uipc_mbuf.c revision 112185
1/* 2 * Copyright (c) 1982, 1986, 1988, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 34 * $FreeBSD: head/sys/kern/uipc_mbuf.c 112185 2003-03-13 09:02:19Z iedowse $ 35 */ 36 37#include "opt_mac.h" 38#include "opt_param.h" 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> 44#include <sys/mac.h> 45#include <sys/malloc.h> 46#include <sys/mbuf.h> 47#include <sys/sysctl.h> 48#include <sys/domain.h> 49#include <sys/protosw.h> 50 51int max_linkhdr; 52int max_protohdr; 53int max_hdr; 54int max_datalen; 55 56/* 57 * sysctl(8) exported objects 58 */ 59SYSCTL_DECL(_kern_ipc); 60SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, 61 &max_linkhdr, 0, ""); 62SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, 63 &max_protohdr, 0, ""); 64SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, ""); 65SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, 66 &max_datalen, 0, ""); 67 68/* 69 * "Move" mbuf pkthdr from "from" to "to". 70 * "from" must have M_PKTHDR set, and "to" must be empty. 71 */ 72void 73m_move_pkthdr(struct mbuf *to, struct mbuf *from) 74{ 75 76#if 0 77 /* see below for why these are not enabled */ 78 KASSERT(to->m_flags & M_PKTHDR, 79 ("m_move_pkthdr: called on non-header")); 80 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), 81 ("m_move_pkthdr: to has tags")); 82#endif 83 KASSERT((to->m_flags & M_EXT) == 0, ("m_move_pkthdr: to has cluster")); 84#ifdef MAC 85 if (to->m_flags & M_PKTHDR) 86 mac_destroy_mbuf(to); 87#endif 88 to->m_flags = from->m_flags & M_COPYFLAGS; 89 to->m_data = to->m_pktdat; 90 to->m_pkthdr = from->m_pkthdr; /* especially tags */ 91#ifdef MAC 92 mac_init_mbuf(to, 1); /* XXXMAC no way to fail */ 93 mac_create_mbuf_from_mbuf(from, to); 94#endif 95 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 96 from->m_flags &= ~M_PKTHDR; 97} 98 99/* 100 * Duplicate "from"'s mbuf pkthdr in "to". 101 * "from" must have M_PKTHDR set, and "to" must be empty. 102 * In particular, this does a deep copy of the packet tags. 103 */ 104int 105m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 106{ 107 108#if 0 109 /* 110 * The mbuf allocator only initializes the pkthdr 111 * when the mbuf is allocated with MGETHDR. Many users 112 * (e.g. m_copy*, m_prepend) use MGET and then 113 * smash the pkthdr as needed causing these 114 * assertions to trip. For now just disable them. 115 */ 116 KASSERT(to->m_flags & M_PKTHDR, ("m_dup_pkthdr: called on non-header")); 117 KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags")); 118#endif 119 KASSERT((to->m_flags & M_EXT) == 0, ("m_dup_pkthdr: to has cluster")); 120#ifdef MAC 121 if (to->m_flags & M_PKTHDR) 122 mac_destroy_mbuf(to); 123#endif 124 to->m_flags = from->m_flags & M_COPYFLAGS; 125 to->m_data = to->m_pktdat; 126 to->m_pkthdr = from->m_pkthdr; 127#ifdef MAC 128 mac_init_mbuf(to, 1); /* XXXMAC no way to fail */ 129 mac_create_mbuf_from_mbuf(from, to); 130#endif 131 SLIST_INIT(&to->m_pkthdr.tags); 132 return (m_tag_copy_chain(to, from, (how & M_TRYWAIT) ? M_WAITOK : 133 M_NOWAIT)); 134} 135 136/* 137 * Lesser-used path for M_PREPEND: 138 * allocate new mbuf to prepend to chain, 139 * copy junk along. 140 */ 141struct mbuf * 142m_prepend(struct mbuf *m, int len, int how) 143{ 144 struct mbuf *mn; 145 146 MGET(mn, how, m->m_type); 147 if (mn == NULL) { 148 m_freem(m); 149 return (NULL); 150 } 151 if (m->m_flags & M_PKTHDR) { 152 M_MOVE_PKTHDR(mn, m); 153#ifdef MAC 154 mac_destroy_mbuf(m); 155#endif 156 } 157 mn->m_next = m; 158 m = mn; 159 if (len < MHLEN) 160 MH_ALIGN(m, len); 161 m->m_len = len; 162 return (m); 163} 164 165/* 166 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 167 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 168 * The wait parameter is a choice of M_TRYWAIT/M_DONTWAIT from caller. 169 * Note that the copy is read-only, because clusters are not copied, 170 * only their reference counts are incremented. 171 */ 172struct mbuf * 173m_copym(struct mbuf *m, int off0, int len, int wait) 174{ 175 struct mbuf *n, **np; 176 int off = off0; 177 struct mbuf *top; 178 int copyhdr = 0; 179 180 KASSERT(off >= 0, ("m_copym, negative off %d", off)); 181 KASSERT(len >= 0, ("m_copym, negative len %d", len)); 182 if (off == 0 && m->m_flags & M_PKTHDR) 183 copyhdr = 1; 184 while (off > 0) { 185 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 186 if (off < m->m_len) 187 break; 188 off -= m->m_len; 189 m = m->m_next; 190 } 191 np = ⊤ 192 top = 0; 193 while (len > 0) { 194 if (m == NULL) { 195 KASSERT(len == M_COPYALL, 196 ("m_copym, length > size of mbuf chain")); 197 break; 198 } 199 MGET(n, wait, m->m_type); 200 *np = n; 201 if (n == NULL) 202 goto nospace; 203 if (copyhdr) { 204 if (!m_dup_pkthdr(n, m, wait)) 205 goto nospace; 206 if (len == M_COPYALL) 207 n->m_pkthdr.len -= off0; 208 else 209 n->m_pkthdr.len = len; 210 copyhdr = 0; 211 } 212 n->m_len = min(len, m->m_len - off); 213 if (m->m_flags & M_EXT) { 214 n->m_data = m->m_data + off; 215 n->m_ext = m->m_ext; 216 n->m_flags |= M_EXT; 217 MEXT_ADD_REF(m); 218 } else 219 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 220 (u_int)n->m_len); 221 if (len != M_COPYALL) 222 len -= n->m_len; 223 off = 0; 224 m = m->m_next; 225 np = &n->m_next; 226 } 227 if (top == NULL) 228 mbstat.m_mcfail++; /* XXX: No consistency. */ 229 230 return (top); 231nospace: 232 m_freem(top); 233 mbstat.m_mcfail++; /* XXX: No consistency. */ 234 return (NULL); 235} 236 237/* 238 * Copy an entire packet, including header (which must be present). 239 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 240 * Note that the copy is read-only, because clusters are not copied, 241 * only their reference counts are incremented. 242 * Preserve alignment of the first mbuf so if the creator has left 243 * some room at the beginning (e.g. for inserting protocol headers) 244 * the copies still have the room available. 245 */ 246struct mbuf * 247m_copypacket(struct mbuf *m, int how) 248{ 249 struct mbuf *top, *n, *o; 250 251 MGET(n, how, m->m_type); 252 top = n; 253 if (n == NULL) 254 goto nospace; 255 256 if (!m_dup_pkthdr(n, m, how)) 257 goto nospace; 258 n->m_len = m->m_len; 259 if (m->m_flags & M_EXT) { 260 n->m_data = m->m_data; 261 n->m_ext = m->m_ext; 262 n->m_flags |= M_EXT; 263 MEXT_ADD_REF(m); 264 } else { 265 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 266 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 267 } 268 269 m = m->m_next; 270 while (m) { 271 MGET(o, how, m->m_type); 272 if (o == NULL) 273 goto nospace; 274 275 n->m_next = o; 276 n = n->m_next; 277 278 n->m_len = m->m_len; 279 if (m->m_flags & M_EXT) { 280 n->m_data = m->m_data; 281 n->m_ext = m->m_ext; 282 n->m_flags |= M_EXT; 283 MEXT_ADD_REF(m); 284 } else { 285 bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 286 } 287 288 m = m->m_next; 289 } 290 return top; 291nospace: 292 m_freem(top); 293 mbstat.m_mcfail++; /* XXX: No consistency. */ 294 return (NULL); 295} 296 297/* 298 * Copy data from an mbuf chain starting "off" bytes from the beginning, 299 * continuing for "len" bytes, into the indicated buffer. 300 */ 301void 302m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 303{ 304 u_int count; 305 306 KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 307 KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 308 while (off > 0) { 309 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 310 if (off < m->m_len) 311 break; 312 off -= m->m_len; 313 m = m->m_next; 314 } 315 while (len > 0) { 316 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 317 count = min(m->m_len - off, len); 318 bcopy(mtod(m, caddr_t) + off, cp, count); 319 len -= count; 320 cp += count; 321 off = 0; 322 m = m->m_next; 323 } 324} 325 326/* 327 * Copy a packet header mbuf chain into a completely new chain, including 328 * copying any mbuf clusters. Use this instead of m_copypacket() when 329 * you need a writable copy of an mbuf chain. 330 */ 331struct mbuf * 332m_dup(struct mbuf *m, int how) 333{ 334 struct mbuf **p, *top = NULL; 335 int remain, moff, nsize; 336 337 /* Sanity check */ 338 if (m == NULL) 339 return (NULL); 340 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__)); 341 342 /* While there's more data, get a new mbuf, tack it on, and fill it */ 343 remain = m->m_pkthdr.len; 344 moff = 0; 345 p = ⊤ 346 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 347 struct mbuf *n; 348 349 /* Get the next new mbuf */ 350 MGET(n, how, m->m_type); 351 if (n == NULL) 352 goto nospace; 353 if (top == NULL) { /* first one, must be PKTHDR */ 354 if (!m_dup_pkthdr(n, m, how)) 355 goto nospace; 356 nsize = MHLEN; 357 } else /* not the first one */ 358 nsize = MLEN; 359 if (remain >= MINCLSIZE) { 360 MCLGET(n, how); 361 if ((n->m_flags & M_EXT) == 0) { 362 (void)m_free(n); 363 goto nospace; 364 } 365 nsize = MCLBYTES; 366 } 367 n->m_len = 0; 368 369 /* Link it into the new chain */ 370 *p = n; 371 p = &n->m_next; 372 373 /* Copy data from original mbuf(s) into new mbuf */ 374 while (n->m_len < nsize && m != NULL) { 375 int chunk = min(nsize - n->m_len, m->m_len - moff); 376 377 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 378 moff += chunk; 379 n->m_len += chunk; 380 remain -= chunk; 381 if (moff == m->m_len) { 382 m = m->m_next; 383 moff = 0; 384 } 385 } 386 387 /* Check correct total mbuf length */ 388 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 389 ("%s: bogus m_pkthdr.len", __func__)); 390 } 391 return (top); 392 393nospace: 394 m_freem(top); 395 mbstat.m_mcfail++; /* XXX: No consistency. */ 396 return (NULL); 397} 398 399/* 400 * Concatenate mbuf chain n to m. 401 * Both chains must be of the same type (e.g. MT_DATA). 402 * Any m_pkthdr is not updated. 403 */ 404void 405m_cat(struct mbuf *m, struct mbuf *n) 406{ 407 while (m->m_next) 408 m = m->m_next; 409 while (n) { 410 if (m->m_flags & M_EXT || 411 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 412 /* just join the two chains */ 413 m->m_next = n; 414 return; 415 } 416 /* splat the data from one into the other */ 417 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 418 (u_int)n->m_len); 419 m->m_len += n->m_len; 420 n = m_free(n); 421 } 422} 423 424void 425m_adj(struct mbuf *mp, int req_len) 426{ 427 int len = req_len; 428 struct mbuf *m; 429 int count; 430 431 if ((m = mp) == NULL) 432 return; 433 if (len >= 0) { 434 /* 435 * Trim from head. 436 */ 437 while (m != NULL && len > 0) { 438 if (m->m_len <= len) { 439 len -= m->m_len; 440 m->m_len = 0; 441 m = m->m_next; 442 } else { 443 m->m_len -= len; 444 m->m_data += len; 445 len = 0; 446 } 447 } 448 m = mp; 449 if (mp->m_flags & M_PKTHDR) 450 m->m_pkthdr.len -= (req_len - len); 451 } else { 452 /* 453 * Trim from tail. Scan the mbuf chain, 454 * calculating its length and finding the last mbuf. 455 * If the adjustment only affects this mbuf, then just 456 * adjust and return. Otherwise, rescan and truncate 457 * after the remaining size. 458 */ 459 len = -len; 460 count = 0; 461 for (;;) { 462 count += m->m_len; 463 if (m->m_next == (struct mbuf *)0) 464 break; 465 m = m->m_next; 466 } 467 if (m->m_len >= len) { 468 m->m_len -= len; 469 if (mp->m_flags & M_PKTHDR) 470 mp->m_pkthdr.len -= len; 471 return; 472 } 473 count -= len; 474 if (count < 0) 475 count = 0; 476 /* 477 * Correct length for chain is "count". 478 * Find the mbuf with last data, adjust its length, 479 * and toss data from remaining mbufs on chain. 480 */ 481 m = mp; 482 if (m->m_flags & M_PKTHDR) 483 m->m_pkthdr.len = count; 484 for (; m; m = m->m_next) { 485 if (m->m_len >= count) { 486 m->m_len = count; 487 break; 488 } 489 count -= m->m_len; 490 } 491 while (m->m_next) 492 (m = m->m_next) ->m_len = 0; 493 } 494} 495 496/* 497 * Rearange an mbuf chain so that len bytes are contiguous 498 * and in the data area of an mbuf (so that mtod and dtom 499 * will work for a structure of size len). Returns the resulting 500 * mbuf chain on success, frees it and returns null on failure. 501 * If there is room, it will add up to max_protohdr-len extra bytes to the 502 * contiguous region in an attempt to avoid being called next time. 503 */ 504struct mbuf * 505m_pullup(struct mbuf *n, int len) 506{ 507 struct mbuf *m; 508 int count; 509 int space; 510 511 /* 512 * If first mbuf has no cluster, and has room for len bytes 513 * without shifting current data, pullup into it, 514 * otherwise allocate a new mbuf to prepend to the chain. 515 */ 516 if ((n->m_flags & M_EXT) == 0 && 517 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 518 if (n->m_len >= len) 519 return (n); 520 m = n; 521 n = n->m_next; 522 len -= m->m_len; 523 } else { 524 if (len > MHLEN) 525 goto bad; 526 MGET(m, M_DONTWAIT, n->m_type); 527 if (m == NULL) 528 goto bad; 529 m->m_len = 0; 530 if (n->m_flags & M_PKTHDR) 531 M_MOVE_PKTHDR(m, n); 532 } 533 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 534 do { 535 count = min(min(max(len, max_protohdr), space), n->m_len); 536 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 537 (u_int)count); 538 len -= count; 539 m->m_len += count; 540 n->m_len -= count; 541 space -= count; 542 if (n->m_len) 543 n->m_data += count; 544 else 545 n = m_free(n); 546 } while (len > 0 && n); 547 if (len > 0) { 548 (void) m_free(m); 549 goto bad; 550 } 551 m->m_next = n; 552 return (m); 553bad: 554 m_freem(n); 555 mbstat.m_mpfail++; /* XXX: No consistency. */ 556 return (NULL); 557} 558 559/* 560 * Partition an mbuf chain in two pieces, returning the tail -- 561 * all but the first len0 bytes. In case of failure, it returns NULL and 562 * attempts to restore the chain to its original state. 563 * 564 * Note that the resulting mbufs might be read-only, because the new 565 * mbuf can end up sharing an mbuf cluster with the original mbuf if 566 * the "breaking point" happens to lie within a cluster mbuf. Use the 567 * M_WRITABLE() macro to check for this case. 568 */ 569struct mbuf * 570m_split(struct mbuf *m0, int len0, int wait) 571{ 572 struct mbuf *m, *n; 573 u_int len = len0, remain; 574 575 for (m = m0; m && len > m->m_len; m = m->m_next) 576 len -= m->m_len; 577 if (m == NULL) 578 return (NULL); 579 remain = m->m_len - len; 580 if (m0->m_flags & M_PKTHDR) { 581 MGETHDR(n, wait, m0->m_type); 582 if (n == NULL) 583 return (NULL); 584 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 585 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 586 m0->m_pkthdr.len = len0; 587 if (m->m_flags & M_EXT) 588 goto extpacket; 589 if (remain > MHLEN) { 590 /* m can't be the lead packet */ 591 MH_ALIGN(n, 0); 592 n->m_next = m_split(m, len, wait); 593 if (n->m_next == NULL) { 594 (void) m_free(n); 595 return (NULL); 596 } else { 597 n->m_len = 0; 598 return (n); 599 } 600 } else 601 MH_ALIGN(n, remain); 602 } else if (remain == 0) { 603 n = m->m_next; 604 m->m_next = NULL; 605 return (n); 606 } else { 607 MGET(n, wait, m->m_type); 608 if (n == NULL) 609 return (NULL); 610 M_ALIGN(n, remain); 611 } 612extpacket: 613 if (m->m_flags & M_EXT) { 614 n->m_flags |= M_EXT; 615 n->m_ext = m->m_ext; 616 MEXT_ADD_REF(m); 617 n->m_data = m->m_data + len; 618 } else { 619 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 620 } 621 n->m_len = remain; 622 m->m_len = len; 623 n->m_next = m->m_next; 624 m->m_next = NULL; 625 return (n); 626} 627/* 628 * Routine to copy from device local memory into mbufs. 629 * Note that `off' argument is offset into first mbuf of target chain from 630 * which to begin copying the data to. 631 */ 632struct mbuf * 633m_devget(char *buf, int totlen, int off, struct ifnet *ifp, 634 void (*copy)(char *from, caddr_t to, u_int len)) 635{ 636 struct mbuf *m; 637 struct mbuf *top = 0, **mp = ⊤ 638 int len; 639 640 if (off < 0 || off > MHLEN) 641 return (NULL); 642 643 MGETHDR(m, M_DONTWAIT, MT_DATA); 644 if (m == NULL) 645 return (NULL); 646 m->m_pkthdr.rcvif = ifp; 647 m->m_pkthdr.len = totlen; 648 len = MHLEN; 649 650 while (totlen > 0) { 651 if (top) { 652 MGET(m, M_DONTWAIT, MT_DATA); 653 if (m == NULL) { 654 m_freem(top); 655 return (NULL); 656 } 657 len = MLEN; 658 } 659 if (totlen + off >= MINCLSIZE) { 660 MCLGET(m, M_DONTWAIT); 661 if (m->m_flags & M_EXT) 662 len = MCLBYTES; 663 } else { 664 /* 665 * Place initial small packet/header at end of mbuf. 666 */ 667 if (top == NULL && totlen + off + max_linkhdr <= len) { 668 m->m_data += max_linkhdr; 669 len -= max_linkhdr; 670 } 671 } 672 if (off) { 673 m->m_data += off; 674 len -= off; 675 off = 0; 676 } 677 m->m_len = len = min(totlen, len); 678 if (copy) 679 copy(buf, mtod(m, caddr_t), (u_int)len); 680 else 681 bcopy(buf, mtod(m, caddr_t), (u_int)len); 682 buf += len; 683 *mp = m; 684 mp = &m->m_next; 685 totlen -= len; 686 } 687 return (top); 688} 689 690/* 691 * Copy data from a buffer back into the indicated mbuf chain, 692 * starting "off" bytes from the beginning, extending the mbuf 693 * chain if necessary. 694 */ 695void 696m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) 697{ 698 int mlen; 699 struct mbuf *m = m0, *n; 700 int totlen = 0; 701 702 if (m0 == NULL) 703 return; 704 while (off > (mlen = m->m_len)) { 705 off -= mlen; 706 totlen += mlen; 707 if (m->m_next == NULL) { 708 n = m_get_clrd(M_DONTWAIT, m->m_type); 709 if (n == NULL) 710 goto out; 711 n->m_len = min(MLEN, len + off); 712 m->m_next = n; 713 } 714 m = m->m_next; 715 } 716 while (len > 0) { 717 mlen = min (m->m_len - off, len); 718 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 719 cp += mlen; 720 len -= mlen; 721 mlen += off; 722 off = 0; 723 totlen += mlen; 724 if (len == 0) 725 break; 726 if (m->m_next == NULL) { 727 n = m_get(M_DONTWAIT, m->m_type); 728 if (n == NULL) 729 break; 730 n->m_len = min(MLEN, len); 731 m->m_next = n; 732 } 733 m = m->m_next; 734 } 735out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 736 m->m_pkthdr.len = totlen; 737} 738 739void 740m_print(const struct mbuf *m) 741{ 742 int len; 743 const struct mbuf *m2; 744 745 len = m->m_pkthdr.len; 746 m2 = m; 747 while (len) { 748 printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); 749 len -= m2->m_len; 750 m2 = m2->m_next; 751 } 752 return; 753} 754 755u_int 756m_fixhdr(struct mbuf *m0) 757{ 758 u_int len; 759 760 len = m_length(m0, NULL); 761 m0->m_pkthdr.len = len; 762 return (len); 763} 764 765u_int 766m_length(struct mbuf *m0, struct mbuf **last) 767{ 768 struct mbuf *m; 769 u_int len; 770 771 len = 0; 772 for (m = m0; m != NULL; m = m->m_next) { 773 len += m->m_len; 774 if (m->m_next == NULL) 775 break; 776 } 777 if (last != NULL) 778 *last = m; 779 return (len); 780} 781