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a4adf6cc65
r354748-354750 replaced the KAME macros with m_pulldown() calls. Contrary to the rest of the network stack m_len checks before m_pulldown() were not put in placed (see r354748). Put these m_len checks in place for now (to go along with the style of the network stack since the initial commits). These are not put in for performance but to avoid an error scenario (even though it also will help performance at the moment as it avoid allocating an extra mbuf; not because of the unconditional function call). The observed error case went like this: (1) an mbuf with M_EXT arrives and we call m_pullup() unconditionally on it. (2) m_pullup() will call m_get() unless the requested length is larger than MHLEN (in which case it'll m_freem() the perfectly fine mbuf) and migrate the requested length of data and pkthdr into the new mbuf. (3) If m_get() succeeds, a further m_pullup() call going over MHLEN will fail. This was observed with failing auto-configuration as an RA packet of 200 bytes exceeded MHLEN and the m_pullup() called from nd6_ra_input() dropped the mbuf. (Re-)adding the m_len checks before m_pullup() calls avoids this problems with mbufs using external storage for now. MFC after: 3 weeks Sponsored by: Netflix
136 lines
3.7 KiB
C
136 lines
3.7 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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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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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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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* $KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_inet.h"
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#include "opt_inet6.h"
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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/domain.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/ip6.h>
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#include <netinet6/ip6_var.h>
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#include <netinet/icmp6.h>
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/*
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* Destination options header processing.
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*/
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int
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dest6_input(struct mbuf **mp, int *offp, int proto)
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{
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struct mbuf *m;
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int off, dstoptlen, optlen;
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struct ip6_dest *dstopts;
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u_int8_t *opt;
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m = *mp;
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off = *offp;
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/* Validation of the length of the header. */
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if (m->m_len < off + sizeof(*dstopts)) {
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m = m_pullup(m, off + sizeof(*dstopts));
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if (m == NULL) {
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IP6STAT_INC(ip6s_exthdrtoolong);
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*mp = m;
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return (IPPROTO_DONE);
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}
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}
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dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
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dstoptlen = (dstopts->ip6d_len + 1) << 3;
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if (m->m_len < off + dstoptlen) {
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m = m_pullup(m, off + dstoptlen);
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if (m == NULL) {
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IP6STAT_INC(ip6s_exthdrtoolong);
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*mp = m;
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return (IPPROTO_DONE);
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}
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}
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dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
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off += dstoptlen;
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dstoptlen -= sizeof(struct ip6_dest);
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opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
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/* search header for all options. */
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for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
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if (*opt != IP6OPT_PAD1 &&
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(dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
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IP6STAT_INC(ip6s_toosmall);
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goto bad;
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}
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switch (*opt) {
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case IP6OPT_PAD1:
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optlen = 1;
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break;
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case IP6OPT_PADN:
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optlen = *(opt + 1) + 2;
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break;
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default: /* unknown option */
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optlen = ip6_unknown_opt(opt, m,
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opt - mtod(m, u_int8_t *));
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if (optlen == -1) {
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*mp = NULL;
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return (IPPROTO_DONE);
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}
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optlen += 2;
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break;
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}
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}
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*offp = off;
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*mp = m;
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return (dstopts->ip6d_nxt);
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bad:
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m_freem(m);
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*mp = NULL;
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return (IPPROTO_DONE);
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}
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