952 lines
22 KiB
C
952 lines
22 KiB
C
/* $NetBSD: fil.c,v 1.14 1997/07/08 05:54:02 mrg Exp $ */
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/*
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* (C)opyright 1993-1996 by Darren Reed.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that this notice is preserved and due credit is given
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* to the original author and the contributors.
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*/
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#if !defined(lint) && defined(LIBC_SCCS)
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static char sccsid[] = "@(#)fil.c 1.36 6/5/96 (C) 1993-1996 Darren Reed";
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static char rcsid[] = "Id: fil.c,v 2.0.2.26 1997/07/05 04:38:38 darrenr Exp";
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#endif
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#include <sys/errno.h>
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/time.h>
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#include <sys/file.h>
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#include <sys/ioctl.h>
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#if defined(_KERNEL) || defined(KERNEL)
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# include <sys/systm.h>
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#else
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# include <stdio.h>
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# include <string.h>
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#endif
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#include <sys/uio.h>
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#if !defined(__SVR4) && !defined(__svr4__)
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# include <sys/mbuf.h>
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#else
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# include <sys/byteorder.h>
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# include <sys/dditypes.h>
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# include <sys/stream.h>
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#endif
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <net/if.h>
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#ifdef sun
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# include <net/af.h>
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#endif
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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/ip_var.h>
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#include <netinet/tcp.h>
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#include <netinet/udp.h>
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#include <netinet/tcpip.h>
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#include <netinet/ip_icmp.h>
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#include "netinet/ip_compat.h"
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#include "netinet/ip_fil.h"
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#include "netinet/ip_proxy.h"
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#include "netinet/ip_nat.h"
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#include "netinet/ip_frag.h"
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#include "netinet/ip_state.h"
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#include "netinet/ip_auth.h"
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#ifndef MIN
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#define MIN(a,b) (((a)<(b))?(a):(b))
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#endif
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#ifndef _KERNEL
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# include "ipf.h"
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# include "ipt.h"
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extern int opts;
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# define FR_IFVERBOSE(ex,second,verb_pr) if (ex) { verbose verb_pr; \
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second; }
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# define FR_IFDEBUG(ex,second,verb_pr) if (ex) { debug verb_pr; \
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second; }
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# define FR_VERBOSE(verb_pr) verbose verb_pr
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# define FR_DEBUG(verb_pr) debug verb_pr
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# define SEND_RESET(ip, qif, if) send_reset(ip, if)
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# define IPLLOG(a, c, d, e) ipllog()
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# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, ip)
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# if SOLARIS
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# define ICMP_ERROR(b, ip, t, c, if, src) icmp_error(ip)
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# else
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# define ICMP_ERROR(b, ip, t, c, if, src) icmp_error(b, ip, if)
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# endif
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#else /* #ifndef _KERNEL */
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# define FR_IFVERBOSE(ex,second,verb_pr) ;
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# define FR_IFDEBUG(ex,second,verb_pr) ;
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# define FR_VERBOSE(verb_pr)
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# define FR_DEBUG(verb_pr)
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# define IPLLOG(a, c, d, e) ipllog(a, IPL_LOGIPF, c, d, e)
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# if SOLARIS
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extern kmutex_t ipf_mutex, ipf_auth;
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# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, \
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ip, qif)
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# define SEND_RESET(ip, qif, if) send_reset(ip, qif)
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# define ICMP_ERROR(b, ip, t, c, if, src) \
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icmp_error(ip, t, c, if, src)
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# else
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# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, ip)
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# define SEND_RESET(ip, qif, if) send_reset((struct tcpiphdr *)ip)
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# if BSD < 199103
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# define ICMP_ERROR(b, ip, t, c, if, src) \
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icmp_error(mtod(b, ip_t *), t, c, if, src)
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# else
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# define ICMP_ERROR(b, ip, t, c, if, src) \
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icmp_error(b, t, c, (src).s_addr, if)
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# endif
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# endif
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#endif
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struct filterstats frstats[2] = {{0,0,0,0,0},{0,0,0,0,0}};
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struct frentry *ipfilter[2][2] = { { NULL, NULL }, { NULL, NULL } },
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*ipacct[2][2] = { { NULL, NULL }, { NULL, NULL } };
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int fr_flags = IPF_LOGGING, fr_active = 0;
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#if defined(IPFILTER_DEFAULT_BLOCK)
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int fr_pass = FR_NOMATCH;
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#else
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int fr_pass = FR_PASS;
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#endif
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fr_info_t frcache[2];
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static void fr_makefrip __P((int, ip_t *, fr_info_t *));
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static int fr_tcpudpchk __P((frentry_t *, fr_info_t *));
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/*
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* bit values for identifying presence of individual IP options
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*/
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struct optlist ipopts[20] = {
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{ IPOPT_NOP, 0x000001 },
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{ IPOPT_RR, 0x000002 },
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{ IPOPT_ZSU, 0x000004 },
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{ IPOPT_MTUP, 0x000008 },
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{ IPOPT_MTUR, 0x000010 },
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{ IPOPT_ENCODE, 0x000020 },
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{ IPOPT_TS, 0x000040 },
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{ IPOPT_TR, 0x000080 },
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{ IPOPT_SECURITY, 0x000100 },
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{ IPOPT_LSRR, 0x000200 },
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{ IPOPT_E_SEC, 0x000400 },
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{ IPOPT_CIPSO, 0x000800 },
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{ IPOPT_SATID, 0x001000 },
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{ IPOPT_SSRR, 0x002000 },
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{ IPOPT_ADDEXT, 0x004000 },
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{ IPOPT_VISA, 0x008000 },
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{ IPOPT_IMITD, 0x010000 },
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{ IPOPT_EIP, 0x020000 },
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{ IPOPT_FINN, 0x040000 },
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{ 0, 0x000000 }
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};
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/*
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* bit values for identifying presence of individual IP security options
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*/
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struct optlist secopt[8] = {
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{ IPSO_CLASS_RES4, 0x01 },
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{ IPSO_CLASS_TOPS, 0x02 },
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{ IPSO_CLASS_SECR, 0x04 },
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{ IPSO_CLASS_RES3, 0x08 },
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{ IPSO_CLASS_CONF, 0x10 },
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{ IPSO_CLASS_UNCL, 0x20 },
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{ IPSO_CLASS_RES2, 0x40 },
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{ IPSO_CLASS_RES1, 0x80 }
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};
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/*
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* compact the IP header into a structure which contains just the info.
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* which is useful for comparing IP headers with.
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*/
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static void fr_makefrip(hlen, ip, fin)
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int hlen;
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ip_t *ip;
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fr_info_t *fin;
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{
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struct optlist *op;
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tcphdr_t *tcp;
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fr_ip_t *fi = &fin->fin_fi;
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u_short optmsk = 0, secmsk = 0, auth = 0;
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int i, mv, ol, off;
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u_char *s, opt;
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fin->fin_fr = NULL;
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fin->fin_tcpf = 0;
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fin->fin_data[0] = 0;
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fin->fin_data[1] = 0;
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fin->fin_rule = -1;
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fin->fin_id = ip->ip_id;
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#ifdef _KERNEL
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fin->fin_icode = ipl_unreach;
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#endif
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fi->fi_v = ip->ip_v;
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fi->fi_tos = ip->ip_tos;
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fin->fin_hlen = hlen;
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fin->fin_dlen = ip->ip_len - hlen;
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tcp = (tcphdr_t *)((char *)ip + hlen);
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fin->fin_dp = (void *)tcp;
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(*(((u_short *)fi) + 1)) = (*(((u_short *)ip) + 4));
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(*(((u_32_t *)fi) + 1)) = (*(((u_32_t *)ip) + 3));
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(*(((u_32_t *)fi) + 2)) = (*(((u_32_t *)ip) + 4));
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fi->fi_fl = (hlen > sizeof(struct ip)) ? FI_OPTIONS : 0;
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off = (ip->ip_off & 0x1fff) << 3;
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if (ip->ip_off & 0x3fff)
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fi->fi_fl |= FI_FRAG;
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switch (ip->ip_p)
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{
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case IPPROTO_ICMP :
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if ((!IPMINLEN(ip, icmp) && !off) ||
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(off && off < sizeof(struct icmp)))
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fi->fi_fl |= FI_SHORT;
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if (fin->fin_dlen > 1)
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fin->fin_data[0] = *(u_short *)tcp;
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break;
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case IPPROTO_TCP :
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fi->fi_fl |= FI_TCPUDP;
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if ((!IPMINLEN(ip, tcphdr) && !off) ||
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(off && off < sizeof(struct tcphdr)))
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fi->fi_fl |= FI_SHORT;
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if (!(fi->fi_fl & FI_SHORT) && !off)
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fin->fin_tcpf = tcp->th_flags;
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goto getports;
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case IPPROTO_UDP :
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fi->fi_fl |= FI_TCPUDP;
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if ((!IPMINLEN(ip, udphdr) && !off) ||
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(off && off < sizeof(struct udphdr)))
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fi->fi_fl |= FI_SHORT;
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getports:
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if (!off && (fin->fin_dlen > 3)) {
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fin->fin_data[0] = ntohs(tcp->th_sport);
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fin->fin_data[1] = ntohs(tcp->th_dport);
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}
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break;
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default :
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break;
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}
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for (s = (u_char *)(ip + 1), hlen -= sizeof(*ip); hlen; ) {
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if (!(opt = *s))
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break;
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ol = (opt == IPOPT_NOP) ? 1 : (int)*(s+1);
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if (opt > 1 && (ol < 2 || ol > hlen))
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break;
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for (i = 9, mv = 4; mv >= 0; ) {
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op = ipopts + i;
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if (opt == (u_char)op->ol_val) {
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optmsk |= op->ol_bit;
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if (opt == IPOPT_SECURITY) {
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struct optlist *sp;
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u_char sec;
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int j, m;
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sec = *(s + 2); /* classification */
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for (j = 3, m = 2; m >= 0; ) {
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sp = secopt + j;
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if (sec == sp->ol_val) {
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secmsk |= sp->ol_bit;
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auth = *(s + 3);
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auth *= 256;
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auth += *(s + 4);
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break;
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}
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if (sec < sp->ol_val)
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j -= m--;
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else
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j += m--;
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}
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}
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break;
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}
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if (opt < op->ol_val)
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i -= mv--;
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else
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i += mv--;
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}
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hlen -= ol;
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s += ol;
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}
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if (auth && !(auth & 0x0100))
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auth &= 0xff00;
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fi->fi_optmsk = optmsk;
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fi->fi_secmsk = secmsk;
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fi->fi_auth = auth;
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}
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/*
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* check an IP packet for TCP/UDP characteristics such as ports and flags.
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*/
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static int fr_tcpudpchk(fr, fin)
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frentry_t *fr;
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fr_info_t *fin;
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{
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register u_short po, tup;
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register char i;
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register int err = 1;
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/*
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* Both ports should *always* be in the first fragment.
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* So far, I cannot find any cases where they can not be.
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*
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* compare destination ports
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*/
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if ((i = (int)fr->fr_dcmp)) {
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po = fr->fr_dport;
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tup = fin->fin_data[1];
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/*
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* Do opposite test to that required and
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* continue if that succeeds.
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*/
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if (!--i && tup != po) /* EQUAL */
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err = 0;
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else if (!--i && tup == po) /* NOTEQUAL */
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err = 0;
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else if (!--i && tup >= po) /* LESSTHAN */
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err = 0;
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else if (!--i && tup <= po) /* GREATERTHAN */
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err = 0;
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else if (!--i && tup > po) /* LT or EQ */
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err = 0;
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else if (!--i && tup < po) /* GT or EQ */
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err = 0;
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else if (!--i && /* Out of range */
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(tup >= po && tup <= fr->fr_dtop))
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err = 0;
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else if (!--i && /* In range */
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(tup <= po || tup >= fr->fr_dtop))
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err = 0;
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}
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/*
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* compare source ports
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*/
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if (err && (i = (int)fr->fr_scmp)) {
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po = fr->fr_sport;
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tup = fin->fin_data[0];
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if (!--i && tup != po)
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err = 0;
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else if (!--i && tup == po)
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err = 0;
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else if (!--i && tup >= po)
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err = 0;
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else if (!--i && tup <= po)
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err = 0;
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else if (!--i && tup > po)
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err = 0;
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else if (!--i && tup < po)
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err = 0;
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else if (!--i && /* Out of range */
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(tup >= po && tup <= fr->fr_stop))
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err = 0;
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else if (!--i && /* In range */
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(tup <= po || tup >= fr->fr_stop))
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err = 0;
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}
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/*
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* If we don't have all the TCP/UDP header, then how can we
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* expect to do any sort of match on it ? If we were looking for
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* TCP flags, then NO match. If not, then match (which should
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* satisfy the "short" class too).
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*/
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if (err && (fin->fin_fi.fi_p == IPPROTO_TCP)) {
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if (fin->fin_fi.fi_fl & FI_SHORT)
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return !(fr->fr_tcpf | fr->fr_tcpfm);
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/*
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* Match the flags ? If not, abort this match.
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*/
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if (fr->fr_tcpf &&
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fr->fr_tcpf != (fin->fin_tcpf & fr->fr_tcpfm)) {
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FR_DEBUG(("f. %#x & %#x != %#x\n", fin->fin_tcpf,
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fr->fr_tcpfm, fr->fr_tcpf));
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err = 0;
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}
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}
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return err;
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}
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/*
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* Check the input/output list of rules for a match and result.
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* Could be per interface, but this gets real nasty when you don't have
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* kernel sauce.
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*/
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int fr_scanlist(pass, ip, fin, m)
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int pass;
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ip_t *ip;
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register fr_info_t *fin;
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void *m;
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{
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register struct frentry *fr;
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register fr_ip_t *fi = &fin->fin_fi;
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int rulen, portcmp = 0, off, skip = 0;
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fr = fin->fin_fr;
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fin->fin_fr = NULL;
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fin->fin_rule = 0;
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off = ip->ip_off & 0x1fff;
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pass |= (fi->fi_fl << 24);
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if ((fi->fi_fl & FI_TCPUDP) && (fin->fin_dlen > 3) && !off)
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portcmp = 1;
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for (rulen = 0; fr; fr = fr->fr_next, rulen++) {
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if (skip) {
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skip--;
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continue;
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}
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/*
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* In all checks below, a null (zero) value in the
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* filter struture is taken to mean a wildcard.
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*
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* check that we are working for the right interface
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*/
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#ifdef _KERNEL
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if (fr->fr_ifa && fr->fr_ifa != fin->fin_ifp)
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continue;
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#else
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if (opts & (OPT_VERBOSE|OPT_DEBUG))
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printf("\n");
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FR_VERBOSE(("%c", (pass & FR_PASS) ? 'p' :
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(pass & FR_AUTH) ? 'a' : 'b'));
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if (fr->fr_ifa && fr->fr_ifa != fin->fin_ifp)
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continue;
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FR_VERBOSE((":i"));
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#endif
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{
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register u_32_t *ld, *lm, *lip;
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register int i;
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lip = (u_32_t *)fi;
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lm = (u_32_t *)&fr->fr_mip;
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ld = (u_32_t *)&fr->fr_ip;
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i = ((lip[0] & lm[0]) != ld[0]);
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FR_IFDEBUG(i,continue,("0. %#08x & %#08x != %#08x\n",
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lip[0], lm[0], ld[0]));
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i |= ((lip[1] & lm[1]) != ld[1]) << 21;
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FR_IFDEBUG(i,continue,("1. %#08x & %#08x != %#08x\n",
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lip[1], lm[1], ld[1]));
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i |= ((lip[2] & lm[2]) != ld[2]) << 22;
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FR_IFDEBUG(i,continue,("2. %#08x & %#08x != %#08x\n",
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lip[2], lm[2], ld[2]));
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i |= ((lip[3] & lm[3]) != ld[3]);
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FR_IFDEBUG(i,continue,("3. %#08x & %#08x != %#08x\n",
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lip[3], lm[3], ld[3]));
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i |= ((lip[4] & lm[4]) != ld[4]);
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FR_IFDEBUG(i,continue,("4. %#08x & %#08x != %#08x\n",
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lip[4], lm[4], ld[4]));
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i ^= (fi->fi_fl & (FR_NOTSRCIP|FR_NOTDSTIP));
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if (i)
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continue;
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}
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/*
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* If a fragment, then only the first has what we're looking
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* for here...
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*/
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if (fi->fi_fl & FI_TCPUDP) {
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if (portcmp) {
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if (!fr_tcpudpchk(fr, fin))
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continue;
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} else if (fr->fr_dcmp || fr->fr_scmp || fr->fr_tcpf ||
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fr->fr_tcpfm)
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continue;
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} else if (fi->fi_p == IPPROTO_ICMP) {
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if (!off && (fin->fin_dlen > 1)) {
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|
if ((fin->fin_data[0] & fr->fr_icmpm) !=
|
|
fr->fr_icmp) {
|
|
FR_DEBUG(("i. %#x & %#x != %#x\n",
|
|
fin->fin_data[0],
|
|
fr->fr_icmpm, fr->fr_icmp));
|
|
continue;
|
|
}
|
|
} else if (fr->fr_icmpm || fr->fr_icmp)
|
|
continue;
|
|
}
|
|
FR_VERBOSE(("*"));
|
|
/*
|
|
* Just log this packet...
|
|
*/
|
|
if (!(skip = fr->fr_skip))
|
|
pass = fr->fr_flags;
|
|
if ((pass & FR_CALLNOW) && fr->fr_func)
|
|
pass = (*fr->fr_func)(pass, ip, fin);
|
|
#ifdef IPFILTER_LOG
|
|
if ((pass & FR_LOGMASK) == FR_LOG) {
|
|
if (!IPLLOG(fr->fr_flags, ip, fin, m))
|
|
frstats[fin->fin_out].fr_skip++;
|
|
frstats[fin->fin_out].fr_pkl++;
|
|
}
|
|
#endif /* IPFILTER_LOG */
|
|
FR_DEBUG(("pass %#x\n", pass));
|
|
fr->fr_hits++;
|
|
if (pass & FR_ACCOUNT)
|
|
fr->fr_bytes += (U_QUAD_T)ip->ip_len;
|
|
else
|
|
fin->fin_icode = fr->fr_icode;
|
|
fin->fin_rule = rulen;
|
|
fin->fin_fr = fr;
|
|
if (pass & FR_QUICK)
|
|
break;
|
|
}
|
|
return pass;
|
|
}
|
|
|
|
|
|
/*
|
|
* frcheck - filter check
|
|
* check using source and destination addresses/pors in a packet whether
|
|
* or not to pass it on or not.
|
|
*/
|
|
int fr_check(ip, hlen, ifp, out
|
|
#if defined(_KERNEL) && SOLARIS
|
|
, qif, mp)
|
|
qif_t *qif;
|
|
#else
|
|
, mp)
|
|
#endif
|
|
mb_t **mp;
|
|
ip_t *ip;
|
|
int hlen;
|
|
struct ifnet *ifp;
|
|
int out;
|
|
{
|
|
/*
|
|
* The above really sucks, but short of writing a diff
|
|
*/
|
|
fr_info_t frinfo, *fc;
|
|
register fr_info_t *fin = &frinfo;
|
|
frentry_t *fr = NULL;
|
|
int pass, changed, apass;
|
|
#if !SOLARIS || !defined(_KERNEL)
|
|
register mb_t *m = *mp;
|
|
#endif
|
|
|
|
#ifdef _KERNEL
|
|
# if !defined(__SVR4) && !defined(__svr4__)
|
|
struct mbuf *mc = NULL;
|
|
|
|
if ((ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP ||
|
|
ip->ip_p == IPPROTO_ICMP)) {
|
|
register int up = MIN(hlen + 8, ip->ip_len);
|
|
|
|
if (up > m->m_len) {
|
|
if ((*mp = m_pullup(m, up)) == 0) {
|
|
frstats[out].fr_pull[1]++;
|
|
return -1;
|
|
} else {
|
|
frstats[out].fr_pull[0]++;
|
|
m = *mp;
|
|
ip = mtod(m, struct ip *);
|
|
}
|
|
}
|
|
}
|
|
# endif
|
|
# if SOLARIS
|
|
mblk_t *mc = NULL, *m = qif->qf_m;
|
|
# endif
|
|
#endif
|
|
fr_makefrip(hlen, ip, fin);
|
|
fin->fin_ifp = ifp;
|
|
fin->fin_out = out;
|
|
fin->fin_mp = mp;
|
|
|
|
MUTEX_ENTER(&ipf_mutex);
|
|
|
|
/*
|
|
* Check auth now. This, combined with the check below to see if apass
|
|
* is 0 is to ensure that we don't count the packet twice, which can
|
|
* otherwise occur when we reprocess it. As it is, we only count it
|
|
* after it has no auth. table matchup. This also stops NAT from
|
|
* occuring until after the packet has been auth'd.
|
|
*/
|
|
apass = fr_checkauth(ip, fin);
|
|
|
|
if (!out) {
|
|
changed = ip_natin(ip, hlen, fin);
|
|
if (!apass && (fin->fin_fr = ipacct[0][fr_active]) &&
|
|
(FR_SCANLIST(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT))
|
|
frstats[0].fr_acct++;
|
|
}
|
|
|
|
if (apass || (!(pass = ipfr_knownfrag(ip, fin)) &&
|
|
!(pass = fr_checkstate(ip, fin)))) {
|
|
/*
|
|
* If a packet is found in the auth table, then skip checking
|
|
* the access lists for permission but we do need to consider
|
|
* the result as if it were from the ACL's.
|
|
*/
|
|
if (!apass) {
|
|
fc = frcache + out;
|
|
if (fc->fin_fr &&
|
|
!bcmp((char *)fin, (char *)fc, FI_CSIZE)) {
|
|
/*
|
|
* copy cached data so we can unlock the mutex
|
|
* earlier.
|
|
*/
|
|
bcopy((char *)fc, (char *)fin, sizeof(*fin));
|
|
frstats[out].fr_chit++;
|
|
pass = fin->fin_fr->fr_flags;
|
|
} else {
|
|
pass = fr_pass;
|
|
if ((fin->fin_fr = ipfilter[out][fr_active]))
|
|
pass = FR_SCANLIST(fr_pass, ip, fin, m);
|
|
bcopy((char *)fin, (char *)fc, FI_CSIZE);
|
|
if (pass & FR_NOMATCH)
|
|
frstats[out].fr_nom++;
|
|
}
|
|
fr = fin->fin_fr;
|
|
} else
|
|
pass = apass;
|
|
|
|
/*
|
|
* If we fail to add a packet to the authorization queue,
|
|
* then we drop the packet later. However, if it was added
|
|
* then pretend we've dropped it already.
|
|
*/
|
|
if ((pass & FR_AUTH))
|
|
if (FR_NEWAUTH(m, fin, ip, qif) != 0)
|
|
#ifdef _KERNEL
|
|
m = *mp = NULL;
|
|
#else
|
|
;
|
|
#endif
|
|
|
|
if (pass & FR_PREAUTH) {
|
|
MUTEX_ENTER(&ipf_auth);
|
|
if ((fin->fin_fr = ipauth) &&
|
|
(pass = FR_SCANLIST(0, ip, fin, m)))
|
|
fr_authstats.fas_hits++;
|
|
else
|
|
fr_authstats.fas_miss++;
|
|
MUTEX_EXIT(&ipf_auth);
|
|
}
|
|
|
|
if (pass & FR_KEEPFRAG) {
|
|
if (fin->fin_fi.fi_fl & FI_FRAG) {
|
|
if (ipfr_newfrag(ip, fin, pass) == -1)
|
|
frstats[out].fr_bnfr++;
|
|
else
|
|
frstats[out].fr_nfr++;
|
|
} else
|
|
frstats[out].fr_cfr++;
|
|
}
|
|
if (pass & FR_KEEPSTATE) {
|
|
if (fr_addstate(ip, fin, pass) == -1)
|
|
frstats[out].fr_bads++;
|
|
else
|
|
frstats[out].fr_ads++;
|
|
}
|
|
}
|
|
|
|
if (fr && fr->fr_func && !(pass & FR_CALLNOW))
|
|
pass = (*fr->fr_func)(pass, ip, fin);
|
|
|
|
/*
|
|
* Only count/translate packets which will be passed on, out the
|
|
* interface.
|
|
*/
|
|
if (out && (pass & FR_PASS)) {
|
|
if ((fin->fin_fr = ipacct[1][fr_active]) &&
|
|
(FR_SCANLIST(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT))
|
|
frstats[1].fr_acct++;
|
|
fin->fin_fr = NULL;
|
|
changed = ip_natout(ip, hlen, fin);
|
|
}
|
|
fin->fin_fr = fr;
|
|
MUTEX_EXIT(&ipf_mutex);
|
|
|
|
#ifdef IPFILTER_LOG
|
|
if ((fr_flags & FF_LOGGING) || (pass & FR_LOGMASK)) {
|
|
if ((fr_flags & FF_LOGNOMATCH) && (pass & FR_NOMATCH)) {
|
|
pass |= FF_LOGNOMATCH;
|
|
frstats[out].fr_npkl++;
|
|
goto logit;
|
|
} else if (((pass & FR_LOGMASK) == FR_LOGP) ||
|
|
((pass & FR_PASS) && (fr_flags & FF_LOGPASS))) {
|
|
if ((pass & FR_LOGMASK) != FR_LOGP)
|
|
pass |= FF_LOGPASS;
|
|
frstats[out].fr_ppkl++;
|
|
goto logit;
|
|
} else if (((pass & FR_LOGMASK) == FR_LOGB) ||
|
|
((pass & FR_BLOCK) && (fr_flags & FF_LOGBLOCK))) {
|
|
if ((pass & FR_LOGMASK) != FR_LOGB)
|
|
pass |= FF_LOGBLOCK;
|
|
frstats[out].fr_bpkl++;
|
|
logit:
|
|
if (!IPLLOG(pass, ip, fin, m)) {
|
|
frstats[out].fr_skip++;
|
|
if ((pass & (FR_PASS|FR_LOGORBLOCK)) ==
|
|
(FR_PASS|FR_LOGORBLOCK))
|
|
pass ^= FR_PASS|FR_BLOCK;
|
|
}
|
|
}
|
|
}
|
|
#endif /* IPFILTER_LOG */
|
|
#ifdef _KERNEL
|
|
/*
|
|
* Only allow FR_DUP to work if a rule matched - it makes no sense to
|
|
* set FR_DUP as a "default" as there are no instructions about where
|
|
* to send the packet.
|
|
*/
|
|
if (fr && (pass & FR_DUP))
|
|
# if SOLARIS
|
|
mc = dupmsg(m);
|
|
# else
|
|
mc = m_copy(m, 0, M_COPYALL);
|
|
# endif
|
|
#endif
|
|
|
|
if (pass & FR_PASS)
|
|
frstats[out].fr_pass++;
|
|
else if (pass & FR_BLOCK) {
|
|
frstats[out].fr_block++;
|
|
/*
|
|
* Should we return an ICMP packet to indicate error
|
|
* status passing through the packet filter ?
|
|
* WARNING: ICMP error packets AND TCP RST packets should
|
|
* ONLY be sent in repsonse to incoming packets. Sending them
|
|
* in response to outbound packets can result in a panic on
|
|
* some operating systems.
|
|
*/
|
|
if (!out) {
|
|
#ifdef _KERNEL
|
|
if (pass & FR_RETICMP) {
|
|
# if SOLARIS
|
|
ICMP_ERROR(q, ip, ICMP_UNREACH, fin->fin_icode,
|
|
qif, ip->ip_src);
|
|
# else
|
|
ICMP_ERROR(m, ip, ICMP_UNREACH, fin->fin_icode,
|
|
ifp, ip->ip_src);
|
|
m = *mp = NULL; /* freed by icmp_error() */
|
|
# endif
|
|
|
|
frstats[0].fr_ret++;
|
|
} else if ((pass & FR_RETRST) &&
|
|
!(fin->fin_fi.fi_fl & FI_SHORT)) {
|
|
if (SEND_RESET(ip, qif, ifp) == 0)
|
|
frstats[1].fr_ret++;
|
|
}
|
|
#else
|
|
if (pass & FR_RETICMP) {
|
|
verbose("- ICMP unreachable sent\n");
|
|
frstats[0].fr_ret++;
|
|
} else if ((pass & FR_RETRST) &&
|
|
!(fin->fin_fi.fi_fl & FI_SHORT)) {
|
|
verbose("- TCP RST sent\n");
|
|
frstats[1].fr_ret++;
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we didn't drop off the bottom of the list of rules (and thus
|
|
* the 'current' rule fr is not NULL), then we may have some extra
|
|
* instructions about what to do with a packet.
|
|
* Once we're finished return to our caller, freeing the packet if
|
|
* we are dropping it (* BSD ONLY *).
|
|
*/
|
|
#ifdef _KERNEL
|
|
# if !SOLARIS
|
|
if (fr) {
|
|
frdest_t *fdp = &fr->fr_tif;
|
|
|
|
if ((pass & FR_FASTROUTE) ||
|
|
(fdp->fd_ifp && fdp->fd_ifp != (struct ifnet *)-1)) {
|
|
ipfr_fastroute(m, fin, fdp);
|
|
m = *mp = NULL;
|
|
}
|
|
if (mc)
|
|
ipfr_fastroute(mc, fin, &fr->fr_dif);
|
|
}
|
|
if (!(pass & FR_PASS) && m)
|
|
m_freem(m);
|
|
return (pass & FR_PASS) ? 0 : -1;
|
|
# else
|
|
if (fr) {
|
|
frdest_t *fdp = &fr->fr_tif;
|
|
|
|
if ((pass & FR_FASTROUTE) ||
|
|
(fdp->fd_ifp && fdp->fd_ifp != (struct ifnet *)-1)) {
|
|
ipfr_fastroute(qif, ip, m, mp, fin, fdp);
|
|
m = *mp = NULL;
|
|
}
|
|
if (mc)
|
|
ipfr_fastroute(qif, ip, mc, mp, fin, &fr->fr_dif);
|
|
}
|
|
return (pass & FR_PASS) ? changed : -1;
|
|
# endif
|
|
#else
|
|
if (pass & FR_NOMATCH)
|
|
return 1;
|
|
if (pass & FR_PASS)
|
|
return 0;
|
|
if (pass & FR_AUTH)
|
|
return -2;
|
|
return -1;
|
|
#endif
|
|
}
|
|
|
|
|
|
#ifdef IPFILTER_LOG
|
|
int fr_copytolog(dev, buf, len)
|
|
int dev;
|
|
char *buf;
|
|
int len;
|
|
{
|
|
register char *bufp = iplbuf[dev], *tp = iplt[dev], *hp = iplh[dev];
|
|
register int clen, tail;
|
|
|
|
tail = (hp >= tp) ? (bufp + IPLLOGSIZE - hp) : (tp - hp);
|
|
clen = MIN(tail, len);
|
|
bcopy(buf, hp, clen);
|
|
len -= clen;
|
|
tail -= clen;
|
|
hp += clen;
|
|
buf += clen;
|
|
if (hp == bufp + IPLLOGSIZE) {
|
|
hp = bufp;
|
|
tail = tp - hp;
|
|
}
|
|
if (len && tail) {
|
|
clen = MIN(tail, len);
|
|
bcopy(buf, hp, clen);
|
|
len -= clen;
|
|
hp += clen;
|
|
}
|
|
iplh[dev] = hp;
|
|
return len;
|
|
}
|
|
#endif
|
|
|
|
|
|
u_short ipf_cksum(addr, len)
|
|
register u_short *addr;
|
|
register int len;
|
|
{
|
|
register u_long sum = 0;
|
|
|
|
for (sum = 0; len > 1; len -= 2)
|
|
sum += *addr++;
|
|
|
|
/* mop up an odd byte, if necessary */
|
|
if (len == 1)
|
|
sum += *(u_char *)addr;
|
|
|
|
/*
|
|
* add back carry outs from top 16 bits to low 16 bits
|
|
*/
|
|
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
|
|
sum += (sum >> 16); /* add carry */
|
|
return (u_short)(~sum);
|
|
}
|
|
|
|
|
|
/*
|
|
* NB: This function assumes we've pullup'd enough for all of the IP header
|
|
* and the TCP header. We also assume that data blocks aren't allocated in
|
|
* odd sizes.
|
|
*/
|
|
u_short fr_tcpsum(m, ip, tcp)
|
|
mb_t *m;
|
|
ip_t *ip;
|
|
tcphdr_t *tcp;
|
|
{
|
|
union {
|
|
u_char c[2];
|
|
u_short s;
|
|
} bytes;
|
|
u_long sum;
|
|
u_short *sp;
|
|
int len, ilen;
|
|
# if SOLARIS
|
|
int add, hlen;
|
|
# endif
|
|
|
|
/*
|
|
* Add up IP Header portion
|
|
*/
|
|
ilen = len = ip->ip_len - (ip->ip_hl << 2);
|
|
bytes.c[0] = 0;
|
|
bytes.c[1] = IPPROTO_TCP;
|
|
sum = bytes.s;
|
|
sum += htons((u_short)len);
|
|
sp = (u_short *)&ip->ip_src;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
if (sp != (u_short *)tcp)
|
|
sp = (u_short *)tcp;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp++;
|
|
sum += *sp;
|
|
sp += 2; /* Skip over checksum */
|
|
sum += *sp++;
|
|
|
|
#if SOLARIS
|
|
/*
|
|
* In case we had to copy the IP & TCP header out of mblks,
|
|
* skip over the mblk bits which are the header
|
|
*/
|
|
if ((caddr_t)ip != (caddr_t)m->b_rptr) {
|
|
hlen = (caddr_t)sp - (caddr_t)ip;
|
|
while (hlen) {
|
|
add = MIN(hlen, m->b_wptr - m->b_rptr);
|
|
sp = (u_short *)((caddr_t)m->b_rptr + add);
|
|
if ((hlen -= add))
|
|
m = m->b_cont;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!(len -= sizeof(*tcp)))
|
|
goto nodata;
|
|
while (len > 1) {
|
|
sum += *sp++;
|
|
len -= 2;
|
|
#if SOLARIS
|
|
if ((caddr_t)sp > (caddr_t)m->b_wptr) {
|
|
m = m->b_cont;
|
|
PANIC((!m),("fr_tcpsum: not enough data"));
|
|
sp = (u_short *)m->b_rptr;
|
|
}
|
|
#else
|
|
# ifdef m_data
|
|
if ((caddr_t)sp > (m->m_data + m->m_len))
|
|
# else
|
|
if ((caddr_t)sp > (caddr_t)(m->m_dat + m->m_off + m->m_len))
|
|
# endif
|
|
{
|
|
m = m->m_next;
|
|
PANIC((!m),("fr_tcpsum: not enough data"));
|
|
sp = mtod(m, u_short *);
|
|
}
|
|
#endif /* SOLARIS */
|
|
}
|
|
if (len) {
|
|
bytes.c[1] = 0;
|
|
bytes.c[0] = *(u_char *)sp;
|
|
sum += bytes.s;
|
|
}
|
|
nodata:
|
|
sum = (sum >> 16) + (sum & 0xffff);
|
|
sum += (sum >> 16);
|
|
sum = (u_short)((~sum) & 0xffff);
|
|
return sum;
|
|
}
|