freebsd-dev/sys/netipsec/ipsec_mbuf.c
Robert Watson 530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00

328 lines
8.0 KiB
C

/*-
* Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
/*
* IPsec-specific mbuf routines.
*/
#include "opt_param.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netipsec/ipsec.h>
/*
* Make space for a new header of length hlen at skip bytes
* into the packet. When doing this we allocate new mbufs only
* when absolutely necessary. The mbuf where the new header
* is to go is returned together with an offset into the mbuf.
* If NULL is returned then the mbuf chain may have been modified;
* the caller is assumed to always free the chain.
*/
struct mbuf *
m_makespace(struct mbuf *m0, int skip, int hlen, int *off)
{
struct mbuf *m;
unsigned remain;
IPSEC_ASSERT(m0 != NULL, ("null mbuf"));
IPSEC_ASSERT(hlen < MHLEN, ("hlen too big: %u", hlen));
for (m = m0; m && skip > m->m_len; m = m->m_next)
skip -= m->m_len;
if (m == NULL)
return (NULL);
/*
* At this point skip is the offset into the mbuf m
* where the new header should be placed. Figure out
* if there's space to insert the new header. If so,
* and copying the remainder makese sense then do so.
* Otherwise insert a new mbuf in the chain, splitting
* the contents of m as needed.
*/
remain = m->m_len - skip; /* data to move */
if (hlen > M_TRAILINGSPACE(m)) {
struct mbuf *n0, *n, **np;
int todo, len, done, alloc;
n0 = NULL;
np = &n0;
alloc = 0;
done = 0;
todo = remain;
while (todo > 0) {
if (todo > MHLEN) {
n = m_getcl(M_DONTWAIT, m->m_type, 0);
len = MCLBYTES;
}
else {
n = m_get(M_DONTWAIT, m->m_type);
len = MHLEN;
}
if (n == NULL) {
m_freem(n0);
return NULL;
}
*np = n;
np = &n->m_next;
alloc++;
len = min(todo, len);
memcpy(n->m_data, mtod(m, char *) + skip + done, len);
n->m_len = len;
done += len;
todo -= len;
}
if (hlen <= M_TRAILINGSPACE(m) + remain) {
m->m_len = skip + hlen;
*off = skip;
if (n0 != NULL) {
*np = m->m_next;
m->m_next = n0;
}
}
else {
n = m_get(M_DONTWAIT, m->m_type);
if (n == NULL) {
m_freem(n0);
return NULL;
}
alloc++;
if ((n->m_next = n0) == NULL)
np = &n->m_next;
n0 = n;
*np = m->m_next;
m->m_next = n0;
n->m_len = hlen;
m->m_len = skip;
m = n; /* header is at front ... */
*off = 0; /* ... of new mbuf */
}
V_ipsec4stat.ips_mbinserted++;
} else {
/*
* Copy the remainder to the back of the mbuf
* so there's space to write the new header.
*/
bcopy(mtod(m, caddr_t) + skip,
mtod(m, caddr_t) + skip + hlen, remain);
m->m_len += hlen;
*off = skip;
}
m0->m_pkthdr.len += hlen; /* adjust packet length */
return m;
}
/*
* m_pad(m, n) pads <m> with <n> bytes at the end. The packet header
* length is updated, and a pointer to the first byte of the padding
* (which is guaranteed to be all in one mbuf) is returned.
*/
caddr_t
m_pad(struct mbuf *m, int n)
{
register struct mbuf *m0, *m1;
register int len, pad;
caddr_t retval;
if (n <= 0) { /* No stupid arguments. */
DPRINTF(("%s: pad length invalid (%d)\n", __func__, n));
m_freem(m);
return NULL;
}
len = m->m_pkthdr.len;
pad = n;
m0 = m;
while (m0->m_len < len) {
len -= m0->m_len;
m0 = m0->m_next;
}
if (m0->m_len != len) {
DPRINTF(("%s: length mismatch (should be %d instead of %d)\n",
__func__, m->m_pkthdr.len,
m->m_pkthdr.len + m0->m_len - len));
m_freem(m);
return NULL;
}
/* Check for zero-length trailing mbufs, and find the last one. */
for (m1 = m0; m1->m_next; m1 = m1->m_next) {
if (m1->m_next->m_len != 0) {
DPRINTF(("%s: length mismatch (should be %d instead "
"of %d)\n", __func__,
m->m_pkthdr.len,
m->m_pkthdr.len + m1->m_next->m_len));
m_freem(m);
return NULL;
}
m0 = m1->m_next;
}
if (pad > M_TRAILINGSPACE(m0)) {
/* Add an mbuf to the chain. */
MGET(m1, M_DONTWAIT, MT_DATA);
if (m1 == 0) {
m_freem(m0);
DPRINTF(("%s: unable to get extra mbuf\n", __func__));
return NULL;
}
m0->m_next = m1;
m0 = m1;
m0->m_len = 0;
}
retval = m0->m_data + m0->m_len;
m0->m_len += pad;
m->m_pkthdr.len += pad;
return retval;
}
/*
* Remove hlen data at offset skip in the packet. This is used by
* the protocols strip protocol headers and associated data (e.g. IV,
* authenticator) on input.
*/
int
m_striphdr(struct mbuf *m, int skip, int hlen)
{
struct mbuf *m1;
int roff;
/* Find beginning of header */
m1 = m_getptr(m, skip, &roff);
if (m1 == NULL)
return (EINVAL);
/* Remove the header and associated data from the mbuf. */
if (roff == 0) {
/* The header was at the beginning of the mbuf */
V_ipsec4stat.ips_input_front++;
m_adj(m1, hlen);
if ((m1->m_flags & M_PKTHDR) == 0)
m->m_pkthdr.len -= hlen;
} else if (roff + hlen >= m1->m_len) {
struct mbuf *mo;
/*
* Part or all of the header is at the end of this mbuf,
* so first let's remove the remainder of the header from
* the beginning of the remainder of the mbuf chain, if any.
*/
V_ipsec4stat.ips_input_end++;
if (roff + hlen > m1->m_len) {
/* Adjust the next mbuf by the remainder */
m_adj(m1->m_next, roff + hlen - m1->m_len);
/* The second mbuf is guaranteed not to have a pkthdr... */
m->m_pkthdr.len -= (roff + hlen - m1->m_len);
}
/* Now, let's unlink the mbuf chain for a second...*/
mo = m1->m_next;
m1->m_next = NULL;
/* ...and trim the end of the first part of the chain...sick */
m_adj(m1, -(m1->m_len - roff));
if ((m1->m_flags & M_PKTHDR) == 0)
m->m_pkthdr.len -= (m1->m_len - roff);
/* Finally, let's relink */
m1->m_next = mo;
} else {
/*
* The header lies in the "middle" of the mbuf; copy
* the remainder of the mbuf down over the header.
*/
V_ipsec4stat.ips_input_middle++;
bcopy(mtod(m1, u_char *) + roff + hlen,
mtod(m1, u_char *) + roff,
m1->m_len - (roff + hlen));
m1->m_len -= hlen;
m->m_pkthdr.len -= hlen;
}
return (0);
}
/*
* Diagnostic routine to check mbuf alignment as required by the
* crypto device drivers (that use DMA).
*/
void
m_checkalignment(const char* where, struct mbuf *m0, int off, int len)
{
int roff;
struct mbuf *m = m_getptr(m0, off, &roff);
caddr_t addr;
if (m == NULL)
return;
printf("%s (off %u len %u): ", where, off, len);
addr = mtod(m, caddr_t) + roff;
do {
int mlen;
if (((uintptr_t) addr) & 3) {
printf("addr misaligned %p,", addr);
break;
}
mlen = m->m_len;
if (mlen > len)
mlen = len;
len -= mlen;
if (len && (mlen & 3)) {
printf("len mismatch %u,", mlen);
break;
}
m = m->m_next;
addr = m ? mtod(m, caddr_t) : NULL;
} while (m && len > 0);
for (m = m0; m; m = m->m_next)
printf(" [%p:%u]", mtod(m, caddr_t), m->m_len);
printf("\n");
}