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bf18dfa28e
Don't assume M_PKTHDR is set only on the first mbuf of the chain. The check is replaced by (m1 != m), which is equivalent to the previous code: we want to modify m->m_pkthdr.len only when 'm' was not passed in m_adj(). Fix a pretty bad mistake, that has always been there: m_adj(m1, -(m1->m_len - roff)); if (m1 != m) m->m_pkthdr.len -= (m1->m_len - roff); This is wrong: m_adj() will modify m1->m_len, so we're using a wrong value when manually adjusting m->m_pkthdr.len. Reported by: Maxime Villard <max at m00nbsd dot net> Obtained from: NetBSD MFC after: 1 week
344 lines
8.5 KiB
C
344 lines
8.5 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* IPsec-specific mbuf routines.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netipsec/ipsec.h>
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/*
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* Make space for a new header of length hlen at skip bytes
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* into the packet. When doing this we allocate new mbufs only
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* when absolutely necessary. The mbuf where the new header
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* is to go is returned together with an offset into the mbuf.
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* If NULL is returned then the mbuf chain may have been modified;
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* the caller is assumed to always free the chain.
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*/
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struct mbuf *
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m_makespace(struct mbuf *m0, int skip, int hlen, int *off)
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{
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struct mbuf *m;
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unsigned remain;
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IPSEC_ASSERT(m0 != NULL, ("null mbuf"));
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IPSEC_ASSERT(hlen < MHLEN, ("hlen too big: %u", hlen));
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for (m = m0; m && skip > m->m_len; m = m->m_next)
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skip -= m->m_len;
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if (m == NULL)
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return (NULL);
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/*
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* At this point skip is the offset into the mbuf m
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* where the new header should be placed. Figure out
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* if there's space to insert the new header. If so,
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* and copying the remainder makes sense then do so.
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* Otherwise insert a new mbuf in the chain, splitting
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* the contents of m as needed.
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*/
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remain = m->m_len - skip; /* data to move */
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if (remain > skip &&
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hlen + max_linkhdr < M_LEADINGSPACE(m)) {
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/*
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* mbuf has enough free space at the beginning.
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* XXX: which operation is the most heavy - copying of
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* possible several hundred of bytes or allocation
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* of new mbuf? We can remove max_linkhdr check
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* here, but it is possible that this will lead
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* to allocation of new mbuf in Layer 2 code.
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*/
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m->m_data -= hlen;
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bcopy(mtodo(m, hlen), mtod(m, caddr_t), skip);
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m->m_len += hlen;
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*off = skip;
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} else if (hlen > M_TRAILINGSPACE(m)) {
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struct mbuf *n0, *n, **np;
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int todo, len, done, alloc;
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n0 = NULL;
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np = &n0;
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alloc = 0;
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done = 0;
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todo = remain;
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while (todo > 0) {
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if (todo > MHLEN) {
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n = m_getcl(M_NOWAIT, m->m_type, 0);
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len = MCLBYTES;
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}
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else {
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n = m_get(M_NOWAIT, m->m_type);
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len = MHLEN;
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}
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if (n == NULL) {
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m_freem(n0);
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return NULL;
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}
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*np = n;
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np = &n->m_next;
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alloc++;
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len = min(todo, len);
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memcpy(n->m_data, mtod(m, char *) + skip + done, len);
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n->m_len = len;
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done += len;
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todo -= len;
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}
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if (hlen <= M_TRAILINGSPACE(m) + remain) {
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m->m_len = skip + hlen;
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*off = skip;
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if (n0 != NULL) {
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*np = m->m_next;
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m->m_next = n0;
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}
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}
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else {
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n = m_get(M_NOWAIT, m->m_type);
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if (n == NULL) {
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m_freem(n0);
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return NULL;
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}
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alloc++;
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if ((n->m_next = n0) == NULL)
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np = &n->m_next;
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n0 = n;
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*np = m->m_next;
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m->m_next = n0;
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n->m_len = hlen;
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m->m_len = skip;
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m = n; /* header is at front ... */
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*off = 0; /* ... of new mbuf */
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}
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IPSECSTAT_INC(ips_mbinserted);
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} else {
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/*
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* Copy the remainder to the back of the mbuf
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* so there's space to write the new header.
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*/
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bcopy(mtod(m, caddr_t) + skip,
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mtod(m, caddr_t) + skip + hlen, remain);
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m->m_len += hlen;
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*off = skip;
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}
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m0->m_pkthdr.len += hlen; /* adjust packet length */
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return m;
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}
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/*
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* m_pad(m, n) pads <m> with <n> bytes at the end. The packet header
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* length is updated, and a pointer to the first byte of the padding
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* (which is guaranteed to be all in one mbuf) is returned.
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*/
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caddr_t
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m_pad(struct mbuf *m, int n)
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{
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struct mbuf *m0, *m1;
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int len, pad;
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caddr_t retval;
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if (n <= 0) { /* No stupid arguments. */
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DPRINTF(("%s: pad length invalid (%d)\n", __func__, n));
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m_freem(m);
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return NULL;
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}
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len = m->m_pkthdr.len;
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pad = n;
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m0 = m;
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while (m0->m_len < len) {
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len -= m0->m_len;
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m0 = m0->m_next;
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}
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if (m0->m_len != len) {
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DPRINTF(("%s: length mismatch (should be %d instead of %d)\n",
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__func__, m->m_pkthdr.len,
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m->m_pkthdr.len + m0->m_len - len));
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m_freem(m);
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return NULL;
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}
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/* Check for zero-length trailing mbufs, and find the last one. */
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for (m1 = m0; m1->m_next; m1 = m1->m_next) {
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if (m1->m_next->m_len != 0) {
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DPRINTF(("%s: length mismatch (should be %d instead "
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"of %d)\n", __func__,
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m->m_pkthdr.len,
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m->m_pkthdr.len + m1->m_next->m_len));
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m_freem(m);
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return NULL;
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}
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m0 = m1->m_next;
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}
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if (pad > M_TRAILINGSPACE(m0)) {
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/* Add an mbuf to the chain. */
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MGET(m1, M_NOWAIT, MT_DATA);
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if (m1 == NULL) {
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m_freem(m0);
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DPRINTF(("%s: unable to get extra mbuf\n", __func__));
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return NULL;
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}
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m0->m_next = m1;
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m0 = m1;
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m0->m_len = 0;
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}
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retval = m0->m_data + m0->m_len;
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m0->m_len += pad;
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m->m_pkthdr.len += pad;
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return retval;
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}
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/*
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* Remove hlen data at offset skip in the packet. This is used by
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* the protocols strip protocol headers and associated data (e.g. IV,
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* authenticator) on input.
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*/
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int
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m_striphdr(struct mbuf *m, int skip, int hlen)
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{
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struct mbuf *m1;
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int roff;
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/* Find beginning of header */
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m1 = m_getptr(m, skip, &roff);
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if (m1 == NULL)
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return (EINVAL);
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/* Remove the header and associated data from the mbuf. */
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if (roff == 0) {
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/* The header was at the beginning of the mbuf */
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IPSECSTAT_INC(ips_input_front);
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m_adj(m1, hlen);
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if (m1 != m)
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m->m_pkthdr.len -= hlen;
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} else if (roff + hlen >= m1->m_len) {
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struct mbuf *mo;
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int adjlen;
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/*
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* Part or all of the header is at the end of this mbuf,
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* so first let's remove the remainder of the header from
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* the beginning of the remainder of the mbuf chain, if any.
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*/
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IPSECSTAT_INC(ips_input_end);
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if (roff + hlen > m1->m_len) {
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adjlen = roff + hlen - m1->m_len;
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/* Adjust the next mbuf by the remainder */
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m_adj(m1->m_next, adjlen);
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/* The second mbuf is guaranteed not to have a pkthdr... */
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m->m_pkthdr.len -= adjlen;
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}
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/* Now, let's unlink the mbuf chain for a second...*/
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mo = m1->m_next;
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m1->m_next = NULL;
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/* ...and trim the end of the first part of the chain...sick */
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adjlen = m1->m_len - roff;
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m_adj(m1, -adjlen);
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if (m1 != m)
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m->m_pkthdr.len -= adjlen;
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/* Finally, let's relink */
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m1->m_next = mo;
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} else {
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/*
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* The header lies in the "middle" of the mbuf; copy
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* the remainder of the mbuf down over the header.
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*/
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IPSECSTAT_INC(ips_input_middle);
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bcopy(mtod(m1, u_char *) + roff + hlen,
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mtod(m1, u_char *) + roff,
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m1->m_len - (roff + hlen));
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m1->m_len -= hlen;
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m->m_pkthdr.len -= hlen;
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}
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return (0);
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}
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/*
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* Diagnostic routine to check mbuf alignment as required by the
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* crypto device drivers (that use DMA).
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*/
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void
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m_checkalignment(const char* where, struct mbuf *m0, int off, int len)
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{
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int roff;
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struct mbuf *m = m_getptr(m0, off, &roff);
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caddr_t addr;
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if (m == NULL)
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return;
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printf("%s (off %u len %u): ", where, off, len);
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addr = mtod(m, caddr_t) + roff;
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do {
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int mlen;
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if (((uintptr_t) addr) & 3) {
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printf("addr misaligned %p,", addr);
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break;
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}
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mlen = m->m_len;
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if (mlen > len)
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mlen = len;
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len -= mlen;
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if (len && (mlen & 3)) {
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printf("len mismatch %u,", mlen);
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break;
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}
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m = m->m_next;
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addr = m ? mtod(m, caddr_t) : NULL;
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} while (m && len > 0);
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for (m = m0; m; m = m->m_next)
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printf(" [%p:%u]", mtod(m, caddr_t), m->m_len);
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printf("\n");
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}
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