mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-24 11:29:10 +00:00
333 lines
8.9 KiB
C
333 lines
8.9 KiB
C
/* $FreeBSD$ */
|
|
/* $KAME: uipc_mbuf2.c,v 1.15 2000/02/22 14:01:37 itojun Exp $ */
|
|
/* $NetBSD: uipc_mbuf.c,v 1.40 1999/04/01 00:23:25 thorpej Exp $ */
|
|
|
|
/*
|
|
* Copyright (C) 1999 WIDE Project.
|
|
* 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 project 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 PROJECT 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 PROJECT 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
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95
|
|
*/
|
|
|
|
/*#define PULLDOWN_DEBUG*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
|
|
/*
|
|
* ensure that [off, off + len) is contiguous on the mbuf chain "m".
|
|
* packet chain before "off" is kept untouched.
|
|
* if offp == NULL, the target will start at <retval, 0> on resulting chain.
|
|
* if offp != NULL, the target will start at <retval, *offp> on resulting chain.
|
|
*
|
|
* on error return (NULL return value), original "m" will be freed.
|
|
*
|
|
* XXX M_TRAILINGSPACE/M_LEADINGSPACE on shared cluster (sharedcluster)
|
|
*/
|
|
struct mbuf *
|
|
m_pulldown(m, off, len, offp)
|
|
struct mbuf *m;
|
|
int off, len;
|
|
int *offp;
|
|
{
|
|
struct mbuf *n, *o;
|
|
int hlen, tlen, olen;
|
|
int sharedcluster;
|
|
|
|
/* check invalid arguments. */
|
|
if (m == NULL)
|
|
panic("m == NULL in m_pulldown()");
|
|
if (len > MCLBYTES) {
|
|
m_freem(m);
|
|
return NULL; /* impossible */
|
|
}
|
|
|
|
#ifdef PULLDOWN_DEBUG
|
|
{
|
|
struct mbuf *t;
|
|
printf("before:");
|
|
for (t = m; t; t = t->m_next)
|
|
printf(" %d", t->m_len);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
n = m;
|
|
while (n != NULL && off > 0) {
|
|
if (n->m_len > off)
|
|
break;
|
|
off -= n->m_len;
|
|
n = n->m_next;
|
|
}
|
|
/* be sure to point non-empty mbuf */
|
|
while (n != NULL && n->m_len == 0)
|
|
n = n->m_next;
|
|
if (!n) {
|
|
m_freem(m);
|
|
return NULL; /* mbuf chain too short */
|
|
}
|
|
|
|
/*
|
|
* the target data is on <n, off>.
|
|
* if we got enough data on the mbuf "n", we're done.
|
|
*/
|
|
if ((off == 0 || offp) && len <= n->m_len - off)
|
|
goto ok;
|
|
|
|
/*
|
|
* when len < n->m_len - off and off != 0, it is a special case.
|
|
* len bytes from <n, off> sits in single mbuf, but the caller does
|
|
* not like the starting position (off).
|
|
* chop the current mbuf into two pieces, set off to 0.
|
|
*/
|
|
if (len < n->m_len - off) {
|
|
o = m_copym(n, off, n->m_len - off, M_DONTWAIT);
|
|
if (o == NULL) {
|
|
m_freem(m);
|
|
return NULL; /* ENOBUFS */
|
|
}
|
|
n->m_len = off;
|
|
o->m_next = n->m_next;
|
|
n->m_next = o;
|
|
n = n->m_next;
|
|
off = 0;
|
|
goto ok;
|
|
}
|
|
|
|
/*
|
|
* we need to take hlen from <n, off> and tlen from <n->m_next, 0>,
|
|
* and construct contiguous mbuf with m_len == len.
|
|
* note that hlen + tlen == len, and tlen > 0.
|
|
*/
|
|
hlen = n->m_len - off;
|
|
tlen = len - hlen;
|
|
|
|
/*
|
|
* ensure that we have enough trailing data on mbuf chain.
|
|
* if not, we can do nothing about the chain.
|
|
*/
|
|
olen = 0;
|
|
for (o = n->m_next; o != NULL; o = o->m_next)
|
|
olen += o->m_len;
|
|
if (hlen + olen < len) {
|
|
m_freem(m);
|
|
return NULL; /* mbuf chain too short */
|
|
}
|
|
|
|
/*
|
|
* easy cases first.
|
|
* we need to use m_copydata() to get data from <n->m_next, 0>.
|
|
*/
|
|
if ((n->m_flags & M_EXT) == 0)
|
|
sharedcluster = 0;
|
|
else {
|
|
if (n->m_ext.ext_free)
|
|
sharedcluster = 1;
|
|
else if (mclrefcnt[mtocl(n->m_ext.ext_buf)] > 1)
|
|
sharedcluster = 1;
|
|
else
|
|
sharedcluster = 0;
|
|
}
|
|
if ((off == 0 || offp) && M_TRAILINGSPACE(n) >= tlen
|
|
&& !sharedcluster) {
|
|
m_copydata(n->m_next, 0, tlen, mtod(n, caddr_t) + n->m_len);
|
|
n->m_len += tlen;
|
|
m_adj(n->m_next, tlen);
|
|
goto ok;
|
|
}
|
|
if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen
|
|
&& !sharedcluster) {
|
|
n->m_next->m_data -= hlen;
|
|
n->m_next->m_len += hlen;
|
|
bcopy(mtod(n, caddr_t) + off, mtod(n->m_next, caddr_t), hlen);
|
|
n->m_len -= hlen;
|
|
n = n->m_next;
|
|
off = 0;
|
|
goto ok;
|
|
}
|
|
|
|
/*
|
|
* now, we need to do the hard way. don't m_copy as there's no room
|
|
* on both end.
|
|
*/
|
|
MGET(o, M_DONTWAIT, m->m_type);
|
|
if (o == NULL) {
|
|
m_freem(m);
|
|
return NULL; /* ENOBUFS */
|
|
}
|
|
if (len > MHLEN) { /* use MHLEN just for safety */
|
|
MCLGET(o, M_DONTWAIT);
|
|
if ((o->m_flags & M_EXT) == 0) {
|
|
m_freem(m);
|
|
m_free(o);
|
|
return NULL; /* ENOBUFS */
|
|
}
|
|
}
|
|
/* get hlen from <n, off> into <o, 0> */
|
|
o->m_len = hlen;
|
|
bcopy(mtod(n, caddr_t) + off, mtod(o, caddr_t), hlen);
|
|
n->m_len -= hlen;
|
|
/* get tlen from <n->m_next, 0> into <o, hlen> */
|
|
m_copydata(n->m_next, 0, tlen, mtod(o, caddr_t) + o->m_len);
|
|
o->m_len += tlen;
|
|
m_adj(n->m_next, tlen);
|
|
o->m_next = n->m_next;
|
|
n->m_next = o;
|
|
n = o;
|
|
off = 0;
|
|
|
|
ok:
|
|
#ifdef PULLDOWN_DEBUG
|
|
{
|
|
struct mbuf *t;
|
|
printf("after:");
|
|
for (t = m; t; t = t->m_next)
|
|
printf("%c%d", t == n ? '*' : ' ', t->m_len);
|
|
printf(" (off=%d)\n", off);
|
|
}
|
|
#endif
|
|
if (offp)
|
|
*offp = off;
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
* pkthdr.aux chain manipulation.
|
|
* we don't allow clusters at this moment.
|
|
*/
|
|
struct mbuf *
|
|
m_aux_add(m, af, type)
|
|
struct mbuf *m;
|
|
int af, type;
|
|
{
|
|
struct mbuf *n;
|
|
struct mauxtag *t;
|
|
|
|
if ((m->m_flags & M_PKTHDR) == 0)
|
|
return NULL;
|
|
|
|
n = m_aux_find(m, af, type);
|
|
if (n)
|
|
return n;
|
|
|
|
MGET(n, M_DONTWAIT, m->m_type);
|
|
if (n == NULL)
|
|
return NULL;
|
|
|
|
t = mtod(n, struct mauxtag *);
|
|
t->af = af;
|
|
t->type = type;
|
|
n->m_data += sizeof(struct mauxtag);
|
|
n->m_len = 0;
|
|
n->m_next = m->m_pkthdr.aux;
|
|
m->m_pkthdr.aux = n;
|
|
return n;
|
|
}
|
|
|
|
struct mbuf *
|
|
m_aux_find(m, af, type)
|
|
struct mbuf *m;
|
|
int af, type;
|
|
{
|
|
struct mbuf *n;
|
|
struct mauxtag *t;
|
|
|
|
if ((m->m_flags & M_PKTHDR) == 0)
|
|
return NULL;
|
|
|
|
for (n = m->m_pkthdr.aux; n; n = n->m_next) {
|
|
t = (struct mauxtag *)n->m_dat;
|
|
if (t->af == af && t->type == type)
|
|
return n;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void
|
|
m_aux_delete(m, victim)
|
|
struct mbuf *m;
|
|
struct mbuf *victim;
|
|
{
|
|
struct mbuf *n, *prev, *next;
|
|
struct mauxtag *t;
|
|
|
|
if ((m->m_flags & M_PKTHDR) == 0)
|
|
return;
|
|
|
|
prev = NULL;
|
|
n = m->m_pkthdr.aux;
|
|
while (n) {
|
|
t = (struct mauxtag *)n->m_dat;
|
|
next = n->m_next;
|
|
if (n == victim) {
|
|
if (prev)
|
|
prev->m_next = n->m_next;
|
|
else
|
|
m->m_pkthdr.aux = n->m_next;
|
|
n->m_next = NULL;
|
|
m_free(n);
|
|
} else
|
|
prev = n;
|
|
n = next;
|
|
}
|
|
}
|