1 /* $NetBSD: uipc_mbuf.c,v 1.126 2008/04/09 05:11:20 thorpej 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1991, 1993 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. Neither the name of the University nor the names of its contributors 53 * may be used to endorse or promote products derived from this software 54 * without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 66 * SUCH DAMAGE. 67 * 68 * @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95 69 */ 70 71 #include <sys/cdefs.h> 72 __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.126 2008/04/09 05:11:20 thorpej Exp $"); 73 74 #include "opt_mbuftrace.h" 75 #include "opt_ddb.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/atomic.h> 80 #include <sys/cpu.h> 81 #include <sys/proc.h> 82 #include <sys/malloc.h> 83 #define MBTYPES 84 #include <sys/mbuf.h> 85 #include <sys/kernel.h> 86 #include <sys/syslog.h> 87 #include <sys/domain.h> 88 #include <sys/protosw.h> 89 #include <sys/percpu.h> 90 #include <sys/pool.h> 91 #include <sys/socket.h> 92 #include <sys/sysctl.h> 93 94 #include <net/if.h> 95 96 #include <uvm/uvm.h> 97 98 pool_cache_t mb_cache; /* mbuf cache */ 99 pool_cache_t mcl_cache; /* mbuf cluster cache */ 100 101 struct mbstat mbstat; 102 int max_linkhdr; 103 int max_protohdr; 104 int max_hdr; 105 int max_datalen; 106 107 static int mb_ctor(void *, void *, int); 108 109 static void *mclpool_alloc(struct pool *, int); 110 static void mclpool_release(struct pool *, void *); 111 112 static struct pool_allocator mclpool_allocator = { 113 .pa_alloc = mclpool_alloc, 114 .pa_free = mclpool_release, 115 }; 116 117 static struct mbuf *m_copym0(struct mbuf *, int, int, int, int); 118 static struct mbuf *m_split0(struct mbuf *, int, int, int); 119 static int m_copyback0(struct mbuf **, int, int, const void *, int, int); 120 121 /* flags for m_copyback0 */ 122 #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */ 123 #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */ 124 #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */ 125 #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */ 126 127 static const char mclpool_warnmsg[] = 128 "WARNING: mclpool limit reached; increase NMBCLUSTERS"; 129 130 MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf"); 131 132 static percpu_t *mbstat_percpu; 133 134 #ifdef MBUFTRACE 135 struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners); 136 struct mowner unknown_mowners[] = { 137 MOWNER_INIT("unknown", "free"), 138 MOWNER_INIT("unknown", "data"), 139 MOWNER_INIT("unknown", "header"), 140 MOWNER_INIT("unknown", "soname"), 141 MOWNER_INIT("unknown", "soopts"), 142 MOWNER_INIT("unknown", "ftable"), 143 MOWNER_INIT("unknown", "control"), 144 MOWNER_INIT("unknown", "oobdata"), 145 }; 146 struct mowner revoked_mowner = MOWNER_INIT("revoked", ""); 147 #endif 148 149 #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m)) 150 151 #define MCLADDREFERENCE(o, n) \ 152 do { \ 153 KASSERT(((o)->m_flags & M_EXT) != 0); \ 154 KASSERT(((n)->m_flags & M_EXT) == 0); \ 155 KASSERT((o)->m_ext.ext_refcnt >= 1); \ 156 (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \ 157 atomic_inc_uint(&(o)->m_ext.ext_refcnt); \ 158 (n)->m_ext_ref = (o)->m_ext_ref; \ 159 mowner_ref((n), (n)->m_flags); \ 160 MCLREFDEBUGN((n), __FILE__, __LINE__); \ 161 } while (/* CONSTCOND */ 0) 162 163 /* 164 * Initialize the mbuf allocator. 165 */ 166 void 167 mbinit(void) 168 { 169 170 KASSERT(sizeof(struct _m_ext) <= MHLEN); 171 KASSERT(sizeof(struct mbuf) == MSIZE); 172 173 mclpool_allocator.pa_backingmap = mb_map; 174 175 mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl", 176 NULL, IPL_VM, mb_ctor, NULL, NULL); 177 KASSERT(mb_cache != NULL); 178 179 mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl", 180 &mclpool_allocator, IPL_VM, NULL, NULL, NULL); 181 KASSERT(mcl_cache != NULL); 182 183 pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL); 184 pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL); 185 186 /* 187 * Set the hard limit on the mclpool to the number of 188 * mbuf clusters the kernel is to support. Log the limit 189 * reached message max once a minute. 190 */ 191 pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60); 192 193 mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu)); 194 195 /* 196 * Set a low water mark for both mbufs and clusters. This should 197 * help ensure that they can be allocated in a memory starvation 198 * situation. This is important for e.g. diskless systems which 199 * must allocate mbufs in order for the pagedaemon to clean pages. 200 */ 201 pool_cache_setlowat(mb_cache, mblowat); 202 pool_cache_setlowat(mcl_cache, mcllowat); 203 204 #ifdef MBUFTRACE 205 { 206 /* 207 * Attach the unknown mowners. 208 */ 209 int i; 210 MOWNER_ATTACH(&revoked_mowner); 211 for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]); 212 i-- > 0; ) 213 MOWNER_ATTACH(&unknown_mowners[i]); 214 } 215 #endif 216 } 217 218 /* 219 * sysctl helper routine for the kern.mbuf subtree. nmbclusters may 220 * or may not be writable, and mblowat and mcllowat need range 221 * checking and pool tweaking after being reset. 222 */ 223 static int 224 sysctl_kern_mbuf(SYSCTLFN_ARGS) 225 { 226 int error, newval; 227 struct sysctlnode node; 228 229 node = *rnode; 230 node.sysctl_data = &newval; 231 switch (rnode->sysctl_num) { 232 case MBUF_NMBCLUSTERS: 233 if (mb_map != NULL) { 234 node.sysctl_flags &= ~CTLFLAG_READWRITE; 235 node.sysctl_flags |= CTLFLAG_READONLY; 236 } 237 /* FALLTHROUGH */ 238 case MBUF_MBLOWAT: 239 case MBUF_MCLLOWAT: 240 newval = *(int*)rnode->sysctl_data; 241 break; 242 default: 243 return (EOPNOTSUPP); 244 } 245 246 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 247 if (error || newp == NULL) 248 return (error); 249 if (newval < 0) 250 return (EINVAL); 251 252 switch (node.sysctl_num) { 253 case MBUF_NMBCLUSTERS: 254 if (newval < nmbclusters) 255 return (EINVAL); 256 nmbclusters = newval; 257 pool_cache_sethardlimit(mcl_cache, nmbclusters, 258 mclpool_warnmsg, 60); 259 break; 260 case MBUF_MBLOWAT: 261 mblowat = newval; 262 pool_cache_setlowat(mb_cache, mblowat); 263 break; 264 case MBUF_MCLLOWAT: 265 mcllowat = newval; 266 pool_cache_setlowat(mcl_cache, mcllowat); 267 break; 268 } 269 270 return (0); 271 } 272 273 #ifdef MBUFTRACE 274 static void 275 mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 276 { 277 struct mowner_counter *mc = v1; 278 struct mowner_user *mo_user = v2; 279 int i; 280 281 for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) { 282 mo_user->mo_counter[i] += mc->mc_counter[i]; 283 } 284 } 285 286 static void 287 mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user) 288 { 289 290 memset(mo_user, 0, sizeof(*mo_user)); 291 KASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name)); 292 KASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr)); 293 memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name)); 294 memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr)); 295 percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user); 296 } 297 298 static int 299 sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS) 300 { 301 struct mowner *mo; 302 size_t len = 0; 303 int error = 0; 304 305 if (namelen != 0) 306 return (EINVAL); 307 if (newp != NULL) 308 return (EPERM); 309 310 LIST_FOREACH(mo, &mowners, mo_link) { 311 struct mowner_user mo_user; 312 313 mowner_convert_to_user(mo, &mo_user); 314 315 if (oldp != NULL) { 316 if (*oldlenp - len < sizeof(mo_user)) { 317 error = ENOMEM; 318 break; 319 } 320 error = copyout(&mo_user, (char *)oldp + len, 321 sizeof(mo_user)); 322 if (error) 323 break; 324 } 325 len += sizeof(mo_user); 326 } 327 328 if (error == 0) 329 *oldlenp = len; 330 331 return (error); 332 } 333 #endif /* MBUFTRACE */ 334 335 static void 336 mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) 337 { 338 struct mbstat_cpu *mbsc = v1; 339 struct mbstat *mbs = v2; 340 int i; 341 342 for (i = 0; i < __arraycount(mbs->m_mtypes); i++) { 343 mbs->m_mtypes[i] += mbsc->m_mtypes[i]; 344 } 345 } 346 347 static void 348 mbstat_convert_to_user(struct mbstat *mbs) 349 { 350 351 memset(mbs, 0, sizeof(*mbs)); 352 mbs->m_drain = mbstat.m_drain; 353 percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs); 354 } 355 356 static int 357 sysctl_kern_mbuf_stats(SYSCTLFN_ARGS) 358 { 359 struct sysctlnode node; 360 struct mbstat mbs; 361 362 mbstat_convert_to_user(&mbs); 363 node = *rnode; 364 node.sysctl_data = &mbs; 365 node.sysctl_size = sizeof(mbs); 366 return sysctl_lookup(SYSCTLFN_CALL(&node)); 367 } 368 369 SYSCTL_SETUP(sysctl_kern_mbuf_setup, "sysctl kern.mbuf subtree setup") 370 { 371 372 sysctl_createv(clog, 0, NULL, NULL, 373 CTLFLAG_PERMANENT, 374 CTLTYPE_NODE, "kern", NULL, 375 NULL, 0, NULL, 0, 376 CTL_KERN, CTL_EOL); 377 sysctl_createv(clog, 0, NULL, NULL, 378 CTLFLAG_PERMANENT, 379 CTLTYPE_NODE, "mbuf", 380 SYSCTL_DESCR("mbuf control variables"), 381 NULL, 0, NULL, 0, 382 CTL_KERN, KERN_MBUF, CTL_EOL); 383 384 sysctl_createv(clog, 0, NULL, NULL, 385 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 386 CTLTYPE_INT, "msize", 387 SYSCTL_DESCR("mbuf base size"), 388 NULL, msize, NULL, 0, 389 CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL); 390 sysctl_createv(clog, 0, NULL, NULL, 391 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 392 CTLTYPE_INT, "mclbytes", 393 SYSCTL_DESCR("mbuf cluster size"), 394 NULL, mclbytes, NULL, 0, 395 CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL); 396 sysctl_createv(clog, 0, NULL, NULL, 397 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 398 CTLTYPE_INT, "nmbclusters", 399 SYSCTL_DESCR("Limit on the number of mbuf clusters"), 400 sysctl_kern_mbuf, 0, &nmbclusters, 0, 401 CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL); 402 sysctl_createv(clog, 0, NULL, NULL, 403 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 404 CTLTYPE_INT, "mblowat", 405 SYSCTL_DESCR("mbuf low water mark"), 406 sysctl_kern_mbuf, 0, &mblowat, 0, 407 CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL); 408 sysctl_createv(clog, 0, NULL, NULL, 409 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 410 CTLTYPE_INT, "mcllowat", 411 SYSCTL_DESCR("mbuf cluster low water mark"), 412 sysctl_kern_mbuf, 0, &mcllowat, 0, 413 CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL); 414 sysctl_createv(clog, 0, NULL, NULL, 415 CTLFLAG_PERMANENT, 416 CTLTYPE_STRUCT, "stats", 417 SYSCTL_DESCR("mbuf allocation statistics"), 418 sysctl_kern_mbuf_stats, 0, NULL, 0, 419 CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL); 420 #ifdef MBUFTRACE 421 sysctl_createv(clog, 0, NULL, NULL, 422 CTLFLAG_PERMANENT, 423 CTLTYPE_STRUCT, "mowners", 424 SYSCTL_DESCR("Information about mbuf owners"), 425 sysctl_kern_mbuf_mowners, 0, NULL, 0, 426 CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL); 427 #endif /* MBUFTRACE */ 428 } 429 430 static void * 431 mclpool_alloc(struct pool *pp, int flags) 432 { 433 bool waitok = (flags & PR_WAITOK) ? true : false; 434 435 return ((void *)uvm_km_alloc_poolpage(mb_map, waitok)); 436 } 437 438 static void 439 mclpool_release(struct pool *pp, void *v) 440 { 441 442 uvm_km_free_poolpage(mb_map, (vaddr_t)v); 443 } 444 445 /*ARGSUSED*/ 446 static int 447 mb_ctor(void *arg, void *object, int flags) 448 { 449 struct mbuf *m = object; 450 451 #ifdef POOL_VTOPHYS 452 m->m_paddr = POOL_VTOPHYS(m); 453 #else 454 m->m_paddr = M_PADDR_INVALID; 455 #endif 456 return (0); 457 } 458 459 void 460 m_reclaim(void *arg, int flags) 461 { 462 struct domain *dp; 463 const struct protosw *pr; 464 struct ifnet *ifp; 465 int s; 466 467 KERNEL_LOCK(1, NULL); 468 s = splvm(); 469 DOMAIN_FOREACH(dp) { 470 for (pr = dp->dom_protosw; 471 pr < dp->dom_protoswNPROTOSW; pr++) 472 if (pr->pr_drain) 473 (*pr->pr_drain)(); 474 } 475 IFNET_FOREACH(ifp) { 476 if (ifp->if_drain) 477 (*ifp->if_drain)(ifp); 478 } 479 splx(s); 480 mbstat.m_drain++; 481 KERNEL_UNLOCK_ONE(NULL); 482 } 483 484 /* 485 * Space allocation routines. 486 * These are also available as macros 487 * for critical paths. 488 */ 489 struct mbuf * 490 m_get(int nowait, int type) 491 { 492 struct mbuf *m; 493 494 m = pool_cache_get(mb_cache, 495 nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0); 496 if (m == NULL) 497 return NULL; 498 499 mbstat_type_add(type, 1); 500 mowner_init(m, type); 501 m->m_ext_ref = m; 502 m->m_type = type; 503 m->m_next = NULL; 504 m->m_nextpkt = NULL; 505 m->m_data = m->m_dat; 506 m->m_flags = 0; 507 508 return m; 509 } 510 511 struct mbuf * 512 m_gethdr(int nowait, int type) 513 { 514 struct mbuf *m; 515 516 m = m_get(nowait, type); 517 if (m == NULL) 518 return NULL; 519 520 m->m_data = m->m_pktdat; 521 m->m_flags = M_PKTHDR; 522 m->m_pkthdr.rcvif = NULL; 523 m->m_pkthdr.csum_flags = 0; 524 m->m_pkthdr.csum_data = 0; 525 SLIST_INIT(&m->m_pkthdr.tags); 526 527 return m; 528 } 529 530 struct mbuf * 531 m_getclr(int nowait, int type) 532 { 533 struct mbuf *m; 534 535 MGET(m, nowait, type); 536 if (m == 0) 537 return (NULL); 538 memset(mtod(m, void *), 0, MLEN); 539 return (m); 540 } 541 542 void 543 m_clget(struct mbuf *m, int nowait) 544 { 545 546 MCLGET(m, nowait); 547 } 548 549 struct mbuf * 550 m_free(struct mbuf *m) 551 { 552 struct mbuf *n; 553 554 MFREE(m, n); 555 return (n); 556 } 557 558 void 559 m_freem(struct mbuf *m) 560 { 561 struct mbuf *n; 562 563 if (m == NULL) 564 return; 565 do { 566 MFREE(m, n); 567 m = n; 568 } while (m); 569 } 570 571 #ifdef MBUFTRACE 572 /* 573 * Walk a chain of mbufs, claiming ownership of each mbuf in the chain. 574 */ 575 void 576 m_claimm(struct mbuf *m, struct mowner *mo) 577 { 578 579 for (; m != NULL; m = m->m_next) 580 MCLAIM(m, mo); 581 } 582 #endif 583 584 /* 585 * Mbuffer utility routines. 586 */ 587 588 /* 589 * Lesser-used path for M_PREPEND: 590 * allocate new mbuf to prepend to chain, 591 * copy junk along. 592 */ 593 struct mbuf * 594 m_prepend(struct mbuf *m, int len, int how) 595 { 596 struct mbuf *mn; 597 598 MGET(mn, how, m->m_type); 599 if (mn == (struct mbuf *)NULL) { 600 m_freem(m); 601 return ((struct mbuf *)NULL); 602 } 603 if (m->m_flags & M_PKTHDR) { 604 M_MOVE_PKTHDR(mn, m); 605 } else { 606 MCLAIM(mn, m->m_owner); 607 } 608 mn->m_next = m; 609 m = mn; 610 if (len < MHLEN) 611 MH_ALIGN(m, len); 612 m->m_len = len; 613 return (m); 614 } 615 616 /* 617 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 618 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 619 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 620 */ 621 int MCFail; 622 623 struct mbuf * 624 m_copym(struct mbuf *m, int off0, int len, int wait) 625 { 626 627 return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */ 628 } 629 630 struct mbuf * 631 m_dup(struct mbuf *m, int off0, int len, int wait) 632 { 633 634 return m_copym0(m, off0, len, wait, 1); /* deep copy */ 635 } 636 637 static struct mbuf * 638 m_copym0(struct mbuf *m, int off0, int len, int wait, int deep) 639 { 640 struct mbuf *n, **np; 641 int off = off0; 642 struct mbuf *top; 643 int copyhdr = 0; 644 645 if (off < 0 || len < 0) 646 panic("m_copym: off %d, len %d", off, len); 647 if (off == 0 && m->m_flags & M_PKTHDR) 648 copyhdr = 1; 649 while (off > 0) { 650 if (m == 0) 651 panic("m_copym: m == 0, off %d", off); 652 if (off < m->m_len) 653 break; 654 off -= m->m_len; 655 m = m->m_next; 656 } 657 np = ⊤ 658 top = 0; 659 while (len > 0) { 660 if (m == 0) { 661 if (len != M_COPYALL) 662 panic("m_copym: m == 0, len %d [!COPYALL]", 663 len); 664 break; 665 } 666 MGET(n, wait, m->m_type); 667 *np = n; 668 if (n == 0) 669 goto nospace; 670 MCLAIM(n, m->m_owner); 671 if (copyhdr) { 672 M_COPY_PKTHDR(n, m); 673 if (len == M_COPYALL) 674 n->m_pkthdr.len -= off0; 675 else 676 n->m_pkthdr.len = len; 677 copyhdr = 0; 678 } 679 n->m_len = min(len, m->m_len - off); 680 if (m->m_flags & M_EXT) { 681 if (!deep) { 682 n->m_data = m->m_data + off; 683 MCLADDREFERENCE(m, n); 684 } else { 685 /* 686 * we are unsure about the way m was allocated. 687 * copy into multiple MCLBYTES cluster mbufs. 688 */ 689 MCLGET(n, wait); 690 n->m_len = 0; 691 n->m_len = M_TRAILINGSPACE(n); 692 n->m_len = min(n->m_len, len); 693 n->m_len = min(n->m_len, m->m_len - off); 694 memcpy(mtod(n, void *), mtod(m, char *) + off, 695 (unsigned)n->m_len); 696 } 697 } else 698 memcpy(mtod(n, void *), mtod(m, char *) + off, 699 (unsigned)n->m_len); 700 if (len != M_COPYALL) 701 len -= n->m_len; 702 off += n->m_len; 703 #ifdef DIAGNOSTIC 704 if (off > m->m_len) 705 panic("m_copym0 overrun"); 706 #endif 707 if (off == m->m_len) { 708 m = m->m_next; 709 off = 0; 710 } 711 np = &n->m_next; 712 } 713 if (top == 0) 714 MCFail++; 715 return (top); 716 nospace: 717 m_freem(top); 718 MCFail++; 719 return (NULL); 720 } 721 722 /* 723 * Copy an entire packet, including header (which must be present). 724 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 725 */ 726 struct mbuf * 727 m_copypacket(struct mbuf *m, int how) 728 { 729 struct mbuf *top, *n, *o; 730 731 MGET(n, how, m->m_type); 732 top = n; 733 if (!n) 734 goto nospace; 735 736 MCLAIM(n, m->m_owner); 737 M_COPY_PKTHDR(n, m); 738 n->m_len = m->m_len; 739 if (m->m_flags & M_EXT) { 740 n->m_data = m->m_data; 741 MCLADDREFERENCE(m, n); 742 } else { 743 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 744 } 745 746 m = m->m_next; 747 while (m) { 748 MGET(o, how, m->m_type); 749 if (!o) 750 goto nospace; 751 752 MCLAIM(o, m->m_owner); 753 n->m_next = o; 754 n = n->m_next; 755 756 n->m_len = m->m_len; 757 if (m->m_flags & M_EXT) { 758 n->m_data = m->m_data; 759 MCLADDREFERENCE(m, n); 760 } else { 761 memcpy(mtod(n, char *), mtod(m, char *), n->m_len); 762 } 763 764 m = m->m_next; 765 } 766 return top; 767 nospace: 768 m_freem(top); 769 MCFail++; 770 return NULL; 771 } 772 773 /* 774 * Copy data from an mbuf chain starting "off" bytes from the beginning, 775 * continuing for "len" bytes, into the indicated buffer. 776 */ 777 void 778 m_copydata(struct mbuf *m, int off, int len, void *vp) 779 { 780 unsigned count; 781 void * cp = vp; 782 783 if (off < 0 || len < 0) 784 panic("m_copydata: off %d, len %d", off, len); 785 while (off > 0) { 786 if (m == NULL) 787 panic("m_copydata: m == NULL, off %d", off); 788 if (off < m->m_len) 789 break; 790 off -= m->m_len; 791 m = m->m_next; 792 } 793 while (len > 0) { 794 if (m == NULL) 795 panic("m_copydata: m == NULL, len %d", len); 796 count = min(m->m_len - off, len); 797 memcpy(cp, mtod(m, char *) + off, count); 798 len -= count; 799 cp = (char *)cp + count; 800 off = 0; 801 m = m->m_next; 802 } 803 } 804 805 /* 806 * Concatenate mbuf chain n to m. 807 * n might be copied into m (when n->m_len is small), therefore data portion of 808 * n could be copied into an mbuf of different mbuf type. 809 * Any m_pkthdr is not updated. 810 */ 811 void 812 m_cat(struct mbuf *m, struct mbuf *n) 813 { 814 815 while (m->m_next) 816 m = m->m_next; 817 while (n) { 818 if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { 819 /* just join the two chains */ 820 m->m_next = n; 821 return; 822 } 823 /* splat the data from one into the other */ 824 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 825 (u_int)n->m_len); 826 m->m_len += n->m_len; 827 n = m_free(n); 828 } 829 } 830 831 void 832 m_adj(struct mbuf *mp, int req_len) 833 { 834 int len = req_len; 835 struct mbuf *m; 836 int count; 837 838 if ((m = mp) == NULL) 839 return; 840 if (len >= 0) { 841 /* 842 * Trim from head. 843 */ 844 while (m != NULL && len > 0) { 845 if (m->m_len <= len) { 846 len -= m->m_len; 847 m->m_len = 0; 848 m = m->m_next; 849 } else { 850 m->m_len -= len; 851 m->m_data += len; 852 len = 0; 853 } 854 } 855 m = mp; 856 if (mp->m_flags & M_PKTHDR) 857 m->m_pkthdr.len -= (req_len - len); 858 } else { 859 /* 860 * Trim from tail. Scan the mbuf chain, 861 * calculating its length and finding the last mbuf. 862 * If the adjustment only affects this mbuf, then just 863 * adjust and return. Otherwise, rescan and truncate 864 * after the remaining size. 865 */ 866 len = -len; 867 count = 0; 868 for (;;) { 869 count += m->m_len; 870 if (m->m_next == (struct mbuf *)0) 871 break; 872 m = m->m_next; 873 } 874 if (m->m_len >= len) { 875 m->m_len -= len; 876 if (mp->m_flags & M_PKTHDR) 877 mp->m_pkthdr.len -= len; 878 return; 879 } 880 count -= len; 881 if (count < 0) 882 count = 0; 883 /* 884 * Correct length for chain is "count". 885 * Find the mbuf with last data, adjust its length, 886 * and toss data from remaining mbufs on chain. 887 */ 888 m = mp; 889 if (m->m_flags & M_PKTHDR) 890 m->m_pkthdr.len = count; 891 for (; m; m = m->m_next) { 892 if (m->m_len >= count) { 893 m->m_len = count; 894 break; 895 } 896 count -= m->m_len; 897 } 898 if (m) 899 while (m->m_next) 900 (m = m->m_next)->m_len = 0; 901 } 902 } 903 904 /* 905 * Rearrange an mbuf chain so that len bytes are contiguous 906 * and in the data area of an mbuf (so that mtod and dtom 907 * will work for a structure of size len). Returns the resulting 908 * mbuf chain on success, frees it and returns null on failure. 909 * If there is room, it will add up to max_protohdr-len extra bytes to the 910 * contiguous region in an attempt to avoid being called next time. 911 */ 912 int MPFail; 913 914 struct mbuf * 915 m_pullup(struct mbuf *n, int len) 916 { 917 struct mbuf *m; 918 int count; 919 int space; 920 921 /* 922 * If first mbuf has no cluster, and has room for len bytes 923 * without shifting current data, pullup into it, 924 * otherwise allocate a new mbuf to prepend to the chain. 925 */ 926 if ((n->m_flags & M_EXT) == 0 && 927 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 928 if (n->m_len >= len) 929 return (n); 930 m = n; 931 n = n->m_next; 932 len -= m->m_len; 933 } else { 934 if (len > MHLEN) 935 goto bad; 936 MGET(m, M_DONTWAIT, n->m_type); 937 if (m == 0) 938 goto bad; 939 MCLAIM(m, n->m_owner); 940 m->m_len = 0; 941 if (n->m_flags & M_PKTHDR) { 942 M_MOVE_PKTHDR(m, n); 943 } 944 } 945 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 946 do { 947 count = min(min(max(len, max_protohdr), space), n->m_len); 948 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 949 (unsigned)count); 950 len -= count; 951 m->m_len += count; 952 n->m_len -= count; 953 space -= count; 954 if (n->m_len) 955 n->m_data += count; 956 else 957 n = m_free(n); 958 } while (len > 0 && n); 959 if (len > 0) { 960 (void) m_free(m); 961 goto bad; 962 } 963 m->m_next = n; 964 return (m); 965 bad: 966 m_freem(n); 967 MPFail++; 968 return (NULL); 969 } 970 971 /* 972 * Like m_pullup(), except a new mbuf is always allocated, and we allow 973 * the amount of empty space before the data in the new mbuf to be specified 974 * (in the event that the caller expects to prepend later). 975 */ 976 int MSFail; 977 978 struct mbuf * 979 m_copyup(struct mbuf *n, int len, int dstoff) 980 { 981 struct mbuf *m; 982 int count, space; 983 984 if (len > (MHLEN - dstoff)) 985 goto bad; 986 MGET(m, M_DONTWAIT, n->m_type); 987 if (m == NULL) 988 goto bad; 989 MCLAIM(m, n->m_owner); 990 m->m_len = 0; 991 if (n->m_flags & M_PKTHDR) { 992 M_MOVE_PKTHDR(m, n); 993 } 994 m->m_data += dstoff; 995 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 996 do { 997 count = min(min(max(len, max_protohdr), space), n->m_len); 998 memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), 999 (unsigned)count); 1000 len -= count; 1001 m->m_len += count; 1002 n->m_len -= count; 1003 space -= count; 1004 if (n->m_len) 1005 n->m_data += count; 1006 else 1007 n = m_free(n); 1008 } while (len > 0 && n); 1009 if (len > 0) { 1010 (void) m_free(m); 1011 goto bad; 1012 } 1013 m->m_next = n; 1014 return (m); 1015 bad: 1016 m_freem(n); 1017 MSFail++; 1018 return (NULL); 1019 } 1020 1021 /* 1022 * Partition an mbuf chain in two pieces, returning the tail -- 1023 * all but the first len0 bytes. In case of failure, it returns NULL and 1024 * attempts to restore the chain to its original state. 1025 */ 1026 struct mbuf * 1027 m_split(struct mbuf *m0, int len0, int wait) 1028 { 1029 1030 return m_split0(m0, len0, wait, 1); 1031 } 1032 1033 static struct mbuf * 1034 m_split0(struct mbuf *m0, int len0, int wait, int copyhdr) 1035 { 1036 struct mbuf *m, *n; 1037 unsigned len = len0, remain, len_save; 1038 1039 for (m = m0; m && len > m->m_len; m = m->m_next) 1040 len -= m->m_len; 1041 if (m == 0) 1042 return (NULL); 1043 remain = m->m_len - len; 1044 if (copyhdr && (m0->m_flags & M_PKTHDR)) { 1045 MGETHDR(n, wait, m0->m_type); 1046 if (n == 0) 1047 return (NULL); 1048 MCLAIM(n, m0->m_owner); 1049 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 1050 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 1051 len_save = m0->m_pkthdr.len; 1052 m0->m_pkthdr.len = len0; 1053 if (m->m_flags & M_EXT) 1054 goto extpacket; 1055 if (remain > MHLEN) { 1056 /* m can't be the lead packet */ 1057 MH_ALIGN(n, 0); 1058 n->m_next = m_split(m, len, wait); 1059 if (n->m_next == 0) { 1060 (void) m_free(n); 1061 m0->m_pkthdr.len = len_save; 1062 return (NULL); 1063 } else 1064 return (n); 1065 } else 1066 MH_ALIGN(n, remain); 1067 } else if (remain == 0) { 1068 n = m->m_next; 1069 m->m_next = 0; 1070 return (n); 1071 } else { 1072 MGET(n, wait, m->m_type); 1073 if (n == 0) 1074 return (NULL); 1075 MCLAIM(n, m->m_owner); 1076 M_ALIGN(n, remain); 1077 } 1078 extpacket: 1079 if (m->m_flags & M_EXT) { 1080 n->m_data = m->m_data + len; 1081 MCLADDREFERENCE(m, n); 1082 } else { 1083 memcpy(mtod(n, void *), mtod(m, char *) + len, remain); 1084 } 1085 n->m_len = remain; 1086 m->m_len = len; 1087 n->m_next = m->m_next; 1088 m->m_next = 0; 1089 return (n); 1090 } 1091 /* 1092 * Routine to copy from device local memory into mbufs. 1093 */ 1094 struct mbuf * 1095 m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, 1096 void (*copy)(const void *from, void *to, size_t len)) 1097 { 1098 struct mbuf *m; 1099 struct mbuf *top = 0, **mp = ⊤ 1100 int off = off0, len; 1101 char *cp; 1102 char *epkt; 1103 1104 cp = buf; 1105 epkt = cp + totlen; 1106 if (off) { 1107 /* 1108 * If 'off' is non-zero, packet is trailer-encapsulated, 1109 * so we have to skip the type and length fields. 1110 */ 1111 cp += off + 2 * sizeof(uint16_t); 1112 totlen -= 2 * sizeof(uint16_t); 1113 } 1114 MGETHDR(m, M_DONTWAIT, MT_DATA); 1115 if (m == 0) 1116 return (NULL); 1117 m->m_pkthdr.rcvif = ifp; 1118 m->m_pkthdr.len = totlen; 1119 m->m_len = MHLEN; 1120 1121 while (totlen > 0) { 1122 if (top) { 1123 MGET(m, M_DONTWAIT, MT_DATA); 1124 if (m == 0) { 1125 m_freem(top); 1126 return (NULL); 1127 } 1128 m->m_len = MLEN; 1129 } 1130 len = min(totlen, epkt - cp); 1131 if (len >= MINCLSIZE) { 1132 MCLGET(m, M_DONTWAIT); 1133 if ((m->m_flags & M_EXT) == 0) { 1134 m_free(m); 1135 m_freem(top); 1136 return (NULL); 1137 } 1138 m->m_len = len = min(len, MCLBYTES); 1139 } else { 1140 /* 1141 * Place initial small packet/header at end of mbuf. 1142 */ 1143 if (len < m->m_len) { 1144 if (top == 0 && len + max_linkhdr <= m->m_len) 1145 m->m_data += max_linkhdr; 1146 m->m_len = len; 1147 } else 1148 len = m->m_len; 1149 } 1150 if (copy) 1151 copy(cp, mtod(m, void *), (size_t)len); 1152 else 1153 memcpy(mtod(m, void *), cp, (size_t)len); 1154 cp += len; 1155 *mp = m; 1156 mp = &m->m_next; 1157 totlen -= len; 1158 if (cp == epkt) 1159 cp = buf; 1160 } 1161 return (top); 1162 } 1163 1164 /* 1165 * Copy data from a buffer back into the indicated mbuf chain, 1166 * starting "off" bytes from the beginning, extending the mbuf 1167 * chain if necessary. 1168 */ 1169 void 1170 m_copyback(struct mbuf *m0, int off, int len, const void *cp) 1171 { 1172 #if defined(DEBUG) 1173 struct mbuf *origm = m0; 1174 int error; 1175 #endif /* defined(DEBUG) */ 1176 1177 if (m0 == NULL) 1178 return; 1179 1180 #if defined(DEBUG) 1181 error = 1182 #endif /* defined(DEBUG) */ 1183 m_copyback0(&m0, off, len, cp, 1184 M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT); 1185 1186 #if defined(DEBUG) 1187 if (error != 0 || (m0 != NULL && origm != m0)) 1188 panic("m_copyback"); 1189 #endif /* defined(DEBUG) */ 1190 } 1191 1192 struct mbuf * 1193 m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how) 1194 { 1195 int error; 1196 1197 /* don't support chain expansion */ 1198 KDASSERT(off + len <= m_length(m0)); 1199 1200 error = m_copyback0(&m0, off, len, cp, 1201 M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how); 1202 if (error) { 1203 /* 1204 * no way to recover from partial success. 1205 * just free the chain. 1206 */ 1207 m_freem(m0); 1208 return NULL; 1209 } 1210 return m0; 1211 } 1212 1213 /* 1214 * m_makewritable: ensure the specified range writable. 1215 */ 1216 int 1217 m_makewritable(struct mbuf **mp, int off, int len, int how) 1218 { 1219 int error; 1220 #if defined(DEBUG) 1221 struct mbuf *n; 1222 int origlen, reslen; 1223 1224 origlen = m_length(*mp); 1225 #endif /* defined(DEBUG) */ 1226 1227 #if 0 /* M_COPYALL is large enough */ 1228 if (len == M_COPYALL) 1229 len = m_length(*mp) - off; /* XXX */ 1230 #endif 1231 1232 error = m_copyback0(mp, off, len, NULL, 1233 M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how); 1234 1235 #if defined(DEBUG) 1236 reslen = 0; 1237 for (n = *mp; n; n = n->m_next) 1238 reslen += n->m_len; 1239 if (origlen != reslen) 1240 panic("m_makewritable: length changed"); 1241 if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len) 1242 panic("m_makewritable: inconsist"); 1243 #endif /* defined(DEBUG) */ 1244 1245 return error; 1246 } 1247 1248 int 1249 m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags, 1250 int how) 1251 { 1252 int mlen; 1253 struct mbuf *m, *n; 1254 struct mbuf **mp; 1255 int totlen = 0; 1256 const char *cp = vp; 1257 1258 KASSERT(mp0 != NULL); 1259 KASSERT(*mp0 != NULL); 1260 KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL); 1261 KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL); 1262 1263 /* 1264 * we don't bother to update "totlen" in the case of M_COPYBACK0_COW, 1265 * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive. 1266 */ 1267 1268 KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0); 1269 1270 mp = mp0; 1271 m = *mp; 1272 while (off > (mlen = m->m_len)) { 1273 off -= mlen; 1274 totlen += mlen; 1275 if (m->m_next == NULL) { 1276 int tspace; 1277 extend: 1278 if ((flags & M_COPYBACK0_EXTEND) == 0) 1279 goto out; 1280 1281 /* 1282 * try to make some space at the end of "m". 1283 */ 1284 1285 mlen = m->m_len; 1286 if (off + len >= MINCLSIZE && 1287 (m->m_flags & M_EXT) == 0 && m->m_len == 0) { 1288 MCLGET(m, how); 1289 } 1290 tspace = M_TRAILINGSPACE(m); 1291 if (tspace > 0) { 1292 tspace = min(tspace, off + len); 1293 KASSERT(tspace > 0); 1294 memset(mtod(m, char *) + m->m_len, 0, 1295 min(off, tspace)); 1296 m->m_len += tspace; 1297 off += mlen; 1298 totlen -= mlen; 1299 continue; 1300 } 1301 1302 /* 1303 * need to allocate an mbuf. 1304 */ 1305 1306 if (off + len >= MINCLSIZE) { 1307 n = m_getcl(how, m->m_type, 0); 1308 } else { 1309 n = m_get(how, m->m_type); 1310 } 1311 if (n == NULL) { 1312 goto out; 1313 } 1314 n->m_len = 0; 1315 n->m_len = min(M_TRAILINGSPACE(n), off + len); 1316 memset(mtod(n, char *), 0, min(n->m_len, off)); 1317 m->m_next = n; 1318 } 1319 mp = &m->m_next; 1320 m = m->m_next; 1321 } 1322 while (len > 0) { 1323 mlen = m->m_len - off; 1324 if (mlen != 0 && M_READONLY(m)) { 1325 char *datap; 1326 int eatlen; 1327 1328 /* 1329 * this mbuf is read-only. 1330 * allocate a new writable mbuf and try again. 1331 */ 1332 1333 #if defined(DIAGNOSTIC) 1334 if ((flags & M_COPYBACK0_COW) == 0) 1335 panic("m_copyback0: read-only"); 1336 #endif /* defined(DIAGNOSTIC) */ 1337 1338 /* 1339 * if we're going to write into the middle of 1340 * a mbuf, split it first. 1341 */ 1342 if (off > 0 && len < mlen) { 1343 n = m_split0(m, off, how, 0); 1344 if (n == NULL) 1345 goto enobufs; 1346 m->m_next = n; 1347 mp = &m->m_next; 1348 m = n; 1349 off = 0; 1350 continue; 1351 } 1352 1353 /* 1354 * XXX TODO coalesce into the trailingspace of 1355 * the previous mbuf when possible. 1356 */ 1357 1358 /* 1359 * allocate a new mbuf. copy packet header if needed. 1360 */ 1361 MGET(n, how, m->m_type); 1362 if (n == NULL) 1363 goto enobufs; 1364 MCLAIM(n, m->m_owner); 1365 if (off == 0 && (m->m_flags & M_PKTHDR) != 0) { 1366 M_MOVE_PKTHDR(n, m); 1367 n->m_len = MHLEN; 1368 } else { 1369 if (len >= MINCLSIZE) 1370 MCLGET(n, M_DONTWAIT); 1371 n->m_len = 1372 (n->m_flags & M_EXT) ? MCLBYTES : MLEN; 1373 } 1374 if (n->m_len > len) 1375 n->m_len = len; 1376 1377 /* 1378 * free the region which has been overwritten. 1379 * copying data from old mbufs if requested. 1380 */ 1381 if (flags & M_COPYBACK0_PRESERVE) 1382 datap = mtod(n, char *); 1383 else 1384 datap = NULL; 1385 eatlen = n->m_len; 1386 KDASSERT(off == 0 || eatlen >= mlen); 1387 if (off > 0) { 1388 KDASSERT(len >= mlen); 1389 m->m_len = off; 1390 m->m_next = n; 1391 if (datap) { 1392 m_copydata(m, off, mlen, datap); 1393 datap += mlen; 1394 } 1395 eatlen -= mlen; 1396 mp = &m->m_next; 1397 m = m->m_next; 1398 } 1399 while (m != NULL && M_READONLY(m) && 1400 n->m_type == m->m_type && eatlen > 0) { 1401 mlen = min(eatlen, m->m_len); 1402 if (datap) { 1403 m_copydata(m, 0, mlen, datap); 1404 datap += mlen; 1405 } 1406 m->m_data += mlen; 1407 m->m_len -= mlen; 1408 eatlen -= mlen; 1409 if (m->m_len == 0) 1410 *mp = m = m_free(m); 1411 } 1412 if (eatlen > 0) 1413 n->m_len -= eatlen; 1414 n->m_next = m; 1415 *mp = m = n; 1416 continue; 1417 } 1418 mlen = min(mlen, len); 1419 if (flags & M_COPYBACK0_COPYBACK) { 1420 memcpy(mtod(m, char *) + off, cp, (unsigned)mlen); 1421 cp += mlen; 1422 } 1423 len -= mlen; 1424 mlen += off; 1425 off = 0; 1426 totlen += mlen; 1427 if (len == 0) 1428 break; 1429 if (m->m_next == NULL) { 1430 goto extend; 1431 } 1432 mp = &m->m_next; 1433 m = m->m_next; 1434 } 1435 out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) { 1436 KASSERT((flags & M_COPYBACK0_EXTEND) != 0); 1437 m->m_pkthdr.len = totlen; 1438 } 1439 1440 return 0; 1441 1442 enobufs: 1443 return ENOBUFS; 1444 } 1445 1446 void 1447 m_move_pkthdr(struct mbuf *to, struct mbuf *from) 1448 { 1449 1450 KASSERT((to->m_flags & M_EXT) == 0); 1451 KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL); 1452 KASSERT((from->m_flags & M_PKTHDR) != 0); 1453 1454 to->m_pkthdr = from->m_pkthdr; 1455 to->m_flags = from->m_flags & M_COPYFLAGS; 1456 to->m_data = to->m_pktdat; 1457 1458 from->m_flags &= ~M_PKTHDR; 1459 } 1460 1461 /* 1462 * Apply function f to the data in an mbuf chain starting "off" bytes from the 1463 * beginning, continuing for "len" bytes. 1464 */ 1465 int 1466 m_apply(struct mbuf *m, int off, int len, 1467 int (*f)(void *, void *, unsigned int), void *arg) 1468 { 1469 unsigned int count; 1470 int rval; 1471 1472 KASSERT(len >= 0); 1473 KASSERT(off >= 0); 1474 1475 while (off > 0) { 1476 KASSERT(m != NULL); 1477 if (off < m->m_len) 1478 break; 1479 off -= m->m_len; 1480 m = m->m_next; 1481 } 1482 while (len > 0) { 1483 KASSERT(m != NULL); 1484 count = min(m->m_len - off, len); 1485 1486 rval = (*f)(arg, mtod(m, char *) + off, count); 1487 if (rval) 1488 return (rval); 1489 1490 len -= count; 1491 off = 0; 1492 m = m->m_next; 1493 } 1494 1495 return (0); 1496 } 1497 1498 /* 1499 * Return a pointer to mbuf/offset of location in mbuf chain. 1500 */ 1501 struct mbuf * 1502 m_getptr(struct mbuf *m, int loc, int *off) 1503 { 1504 1505 while (loc >= 0) { 1506 /* Normal end of search */ 1507 if (m->m_len > loc) { 1508 *off = loc; 1509 return (m); 1510 } else { 1511 loc -= m->m_len; 1512 1513 if (m->m_next == NULL) { 1514 if (loc == 0) { 1515 /* Point at the end of valid data */ 1516 *off = m->m_len; 1517 return (m); 1518 } else 1519 return (NULL); 1520 } else 1521 m = m->m_next; 1522 } 1523 } 1524 1525 return (NULL); 1526 } 1527 1528 /* 1529 * m_ext_free: release a reference to the mbuf external storage. 1530 * 1531 * => free the mbuf m itsself as well. 1532 */ 1533 1534 void 1535 m_ext_free(struct mbuf *m) 1536 { 1537 bool embedded = MEXT_ISEMBEDDED(m); 1538 bool dofree = true; 1539 u_int refcnt; 1540 1541 KASSERT((m->m_flags & M_EXT) != 0); 1542 KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref)); 1543 KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0); 1544 KASSERT((m->m_flags & M_EXT_CLUSTER) == 1545 (m->m_ext_ref->m_flags & M_EXT_CLUSTER)); 1546 1547 if (__predict_true(m->m_ext.ext_refcnt == 1)) { 1548 refcnt = m->m_ext.ext_refcnt = 0; 1549 } else { 1550 refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt); 1551 } 1552 if (refcnt > 0) { 1553 if (embedded) { 1554 /* 1555 * other mbuf's m_ext_ref still points to us. 1556 */ 1557 dofree = false; 1558 } else { 1559 m->m_ext_ref = m; 1560 } 1561 } else { 1562 /* 1563 * dropping the last reference 1564 */ 1565 if (!embedded) { 1566 m->m_ext.ext_refcnt++; /* XXX */ 1567 m_ext_free(m->m_ext_ref); 1568 m->m_ext_ref = m; 1569 } else if ((m->m_flags & M_EXT_CLUSTER) != 0) { 1570 pool_cache_put_paddr((struct pool_cache *) 1571 m->m_ext.ext_arg, 1572 m->m_ext.ext_buf, m->m_ext.ext_paddr); 1573 } else if (m->m_ext.ext_free) { 1574 (*m->m_ext.ext_free)(m, 1575 m->m_ext.ext_buf, m->m_ext.ext_size, 1576 m->m_ext.ext_arg); 1577 /* 1578 * 'm' is already freed by the ext_free callback. 1579 */ 1580 dofree = false; 1581 } else { 1582 free(m->m_ext.ext_buf, m->m_ext.ext_type); 1583 } 1584 } 1585 if (dofree) { 1586 pool_cache_put(mb_cache, m); 1587 } 1588 } 1589 1590 #if defined(DDB) 1591 void 1592 m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...)) 1593 { 1594 char ch; 1595 bool opt_c = false; 1596 char buf[512]; 1597 1598 while ((ch = *(modif++)) != '\0') { 1599 switch (ch) { 1600 case 'c': 1601 opt_c = true; 1602 break; 1603 } 1604 } 1605 1606 nextchain: 1607 (*pr)("MBUF %p\n", m); 1608 bitmask_snprintf((u_int)m->m_flags, M_FLAGS_BITS, buf, sizeof(buf)); 1609 (*pr)(" data=%p, len=%d, type=%d, flags=0x%s\n", 1610 m->m_data, m->m_len, m->m_type, buf); 1611 (*pr)(" owner=%p, next=%p, nextpkt=%p\n", m->m_owner, m->m_next, 1612 m->m_nextpkt); 1613 (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n", 1614 (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m), 1615 (int)M_READONLY(m)); 1616 if ((m->m_flags & M_PKTHDR) != 0) { 1617 bitmask_snprintf(m->m_pkthdr.csum_flags, M_CSUM_BITS, buf, 1618 sizeof(buf)); 1619 (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%" 1620 PRIx32 ", segsz=%u\n", 1621 m->m_pkthdr.len, m->m_pkthdr.rcvif, 1622 buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz); 1623 } 1624 if ((m->m_flags & M_EXT)) { 1625 (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, " 1626 "ext_free=%p, ext_arg=%p\n", 1627 m->m_ext.ext_refcnt, 1628 m->m_ext.ext_buf, m->m_ext.ext_size, 1629 m->m_ext.ext_free, m->m_ext.ext_arg); 1630 } 1631 if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) { 1632 vaddr_t sva = (vaddr_t)m->m_ext.ext_buf; 1633 vaddr_t eva = sva + m->m_ext.ext_size; 1634 int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT; 1635 int i; 1636 1637 (*pr)(" pages:"); 1638 for (i = 0; i < n; i ++) { 1639 (*pr)(" %p", m->m_ext.ext_pgs[i]); 1640 } 1641 (*pr)("\n"); 1642 } 1643 1644 if (opt_c) { 1645 m = m->m_next; 1646 if (m != NULL) { 1647 goto nextchain; 1648 } 1649 } 1650 } 1651 #endif /* defined(DDB) */ 1652 1653 void 1654 mbstat_type_add(int type, int diff) 1655 { 1656 struct mbstat_cpu *mb; 1657 int s; 1658 1659 s = splvm(); 1660 mb = percpu_getref(mbstat_percpu); 1661 mb->m_mtypes[type] += diff; 1662 percpu_putref(mbstat_percpu); 1663 splx(s); 1664 } 1665 1666 #if defined(MBUFTRACE) 1667 void 1668 mowner_attach(struct mowner *mo) 1669 { 1670 1671 KASSERT(mo->mo_counters == NULL); 1672 mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter)); 1673 1674 /* XXX lock */ 1675 LIST_INSERT_HEAD(&mowners, mo, mo_link); 1676 } 1677 1678 void 1679 mowner_detach(struct mowner *mo) 1680 { 1681 1682 KASSERT(mo->mo_counters != NULL); 1683 1684 /* XXX lock */ 1685 LIST_REMOVE(mo, mo_link); 1686 1687 percpu_free(mo->mo_counters, sizeof(struct mowner_counter)); 1688 mo->mo_counters = NULL; 1689 } 1690 1691 void 1692 mowner_init(struct mbuf *m, int type) 1693 { 1694 struct mowner_counter *mc; 1695 struct mowner *mo; 1696 int s; 1697 1698 m->m_owner = mo = &unknown_mowners[type]; 1699 s = splvm(); 1700 mc = percpu_getref(mo->mo_counters); 1701 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1702 percpu_putref(mo->mo_counters); 1703 splx(s); 1704 } 1705 1706 void 1707 mowner_ref(struct mbuf *m, int flags) 1708 { 1709 struct mowner *mo = m->m_owner; 1710 struct mowner_counter *mc; 1711 int s; 1712 1713 s = splvm(); 1714 mc = percpu_getref(mo->mo_counters); 1715 if ((flags & M_EXT) != 0) 1716 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1717 if ((flags & M_CLUSTER) != 0) 1718 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1719 percpu_putref(mo->mo_counters); 1720 splx(s); 1721 } 1722 1723 void 1724 mowner_revoke(struct mbuf *m, bool all, int flags) 1725 { 1726 struct mowner *mo = m->m_owner; 1727 struct mowner_counter *mc; 1728 int s; 1729 1730 s = splvm(); 1731 mc = percpu_getref(mo->mo_counters); 1732 if ((flags & M_EXT) != 0) 1733 mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++; 1734 if ((flags & M_CLUSTER) != 0) 1735 mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++; 1736 if (all) 1737 mc->mc_counter[MOWNER_COUNTER_RELEASES]++; 1738 percpu_putref(mo->mo_counters); 1739 splx(s); 1740 if (all) 1741 m->m_owner = &revoked_mowner; 1742 } 1743 1744 static void 1745 mowner_claim(struct mbuf *m, struct mowner *mo) 1746 { 1747 struct mowner_counter *mc; 1748 int flags = m->m_flags; 1749 int s; 1750 1751 s = splvm(); 1752 mc = percpu_getref(mo->mo_counters); 1753 mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; 1754 if ((flags & M_EXT) != 0) 1755 mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; 1756 if ((flags & M_CLUSTER) != 0) 1757 mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; 1758 percpu_putref(mo->mo_counters); 1759 splx(s); 1760 m->m_owner = mo; 1761 } 1762 1763 void 1764 m_claim(struct mbuf *m, struct mowner *mo) 1765 { 1766 1767 if (m->m_owner == mo || mo == NULL) 1768 return; 1769 1770 mowner_revoke(m, true, m->m_flags); 1771 mowner_claim(m, mo); 1772 } 1773 #endif /* defined(MBUFTRACE) */ 1774