len) 749 break; 750 off -= m->m_len; 751 m = m->m_next; 752 } 753 np = ⊤ 754 top = 0; 755 while (len == M_COPYALL || len > 0) { 756 if (m == 0) { 757 if (len != M_COPYALL) 758 panic("m_copym: m == 0, len %d [!COPYALL]", 759 len); 760 break; 761 } 762 n = m_get(wait, m->m_type); 763 *np = n; 764 if (n == 0) 765 goto nospace; 766 MCLAIM(n, m->m_owner); 767 if (copyhdr) { 768 M_COPY_PKTHDR(n, m); 769 if (len == M_COPYALL) 770 n->m_pkthdr.len -= off0; 771 else 772 n->m_pkthdr.len = len; 773 copyhdr = 0; 774 } 775 n->m_len = m_copylen(len, m->m_len - off); 776 if (m->m_flags & M_EXT) { 777 if (!deep) { 778 n->m_data = m->m_data + off; 779 MCLADDREFERENCE(m, n); 780 } else { 781 /* 782 * we are unsure about the way m was allocated. 783 * copy into multiple MCLBYTES cluster mbufs. 784 * 785 * recompute m_len, it is no longer valid if MCLGET() 786 * fails to allocate a cluster. Then we try to split 787 * the source into normal sized mbufs. 788 */ 789 MCLGET(n, wait); 790 n->m_len = 0; 791 n->m_len = M_TRAILINGSPACE(n); 792 n->m_len = m_copylen(len, n->m_len); 793 n->m_len = min(n->m_len, m->m_len - off); 794 memcpy(mtod(n, void *), mtod(m, char *) + off, 795 (unsigned)n->m_len); 796 } 797 } else 798 memcpy(mtod(n, void *), mtod(m, char *) + off, 799 (unsigned)n->m_len); 800 if (len != M_COPYALL) 801 len -= n->m_len; 802 off += n->m_len; 803 #ifdef DIAGNOSTIC 804 if (off > m->m_len) 805 panic("m_copym0 overrun %d %d", off, m->m_len); 806 #endif 807 if (off == m->m_len) { 808 m = m->m_next; 809 off = 0; 810 } 811 np = &n->m_next; 812 } 813 if (top == 0) 814 MCFail++; 815 return (top); 816 nospace: 817 m_freem(top); 818 MCFail++; 819 return (NULL); 820 } 821 822 /* 823 * Copy an entire packet, including header (which must be present). 824 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 825 */ 826 struct mbuf * 827 m_copypacket(struct mbuf *m, int how) 828 { 829 struct mbuf *top, *n, *o; 830 831 n = m_get(how, m->m_type); 832 top = n; 833 if (!n) 834 goto nospace; 835 836 MCLAIM(n, m->m_owner); 837 M_COPY_PKTHDR(n, m); 838 n->m_len = m->m_len; 839 if (m->m_flags & M_EXT) { 840 n->m_data = m->m_data; 841 MCLADDREFERENCE(m, n); 842 } else { 843 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 844 } 845 846 m = m->m_next; 847 while (m) { 848 o = m_get(how, m->m_type); 849 if (!o) 850 goto nospace; 851 852 MCLAIM(o, m->m_owner); 853 n->m_next = o; 854 n = n->m_next; 855 856 n->m_len = m->m_len; 857 if (m->m_flags & M_EXT) { 858 n->m_data = m->m_data; 859 MCLADDREFERENCE(m, n); 860 } else { 861 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 862 } 863 864 m = m->m_next; 865 } 866 return top; 867 nospace: 868 m_freem(top); 869 MCFail++; 870 return NULL; 871 } 872 873 /* 874 * Copy data from an mbuf chain starting "off" bytes from the beginning, 875 * continuing for "len" bytes, into the indicated buffer. 876 */ 877 void 878 m_copydata(struct mbuf *m, int off, int len, void *vp) 879 { 880 unsigned count; 881 void * cp = vp; 882 struct mbuf *m0 = m; 883 int len0 = len; 884 int off0 = off; 885 void *vp0 = vp; 886 887 KASSERT(len != M_COPYALL); 888 if (off < 0 || len < 0) 889 panic("m_copydata: off %d, len %d", off, len); 890 while (off > 0) { 891 if (m == NULL) 892 panic("m_copydata(%p,%d,%d,%p): m=NULL, off=%d (%d)", 893 m0, len0, off0, vp0, off, off0 - off); 894 if (off < m->m_len) 895 break; 896 off -= m->m_len; 897 m = m->m_next; 898 } 899 while (len > 0) { 900 if (m == NULL) 901 panic("m_copydata(%p,%d,%d,%p): " 902 "m=NULL, off=%d (%d), len=%d (%d)", 903 m0, len0, off0, vp0, 904 off, off0 - off, len, len0 - len); 905 count = min(m->m_len - off, len); 906 memcpy(cp, mtod(m, char *) + off, count); 907 len -= count; 908 cp = (char *)cp + count; 909 off = 0; 910 m = m->m_next; 911 } 912 } 913 914 /* 915 * Concatenate mbuf chain n to m. 916 * n might be copied into m (when n->m_len is small), therefore data portion of 917 * n could be copied into an mbuf of different mbuf type. 918 * Any m_pkthdr is not updated. 919 */ 920 void 921 m_cat(struct mbuf *m, struct mbuf *n) 922 { 923 924 while (m->m_next) 925 m = m->m_next; 926 while (n) { 927 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { 928 /* just join the two chains */ 929 m->m_next = n; 930 return; 931 } 932 /* splat the data from one into the other */ 933 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 934 (u_int)n->m_len); 935 m->m_len += n->m_len; 936 n = m_free(n); 937 } 938 } 939 940 void 941 m_adj(struct mbuf *mp, int req_len) 942 { 943 int len = req_len; 944 struct mbuf *m; 945 int count; 946 947 if ((m = mp) == NULL) 948 return; 949 if (len >= 0) { 950 /* 951 * Trim from head. 952 */ 953 while (m != NULL && len > 0) { 954 if (m->m_len <= len) { 955 len -= m->m_len; 956 m->m_len = 0; 957 m = m->m_next; 958 } else { 959 m->m_len -= len; 960 m->m_data += len; 961 len = 0; 962 } 963 } 964 m = mp; 965 if (mp->m_flags & M_PKTHDR) 966 m->m_pkthdr.len -= (req_len - len); 967 } else { 968 /* 969 * Trim from tail. Scan the mbuf chain, 970 * calculating its length and finding the last mbuf. 971 * If the adjustment only affects this mbuf, then just 972 * adjust and return. Otherwise, rescan and truncate 973 * after the remaining size. 974 */ 975 len = -len; 976 count = 0; 977 for (;;) { 978 count += m->m_len; 979 if (m->m_next == (struct mbuf *)0) 980 break; 981 m = m->m_next; 982 } 983 if (m->m_len >= len) { 984 m->m_len -= len; 985 if (mp->m_flags & M_PKTHDR) 986 mp->m_pkthdr.len -= len; 987 return; 988 } 989 count -= len; 990 if (count < 0) 991 count = 0; 992 /* 993 * Correct length for chain is "count". 994 * Find the mbuf with last data, adjust its length, 995 * and toss data from remaining mbufs on chain. 996 */ 997 m = mp; 998 if (m->m_flags & M_PKTHDR) 999 m->m_pkthdr.len = count; 1000 for (; m; m = m->m_next) { 1001 if (m->m_len >= count) { 1002 m->m_len = count; 1003 break; 1004 } 1005 count -= m->m_len; 1006 } 1007 if (m) 1008 while (m->m_next) 1009 (m = m->m_next)->m_len = 0; 1010 } 1011 } 1012 1013 /* 1014 * m_ensure_contig: rearrange an mbuf chain that given length of bytes 1015 * would be contiguous and in the data area of an mbuf (therefore, mtod() 1016 * would work for a structure of given length). 1017 * 1018 * => On success, returns true and the resulting mbuf chain; false otherwise. 1019 * => The mbuf chain may change, but is always preserved valid. 1020 */ 1021 bool 1022 m_ensure_contig(struct mbuf **m0, int len) 1023 { 1024 struct mbuf *n = *m0, *m; 1025 size_t count, space; 1026 1027 KASSERT(len != M_COPYALL); 1028 /* 1029 * If first mbuf has no cluster, and has room for len bytes 1030 * without shifting current data, pullup into it, 1031 * otherwise allocate a new mbuf to prepend to the chain. 1032 */ 1033 if ((n->m_flags & M_EXT) == 0 && 1034 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 1035 if (n->m_len >= len) { 1036 return true; 1037 } 1038 m = n; 1039 n = n->m_next; 1040 len -= m->m_len; 1041 } else { 1042 if (len > MHLEN) { 1043 return false; 1044 } 1045 m = m_get(M_DONTWAIT, n->m_type); 1046 if (m == NULL) { 1047 return false; 1048 } 1049 MCLAIM(m, n->m_owner); 1050 if (n->m_flags & M_PKTHDR) { 1051 M_MOVE_PKTHDR(m, n); 1052 } 1053 } 1054 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1055 do { 1056 count = MIN(MIN(MAX(len, max_protohdr), space), n->m_len); 1057 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1058 (unsigned)count); 1059 len -= count; 1060 m->m_len += count; 1061 n->m_len -= count; 1062 space -= count; 1063 if (n->m_len) 1064 n->m_data += count; 1065 else 1066 n = m_free(n); 1067 } while (len > 0 && n); 1068 1069 m->m_next = n; 1070 *m0 = m; 1071 1072 return len <= 0; 1073 } 1074 1075 /* 1076 * m_pullup: same as m_ensure_contig(), but destroys mbuf chain on error. 1077 */ 1078 int MPFail; 1079 1080 struct mbuf * 1081 m_pullup(struct mbuf *n, int len) 1082 { 1083 struct mbuf *m = n; 1084 1085 KASSERT(len != M_COPYALL); 1086 if (!m_ensure_contig(&m, len)) { 1087 KASSERT(m != NULL); 1088 m_freem(m); 1089 MPFail++; 1090 m = NULL; 1091 } 1092 return m; 1093 } 1094 1095 /* 1096 * Like m_pullup(), except a new mbuf is always allocated, and we allow 1097 * the amount of empty space before the data in the new mbuf to be specified 1098 * (in the event that the caller expects to prepend later). 1099 */ 1100 int MSFail; 1101 1102 struct mbuf * 1103 m_copyup(struct mbuf *n, int len, int dstoff) 1104 { 1105 struct mbuf *m; 1106 int count, space; 1107 1108 KASSERT(len != M_COPYALL); 1109 if (len > (MHLEN - dstoff)) 1110 goto bad; 1111 m = m_get(M_DONTWAIT, n->m_type); 1112 if (m == NULL) 1113 goto bad; 1114 MCLAIM(m, n->m_owner); 1115 if (n->m_flags & M_PKTHDR) { 1116 M_MOVE_PKTHDR(m, n); 1117 } 1118 m->m_data += dstoff; 1119 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1120 do { 1121 count = min(min(max(len, max_protohdr), space), n->m_len); 1122 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 1123 (unsigned)count); 1124 len -= count; 1125 m->m_len += count; 1126 n->m_len -= count; 1127 space -= count; 1128 if (n->m_len) 1129 n->m_data += count; 1130 else 1131 n = m_free(n); 1132 } while (len > 0 && n); 1133 if (len > 0) { 1134 (void) m_free(m); 1135 goto bad; 1136 } 1137 m->m_next = n; 1138 return (m); 1139 bad: 1140 m_freem(n); 1141 MSFail++; 1142 return (NULL); 1143 } 1144 1145 /* 1146 * Partition an mbuf chain in two pieces, returning the tail -- 1147 * all but the first len0 bytes. In case of failure, it returns NULL and 1148 * attempts to restore the chain to its original state. 1149 */ 1150 struct mbuf * 1151 m_split(struct mbuf *m0, int len0, int wait) 1152 { 1153 1154 return m_split0(m0, len0, wait, 1); 1155 } 1156 1157 static struct mbuf * 1158 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr) 1159 { 1160 struct mbuf *m, *n; 1161 unsigned len = len0, remain, len_save; 1162 1163 KASSERT(len0 != M_COPYALL); 1164 for (m = m0; m && len > m->m_len; m = m->m_next) 1165 len -= m->m_len; 1166 if (m == 0) 1167 return (NULL); 1168 remain = m->m_len - len; 1169 if (copyhdr && (m0->m_flags & M_PKTHDR)) { 1170 n = m_gethdr(wait, m0->m_type); 1171 if (n == NULL) 1172 return NULL; 1173 MCLAIM(n, m0->m_owner); 1174 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1175 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1176 len_save = m0->m_pkthdr.len; 1177 m0->m_pkthdr.len = len0; 1178 if (m->m_flags & M_EXT) 1179 goto extpacket; 1180 if (remain > MHLEN) { 1181 /* m can't be the lead packet */ 1182 MH_ALIGN(n, 0); 1183 n->m_len = 0; 1184 n->m_next = m_split(m, len, wait); 1185 if (n->m_next == 0) { 1186 (void) m_free(n); 1187 m0->m_pkthdr.len = len_save; 1188 return (NULL); 1189 } else 1190 return (n); 1191 } else 1192 MH_ALIGN(n, remain); 1193 } else if (remain == 0) { 1194 n = m->m_next; 1195 m->m_next = 0; 1196 return (n); 1197 } else { 1198 n = m_get(wait, m->m_type); 1199 if (n == 0) 1200 return (NULL); 1201 MCLAIM(n, m->m_owner); 1202 M_ALIGN(n, remain); 1203 } 1204 extpacket: 1205 if (m->m_flags & M_EXT) { 1206 n->m_data = m->m_data + len; 1207 MCLADDREFERENCE(m, n); 1208 } else { 1209 memcpy(mtod(n, void *), mtod(m, char *) + len, remain); 1210 } 1211 n->m_len = remain; 1212 m->m_len = len; 1213 n->m_next = m->m_next; 1214 m->m_next = 0; 1215 return (n); 1216 } 1217 /* 1218 * Routine to copy from device local memory into mbufs. 1219 */ 1220 struct mbuf * 1221 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, 1222 void (*copy)(const void *from, void *to, size_t len)) 1223 { 1224 struct mbuf *m; 1225 struct mbuf *top = 0, **mp = ⊤ 1226 int off = off0, len; 1227 char *cp; 1228 char *epkt; 1229 1230 cp = buf; 1231 epkt = cp + totlen; 1232 if (off) { 1233 /* 1234 * If 'off' is non-zero, packet is trailer-encapsulated, 1235 * so we have to skip the type and length fields. 1236 */ 1237 cp += off + 2 * sizeof(uint16_t); 1238 totlen -= 2 * sizeof(uint16_t); 1239 } 1240 m = m_gethdr(M_DONTWAIT, MT_DATA); 1241 if (m == NULL) 1242 return NULL; 1243 m->m_pkthdr.rcvif = ifp; 1244 m->m_pkthdr.len = totlen; 1245 m->m_len = MHLEN; 1246 1247 while (totlen > 0) { 1248 if (top) { 1249 m = m_get(M_DONTWAIT, MT_DATA); 1250 if (m == 0) { 1251 m_freem(top); 1252 return (NULL); 1253 } 1254 m->m_len = MLEN; 1255 } 1256 len = min(totlen, epkt - cp); 1257 if (len >= MINCLSIZE) { 1258 MCLGET(m, M_DONTWAIT); 1259 if ((m->m_flags & M_EXT) == 0) { 1260 m_free(m); 1261 m_freem(top); 1262 return (NULL); 1263 } 1264 m->m_len = len = min(len, MCLBYTES); 1265 } else { 1266 /* 1267 * Place initial small packet/header at end of mbuf. 1268 */ 1269 if (len < m->m_len) { 1270 if (top == 0 && len + max_linkhdr <= m->m_len) 1271 m->m_data += max_linkhdr; 1272 m->m_len = len; 1273 } else 1274 len = m->m_len; 1275 } 1276 if (copy) 1277 copy(cp, mtod(m, void *), (size_t)len); 1278 else 1279 memcpy(mtod(m, void *), cp, (size_t)len); 1280 cp += len; 1281 *mp = m; 1282 mp = &m->m_next; 1283 totlen -= len; 1284 if (cp == epkt) 1285 cp = buf; 1286 } 1287 return (top); 1288 } 1289 1290 /* 1291 * Copy data from a buffer back into the indicated mbuf chain, 1292 * starting "off" bytes from the beginning, extending the mbuf 1293 * chain if necessary. 1294 */ 1295 void 1296 m_copyback(struct mbuf *m0, int off, int len, const void *cp) 1297 { 1298 #if defined(DEBUG) 1299 struct mbuf *origm = m0; 1300 int error; 1301 #endif /* defined(DEBUG) */ 1302 1303 if (m0 == NULL) 1304 return; 1305 1306 #if defined(DEBUG) 1307 error = 1308 #endif /* defined(DEBUG) */ 1309 m_copyback0(&m0, off, len, cp, 1310 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT); 1311 1312 #if defined(DEBUG) 1313 if (error != 0 || (m0 != NULL && origm != m0)) 1314 panic("m_copyback"); 1315 #endif /* defined(DEBUG) */ 1316 } 1317 1318 struct mbuf * 1319 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how) 1320 { 1321 int error; 1322 1323 /* don't support chain expansion */ 1324 KASSERT(len != M_COPYALL); 1325 KDASSERT(off + len <= m_length(m0)); 1326 1327 error = m_copyback0(&m0, off, len, cp, 1328 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how); 1329 if (error) { 1330 /* 1331 * no way to recover from partial success. 1332 * just free the chain. 1333 */ 1334 m_freem(m0); 1335 return NULL; 1336 } 1337 return m0; 1338 } 1339 1340 /* 1341 * m_makewritable: ensure the specified range writable. 1342 */ 1343 int 1344 m_makewritable(struct mbuf **mp, int off, int len, int how) 1345 { 1346 int error; 1347 #if defined(DEBUG) 1348 int origlen = m_length(*mp); 1349 #endif /* defined(DEBUG) */ 1350 1351 error = m_copyback0(mp, off, len, NULL, 1352 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how); 1353 1354 #if defined(DEBUG) 1355 int reslen = 0; 1356 for (struct mbuf *n = *mp; n; n = n->m_next) 1357 reslen += n->m_len; 1358 if (origlen != reslen) 1359 panic("m_makewritable: length changed"); 1360 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len) 1361 panic("m_makewritable: inconsist"); 1362 #endif /* defined(DEBUG) */ 1363 1364 return error; 1365 } 1366 1367 /* 1368 * Copy the mbuf chain to a new mbuf chain that is as short as possible. 1369 * Return the new mbuf chain on success, NULL on failure. On success, 1370 * free the old mbuf chain. 1371 */ 1372 struct mbuf * 1373 m_defrag(struct mbuf *mold, int flags) 1374 { 1375 struct mbuf *m0, *mn, *n; 1376 size_t sz = mold->m_pkthdr.len; 1377 1378 #ifdef DIAGNOSTIC 1379 if ((mold->m_flags & M_PKTHDR) == 0) 1380 panic("m_defrag: not a mbuf chain header"); 1381 #endif 1382 1383 m0 = m_gethdr(flags, MT_DATA); 1384 if (m0 == NULL) 1385 return NULL; 1386 M_COPY_PKTHDR(m0, mold); 1387 mn = m0; 1388 1389 do { 1390 if (sz > MHLEN) { 1391 MCLGET(mn, M_DONTWAIT); 1392 if ((mn->m_flags & M_EXT) == 0) { 1393 m_freem(m0); 1394 return NULL; 1395 } 1396 } 1397 1398 mn->m_len = MIN(sz, MCLBYTES); 1399 1400 m_copydata(mold, mold->m_pkthdr.len - sz, mn->m_len, 1401 mtod(mn, void *)); 1402 1403 sz -= mn->m_len; 1404 1405 if (sz > 0) { 1406 /* need more mbufs */ 1407 n = m_get(M_NOWAIT, MT_DATA); 1408 if (n == NULL) { 1409 m_freem(m0); 1410 return NULL; 1411 } 1412 1413 mn->m_next = n; 1414 mn = n; 1415 } 1416 } while (sz > 0); 1417 1418 m_freem(mold); 1419 1420 return m0; 1421 } 1422 1423 int 1424 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags, 1425 int how) 1426 { 1427 int mlen; 1428 struct mbuf *m, *n; 1429 struct mbuf **mp; 1430 int totlen = 0; 1431 const char *cp = vp; 1432 1433 KASSERT(mp0 != NULL); 1434 KASSERT(*mp0 != NULL); 1435 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL); 1436 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL); 1437 1438 if (len == M_COPYALL) 1439 len = m_length(*mp0) - off; 1440 1441 /* 1442 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW, 1443 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive. 1444 */ 1445 1446 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0); 1447 1448 mp = mp0; 1449 m = *mp; 1450 while (off > (mlen = m->m_len)) { 1451 off -= mlen; 1452 totlen += mlen; 1453 if (m->m_next == NULL) { 1454 int tspace; 1455 extend: 1456 if ((flags & M_COPYBACK0_EXTEND) == 0) 1457 goto out; 1458 1459 /* 1460 * try to make some space at the end of "m". 1461 */ 1462 1463 mlen = m->m_len; 1464 if (off + len >= MINCLSIZE && 1465 (m->m_flags & M_EXT) == 0 && m->m_len == 0) { 1466 MCLGET(m, how); 1467 } 1468 tspace = M_TRAILINGSPACE(m); 1469 if (tspace > 0) { 1470 tspace = min(tspace, off + len); 1471 KASSERT(tspace > 0); 1472 memset(mtod(m, char *) + m->m_len, 0, 1473 min(off, tspace)); 1474 m->m_len += tspace; 1475 off += mlen; 1476 totlen -= mlen; 1477 continue; 1478 } 1479 1480 /* 1481 * need to allocate an mbuf. 1482 */ 1483 1484 if (off + len >= MINCLSIZE) { 1485 n = m_getcl(how, m->m_type, 0); 1486 } else { 1487 n = m_get(how, m->m_type); 1488 } 1489 if (n == NULL) { 1490 goto out; 1491 } 1492 n->m_len = min(M_TRAILINGSPACE(n), off + len); 1493 memset(mtod(n, char *), 0, min(n->m_len, off)); 1494 m->m_next = n; 1495 } 1496 mp = &m->m_next; 1497 m = m->m_next; 1498 } 1499 while (len > 0) { 1500 mlen = m->m_len - off; 1501 if (mlen != 0 && M_READONLY(m)) { 1502 char *datap; 1503 int eatlen; 1504 1505 /* 1506 * this mbuf is read-only. 1507 * allocate a new writable mbuf and try again. 1508 */ 1509 1510 #if defined(DIAGNOSTIC) 1511 if ((flags & M_COPYBACK0_COW) == 0) 1512 panic("m_copyback0: read-only"); 1513 #endif /* defined(DIAGNOSTIC) */ 1514 1515 /* 1516 * if we're going to write into the middle of 1517 * a mbuf, split it first. 1518 */ 1519 if (off > 0) { 1520 n = m_split0(m, off, how, 0); 1521 if (n == NULL) 1522 goto enobufs; 1523 m->m_next = n; 1524 mp = &m->m_next; 1525 m = n; 1526 off = 0; 1527 continue; 1528 } 1529 1530 /* 1531 * XXX TODO coalesce into the trailingspace of 1532 * the previous mbuf when possible. 1533 */ 1534 1535 /* 1536 * allocate a new mbuf. copy packet header if needed. 1537 */ 1538 n = m_get(how, m->m_type); 1539 if (n == NULL) 1540 goto enobufs; 1541 MCLAIM(n, m->m_owner); 1542 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) { 1543 M_MOVE_PKTHDR(n, m); 1544 n->m_len = MHLEN; 1545 } else { 1546 if (len >= MINCLSIZE) 1547 MCLGET(n, M_DONTWAIT); 1548 n->m_len = 1549 (n->m_flags & M_EXT) ? MCLBYTES : MLEN; 1550 } 1551 if (n->m_len > len) 1552 n->m_len = len; 1553 1554 /* 1555 * free the region which has been overwritten. 1556 * copying data from old mbufs if requested. 1557 */ 1558 if (flags & M_COPYBACK0_PRESERVE) 1559 datap = mtod(n, char *); 1560 else 1561 datap = NULL; 1562 eatlen = n->m_len; 1563 while (m != NULL && M_READONLY(m) && 1564 n->m_type == m->m_type && eatlen > 0) { 1565 mlen = min(eatlen, m->m_len); 1566 if (datap) { 1567 m_copydata(m, 0, mlen, datap); 1568 datap += mlen; 1569 } 1570 m->m_data += mlen; 1571 m->m_len -= mlen; 1572 eatlen -= mlen; 1573 if (m->m_len == 0) 1574 *mp = m = m_free(m); 1575 } 1576 if (eatlen > 0) 1577 n->m_len -= eatlen; 1578 n->m_next = m; 1579 *mp = m = n; 1580 continue; 1581 } 1582 mlen = min(mlen, len); 1583 if (flags & M_COPYBACK0_COPYBACK) { 1584 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen); 1585 cp += mlen; 1586 } 1587 len -= mlen; 1588 mlen += off; 1589 off = 0; 1590 totlen += mlen; 1591 if (len == 0) 1592 break; 1593 if (m->m_next == NULL) { 1594 goto extend; 1595 } 1596 mp = &m->m_next; 1597 m = m->m_next; 1598 } 1599 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) { 1600 KASSERT((flags & M_COPYBACK0_EXTEND) != 0); 1601 m->m_pkthdr.len = totlen; 1602 } 1603 1604 return 0; 1605 1606 enobufs: 1607 return ENOBUFS; 1608 } 1609 1610 void 1611 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1612 { 1613 1614 KASSERT((to->m_flags & M_EXT) == 0); 1615 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL); 1616 KASSERT((from->m_flags & M_PKTHDR) != 0); 1617 1618 to->m_pkthdr = from->m_pkthdr; 1619 to->m_flags = from->m_flags & M_COPYFLAGS; 1620 to->m_data = to->m_pktdat; 1621 1622 from->m_flags &= ~M_PKTHDR; 1623 } 1624 1625 /* 1626 * Apply function f to the data in an mbuf chain starting "off" bytes from the 1627 * beginning, continuing for "len" bytes. 1628 */ 1629 int 1630 m_apply(struct mbuf *m, int off, int len, 1631 int (*f)(void *, void *, unsigned int), void *arg) 1632 { 1633 unsigned int count; 1634 int rval; 1635 1636 KASSERT(len != M_COPYALL); 1637 KASSERT(len >= 0); 1638 KASSERT(off >= 0); 1639 1640 while (off > 0) { 1641 KASSERT(m != NULL); 1642 if (off < m->m_len) 1643 break; 1644 off -= m->m_len; 1645 m = m->m_next; 1646 } 1647 while (len > 0) { 1648 KASSERT(m != NULL); 1649 count = min(m->m_len - off, len); 1650 1651 rval = (*f)(arg, mtod(m, char *) + off, count); 1652 if (rval) 1653 return (rval); 1654 1655 len -= count; 1656 off = 0; 1657 m = m->m_next; 1658 } 1659 1660 return (0); 1661 } 1662 1663 /* 1664 * Return a pointer to mbuf/offset of location in mbuf chain. 1665 */ 1666 struct mbuf * 1667 m_getptr(struct mbuf *m, int loc, int *off) 1668 { 1669 1670 while (loc >= 0) { 1671 /* Normal end of search */ 1672 if (m->m_len > loc) { 1673 *off = loc; 1674 return (m); 1675 } else { 1676 loc -= m->m_len; 1677 1678 if (m->m_next == NULL) { 1679 if (loc == 0) { 1680 /* Point at the end of valid data */ 1681 *off = m->m_len; 1682 return (m); 1683 } else 1684 return (NULL); 1685 } else 1686 m = m->m_next; 1687 } 1688 } 1689 1690 return (NULL); 1691 } 1692 1693 /* 1694 * m_ext_free: release a reference to the mbuf external storage. 1695 * 1696 * => free the mbuf m itself as well. 1697 */ 1698 1699 void 1700 m_ext_free(struct mbuf *m) 1701 { 1702 bool embedded = MEXT_ISEMBEDDED(m); 1703 bool dofree = true; 1704 u_int refcnt; 1705 1706 KASSERT((m->m_flags & M_EXT) != 0); 1707 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref)); 1708 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0); 1709 KASSERT((m->m_flags & M_EXT_CLUSTER) == 1710 (m->m_ext_ref->m_flags & M_EXT_CLUSTER)); 1711 1712 if (__predict_true(m->m_ext.ext_refcnt == 1)) { 1713 refcnt = m->m_ext.ext_refcnt = 0; 1714 } else { 1715 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt); 1716 } 1717 if (refcnt > 0) { 1718 if (embedded) { 1719 /* 1720 * other mbuf's m_ext_ref still points to us. 1721 */ 1722 dofree = false; 1723 } else { 1724 m->m_ext_ref = m; 1725 } 1726 } else { 1727 /* 1728 * dropping the last reference 1729 */ 1730 if (!embedded) { 1731 m->m_ext.ext_refcnt++; /* XXX */ 1732 m_ext_free(m->m_ext_ref); 1733 m->m_ext_ref = m; 1734 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) { 1735 pool_cache_put_paddr((struct pool_cache *) 1736 m->m_ext.ext_arg, 1737 m->m_ext.ext_buf, m->m_ext.ext_paddr); 1738 } else if (m->m_ext.ext_free) { 1739 (*m->m_ext.ext_free)(m, 1740 m->m_ext.ext_buf, m->m_ext.ext_size, 1741 m->m_ext.ext_arg); 1742 /* 1743 * 'm' is already freed by the ext_free callback. 1744 */ 1745 dofree = false; 1746 } else { 1747 free(m->m_ext.ext_buf, m->m_ext.ext_type); 1748 } 1749 } 1750 if (dofree) { 1751 m->m_type = MT_FREE; 1752 pool_cache_put(mb_cache, m); 1753 } 1754 } 1755 1756 #if defined(DDB) 1757 void 1758 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...)) 1759 { 1760 char ch; 1761 bool opt_c = false; 1762 char buf[512]; 1763 1764 while ((ch = *(modif++)) != '\0') { 1765 switch (ch) { 1766 case 'c': 1767 opt_c = true; 1768 break; 1769 } 1770 } 1771 1772 nextchain: 1773 (*pr)("MBUF %p\n", m); 1774 snprintb(buf, sizeof(buf), M_FLAGS_BITS, (u_int)m->m_flags); 1775 (*pr)(" data=%p, len=%d, type=%d, flags=%s\n", 1776 m->m_data, m->m_len, m->m_type, buf); 1777 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next, 1778 m->m_nextpkt); 1779 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n", 1780 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m), 1781 (int)M_READONLY(m)); 1782 if ((m->m_flags & M_PKTHDR) != 0) { 1783 snprintb(buf, sizeof(buf), M_CSUM_BITS, m->m_pkthdr.csum_flags); 1784 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%" 1785 PRIx32 ", segsz=%u\n", 1786 m->m_pkthdr.len, m->m_pkthdr.rcvif, 1787 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz); 1788 } 1789 if ((m->m_flags & M_EXT)) { 1790 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, " 1791 "ext_free=%p, ext_arg=%p\n", 1792 m->m_ext.ext_refcnt, 1793 m->m_ext.ext_buf, m->m_ext.ext_size, 1794 m->m_ext.ext_free, m->m_ext.ext_arg); 1795 } 1796 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) { 1797 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf; 1798 vaddr_t eva = sva + m->m_ext.ext_size; 1799 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT; 1800 int i; 1801 1802 (*pr)(" pages:"); 1803 for (i = 0; i < n; i ++) { 1804 (*pr)(" %p", m->m_ext.ext_pgs[i]); 1805 } 1806 (*pr)("\n"); 1807 } 1808 1809 if (opt_c) { 1810 m = m->m_next; 1811 if (m != NULL) { 1812 goto nextchain; 1813 } 1814 } 1815 } 1816 #endif /* defined(DDB) */ 1817 1818 void 1819 mbstat_type_add(int type, int diff) 1820 { 1821 struct mbstat_cpu *mb; 1822 int s; 1823 1824 s = splvm(); 1825 mb = percpu_getref(mbstat_percpu); 1826 mb->m_mtypes[type] += diff; 1827 percpu_putref(mbstat_percpu); 1828 splx(s); 1829 } 1830 1831 #if defined(MBUFTRACE) 1832 void 1833 mowner_attach(struct mowner *mo) 1834 { 1835 1836 KASSERT(mo->mo_counters == NULL); 1837 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter)); 1838 1839 /* XXX lock */ 1840 LIST_INSERT_HEAD(&mowners, mo, mo_link); 1841 } 1842 1843 void 1844 mowner_detach(struct mowner *mo) 1845 { 1846 1847 KASSERT(mo->mo_counters != NULL); 1848 1849 /* XXX lock */ 1850 LIST_REMOVE(mo, mo_link); 1851 1852 percpu_free(mo->mo_counters, sizeof(struct mowner_counter)); 1853 mo->mo_counters = NULL; 1854 } 1855 1856 void 1857 mowner_init(struct mbuf *m, int type) 1858 { 1859 struct mowner_counter *mc; 1860 struct mowner *mo; 1861 int s; 1862 1863 m->m_owner = mo = &unknown_mowners[type]; 1864 s = splvm(); 1865 mc = percpu_getref(mo->mo_counters); 1866 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1867 percpu_putref(mo->mo_counters); 1868 splx(s); 1869 } 1870 1871 void 1872 mowner_ref(struct mbuf *m, int flags) 1873 { 1874 struct mowner *mo = m->m_owner; 1875 struct mowner_counter *mc; 1876 int s; 1877 1878 s = splvm(); 1879 mc = percpu_getref(mo->mo_counters); 1880 if ((flags & M_EXT) != 0) 1881 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1882 if ((flags & M_CLUSTER) != 0) 1883 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1884 percpu_putref(mo->mo_counters); 1885 splx(s); 1886 } 1887 1888 void 1889 mowner_revoke(struct mbuf *m, bool all, int flags) 1890 { 1891 struct mowner *mo = m->m_owner; 1892 struct mowner_counter *mc; 1893 int s; 1894 1895 s = splvm(); 1896 mc = percpu_getref(mo->mo_counters); 1897 if ((flags & M_EXT) != 0) 1898 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++; 1899 if ((flags & M_CLUSTER) != 0) 1900 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++; 1901 if (all) 1902 mc->mc_counter[MOWNER_COUNTER_RELEASES]++; 1903 percpu_putref(mo->mo_counters); 1904 splx(s); 1905 if (all) 1906 m->m_owner = &revoked_mowner; 1907 } 1908 1909 static void 1910 mowner_claim(struct mbuf *m, struct mowner *mo) 1911 { 1912 struct mowner_counter *mc; 1913 int flags = m->m_flags; 1914 int s; 1915 1916 s = splvm(); 1917 mc = percpu_getref(mo->mo_counters); 1918 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1919 if ((flags & M_EXT) != 0) 1920 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1921 if ((flags & M_CLUSTER) != 0) 1922 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1923 percpu_putref(mo->mo_counters); 1924 splx(s); 1925 m->m_owner = mo; 1926 } 1927 1928 void 1929 m_claim(struct mbuf *m, struct mowner *mo) 1930 { 1931 1932 if (m->m_owner == mo || mo == NULL) 1933 return; 1934 1935 mowner_revoke(m, true, m->m_flags); 1936 mowner_claim(m, mo); 1937 } 1938 #endif /* defined(MBUFTRACE) */ 1939