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dest6.c revision 1.2 
      1 /*
      2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. Neither the name of the project nor the names of its contributors
     14  *    may be used to endorse or promote products derived from this software
     15  *    without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     27  * SUCH DAMAGE.
     28  */
     29 
     30 #include <sys/param.h>
     31 #include <sys/systm.h>
     32 #include <sys/malloc.h>
     33 #include <sys/mbuf.h>
     34 #include <sys/domain.h>
     35 #include <sys/protosw.h>
     36 #include <sys/socket.h>
     37 #include <sys/errno.h>
     38 #include <sys/time.h>
     39 #include <sys/kernel.h>
     40 
     41 #include <net/if.h>
     42 #include <net/route.h>
     43 
     44 #include <netinet/in.h>
     45 #include <netinet/in_var.h>
     46 #include <netinet6/in6_systm.h>
     47 #include <netinet6/ip6.h>
     48 #if !defined(__FreeBSD__) || __FreeBSD__ < 3
     49 #include <netinet6/in6_pcb.h>
     50 #endif
     51 #include <netinet6/ip6_var.h>
     52 #include <netinet6/icmp6.h>
     53 
     54 /*
     55  * Destination options header processing.
     56  */
     57 int
     58 dest6_input(mp, offp, proto)
     59 	struct mbuf **mp;
     60 	int *offp, proto;
     61 {
     62 	register struct mbuf *m = *mp;
     63 	int off = *offp, dstoptlen, optlen;
     64 	struct ip6_dest *dstopts;
     65 	u_int8_t *opt;
     66 
     67 	/* validation of the length of the header */
     68 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
     69 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
     70 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
     71 
     72 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
     73 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
     74 	off += dstoptlen;
     75 	dstoptlen -= sizeof(struct ip6_dest);
     76 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
     77 
     78 	/* search header for all options. */
     79 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
     80 		switch(*opt) {
     81 		 case IP6OPT_PAD1:
     82 			 optlen = 1;
     83 			 break;
     84 		 case IP6OPT_PADN:
     85 			 if (dstoptlen < IP6OPT_MINLEN) {
     86 				 ip6stat.ip6s_toosmall++;
     87 				 goto bad;
     88 			 }
     89 			 optlen = *(opt + 1) + 2;
     90 			 break;
     91 		 default:		/* unknown option */
     92 			 if (dstoptlen < IP6OPT_MINLEN) {
     93 				 ip6stat.ip6s_toosmall++;
     94 				 goto bad;
     95 			 }
     96 			 if ((optlen = ip6_unknown_opt(opt, m,
     97 						       opt-mtod(m, u_int8_t *))) == -1)
     98 				 return(IPPROTO_DONE);
     99 			 optlen += 2;
    100 			 break;
    101 		}
    102 	}
    103 
    104 	*offp = off;
    105 	return(dstopts->ip6d_nxt);
    106 
    107   bad:
    108 	m_freem(m);
    109 	return(IPPROTO_DONE);
    110 }
    111