824 lines
19 KiB
C
824 lines
19 KiB
C
/*
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* Copyright (c) 1996 Alex Nash
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* Copyright (c) 1993 Daniel Boulet
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* Copyright (c) 1994 Ugen J.S.Antsilevich
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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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* $Id: ip_fw.c,v 1.48 1996/08/13 19:43:40 pst Exp $
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*/
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/*
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* Implement IP packet firewall
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*/
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#ifndef IPFIREWALL_MODULE
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#include "opt_ipfw.h"
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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/queue.h>
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#include <sys/kernel.h>
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#include <sys/time.h>
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#include <sys/sysctl.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/ip.h>
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#include <netinet/tcp.h>
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#include <netinet/udp.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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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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#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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LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain;
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#ifdef SYSCTL_NODE
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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, debug, CTLFLAG_RW, &fw_debug, 0, "");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw_verbose, 0, "");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw_verbose_limit, 0, "");
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#endif
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#define dprintf(a) if (!fw_debug); else printf a
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#define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\
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(ntohl(a.s_addr)>>16)&0xFF,\
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(ntohl(a.s_addr)>>8)&0xFF,\
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(ntohl(a.s_addr))&0xFF);
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#define dprint_ip(a) if (!fw_debug); else print_ip(a)
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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, struct ip_fw *frwl));
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static int zero_entry __P((struct mbuf *m));
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static struct ip_fw *
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check_ipfw_struct __P(( struct mbuf *m));
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static int ipopts_match __P((struct ip *ip, struct ip_fw *f));
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static int port_match __P((u_short *portptr, int nports, u_short port,
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int range_flag));
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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((char *txt, int rule, struct ip *ip, int counter));
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#ifdef IPFIREWALL_MODULE
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static ip_fw_chk_t *old_chk_ptr;
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static ip_fw_ctl_t *old_ctl_ptr;
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#endif
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static int ip_fw_chk __P((struct ip **pip, int hlen, struct ifnet *rif,
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int dirport, struct mbuf **m));
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static int ip_fw_ctl __P((int stage, struct mbuf **mm));
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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)
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{
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if (!nports)
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return 1;
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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 (f->fw_icmptypes[type / (sizeof(unsigned) * 8)] &
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(1U << (type % (8 * sizeof(unsigned)))))
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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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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 void
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ipfw_report(char *txt, int rule, struct ip *ip, int counter)
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{
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struct tcphdr *tcp = (struct tcphdr *) ((u_long *) ip + ip->ip_hl);
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struct udphdr *udp = (struct udphdr *) ((u_long *) ip + ip->ip_hl);
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struct icmp *icmp = (struct icmp *) ((u_long *) ip + ip->ip_hl);
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if (!fw_verbose)
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return;
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if (fw_verbose_limit != 0 && counter > fw_verbose_limit)
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return;
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printf("ipfw: %d %s ",rule, txt);
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switch (ip->ip_p) {
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case IPPROTO_TCP:
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printf("TCP ");
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print_ip(ip->ip_src);
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printf(":%d ", ntohs(tcp->th_sport));
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print_ip(ip->ip_dst);
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printf(":%d", ntohs(tcp->th_dport));
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break;
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case IPPROTO_UDP:
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printf("UDP ");
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print_ip(ip->ip_src);
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printf(":%d ", ntohs(udp->uh_sport));
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print_ip(ip->ip_dst);
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printf(":%d", ntohs(udp->uh_dport));
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break;
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case IPPROTO_ICMP:
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printf("ICMP:%u.%u ", icmp->icmp_type, icmp->icmp_code);
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print_ip(ip->ip_src);
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printf(" ");
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print_ip(ip->ip_dst);
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break;
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default:
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printf("P:%d ", ip->ip_p);
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print_ip(ip->ip_src);
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printf(" ");
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print_ip(ip->ip_dst);
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break;
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}
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if ((ip->ip_off & IP_OFFMASK))
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printf(" Fragment = %d",ip->ip_off & IP_OFFMASK);
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printf("\n");
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if (fw_verbose_limit != 0 && counter == fw_verbose_limit)
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printf("ipfw: limit reached on rule #%d\n", rule);
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}
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/*
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* We overload the "dirport" parameter:
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*
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* If dirport is negative, packet is outgoing; otherwise incoming.
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* The low order 16 bits of dirport, if non-zero, indicate that
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* we should ignore all ``divert <port>'' rules, where <port> is
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* the low order 16 bits.
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*
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* Return value:
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*
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* -1 The packet was denied/rejected and has been dropped
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* 0 The packet is to be accepted; route normally
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* <port> Divert the packet to divert <port>, if any socket
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* is bound to it; otherwise just drop it.
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*/
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static int
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ip_fw_chk(struct ip **pip, int hlen,
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struct ifnet *rif, int dirport, struct mbuf **m)
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{
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struct ip_fw_chain *chain;
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register struct ip_fw *f = NULL;
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struct ip *ip = *pip;
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struct tcphdr *tcp = (struct tcphdr *) ((u_long *) ip + ip->ip_hl);
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struct udphdr *udp = (struct udphdr *) ((u_long *) ip + ip->ip_hl);
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struct icmp *icmp = (struct icmp *) ((u_long *) ip + ip->ip_hl);
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struct ifaddr *ia = NULL, *ia_p;
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struct in_addr src, dst, ia_i;
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u_short src_port, dst_port, offset;
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src = ip->ip_src;
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dst = ip->ip_dst;
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/*
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* If we got interface from which packet came-store pointer to it's
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* first adress
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*/
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if (rif != NULL)
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ia = rif->if_addrlist;
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/*
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* Go down the chain, looking for enlightment
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*/
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for (chain=ip_fw_chain.lh_first; chain; chain = chain->chain.le_next) {
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f = chain->rule;
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/* Check direction inbound */
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if (dirport >= 0 && !(f->fw_flg & IP_FW_F_IN))
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continue;
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/* Check direction outbound */
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if (dirport < 0 && !(f->fw_flg & IP_FW_F_OUT))
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continue;
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/* Fragments */
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if ((f->fw_flg & IP_FW_F_FRAG) && !(ip->ip_off & IP_OFFMASK))
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continue;
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/* If src-addr doesn't match, not this rule. */
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if ((src.s_addr & f->fw_smsk.s_addr) != f->fw_src.s_addr)
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continue;
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/* If dest-addr doesn't match, not this rule. */
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if ((dst.s_addr & f->fw_dmsk.s_addr) != f->fw_dst.s_addr)
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continue;
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/* If a i/f name was specified, and we don't know */
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if ((f->fw_flg & IP_FW_F_IFNAME) && !rif)
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continue;
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/* If a i/f name was specified, check it */
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if ((f->fw_flg & IP_FW_F_IFNAME) && f->fw_via_name[0]) {
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/* Not same unit, don't match */
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if (!(f->fw_flg & IP_FW_F_IFUWILD) && rif->if_unit != f->fw_via_unit)
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continue;
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/* Not same name */
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if (strncmp(rif->if_name, f->fw_via_name, FW_IFNLEN))
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continue;
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}
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/* If a i/f addr was specified, check it */
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if (!(f->fw_flg & IP_FW_F_IFNAME) && f->fw_via_ip.s_addr) {
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int match = 0;
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for (ia_p = ia; ia_p != NULL; ia_p = ia_p->ifa_next) {
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if ((ia_p->ifa_addr == NULL))
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continue;
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if (ia_p->ifa_addr->sa_family != AF_INET)
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continue;
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ia_i.s_addr =
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((struct sockaddr_in *)
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(ia_p->ifa_addr))->sin_addr.s_addr;
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if (ia_i.s_addr != f->fw_via_ip.s_addr)
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continue;
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match = 1;
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break;
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}
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if (!match)
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continue;
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}
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/*
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* Check IP options
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*/
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if (f->fw_ipopt != f->fw_ipnopt)
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if (!ipopts_match(ip, f))
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continue;
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/* If wildcard, match */
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if (f->fw_prot == IPPROTO_IP)
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goto got_match;
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/* If different, dont match */
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if (ip->ip_p != f->fw_prot)
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continue;
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switch (ip->ip_p) {
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case IPPROTO_TCP:
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offset = ip->ip_off & IP_OFFMASK;
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if (offset == 1) {
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static int frag_counter = 0;
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++frag_counter;
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ipfw_report("Refuse", -1, ip, frag_counter);
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m_freem(*m);
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return -1;
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}
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if ((offset == 0) &&
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(f->fw_tcpf != f->fw_tcpnf) &&
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!tcpflg_match(tcp, f))
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continue;
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src_port = ntohs(tcp->th_sport);
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dst_port = ntohs(tcp->th_dport);
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goto check_ports;
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case IPPROTO_UDP:
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src_port = ntohs(udp->uh_sport);
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dst_port = ntohs(udp->uh_dport);
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check_ports:
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if (!port_match(&f->fw_pts[0], f->fw_nsp,
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src_port, f->fw_flg & IP_FW_F_SRNG))
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continue;
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if (!port_match(&f->fw_pts[f->fw_nsp], f->fw_ndp,
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dst_port, f->fw_flg & IP_FW_F_DRNG))
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continue;
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break;
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case IPPROTO_ICMP:
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if (!icmptype_match(icmp, f))
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continue;
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goto got_match;
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default:
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break;
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}
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got_match:
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f->fw_pcnt++;
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f->fw_bcnt+=ip->ip_len;
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f->timestamp = time.tv_sec;
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if (f->fw_flg & IP_FW_F_PRN) {
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if ((f->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_ACCEPT) {
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ipfw_report("Allow",
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f->fw_number, ip, f->fw_pcnt);
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} else if ((f->fw_flg & IP_FW_F_COMMAND)
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== IP_FW_F_DIVERT) {
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if (f->fw_divert_port != (dirport & 0xffff))
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ipfw_report("Divert", f->fw_number,
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ip, f->fw_pcnt);
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} else if ((f->fw_flg & IP_FW_F_COMMAND)
|
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== IP_FW_F_COUNT) {
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ipfw_report("Count",
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f->fw_number, ip, f->fw_pcnt);
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} else {
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ipfw_report("Deny",
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f->fw_number, ip, f->fw_pcnt);
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}
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}
|
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|
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/* Take appropriate action */
|
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if ((f->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_ACCEPT) {
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return 0;
|
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} else if ((f->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_COUNT) {
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continue;
|
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} else if ((f->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_DIVERT) {
|
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if (f->fw_divert_port == (dirport & 0xffff))
|
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continue; /* ignore this rule */
|
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return (f->fw_divert_port);
|
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} else
|
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break; /* ie, deny/reject */
|
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}
|
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|
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#ifdef DIAGNOSTIC
|
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if (!chain) /* rule 65535 should always be there */
|
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panic("ip_fw: chain");
|
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if (!f)
|
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panic("ip_fw: entry");
|
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#endif
|
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|
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/*
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* At this point, we're going to drop the packet.
|
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* Send an ICMP only if all of the following are true:
|
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*
|
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* - The packet is an incoming packet
|
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* - The packet matched a deny rule
|
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* - The packet is not an ICMP packet
|
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* - The rule has the special ICMP reply flag set
|
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*/
|
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if (dirport >= 0
|
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&& (f->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_DENY
|
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&& (ip->ip_p != IPPROTO_ICMP)
|
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&& (f->fw_flg & IP_FW_F_ICMPRPL)) {
|
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icmp_error(*m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0L, 0);
|
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return -1;
|
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}
|
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m_freem(*m);
|
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return -1;
|
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}
|
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|
|
static int
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add_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl)
|
|
{
|
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struct ip_fw *ftmp = 0;
|
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struct ip_fw_chain *fwc = 0, *fcp, *fcpl = 0;
|
|
u_short nbr = 0;
|
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int s;
|
|
|
|
fwc = malloc(sizeof *fwc, M_IPFW, M_DONTWAIT);
|
|
ftmp = malloc(sizeof *ftmp, M_IPFW, M_DONTWAIT);
|
|
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);
|
|
}
|
|
|
|
bcopy(frwl, ftmp, sizeof(struct ip_fw));
|
|
ftmp->fw_pcnt = 0L;
|
|
ftmp->fw_bcnt = 0L;
|
|
fwc->rule = ftmp;
|
|
|
|
s = splnet();
|
|
|
|
if (!chainptr->lh_first) {
|
|
LIST_INSERT_HEAD(chainptr, fwc, chain);
|
|
splx(s);
|
|
return(0);
|
|
} else if (ftmp->fw_number == (u_short)-1) {
|
|
if (fwc) free(fwc, M_IPFW);
|
|
if (ftmp) free(ftmp, M_IPFW);
|
|
splx(s);
|
|
return (EINVAL);
|
|
}
|
|
|
|
/* If entry number is 0, find highest numbered rule and add 100 */
|
|
if (ftmp->fw_number == 0) {
|
|
for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
|
|
if (fcp->rule->fw_number != (u_short)-1)
|
|
nbr = fcp->rule->fw_number;
|
|
else
|
|
break;
|
|
}
|
|
if (nbr < (u_short)-1 - 100)
|
|
nbr += 100;
|
|
ftmp->fw_number = nbr;
|
|
}
|
|
|
|
/* Got a valid number; now insert it, keeping the list ordered */
|
|
for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
|
|
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;
|
|
}
|
|
}
|
|
|
|
splx(s);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
del_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
int s;
|
|
|
|
s = splnet();
|
|
|
|
fcp = chainptr->lh_first;
|
|
if (frwl->fw_number != (u_short)-1) {
|
|
for (; fcp; fcp = fcp->chain.le_next) {
|
|
if (fcp->rule->fw_number == frwl->fw_number) {
|
|
LIST_REMOVE(fcp, chain);
|
|
splx(s);
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
splx(s);
|
|
return (EINVAL);
|
|
}
|
|
|
|
static int
|
|
zero_entry(struct mbuf *m)
|
|
{
|
|
struct ip_fw *frwl;
|
|
struct ip_fw_chain *fcp;
|
|
int s;
|
|
|
|
if (m) {
|
|
frwl = check_ipfw_struct(m);
|
|
|
|
if (!frwl)
|
|
return(EINVAL);
|
|
}
|
|
else
|
|
frwl = NULL;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
s = splnet();
|
|
for (fcp = ip_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
|
|
if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
|
|
fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
|
|
fcp->rule->timestamp = 0;
|
|
}
|
|
splx(s);
|
|
|
|
if ( frwl )
|
|
printf("ipfw: Entry %d cleared.\n", frwl->fw_number);
|
|
else
|
|
printf("ipfw: Accounting cleared.\n");
|
|
return(0);
|
|
}
|
|
|
|
static struct ip_fw *
|
|
check_ipfw_struct(struct mbuf *m)
|
|
{
|
|
struct ip_fw *frwl;
|
|
|
|
if (m->m_len != sizeof(struct ip_fw)) {
|
|
dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
|
|
sizeof(struct ip_fw)));
|
|
return (NULL);
|
|
}
|
|
frwl = mtod(m, struct ip_fw *);
|
|
|
|
if ((frwl->fw_flg & ~IP_FW_F_MASK) != 0) {
|
|
dprintf(("%s undefined flag bits set (flags=%x)\n",
|
|
err_prefix, frwl->fw_flg));
|
|
return (NULL);
|
|
}
|
|
|
|
/* If neither In nor Out, then both */
|
|
if (!(frwl->fw_flg & (IP_FW_F_IN | IP_FW_F_OUT)))
|
|
frwl->fw_flg |= IP_FW_F_IN | IP_FW_F_OUT;
|
|
|
|
if ((frwl->fw_flg & IP_FW_F_SRNG) && frwl->fw_nsp < 2) {
|
|
dprintf(("%s src range set but n_src_p=%d\n",
|
|
err_prefix, frwl->fw_nsp));
|
|
return (NULL);
|
|
}
|
|
if ((frwl->fw_flg & IP_FW_F_DRNG) && frwl->fw_ndp < 2) {
|
|
dprintf(("%s dst range set but n_dst_p=%d\n",
|
|
err_prefix, frwl->fw_ndp));
|
|
return (NULL);
|
|
}
|
|
if (frwl->fw_nsp + frwl->fw_ndp > IP_FW_MAX_PORTS) {
|
|
dprintf(("%s too many ports (%d+%d)\n",
|
|
err_prefix, frwl->fw_nsp, frwl->fw_ndp));
|
|
return (NULL);
|
|
}
|
|
/*
|
|
* ICMP protocol doesn't use port range
|
|
*/
|
|
if ((frwl->fw_prot != IPPROTO_TCP) &&
|
|
(frwl->fw_prot != IPPROTO_UDP) &&
|
|
(frwl->fw_nsp || frwl->fw_ndp)) {
|
|
dprintf(("%s port(s) specified for non TCP/UDP rule\n",
|
|
err_prefix));
|
|
return(NULL);
|
|
}
|
|
|
|
/*
|
|
* 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(NULL);
|
|
}
|
|
|
|
/* Diverting to port zero is illegal */
|
|
if ((frwl->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_DIVERT
|
|
&& frwl->fw_divert_port == 0) {
|
|
dprintf(("ip_fw_ctl: can't divert to port 0\n"));
|
|
return (NULL);
|
|
}
|
|
return frwl;
|
|
}
|
|
|
|
static int
|
|
ip_fw_ctl(int stage, struct mbuf **mm)
|
|
{
|
|
int error;
|
|
struct mbuf *m;
|
|
|
|
if (stage == IP_FW_GET) {
|
|
struct ip_fw_chain *fcp = ip_fw_chain.lh_first;
|
|
*mm = m = m_get(M_WAIT, MT_SOOPTS);
|
|
for (; fcp; fcp = fcp->chain.le_next) {
|
|
memcpy(m->m_data, fcp->rule, sizeof *(fcp->rule));
|
|
m->m_len = sizeof *(fcp->rule);
|
|
m->m_next = m_get(M_WAIT, MT_SOOPTS);
|
|
m = m->m_next;
|
|
m->m_len = 0;
|
|
}
|
|
return (0);
|
|
}
|
|
m = *mm;
|
|
/* only allow get calls if secure mode > 2 */
|
|
if (securelevel > 2) {
|
|
if (m) (void)m_free(m);
|
|
return(EPERM);
|
|
}
|
|
if (stage == IP_FW_FLUSH) {
|
|
while (ip_fw_chain.lh_first != NULL &&
|
|
ip_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
|
|
struct ip_fw_chain *fcp = ip_fw_chain.lh_first;
|
|
int s = splnet();
|
|
LIST_REMOVE(ip_fw_chain.lh_first, chain);
|
|
splx(s);
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
}
|
|
if (m) (void)m_free(m);
|
|
return (0);
|
|
}
|
|
if (stage == IP_FW_ZERO) {
|
|
error = zero_entry(m);
|
|
if (m) (void)m_free(m);
|
|
return (error);
|
|
}
|
|
if (m == NULL) {
|
|
printf("%s NULL mbuf ptr\n", err_prefix);
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (stage == IP_FW_ADD || stage == IP_FW_DEL) {
|
|
struct ip_fw *frwl = check_ipfw_struct(m);
|
|
|
|
if (!frwl) {
|
|
if (m) (void)m_free(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (stage == IP_FW_ADD)
|
|
error = add_entry(&ip_fw_chain, frwl);
|
|
else
|
|
error = del_entry(&ip_fw_chain, frwl);
|
|
if (m) (void)m_free(m);
|
|
return error;
|
|
}
|
|
dprintf(("%s unknown request %d\n", err_prefix, stage));
|
|
if (m) (void)m_free(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
void
|
|
ip_fw_init(void)
|
|
{
|
|
struct ip_fw deny;
|
|
|
|
ip_fw_chk_ptr = ip_fw_chk;
|
|
ip_fw_ctl_ptr = ip_fw_ctl;
|
|
LIST_INIT(&ip_fw_chain);
|
|
|
|
bzero(&deny, sizeof deny);
|
|
deny.fw_prot = IPPROTO_IP;
|
|
deny.fw_number = (u_short)-1;
|
|
add_entry(&ip_fw_chain, &deny);
|
|
|
|
printf("IP packet filtering initialized, "
|
|
#ifdef IPDIVERT
|
|
"divert enabled, ");
|
|
#else
|
|
"divert disabled, ");
|
|
#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\n",
|
|
fw_verbose_limit);
|
|
#endif
|
|
}
|
|
|
|
#ifdef IPFIREWALL_MODULE
|
|
|
|
#include <sys/exec.h>
|
|
#include <sys/sysent.h>
|
|
#include <sys/lkm.h>
|
|
|
|
MOD_MISC(ipfw);
|
|
|
|
static int
|
|
ipfw_load(struct lkm_table *lkmtp, int cmd)
|
|
{
|
|
int s=splnet();
|
|
|
|
old_chk_ptr = ip_fw_chk_ptr;
|
|
old_ctl_ptr = ip_fw_ctl_ptr;
|
|
|
|
ip_fw_init();
|
|
splx(s);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ipfw_unload(struct lkm_table *lkmtp, int cmd)
|
|
{
|
|
int s=splnet();
|
|
|
|
ip_fw_chk_ptr = old_chk_ptr;
|
|
ip_fw_ctl_ptr = old_ctl_ptr;
|
|
|
|
while (ip_fw_chain.lh_first != NULL) {
|
|
struct ip_fw_chain *fcp = ip_fw_chain.lh_first;
|
|
LIST_REMOVE(ip_fw_chain.lh_first, chain);
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
}
|
|
|
|
splx(s);
|
|
printf("IP firewall unloaded\n");
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ipfw_mod(struct lkm_table *lkmtp, int cmd, int ver)
|
|
{
|
|
DISPATCH(lkmtp, cmd, ver, ipfw_load, ipfw_unload, lkm_nullcmd);
|
|
}
|
|
#endif
|