uipc_mbuf.c revision 32036
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 3432036Sbde * $Id: uipc_mbuf.c,v 1.32 1997/10/28 15:58:22 bde Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 381541Srgrimes#include <sys/systm.h> 3932036Sbde#include <sys/malloc.h> 401541Srgrimes#include <sys/mbuf.h> 411541Srgrimes#include <sys/kernel.h> 4223081Swollman#include <sys/sysctl.h> 431541Srgrimes#include <sys/domain.h> 441541Srgrimes#include <sys/protosw.h> 451541Srgrimes 461541Srgrimes#include <vm/vm.h> 479759Sbde#include <vm/vm_kern.h> 4812662Sdg#include <vm/vm_extern.h> 491541Srgrimes 5010653Sdgstatic void mbinit __P((void *)); 5110358SjulianSYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) 5210358Sjulian 539759Sbdestruct mbuf *mbutl; 541541Srgrimeschar *mclrefcnt; 559759Sbdestruct mbstat mbstat; 5615689Swollmanstruct mbuf *mmbfree; 579759Sbdeunion mcluster *mclfree; 589759Sbdeint max_linkhdr; 599759Sbdeint max_protohdr; 609759Sbdeint max_hdr; 619759Sbdeint max_datalen; 621541Srgrimes 6323081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, 6423081Swollman &max_linkhdr, 0, ""); 6523081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, 6623081Swollman &max_protohdr, 0, ""); 6723081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, ""); 6823081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, 6923081Swollman &max_datalen, 0, ""); 7023081SwollmanSYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, ""); 7123081Swollman 7212819Sphkstatic void m_reclaim __P((void)); 7312819Sphk 7415736Sphk/* "number of clusters of pages" */ 7515736Sphk#define NCL_INIT 1 7615736Sphk 7715744Sphk#define NMB_INIT 16 7815744Sphk 7910358Sjulian/* ARGSUSED*/ 8010358Sjulianstatic void 8112569Sbdembinit(dummy) 8212569Sbde void *dummy; 831541Srgrimes{ 841541Srgrimes int s; 851541Srgrimes 8615689Swollman mmbfree = NULL; mclfree = NULL; 8723081Swollman mbstat.m_msize = MSIZE; 8823081Swollman mbstat.m_mclbytes = MCLBYTES; 8923081Swollman mbstat.m_minclsize = MINCLSIZE; 9023081Swollman mbstat.m_mlen = MLEN; 9123081Swollman mbstat.m_mhlen = MHLEN; 9223081Swollman 931541Srgrimes s = splimp(); 9415689Swollman if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0) 9515689Swollman goto bad; 9622671Swollman#if MCLBYTES <= PAGE_SIZE 971541Srgrimes if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) 981541Srgrimes goto bad; 9922671Swollman#else 10022671Swollman /* It's OK to call contigmalloc in this context. */ 10132036Sbde if (m_clalloc(16, M_WAIT) == 0) 10222671Swollman goto bad; 10322671Swollman#endif 1041541Srgrimes splx(s); 1051541Srgrimes return; 1061541Srgrimesbad: 1071541Srgrimes panic("mbinit"); 1081541Srgrimes} 1091541Srgrimes 1101541Srgrimes/* 11115689Swollman * Allocate at least nmb mbufs and place on mbuf free list. 11215689Swollman * Must be called at splimp. 11315689Swollman */ 11415689Swollman/* ARGSUSED */ 11515689Swollmanint 11632036Sbdem_mballoc(nmb, how) 11715689Swollman register int nmb; 11832036Sbde int how; 11915689Swollman{ 12015689Swollman register caddr_t p; 12115689Swollman register int i; 12215689Swollman int nbytes; 12315689Swollman 12415689Swollman /* Once we run out of map space, it will be impossible to get 12515689Swollman * any more (nothing is ever freed back to the map) (XXX which 12615689Swollman * is dumb). (however you are not dead as m_reclaim might 12715689Swollman * still be able to free a substantial amount of space). 12815689Swollman */ 12915689Swollman if (mb_map_full) 13015689Swollman return (0); 13115689Swollman 13215689Swollman nbytes = round_page(nmb * MSIZE); 13322899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT); 13432036Sbde if (p == 0 && how == M_WAIT) { 13522899Swollman mbstat.m_wait++; 13622899Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, M_WAITOK); 13722899Swollman } 13822899Swollman 13915689Swollman /* 14032036Sbde * Either the map is now full, or `how' is M_NOWAIT and there 14115689Swollman * are no pages left. 14215689Swollman */ 14315689Swollman if (p == NULL) 14415689Swollman return (0); 14515689Swollman 14615689Swollman nmb = nbytes / MSIZE; 14715689Swollman for (i = 0; i < nmb; i++) { 14815689Swollman ((struct mbuf *)p)->m_next = mmbfree; 14915689Swollman mmbfree = (struct mbuf *)p; 15015689Swollman p += MSIZE; 15115689Swollman } 15215689Swollman mbstat.m_mbufs += nmb; 15315689Swollman return (1); 15415689Swollman} 15515689Swollman 15622671Swollman#if MCLBYTES > PAGE_SIZE 15722899Swollmanstatic int i_want_my_mcl; 15822671Swollman 15922899Swollmanstatic void 16022671Swollmankproc_mclalloc(void) 16122671Swollman{ 16222671Swollman int status; 16322671Swollman 16422671Swollman while (1) { 16522671Swollman tsleep(&i_want_my_mcl, PVM, "mclalloc", 0); 16622671Swollman 16722671Swollman for (; i_want_my_mcl; i_want_my_mcl--) { 16832036Sbde if (m_clalloc(1, M_WAIT) == 0) 16922671Swollman printf("m_clalloc failed even in process context!\n"); 17022671Swollman } 17122671Swollman } 17222671Swollman} 17322671Swollman 17422671Swollmanstatic struct proc *mclallocproc; 17522671Swollmanstatic struct kproc_desc mclalloc_kp = { 17622671Swollman "mclalloc", 17722671Swollman kproc_mclalloc, 17822671Swollman &mclallocproc 17922671Swollman}; 18022671SwollmanSYSINIT_KT(mclallocproc, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start, 18122671Swollman &mclalloc_kp); 18222671Swollman#endif 18322671Swollman 18415689Swollman/* 1851541Srgrimes * Allocate some number of mbuf clusters 1861541Srgrimes * and place on cluster free list. 1871541Srgrimes * Must be called at splimp. 1881541Srgrimes */ 1891541Srgrimes/* ARGSUSED */ 1901549Srgrimesint 19132036Sbdem_clalloc(ncl, how) 1921541Srgrimes register int ncl; 19332036Sbde int how; 1941541Srgrimes{ 1951541Srgrimes register caddr_t p; 1961541Srgrimes register int i; 1971541Srgrimes int npg; 1981541Srgrimes 1997066Sdg /* 2007066Sdg * Once we run out of map space, it will be impossible 2017066Sdg * to get any more (nothing is ever freed back to the 2027066Sdg * map). 2037066Sdg */ 20422899Swollman if (mb_map_full) { 20522899Swollman mbstat.m_drops++; 2067066Sdg return (0); 20722899Swollman } 2087066Sdg 20922671Swollman#if MCLBYTES > PAGE_SIZE 21032036Sbde if (how != M_WAIT) { 21122671Swollman i_want_my_mcl += ncl; 21222671Swollman wakeup(&i_want_my_mcl); 21322899Swollman mbstat.m_wait++; 21422671Swollman p = 0; 21522671Swollman } else { 21622671Swollman p = contigmalloc1(MCLBYTES * ncl, M_DEVBUF, M_WAITOK, 0ul, 21722671Swollman ~0ul, PAGE_SIZE, 0, mb_map); 21822671Swollman } 21922671Swollman#else 22015543Sphk npg = ncl; 22121737Sdg p = (caddr_t)kmem_malloc(mb_map, ctob(npg), 22232036Sbde how != M_WAIT ? M_NOWAIT : M_WAITOK); 22322671Swollman ncl = ncl * PAGE_SIZE / MCLBYTES; 22422671Swollman#endif 2257066Sdg /* 22632036Sbde * Either the map is now full, or `how' is M_NOWAIT and there 2277066Sdg * are no pages left. 2287066Sdg */ 22922899Swollman if (p == NULL) { 23022899Swollman mbstat.m_drops++; 2311541Srgrimes return (0); 23222899Swollman } 2337066Sdg 2341541Srgrimes for (i = 0; i < ncl; i++) { 2351541Srgrimes ((union mcluster *)p)->mcl_next = mclfree; 2361541Srgrimes mclfree = (union mcluster *)p; 2371541Srgrimes p += MCLBYTES; 2381541Srgrimes mbstat.m_clfree++; 2391541Srgrimes } 2401541Srgrimes mbstat.m_clusters += ncl; 2411541Srgrimes return (1); 2421541Srgrimes} 2431541Srgrimes 2441541Srgrimes/* 2451541Srgrimes * When MGET failes, ask protocols to free space when short of memory, 2461541Srgrimes * then re-attempt to allocate an mbuf. 2471541Srgrimes */ 2481541Srgrimesstruct mbuf * 2491541Srgrimesm_retry(i, t) 2501541Srgrimes int i, t; 2511541Srgrimes{ 2521541Srgrimes register struct mbuf *m; 2531541Srgrimes 2541541Srgrimes m_reclaim(); 2551541Srgrimes#define m_retry(i, t) (struct mbuf *)0 2561541Srgrimes MGET(m, i, t); 2571541Srgrimes#undef m_retry 2586669Sdg if (m != NULL) 2596669Sdg mbstat.m_wait++; 2606669Sdg else 2616669Sdg mbstat.m_drops++; 2621541Srgrimes return (m); 2631541Srgrimes} 2641541Srgrimes 2651541Srgrimes/* 2661541Srgrimes * As above; retry an MGETHDR. 2671541Srgrimes */ 2681541Srgrimesstruct mbuf * 2691541Srgrimesm_retryhdr(i, t) 2701541Srgrimes int i, t; 2711541Srgrimes{ 2721541Srgrimes register struct mbuf *m; 2731541Srgrimes 2741541Srgrimes m_reclaim(); 2751541Srgrimes#define m_retryhdr(i, t) (struct mbuf *)0 2761541Srgrimes MGETHDR(m, i, t); 2771541Srgrimes#undef m_retryhdr 2786669Sdg if (m != NULL) 2796669Sdg mbstat.m_wait++; 2806669Sdg else 2816669Sdg mbstat.m_drops++; 2821541Srgrimes return (m); 2831541Srgrimes} 2841541Srgrimes 28512819Sphkstatic void 2861541Srgrimesm_reclaim() 2871541Srgrimes{ 2881541Srgrimes register struct domain *dp; 2891541Srgrimes register struct protosw *pr; 2901541Srgrimes int s = splimp(); 2911541Srgrimes 2921541Srgrimes for (dp = domains; dp; dp = dp->dom_next) 2931541Srgrimes for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) 2941541Srgrimes if (pr->pr_drain) 2951541Srgrimes (*pr->pr_drain)(); 2961541Srgrimes splx(s); 2971541Srgrimes mbstat.m_drain++; 2981541Srgrimes} 2991541Srgrimes 3001541Srgrimes/* 3011541Srgrimes * Space allocation routines. 3021541Srgrimes * These are also available as macros 3031541Srgrimes * for critical paths. 3041541Srgrimes */ 3051541Srgrimesstruct mbuf * 30632036Sbdem_get(how, type) 30732036Sbde int how, type; 3081541Srgrimes{ 3091541Srgrimes register struct mbuf *m; 3101541Srgrimes 31132036Sbde MGET(m, how, type); 3121541Srgrimes return (m); 3131541Srgrimes} 3141541Srgrimes 3151541Srgrimesstruct mbuf * 31632036Sbdem_gethdr(how, type) 31732036Sbde int how, type; 3181541Srgrimes{ 3191541Srgrimes register struct mbuf *m; 3201541Srgrimes 32132036Sbde MGETHDR(m, how, type); 3221541Srgrimes return (m); 3231541Srgrimes} 3241541Srgrimes 3251541Srgrimesstruct mbuf * 32632036Sbdem_getclr(how, type) 32732036Sbde int how, type; 3281541Srgrimes{ 3291541Srgrimes register struct mbuf *m; 3301541Srgrimes 33132036Sbde MGET(m, how, type); 3321541Srgrimes if (m == 0) 3331541Srgrimes return (0); 3341541Srgrimes bzero(mtod(m, caddr_t), MLEN); 3351541Srgrimes return (m); 3361541Srgrimes} 3371541Srgrimes 3381541Srgrimesstruct mbuf * 3391541Srgrimesm_free(m) 3401541Srgrimes struct mbuf *m; 3411541Srgrimes{ 3421541Srgrimes register struct mbuf *n; 3431541Srgrimes 3441541Srgrimes MFREE(m, n); 3451541Srgrimes return (n); 3461541Srgrimes} 3471541Srgrimes 3481541Srgrimesvoid 3491541Srgrimesm_freem(m) 3501541Srgrimes register struct mbuf *m; 3511541Srgrimes{ 3521541Srgrimes register struct mbuf *n; 3531541Srgrimes 3541541Srgrimes if (m == NULL) 3551541Srgrimes return; 3561541Srgrimes do { 3571541Srgrimes MFREE(m, n); 3583308Sphk m = n; 3593308Sphk } while (m); 3601541Srgrimes} 3611541Srgrimes 3621541Srgrimes/* 3631541Srgrimes * Mbuffer utility routines. 3641541Srgrimes */ 3651541Srgrimes 3661541Srgrimes/* 3671541Srgrimes * Lesser-used path for M_PREPEND: 3681541Srgrimes * allocate new mbuf to prepend to chain, 3691541Srgrimes * copy junk along. 3701541Srgrimes */ 3711541Srgrimesstruct mbuf * 3721541Srgrimesm_prepend(m, len, how) 3731541Srgrimes register struct mbuf *m; 3741541Srgrimes int len, how; 3751541Srgrimes{ 3761541Srgrimes struct mbuf *mn; 3771541Srgrimes 3781541Srgrimes MGET(mn, how, m->m_type); 3791541Srgrimes if (mn == (struct mbuf *)NULL) { 3801541Srgrimes m_freem(m); 3811541Srgrimes return ((struct mbuf *)NULL); 3821541Srgrimes } 3831541Srgrimes if (m->m_flags & M_PKTHDR) { 3841541Srgrimes M_COPY_PKTHDR(mn, m); 3851541Srgrimes m->m_flags &= ~M_PKTHDR; 3861541Srgrimes } 3871541Srgrimes mn->m_next = m; 3881541Srgrimes m = mn; 3891541Srgrimes if (len < MHLEN) 3901541Srgrimes MH_ALIGN(m, len); 3911541Srgrimes m->m_len = len; 3921541Srgrimes return (m); 3931541Srgrimes} 3941541Srgrimes 3951541Srgrimes/* 3961541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 3971541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 3981541Srgrimes * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 3991541Srgrimes */ 40023081Swollman#define MCFail (mbstat.m_mcfail) 4011541Srgrimes 4021541Srgrimesstruct mbuf * 4031541Srgrimesm_copym(m, off0, len, wait) 4041541Srgrimes register struct mbuf *m; 4051541Srgrimes int off0, wait; 4061541Srgrimes register int len; 4071541Srgrimes{ 4081541Srgrimes register struct mbuf *n, **np; 4091541Srgrimes register int off = off0; 4101541Srgrimes struct mbuf *top; 4111541Srgrimes int copyhdr = 0; 4121541Srgrimes 4131541Srgrimes if (off < 0 || len < 0) 4141541Srgrimes panic("m_copym"); 4151541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 4161541Srgrimes copyhdr = 1; 4171541Srgrimes while (off > 0) { 4181541Srgrimes if (m == 0) 4191541Srgrimes panic("m_copym"); 4201541Srgrimes if (off < m->m_len) 4211541Srgrimes break; 4221541Srgrimes off -= m->m_len; 4231541Srgrimes m = m->m_next; 4241541Srgrimes } 4251541Srgrimes np = ⊤ 4261541Srgrimes top = 0; 4271541Srgrimes while (len > 0) { 4281541Srgrimes if (m == 0) { 4291541Srgrimes if (len != M_COPYALL) 4301541Srgrimes panic("m_copym"); 4311541Srgrimes break; 4321541Srgrimes } 4331541Srgrimes MGET(n, wait, m->m_type); 4341541Srgrimes *np = n; 4351541Srgrimes if (n == 0) 4361541Srgrimes goto nospace; 4371541Srgrimes if (copyhdr) { 4381541Srgrimes M_COPY_PKTHDR(n, m); 4391541Srgrimes if (len == M_COPYALL) 4401541Srgrimes n->m_pkthdr.len -= off0; 4411541Srgrimes else 4421541Srgrimes n->m_pkthdr.len = len; 4431541Srgrimes copyhdr = 0; 4441541Srgrimes } 4451541Srgrimes n->m_len = min(len, m->m_len - off); 4461541Srgrimes if (m->m_flags & M_EXT) { 4471541Srgrimes n->m_data = m->m_data + off; 44817663Sjulian if(!m->m_ext.ext_ref) 44917663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 45017663Sjulian else 45117663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 45217663Sjulian m->m_ext.ext_size); 4531541Srgrimes n->m_ext = m->m_ext; 4541541Srgrimes n->m_flags |= M_EXT; 4551541Srgrimes } else 4561541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 4571541Srgrimes (unsigned)n->m_len); 4581541Srgrimes if (len != M_COPYALL) 4591541Srgrimes len -= n->m_len; 4601541Srgrimes off = 0; 4611541Srgrimes m = m->m_next; 4621541Srgrimes np = &n->m_next; 4631541Srgrimes } 4641541Srgrimes if (top == 0) 4651541Srgrimes MCFail++; 4661541Srgrimes return (top); 4671541Srgrimesnospace: 4681541Srgrimes m_freem(top); 4691541Srgrimes MCFail++; 4701541Srgrimes return (0); 4711541Srgrimes} 4721541Srgrimes 4731541Srgrimes/* 47415689Swollman * Copy an entire packet, including header (which must be present). 47515689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 47615689Swollman */ 47715689Swollmanstruct mbuf * 47815689Swollmanm_copypacket(m, how) 47915689Swollman struct mbuf *m; 48015689Swollman int how; 48115689Swollman{ 48215689Swollman struct mbuf *top, *n, *o; 48315689Swollman 48415689Swollman MGET(n, how, m->m_type); 48515689Swollman top = n; 48615689Swollman if (!n) 48715689Swollman goto nospace; 48815689Swollman 48915689Swollman M_COPY_PKTHDR(n, m); 49015689Swollman n->m_len = m->m_len; 49115689Swollman if (m->m_flags & M_EXT) { 49215689Swollman n->m_data = m->m_data; 49315689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 49415689Swollman n->m_ext = m->m_ext; 49515689Swollman n->m_flags |= M_EXT; 49615689Swollman } else { 49715689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 49815689Swollman } 49915689Swollman 50015689Swollman m = m->m_next; 50115689Swollman while (m) { 50215689Swollman MGET(o, how, m->m_type); 50315689Swollman if (!o) 50415689Swollman goto nospace; 50515689Swollman 50615689Swollman n->m_next = o; 50715689Swollman n = n->m_next; 50815689Swollman 50915689Swollman n->m_len = m->m_len; 51015689Swollman if (m->m_flags & M_EXT) { 51115689Swollman n->m_data = m->m_data; 51215689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 51315689Swollman n->m_ext = m->m_ext; 51415689Swollman n->m_flags |= M_EXT; 51515689Swollman } else { 51615689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 51715689Swollman } 51815689Swollman 51915689Swollman m = m->m_next; 52015689Swollman } 52115689Swollman return top; 52215689Swollmannospace: 52315689Swollman m_freem(top); 52415689Swollman MCFail++; 52515689Swollman return 0; 52615689Swollman} 52715689Swollman 52815689Swollman/* 5291541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 5301541Srgrimes * continuing for "len" bytes, into the indicated buffer. 5311541Srgrimes */ 5321549Srgrimesvoid 5331541Srgrimesm_copydata(m, off, len, cp) 5341541Srgrimes register struct mbuf *m; 5351541Srgrimes register int off; 5361541Srgrimes register int len; 5371541Srgrimes caddr_t cp; 5381541Srgrimes{ 5391541Srgrimes register unsigned count; 5401541Srgrimes 5411541Srgrimes if (off < 0 || len < 0) 5421541Srgrimes panic("m_copydata"); 5431541Srgrimes while (off > 0) { 5441541Srgrimes if (m == 0) 5451541Srgrimes panic("m_copydata"); 5461541Srgrimes if (off < m->m_len) 5471541Srgrimes break; 5481541Srgrimes off -= m->m_len; 5491541Srgrimes m = m->m_next; 5501541Srgrimes } 5511541Srgrimes while (len > 0) { 5521541Srgrimes if (m == 0) 5531541Srgrimes panic("m_copydata"); 5541541Srgrimes count = min(m->m_len - off, len); 5551541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 5561541Srgrimes len -= count; 5571541Srgrimes cp += count; 5581541Srgrimes off = 0; 5591541Srgrimes m = m->m_next; 5601541Srgrimes } 5611541Srgrimes} 5621541Srgrimes 5631541Srgrimes/* 5641541Srgrimes * Concatenate mbuf chain n to m. 5651541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 5661541Srgrimes * Any m_pkthdr is not updated. 5671541Srgrimes */ 5681549Srgrimesvoid 5691541Srgrimesm_cat(m, n) 5701541Srgrimes register struct mbuf *m, *n; 5711541Srgrimes{ 5721541Srgrimes while (m->m_next) 5731541Srgrimes m = m->m_next; 5741541Srgrimes while (n) { 5751541Srgrimes if (m->m_flags & M_EXT || 5761541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 5771541Srgrimes /* just join the two chains */ 5781541Srgrimes m->m_next = n; 5791541Srgrimes return; 5801541Srgrimes } 5811541Srgrimes /* splat the data from one into the other */ 5821541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 5831541Srgrimes (u_int)n->m_len); 5841541Srgrimes m->m_len += n->m_len; 5851541Srgrimes n = m_free(n); 5861541Srgrimes } 5871541Srgrimes} 5881541Srgrimes 5891549Srgrimesvoid 5901541Srgrimesm_adj(mp, req_len) 5911541Srgrimes struct mbuf *mp; 5921541Srgrimes int req_len; 5931541Srgrimes{ 5941541Srgrimes register int len = req_len; 5951541Srgrimes register struct mbuf *m; 5961541Srgrimes register count; 5971541Srgrimes 5981541Srgrimes if ((m = mp) == NULL) 5991541Srgrimes return; 6001541Srgrimes if (len >= 0) { 6011541Srgrimes /* 6021541Srgrimes * Trim from head. 6031541Srgrimes */ 6041541Srgrimes while (m != NULL && len > 0) { 6051541Srgrimes if (m->m_len <= len) { 6061541Srgrimes len -= m->m_len; 6071541Srgrimes m->m_len = 0; 6081541Srgrimes m = m->m_next; 6091541Srgrimes } else { 6101541Srgrimes m->m_len -= len; 6111541Srgrimes m->m_data += len; 6121541Srgrimes len = 0; 6131541Srgrimes } 6141541Srgrimes } 6151541Srgrimes m = mp; 6161541Srgrimes if (mp->m_flags & M_PKTHDR) 6171541Srgrimes m->m_pkthdr.len -= (req_len - len); 6181541Srgrimes } else { 6191541Srgrimes /* 6201541Srgrimes * Trim from tail. Scan the mbuf chain, 6211541Srgrimes * calculating its length and finding the last mbuf. 6221541Srgrimes * If the adjustment only affects this mbuf, then just 6231541Srgrimes * adjust and return. Otherwise, rescan and truncate 6241541Srgrimes * after the remaining size. 6251541Srgrimes */ 6261541Srgrimes len = -len; 6271541Srgrimes count = 0; 6281541Srgrimes for (;;) { 6291541Srgrimes count += m->m_len; 6301541Srgrimes if (m->m_next == (struct mbuf *)0) 6311541Srgrimes break; 6321541Srgrimes m = m->m_next; 6331541Srgrimes } 6341541Srgrimes if (m->m_len >= len) { 6351541Srgrimes m->m_len -= len; 6361541Srgrimes if (mp->m_flags & M_PKTHDR) 6371541Srgrimes mp->m_pkthdr.len -= len; 6381541Srgrimes return; 6391541Srgrimes } 6401541Srgrimes count -= len; 6411541Srgrimes if (count < 0) 6421541Srgrimes count = 0; 6431541Srgrimes /* 6441541Srgrimes * Correct length for chain is "count". 6451541Srgrimes * Find the mbuf with last data, adjust its length, 6461541Srgrimes * and toss data from remaining mbufs on chain. 6471541Srgrimes */ 6481541Srgrimes m = mp; 6491541Srgrimes if (m->m_flags & M_PKTHDR) 6501541Srgrimes m->m_pkthdr.len = count; 6511541Srgrimes for (; m; m = m->m_next) { 6521541Srgrimes if (m->m_len >= count) { 6531541Srgrimes m->m_len = count; 6541541Srgrimes break; 6551541Srgrimes } 6561541Srgrimes count -= m->m_len; 6571541Srgrimes } 6583308Sphk while (m->m_next) 6593308Sphk (m = m->m_next) ->m_len = 0; 6601541Srgrimes } 6611541Srgrimes} 6621541Srgrimes 6631541Srgrimes/* 6641541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 6651541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 6661541Srgrimes * will work for a structure of size len). Returns the resulting 6671541Srgrimes * mbuf chain on success, frees it and returns null on failure. 6681541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 6691541Srgrimes * contiguous region in an attempt to avoid being called next time. 6701541Srgrimes */ 67123081Swollman#define MPFail (mbstat.m_mpfail) 6721541Srgrimes 6731541Srgrimesstruct mbuf * 6741541Srgrimesm_pullup(n, len) 6751541Srgrimes register struct mbuf *n; 6761541Srgrimes int len; 6771541Srgrimes{ 6781541Srgrimes register struct mbuf *m; 6791541Srgrimes register int count; 6801541Srgrimes int space; 6811541Srgrimes 6821541Srgrimes /* 6831541Srgrimes * If first mbuf has no cluster, and has room for len bytes 6841541Srgrimes * without shifting current data, pullup into it, 6851541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 6861541Srgrimes */ 6871541Srgrimes if ((n->m_flags & M_EXT) == 0 && 6881541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 6891541Srgrimes if (n->m_len >= len) 6901541Srgrimes return (n); 6911541Srgrimes m = n; 6921541Srgrimes n = n->m_next; 6931541Srgrimes len -= m->m_len; 6941541Srgrimes } else { 6951541Srgrimes if (len > MHLEN) 6961541Srgrimes goto bad; 6971541Srgrimes MGET(m, M_DONTWAIT, n->m_type); 6981541Srgrimes if (m == 0) 6991541Srgrimes goto bad; 7001541Srgrimes m->m_len = 0; 7011541Srgrimes if (n->m_flags & M_PKTHDR) { 7021541Srgrimes M_COPY_PKTHDR(m, n); 7031541Srgrimes n->m_flags &= ~M_PKTHDR; 7041541Srgrimes } 7051541Srgrimes } 7061541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 7071541Srgrimes do { 7081541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 7091541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 7101541Srgrimes (unsigned)count); 7111541Srgrimes len -= count; 7121541Srgrimes m->m_len += count; 7131541Srgrimes n->m_len -= count; 7141541Srgrimes space -= count; 7151541Srgrimes if (n->m_len) 7161541Srgrimes n->m_data += count; 7171541Srgrimes else 7181541Srgrimes n = m_free(n); 7191541Srgrimes } while (len > 0 && n); 7201541Srgrimes if (len > 0) { 7211541Srgrimes (void) m_free(m); 7221541Srgrimes goto bad; 7231541Srgrimes } 7241541Srgrimes m->m_next = n; 7251541Srgrimes return (m); 7261541Srgrimesbad: 7271541Srgrimes m_freem(n); 7281541Srgrimes MPFail++; 7291541Srgrimes return (0); 7301541Srgrimes} 7311541Srgrimes 7321541Srgrimes/* 7331541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 7341541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 7351541Srgrimes * attempts to restore the chain to its original state. 7361541Srgrimes */ 7371541Srgrimesstruct mbuf * 7381541Srgrimesm_split(m0, len0, wait) 7391541Srgrimes register struct mbuf *m0; 7401541Srgrimes int len0, wait; 7411541Srgrimes{ 7421541Srgrimes register struct mbuf *m, *n; 7431541Srgrimes unsigned len = len0, remain; 7441541Srgrimes 7451541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 7461541Srgrimes len -= m->m_len; 7471541Srgrimes if (m == 0) 7481541Srgrimes return (0); 7491541Srgrimes remain = m->m_len - len; 7501541Srgrimes if (m0->m_flags & M_PKTHDR) { 7511541Srgrimes MGETHDR(n, wait, m0->m_type); 7521541Srgrimes if (n == 0) 7531541Srgrimes return (0); 7541541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 7551541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 7561541Srgrimes m0->m_pkthdr.len = len0; 7571541Srgrimes if (m->m_flags & M_EXT) 7581541Srgrimes goto extpacket; 7591541Srgrimes if (remain > MHLEN) { 7601541Srgrimes /* m can't be the lead packet */ 7611541Srgrimes MH_ALIGN(n, 0); 7621541Srgrimes n->m_next = m_split(m, len, wait); 7631541Srgrimes if (n->m_next == 0) { 7641541Srgrimes (void) m_free(n); 7651541Srgrimes return (0); 7661541Srgrimes } else 7671541Srgrimes return (n); 7681541Srgrimes } else 7691541Srgrimes MH_ALIGN(n, remain); 7701541Srgrimes } else if (remain == 0) { 7711541Srgrimes n = m->m_next; 7721541Srgrimes m->m_next = 0; 7731541Srgrimes return (n); 7741541Srgrimes } else { 7751541Srgrimes MGET(n, wait, m->m_type); 7761541Srgrimes if (n == 0) 7771541Srgrimes return (0); 7781541Srgrimes M_ALIGN(n, remain); 7791541Srgrimes } 7801541Srgrimesextpacket: 7811541Srgrimes if (m->m_flags & M_EXT) { 7821541Srgrimes n->m_flags |= M_EXT; 7831541Srgrimes n->m_ext = m->m_ext; 78417663Sjulian if(!m->m_ext.ext_ref) 78517663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 78617663Sjulian else 78717663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 78817663Sjulian m->m_ext.ext_size); 7891541Srgrimes m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ 7901541Srgrimes n->m_data = m->m_data + len; 7911541Srgrimes } else { 7921541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 7931541Srgrimes } 7941541Srgrimes n->m_len = remain; 7951541Srgrimes m->m_len = len; 7961541Srgrimes n->m_next = m->m_next; 7971541Srgrimes m->m_next = 0; 7981541Srgrimes return (n); 7991541Srgrimes} 8001541Srgrimes/* 8011541Srgrimes * Routine to copy from device local memory into mbufs. 8021541Srgrimes */ 8031541Srgrimesstruct mbuf * 8041541Srgrimesm_devget(buf, totlen, off0, ifp, copy) 8051541Srgrimes char *buf; 8061541Srgrimes int totlen, off0; 8071541Srgrimes struct ifnet *ifp; 80812577Sbde void (*copy) __P((char *from, caddr_t to, u_int len)); 8091541Srgrimes{ 8101541Srgrimes register struct mbuf *m; 8111541Srgrimes struct mbuf *top = 0, **mp = ⊤ 8121541Srgrimes register int off = off0, len; 8131541Srgrimes register char *cp; 8141541Srgrimes char *epkt; 8151541Srgrimes 8161541Srgrimes cp = buf; 8171541Srgrimes epkt = cp + totlen; 8181541Srgrimes if (off) { 8191541Srgrimes cp += off + 2 * sizeof(u_short); 8201541Srgrimes totlen -= 2 * sizeof(u_short); 8211541Srgrimes } 8221541Srgrimes MGETHDR(m, M_DONTWAIT, MT_DATA); 8231541Srgrimes if (m == 0) 8241541Srgrimes return (0); 8251541Srgrimes m->m_pkthdr.rcvif = ifp; 8261541Srgrimes m->m_pkthdr.len = totlen; 8271541Srgrimes m->m_len = MHLEN; 8281541Srgrimes 8291541Srgrimes while (totlen > 0) { 8301541Srgrimes if (top) { 8311541Srgrimes MGET(m, M_DONTWAIT, MT_DATA); 8321541Srgrimes if (m == 0) { 8331541Srgrimes m_freem(top); 8341541Srgrimes return (0); 8351541Srgrimes } 8361541Srgrimes m->m_len = MLEN; 8371541Srgrimes } 8381541Srgrimes len = min(totlen, epkt - cp); 8391541Srgrimes if (len >= MINCLSIZE) { 8401541Srgrimes MCLGET(m, M_DONTWAIT); 8411541Srgrimes if (m->m_flags & M_EXT) 8421541Srgrimes m->m_len = len = min(len, MCLBYTES); 8431541Srgrimes else 8441541Srgrimes len = m->m_len; 8451541Srgrimes } else { 8461541Srgrimes /* 8471541Srgrimes * Place initial small packet/header at end of mbuf. 8481541Srgrimes */ 8491541Srgrimes if (len < m->m_len) { 8501541Srgrimes if (top == 0 && len + max_linkhdr <= m->m_len) 8511541Srgrimes m->m_data += max_linkhdr; 8521541Srgrimes m->m_len = len; 8531541Srgrimes } else 8541541Srgrimes len = m->m_len; 8551541Srgrimes } 8561541Srgrimes if (copy) 8571541Srgrimes copy(cp, mtod(m, caddr_t), (unsigned)len); 8581541Srgrimes else 8591541Srgrimes bcopy(cp, mtod(m, caddr_t), (unsigned)len); 8601541Srgrimes cp += len; 8611541Srgrimes *mp = m; 8621541Srgrimes mp = &m->m_next; 8631541Srgrimes totlen -= len; 8641541Srgrimes if (cp == epkt) 8651541Srgrimes cp = buf; 8661541Srgrimes } 8671541Srgrimes return (top); 8681541Srgrimes} 8693352Sphk 8703352Sphk/* 8713352Sphk * Copy data from a buffer back into the indicated mbuf chain, 8723352Sphk * starting "off" bytes from the beginning, extending the mbuf 8733352Sphk * chain if necessary. 8743352Sphk */ 8753352Sphkvoid 8763352Sphkm_copyback(m0, off, len, cp) 8773352Sphk struct mbuf *m0; 8783352Sphk register int off; 8793352Sphk register int len; 8803352Sphk caddr_t cp; 8813352Sphk{ 8823352Sphk register int mlen; 8833352Sphk register struct mbuf *m = m0, *n; 8843352Sphk int totlen = 0; 8853352Sphk 8863352Sphk if (m0 == 0) 8873352Sphk return; 8883352Sphk while (off > (mlen = m->m_len)) { 8893352Sphk off -= mlen; 8903352Sphk totlen += mlen; 8913352Sphk if (m->m_next == 0) { 8923352Sphk n = m_getclr(M_DONTWAIT, m->m_type); 8933352Sphk if (n == 0) 8943352Sphk goto out; 8953352Sphk n->m_len = min(MLEN, len + off); 8963352Sphk m->m_next = n; 8973352Sphk } 8983352Sphk m = m->m_next; 8993352Sphk } 9003352Sphk while (len > 0) { 9013352Sphk mlen = min (m->m_len - off, len); 9023352Sphk bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 9033352Sphk cp += mlen; 9043352Sphk len -= mlen; 9053352Sphk mlen += off; 9063352Sphk off = 0; 9073352Sphk totlen += mlen; 9083352Sphk if (len == 0) 9093352Sphk break; 9103352Sphk if (m->m_next == 0) { 9113352Sphk n = m_get(M_DONTWAIT, m->m_type); 9123352Sphk if (n == 0) 9133352Sphk break; 9143352Sphk n->m_len = min(MLEN, len); 9153352Sphk m->m_next = n; 9163352Sphk } 9173352Sphk m = m->m_next; 9183352Sphk } 9193352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 9203352Sphk m->m_pkthdr.len = totlen; 9213352Sphk} 922