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-rw-r--r--ip_h323_pxy.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/ip_h323_pxy.c b/ip_h323_pxy.c
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+/* $NetBSD$ */
+
+/*
+ * 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;
+}
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