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1636 lines
40 KiB
C
1636 lines
40 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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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* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
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* $Id: ip_input.c,v 1.109 1998/12/14 18:09:13 luigi Exp $
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* $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $
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*/
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#define _IP_VHL
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#include "opt_bootp.h"
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#include "opt_ipfw.h"
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#include "opt_ipdn.h"
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#include "opt_ipdivert.h"
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#include "opt_ipfilter.h"
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#include <stddef.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.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/time.h>
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#include <sys/kernel.h>
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#include <sys/syslog.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/if_dl.h>
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#include <net/route.h>
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#include <net/netisr.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_var.h>
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#include <netinet/ip.h>
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#include <netinet/in_pcb.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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#include <machine/in_cksum.h>
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#include <sys/socketvar.h>
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#ifdef IPFIREWALL
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#include <netinet/ip_fw.h>
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#endif
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#ifdef DUMMYNET
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#include <netinet/ip_dummynet.h>
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#endif
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int rsvp_on = 0;
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static int ip_rsvp_on;
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struct socket *ip_rsvpd;
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int ipforwarding = 0;
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SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
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&ipforwarding, 0, "");
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static int ipsendredirects = 1; /* XXX */
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SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
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&ipsendredirects, 0, "");
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int ip_defttl = IPDEFTTL;
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SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
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&ip_defttl, 0, "");
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static int ip_dosourceroute = 0;
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SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
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&ip_dosourceroute, 0, "");
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static int ip_acceptsourceroute = 0;
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SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
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CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
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#ifdef DIAGNOSTIC
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static int ipprintfs = 0;
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#endif
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extern struct domain inetdomain;
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extern struct protosw inetsw[];
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u_char ip_protox[IPPROTO_MAX];
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static int ipqmaxlen = IFQ_MAXLEN;
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struct in_ifaddrhead in_ifaddrhead; /* first inet address */
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struct ifqueue ipintrq;
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SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
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&ipintrq.ifq_maxlen, 0, "");
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SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
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&ipintrq.ifq_drops, 0, "");
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struct ipstat ipstat;
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SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RD,
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&ipstat, ipstat, "");
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/* Packet reassembly stuff */
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#define IPREASS_NHASH_LOG2 6
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#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
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#define IPREASS_HMASK (IPREASS_NHASH - 1)
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#define IPREASS_HASH(x,y) \
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((((x) & 0xF | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
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static struct ipq ipq[IPREASS_NHASH];
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static int nipq = 0; /* total # of reass queues */
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static int maxnipq;
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#ifdef IPCTL_DEFMTU
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SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
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&ip_mtu, 0, "");
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#endif
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#if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1
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#undef COMPAT_IPFW
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#define COMPAT_IPFW 1
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#else
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#undef COMPAT_IPFW
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#endif
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#ifdef COMPAT_IPFW
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#include <netinet/ip_fw.h>
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/* Firewall hooks */
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ip_fw_chk_t *ip_fw_chk_ptr;
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ip_fw_ctl_t *ip_fw_ctl_ptr;
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#ifdef DUMMYNET
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ip_dn_ctl_t *ip_dn_ctl_ptr;
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#endif
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/* IP Network Address Translation (NAT) hooks */
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ip_nat_t *ip_nat_ptr;
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ip_nat_ctl_t *ip_nat_ctl_ptr;
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#endif
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#if defined(IPFILTER_LKM) || defined(IPFILTER)
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int iplattach __P((void));
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int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)) = NULL;
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#endif
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/*
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* We need to save the IP options in case a protocol wants to respond
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* to an incoming packet over the same route if the packet got here
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* using IP source routing. This allows connection establishment and
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* maintenance when the remote end is on a network that is not known
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* to us.
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*/
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static int ip_nhops = 0;
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static struct ip_srcrt {
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struct in_addr dst; /* final destination */
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char nop; /* one NOP to align */
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char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
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struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
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} ip_srcrt;
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#ifdef IPDIVERT
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/*
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* Shared variable between ip_input() and ip_reass() to communicate
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* about which packets, once assembled from fragments, get diverted,
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* and to which port.
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*/
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static u_short frag_divert_port;
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#endif
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struct sockaddr_in *ip_fw_fwd_addr;
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static void save_rte __P((u_char *, struct in_addr));
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static int ip_dooptions __P((struct mbuf *));
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static void ip_forward __P((struct mbuf *, int));
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static void ip_freef __P((struct ipq *));
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static struct ip *
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ip_reass __P((struct mbuf *, struct ipq *, struct ipq *));
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static struct in_ifaddr *
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ip_rtaddr __P((struct in_addr));
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static void ipintr __P((void));
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/*
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* IP initialization: fill in IP protocol switch table.
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* All protocols not implemented in kernel go to raw IP protocol handler.
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*/
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void
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ip_init()
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{
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register struct protosw *pr;
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register int i;
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TAILQ_INIT(&in_ifaddrhead);
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pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
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if (pr == 0)
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panic("ip_init");
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for (i = 0; i < IPPROTO_MAX; i++)
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ip_protox[i] = pr - inetsw;
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for (pr = inetdomain.dom_protosw;
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pr < inetdomain.dom_protoswNPROTOSW; pr++)
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if (pr->pr_domain->dom_family == PF_INET &&
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pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
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ip_protox[pr->pr_protocol] = pr - inetsw;
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for (i = 0; i < IPREASS_NHASH; i++)
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ipq[i].next = ipq[i].prev = &ipq[i];
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maxnipq = nmbclusters/4;
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ip_id = time_second & 0xffff;
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ipintrq.ifq_maxlen = ipqmaxlen;
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#ifdef DUMMYNET
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ip_dn_init();
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#endif
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#ifdef IPNAT
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ip_nat_init();
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#endif
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#ifdef IPFILTER
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iplattach();
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#endif
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}
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static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
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static struct route ipforward_rt;
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/*
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* Ip input routine. Checksum and byte swap header. If fragmented
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* try to reassemble. Process options. Pass to next level.
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*/
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void
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ip_input(struct mbuf *m)
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{
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struct ip *ip;
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struct ipq *fp;
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struct in_ifaddr *ia;
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int i, hlen, mff;
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u_short sum;
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#ifndef IPDIVERT /* dummy variable for the firewall code to play with */
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u_short ip_divert_cookie = 0 ;
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#endif
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#ifdef COMPAT_IPFW
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struct ip_fw_chain *rule = NULL ;
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#endif
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#if defined(IPFIREWALL) && defined(DUMMYNET)
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/*
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* dummynet packet are prepended a vestigial mbuf with
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* m_type = MT_DUMMYNET and m_data pointing to the matching
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* rule.
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*/
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if (m->m_type == MT_DUMMYNET) {
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struct mbuf *m0 = m ;
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rule = (struct ip_fw_chain *)(m->m_data) ;
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m = m->m_next ;
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free(m0, M_IPFW);
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ip = mtod(m, struct ip *);
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hlen = IP_VHL_HL(ip->ip_vhl) << 2;
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goto iphack ;
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} else
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rule = NULL ;
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#endif
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#ifdef DIAGNOSTIC
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if (m == NULL || (m->m_flags & M_PKTHDR) == 0)
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panic("ip_input no HDR");
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#endif
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/*
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* If no IP addresses have been set yet but the interfaces
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* are receiving, can't do anything with incoming packets yet.
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* XXX This is broken! We should be able to receive broadcasts
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* and multicasts even without any local addresses configured.
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*/
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if (TAILQ_EMPTY(&in_ifaddrhead))
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goto bad;
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ipstat.ips_total++;
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if (m->m_pkthdr.len < sizeof(struct ip))
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goto tooshort;
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if (m->m_len < sizeof (struct ip) &&
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(m = m_pullup(m, sizeof (struct ip))) == 0) {
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ipstat.ips_toosmall++;
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return;
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}
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ip = mtod(m, struct ip *);
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if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
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ipstat.ips_badvers++;
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goto bad;
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}
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hlen = IP_VHL_HL(ip->ip_vhl) << 2;
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if (hlen < sizeof(struct ip)) { /* minimum header length */
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ipstat.ips_badhlen++;
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goto bad;
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}
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if (hlen > m->m_len) {
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if ((m = m_pullup(m, hlen)) == 0) {
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ipstat.ips_badhlen++;
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return;
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}
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ip = mtod(m, struct ip *);
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}
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if (hlen == sizeof(struct ip)) {
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sum = in_cksum_hdr(ip);
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} else {
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sum = in_cksum(m, hlen);
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}
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if (sum) {
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ipstat.ips_badsum++;
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goto bad;
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}
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/*
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* Convert fields to host representation.
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*/
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NTOHS(ip->ip_len);
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if (ip->ip_len < hlen) {
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ipstat.ips_badlen++;
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goto bad;
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}
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NTOHS(ip->ip_id);
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NTOHS(ip->ip_off);
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/*
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* Check that the amount of data in the buffers
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* is as at least much as the IP header would have us expect.
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* Trim mbufs if longer than we expect.
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* Drop packet if shorter than we expect.
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*/
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if (m->m_pkthdr.len < ip->ip_len) {
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tooshort:
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ipstat.ips_tooshort++;
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goto bad;
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}
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if (m->m_pkthdr.len > ip->ip_len) {
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if (m->m_len == m->m_pkthdr.len) {
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m->m_len = ip->ip_len;
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m->m_pkthdr.len = ip->ip_len;
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} else
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m_adj(m, ip->ip_len - m->m_pkthdr.len);
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}
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/*
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* IpHack's section.
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* Right now when no processing on packet has done
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* and it is still fresh out of network we do our black
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* deals with it.
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* - Firewall: deny/allow/divert
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* - Xlate: translate packet's addr/port (NAT).
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* - Pipe: pass pkt through dummynet.
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* - Wrap: fake packet's addr/port <unimpl.>
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* - Encapsulate: put it in another IP and send out. <unimp.>
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*/
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iphack:
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#if defined(IPFILTER) || defined(IPFILTER_LKM)
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/*
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* Check if we want to allow this packet to be processed.
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* Consider it to be bad if not.
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*/
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if (fr_checkp) {
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struct mbuf *m1 = m;
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if ((*fr_checkp)(ip, hlen, m->m_pkthdr.rcvif, 0, &m1) || !m1)
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return;
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ip = mtod(m = m1, struct ip *);
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}
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#endif
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#ifdef COMPAT_IPFW
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if (ip_fw_chk_ptr) {
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#ifdef IPFIREWALL_FORWARD
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/*
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* If we've been forwarded from the output side, then
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* skip the firewall a second time
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*/
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if (ip_fw_fwd_addr)
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goto ours;
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#endif /* IPFIREWALL_FORWARD */
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i = (*ip_fw_chk_ptr)(&ip, hlen, NULL, &ip_divert_cookie,
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&m, &rule, &ip_fw_fwd_addr);
|
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/*
|
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* see the comment in ip_output for the return values
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* produced by the firewall.
|
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*/
|
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if (!m) /* packet discarded by firewall */
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return ;
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if (i == 0 && ip_fw_fwd_addr == NULL) /* common case */
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goto pass ;
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|
#ifdef DUMMYNET
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if (i & 0x10000) {
|
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/* send packet to the appropriate pipe */
|
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dummynet_io(i&0xffff,DN_TO_IP_IN,m,NULL,NULL,0, rule);
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return ;
|
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}
|
|
#endif
|
|
#ifdef IPDIVERT
|
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if (i > 0 && i < 0x10000) {
|
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/* Divert packet */
|
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frag_divert_port = i & 0xffff ;
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goto ours;
|
|
}
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
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if (i == 0 && ip_fw_fwd_addr != NULL)
|
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goto pass ;
|
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#endif
|
|
/*
|
|
* if we get here, the packet must be dropped
|
|
*/
|
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m_freem(m);
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return;
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}
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pass:
|
|
|
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if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN))
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return;
|
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#endif /* !COMPAT_IPFW */
|
|
|
|
/*
|
|
* Process options and, if not destined for us,
|
|
* ship it on. ip_dooptions returns 1 when an
|
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* error was detected (causing an icmp message
|
|
* to be sent and the original packet to be freed).
|
|
*/
|
|
ip_nhops = 0; /* for source routed packets */
|
|
if (hlen > sizeof (struct ip) && ip_dooptions(m))
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|
return;
|
|
|
|
/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
|
|
* matter if it is destined to another node, or whether it is
|
|
* a multicast one, RSVP wants it! and prevents it from being forwarded
|
|
* anywhere else. Also checks if the rsvp daemon is running before
|
|
* grabbing the packet.
|
|
*/
|
|
if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
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goto ours;
|
|
|
|
/*
|
|
* Check our list of addresses, to see if the packet is for us.
|
|
*/
|
|
for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
|
|
ia = TAILQ_NEXT(ia, ia_link)) {
|
|
#define satosin(sa) ((struct sockaddr_in *)(sa))
|
|
|
|
if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
|
|
goto ours;
|
|
#ifdef BOOTP_COMPAT
|
|
if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
|
|
goto ours;
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
|
|
/*
|
|
* If the addr to forward to is one of ours, we pretend to
|
|
* be the destination for this packet.
|
|
*/
|
|
if (ip_fw_fwd_addr != NULL &&
|
|
IA_SIN(ia)->sin_addr.s_addr ==
|
|
ip_fw_fwd_addr->sin_addr.s_addr)
|
|
goto ours;
|
|
#endif
|
|
if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
|
|
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
|
|
ip->ip_dst.s_addr)
|
|
goto ours;
|
|
if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
|
|
goto ours;
|
|
}
|
|
}
|
|
if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
|
|
struct in_multi *inm;
|
|
if (ip_mrouter) {
|
|
/*
|
|
* If we are acting as a multicast router, all
|
|
* incoming multicast packets are passed to the
|
|
* kernel-level multicast forwarding function.
|
|
* The packet is returned (relatively) intact; if
|
|
* ip_mforward() returns a non-zero value, the packet
|
|
* must be discarded, else it may be accepted below.
|
|
*
|
|
* (The IP ident field is put in the same byte order
|
|
* as expected when ip_mforward() is called from
|
|
* ip_output().)
|
|
*/
|
|
ip->ip_id = htons(ip->ip_id);
|
|
if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
ip->ip_id = ntohs(ip->ip_id);
|
|
|
|
/*
|
|
* The process-level routing demon needs to receive
|
|
* all multicast IGMP packets, whether or not this
|
|
* host belongs to their destination groups.
|
|
*/
|
|
if (ip->ip_p == IPPROTO_IGMP)
|
|
goto ours;
|
|
ipstat.ips_forward++;
|
|
}
|
|
/*
|
|
* See if we belong to the destination multicast group on the
|
|
* arrival interface.
|
|
*/
|
|
IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
|
|
if (inm == NULL) {
|
|
ipstat.ips_notmember++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
goto ours;
|
|
}
|
|
if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
|
|
goto ours;
|
|
if (ip->ip_dst.s_addr == INADDR_ANY)
|
|
goto ours;
|
|
|
|
/*
|
|
* Not for us; forward if possible and desirable.
|
|
*/
|
|
if (ipforwarding == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
} else
|
|
ip_forward(m, 0);
|
|
return;
|
|
|
|
ours:
|
|
|
|
/*
|
|
* If offset or IP_MF are set, must reassemble.
|
|
* Otherwise, nothing need be done.
|
|
* (We could look in the reassembly queue to see
|
|
* if the packet was previously fragmented,
|
|
* but it's not worth the time; just let them time out.)
|
|
*/
|
|
if (ip->ip_off & (IP_MF | IP_OFFMASK | IP_RF)) {
|
|
if (m->m_flags & M_EXT) { /* XXX */
|
|
if ((m = m_pullup(m, hlen)) == 0) {
|
|
ipstat.ips_toosmall++;
|
|
#ifdef IPDIVERT
|
|
frag_divert_port = 0;
|
|
ip_divert_cookie = 0;
|
|
#endif
|
|
return;
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
}
|
|
sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
|
|
/*
|
|
* Look for queue of fragments
|
|
* of this datagram.
|
|
*/
|
|
for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
|
|
if (ip->ip_id == fp->ipq_id &&
|
|
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
|
|
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
|
|
ip->ip_p == fp->ipq_p)
|
|
goto found;
|
|
|
|
fp = 0;
|
|
|
|
/* check if there's a place for the new queue */
|
|
if (nipq > maxnipq) {
|
|
/*
|
|
* drop something from the tail of the current queue
|
|
* before proceeding further
|
|
*/
|
|
if (ipq[sum].prev == &ipq[sum]) { /* gak */
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
if (ipq[i].prev != &ipq[i]) {
|
|
ip_freef(ipq[i].prev);
|
|
break;
|
|
}
|
|
}
|
|
} else
|
|
ip_freef(ipq[sum].prev);
|
|
}
|
|
found:
|
|
/*
|
|
* Adjust ip_len to not reflect header,
|
|
* set ip_mff if more fragments are expected,
|
|
* convert offset of this to bytes.
|
|
*/
|
|
ip->ip_len -= hlen;
|
|
mff = (ip->ip_off & IP_MF) != 0;
|
|
if (mff) {
|
|
/*
|
|
* Make sure that fragments have a data length
|
|
* that's a non-zero multiple of 8 bytes.
|
|
*/
|
|
if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
|
|
ipstat.ips_toosmall++; /* XXX */
|
|
goto bad;
|
|
}
|
|
m->m_flags |= M_FRAG;
|
|
}
|
|
ip->ip_off <<= 3;
|
|
|
|
/*
|
|
* If datagram marked as having more fragments
|
|
* or if this is not the first fragment,
|
|
* attempt reassembly; if it succeeds, proceed.
|
|
*/
|
|
if (mff || ip->ip_off) {
|
|
ipstat.ips_fragments++;
|
|
m->m_pkthdr.header = ip;
|
|
ip = ip_reass(m, fp, &ipq[sum]);
|
|
if (ip == 0) {
|
|
#ifdef IPFIREWALL_FORWARD
|
|
ip_fw_fwd_addr = NULL;
|
|
#endif
|
|
return;
|
|
}
|
|
/* Get the length of the reassembled packets header */
|
|
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
|
|
ipstat.ips_reassembled++;
|
|
m = dtom(ip);
|
|
#ifdef IPDIVERT
|
|
if (frag_divert_port) {
|
|
ip->ip_len += hlen;
|
|
HTONS(ip->ip_len);
|
|
HTONS(ip->ip_off);
|
|
HTONS(ip->ip_id);
|
|
ip->ip_sum = 0;
|
|
ip->ip_sum = in_cksum_hdr(ip);
|
|
NTOHS(ip->ip_id);
|
|
NTOHS(ip->ip_off);
|
|
NTOHS(ip->ip_len);
|
|
ip->ip_len -= hlen;
|
|
}
|
|
#endif
|
|
} else
|
|
if (fp)
|
|
ip_freef(fp);
|
|
} else
|
|
ip->ip_len -= hlen;
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* Divert reassembled packets to the divert protocol if required
|
|
* If divert port is null then cookie should be too,
|
|
* so we shouldn't need to clear them here. Assume ip_divert does so.
|
|
*/
|
|
if (frag_divert_port) {
|
|
ipstat.ips_delivered++;
|
|
ip_divert_port = frag_divert_port;
|
|
frag_divert_port = 0;
|
|
(*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen);
|
|
return;
|
|
}
|
|
|
|
/* Don't let packets divert themselves */
|
|
if (ip->ip_p == IPPROTO_DIVERT) {
|
|
ipstat.ips_noproto++;
|
|
goto bad;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Switch out to protocol's input routine.
|
|
*/
|
|
ipstat.ips_delivered++;
|
|
(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
|
|
#ifdef IPFIREWALL_FORWARD
|
|
ip_fw_fwd_addr = NULL; /* tcp needed it */
|
|
#endif
|
|
return;
|
|
bad:
|
|
#ifdef IPFIREWALL_FORWARD
|
|
ip_fw_fwd_addr = NULL;
|
|
#endif
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* IP software interrupt routine - to go away sometime soon
|
|
*/
|
|
static void
|
|
ipintr(void)
|
|
{
|
|
int s;
|
|
struct mbuf *m;
|
|
|
|
while(1) {
|
|
s = splimp();
|
|
IF_DEQUEUE(&ipintrq, m);
|
|
splx(s);
|
|
if (m == 0)
|
|
return;
|
|
ip_input(m);
|
|
}
|
|
}
|
|
|
|
NETISR_SET(NETISR_IP, ipintr);
|
|
|
|
/*
|
|
* Take incoming datagram fragment and try to
|
|
* reassemble it into whole datagram. If a chain for
|
|
* reassembly of this datagram already exists, then it
|
|
* is given as fp; otherwise have to make a chain.
|
|
*/
|
|
static struct ip *
|
|
ip_reass(m, fp, where)
|
|
register struct mbuf *m;
|
|
register struct ipq *fp;
|
|
struct ipq *where;
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
register struct mbuf *p = 0, *q, *nq;
|
|
struct mbuf *t;
|
|
int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
|
|
int i, next;
|
|
|
|
/*
|
|
* Presence of header sizes in mbufs
|
|
* would confuse code below.
|
|
*/
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
|
|
/*
|
|
* If first fragment to arrive, create a reassembly queue.
|
|
*/
|
|
if (fp == 0) {
|
|
if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
|
|
goto dropfrag;
|
|
fp = mtod(t, struct ipq *);
|
|
insque(fp, where);
|
|
nipq++;
|
|
fp->ipq_ttl = IPFRAGTTL;
|
|
fp->ipq_p = ip->ip_p;
|
|
fp->ipq_id = ip->ip_id;
|
|
fp->ipq_src = ip->ip_src;
|
|
fp->ipq_dst = ip->ip_dst;
|
|
fp->ipq_frags = m;
|
|
m->m_nextpkt = NULL;
|
|
#ifdef IPDIVERT
|
|
fp->ipq_divert = 0;
|
|
fp->ipq_div_cookie = 0;
|
|
#endif
|
|
goto inserted;
|
|
}
|
|
|
|
#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
|
|
|
|
/*
|
|
* Find a segment which begins after this one does.
|
|
*/
|
|
for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
|
|
if (GETIP(q)->ip_off > ip->ip_off)
|
|
break;
|
|
|
|
/*
|
|
* If there is a preceding segment, it may provide some of
|
|
* our data already. If so, drop the data from the incoming
|
|
* segment. If it provides all of our data, drop us, otherwise
|
|
* stick new segment in the proper place.
|
|
*/
|
|
if (p) {
|
|
i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
|
|
if (i > 0) {
|
|
if (i >= ip->ip_len)
|
|
goto dropfrag;
|
|
m_adj(dtom(ip), i);
|
|
ip->ip_off += i;
|
|
ip->ip_len -= i;
|
|
}
|
|
m->m_nextpkt = p->m_nextpkt;
|
|
p->m_nextpkt = m;
|
|
} else {
|
|
m->m_nextpkt = fp->ipq_frags;
|
|
fp->ipq_frags = m;
|
|
}
|
|
|
|
/*
|
|
* While we overlap succeeding segments trim them or,
|
|
* if they are completely covered, dequeue them.
|
|
*/
|
|
for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
|
|
q = nq) {
|
|
i = (ip->ip_off + ip->ip_len) -
|
|
GETIP(q)->ip_off;
|
|
if (i < GETIP(q)->ip_len) {
|
|
GETIP(q)->ip_len -= i;
|
|
GETIP(q)->ip_off += i;
|
|
m_adj(q, i);
|
|
break;
|
|
}
|
|
nq = q->m_nextpkt;
|
|
m->m_nextpkt = nq;
|
|
m_freem(q);
|
|
}
|
|
|
|
inserted:
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* Any fragment diverting causes the whole packet to divert
|
|
*/
|
|
if (frag_divert_port) {
|
|
fp->ipq_divert = frag_divert_port;
|
|
fp->ipq_div_cookie = ip_divert_cookie;
|
|
}
|
|
frag_divert_port = 0;
|
|
ip_divert_cookie = 0;
|
|
#endif
|
|
|
|
/*
|
|
* Check for complete reassembly.
|
|
*/
|
|
next = 0;
|
|
for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
|
|
if (GETIP(q)->ip_off != next)
|
|
return (0);
|
|
next += GETIP(q)->ip_len;
|
|
}
|
|
/* Make sure the last packet didn't have the IP_MF flag */
|
|
if (p->m_flags & M_FRAG)
|
|
return (0);
|
|
|
|
/*
|
|
* Reassembly is complete. Make sure the packet is a sane size.
|
|
*/
|
|
q = fp->ipq_frags;
|
|
ip = GETIP(q);
|
|
if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
|
|
ipstat.ips_toolong++;
|
|
ip_freef(fp);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Concatenate fragments.
|
|
*/
|
|
m = q;
|
|
t = m->m_next;
|
|
m->m_next = 0;
|
|
m_cat(m, t);
|
|
nq = q->m_nextpkt;
|
|
q->m_nextpkt = 0;
|
|
for (q = nq; q != NULL; q = nq) {
|
|
nq = q->m_nextpkt;
|
|
q->m_nextpkt = NULL;
|
|
m_cat(m, q);
|
|
}
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* extract divert port for packet, if any
|
|
*/
|
|
frag_divert_port = fp->ipq_divert;
|
|
ip_divert_cookie = fp->ipq_div_cookie;
|
|
#endif
|
|
|
|
/*
|
|
* Create header for new ip packet by
|
|
* modifying header of first packet;
|
|
* dequeue and discard fragment reassembly header.
|
|
* Make header visible.
|
|
*/
|
|
ip->ip_len = next;
|
|
ip->ip_src = fp->ipq_src;
|
|
ip->ip_dst = fp->ipq_dst;
|
|
remque(fp);
|
|
nipq--;
|
|
(void) m_free(dtom(fp));
|
|
m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
|
|
m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
|
|
/* some debugging cruft by sklower, below, will go away soon */
|
|
if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
|
|
register int plen = 0;
|
|
for (t = m; m; m = m->m_next)
|
|
plen += m->m_len;
|
|
t->m_pkthdr.len = plen;
|
|
}
|
|
return (ip);
|
|
|
|
dropfrag:
|
|
#ifdef IPDIVERT
|
|
frag_divert_port = 0;
|
|
ip_divert_cookie = 0;
|
|
#endif
|
|
ipstat.ips_fragdropped++;
|
|
m_freem(m);
|
|
return (0);
|
|
|
|
#undef GETIP
|
|
}
|
|
|
|
/*
|
|
* Free a fragment reassembly header and all
|
|
* associated datagrams.
|
|
*/
|
|
static void
|
|
ip_freef(fp)
|
|
struct ipq *fp;
|
|
{
|
|
register struct mbuf *q;
|
|
|
|
while (fp->ipq_frags) {
|
|
q = fp->ipq_frags;
|
|
fp->ipq_frags = q->m_nextpkt;
|
|
m_freem(q);
|
|
}
|
|
remque(fp);
|
|
(void) m_free(dtom(fp));
|
|
nipq--;
|
|
}
|
|
|
|
/*
|
|
* IP timer processing;
|
|
* if a timer expires on a reassembly
|
|
* queue, discard it.
|
|
*/
|
|
void
|
|
ip_slowtimo()
|
|
{
|
|
register struct ipq *fp;
|
|
int s = splnet();
|
|
int i;
|
|
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
fp = ipq[i].next;
|
|
if (fp == 0)
|
|
continue;
|
|
while (fp != &ipq[i]) {
|
|
--fp->ipq_ttl;
|
|
fp = fp->next;
|
|
if (fp->prev->ipq_ttl == 0) {
|
|
ipstat.ips_fragtimeout++;
|
|
ip_freef(fp->prev);
|
|
}
|
|
}
|
|
}
|
|
ipflow_slowtimo();
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Drain off all datagram fragments.
|
|
*/
|
|
void
|
|
ip_drain()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
while (ipq[i].next != &ipq[i]) {
|
|
ipstat.ips_fragdropped++;
|
|
ip_freef(ipq[i].next);
|
|
}
|
|
}
|
|
in_rtqdrain();
|
|
}
|
|
|
|
/*
|
|
* Do option processing on a datagram,
|
|
* possibly discarding it if bad options are encountered,
|
|
* or forwarding it if source-routed.
|
|
* Returns 1 if packet has been forwarded/freed,
|
|
* 0 if the packet should be processed further.
|
|
*/
|
|
static int
|
|
ip_dooptions(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register u_char *cp;
|
|
register struct ip_timestamp *ipt;
|
|
register struct in_ifaddr *ia;
|
|
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
|
|
struct in_addr *sin, dst;
|
|
n_time ntime;
|
|
|
|
dst = ip->ip_dst;
|
|
cp = (u_char *)(ip + 1);
|
|
cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
|
|
for (; cnt > 0; cnt -= optlen, cp += optlen) {
|
|
opt = cp[IPOPT_OPTVAL];
|
|
if (opt == IPOPT_EOL)
|
|
break;
|
|
if (opt == IPOPT_NOP)
|
|
optlen = 1;
|
|
else {
|
|
optlen = cp[IPOPT_OLEN];
|
|
if (optlen <= 0 || optlen > cnt) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
}
|
|
switch (opt) {
|
|
|
|
default:
|
|
break;
|
|
|
|
/*
|
|
* Source routing with record.
|
|
* Find interface with current destination address.
|
|
* If none on this machine then drop if strictly routed,
|
|
* or do nothing if loosely routed.
|
|
* Record interface address and bring up next address
|
|
* component. If strictly routed make sure next
|
|
* address is on directly accessible net.
|
|
*/
|
|
case IPOPT_LSRR:
|
|
case IPOPT_SSRR:
|
|
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
ipaddr.sin_addr = ip->ip_dst;
|
|
ia = (struct in_ifaddr *)
|
|
ifa_ifwithaddr((struct sockaddr *)&ipaddr);
|
|
if (ia == 0) {
|
|
if (opt == IPOPT_SSRR) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
}
|
|
if (!ip_dosourceroute)
|
|
goto nosourcerouting;
|
|
/*
|
|
* Loose routing, and not at next destination
|
|
* yet; nothing to do except forward.
|
|
*/
|
|
break;
|
|
}
|
|
off--; /* 0 origin */
|
|
if (off > optlen - sizeof(struct in_addr)) {
|
|
/*
|
|
* End of source route. Should be for us.
|
|
*/
|
|
if (!ip_acceptsourceroute)
|
|
goto nosourcerouting;
|
|
save_rte(cp, ip->ip_src);
|
|
break;
|
|
}
|
|
|
|
if (!ip_dosourceroute) {
|
|
if (ipforwarding) {
|
|
char buf[16]; /* aaa.bbb.ccc.ddd\0 */
|
|
/*
|
|
* Acting as a router, so generate ICMP
|
|
*/
|
|
nosourcerouting:
|
|
strcpy(buf, inet_ntoa(ip->ip_dst));
|
|
log(LOG_WARNING,
|
|
"attempted source route from %s to %s\n",
|
|
inet_ntoa(ip->ip_src), buf);
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
} else {
|
|
/*
|
|
* Not acting as a router, so silently drop.
|
|
*/
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return (1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* locate outgoing interface
|
|
*/
|
|
(void)memcpy(&ipaddr.sin_addr, cp + off,
|
|
sizeof(ipaddr.sin_addr));
|
|
|
|
if (opt == IPOPT_SSRR) {
|
|
#define INA struct in_ifaddr *
|
|
#define SA struct sockaddr *
|
|
if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
|
|
ia = (INA)ifa_ifwithnet((SA)&ipaddr);
|
|
} else
|
|
ia = ip_rtaddr(ipaddr.sin_addr);
|
|
if (ia == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
}
|
|
ip->ip_dst = ipaddr.sin_addr;
|
|
(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
|
|
sizeof(struct in_addr));
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
/*
|
|
* Let ip_intr's mcast routing check handle mcast pkts
|
|
*/
|
|
forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
|
|
break;
|
|
|
|
case IPOPT_RR:
|
|
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
/*
|
|
* If no space remains, ignore.
|
|
*/
|
|
off--; /* 0 origin */
|
|
if (off > optlen - sizeof(struct in_addr))
|
|
break;
|
|
(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
|
|
sizeof(ipaddr.sin_addr));
|
|
/*
|
|
* locate outgoing interface; if we're the destination,
|
|
* use the incoming interface (should be same).
|
|
*/
|
|
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
|
|
(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_HOST;
|
|
goto bad;
|
|
}
|
|
(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
|
|
sizeof(struct in_addr));
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
break;
|
|
|
|
case IPOPT_TS:
|
|
code = cp - (u_char *)ip;
|
|
ipt = (struct ip_timestamp *)cp;
|
|
if (ipt->ipt_len < 5)
|
|
goto bad;
|
|
if (ipt->ipt_ptr > ipt->ipt_len - sizeof(int32_t)) {
|
|
if (++ipt->ipt_oflw == 0)
|
|
goto bad;
|
|
break;
|
|
}
|
|
sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
|
|
switch (ipt->ipt_flg) {
|
|
|
|
case IPOPT_TS_TSONLY:
|
|
break;
|
|
|
|
case IPOPT_TS_TSANDADDR:
|
|
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
|
|
sizeof(struct in_addr) > ipt->ipt_len)
|
|
goto bad;
|
|
ipaddr.sin_addr = dst;
|
|
ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
|
|
m->m_pkthdr.rcvif);
|
|
if (ia == 0)
|
|
continue;
|
|
(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
|
|
sizeof(struct in_addr));
|
|
ipt->ipt_ptr += sizeof(struct in_addr);
|
|
break;
|
|
|
|
case IPOPT_TS_PRESPEC:
|
|
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
|
|
sizeof(struct in_addr) > ipt->ipt_len)
|
|
goto bad;
|
|
(void)memcpy(&ipaddr.sin_addr, sin,
|
|
sizeof(struct in_addr));
|
|
if (ifa_ifwithaddr((SA)&ipaddr) == 0)
|
|
continue;
|
|
ipt->ipt_ptr += sizeof(struct in_addr);
|
|
break;
|
|
|
|
default:
|
|
goto bad;
|
|
}
|
|
ntime = iptime();
|
|
(void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
|
|
sizeof(n_time));
|
|
ipt->ipt_ptr += sizeof(n_time);
|
|
}
|
|
}
|
|
if (forward && ipforwarding) {
|
|
ip_forward(m, 1);
|
|
return (1);
|
|
}
|
|
return (0);
|
|
bad:
|
|
ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */
|
|
icmp_error(m, type, code, 0, 0);
|
|
ipstat.ips_badoptions++;
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* Given address of next destination (final or next hop),
|
|
* return internet address info of interface to be used to get there.
|
|
*/
|
|
static struct in_ifaddr *
|
|
ip_rtaddr(dst)
|
|
struct in_addr dst;
|
|
{
|
|
register struct sockaddr_in *sin;
|
|
|
|
sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
|
|
|
|
if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) {
|
|
if (ipforward_rt.ro_rt) {
|
|
RTFREE(ipforward_rt.ro_rt);
|
|
ipforward_rt.ro_rt = 0;
|
|
}
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_len = sizeof(*sin);
|
|
sin->sin_addr = dst;
|
|
|
|
rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
|
|
}
|
|
if (ipforward_rt.ro_rt == 0)
|
|
return ((struct in_ifaddr *)0);
|
|
return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
|
|
}
|
|
|
|
/*
|
|
* Save incoming source route for use in replies,
|
|
* to be picked up later by ip_srcroute if the receiver is interested.
|
|
*/
|
|
void
|
|
save_rte(option, dst)
|
|
u_char *option;
|
|
struct in_addr dst;
|
|
{
|
|
unsigned olen;
|
|
|
|
olen = option[IPOPT_OLEN];
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("save_rte: olen %d\n", olen);
|
|
#endif
|
|
if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
|
|
return;
|
|
bcopy(option, ip_srcrt.srcopt, olen);
|
|
ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
|
|
ip_srcrt.dst = dst;
|
|
}
|
|
|
|
/*
|
|
* Retrieve incoming source route for use in replies,
|
|
* in the same form used by setsockopt.
|
|
* The first hop is placed before the options, will be removed later.
|
|
*/
|
|
struct mbuf *
|
|
ip_srcroute()
|
|
{
|
|
register struct in_addr *p, *q;
|
|
register struct mbuf *m;
|
|
|
|
if (ip_nhops == 0)
|
|
return ((struct mbuf *)0);
|
|
m = m_get(M_DONTWAIT, MT_HEADER);
|
|
if (m == 0)
|
|
return ((struct mbuf *)0);
|
|
|
|
#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
|
|
|
|
/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
|
|
m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
|
|
OPTSIZ;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
|
|
#endif
|
|
|
|
/*
|
|
* First save first hop for return route
|
|
*/
|
|
p = &ip_srcrt.route[ip_nhops - 1];
|
|
*(mtod(m, struct in_addr *)) = *p--;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" hops %lx", (u_long)ntohl(mtod(m, struct in_addr *)->s_addr));
|
|
#endif
|
|
|
|
/*
|
|
* Copy option fields and padding (nop) to mbuf.
|
|
*/
|
|
ip_srcrt.nop = IPOPT_NOP;
|
|
ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
|
|
(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
|
|
&ip_srcrt.nop, OPTSIZ);
|
|
q = (struct in_addr *)(mtod(m, caddr_t) +
|
|
sizeof(struct in_addr) + OPTSIZ);
|
|
#undef OPTSIZ
|
|
/*
|
|
* Record return path as an IP source route,
|
|
* reversing the path (pointers are now aligned).
|
|
*/
|
|
while (p >= ip_srcrt.route) {
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" %lx", (u_long)ntohl(q->s_addr));
|
|
#endif
|
|
*q++ = *p--;
|
|
}
|
|
/*
|
|
* Last hop goes to final destination.
|
|
*/
|
|
*q = ip_srcrt.dst;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" %lx\n", (u_long)ntohl(q->s_addr));
|
|
#endif
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Strip out IP options, at higher
|
|
* level protocol in the kernel.
|
|
* Second argument is buffer to which options
|
|
* will be moved, and return value is their length.
|
|
* XXX should be deleted; last arg currently ignored.
|
|
*/
|
|
void
|
|
ip_stripoptions(m, mopt)
|
|
register struct mbuf *m;
|
|
struct mbuf *mopt;
|
|
{
|
|
register int i;
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
register caddr_t opts;
|
|
int olen;
|
|
|
|
olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
|
|
opts = (caddr_t)(ip + 1);
|
|
i = m->m_len - (sizeof (struct ip) + olen);
|
|
bcopy(opts + olen, opts, (unsigned)i);
|
|
m->m_len -= olen;
|
|
if (m->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len -= olen;
|
|
ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
|
|
}
|
|
|
|
u_char inetctlerrmap[PRC_NCMDS] = {
|
|
0, 0, 0, 0,
|
|
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
|
|
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
|
|
EMSGSIZE, EHOSTUNREACH, 0, 0,
|
|
0, 0, 0, 0,
|
|
ENOPROTOOPT
|
|
};
|
|
|
|
/*
|
|
* Forward a packet. If some error occurs return the sender
|
|
* an icmp packet. Note we can't always generate a meaningful
|
|
* icmp message because icmp doesn't have a large enough repertoire
|
|
* of codes and types.
|
|
*
|
|
* If not forwarding, just drop the packet. This could be confusing
|
|
* if ipforwarding was zero but some routing protocol was advancing
|
|
* us as a gateway to somewhere. However, we must let the routing
|
|
* protocol deal with that.
|
|
*
|
|
* The srcrt parameter indicates whether the packet is being forwarded
|
|
* via a source route.
|
|
*/
|
|
static void
|
|
ip_forward(m, srcrt)
|
|
struct mbuf *m;
|
|
int srcrt;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register struct sockaddr_in *sin;
|
|
register struct rtentry *rt;
|
|
int error, type = 0, code = 0;
|
|
struct mbuf *mcopy;
|
|
n_long dest;
|
|
struct ifnet *destifp;
|
|
|
|
dest = 0;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("forward: src %lx dst %lx ttl %x\n",
|
|
(u_long)ip->ip_src.s_addr, (u_long)ip->ip_dst.s_addr,
|
|
ip->ip_ttl);
|
|
#endif
|
|
|
|
|
|
if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
HTONS(ip->ip_id);
|
|
if (ip->ip_ttl <= IPTTLDEC) {
|
|
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
|
|
return;
|
|
}
|
|
ip->ip_ttl -= IPTTLDEC;
|
|
|
|
sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
|
|
if ((rt = ipforward_rt.ro_rt) == 0 ||
|
|
ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
|
|
if (ipforward_rt.ro_rt) {
|
|
RTFREE(ipforward_rt.ro_rt);
|
|
ipforward_rt.ro_rt = 0;
|
|
}
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_len = sizeof(*sin);
|
|
sin->sin_addr = ip->ip_dst;
|
|
|
|
rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
|
|
if (ipforward_rt.ro_rt == 0) {
|
|
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
|
|
return;
|
|
}
|
|
rt = ipforward_rt.ro_rt;
|
|
}
|
|
|
|
/*
|
|
* Save at most 64 bytes of the packet in case
|
|
* we need to generate an ICMP message to the src.
|
|
*/
|
|
mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
|
|
|
|
/*
|
|
* If forwarding packet using same interface that it came in on,
|
|
* perhaps should send a redirect to sender to shortcut a hop.
|
|
* Only send redirect if source is sending directly to us,
|
|
* and if packet was not source routed (or has any options).
|
|
* Also, don't send redirect if forwarding using a default route
|
|
* or a route modified by a redirect.
|
|
*/
|
|
#define satosin(sa) ((struct sockaddr_in *)(sa))
|
|
if (rt->rt_ifp == m->m_pkthdr.rcvif &&
|
|
(rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
|
|
satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
|
|
ipsendredirects && !srcrt) {
|
|
#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
|
|
u_long src = ntohl(ip->ip_src.s_addr);
|
|
|
|
if (RTA(rt) &&
|
|
(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
|
dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
|
|
else
|
|
dest = ip->ip_dst.s_addr;
|
|
/* Router requirements says to only send host redirects */
|
|
type = ICMP_REDIRECT;
|
|
code = ICMP_REDIRECT_HOST;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("redirect (%d) to %lx\n", code, (u_long)dest);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
|
|
IP_FORWARDING, 0);
|
|
if (error)
|
|
ipstat.ips_cantforward++;
|
|
else {
|
|
ipstat.ips_forward++;
|
|
if (type)
|
|
ipstat.ips_redirectsent++;
|
|
else {
|
|
if (mcopy) {
|
|
ipflow_create(&ipforward_rt, mcopy);
|
|
m_freem(mcopy);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
if (mcopy == NULL)
|
|
return;
|
|
destifp = NULL;
|
|
|
|
switch (error) {
|
|
|
|
case 0: /* forwarded, but need redirect */
|
|
/* type, code set above */
|
|
break;
|
|
|
|
case ENETUNREACH: /* shouldn't happen, checked above */
|
|
case EHOSTUNREACH:
|
|
case ENETDOWN:
|
|
case EHOSTDOWN:
|
|
default:
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_HOST;
|
|
break;
|
|
|
|
case EMSGSIZE:
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_NEEDFRAG;
|
|
if (ipforward_rt.ro_rt)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
ipstat.ips_cantfrag++;
|
|
break;
|
|
|
|
case ENOBUFS:
|
|
type = ICMP_SOURCEQUENCH;
|
|
code = 0;
|
|
break;
|
|
}
|
|
icmp_error(mcopy, type, code, dest, destifp);
|
|
}
|
|
|
|
void
|
|
ip_savecontrol(inp, mp, ip, m)
|
|
register struct inpcb *inp;
|
|
register struct mbuf **mp;
|
|
register struct ip *ip;
|
|
register struct mbuf *m;
|
|
{
|
|
if (inp->inp_socket->so_options & SO_TIMESTAMP) {
|
|
struct timeval tv;
|
|
|
|
microtime(&tv);
|
|
*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
|
|
SCM_TIMESTAMP, SOL_SOCKET);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
if (inp->inp_flags & INP_RECVDSTADDR) {
|
|
*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
|
|
sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
#ifdef notyet
|
|
/* XXX
|
|
* Moving these out of udp_input() made them even more broken
|
|
* than they already were.
|
|
*/
|
|
/* options were tossed already */
|
|
if (inp->inp_flags & INP_RECVOPTS) {
|
|
*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
|
|
sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
/* ip_srcroute doesn't do what we want here, need to fix */
|
|
if (inp->inp_flags & INP_RECVRETOPTS) {
|
|
*mp = sbcreatecontrol((caddr_t) ip_srcroute(),
|
|
sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
#endif
|
|
if (inp->inp_flags & INP_RECVIF) {
|
|
struct ifnet *ifp;
|
|
struct sdlbuf {
|
|
struct sockaddr_dl sdl;
|
|
u_char pad[32];
|
|
} sdlbuf;
|
|
struct sockaddr_dl *sdp;
|
|
struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
|
|
|
|
if (((ifp = m->m_pkthdr.rcvif))
|
|
&& ( ifp->if_index && (ifp->if_index <= if_index))) {
|
|
sdp = (struct sockaddr_dl *)(ifnet_addrs
|
|
[ifp->if_index - 1]->ifa_addr);
|
|
/*
|
|
* Change our mind and don't try copy.
|
|
*/
|
|
if ((sdp->sdl_family != AF_LINK)
|
|
|| (sdp->sdl_len > sizeof(sdlbuf))) {
|
|
goto makedummy;
|
|
}
|
|
bcopy(sdp, sdl2, sdp->sdl_len);
|
|
} else {
|
|
makedummy:
|
|
sdl2->sdl_len
|
|
= offsetof(struct sockaddr_dl, sdl_data[0]);
|
|
sdl2->sdl_family = AF_LINK;
|
|
sdl2->sdl_index = 0;
|
|
sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
|
|
}
|
|
*mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
|
|
IP_RECVIF, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
}
|
|
|
|
int
|
|
ip_rsvp_init(struct socket *so)
|
|
{
|
|
if (so->so_type != SOCK_RAW ||
|
|
so->so_proto->pr_protocol != IPPROTO_RSVP)
|
|
return EOPNOTSUPP;
|
|
|
|
if (ip_rsvpd != NULL)
|
|
return EADDRINUSE;
|
|
|
|
ip_rsvpd = so;
|
|
/*
|
|
* This may seem silly, but we need to be sure we don't over-increment
|
|
* the RSVP counter, in case something slips up.
|
|
*/
|
|
if (!ip_rsvp_on) {
|
|
ip_rsvp_on = 1;
|
|
rsvp_on++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ip_rsvp_done(void)
|
|
{
|
|
ip_rsvpd = NULL;
|
|
/*
|
|
* This may seem silly, but we need to be sure we don't over-decrement
|
|
* the RSVP counter, in case something slips up.
|
|
*/
|
|
if (ip_rsvp_on) {
|
|
ip_rsvp_on = 0;
|
|
rsvp_on--;
|
|
}
|
|
return 0;
|
|
}
|