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d137714f11
PR: 17319 Submitted by: Mike Heffner <spock@techfour.net>
1999 lines
52 KiB
C
1999 lines
52 KiB
C
/*
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* Copyright (c) 1993 Daniel Boulet
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* Copyright (c) 1994 Ugen J.S.Antsilevich
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* Copyright (c) 1996 Alex Nash
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* Copyright (c) 2000 Luigi Rizzo
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*
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* Redistribution and use in source forms, with and without modification,
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* are permitted provided that this entire comment appears intact.
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*
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* Redistribution in binary form may occur without any restrictions.
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* Obviously, it would be nice if you gave credit where credit is due
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* but requiring it would be too onerous.
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*
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* This software is provided ``AS IS'' without any warranties of any kind.
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*
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* $FreeBSD$
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*/
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#define STATEFUL 1
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#define DEB(x)
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#define DDB(x) x
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/*
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* Implement IP packet firewall
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*/
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#if !defined(KLD_MODULE)
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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_inet.h"
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#ifndef INET
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#error IPFIREWALL requires INET.
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#endif /* INET */
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#endif
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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#include <sys/syslog.h>
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#include <sys/ucred.h>
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#include <net/if.h>
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#include <net/route.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_pcb.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip_fw.h>
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#ifdef DUMMYNET
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#include <netinet/ip_dummynet.h>
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#endif
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#include <netinet/tcp.h>
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#include <netinet/tcp_timer.h>
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#include <netinet/tcp_var.h>
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#include <netinet/tcpip.h>
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#include <netinet/udp.h>
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#include <netinet/udp_var.h>
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#include <netinet/if_ether.h> /* XXX ethertype_ip */
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static int fw_debug = 1;
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#ifdef IPFIREWALL_VERBOSE
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static int fw_verbose = 1;
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#else
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static int fw_verbose = 0;
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#endif
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int fw_one_pass = 1 ;
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#ifdef IPFIREWALL_VERBOSE_LIMIT
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static int fw_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
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#else
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static int fw_verbose_limit = 0;
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#endif
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static u_int64_t counter; /* counter for ipfw_report(NULL...) */
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struct ipfw_flow_id last_pkt ;
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#define IPFW_DEFAULT_RULE ((u_int)(u_short)~0)
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LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain;
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MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
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#ifdef SYSCTL_NODE
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SYSCTL_DECL(_net_inet_ip);
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SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW,
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&fw_enable, 0, "Enable ipfw");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
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&fw_one_pass, 0,
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"Only do a single pass through ipfw when using divert(4)/dummynet(4)");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
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&fw_debug, 0, "Enable printing of debug ip_fw statements");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
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&fw_verbose, 0, "Log matches to ipfw rules");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
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&fw_verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
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#if STATEFUL
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/*
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* Extension for stateful ipfw.
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*
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* Dynamic rules are stored in lists accessed through a hash table
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* (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
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* be modified through the sysctl variable dyn_buckets which is
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* updated when the table becomes empty.
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*
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* XXX currently there is only one list, ipfw_dyn.
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*
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* When a packet is received, it is first hashed, then matched
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* against the entries in the corresponding list.
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* Matching occurs according to the rule type. The default is to
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* match the four fields and the protocol, and rules are bidirectional.
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*
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* For a busy proxy/web server we will have lots of connections to
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* the server. We could decide for a rule type where we ignore
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* ports (different hashing) and avoid special SYN/RST/FIN handling.
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*
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* XXX when we decide to support more than one rule type, we should
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* repeat the hashing multiple times uing only the useful fields.
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* Or, we could run the various tests in parallel, because the
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* 'move to front' technique should shorten the average search.
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*
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* The lifetime of dynamic rules is regulated by dyn_*_lifetime,
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* measured in seconds and depending on the flags.
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*
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* The total number of dynamic rules is stored in dyn_count.
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* The max number of dynamic rules is dyn_max. When we reach
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* the maximum number of rules we do not create anymore. This is
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* done to avoid consuming too much memory, but also too much
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* time when searching on each packet (ideally, we should try instead
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* to put a limit on the length of the list on each bucket...).
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*
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* Each dynamic rules holds a pointer to the parent ipfw rule so
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* we know what action to perform. Dynamic rules are removed when
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* the parent rule is deleted.
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* There are some limitations with dynamic rules -- we do not
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* obey the 'randomized match', and we do not do multiple
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* passes through the firewall.
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* XXX check the latter!!!
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*/
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static struct ipfw_dyn_rule **ipfw_dyn_v = NULL ;
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static u_int32_t dyn_buckets = 256 ; /* must be power of 2 */
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static u_int32_t curr_dyn_buckets = 256 ; /* must be power of 2 */
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static u_int32_t dyn_ack_lifetime = 300 ;
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static u_int32_t dyn_syn_lifetime = 20 ;
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static u_int32_t dyn_fin_lifetime = 20 ;
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static u_int32_t dyn_rst_lifetime = 5 ;
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static u_int32_t dyn_short_lifetime = 30 ;
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static u_int32_t dyn_count = 0 ;
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static u_int32_t dyn_max = 1000 ;
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
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&dyn_buckets, 0, "Number of dyn. buckets");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
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&curr_dyn_buckets, 0, "Current Number of dyn. buckets");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
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&dyn_count, 0, "Number of dyn. rules");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
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&dyn_max, 0, "Max number of dyn. rules");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
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&dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
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&dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
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&dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
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&dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
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&dyn_rst_lifetime, 0, "Lifetime of dyn. rules for other situations");
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#endif /* STATEFUL */
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#endif
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#define dprintf(a) do { \
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if (fw_debug) \
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printf a; \
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} while (0)
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#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
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static int add_entry __P((struct ip_fw_head *chainptr, struct ip_fw *frwl));
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static int del_entry __P((struct ip_fw_head *chainptr, u_short number));
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static int zero_entry __P((struct ip_fw *));
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static int resetlog_entry __P((struct ip_fw *));
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static int check_ipfw_struct __P((struct ip_fw *m));
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static __inline int
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iface_match __P((struct ifnet *ifp, union ip_fw_if *ifu,
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int byname));
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static int ipopts_match __P((struct ip *ip, struct ip_fw *f));
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static __inline int
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port_match __P((u_short *portptr, int nports, u_short port,
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int range_flag, int mask));
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static int tcpflg_match __P((struct tcphdr *tcp, struct ip_fw *f));
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static int icmptype_match __P((struct icmp * icmp, struct ip_fw * f));
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static void ipfw_report __P((struct ip_fw *f, struct ip *ip,
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struct ifnet *rif, struct ifnet *oif));
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static void flush_rule_ptrs(void);
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static int ip_fw_chk __P((struct ip **pip, int hlen,
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struct ifnet *oif, u_int16_t *cookie, struct mbuf **m,
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struct ip_fw_chain **flow_id,
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struct sockaddr_in **next_hop));
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static int ip_fw_ctl __P((struct sockopt *sopt));
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static char err_prefix[] = "ip_fw_ctl:";
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/*
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* Returns 1 if the port is matched by the vector, 0 otherwise
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*/
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static __inline int
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port_match(u_short *portptr, int nports, u_short port, int range_flag, int mask)
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{
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if (!nports)
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return 1;
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if (mask) {
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if ( 0 == ((portptr[0] ^ port) & portptr[1]) )
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return 1;
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nports -= 2;
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portptr += 2;
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}
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if (range_flag) {
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if (portptr[0] <= port && port <= portptr[1]) {
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return 1;
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}
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nports -= 2;
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portptr += 2;
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}
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while (nports-- > 0) {
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if (*portptr++ == port) {
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return 1;
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}
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}
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return 0;
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}
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static int
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tcpflg_match(struct tcphdr *tcp, struct ip_fw *f)
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{
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u_char flg_set, flg_clr;
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if ((f->fw_tcpf & IP_FW_TCPF_ESTAB) &&
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(tcp->th_flags & (IP_FW_TCPF_RST | IP_FW_TCPF_ACK)))
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return 1;
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flg_set = tcp->th_flags & f->fw_tcpf;
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flg_clr = tcp->th_flags & f->fw_tcpnf;
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if (flg_set != f->fw_tcpf)
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return 0;
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if (flg_clr)
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return 0;
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return 1;
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}
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static int
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icmptype_match(struct icmp *icmp, struct ip_fw *f)
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{
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int type;
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if (!(f->fw_flg & IP_FW_F_ICMPBIT))
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return(1);
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type = icmp->icmp_type;
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/* check for matching type in the bitmap */
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if (type < IP_FW_ICMPTYPES_MAX &&
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(f->fw_uar.fw_icmptypes[type / (sizeof(unsigned) * NBBY)] &
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(1U << (type % (sizeof(unsigned) * NBBY)))))
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return(1);
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return(0); /* no match */
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}
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static int
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is_icmp_query(struct ip *ip)
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{
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const struct icmp *icmp;
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int icmp_type;
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icmp = (struct icmp *)((u_int32_t *)ip + ip->ip_hl);
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icmp_type = icmp->icmp_type;
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if (icmp_type == ICMP_ECHO || icmp_type == ICMP_ROUTERSOLICIT ||
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icmp_type == ICMP_TSTAMP || icmp_type == ICMP_IREQ ||
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icmp_type == ICMP_MASKREQ)
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return(1);
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return(0);
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}
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static int
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ipopts_match(struct ip *ip, struct ip_fw *f)
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{
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register u_char *cp;
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int opt, optlen, cnt;
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u_char opts, nopts, nopts_sve;
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cp = (u_char *)(ip + 1);
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cnt = (ip->ip_hl << 2) - sizeof (struct ip);
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opts = f->fw_ipopt;
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nopts = nopts_sve = f->fw_ipnopt;
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for (; cnt > 0; cnt -= optlen, cp += optlen) {
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opt = cp[IPOPT_OPTVAL];
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if (opt == IPOPT_EOL)
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break;
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if (opt == IPOPT_NOP)
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optlen = 1;
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else {
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optlen = cp[IPOPT_OLEN];
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if (optlen <= 0 || optlen > cnt) {
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return 0; /*XXX*/
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}
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}
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switch (opt) {
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default:
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break;
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case IPOPT_LSRR:
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opts &= ~IP_FW_IPOPT_LSRR;
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nopts &= ~IP_FW_IPOPT_LSRR;
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break;
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case IPOPT_SSRR:
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opts &= ~IP_FW_IPOPT_SSRR;
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nopts &= ~IP_FW_IPOPT_SSRR;
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break;
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case IPOPT_RR:
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opts &= ~IP_FW_IPOPT_RR;
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nopts &= ~IP_FW_IPOPT_RR;
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break;
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case IPOPT_TS:
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opts &= ~IP_FW_IPOPT_TS;
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nopts &= ~IP_FW_IPOPT_TS;
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break;
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}
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if (opts == nopts)
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break;
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}
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if (opts == 0 && nopts == nopts_sve)
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return 1;
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else
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return 0;
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}
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static __inline int
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iface_match(struct ifnet *ifp, union ip_fw_if *ifu, int byname)
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{
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/* Check by name or by IP address */
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if (byname) {
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/* Check unit number (-1 is wildcard) */
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if (ifu->fu_via_if.unit != -1
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&& ifp->if_unit != ifu->fu_via_if.unit)
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return(0);
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/* Check name */
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if (strncmp(ifp->if_name, ifu->fu_via_if.name, FW_IFNLEN))
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return(0);
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return(1);
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} else if (ifu->fu_via_ip.s_addr != 0) { /* Zero == wildcard */
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struct ifaddr *ia;
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for (ia = ifp->if_addrhead.tqh_first;
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ia != NULL; ia = ia->ifa_link.tqe_next) {
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if (ia->ifa_addr == NULL)
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continue;
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if (ia->ifa_addr->sa_family != AF_INET)
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continue;
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if (ifu->fu_via_ip.s_addr != ((struct sockaddr_in *)
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(ia->ifa_addr))->sin_addr.s_addr)
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continue;
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return(1);
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}
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return(0);
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}
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return(1);
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}
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static void
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ipfw_report(struct ip_fw *f, struct ip *ip,
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struct ifnet *rif, struct ifnet *oif)
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{
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if (ip) {
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struct tcphdr *const tcp = (struct tcphdr *) ((u_int32_t *) ip+ ip->ip_hl);
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struct udphdr *const udp = (struct udphdr *) ((u_int32_t *) ip+ ip->ip_hl);
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struct icmp *const icmp = (struct icmp *) ((u_int32_t *) ip + ip->ip_hl);
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u_int64_t count;
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char *action;
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char action2[32], proto[47], name[18], fragment[17];
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int len;
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count = f ? f->fw_pcnt : ++counter;
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if ((f == NULL && fw_verbose_limit != 0 && count > fw_verbose_limit) ||
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(f && f->fw_logamount != 0 && count > f->fw_loghighest))
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return;
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/* Print command name */
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snprintf(SNPARGS(name, 0), "ipfw: %d", f ? f->fw_number : -1);
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action = action2;
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if (!f)
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action = "Refuse";
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else {
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switch (f->fw_flg & IP_FW_F_COMMAND) {
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case IP_FW_F_DENY:
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action = "Deny";
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break;
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case IP_FW_F_REJECT:
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if (f->fw_reject_code == IP_FW_REJECT_RST)
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action = "Reset";
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else
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action = "Unreach";
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break;
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case IP_FW_F_ACCEPT:
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action = "Accept";
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break;
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case IP_FW_F_COUNT:
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action = "Count";
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break;
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#ifdef IPDIVERT
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case IP_FW_F_DIVERT:
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snprintf(SNPARGS(action2, 0), "Divert %d",
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f->fw_divert_port);
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break;
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case IP_FW_F_TEE:
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snprintf(SNPARGS(action2, 0), "Tee %d",
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f->fw_divert_port);
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break;
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#endif
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case IP_FW_F_SKIPTO:
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snprintf(SNPARGS(action2, 0), "SkipTo %d",
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f->fw_skipto_rule);
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break;
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#ifdef DUMMYNET
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case IP_FW_F_PIPE:
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snprintf(SNPARGS(action2, 0), "Pipe %d",
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f->fw_skipto_rule);
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break;
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#endif
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#ifdef IPFIREWALL_FORWARD
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case IP_FW_F_FWD:
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if (f->fw_fwd_ip.sin_port)
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snprintf(SNPARGS(action2, 0),
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"Forward to %s:%d",
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inet_ntoa(f->fw_fwd_ip.sin_addr),
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f->fw_fwd_ip.sin_port);
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else
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snprintf(SNPARGS(action2, 0), "Forward to %s",
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inet_ntoa(f->fw_fwd_ip.sin_addr));
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break;
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#endif
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default:
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|
action = "UNKNOWN";
|
|
break;
|
|
}
|
|
}
|
|
|
|
switch (ip->ip_p) {
|
|
case IPPROTO_TCP:
|
|
len = snprintf(SNPARGS(proto, 0), "TCP %s",
|
|
inet_ntoa(ip->ip_src));
|
|
if ((ip->ip_off & IP_OFFMASK) == 0)
|
|
len += snprintf(SNPARGS(proto, len), ":%d ",
|
|
ntohs(tcp->th_sport));
|
|
else
|
|
len += snprintf(SNPARGS(proto, len), " ");
|
|
len += snprintf(SNPARGS(proto, len), "%s",
|
|
inet_ntoa(ip->ip_dst));
|
|
if ((ip->ip_off & IP_OFFMASK) == 0)
|
|
snprintf(SNPARGS(proto, len), ":%d",
|
|
ntohs(tcp->th_dport));
|
|
break;
|
|
case IPPROTO_UDP:
|
|
len = snprintf(SNPARGS(proto, 0), "UDP %s",
|
|
inet_ntoa(ip->ip_src));
|
|
if ((ip->ip_off & IP_OFFMASK) == 0)
|
|
len += snprintf(SNPARGS(proto, len), ":%d ",
|
|
ntohs(udp->uh_sport));
|
|
else
|
|
len += snprintf(SNPARGS(proto, len), " ");
|
|
len += snprintf(SNPARGS(proto, len), "%s",
|
|
inet_ntoa(ip->ip_dst));
|
|
if ((ip->ip_off & IP_OFFMASK) == 0)
|
|
snprintf(SNPARGS(proto, len), ":%d",
|
|
ntohs(udp->uh_dport));
|
|
break;
|
|
case IPPROTO_ICMP:
|
|
if ((ip->ip_off & IP_OFFMASK) == 0)
|
|
len = snprintf(SNPARGS(proto, 0), "ICMP:%u.%u ",
|
|
icmp->icmp_type, icmp->icmp_code);
|
|
else
|
|
len = snprintf(SNPARGS(proto, 0), "ICMP ");
|
|
len += snprintf(SNPARGS(proto, len), "%s",
|
|
inet_ntoa(ip->ip_src));
|
|
snprintf(SNPARGS(proto, len), " %s", inet_ntoa(ip->ip_dst));
|
|
break;
|
|
default:
|
|
len = snprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
|
|
inet_ntoa(ip->ip_src));
|
|
snprintf(SNPARGS(proto, len), " %s", inet_ntoa(ip->ip_dst));
|
|
break;
|
|
}
|
|
|
|
if ((ip->ip_off & IP_OFFMASK))
|
|
snprintf(SNPARGS(fragment, 0), " Fragment = %d",
|
|
ip->ip_off & IP_OFFMASK);
|
|
else
|
|
fragment[0] = '\0';
|
|
if (oif)
|
|
log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s%d%s\n",
|
|
name, action, proto, oif->if_name, oif->if_unit, fragment);
|
|
else if (rif)
|
|
log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s%d%s\n", name,
|
|
action, proto, rif->if_name, rif->if_unit, fragment);
|
|
else
|
|
log(LOG_SECURITY | LOG_INFO, "%s %s %s%s\n", name, action,
|
|
proto, fragment);
|
|
if ((f ? f->fw_logamount != 0 : 1) &&
|
|
count == (f ? f->fw_loghighest : fw_verbose_limit))
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: limit %d reached on entry %d\n",
|
|
f ? f->fw_logamount : fw_verbose_limit,
|
|
f ? f->fw_number : -1);
|
|
}
|
|
}
|
|
|
|
#if STATEFUL
|
|
static __inline int
|
|
hash_packet(struct ipfw_flow_id *id)
|
|
{
|
|
u_int32_t i ;
|
|
|
|
i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
|
|
i &= (curr_dyn_buckets - 1) ;
|
|
return i ;
|
|
}
|
|
|
|
#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
|
|
/*
|
|
* Remove all dynamic rules pointing to a given chain, or all
|
|
* rules if chain == NULL. Second parameter is 1 if we want to
|
|
* delete unconditionally, otherwise only expired rules are removed.
|
|
*/
|
|
static void
|
|
remove_dyn_rule(struct ip_fw_chain *chain, int force)
|
|
{
|
|
struct ipfw_dyn_rule *prev, *q, *old_q ;
|
|
int i ;
|
|
static u_int32_t last_remove = 0 ;
|
|
|
|
if (ipfw_dyn_v == NULL || dyn_count == 0)
|
|
return ;
|
|
/* do not expire more than once per second, it is useless */
|
|
if (force == 0 && last_remove == time_second)
|
|
return ;
|
|
last_remove = time_second ;
|
|
|
|
for (i = 0 ; i < curr_dyn_buckets ; i++) {
|
|
for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
|
|
if ( (chain == NULL || chain == q->chain) &&
|
|
(force || TIME_LEQ( q->expire , time_second ) ) ) {
|
|
DEB(printf("-- remove entry 0x%08x %d -> 0x%08x %d, %d left\n",
|
|
(q->id.src_ip), (q->id.src_port),
|
|
(q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); )
|
|
old_q = q ;
|
|
if (prev != NULL)
|
|
prev->next = q = q->next ;
|
|
else
|
|
ipfw_dyn_v[i] = q = q->next ;
|
|
dyn_count-- ;
|
|
free(old_q, M_IPFW);
|
|
continue ;
|
|
} else {
|
|
prev = q ;
|
|
q = q->next ;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct ipfw_dyn_rule *
|
|
lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction)
|
|
{
|
|
/*
|
|
* stateful ipfw extensions.
|
|
* Lookup into dynamic session queue
|
|
*/
|
|
struct ipfw_dyn_rule *prev, *q, *old_q ;
|
|
int i, dir = 0;
|
|
#define MATCH_FORWARD 1
|
|
|
|
if (ipfw_dyn_v == NULL)
|
|
return NULL ;
|
|
i = hash_packet( pkt );
|
|
for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
|
|
if (TIME_LEQ( q->expire , time_second ) ) { /* expire entry */
|
|
old_q = q ;
|
|
if (prev != NULL)
|
|
prev->next = q = q->next ;
|
|
else
|
|
ipfw_dyn_v[i] = q = q->next ;
|
|
dyn_count-- ;
|
|
free(old_q, M_IPFW);
|
|
continue ;
|
|
}
|
|
if ( pkt->proto == q->id.proto) {
|
|
switch (q->type) {
|
|
default: /* bidirectional rule, no masks */
|
|
if (pkt->src_ip == q->id.src_ip &&
|
|
pkt->dst_ip == q->id.dst_ip &&
|
|
pkt->src_port == q->id.src_port &&
|
|
pkt->dst_port == q->id.dst_port ) {
|
|
dir = MATCH_FORWARD ;
|
|
goto found ;
|
|
}
|
|
if (pkt->src_ip == q->id.dst_ip &&
|
|
pkt->dst_ip == q->id.src_ip &&
|
|
pkt->src_port == q->id.dst_port &&
|
|
pkt->dst_port == q->id.src_port ) {
|
|
dir = 0 ; /* reverse match */
|
|
goto found ;
|
|
}
|
|
break ;
|
|
}
|
|
}
|
|
prev = q ;
|
|
q = q->next ;
|
|
}
|
|
return NULL ; /* clearly not found */
|
|
found:
|
|
if ( prev != NULL) { /* found and not in front */
|
|
prev->next = q->next ;
|
|
q->next = ipfw_dyn_v[i] ;
|
|
ipfw_dyn_v[i] = q ;
|
|
}
|
|
if (pkt->proto == IPPROTO_TCP) {
|
|
/* update state according to flags */
|
|
u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
|
|
q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
|
|
switch (q->state) {
|
|
case TH_SYN :
|
|
/* opening */
|
|
q->expire = time_second + dyn_syn_lifetime ;
|
|
break ;
|
|
case TH_SYN | (TH_SYN << 8) :
|
|
/* move to established */
|
|
q->expire = time_second + dyn_ack_lifetime ;
|
|
break ;
|
|
case TH_SYN | (TH_SYN << 8) | TH_FIN :
|
|
case TH_SYN | (TH_SYN << 8) | (TH_FIN << 8) :
|
|
/* one side tries to close */
|
|
q->expire = time_second + dyn_fin_lifetime ;
|
|
break ;
|
|
case TH_SYN | (TH_SYN << 8) | TH_FIN | (TH_FIN << 8) :
|
|
/* both sides closed */
|
|
q->expire = time_second + dyn_fin_lifetime ;
|
|
break ;
|
|
default:
|
|
/* reset or some invalid combination */
|
|
if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
|
|
printf("invalid state: 0x%x\n", q->state);
|
|
q->expire = time_second + dyn_rst_lifetime ;
|
|
break ;
|
|
}
|
|
} else {
|
|
/* should do something for UDP and others... */
|
|
q->expire = time_second + dyn_short_lifetime ;
|
|
}
|
|
if (match_direction)
|
|
*match_direction = dir ;
|
|
return q ;
|
|
}
|
|
|
|
/*
|
|
* Install state for a dynamic session.
|
|
*/
|
|
|
|
static void
|
|
add_dyn_rule(struct ipfw_flow_id *id, struct ipfw_flow_id *mask,
|
|
struct ip_fw_chain *chain)
|
|
{
|
|
struct ipfw_dyn_rule *r ;
|
|
|
|
int i ;
|
|
if (ipfw_dyn_v == NULL ||
|
|
(dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
|
|
/* try reallocation, make sure we have a power of 2 */
|
|
u_int32_t i = dyn_buckets ;
|
|
while ( i > 0 && (i & 1) == 0 )
|
|
i >>= 1 ;
|
|
if (i != 1) /* not a power of 2 */
|
|
dyn_buckets = curr_dyn_buckets ; /* reset */
|
|
else {
|
|
if (ipfw_dyn_v != NULL)
|
|
free(ipfw_dyn_v, M_IPFW);
|
|
ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof r,
|
|
M_IPFW, M_DONTWAIT);
|
|
if (ipfw_dyn_v == NULL)
|
|
return ; /* failed ! */
|
|
bzero(ipfw_dyn_v, curr_dyn_buckets * sizeof r);
|
|
}
|
|
}
|
|
i = hash_packet(id);
|
|
|
|
r = malloc(sizeof *r, M_IPFW, M_DONTWAIT);
|
|
if (r == NULL) {
|
|
printf ("sorry cannot allocate state\n");
|
|
return ;
|
|
}
|
|
bzero (r, sizeof (*r) );
|
|
|
|
if (mask)
|
|
r->mask = *mask ;
|
|
r->id = *id ;
|
|
r->expire = time_second + dyn_syn_lifetime ;
|
|
r->chain = chain ;
|
|
r->type = ((struct ip_fw_ext *)chain->rule)->dyn_type ;
|
|
|
|
r->bucket = i ;
|
|
r->next = ipfw_dyn_v[i] ;
|
|
ipfw_dyn_v[i] = r ;
|
|
dyn_count++ ;
|
|
DEB(printf("-- add entry 0x%08x %d -> 0x%08x %d, %d left\n",
|
|
(r->id.src_ip), (r->id.src_port),
|
|
(r->id.dst_ip), (r->id.dst_port),
|
|
dyn_count ); )
|
|
}
|
|
|
|
/*
|
|
* Install dynamic state.
|
|
* There are different types of dynamic rules which can be installed.
|
|
* The type is in chain->dyn_type.
|
|
* Type 0 (default) is a bidirectional rule
|
|
*/
|
|
static void
|
|
install_state(struct ip_fw_chain *chain, struct ip **pip, struct ip *ip)
|
|
{
|
|
struct ipfw_dyn_rule *q ;
|
|
u_long type = ((struct ip_fw_ext *)chain->rule)->dyn_type ;
|
|
|
|
DEB(printf("-- install state type %d 0x%08lx %u -> 0x%08lx %u\n",
|
|
type,
|
|
(last_pkt.src_ip), (last_pkt.src_port),
|
|
(last_pkt.dst_ip), (last_pkt.dst_port) );)
|
|
|
|
q = lookup_dyn_rule(&last_pkt, NULL) ;
|
|
if (q != NULL) {
|
|
printf(" entry already present, done\n");
|
|
return ;
|
|
}
|
|
if (dyn_count >= dyn_max) /* try remove old ones... */
|
|
remove_dyn_rule(NULL, 0 /* expire */);
|
|
if (dyn_count >= dyn_max) {
|
|
printf(" Too many dynamic rules, sorry\n");
|
|
return ;
|
|
}
|
|
switch (type) {
|
|
default: /* bidir rule */
|
|
add_dyn_rule(&last_pkt, NULL, chain);
|
|
break ;
|
|
}
|
|
q = lookup_dyn_rule(&last_pkt, NULL) ; /* XXX this just sets the lifetime ... */
|
|
}
|
|
#endif /* STATEFUL */
|
|
|
|
/*
|
|
* given an ip_fw_chain *, lookup_next_rule will return a pointer
|
|
* of the same type to the next one. This can be either the jump
|
|
* target (for skipto instructions) or the next one in the chain (in
|
|
* all other cases including a missing jump target).
|
|
* Backward jumps are not allowed, so start looking from the next
|
|
* rule...
|
|
*/
|
|
static struct ip_fw_chain * lookup_next_rule(struct ip_fw_chain *me);
|
|
|
|
static struct ip_fw_chain *
|
|
lookup_next_rule(struct ip_fw_chain *me)
|
|
{
|
|
struct ip_fw_chain *chain ;
|
|
int rule = me->rule->fw_skipto_rule ; /* guess... */
|
|
|
|
if ( (me->rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_SKIPTO )
|
|
for (chain = me->chain.le_next; chain ; chain = chain->chain.le_next )
|
|
if (chain->rule->fw_number >= rule)
|
|
return chain ;
|
|
return me->chain.le_next ; /* failure or not a skipto */
|
|
}
|
|
|
|
/*
|
|
* Parameters:
|
|
*
|
|
* pip Pointer to packet header (struct ip **)
|
|
* bridge_ipfw extension: pip = NULL means a complete ethernet packet
|
|
* including ethernet header in the mbuf. Other fields
|
|
* are ignored/invalid.
|
|
*
|
|
* hlen Packet header length
|
|
* oif Outgoing interface, or NULL if packet is incoming
|
|
* *cookie Skip up to the first rule past this rule number;
|
|
* upon return, non-zero port number for divert or tee
|
|
* *m The packet; we set to NULL when/if we nuke it.
|
|
* *flow_id pointer to the last matching rule (in/out)
|
|
* *next_hop socket we are forwarding to (in/out).
|
|
*
|
|
* Return value:
|
|
*
|
|
* 0 The packet is to be accepted and routed normally OR
|
|
* the packet was denied/rejected and has been dropped;
|
|
* in the latter case, *m is equal to NULL upon return.
|
|
* port Divert the packet to port, with these caveats:
|
|
*
|
|
* - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
|
|
* of diverting it (ie, 'ipfw tee').
|
|
*
|
|
* - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
|
|
* 16 bits as a dummynet pipe number instead of diverting
|
|
*/
|
|
|
|
static int
|
|
ip_fw_chk(struct ip **pip, int hlen,
|
|
struct ifnet *oif, u_int16_t *cookie, struct mbuf **m,
|
|
struct ip_fw_chain **flow_id,
|
|
struct sockaddr_in **next_hop)
|
|
{
|
|
struct ip_fw_chain *chain;
|
|
struct ip_fw *f = NULL, *rule = NULL;
|
|
struct ip *ip = NULL ;
|
|
struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
|
|
u_short offset = 0 ;
|
|
u_short src_port = 0, dst_port = 0;
|
|
struct in_addr src_ip, dst_ip; /* XXX */
|
|
u_int8_t proto= 0, flags = 0 ; /* XXX */
|
|
u_int16_t skipto;
|
|
|
|
#if STATEFUL
|
|
int dyn_checked = 0 ; /* set after dyn.rules have been checked. */
|
|
int direction = MATCH_FORWARD ; /* dirty trick... */
|
|
struct ipfw_dyn_rule *q = NULL ;
|
|
#endif
|
|
/* Grab and reset cookie */
|
|
skipto = *cookie;
|
|
*cookie = 0;
|
|
|
|
/*
|
|
* here, pip==NULL for bridged pkts -- they include the ethernet
|
|
* header so i have to adjust lengths accordingly
|
|
*/
|
|
#define PULLUP_TO(l) do { \
|
|
int len = (pip ? (l) : (l) + 14 ); \
|
|
if ((*m)->m_len < (len) ) { \
|
|
if ( (*m = m_pullup(*m, (len))) == 0) \
|
|
goto bogusfrag; \
|
|
ip = mtod(*m, struct ip *); \
|
|
if (pip) \
|
|
*pip = ip ; \
|
|
else \
|
|
ip = (struct ip *)((char *)ip + 14);\
|
|
offset = (ip->ip_off & IP_OFFMASK); \
|
|
} \
|
|
} while (0)
|
|
|
|
if (pip) { /* normal ip packet */
|
|
ip = *pip;
|
|
offset = (ip->ip_off & IP_OFFMASK);
|
|
} else { /* bridged or non-ip packet */
|
|
struct ether_header *eh = mtod(*m, struct ether_header *);
|
|
switch (ntohs(eh->ether_type)) {
|
|
case ETHERTYPE_IP :
|
|
if ((*m)->m_len<sizeof(struct ether_header) + sizeof(struct ip))
|
|
goto non_ip ;
|
|
ip = (struct ip *)(eh + 1 );
|
|
if (ip->ip_v != IPVERSION)
|
|
goto non_ip ;
|
|
hlen = ip->ip_hl << 2;
|
|
if (hlen < sizeof(struct ip)) /* minimum header length */
|
|
goto non_ip ;
|
|
if ((*m)->m_len < 14 + hlen + 14) {
|
|
printf("-- m_len %d, need more...\n", (*m)->m_len);
|
|
goto non_ip ;
|
|
}
|
|
offset = (ip->ip_off & IP_OFFMASK);
|
|
break ;
|
|
default :
|
|
non_ip: ip = NULL ;
|
|
break ;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* collect parameters into local variables for faster matching.
|
|
*/
|
|
if (ip) {
|
|
struct tcphdr *tcp;
|
|
struct udphdr *udp;
|
|
|
|
dst_ip = ip->ip_dst ;
|
|
src_ip = ip->ip_src ;
|
|
proto = ip->ip_p ;
|
|
/*
|
|
* warning - if offset != 0, port values are bogus.
|
|
* Not a problem for ipfw, but could be for dummynet.
|
|
*/
|
|
switch (proto) {
|
|
case IPPROTO_TCP :
|
|
PULLUP_TO(hlen + 14);
|
|
tcp =(struct tcphdr *)((u_int32_t *)ip + ip->ip_hl);
|
|
dst_port = tcp->th_dport ;
|
|
src_port = tcp->th_sport ;
|
|
flags = tcp->th_flags ;
|
|
break ;
|
|
|
|
case IPPROTO_UDP :
|
|
PULLUP_TO(hlen + 4);
|
|
udp =(struct udphdr *)((u_int32_t *)ip + ip->ip_hl);
|
|
dst_port = udp->uh_dport ;
|
|
src_port = udp->uh_sport ;
|
|
break;
|
|
|
|
case IPPROTO_ICMP:
|
|
PULLUP_TO(hlen + 2);
|
|
flags = ((struct icmp *)
|
|
((u_int32_t *)ip + ip->ip_hl))->icmp_type ;
|
|
break ;
|
|
|
|
default :
|
|
src_port = dst_port = 0 ;
|
|
}
|
|
#undef PULLUP_TO
|
|
last_pkt.src_ip = ntohl(src_ip.s_addr) ;
|
|
last_pkt.dst_ip = ntohl(dst_ip.s_addr) ;
|
|
last_pkt.proto = proto ;
|
|
last_pkt.src_port = ntohs(src_port) ;
|
|
last_pkt.dst_port = ntohs(dst_port) ;
|
|
last_pkt.flags = flags ;
|
|
}
|
|
|
|
if (*flow_id) {
|
|
/* Accept if passed first test */
|
|
if (fw_one_pass)
|
|
return 0;
|
|
/*
|
|
* Packet has already been tagged. Look for the next rule
|
|
* to restart processing.
|
|
*/
|
|
chain = LIST_NEXT(*flow_id, chain);
|
|
|
|
if ((chain = (*flow_id)->rule->next_rule_ptr) == NULL)
|
|
chain = (*flow_id)->rule->next_rule_ptr =
|
|
lookup_next_rule(*flow_id);
|
|
if (chain == NULL)
|
|
goto dropit;
|
|
} else {
|
|
/*
|
|
* Go down the chain, looking for enlightment.
|
|
* If we've been asked to start at a given rule, do so.
|
|
*/
|
|
chain = LIST_FIRST(&ip_fw_chain);
|
|
if (skipto != 0) {
|
|
if (skipto >= IPFW_DEFAULT_RULE)
|
|
goto dropit;
|
|
while (chain && chain->rule->fw_number <= skipto)
|
|
chain = LIST_NEXT(chain, chain);
|
|
if (chain == NULL)
|
|
goto dropit;
|
|
}
|
|
}
|
|
|
|
|
|
for (; chain; chain = LIST_NEXT(chain, chain)) {
|
|
again:
|
|
f = chain->rule;
|
|
if (f->fw_number == IPFW_DEFAULT_RULE)
|
|
goto got_match ;
|
|
|
|
#if STATEFUL
|
|
/*
|
|
* dynamic rules are checked at the first keep-state or
|
|
* check-state occurrence.
|
|
*/
|
|
if (f->fw_flg & (IP_FW_F_KEEP_S|IP_FW_F_CHECK_S) &&
|
|
dyn_checked == 0 ) {
|
|
dyn_checked = 1 ;
|
|
if (ip)
|
|
q = lookup_dyn_rule(&last_pkt, &direction);
|
|
if (q != NULL) {
|
|
DEB(printf("-- dynamic match 0x%08x %d %s 0x%08x %d\n",
|
|
(q->id.src_ip), (q->id.src_port),
|
|
(direction == MATCH_FORWARD ? "-->" : "<--"),
|
|
(q->id.dst_ip), (q->id.dst_port) ); )
|
|
chain = q->chain ;
|
|
f = chain->rule ;
|
|
q->pcnt++ ;
|
|
if (ip)
|
|
q->bcnt += ip->ip_len;
|
|
goto got_match ; /* random not allowed here */
|
|
}
|
|
/* if this was a check-only rule, continue with next */
|
|
if (f->fw_flg & IP_FW_F_CHECK_S)
|
|
continue ;
|
|
}
|
|
#endif /* stateful ipfw */
|
|
/*
|
|
* Rule only valid for bridged packets, skip if this
|
|
* is not one of those (pip != NULL)
|
|
*/
|
|
if (pip != NULL && f->fw_flg & IP_FW_BRIDGED )
|
|
continue ;
|
|
|
|
if (oif) {
|
|
/* Check direction outbound */
|
|
if (!(f->fw_flg & IP_FW_F_OUT))
|
|
continue;
|
|
} else {
|
|
/* Check direction inbound */
|
|
if (!(f->fw_flg & IP_FW_F_IN))
|
|
continue;
|
|
}
|
|
if (ip == NULL ) {
|
|
/*
|
|
* do relevant checks for non-ip packets:
|
|
* after this, only goto got_match or continue
|
|
*/
|
|
struct ether_header *eh = mtod(*m, struct ether_header *);
|
|
/*
|
|
* temporary hack:
|
|
* udp from 0.0.0.0 means this rule applies.
|
|
* 1 src port is match ether type
|
|
* 2 src ports (interval) is match ether type
|
|
* 3 src ports is match ether address
|
|
*/
|
|
if ( f->fw_src.s_addr != 0 || f->fw_prot != IPPROTO_UDP
|
|
|| f->fw_smsk.s_addr != 0xffffffff )
|
|
continue;
|
|
switch (IP_FW_GETNSRCP(f)) {
|
|
case 1: /* match one type */
|
|
if ( /* ( (f->fw_flg & IP_FW_F_INVSRC) != 0) ^ */
|
|
( f->fw_uar.fw_pts[0] == ntohs(eh->ether_type) ) ) {
|
|
goto got_match ;
|
|
}
|
|
break ;
|
|
default:
|
|
break ;
|
|
}
|
|
continue ;
|
|
}
|
|
|
|
/* Fragments */
|
|
if ((f->fw_flg & IP_FW_F_FRAG) && offset == 0 )
|
|
continue;
|
|
|
|
/* If src-addr doesn't match, not this rule. */
|
|
if (((f->fw_flg & IP_FW_F_INVSRC) != 0) ^ ((src_ip.s_addr
|
|
& f->fw_smsk.s_addr) != f->fw_src.s_addr))
|
|
continue;
|
|
|
|
/* If dest-addr doesn't match, not this rule. */
|
|
if (((f->fw_flg & IP_FW_F_INVDST) != 0) ^ ((dst_ip.s_addr
|
|
& f->fw_dmsk.s_addr) != f->fw_dst.s_addr))
|
|
continue;
|
|
|
|
/* Interface check */
|
|
if ((f->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) {
|
|
struct ifnet *const iface = oif ? oif : rif;
|
|
|
|
/* Backwards compatibility hack for "via" */
|
|
if (!iface || !iface_match(iface,
|
|
&f->fw_in_if, f->fw_flg & IP_FW_F_OIFNAME))
|
|
continue;
|
|
} else {
|
|
/* Check receive interface */
|
|
if ((f->fw_flg & IP_FW_F_IIFACE)
|
|
&& (!rif || !iface_match(rif,
|
|
&f->fw_in_if, f->fw_flg & IP_FW_F_IIFNAME)))
|
|
continue;
|
|
/* Check outgoing interface */
|
|
if ((f->fw_flg & IP_FW_F_OIFACE)
|
|
&& (!oif || !iface_match(oif,
|
|
&f->fw_out_if, f->fw_flg & IP_FW_F_OIFNAME)))
|
|
continue;
|
|
}
|
|
|
|
/* Check IP options */
|
|
if (f->fw_ipopt != f->fw_ipnopt && !ipopts_match(ip, f))
|
|
continue;
|
|
|
|
/* Check protocol; if wildcard, and no [ug]id, match */
|
|
if (f->fw_prot == IPPROTO_IP) {
|
|
if (!(f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID)))
|
|
goto rnd_then_got_match;
|
|
} else
|
|
/* If different, don't match */
|
|
if (proto != f->fw_prot)
|
|
continue;
|
|
|
|
/* Protocol specific checks for uid only */
|
|
if (f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID)) {
|
|
switch (proto) {
|
|
case IPPROTO_TCP:
|
|
{
|
|
struct inpcb *P;
|
|
|
|
if (offset == 1) /* cf. RFC 1858 */
|
|
goto bogusfrag;
|
|
if (offset != 0)
|
|
continue;
|
|
|
|
if (oif)
|
|
P = in_pcblookup_hash(&tcbinfo, dst_ip,
|
|
dst_port, src_ip, src_port, 0,
|
|
oif);
|
|
else
|
|
P = in_pcblookup_hash(&tcbinfo, src_ip,
|
|
src_port, dst_ip, dst_port, 0,
|
|
NULL);
|
|
|
|
if (P && P->inp_socket) {
|
|
if (f->fw_flg & IP_FW_F_UID) {
|
|
if (P->inp_socket->so_cred->cr_uid !=
|
|
f->fw_uid)
|
|
continue;
|
|
} else if (!groupmember(f->fw_gid,
|
|
P->inp_socket->so_cred))
|
|
continue;
|
|
} else
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
case IPPROTO_UDP:
|
|
{
|
|
struct inpcb *P;
|
|
|
|
if (offset != 0)
|
|
continue;
|
|
|
|
if (oif)
|
|
P = in_pcblookup_hash(&udbinfo, dst_ip,
|
|
dst_port, src_ip, src_port, 1,
|
|
oif);
|
|
else
|
|
P = in_pcblookup_hash(&udbinfo, src_ip,
|
|
src_port, dst_ip, dst_port, 1,
|
|
NULL);
|
|
|
|
if (P && P->inp_socket) {
|
|
if (f->fw_flg & IP_FW_F_UID) {
|
|
if (P->inp_socket->so_cred->cr_uid !=
|
|
f->fw_uid)
|
|
continue;
|
|
} else if (!groupmember(f->fw_gid,
|
|
P->inp_socket->so_cred))
|
|
continue;
|
|
} else
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* Protocol specific checks */
|
|
switch (proto) {
|
|
case IPPROTO_TCP:
|
|
{
|
|
struct tcphdr *tcp;
|
|
|
|
if (offset == 1) /* cf. RFC 1858 */
|
|
goto bogusfrag;
|
|
if (offset != 0) {
|
|
/*
|
|
* TCP flags and ports aren't available in this
|
|
* packet -- if this rule specified either one,
|
|
* we consider the rule a non-match.
|
|
*/
|
|
if (f->fw_nports != 0 ||
|
|
f->fw_tcpf != f->fw_tcpnf)
|
|
continue;
|
|
|
|
break;
|
|
}
|
|
tcp = (struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl);
|
|
if (f->fw_tcpf != f->fw_tcpnf && !tcpflg_match(tcp, f))
|
|
continue;
|
|
goto check_ports;
|
|
}
|
|
|
|
case IPPROTO_UDP:
|
|
if (offset != 0) {
|
|
/*
|
|
* Port specification is unavailable -- if this
|
|
* rule specifies a port, we consider the rule
|
|
* a non-match.
|
|
*/
|
|
if (f->fw_nports != 0)
|
|
continue;
|
|
|
|
break;
|
|
}
|
|
check_ports:
|
|
if (!port_match(&f->fw_uar.fw_pts[0],
|
|
IP_FW_GETNSRCP(f), ntohs(src_port),
|
|
f->fw_flg & IP_FW_F_SRNG,
|
|
f->fw_flg & IP_FW_F_SMSK))
|
|
continue;
|
|
if (!port_match(&f->fw_uar.fw_pts[IP_FW_GETNSRCP(f)],
|
|
IP_FW_GETNDSTP(f), ntohs(dst_port),
|
|
f->fw_flg & IP_FW_F_DRNG,
|
|
f->fw_flg & IP_FW_F_DMSK))
|
|
continue;
|
|
break;
|
|
|
|
case IPPROTO_ICMP:
|
|
{
|
|
struct icmp *icmp;
|
|
|
|
if (offset != 0) /* Type isn't valid */
|
|
break;
|
|
icmp = (struct icmp *) ((u_int32_t *)ip + ip->ip_hl);
|
|
if (!icmptype_match(icmp, f))
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
|
|
bogusfrag:
|
|
if (fw_verbose)
|
|
ipfw_report(NULL, ip, rif, oif);
|
|
goto dropit;
|
|
|
|
}
|
|
|
|
rnd_then_got_match:
|
|
if ( ((struct ip_fw_ext *)f)->dont_match_prob &&
|
|
random() < ((struct ip_fw_ext *)f)->dont_match_prob )
|
|
continue ;
|
|
got_match:
|
|
#if STATEFUL /* stateful ipfw */
|
|
/*
|
|
* If not a dynamic match (q == NULL) and keep-state, install
|
|
* a new dynamic entry.
|
|
*/
|
|
if (q == NULL && f->fw_flg & IP_FW_F_KEEP_S)
|
|
install_state(chain, pip, ip);
|
|
#endif
|
|
*flow_id = chain ; /* XXX set flow id */
|
|
/* Update statistics */
|
|
f->fw_pcnt += 1;
|
|
if (ip) {
|
|
f->fw_bcnt += ip->ip_len;
|
|
}
|
|
f->timestamp = time_second;
|
|
|
|
/* Log to console if desired */
|
|
if ((f->fw_flg & IP_FW_F_PRN) && fw_verbose)
|
|
ipfw_report(f, ip, rif, oif);
|
|
|
|
/* Take appropriate action */
|
|
switch (f->fw_flg & IP_FW_F_COMMAND) {
|
|
case IP_FW_F_ACCEPT:
|
|
return(0);
|
|
case IP_FW_F_COUNT:
|
|
continue;
|
|
#ifdef IPDIVERT
|
|
case IP_FW_F_DIVERT:
|
|
*cookie = f->fw_number;
|
|
return(f->fw_divert_port);
|
|
case IP_FW_F_TEE:
|
|
*cookie = f->fw_number;
|
|
return(f->fw_divert_port | IP_FW_PORT_TEE_FLAG);
|
|
#endif
|
|
case IP_FW_F_SKIPTO: /* XXX check */
|
|
if ( f->next_rule_ptr )
|
|
chain = f->next_rule_ptr ;
|
|
else
|
|
chain = lookup_next_rule(chain) ;
|
|
if (! chain) goto dropit;
|
|
goto again ;
|
|
#ifdef DUMMYNET
|
|
case IP_FW_F_PIPE:
|
|
return(f->fw_pipe_nr | IP_FW_PORT_DYNT_FLAG);
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
|
|
case IP_FW_F_FWD:
|
|
/* Change the next-hop address for this packet.
|
|
* Initially we'll only worry about directly
|
|
* reachable next-hop's, but ultimately
|
|
* we will work out for next-hops that aren't
|
|
* direct the route we would take for it. We
|
|
* [cs]ould leave this latter problem to
|
|
* ip_output.c. We hope to high [name the abode of
|
|
* your favourite deity] that ip_output doesn't modify
|
|
* the new value of next_hop (which is dst there)
|
|
*/
|
|
if (next_hop != NULL /* Make sure, first... */
|
|
&& (q == NULL || direction == MATCH_FORWARD) )
|
|
*next_hop = &(f->fw_fwd_ip);
|
|
return(0); /* Allow the packet */
|
|
#endif
|
|
}
|
|
|
|
/* Deny/reject this packet using this rule */
|
|
rule = f;
|
|
break;
|
|
|
|
}
|
|
|
|
#ifdef DIAGNOSTIC
|
|
/* Rule IPFW_DEFAULT_RULE should always be there and should always match */
|
|
if (!chain)
|
|
panic("ip_fw: chain");
|
|
#endif
|
|
|
|
/*
|
|
* At this point, we're going to drop the packet.
|
|
* Send a reject notice if all of the following are true:
|
|
*
|
|
* - The packet matched a reject rule
|
|
* - The packet is not an ICMP packet, or is an ICMP query packet
|
|
* - The packet is not a multicast or broadcast packet
|
|
*/
|
|
if ((rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_REJECT
|
|
&& ip
|
|
&& (ip->ip_p != IPPROTO_ICMP || is_icmp_query(ip))
|
|
&& !((*m)->m_flags & (M_BCAST|M_MCAST))
|
|
&& !IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
|
|
switch (rule->fw_reject_code) {
|
|
case IP_FW_REJECT_RST:
|
|
{
|
|
struct tcphdr *const tcp =
|
|
(struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl);
|
|
struct tcpiphdr ti, *const tip = (struct tcpiphdr *) ip;
|
|
|
|
if (offset != 0 || (tcp->th_flags & TH_RST))
|
|
break;
|
|
ti.ti_i = *((struct ipovly *) ip);
|
|
ti.ti_t = *tcp;
|
|
bcopy(&ti, ip, sizeof(ti));
|
|
NTOHL(tip->ti_seq);
|
|
NTOHL(tip->ti_ack);
|
|
tip->ti_len = ip->ip_len - hlen - (tip->ti_off << 2);
|
|
if (tcp->th_flags & TH_ACK) {
|
|
tcp_respond(NULL, (void *)ip, tcp, *m,
|
|
(tcp_seq)0, ntohl(tcp->th_ack), TH_RST);
|
|
} else {
|
|
if (tcp->th_flags & TH_SYN)
|
|
tip->ti_len++;
|
|
tcp_respond(NULL, (void *)ip, tcp, *m,
|
|
tip->ti_seq + tip->ti_len,
|
|
(tcp_seq)0, TH_RST|TH_ACK);
|
|
}
|
|
*m = NULL;
|
|
break;
|
|
}
|
|
default: /* Send an ICMP unreachable using code */
|
|
icmp_error(*m, ICMP_UNREACH,
|
|
rule->fw_reject_code, 0L, 0);
|
|
*m = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
dropit:
|
|
/*
|
|
* Finally, drop the packet.
|
|
*/
|
|
if (*m) {
|
|
m_freem(*m);
|
|
*m = NULL;
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* when a rule is added/deleted, zero the direct pointers within
|
|
* all firewall rules. These will be reconstructed on the fly
|
|
* as packets are matched.
|
|
* Must be called at splnet().
|
|
*/
|
|
static void
|
|
flush_rule_ptrs()
|
|
{
|
|
struct ip_fw_chain *fcp ;
|
|
|
|
for (fcp = ip_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next) {
|
|
fcp->rule->next_rule_ptr = NULL ;
|
|
}
|
|
}
|
|
|
|
static int
|
|
add_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw *ftmp = 0;
|
|
struct ip_fw_ext *ftmp_ext = 0 ;
|
|
struct ip_fw_chain *fwc = 0, *fcp, *fcpl = 0;
|
|
u_short nbr = 0;
|
|
int s;
|
|
|
|
fwc = malloc(sizeof *fwc, M_IPFW, M_DONTWAIT);
|
|
ftmp_ext = malloc(sizeof *ftmp_ext, M_IPFW, M_DONTWAIT);
|
|
ftmp = &ftmp_ext->rule ;
|
|
if (!fwc || !ftmp) {
|
|
dprintf(("%s malloc said no\n", err_prefix));
|
|
if (fwc) free(fwc, M_IPFW);
|
|
if (ftmp) free(ftmp, M_IPFW);
|
|
return (ENOSPC);
|
|
}
|
|
|
|
bzero(ftmp_ext, sizeof(*ftmp_ext)); /* play safe! */
|
|
bcopy(frwl, ftmp, sizeof(*ftmp));
|
|
if (ftmp->fw_flg & IP_FW_F_RND_MATCH)
|
|
ftmp_ext->dont_match_prob = (intptr_t)ftmp->pipe_ptr;
|
|
if (ftmp->fw_flg & IP_FW_F_KEEP_S)
|
|
ftmp_ext->dyn_type = (u_long)(ftmp->next_rule_ptr) ;
|
|
|
|
ftmp->fw_in_if.fu_via_if.name[FW_IFNLEN - 1] = '\0';
|
|
ftmp->fw_pcnt = 0L;
|
|
ftmp->fw_bcnt = 0L;
|
|
ftmp->next_rule_ptr = NULL ;
|
|
ftmp->pipe_ptr = NULL ;
|
|
fwc->rule = ftmp;
|
|
|
|
s = splnet();
|
|
|
|
if (chainptr->lh_first == 0) {
|
|
LIST_INSERT_HEAD(chainptr, fwc, chain);
|
|
splx(s);
|
|
return(0);
|
|
}
|
|
|
|
/* If entry number is 0, find highest numbered rule and add 100 */
|
|
if (ftmp->fw_number == 0) {
|
|
for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number != (u_short)-1)
|
|
nbr = fcp->rule->fw_number;
|
|
else
|
|
break;
|
|
}
|
|
if (nbr < IPFW_DEFAULT_RULE - 100)
|
|
nbr += 100;
|
|
ftmp->fw_number = nbr;
|
|
}
|
|
|
|
/* Got a valid number; now insert it, keeping the list ordered */
|
|
for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number > ftmp->fw_number) {
|
|
if (fcpl) {
|
|
LIST_INSERT_AFTER(fcpl, fwc, chain);
|
|
} else {
|
|
LIST_INSERT_HEAD(chainptr, fwc, chain);
|
|
}
|
|
break;
|
|
} else {
|
|
fcpl = fcp;
|
|
}
|
|
}
|
|
flush_rule_ptrs();
|
|
|
|
splx(s);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
del_entry(struct ip_fw_head *chainptr, u_short number)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
|
|
fcp = LIST_FIRST(chainptr);
|
|
if (number != (u_short)-1) {
|
|
for (; fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number == number) {
|
|
int s;
|
|
|
|
/* prevent access to rules while removing them */
|
|
s = splnet();
|
|
while (fcp && fcp->rule->fw_number == number) {
|
|
struct ip_fw_chain *next;
|
|
|
|
#if STATEFUL
|
|
remove_dyn_rule(fcp, 1 /* force_delete */);
|
|
#endif
|
|
next = LIST_NEXT(fcp, chain);
|
|
LIST_REMOVE(fcp, chain);
|
|
#ifdef DUMMYNET
|
|
dn_rule_delete(fcp) ;
|
|
#endif
|
|
flush_rule_ptrs();
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
fcp = next;
|
|
}
|
|
splx(s);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (EINVAL);
|
|
}
|
|
|
|
static int
|
|
zero_entry(struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
int s, cleared;
|
|
|
|
if (frwl == 0) {
|
|
s = splnet();
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
|
|
fcp->rule->fw_loghighest = fcp->rule->fw_logamount;
|
|
fcp->rule->timestamp = 0;
|
|
}
|
|
splx(s);
|
|
}
|
|
else {
|
|
cleared = 0;
|
|
|
|
/*
|
|
* It's possible to insert multiple chain entries with the
|
|
* same number, so we don't stop after finding the first
|
|
* match if zeroing a specific entry.
|
|
*/
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
if (frwl->fw_number == fcp->rule->fw_number) {
|
|
s = splnet();
|
|
while (fcp && frwl->fw_number == fcp->rule->fw_number) {
|
|
fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
|
|
fcp->rule->fw_loghighest =
|
|
fcp->rule->fw_logamount;
|
|
fcp->rule->timestamp = 0;
|
|
fcp = LIST_NEXT(fcp, chain);
|
|
}
|
|
splx(s);
|
|
cleared = 1;
|
|
break;
|
|
}
|
|
if (!cleared) /* we didn't find any matching rules */
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (fw_verbose) {
|
|
if (frwl)
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Entry %d cleared.\n", frwl->fw_number);
|
|
else
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Accounting cleared.\n");
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
resetlog_entry(struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
int s, cleared;
|
|
|
|
if (frwl == 0) {
|
|
s = splnet();
|
|
counter = 0;
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
fcp->rule->fw_loghighest = fcp->rule->fw_pcnt +
|
|
fcp->rule->fw_logamount;
|
|
splx(s);
|
|
}
|
|
else {
|
|
cleared = 0;
|
|
|
|
/*
|
|
* It's possible to insert multiple chain entries with the
|
|
* same number, so we don't stop after finding the first
|
|
* match if zeroing a specific entry.
|
|
*/
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
if (frwl->fw_number == fcp->rule->fw_number) {
|
|
s = splnet();
|
|
while (fcp && frwl->fw_number == fcp->rule->fw_number) {
|
|
fcp->rule->fw_loghighest =
|
|
fcp->rule->fw_pcnt +
|
|
fcp->rule->fw_logamount;
|
|
fcp = LIST_NEXT(fcp, chain);
|
|
}
|
|
splx(s);
|
|
cleared = 1;
|
|
break;
|
|
}
|
|
if (!cleared) /* we didn't find any matching rules */
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (fw_verbose) {
|
|
if (frwl)
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Entry %d logging count reset.\n",
|
|
frwl->fw_number);
|
|
else
|
|
log(LOG_SECURITY | LOG_NOTICE, "
|
|
ipfw: All logging counts cleared.\n");
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
check_ipfw_struct(struct ip_fw *frwl)
|
|
{
|
|
/* Check for invalid flag bits */
|
|
if ((frwl->fw_flg & ~IP_FW_F_MASK) != 0) {
|
|
dprintf(("%s undefined flag bits set (flags=%x)\n",
|
|
err_prefix, frwl->fw_flg));
|
|
return (EINVAL);
|
|
}
|
|
if (frwl->fw_flg == IP_FW_F_CHECK_S) {
|
|
printf("check dynamic rules...\n");
|
|
return 0 ;
|
|
}
|
|
/* Must apply to incoming or outgoing (or both) */
|
|
if (!(frwl->fw_flg & (IP_FW_F_IN | IP_FW_F_OUT))) {
|
|
dprintf(("%s neither in nor out\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Empty interface name is no good */
|
|
if (((frwl->fw_flg & IP_FW_F_IIFNAME)
|
|
&& !*frwl->fw_in_if.fu_via_if.name)
|
|
|| ((frwl->fw_flg & IP_FW_F_OIFNAME)
|
|
&& !*frwl->fw_out_if.fu_via_if.name)) {
|
|
dprintf(("%s empty interface name\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Sanity check interface matching */
|
|
if ((frwl->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) {
|
|
; /* allow "via" backwards compatibility */
|
|
} else if ((frwl->fw_flg & IP_FW_F_IN)
|
|
&& (frwl->fw_flg & IP_FW_F_OIFACE)) {
|
|
dprintf(("%s outgoing interface check on incoming\n",
|
|
err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Sanity check port ranges */
|
|
if ((frwl->fw_flg & IP_FW_F_SRNG) && IP_FW_GETNSRCP(frwl) < 2) {
|
|
dprintf(("%s src range set but n_src_p=%d\n",
|
|
err_prefix, IP_FW_GETNSRCP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
if ((frwl->fw_flg & IP_FW_F_DRNG) && IP_FW_GETNDSTP(frwl) < 2) {
|
|
dprintf(("%s dst range set but n_dst_p=%d\n",
|
|
err_prefix, IP_FW_GETNDSTP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
if (IP_FW_GETNSRCP(frwl) + IP_FW_GETNDSTP(frwl) > IP_FW_MAX_PORTS) {
|
|
dprintf(("%s too many ports (%d+%d)\n",
|
|
err_prefix, IP_FW_GETNSRCP(frwl), IP_FW_GETNDSTP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
/*
|
|
* Protocols other than TCP/UDP don't use port range
|
|
*/
|
|
if ((frwl->fw_prot != IPPROTO_TCP) &&
|
|
(frwl->fw_prot != IPPROTO_UDP) &&
|
|
(IP_FW_GETNSRCP(frwl) || IP_FW_GETNDSTP(frwl))) {
|
|
dprintf(("%s port(s) specified for non TCP/UDP rule\n",
|
|
err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
/*
|
|
* Rather than modify the entry to make such entries work,
|
|
* we reject this rule and require user level utilities
|
|
* to enforce whatever policy they deem appropriate.
|
|
*/
|
|
if ((frwl->fw_src.s_addr & (~frwl->fw_smsk.s_addr)) ||
|
|
(frwl->fw_dst.s_addr & (~frwl->fw_dmsk.s_addr))) {
|
|
dprintf(("%s rule never matches\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
if ((frwl->fw_flg & IP_FW_F_FRAG) &&
|
|
(frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
|
|
if (frwl->fw_nports) {
|
|
dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
if (frwl->fw_prot == IPPROTO_TCP &&
|
|
frwl->fw_tcpf != frwl->fw_tcpnf) {
|
|
dprintf(("%s cannot mix 'frag' and TCP flags\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
}
|
|
|
|
/* Check command specific stuff */
|
|
switch (frwl->fw_flg & IP_FW_F_COMMAND)
|
|
{
|
|
case IP_FW_F_REJECT:
|
|
if (frwl->fw_reject_code >= 0x100
|
|
&& !(frwl->fw_prot == IPPROTO_TCP
|
|
&& frwl->fw_reject_code == IP_FW_REJECT_RST)) {
|
|
dprintf(("%s unknown reject code\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
break;
|
|
#if defined(IPDIVERT) || defined(DUMMYNET)
|
|
#ifdef IPDIVERT
|
|
case IP_FW_F_DIVERT: /* Diverting to port zero is invalid */
|
|
case IP_FW_F_TEE:
|
|
#endif
|
|
#ifdef DUMMYNET
|
|
case IP_FW_F_PIPE: /* piping through 0 is invalid */
|
|
#endif
|
|
if (frwl->fw_divert_port == 0) {
|
|
dprintf(("%s can't divert to port 0\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
break;
|
|
#endif /* IPDIVERT || DUMMYNET */
|
|
case IP_FW_F_DENY:
|
|
case IP_FW_F_ACCEPT:
|
|
case IP_FW_F_COUNT:
|
|
case IP_FW_F_SKIPTO:
|
|
#ifdef IPFIREWALL_FORWARD
|
|
case IP_FW_F_FWD:
|
|
#endif
|
|
case IP_FW_F_UID:
|
|
case IP_FW_F_GID:
|
|
break;
|
|
default:
|
|
dprintf(("%s invalid command\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ip_fw_ctl(struct sockopt *sopt)
|
|
{
|
|
int error, s;
|
|
size_t size;
|
|
struct ip_fw_chain *fcp;
|
|
struct ip_fw frwl, *bp , *buf;
|
|
|
|
/*
|
|
* Disallow sets in really-really secure mode, but still allow
|
|
* the logging counters to be reset.
|
|
*/
|
|
if (sopt->sopt_dir == SOPT_SET && securelevel >= 3 &&
|
|
sopt->sopt_name != IP_FW_RESETLOG)
|
|
return (EPERM);
|
|
error = 0;
|
|
|
|
switch (sopt->sopt_name) {
|
|
case IP_FW_GET:
|
|
for (fcp = LIST_FIRST(&ip_fw_chain), size = 0; fcp;
|
|
fcp = LIST_NEXT(fcp, chain))
|
|
size += sizeof *fcp->rule;
|
|
#if STATEFUL
|
|
if (ipfw_dyn_v) {
|
|
int i ;
|
|
struct ipfw_dyn_rule *p ;
|
|
|
|
for (i = 0 ; i < curr_dyn_buckets ; i++ )
|
|
for ( p = ipfw_dyn_v[i] ; p != NULL ; p = p->next )
|
|
size += sizeof(*p) ;
|
|
}
|
|
#endif
|
|
buf = malloc(size, M_TEMP, M_WAITOK);
|
|
if (buf == 0) {
|
|
error = ENOBUFS;
|
|
break;
|
|
}
|
|
|
|
for (fcp = LIST_FIRST(&ip_fw_chain), bp = buf; fcp;
|
|
fcp = LIST_NEXT(fcp, chain)) {
|
|
bcopy(fcp->rule, bp, sizeof *fcp->rule);
|
|
bp->pipe_ptr = (void *)(intptr_t)
|
|
((struct ip_fw_ext *)fcp->rule)->dont_match_prob;
|
|
bp->next_rule_ptr = (void *)(intptr_t)
|
|
((struct ip_fw_ext *)fcp->rule)->dyn_type;
|
|
bp++;
|
|
}
|
|
#if STATEFUL
|
|
if (ipfw_dyn_v) {
|
|
int i ;
|
|
struct ipfw_dyn_rule *p, *dst, *last = NULL ;
|
|
|
|
dst = (struct ipfw_dyn_rule *)bp ;
|
|
for (i = 0 ; i < curr_dyn_buckets ; i++ )
|
|
for ( p = ipfw_dyn_v[i] ; p != NULL ; p = p->next, dst++ ) {
|
|
bcopy(p, dst, sizeof *p);
|
|
(int)dst->chain = p->chain->rule->fw_number ;
|
|
dst->next = dst ; /* fake non-null pointer... */
|
|
last = dst ;
|
|
if (TIME_LEQ(dst->expire, time_second) )
|
|
dst->expire = 0 ;
|
|
else
|
|
dst->expire -= time_second ;
|
|
}
|
|
if (last != NULL)
|
|
last->next = NULL ;
|
|
}
|
|
#endif
|
|
error = sooptcopyout(sopt, buf, size);
|
|
FREE(buf, M_TEMP);
|
|
break;
|
|
|
|
case IP_FW_FLUSH:
|
|
#if STATEFUL
|
|
s = splnet();
|
|
remove_dyn_rule(NULL, 1 /* force delete */);
|
|
splx(s);
|
|
#endif
|
|
for (fcp = ip_fw_chain.lh_first;
|
|
fcp != 0 && fcp->rule->fw_number != IPFW_DEFAULT_RULE;
|
|
fcp = ip_fw_chain.lh_first) {
|
|
s = splnet();
|
|
LIST_REMOVE(fcp, chain);
|
|
#ifdef DUMMYNET
|
|
dn_rule_delete(fcp);
|
|
#endif
|
|
FREE(fcp->rule, M_IPFW);
|
|
FREE(fcp, M_IPFW);
|
|
splx(s);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_ZERO:
|
|
if (sopt->sopt_val != 0) {
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl,
|
|
sizeof frwl);
|
|
if (error || (error = zero_entry(&frwl)))
|
|
break;
|
|
} else {
|
|
error = zero_entry(0);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_ADD:
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl);
|
|
if (error || (error = check_ipfw_struct(&frwl)))
|
|
break;
|
|
|
|
if (frwl.fw_number == IPFW_DEFAULT_RULE) {
|
|
dprintf(("%s can't add rule %u\n", err_prefix,
|
|
(unsigned)IPFW_DEFAULT_RULE));
|
|
error = EINVAL;
|
|
} else {
|
|
error = add_entry(&ip_fw_chain, &frwl);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_DEL:
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl);
|
|
if (error)
|
|
break;
|
|
|
|
if (frwl.fw_number == IPFW_DEFAULT_RULE) {
|
|
dprintf(("%s can't delete rule %u\n", err_prefix,
|
|
(unsigned)IPFW_DEFAULT_RULE));
|
|
error = EINVAL;
|
|
} else {
|
|
error = del_entry(&ip_fw_chain, frwl.fw_number);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_RESETLOG:
|
|
if (sopt->sopt_val != 0) {
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl,
|
|
sizeof frwl);
|
|
if (error || (error = resetlog_entry(&frwl)))
|
|
break;
|
|
} else {
|
|
error = resetlog_entry(0);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
printf("ip_fw_ctl invalid option %d\n", sopt->sopt_name);
|
|
error = EINVAL ;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
struct ip_fw_chain *ip_fw_default_rule ;
|
|
|
|
void
|
|
ip_fw_init(void)
|
|
{
|
|
struct ip_fw default_rule;
|
|
|
|
ip_fw_chk_ptr = ip_fw_chk;
|
|
ip_fw_ctl_ptr = ip_fw_ctl;
|
|
LIST_INIT(&ip_fw_chain);
|
|
|
|
bzero(&default_rule, sizeof default_rule);
|
|
default_rule.fw_prot = IPPROTO_IP;
|
|
default_rule.fw_number = IPFW_DEFAULT_RULE;
|
|
#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
|
|
default_rule.fw_flg |= IP_FW_F_ACCEPT;
|
|
#else
|
|
default_rule.fw_flg |= IP_FW_F_DENY;
|
|
#endif
|
|
default_rule.fw_flg |= IP_FW_F_IN | IP_FW_F_OUT;
|
|
if (check_ipfw_struct(&default_rule) != 0 ||
|
|
add_entry(&ip_fw_chain, &default_rule))
|
|
panic("ip_fw_init");
|
|
|
|
ip_fw_default_rule = ip_fw_chain.lh_first ;
|
|
printf("IP packet filtering initialized, "
|
|
#ifdef IPDIVERT
|
|
"divert enabled, "
|
|
#else
|
|
"divert disabled, "
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
|
|
"rule-based forwarding enabled, "
|
|
#else
|
|
"rule-based forwarding disabled, "
|
|
#endif
|
|
#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
|
|
"default to accept, ");
|
|
#else
|
|
"default to deny, " );
|
|
#endif
|
|
#ifndef IPFIREWALL_VERBOSE
|
|
printf("logging disabled\n");
|
|
#else
|
|
if (fw_verbose_limit == 0)
|
|
printf("unlimited logging\n");
|
|
else
|
|
printf("logging limited to %d packets/entry by default\n",
|
|
fw_verbose_limit);
|
|
#endif
|
|
}
|
|
|
|
static ip_fw_chk_t *old_chk_ptr;
|
|
static ip_fw_ctl_t *old_ctl_ptr;
|
|
|
|
static int
|
|
ipfw_modevent(module_t mod, int type, void *unused)
|
|
{
|
|
int s;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
s = splnet();
|
|
|
|
old_chk_ptr = ip_fw_chk_ptr;
|
|
old_ctl_ptr = ip_fw_ctl_ptr;
|
|
|
|
ip_fw_init();
|
|
splx(s);
|
|
return 0;
|
|
case MOD_UNLOAD:
|
|
s = splnet();
|
|
ip_fw_chk_ptr = old_chk_ptr;
|
|
ip_fw_ctl_ptr = old_ctl_ptr;
|
|
#if STATEFUL
|
|
remove_dyn_rule(NULL, 1 /* force delete */);
|
|
#endif
|
|
while (LIST_FIRST(&ip_fw_chain) != NULL) {
|
|
struct ip_fw_chain *fcp = LIST_FIRST(&ip_fw_chain);
|
|
LIST_REMOVE(LIST_FIRST(&ip_fw_chain), chain);
|
|
#ifdef DUMMYNET
|
|
dn_rule_delete(fcp);
|
|
#endif
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
}
|
|
|
|
splx(s);
|
|
printf("IP firewall unloaded\n");
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static moduledata_t ipfwmod = {
|
|
"ipfw",
|
|
ipfw_modevent,
|
|
0
|
|
};
|
|
DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
|