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7d03271452
to accomodate the changes. Here's a list of things that have changed (I may have left out a few); for a relatively complete list, see http://people.freebsd.org/~bmilekic/mtx_journal * Remove old (once useful) mcluster code for MCLBYTES > PAGE_SIZE which nobody uses anymore. It was great while it lasted, but now we're moving onto bigger and better things (Approved by: wollman). * Practically re-wrote the allocation macros in sys/sys/mbuf.h to accomodate new allocations which grab the necessary lock. * Make sure that necessary mbstat variables are manipulated with corresponding atomic() routines. * Changed the "wait" routines, cleaned it up, made one routine that does the job. * Generalized MWAKEUP() macro. Got rid of m_retry and m_retryhdr, as they are now included in the generalized "wait" routines. * Sleep routines now use msleep(). * Free lists have locks. * etc... probably other stuff I'm missing... Things to look out for and work on later: * find a better way to (dynamically) adjust EXT_COUNTERS * move necessity to recurse on a lock from drain routines by providing lock-free lower-level version of MFREE() (and possibly m_free()?). * checkout include of mutex.h in sys/sys/mbuf.h - probably violating general philosophy here. The code has been reviewed quite a bit, but problems may arise... please, don't panic! Send me Emails: bmilekic@freebsd.org Reviewed by: jlemon, cp, alfred, others?
1184 lines
28 KiB
C
1184 lines
28 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
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* $FreeBSD$
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*/
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#include "opt_param.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/domain.h>
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#include <sys/protosw.h>
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#include <vm/vm.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <machine/mutex.h>
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static void mbinit __P((void *));
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SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL)
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struct mbuf *mbutl;
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struct mbstat mbstat;
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u_long mbtypes[MT_NTYPES];
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int max_linkhdr;
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int max_protohdr;
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int max_hdr;
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int max_datalen;
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int nmbclusters;
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int nmbufs;
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u_long m_mballoc_wid = 0;
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u_long m_clalloc_wid = 0;
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/*
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* freelist header structures...
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* mbffree_lst, mclfree_lst, mcntfree_lst
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*/
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struct mbffree_lst mmbfree;
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struct mclfree_lst mclfree;
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struct mcntfree_lst mcntfree;
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/*
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* sysctl(8) exported objects
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*/
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SYSCTL_DECL(_kern_ipc);
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SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW,
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&max_linkhdr, 0, "");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW,
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&max_protohdr, 0, "");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, "");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW,
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&max_datalen, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW,
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&mbuf_wait, 0, "");
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SYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RD, &mbstat, mbstat, "");
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SYSCTL_OPAQUE(_kern_ipc, OID_AUTO, mbtypes, CTLFLAG_RD, mbtypes,
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sizeof(mbtypes), "LU", "");
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SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD,
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&nmbclusters, 0, "Maximum number of mbuf clusters available");
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SYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RD, &nmbufs, 0,
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"Maximum number of mbufs available");
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#ifndef NMBCLUSTERS
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#define NMBCLUSTERS (512 + MAXUSERS * 16)
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#endif
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TUNABLE_INT_DECL("kern.ipc.nmbclusters", NMBCLUSTERS, nmbclusters);
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TUNABLE_INT_DECL("kern.ipc.nmbufs", NMBCLUSTERS * 4, nmbufs);
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static void m_reclaim __P((void));
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/* Initial allocation numbers */
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#define NCL_INIT 2
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#define NMB_INIT 16
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#define REF_INIT NMBCLUSTERS
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/*
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* Full mbuf subsystem initialization done here.
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*
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* XXX: If ever we have system specific map setups to do, then move them to
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* machdep.c - for now, there is no reason for this stuff to go there.
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*/
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static void
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mbinit(dummy)
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void *dummy;
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{
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vm_offset_t maxaddr, mb_map_size;
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/*
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* Setup the mb_map, allocate requested VM space.
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*/
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mb_map_size = nmbufs * MSIZE + nmbclusters * MCLBYTES + EXT_COUNTERS
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* sizeof(union mext_refcnt);
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mb_map_size = roundup2(mb_map_size, PAGE_SIZE);
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mb_map = kmem_suballoc(kmem_map, (vm_offset_t *)&mbutl, &maxaddr,
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mb_map_size);
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/* XXX: mb_map->system_map = 1; */
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/*
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* Initialize the free list headers, and setup locks for lists.
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*/
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mmbfree.m_head = NULL;
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mclfree.m_head = NULL;
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mcntfree.m_head = NULL;
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mtx_init(&mmbfree.m_mtx, "mbuf free list lock", MTX_DEF);
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mtx_init(&mclfree.m_mtx, "mcluster free list lock", MTX_DEF);
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mtx_init(&mcntfree.m_mtx, "m_ext counter free list lock", MTX_DEF);
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/*
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* Initialize mbuf subsystem (sysctl exported) statistics structure.
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*/
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mbstat.m_msize = MSIZE;
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mbstat.m_mclbytes = MCLBYTES;
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mbstat.m_minclsize = MINCLSIZE;
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mbstat.m_mlen = MLEN;
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mbstat.m_mhlen = MHLEN;
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/*
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* Perform some initial allocations.
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*/
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mtx_enter(&mcntfree.m_mtx, MTX_DEF);
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if (m_alloc_ref(REF_INIT, M_DONTWAIT) == 0)
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goto bad;
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mtx_exit(&mcntfree.m_mtx, MTX_DEF);
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mtx_enter(&mmbfree.m_mtx, MTX_DEF);
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if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0)
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goto bad;
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mtx_exit(&mmbfree.m_mtx, MTX_DEF);
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mtx_enter(&mclfree.m_mtx, MTX_DEF);
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if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0)
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goto bad;
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mtx_exit(&mclfree.m_mtx, MTX_DEF);
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return;
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bad:
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panic("mbinit: failed to initialize mbuf subsystem!");
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}
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/*
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* Allocate at least nmb reference count structs and place them
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* on the ref cnt free list.
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*
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* Must be called with the mcntfree lock held.
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*/
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int
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m_alloc_ref(nmb, how)
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u_int nmb;
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int how;
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{
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caddr_t p;
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u_int nbytes;
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int i;
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/*
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* We don't cap the amount of memory that can be used
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* by the reference counters, like we do for mbufs and
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* mbuf clusters. In fact, we're absolutely sure that we
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* won't ever be going over our allocated space. We keep enough
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* space in mb_map to accomodate maximum values of allocatable
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* external buffers including, but not limited to, clusters.
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* (That's also why we won't have to have wait routines for
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* counters).
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*
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* If we're in here, we're absolutely certain to be returning
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* succesfully, as long as there is physical memory to accomodate
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* us. And if there isn't, but we're willing to wait, then
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* kmem_malloc() will do the only waiting needed.
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*/
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nbytes = round_page(nmb * sizeof(union mext_refcnt));
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mtx_exit(&mcntfree.m_mtx, MTX_DEF);
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mtx_enter(&Giant, MTX_DEF);
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if ((p = (caddr_t)kmem_malloc(mb_map, nbytes, how == M_WAIT ? M_WAIT :
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M_NOWAIT)) == NULL) {
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mtx_exit(&Giant, MTX_DEF);
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mtx_enter(&mcntfree.m_mtx, MTX_DEF); /* XXX: We must be holding
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it going out. */
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return (0);
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}
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mtx_exit(&Giant, MTX_DEF);
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nmb = nbytes / sizeof(union mext_refcnt);
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/*
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* We don't let go of the mutex in order to avoid a race.
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* It is up to the caller to let go of the mutex.
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*/
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mtx_enter(&mcntfree.m_mtx, MTX_DEF);
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for (i = 0; i < nmb; i++) {
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((union mext_refcnt *)p)->next_ref = mcntfree.m_head;
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mcntfree.m_head = (union mext_refcnt *)p;
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p += sizeof(union mext_refcnt);
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mbstat.m_refree++;
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}
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mbstat.m_refcnt += nmb;
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return (1);
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}
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/*
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* Allocate at least nmb mbufs and place on mbuf free list.
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*
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* Must be called with the mmbfree lock held.
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*/
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int
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m_mballoc(nmb, how)
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register int nmb;
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int how;
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{
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register caddr_t p;
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register int i;
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int nbytes;
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/*
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* If we've hit the mbuf limit, stop allocating from mb_map.
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* Also, once we run out of map space, it will be impossible to
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* get any more (nothing is ever freed back to the map).
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*/
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if (mb_map_full || ((nmb + mbstat.m_mbufs) > nmbufs)) {
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/*
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* Needs to be atomic as we may be incrementing it
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* while holding another mutex, like mclfree. In other
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* words, m_drops is not reserved solely for mbufs,
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* but is also available for clusters.
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*/
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atomic_add_long(&mbstat.m_drops, 1);
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return (0);
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}
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nbytes = round_page(nmb * MSIZE);
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/* XXX: The letting go of the mmbfree lock here may eventually
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be moved to only be done for M_WAIT calls to kmem_malloc() */
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mtx_exit(&mmbfree.m_mtx, MTX_DEF);
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mtx_enter(&Giant, MTX_DEF);
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p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT);
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if (p == 0 && how == M_WAIT) {
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atomic_add_long(&mbstat.m_wait, 1);
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p = (caddr_t)kmem_malloc(mb_map, nbytes, M_WAITOK);
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}
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mtx_exit(&Giant, MTX_DEF);
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mtx_enter(&mmbfree.m_mtx, MTX_DEF);
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/*
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* Either the map is now full, or `how' is M_DONTWAIT and there
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* are no pages left.
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*/
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if (p == NULL)
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return (0);
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nmb = nbytes / MSIZE;
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|
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/*
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* We don't let go of the mutex in order to avoid a race.
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* It is up to the caller to let go of the mutex when done
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* with grabbing the mbuf from the free list.
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*/
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for (i = 0; i < nmb; i++) {
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((struct mbuf *)p)->m_next = mmbfree.m_head;
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mmbfree.m_head = (struct mbuf *)p;
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p += MSIZE;
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}
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mbstat.m_mbufs += nmb;
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mbtypes[MT_FREE] += nmb;
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return (1);
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}
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/*
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* Once the mb_map has been exhausted and if the call to the allocation macros
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* (or, in some cases, functions) is with M_WAIT, then it is necessary to rely
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* solely on reclaimed mbufs.
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*
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* Here we request for the protocols to free up some resources and, if we
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* still cannot get anything, then we wait for an mbuf to be freed for a
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* designated (mbuf_wait) time.
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*
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* Must be called with the mmbfree mutex held, and we will probably end
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* up recursing into that lock from some of the drain routines, but
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* this should be okay, as long as we don't block there, or attempt
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* to allocate from them (theoretically impossible).
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*/
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struct mbuf *
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m_mballoc_wait(void)
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{
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struct mbuf *p = NULL;
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/*
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* See if we can drain some resources out of the protocols.
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*/
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m_reclaim();
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_MGET(p, M_DONTWAIT);
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|
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if (p == NULL) {
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m_mballoc_wid++;
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if (msleep(&m_mballoc_wid, &mmbfree.m_mtx, PVM, "mballc",
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mbuf_wait) == EWOULDBLOCK)
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m_mballoc_wid--;
|
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|
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/*
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* Try again (one last time).
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*
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* We retry to fetch _even_ if the sleep timed out. This
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* is left this way, purposely, in the [unlikely] case
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* that an mbuf was freed but the sleep was not awoken
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* in time.
|
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*
|
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* If the sleep didn't time out (i.e. we got woken up) then
|
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* we have the lock so we just grab an mbuf, hopefully.
|
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*/
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_MGET(p, M_DONTWAIT);
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}
|
|
|
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/* If we waited and got something... */
|
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if (p != NULL) {
|
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atomic_add_long(&mbstat.m_wait, 1);
|
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if (mmbfree.m_head != NULL)
|
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MBWAKEUP(m_mballoc_wid);
|
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} else
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atomic_add_long(&mbstat.m_drops, 1);
|
|
|
|
return (p);
|
|
}
|
|
|
|
/*
|
|
* Allocate some number of mbuf clusters
|
|
* and place on cluster free list.
|
|
*
|
|
* Must be called with the mclfree lock held.
|
|
*/
|
|
int
|
|
m_clalloc(ncl, how)
|
|
register int ncl;
|
|
int how;
|
|
{
|
|
register caddr_t p;
|
|
register int i;
|
|
int npg;
|
|
|
|
/*
|
|
* If the map is now full (nothing will ever be freed to it).
|
|
* If we've hit the mcluster number limit, stop allocating from
|
|
* mb_map.
|
|
*/
|
|
if (mb_map_full || ((ncl + mbstat.m_clusters) > nmbclusters)) {
|
|
atomic_add_long(&mbstat.m_drops, 1);
|
|
return (0);
|
|
}
|
|
|
|
npg = ncl;
|
|
mtx_exit(&mclfree.m_mtx, MTX_DEF);
|
|
mtx_enter(&Giant, MTX_DEF);
|
|
p = (caddr_t)kmem_malloc(mb_map, ctob(npg),
|
|
how != M_WAIT ? M_NOWAIT : M_WAITOK);
|
|
mtx_exit(&Giant, MTX_DEF);
|
|
ncl = ncl * PAGE_SIZE / MCLBYTES;
|
|
mtx_enter(&mclfree.m_mtx, MTX_DEF);
|
|
|
|
/*
|
|
* Either the map is now full, or `how' is M_DONTWAIT and there
|
|
* are no pages left.
|
|
*/
|
|
if (p == NULL) {
|
|
atomic_add_long(&mbstat.m_drops, 1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* We don't let go of the mutex in order to avoid a race.
|
|
*/
|
|
for (i = 0; i < ncl; i++) {
|
|
((union mcluster *)p)->mcl_next = mclfree.m_head;
|
|
mclfree.m_head = (union mcluster *)p;
|
|
p += MCLBYTES;
|
|
mbstat.m_clfree++;
|
|
}
|
|
mbstat.m_clusters += ncl;
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* Once the mb_map submap has been exhausted and the allocation is called with
|
|
* M_WAIT, we rely on the mclfree list. If nothing is free, we will
|
|
* sleep for a designated amount of time (mbuf_wait) or until we're woken up
|
|
* due to sudden mcluster availability.
|
|
*
|
|
* Must be called with the mclfree lock held.
|
|
*/
|
|
caddr_t
|
|
m_clalloc_wait(void)
|
|
{
|
|
caddr_t p = NULL;
|
|
|
|
m_clalloc_wid++;
|
|
if (msleep(&m_clalloc_wid, &mclfree.m_mtx, PVM, "mclalc", mbuf_wait)
|
|
== EWOULDBLOCK)
|
|
m_clalloc_wid--;
|
|
|
|
/*
|
|
* Now that we (think) that we've got something, try again.
|
|
*/
|
|
_MCLALLOC(p, M_DONTWAIT);
|
|
|
|
/* If we waited and got something ... */
|
|
if (p != NULL) {
|
|
atomic_add_long(&mbstat.m_wait, 1);
|
|
if (mclfree.m_head != NULL)
|
|
MBWAKEUP(m_clalloc_wid);
|
|
} else
|
|
atomic_add_long(&mbstat.m_drops, 1);
|
|
|
|
return (p);
|
|
}
|
|
|
|
/*
|
|
* m_reclaim: drain protocols in hopes to free up some resources...
|
|
*
|
|
* Should be called with mmbfree.m_mtx mutex held. We will most likely
|
|
* recursively grab it from within some drain routines, but that's okay,
|
|
* as the mutex will never be completely released until we let go of it
|
|
* after our m_reclaim() is over.
|
|
*
|
|
* Note: Drain routines are only allowed to free mbufs (and mclusters,
|
|
* as a consequence, if need be). They are not allowed to allocate
|
|
* new ones (that would defeat the purpose, anyway).
|
|
*/
|
|
static void
|
|
m_reclaim()
|
|
{
|
|
register struct domain *dp;
|
|
register struct protosw *pr;
|
|
|
|
for (dp = domains; dp; dp = dp->dom_next)
|
|
for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
|
|
if (pr->pr_drain)
|
|
(*pr->pr_drain)();
|
|
mbstat.m_drain++;
|
|
}
|
|
|
|
/*
|
|
* Space allocation routines.
|
|
* These are also available as macros
|
|
* for critical paths.
|
|
*/
|
|
struct mbuf *
|
|
m_get(how, type)
|
|
int how, type;
|
|
{
|
|
register struct mbuf *m;
|
|
|
|
MGET(m, how, type);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_gethdr(how, type)
|
|
int how, type;
|
|
{
|
|
register struct mbuf *m;
|
|
|
|
MGETHDR(m, how, type);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_getclr(how, type)
|
|
int how, type;
|
|
{
|
|
register struct mbuf *m;
|
|
|
|
MGET(m, how, type);
|
|
if (m == 0)
|
|
return (0);
|
|
bzero(mtod(m, caddr_t), MLEN);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_free(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct mbuf *n;
|
|
|
|
MFREE(m, n);
|
|
return (n);
|
|
}
|
|
|
|
void
|
|
m_freem(m)
|
|
register struct mbuf *m;
|
|
{
|
|
register struct mbuf *n;
|
|
|
|
if (m == NULL)
|
|
return;
|
|
do {
|
|
/*
|
|
* we do need to check non-first mbuf, since some of existing
|
|
* code does not call M_PREPEND properly.
|
|
* (example: call to bpf_mtap from drivers)
|
|
*/
|
|
if ((m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.aux) {
|
|
m_freem(m->m_pkthdr.aux);
|
|
m->m_pkthdr.aux = NULL;
|
|
}
|
|
MFREE(m, n);
|
|
m = n;
|
|
} while (m);
|
|
}
|
|
|
|
/*
|
|
* Mbuffer utility routines.
|
|
*/
|
|
|
|
/*
|
|
* Lesser-used path for M_PREPEND:
|
|
* allocate new mbuf to prepend to chain,
|
|
* copy junk along.
|
|
*/
|
|
struct mbuf *
|
|
m_prepend(m, len, how)
|
|
register struct mbuf *m;
|
|
int len, how;
|
|
{
|
|
struct mbuf *mn;
|
|
|
|
MGET(mn, how, m->m_type);
|
|
if (mn == (struct mbuf *)NULL) {
|
|
m_freem(m);
|
|
return ((struct mbuf *)NULL);
|
|
}
|
|
if (m->m_flags & M_PKTHDR) {
|
|
M_COPY_PKTHDR(mn, m);
|
|
m->m_flags &= ~M_PKTHDR;
|
|
}
|
|
mn->m_next = m;
|
|
m = mn;
|
|
if (len < MHLEN)
|
|
MH_ALIGN(m, len);
|
|
m->m_len = len;
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Make a copy of an mbuf chain starting "off0" bytes from the beginning,
|
|
* continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
|
|
* The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.
|
|
* Note that the copy is read-only, because clusters are not copied,
|
|
* only their reference counts are incremented.
|
|
*/
|
|
#define MCFail (mbstat.m_mcfail)
|
|
|
|
struct mbuf *
|
|
m_copym(m, off0, len, wait)
|
|
register struct mbuf *m;
|
|
int off0, wait;
|
|
register int len;
|
|
{
|
|
register struct mbuf *n, **np;
|
|
register int off = off0;
|
|
struct mbuf *top;
|
|
int copyhdr = 0;
|
|
|
|
KASSERT(off >= 0, ("m_copym, negative off %d", off));
|
|
KASSERT(len >= 0, ("m_copym, negative len %d", len));
|
|
if (off == 0 && m->m_flags & M_PKTHDR)
|
|
copyhdr = 1;
|
|
while (off > 0) {
|
|
KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
|
|
if (off < m->m_len)
|
|
break;
|
|
off -= m->m_len;
|
|
m = m->m_next;
|
|
}
|
|
np = ⊤
|
|
top = 0;
|
|
while (len > 0) {
|
|
if (m == 0) {
|
|
KASSERT(len == M_COPYALL,
|
|
("m_copym, length > size of mbuf chain"));
|
|
break;
|
|
}
|
|
MGET(n, wait, m->m_type);
|
|
*np = n;
|
|
if (n == 0)
|
|
goto nospace;
|
|
if (copyhdr) {
|
|
M_COPY_PKTHDR(n, m);
|
|
if (len == M_COPYALL)
|
|
n->m_pkthdr.len -= off0;
|
|
else
|
|
n->m_pkthdr.len = len;
|
|
copyhdr = 0;
|
|
}
|
|
n->m_len = min(len, m->m_len - off);
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data + off;
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
MEXT_ADD_REF(m);
|
|
} else
|
|
bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
|
|
(unsigned)n->m_len);
|
|
if (len != M_COPYALL)
|
|
len -= n->m_len;
|
|
off = 0;
|
|
m = m->m_next;
|
|
np = &n->m_next;
|
|
}
|
|
if (top == 0)
|
|
atomic_add_long(&MCFail, 1);
|
|
return (top);
|
|
nospace:
|
|
m_freem(top);
|
|
atomic_add_long(&MCFail, 1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Copy an entire packet, including header (which must be present).
|
|
* An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
|
|
* Note that the copy is read-only, because clusters are not copied,
|
|
* only their reference counts are incremented.
|
|
*/
|
|
struct mbuf *
|
|
m_copypacket(m, how)
|
|
struct mbuf *m;
|
|
int how;
|
|
{
|
|
struct mbuf *top, *n, *o;
|
|
|
|
MGET(n, how, m->m_type);
|
|
top = n;
|
|
if (!n)
|
|
goto nospace;
|
|
|
|
M_COPY_PKTHDR(n, m);
|
|
n->m_len = m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data;
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
MEXT_ADD_REF(m);
|
|
} else {
|
|
bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
while (m) {
|
|
MGET(o, how, m->m_type);
|
|
if (!o)
|
|
goto nospace;
|
|
|
|
n->m_next = o;
|
|
n = n->m_next;
|
|
|
|
n->m_len = m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data;
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
MEXT_ADD_REF(m);
|
|
} else {
|
|
bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
}
|
|
return top;
|
|
nospace:
|
|
m_freem(top);
|
|
atomic_add_long(&MCFail, 1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy data from an mbuf chain starting "off" bytes from the beginning,
|
|
* continuing for "len" bytes, into the indicated buffer.
|
|
*/
|
|
void
|
|
m_copydata(m, off, len, cp)
|
|
register struct mbuf *m;
|
|
register int off;
|
|
register int len;
|
|
caddr_t cp;
|
|
{
|
|
register unsigned count;
|
|
|
|
KASSERT(off >= 0, ("m_copydata, negative off %d", off));
|
|
KASSERT(len >= 0, ("m_copydata, negative len %d", len));
|
|
while (off > 0) {
|
|
KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
|
|
if (off < m->m_len)
|
|
break;
|
|
off -= m->m_len;
|
|
m = m->m_next;
|
|
}
|
|
while (len > 0) {
|
|
KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
|
|
count = min(m->m_len - off, len);
|
|
bcopy(mtod(m, caddr_t) + off, cp, count);
|
|
len -= count;
|
|
cp += count;
|
|
off = 0;
|
|
m = m->m_next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy a packet header mbuf chain into a completely new chain, including
|
|
* copying any mbuf clusters. Use this instead of m_copypacket() when
|
|
* you need a writable copy of an mbuf chain.
|
|
*/
|
|
struct mbuf *
|
|
m_dup(m, how)
|
|
struct mbuf *m;
|
|
int how;
|
|
{
|
|
struct mbuf **p, *top = NULL;
|
|
int remain, moff, nsize;
|
|
|
|
/* Sanity check */
|
|
if (m == NULL)
|
|
return (0);
|
|
KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __FUNCTION__));
|
|
|
|
/* While there's more data, get a new mbuf, tack it on, and fill it */
|
|
remain = m->m_pkthdr.len;
|
|
moff = 0;
|
|
p = ⊤
|
|
while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
|
|
struct mbuf *n;
|
|
|
|
/* Get the next new mbuf */
|
|
MGET(n, how, m->m_type);
|
|
if (n == NULL)
|
|
goto nospace;
|
|
if (top == NULL) { /* first one, must be PKTHDR */
|
|
M_COPY_PKTHDR(n, m);
|
|
nsize = MHLEN;
|
|
} else /* not the first one */
|
|
nsize = MLEN;
|
|
if (remain >= MINCLSIZE) {
|
|
MCLGET(n, how);
|
|
if ((n->m_flags & M_EXT) == 0) {
|
|
(void)m_free(n);
|
|
goto nospace;
|
|
}
|
|
nsize = MCLBYTES;
|
|
}
|
|
n->m_len = 0;
|
|
|
|
/* Link it into the new chain */
|
|
*p = n;
|
|
p = &n->m_next;
|
|
|
|
/* Copy data from original mbuf(s) into new mbuf */
|
|
while (n->m_len < nsize && m != NULL) {
|
|
int chunk = min(nsize - n->m_len, m->m_len - moff);
|
|
|
|
bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
|
|
moff += chunk;
|
|
n->m_len += chunk;
|
|
remain -= chunk;
|
|
if (moff == m->m_len) {
|
|
m = m->m_next;
|
|
moff = 0;
|
|
}
|
|
}
|
|
|
|
/* Check correct total mbuf length */
|
|
KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
|
|
("%s: bogus m_pkthdr.len", __FUNCTION__));
|
|
}
|
|
return (top);
|
|
|
|
nospace:
|
|
m_freem(top);
|
|
atomic_add_long(&MCFail, 1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Concatenate mbuf chain n to m.
|
|
* Both chains must be of the same type (e.g. MT_DATA).
|
|
* Any m_pkthdr is not updated.
|
|
*/
|
|
void
|
|
m_cat(m, n)
|
|
register struct mbuf *m, *n;
|
|
{
|
|
while (m->m_next)
|
|
m = m->m_next;
|
|
while (n) {
|
|
if (m->m_flags & M_EXT ||
|
|
m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
|
|
/* just join the two chains */
|
|
m->m_next = n;
|
|
return;
|
|
}
|
|
/* splat the data from one into the other */
|
|
bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
|
|
(u_int)n->m_len);
|
|
m->m_len += n->m_len;
|
|
n = m_free(n);
|
|
}
|
|
}
|
|
|
|
void
|
|
m_adj(mp, req_len)
|
|
struct mbuf *mp;
|
|
int req_len;
|
|
{
|
|
register int len = req_len;
|
|
register struct mbuf *m;
|
|
register int count;
|
|
|
|
if ((m = mp) == NULL)
|
|
return;
|
|
if (len >= 0) {
|
|
/*
|
|
* Trim from head.
|
|
*/
|
|
while (m != NULL && len > 0) {
|
|
if (m->m_len <= len) {
|
|
len -= m->m_len;
|
|
m->m_len = 0;
|
|
m = m->m_next;
|
|
} else {
|
|
m->m_len -= len;
|
|
m->m_data += len;
|
|
len = 0;
|
|
}
|
|
}
|
|
m = mp;
|
|
if (mp->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len -= (req_len - len);
|
|
} else {
|
|
/*
|
|
* Trim from tail. Scan the mbuf chain,
|
|
* calculating its length and finding the last mbuf.
|
|
* If the adjustment only affects this mbuf, then just
|
|
* adjust and return. Otherwise, rescan and truncate
|
|
* after the remaining size.
|
|
*/
|
|
len = -len;
|
|
count = 0;
|
|
for (;;) {
|
|
count += m->m_len;
|
|
if (m->m_next == (struct mbuf *)0)
|
|
break;
|
|
m = m->m_next;
|
|
}
|
|
if (m->m_len >= len) {
|
|
m->m_len -= len;
|
|
if (mp->m_flags & M_PKTHDR)
|
|
mp->m_pkthdr.len -= len;
|
|
return;
|
|
}
|
|
count -= len;
|
|
if (count < 0)
|
|
count = 0;
|
|
/*
|
|
* Correct length for chain is "count".
|
|
* Find the mbuf with last data, adjust its length,
|
|
* and toss data from remaining mbufs on chain.
|
|
*/
|
|
m = mp;
|
|
if (m->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len = count;
|
|
for (; m; m = m->m_next) {
|
|
if (m->m_len >= count) {
|
|
m->m_len = count;
|
|
break;
|
|
}
|
|
count -= m->m_len;
|
|
}
|
|
while (m->m_next)
|
|
(m = m->m_next) ->m_len = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Rearange an mbuf chain so that len bytes are contiguous
|
|
* and in the data area of an mbuf (so that mtod and dtom
|
|
* will work for a structure of size len). Returns the resulting
|
|
* mbuf chain on success, frees it and returns null on failure.
|
|
* If there is room, it will add up to max_protohdr-len extra bytes to the
|
|
* contiguous region in an attempt to avoid being called next time.
|
|
*/
|
|
#define MPFail (mbstat.m_mpfail)
|
|
|
|
struct mbuf *
|
|
m_pullup(n, len)
|
|
register struct mbuf *n;
|
|
int len;
|
|
{
|
|
register struct mbuf *m;
|
|
register int count;
|
|
int space;
|
|
|
|
/*
|
|
* If first mbuf has no cluster, and has room for len bytes
|
|
* without shifting current data, pullup into it,
|
|
* otherwise allocate a new mbuf to prepend to the chain.
|
|
*/
|
|
if ((n->m_flags & M_EXT) == 0 &&
|
|
n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
|
|
if (n->m_len >= len)
|
|
return (n);
|
|
m = n;
|
|
n = n->m_next;
|
|
len -= m->m_len;
|
|
} else {
|
|
if (len > MHLEN)
|
|
goto bad;
|
|
MGET(m, M_DONTWAIT, n->m_type);
|
|
if (m == 0)
|
|
goto bad;
|
|
m->m_len = 0;
|
|
if (n->m_flags & M_PKTHDR) {
|
|
M_COPY_PKTHDR(m, n);
|
|
n->m_flags &= ~M_PKTHDR;
|
|
}
|
|
}
|
|
space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
|
|
do {
|
|
count = min(min(max(len, max_protohdr), space), n->m_len);
|
|
bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
|
|
(unsigned)count);
|
|
len -= count;
|
|
m->m_len += count;
|
|
n->m_len -= count;
|
|
space -= count;
|
|
if (n->m_len)
|
|
n->m_data += count;
|
|
else
|
|
n = m_free(n);
|
|
} while (len > 0 && n);
|
|
if (len > 0) {
|
|
(void) m_free(m);
|
|
goto bad;
|
|
}
|
|
m->m_next = n;
|
|
return (m);
|
|
bad:
|
|
m_freem(n);
|
|
atomic_add_long(&MPFail, 1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Partition an mbuf chain in two pieces, returning the tail --
|
|
* all but the first len0 bytes. In case of failure, it returns NULL and
|
|
* attempts to restore the chain to its original state.
|
|
*/
|
|
struct mbuf *
|
|
m_split(m0, len0, wait)
|
|
register struct mbuf *m0;
|
|
int len0, wait;
|
|
{
|
|
register struct mbuf *m, *n;
|
|
unsigned len = len0, remain;
|
|
|
|
for (m = m0; m && len > m->m_len; m = m->m_next)
|
|
len -= m->m_len;
|
|
if (m == 0)
|
|
return (0);
|
|
remain = m->m_len - len;
|
|
if (m0->m_flags & M_PKTHDR) {
|
|
MGETHDR(n, wait, m0->m_type);
|
|
if (n == 0)
|
|
return (0);
|
|
n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
|
|
n->m_pkthdr.len = m0->m_pkthdr.len - len0;
|
|
m0->m_pkthdr.len = len0;
|
|
if (m->m_flags & M_EXT)
|
|
goto extpacket;
|
|
if (remain > MHLEN) {
|
|
/* m can't be the lead packet */
|
|
MH_ALIGN(n, 0);
|
|
n->m_next = m_split(m, len, wait);
|
|
if (n->m_next == 0) {
|
|
(void) m_free(n);
|
|
return (0);
|
|
} else
|
|
return (n);
|
|
} else
|
|
MH_ALIGN(n, remain);
|
|
} else if (remain == 0) {
|
|
n = m->m_next;
|
|
m->m_next = 0;
|
|
return (n);
|
|
} else {
|
|
MGET(n, wait, m->m_type);
|
|
if (n == 0)
|
|
return (0);
|
|
M_ALIGN(n, remain);
|
|
}
|
|
extpacket:
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_flags |= M_EXT;
|
|
n->m_ext = m->m_ext;
|
|
MEXT_ADD_REF(m);
|
|
m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */
|
|
n->m_data = m->m_data + len;
|
|
} else {
|
|
bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
|
|
}
|
|
n->m_len = remain;
|
|
m->m_len = len;
|
|
n->m_next = m->m_next;
|
|
m->m_next = 0;
|
|
return (n);
|
|
}
|
|
/*
|
|
* Routine to copy from device local memory into mbufs.
|
|
*/
|
|
struct mbuf *
|
|
m_devget(buf, totlen, off0, ifp, copy)
|
|
char *buf;
|
|
int totlen, off0;
|
|
struct ifnet *ifp;
|
|
void (*copy) __P((char *from, caddr_t to, u_int len));
|
|
{
|
|
register struct mbuf *m;
|
|
struct mbuf *top = 0, **mp = ⊤
|
|
register int off = off0, len;
|
|
register char *cp;
|
|
char *epkt;
|
|
|
|
cp = buf;
|
|
epkt = cp + totlen;
|
|
if (off) {
|
|
cp += off + 2 * sizeof(u_short);
|
|
totlen -= 2 * sizeof(u_short);
|
|
}
|
|
MGETHDR(m, M_DONTWAIT, MT_DATA);
|
|
if (m == 0)
|
|
return (0);
|
|
m->m_pkthdr.rcvif = ifp;
|
|
m->m_pkthdr.len = totlen;
|
|
m->m_len = MHLEN;
|
|
|
|
while (totlen > 0) {
|
|
if (top) {
|
|
MGET(m, M_DONTWAIT, MT_DATA);
|
|
if (m == 0) {
|
|
m_freem(top);
|
|
return (0);
|
|
}
|
|
m->m_len = MLEN;
|
|
}
|
|
len = min(totlen, epkt - cp);
|
|
if (len >= MINCLSIZE) {
|
|
MCLGET(m, M_DONTWAIT);
|
|
if (m->m_flags & M_EXT)
|
|
m->m_len = len = min(len, MCLBYTES);
|
|
else
|
|
len = m->m_len;
|
|
} else {
|
|
/*
|
|
* Place initial small packet/header at end of mbuf.
|
|
*/
|
|
if (len < m->m_len) {
|
|
if (top == 0 && len + max_linkhdr <= m->m_len)
|
|
m->m_data += max_linkhdr;
|
|
m->m_len = len;
|
|
} else
|
|
len = m->m_len;
|
|
}
|
|
if (copy)
|
|
copy(cp, mtod(m, caddr_t), (unsigned)len);
|
|
else
|
|
bcopy(cp, mtod(m, caddr_t), (unsigned)len);
|
|
cp += len;
|
|
*mp = m;
|
|
mp = &m->m_next;
|
|
totlen -= len;
|
|
if (cp == epkt)
|
|
cp = buf;
|
|
}
|
|
return (top);
|
|
}
|
|
|
|
/*
|
|
* Copy data from a buffer back into the indicated mbuf chain,
|
|
* starting "off" bytes from the beginning, extending the mbuf
|
|
* chain if necessary.
|
|
*/
|
|
void
|
|
m_copyback(m0, off, len, cp)
|
|
struct mbuf *m0;
|
|
register int off;
|
|
register int len;
|
|
caddr_t cp;
|
|
{
|
|
register int mlen;
|
|
register struct mbuf *m = m0, *n;
|
|
int totlen = 0;
|
|
|
|
if (m0 == 0)
|
|
return;
|
|
while (off > (mlen = m->m_len)) {
|
|
off -= mlen;
|
|
totlen += mlen;
|
|
if (m->m_next == 0) {
|
|
n = m_getclr(M_DONTWAIT, m->m_type);
|
|
if (n == 0)
|
|
goto out;
|
|
n->m_len = min(MLEN, len + off);
|
|
m->m_next = n;
|
|
}
|
|
m = m->m_next;
|
|
}
|
|
while (len > 0) {
|
|
mlen = min (m->m_len - off, len);
|
|
bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
|
|
cp += mlen;
|
|
len -= mlen;
|
|
mlen += off;
|
|
off = 0;
|
|
totlen += mlen;
|
|
if (len == 0)
|
|
break;
|
|
if (m->m_next == 0) {
|
|
n = m_get(M_DONTWAIT, m->m_type);
|
|
if (n == 0)
|
|
break;
|
|
n->m_len = min(MLEN, len);
|
|
m->m_next = n;
|
|
}
|
|
m = m->m_next;
|
|
}
|
|
out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
|
|
m->m_pkthdr.len = totlen;
|
|
}
|
|
|
|
void
|
|
m_print(const struct mbuf *m)
|
|
{
|
|
int len;
|
|
const struct mbuf *m2;
|
|
|
|
len = m->m_pkthdr.len;
|
|
m2 = m;
|
|
while (len) {
|
|
printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-");
|
|
len -= m2->m_len;
|
|
m2 = m2->m_next;
|
|
}
|
|
return;
|
|
}
|