uipc_mbuf.c revision 55171
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 3450477Speter * $FreeBSD: head/sys/kern/uipc_mbuf.c 55171 1999-12-28 06:35:57Z msmith $ 351541Srgrimes */ 361541Srgrimes 3748579Smsmith#include "opt_param.h" 381541Srgrimes#include <sys/param.h> 391541Srgrimes#include <sys/systm.h> 4032036Sbde#include <sys/malloc.h> 411541Srgrimes#include <sys/mbuf.h> 421541Srgrimes#include <sys/kernel.h> 4323081Swollman#include <sys/sysctl.h> 441541Srgrimes#include <sys/domain.h> 451541Srgrimes#include <sys/protosw.h> 461541Srgrimes 471541Srgrimes#include <vm/vm.h> 489759Sbde#include <vm/vm_kern.h> 4912662Sdg#include <vm/vm_extern.h> 501541Srgrimes 5154478Sgreen#ifdef INVARIANTS 5254478Sgreen#include <machine/cpu.h> 5354478Sgreen#endif 5454478Sgreen 5510653Sdgstatic void mbinit __P((void *)); 5610358SjulianSYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) 5710358Sjulian 589759Sbdestruct mbuf *mbutl; 591541Srgrimeschar *mclrefcnt; 609759Sbdestruct mbstat mbstat; 6115689Swollmanstruct mbuf *mmbfree; 629759Sbdeunion mcluster *mclfree; 639759Sbdeint max_linkhdr; 649759Sbdeint max_protohdr; 659759Sbdeint max_hdr; 669759Sbdeint max_datalen; 6748579Smsmithint nmbclusters; 6848579Smsmithint nmbufs; 6954584Sgreenu_int m_mballoc_wid = 0; 7054584Sgreenu_int m_clalloc_wid = 0; 711541Srgrimes 7244078SdfrSYSCTL_DECL(_kern_ipc); 7323081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, 7423081Swollman &max_linkhdr, 0, ""); 7523081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, 7623081Swollman &max_protohdr, 0, ""); 7723081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, ""); 7823081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, 7923081Swollman &max_datalen, 0, ""); 8054478SgreenSYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW, 8154478Sgreen &mbuf_wait, 0, ""); 8223081SwollmanSYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, ""); 8348579SmsmithSYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD, 8455171Smsmith &nmbclusters, 0, "Maximum number of mbuf clusters available"); 8555171SmsmithSYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RD, &nmbufs, 0, 8655171Smsmith "Maximum number of mbufs available"); 8748579Smsmith#ifndef NMBCLUSTERS 8848579Smsmith#define NMBCLUSTERS (512 + MAXUSERS * 16) 8948579Smsmith#endif 9048579SmsmithTUNABLE_INT_DECL("kern.ipc.nmbclusters", NMBCLUSTERS, nmbclusters); 9155171SmsmithTUNABLE_INT_DECL("kern.ipc.nmbufs", NMBCLUSTERS * 4, nmbufs); 9223081Swollman 9312819Sphkstatic void m_reclaim __P((void)); 9412819Sphk 9515736Sphk/* "number of clusters of pages" */ 9615736Sphk#define NCL_INIT 1 9715736Sphk 9815744Sphk#define NMB_INIT 16 9915744Sphk 10010358Sjulian/* ARGSUSED*/ 10110358Sjulianstatic void 10212569Sbdembinit(dummy) 10312569Sbde void *dummy; 1041541Srgrimes{ 1051541Srgrimes int s; 1061541Srgrimes 10715689Swollman mmbfree = NULL; mclfree = NULL; 10823081Swollman mbstat.m_msize = MSIZE; 10923081Swollman mbstat.m_mclbytes = MCLBYTES; 11023081Swollman mbstat.m_minclsize = MINCLSIZE; 11123081Swollman mbstat.m_mlen = MLEN; 11223081Swollman mbstat.m_mhlen = MHLEN; 11323081Swollman 1141541Srgrimes s = splimp(); 11515689Swollman if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0) 11615689Swollman goto bad; 11722671Swollman#if MCLBYTES <= PAGE_SIZE 1181541Srgrimes if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) 1191541Srgrimes goto bad; 12022671Swollman#else 12122671Swollman /* It's OK to call contigmalloc in this context. */ 12232036Sbde if (m_clalloc(16, M_WAIT) == 0) 12322671Swollman goto bad; 12422671Swollman#endif 1251541Srgrimes splx(s); 1261541Srgrimes return; 1271541Srgrimesbad: 1281541Srgrimes panic("mbinit"); 1291541Srgrimes} 1301541Srgrimes 1311541Srgrimes/* 13215689Swollman * Allocate at least nmb mbufs and place on mbuf free list. 13315689Swollman * Must be called at splimp. 13415689Swollman */ 13515689Swollman/* ARGSUSED */ 13615689Swollmanint 13732036Sbdem_mballoc(nmb, how) 13815689Swollman register int nmb; 13932036Sbde int how; 14015689Swollman{ 14115689Swollman register caddr_t p; 14215689Swollman register int i; 14315689Swollman int nbytes; 14415689Swollman 14554478Sgreen /* 14655171Smsmith * If we've hit the mbuf limit, stop allocating from mb_map, 14755171Smsmith * (or trying to) in order to avoid dipping into the section of 14855171Smsmith * mb_map which we've "reserved" for clusters. 14955171Smsmith */ 15055171Smsmith if ((nmb + mbstat.m_mbufs) > nmbufs) 15155171Smsmith return (0); 15255171Smsmith 15355171Smsmith /* 15454478Sgreen * Once we run out of map space, it will be impossible to get 15554478Sgreen * any more (nothing is ever freed back to the map) 15654478Sgreen * -- however you are not dead as m_reclaim might 15754478Sgreen * still be able to free a substantial amount of space. 15854478Sgreen * 15954478Sgreen * XXX Furthermore, we can also work with "recycled" mbufs (when 16054478Sgreen * we're calling with M_WAIT the sleep procedure will be woken 16154478Sgreen * up when an mbuf is freed. See m_mballoc_wait()). 16215689Swollman */ 16315689Swollman if (mb_map_full) 16415689Swollman return (0); 16515689Swollman 16615689Swollman nbytes = round_page(nmb * MSIZE); 16722899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT); 16832036Sbde if (p == 0 && how == M_WAIT) { 16922899Swollman mbstat.m_wait++; 17022899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_WAITOK); 17122899Swollman } 17222899Swollman 17315689Swollman /* 17432036Sbde * Either the map is now full, or `how' is M_NOWAIT and there 17515689Swollman * are no pages left. 17615689Swollman */ 17715689Swollman if (p == NULL) 17815689Swollman return (0); 17915689Swollman 18015689Swollman nmb = nbytes / MSIZE; 18115689Swollman for (i = 0; i < nmb; i++) { 18215689Swollman ((struct mbuf *)p)->m_next = mmbfree; 18315689Swollman mmbfree = (struct mbuf *)p; 18415689Swollman p += MSIZE; 18515689Swollman } 18615689Swollman mbstat.m_mbufs += nmb; 18715689Swollman return (1); 18815689Swollman} 18915689Swollman 19054478Sgreen/* 19154478Sgreen * Once the mb_map has been exhausted and if the call to the allocation macros 19254478Sgreen * (or, in some cases, functions) is with M_WAIT, then it is necessary to rely 19354478Sgreen * solely on reclaimed mbufs. Here we wait for an mbuf to be freed for a 19454478Sgreen * designated (mbuf_wait) time. 19554478Sgreen */ 19654478Sgreenstruct mbuf * 19754478Sgreenm_mballoc_wait(int caller, int type) 19854478Sgreen{ 19954478Sgreen struct mbuf *p; 20054478Sgreen int s; 20154478Sgreen 20254478Sgreen m_mballoc_wid++; 20354478Sgreen if ((tsleep(&m_mballoc_wid, PVM, "mballc", mbuf_wait)) == EWOULDBLOCK) 20454478Sgreen m_mballoc_wid--; 20554478Sgreen 20654478Sgreen /* 20754478Sgreen * Now that we (think) that we've got something, we will redo an 20854478Sgreen * MGET, but avoid getting into another instance of m_mballoc_wait() 20954478Sgreen * XXX: We retry to fetch _even_ if the sleep timed out. This is left 21054478Sgreen * this way, purposely, in the [unlikely] case that an mbuf was 21154478Sgreen * freed but the sleep was not awakened in time. 21254478Sgreen */ 21354478Sgreen p = NULL; 21454478Sgreen switch (caller) { 21554478Sgreen case MGET_C: 21654478Sgreen MGET(p, M_DONTWAIT, type); 21754478Sgreen break; 21854478Sgreen case MGETHDR_C: 21954478Sgreen MGETHDR(p, M_DONTWAIT, type); 22054478Sgreen break; 22154478Sgreen default: 22254478Sgreen panic("m_mballoc_wait: invalid caller (%d)", caller); 22354478Sgreen } 22454478Sgreen 22554478Sgreen s = splimp(); 22654478Sgreen if (p != NULL) { /* We waited and got something... */ 22754478Sgreen mbstat.m_wait++; 22854478Sgreen /* Wake up another if we have more free. */ 22954478Sgreen if (mmbfree != NULL) 23054787Sgreen MMBWAKEUP(); 23154478Sgreen } 23254478Sgreen splx(s); 23354478Sgreen return (p); 23454478Sgreen} 23554478Sgreen 23622671Swollman#if MCLBYTES > PAGE_SIZE 23722899Swollmanstatic int i_want_my_mcl; 23822671Swollman 23922899Swollmanstatic void 24022671Swollmankproc_mclalloc(void) 24122671Swollman{ 24222671Swollman int status; 24322671Swollman 24422671Swollman while (1) { 24522671Swollman tsleep(&i_want_my_mcl, PVM, "mclalloc", 0); 24622671Swollman 24722671Swollman for (; i_want_my_mcl; i_want_my_mcl--) { 24832036Sbde if (m_clalloc(1, M_WAIT) == 0) 24922671Swollman printf("m_clalloc failed even in process context!\n"); 25022671Swollman } 25122671Swollman } 25222671Swollman} 25322671Swollman 25422671Swollmanstatic struct proc *mclallocproc; 25522671Swollmanstatic struct kproc_desc mclalloc_kp = { 25622671Swollman "mclalloc", 25722671Swollman kproc_mclalloc, 25822671Swollman &mclallocproc 25922671Swollman}; 26048391SpeterSYSINIT(mclallocproc, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start, 26122671Swollman &mclalloc_kp); 26222671Swollman#endif 26322671Swollman 26415689Swollman/* 2651541Srgrimes * Allocate some number of mbuf clusters 2661541Srgrimes * and place on cluster free list. 2671541Srgrimes * Must be called at splimp. 2681541Srgrimes */ 2691541Srgrimes/* ARGSUSED */ 2701549Srgrimesint 27132036Sbdem_clalloc(ncl, how) 2721541Srgrimes register int ncl; 27332036Sbde int how; 2741541Srgrimes{ 2751541Srgrimes register caddr_t p; 2761541Srgrimes register int i; 2771541Srgrimes int npg; 2781541Srgrimes 2797066Sdg /* 28055171Smsmith * If we've hit the mcluster number limit, stop allocating from 28155171Smsmith * mb_map, (or trying to) in order to avoid dipping into the section 28255171Smsmith * of mb_map which we've "reserved" for mbufs. 28355171Smsmith */ 28455171Smsmith if ((ncl + mbstat.m_clusters) > nmbclusters) { 28555171Smsmith mbstat.m_drops++; 28655171Smsmith return (0); 28755171Smsmith } 28855171Smsmith 28955171Smsmith /* 2907066Sdg * Once we run out of map space, it will be impossible 2917066Sdg * to get any more (nothing is ever freed back to the 29254478Sgreen * map). From this point on, we solely rely on freed 29354478Sgreen * mclusters. 2947066Sdg */ 29522899Swollman if (mb_map_full) { 29622899Swollman mbstat.m_drops++; 2977066Sdg return (0); 29822899Swollman } 2997066Sdg 30022671Swollman#if MCLBYTES > PAGE_SIZE 30132036Sbde if (how != M_WAIT) { 30222671Swollman i_want_my_mcl += ncl; 30322671Swollman wakeup(&i_want_my_mcl); 30422899Swollman mbstat.m_wait++; 30522671Swollman p = 0; 30622671Swollman } else { 30722671Swollman p = contigmalloc1(MCLBYTES * ncl, M_DEVBUF, M_WAITOK, 0ul, 30822671Swollman ~0ul, PAGE_SIZE, 0, mb_map); 30922671Swollman } 31022671Swollman#else 31115543Sphk npg = ncl; 31221737Sdg p = (caddr_t)kmem_malloc(mb_map, ctob(npg), 31332036Sbde how != M_WAIT ? M_NOWAIT : M_WAITOK); 31422671Swollman ncl = ncl * PAGE_SIZE / MCLBYTES; 31522671Swollman#endif 3167066Sdg /* 31732036Sbde * Either the map is now full, or `how' is M_NOWAIT and there 3187066Sdg * are no pages left. 3197066Sdg */ 32022899Swollman if (p == NULL) { 32122899Swollman mbstat.m_drops++; 3221541Srgrimes return (0); 32322899Swollman } 3247066Sdg 3251541Srgrimes for (i = 0; i < ncl; i++) { 3261541Srgrimes ((union mcluster *)p)->mcl_next = mclfree; 3271541Srgrimes mclfree = (union mcluster *)p; 3281541Srgrimes p += MCLBYTES; 3291541Srgrimes mbstat.m_clfree++; 3301541Srgrimes } 3311541Srgrimes mbstat.m_clusters += ncl; 3321541Srgrimes return (1); 3331541Srgrimes} 3341541Srgrimes 3351541Srgrimes/* 33654478Sgreen * Once the mb_map submap has been exhausted and the allocation is called with 33754478Sgreen * M_WAIT, we rely on the mclfree union pointers. If nothing is free, we will 33854478Sgreen * sleep for a designated amount of time (mbuf_wait) or until we're woken up 33954478Sgreen * due to sudden mcluster availability. 34054478Sgreen */ 34154478Sgreencaddr_t 34254478Sgreenm_clalloc_wait(void) 34354478Sgreen{ 34454478Sgreen caddr_t p; 34554478Sgreen int s; 34654478Sgreen 34754478Sgreen#ifdef __i386__ 34854478Sgreen /* If in interrupt context, and INVARIANTS, maintain sanity and die. */ 34954478Sgreen KASSERT(intr_nesting_level == 0, ("CLALLOC: CANNOT WAIT IN INTERRUPT")); 35054478Sgreen#endif 35154478Sgreen 35254478Sgreen /* Sleep until something's available or until we expire. */ 35354478Sgreen m_clalloc_wid++; 35454478Sgreen if ((tsleep(&m_clalloc_wid, PVM, "mclalc", mbuf_wait)) == EWOULDBLOCK) 35554478Sgreen m_clalloc_wid--; 35654478Sgreen 35754478Sgreen /* 35854478Sgreen * Now that we (think) that we've got something, we will redo and 35954478Sgreen * MGET, but avoid getting into another instance of m_clalloc_wait() 36054478Sgreen */ 36154478Sgreen p = NULL; 36254478Sgreen MCLALLOC(p, M_DONTWAIT); 36354478Sgreen 36454478Sgreen s = splimp(); 36554478Sgreen if (p != NULL) { /* We waited and got something... */ 36654478Sgreen mbstat.m_wait++; 36754478Sgreen /* Wake up another if we have more free. */ 36854478Sgreen if (mclfree != NULL) 36954787Sgreen MCLWAKEUP(); 37054478Sgreen } 37154478Sgreen 37254478Sgreen splx(s); 37354478Sgreen return (p); 37454478Sgreen} 37554478Sgreen 37654478Sgreen/* 37745615Sdes * When MGET fails, ask protocols to free space when short of memory, 3781541Srgrimes * then re-attempt to allocate an mbuf. 3791541Srgrimes */ 3801541Srgrimesstruct mbuf * 3811541Srgrimesm_retry(i, t) 3821541Srgrimes int i, t; 3831541Srgrimes{ 3841541Srgrimes register struct mbuf *m; 3851541Srgrimes 38637878Sdg /* 38737878Sdg * Must only do the reclaim if not in an interrupt context. 38837878Sdg */ 38954478Sgreen if (i == M_WAIT) { 39054478Sgreen#ifdef __i386__ 39154478Sgreen KASSERT(intr_nesting_level == 0, 39254478Sgreen ("MBALLOC: CANNOT WAIT IN INTERRUPT")); 39354478Sgreen#endif 39437878Sdg m_reclaim(); 39554478Sgreen } 39654478Sgreen 39754478Sgreen /* 39854478Sgreen * Both m_mballoc_wait and m_retry must be nulled because 39954478Sgreen * when the MGET macro is run from here, we deffinately do _not_ 40054478Sgreen * want to enter an instance of m_mballoc_wait() or m_retry() (again!) 40154478Sgreen */ 40254478Sgreen#define m_mballoc_wait(caller,type) (struct mbuf *)0 4031541Srgrimes#define m_retry(i, t) (struct mbuf *)0 4041541Srgrimes MGET(m, i, t); 4051541Srgrimes#undef m_retry 40654478Sgreen#undef m_mballoc_wait 40754478Sgreen 40854478Sgreen if (m != NULL) 4096669Sdg mbstat.m_wait++; 41054478Sgreen else 41154478Sgreen mbstat.m_drops++; 41254478Sgreen 4131541Srgrimes return (m); 4141541Srgrimes} 4151541Srgrimes 4161541Srgrimes/* 4171541Srgrimes * As above; retry an MGETHDR. 4181541Srgrimes */ 4191541Srgrimesstruct mbuf * 4201541Srgrimesm_retryhdr(i, t) 4211541Srgrimes int i, t; 4221541Srgrimes{ 4231541Srgrimes register struct mbuf *m; 4241541Srgrimes 42537878Sdg /* 42637878Sdg * Must only do the reclaim if not in an interrupt context. 42737878Sdg */ 42854478Sgreen if (i == M_WAIT) { 42954478Sgreen#ifdef __i386__ 43054478Sgreen KASSERT(intr_nesting_level == 0, 43154478Sgreen ("MBALLOC: CANNOT WAIT IN INTERRUPT")); 43254478Sgreen#endif 43337878Sdg m_reclaim(); 43454478Sgreen } 43554478Sgreen 43654478Sgreen#define m_mballoc_wait(caller,type) (struct mbuf *)0 4371541Srgrimes#define m_retryhdr(i, t) (struct mbuf *)0 4381541Srgrimes MGETHDR(m, i, t); 4391541Srgrimes#undef m_retryhdr 44054478Sgreen#undef m_mballoc_wait 44154478Sgreen 44254478Sgreen if (m != NULL) 4436669Sdg mbstat.m_wait++; 44454478Sgreen else 44554478Sgreen mbstat.m_drops++; 44654478Sgreen 4471541Srgrimes return (m); 4481541Srgrimes} 4491541Srgrimes 45012819Sphkstatic void 4511541Srgrimesm_reclaim() 4521541Srgrimes{ 4531541Srgrimes register struct domain *dp; 4541541Srgrimes register struct protosw *pr; 4551541Srgrimes int s = splimp(); 4561541Srgrimes 4571541Srgrimes for (dp = domains; dp; dp = dp->dom_next) 4581541Srgrimes for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) 4591541Srgrimes if (pr->pr_drain) 4601541Srgrimes (*pr->pr_drain)(); 4611541Srgrimes splx(s); 4621541Srgrimes mbstat.m_drain++; 4631541Srgrimes} 4641541Srgrimes 4651541Srgrimes/* 4661541Srgrimes * Space allocation routines. 4671541Srgrimes * These are also available as macros 4681541Srgrimes * for critical paths. 4691541Srgrimes */ 4701541Srgrimesstruct mbuf * 47132036Sbdem_get(how, type) 47232036Sbde int how, type; 4731541Srgrimes{ 4741541Srgrimes register struct mbuf *m; 4751541Srgrimes 47632036Sbde MGET(m, how, type); 4771541Srgrimes return (m); 4781541Srgrimes} 4791541Srgrimes 4801541Srgrimesstruct mbuf * 48132036Sbdem_gethdr(how, type) 48232036Sbde int how, type; 4831541Srgrimes{ 4841541Srgrimes register struct mbuf *m; 4851541Srgrimes 48632036Sbde MGETHDR(m, how, type); 4871541Srgrimes return (m); 4881541Srgrimes} 4891541Srgrimes 4901541Srgrimesstruct mbuf * 49132036Sbdem_getclr(how, type) 49232036Sbde int how, type; 4931541Srgrimes{ 4941541Srgrimes register struct mbuf *m; 4951541Srgrimes 49632036Sbde MGET(m, how, type); 4971541Srgrimes if (m == 0) 4981541Srgrimes return (0); 4991541Srgrimes bzero(mtod(m, caddr_t), MLEN); 5001541Srgrimes return (m); 5011541Srgrimes} 5021541Srgrimes 5031541Srgrimesstruct mbuf * 5041541Srgrimesm_free(m) 5051541Srgrimes struct mbuf *m; 5061541Srgrimes{ 5071541Srgrimes register struct mbuf *n; 5081541Srgrimes 5091541Srgrimes MFREE(m, n); 5101541Srgrimes return (n); 5111541Srgrimes} 5121541Srgrimes 5131541Srgrimesvoid 5141541Srgrimesm_freem(m) 5151541Srgrimes register struct mbuf *m; 5161541Srgrimes{ 5171541Srgrimes register struct mbuf *n; 5181541Srgrimes 5191541Srgrimes if (m == NULL) 5201541Srgrimes return; 5211541Srgrimes do { 5221541Srgrimes MFREE(m, n); 5233308Sphk m = n; 5243308Sphk } while (m); 5251541Srgrimes} 5261541Srgrimes 5271541Srgrimes/* 5281541Srgrimes * Mbuffer utility routines. 5291541Srgrimes */ 5301541Srgrimes 5311541Srgrimes/* 5321541Srgrimes * Lesser-used path for M_PREPEND: 5331541Srgrimes * allocate new mbuf to prepend to chain, 5341541Srgrimes * copy junk along. 5351541Srgrimes */ 5361541Srgrimesstruct mbuf * 5371541Srgrimesm_prepend(m, len, how) 5381541Srgrimes register struct mbuf *m; 5391541Srgrimes int len, how; 5401541Srgrimes{ 5411541Srgrimes struct mbuf *mn; 5421541Srgrimes 5431541Srgrimes MGET(mn, how, m->m_type); 5441541Srgrimes if (mn == (struct mbuf *)NULL) { 5451541Srgrimes m_freem(m); 5461541Srgrimes return ((struct mbuf *)NULL); 5471541Srgrimes } 5481541Srgrimes if (m->m_flags & M_PKTHDR) { 5491541Srgrimes M_COPY_PKTHDR(mn, m); 5501541Srgrimes m->m_flags &= ~M_PKTHDR; 5511541Srgrimes } 5521541Srgrimes mn->m_next = m; 5531541Srgrimes m = mn; 5541541Srgrimes if (len < MHLEN) 5551541Srgrimes MH_ALIGN(m, len); 5561541Srgrimes m->m_len = len; 5571541Srgrimes return (m); 5581541Srgrimes} 5591541Srgrimes 5601541Srgrimes/* 5611541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 5621541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 5631541Srgrimes * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 56454002Sarchie * Note that the copy is read-only, because clusters are not copied, 56554002Sarchie * only their reference counts are incremented. 5661541Srgrimes */ 56723081Swollman#define MCFail (mbstat.m_mcfail) 5681541Srgrimes 5691541Srgrimesstruct mbuf * 5701541Srgrimesm_copym(m, off0, len, wait) 5711541Srgrimes register struct mbuf *m; 5721541Srgrimes int off0, wait; 5731541Srgrimes register int len; 5741541Srgrimes{ 5751541Srgrimes register struct mbuf *n, **np; 5761541Srgrimes register int off = off0; 5771541Srgrimes struct mbuf *top; 5781541Srgrimes int copyhdr = 0; 5791541Srgrimes 58052201Salfred KASSERT(off >= 0, ("m_copym, negative off %d", off)); 58152201Salfred KASSERT(len >= 0, ("m_copym, negative len %d", len)); 5821541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 5831541Srgrimes copyhdr = 1; 5841541Srgrimes while (off > 0) { 58552201Salfred KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 5861541Srgrimes if (off < m->m_len) 5871541Srgrimes break; 5881541Srgrimes off -= m->m_len; 5891541Srgrimes m = m->m_next; 5901541Srgrimes } 5911541Srgrimes np = ⊤ 5921541Srgrimes top = 0; 5931541Srgrimes while (len > 0) { 5941541Srgrimes if (m == 0) { 59552201Salfred KASSERT(len == M_COPYALL, 59652201Salfred ("m_copym, length > size of mbuf chain")); 5971541Srgrimes break; 5981541Srgrimes } 5991541Srgrimes MGET(n, wait, m->m_type); 6001541Srgrimes *np = n; 6011541Srgrimes if (n == 0) 6021541Srgrimes goto nospace; 6031541Srgrimes if (copyhdr) { 6041541Srgrimes M_COPY_PKTHDR(n, m); 6051541Srgrimes if (len == M_COPYALL) 6061541Srgrimes n->m_pkthdr.len -= off0; 6071541Srgrimes else 6081541Srgrimes n->m_pkthdr.len = len; 6091541Srgrimes copyhdr = 0; 6101541Srgrimes } 6111541Srgrimes n->m_len = min(len, m->m_len - off); 6121541Srgrimes if (m->m_flags & M_EXT) { 6131541Srgrimes n->m_data = m->m_data + off; 61417663Sjulian if(!m->m_ext.ext_ref) 61517663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 61617663Sjulian else 61717663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 61817663Sjulian m->m_ext.ext_size); 6191541Srgrimes n->m_ext = m->m_ext; 6201541Srgrimes n->m_flags |= M_EXT; 6211541Srgrimes } else 6221541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 6231541Srgrimes (unsigned)n->m_len); 6241541Srgrimes if (len != M_COPYALL) 6251541Srgrimes len -= n->m_len; 6261541Srgrimes off = 0; 6271541Srgrimes m = m->m_next; 6281541Srgrimes np = &n->m_next; 6291541Srgrimes } 6301541Srgrimes if (top == 0) 6311541Srgrimes MCFail++; 6321541Srgrimes return (top); 6331541Srgrimesnospace: 6341541Srgrimes m_freem(top); 6351541Srgrimes MCFail++; 6361541Srgrimes return (0); 6371541Srgrimes} 6381541Srgrimes 6391541Srgrimes/* 64015689Swollman * Copy an entire packet, including header (which must be present). 64115689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 64254002Sarchie * Note that the copy is read-only, because clusters are not copied, 64354002Sarchie * only their reference counts are incremented. 64415689Swollman */ 64515689Swollmanstruct mbuf * 64615689Swollmanm_copypacket(m, how) 64715689Swollman struct mbuf *m; 64815689Swollman int how; 64915689Swollman{ 65015689Swollman struct mbuf *top, *n, *o; 65115689Swollman 65215689Swollman MGET(n, how, m->m_type); 65315689Swollman top = n; 65415689Swollman if (!n) 65515689Swollman goto nospace; 65615689Swollman 65715689Swollman M_COPY_PKTHDR(n, m); 65815689Swollman n->m_len = m->m_len; 65915689Swollman if (m->m_flags & M_EXT) { 66015689Swollman n->m_data = m->m_data; 66137350Sphk if(!m->m_ext.ext_ref) 66237350Sphk mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 66337350Sphk else 66437350Sphk (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 66537350Sphk m->m_ext.ext_size); 66615689Swollman n->m_ext = m->m_ext; 66715689Swollman n->m_flags |= M_EXT; 66815689Swollman } else { 66915689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 67015689Swollman } 67115689Swollman 67215689Swollman m = m->m_next; 67315689Swollman while (m) { 67415689Swollman MGET(o, how, m->m_type); 67515689Swollman if (!o) 67615689Swollman goto nospace; 67715689Swollman 67815689Swollman n->m_next = o; 67915689Swollman n = n->m_next; 68015689Swollman 68115689Swollman n->m_len = m->m_len; 68215689Swollman if (m->m_flags & M_EXT) { 68315689Swollman n->m_data = m->m_data; 68437350Sphk if(!m->m_ext.ext_ref) 68537350Sphk mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 68637350Sphk else 68737350Sphk (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 68837350Sphk m->m_ext.ext_size); 68915689Swollman n->m_ext = m->m_ext; 69015689Swollman n->m_flags |= M_EXT; 69115689Swollman } else { 69215689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 69315689Swollman } 69415689Swollman 69515689Swollman m = m->m_next; 69615689Swollman } 69715689Swollman return top; 69815689Swollmannospace: 69915689Swollman m_freem(top); 70015689Swollman MCFail++; 70115689Swollman return 0; 70215689Swollman} 70315689Swollman 70415689Swollman/* 7051541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 7061541Srgrimes * continuing for "len" bytes, into the indicated buffer. 7071541Srgrimes */ 7081549Srgrimesvoid 7091541Srgrimesm_copydata(m, off, len, cp) 7101541Srgrimes register struct mbuf *m; 7111541Srgrimes register int off; 7121541Srgrimes register int len; 7131541Srgrimes caddr_t cp; 7141541Srgrimes{ 7151541Srgrimes register unsigned count; 7161541Srgrimes 71752201Salfred KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 71852201Salfred KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 7191541Srgrimes while (off > 0) { 72052201Salfred KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 7211541Srgrimes if (off < m->m_len) 7221541Srgrimes break; 7231541Srgrimes off -= m->m_len; 7241541Srgrimes m = m->m_next; 7251541Srgrimes } 7261541Srgrimes while (len > 0) { 72752201Salfred KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 7281541Srgrimes count = min(m->m_len - off, len); 7291541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 7301541Srgrimes len -= count; 7311541Srgrimes cp += count; 7321541Srgrimes off = 0; 7331541Srgrimes m = m->m_next; 7341541Srgrimes } 7351541Srgrimes} 7361541Srgrimes 7371541Srgrimes/* 73854002Sarchie * Copy a packet header mbuf chain into a completely new chain, including 73954002Sarchie * copying any mbuf clusters. Use this instead of m_copypacket() when 74054002Sarchie * you need a writable copy of an mbuf chain. 74154002Sarchie */ 74254002Sarchiestruct mbuf * 74354002Sarchiem_dup(m, how) 74454002Sarchie struct mbuf *m; 74554002Sarchie int how; 74654002Sarchie{ 74754002Sarchie struct mbuf **p, *top = NULL; 74854002Sarchie int remain, moff, nsize; 74954002Sarchie 75054002Sarchie /* Sanity check */ 75154002Sarchie if (m == NULL) 75254002Sarchie return (0); 75354002Sarchie KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __FUNCTION__)); 75454002Sarchie 75554002Sarchie /* While there's more data, get a new mbuf, tack it on, and fill it */ 75654002Sarchie remain = m->m_pkthdr.len; 75754002Sarchie moff = 0; 75854002Sarchie p = ⊤ 75954002Sarchie while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 76054002Sarchie struct mbuf *n; 76154002Sarchie 76254002Sarchie /* Get the next new mbuf */ 76354002Sarchie MGET(n, how, m->m_type); 76454002Sarchie if (n == NULL) 76554002Sarchie goto nospace; 76654002Sarchie if (top == NULL) { /* first one, must be PKTHDR */ 76754002Sarchie M_COPY_PKTHDR(n, m); 76854002Sarchie nsize = MHLEN; 76954002Sarchie } else /* not the first one */ 77054002Sarchie nsize = MLEN; 77154002Sarchie if (remain >= MINCLSIZE) { 77254002Sarchie MCLGET(n, how); 77354002Sarchie if ((n->m_flags & M_EXT) == 0) { 77454002Sarchie (void)m_free(n); 77554002Sarchie goto nospace; 77654002Sarchie } 77754002Sarchie nsize = MCLBYTES; 77854002Sarchie } 77954002Sarchie n->m_len = 0; 78054002Sarchie 78154002Sarchie /* Link it into the new chain */ 78254002Sarchie *p = n; 78354002Sarchie p = &n->m_next; 78454002Sarchie 78554002Sarchie /* Copy data from original mbuf(s) into new mbuf */ 78654002Sarchie while (n->m_len < nsize && m != NULL) { 78754002Sarchie int chunk = min(nsize - n->m_len, m->m_len - moff); 78854002Sarchie 78954002Sarchie bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 79054002Sarchie moff += chunk; 79154002Sarchie n->m_len += chunk; 79254002Sarchie remain -= chunk; 79354002Sarchie if (moff == m->m_len) { 79454002Sarchie m = m->m_next; 79554002Sarchie moff = 0; 79654002Sarchie } 79754002Sarchie } 79854002Sarchie 79954002Sarchie /* Check correct total mbuf length */ 80054002Sarchie KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 80154002Sarchie ("%s: bogus m_pkthdr.len", __FUNCTION__)); 80254002Sarchie } 80354002Sarchie return (top); 80454002Sarchie 80554002Sarchienospace: 80654002Sarchie m_freem(top); 80754002Sarchie MCFail++; 80854002Sarchie return (0); 80954002Sarchie} 81054002Sarchie 81154002Sarchie/* 8121541Srgrimes * Concatenate mbuf chain n to m. 8131541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 8141541Srgrimes * Any m_pkthdr is not updated. 8151541Srgrimes */ 8161549Srgrimesvoid 8171541Srgrimesm_cat(m, n) 8181541Srgrimes register struct mbuf *m, *n; 8191541Srgrimes{ 8201541Srgrimes while (m->m_next) 8211541Srgrimes m = m->m_next; 8221541Srgrimes while (n) { 8231541Srgrimes if (m->m_flags & M_EXT || 8241541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 8251541Srgrimes /* just join the two chains */ 8261541Srgrimes m->m_next = n; 8271541Srgrimes return; 8281541Srgrimes } 8291541Srgrimes /* splat the data from one into the other */ 8301541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 8311541Srgrimes (u_int)n->m_len); 8321541Srgrimes m->m_len += n->m_len; 8331541Srgrimes n = m_free(n); 8341541Srgrimes } 8351541Srgrimes} 8361541Srgrimes 8371549Srgrimesvoid 8381541Srgrimesm_adj(mp, req_len) 8391541Srgrimes struct mbuf *mp; 8401541Srgrimes int req_len; 8411541Srgrimes{ 8421541Srgrimes register int len = req_len; 8431541Srgrimes register struct mbuf *m; 84433678Sbde register int count; 8451541Srgrimes 8461541Srgrimes if ((m = mp) == NULL) 8471541Srgrimes return; 8481541Srgrimes if (len >= 0) { 8491541Srgrimes /* 8501541Srgrimes * Trim from head. 8511541Srgrimes */ 8521541Srgrimes while (m != NULL && len > 0) { 8531541Srgrimes if (m->m_len <= len) { 8541541Srgrimes len -= m->m_len; 8551541Srgrimes m->m_len = 0; 8561541Srgrimes m = m->m_next; 8571541Srgrimes } else { 8581541Srgrimes m->m_len -= len; 8591541Srgrimes m->m_data += len; 8601541Srgrimes len = 0; 8611541Srgrimes } 8621541Srgrimes } 8631541Srgrimes m = mp; 8641541Srgrimes if (mp->m_flags & M_PKTHDR) 8651541Srgrimes m->m_pkthdr.len -= (req_len - len); 8661541Srgrimes } else { 8671541Srgrimes /* 8681541Srgrimes * Trim from tail. Scan the mbuf chain, 8691541Srgrimes * calculating its length and finding the last mbuf. 8701541Srgrimes * If the adjustment only affects this mbuf, then just 8711541Srgrimes * adjust and return. Otherwise, rescan and truncate 8721541Srgrimes * after the remaining size. 8731541Srgrimes */ 8741541Srgrimes len = -len; 8751541Srgrimes count = 0; 8761541Srgrimes for (;;) { 8771541Srgrimes count += m->m_len; 8781541Srgrimes if (m->m_next == (struct mbuf *)0) 8791541Srgrimes break; 8801541Srgrimes m = m->m_next; 8811541Srgrimes } 8821541Srgrimes if (m->m_len >= len) { 8831541Srgrimes m->m_len -= len; 8841541Srgrimes if (mp->m_flags & M_PKTHDR) 8851541Srgrimes mp->m_pkthdr.len -= len; 8861541Srgrimes return; 8871541Srgrimes } 8881541Srgrimes count -= len; 8891541Srgrimes if (count < 0) 8901541Srgrimes count = 0; 8911541Srgrimes /* 8921541Srgrimes * Correct length for chain is "count". 8931541Srgrimes * Find the mbuf with last data, adjust its length, 8941541Srgrimes * and toss data from remaining mbufs on chain. 8951541Srgrimes */ 8961541Srgrimes m = mp; 8971541Srgrimes if (m->m_flags & M_PKTHDR) 8981541Srgrimes m->m_pkthdr.len = count; 8991541Srgrimes for (; m; m = m->m_next) { 9001541Srgrimes if (m->m_len >= count) { 9011541Srgrimes m->m_len = count; 9021541Srgrimes break; 9031541Srgrimes } 9041541Srgrimes count -= m->m_len; 9051541Srgrimes } 9063308Sphk while (m->m_next) 9073308Sphk (m = m->m_next) ->m_len = 0; 9081541Srgrimes } 9091541Srgrimes} 9101541Srgrimes 9111541Srgrimes/* 9121541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 9131541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 9141541Srgrimes * will work for a structure of size len). Returns the resulting 9151541Srgrimes * mbuf chain on success, frees it and returns null on failure. 9161541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 9171541Srgrimes * contiguous region in an attempt to avoid being called next time. 9181541Srgrimes */ 91923081Swollman#define MPFail (mbstat.m_mpfail) 9201541Srgrimes 9211541Srgrimesstruct mbuf * 9221541Srgrimesm_pullup(n, len) 9231541Srgrimes register struct mbuf *n; 9241541Srgrimes int len; 9251541Srgrimes{ 9261541Srgrimes register struct mbuf *m; 9271541Srgrimes register int count; 9281541Srgrimes int space; 9291541Srgrimes 9301541Srgrimes /* 9311541Srgrimes * If first mbuf has no cluster, and has room for len bytes 9321541Srgrimes * without shifting current data, pullup into it, 9331541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 9341541Srgrimes */ 9351541Srgrimes if ((n->m_flags & M_EXT) == 0 && 9361541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 9371541Srgrimes if (n->m_len >= len) 9381541Srgrimes return (n); 9391541Srgrimes m = n; 9401541Srgrimes n = n->m_next; 9411541Srgrimes len -= m->m_len; 9421541Srgrimes } else { 9431541Srgrimes if (len > MHLEN) 9441541Srgrimes goto bad; 9451541Srgrimes MGET(m, M_DONTWAIT, n->m_type); 9461541Srgrimes if (m == 0) 9471541Srgrimes goto bad; 9481541Srgrimes m->m_len = 0; 9491541Srgrimes if (n->m_flags & M_PKTHDR) { 9501541Srgrimes M_COPY_PKTHDR(m, n); 9511541Srgrimes n->m_flags &= ~M_PKTHDR; 9521541Srgrimes } 9531541Srgrimes } 9541541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 9551541Srgrimes do { 9561541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 9571541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 9581541Srgrimes (unsigned)count); 9591541Srgrimes len -= count; 9601541Srgrimes m->m_len += count; 9611541Srgrimes n->m_len -= count; 9621541Srgrimes space -= count; 9631541Srgrimes if (n->m_len) 9641541Srgrimes n->m_data += count; 9651541Srgrimes else 9661541Srgrimes n = m_free(n); 9671541Srgrimes } while (len > 0 && n); 9681541Srgrimes if (len > 0) { 9691541Srgrimes (void) m_free(m); 9701541Srgrimes goto bad; 9711541Srgrimes } 9721541Srgrimes m->m_next = n; 9731541Srgrimes return (m); 9741541Srgrimesbad: 9751541Srgrimes m_freem(n); 9761541Srgrimes MPFail++; 9771541Srgrimes return (0); 9781541Srgrimes} 9791541Srgrimes 9801541Srgrimes/* 9811541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 9821541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 9831541Srgrimes * attempts to restore the chain to its original state. 9841541Srgrimes */ 9851541Srgrimesstruct mbuf * 9861541Srgrimesm_split(m0, len0, wait) 9871541Srgrimes register struct mbuf *m0; 9881541Srgrimes int len0, wait; 9891541Srgrimes{ 9901541Srgrimes register struct mbuf *m, *n; 9911541Srgrimes unsigned len = len0, remain; 9921541Srgrimes 9931541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 9941541Srgrimes len -= m->m_len; 9951541Srgrimes if (m == 0) 9961541Srgrimes return (0); 9971541Srgrimes remain = m->m_len - len; 9981541Srgrimes if (m0->m_flags & M_PKTHDR) { 9991541Srgrimes MGETHDR(n, wait, m0->m_type); 10001541Srgrimes if (n == 0) 10011541Srgrimes return (0); 10021541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 10031541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 10041541Srgrimes m0->m_pkthdr.len = len0; 10051541Srgrimes if (m->m_flags & M_EXT) 10061541Srgrimes goto extpacket; 10071541Srgrimes if (remain > MHLEN) { 10081541Srgrimes /* m can't be the lead packet */ 10091541Srgrimes MH_ALIGN(n, 0); 10101541Srgrimes n->m_next = m_split(m, len, wait); 10111541Srgrimes if (n->m_next == 0) { 10121541Srgrimes (void) m_free(n); 10131541Srgrimes return (0); 10141541Srgrimes } else 10151541Srgrimes return (n); 10161541Srgrimes } else 10171541Srgrimes MH_ALIGN(n, remain); 10181541Srgrimes } else if (remain == 0) { 10191541Srgrimes n = m->m_next; 10201541Srgrimes m->m_next = 0; 10211541Srgrimes return (n); 10221541Srgrimes } else { 10231541Srgrimes MGET(n, wait, m->m_type); 10241541Srgrimes if (n == 0) 10251541Srgrimes return (0); 10261541Srgrimes M_ALIGN(n, remain); 10271541Srgrimes } 10281541Srgrimesextpacket: 10291541Srgrimes if (m->m_flags & M_EXT) { 10301541Srgrimes n->m_flags |= M_EXT; 10311541Srgrimes n->m_ext = m->m_ext; 103217663Sjulian if(!m->m_ext.ext_ref) 103317663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 103417663Sjulian else 103517663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 103617663Sjulian m->m_ext.ext_size); 10371541Srgrimes m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ 10381541Srgrimes n->m_data = m->m_data + len; 10391541Srgrimes } else { 10401541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 10411541Srgrimes } 10421541Srgrimes n->m_len = remain; 10431541Srgrimes m->m_len = len; 10441541Srgrimes n->m_next = m->m_next; 10451541Srgrimes m->m_next = 0; 10461541Srgrimes return (n); 10471541Srgrimes} 10481541Srgrimes/* 10491541Srgrimes * Routine to copy from device local memory into mbufs. 10501541Srgrimes */ 10511541Srgrimesstruct mbuf * 10521541Srgrimesm_devget(buf, totlen, off0, ifp, copy) 10531541Srgrimes char *buf; 10541541Srgrimes int totlen, off0; 10551541Srgrimes struct ifnet *ifp; 105612577Sbde void (*copy) __P((char *from, caddr_t to, u_int len)); 10571541Srgrimes{ 10581541Srgrimes register struct mbuf *m; 10591541Srgrimes struct mbuf *top = 0, **mp = ⊤ 10601541Srgrimes register int off = off0, len; 10611541Srgrimes register char *cp; 10621541Srgrimes char *epkt; 10631541Srgrimes 10641541Srgrimes cp = buf; 10651541Srgrimes epkt = cp + totlen; 10661541Srgrimes if (off) { 10671541Srgrimes cp += off + 2 * sizeof(u_short); 10681541Srgrimes totlen -= 2 * sizeof(u_short); 10691541Srgrimes } 10701541Srgrimes MGETHDR(m, M_DONTWAIT, MT_DATA); 10711541Srgrimes if (m == 0) 10721541Srgrimes return (0); 10731541Srgrimes m->m_pkthdr.rcvif = ifp; 10741541Srgrimes m->m_pkthdr.len = totlen; 10751541Srgrimes m->m_len = MHLEN; 10761541Srgrimes 10771541Srgrimes while (totlen > 0) { 10781541Srgrimes if (top) { 10791541Srgrimes MGET(m, M_DONTWAIT, MT_DATA); 10801541Srgrimes if (m == 0) { 10811541Srgrimes m_freem(top); 10821541Srgrimes return (0); 10831541Srgrimes } 10841541Srgrimes m->m_len = MLEN; 10851541Srgrimes } 10861541Srgrimes len = min(totlen, epkt - cp); 10871541Srgrimes if (len >= MINCLSIZE) { 10881541Srgrimes MCLGET(m, M_DONTWAIT); 10891541Srgrimes if (m->m_flags & M_EXT) 10901541Srgrimes m->m_len = len = min(len, MCLBYTES); 10911541Srgrimes else 10921541Srgrimes len = m->m_len; 10931541Srgrimes } else { 10941541Srgrimes /* 10951541Srgrimes * Place initial small packet/header at end of mbuf. 10961541Srgrimes */ 10971541Srgrimes if (len < m->m_len) { 10981541Srgrimes if (top == 0 && len + max_linkhdr <= m->m_len) 10991541Srgrimes m->m_data += max_linkhdr; 11001541Srgrimes m->m_len = len; 11011541Srgrimes } else 11021541Srgrimes len = m->m_len; 11031541Srgrimes } 11041541Srgrimes if (copy) 11051541Srgrimes copy(cp, mtod(m, caddr_t), (unsigned)len); 11061541Srgrimes else 11071541Srgrimes bcopy(cp, mtod(m, caddr_t), (unsigned)len); 11081541Srgrimes cp += len; 11091541Srgrimes *mp = m; 11101541Srgrimes mp = &m->m_next; 11111541Srgrimes totlen -= len; 11121541Srgrimes if (cp == epkt) 11131541Srgrimes cp = buf; 11141541Srgrimes } 11151541Srgrimes return (top); 11161541Srgrimes} 11173352Sphk 11183352Sphk/* 11193352Sphk * Copy data from a buffer back into the indicated mbuf chain, 11203352Sphk * starting "off" bytes from the beginning, extending the mbuf 11213352Sphk * chain if necessary. 11223352Sphk */ 11233352Sphkvoid 11243352Sphkm_copyback(m0, off, len, cp) 11253352Sphk struct mbuf *m0; 11263352Sphk register int off; 11273352Sphk register int len; 11283352Sphk caddr_t cp; 11293352Sphk{ 11303352Sphk register int mlen; 11313352Sphk register struct mbuf *m = m0, *n; 11323352Sphk int totlen = 0; 11333352Sphk 11343352Sphk if (m0 == 0) 11353352Sphk return; 11363352Sphk while (off > (mlen = m->m_len)) { 11373352Sphk off -= mlen; 11383352Sphk totlen += mlen; 11393352Sphk if (m->m_next == 0) { 11403352Sphk n = m_getclr(M_DONTWAIT, m->m_type); 11413352Sphk if (n == 0) 11423352Sphk goto out; 11433352Sphk n->m_len = min(MLEN, len + off); 11443352Sphk m->m_next = n; 11453352Sphk } 11463352Sphk m = m->m_next; 11473352Sphk } 11483352Sphk while (len > 0) { 11493352Sphk mlen = min (m->m_len - off, len); 11503352Sphk bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 11513352Sphk cp += mlen; 11523352Sphk len -= mlen; 11533352Sphk mlen += off; 11543352Sphk off = 0; 11553352Sphk totlen += mlen; 11563352Sphk if (len == 0) 11573352Sphk break; 11583352Sphk if (m->m_next == 0) { 11593352Sphk n = m_get(M_DONTWAIT, m->m_type); 11603352Sphk if (n == 0) 11613352Sphk break; 11623352Sphk n->m_len = min(MLEN, len); 11633352Sphk m->m_next = n; 11643352Sphk } 11653352Sphk m = m->m_next; 11663352Sphk } 11673352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 11683352Sphk m->m_pkthdr.len = totlen; 11693352Sphk} 117052756Sphk 117152756Sphkvoid 117252756Sphkm_print(const struct mbuf *m) 117352756Sphk{ 117452756Sphk int len; 117554906Seivind const struct mbuf *m2; 117652756Sphk 117752756Sphk len = m->m_pkthdr.len; 117852756Sphk m2 = m; 117952756Sphk while (len) { 118052756Sphk printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); 118152756Sphk len -= m2->m_len; 118252756Sphk m2 = m2->m_next; 118352756Sphk } 118452756Sphk return; 118552756Sphk} 1186