455 lines
12 KiB
C
455 lines
12 KiB
C
/* $KAME: uipc_mbuf2.c,v 1.31 2001/11/28 11:08:53 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.
|
|
* 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
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
/*#define PULLDOWN_DEBUG*/
|
|
|
|
#include "opt_mac.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mac.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/mutex.h>
|
|
|
|
MALLOC_DEFINE(M_PACKET_TAGS, "tag", "packet-attached information");
|
|
|
|
/* can't call it m_dup(), as freebsd[34] uses m_dup() with different arg */
|
|
static struct mbuf *m_dup1(struct mbuf *, int, int, int);
|
|
|
|
/*
|
|
* 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 only permitted on writable ext_buf.
|
|
*/
|
|
struct mbuf *
|
|
m_pulldown(struct mbuf *m, int off, int len, int *offp)
|
|
{
|
|
struct mbuf *n, *o;
|
|
int hlen, tlen, olen;
|
|
int writable;
|
|
|
|
/* 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 */
|
|
}
|
|
|
|
/*
|
|
* XXX: This code is flawed because it considers a "writable" mbuf
|
|
* data region to require all of the following:
|
|
* (i) mbuf _has_ to have M_EXT set; if it is just a regular
|
|
* mbuf, it is still not considered "writable."
|
|
* (ii) since mbuf has M_EXT, the ext_type _has_ to be
|
|
* EXT_CLUSTER. Anything else makes it non-writable.
|
|
* (iii) M_WRITABLE() must evaluate true.
|
|
* Ideally, the requirement should only be (iii).
|
|
*
|
|
* If we're writable, we're sure we're writable, because the ref. count
|
|
* cannot increase from 1, as that would require posession of mbuf
|
|
* n by someone else (which is impossible). However, if we're _not_
|
|
* writable, we may eventually become writable )if the ref. count drops
|
|
* to 1), but we'll fail to notice it unless we re-evaluate
|
|
* M_WRITABLE(). For now, we only evaluate once at the beginning and
|
|
* live with this.
|
|
*/
|
|
/*
|
|
* XXX: This is dumb. If we're just a regular mbuf with no M_EXT,
|
|
* then we're not "writable," according to this code.
|
|
*/
|
|
writable = 0;
|
|
if ((n->m_flags & M_EXT) == 0 ||
|
|
(n->m_ext.ext_type == EXT_CLUSTER && M_WRITABLE(n)))
|
|
writable = 1;
|
|
|
|
/*
|
|
* 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 && writable)
|
|
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_dup1(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 ((off == 0 || offp) && M_TRAILINGSPACE(n) >= tlen
|
|
&& writable) {
|
|
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
|
|
&& writable) {
|
|
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 && len > MLEN) {
|
|
MCLGET(o, M_DONTWAIT);
|
|
if ((o->m_flags & M_EXT) == 0) {
|
|
m_free(o);
|
|
o = NULL;
|
|
}
|
|
}
|
|
if (!o) {
|
|
m_freem(m);
|
|
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;
|
|
}
|
|
|
|
static struct mbuf *
|
|
m_dup1(struct mbuf *m, int off, int len, int wait)
|
|
{
|
|
struct mbuf *n;
|
|
int l;
|
|
int copyhdr;
|
|
|
|
if (len > MCLBYTES)
|
|
return NULL;
|
|
if (off == 0 && (m->m_flags & M_PKTHDR) != 0) {
|
|
copyhdr = 1;
|
|
MGETHDR(n, wait, m->m_type);
|
|
l = MHLEN;
|
|
} else {
|
|
copyhdr = 0;
|
|
MGET(n, wait, m->m_type);
|
|
l = MLEN;
|
|
}
|
|
if (n && len > l) {
|
|
MCLGET(n, wait);
|
|
if ((n->m_flags & M_EXT) == 0) {
|
|
m_free(n);
|
|
n = NULL;
|
|
}
|
|
}
|
|
if (!n)
|
|
return NULL;
|
|
|
|
if (copyhdr && !m_dup_pkthdr(n, m, wait)) {
|
|
m_free(n);
|
|
return NULL;
|
|
}
|
|
m_copydata(m, off, len, mtod(n, caddr_t));
|
|
return n;
|
|
}
|
|
|
|
/* Free a packet tag. */
|
|
static void
|
|
_m_tag_free(struct m_tag *t)
|
|
{
|
|
#ifdef MAC
|
|
if (t->m_tag_id == PACKET_TAG_MACLABEL)
|
|
mac_destroy_mbuf_tag(t);
|
|
#endif
|
|
free(t, M_PACKET_TAGS);
|
|
}
|
|
|
|
/* Get a packet tag structure along with specified data following. */
|
|
struct m_tag *
|
|
m_tag_alloc(u_int32_t cookie, int type, int len, int wait)
|
|
{
|
|
struct m_tag *t;
|
|
|
|
if (len < 0)
|
|
return NULL;
|
|
t = malloc(len + sizeof(struct m_tag), M_PACKET_TAGS, wait);
|
|
if (t == NULL)
|
|
return NULL;
|
|
m_tag_setup(t, cookie, type, len);
|
|
t->m_tag_free = _m_tag_free;
|
|
return t;
|
|
}
|
|
|
|
/* Unlink and free a packet tag. */
|
|
void
|
|
m_tag_delete(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
KASSERT(m && t, ("m_tag_delete: null argument, m %p t %p", m, t));
|
|
m_tag_unlink(m, t);
|
|
m_tag_free(t);
|
|
}
|
|
|
|
/* Unlink and free a packet tag chain, starting from given tag. */
|
|
void
|
|
m_tag_delete_chain(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
struct m_tag *p, *q;
|
|
|
|
KASSERT(m, ("m_tag_delete_chain: null mbuf"));
|
|
if (t != NULL)
|
|
p = t;
|
|
else
|
|
p = SLIST_FIRST(&m->m_pkthdr.tags);
|
|
if (p == NULL)
|
|
return;
|
|
while ((q = SLIST_NEXT(p, m_tag_link)) != NULL)
|
|
m_tag_delete(m, q);
|
|
m_tag_delete(m, p);
|
|
}
|
|
|
|
/*
|
|
* Strip off all tags that would normally vanish when
|
|
* passing through a network interface. Only persistent
|
|
* tags will exist after this; these are expected to remain
|
|
* so long as the mbuf chain exists, regardless of the
|
|
* path the mbufs take.
|
|
*/
|
|
void
|
|
m_tag_delete_nonpersistent(struct mbuf *m)
|
|
{
|
|
struct m_tag *p, *q;
|
|
|
|
SLIST_FOREACH_SAFE(p, &m->m_pkthdr.tags, m_tag_link, q)
|
|
if ((p->m_tag_id & MTAG_PERSISTENT) == 0)
|
|
m_tag_delete(m, p);
|
|
}
|
|
|
|
/* Find a tag, starting from a given position. */
|
|
struct m_tag *
|
|
m_tag_locate(struct mbuf *m, u_int32_t cookie, int type, struct m_tag *t)
|
|
{
|
|
struct m_tag *p;
|
|
|
|
KASSERT(m, ("m_tag_locate: null mbuf"));
|
|
if (t == NULL)
|
|
p = SLIST_FIRST(&m->m_pkthdr.tags);
|
|
else
|
|
p = SLIST_NEXT(t, m_tag_link);
|
|
while (p != NULL) {
|
|
if (p->m_tag_cookie == cookie && p->m_tag_id == type)
|
|
return p;
|
|
p = SLIST_NEXT(p, m_tag_link);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Copy a single tag. */
|
|
struct m_tag *
|
|
m_tag_copy(struct m_tag *t, int how)
|
|
{
|
|
struct m_tag *p;
|
|
|
|
KASSERT(t, ("m_tag_copy: null tag"));
|
|
p = m_tag_alloc(t->m_tag_cookie, t->m_tag_id, t->m_tag_len, how);
|
|
if (p == NULL)
|
|
return (NULL);
|
|
#ifdef MAC
|
|
/*
|
|
* XXXMAC: we should probably pass off the initialization, and
|
|
* copying here? can we hide that PACKET_TAG_MACLABEL is
|
|
* special from the mbuf code?
|
|
*/
|
|
if (t->m_tag_id == PACKET_TAG_MACLABEL) {
|
|
if (mac_init_mbuf_tag(p, how) != 0) {
|
|
m_tag_free(p);
|
|
return (NULL);
|
|
}
|
|
mac_copy_mbuf_tag(t, p);
|
|
} else
|
|
#endif
|
|
bcopy(t + 1, p + 1, t->m_tag_len); /* Copy the data */
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* Copy two tag chains. The destination mbuf (to) loses any attached
|
|
* tags even if the operation fails. This should not be a problem, as
|
|
* m_tag_copy_chain() is typically called with a newly-allocated
|
|
* destination mbuf.
|
|
*/
|
|
int
|
|
m_tag_copy_chain(struct mbuf *to, struct mbuf *from, int how)
|
|
{
|
|
struct m_tag *p, *t, *tprev = NULL;
|
|
|
|
KASSERT(to && from,
|
|
("m_tag_copy_chain: null argument, to %p from %p", to, from));
|
|
m_tag_delete_chain(to, NULL);
|
|
SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) {
|
|
t = m_tag_copy(p, how);
|
|
if (t == NULL) {
|
|
m_tag_delete_chain(to, NULL);
|
|
return 0;
|
|
}
|
|
if (tprev == NULL)
|
|
SLIST_INSERT_HEAD(&to->m_pkthdr.tags, t, m_tag_link);
|
|
else
|
|
SLIST_INSERT_AFTER(tprev, t, m_tag_link);
|
|
tprev = t;
|
|
}
|
|
return 1;
|
|
}
|