of data is less than or equal to MHLEN instead of MLEN when placing initial small packet header at end of mbuf. Reviewed by: glebius MFC after: 3 days
1870 lines
45 KiB
C
1870 lines
45 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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* 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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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_param.h"
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#include "opt_mbuf_stress_test.h"
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#include "opt_mbuf_profiling.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.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 <sys/uio.h>
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#include <sys/sdt.h>
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SDT_PROBE_DEFINE5_XLATE(sdt, , , m__init,
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"struct mbuf *", "mbufinfo_t *",
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"uint32_t", "uint32_t",
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"uint16_t", "uint16_t",
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"uint32_t", "uint32_t",
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"uint32_t", "uint32_t");
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SDT_PROBE_DEFINE3_XLATE(sdt, , , m__gethdr,
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"uint32_t", "uint32_t",
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"uint16_t", "uint16_t",
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"struct mbuf *", "mbufinfo_t *");
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SDT_PROBE_DEFINE3_XLATE(sdt, , , m__get,
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"uint32_t", "uint32_t",
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"uint16_t", "uint16_t",
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"struct mbuf *", "mbufinfo_t *");
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SDT_PROBE_DEFINE4_XLATE(sdt, , , m__getcl,
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"uint32_t", "uint32_t",
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"uint16_t", "uint16_t",
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"uint32_t", "uint32_t",
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"struct mbuf *", "mbufinfo_t *");
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SDT_PROBE_DEFINE3_XLATE(sdt, , , m__clget,
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"struct mbuf *", "mbufinfo_t *",
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"uint32_t", "uint32_t",
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"uint32_t", "uint32_t");
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SDT_PROBE_DEFINE4_XLATE(sdt, , , m__cljget,
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"struct mbuf *", "mbufinfo_t *",
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"uint32_t", "uint32_t",
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"uint32_t", "uint32_t",
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"void*", "void*");
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SDT_PROBE_DEFINE(sdt, , , m__cljset);
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SDT_PROBE_DEFINE1_XLATE(sdt, , , m__free,
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"struct mbuf *", "mbufinfo_t *");
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SDT_PROBE_DEFINE1_XLATE(sdt, , , m__freem,
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"struct mbuf *", "mbufinfo_t *");
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#include <security/mac/mac_framework.h>
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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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#ifdef MBUF_STRESS_TEST
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int m_defragpackets;
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int m_defragbytes;
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int m_defraguseless;
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int m_defragfailure;
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int m_defragrandomfailures;
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#endif
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/*
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* sysctl(8) exported objects
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*/
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SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RD,
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&max_linkhdr, 0, "Size of largest link layer header");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RD,
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&max_protohdr, 0, "Size of largest protocol layer header");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RD,
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&max_hdr, 0, "Size of largest link plus protocol header");
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SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RD,
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&max_datalen, 0, "Minimum space left in mbuf after max_hdr");
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#ifdef MBUF_STRESS_TEST
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SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD,
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&m_defragpackets, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD,
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&m_defragbytes, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD,
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&m_defraguseless, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD,
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&m_defragfailure, 0, "");
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SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW,
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&m_defragrandomfailures, 0, "");
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#endif
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/*
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* Ensure the correct size of various mbuf parameters. It could be off due
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* to compiler-induced padding and alignment artifacts.
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*/
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CTASSERT(MSIZE - offsetof(struct mbuf, m_dat) == MLEN);
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CTASSERT(MSIZE - offsetof(struct mbuf, m_pktdat) == MHLEN);
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/*
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* mbuf data storage should be 64-bit aligned regardless of architectural
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* pointer size; check this is the case with and without a packet header.
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*/
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CTASSERT(offsetof(struct mbuf, m_dat) % 8 == 0);
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CTASSERT(offsetof(struct mbuf, m_pktdat) % 8 == 0);
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/*
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* While the specific values here don't matter too much (i.e., +/- a few
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* words), we do want to ensure that changes to these values are carefully
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* reasoned about and properly documented. This is especially the case as
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* network-protocol and device-driver modules encode these layouts, and must
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* be recompiled if the structures change. Check these values at compile time
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* against the ones documented in comments in mbuf.h.
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*
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* NB: Possibly they should be documented there via #define's and not just
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* comments.
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*/
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#if defined(__LP64__)
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CTASSERT(offsetof(struct mbuf, m_dat) == 32);
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CTASSERT(sizeof(struct pkthdr) == 56);
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CTASSERT(sizeof(struct m_ext) == 48);
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#else
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CTASSERT(offsetof(struct mbuf, m_dat) == 24);
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CTASSERT(sizeof(struct pkthdr) == 48);
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CTASSERT(sizeof(struct m_ext) == 28);
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#endif
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/*
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* Assert that the queue(3) macros produce code of the same size as an old
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* plain pointer does.
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*/
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#ifdef INVARIANTS
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static struct mbuf m_assertbuf;
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CTASSERT(sizeof(m_assertbuf.m_slist) == sizeof(m_assertbuf.m_next));
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CTASSERT(sizeof(m_assertbuf.m_stailq) == sizeof(m_assertbuf.m_next));
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CTASSERT(sizeof(m_assertbuf.m_slistpkt) == sizeof(m_assertbuf.m_nextpkt));
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CTASSERT(sizeof(m_assertbuf.m_stailqpkt) == sizeof(m_assertbuf.m_nextpkt));
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#endif
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/*
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* Attach the cluster from *m to *n, set up m_ext in *n
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* and bump the refcount of the cluster.
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*/
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void
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mb_dupcl(struct mbuf *n, struct mbuf *m)
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{
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volatile u_int *refcnt;
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KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m));
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KASSERT(!(n->m_flags & M_EXT), ("%s: M_EXT set on %p", __func__, n));
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n->m_ext = m->m_ext;
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n->m_flags |= M_EXT;
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n->m_flags |= m->m_flags & M_RDONLY;
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/* See if this is the mbuf that holds the embedded refcount. */
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if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) {
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refcnt = n->m_ext.ext_cnt = &m->m_ext.ext_count;
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n->m_ext.ext_flags &= ~EXT_FLAG_EMBREF;
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} else {
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KASSERT(m->m_ext.ext_cnt != NULL,
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("%s: no refcounting pointer on %p", __func__, m));
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refcnt = m->m_ext.ext_cnt;
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}
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if (*refcnt == 1)
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*refcnt += 1;
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else
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atomic_add_int(refcnt, 1);
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}
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void
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m_demote_pkthdr(struct mbuf *m)
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{
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M_ASSERTPKTHDR(m);
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m_tag_delete_chain(m, NULL);
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m->m_flags &= ~M_PKTHDR;
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bzero(&m->m_pkthdr, sizeof(struct pkthdr));
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}
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/*
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* Clean up mbuf (chain) from any tags and packet headers.
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* If "all" is set then the first mbuf in the chain will be
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* cleaned too.
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*/
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void
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m_demote(struct mbuf *m0, int all, int flags)
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{
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struct mbuf *m;
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for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) {
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KASSERT(m->m_nextpkt == NULL, ("%s: m_nextpkt in m %p, m0 %p",
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__func__, m, m0));
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if (m->m_flags & M_PKTHDR)
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m_demote_pkthdr(m);
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m->m_flags = m->m_flags & (M_EXT | M_RDONLY | M_NOFREE | flags);
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}
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}
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/*
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* Sanity checks on mbuf (chain) for use in KASSERT() and general
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* debugging.
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* Returns 0 or panics when bad and 1 on all tests passed.
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* Sanitize, 0 to run M_SANITY_ACTION, 1 to garble things so they
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* blow up later.
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*/
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int
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m_sanity(struct mbuf *m0, int sanitize)
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{
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struct mbuf *m;
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caddr_t a, b;
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int pktlen = 0;
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#ifdef INVARIANTS
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#define M_SANITY_ACTION(s) panic("mbuf %p: " s, m)
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#else
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#define M_SANITY_ACTION(s) printf("mbuf %p: " s, m)
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#endif
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for (m = m0; m != NULL; m = m->m_next) {
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/*
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* Basic pointer checks. If any of these fails then some
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* unrelated kernel memory before or after us is trashed.
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* No way to recover from that.
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*/
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a = M_START(m);
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b = a + M_SIZE(m);
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if ((caddr_t)m->m_data < a)
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M_SANITY_ACTION("m_data outside mbuf data range left");
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if ((caddr_t)m->m_data > b)
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M_SANITY_ACTION("m_data outside mbuf data range right");
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if ((caddr_t)m->m_data + m->m_len > b)
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M_SANITY_ACTION("m_data + m_len exeeds mbuf space");
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/* m->m_nextpkt may only be set on first mbuf in chain. */
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if (m != m0 && m->m_nextpkt != NULL) {
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if (sanitize) {
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m_freem(m->m_nextpkt);
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m->m_nextpkt = (struct mbuf *)0xDEADC0DE;
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} else
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M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf");
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}
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/* packet length (not mbuf length!) calculation */
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if (m0->m_flags & M_PKTHDR)
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pktlen += m->m_len;
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/* m_tags may only be attached to first mbuf in chain. */
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if (m != m0 && m->m_flags & M_PKTHDR &&
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!SLIST_EMPTY(&m->m_pkthdr.tags)) {
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if (sanitize) {
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m_tag_delete_chain(m, NULL);
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/* put in 0xDEADC0DE perhaps? */
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} else
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M_SANITY_ACTION("m_tags on in-chain mbuf");
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}
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/* M_PKTHDR may only be set on first mbuf in chain */
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if (m != m0 && m->m_flags & M_PKTHDR) {
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if (sanitize) {
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bzero(&m->m_pkthdr, sizeof(m->m_pkthdr));
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m->m_flags &= ~M_PKTHDR;
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/* put in 0xDEADCODE and leave hdr flag in */
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} else
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M_SANITY_ACTION("M_PKTHDR on in-chain mbuf");
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}
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}
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m = m0;
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if (pktlen && pktlen != m->m_pkthdr.len) {
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if (sanitize)
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m->m_pkthdr.len = 0;
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else
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M_SANITY_ACTION("m_pkthdr.len != mbuf chain length");
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}
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return 1;
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#undef M_SANITY_ACTION
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}
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|
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/*
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* Non-inlined part of m_init().
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*/
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int
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m_pkthdr_init(struct mbuf *m, int how)
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{
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#ifdef MAC
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int error;
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#endif
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m->m_data = m->m_pktdat;
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bzero(&m->m_pkthdr, sizeof(m->m_pkthdr));
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#ifdef MAC
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/* If the label init fails, fail the alloc */
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error = mac_mbuf_init(m, how);
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if (error)
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return (error);
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#endif
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return (0);
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}
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|
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/*
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* "Move" mbuf pkthdr from "from" to "to".
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* "from" must have M_PKTHDR set, and "to" must be empty.
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*/
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void
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m_move_pkthdr(struct mbuf *to, struct mbuf *from)
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{
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#if 0
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/* see below for why these are not enabled */
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M_ASSERTPKTHDR(to);
|
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/* Note: with MAC, this may not be a good assertion. */
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KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags),
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("m_move_pkthdr: to has tags"));
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#endif
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#ifdef MAC
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/*
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* XXXMAC: It could be this should also occur for non-MAC?
|
|
*/
|
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if (to->m_flags & M_PKTHDR)
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m_tag_delete_chain(to, NULL);
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#endif
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to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
|
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if ((to->m_flags & M_EXT) == 0)
|
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to->m_data = to->m_pktdat;
|
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to->m_pkthdr = from->m_pkthdr; /* especially tags */
|
|
SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
|
|
from->m_flags &= ~M_PKTHDR;
|
|
}
|
|
|
|
/*
|
|
* Duplicate "from"'s mbuf pkthdr in "to".
|
|
* "from" must have M_PKTHDR set, and "to" must be empty.
|
|
* In particular, this does a deep copy of the packet tags.
|
|
*/
|
|
int
|
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m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how)
|
|
{
|
|
|
|
#if 0
|
|
/*
|
|
* The mbuf allocator only initializes the pkthdr
|
|
* when the mbuf is allocated with m_gethdr(). Many users
|
|
* (e.g. m_copy*, m_prepend) use m_get() and then
|
|
* smash the pkthdr as needed causing these
|
|
* assertions to trip. For now just disable them.
|
|
*/
|
|
M_ASSERTPKTHDR(to);
|
|
/* Note: with MAC, this may not be a good assertion. */
|
|
KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags"));
|
|
#endif
|
|
MBUF_CHECKSLEEP(how);
|
|
#ifdef MAC
|
|
if (to->m_flags & M_PKTHDR)
|
|
m_tag_delete_chain(to, NULL);
|
|
#endif
|
|
to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
|
|
if ((to->m_flags & M_EXT) == 0)
|
|
to->m_data = to->m_pktdat;
|
|
to->m_pkthdr = from->m_pkthdr;
|
|
SLIST_INIT(&to->m_pkthdr.tags);
|
|
return (m_tag_copy_chain(to, from, how));
|
|
}
|
|
|
|
/*
|
|
* Lesser-used path for M_PREPEND:
|
|
* allocate new mbuf to prepend to chain,
|
|
* copy junk along.
|
|
*/
|
|
struct mbuf *
|
|
m_prepend(struct mbuf *m, int len, int how)
|
|
{
|
|
struct mbuf *mn;
|
|
|
|
if (m->m_flags & M_PKTHDR)
|
|
mn = m_gethdr(how, m->m_type);
|
|
else
|
|
mn = m_get(how, m->m_type);
|
|
if (mn == NULL) {
|
|
m_freem(m);
|
|
return (NULL);
|
|
}
|
|
if (m->m_flags & M_PKTHDR)
|
|
m_move_pkthdr(mn, m);
|
|
mn->m_next = m;
|
|
m = mn;
|
|
if (len < M_SIZE(m))
|
|
M_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_WAITOK/M_NOWAIT from caller.
|
|
* Note that the copy is read-only, because clusters are not copied,
|
|
* only their reference counts are incremented.
|
|
*/
|
|
struct mbuf *
|
|
m_copym(struct mbuf *m, int off0, int len, int wait)
|
|
{
|
|
struct mbuf *n, **np;
|
|
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));
|
|
MBUF_CHECKSLEEP(wait);
|
|
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 = NULL;
|
|
while (len > 0) {
|
|
if (m == NULL) {
|
|
KASSERT(len == M_COPYALL,
|
|
("m_copym, length > size of mbuf chain"));
|
|
break;
|
|
}
|
|
if (copyhdr)
|
|
n = m_gethdr(wait, m->m_type);
|
|
else
|
|
n = m_get(wait, m->m_type);
|
|
*np = n;
|
|
if (n == NULL)
|
|
goto nospace;
|
|
if (copyhdr) {
|
|
if (!m_dup_pkthdr(n, m, wait))
|
|
goto nospace;
|
|
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;
|
|
mb_dupcl(n, m);
|
|
} else
|
|
bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
|
|
(u_int)n->m_len);
|
|
if (len != M_COPYALL)
|
|
len -= n->m_len;
|
|
off = 0;
|
|
m = m->m_next;
|
|
np = &n->m_next;
|
|
}
|
|
|
|
return (top);
|
|
nospace:
|
|
m_freem(top);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
* Preserve alignment of the first mbuf so if the creator has left
|
|
* some room at the beginning (e.g. for inserting protocol headers)
|
|
* the copies still have the room available.
|
|
*/
|
|
struct mbuf *
|
|
m_copypacket(struct mbuf *m, int how)
|
|
{
|
|
struct mbuf *top, *n, *o;
|
|
|
|
MBUF_CHECKSLEEP(how);
|
|
n = m_get(how, m->m_type);
|
|
top = n;
|
|
if (n == NULL)
|
|
goto nospace;
|
|
|
|
if (!m_dup_pkthdr(n, m, how))
|
|
goto nospace;
|
|
n->m_len = m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data;
|
|
mb_dupcl(n, m);
|
|
} else {
|
|
n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
|
|
bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
while (m) {
|
|
o = m_get(how, m->m_type);
|
|
if (o == NULL)
|
|
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;
|
|
mb_dupcl(n, m);
|
|
} else {
|
|
bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
}
|
|
return top;
|
|
nospace:
|
|
m_freem(top);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Copy data from an mbuf chain starting "off" bytes from the beginning,
|
|
* continuing for "len" bytes, into the indicated buffer.
|
|
*/
|
|
void
|
|
m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
|
|
{
|
|
u_int 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(const struct mbuf *m, int how)
|
|
{
|
|
struct mbuf **p, *top = NULL;
|
|
int remain, moff, nsize;
|
|
|
|
MBUF_CHECKSLEEP(how);
|
|
/* Sanity check */
|
|
if (m == NULL)
|
|
return (NULL);
|
|
M_ASSERTPKTHDR(m);
|
|
|
|
/* 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 */
|
|
if (remain >= MINCLSIZE) {
|
|
n = m_getcl(how, m->m_type, 0);
|
|
nsize = MCLBYTES;
|
|
} else {
|
|
n = m_get(how, m->m_type);
|
|
nsize = MLEN;
|
|
}
|
|
if (n == NULL)
|
|
goto nospace;
|
|
|
|
if (top == NULL) { /* First one, must be PKTHDR */
|
|
if (!m_dup_pkthdr(n, m, how)) {
|
|
m_free(n);
|
|
goto nospace;
|
|
}
|
|
if ((n->m_flags & M_EXT) == 0)
|
|
nsize = MHLEN;
|
|
n->m_flags &= ~M_RDONLY;
|
|
}
|
|
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", __func__));
|
|
}
|
|
return (top);
|
|
|
|
nospace:
|
|
m_freem(top);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* 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(struct mbuf *m, struct mbuf *n)
|
|
{
|
|
while (m->m_next)
|
|
m = m->m_next;
|
|
while (n) {
|
|
if (!M_WRITABLE(m) ||
|
|
M_TRAILINGSPACE(m) < n->m_len) {
|
|
/* 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Concatenate two pkthdr mbuf chains.
|
|
*/
|
|
void
|
|
m_catpkt(struct mbuf *m, struct mbuf *n)
|
|
{
|
|
|
|
M_ASSERTPKTHDR(m);
|
|
M_ASSERTPKTHDR(n);
|
|
|
|
m->m_pkthdr.len += n->m_pkthdr.len;
|
|
m_demote(n, 1, 0);
|
|
|
|
m_cat(m, n);
|
|
}
|
|
|
|
void
|
|
m_adj(struct mbuf *mp, int req_len)
|
|
{
|
|
int len = req_len;
|
|
struct mbuf *m;
|
|
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;
|
|
}
|
|
}
|
|
if (mp->m_flags & M_PKTHDR)
|
|
mp->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;
|
|
if (m->m_next != NULL) {
|
|
m_freem(m->m_next);
|
|
m->m_next = NULL;
|
|
}
|
|
break;
|
|
}
|
|
count -= m->m_len;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Rearange an mbuf chain so that len bytes are contiguous
|
|
* and in the data area of an mbuf (so that mtod 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.
|
|
*/
|
|
struct mbuf *
|
|
m_pullup(struct mbuf *n, int len)
|
|
{
|
|
struct mbuf *m;
|
|
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;
|
|
m = m_get(M_NOWAIT, n->m_type);
|
|
if (m == NULL)
|
|
goto bad;
|
|
if (n->m_flags & M_PKTHDR)
|
|
m_move_pkthdr(m, n);
|
|
}
|
|
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,
|
|
(u_int)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);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Like m_pullup(), except a new mbuf is always allocated, and we allow
|
|
* the amount of empty space before the data in the new mbuf to be specified
|
|
* (in the event that the caller expects to prepend later).
|
|
*/
|
|
struct mbuf *
|
|
m_copyup(struct mbuf *n, int len, int dstoff)
|
|
{
|
|
struct mbuf *m;
|
|
int count, space;
|
|
|
|
if (len > (MHLEN - dstoff))
|
|
goto bad;
|
|
m = m_get(M_NOWAIT, n->m_type);
|
|
if (m == NULL)
|
|
goto bad;
|
|
if (n->m_flags & M_PKTHDR)
|
|
m_move_pkthdr(m, n);
|
|
m->m_data += dstoff;
|
|
space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
|
|
do {
|
|
count = min(min(max(len, max_protohdr), space), n->m_len);
|
|
memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t),
|
|
(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);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* Note that the resulting mbufs might be read-only, because the new
|
|
* mbuf can end up sharing an mbuf cluster with the original mbuf if
|
|
* the "breaking point" happens to lie within a cluster mbuf. Use the
|
|
* M_WRITABLE() macro to check for this case.
|
|
*/
|
|
struct mbuf *
|
|
m_split(struct mbuf *m0, int len0, int wait)
|
|
{
|
|
struct mbuf *m, *n;
|
|
u_int len = len0, remain;
|
|
|
|
MBUF_CHECKSLEEP(wait);
|
|
for (m = m0; m && len > m->m_len; m = m->m_next)
|
|
len -= m->m_len;
|
|
if (m == NULL)
|
|
return (NULL);
|
|
remain = m->m_len - len;
|
|
if (m0->m_flags & M_PKTHDR && remain == 0) {
|
|
n = m_gethdr(wait, m0->m_type);
|
|
if (n == NULL)
|
|
return (NULL);
|
|
n->m_next = m->m_next;
|
|
m->m_next = NULL;
|
|
n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
|
|
n->m_pkthdr.len = m0->m_pkthdr.len - len0;
|
|
m0->m_pkthdr.len = len0;
|
|
return (n);
|
|
} else if (m0->m_flags & M_PKTHDR) {
|
|
n = m_gethdr(wait, m0->m_type);
|
|
if (n == NULL)
|
|
return (NULL);
|
|
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 */
|
|
M_ALIGN(n, 0);
|
|
n->m_next = m_split(m, len, wait);
|
|
if (n->m_next == NULL) {
|
|
(void) m_free(n);
|
|
return (NULL);
|
|
} else {
|
|
n->m_len = 0;
|
|
return (n);
|
|
}
|
|
} else
|
|
M_ALIGN(n, remain);
|
|
} else if (remain == 0) {
|
|
n = m->m_next;
|
|
m->m_next = NULL;
|
|
return (n);
|
|
} else {
|
|
n = m_get(wait, m->m_type);
|
|
if (n == NULL)
|
|
return (NULL);
|
|
M_ALIGN(n, remain);
|
|
}
|
|
extpacket:
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data + len;
|
|
mb_dupcl(n, m);
|
|
} 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 = NULL;
|
|
return (n);
|
|
}
|
|
/*
|
|
* Routine to copy from device local memory into mbufs.
|
|
* Note that `off' argument is offset into first mbuf of target chain from
|
|
* which to begin copying the data to.
|
|
*/
|
|
struct mbuf *
|
|
m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
|
|
void (*copy)(char *from, caddr_t to, u_int len))
|
|
{
|
|
struct mbuf *m;
|
|
struct mbuf *top = NULL, **mp = ⊤
|
|
int len;
|
|
|
|
if (off < 0 || off > MHLEN)
|
|
return (NULL);
|
|
|
|
while (totlen > 0) {
|
|
if (top == NULL) { /* First one, must be PKTHDR */
|
|
if (totlen + off >= MINCLSIZE) {
|
|
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
|
|
len = MCLBYTES;
|
|
} else {
|
|
m = m_gethdr(M_NOWAIT, MT_DATA);
|
|
len = MHLEN;
|
|
|
|
/* Place initial small packet/header at end of mbuf */
|
|
if (m && totlen + off + max_linkhdr <= MHLEN) {
|
|
m->m_data += max_linkhdr;
|
|
len -= max_linkhdr;
|
|
}
|
|
}
|
|
if (m == NULL)
|
|
return NULL;
|
|
m->m_pkthdr.rcvif = ifp;
|
|
m->m_pkthdr.len = totlen;
|
|
} else {
|
|
if (totlen + off >= MINCLSIZE) {
|
|
m = m_getcl(M_NOWAIT, MT_DATA, 0);
|
|
len = MCLBYTES;
|
|
} else {
|
|
m = m_get(M_NOWAIT, MT_DATA);
|
|
len = MLEN;
|
|
}
|
|
if (m == NULL) {
|
|
m_freem(top);
|
|
return NULL;
|
|
}
|
|
}
|
|
if (off) {
|
|
m->m_data += off;
|
|
len -= off;
|
|
off = 0;
|
|
}
|
|
m->m_len = len = min(totlen, len);
|
|
if (copy)
|
|
copy(buf, mtod(m, caddr_t), (u_int)len);
|
|
else
|
|
bcopy(buf, mtod(m, caddr_t), (u_int)len);
|
|
buf += len;
|
|
*mp = m;
|
|
mp = &m->m_next;
|
|
totlen -= len;
|
|
}
|
|
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(struct mbuf *m0, int off, int len, c_caddr_t cp)
|
|
{
|
|
int mlen;
|
|
struct mbuf *m = m0, *n;
|
|
int totlen = 0;
|
|
|
|
if (m0 == NULL)
|
|
return;
|
|
while (off > (mlen = m->m_len)) {
|
|
off -= mlen;
|
|
totlen += mlen;
|
|
if (m->m_next == NULL) {
|
|
n = m_get(M_NOWAIT, m->m_type);
|
|
if (n == NULL)
|
|
goto out;
|
|
bzero(mtod(n, caddr_t), MLEN);
|
|
n->m_len = min(MLEN, len + off);
|
|
m->m_next = n;
|
|
}
|
|
m = m->m_next;
|
|
}
|
|
while (len > 0) {
|
|
if (m->m_next == NULL && (len > m->m_len - off)) {
|
|
m->m_len += min(len - (m->m_len - off),
|
|
M_TRAILINGSPACE(m));
|
|
}
|
|
mlen = min (m->m_len - off, len);
|
|
bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen);
|
|
cp += mlen;
|
|
len -= mlen;
|
|
mlen += off;
|
|
off = 0;
|
|
totlen += mlen;
|
|
if (len == 0)
|
|
break;
|
|
if (m->m_next == NULL) {
|
|
n = m_get(M_NOWAIT, m->m_type);
|
|
if (n == NULL)
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Append the specified data to the indicated mbuf chain,
|
|
* Extend the mbuf chain if the new data does not fit in
|
|
* existing space.
|
|
*
|
|
* Return 1 if able to complete the job; otherwise 0.
|
|
*/
|
|
int
|
|
m_append(struct mbuf *m0, int len, c_caddr_t cp)
|
|
{
|
|
struct mbuf *m, *n;
|
|
int remainder, space;
|
|
|
|
for (m = m0; m->m_next != NULL; m = m->m_next)
|
|
;
|
|
remainder = len;
|
|
space = M_TRAILINGSPACE(m);
|
|
if (space > 0) {
|
|
/*
|
|
* Copy into available space.
|
|
*/
|
|
if (space > remainder)
|
|
space = remainder;
|
|
bcopy(cp, mtod(m, caddr_t) + m->m_len, space);
|
|
m->m_len += space;
|
|
cp += space, remainder -= space;
|
|
}
|
|
while (remainder > 0) {
|
|
/*
|
|
* Allocate a new mbuf; could check space
|
|
* and allocate a cluster instead.
|
|
*/
|
|
n = m_get(M_NOWAIT, m->m_type);
|
|
if (n == NULL)
|
|
break;
|
|
n->m_len = min(MLEN, remainder);
|
|
bcopy(cp, mtod(n, caddr_t), n->m_len);
|
|
cp += n->m_len, remainder -= n->m_len;
|
|
m->m_next = n;
|
|
m = n;
|
|
}
|
|
if (m0->m_flags & M_PKTHDR)
|
|
m0->m_pkthdr.len += len - remainder;
|
|
return (remainder == 0);
|
|
}
|
|
|
|
/*
|
|
* Apply function f to the data in an mbuf chain starting "off" bytes from
|
|
* the beginning, continuing for "len" bytes.
|
|
*/
|
|
int
|
|
m_apply(struct mbuf *m, int off, int len,
|
|
int (*f)(void *, void *, u_int), void *arg)
|
|
{
|
|
u_int count;
|
|
int rval;
|
|
|
|
KASSERT(off >= 0, ("m_apply, negative off %d", off));
|
|
KASSERT(len >= 0, ("m_apply, negative len %d", len));
|
|
while (off > 0) {
|
|
KASSERT(m != NULL, ("m_apply, 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_apply, offset > size of mbuf chain"));
|
|
count = min(m->m_len - off, len);
|
|
rval = (*f)(arg, mtod(m, caddr_t) + off, count);
|
|
if (rval)
|
|
return (rval);
|
|
len -= count;
|
|
off = 0;
|
|
m = m->m_next;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to mbuf/offset of location in mbuf chain.
|
|
*/
|
|
struct mbuf *
|
|
m_getptr(struct mbuf *m, int loc, int *off)
|
|
{
|
|
|
|
while (loc >= 0) {
|
|
/* Normal end of search. */
|
|
if (m->m_len > loc) {
|
|
*off = loc;
|
|
return (m);
|
|
} else {
|
|
loc -= m->m_len;
|
|
if (m->m_next == NULL) {
|
|
if (loc == 0) {
|
|
/* Point at the end of valid data. */
|
|
*off = m->m_len;
|
|
return (m);
|
|
}
|
|
return (NULL);
|
|
}
|
|
m = m->m_next;
|
|
}
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
void
|
|
m_print(const struct mbuf *m, int maxlen)
|
|
{
|
|
int len;
|
|
int pdata;
|
|
const struct mbuf *m2;
|
|
|
|
if (m == NULL) {
|
|
printf("mbuf: %p\n", m);
|
|
return;
|
|
}
|
|
|
|
if (m->m_flags & M_PKTHDR)
|
|
len = m->m_pkthdr.len;
|
|
else
|
|
len = -1;
|
|
m2 = m;
|
|
while (m2 != NULL && (len == -1 || len)) {
|
|
pdata = m2->m_len;
|
|
if (maxlen != -1 && pdata > maxlen)
|
|
pdata = maxlen;
|
|
printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len,
|
|
m2->m_next, m2->m_flags, "\20\20freelist\17skipfw"
|
|
"\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly"
|
|
"\3eor\2pkthdr\1ext", pdata ? "" : "\n");
|
|
if (pdata)
|
|
printf(", %*D\n", pdata, (u_char *)m2->m_data, "-");
|
|
if (len != -1)
|
|
len -= m2->m_len;
|
|
m2 = m2->m_next;
|
|
}
|
|
if (len > 0)
|
|
printf("%d bytes unaccounted for.\n", len);
|
|
return;
|
|
}
|
|
|
|
u_int
|
|
m_fixhdr(struct mbuf *m0)
|
|
{
|
|
u_int len;
|
|
|
|
len = m_length(m0, NULL);
|
|
m0->m_pkthdr.len = len;
|
|
return (len);
|
|
}
|
|
|
|
u_int
|
|
m_length(struct mbuf *m0, struct mbuf **last)
|
|
{
|
|
struct mbuf *m;
|
|
u_int len;
|
|
|
|
len = 0;
|
|
for (m = m0; m != NULL; m = m->m_next) {
|
|
len += m->m_len;
|
|
if (m->m_next == NULL)
|
|
break;
|
|
}
|
|
if (last != NULL)
|
|
*last = m;
|
|
return (len);
|
|
}
|
|
|
|
/*
|
|
* Defragment a mbuf chain, returning the shortest possible
|
|
* chain of mbufs and clusters. If allocation fails and
|
|
* this cannot be completed, NULL will be returned, but
|
|
* the passed in chain will be unchanged. Upon success,
|
|
* the original chain will be freed, and the new chain
|
|
* will be returned.
|
|
*
|
|
* If a non-packet header is passed in, the original
|
|
* mbuf (chain?) will be returned unharmed.
|
|
*/
|
|
struct mbuf *
|
|
m_defrag(struct mbuf *m0, int how)
|
|
{
|
|
struct mbuf *m_new = NULL, *m_final = NULL;
|
|
int progress = 0, length;
|
|
|
|
MBUF_CHECKSLEEP(how);
|
|
if (!(m0->m_flags & M_PKTHDR))
|
|
return (m0);
|
|
|
|
m_fixhdr(m0); /* Needed sanity check */
|
|
|
|
#ifdef MBUF_STRESS_TEST
|
|
if (m_defragrandomfailures) {
|
|
int temp = arc4random() & 0xff;
|
|
if (temp == 0xba)
|
|
goto nospace;
|
|
}
|
|
#endif
|
|
|
|
if (m0->m_pkthdr.len > MHLEN)
|
|
m_final = m_getcl(how, MT_DATA, M_PKTHDR);
|
|
else
|
|
m_final = m_gethdr(how, MT_DATA);
|
|
|
|
if (m_final == NULL)
|
|
goto nospace;
|
|
|
|
if (m_dup_pkthdr(m_final, m0, how) == 0)
|
|
goto nospace;
|
|
|
|
m_new = m_final;
|
|
|
|
while (progress < m0->m_pkthdr.len) {
|
|
length = m0->m_pkthdr.len - progress;
|
|
if (length > MCLBYTES)
|
|
length = MCLBYTES;
|
|
|
|
if (m_new == NULL) {
|
|
if (length > MLEN)
|
|
m_new = m_getcl(how, MT_DATA, 0);
|
|
else
|
|
m_new = m_get(how, MT_DATA);
|
|
if (m_new == NULL)
|
|
goto nospace;
|
|
}
|
|
|
|
m_copydata(m0, progress, length, mtod(m_new, caddr_t));
|
|
progress += length;
|
|
m_new->m_len = length;
|
|
if (m_new != m_final)
|
|
m_cat(m_final, m_new);
|
|
m_new = NULL;
|
|
}
|
|
#ifdef MBUF_STRESS_TEST
|
|
if (m0->m_next == NULL)
|
|
m_defraguseless++;
|
|
#endif
|
|
m_freem(m0);
|
|
m0 = m_final;
|
|
#ifdef MBUF_STRESS_TEST
|
|
m_defragpackets++;
|
|
m_defragbytes += m0->m_pkthdr.len;
|
|
#endif
|
|
return (m0);
|
|
nospace:
|
|
#ifdef MBUF_STRESS_TEST
|
|
m_defragfailure++;
|
|
#endif
|
|
if (m_final)
|
|
m_freem(m_final);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Defragment an mbuf chain, returning at most maxfrags separate
|
|
* mbufs+clusters. If this is not possible NULL is returned and
|
|
* the original mbuf chain is left in it's present (potentially
|
|
* modified) state. We use two techniques: collapsing consecutive
|
|
* mbufs and replacing consecutive mbufs by a cluster.
|
|
*
|
|
* NB: this should really be named m_defrag but that name is taken
|
|
*/
|
|
struct mbuf *
|
|
m_collapse(struct mbuf *m0, int how, int maxfrags)
|
|
{
|
|
struct mbuf *m, *n, *n2, **prev;
|
|
u_int curfrags;
|
|
|
|
/*
|
|
* Calculate the current number of frags.
|
|
*/
|
|
curfrags = 0;
|
|
for (m = m0; m != NULL; m = m->m_next)
|
|
curfrags++;
|
|
/*
|
|
* First, try to collapse mbufs. Note that we always collapse
|
|
* towards the front so we don't need to deal with moving the
|
|
* pkthdr. This may be suboptimal if the first mbuf has much
|
|
* less data than the following.
|
|
*/
|
|
m = m0;
|
|
again:
|
|
for (;;) {
|
|
n = m->m_next;
|
|
if (n == NULL)
|
|
break;
|
|
if (M_WRITABLE(m) &&
|
|
n->m_len < M_TRAILINGSPACE(m)) {
|
|
bcopy(mtod(n, void *), mtod(m, char *) + m->m_len,
|
|
n->m_len);
|
|
m->m_len += n->m_len;
|
|
m->m_next = n->m_next;
|
|
m_free(n);
|
|
if (--curfrags <= maxfrags)
|
|
return m0;
|
|
} else
|
|
m = n;
|
|
}
|
|
KASSERT(maxfrags > 1,
|
|
("maxfrags %u, but normal collapse failed", maxfrags));
|
|
/*
|
|
* Collapse consecutive mbufs to a cluster.
|
|
*/
|
|
prev = &m0->m_next; /* NB: not the first mbuf */
|
|
while ((n = *prev) != NULL) {
|
|
if ((n2 = n->m_next) != NULL &&
|
|
n->m_len + n2->m_len < MCLBYTES) {
|
|
m = m_getcl(how, MT_DATA, 0);
|
|
if (m == NULL)
|
|
goto bad;
|
|
bcopy(mtod(n, void *), mtod(m, void *), n->m_len);
|
|
bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len,
|
|
n2->m_len);
|
|
m->m_len = n->m_len + n2->m_len;
|
|
m->m_next = n2->m_next;
|
|
*prev = m;
|
|
m_free(n);
|
|
m_free(n2);
|
|
if (--curfrags <= maxfrags) /* +1 cl -2 mbufs */
|
|
return m0;
|
|
/*
|
|
* Still not there, try the normal collapse
|
|
* again before we allocate another cluster.
|
|
*/
|
|
goto again;
|
|
}
|
|
prev = &n->m_next;
|
|
}
|
|
/*
|
|
* No place where we can collapse to a cluster; punt.
|
|
* This can occur if, for example, you request 2 frags
|
|
* but the packet requires that both be clusters (we
|
|
* never reallocate the first mbuf to avoid moving the
|
|
* packet header).
|
|
*/
|
|
bad:
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef MBUF_STRESS_TEST
|
|
|
|
/*
|
|
* Fragment an mbuf chain. There's no reason you'd ever want to do
|
|
* this in normal usage, but it's great for stress testing various
|
|
* mbuf consumers.
|
|
*
|
|
* If fragmentation is not possible, the original chain will be
|
|
* returned.
|
|
*
|
|
* Possible length values:
|
|
* 0 no fragmentation will occur
|
|
* > 0 each fragment will be of the specified length
|
|
* -1 each fragment will be the same random value in length
|
|
* -2 each fragment's length will be entirely random
|
|
* (Random values range from 1 to 256)
|
|
*/
|
|
struct mbuf *
|
|
m_fragment(struct mbuf *m0, int how, int length)
|
|
{
|
|
struct mbuf *m_new = NULL, *m_final = NULL;
|
|
int progress = 0;
|
|
|
|
if (!(m0->m_flags & M_PKTHDR))
|
|
return (m0);
|
|
|
|
if ((length == 0) || (length < -2))
|
|
return (m0);
|
|
|
|
m_fixhdr(m0); /* Needed sanity check */
|
|
|
|
m_final = m_getcl(how, MT_DATA, M_PKTHDR);
|
|
|
|
if (m_final == NULL)
|
|
goto nospace;
|
|
|
|
if (m_dup_pkthdr(m_final, m0, how) == 0)
|
|
goto nospace;
|
|
|
|
m_new = m_final;
|
|
|
|
if (length == -1)
|
|
length = 1 + (arc4random() & 255);
|
|
|
|
while (progress < m0->m_pkthdr.len) {
|
|
int fraglen;
|
|
|
|
if (length > 0)
|
|
fraglen = length;
|
|
else
|
|
fraglen = 1 + (arc4random() & 255);
|
|
if (fraglen > m0->m_pkthdr.len - progress)
|
|
fraglen = m0->m_pkthdr.len - progress;
|
|
|
|
if (fraglen > MCLBYTES)
|
|
fraglen = MCLBYTES;
|
|
|
|
if (m_new == NULL) {
|
|
m_new = m_getcl(how, MT_DATA, 0);
|
|
if (m_new == NULL)
|
|
goto nospace;
|
|
}
|
|
|
|
m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t));
|
|
progress += fraglen;
|
|
m_new->m_len = fraglen;
|
|
if (m_new != m_final)
|
|
m_cat(m_final, m_new);
|
|
m_new = NULL;
|
|
}
|
|
m_freem(m0);
|
|
m0 = m_final;
|
|
return (m0);
|
|
nospace:
|
|
if (m_final)
|
|
m_freem(m_final);
|
|
/* Return the original chain on failure */
|
|
return (m0);
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Copy the contents of uio into a properly sized mbuf chain.
|
|
*/
|
|
struct mbuf *
|
|
m_uiotombuf(struct uio *uio, int how, int len, int align, int flags)
|
|
{
|
|
struct mbuf *m, *mb;
|
|
int error, length;
|
|
ssize_t total;
|
|
int progress = 0;
|
|
|
|
/*
|
|
* len can be zero or an arbitrary large value bound by
|
|
* the total data supplied by the uio.
|
|
*/
|
|
if (len > 0)
|
|
total = min(uio->uio_resid, len);
|
|
else
|
|
total = uio->uio_resid;
|
|
|
|
/*
|
|
* The smallest unit returned by m_getm2() is a single mbuf
|
|
* with pkthdr. We can't align past it.
|
|
*/
|
|
if (align >= MHLEN)
|
|
return (NULL);
|
|
|
|
/*
|
|
* Give us the full allocation or nothing.
|
|
* If len is zero return the smallest empty mbuf.
|
|
*/
|
|
m = m_getm2(NULL, max(total + align, 1), how, MT_DATA, flags);
|
|
if (m == NULL)
|
|
return (NULL);
|
|
m->m_data += align;
|
|
|
|
/* Fill all mbufs with uio data and update header information. */
|
|
for (mb = m; mb != NULL; mb = mb->m_next) {
|
|
length = min(M_TRAILINGSPACE(mb), total - progress);
|
|
|
|
error = uiomove(mtod(mb, void *), length, uio);
|
|
if (error) {
|
|
m_freem(m);
|
|
return (NULL);
|
|
}
|
|
|
|
mb->m_len = length;
|
|
progress += length;
|
|
if (flags & M_PKTHDR)
|
|
m->m_pkthdr.len += length;
|
|
}
|
|
KASSERT(progress == total, ("%s: progress != total", __func__));
|
|
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Copy an mbuf chain into a uio limited by len if set.
|
|
*/
|
|
int
|
|
m_mbuftouio(struct uio *uio, struct mbuf *m, int len)
|
|
{
|
|
int error, length, total;
|
|
int progress = 0;
|
|
|
|
if (len > 0)
|
|
total = min(uio->uio_resid, len);
|
|
else
|
|
total = uio->uio_resid;
|
|
|
|
/* Fill the uio with data from the mbufs. */
|
|
for (; m != NULL; m = m->m_next) {
|
|
length = min(m->m_len, total - progress);
|
|
|
|
error = uiomove(mtod(m, void *), length, uio);
|
|
if (error)
|
|
return (error);
|
|
|
|
progress += length;
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Create a writable copy of the mbuf chain. While doing this
|
|
* we compact the chain with a goal of producing a chain with
|
|
* at most two mbufs. The second mbuf in this chain is likely
|
|
* to be a cluster. The primary purpose of this work is to create
|
|
* a writable packet for encryption, compression, etc. The
|
|
* secondary goal is to linearize the data so the data can be
|
|
* passed to crypto hardware in the most efficient manner possible.
|
|
*/
|
|
struct mbuf *
|
|
m_unshare(struct mbuf *m0, int how)
|
|
{
|
|
struct mbuf *m, *mprev;
|
|
struct mbuf *n, *mfirst, *mlast;
|
|
int len, off;
|
|
|
|
mprev = NULL;
|
|
for (m = m0; m != NULL; m = mprev->m_next) {
|
|
/*
|
|
* Regular mbufs are ignored unless there's a cluster
|
|
* in front of it that we can use to coalesce. We do
|
|
* the latter mainly so later clusters can be coalesced
|
|
* also w/o having to handle them specially (i.e. convert
|
|
* mbuf+cluster -> cluster). This optimization is heavily
|
|
* influenced by the assumption that we're running over
|
|
* Ethernet where MCLBYTES is large enough that the max
|
|
* packet size will permit lots of coalescing into a
|
|
* single cluster. This in turn permits efficient
|
|
* crypto operations, especially when using hardware.
|
|
*/
|
|
if ((m->m_flags & M_EXT) == 0) {
|
|
if (mprev && (mprev->m_flags & M_EXT) &&
|
|
m->m_len <= M_TRAILINGSPACE(mprev)) {
|
|
/* XXX: this ignores mbuf types */
|
|
memcpy(mtod(mprev, caddr_t) + mprev->m_len,
|
|
mtod(m, caddr_t), m->m_len);
|
|
mprev->m_len += m->m_len;
|
|
mprev->m_next = m->m_next; /* unlink from chain */
|
|
m_free(m); /* reclaim mbuf */
|
|
#if 0
|
|
newipsecstat.ips_mbcoalesced++;
|
|
#endif
|
|
} else {
|
|
mprev = m;
|
|
}
|
|
continue;
|
|
}
|
|
/*
|
|
* Writable mbufs are left alone (for now).
|
|
*/
|
|
if (M_WRITABLE(m)) {
|
|
mprev = m;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Not writable, replace with a copy or coalesce with
|
|
* the previous mbuf if possible (since we have to copy
|
|
* it anyway, we try to reduce the number of mbufs and
|
|
* clusters so that future work is easier).
|
|
*/
|
|
KASSERT(m->m_flags & M_EXT, ("m_flags 0x%x", m->m_flags));
|
|
/* NB: we only coalesce into a cluster or larger */
|
|
if (mprev != NULL && (mprev->m_flags & M_EXT) &&
|
|
m->m_len <= M_TRAILINGSPACE(mprev)) {
|
|
/* XXX: this ignores mbuf types */
|
|
memcpy(mtod(mprev, caddr_t) + mprev->m_len,
|
|
mtod(m, caddr_t), m->m_len);
|
|
mprev->m_len += m->m_len;
|
|
mprev->m_next = m->m_next; /* unlink from chain */
|
|
m_free(m); /* reclaim mbuf */
|
|
#if 0
|
|
newipsecstat.ips_clcoalesced++;
|
|
#endif
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Allocate new space to hold the copy and copy the data.
|
|
* We deal with jumbo mbufs (i.e. m_len > MCLBYTES) by
|
|
* splitting them into clusters. We could just malloc a
|
|
* buffer and make it external but too many device drivers
|
|
* don't know how to break up the non-contiguous memory when
|
|
* doing DMA.
|
|
*/
|
|
n = m_getcl(how, m->m_type, m->m_flags & M_COPYFLAGS);
|
|
if (n == NULL) {
|
|
m_freem(m0);
|
|
return (NULL);
|
|
}
|
|
if (m->m_flags & M_PKTHDR) {
|
|
KASSERT(mprev == NULL, ("%s: m0 %p, m %p has M_PKTHDR",
|
|
__func__, m0, m));
|
|
m_move_pkthdr(n, m);
|
|
}
|
|
len = m->m_len;
|
|
off = 0;
|
|
mfirst = n;
|
|
mlast = NULL;
|
|
for (;;) {
|
|
int cc = min(len, MCLBYTES);
|
|
memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, cc);
|
|
n->m_len = cc;
|
|
if (mlast != NULL)
|
|
mlast->m_next = n;
|
|
mlast = n;
|
|
#if 0
|
|
newipsecstat.ips_clcopied++;
|
|
#endif
|
|
|
|
len -= cc;
|
|
if (len <= 0)
|
|
break;
|
|
off += cc;
|
|
|
|
n = m_getcl(how, m->m_type, m->m_flags & M_COPYFLAGS);
|
|
if (n == NULL) {
|
|
m_freem(mfirst);
|
|
m_freem(m0);
|
|
return (NULL);
|
|
}
|
|
}
|
|
n->m_next = m->m_next;
|
|
if (mprev == NULL)
|
|
m0 = mfirst; /* new head of chain */
|
|
else
|
|
mprev->m_next = mfirst; /* replace old mbuf */
|
|
m_free(m); /* release old mbuf */
|
|
mprev = mfirst;
|
|
}
|
|
return (m0);
|
|
}
|
|
|
|
#ifdef MBUF_PROFILING
|
|
|
|
#define MP_BUCKETS 32 /* don't just change this as things may overflow.*/
|
|
struct mbufprofile {
|
|
uintmax_t wasted[MP_BUCKETS];
|
|
uintmax_t used[MP_BUCKETS];
|
|
uintmax_t segments[MP_BUCKETS];
|
|
} mbprof;
|
|
|
|
#define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */
|
|
#define MP_NUMLINES 6
|
|
#define MP_NUMSPERLINE 16
|
|
#define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */
|
|
/* work out max space needed and add a bit of spare space too */
|
|
#define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE)
|
|
#define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES)
|
|
|
|
char mbprofbuf[MP_BUFSIZE];
|
|
|
|
void
|
|
m_profile(struct mbuf *m)
|
|
{
|
|
int segments = 0;
|
|
int used = 0;
|
|
int wasted = 0;
|
|
|
|
while (m) {
|
|
segments++;
|
|
used += m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
wasted += MHLEN - sizeof(m->m_ext) +
|
|
m->m_ext.ext_size - m->m_len;
|
|
} else {
|
|
if (m->m_flags & M_PKTHDR)
|
|
wasted += MHLEN - m->m_len;
|
|
else
|
|
wasted += MLEN - m->m_len;
|
|
}
|
|
m = m->m_next;
|
|
}
|
|
/* be paranoid.. it helps */
|
|
if (segments > MP_BUCKETS - 1)
|
|
segments = MP_BUCKETS - 1;
|
|
if (used > 100000)
|
|
used = 100000;
|
|
if (wasted > 100000)
|
|
wasted = 100000;
|
|
/* store in the appropriate bucket */
|
|
/* don't bother locking. if it's slightly off, so what? */
|
|
mbprof.segments[segments]++;
|
|
mbprof.used[fls(used)]++;
|
|
mbprof.wasted[fls(wasted)]++;
|
|
}
|
|
|
|
static void
|
|
mbprof_textify(void)
|
|
{
|
|
int offset;
|
|
char *c;
|
|
uint64_t *p;
|
|
|
|
p = &mbprof.wasted[0];
|
|
c = mbprofbuf;
|
|
offset = snprintf(c, MP_MAXLINE + 10,
|
|
"wasted:\n"
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju\n",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#ifdef BIG_ARRAY
|
|
p = &mbprof.wasted[16];
|
|
c += offset;
|
|
offset = snprintf(c, MP_MAXLINE,
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju\n",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#endif
|
|
p = &mbprof.used[0];
|
|
c += offset;
|
|
offset = snprintf(c, MP_MAXLINE + 10,
|
|
"used:\n"
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju\n",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#ifdef BIG_ARRAY
|
|
p = &mbprof.used[16];
|
|
c += offset;
|
|
offset = snprintf(c, MP_MAXLINE,
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju\n",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#endif
|
|
p = &mbprof.segments[0];
|
|
c += offset;
|
|
offset = snprintf(c, MP_MAXLINE + 10,
|
|
"segments:\n"
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju\n",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#ifdef BIG_ARRAY
|
|
p = &mbprof.segments[16];
|
|
c += offset;
|
|
offset = snprintf(c, MP_MAXLINE,
|
|
"%ju %ju %ju %ju %ju %ju %ju %ju "
|
|
"%ju %ju %ju %ju %ju %ju %ju %jju",
|
|
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
|
|
p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
mbprof_handler(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
|
|
mbprof_textify();
|
|
error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
mbprof_clr_handler(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int clear, error;
|
|
|
|
clear = 0;
|
|
error = sysctl_handle_int(oidp, &clear, 0, req);
|
|
if (error || !req->newptr)
|
|
return (error);
|
|
|
|
if (clear) {
|
|
bzero(&mbprof, sizeof(mbprof));
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
|
|
SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD,
|
|
NULL, 0, mbprof_handler, "A", "mbuf profiling statistics");
|
|
|
|
SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW,
|
|
NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics");
|
|
#endif
|
|
|