175 lines
3.5 KiB
C
175 lines
3.5 KiB
C
/*
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* $Id: ip_rcmd_pxy.c,v 1.4.2.3 2000/10/27 22:54:04 darrenr Exp $
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*/
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/*
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* Simple RCMD transparent proxy for in-kernel use. For use with the NAT
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* code.
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* $FreeBSD$
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*/
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#if SOLARIS && defined(_KERNEL)
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extern kmutex_t ipf_rw;
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#endif
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#define isdigit(x) ((x) >= '0' && (x) <= '9')
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#define IPF_RCMD_PROXY
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int ippr_rcmd_init __P((void));
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int ippr_rcmd_new __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
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int ippr_rcmd_out __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
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u_short ipf_rcmd_atoi __P((char *));
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int ippr_rcmd_portmsg __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
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static frentry_t rcmdfr;
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/*
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* RCMD application proxy initialization.
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*/
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int ippr_rcmd_init()
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{
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bzero((char *)&rcmdfr, sizeof(rcmdfr));
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rcmdfr.fr_ref = 1;
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rcmdfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
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return 0;
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}
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/*
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* Setup for a new RCMD proxy.
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*/
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int ippr_rcmd_new(fin, ip, aps, nat)
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fr_info_t *fin;
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ip_t *ip;
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ap_session_t *aps;
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nat_t *nat;
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{
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tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp;
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aps->aps_psiz = sizeof(u_32_t);
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KMALLOCS(aps->aps_data, u_32_t *, sizeof(u_32_t));
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if (aps->aps_data == NULL)
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return -1;
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*(u_32_t *)aps->aps_data = 0;
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aps->aps_sport = tcp->th_sport;
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aps->aps_dport = tcp->th_dport;
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return 0;
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}
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/*
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* ipf_rcmd_atoi - implement a simple version of atoi
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*/
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u_short ipf_rcmd_atoi(ptr)
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char *ptr;
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{
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register char *s = ptr, c;
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register u_short i = 0;
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while ((c = *s++) && isdigit(c)) {
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i *= 10;
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i += c - '0';
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}
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return i;
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}
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int ippr_rcmd_portmsg(fin, ip, aps, nat)
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fr_info_t *fin;
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ip_t *ip;
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ap_session_t *aps;
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nat_t *nat;
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{
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char portbuf[8], *s;
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struct in_addr swip;
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u_short sp, dp;
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int off, dlen;
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tcphdr_t *tcp, tcph, *tcp2 = &tcph;
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fr_info_t fi;
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nat_t *ipn;
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mb_t *m;
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#if SOLARIS
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mb_t *m1;
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#endif
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tcp = (tcphdr_t *)fin->fin_dp;
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if (tcp->th_flags & TH_SYN) {
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*(u_32_t *)aps->aps_data = htonl(ntohl(tcp->th_seq) + 1);
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return 0;
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}
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if ((*(u_32_t *)aps->aps_data != 0) &&
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(tcp->th_seq != *(u_32_t *)aps->aps_data))
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return 0;
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off = (ip->ip_hl << 2) + (tcp->th_off << 2);
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#if SOLARIS
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m = fin->fin_qfm;
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dlen = msgdsize(m) - off;
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bzero(portbuf, sizeof(portbuf));
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copyout_mblk(m, off, MIN(sizeof(portbuf), dlen), portbuf);
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#else
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m = *(mb_t **)fin->fin_mp;
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dlen = mbufchainlen(m) - off;
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bzero(portbuf, sizeof(portbuf));
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m_copydata(m, off, MIN(sizeof(portbuf), dlen), portbuf);
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#endif
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portbuf[sizeof(portbuf) - 1] = '\0';
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s = portbuf;
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sp = ipf_rcmd_atoi(s);
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if (!sp)
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return 0;
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/*
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* Add skeleton NAT entry for connection which will come back the
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* other way.
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*/
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sp = htons(sp);
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dp = htons(fin->fin_data[1]);
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ipn = nat_outlookup(fin->fin_ifp, IPN_TCP, nat->nat_p, nat->nat_inip,
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ip->ip_dst, (dp << 16) | sp);
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if (ipn == NULL) {
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int slen;
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slen = ip->ip_len;
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ip->ip_len = fin->fin_hlen + sizeof(*tcp);
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bcopy((char *)fin, (char *)&fi, sizeof(fi));
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bzero((char *)tcp2, sizeof(*tcp2));
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tcp2->th_win = htons(8192);
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tcp2->th_sport = sp;
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tcp2->th_dport = 0; /* XXX - don't specify remote port */
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tcp2->th_off = 5;
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fi.fin_data[0] = ntohs(sp);
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fi.fin_data[1] = 0;
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fi.fin_dp = (char *)tcp2;
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fi.fin_dlen = sizeof(*tcp2);
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swip = ip->ip_src;
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ip->ip_src = nat->nat_inip;
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ipn = nat_new(nat->nat_ptr, ip, &fi, IPN_TCP|FI_W_DPORT,
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NAT_OUTBOUND);
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if (ipn != NULL) {
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ipn->nat_age = fr_defnatage;
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fi.fin_fr = &rcmdfr;
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(void) fr_addstate(ip, &fi, FI_W_DPORT);
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}
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ip->ip_len = slen;
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ip->ip_src = swip;
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}
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return 0;
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}
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int ippr_rcmd_out(fin, ip, aps, nat)
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fr_info_t *fin;
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ip_t *ip;
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ap_session_t *aps;
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nat_t *nat;
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{
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return ippr_rcmd_portmsg(fin, ip, aps, nat);
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}
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