1c38f2ea70
because in the case of mbuf clusters they only increment the reference count rather than actually copying the data. Add comments to this effect, and add a new routine called m_dup() that returns a real, writable copy of an mbuf chain. This is preliminary work required for implementing 'ipfw tee'. Reviewed by: julian
1048 lines
22 KiB
C
1048 lines
22 KiB
C
/*
|
|
* Copyright (c) 1982, 1986, 1988, 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "opt_param.h"
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/domain.h>
|
|
#include <sys/protosw.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_kern.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
static void mbinit __P((void *));
|
|
SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL)
|
|
|
|
struct mbuf *mbutl;
|
|
char *mclrefcnt;
|
|
struct mbstat mbstat;
|
|
struct mbuf *mmbfree;
|
|
union mcluster *mclfree;
|
|
int max_linkhdr;
|
|
int max_protohdr;
|
|
int max_hdr;
|
|
int max_datalen;
|
|
int nmbclusters;
|
|
int nmbufs;
|
|
|
|
SYSCTL_DECL(_kern_ipc);
|
|
SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW,
|
|
&max_linkhdr, 0, "");
|
|
SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW,
|
|
&max_protohdr, 0, "");
|
|
SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, "");
|
|
SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW,
|
|
&max_datalen, 0, "");
|
|
SYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, "");
|
|
SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD,
|
|
&nmbclusters, 0, "Maximum number of mbuf clusters avaliable");
|
|
#ifndef NMBCLUSTERS
|
|
#define NMBCLUSTERS (512 + MAXUSERS * 16)
|
|
#endif
|
|
TUNABLE_INT_DECL("kern.ipc.nmbclusters", NMBCLUSTERS, nmbclusters);
|
|
TUNABLE_INT_DECL("kern.ipc.nmbufs", NMBCLUSTERS * 4, nmbufs); /* XXX fixup? */
|
|
|
|
static void m_reclaim __P((void));
|
|
|
|
/* "number of clusters of pages" */
|
|
#define NCL_INIT 1
|
|
|
|
#define NMB_INIT 16
|
|
|
|
/* ARGSUSED*/
|
|
static void
|
|
mbinit(dummy)
|
|
void *dummy;
|
|
{
|
|
int s;
|
|
|
|
mmbfree = NULL; mclfree = NULL;
|
|
mbstat.m_msize = MSIZE;
|
|
mbstat.m_mclbytes = MCLBYTES;
|
|
mbstat.m_minclsize = MINCLSIZE;
|
|
mbstat.m_mlen = MLEN;
|
|
mbstat.m_mhlen = MHLEN;
|
|
|
|
s = splimp();
|
|
if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0)
|
|
goto bad;
|
|
#if MCLBYTES <= PAGE_SIZE
|
|
if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0)
|
|
goto bad;
|
|
#else
|
|
/* It's OK to call contigmalloc in this context. */
|
|
if (m_clalloc(16, M_WAIT) == 0)
|
|
goto bad;
|
|
#endif
|
|
splx(s);
|
|
return;
|
|
bad:
|
|
panic("mbinit");
|
|
}
|
|
|
|
/*
|
|
* Allocate at least nmb mbufs and place on mbuf free list.
|
|
* Must be called at splimp.
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
m_mballoc(nmb, how)
|
|
register int nmb;
|
|
int how;
|
|
{
|
|
register caddr_t p;
|
|
register int i;
|
|
int nbytes;
|
|
|
|
/* Once we run out of map space, it will be impossible to get
|
|
* any more (nothing is ever freed back to the map) (XXX which
|
|
* is dumb). (however you are not dead as m_reclaim might
|
|
* still be able to free a substantial amount of space).
|
|
*/
|
|
if (mb_map_full)
|
|
return (0);
|
|
|
|
nbytes = round_page(nmb * MSIZE);
|
|
p = (caddr_t)kmem_malloc(mb_map, nbytes, M_NOWAIT);
|
|
if (p == 0 && how == M_WAIT) {
|
|
mbstat.m_wait++;
|
|
p = (caddr_t)kmem_malloc(mb_map, nbytes, M_WAITOK);
|
|
}
|
|
|
|
/*
|
|
* Either the map is now full, or `how' is M_NOWAIT and there
|
|
* are no pages left.
|
|
*/
|
|
if (p == NULL)
|
|
return (0);
|
|
|
|
nmb = nbytes / MSIZE;
|
|
for (i = 0; i < nmb; i++) {
|
|
((struct mbuf *)p)->m_next = mmbfree;
|
|
mmbfree = (struct mbuf *)p;
|
|
p += MSIZE;
|
|
}
|
|
mbstat.m_mbufs += nmb;
|
|
return (1);
|
|
}
|
|
|
|
#if MCLBYTES > PAGE_SIZE
|
|
static int i_want_my_mcl;
|
|
|
|
static void
|
|
kproc_mclalloc(void)
|
|
{
|
|
int status;
|
|
|
|
while (1) {
|
|
tsleep(&i_want_my_mcl, PVM, "mclalloc", 0);
|
|
|
|
for (; i_want_my_mcl; i_want_my_mcl--) {
|
|
if (m_clalloc(1, M_WAIT) == 0)
|
|
printf("m_clalloc failed even in process context!\n");
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct proc *mclallocproc;
|
|
static struct kproc_desc mclalloc_kp = {
|
|
"mclalloc",
|
|
kproc_mclalloc,
|
|
&mclallocproc
|
|
};
|
|
SYSINIT(mclallocproc, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start,
|
|
&mclalloc_kp);
|
|
#endif
|
|
|
|
/*
|
|
* Allocate some number of mbuf clusters
|
|
* and place on cluster free list.
|
|
* Must be called at splimp.
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
m_clalloc(ncl, how)
|
|
register int ncl;
|
|
int how;
|
|
{
|
|
register caddr_t p;
|
|
register int i;
|
|
int npg;
|
|
|
|
/*
|
|
* Once we run out of map space, it will be impossible
|
|
* to get any more (nothing is ever freed back to the
|
|
* map).
|
|
*/
|
|
if (mb_map_full) {
|
|
mbstat.m_drops++;
|
|
return (0);
|
|
}
|
|
|
|
#if MCLBYTES > PAGE_SIZE
|
|
if (how != M_WAIT) {
|
|
i_want_my_mcl += ncl;
|
|
wakeup(&i_want_my_mcl);
|
|
mbstat.m_wait++;
|
|
p = 0;
|
|
} else {
|
|
p = contigmalloc1(MCLBYTES * ncl, M_DEVBUF, M_WAITOK, 0ul,
|
|
~0ul, PAGE_SIZE, 0, mb_map);
|
|
}
|
|
#else
|
|
npg = ncl;
|
|
p = (caddr_t)kmem_malloc(mb_map, ctob(npg),
|
|
how != M_WAIT ? M_NOWAIT : M_WAITOK);
|
|
ncl = ncl * PAGE_SIZE / MCLBYTES;
|
|
#endif
|
|
/*
|
|
* Either the map is now full, or `how' is M_NOWAIT and there
|
|
* are no pages left.
|
|
*/
|
|
if (p == NULL) {
|
|
mbstat.m_drops++;
|
|
return (0);
|
|
}
|
|
|
|
for (i = 0; i < ncl; i++) {
|
|
((union mcluster *)p)->mcl_next = mclfree;
|
|
mclfree = (union mcluster *)p;
|
|
p += MCLBYTES;
|
|
mbstat.m_clfree++;
|
|
}
|
|
mbstat.m_clusters += ncl;
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* When MGET fails, ask protocols to free space when short of memory,
|
|
* then re-attempt to allocate an mbuf.
|
|
*/
|
|
struct mbuf *
|
|
m_retry(i, t)
|
|
int i, t;
|
|
{
|
|
register struct mbuf *m;
|
|
|
|
/*
|
|
* Must only do the reclaim if not in an interrupt context.
|
|
*/
|
|
if (i == M_WAIT)
|
|
m_reclaim();
|
|
#define m_retry(i, t) (struct mbuf *)0
|
|
MGET(m, i, t);
|
|
#undef m_retry
|
|
if (m != NULL) {
|
|
mbstat.m_wait++;
|
|
} else {
|
|
if (i == M_DONTWAIT)
|
|
mbstat.m_drops++;
|
|
else
|
|
panic("Out of mbuf clusters");
|
|
}
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* As above; retry an MGETHDR.
|
|
*/
|
|
struct mbuf *
|
|
m_retryhdr(i, t)
|
|
int i, t;
|
|
{
|
|
register struct mbuf *m;
|
|
|
|
/*
|
|
* Must only do the reclaim if not in an interrupt context.
|
|
*/
|
|
if (i == M_WAIT)
|
|
m_reclaim();
|
|
#define m_retryhdr(i, t) (struct mbuf *)0
|
|
MGETHDR(m, i, t);
|
|
#undef m_retryhdr
|
|
if (m != NULL) {
|
|
mbstat.m_wait++;
|
|
} else {
|
|
if (i == M_DONTWAIT)
|
|
mbstat.m_drops++;
|
|
else
|
|
panic("Out of mbuf clusters");
|
|
}
|
|
return (m);
|
|
}
|
|
|
|
static void
|
|
m_reclaim()
|
|
{
|
|
register struct domain *dp;
|
|
register struct protosw *pr;
|
|
int s = splimp();
|
|
|
|
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)();
|
|
splx(s);
|
|
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 {
|
|
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;
|
|
if(!m->m_ext.ext_ref)
|
|
mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
|
|
else
|
|
(*(m->m_ext.ext_ref))(m->m_ext.ext_buf,
|
|
m->m_ext.ext_size);
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
} 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)
|
|
MCFail++;
|
|
return (top);
|
|
nospace:
|
|
m_freem(top);
|
|
MCFail++;
|
|
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;
|
|
if(!m->m_ext.ext_ref)
|
|
mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
|
|
else
|
|
(*(m->m_ext.ext_ref))(m->m_ext.ext_buf,
|
|
m->m_ext.ext_size);
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
} 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;
|
|
if(!m->m_ext.ext_ref)
|
|
mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
|
|
else
|
|
(*(m->m_ext.ext_ref))(m->m_ext.ext_buf,
|
|
m->m_ext.ext_size);
|
|
n->m_ext = m->m_ext;
|
|
n->m_flags |= M_EXT;
|
|
} else {
|
|
bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
}
|
|
return top;
|
|
nospace:
|
|
m_freem(top);
|
|
MCFail++;
|
|
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);
|
|
MCFail++;
|
|
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);
|
|
MPFail++;
|
|
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;
|
|
if(!m->m_ext.ext_ref)
|
|
mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
|
|
else
|
|
(*(m->m_ext.ext_ref))(m->m_ext.ext_buf,
|
|
m->m_ext.ext_size);
|
|
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;
|
|
}
|