File: [local] / sys / kern / uipc_mbuf.c (download)
Revision 1.1.1.1 (vendor branch), Tue Mar 4 16:15:03 2008 UTC (16 years, 4 months ago) by nbrk
Branch: OPENBSD_4_2_BASE, MAIN
CVS Tags: jornada-partial-support-wip, HEAD Changes since 1.1: +0 -0 lines
Import of OpenBSD 4.2 release kernel tree with initial code to support
Jornada 720/728, StrongARM 1110-based handheld PC.
At this point kernel roots on NFS and boots into vfs_mountroot() and traps.
What is supported:
- glass console, Jornada framebuffer (jfb) works in 16bpp direct color mode
(needs some palette tweaks for non black/white/blue colors, i think)
- saic, SA11x0 interrupt controller (needs cleanup)
- sacom, SA11x0 UART (supported only as boot console for now)
- SA11x0 GPIO controller fully supported (but can't handle multiple interrupt
handlers on one gpio pin)
- sassp, SSP port on SA11x0 that attaches spibus
- Jornada microcontroller (jmcu) to control kbd, battery, etc throught
the SPI bus (wskbd attaches on jmcu, but not tested)
- tod functions seem work
- initial code for SA-1111 (chip companion) : this is TODO
Next important steps, i think:
- gpio and intc on sa1111
- pcmcia support for sa11x0 (and sa1111 help logic)
- REAL root on nfs when we have PCMCIA support (we may use any of supported pccard NICs)
- root on wd0! (using already supported PCMCIA-ATA)
|
/* $OpenBSD: uipc_mbuf.c,v 1.85 2007/07/20 09:59:19 claudio Exp $ */
/* $NetBSD: uipc_mbuf.c,v 1.15.4.1 1996/06/13 17:11:44 cgd Exp $ */
/*
* 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. 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
*/
/*
* @(#)COPYRIGHT 1.1 (NRL) 17 January 1995
*
* NRL grants permission for redistribution and use in source and binary
* forms, with or without modification, of the software and documentation
* created at NRL 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 acknowledgements:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* This product includes software developed at the Information
* Technology Division, US Naval Research Laboratory.
* 4. Neither the name of the NRL nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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.
*
* The views and conclusions contained in the software and documentation
* are those of the authors and should not be interpreted as representing
* official policies, either expressed or implied, of the US Naval
* Research Laboratory (NRL).
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.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 <machine/cpu.h>
#include <uvm/uvm_extern.h>
struct mbstat mbstat; /* mbuf stats */
struct pool mbpool; /* mbuf pool */
struct pool mclpool; /* mbuf cluster pool */
int max_linkhdr; /* largest link-level header */
int max_protohdr; /* largest protocol header */
int max_hdr; /* largest link+protocol header */
int max_datalen; /* MHLEN - max_hdr */
struct mbuf *m_copym0(struct mbuf *, int, int, int, int);
void nmbclust_update(void);
const char *mclpool_warnmsg =
"WARNING: mclpool limit reached; increase kern.maxclusters";
/*
* Initialize the mbuf allocator.
*/
void
mbinit(void)
{
pool_init(&mbpool, MSIZE, 0, 0, 0, "mbpl", NULL);
pool_init(&mclpool, MCLBYTES, 0, 0, 0, "mclpl", NULL);
nmbclust_update();
/*
* 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);
}
void
nmbclust_update(void)
{
/*
* 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.
*/
(void)pool_sethardlimit(&mclpool, nmbclust, mclpool_warnmsg, 60);
pool_sethiwat(&mbpool, nmbclust);
}
void
m_reclaim(void *arg, int flags)
{
struct domain *dp;
struct protosw *pr;
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)();
splx(s);
mbstat.m_drain++;
}
/*
* Space allocation routines.
*/
struct mbuf *
m_get(int nowait, int type)
{
struct mbuf *m;
int s;
s = splvm();
m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0);
if (m) {
m->m_type = type;
mbstat.m_mtypes[type]++;
m->m_next = (struct mbuf *)NULL;
m->m_nextpkt = (struct mbuf *)NULL;
m->m_data = m->m_dat;
m->m_flags = 0;
}
splx(s);
return (m);
}
struct mbuf *
m_gethdr(int nowait, int type)
{
struct mbuf *m;
int s;
s = splvm();
m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0);
if (m) {
m->m_type = type;
mbstat.m_mtypes[type]++;
m->m_next = (struct mbuf *)NULL;
m->m_nextpkt = (struct mbuf *)NULL;
m->m_data = m->m_pktdat;
m->m_flags = M_PKTHDR;
m->m_pkthdr.rcvif = NULL;
SLIST_INIT(&m->m_pkthdr.tags);
m->m_pkthdr.csum_flags = 0;
m->m_pkthdr.pf.hdr = NULL;
m->m_pkthdr.pf.rtableid = 0;
m->m_pkthdr.pf.qid = 0;
m->m_pkthdr.pf.tag = 0;
m->m_pkthdr.pf.flags = 0;
m->m_pkthdr.pf.routed = 0;
}
splx(s);
return (m);
}
struct mbuf *
m_getclr(int nowait, int type)
{
struct mbuf *m;
MGET(m, nowait, type);
if (m == NULL)
return (NULL);
memset(mtod(m, caddr_t), 0, MLEN);
return (m);
}
void
m_clget(struct mbuf *m, int how)
{
int s;
s = splvm();
m->m_ext.ext_buf =
pool_get(&mclpool, how == M_WAIT ? (PR_WAITOK|PR_LIMITFAIL) : 0);
splx(s);
if (m->m_ext.ext_buf != NULL) {
m->m_data = m->m_ext.ext_buf;
m->m_flags |= M_EXT|M_CLUSTER;
m->m_ext.ext_size = MCLBYTES;
m->m_ext.ext_free = NULL;
m->m_ext.ext_arg = NULL;
MCLINITREFERENCE(m);
}
}
struct mbuf *
m_free(struct mbuf *m)
{
struct mbuf *n;
int s;
s = splvm();
mbstat.m_mtypes[m->m_type]--;
if (m->m_flags & M_PKTHDR)
m_tag_delete_chain(m);
if (m->m_flags & M_EXT) {
if (MCLISREFERENCED(m))
_MCLDEREFERENCE(m);
else if (m->m_flags & M_CLUSTER)
pool_put(&mclpool, m->m_ext.ext_buf);
else if (m->m_ext.ext_free)
(*(m->m_ext.ext_free))(m->m_ext.ext_buf,
m->m_ext.ext_size, m->m_ext.ext_arg);
else
free(m->m_ext.ext_buf,m->m_ext.ext_type);
m->m_flags &= ~(M_CLUSTER|M_EXT);
m->m_ext.ext_size = 0;
}
n = m->m_next;
pool_put(&mbpool, m);
splx(s);
return (n);
}
void
m_freem(struct mbuf *m)
{
struct mbuf *n;
if (m == NULL)
return;
do {
MFREE(m, n);
} while ((m = n) != NULL);
}
/*
* Mbuffer utility routines.
*/
/*
* 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 (len > MHLEN)
panic("mbuf prepend length too big");
MGET(mn, 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;
MH_ALIGN(m, len);
m->m_len = len;
return (m);
}
/*
* Make a copy of an mbuf chain starting "off" 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(struct mbuf *m, int off, int len, int wait)
{
return m_copym0(m, off, len, wait, 0); /* shallow copy on M_EXT */
}
/*
* m_copym2() is like m_copym(), except it COPIES cluster mbufs, instead
* of merely bumping the reference count.
*/
struct mbuf *
m_copym2(struct mbuf *m, int off, int len, int wait)
{
return m_copym0(m, off, len, wait, 1); /* deep copy */
}
struct mbuf *
m_copym0(struct mbuf *m, int off, int len, int wait, int deep)
{
struct mbuf *n, **np;
struct mbuf *top;
int copyhdr = 0;
if (off < 0 || len < 0)
panic("m_copym0: off %d, len %d", off, len);
if (off == 0 && m->m_flags & M_PKTHDR)
copyhdr = 1;
while (off > 0) {
if (m == NULL)
panic("m_copym0: null mbuf");
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
np = ⊤
top = NULL;
while (len > 0) {
if (m == NULL) {
if (len != M_COPYALL)
panic("m_copym0: m == NULL and not COPYALL");
break;
}
MGET(n, wait, m->m_type);
*np = n;
if (n == NULL)
goto nospace;
if (copyhdr) {
M_DUP_PKTHDR(n, m);
if (len != M_COPYALL)
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 == NULL)
MCFail++;
return (top);
nospace:
m_freem(top);
MCFail++;
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(struct mbuf *m, int off, int len, caddr_t cp)
{
unsigned count;
if (off < 0)
panic("m_copydata: off %d < 0", off);
if (len < 0)
panic("m_copydata: len %d < 0", len);
while (off > 0) {
if (m == NULL)
panic("m_copydata: null mbuf in skip");
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
while (len > 0) {
if (m == NULL)
panic("m_copydata: null mbuf");
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 data from a buffer back into the indicated mbuf chain,
* starting "off" bytes from the beginning, extending the mbuf
* chain if necessary. The mbuf needs to be properly initialized
* including the setting of m_len.
*/
void
m_copyback(struct mbuf *m0, int off, int len, const void *_cp)
{
int mlen;
struct mbuf *m = m0, *n;
int totlen = 0;
caddr_t cp = (caddr_t)_cp;
if (m0 == NULL)
return;
while (off > (mlen = m->m_len)) {
off -= mlen;
totlen += mlen;
if (m->m_next == NULL) {
n = m_getclr(M_DONTWAIT, m->m_type);
if (n == NULL)
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 == NULL) {
n = m_get(M_DONTWAIT, 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;
}
/*
* Concatenate mbuf chain n to m.
* n might be copied into m (when n->m_len is small), therefore data portion of
* n could be copied into an mbuf of different mbuf type.
* Therefore both chains should 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_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) {
/* 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(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 == NULL)
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->m_next) != NULL)
m->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(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 == NULL)
goto bad;
m->m_len = 0;
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,
(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 (NULL);
}
/*
* m_pullup2() works like m_pullup, save that len can be <= MCLBYTES.
* m_pullup2() only works on values of len such that MHLEN < len <= MCLBYTES,
* it calls m_pullup() for values <= MHLEN. It also only coagulates the
* reqested number of bytes. (For those of us who expect unwieldly option
* headers.
*
* KEBE SAYS: Remember that dtom() calls with data in clusters does not work!
*/
struct mbuf *
m_pullup2(struct mbuf *n, int len)
{
struct mbuf *m;
int count;
if (len <= MHLEN)
return m_pullup(n, len);
if ((n->m_flags & M_EXT) != 0 &&
n->m_data + len < &n->m_data[MCLBYTES] && n->m_next) {
if (n->m_len >= len)
return (n);
m = n;
n = n->m_next;
len -= m->m_len;
} else {
if (len > MCLBYTES)
goto bad;
MGET(m, M_DONTWAIT, n->m_type);
if (m == NULL)
goto bad;
MCLGET(m, M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0)
goto bad;
m->m_len = 0;
if (n->m_flags & M_PKTHDR) {
/* Too many adverse side effects. */
/* M_MOVE_PKTHDR(m, n); */
m->m_flags = (n->m_flags & M_COPYFLAGS) |
M_EXT | M_CLUSTER;
M_MOVE_HDR(m, n);
/* n->m_data is cool. */
}
}
do {
count = min(len, 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;
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 (NULL);
}
/*
* 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);
}
else
return (NULL);
} else
m = m->m_next;
}
}
return (NULL);
}
/*
* Inject a new mbuf chain of length siz in mbuf chain m0 at
* position len0. Returns a pointer to the first injected mbuf, or
* NULL on failure (m0 is left undisturbed). Note that if there is
* enough space for an object of size siz in the appropriate position,
* no memory will be allocated. Also, there will be no data movement in
* the first len0 bytes (pointers to that will remain valid).
*
* XXX It is assumed that siz is less than the size of an mbuf at the moment.
*/
struct mbuf *
m_inject(struct mbuf *m0, int len0, int siz, int wait)
{
struct mbuf *m, *n, *n2 = NULL, *n3;
unsigned len = len0, remain;
if ((siz >= MHLEN) || (len0 <= 0))
return (NULL);
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 (remain == 0) {
if ((m->m_next) && (M_LEADINGSPACE(m->m_next) >= siz)) {
m->m_next->m_len += siz;
if (m0->m_flags & M_PKTHDR)
m0->m_pkthdr.len += siz;
m->m_next->m_data -= siz;
return m->m_next;
}
} else {
n2 = m_copym2(m, len, remain, wait);
if (n2 == NULL)
return (NULL);
}
MGET(n, wait, MT_DATA);
if (n == NULL) {
if (n2)
m_freem(n2);
return (NULL);
}
n->m_len = siz;
if (m0->m_flags & M_PKTHDR)
m0->m_pkthdr.len += siz;
m->m_len -= remain; /* Trim */
if (n2) {
for (n3 = n; n3->m_next != NULL; n3 = n3->m_next)
;
n3->m_next = n2;
} else
n3 = n;
for (; n3->m_next != NULL; n3 = n3->m_next)
;
n3->m_next = m->m_next;
m->m_next = n;
return n;
}
/*
* 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(struct mbuf *m0, int len0, int wait)
{
struct mbuf *m, *n;
unsigned len = len0, remain, olen;
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) {
MGETHDR(n, wait, m0->m_type);
if (n == NULL)
return (NULL);
M_DUP_PKTHDR(n, m0);
n->m_pkthdr.len -= len0;
olen = 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 == NULL) {
(void) m_free(n);
m0->m_pkthdr.len = olen;
return (NULL);
} else
return (n);
} else
MH_ALIGN(n, remain);
} else if (remain == 0) {
n = m->m_next;
m->m_next = NULL;
return (n);
} else {
MGET(n, wait, m->m_type);
if (n == NULL)
return (NULL);
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 {
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.
*/
struct mbuf *
m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
void (*copy)(const void *, void *, size_t))
{
struct mbuf *m;
struct mbuf *top = NULL, **mp = ⊤
int 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 == NULL)
return (NULL);
m->m_pkthdr.rcvif = ifp;
m->m_pkthdr.len = totlen;
m->m_len = MHLEN;
while (totlen > 0) {
if (top != NULL) {
MGET(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
m_freem(top);
return (NULL);
}
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 == NULL &&
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
bcopy(cp, mtod(m, caddr_t), (size_t)len);
cp += len;
*mp = m;
mp = &m->m_next;
totlen -= len;
if (cp == epkt)
cp = buf;
}
return (top);
}
void
m_zero(struct mbuf *m)
{
while (m) {
#ifdef DIAGNOSTIC
if (M_READONLY(m))
panic("m_zero: M_READONLY");
#endif /* DIAGNOSTIC */
if (m->m_flags & M_EXT)
memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
else {
if (m->m_flags & M_PKTHDR)
memset(m->m_pktdat, 0, MHLEN);
else
memset(m->m_dat, 0, MLEN);
}
m = m->m_next;
}
}
/*
* 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)(caddr_t, caddr_t, unsigned int), caddr_t fstate)
{
int rval;
unsigned int count;
if (len < 0)
panic("m_apply: len %d < 0", len);
if (off < 0)
panic("m_apply: off %d < 0", off);
while (off > 0) {
if (m == NULL)
panic("m_apply: null mbuf in skip");
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
while (len > 0) {
if (m == NULL)
panic("m_apply: null mbuf");
count = min(m->m_len - off, len);
rval = f(fstate, mtod(m, caddr_t) + off, count);
if (rval)
return (rval);
len -= count;
off = 0;
m = m->m_next;
}
return (0);
}