Set/delete functionality in BSD routing table.

node/BSDRoutingTable.cpp

@@ -48,6 +48,8 @@
 
 // All I wanted was the bloody rounting table. I didn't expect the Spanish inquisition.
 
+#define ZT_BSD_ROUTE_CMD "/sbin/route"
+
 namespace ZeroTier {
 
 BSDRoutingTable::BSDRoutingTable()
@@ -180,6 +182,8 @@ std::vector<RoutingTable::Entry> BSDRoutingTable::get(bool includeLinkLocal,bool
 						}
 
 						e.metric = (int)rtm->rtm_rmx.rmx_hopcount;
+						if (e.metric < 0)
+							e.metric = 0;
 
 						if (((includeLinkLocal)||(!e.destination.isLinkLocal()))&&((includeLoopback)||((!e.destination.isLoopback())&&(!e.gateway.isLoopback()))))
 							entries.push_back(e);
@@ -214,21 +218,109 @@ std::vector<RoutingTable::Entry> BSDRoutingTable::get(bool includeLinkLocal,bool
 	return entries;
 }
 
-bool BSDRoutingTable::set(const RoutingTable::Entry &re)
+RoutingTable::Entry BSDRoutingTable::set(const InetAddress &destination,const InetAddress &gateway,const char *device,int metric)
 {
-	return true;
+	if ((!gateway)&&((!device)||(!device[0])))
+		return RoutingTable::Entry();
+
+	std::vector<RoutingTable::Entry> rtab(get(true,true));
+
+	for(std::vector<RoutingTable::Entry>::iterator e(rtab.begin());e!=rtab.end();++e) {
+		if (e->destination == destination) {
+			if (((!device)||(!device[0]))||(!strcmp(device,e->device))) {
+				long p = (long)fork();
+				if (p > 0) {
+					int exitcode = -1;
+					::waitpid(p,&exitcode,0);
+				} else if (p == 0) {
+					::close(STDOUT_FILENO);
+					::close(STDERR_FILENO);
+					::execl(ZT_BSD_ROUTE_CMD,ZT_BSD_ROUTE_CMD,"delete",(destination.isV6() ? "-inet6" : "-inet"),destination.toString().c_str(),(const char *)0);
+					::_exit(-1);
+				}
+			}
+		}
+	}
+
+	if (metric < 0)
+		return RoutingTable::Entry();
+
+	{
+		char hcstr[64];
+		Utils::snprintf(hcstr,sizeof(hcstr),"%d",metric);
+		long p = (long)fork();
+		if (p > 0) {
+			int exitcode = -1;
+			::waitpid(p,&exitcode,0);
+		} else if (p == 0) {
+			::close(STDOUT_FILENO);
+			::close(STDERR_FILENO);
+			if (gateway) {
+				::execl(ZT_BSD_ROUTE_CMD,ZT_BSD_ROUTE_CMD,"add",(destination.isV6() ? "-inet6" : "-inet"),destination.toString().c_str(),gateway.toIpString().c_str(),"-hopcount",hcstr,(const char *)0);
+			} else if ((device)&&(device[0])) {
+				::execl(ZT_BSD_ROUTE_CMD,ZT_BSD_ROUTE_CMD,"add",(destination.isV6() ? "-inet6" : "-inet"),destination.toString().c_str(),"-interface",device,"-hopcount",hcstr,(const char *)0);
+			}
+			::_exit(-1);
+		}
+	}
+
+	rtab = get(true,true);
+	std::vector<RoutingTable::Entry>::iterator bestEntry(rtab.end());
+	for(std::vector<RoutingTable::Entry>::iterator e(rtab.begin());e!=rtab.end();++e) {
+		if ((e->destination == destination)&&(e->gateway.ipsEqual(gateway))) {
+			if ((device)&&(device[0])) {
+				if (!strcmp(device,e->device)) {
+					if (metric == e->metric)
+						bestEntry = e;
+				}
+			}
+			if (bestEntry == rtab.end())
+				bestEntry = e;
+		}
+	}
+	if (bestEntry != rtab.end())
+		return *bestEntry;
+
+	return RoutingTable::Entry();
 }
 
 } // namespace ZeroTier
 
 // Enable and build to test routing table interface
-///*
+#if 0
+using namespace ZeroTier;
 int main(int argc,char **argv)
 {
-	ZeroTier::BSDRoutingTable rt;
-	std::vector<ZeroTier::RoutingTable::Entry> ents(rt.get());
-	for(std::vector<ZeroTier::RoutingTable::Entry>::iterator e(ents.begin());e!=ents.end();++e)
+	BSDRoutingTable rt;
+
+	printf("<destination> <gateway> <interface> <metric>\n");
+	std::vector<RoutingTable::Entry> ents(rt.get());
+	for(std::vector<RoutingTable::Entry>::iterator e(ents.begin());e!=ents.end();++e)
 		printf("%s\n",e->toString().c_str());
+	printf("\n");
+
+	printf("adding 1.1.1.0 and 2.2.2.0...\n");
+	rt.set(InetAddress("1.1.1.0",24),InetAddress("1.2.3.4",0),(const char *)0,1);
+	rt.set(InetAddress("2.2.2.0",24),InetAddress(),"en0",1);
+	printf("\n");
+
+	printf("<destination> <gateway> <interface> <metric>\n");
+	ents = rt.get();
+	for(std::vector<RoutingTable::Entry>::iterator e(ents.begin());e!=ents.end();++e)
+		printf("%s\n",e->toString().c_str());
+	printf("\n");
+
+	printf("deleting 1.1.1.0 and 2.2.2.0...\n");
+	rt.set(InetAddress("1.1.1.0",24),InetAddress("1.2.3.4",0),(const char *)0,-1);
+	rt.set(InetAddress("2.2.2.0",24),InetAddress(),"en0",-1);
+	printf("\n");
+
+	printf("<destination> <gateway> <interface> <metric>\n");
+	ents = rt.get();
+	for(std::vector<RoutingTable::Entry>::iterator e(ents.begin());e!=ents.end();++e)
+		printf("%s\n",e->toString().c_str());
+	printf("\n");
+
 	return 0;
 }
-//*/
+#endif

node/BSDRoutingTable.hpp

@@ -43,7 +43,7 @@ public:
 	BSDRoutingTable();
 	virtual ~BSDRoutingTable();
 	virtual std::vector<RoutingTable::Entry> get(bool includeLinkLocal = false,bool includeLoopback = false) const;
-	virtual bool set(const RoutingTable::Entry &re);
+	virtual RoutingTable::Entry set(const InetAddress &destination,const InetAddress &gateway,const char *device,int metric);
 };
 
 } // namespace ZeroTier

node/RoutingTable.hpp

@@ -45,16 +45,43 @@ public:
 	class Entry
 	{
 	public:
-		Entry() { device[0] = (char)0; }
+		Entry() throw() { device[0] = (char)0; }
 
+		/**
+		 * Destination IP and netmask bits (CIDR format)
+		 */
 		InetAddress destination;
-		InetAddress gateway; // port/netmaskBits field not used, should be 0 -- null if direct-to-device route
-		char device[128];
-		int deviceIndex; // may not always be set, depending on OS -- for internal use only
-		int metric; // higher = lower priority -- on some OSes this is "hop count," etc.
 
+		/**
+		 * Gateway or null address if direct link-level route, netmask/port part of InetAddress not used
+		 */
+		InetAddress gateway;
+
+		/**
+		 * System device index or ID (not included in comparison operators, may not be set on all platforms)
+		 */
+		int deviceIndex;
+
+		/**
+		 * Metric or hop count -- higher = lower routing priority
+		 */
+		int metric;
+
+		/**
+		 * System device name
+		 */
+		char device[128];
+
+		/**
+		 * @return Human-readable representation of this route
+		 */
 		std::string toString() const;
 
+		/**
+		 * @return True if at least one required field is present (object is not null)
+		 */
+		inline operator bool() const { return ((destination)||(gateway)||(device[0])); }
+
 		bool operator==(const Entry &re) const;
 		inline bool operator!=(const Entry &re) const { return (!(*this == re)); }
 		bool operator<(const Entry &re) const;
@@ -73,15 +100,21 @@ public:
 	 * @param includeLoopback Include loopback (default: false)
 	 * @return Sorted routing table entries
 	 */
-	virtual std::vector<Entry> get(bool includeLinkLocal = false,bool includeLoopback = false) const = 0;
+	virtual std::vector<RoutingTable::Entry> get(bool includeLinkLocal = false,bool includeLoopback = false) const = 0;
 
 	/**
 	 * Add or update a routing table entry
 	 *
-	 * @param re Entry to add/update
-	 * @return True if change successful (or unchanged)
+	 * If there is no change, the existing entry is returned. Use a value of -1
+	 * for metric to delete a route.
+	 *
+	 * @param destination Destination IP/netmask
+	 * @param gateway Gateway IP (netmask/port part unused) or NULL/zero for device-level route
+	 * @param device Device name (can be null for gateway routes)
+	 * @param metric Route metric or hop count (higher = lower priority) or negative to delete
+	 * @return Entry or null entry on failure (or delete)
 	 */
-	virtual bool set(const Entry &re) = 0;
+	virtual RoutingTable::Entry set(const InetAddress &destination,const InetAddress &gateway,const char *device,int metric) = 0;
 
 	/**
 	 * Compute a 64-bit value that hashes the current state of the network environment