2163 lines
54 KiB
C
2163 lines
54 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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* $FreeBSD$
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*/
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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 "opt_ipstealth.h"
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#include "opt_ipsec.h"
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#include "opt_mac.h"
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#include "opt_pfil_hooks.h"
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#include "opt_random_ip_id.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mac.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/pfil.h>
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#include <net/if.h>
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#include <net/if_types.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 <net/intrq.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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#include <netinet/ip_fw.h>
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#include <netinet/ip_dummynet.h>
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#ifdef IPSEC
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#include <netinet6/ipsec.h>
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#include <netkey/key.h>
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#endif
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#ifdef FAST_IPSEC
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#include <netipsec/ipsec.h>
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#include <netipsec/key.h>
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#endif
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int rsvp_on = 0;
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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, "Enable IP forwarding between interfaces");
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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, "Enable sending IP redirects");
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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, "Maximum TTL on IP packets");
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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, "Enable forwarding source routed IP packets");
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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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"Enable accepting source routed IP packets");
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static int ip_keepfaith = 0;
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SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
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&ip_keepfaith, 0,
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"Enable packet capture for FAITH IPv4->IPv6 translater daemon");
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static int nipq = 0; /* total # of reass queues */
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static int maxnipq;
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SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
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&maxnipq, 0,
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"Maximum number of IPv4 fragment reassembly queue entries");
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static int ip_sendsourcequench = 0;
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SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
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&ip_sendsourcequench, 0,
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"Enable the transmission of source quench packets");
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/*
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* XXX - Setting ip_checkinterface mostly implements the receive side of
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* the Strong ES model described in RFC 1122, but since the routing table
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* and transmit implementation do not implement the Strong ES model,
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* setting this to 1 results in an odd hybrid.
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*
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* XXX - ip_checkinterface currently must be disabled if you use ipnat
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* to translate the destination address to another local interface.
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*
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* XXX - ip_checkinterface must be disabled if you add IP aliases
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* to the loopback interface instead of the interface where the
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* packets for those addresses are received.
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*/
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static int ip_checkinterface = 1;
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SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
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&ip_checkinterface, 0, "Verify packet arrives on correct interface");
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#ifdef DIAGNOSTIC
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static int ipprintfs = 0;
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#endif
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static int ipqmaxlen = IFQ_MAXLEN;
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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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struct in_ifaddrhead in_ifaddrhead; /* first inet address */
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struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */
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u_long in_ifaddrhmask; /* mask for hash table */
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SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
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&ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
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SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
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&ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
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struct ipstat ipstat;
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SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
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&ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
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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 TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
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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, "Default MTU");
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#endif
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#ifdef IPSTEALTH
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static int ipstealth = 0;
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SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
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&ipstealth, 0, "");
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#endif
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/* Firewall hooks */
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ip_fw_chk_t *ip_fw_chk_ptr;
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int fw_enable = 1 ;
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int fw_one_pass = 1;
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/* Dummynet hooks */
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ip_dn_io_t *ip_dn_io_ptr;
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/*
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* XXX this is ugly -- the following two global variables are
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* used to store packet state while it travels through the stack.
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* Note that the code even makes assumptions on the size and
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* alignment of fields inside struct ip_srcrt so e.g. adding some
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* fields will break the code. This needs to be fixed.
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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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static void save_rte(u_char *, struct in_addr);
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static int ip_dooptions(struct mbuf *m, int,
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struct sockaddr_in *next_hop);
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static void ip_forward(struct mbuf *m, int srcrt,
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struct sockaddr_in *next_hop);
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static void ip_freef(struct ipqhead *, struct ipq *);
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static struct mbuf *ip_reass(struct mbuf *, struct ipqhead *,
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struct ipq *, u_int32_t *, u_int16_t *);
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static void ipintr(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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in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
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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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TAILQ_INIT(&ipq[i]);
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maxnipq = nmbclusters / 4;
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#ifndef RANDOM_IP_ID
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ip_id = time_second & 0xffff;
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#endif
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ipintrq.ifq_maxlen = ipqmaxlen;
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mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF);
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ipintrq_present = 1;
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register_netisr(NETISR_IP, ipintr);
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}
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/*
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* XXX watch out this one. It is perhaps used as a cache for
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* the most recently used route ? it is cleared in in_addroute()
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* when a new route is successfully created.
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*/
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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 = NULL;
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struct ifaddr *ifa;
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int i, hlen, checkif;
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u_short sum;
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struct in_addr pkt_dst;
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u_int32_t divert_info = 0; /* packet divert/tee info */
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struct ip_fw_args args;
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#ifdef PFIL_HOOKS
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struct packet_filter_hook *pfh;
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struct mbuf *m0;
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int rv;
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#endif /* PFIL_HOOKS */
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#ifdef FAST_IPSEC
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struct m_tag *mtag;
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struct tdb_ident *tdbi;
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struct secpolicy *sp;
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int s, error;
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#endif /* FAST_IPSEC */
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args.eh = NULL;
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args.oif = NULL;
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args.rule = NULL;
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args.divert_rule = 0; /* divert cookie */
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args.next_hop = NULL;
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/* Grab info from MT_TAG mbufs prepended to the chain. */
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for (; m && m->m_type == MT_TAG; m = m->m_next) {
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switch(m->_m_tag_id) {
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default:
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printf("ip_input: unrecognised MT_TAG tag %d\n",
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m->_m_tag_id);
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break;
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case PACKET_TAG_DUMMYNET:
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args.rule = ((struct dn_pkt *)m)->rule;
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break;
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case PACKET_TAG_DIVERT:
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args.divert_rule = (intptr_t)m->m_hdr.mh_data & 0xffff;
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break;
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case PACKET_TAG_IPFORWARD:
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args.next_hop = (struct sockaddr_in *)m->m_hdr.mh_data;
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break;
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}
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}
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KASSERT(m != NULL && (m->m_flags & M_PKTHDR) != 0,
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("ip_input: no HDR"));
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if (args.rule) { /* dummynet already filtered us */
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ip = mtod(m, struct ip *);
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hlen = ip->ip_hl << 2;
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goto iphack ;
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}
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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->ip_v != IPVERSION) {
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ipstat.ips_badvers++;
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goto bad;
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}
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hlen = ip->ip_hl << 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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/* 127/8 must not appear on wire - RFC1122 */
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if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
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(ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
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if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
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ipstat.ips_badaddr++;
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goto bad;
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}
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}
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if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
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sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
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} else {
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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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}
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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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/*
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* Convert fields to host representation.
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*/
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ip->ip_len = 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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ip->ip_off = ntohs(ip->ip_off);
|
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|
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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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* 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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*/
|
|
|
|
iphack:
|
|
|
|
#ifdef PFIL_HOOKS
|
|
/*
|
|
* Run through list of hooks for input packets. If there are any
|
|
* filters which require that additional packets in the flow are
|
|
* not fast-forwarded, they must clear the M_CANFASTFWD flag.
|
|
* Note that filters must _never_ set this flag, as another filter
|
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* in the list may have previously cleared it.
|
|
*/
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|
m0 = m;
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pfh = pfil_hook_get(PFIL_IN, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
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|
for (; pfh; pfh = TAILQ_NEXT(pfh, pfil_link))
|
|
if (pfh->pfil_func) {
|
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rv = pfh->pfil_func(ip, hlen,
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m->m_pkthdr.rcvif, 0, &m0);
|
|
if (rv)
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return;
|
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m = m0;
|
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if (m == NULL)
|
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return;
|
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ip = mtod(m, struct ip *);
|
|
}
|
|
#endif /* PFIL_HOOKS */
|
|
|
|
if (fw_enable && IPFW_LOADED) {
|
|
/*
|
|
* If we've been forwarded from the output side, then
|
|
* skip the firewall a second time
|
|
*/
|
|
if (args.next_hop)
|
|
goto ours;
|
|
|
|
args.m = m;
|
|
i = ip_fw_chk_ptr(&args);
|
|
m = args.m;
|
|
|
|
if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
|
|
if (m)
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
ip = mtod(m, struct ip *); /* just in case m changed */
|
|
if (i == 0 && args.next_hop == NULL) /* common case */
|
|
goto pass;
|
|
if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG) != 0) {
|
|
/* Send packet to the appropriate pipe */
|
|
ip_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args);
|
|
return;
|
|
}
|
|
#ifdef IPDIVERT
|
|
if (i != 0 && (i & IP_FW_PORT_DYNT_FLAG) == 0) {
|
|
/* Divert or tee packet */
|
|
divert_info = i;
|
|
goto ours;
|
|
}
|
|
#endif
|
|
if (i == 0 && args.next_hop != NULL)
|
|
goto pass;
|
|
/*
|
|
* if we get here, the packet must be dropped
|
|
*/
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
pass:
|
|
|
|
/*
|
|
* Process options and, if not destined for us,
|
|
* ship it on. ip_dooptions returns 1 when an
|
|
* 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, 0, args.next_hop))
|
|
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)
|
|
goto ours;
|
|
|
|
/*
|
|
* Check our list of addresses, to see if the packet is for us.
|
|
* If we don't have any addresses, assume any unicast packet
|
|
* we receive might be for us (and let the upper layers deal
|
|
* with it).
|
|
*/
|
|
if (TAILQ_EMPTY(&in_ifaddrhead) &&
|
|
(m->m_flags & (M_MCAST|M_BCAST)) == 0)
|
|
goto ours;
|
|
|
|
/*
|
|
* Cache the destination address of the packet; this may be
|
|
* changed by use of 'ipfw fwd'.
|
|
*/
|
|
pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
|
|
|
|
/*
|
|
* Enable a consistency check between the destination address
|
|
* and the arrival interface for a unicast packet (the RFC 1122
|
|
* strong ES model) if IP forwarding is disabled and the packet
|
|
* is not locally generated and the packet is not subject to
|
|
* 'ipfw fwd'.
|
|
*
|
|
* XXX - Checking also should be disabled if the destination
|
|
* address is ipnat'ed to a different interface.
|
|
*
|
|
* XXX - Checking is incompatible with IP aliases added
|
|
* to the loopback interface instead of the interface where
|
|
* the packets are received.
|
|
*/
|
|
checkif = ip_checkinterface && (ipforwarding == 0) &&
|
|
m->m_pkthdr.rcvif != NULL &&
|
|
((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
|
|
(args.next_hop == NULL);
|
|
|
|
/*
|
|
* Check for exact addresses in the hash bucket.
|
|
*/
|
|
LIST_FOREACH(ia, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
|
|
/*
|
|
* If the address matches, verify that the packet
|
|
* arrived via the correct interface if checking is
|
|
* enabled.
|
|
*/
|
|
if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
|
|
(!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
|
|
goto ours;
|
|
}
|
|
/*
|
|
* Check for broadcast addresses.
|
|
*
|
|
* Only accept broadcast packets that arrive via the matching
|
|
* interface. Reception of forwarded directed broadcasts would
|
|
* be handled via ip_forward() and ether_output() with the loopback
|
|
* into the stack for SIMPLEX interfaces handled by ether_output().
|
|
*/
|
|
if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
|
|
TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
|
|
if (ifa->ifa_addr->sa_family != AF_INET)
|
|
continue;
|
|
ia = ifatoia(ifa);
|
|
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
|
|
pkt_dst.s_addr)
|
|
goto ours;
|
|
if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
|
|
goto ours;
|
|
#ifdef BOOTP_COMPAT
|
|
if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
|
|
goto ours;
|
|
#endif
|
|
}
|
|
}
|
|
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.
|
|
*/
|
|
if (ip_mforward &&
|
|
ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The process-level routing daemon 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;
|
|
|
|
/*
|
|
* FAITH(Firewall Aided Internet Translator)
|
|
*/
|
|
if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
|
|
if (ip_keepfaith) {
|
|
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
|
|
goto ours;
|
|
}
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Not for us; forward if possible and desirable.
|
|
*/
|
|
if (ipforwarding == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
} else {
|
|
#ifdef IPSEC
|
|
/*
|
|
* Enforce inbound IPsec SPD.
|
|
*/
|
|
if (ipsec4_in_reject(m, NULL)) {
|
|
ipsecstat.in_polvio++;
|
|
goto bad;
|
|
}
|
|
#endif /* IPSEC */
|
|
#ifdef FAST_IPSEC
|
|
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
|
|
s = splnet();
|
|
if (mtag != NULL) {
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
|
|
} else {
|
|
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
|
|
IP_FORWARDING, &error);
|
|
}
|
|
if (sp == NULL) { /* NB: can happen if error */
|
|
splx(s);
|
|
/*XXX error stat???*/
|
|
DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* Check security policy against packet attributes.
|
|
*/
|
|
error = ipsec_in_reject(sp, m);
|
|
KEY_FREESP(&sp);
|
|
splx(s);
|
|
if (error) {
|
|
ipstat.ips_cantforward++;
|
|
goto bad;
|
|
}
|
|
#endif /* FAST_IPSEC */
|
|
ip_forward(m, 0, args.next_hop);
|
|
}
|
|
return;
|
|
|
|
ours:
|
|
#ifdef IPSTEALTH
|
|
/*
|
|
* IPSTEALTH: Process non-routing options only
|
|
* if the packet is destined for us.
|
|
*/
|
|
if (ipstealth && hlen > sizeof (struct ip) &&
|
|
ip_dooptions(m, 1, args.next_hop))
|
|
return;
|
|
#endif /* IPSTEALTH */
|
|
|
|
/* Count the packet in the ip address stats */
|
|
if (ia != NULL) {
|
|
ia->ia_ifa.if_ipackets++;
|
|
ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
|
|
}
|
|
|
|
/*
|
|
* 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)) {
|
|
|
|
/* If maxnipq is 0, never accept fragments. */
|
|
if (maxnipq == 0) {
|
|
ipstat.ips_fragments++;
|
|
ipstat.ips_fragdropped++;
|
|
goto bad;
|
|
}
|
|
|
|
sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
|
|
/*
|
|
* Look for queue of fragments
|
|
* of this datagram.
|
|
*/
|
|
TAILQ_FOREACH(fp, &ipq[sum], ipq_list)
|
|
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 &&
|
|
#ifdef MAC
|
|
mac_fragment_match(m, fp) &&
|
|
#endif
|
|
ip->ip_p == fp->ipq_p)
|
|
goto found;
|
|
|
|
fp = 0;
|
|
|
|
/*
|
|
* Enforce upper bound on number of fragmented packets
|
|
* for which we attempt reassembly;
|
|
* If maxnipq is -1, accept all fragments without limitation.
|
|
*/
|
|
if ((nipq > maxnipq) && (maxnipq > 0)) {
|
|
/*
|
|
* drop something from the tail of the current queue
|
|
* before proceeding further
|
|
*/
|
|
struct ipq *q = TAILQ_LAST(&ipq[sum], ipqhead);
|
|
if (q == NULL) { /* gak */
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
|
|
if (r) {
|
|
ip_freef(&ipq[i], r);
|
|
ipstat.ips_fragtimeout++;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
ip_freef(&ipq[sum], q);
|
|
ipstat.ips_fragtimeout++;
|
|
}
|
|
}
|
|
found:
|
|
/*
|
|
* Adjust ip_len to not reflect header,
|
|
* convert offset of this to bytes.
|
|
*/
|
|
ip->ip_len -= hlen;
|
|
if (ip->ip_off & IP_MF) {
|
|
/*
|
|
* 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;
|
|
} else
|
|
m->m_flags &= ~M_FRAG;
|
|
ip->ip_off <<= 3;
|
|
|
|
/*
|
|
* Attempt reassembly; if it succeeds, proceed.
|
|
* ip_reass() will return a different mbuf, and update
|
|
* the divert info in divert_info and args.divert_rule.
|
|
*/
|
|
ipstat.ips_fragments++;
|
|
m->m_pkthdr.header = ip;
|
|
m = ip_reass(m,
|
|
&ipq[sum], fp, &divert_info, &args.divert_rule);
|
|
if (m == 0)
|
|
return;
|
|
ipstat.ips_reassembled++;
|
|
ip = mtod(m, struct ip *);
|
|
/* Get the header length of the reassembled packet */
|
|
hlen = ip->ip_hl << 2;
|
|
#ifdef IPDIVERT
|
|
/* Restore original checksum before diverting packet */
|
|
if (divert_info != 0) {
|
|
ip->ip_len += hlen;
|
|
ip->ip_len = htons(ip->ip_len);
|
|
ip->ip_off = htons(ip->ip_off);
|
|
ip->ip_sum = 0;
|
|
if (hlen == sizeof(struct ip))
|
|
ip->ip_sum = in_cksum_hdr(ip);
|
|
else
|
|
ip->ip_sum = in_cksum(m, hlen);
|
|
ip->ip_off = ntohs(ip->ip_off);
|
|
ip->ip_len = ntohs(ip->ip_len);
|
|
ip->ip_len -= hlen;
|
|
}
|
|
#endif
|
|
} else
|
|
ip->ip_len -= hlen;
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* Divert or tee packet to the divert protocol if required.
|
|
*/
|
|
if (divert_info != 0) {
|
|
struct mbuf *clone = NULL;
|
|
|
|
/* Clone packet if we're doing a 'tee' */
|
|
if ((divert_info & IP_FW_PORT_TEE_FLAG) != 0)
|
|
clone = m_dup(m, M_NOWAIT);
|
|
|
|
/* Restore packet header fields to original values */
|
|
ip->ip_len += hlen;
|
|
ip->ip_len = htons(ip->ip_len);
|
|
ip->ip_off = htons(ip->ip_off);
|
|
|
|
/* Deliver packet to divert input routine */
|
|
divert_packet(m, 1, divert_info & 0xffff, args.divert_rule);
|
|
ipstat.ips_delivered++;
|
|
|
|
/* If 'tee', continue with original packet */
|
|
if (clone == NULL)
|
|
return;
|
|
m = clone;
|
|
ip = mtod(m, struct ip *);
|
|
ip->ip_len += hlen;
|
|
/*
|
|
* Jump backwards to complete processing of the
|
|
* packet. But first clear divert_info to avoid
|
|
* entering this block again.
|
|
* We do not need to clear args.divert_rule
|
|
* or args.next_hop as they will not be used.
|
|
*/
|
|
divert_info = 0;
|
|
goto pass;
|
|
}
|
|
#endif
|
|
|
|
#ifdef IPSEC
|
|
/*
|
|
* enforce IPsec policy checking if we are seeing last header.
|
|
* note that we do not visit this with protocols with pcb layer
|
|
* code - like udp/tcp/raw ip.
|
|
*/
|
|
if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
|
|
ipsec4_in_reject(m, NULL)) {
|
|
ipsecstat.in_polvio++;
|
|
goto bad;
|
|
}
|
|
#endif
|
|
#if FAST_IPSEC
|
|
/*
|
|
* enforce IPsec policy checking if we are seeing last header.
|
|
* note that we do not visit this with protocols with pcb layer
|
|
* code - like udp/tcp/raw ip.
|
|
*/
|
|
if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
|
|
/*
|
|
* Check if the packet has already had IPsec processing
|
|
* done. If so, then just pass it along. This tag gets
|
|
* set during AH, ESP, etc. input handling, before the
|
|
* packet is returned to the ip input queue for delivery.
|
|
*/
|
|
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
|
|
s = splnet();
|
|
if (mtag != NULL) {
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
|
|
} else {
|
|
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
|
|
IP_FORWARDING, &error);
|
|
}
|
|
if (sp != NULL) {
|
|
/*
|
|
* Check security policy against packet attributes.
|
|
*/
|
|
error = ipsec_in_reject(sp, m);
|
|
KEY_FREESP(&sp);
|
|
} else {
|
|
/* XXX error stat??? */
|
|
error = EINVAL;
|
|
DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
|
|
goto bad;
|
|
}
|
|
splx(s);
|
|
if (error)
|
|
goto bad;
|
|
}
|
|
#endif /* FAST_IPSEC */
|
|
|
|
/*
|
|
* Switch out to protocol's input routine.
|
|
*/
|
|
ipstat.ips_delivered++;
|
|
if (args.next_hop && ip->ip_p == IPPROTO_TCP) {
|
|
/* TCP needs IPFORWARD info if available */
|
|
struct m_hdr tag;
|
|
|
|
tag.mh_type = MT_TAG;
|
|
tag.mh_flags = PACKET_TAG_IPFORWARD;
|
|
tag.mh_data = (caddr_t)args.next_hop;
|
|
tag.mh_next = m;
|
|
|
|
(*inetsw[ip_protox[ip->ip_p]].pr_input)(
|
|
(struct mbuf *)&tag, hlen);
|
|
} else
|
|
(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
|
|
return;
|
|
bad:
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* IP software interrupt routine - to go away sometime soon
|
|
*/
|
|
static void
|
|
ipintr(void)
|
|
{
|
|
struct mbuf *m;
|
|
|
|
while (1) {
|
|
IF_DEQUEUE(&ipintrq, m);
|
|
if (m == 0)
|
|
return;
|
|
ip_input(m);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* When IPDIVERT enabled, keep additional state with each packet that
|
|
* tells us if we need to divert or tee the packet we're building.
|
|
* In particular, *divinfo includes the port and TEE flag,
|
|
* *divert_rule is the number of the matching rule.
|
|
*/
|
|
|
|
static struct mbuf *
|
|
ip_reass(struct mbuf *m, struct ipqhead *head, struct ipq *fp,
|
|
u_int32_t *divinfo, u_int16_t *divert_rule)
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
register struct mbuf *p, *q, *nq;
|
|
struct mbuf *t;
|
|
int hlen = ip->ip_hl << 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_NOWAIT, MT_FTABLE)) == NULL)
|
|
goto dropfrag;
|
|
fp = mtod(t, struct ipq *);
|
|
#ifdef MAC
|
|
mac_init_ipq(fp);
|
|
mac_create_ipq(m, fp);
|
|
#endif
|
|
TAILQ_INSERT_HEAD(head, fp, ipq_list);
|
|
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_div_info = 0;
|
|
fp->ipq_div_cookie = 0;
|
|
#endif
|
|
goto inserted;
|
|
} else {
|
|
#ifdef MAC
|
|
mac_update_ipq(m, fp);
|
|
#endif
|
|
}
|
|
|
|
#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 some of the data is dropped from the the preceding
|
|
* segment, then it's checksum is invalidated.
|
|
*/
|
|
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(m, i);
|
|
m->m_pkthdr.csum_flags = 0;
|
|
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);
|
|
q->m_pkthdr.csum_flags = 0;
|
|
break;
|
|
}
|
|
nq = q->m_nextpkt;
|
|
m->m_nextpkt = nq;
|
|
m_freem(q);
|
|
}
|
|
|
|
inserted:
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* Transfer firewall instructions to the fragment structure.
|
|
* Only trust info in the fragment at offset 0.
|
|
*/
|
|
if (ip->ip_off == 0) {
|
|
fp->ipq_div_info = *divinfo;
|
|
fp->ipq_div_cookie = *divert_rule;
|
|
}
|
|
*divinfo = 0;
|
|
*divert_rule = 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->ip_hl << 2) > IP_MAXPACKET) {
|
|
ipstat.ips_toolong++;
|
|
ip_freef(head, 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->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
|
|
m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
|
|
m_cat(m, q);
|
|
}
|
|
#ifdef MAC
|
|
mac_create_datagram_from_ipq(fp, m);
|
|
mac_destroy_ipq(fp);
|
|
#endif
|
|
|
|
#ifdef IPDIVERT
|
|
/*
|
|
* Extract firewall instructions from the fragment structure.
|
|
*/
|
|
*divinfo = fp->ipq_div_info;
|
|
*divert_rule = 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;
|
|
TAILQ_REMOVE(head, fp, ipq_list);
|
|
nipq--;
|
|
(void) m_free(dtom(fp));
|
|
m->m_len += (ip->ip_hl << 2);
|
|
m->m_data -= (ip->ip_hl << 2);
|
|
/* some debugging cruft by sklower, below, will go away soon */
|
|
if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
|
|
m_fixhdr(m);
|
|
return (m);
|
|
|
|
dropfrag:
|
|
#ifdef IPDIVERT
|
|
*divinfo = 0;
|
|
*divert_rule = 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(fhp, fp)
|
|
struct ipqhead *fhp;
|
|
struct ipq *fp;
|
|
{
|
|
register struct mbuf *q;
|
|
|
|
while (fp->ipq_frags) {
|
|
q = fp->ipq_frags;
|
|
fp->ipq_frags = q->m_nextpkt;
|
|
m_freem(q);
|
|
}
|
|
TAILQ_REMOVE(fhp, fp, ipq_list);
|
|
(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++) {
|
|
for(fp = TAILQ_FIRST(&ipq[i]); fp;) {
|
|
struct ipq *fpp;
|
|
|
|
fpp = fp;
|
|
fp = TAILQ_NEXT(fp, ipq_list);
|
|
if(--fpp->ipq_ttl == 0) {
|
|
ipstat.ips_fragtimeout++;
|
|
ip_freef(&ipq[i], fpp);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* If we are over the maximum number of fragments
|
|
* (due to the limit being lowered), drain off
|
|
* enough to get down to the new limit.
|
|
*/
|
|
if (maxnipq > 0 && nipq > maxnipq) {
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
while (nipq > maxnipq &&
|
|
!TAILQ_EMPTY(&ipq[i])) {
|
|
ipstat.ips_fragdropped++;
|
|
ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
|
|
}
|
|
}
|
|
}
|
|
ipflow_slowtimo();
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Drain off all datagram fragments.
|
|
*/
|
|
void
|
|
ip_drain()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < IPREASS_NHASH; i++) {
|
|
while(!TAILQ_EMPTY(&ipq[i])) {
|
|
ipstat.ips_fragdropped++;
|
|
ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
|
|
}
|
|
}
|
|
in_rtqdrain();
|
|
}
|
|
|
|
/*
|
|
* Do option processing on a datagram,
|
|
* possibly discarding it if bad options are encountered,
|
|
* or forwarding it if source-routed.
|
|
* The pass argument is used when operating in the IPSTEALTH
|
|
* mode to tell what options to process:
|
|
* [LS]SRR (pass 0) or the others (pass 1).
|
|
* The reason for as many as two passes is that when doing IPSTEALTH,
|
|
* non-routing options should be processed only if the packet is for us.
|
|
* Returns 1 if packet has been forwarded/freed,
|
|
* 0 if the packet should be processed further.
|
|
*/
|
|
static int
|
|
ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
u_char *cp;
|
|
struct in_ifaddr *ia;
|
|
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
|
|
struct in_addr *sin, dst;
|
|
n_time ntime;
|
|
struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
|
|
|
|
dst = ip->ip_dst;
|
|
cp = (u_char *)(ip + 1);
|
|
cnt = (ip->ip_hl << 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 {
|
|
if (cnt < IPOPT_OLEN + sizeof(*cp)) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
optlen = cp[IPOPT_OLEN];
|
|
if (optlen < IPOPT_OLEN + sizeof(*cp) || 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:
|
|
#ifdef IPSTEALTH
|
|
if (ipstealth && pass > 0)
|
|
break;
|
|
#endif
|
|
if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
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 - (int)sizeof(struct in_addr)) {
|
|
/*
|
|
* End of source route. Should be for us.
|
|
*/
|
|
if (!ip_acceptsourceroute)
|
|
goto nosourcerouting;
|
|
save_rte(cp, ip->ip_src);
|
|
break;
|
|
}
|
|
#ifdef IPSTEALTH
|
|
if (ipstealth)
|
|
goto dropit;
|
|
#endif
|
|
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.
|
|
*/
|
|
#ifdef IPSTEALTH
|
|
dropit:
|
|
#endif
|
|
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, &ipforward_rt);
|
|
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:
|
|
#ifdef IPSTEALTH
|
|
if (ipstealth && pass == 0)
|
|
break;
|
|
#endif
|
|
if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
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 - (int)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,
|
|
&ipforward_rt)) == 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:
|
|
#ifdef IPSTEALTH
|
|
if (ipstealth && pass == 0)
|
|
break;
|
|
#endif
|
|
code = cp - (u_char *)ip;
|
|
if (optlen < 4 || optlen > 40) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
if ((off = cp[IPOPT_OFFSET]) < 5) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
if (off > optlen - (int)sizeof(int32_t)) {
|
|
cp[IPOPT_OFFSET + 1] += (1 << 4);
|
|
if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
break;
|
|
}
|
|
off--; /* 0 origin */
|
|
sin = (struct in_addr *)(cp + off);
|
|
switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
|
|
|
|
case IPOPT_TS_TSONLY:
|
|
break;
|
|
|
|
case IPOPT_TS_TSANDADDR:
|
|
if (off + sizeof(n_time) +
|
|
sizeof(struct in_addr) > optlen) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
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));
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
off += sizeof(struct in_addr);
|
|
break;
|
|
|
|
case IPOPT_TS_PRESPEC:
|
|
if (off + sizeof(n_time) +
|
|
sizeof(struct in_addr) > optlen) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
(void)memcpy(&ipaddr.sin_addr, sin,
|
|
sizeof(struct in_addr));
|
|
if (ifa_ifwithaddr((SA)&ipaddr) == 0)
|
|
continue;
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
off += sizeof(struct in_addr);
|
|
break;
|
|
|
|
default:
|
|
code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
ntime = iptime();
|
|
(void)memcpy(cp + off, &ntime, sizeof(n_time));
|
|
cp[IPOPT_OFFSET] += sizeof(n_time);
|
|
}
|
|
}
|
|
if (forward && ipforwarding) {
|
|
ip_forward(m, 1, next_hop);
|
|
return (1);
|
|
}
|
|
return (0);
|
|
bad:
|
|
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.
|
|
*/
|
|
struct in_ifaddr *
|
|
ip_rtaddr(dst, rt)
|
|
struct in_addr dst;
|
|
struct route *rt;
|
|
{
|
|
register struct sockaddr_in *sin;
|
|
|
|
sin = (struct sockaddr_in *)&rt->ro_dst;
|
|
|
|
if (rt->ro_rt == 0 ||
|
|
!(rt->ro_rt->rt_flags & RTF_UP) ||
|
|
dst.s_addr != sin->sin_addr.s_addr) {
|
|
if (rt->ro_rt) {
|
|
RTFREE(rt->ro_rt);
|
|
rt->ro_rt = 0;
|
|
}
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_len = sizeof(*sin);
|
|
sin->sin_addr = dst;
|
|
|
|
rtalloc_ign(rt, RTF_PRCLONING);
|
|
}
|
|
if (rt->ro_rt == 0)
|
|
return ((struct in_ifaddr *)0);
|
|
return (ifatoia(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.
|
|
*/
|
|
static 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_NOWAIT, 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->ip_hl << 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_v = IPVERSION;
|
|
ip->ip_hl = 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, ECONNREFUSED
|
|
};
|
|
|
|
/*
|
|
* 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(struct mbuf *m, int srcrt, struct sockaddr_in *next_hop)
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
struct rtentry *rt;
|
|
int error, type = 0, code = 0;
|
|
struct mbuf *mcopy;
|
|
n_long dest;
|
|
struct in_addr pkt_dst;
|
|
struct ifnet *destifp;
|
|
#if defined(IPSEC) || defined(FAST_IPSEC)
|
|
struct ifnet dummyifp;
|
|
#endif
|
|
|
|
dest = 0;
|
|
/*
|
|
* Cache the destination address of the packet; this may be
|
|
* changed by use of 'ipfw fwd'.
|
|
*/
|
|
pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("forward: src %lx dst %lx ttl %x\n",
|
|
(u_long)ip->ip_src.s_addr, (u_long)pkt_dst.s_addr,
|
|
ip->ip_ttl);
|
|
#endif
|
|
|
|
|
|
if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(pkt_dst) == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
#ifdef IPSTEALTH
|
|
if (!ipstealth) {
|
|
#endif
|
|
if (ip->ip_ttl <= IPTTLDEC) {
|
|
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
|
|
dest, 0);
|
|
return;
|
|
}
|
|
#ifdef IPSTEALTH
|
|
}
|
|
#endif
|
|
|
|
if (ip_rtaddr(pkt_dst, &ipforward_rt) == 0) {
|
|
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
|
|
return;
|
|
} else
|
|
rt = ipforward_rt.ro_rt;
|
|
|
|
/*
|
|
* Save the IP header and at most 8 bytes of the payload,
|
|
* in case we need to generate an ICMP message to the src.
|
|
*
|
|
* XXX this can be optimized a lot by saving the data in a local
|
|
* buffer on the stack (72 bytes at most), and only allocating the
|
|
* mbuf if really necessary. The vast majority of the packets
|
|
* are forwarded without having to send an ICMP back (either
|
|
* because unnecessary, or because rate limited), so we are
|
|
* really we are wasting a lot of work here.
|
|
*
|
|
* We don't use m_copy() because it might return a reference
|
|
* to a shared cluster. Both this function and ip_output()
|
|
* assume exclusive access to the IP header in `m', so any
|
|
* data in a cluster may change before we reach icmp_error().
|
|
*/
|
|
MGET(mcopy, M_NOWAIT, m->m_type);
|
|
if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
|
|
/*
|
|
* It's probably ok if the pkthdr dup fails (because
|
|
* the deep copy of the tag chain failed), but for now
|
|
* be conservative and just discard the copy since
|
|
* code below may some day want the tags.
|
|
*/
|
|
m_free(mcopy);
|
|
mcopy = NULL;
|
|
}
|
|
if (mcopy != NULL) {
|
|
mcopy->m_len = imin((ip->ip_hl << 2) + 8,
|
|
(int)ip->ip_len);
|
|
m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
|
|
#ifdef MAC
|
|
/*
|
|
* XXXMAC: This will eventually become an explicit
|
|
* labeling point.
|
|
*/
|
|
mac_create_mbuf_from_mbuf(m, mcopy);
|
|
#endif
|
|
}
|
|
|
|
#ifdef IPSTEALTH
|
|
if (!ipstealth) {
|
|
#endif
|
|
ip->ip_ttl -= IPTTLDEC;
|
|
#ifdef IPSTEALTH
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
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 && !next_hop) {
|
|
#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 = pkt_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
|
|
}
|
|
}
|
|
|
|
{
|
|
struct m_hdr tag;
|
|
|
|
if (next_hop) {
|
|
/* Pass IPFORWARD info if available */
|
|
|
|
tag.mh_type = MT_TAG;
|
|
tag.mh_flags = PACKET_TAG_IPFORWARD;
|
|
tag.mh_data = (caddr_t)next_hop;
|
|
tag.mh_next = m;
|
|
m = (struct mbuf *)&tag;
|
|
}
|
|
error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
|
|
IP_FORWARDING, 0, NULL);
|
|
}
|
|
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;
|
|
#ifdef IPSEC
|
|
/*
|
|
* If the packet is routed over IPsec tunnel, tell the
|
|
* originator the tunnel MTU.
|
|
* tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
|
|
* XXX quickhack!!!
|
|
*/
|
|
if (ipforward_rt.ro_rt) {
|
|
struct secpolicy *sp = NULL;
|
|
int ipsecerror;
|
|
int ipsechdr;
|
|
struct route *ro;
|
|
|
|
sp = ipsec4_getpolicybyaddr(mcopy,
|
|
IPSEC_DIR_OUTBOUND,
|
|
IP_FORWARDING,
|
|
&ipsecerror);
|
|
|
|
if (sp == NULL)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
else {
|
|
/* count IPsec header size */
|
|
ipsechdr = ipsec4_hdrsiz(mcopy,
|
|
IPSEC_DIR_OUTBOUND,
|
|
NULL);
|
|
|
|
/*
|
|
* find the correct route for outer IPv4
|
|
* header, compute tunnel MTU.
|
|
*
|
|
* XXX BUG ALERT
|
|
* The "dummyifp" code relies upon the fact
|
|
* that icmp_error() touches only ifp->if_mtu.
|
|
*/
|
|
/*XXX*/
|
|
destifp = NULL;
|
|
if (sp->req != NULL
|
|
&& sp->req->sav != NULL
|
|
&& sp->req->sav->sah != NULL) {
|
|
ro = &sp->req->sav->sah->sa_route;
|
|
if (ro->ro_rt && ro->ro_rt->rt_ifp) {
|
|
dummyifp.if_mtu =
|
|
ro->ro_rt->rt_ifp->if_mtu;
|
|
dummyifp.if_mtu -= ipsechdr;
|
|
destifp = &dummyifp;
|
|
}
|
|
}
|
|
|
|
key_freesp(sp);
|
|
}
|
|
}
|
|
#elif FAST_IPSEC
|
|
/*
|
|
* If the packet is routed over IPsec tunnel, tell the
|
|
* originator the tunnel MTU.
|
|
* tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
|
|
* XXX quickhack!!!
|
|
*/
|
|
if (ipforward_rt.ro_rt) {
|
|
struct secpolicy *sp = NULL;
|
|
int ipsecerror;
|
|
int ipsechdr;
|
|
struct route *ro;
|
|
|
|
sp = ipsec_getpolicybyaddr(mcopy,
|
|
IPSEC_DIR_OUTBOUND,
|
|
IP_FORWARDING,
|
|
&ipsecerror);
|
|
|
|
if (sp == NULL)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
else {
|
|
/* count IPsec header size */
|
|
ipsechdr = ipsec4_hdrsiz(mcopy,
|
|
IPSEC_DIR_OUTBOUND,
|
|
NULL);
|
|
|
|
/*
|
|
* find the correct route for outer IPv4
|
|
* header, compute tunnel MTU.
|
|
*
|
|
* XXX BUG ALERT
|
|
* The "dummyifp" code relies upon the fact
|
|
* that icmp_error() touches only ifp->if_mtu.
|
|
*/
|
|
/*XXX*/
|
|
destifp = NULL;
|
|
if (sp->req != NULL
|
|
&& sp->req->sav != NULL
|
|
&& sp->req->sav->sah != NULL) {
|
|
ro = &sp->req->sav->sah->sa_route;
|
|
if (ro->ro_rt && ro->ro_rt->rt_ifp) {
|
|
dummyifp.if_mtu =
|
|
ro->ro_rt->rt_ifp->if_mtu;
|
|
dummyifp.if_mtu -= ipsechdr;
|
|
destifp = &dummyifp;
|
|
}
|
|
}
|
|
|
|
KEY_FREESP(&sp);
|
|
}
|
|
}
|
|
#else /* !IPSEC && !FAST_IPSEC */
|
|
if (ipforward_rt.ro_rt)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
#endif /*IPSEC*/
|
|
ipstat.ips_cantfrag++;
|
|
break;
|
|
|
|
case ENOBUFS:
|
|
/*
|
|
* A router should not generate ICMP_SOURCEQUENCH as
|
|
* required in RFC1812 Requirements for IP Version 4 Routers.
|
|
* Source quench could be a big problem under DoS attacks,
|
|
* or if the underlying interface is rate-limited.
|
|
* Those who need source quench packets may re-enable them
|
|
* via the net.inet.ip.sendsourcequench sysctl.
|
|
*/
|
|
if (ip_sendsourcequench == 0) {
|
|
m_freem(mcopy);
|
|
return;
|
|
} else {
|
|
type = ICMP_SOURCEQUENCH;
|
|
code = 0;
|
|
}
|
|
break;
|
|
|
|
case EACCES: /* ipfw denied packet */
|
|
m_freem(mcopy);
|
|
return;
|
|
}
|
|
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 *)
|
|
(ifaddr_byindex(ifp->if_index)->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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* XXX these routines are called from the upper part of the kernel.
|
|
* They need to be locked when we remove Giant.
|
|
*
|
|
* They could also be moved to ip_mroute.c, since all the RSVP
|
|
* handling is done there already.
|
|
*/
|
|
static int ip_rsvp_on;
|
|
struct socket *ip_rsvpd;
|
|
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;
|
|
}
|
|
|
|
void
|
|
rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
|
|
{
|
|
if (rsvp_input_p) { /* call the real one if loaded */
|
|
rsvp_input_p(m, off);
|
|
return;
|
|
}
|
|
|
|
/* Can still get packets with rsvp_on = 0 if there is a local member
|
|
* of the group to which the RSVP packet is addressed. But in this
|
|
* case we want to throw the packet away.
|
|
*/
|
|
|
|
if (!rsvp_on) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
if (ip_rsvpd != NULL) {
|
|
rip_input(m, off);
|
|
return;
|
|
}
|
|
/* Drop the packet */
|
|
m_freem(m);
|
|
}
|