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 * $Id: uipc_mbuf.c,v 1.6 1994/10/09 07:34:59 davidg Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/proc.h> 40 #include <sys/malloc.h> 41 #define MBTYPES 42 #include <sys/mbuf.h> 43 #include <sys/kernel.h> 44 #include <sys/syslog.h> 45 #include <sys/domain.h> 46 #include <sys/protosw.h> 47 48 #include <vm/vm.h> 49 50 extern vm_map_t mb_map; 51 struct mbuf *mbutl; 52 char *mclrefcnt; 53 54 void 55 mbinit() 56 { 57 int s; 58 59 #if CLBYTES < 4096 60 #define NCL_INIT (4096/CLBYTES) 61 #else 62 #define NCL_INIT 1 63 #endif 64 s = splimp(); 65 if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) 66 goto bad; 67 splx(s); 68 return; 69 bad: 70 panic("mbinit"); 71 } 72 73 /* 74 * Allocate some number of mbuf clusters 75 * and place on cluster free list. 76 * Must be called at splimp. 77 */ 78 /* ARGSUSED */ 79 int 80 m_clalloc(ncl, nowait) 81 register int ncl; 82 int nowait; 83 { 84 static int logged; 85 register caddr_t p; 86 register int i; 87 int npg; 88 89 npg = ncl * CLSIZE; 90 p = (caddr_t)kmem_malloc(mb_map, ctob(npg), 91 nowait ? M_NOWAIT : M_WAITOK); 92 if (p == NULL) { 93 if (logged == 0) { 94 logged++; 95 log(LOG_ERR, "mb_map full\n"); 96 } 97 return (0); 98 } 99 ncl = ncl * CLBYTES / MCLBYTES; 100 for (i = 0; i < ncl; i++) { 101 ((union mcluster *)p)->mcl_next = mclfree; 102 mclfree = (union mcluster *)p; 103 p += MCLBYTES; 104 mbstat.m_clfree++; 105 } 106 mbstat.m_clusters += ncl; 107 return (1); 108 } 109 110 /* 111 * When MGET failes, ask protocols to free space when short of memory, 112 * then re-attempt to allocate an mbuf. 113 */ 114 struct mbuf * 115 m_retry(i, t) 116 int i, t; 117 { 118 register struct mbuf *m; 119 120 m_reclaim(); 121 #define m_retry(i, t) (struct mbuf *)0 122 MGET(m, i, t); 123 #undef m_retry 124 return (m); 125 } 126 127 /* 128 * As above; retry an MGETHDR. 129 */ 130 struct mbuf * 131 m_retryhdr(i, t) 132 int i, t; 133 { 134 register struct mbuf *m; 135 136 m_reclaim(); 137 #define m_retryhdr(i, t) (struct mbuf *)0 138 MGETHDR(m, i, t); 139 #undef m_retryhdr 140 return (m); 141 } 142 143 void 144 m_reclaim() 145 { 146 register struct domain *dp; 147 register struct protosw *pr; 148 int s = splimp(); 149 150 for (dp = domains; dp; dp = dp->dom_next) 151 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) 152 if (pr->pr_drain) 153 (*pr->pr_drain)(); 154 splx(s); 155 mbstat.m_drain++; 156 } 157 158 /* 159 * Space allocation routines. 160 * These are also available as macros 161 * for critical paths. 162 */ 163 struct mbuf * 164 m_get(nowait, type) 165 int nowait, type; 166 { 167 register struct mbuf *m; 168 169 MGET(m, nowait, type); 170 return (m); 171 } 172 173 struct mbuf * 174 m_gethdr(nowait, type) 175 int nowait, type; 176 { 177 register struct mbuf *m; 178 179 MGETHDR(m, nowait, type); 180 return (m); 181 } 182 183 struct mbuf * 184 m_getclr(nowait, type) 185 int nowait, type; 186 { 187 register struct mbuf *m; 188 189 MGET(m, nowait, type); 190 if (m == 0) 191 return (0); 192 bzero(mtod(m, caddr_t), MLEN); 193 return (m); 194 } 195 196 struct mbuf * 197 m_free(m) 198 struct mbuf *m; 199 { 200 register struct mbuf *n; 201 202 MFREE(m, n); 203 return (n); 204 } 205 206 void 207 m_freem(m) 208 register struct mbuf *m; 209 { 210 register struct mbuf *n; 211 212 if (m == NULL) 213 return; 214 do { 215 MFREE(m, n); 216 m = n; 217 } while (m); 218 } 219 220 /* 221 * Mbuffer utility routines. 222 */ 223 224 /* 225 * Lesser-used path for M_PREPEND: 226 * allocate new mbuf to prepend to chain, 227 * copy junk along. 228 */ 229 struct mbuf * 230 m_prepend(m, len, how) 231 register struct mbuf *m; 232 int len, how; 233 { 234 struct mbuf *mn; 235 236 MGET(mn, how, m->m_type); 237 if (mn == (struct mbuf *)NULL) { 238 m_freem(m); 239 return ((struct mbuf *)NULL); 240 } 241 if (m->m_flags & M_PKTHDR) { 242 M_COPY_PKTHDR(mn, m); 243 m->m_flags &= ~M_PKTHDR; 244 } 245 mn->m_next = m; 246 m = mn; 247 if (len < MHLEN) 248 MH_ALIGN(m, len); 249 m->m_len = len; 250 return (m); 251 } 252 253 /* 254 * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 255 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 256 * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 257 */ 258 int MCFail; 259 260 struct mbuf * 261 m_copym(m, off0, len, wait) 262 register struct mbuf *m; 263 int off0, wait; 264 register int len; 265 { 266 register struct mbuf *n, **np; 267 register int off = off0; 268 struct mbuf *top; 269 int copyhdr = 0; 270 271 if (off < 0 || len < 0) 272 panic("m_copym"); 273 if (off == 0 && m->m_flags & M_PKTHDR) 274 copyhdr = 1; 275 while (off > 0) { 276 if (m == 0) 277 panic("m_copym"); 278 if (off < m->m_len) 279 break; 280 off -= m->m_len; 281 m = m->m_next; 282 } 283 np = ⊤ 284 top = 0; 285 while (len > 0) { 286 if (m == 0) { 287 if (len != M_COPYALL) 288 panic("m_copym"); 289 break; 290 } 291 MGET(n, wait, m->m_type); 292 *np = n; 293 if (n == 0) 294 goto nospace; 295 if (copyhdr) { 296 M_COPY_PKTHDR(n, m); 297 if (len == M_COPYALL) 298 n->m_pkthdr.len -= off0; 299 else 300 n->m_pkthdr.len = len; 301 copyhdr = 0; 302 } 303 n->m_len = min(len, m->m_len - off); 304 if (m->m_flags & M_EXT) { 305 n->m_data = m->m_data + off; 306 mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 307 n->m_ext = m->m_ext; 308 n->m_flags |= M_EXT; 309 } else 310 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 311 (unsigned)n->m_len); 312 if (len != M_COPYALL) 313 len -= n->m_len; 314 off = 0; 315 m = m->m_next; 316 np = &n->m_next; 317 } 318 if (top == 0) 319 MCFail++; 320 return (top); 321 nospace: 322 m_freem(top); 323 MCFail++; 324 return (0); 325 } 326 327 /* 328 * Copy data from an mbuf chain starting "off" bytes from the beginning, 329 * continuing for "len" bytes, into the indicated buffer. 330 */ 331 void 332 m_copydata(m, off, len, cp) 333 register struct mbuf *m; 334 register int off; 335 register int len; 336 caddr_t cp; 337 { 338 register unsigned count; 339 340 if (off < 0 || len < 0) 341 panic("m_copydata"); 342 while (off > 0) { 343 if (m == 0) 344 panic("m_copydata"); 345 if (off < m->m_len) 346 break; 347 off -= m->m_len; 348 m = m->m_next; 349 } 350 while (len > 0) { 351 if (m == 0) 352 panic("m_copydata"); 353 count = min(m->m_len - off, len); 354 bcopy(mtod(m, caddr_t) + off, cp, count); 355 len -= count; 356 cp += count; 357 off = 0; 358 m = m->m_next; 359 } 360 } 361 362 /* 363 * Concatenate mbuf chain n to m. 364 * Both chains must be of the same type (e.g. MT_DATA). 365 * Any m_pkthdr is not updated. 366 */ 367 void 368 m_cat(m, n) 369 register struct mbuf *m, *n; 370 { 371 while (m->m_next) 372 m = m->m_next; 373 while (n) { 374 if (m->m_flags & M_EXT || 375 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 376 /* just join the two chains */ 377 m->m_next = n; 378 return; 379 } 380 /* splat the data from one into the other */ 381 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 382 (u_int)n->m_len); 383 m->m_len += n->m_len; 384 n = m_free(n); 385 } 386 } 387 388 void 389 m_adj(mp, req_len) 390 struct mbuf *mp; 391 int req_len; 392 { 393 register int len = req_len; 394 register struct mbuf *m; 395 register count; 396 397 if ((m = mp) == NULL) 398 return; 399 if (len >= 0) { 400 /* 401 * Trim from head. 402 */ 403 while (m != NULL && len > 0) { 404 if (m->m_len <= len) { 405 len -= m->m_len; 406 m->m_len = 0; 407 m = m->m_next; 408 } else { 409 m->m_len -= len; 410 m->m_data += len; 411 len = 0; 412 } 413 } 414 m = mp; 415 if (mp->m_flags & M_PKTHDR) 416 m->m_pkthdr.len -= (req_len - len); 417 } else { 418 /* 419 * Trim from tail. Scan the mbuf chain, 420 * calculating its length and finding the last mbuf. 421 * If the adjustment only affects this mbuf, then just 422 * adjust and return. Otherwise, rescan and truncate 423 * after the remaining size. 424 */ 425 len = -len; 426 count = 0; 427 for (;;) { 428 count += m->m_len; 429 if (m->m_next == (struct mbuf *)0) 430 break; 431 m = m->m_next; 432 } 433 if (m->m_len >= len) { 434 m->m_len -= len; 435 if (mp->m_flags & M_PKTHDR) 436 mp->m_pkthdr.len -= len; 437 return; 438 } 439 count -= len; 440 if (count < 0) 441 count = 0; 442 /* 443 * Correct length for chain is "count". 444 * Find the mbuf with last data, adjust its length, 445 * and toss data from remaining mbufs on chain. 446 */ 447 m = mp; 448 if (m->m_flags & M_PKTHDR) 449 m->m_pkthdr.len = count; 450 for (; m; m = m->m_next) { 451 if (m->m_len >= count) { 452 m->m_len = count; 453 break; 454 } 455 count -= m->m_len; 456 } 457 while (m->m_next) 458 (m = m->m_next) ->m_len = 0; 459 } 460 } 461 462 /* 463 * Rearange an mbuf chain so that len bytes are contiguous 464 * and in the data area of an mbuf (so that mtod and dtom 465 * will work for a structure of size len). Returns the resulting 466 * mbuf chain on success, frees it and returns null on failure. 467 * If there is room, it will add up to max_protohdr-len extra bytes to the 468 * contiguous region in an attempt to avoid being called next time. 469 */ 470 int MPFail; 471 472 struct mbuf * 473 m_pullup(n, len) 474 register struct mbuf *n; 475 int len; 476 { 477 register struct mbuf *m; 478 register int count; 479 int space; 480 481 /* 482 * If first mbuf has no cluster, and has room for len bytes 483 * without shifting current data, pullup into it, 484 * otherwise allocate a new mbuf to prepend to the chain. 485 */ 486 if ((n->m_flags & M_EXT) == 0 && 487 n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 488 if (n->m_len >= len) 489 return (n); 490 m = n; 491 n = n->m_next; 492 len -= m->m_len; 493 } else { 494 if (len > MHLEN) 495 goto bad; 496 MGET(m, M_DONTWAIT, n->m_type); 497 if (m == 0) 498 goto bad; 499 m->m_len = 0; 500 if (n->m_flags & M_PKTHDR) { 501 M_COPY_PKTHDR(m, n); 502 n->m_flags &= ~M_PKTHDR; 503 } 504 } 505 space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 506 do { 507 count = min(min(max(len, max_protohdr), space), n->m_len); 508 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 509 (unsigned)count); 510 len -= count; 511 m->m_len += count; 512 n->m_len -= count; 513 space -= count; 514 if (n->m_len) 515 n->m_data += count; 516 else 517 n = m_free(n); 518 } while (len > 0 && n); 519 if (len > 0) { 520 (void) m_free(m); 521 goto bad; 522 } 523 m->m_next = n; 524 return (m); 525 bad: 526 m_freem(n); 527 MPFail++; 528 return (0); 529 } 530 531 /* 532 * Partition an mbuf chain in two pieces, returning the tail -- 533 * all but the first len0 bytes. In case of failure, it returns NULL and 534 * attempts to restore the chain to its original state. 535 */ 536 struct mbuf * 537 m_split(m0, len0, wait) 538 register struct mbuf *m0; 539 int len0, wait; 540 { 541 register struct mbuf *m, *n; 542 unsigned len = len0, remain; 543 544 for (m = m0; m && len > m->m_len; m = m->m_next) 545 len -= m->m_len; 546 if (m == 0) 547 return (0); 548 remain = m->m_len - len; 549 if (m0->m_flags & M_PKTHDR) { 550 MGETHDR(n, wait, m0->m_type); 551 if (n == 0) 552 return (0); 553 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 554 n->m_pkthdr.len = m0->m_pkthdr.len - len0; 555 m0->m_pkthdr.len = len0; 556 if (m->m_flags & M_EXT) 557 goto extpacket; 558 if (remain > MHLEN) { 559 /* m can't be the lead packet */ 560 MH_ALIGN(n, 0); 561 n->m_next = m_split(m, len, wait); 562 if (n->m_next == 0) { 563 (void) m_free(n); 564 return (0); 565 } else 566 return (n); 567 } else 568 MH_ALIGN(n, remain); 569 } else if (remain == 0) { 570 n = m->m_next; 571 m->m_next = 0; 572 return (n); 573 } else { 574 MGET(n, wait, m->m_type); 575 if (n == 0) 576 return (0); 577 M_ALIGN(n, remain); 578 } 579 extpacket: 580 if (m->m_flags & M_EXT) { 581 n->m_flags |= M_EXT; 582 n->m_ext = m->m_ext; 583 mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 584 m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ 585 n->m_data = m->m_data + len; 586 } else { 587 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 588 } 589 n->m_len = remain; 590 m->m_len = len; 591 n->m_next = m->m_next; 592 m->m_next = 0; 593 return (n); 594 } 595 /* 596 * Routine to copy from device local memory into mbufs. 597 */ 598 struct mbuf * 599 m_devget(buf, totlen, off0, ifp, copy) 600 char *buf; 601 int totlen, off0; 602 struct ifnet *ifp; 603 void (*copy)(); 604 { 605 register struct mbuf *m; 606 struct mbuf *top = 0, **mp = ⊤ 607 register int off = off0, len; 608 register char *cp; 609 char *epkt; 610 611 cp = buf; 612 epkt = cp + totlen; 613 if (off) { 614 cp += off + 2 * sizeof(u_short); 615 totlen -= 2 * sizeof(u_short); 616 } 617 MGETHDR(m, M_DONTWAIT, MT_DATA); 618 if (m == 0) 619 return (0); 620 m->m_pkthdr.rcvif = ifp; 621 m->m_pkthdr.len = totlen; 622 m->m_len = MHLEN; 623 624 while (totlen > 0) { 625 if (top) { 626 MGET(m, M_DONTWAIT, MT_DATA); 627 if (m == 0) { 628 m_freem(top); 629 return (0); 630 } 631 m->m_len = MLEN; 632 } 633 len = min(totlen, epkt - cp); 634 if (len >= MINCLSIZE) { 635 MCLGET(m, M_DONTWAIT); 636 if (m->m_flags & M_EXT) 637 m->m_len = len = min(len, MCLBYTES); 638 else 639 len = m->m_len; 640 } else { 641 /* 642 * Place initial small packet/header at end of mbuf. 643 */ 644 if (len < m->m_len) { 645 if (top == 0 && len + max_linkhdr <= m->m_len) 646 m->m_data += max_linkhdr; 647 m->m_len = len; 648 } else 649 len = m->m_len; 650 } 651 if (copy) 652 copy(cp, mtod(m, caddr_t), (unsigned)len); 653 else 654 bcopy(cp, mtod(m, caddr_t), (unsigned)len); 655 cp += len; 656 *mp = m; 657 mp = &m->m_next; 658 totlen -= len; 659 if (cp == epkt) 660 cp = buf; 661 } 662 return (top); 663 } 664 665 /* 666 * Copy data from a buffer back into the indicated mbuf chain, 667 * starting "off" bytes from the beginning, extending the mbuf 668 * chain if necessary. 669 */ 670 void 671 m_copyback(m0, off, len, cp) 672 struct mbuf *m0; 673 register int off; 674 register int len; 675 caddr_t cp; 676 { 677 register int mlen; 678 register struct mbuf *m = m0, *n; 679 int totlen = 0; 680 681 if (m0 == 0) 682 return; 683 while (off > (mlen = m->m_len)) { 684 off -= mlen; 685 totlen += mlen; 686 if (m->m_next == 0) { 687 n = m_getclr(M_DONTWAIT, m->m_type); 688 if (n == 0) 689 goto out; 690 n->m_len = min(MLEN, len + off); 691 m->m_next = n; 692 } 693 m = m->m_next; 694 } 695 while (len > 0) { 696 mlen = min (m->m_len - off, len); 697 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 698 cp += mlen; 699 len -= mlen; 700 mlen += off; 701 off = 0; 702 totlen += mlen; 703 if (len == 0) 704 break; 705 if (m->m_next == 0) { 706 n = m_get(M_DONTWAIT, m->m_type); 707 if (n == 0) 708 break; 709 n->m_len = min(MLEN, len); 710 m->m_next = n; 711 } 712 m = m->m_next; 713 } 714 out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 715 m->m_pkthdr.len = totlen; 716 } 717