freebsd-nq/sys/netinet6/dest6.c
Jonathan T. Looney c187c03466 Remove some unneccessary variable sets in IPv6 code, as detected by
clang's static analyzer.

Reviewed by:	bz
MFC after:	2 weeks
Sponsored by:	Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D10940
2018-03-24 12:43:34 +00:00

127 lines
3.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 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.
*
* $KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
/*
* Destination options header processing.
*/
int
dest6_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp;
int off = *offp, dstoptlen, optlen;
struct ip6_dest *dstopts;
u_int8_t *opt;
/* validation of the length of the header */
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
if (dstopts == NULL)
return IPPROTO_DONE;
#endif
dstoptlen = (dstopts->ip6d_len + 1) << 3;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
if (dstopts == NULL)
return IPPROTO_DONE;
#endif
off += dstoptlen;
dstoptlen -= sizeof(struct ip6_dest);
opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
/* search header for all options. */
for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
if (*opt != IP6OPT_PAD1 &&
(dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
IP6STAT_INC(ip6s_toosmall);
goto bad;
}
switch (*opt) {
case IP6OPT_PAD1:
optlen = 1;
break;
case IP6OPT_PADN:
optlen = *(opt + 1) + 2;
break;
default: /* unknown option */
optlen = ip6_unknown_opt(opt, m,
opt - mtod(m, u_int8_t *));
if (optlen == -1)
return (IPPROTO_DONE);
optlen += 2;
break;
}
}
*offp = off;
return (dstopts->ip6d_nxt);
bad:
m_freem(m);
return (IPPROTO_DONE);
}