diff options
Diffstat (limited to 'ip_h323_pxy.c')
-rw-r--r-- | ip_h323_pxy.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/ip_h323_pxy.c b/ip_h323_pxy.c new file mode 100644 index 0000000..b6e7c7b --- /dev/null +++ b/ip_h323_pxy.c @@ -0,0 +1,296 @@ +/* $NetBSD$ */ + +/* + * Copyright 2001, QNX Software Systems Ltd. All Rights Reserved + * + * This source code has been published by QNX Software Systems Ltd. (QSSL). + * However, any use, reproduction, modification, distribution or transfer of + * this software, or any software which includes or is based upon any of this + * code, is only permitted under the terms of the QNX Open Community License + * version 1.0 (see licensing.qnx.com for details) or as otherwise expressly + * authorized by a written license agreement from QSSL. For more information, + * please email licensing@qnx.com. + * + * For more details, see QNX_OCL.txt provided with this distribution. + */ + +/* + * Simple H.323 proxy + * + * by xtang@canada.com + * ported to ipfilter 3.4.20 by Michael Grant mg-ipf@grant.org + */ + +#if __FreeBSD_version >= 220000 && defined(_KERNEL) +# include <sys/fcntl.h> +# include <sys/filio.h> +#else +# ifndef linux +# include <sys/ioctl.h> +# endif +#endif + +#define IPF_H323_PROXY + +int ippr_h323_init __P((void)); +void ippr_h323_fini __P((void)); +int ippr_h323_new __P((fr_info_t *, ap_session_t *, nat_t *)); +void ippr_h323_del __P((ap_session_t *)); +int ippr_h323_out __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_h323_in __P((fr_info_t *, ap_session_t *, nat_t *)); + +int ippr_h245_new __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_h245_out __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_h245_in __P((fr_info_t *, ap_session_t *, nat_t *)); + +static frentry_t h323_fr; + +int h323_proxy_init = 0; + +static int find_port __P((int, caddr_t, int datlen, int *, u_short *)); + + +static int find_port(ipaddr, data, datlen, off, port) +int ipaddr; +caddr_t data; +int datlen, *off; +unsigned short *port; +{ + u_32_t addr, netaddr; + u_char *dp; + int offset; + + if (datlen < 6) + return -1; + + *port = 0; + offset = *off; + dp = (u_char *)data; + netaddr = ntohl(ipaddr); + + for (offset = 0; offset <= datlen - 6; offset++, dp++) { + addr = (dp[0] << 24) | (dp[1] << 16) | (dp[2] << 8) | dp[3]; + if (netaddr == addr) + { + *port = (*(dp + 4) << 8) | *(dp + 5); + break; + } + } + *off = offset; + return (offset > datlen - 6) ? -1 : 0; +} + +/* + * Initialize local structures. + */ +int ippr_h323_init() +{ + bzero((char *)&h323_fr, sizeof(h323_fr)); + h323_fr.fr_ref = 1; + h323_fr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; + MUTEX_INIT(&h323_fr.fr_lock, "H323 proxy rule lock"); + h323_proxy_init = 1; + + return 0; +} + + +void ippr_h323_fini() +{ + if (h323_proxy_init == 1) { + MUTEX_DESTROY(&h323_fr.fr_lock); + h323_proxy_init = 0; + } +} + + +int ippr_h323_new(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + fin = fin; /* LINT */ + nat = nat; /* LINT */ + + aps->aps_data = NULL; + aps->aps_psiz = 0; + + return 0; +} + + +void ippr_h323_del(aps) +ap_session_t *aps; +{ + int i; + ipnat_t *ipn; + + if (aps->aps_data) { + for (i = 0, ipn = aps->aps_data; + i < (aps->aps_psiz / sizeof(ipnat_t)); + i++, ipn = (ipnat_t *)((char *)ipn + sizeof(*ipn))) + { + /* + * Check the comment in ippr_h323_in() function, + * just above fr_nat_ioctl() call. + * We are lucky here because this function is not + * called with ipf_nat locked. + */ + if (fr_nat_ioctl((caddr_t)ipn, SIOCRMNAT, NAT_SYSSPACE| + NAT_LOCKHELD|FWRITE) == -1) { + /*EMPTY*/; + /* log the error */ + } + } + KFREES(aps->aps_data, aps->aps_psiz); + /* avoid double free */ + aps->aps_data = NULL; + aps->aps_psiz = 0; + } + return; +} + + +int ippr_h323_in(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + int ipaddr, off, datlen; + unsigned short port; + caddr_t data; + tcphdr_t *tcp; + ip_t *ip; + + ip = fin->fin_ip; + tcp = (tcphdr_t *)fin->fin_dp; + ipaddr = ip->ip_src.s_addr; + + data = (caddr_t)tcp + (TCP_OFF(tcp) << 2); + datlen = fin->fin_dlen - (TCP_OFF(tcp) << 2); + if (find_port(ipaddr, data, datlen, &off, &port) == 0) { + ipnat_t *ipn; + char *newarray; + + /* setup a nat rule to set a h245 proxy on tcp-port "port" + * it's like: + * map <if> <inter_ip>/<mask> -> <gate_ip>/<mask> proxy port <port> <port>/tcp + */ + KMALLOCS(newarray, char *, aps->aps_psiz + sizeof(*ipn)); + if (newarray == NULL) { + return -1; + } + ipn = (ipnat_t *)&newarray[aps->aps_psiz]; + bcopy((caddr_t)nat->nat_ptr, (caddr_t)ipn, sizeof(ipnat_t)); + (void) strncpy(ipn->in_plabel, "h245", APR_LABELLEN); + + ipn->in_inip = nat->nat_inip.s_addr; + ipn->in_inmsk = 0xffffffff; + ipn->in_dport = htons(port); + /* + * we got a problem here. we need to call fr_nat_ioctl() to add + * the h245 proxy rule, but since we already hold (READ locked) + * the nat table rwlock (ipf_nat), if we go into fr_nat_ioctl(), + * it will try to WRITE lock it. This will causing dead lock + * on RTP. + * + * The quick & dirty solution here is release the read lock, + * call fr_nat_ioctl() and re-lock it. + * A (maybe better) solution is do a UPGRADE(), and instead + * of calling fr_nat_ioctl(), we add the nat rule ourself. + */ + RWLOCK_EXIT(&ipf_nat); + if (fr_nat_ioctl((caddr_t)ipn, SIOCADNAT, + NAT_SYSSPACE|FWRITE) == -1) { + READ_ENTER(&ipf_nat); + return -1; + } + READ_ENTER(&ipf_nat); + if (aps->aps_data != NULL && aps->aps_psiz > 0) { + bcopy(aps->aps_data, newarray, aps->aps_psiz); + KFREES(aps->aps_data, aps->aps_psiz); + } + aps->aps_data = newarray; + aps->aps_psiz += sizeof(*ipn); + } + return 0; +} + + +int ippr_h245_new(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + fin = fin; /* LINT */ + nat = nat; /* LINT */ + + aps->aps_data = NULL; + aps->aps_psiz = 0; + return 0; +} + + +int ippr_h245_out(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + int ipaddr, off, datlen; + tcphdr_t *tcp; + caddr_t data; + u_short port; + ip_t *ip; + + aps = aps; /* LINT */ + + ip = fin->fin_ip; + tcp = (tcphdr_t *)fin->fin_dp; + ipaddr = nat->nat_inip.s_addr; + data = (caddr_t)tcp + (TCP_OFF(tcp) << 2); + datlen = ip->ip_len - fin->fin_hlen - (TCP_OFF(tcp) << 2); + if (find_port(ipaddr, data, datlen, &off, &port) == 0) { + fr_info_t fi; + nat_t *nat2; + +/* port = htons(port); */ + nat2 = nat_outlookup(fin->fin_ifp, IPN_UDP, IPPROTO_UDP, + ip->ip_src, ip->ip_dst); + if (nat2 == NULL) { + struct ip newip; + struct udphdr udp; + + bcopy((caddr_t)ip, (caddr_t)&newip, sizeof(newip)); + newip.ip_len = fin->fin_hlen + sizeof(udp); + newip.ip_p = IPPROTO_UDP; + newip.ip_src = nat->nat_inip; + + bzero((char *)&udp, sizeof(udp)); + udp.uh_sport = port; + + bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi)); + fi.fin_fi.fi_p = IPPROTO_UDP; + fi.fin_data[0] = port; + fi.fin_data[1] = 0; + fi.fin_dp = (char *)&udp; + + nat2 = nat_new(&fi, nat->nat_ptr, NULL, + NAT_SLAVE|IPN_UDP|SI_W_DPORT, + NAT_OUTBOUND); + if (nat2 != NULL) { + (void) nat_proto(&fi, nat2, IPN_UDP); + nat_update(&fi, nat2, nat2->nat_ptr); + + nat2->nat_ptr->in_hits++; +#ifdef IPFILTER_LOG + nat_log(nat2, (u_int)(nat->nat_ptr->in_redir)); +#endif + bcopy((caddr_t)&ip->ip_src.s_addr, + data + off, 4); + bcopy((caddr_t)&nat2->nat_outport, + data + off + 4, 2); + } + } + } + return 0; +} |