uipc_mbuf.c revision 22899
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1982, 1986, 1988, 1991, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 331541Srgrimes * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 3422899Swollman * $Id$ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 381541Srgrimes#include <sys/systm.h> 391541Srgrimes#include <sys/proc.h> 401541Srgrimes#include <sys/malloc.h> 411541Srgrimes#define MBTYPES 421541Srgrimes#include <sys/mbuf.h> 431541Srgrimes#include <sys/kernel.h> 441541Srgrimes#include <sys/syslog.h> 451541Srgrimes#include <sys/domain.h> 461541Srgrimes#include <sys/protosw.h> 471541Srgrimes 481541Srgrimes#include <vm/vm.h> 4912662Sdg#include <vm/vm_param.h> 509759Sbde#include <vm/vm_kern.h> 5112662Sdg#include <vm/vm_extern.h> 521541Srgrimes 5310653Sdgstatic void mbinit __P((void *)); 5410358SjulianSYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) 5510358Sjulian 569759Sbdestruct mbuf *mbutl; 571541Srgrimeschar *mclrefcnt; 589759Sbdestruct mbstat mbstat; 5915689Swollmanstruct mbuf *mmbfree; 609759Sbdeunion mcluster *mclfree; 619759Sbdeint max_linkhdr; 629759Sbdeint max_protohdr; 639759Sbdeint max_hdr; 649759Sbdeint max_datalen; 651541Srgrimes 6612819Sphkstatic void m_reclaim __P((void)); 6712819Sphk 6815736Sphk/* "number of clusters of pages" */ 6915736Sphk#define NCL_INIT 1 7015736Sphk 7115744Sphk#define NMB_INIT 16 7215744Sphk 7310358Sjulian/* ARGSUSED*/ 7410358Sjulianstatic void 7512569Sbdembinit(dummy) 7612569Sbde void *dummy; 771541Srgrimes{ 781541Srgrimes int s; 791541Srgrimes 8015689Swollman mmbfree = NULL; mclfree = NULL; 811541Srgrimes s = splimp(); 8215689Swollman if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0) 8315689Swollman goto bad; 8422671Swollman#if MCLBYTES <= PAGE_SIZE 851541Srgrimes if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) 861541Srgrimes goto bad; 8722671Swollman#else 8822671Swollman /* It's OK to call contigmalloc in this context. */ 8922671Swollman if (m_clalloc(16, 0) == 0) 9022671Swollman goto bad; 9122671Swollman#endif 921541Srgrimes splx(s); 931541Srgrimes return; 941541Srgrimesbad: 951541Srgrimes panic("mbinit"); 961541Srgrimes} 971541Srgrimes 981541Srgrimes/* 9915689Swollman * Allocate at least nmb mbufs and place on mbuf free list. 10015689Swollman * Must be called at splimp. 10115689Swollman */ 10215689Swollman/* ARGSUSED */ 10315689Swollmanint 10415689Swollmanm_mballoc(nmb, nowait) 10515689Swollman register int nmb; 10615689Swollman int nowait; 10715689Swollman{ 10815689Swollman register caddr_t p; 10915689Swollman register int i; 11015689Swollman int nbytes; 11115689Swollman 11215689Swollman /* Once we run out of map space, it will be impossible to get 11315689Swollman * any more (nothing is ever freed back to the map) (XXX which 11415689Swollman * is dumb). (however you are not dead as m_reclaim might 11515689Swollman * still be able to free a substantial amount of space). 11615689Swollman */ 11715689Swollman if (mb_map_full) 11815689Swollman return (0); 11915689Swollman 12015689Swollman nbytes = round_page(nmb * MSIZE); 12122899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT); 12222899Swollman if (p == 0 && !nowait) { 12322899Swollman mbstat.m_wait++; 12422899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_WAITOK); 12522899Swollman } 12622899Swollman 12715689Swollman /* 12815689Swollman * Either the map is now full, or this is nowait and there 12915689Swollman * are no pages left. 13015689Swollman */ 13115689Swollman if (p == NULL) 13215689Swollman return (0); 13315689Swollman 13415689Swollman nmb = nbytes / MSIZE; 13515689Swollman for (i = 0; i < nmb; i++) { 13615689Swollman ((struct mbuf *)p)->m_next = mmbfree; 13715689Swollman mmbfree = (struct mbuf *)p; 13815689Swollman p += MSIZE; 13915689Swollman } 14015689Swollman mbstat.m_mbufs += nmb; 14115689Swollman return (1); 14215689Swollman} 14315689Swollman 14422671Swollman#if MCLBYTES > PAGE_SIZE 14522899Swollmanstatic int i_want_my_mcl; 14622671Swollman 14722899Swollmanstatic void 14822671Swollmankproc_mclalloc(void) 14922671Swollman{ 15022671Swollman int status; 15122671Swollman 15222671Swollman while (1) { 15322671Swollman tsleep(&i_want_my_mcl, PVM, "mclalloc", 0); 15422671Swollman 15522671Swollman for (; i_want_my_mcl; i_want_my_mcl--) { 15622671Swollman if (m_clalloc(1, 0) == 0) 15722671Swollman printf("m_clalloc failed even in process context!\n"); 15822671Swollman } 15922671Swollman } 16022671Swollman} 16122671Swollman 16222671Swollmanstatic struct proc *mclallocproc; 16322671Swollmanstatic struct kproc_desc mclalloc_kp = { 16422671Swollman "mclalloc", 16522671Swollman kproc_mclalloc, 16622671Swollman &mclallocproc 16722671Swollman}; 16822671SwollmanSYSINIT_KT(mclallocproc, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start, 16922671Swollman &mclalloc_kp); 17022671Swollman#endif 17122671Swollman 17215689Swollman/* 1731541Srgrimes * Allocate some number of mbuf clusters 1741541Srgrimes * and place on cluster free list. 1751541Srgrimes * Must be called at splimp. 1761541Srgrimes */ 1771541Srgrimes/* ARGSUSED */ 1781549Srgrimesint 1791541Srgrimesm_clalloc(ncl, nowait) 1801541Srgrimes register int ncl; 1811541Srgrimes int nowait; 1821541Srgrimes{ 1831541Srgrimes register caddr_t p; 1841541Srgrimes register int i; 1851541Srgrimes int npg; 1861541Srgrimes 1877066Sdg /* 1887066Sdg * Once we run out of map space, it will be impossible 1897066Sdg * to get any more (nothing is ever freed back to the 1907066Sdg * map). 1917066Sdg */ 19222899Swollman if (mb_map_full) { 19322899Swollman mbstat.m_drops++; 1947066Sdg return (0); 19522899Swollman } 1967066Sdg 19722671Swollman#if MCLBYTES > PAGE_SIZE 19822671Swollman if (nowait) { 19922671Swollman i_want_my_mcl += ncl; 20022671Swollman wakeup(&i_want_my_mcl); 20122899Swollman mbstat.m_wait++; 20222671Swollman p = 0; 20322671Swollman } else { 20422671Swollman p = contigmalloc1(MCLBYTES * ncl, M_DEVBUF, M_WAITOK, 0ul, 20522671Swollman ~0ul, PAGE_SIZE, 0, mb_map); 20622671Swollman } 20722671Swollman#else 20815543Sphk npg = ncl; 20921737Sdg p = (caddr_t)kmem_malloc(mb_map, ctob(npg), 2106191Sbde nowait ? M_NOWAIT : M_WAITOK); 21122671Swollman ncl = ncl * PAGE_SIZE / MCLBYTES; 21222671Swollman#endif 2137066Sdg /* 2147066Sdg * Either the map is now full, or this is nowait and there 2157066Sdg * are no pages left. 2167066Sdg */ 21722899Swollman if (p == NULL) { 21822899Swollman mbstat.m_drops++; 2191541Srgrimes return (0); 22022899Swollman } 2217066Sdg 2221541Srgrimes for (i = 0; i < ncl; i++) { 2231541Srgrimes ((union mcluster *)p)->mcl_next = mclfree; 2241541Srgrimes mclfree = (union mcluster *)p; 2251541Srgrimes p += MCLBYTES; 2261541Srgrimes mbstat.m_clfree++; 2271541Srgrimes } 2281541Srgrimes mbstat.m_clusters += ncl; 2291541Srgrimes return (1); 2301541Srgrimes} 2311541Srgrimes 2321541Srgrimes/* 2331541Srgrimes * When MGET failes, ask protocols to free space when short of memory, 2341541Srgrimes * then re-attempt to allocate an mbuf. 2351541Srgrimes */ 2361541Srgrimesstruct mbuf * 2371541Srgrimesm_retry(i, t) 2381541Srgrimes int i, t; 2391541Srgrimes{ 2401541Srgrimes register struct mbuf *m; 2411541Srgrimes 2421541Srgrimes m_reclaim(); 2431541Srgrimes#define m_retry(i, t) (struct mbuf *)0 2441541Srgrimes MGET(m, i, t); 2451541Srgrimes#undef m_retry 2466669Sdg if (m != NULL) 2476669Sdg mbstat.m_wait++; 2486669Sdg else 2496669Sdg mbstat.m_drops++; 2501541Srgrimes return (m); 2511541Srgrimes} 2521541Srgrimes 2531541Srgrimes/* 2541541Srgrimes * As above; retry an MGETHDR. 2551541Srgrimes */ 2561541Srgrimesstruct mbuf * 2571541Srgrimesm_retryhdr(i, t) 2581541Srgrimes int i, t; 2591541Srgrimes{ 2601541Srgrimes register struct mbuf *m; 2611541Srgrimes 2621541Srgrimes m_reclaim(); 2631541Srgrimes#define m_retryhdr(i, t) (struct mbuf *)0 2641541Srgrimes MGETHDR(m, i, t); 2651541Srgrimes#undef m_retryhdr 2666669Sdg if (m != NULL) 2676669Sdg mbstat.m_wait++; 2686669Sdg else 2696669Sdg mbstat.m_drops++; 2701541Srgrimes return (m); 2711541Srgrimes} 2721541Srgrimes 27312819Sphkstatic void 2741541Srgrimesm_reclaim() 2751541Srgrimes{ 2761541Srgrimes register struct domain *dp; 2771541Srgrimes register struct protosw *pr; 2781541Srgrimes int s = splimp(); 2791541Srgrimes 2801541Srgrimes for (dp = domains; dp; dp = dp->dom_next) 2811541Srgrimes for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) 2821541Srgrimes if (pr->pr_drain) 2831541Srgrimes (*pr->pr_drain)(); 2841541Srgrimes splx(s); 2851541Srgrimes mbstat.m_drain++; 2861541Srgrimes} 2871541Srgrimes 2881541Srgrimes/* 2891541Srgrimes * Space allocation routines. 2901541Srgrimes * These are also available as macros 2911541Srgrimes * for critical paths. 2921541Srgrimes */ 2931541Srgrimesstruct mbuf * 2941541Srgrimesm_get(nowait, type) 2951541Srgrimes int nowait, type; 2961541Srgrimes{ 2971541Srgrimes register struct mbuf *m; 2981541Srgrimes 2991541Srgrimes MGET(m, nowait, type); 3001541Srgrimes return (m); 3011541Srgrimes} 3021541Srgrimes 3031541Srgrimesstruct mbuf * 3041541Srgrimesm_gethdr(nowait, type) 3051541Srgrimes int nowait, type; 3061541Srgrimes{ 3071541Srgrimes register struct mbuf *m; 3081541Srgrimes 3091541Srgrimes MGETHDR(m, nowait, type); 3101541Srgrimes return (m); 3111541Srgrimes} 3121541Srgrimes 3131541Srgrimesstruct mbuf * 3141541Srgrimesm_getclr(nowait, type) 3151541Srgrimes int nowait, type; 3161541Srgrimes{ 3171541Srgrimes register struct mbuf *m; 3181541Srgrimes 3191541Srgrimes MGET(m, nowait, type); 3201541Srgrimes if (m == 0) 3211541Srgrimes return (0); 3221541Srgrimes bzero(mtod(m, caddr_t), MLEN); 3231541Srgrimes return (m); 3241541Srgrimes} 3251541Srgrimes 3261541Srgrimesstruct mbuf * 3271541Srgrimesm_free(m) 3281541Srgrimes struct mbuf *m; 3291541Srgrimes{ 3301541Srgrimes register struct mbuf *n; 3311541Srgrimes 3321541Srgrimes MFREE(m, n); 3331541Srgrimes return (n); 3341541Srgrimes} 3351541Srgrimes 3361541Srgrimesvoid 3371541Srgrimesm_freem(m) 3381541Srgrimes register struct mbuf *m; 3391541Srgrimes{ 3401541Srgrimes register struct mbuf *n; 3411541Srgrimes 3421541Srgrimes if (m == NULL) 3431541Srgrimes return; 3441541Srgrimes do { 3451541Srgrimes MFREE(m, n); 3463308Sphk m = n; 3473308Sphk } while (m); 3481541Srgrimes} 3491541Srgrimes 3501541Srgrimes/* 3511541Srgrimes * Mbuffer utility routines. 3521541Srgrimes */ 3531541Srgrimes 3541541Srgrimes/* 3551541Srgrimes * Lesser-used path for M_PREPEND: 3561541Srgrimes * allocate new mbuf to prepend to chain, 3571541Srgrimes * copy junk along. 3581541Srgrimes */ 3591541Srgrimesstruct mbuf * 3601541Srgrimesm_prepend(m, len, how) 3611541Srgrimes register struct mbuf *m; 3621541Srgrimes int len, how; 3631541Srgrimes{ 3641541Srgrimes struct mbuf *mn; 3651541Srgrimes 3661541Srgrimes MGET(mn, how, m->m_type); 3671541Srgrimes if (mn == (struct mbuf *)NULL) { 3681541Srgrimes m_freem(m); 3691541Srgrimes return ((struct mbuf *)NULL); 3701541Srgrimes } 3711541Srgrimes if (m->m_flags & M_PKTHDR) { 3721541Srgrimes M_COPY_PKTHDR(mn, m); 3731541Srgrimes m->m_flags &= ~M_PKTHDR; 3741541Srgrimes } 3751541Srgrimes mn->m_next = m; 3761541Srgrimes m = mn; 3771541Srgrimes if (len < MHLEN) 3781541Srgrimes MH_ALIGN(m, len); 3791541Srgrimes m->m_len = len; 3801541Srgrimes return (m); 3811541Srgrimes} 3821541Srgrimes 3831541Srgrimes/* 3841541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 3851541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 3861541Srgrimes * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 3871541Srgrimes */ 38812819Sphkstatic int MCFail; 3891541Srgrimes 3901541Srgrimesstruct mbuf * 3911541Srgrimesm_copym(m, off0, len, wait) 3921541Srgrimes register struct mbuf *m; 3931541Srgrimes int off0, wait; 3941541Srgrimes register int len; 3951541Srgrimes{ 3961541Srgrimes register struct mbuf *n, **np; 3971541Srgrimes register int off = off0; 3981541Srgrimes struct mbuf *top; 3991541Srgrimes int copyhdr = 0; 4001541Srgrimes 4011541Srgrimes if (off < 0 || len < 0) 4021541Srgrimes panic("m_copym"); 4031541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 4041541Srgrimes copyhdr = 1; 4051541Srgrimes while (off > 0) { 4061541Srgrimes if (m == 0) 4071541Srgrimes panic("m_copym"); 4081541Srgrimes if (off < m->m_len) 4091541Srgrimes break; 4101541Srgrimes off -= m->m_len; 4111541Srgrimes m = m->m_next; 4121541Srgrimes } 4131541Srgrimes np = ⊤ 4141541Srgrimes top = 0; 4151541Srgrimes while (len > 0) { 4161541Srgrimes if (m == 0) { 4171541Srgrimes if (len != M_COPYALL) 4181541Srgrimes panic("m_copym"); 4191541Srgrimes break; 4201541Srgrimes } 4211541Srgrimes MGET(n, wait, m->m_type); 4221541Srgrimes *np = n; 4231541Srgrimes if (n == 0) 4241541Srgrimes goto nospace; 4251541Srgrimes if (copyhdr) { 4261541Srgrimes M_COPY_PKTHDR(n, m); 4271541Srgrimes if (len == M_COPYALL) 4281541Srgrimes n->m_pkthdr.len -= off0; 4291541Srgrimes else 4301541Srgrimes n->m_pkthdr.len = len; 4311541Srgrimes copyhdr = 0; 4321541Srgrimes } 4331541Srgrimes n->m_len = min(len, m->m_len - off); 4341541Srgrimes if (m->m_flags & M_EXT) { 4351541Srgrimes n->m_data = m->m_data + off; 43617663Sjulian if(!m->m_ext.ext_ref) 43717663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 43817663Sjulian else 43917663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 44017663Sjulian m->m_ext.ext_size); 4411541Srgrimes n->m_ext = m->m_ext; 4421541Srgrimes n->m_flags |= M_EXT; 4431541Srgrimes } else 4441541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 4451541Srgrimes (unsigned)n->m_len); 4461541Srgrimes if (len != M_COPYALL) 4471541Srgrimes len -= n->m_len; 4481541Srgrimes off = 0; 4491541Srgrimes m = m->m_next; 4501541Srgrimes np = &n->m_next; 4511541Srgrimes } 4521541Srgrimes if (top == 0) 4531541Srgrimes MCFail++; 4541541Srgrimes return (top); 4551541Srgrimesnospace: 4561541Srgrimes m_freem(top); 4571541Srgrimes MCFail++; 4581541Srgrimes return (0); 4591541Srgrimes} 4601541Srgrimes 4611541Srgrimes/* 46215689Swollman * Copy an entire packet, including header (which must be present). 46315689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 46415689Swollman */ 46515689Swollmanstruct mbuf * 46615689Swollmanm_copypacket(m, how) 46715689Swollman struct mbuf *m; 46815689Swollman int how; 46915689Swollman{ 47015689Swollman struct mbuf *top, *n, *o; 47115689Swollman 47215689Swollman MGET(n, how, m->m_type); 47315689Swollman top = n; 47415689Swollman if (!n) 47515689Swollman goto nospace; 47615689Swollman 47715689Swollman M_COPY_PKTHDR(n, m); 47815689Swollman n->m_len = m->m_len; 47915689Swollman if (m->m_flags & M_EXT) { 48015689Swollman n->m_data = m->m_data; 48115689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 48215689Swollman n->m_ext = m->m_ext; 48315689Swollman n->m_flags |= M_EXT; 48415689Swollman } else { 48515689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 48615689Swollman } 48715689Swollman 48815689Swollman m = m->m_next; 48915689Swollman while (m) { 49015689Swollman MGET(o, how, m->m_type); 49115689Swollman if (!o) 49215689Swollman goto nospace; 49315689Swollman 49415689Swollman n->m_next = o; 49515689Swollman n = n->m_next; 49615689Swollman 49715689Swollman n->m_len = m->m_len; 49815689Swollman if (m->m_flags & M_EXT) { 49915689Swollman n->m_data = m->m_data; 50015689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 50115689Swollman n->m_ext = m->m_ext; 50215689Swollman n->m_flags |= M_EXT; 50315689Swollman } else { 50415689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 50515689Swollman } 50615689Swollman 50715689Swollman m = m->m_next; 50815689Swollman } 50915689Swollman return top; 51015689Swollmannospace: 51115689Swollman m_freem(top); 51215689Swollman MCFail++; 51315689Swollman return 0; 51415689Swollman} 51515689Swollman 51615689Swollman/* 5171541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 5181541Srgrimes * continuing for "len" bytes, into the indicated buffer. 5191541Srgrimes */ 5201549Srgrimesvoid 5211541Srgrimesm_copydata(m, off, len, cp) 5221541Srgrimes register struct mbuf *m; 5231541Srgrimes register int off; 5241541Srgrimes register int len; 5251541Srgrimes caddr_t cp; 5261541Srgrimes{ 5271541Srgrimes register unsigned count; 5281541Srgrimes 5291541Srgrimes if (off < 0 || len < 0) 5301541Srgrimes panic("m_copydata"); 5311541Srgrimes while (off > 0) { 5321541Srgrimes if (m == 0) 5331541Srgrimes panic("m_copydata"); 5341541Srgrimes if (off < m->m_len) 5351541Srgrimes break; 5361541Srgrimes off -= m->m_len; 5371541Srgrimes m = m->m_next; 5381541Srgrimes } 5391541Srgrimes while (len > 0) { 5401541Srgrimes if (m == 0) 5411541Srgrimes panic("m_copydata"); 5421541Srgrimes count = min(m->m_len - off, len); 5431541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 5441541Srgrimes len -= count; 5451541Srgrimes cp += count; 5461541Srgrimes off = 0; 5471541Srgrimes m = m->m_next; 5481541Srgrimes } 5491541Srgrimes} 5501541Srgrimes 5511541Srgrimes/* 5521541Srgrimes * Concatenate mbuf chain n to m. 5531541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 5541541Srgrimes * Any m_pkthdr is not updated. 5551541Srgrimes */ 5561549Srgrimesvoid 5571541Srgrimesm_cat(m, n) 5581541Srgrimes register struct mbuf *m, *n; 5591541Srgrimes{ 5601541Srgrimes while (m->m_next) 5611541Srgrimes m = m->m_next; 5621541Srgrimes while (n) { 5631541Srgrimes if (m->m_flags & M_EXT || 5641541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 5651541Srgrimes /* just join the two chains */ 5661541Srgrimes m->m_next = n; 5671541Srgrimes return; 5681541Srgrimes } 5691541Srgrimes /* splat the data from one into the other */ 5701541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 5711541Srgrimes (u_int)n->m_len); 5721541Srgrimes m->m_len += n->m_len; 5731541Srgrimes n = m_free(n); 5741541Srgrimes } 5751541Srgrimes} 5761541Srgrimes 5771549Srgrimesvoid 5781541Srgrimesm_adj(mp, req_len) 5791541Srgrimes struct mbuf *mp; 5801541Srgrimes int req_len; 5811541Srgrimes{ 5821541Srgrimes register int len = req_len; 5831541Srgrimes register struct mbuf *m; 5841541Srgrimes register count; 5851541Srgrimes 5861541Srgrimes if ((m = mp) == NULL) 5871541Srgrimes return; 5881541Srgrimes if (len >= 0) { 5891541Srgrimes /* 5901541Srgrimes * Trim from head. 5911541Srgrimes */ 5921541Srgrimes while (m != NULL && len > 0) { 5931541Srgrimes if (m->m_len <= len) { 5941541Srgrimes len -= m->m_len; 5951541Srgrimes m->m_len = 0; 5961541Srgrimes m = m->m_next; 5971541Srgrimes } else { 5981541Srgrimes m->m_len -= len; 5991541Srgrimes m->m_data += len; 6001541Srgrimes len = 0; 6011541Srgrimes } 6021541Srgrimes } 6031541Srgrimes m = mp; 6041541Srgrimes if (mp->m_flags & M_PKTHDR) 6051541Srgrimes m->m_pkthdr.len -= (req_len - len); 6061541Srgrimes } else { 6071541Srgrimes /* 6081541Srgrimes * Trim from tail. Scan the mbuf chain, 6091541Srgrimes * calculating its length and finding the last mbuf. 6101541Srgrimes * If the adjustment only affects this mbuf, then just 6111541Srgrimes * adjust and return. Otherwise, rescan and truncate 6121541Srgrimes * after the remaining size. 6131541Srgrimes */ 6141541Srgrimes len = -len; 6151541Srgrimes count = 0; 6161541Srgrimes for (;;) { 6171541Srgrimes count += m->m_len; 6181541Srgrimes if (m->m_next == (struct mbuf *)0) 6191541Srgrimes break; 6201541Srgrimes m = m->m_next; 6211541Srgrimes } 6221541Srgrimes if (m->m_len >= len) { 6231541Srgrimes m->m_len -= len; 6241541Srgrimes if (mp->m_flags & M_PKTHDR) 6251541Srgrimes mp->m_pkthdr.len -= len; 6261541Srgrimes return; 6271541Srgrimes } 6281541Srgrimes count -= len; 6291541Srgrimes if (count < 0) 6301541Srgrimes count = 0; 6311541Srgrimes /* 6321541Srgrimes * Correct length for chain is "count". 6331541Srgrimes * Find the mbuf with last data, adjust its length, 6341541Srgrimes * and toss data from remaining mbufs on chain. 6351541Srgrimes */ 6361541Srgrimes m = mp; 6371541Srgrimes if (m->m_flags & M_PKTHDR) 6381541Srgrimes m->m_pkthdr.len = count; 6391541Srgrimes for (; m; m = m->m_next) { 6401541Srgrimes if (m->m_len >= count) { 6411541Srgrimes m->m_len = count; 6421541Srgrimes break; 6431541Srgrimes } 6441541Srgrimes count -= m->m_len; 6451541Srgrimes } 6463308Sphk while (m->m_next) 6473308Sphk (m = m->m_next) ->m_len = 0; 6481541Srgrimes } 6491541Srgrimes} 6501541Srgrimes 6511541Srgrimes/* 6521541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 6531541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 6541541Srgrimes * will work for a structure of size len). Returns the resulting 6551541Srgrimes * mbuf chain on success, frees it and returns null on failure. 6561541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 6571541Srgrimes * contiguous region in an attempt to avoid being called next time. 6581541Srgrimes */ 65912819Sphkstatic int MPFail; 6601541Srgrimes 6611541Srgrimesstruct mbuf * 6621541Srgrimesm_pullup(n, len) 6631541Srgrimes register struct mbuf *n; 6641541Srgrimes int len; 6651541Srgrimes{ 6661541Srgrimes register struct mbuf *m; 6671541Srgrimes register int count; 6681541Srgrimes int space; 6691541Srgrimes 6701541Srgrimes /* 6711541Srgrimes * If first mbuf has no cluster, and has room for len bytes 6721541Srgrimes * without shifting current data, pullup into it, 6731541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 6741541Srgrimes */ 6751541Srgrimes if ((n->m_flags & M_EXT) == 0 && 6761541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 6771541Srgrimes if (n->m_len >= len) 6781541Srgrimes return (n); 6791541Srgrimes m = n; 6801541Srgrimes n = n->m_next; 6811541Srgrimes len -= m->m_len; 6821541Srgrimes } else { 6831541Srgrimes if (len > MHLEN) 6841541Srgrimes goto bad; 6851541Srgrimes MGET(m, M_DONTWAIT, n->m_type); 6861541Srgrimes if (m == 0) 6871541Srgrimes goto bad; 6881541Srgrimes m->m_len = 0; 6891541Srgrimes if (n->m_flags & M_PKTHDR) { 6901541Srgrimes M_COPY_PKTHDR(m, n); 6911541Srgrimes n->m_flags &= ~M_PKTHDR; 6921541Srgrimes } 6931541Srgrimes } 6941541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 6951541Srgrimes do { 6961541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 6971541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 6981541Srgrimes (unsigned)count); 6991541Srgrimes len -= count; 7001541Srgrimes m->m_len += count; 7011541Srgrimes n->m_len -= count; 7021541Srgrimes space -= count; 7031541Srgrimes if (n->m_len) 7041541Srgrimes n->m_data += count; 7051541Srgrimes else 7061541Srgrimes n = m_free(n); 7071541Srgrimes } while (len > 0 && n); 7081541Srgrimes if (len > 0) { 7091541Srgrimes (void) m_free(m); 7101541Srgrimes goto bad; 7111541Srgrimes } 7121541Srgrimes m->m_next = n; 7131541Srgrimes return (m); 7141541Srgrimesbad: 7151541Srgrimes m_freem(n); 7161541Srgrimes MPFail++; 7171541Srgrimes return (0); 7181541Srgrimes} 7191541Srgrimes 7201541Srgrimes/* 7211541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 7221541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 7231541Srgrimes * attempts to restore the chain to its original state. 7241541Srgrimes */ 7251541Srgrimesstruct mbuf * 7261541Srgrimesm_split(m0, len0, wait) 7271541Srgrimes register struct mbuf *m0; 7281541Srgrimes int len0, wait; 7291541Srgrimes{ 7301541Srgrimes register struct mbuf *m, *n; 7311541Srgrimes unsigned len = len0, remain; 7321541Srgrimes 7331541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 7341541Srgrimes len -= m->m_len; 7351541Srgrimes if (m == 0) 7361541Srgrimes return (0); 7371541Srgrimes remain = m->m_len - len; 7381541Srgrimes if (m0->m_flags & M_PKTHDR) { 7391541Srgrimes MGETHDR(n, wait, m0->m_type); 7401541Srgrimes if (n == 0) 7411541Srgrimes return (0); 7421541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 7431541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 7441541Srgrimes m0->m_pkthdr.len = len0; 7451541Srgrimes if (m->m_flags & M_EXT) 7461541Srgrimes goto extpacket; 7471541Srgrimes if (remain > MHLEN) { 7481541Srgrimes /* m can't be the lead packet */ 7491541Srgrimes MH_ALIGN(n, 0); 7501541Srgrimes n->m_next = m_split(m, len, wait); 7511541Srgrimes if (n->m_next == 0) { 7521541Srgrimes (void) m_free(n); 7531541Srgrimes return (0); 7541541Srgrimes } else 7551541Srgrimes return (n); 7561541Srgrimes } else 7571541Srgrimes MH_ALIGN(n, remain); 7581541Srgrimes } else if (remain == 0) { 7591541Srgrimes n = m->m_next; 7601541Srgrimes m->m_next = 0; 7611541Srgrimes return (n); 7621541Srgrimes } else { 7631541Srgrimes MGET(n, wait, m->m_type); 7641541Srgrimes if (n == 0) 7651541Srgrimes return (0); 7661541Srgrimes M_ALIGN(n, remain); 7671541Srgrimes } 7681541Srgrimesextpacket: 7691541Srgrimes if (m->m_flags & M_EXT) { 7701541Srgrimes n->m_flags |= M_EXT; 7711541Srgrimes n->m_ext = m->m_ext; 77217663Sjulian if(!m->m_ext.ext_ref) 77317663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 77417663Sjulian else 77517663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 77617663Sjulian m->m_ext.ext_size); 7771541Srgrimes m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ 7781541Srgrimes n->m_data = m->m_data + len; 7791541Srgrimes } else { 7801541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 7811541Srgrimes } 7821541Srgrimes n->m_len = remain; 7831541Srgrimes m->m_len = len; 7841541Srgrimes n->m_next = m->m_next; 7851541Srgrimes m->m_next = 0; 7861541Srgrimes return (n); 7871541Srgrimes} 7881541Srgrimes/* 7891541Srgrimes * Routine to copy from device local memory into mbufs. 7901541Srgrimes */ 7911541Srgrimesstruct mbuf * 7921541Srgrimesm_devget(buf, totlen, off0, ifp, copy) 7931541Srgrimes char *buf; 7941541Srgrimes int totlen, off0; 7951541Srgrimes struct ifnet *ifp; 79612577Sbde void (*copy) __P((char *from, caddr_t to, u_int len)); 7971541Srgrimes{ 7981541Srgrimes register struct mbuf *m; 7991541Srgrimes struct mbuf *top = 0, **mp = ⊤ 8001541Srgrimes register int off = off0, len; 8011541Srgrimes register char *cp; 8021541Srgrimes char *epkt; 8031541Srgrimes 8041541Srgrimes cp = buf; 8051541Srgrimes epkt = cp + totlen; 8061541Srgrimes if (off) { 8071541Srgrimes cp += off + 2 * sizeof(u_short); 8081541Srgrimes totlen -= 2 * sizeof(u_short); 8091541Srgrimes } 8101541Srgrimes MGETHDR(m, M_DONTWAIT, MT_DATA); 8111541Srgrimes if (m == 0) 8121541Srgrimes return (0); 8131541Srgrimes m->m_pkthdr.rcvif = ifp; 8141541Srgrimes m->m_pkthdr.len = totlen; 8151541Srgrimes m->m_len = MHLEN; 8161541Srgrimes 8171541Srgrimes while (totlen > 0) { 8181541Srgrimes if (top) { 8191541Srgrimes MGET(m, M_DONTWAIT, MT_DATA); 8201541Srgrimes if (m == 0) { 8211541Srgrimes m_freem(top); 8221541Srgrimes return (0); 8231541Srgrimes } 8241541Srgrimes m->m_len = MLEN; 8251541Srgrimes } 8261541Srgrimes len = min(totlen, epkt - cp); 8271541Srgrimes if (len >= MINCLSIZE) { 8281541Srgrimes MCLGET(m, M_DONTWAIT); 8291541Srgrimes if (m->m_flags & M_EXT) 8301541Srgrimes m->m_len = len = min(len, MCLBYTES); 8311541Srgrimes else 8321541Srgrimes len = m->m_len; 8331541Srgrimes } else { 8341541Srgrimes /* 8351541Srgrimes * Place initial small packet/header at end of mbuf. 8361541Srgrimes */ 8371541Srgrimes if (len < m->m_len) { 8381541Srgrimes if (top == 0 && len + max_linkhdr <= m->m_len) 8391541Srgrimes m->m_data += max_linkhdr; 8401541Srgrimes m->m_len = len; 8411541Srgrimes } else 8421541Srgrimes len = m->m_len; 8431541Srgrimes } 8441541Srgrimes if (copy) 8451541Srgrimes copy(cp, mtod(m, caddr_t), (unsigned)len); 8461541Srgrimes else 8471541Srgrimes bcopy(cp, mtod(m, caddr_t), (unsigned)len); 8481541Srgrimes cp += len; 8491541Srgrimes *mp = m; 8501541Srgrimes mp = &m->m_next; 8511541Srgrimes totlen -= len; 8521541Srgrimes if (cp == epkt) 8531541Srgrimes cp = buf; 8541541Srgrimes } 8551541Srgrimes return (top); 8561541Srgrimes} 8573352Sphk 8583352Sphk/* 8593352Sphk * Copy data from a buffer back into the indicated mbuf chain, 8603352Sphk * starting "off" bytes from the beginning, extending the mbuf 8613352Sphk * chain if necessary. 8623352Sphk */ 8633352Sphkvoid 8643352Sphkm_copyback(m0, off, len, cp) 8653352Sphk struct mbuf *m0; 8663352Sphk register int off; 8673352Sphk register int len; 8683352Sphk caddr_t cp; 8693352Sphk{ 8703352Sphk register int mlen; 8713352Sphk register struct mbuf *m = m0, *n; 8723352Sphk int totlen = 0; 8733352Sphk 8743352Sphk if (m0 == 0) 8753352Sphk return; 8763352Sphk while (off > (mlen = m->m_len)) { 8773352Sphk off -= mlen; 8783352Sphk totlen += mlen; 8793352Sphk if (m->m_next == 0) { 8803352Sphk n = m_getclr(M_DONTWAIT, m->m_type); 8813352Sphk if (n == 0) 8823352Sphk goto out; 8833352Sphk n->m_len = min(MLEN, len + off); 8843352Sphk m->m_next = n; 8853352Sphk } 8863352Sphk m = m->m_next; 8873352Sphk } 8883352Sphk while (len > 0) { 8893352Sphk mlen = min (m->m_len - off, len); 8903352Sphk bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 8913352Sphk cp += mlen; 8923352Sphk len -= mlen; 8933352Sphk mlen += off; 8943352Sphk off = 0; 8953352Sphk totlen += mlen; 8963352Sphk if (len == 0) 8973352Sphk break; 8983352Sphk if (m->m_next == 0) { 8993352Sphk n = m_get(M_DONTWAIT, m->m_type); 9003352Sphk if (n == 0) 9013352Sphk break; 9023352Sphk n->m_len = min(MLEN, len); 9033352Sphk m->m_next = n; 9043352Sphk } 9053352Sphk m = m->m_next; 9063352Sphk } 9073352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 9083352Sphk m->m_pkthdr.len = totlen; 9093352Sphk} 910