* $Id: uipc_mbuf.c,v 1.3 1997/09/01 14:46:08 nigel Exp $ */
/*
* Copyright (c) 1982, 1986, 1988, 1991 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 7.19 (Berkeley) 4/20/91
*/
#include "param.h"
#include "proc.h"
#include "malloc.h"
#include "map.h"
#define MBTYPES
#include "mbuf.h"
#include "kernel.h"
#include "syslog.h"
#include "domain.h"
#include "protosw.h"
#include "vm/vm.h"
extern vm_map_t mb_map;
struct mbuf *mbutl;
char *mclrefcnt;
mbinit()
{
int s;
#if CLBYTES < 4096
#define NCL_INIT (4096/CLBYTES)
#else
#define NCL_INIT 1
#endif
s = splimp();
if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0)
goto bad;
splx(s);
return;
bad:
panic("mbinit");
}
/*
* Allocate some number of mbuf clusters
* and place on cluster free list.
* Must be called at splimp.
*/
/* ARGSUSED */
m_clalloc(ncl, canwait)
register int ncl;
{
int npg, mbx;
register caddr_t p;
register int i;
static int logged;
npg = ncl * CLSIZE;
p = (caddr_t)kmem_malloc(mb_map, ctob(npg), canwait);
if (p == NULL) {
if (logged == 0) {
logged++;
log(LOG_INFO, "mb_map full\n");
}
m_reclaim();
if (mclfree != NULL)
return (1);
}
if (p == NULL)
return (0);
if (!mbutl)
mbutl = (struct mbuf *)p;
ncl = ncl * CLBYTES / MCLBYTES;
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 failes, 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;
m_reclaim();
#define m_retry(i, t) (struct mbuf *)0
MGET(m, i, t);
#undef m_retry
return (m);
}
/*
* As above; retry an MGETHDR.
*/
struct mbuf *
m_retryhdr(i, t)
int i, t;
{
register struct mbuf *m;
m_reclaim();
#define m_retryhdr(i, t) (struct mbuf *)0
MGETHDR(m, i, t);
#undef m_retryhdr
return (m);
}
m_reclaim()
{
register struct domain *dp;
register const 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(canwait, type)
int canwait, type;
{
register struct mbuf *m;
MGET(m, canwait, type);
return (m);
}
struct mbuf *
m_gethdr(canwait, type)
int canwait, type;
{
register struct mbuf *m;
MGETHDR(m, canwait, type);
return (m);
}
struct mbuf *
m_getclr(canwait, type)
int canwait, type;
{
register struct mbuf *m;
MGET(m, canwait, 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);
}
m_freem(m)
register struct mbuf *m;
{
register struct mbuf *n;
if (m == NULL)
return;
do {
MFREE(m, n);
} while (m = n);
}
/*
* 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.
*/
int 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;
if (off < 0 || len < 0)
panic("m_copym");
if (off == 0 && m->m_flags & M_PKTHDR)
copyhdr = 1;
while (off > 0) {
if (m == 0)
panic("m_copym");
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");
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;
mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
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 data from an mbuf chain starting "off" bytes from the beginning,
* continuing for "len" bytes, into the indicated buffer.
*/
m_copydata(m, off, len, cp)
register struct mbuf *m;
register int off;
register int len;
caddr_t cp;
{
register 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);
bcopy(mtod(m, caddr_t) + off, cp, 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.
*/
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);
}
}
m_adj(mp, req_len)
struct mbuf *mp;
{
register int len = req_len;
register struct mbuf *m;
register 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 (m->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;
m = mp;
if (m->m_flags & M_PKTHDR)
m->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)
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(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);
}