uipc_mbuf.c revision 22671
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 3421673Sjkh * $FreeBSD: head/sys/kern/uipc_mbuf.c 22671 1997-02-13 19:41:40Z wollman $ 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); 12115689Swollman p = (caddr_t)kmem_malloc(mb_map, nbytes, nowait ? M_NOWAIT : M_WAITOK); 12215689Swollman /* 12315689Swollman * Either the map is now full, or this is nowait and there 12415689Swollman * are no pages left. 12515689Swollman */ 12615689Swollman if (p == NULL) 12715689Swollman return (0); 12815689Swollman 12915689Swollman nmb = nbytes / MSIZE; 13015689Swollman for (i = 0; i < nmb; i++) { 13115689Swollman ((struct mbuf *)p)->m_next = mmbfree; 13215689Swollman mmbfree = (struct mbuf *)p; 13315689Swollman p += MSIZE; 13415689Swollman } 13515689Swollman mbstat.m_mbufs += nmb; 13615689Swollman return (1); 13715689Swollman} 13815689Swollman 13922671Swollman#if MCLBYTES > PAGE_SIZE 14022671Swollmanint i_want_my_mcl; 14122671Swollman 14222671Swollmanvoid 14322671Swollmankproc_mclalloc(void) 14422671Swollman{ 14522671Swollman int status; 14622671Swollman 14722671Swollman while (1) { 14822671Swollman tsleep(&i_want_my_mcl, PVM, "mclalloc", 0); 14922671Swollman 15022671Swollman for (; i_want_my_mcl; i_want_my_mcl--) { 15122671Swollman if (m_clalloc(1, 0) == 0) 15222671Swollman printf("m_clalloc failed even in process context!\n"); 15322671Swollman } 15422671Swollman } 15522671Swollman} 15622671Swollman 15722671Swollmanstatic struct proc *mclallocproc; 15822671Swollmanstatic struct kproc_desc mclalloc_kp = { 15922671Swollman "mclalloc", 16022671Swollman kproc_mclalloc, 16122671Swollman &mclallocproc 16222671Swollman}; 16322671SwollmanSYSINIT_KT(mclallocproc, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start, 16422671Swollman &mclalloc_kp); 16522671Swollman#endif 16622671Swollman 16715689Swollman/* 1681541Srgrimes * Allocate some number of mbuf clusters 1691541Srgrimes * and place on cluster free list. 1701541Srgrimes * Must be called at splimp. 1711541Srgrimes */ 1721541Srgrimes/* ARGSUSED */ 1731549Srgrimesint 1741541Srgrimesm_clalloc(ncl, nowait) 1751541Srgrimes register int ncl; 1761541Srgrimes int nowait; 1771541Srgrimes{ 1781541Srgrimes register caddr_t p; 1791541Srgrimes register int i; 1801541Srgrimes int npg; 1811541Srgrimes 1827066Sdg /* 1837066Sdg * Once we run out of map space, it will be impossible 1847066Sdg * to get any more (nothing is ever freed back to the 1857066Sdg * map). 1867066Sdg */ 18721737Sdg if (mb_map_full) 1887066Sdg return (0); 1897066Sdg 19022671Swollman#if MCLBYTES > PAGE_SIZE 19122671Swollman if (nowait) { 19222671Swollman i_want_my_mcl += ncl; 19322671Swollman wakeup(&i_want_my_mcl); 19422671Swollman p = 0; 19522671Swollman } else { 19622671Swollman p = contigmalloc1(MCLBYTES * ncl, M_DEVBUF, M_WAITOK, 0ul, 19722671Swollman ~0ul, PAGE_SIZE, 0, mb_map); 19822671Swollman } 19922671Swollman#else 20015543Sphk npg = ncl; 20121737Sdg p = (caddr_t)kmem_malloc(mb_map, ctob(npg), 2026191Sbde nowait ? M_NOWAIT : M_WAITOK); 20322671Swollman ncl = ncl * PAGE_SIZE / MCLBYTES; 20422671Swollman#endif 2057066Sdg /* 2067066Sdg * Either the map is now full, or this is nowait and there 2077066Sdg * are no pages left. 2087066Sdg */ 2097066Sdg if (p == NULL) 2101541Srgrimes return (0); 2117066Sdg 2121541Srgrimes for (i = 0; i < ncl; i++) { 2131541Srgrimes ((union mcluster *)p)->mcl_next = mclfree; 2141541Srgrimes mclfree = (union mcluster *)p; 2151541Srgrimes p += MCLBYTES; 2161541Srgrimes mbstat.m_clfree++; 2171541Srgrimes } 2181541Srgrimes mbstat.m_clusters += ncl; 2191541Srgrimes return (1); 2201541Srgrimes} 2211541Srgrimes 2221541Srgrimes/* 2231541Srgrimes * When MGET failes, ask protocols to free space when short of memory, 2241541Srgrimes * then re-attempt to allocate an mbuf. 2251541Srgrimes */ 2261541Srgrimesstruct mbuf * 2271541Srgrimesm_retry(i, t) 2281541Srgrimes int i, t; 2291541Srgrimes{ 2301541Srgrimes register struct mbuf *m; 2311541Srgrimes 2321541Srgrimes m_reclaim(); 2331541Srgrimes#define m_retry(i, t) (struct mbuf *)0 2341541Srgrimes MGET(m, i, t); 2351541Srgrimes#undef m_retry 2366669Sdg if (m != NULL) 2376669Sdg mbstat.m_wait++; 2386669Sdg else 2396669Sdg mbstat.m_drops++; 2401541Srgrimes return (m); 2411541Srgrimes} 2421541Srgrimes 2431541Srgrimes/* 2441541Srgrimes * As above; retry an MGETHDR. 2451541Srgrimes */ 2461541Srgrimesstruct mbuf * 2471541Srgrimesm_retryhdr(i, t) 2481541Srgrimes int i, t; 2491541Srgrimes{ 2501541Srgrimes register struct mbuf *m; 2511541Srgrimes 2521541Srgrimes m_reclaim(); 2531541Srgrimes#define m_retryhdr(i, t) (struct mbuf *)0 2541541Srgrimes MGETHDR(m, i, t); 2551541Srgrimes#undef m_retryhdr 2566669Sdg if (m != NULL) 2576669Sdg mbstat.m_wait++; 2586669Sdg else 2596669Sdg mbstat.m_drops++; 2601541Srgrimes return (m); 2611541Srgrimes} 2621541Srgrimes 26312819Sphkstatic void 2641541Srgrimesm_reclaim() 2651541Srgrimes{ 2661541Srgrimes register struct domain *dp; 2671541Srgrimes register struct protosw *pr; 2681541Srgrimes int s = splimp(); 2691541Srgrimes 2701541Srgrimes for (dp = domains; dp; dp = dp->dom_next) 2711541Srgrimes for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) 2721541Srgrimes if (pr->pr_drain) 2731541Srgrimes (*pr->pr_drain)(); 2741541Srgrimes splx(s); 2751541Srgrimes mbstat.m_drain++; 2761541Srgrimes} 2771541Srgrimes 2781541Srgrimes/* 2791541Srgrimes * Space allocation routines. 2801541Srgrimes * These are also available as macros 2811541Srgrimes * for critical paths. 2821541Srgrimes */ 2831541Srgrimesstruct mbuf * 2841541Srgrimesm_get(nowait, type) 2851541Srgrimes int nowait, type; 2861541Srgrimes{ 2871541Srgrimes register struct mbuf *m; 2881541Srgrimes 2891541Srgrimes MGET(m, nowait, type); 2901541Srgrimes return (m); 2911541Srgrimes} 2921541Srgrimes 2931541Srgrimesstruct mbuf * 2941541Srgrimesm_gethdr(nowait, type) 2951541Srgrimes int nowait, type; 2961541Srgrimes{ 2971541Srgrimes register struct mbuf *m; 2981541Srgrimes 2991541Srgrimes MGETHDR(m, nowait, type); 3001541Srgrimes return (m); 3011541Srgrimes} 3021541Srgrimes 3031541Srgrimesstruct mbuf * 3041541Srgrimesm_getclr(nowait, type) 3051541Srgrimes int nowait, type; 3061541Srgrimes{ 3071541Srgrimes register struct mbuf *m; 3081541Srgrimes 3091541Srgrimes MGET(m, nowait, type); 3101541Srgrimes if (m == 0) 3111541Srgrimes return (0); 3121541Srgrimes bzero(mtod(m, caddr_t), MLEN); 3131541Srgrimes return (m); 3141541Srgrimes} 3151541Srgrimes 3161541Srgrimesstruct mbuf * 3171541Srgrimesm_free(m) 3181541Srgrimes struct mbuf *m; 3191541Srgrimes{ 3201541Srgrimes register struct mbuf *n; 3211541Srgrimes 3221541Srgrimes MFREE(m, n); 3231541Srgrimes return (n); 3241541Srgrimes} 3251541Srgrimes 3261541Srgrimesvoid 3271541Srgrimesm_freem(m) 3281541Srgrimes register struct mbuf *m; 3291541Srgrimes{ 3301541Srgrimes register struct mbuf *n; 3311541Srgrimes 3321541Srgrimes if (m == NULL) 3331541Srgrimes return; 3341541Srgrimes do { 3351541Srgrimes MFREE(m, n); 3363308Sphk m = n; 3373308Sphk } while (m); 3381541Srgrimes} 3391541Srgrimes 3401541Srgrimes/* 3411541Srgrimes * Mbuffer utility routines. 3421541Srgrimes */ 3431541Srgrimes 3441541Srgrimes/* 3451541Srgrimes * Lesser-used path for M_PREPEND: 3461541Srgrimes * allocate new mbuf to prepend to chain, 3471541Srgrimes * copy junk along. 3481541Srgrimes */ 3491541Srgrimesstruct mbuf * 3501541Srgrimesm_prepend(m, len, how) 3511541Srgrimes register struct mbuf *m; 3521541Srgrimes int len, how; 3531541Srgrimes{ 3541541Srgrimes struct mbuf *mn; 3551541Srgrimes 3561541Srgrimes MGET(mn, how, m->m_type); 3571541Srgrimes if (mn == (struct mbuf *)NULL) { 3581541Srgrimes m_freem(m); 3591541Srgrimes return ((struct mbuf *)NULL); 3601541Srgrimes } 3611541Srgrimes if (m->m_flags & M_PKTHDR) { 3621541Srgrimes M_COPY_PKTHDR(mn, m); 3631541Srgrimes m->m_flags &= ~M_PKTHDR; 3641541Srgrimes } 3651541Srgrimes mn->m_next = m; 3661541Srgrimes m = mn; 3671541Srgrimes if (len < MHLEN) 3681541Srgrimes MH_ALIGN(m, len); 3691541Srgrimes m->m_len = len; 3701541Srgrimes return (m); 3711541Srgrimes} 3721541Srgrimes 3731541Srgrimes/* 3741541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 3751541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 3761541Srgrimes * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. 3771541Srgrimes */ 37812819Sphkstatic int MCFail; 3791541Srgrimes 3801541Srgrimesstruct mbuf * 3811541Srgrimesm_copym(m, off0, len, wait) 3821541Srgrimes register struct mbuf *m; 3831541Srgrimes int off0, wait; 3841541Srgrimes register int len; 3851541Srgrimes{ 3861541Srgrimes register struct mbuf *n, **np; 3871541Srgrimes register int off = off0; 3881541Srgrimes struct mbuf *top; 3891541Srgrimes int copyhdr = 0; 3901541Srgrimes 3911541Srgrimes if (off < 0 || len < 0) 3921541Srgrimes panic("m_copym"); 3931541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 3941541Srgrimes copyhdr = 1; 3951541Srgrimes while (off > 0) { 3961541Srgrimes if (m == 0) 3971541Srgrimes panic("m_copym"); 3981541Srgrimes if (off < m->m_len) 3991541Srgrimes break; 4001541Srgrimes off -= m->m_len; 4011541Srgrimes m = m->m_next; 4021541Srgrimes } 4031541Srgrimes np = ⊤ 4041541Srgrimes top = 0; 4051541Srgrimes while (len > 0) { 4061541Srgrimes if (m == 0) { 4071541Srgrimes if (len != M_COPYALL) 4081541Srgrimes panic("m_copym"); 4091541Srgrimes break; 4101541Srgrimes } 4111541Srgrimes MGET(n, wait, m->m_type); 4121541Srgrimes *np = n; 4131541Srgrimes if (n == 0) 4141541Srgrimes goto nospace; 4151541Srgrimes if (copyhdr) { 4161541Srgrimes M_COPY_PKTHDR(n, m); 4171541Srgrimes if (len == M_COPYALL) 4181541Srgrimes n->m_pkthdr.len -= off0; 4191541Srgrimes else 4201541Srgrimes n->m_pkthdr.len = len; 4211541Srgrimes copyhdr = 0; 4221541Srgrimes } 4231541Srgrimes n->m_len = min(len, m->m_len - off); 4241541Srgrimes if (m->m_flags & M_EXT) { 4251541Srgrimes n->m_data = m->m_data + off; 42617663Sjulian if(!m->m_ext.ext_ref) 42717663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 42817663Sjulian else 42917663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 43017663Sjulian m->m_ext.ext_size); 4311541Srgrimes n->m_ext = m->m_ext; 4321541Srgrimes n->m_flags |= M_EXT; 4331541Srgrimes } else 4341541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 4351541Srgrimes (unsigned)n->m_len); 4361541Srgrimes if (len != M_COPYALL) 4371541Srgrimes len -= n->m_len; 4381541Srgrimes off = 0; 4391541Srgrimes m = m->m_next; 4401541Srgrimes np = &n->m_next; 4411541Srgrimes } 4421541Srgrimes if (top == 0) 4431541Srgrimes MCFail++; 4441541Srgrimes return (top); 4451541Srgrimesnospace: 4461541Srgrimes m_freem(top); 4471541Srgrimes MCFail++; 4481541Srgrimes return (0); 4491541Srgrimes} 4501541Srgrimes 4511541Srgrimes/* 45215689Swollman * Copy an entire packet, including header (which must be present). 45315689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 45415689Swollman */ 45515689Swollmanstruct mbuf * 45615689Swollmanm_copypacket(m, how) 45715689Swollman struct mbuf *m; 45815689Swollman int how; 45915689Swollman{ 46015689Swollman struct mbuf *top, *n, *o; 46115689Swollman 46215689Swollman MGET(n, how, m->m_type); 46315689Swollman top = n; 46415689Swollman if (!n) 46515689Swollman goto nospace; 46615689Swollman 46715689Swollman M_COPY_PKTHDR(n, m); 46815689Swollman n->m_len = m->m_len; 46915689Swollman if (m->m_flags & M_EXT) { 47015689Swollman n->m_data = m->m_data; 47115689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 47215689Swollman n->m_ext = m->m_ext; 47315689Swollman n->m_flags |= M_EXT; 47415689Swollman } else { 47515689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 47615689Swollman } 47715689Swollman 47815689Swollman m = m->m_next; 47915689Swollman while (m) { 48015689Swollman MGET(o, how, m->m_type); 48115689Swollman if (!o) 48215689Swollman goto nospace; 48315689Swollman 48415689Swollman n->m_next = o; 48515689Swollman n = n->m_next; 48615689Swollman 48715689Swollman n->m_len = m->m_len; 48815689Swollman if (m->m_flags & M_EXT) { 48915689Swollman n->m_data = m->m_data; 49015689Swollman mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 49115689Swollman n->m_ext = m->m_ext; 49215689Swollman n->m_flags |= M_EXT; 49315689Swollman } else { 49415689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 49515689Swollman } 49615689Swollman 49715689Swollman m = m->m_next; 49815689Swollman } 49915689Swollman return top; 50015689Swollmannospace: 50115689Swollman m_freem(top); 50215689Swollman MCFail++; 50315689Swollman return 0; 50415689Swollman} 50515689Swollman 50615689Swollman/* 5071541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 5081541Srgrimes * continuing for "len" bytes, into the indicated buffer. 5091541Srgrimes */ 5101549Srgrimesvoid 5111541Srgrimesm_copydata(m, off, len, cp) 5121541Srgrimes register struct mbuf *m; 5131541Srgrimes register int off; 5141541Srgrimes register int len; 5151541Srgrimes caddr_t cp; 5161541Srgrimes{ 5171541Srgrimes register unsigned count; 5181541Srgrimes 5191541Srgrimes if (off < 0 || len < 0) 5201541Srgrimes panic("m_copydata"); 5211541Srgrimes while (off > 0) { 5221541Srgrimes if (m == 0) 5231541Srgrimes panic("m_copydata"); 5241541Srgrimes if (off < m->m_len) 5251541Srgrimes break; 5261541Srgrimes off -= m->m_len; 5271541Srgrimes m = m->m_next; 5281541Srgrimes } 5291541Srgrimes while (len > 0) { 5301541Srgrimes if (m == 0) 5311541Srgrimes panic("m_copydata"); 5321541Srgrimes count = min(m->m_len - off, len); 5331541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 5341541Srgrimes len -= count; 5351541Srgrimes cp += count; 5361541Srgrimes off = 0; 5371541Srgrimes m = m->m_next; 5381541Srgrimes } 5391541Srgrimes} 5401541Srgrimes 5411541Srgrimes/* 5421541Srgrimes * Concatenate mbuf chain n to m. 5431541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 5441541Srgrimes * Any m_pkthdr is not updated. 5451541Srgrimes */ 5461549Srgrimesvoid 5471541Srgrimesm_cat(m, n) 5481541Srgrimes register struct mbuf *m, *n; 5491541Srgrimes{ 5501541Srgrimes while (m->m_next) 5511541Srgrimes m = m->m_next; 5521541Srgrimes while (n) { 5531541Srgrimes if (m->m_flags & M_EXT || 5541541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 5551541Srgrimes /* just join the two chains */ 5561541Srgrimes m->m_next = n; 5571541Srgrimes return; 5581541Srgrimes } 5591541Srgrimes /* splat the data from one into the other */ 5601541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 5611541Srgrimes (u_int)n->m_len); 5621541Srgrimes m->m_len += n->m_len; 5631541Srgrimes n = m_free(n); 5641541Srgrimes } 5651541Srgrimes} 5661541Srgrimes 5671549Srgrimesvoid 5681541Srgrimesm_adj(mp, req_len) 5691541Srgrimes struct mbuf *mp; 5701541Srgrimes int req_len; 5711541Srgrimes{ 5721541Srgrimes register int len = req_len; 5731541Srgrimes register struct mbuf *m; 5741541Srgrimes register count; 5751541Srgrimes 5761541Srgrimes if ((m = mp) == NULL) 5771541Srgrimes return; 5781541Srgrimes if (len >= 0) { 5791541Srgrimes /* 5801541Srgrimes * Trim from head. 5811541Srgrimes */ 5821541Srgrimes while (m != NULL && len > 0) { 5831541Srgrimes if (m->m_len <= len) { 5841541Srgrimes len -= m->m_len; 5851541Srgrimes m->m_len = 0; 5861541Srgrimes m = m->m_next; 5871541Srgrimes } else { 5881541Srgrimes m->m_len -= len; 5891541Srgrimes m->m_data += len; 5901541Srgrimes len = 0; 5911541Srgrimes } 5921541Srgrimes } 5931541Srgrimes m = mp; 5941541Srgrimes if (mp->m_flags & M_PKTHDR) 5951541Srgrimes m->m_pkthdr.len -= (req_len - len); 5961541Srgrimes } else { 5971541Srgrimes /* 5981541Srgrimes * Trim from tail. Scan the mbuf chain, 5991541Srgrimes * calculating its length and finding the last mbuf. 6001541Srgrimes * If the adjustment only affects this mbuf, then just 6011541Srgrimes * adjust and return. Otherwise, rescan and truncate 6021541Srgrimes * after the remaining size. 6031541Srgrimes */ 6041541Srgrimes len = -len; 6051541Srgrimes count = 0; 6061541Srgrimes for (;;) { 6071541Srgrimes count += m->m_len; 6081541Srgrimes if (m->m_next == (struct mbuf *)0) 6091541Srgrimes break; 6101541Srgrimes m = m->m_next; 6111541Srgrimes } 6121541Srgrimes if (m->m_len >= len) { 6131541Srgrimes m->m_len -= len; 6141541Srgrimes if (mp->m_flags & M_PKTHDR) 6151541Srgrimes mp->m_pkthdr.len -= len; 6161541Srgrimes return; 6171541Srgrimes } 6181541Srgrimes count -= len; 6191541Srgrimes if (count < 0) 6201541Srgrimes count = 0; 6211541Srgrimes /* 6221541Srgrimes * Correct length for chain is "count". 6231541Srgrimes * Find the mbuf with last data, adjust its length, 6241541Srgrimes * and toss data from remaining mbufs on chain. 6251541Srgrimes */ 6261541Srgrimes m = mp; 6271541Srgrimes if (m->m_flags & M_PKTHDR) 6281541Srgrimes m->m_pkthdr.len = count; 6291541Srgrimes for (; m; m = m->m_next) { 6301541Srgrimes if (m->m_len >= count) { 6311541Srgrimes m->m_len = count; 6321541Srgrimes break; 6331541Srgrimes } 6341541Srgrimes count -= m->m_len; 6351541Srgrimes } 6363308Sphk while (m->m_next) 6373308Sphk (m = m->m_next) ->m_len = 0; 6381541Srgrimes } 6391541Srgrimes} 6401541Srgrimes 6411541Srgrimes/* 6421541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 6431541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 6441541Srgrimes * will work for a structure of size len). Returns the resulting 6451541Srgrimes * mbuf chain on success, frees it and returns null on failure. 6461541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 6471541Srgrimes * contiguous region in an attempt to avoid being called next time. 6481541Srgrimes */ 64912819Sphkstatic int MPFail; 6501541Srgrimes 6511541Srgrimesstruct mbuf * 6521541Srgrimesm_pullup(n, len) 6531541Srgrimes register struct mbuf *n; 6541541Srgrimes int len; 6551541Srgrimes{ 6561541Srgrimes register struct mbuf *m; 6571541Srgrimes register int count; 6581541Srgrimes int space; 6591541Srgrimes 6601541Srgrimes /* 6611541Srgrimes * If first mbuf has no cluster, and has room for len bytes 6621541Srgrimes * without shifting current data, pullup into it, 6631541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 6641541Srgrimes */ 6651541Srgrimes if ((n->m_flags & M_EXT) == 0 && 6661541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 6671541Srgrimes if (n->m_len >= len) 6681541Srgrimes return (n); 6691541Srgrimes m = n; 6701541Srgrimes n = n->m_next; 6711541Srgrimes len -= m->m_len; 6721541Srgrimes } else { 6731541Srgrimes if (len > MHLEN) 6741541Srgrimes goto bad; 6751541Srgrimes MGET(m, M_DONTWAIT, n->m_type); 6761541Srgrimes if (m == 0) 6771541Srgrimes goto bad; 6781541Srgrimes m->m_len = 0; 6791541Srgrimes if (n->m_flags & M_PKTHDR) { 6801541Srgrimes M_COPY_PKTHDR(m, n); 6811541Srgrimes n->m_flags &= ~M_PKTHDR; 6821541Srgrimes } 6831541Srgrimes } 6841541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 6851541Srgrimes do { 6861541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 6871541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 6881541Srgrimes (unsigned)count); 6891541Srgrimes len -= count; 6901541Srgrimes m->m_len += count; 6911541Srgrimes n->m_len -= count; 6921541Srgrimes space -= count; 6931541Srgrimes if (n->m_len) 6941541Srgrimes n->m_data += count; 6951541Srgrimes else 6961541Srgrimes n = m_free(n); 6971541Srgrimes } while (len > 0 && n); 6981541Srgrimes if (len > 0) { 6991541Srgrimes (void) m_free(m); 7001541Srgrimes goto bad; 7011541Srgrimes } 7021541Srgrimes m->m_next = n; 7031541Srgrimes return (m); 7041541Srgrimesbad: 7051541Srgrimes m_freem(n); 7061541Srgrimes MPFail++; 7071541Srgrimes return (0); 7081541Srgrimes} 7091541Srgrimes 7101541Srgrimes/* 7111541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 7121541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 7131541Srgrimes * attempts to restore the chain to its original state. 7141541Srgrimes */ 7151541Srgrimesstruct mbuf * 7161541Srgrimesm_split(m0, len0, wait) 7171541Srgrimes register struct mbuf *m0; 7181541Srgrimes int len0, wait; 7191541Srgrimes{ 7201541Srgrimes register struct mbuf *m, *n; 7211541Srgrimes unsigned len = len0, remain; 7221541Srgrimes 7231541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 7241541Srgrimes len -= m->m_len; 7251541Srgrimes if (m == 0) 7261541Srgrimes return (0); 7271541Srgrimes remain = m->m_len - len; 7281541Srgrimes if (m0->m_flags & M_PKTHDR) { 7291541Srgrimes MGETHDR(n, wait, m0->m_type); 7301541Srgrimes if (n == 0) 7311541Srgrimes return (0); 7321541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 7331541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 7341541Srgrimes m0->m_pkthdr.len = len0; 7351541Srgrimes if (m->m_flags & M_EXT) 7361541Srgrimes goto extpacket; 7371541Srgrimes if (remain > MHLEN) { 7381541Srgrimes /* m can't be the lead packet */ 7391541Srgrimes MH_ALIGN(n, 0); 7401541Srgrimes n->m_next = m_split(m, len, wait); 7411541Srgrimes if (n->m_next == 0) { 7421541Srgrimes (void) m_free(n); 7431541Srgrimes return (0); 7441541Srgrimes } else 7451541Srgrimes return (n); 7461541Srgrimes } else 7471541Srgrimes MH_ALIGN(n, remain); 7481541Srgrimes } else if (remain == 0) { 7491541Srgrimes n = m->m_next; 7501541Srgrimes m->m_next = 0; 7511541Srgrimes return (n); 7521541Srgrimes } else { 7531541Srgrimes MGET(n, wait, m->m_type); 7541541Srgrimes if (n == 0) 7551541Srgrimes return (0); 7561541Srgrimes M_ALIGN(n, remain); 7571541Srgrimes } 7581541Srgrimesextpacket: 7591541Srgrimes if (m->m_flags & M_EXT) { 7601541Srgrimes n->m_flags |= M_EXT; 7611541Srgrimes n->m_ext = m->m_ext; 76217663Sjulian if(!m->m_ext.ext_ref) 76317663Sjulian mclrefcnt[mtocl(m->m_ext.ext_buf)]++; 76417663Sjulian else 76517663Sjulian (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, 76617663Sjulian m->m_ext.ext_size); 7671541Srgrimes m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ 7681541Srgrimes n->m_data = m->m_data + len; 7691541Srgrimes } else { 7701541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 7711541Srgrimes } 7721541Srgrimes n->m_len = remain; 7731541Srgrimes m->m_len = len; 7741541Srgrimes n->m_next = m->m_next; 7751541Srgrimes m->m_next = 0; 7761541Srgrimes return (n); 7771541Srgrimes} 7781541Srgrimes/* 7791541Srgrimes * Routine to copy from device local memory into mbufs. 7801541Srgrimes */ 7811541Srgrimesstruct mbuf * 7821541Srgrimesm_devget(buf, totlen, off0, ifp, copy) 7831541Srgrimes char *buf; 7841541Srgrimes int totlen, off0; 7851541Srgrimes struct ifnet *ifp; 78612577Sbde void (*copy) __P((char *from, caddr_t to, u_int len)); 7871541Srgrimes{ 7881541Srgrimes register struct mbuf *m; 7891541Srgrimes struct mbuf *top = 0, **mp = ⊤ 7901541Srgrimes register int off = off0, len; 7911541Srgrimes register char *cp; 7921541Srgrimes char *epkt; 7931541Srgrimes 7941541Srgrimes cp = buf; 7951541Srgrimes epkt = cp + totlen; 7961541Srgrimes if (off) { 7971541Srgrimes cp += off + 2 * sizeof(u_short); 7981541Srgrimes totlen -= 2 * sizeof(u_short); 7991541Srgrimes } 8001541Srgrimes MGETHDR(m, M_DONTWAIT, MT_DATA); 8011541Srgrimes if (m == 0) 8021541Srgrimes return (0); 8031541Srgrimes m->m_pkthdr.rcvif = ifp; 8041541Srgrimes m->m_pkthdr.len = totlen; 8051541Srgrimes m->m_len = MHLEN; 8061541Srgrimes 8071541Srgrimes while (totlen > 0) { 8081541Srgrimes if (top) { 8091541Srgrimes MGET(m, M_DONTWAIT, MT_DATA); 8101541Srgrimes if (m == 0) { 8111541Srgrimes m_freem(top); 8121541Srgrimes return (0); 8131541Srgrimes } 8141541Srgrimes m->m_len = MLEN; 8151541Srgrimes } 8161541Srgrimes len = min(totlen, epkt - cp); 8171541Srgrimes if (len >= MINCLSIZE) { 8181541Srgrimes MCLGET(m, M_DONTWAIT); 8191541Srgrimes if (m->m_flags & M_EXT) 8201541Srgrimes m->m_len = len = min(len, MCLBYTES); 8211541Srgrimes else 8221541Srgrimes len = m->m_len; 8231541Srgrimes } else { 8241541Srgrimes /* 8251541Srgrimes * Place initial small packet/header at end of mbuf. 8261541Srgrimes */ 8271541Srgrimes if (len < m->m_len) { 8281541Srgrimes if (top == 0 && len + max_linkhdr <= m->m_len) 8291541Srgrimes m->m_data += max_linkhdr; 8301541Srgrimes m->m_len = len; 8311541Srgrimes } else 8321541Srgrimes len = m->m_len; 8331541Srgrimes } 8341541Srgrimes if (copy) 8351541Srgrimes copy(cp, mtod(m, caddr_t), (unsigned)len); 8361541Srgrimes else 8371541Srgrimes bcopy(cp, mtod(m, caddr_t), (unsigned)len); 8381541Srgrimes cp += len; 8391541Srgrimes *mp = m; 8401541Srgrimes mp = &m->m_next; 8411541Srgrimes totlen -= len; 8421541Srgrimes if (cp == epkt) 8431541Srgrimes cp = buf; 8441541Srgrimes } 8451541Srgrimes return (top); 8461541Srgrimes} 8473352Sphk 8483352Sphk/* 8493352Sphk * Copy data from a buffer back into the indicated mbuf chain, 8503352Sphk * starting "off" bytes from the beginning, extending the mbuf 8513352Sphk * chain if necessary. 8523352Sphk */ 8533352Sphkvoid 8543352Sphkm_copyback(m0, off, len, cp) 8553352Sphk struct mbuf *m0; 8563352Sphk register int off; 8573352Sphk register int len; 8583352Sphk caddr_t cp; 8593352Sphk{ 8603352Sphk register int mlen; 8613352Sphk register struct mbuf *m = m0, *n; 8623352Sphk int totlen = 0; 8633352Sphk 8643352Sphk if (m0 == 0) 8653352Sphk return; 8663352Sphk while (off > (mlen = m->m_len)) { 8673352Sphk off -= mlen; 8683352Sphk totlen += mlen; 8693352Sphk if (m->m_next == 0) { 8703352Sphk n = m_getclr(M_DONTWAIT, m->m_type); 8713352Sphk if (n == 0) 8723352Sphk goto out; 8733352Sphk n->m_len = min(MLEN, len + off); 8743352Sphk m->m_next = n; 8753352Sphk } 8763352Sphk m = m->m_next; 8773352Sphk } 8783352Sphk while (len > 0) { 8793352Sphk mlen = min (m->m_len - off, len); 8803352Sphk bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); 8813352Sphk cp += mlen; 8823352Sphk len -= mlen; 8833352Sphk mlen += off; 8843352Sphk off = 0; 8853352Sphk totlen += mlen; 8863352Sphk if (len == 0) 8873352Sphk break; 8883352Sphk if (m->m_next == 0) { 8893352Sphk n = m_get(M_DONTWAIT, m->m_type); 8903352Sphk if (n == 0) 8913352Sphk break; 8923352Sphk n->m_len = min(MLEN, len); 8933352Sphk m->m_next = n; 8943352Sphk } 8953352Sphk m = m->m_next; 8963352Sphk } 8973352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 8983352Sphk m->m_pkthdr.len = totlen; 8993352Sphk} 900