Use UPnP to punch holes in NATs

lib/ZInit.c

@@ -24,6 +24,9 @@ static const char rcsid_ZInitialize_c[] =
 #ifdef HAVE_KRB5
 #include <krb5.h>
 #endif
+#if defined(__APPLE__) && defined(__MACH__)
+#include "nwi/network_state_information_priv.h"
+#endif
 
 #ifndef INADDR_NONE
 #define INADDR_NONE 0xffffffff
@@ -196,6 +199,20 @@ ZInitialize(void)
 	    close(s);
 	}
     }
+#if defined(__APPLE__) && defined(__MACH__)
+    if (__My_addr.s_addr == INADDR_NONE) {
+      nwi_state_t state;
+      state = nwi_state_copy();
+      nwi_ifstate_t ifstate;
+      ifstate = nwi_state_get_first_ifstate(state, AF_INET);
+      if (ifstate != NULL) {
+	memcpy(&__My_addr, &ifstate->iaddr, sizeof(__My_addr));
+      }
+      if (state != NULL) {
+	nwi_state_release(state);
+      }
+    }
+#endif
     if (__My_addr.s_addr == INADDR_NONE) {
 	/* We couldn't figure out the local interface address by the
 	 * above method.  Try by resolving the local hostname.  (This

lib/nwi/network_information.h

@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2011-2019 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+#ifndef _NETWORK_INFORMATION_H_
+#define _NETWORK_INFORMATION_H_
+
+#include <os/availability.h>
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+typedef struct _nwi_state * nwi_state_t;
+typedef struct _nwi_ifstate * nwi_ifstate_t;
+
+__BEGIN_DECLS
+
+/*
+ * Function: nwi_state_copy
+ * Purpose:
+ *   Returns the current network state information; NULL if no state
+ *	information is currently available.
+ *   Release after use by calling nwi_state_release().
+ */
+nwi_state_t
+nwi_state_copy(void);
+
+/*
+ * Function: nwi_state_release
+ * Purpose:
+ *   Release the memory associated with the network state.
+ */
+void
+nwi_state_release(nwi_state_t state);
+
+/*
+ * Function: nwi_state_get_notify_key
+ * Purpose:
+ *   Returns the BSD notify key to use to monitor when the state changes.
+ *
+ * Note:
+ *   The nwi_state_copy API uses this notify key to monitor when the state
+ *   changes, so each invocation of nwi_state_copy returns the current
+ *   information.
+ */
+const char *
+nwi_state_get_notify_key(void);
+
+/*
+ * Function: nwi_state_get_first_ifstate
+ * Purpose:
+ *   Returns the first and highest priority interface that has connectivity
+ *   for the specified address family 'af'. 'af' is either AF_INET or AF_INET6.
+ *   The connectivity provided is for general networking.   To get information
+ *   about an interface that isn't available for general networking, use
+ *   nwi_state_get_ifstate().
+ *
+ *   Use nwi_ifstate_get_next() to get the next, lower priority interface
+ *   in the list.
+ *
+ *   Returns NULL if no connectivity for the specified address family is
+ *   available.
+ */
+nwi_ifstate_t
+nwi_state_get_first_ifstate(nwi_state_t state, int af);
+
+/*
+ * Function: nwi_state_get_generation
+ * Purpose:
+ *   Returns the generation of the nwi_state data.
+ *   Every time the data is updated due to changes
+ *   in the network, this value will change.
+ */
+uint64_t
+nwi_state_get_generation(nwi_state_t state);
+
+/*
+ * Function: nwi_ifstate_get_generation
+ * Purpose:
+ *   Returns the generation of the nwi_ifstate data.
+ */
+uint64_t
+nwi_ifstate_get_generation(nwi_ifstate_t ifstate);
+
+/*
+ * Function: nwi_state_get_ifstate
+ * Purpose:
+ *   Return information for the specified interface 'ifname'.
+ *
+ *   This API directly returns the ifstate for the specified interface.
+ *   This is the only way to access information about an interface that isn't
+ *   available for general networking.
+ *
+ *   Returns NULL if no information is available for that interface.
+ */
+nwi_ifstate_t
+nwi_state_get_ifstate(nwi_state_t state, const char * ifname);
+
+/*
+ * Function: nwi_ifstate_get_ifname
+ * Purpose:
+ *   Return the interface name of the specified ifstate.
+ */
+const char *
+nwi_ifstate_get_ifname(nwi_ifstate_t ifstate);
+
+/*
+ * Type: nwi_ifstate_flags
+ * Purpose:
+ *   Provide information about the interface, including its IPv4 and IPv6
+ *   connectivity, and whether DNS is configured or not.
+ */
+#define NWI_IFSTATE_FLAGS_HAS_IPV4	0x1	/* has IPv4 connectivity */
+#define NWI_IFSTATE_FLAGS_HAS_IPV6	0x2	/* has IPv6 connectivity */
+#define NWI_IFSTATE_FLAGS_HAS_DNS	0x4	/* has DNS configured */
+#define NWI_IFSTATE_FLAGS_HAS_CLAT46	0x0040	/* has CLAT46 configured */
+
+typedef uint64_t nwi_ifstate_flags;
+/*
+ * Function: nwi_ifstate_get_flags
+ * Purpose:
+ *   Return the flags for the given ifstate (see above for bit definitions).
+ */
+nwi_ifstate_flags
+nwi_ifstate_get_flags(nwi_ifstate_t ifstate);
+
+/*
+ * Function: nwi_ifstate_get_next
+ * Purpose:
+ *   Returns the next, lower priority nwi_ifstate_t after the specified
+ *   'ifstate' for the protocol family 'af'.
+ *
+ *   Returns NULL when the end of the list is reached.
+ */
+nwi_ifstate_t
+nwi_ifstate_get_next(nwi_ifstate_t ifstate, int af);
+
+/*
+ * Function: nwi_ifstate_compare_rank
+ * Purpose:
+ *   Compare the relative rank of two nwi_ifstate_t objects.
+ *
+ *   The "rank" indicates the importance of the underlying interface.
+ *
+ * Returns:
+ *   0 	if ifstate1 and ifstate2 are ranked equally
+ *  -1	if ifstate1 is ranked ahead of ifstate2
+ *   1	if ifstate2 is ranked ahead of ifstate1
+ */
+int
+nwi_ifstate_compare_rank(nwi_ifstate_t ifstate1, nwi_ifstate_t ifstate2);
+
+/*
+ * Function: _nwi_state_ack
+ * Purpose:
+ *   Acknowledge receipt and any changes associated with the [new or
+ *   updated] network state.
+ */
+void
+_nwi_state_ack(nwi_state_t state, const char *bundle_id)
+	API_AVAILABLE(macos(10.8), ios(6.0));
+
+/*
+ * Function: nwi_state_get_reachability_flags
+ * Purpose:
+ * Returns the global reachability flags for a given address family.
+ * If no address family is passed in, it returns the global reachability
+ * flags for either families.
+ *
+ * The reachability flags returned follow the definition of
+ * SCNetworkReachabilityFlags.
+ *
+ * If the flags are zero (i.e. do not contain kSCNetworkReachabilityFlagsReachable), there is no connectivity.
+ *
+ * Otherwise, at least kSCNetworkReachabilityFlagsReachable is set:
+ *        Reachable only
+ *          No other connection flags are set.
+ *        Reachable and no ConnectionRequired
+ *          If we have connectivity for the specified address family (and we'd
+ *          be returning the reachability flags associated with the default route)
+ *        Reachable and ConnectionRequired
+ *          If we do not currently have an active/primary network but we may
+ *          be able to establish connectivity.
+ *        Reachable and OnDemand
+ *          If we do not currently have an active/primary network but we may
+ *          be able to establish connective on demand.
+ *        Reachable and TransientConnection
+ *          This connection is transient.
+ *        Reachable and WWAN
+ *          This connection will be going over the cellular network.
+ */
+uint32_t
+nwi_state_get_reachability_flags(nwi_state_t nwi_state, int af);
+
+/*
+ * Function: nwi_state_get_interface_names
+ * Purpose:
+ *   Returns the list of network interface names that have connectivity.
+ *   The list is sorted from highest priority to least, highest priority
+ *   appearing at index 0.
+ *
+ *   If 'names' is NULL or 'names_count' is zero, this function returns
+ *   the number of elements that 'names' must contain to get the complete
+ *   list of interface names.
+ *
+ *   If 'names' is not NULL and 'names_count' is not zero, fills 'names' with
+ *   the list of interface names not exceeding 'names_count'. Returns the
+ *   number of elements that were actually populated.
+ *
+ * Notes:
+ * 1. The connectivity that an interface in this list provides may not be for
+ *    general purpose use.
+ * 2. The string pointers remain valid only as long as 'state' remains
+ *    valid.
+ */
+unsigned int
+nwi_state_get_interface_names(nwi_state_t state,
+			      const char * names[],
+			      unsigned int names_count);
+
+/*
+ * nwi_ifstate_get_vpn_server
+ *
+ * returns a sockaddr representation of the vpn server address.
+ * NULL if PPP/VPN/IPSec server address does not exist.
+ */
+const struct sockaddr *
+nwi_ifstate_get_vpn_server(nwi_ifstate_t ifstate);
+
+/*
+ * nwi_ifstate_get_reachability_flags
+ *
+ * returns the reachability flags for the interface given an address family.
+ * The flags returned are those determined outside of
+ * the routing table.  [None, ConnectionRequired, OnDemand,
+ * Transient Connection, WWAN].
+ */
+uint32_t
+nwi_ifstate_get_reachability_flags(nwi_ifstate_t ifstate);
+
+/*
+ * nwi_ifstate_get_signature
+ *
+ * returns the signature and its length for an ifstate given an address family.
+ * If AF_UNSPEC is passed in, the signature for a given ifstate is returned.
+ *
+ * If the signature does not exist, NULL is returned.
+ */
+const uint8_t *
+nwi_ifstate_get_signature(nwi_ifstate_t ifstate, int af, int * length);
+
+
+/*
+ * nwi_ifstate_get_dns_signature
+ *
+ * returns the signature and its length for given
+ * ifstate with a valid dns configuration.
+ *
+ * If the signature does not exist, NULL is returned.
+ *
+ */
+const uint8_t *
+nwi_ifstate_get_dns_signature(nwi_ifstate_t ifstate, int * length);
+
+__END_DECLS
+
+#endif