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@@ -0,0 +1,97 @@
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/*! NOTE: Most kern_mbuf functions are implemented by our mbuf.c; however,
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* a certain few non-allocation-related ones which we can copy wholesale
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* from FreeBSD live here. */
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/*-
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* Copyright (c) 2004, 2005,
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* Bosko Milekic <[email protected]>. 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 unmodified, this list of conditions and the following
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* 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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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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#include <sys/cdefs.h>
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#include <sys/mbuf.h>
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/*
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* Allocate a given length worth of mbufs and/or clusters (whatever fits
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* best) and return a pointer to the top of the allocated chain. If an
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* existing mbuf chain is provided, then we will append the new chain
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* to the existing one but still return the top of the newly allocated
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* chain.
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*/
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struct mbuf *
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m_getm2(struct mbuf *m, int len, int how, short type, int flags)
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{
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struct mbuf *mb, *nm = NULL, *mtail = NULL;
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KASSERT(len >= 0, ("%s: len is < 0", __func__));
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/* Validate flags. */
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flags &= (M_PKTHDR | M_EOR);
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/* Packet header mbuf must be first in chain. */
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if ((flags & M_PKTHDR) && m != NULL)
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flags &= ~M_PKTHDR;
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/* Loop and append maximum sized mbufs to the chain tail. */
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while (len > 0) {
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if (len > MCLBYTES)
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mb = m_getjcl(how, type, (flags & M_PKTHDR),
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MJUMPAGESIZE);
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else if (len >= MINCLSIZE)
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mb = m_getcl(how, type, (flags & M_PKTHDR));
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else if (flags & M_PKTHDR)
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mb = m_gethdr(how, type);
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else
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mb = m_get(how, type);
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/* Fail the whole operation if one mbuf can't be allocated. */
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if (mb == NULL) {
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if (nm != NULL)
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m_freem(nm);
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return (NULL);
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}
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/* Book keeping. */
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len -= M_SIZE(mb);
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if (mtail != NULL)
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mtail->m_next = mb;
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else
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nm = mb;
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mtail = mb;
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flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */
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}
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if (flags & M_EOR)
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mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */
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/* If mbuf was supplied, append new chain to the end of it. */
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if (m != NULL) {
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for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
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;
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mtail->m_next = nm;
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mtail->m_flags &= ~M_EOR;
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} else
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m = nm;
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return (m);
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}
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