10c252ba47
as necessary: * Implement a new mbuf utility routine, m_copyup(), is is like m_pullup(), except that it always prepends and copies, rather than only doing so if the desired length is larger than m->m_len. m_copyup() also allows an offset into the destination mbuf, which allows space for packet headers, in the forwarding case. * Add *_HDR_ALIGNED_P() macros for IP, IPv6, ICMP, and IGMP. These macros expand to 1 if __NO_STRICT_ALIGNMENT is defined, so that architectures which do not have strict alignment constraints don't pay for the test or visit the new align-if-needed path. * Use the new macros to check if a header needs to be aligned, or to assert that it already is, as appropriate. Note: This code is still somewhat experimental. However, the new code path won't be visited if individual device drivers continue to guarantee that packets are delivered to layer 3 already properly aligned (which are rules that are already in use).
973 lines
22 KiB
C
973 lines
22 KiB
C
/* $NetBSD: uipc_mbuf.c,v 1.60 2002/06/30 22:40:32 thorpej Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
|
|
* NASA Ames Research Center.
|
|
*
|
|
* 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 NetBSD
|
|
* Foundation, Inc. and its contributors.
|
|
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*/
|
|
|
|
/*
|
|
* 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
|
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
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* @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.60 2002/06/30 22:40:32 thorpej Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/map.h>
|
|
#define MBTYPES
|
|
#include <sys/mbuf.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/syslog.h>
|
|
#include <sys/domain.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/pool.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <net/if.h>
|
|
|
|
#include <uvm/uvm_extern.h>
|
|
|
|
|
|
struct pool mbpool; /* mbuf pool */
|
|
struct pool mclpool; /* mbuf cluster pool */
|
|
|
|
struct pool_cache mbpool_cache;
|
|
struct pool_cache mclpool_cache;
|
|
|
|
struct mbstat mbstat;
|
|
int max_linkhdr;
|
|
int max_protohdr;
|
|
int max_hdr;
|
|
int max_datalen;
|
|
|
|
void *mclpool_alloc __P((struct pool *, int));
|
|
void mclpool_release __P((struct pool *, void *));
|
|
|
|
struct pool_allocator mclpool_allocator = {
|
|
mclpool_alloc, mclpool_release, 0,
|
|
};
|
|
|
|
static struct mbuf *m_copym0 __P((struct mbuf *, int, int, int, int));
|
|
|
|
const char mclpool_warnmsg[] =
|
|
"WARNING: mclpool limit reached; increase NMBCLUSTERS";
|
|
|
|
/*
|
|
* Initialize the mbuf allcator.
|
|
*/
|
|
void
|
|
mbinit()
|
|
{
|
|
|
|
pool_init(&mbpool, msize, 0, 0, 0, "mbpl", NULL);
|
|
pool_init(&mclpool, mclbytes, 0, 0, 0, "mclpl", &mclpool_allocator);
|
|
|
|
pool_set_drain_hook(&mbpool, m_reclaim, NULL);
|
|
pool_set_drain_hook(&mclpool, m_reclaim, NULL);
|
|
|
|
pool_cache_init(&mbpool_cache, &mbpool, NULL, NULL, NULL);
|
|
pool_cache_init(&mclpool_cache, &mclpool, NULL, NULL, NULL);
|
|
|
|
/*
|
|
* Set the hard limit on the mclpool to the number of
|
|
* mbuf clusters the kernel is to support. Log the limit
|
|
* reached message max once a minute.
|
|
*/
|
|
pool_sethardlimit(&mclpool, nmbclusters, mclpool_warnmsg, 60);
|
|
|
|
/*
|
|
* Set a low water mark for both mbufs and clusters. This should
|
|
* help ensure that they can be allocated in a memory starvation
|
|
* situation. This is important for e.g. diskless systems which
|
|
* must allocate mbufs in order for the pagedaemon to clean pages.
|
|
*/
|
|
pool_setlowat(&mbpool, mblowat);
|
|
pool_setlowat(&mclpool, mcllowat);
|
|
}
|
|
|
|
int
|
|
sysctl_dombuf(name, namelen, oldp, oldlenp, newp, newlen)
|
|
int *name;
|
|
u_int namelen;
|
|
void *oldp;
|
|
size_t *oldlenp;
|
|
void *newp;
|
|
size_t newlen;
|
|
{
|
|
int error, newval;
|
|
|
|
/* All sysctl names at this level are terminal. */
|
|
if (namelen != 1)
|
|
return (ENOTDIR); /* overloaded */
|
|
|
|
switch (name[0]) {
|
|
case MBUF_MSIZE:
|
|
return (sysctl_rdint(oldp, oldlenp, newp, msize));
|
|
case MBUF_MCLBYTES:
|
|
return (sysctl_rdint(oldp, oldlenp, newp, mclbytes));
|
|
case MBUF_NMBCLUSTERS:
|
|
/*
|
|
* If we have direct-mapped pool pages, we can adjust this
|
|
* number on the fly. If not, we're limited by the size
|
|
* of mb_map, and cannot change this value.
|
|
*
|
|
* Note: we only allow the value to be increased, never
|
|
* decreased.
|
|
*/
|
|
if (mb_map == NULL) {
|
|
newval = nmbclusters;
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&newval);
|
|
if (error != 0)
|
|
return (error);
|
|
if (newp != NULL) {
|
|
if (newval >= nmbclusters) {
|
|
nmbclusters = newval;
|
|
pool_sethardlimit(&mclpool,
|
|
nmbclusters, mclpool_warnmsg, 60);
|
|
} else
|
|
error = EINVAL;
|
|
}
|
|
return (error);
|
|
} else
|
|
return (sysctl_rdint(oldp, oldlenp, newp, nmbclusters));
|
|
case MBUF_MBLOWAT:
|
|
case MBUF_MCLLOWAT:
|
|
/* New value must be >= 0. */
|
|
newval = (name[0] == MBUF_MBLOWAT) ? mblowat : mcllowat;
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &newval);
|
|
if (error != 0)
|
|
return (error);
|
|
if (newp != NULL) {
|
|
if (newval >= 0) {
|
|
if (name[0] == MBUF_MBLOWAT) {
|
|
mblowat = newval;
|
|
pool_setlowat(&mbpool, newval);
|
|
} else {
|
|
mcllowat = newval;
|
|
pool_setlowat(&mclpool, newval);
|
|
}
|
|
} else
|
|
error = EINVAL;
|
|
}
|
|
return (error);
|
|
default:
|
|
return (EOPNOTSUPP);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
void *
|
|
mclpool_alloc(pp, flags)
|
|
struct pool *pp;
|
|
int flags;
|
|
{
|
|
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
|
|
|
|
return ((void *)uvm_km_alloc_poolpage1(mb_map, NULL, waitok));
|
|
}
|
|
|
|
void
|
|
mclpool_release(pp, v)
|
|
struct pool *pp;
|
|
void *v;
|
|
{
|
|
|
|
uvm_km_free_poolpage1(mb_map, (vaddr_t)v);
|
|
}
|
|
|
|
void
|
|
m_reclaim(void *arg, int flags)
|
|
{
|
|
struct domain *dp;
|
|
struct protosw *pr;
|
|
struct ifnet *ifp;
|
|
int s = splvm();
|
|
|
|
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)();
|
|
for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
|
|
if (ifp->if_drain)
|
|
(*ifp->if_drain)(ifp);
|
|
splx(s);
|
|
mbstat.m_drain++;
|
|
}
|
|
|
|
/*
|
|
* Space allocation routines.
|
|
* These are also available as macros
|
|
* for critical paths.
|
|
*/
|
|
struct mbuf *
|
|
m_get(nowait, type)
|
|
int nowait, type;
|
|
{
|
|
struct mbuf *m;
|
|
|
|
MGET(m, nowait, type);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_gethdr(nowait, type)
|
|
int nowait, type;
|
|
{
|
|
struct mbuf *m;
|
|
|
|
MGETHDR(m, nowait, type);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_getclr(nowait, type)
|
|
int nowait, type;
|
|
{
|
|
struct mbuf *m;
|
|
|
|
MGET(m, nowait, type);
|
|
if (m == 0)
|
|
return (0);
|
|
memset(mtod(m, caddr_t), 0, MLEN);
|
|
return (m);
|
|
}
|
|
|
|
struct mbuf *
|
|
m_free(m)
|
|
struct mbuf *m;
|
|
{
|
|
struct mbuf *n;
|
|
|
|
MFREE(m, n);
|
|
return (n);
|
|
}
|
|
|
|
void
|
|
m_freem(m)
|
|
struct mbuf *m;
|
|
{
|
|
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)
|
|
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.
|
|
*/
|
|
int MCFail;
|
|
|
|
struct mbuf *
|
|
m_copym(m, off0, len, wait)
|
|
struct mbuf *m;
|
|
int off0, wait;
|
|
int len;
|
|
{
|
|
return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */
|
|
}
|
|
|
|
struct mbuf *
|
|
m_dup(m, off0, len, wait)
|
|
struct mbuf *m;
|
|
int off0, wait;
|
|
int len;
|
|
{
|
|
return m_copym0(m, off0, len, wait, 1); /* deep copy */
|
|
}
|
|
|
|
static struct mbuf *
|
|
m_copym0(m, off0, len, wait, deep)
|
|
struct mbuf *m;
|
|
int off0, wait;
|
|
int len;
|
|
int deep; /* deep copy */
|
|
{
|
|
struct mbuf *n, **np;
|
|
int off = off0;
|
|
struct mbuf *top;
|
|
int copyhdr = 0;
|
|
|
|
if (off < 0 || len < 0)
|
|
panic("m_copym: off %d, len %d", off, len);
|
|
if (off == 0 && m->m_flags & M_PKTHDR)
|
|
copyhdr = 1;
|
|
while (off > 0) {
|
|
if (m == 0)
|
|
panic("m_copym: m == 0");
|
|
if (off < m->m_len)
|
|
break;
|
|
off -= m->m_len;
|
|
m = m->m_next;
|
|
}
|
|
np = ⊤
|
|
top = 0;
|
|
while (len > 0) {
|
|
if (m == 0) {
|
|
if (len != M_COPYALL)
|
|
panic("m_copym: m == 0 and not COPYALL");
|
|
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) {
|
|
if (!deep) {
|
|
n->m_data = m->m_data + off;
|
|
n->m_ext = m->m_ext;
|
|
MCLADDREFERENCE(m, n);
|
|
} else {
|
|
/*
|
|
* we are unsure about the way m was allocated.
|
|
* copy into multiple MCLBYTES cluster mbufs.
|
|
*/
|
|
MCLGET(n, wait);
|
|
n->m_len = 0;
|
|
n->m_len = M_TRAILINGSPACE(n);
|
|
n->m_len = min(n->m_len, len);
|
|
n->m_len = min(n->m_len, m->m_len - off);
|
|
memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off,
|
|
(unsigned)n->m_len);
|
|
}
|
|
} else
|
|
memcpy(mtod(n, caddr_t), mtod(m, caddr_t)+off,
|
|
(unsigned)n->m_len);
|
|
if (len != M_COPYALL)
|
|
len -= n->m_len;
|
|
off += n->m_len;
|
|
#ifdef DIAGNOSTIC
|
|
if (off > m->m_len)
|
|
panic("m_copym0 overrun");
|
|
#endif
|
|
if (off == m->m_len) {
|
|
m = m->m_next;
|
|
off = 0;
|
|
}
|
|
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)'.
|
|
*/
|
|
struct mbuf *
|
|
m_copypacket(m, how)
|
|
struct mbuf *m;
|
|
int how;
|
|
{
|
|
struct mbuf *top, *n, *o;
|
|
|
|
MGET(n, how, m->m_type);
|
|
top = n;
|
|
if (!n)
|
|
goto nospace;
|
|
|
|
M_COPY_PKTHDR(n, m);
|
|
n->m_len = m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data;
|
|
n->m_ext = m->m_ext;
|
|
MCLADDREFERENCE(m, n);
|
|
} else {
|
|
memcpy(mtod(n, char *), mtod(m, char *), n->m_len);
|
|
}
|
|
|
|
m = m->m_next;
|
|
while (m) {
|
|
MGET(o, how, m->m_type);
|
|
if (!o)
|
|
goto nospace;
|
|
|
|
n->m_next = o;
|
|
n = n->m_next;
|
|
|
|
n->m_len = m->m_len;
|
|
if (m->m_flags & M_EXT) {
|
|
n->m_data = m->m_data;
|
|
n->m_ext = m->m_ext;
|
|
MCLADDREFERENCE(m, n);
|
|
} else {
|
|
memcpy(mtod(n, char *), mtod(m, 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)
|
|
struct mbuf *m;
|
|
int off;
|
|
int len;
|
|
caddr_t cp;
|
|
{
|
|
unsigned count;
|
|
|
|
if (off < 0 || len < 0)
|
|
panic("m_copydata");
|
|
while (off > 0) {
|
|
if (m == 0)
|
|
panic("m_copydata");
|
|
if (off < m->m_len)
|
|
break;
|
|
off -= m->m_len;
|
|
m = m->m_next;
|
|
}
|
|
while (len > 0) {
|
|
if (m == 0)
|
|
panic("m_copydata");
|
|
count = min(m->m_len - off, len);
|
|
memcpy(cp, mtod(m, caddr_t) + off, count);
|
|
len -= count;
|
|
cp += count;
|
|
off = 0;
|
|
m = m->m_next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
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 */
|
|
memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t),
|
|
(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;
|
|
{
|
|
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;
|
|
}
|
|
}
|
|
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.
|
|
*/
|
|
int MPFail;
|
|
|
|
struct mbuf *
|
|
m_pullup(n, len)
|
|
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;
|
|
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);
|
|
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);
|
|
MPFail++;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* 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).
|
|
*/
|
|
int MSFail;
|
|
|
|
struct mbuf *
|
|
m_copyup(struct mbuf *n, int len, int dstoff)
|
|
{
|
|
struct mbuf *m;
|
|
int count, space;
|
|
|
|
if (len > (MHLEN - dstoff))
|
|
goto bad;
|
|
MGET(m, M_DONTWAIT, n->m_type);
|
|
if (m == NULL)
|
|
goto bad;
|
|
m->m_len = 0;
|
|
if (n->m_flags & M_PKTHDR) {
|
|
M_COPY_PKTHDR(m, n);
|
|
n->m_flags &= ~M_PKTHDR;
|
|
}
|
|
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);
|
|
MSFail++;
|
|
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.
|
|
*/
|
|
struct mbuf *
|
|
m_split(m0, len0, wait)
|
|
struct mbuf *m0;
|
|
int len0, wait;
|
|
{
|
|
struct mbuf *m, *n;
|
|
unsigned len = len0, remain, len_save;
|
|
|
|
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;
|
|
len_save = m0->m_pkthdr.len;
|
|
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);
|
|
m0->m_pkthdr.len = len_save;
|
|
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_ext = m->m_ext;
|
|
MCLADDREFERENCE(m, n);
|
|
n->m_data = m->m_data + len;
|
|
} else {
|
|
memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + len, 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((const void *from, void *to, size_t len));
|
|
{
|
|
struct mbuf *m;
|
|
struct mbuf *top = 0, **mp = ⊤
|
|
int off = off0, len;
|
|
char *cp;
|
|
char *epkt;
|
|
|
|
cp = buf;
|
|
epkt = cp + totlen;
|
|
if (off) {
|
|
/*
|
|
* If 'off' is non-zero, packet is trailer-encapsulated,
|
|
* so we have to skip the type and length fields.
|
|
*/
|
|
cp += off + 2 * sizeof(u_int16_t);
|
|
totlen -= 2 * sizeof(u_int16_t);
|
|
}
|
|
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) == 0) {
|
|
m_free(m);
|
|
m_freem(top);
|
|
return (0);
|
|
}
|
|
m->m_len = len = min(len, MCLBYTES);
|
|
} 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), (size_t)len);
|
|
else
|
|
memcpy(mtod(m, caddr_t), cp, (size_t)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;
|
|
int off;
|
|
int len;
|
|
caddr_t cp;
|
|
{
|
|
int mlen;
|
|
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);
|
|
memcpy(mtod(m, caddr_t) + off, cp, (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;
|
|
}
|