diff options
Diffstat (limited to 'contrib/ipfilter/ip_pptp_pxy.c')
-rw-r--r-- | contrib/ipfilter/ip_pptp_pxy.c | 527 |
1 files changed, 0 insertions, 527 deletions
diff --git a/contrib/ipfilter/ip_pptp_pxy.c b/contrib/ipfilter/ip_pptp_pxy.c deleted file mode 100644 index b7ec697..0000000 --- a/contrib/ipfilter/ip_pptp_pxy.c +++ /dev/null @@ -1,527 +0,0 @@ -/* $FreeBSD$ */ - -/* - * Copyright (C) 2002-2003 by Darren Reed - * - * Simple PPTP transparent proxy for in-kernel use. For use with the NAT - * code. - * - * Id: ip_pptp_pxy.c,v 2.10.2.9 2005/03/16 18:17:34 darrenr Exp - * - */ -#define IPF_PPTP_PROXY - -typedef struct pptp_hdr { - u_short pptph_len; - u_short pptph_type; - u_32_t pptph_cookie; -} pptp_hdr_t; - -#define PPTP_MSGTYPE_CTL 1 -#define PPTP_MTCTL_STARTREQ 1 -#define PPTP_MTCTL_STARTREP 2 -#define PPTP_MTCTL_STOPREQ 3 -#define PPTP_MTCTL_STOPREP 4 -#define PPTP_MTCTL_ECHOREQ 5 -#define PPTP_MTCTL_ECHOREP 6 -#define PPTP_MTCTL_OUTREQ 7 -#define PPTP_MTCTL_OUTREP 8 -#define PPTP_MTCTL_INREQ 9 -#define PPTP_MTCTL_INREP 10 -#define PPTP_MTCTL_INCONNECT 11 -#define PPTP_MTCTL_CLEAR 12 -#define PPTP_MTCTL_DISCONNECT 13 -#define PPTP_MTCTL_WANERROR 14 -#define PPTP_MTCTL_LINKINFO 15 - - -int ippr_pptp_init __P((void)); -void ippr_pptp_fini __P((void)); -int ippr_pptp_new __P((fr_info_t *, ap_session_t *, nat_t *)); -void ippr_pptp_del __P((ap_session_t *)); -int ippr_pptp_inout __P((fr_info_t *, ap_session_t *, nat_t *)); -void ippr_pptp_donatstate __P((fr_info_t *, nat_t *, pptp_pxy_t *)); -int ippr_pptp_message __P((fr_info_t *, nat_t *, pptp_pxy_t *, pptp_side_t *)); -int ippr_pptp_nextmessage __P((fr_info_t *, nat_t *, pptp_pxy_t *, int)); -int ippr_pptp_mctl __P((fr_info_t *, nat_t *, pptp_pxy_t *, pptp_side_t *)); - -static frentry_t pptpfr; - -int pptp_proxy_init = 0; -int ippr_pptp_debug = 0; -int ippr_pptp_gretimeout = IPF_TTLVAL(120); /* 2 minutes */ - - -/* - * PPTP application proxy initialization. - */ -int ippr_pptp_init() -{ - bzero((char *)&pptpfr, sizeof(pptpfr)); - pptpfr.fr_ref = 1; - pptpfr.fr_age[0] = ippr_pptp_gretimeout; - pptpfr.fr_age[1] = ippr_pptp_gretimeout; - pptpfr.fr_flags = FR_OUTQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; - MUTEX_INIT(&pptpfr.fr_lock, "PPTP proxy rule lock"); - pptp_proxy_init = 1; - - return 0; -} - - -void ippr_pptp_fini() -{ - if (pptp_proxy_init == 1) { - MUTEX_DESTROY(&pptpfr.fr_lock); - pptp_proxy_init = 0; - } -} - - -/* - * Setup for a new PPTP proxy. - */ -int ippr_pptp_new(fin, aps, nat) -fr_info_t *fin; -ap_session_t *aps; -nat_t *nat; -{ - pptp_pxy_t *pptp; - ipnat_t *ipn; - ip_t *ip; - int off; - - ip = fin->fin_ip; - off = fin->fin_hlen + sizeof(udphdr_t); - - if (nat_outlookup(fin, 0, IPPROTO_GRE, nat->nat_inip, - ip->ip_dst) != NULL) { - if (ippr_pptp_debug > 0) - printf("ippr_pptp_new: GRE session already exists\n"); - return -1; - } - - aps->aps_psiz = sizeof(*pptp); - KMALLOCS(aps->aps_data, pptp_pxy_t *, sizeof(*pptp)); - if (aps->aps_data == NULL) { - if (ippr_pptp_debug > 0) - printf("ippr_pptp_new: malloc for aps_data failed\n"); - return -1; - } - - /* - * Create NAT rule against which the tunnel/transport mapping is - * created. This is required because the current NAT rule does not - * describe GRE but TCP instead. - */ - pptp = aps->aps_data; - bzero((char *)pptp, sizeof(*pptp)); - ipn = &pptp->pptp_rule; - ipn->in_ifps[0] = fin->fin_ifp; - ipn->in_apr = NULL; - ipn->in_use = 1; - ipn->in_hits = 1; - ipn->in_ippip = 1; - if (nat->nat_dir == NAT_OUTBOUND) { - ipn->in_nip = ntohl(nat->nat_outip.s_addr); - ipn->in_outip = fin->fin_saddr; - ipn->in_redir = NAT_MAP; - } else if (nat->nat_dir == NAT_INBOUND) { - ipn->in_nip = 0; - ipn->in_outip = nat->nat_outip.s_addr; - ipn->in_redir = NAT_REDIRECT; - } - ipn->in_inip = nat->nat_inip.s_addr; - ipn->in_inmsk = 0xffffffff; - ipn->in_outmsk = 0xffffffff; - ipn->in_srcip = fin->fin_saddr; - ipn->in_srcmsk = 0xffffffff; - bcopy(nat->nat_ptr->in_ifnames[0], ipn->in_ifnames[0], - sizeof(ipn->in_ifnames[0])); - ipn->in_p = IPPROTO_GRE; - - pptp->pptp_side[0].pptps_wptr = pptp->pptp_side[0].pptps_buffer; - pptp->pptp_side[1].pptps_wptr = pptp->pptp_side[1].pptps_buffer; - return 0; -} - - -void ippr_pptp_donatstate(fin, nat, pptp) -fr_info_t *fin; -nat_t *nat; -pptp_pxy_t *pptp; -{ - fr_info_t fi; - grehdr_t gre; - nat_t *nat2; - u_char p; - ip_t *ip; - - ip = fin->fin_ip; - p = ip->ip_p; - - nat2 = pptp->pptp_nat; - if ((nat2 == NULL) || (pptp->pptp_state == NULL)) { - bcopy((char *)fin, (char *)&fi, sizeof(fi)); - bzero((char *)&gre, sizeof(gre)); - fi.fin_state = NULL; - fi.fin_nat = NULL; - fi.fin_fi.fi_p = IPPROTO_GRE; - fi.fin_fr = &pptpfr; - if ((nat->nat_dir == NAT_OUTBOUND && fin->fin_out) || - (nat->nat_dir == NAT_INBOUND && !fin->fin_out)) { - fi.fin_data[0] = pptp->pptp_call[0]; - fi.fin_data[1] = pptp->pptp_call[1]; - } else { - fi.fin_data[0] = pptp->pptp_call[1]; - fi.fin_data[1] = pptp->pptp_call[0]; - } - ip = fin->fin_ip; - ip->ip_p = IPPROTO_GRE; - fi.fin_flx &= ~(FI_TCPUDP|FI_STATE|FI_FRAG); - fi.fin_flx |= FI_IGNORE; - fi.fin_dp = &gre; - gre.gr_flags = htons(1 << 13); - if (fin->fin_out && nat->nat_dir == NAT_INBOUND) { - fi.fin_fi.fi_saddr = fin->fin_fi.fi_daddr; - fi.fin_fi.fi_daddr = nat->nat_outip.s_addr; - } else if (!fin->fin_out && nat->nat_dir == NAT_OUTBOUND) { - fi.fin_fi.fi_saddr = nat->nat_inip.s_addr; - fi.fin_fi.fi_daddr = fin->fin_fi.fi_saddr; - } - } - - /* - * Update NAT timeout/create NAT if missing. - */ - if (nat2 != NULL) - fr_queueback(&nat2->nat_tqe); - else { - nat2 = nat_new(&fi, &pptp->pptp_rule, &pptp->pptp_nat, - NAT_SLAVE, nat->nat_dir); - pptp->pptp_nat = nat2; - if (nat2 != NULL) { - (void) nat_proto(&fi, nat2, 0); - nat_update(&fi, nat2, nat2->nat_ptr); - } - } - - READ_ENTER(&ipf_state); - if (pptp->pptp_state != NULL) { - fr_queueback(&pptp->pptp_state->is_sti); - RWLOCK_EXIT(&ipf_state); - } else { - RWLOCK_EXIT(&ipf_state); - if (nat->nat_dir == NAT_INBOUND) - fi.fin_fi.fi_daddr = nat2->nat_inip.s_addr; - else - fi.fin_fi.fi_saddr = nat2->nat_inip.s_addr; - fi.fin_ifp = NULL; - pptp->pptp_state = fr_addstate(&fi, &pptp->pptp_state, - 0); - if (fi.fin_state != NULL) - fr_statederef(&fi, (ipstate_t **)&fi.fin_state); - } - ip->ip_p = p; - return; -} - - -/* - * Try and build up the next PPTP message in the TCP stream and if we can - * build it up completely (fits in our buffer) then pass it off to the message - * parsing function. - */ -int ippr_pptp_nextmessage(fin, nat, pptp, rev) -fr_info_t *fin; -nat_t *nat; -pptp_pxy_t *pptp; -int rev; -{ - static char *funcname = "ippr_pptp_nextmessage"; - pptp_side_t *pptps; - u_32_t start, end; - pptp_hdr_t *hdr; - tcphdr_t *tcp; - int dlen, off; - u_short len; - char *msg; - - tcp = fin->fin_dp; - dlen = fin->fin_dlen - (TCP_OFF(tcp) << 2); - start = ntohl(tcp->th_seq); - pptps = &pptp->pptp_side[rev]; - off = (char *)tcp - (char *)fin->fin_ip + (TCP_OFF(tcp) << 2) + - fin->fin_ipoff; - - if (dlen <= 0) - return 0; - /* - * If the complete data packet is before what we expect to see - * "next", just ignore it as the chances are we've already seen it. - * The next if statement following this one really just causes packets - * ahead of what we've seen to be dropped, implying that something in - * the middle went missing and we want to see that first. - */ - end = start + dlen; - if (pptps->pptps_next > end && pptps->pptps_next > start) - return 0; - - if (pptps->pptps_next != start) { - if (ippr_pptp_debug > 5) - printf("%s: next (%x) != start (%x)\n", funcname, - pptps->pptps_next, start); - return -1; - } - - msg = (char *)fin->fin_dp + (TCP_OFF(tcp) << 2); - - while (dlen > 0) { - off += pptps->pptps_bytes; - if (pptps->pptps_gothdr == 0) { - /* - * PPTP has an 8 byte header that inclues the cookie. - * The start of every message should include one and - * it should match 1a2b3c4d. Byte order is ignored, - * deliberately, when printing out the error. - */ - len = MIN(8 - pptps->pptps_bytes, dlen); - COPYDATA(fin->fin_m, off, len, pptps->pptps_wptr); - pptps->pptps_bytes += len; - pptps->pptps_wptr += len; - hdr = (pptp_hdr_t *)pptps->pptps_buffer; - if (pptps->pptps_bytes == 8) { - pptps->pptps_next += 8; - if (ntohl(hdr->pptph_cookie) != 0x1a2b3c4d) { - if (ippr_pptp_debug > 1) - printf("%s: bad cookie (%x)\n", - funcname, - hdr->pptph_cookie); - return -1; - } - } - dlen -= len; - msg += len; - off += len; - - pptps->pptps_gothdr = 1; - len = ntohs(hdr->pptph_len); - pptps->pptps_len = len; - pptps->pptps_nexthdr += len; - - /* - * If a message is too big for the buffer, just set - * the fields for the next message to come along. - * The messages defined in RFC 2637 will not exceed - * 512 bytes (in total length) so this is likely a - * bad data packet, anyway. - */ - if (len > sizeof(pptps->pptps_buffer)) { - if (ippr_pptp_debug > 3) - printf("%s: message too big (%d)\n", - funcname, len); - pptps->pptps_next = pptps->pptps_nexthdr; - pptps->pptps_wptr = pptps->pptps_buffer; - pptps->pptps_gothdr = 0; - pptps->pptps_bytes = 0; - pptps->pptps_len = 0; - break; - } - } - - len = MIN(pptps->pptps_len - pptps->pptps_bytes, dlen); - COPYDATA(fin->fin_m, off, len, pptps->pptps_wptr); - pptps->pptps_bytes += len; - pptps->pptps_wptr += len; - pptps->pptps_next += len; - - if (pptps->pptps_len > pptps->pptps_bytes) - break; - - ippr_pptp_message(fin, nat, pptp, pptps); - pptps->pptps_wptr = pptps->pptps_buffer; - pptps->pptps_gothdr = 0; - pptps->pptps_bytes = 0; - pptps->pptps_len = 0; - - start += len; - msg += len; - dlen -= len; - } - - return 0; -} - - -/* - * handle a complete PPTP message - */ -int ippr_pptp_message(fin, nat, pptp, pptps) -fr_info_t *fin; -nat_t *nat; -pptp_pxy_t *pptp; -pptp_side_t *pptps; -{ - pptp_hdr_t *hdr = (pptp_hdr_t *)pptps->pptps_buffer; - - switch (ntohs(hdr->pptph_type)) - { - case PPTP_MSGTYPE_CTL : - ippr_pptp_mctl(fin, nat, pptp, pptps); - break; - - default : - break; - } - return 0; -} - - -/* - * handle a complete PPTP control message - */ -int ippr_pptp_mctl(fin, nat, pptp, pptps) -fr_info_t *fin; -nat_t *nat; -pptp_pxy_t *pptp; -pptp_side_t *pptps; -{ - u_short *buffer = (u_short *)(pptps->pptps_buffer); - pptp_side_t *pptpo; - - if (pptps == &pptp->pptp_side[0]) - pptpo = &pptp->pptp_side[1]; - else - pptpo = &pptp->pptp_side[0]; - - /* - * Breakout to handle all the various messages. Most are just state - * transition. - */ - switch (ntohs(buffer[4])) - { - case PPTP_MTCTL_STARTREQ : - pptps->pptps_state = PPTP_MTCTL_STARTREQ; - break; - case PPTP_MTCTL_STARTREP : - if (pptpo->pptps_state == PPTP_MTCTL_STARTREQ) - pptps->pptps_state = PPTP_MTCTL_STARTREP; - break; - case PPTP_MTCTL_STOPREQ : - pptps->pptps_state = PPTP_MTCTL_STOPREQ; - break; - case PPTP_MTCTL_STOPREP : - if (pptpo->pptps_state == PPTP_MTCTL_STOPREQ) - pptps->pptps_state = PPTP_MTCTL_STOPREP; - break; - case PPTP_MTCTL_ECHOREQ : - pptps->pptps_state = PPTP_MTCTL_ECHOREQ; - break; - case PPTP_MTCTL_ECHOREP : - if (pptpo->pptps_state == PPTP_MTCTL_ECHOREQ) - pptps->pptps_state = PPTP_MTCTL_ECHOREP; - break; - case PPTP_MTCTL_OUTREQ : - pptps->pptps_state = PPTP_MTCTL_OUTREQ; - break; - case PPTP_MTCTL_OUTREP : - if (pptpo->pptps_state == PPTP_MTCTL_OUTREQ) { - pptps->pptps_state = PPTP_MTCTL_OUTREP; - pptp->pptp_call[0] = buffer[7]; - pptp->pptp_call[1] = buffer[6]; - ippr_pptp_donatstate(fin, nat, pptp); - } - break; - case PPTP_MTCTL_INREQ : - pptps->pptps_state = PPTP_MTCTL_INREQ; - break; - case PPTP_MTCTL_INREP : - if (pptpo->pptps_state == PPTP_MTCTL_INREQ) { - pptps->pptps_state = PPTP_MTCTL_INREP; - pptp->pptp_call[0] = buffer[7]; - pptp->pptp_call[1] = buffer[6]; - ippr_pptp_donatstate(fin, nat, pptp); - } - break; - case PPTP_MTCTL_INCONNECT : - pptps->pptps_state = PPTP_MTCTL_INCONNECT; - break; - case PPTP_MTCTL_CLEAR : - pptps->pptps_state = PPTP_MTCTL_CLEAR; - break; - case PPTP_MTCTL_DISCONNECT : - pptps->pptps_state = PPTP_MTCTL_DISCONNECT; - break; - case PPTP_MTCTL_WANERROR : - pptps->pptps_state = PPTP_MTCTL_WANERROR; - break; - case PPTP_MTCTL_LINKINFO : - pptps->pptps_state = PPTP_MTCTL_LINKINFO; - break; - } - - return 0; -} - - -/* - * For outgoing PPTP packets. refresh timeouts for NAT & state entries, if - * we can. If they have disappeared, recreate them. - */ -int ippr_pptp_inout(fin, aps, nat) -fr_info_t *fin; -ap_session_t *aps; -nat_t *nat; -{ - pptp_pxy_t *pptp; - tcphdr_t *tcp; - int rev; - - if ((fin->fin_out == 1) && (nat->nat_dir == NAT_INBOUND)) - rev = 1; - else if ((fin->fin_out == 0) && (nat->nat_dir == NAT_OUTBOUND)) - rev = 1; - else - rev = 0; - - tcp = (tcphdr_t *)fin->fin_dp; - if ((tcp->th_flags & TH_OPENING) == TH_OPENING) { - pptp = (pptp_pxy_t *)aps->aps_data; - pptp->pptp_side[1 - rev].pptps_next = ntohl(tcp->th_ack); - pptp->pptp_side[1 - rev].pptps_nexthdr = ntohl(tcp->th_ack); - pptp->pptp_side[rev].pptps_next = ntohl(tcp->th_seq) + 1; - pptp->pptp_side[rev].pptps_nexthdr = ntohl(tcp->th_seq) + 1; - } - return ippr_pptp_nextmessage(fin, nat, (pptp_pxy_t *)aps->aps_data, - rev); -} - - -/* - * clean up after ourselves. - */ -void ippr_pptp_del(aps) -ap_session_t *aps; -{ - pptp_pxy_t *pptp; - - pptp = aps->aps_data; - - if (pptp != NULL) { - /* - * Don't bother changing any of the NAT structure details, - * *_del() is on a callback from aps_free(), from nat_delete() - */ - - READ_ENTER(&ipf_state); - if (pptp->pptp_state != NULL) { - pptp->pptp_state->is_die = fr_ticks + 1; - pptp->pptp_state->is_me = NULL; - fr_queuefront(&pptp->pptp_state->is_sti); - } - RWLOCK_EXIT(&ipf_state); - - pptp->pptp_state = NULL; - pptp->pptp_nat = NULL; - } -} |