fa24e6f3f8
mbuf chains which are recycled (e.g., ICMP reflection, loopback interface). A consensus was reached that such recycled packets should behave (more-or-less) the same way if a new chain had been allocated and the contents copied to that chain. Some packet tags may in future be marked as "persistent" (e.g., for mandatory access controls) and should persist across such deletion. NetBSD as yet hos no persistent tags, so m_tag_delete_nonpersistent() just deletes all tags. This should not be relied upon.
383 lines
10 KiB
C
383 lines
10 KiB
C
/* $NetBSD: uipc_mbuf2.c,v 1.16 2003/11/13 01:48:12 jonathan Exp $ */
|
|
/* $KAME: uipc_mbuf2.c,v 1.29 2001/02/14 13:42:10 itojun 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. 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>
|
|
__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf2.c,v 1.16 2003/11/13 01:48:12 jonathan Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
|
|
MALLOC_DEFINE(M_PACKET_TAGS, "packet tags", "Packet-attached information");
|
|
|
|
/*
|
|
* 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(struct mbuf *m, int off, int 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 */
|
|
}
|
|
|
|
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 */
|
|
}
|
|
|
|
sharedcluster = M_READONLY(n);
|
|
|
|
/*
|
|
* 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 && !sharedcluster)
|
|
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_dup(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 &&
|
|
!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;
|
|
memcpy(mtod(n->m_next, caddr_t), mtod(n, caddr_t) + off, 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;
|
|
memcpy(mtod(o, caddr_t), mtod(n, caddr_t) + off, 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:
|
|
if (offp)
|
|
*offp = off;
|
|
return n;
|
|
}
|
|
|
|
/* Get a packet tag structure along with specified data following. */
|
|
struct m_tag *
|
|
m_tag_get(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);
|
|
t->m_tag_id = type;
|
|
t->m_tag_len = len;
|
|
return (t);
|
|
}
|
|
|
|
/* Free a packet tag. */
|
|
void
|
|
m_tag_free(struct m_tag *t)
|
|
{
|
|
|
|
free(t, M_PACKET_TAGS);
|
|
}
|
|
|
|
/* Prepend a packet tag. */
|
|
void
|
|
m_tag_prepend(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
|
|
SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
|
|
}
|
|
|
|
/* Unlink a packet tag. */
|
|
void
|
|
m_tag_unlink(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
|
|
SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
|
|
}
|
|
|
|
/* Unlink and free a packet tag. */
|
|
void
|
|
m_tag_delete(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
|
|
m_tag_unlink(m, t);
|
|
m_tag_free(t);
|
|
}
|
|
|
|
/* Unlink and free a packet tag chain, starting from given tag. */
|
|
__inline void
|
|
m_tag_delete_chain(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
struct m_tag *p, *q;
|
|
|
|
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)
|
|
{
|
|
/* NetBSD has no persistent tags yet, so just delete all tags. */
|
|
return m_tag_delete_chain(m, NULL);
|
|
}
|
|
|
|
|
|
/* Find a tag, starting from a given position. */
|
|
struct m_tag *
|
|
m_tag_find(struct mbuf *m, int type, struct m_tag *t)
|
|
{
|
|
struct m_tag *p;
|
|
|
|
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_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)
|
|
{
|
|
struct m_tag *p;
|
|
|
|
p = m_tag_get(t->m_tag_id, t->m_tag_len, M_NOWAIT);
|
|
if (p == NULL)
|
|
return (NULL);
|
|
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)
|
|
{
|
|
struct m_tag *p, *t, *tprev = NULL;
|
|
|
|
m_tag_delete_chain(to, NULL);
|
|
SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) {
|
|
t = m_tag_copy(p);
|
|
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);
|
|
}
|
|
|
|
/* Initialize tags on an mbuf. */
|
|
void
|
|
m_tag_init(struct mbuf *m)
|
|
{
|
|
|
|
SLIST_INIT(&m->m_pkthdr.tags);
|
|
}
|
|
|
|
/* Get first tag in chain. */
|
|
struct m_tag *
|
|
m_tag_first(struct mbuf *m)
|
|
{
|
|
|
|
return (SLIST_FIRST(&m->m_pkthdr.tags));
|
|
}
|
|
|
|
/* Get next tag in chain. */
|
|
struct m_tag *
|
|
m_tag_next(struct mbuf *m, struct m_tag *t)
|
|
{
|
|
|
|
return (SLIST_NEXT(t, m_tag_link));
|
|
}
|