Implemented (virtual) interface address cache and ipx_interface utility functions.

src/interface.c

@@ -18,17 +18,25 @@
 #include <windows.h>
 #include <iphlpapi.h>
 #include <utlist.h>
+#include <time.h>
 
 #include "interface.h"
 #include "common.h"
 #include "config.h"
 
+#define INTERFACE_CACHE_TTL 5
+
+static CRITICAL_SECTION interface_cache_cs;
+
+static ipx_interface_t *interface_cache = NULL;
+static time_t interface_cache_ctime = 0;
+
 /* Fetch a list of network interfaces available on the system.
  *
  * Returns a linked list of IP_ADAPTER_INFO structures, all allocated within a
  * single memory block beginning at the first node.
 */
-IP_ADAPTER_INFO *get_sys_interfaces(void)
+IP_ADAPTER_INFO *load_sys_interfaces(void)
 {
 	IP_ADAPTER_INFO *ifroot = NULL, *ifptr;
 	ULONG bufsize = sizeof(IP_ADAPTER_INFO) * 8;
@@ -68,12 +76,10 @@ IP_ADAPTER_INFO *get_sys_interfaces(void)
 	return ifroot;
 }
 
-/* Get virtual IPX interfaces
+/* Load a list of virtual IPX interfaces. */
- * Select a single interface by setting ifnum >= 0
+ipx_interface_t *load_ipx_interfaces(void)
-*/
-ipx_interface_t *get_interfaces(int ifnum)
 {
-	IP_ADAPTER_INFO *ifroot = get_sys_interfaces(), *ifptr;
+	IP_ADAPTER_INFO *ifroot = load_sys_interfaces(), *ifptr;
 	
 	addr48_t primary = get_primary_iface();
 	
@@ -98,7 +104,7 @@ ipx_interface_t *get_interfaces(int ifnum)
 		{
 			log_printf(LOG_ERROR, "Couldn't allocate ipx_interface!");
 			
-			free_ipx_interfaces(&nics);
+			free_ipx_interface_list(&nics);
 			return NULL;
 		}
 		
@@ -126,7 +132,7 @@ ipx_interface_t *get_interfaces(int ifnum)
 				log_printf(LOG_ERROR, "Couldn't allocate ipx_interface_ip!");
 				
 				free_ipx_interface(iface);
-				free_ipx_interfaces(&nics);
+				free_ipx_interface_list(&nics);
 				
 				continue;
 			}
@@ -169,28 +175,46 @@ ipx_interface_t *get_interfaces(int ifnum)
 	
 	free(ifroot);
 	
-	/* Delete every entry in the NIC list except the requested one.
+	return nics;
-	 *
+}
-	 * This is done here rather than when building the list as the primary
+
-	 * interface may change the indexes if it isn't the first.
+/* Deep copy an ipx_interface structure.
-	*/
+ * Returns NULL on malloc failure.
-	
+*/
-	if(ifnum >= 0)
+ipx_interface_t *copy_ipx_interface(const ipx_interface_t *src)
+{
+	ipx_interface_t *dest = malloc(sizeof(ipx_interface_t));
+	if(!dest)
 	{
-		int this_ifnum = 0;
+		log_printf(LOG_ERROR, "Cannot allocate ipx_interface!");
-		ipx_interface_t *iface, *tmp;
+		return NULL;
-		
-		DL_FOREACH_SAFE(nics, iface, tmp)
-		{
-			if(this_ifnum++ != ifnum)
-			{
-				DL_DELETE(nics, iface);
-				free_ipx_interface(iface);
-			}
-		}
 	}
 	
-	return nics;
+	*dest = *src;
+	
+	dest->ipaddr = NULL;
+	dest->prev   = NULL;
+	dest->next   = NULL;
+	
+	ipx_interface_ip_t *ip;
+	
+	DL_FOREACH(src->ipaddr, ip)
+	{
+		ipx_interface_ip_t *new_ip = malloc(sizeof(ipx_interface_ip_t));
+		if(!new_ip)
+		{
+			log_printf(LOG_ERROR, "Cannot allocate ipx_interface_ip!");
+			
+			free_ipx_interface(dest);
+			return NULL;
+		}
+		
+		*new_ip = *ip;
+		
+		DL_APPEND(dest->ipaddr, new_ip);
+	}
+	
+	return dest;
 }
 
 /* Free an ipx_interface structure and any memory allocated within. */
@@ -207,8 +231,32 @@ void free_ipx_interface(ipx_interface_t *iface)
 	free(iface);
 }
 
+/* Deep copy an entire list of ipx_interface structures.
+ * Returns NULL on malloc failure.
+*/
+ipx_interface_t *copy_ipx_interface_list(const ipx_interface_t *src)
+{
+	ipx_interface_t *dest = NULL;
+	
+	const ipx_interface_t *s;
+	
+	DL_FOREACH(src, s)
+	{
+		ipx_interface_t *d = copy_ipx_interface(s);
+		if(!d)
+		{
+			free_ipx_interface_list(&dest);
+			return NULL;
+		}
+		
+		DL_APPEND(dest, d);
+	}
+	
+	return dest;
+}
+
 /* Free a list of ipx_interface structures */
-void free_ipx_interfaces(ipx_interface_t **list)
+void free_ipx_interface_list(ipx_interface_t **list)
 {
 	ipx_interface_t *iface, *tmp;
 	
@@ -218,3 +266,125 @@ void free_ipx_interfaces(ipx_interface_t **list)
 		free_ipx_interface(iface);
 	}
 }
+
+/* Initialise the IPX interface cache. */
+void ipx_interfaces_init(void)
+{
+	interface_cache       = NULL;
+	interface_cache_ctime = 0;
+	
+	if(!InitializeCriticalSectionAndSpinCount(&interface_cache_cs, 0x80000000))
+	{
+		log_printf(LOG_ERROR, "Failed to initialise critical section: %s", w32_error(GetLastError()));
+		abort();
+	}
+}
+
+/* Release any resources used by the IPX interface cache. */
+void ipx_interfaces_cleanup(void)
+{
+	DeleteCriticalSection(&interface_cache_cs);
+	
+	free_ipx_interface_list(&interface_cache);
+}
+
+/* Check the age of the IPX interface cache and reload it if necessary.
+ * Ensure you hold interface_cache_cs before calling.
+*/
+static void renew_interface_cache(void)
+{
+	if(time(NULL) - interface_cache_ctime > INTERFACE_CACHE_TTL)
+	{
+		free_ipx_interface_list(&interface_cache);
+		
+		interface_cache       = load_ipx_interfaces();
+		interface_cache_ctime = time(NULL);
+	}
+}
+
+/* Return a copy of the IPX interface cache. The cache will be reloaded before
+ * copying if too old.
+*/
+ipx_interface_t *get_ipx_interfaces(void)
+{
+	EnterCriticalSection(&interface_cache_cs);
+	
+	renew_interface_cache();
+	
+	ipx_interface_t *copy = copy_ipx_interface_list(interface_cache);
+	
+	LeaveCriticalSection(&interface_cache_cs);
+	
+	return copy;
+}
+
+/* Search for an IPX interface by address.
+ * Returns NULL if the interface doesn't exist or malloc failure.
+*/
+ipx_interface_t *ipx_interface_by_addr(addr32_t net, addr48_t node)
+{
+	EnterCriticalSection(&interface_cache_cs);
+	
+	renew_interface_cache();
+	
+	ipx_interface_t *iface;
+	
+	DL_FOREACH(interface_cache, iface)
+	{
+		if(iface->ipx_net == net && iface->ipx_node == node)
+		{
+			iface = copy_ipx_interface(iface);
+			break;
+		}
+	}
+	
+	LeaveCriticalSection(&interface_cache_cs);
+	
+	return iface;
+}
+
+/* Search for an IPX interface by index.
+ * Returns NULL if the interface doesn't exist or malloc failure.
+*/
+ipx_interface_t *ipx_interface_by_index(int index)
+{
+	EnterCriticalSection(&interface_cache_cs);
+	
+	renew_interface_cache();
+	
+	int iface_index = 0;
+	ipx_interface_t *iface;
+	
+	DL_FOREACH(interface_cache, iface)
+	{
+		if(iface_index++ == index)
+		{
+			iface = copy_ipx_interface(iface);
+			break;
+		}
+	}
+	
+	LeaveCriticalSection(&interface_cache_cs);
+	
+	return iface;
+}
+
+/* Returns the number of IPX interfaces. */
+int ipx_interface_count(void)
+{
+	EnterCriticalSection(&interface_cache_cs);
+	
+	renew_interface_cache();
+	
+	int count = 0;
+	ipx_interface_t *iface;
+	
+	DL_FOREACH(interface_cache, iface)
+	{
+		count++;
+	}
+	
+	LeaveCriticalSection(&interface_cache_cs);
+	
+	return count;
+}

src/interface.h

@@ -52,12 +52,22 @@ struct ipx_interface {
 	ipx_interface_t *next;
 };
 
-IP_ADAPTER_INFO *get_sys_interfaces(void);
+IP_ADAPTER_INFO *load_sys_interfaces(void);
-
+ipx_interface_t *load_ipx_interfaces(void);
-ipx_interface_t *get_interfaces(int ifnum);
 
+ipx_interface_t *copy_ipx_interface(const ipx_interface_t *src);
 void free_ipx_interface(ipx_interface_t *iface);
-void free_ipx_interfaces(ipx_interface_t **list);
+
+ipx_interface_t *copy_ipx_interface_list(const ipx_interface_t *src);
+void free_ipx_interface_list(ipx_interface_t **list);
+
+void ipx_interfaces_init(void);
+void ipx_interfaces_cleanup(void);
+
+ipx_interface_t *get_ipx_interfaces(void);
+ipx_interface_t *ipx_interface_by_addr(addr32_t net, addr48_t node);
+ipx_interface_t *ipx_interface_by_index(int index);
+int ipx_interface_count(void);
 
 #ifdef __cplusplus
 }

src/ipxwrapper.c

@@ -86,6 +86,8 @@ BOOL WINAPI DllMain(HINSTANCE me, DWORD why, LPVOID res) {
 		
 		addr_cache_init();
 		
+		ipx_interfaces_init();
+		
 		if(!rclient_init(&g_rclient)) {
 			return FALSE;
 		}
@@ -140,6 +142,8 @@ BOOL WINAPI DllMain(HINSTANCE me, DWORD why, LPVOID res) {
 		DeleteCriticalSection(&addrs_cs);
 		DeleteCriticalSection(&sockets_cs);
 		
+		ipx_interfaces_cleanup();
+		
 		addr_cache_cleanup();
 		
 		unload_dlls();
@@ -192,7 +196,7 @@ BOOL ip_is_local(uint32_t ipaddr) {
 	if(local_updated + main_config.iface_ttl < time(NULL)) {
 		/* TODO: Use all local IPs rather than just the ones with associated IPX addresses? */
 		
-		struct ipx_interface *ifaces = get_interfaces(-1);
+		struct ipx_interface *ifaces = get_ipx_interfaces();
 		struct ipx_interface *i = ifaces;
 		
 		while(i) {
@@ -215,7 +219,7 @@ BOOL ip_is_local(uint32_t ipaddr) {
 			i = i->next;
 		}
 		
-		free_ipx_interfaces(&ifaces);
+		free_ipx_interface_list(&ifaces);
 		
 		local_updated = time(NULL);
 	}

src/router.c

@@ -336,7 +336,7 @@ static int router_bind(struct router_vars *router, SOCKET control, SOCKET sock,
 	 * PLEASE email me with corrections!
 	*/
 	
-	struct ipx_interface *ifaces = get_interfaces(-1), *iface;
+	struct ipx_interface *ifaces = get_ipx_interfaces(), *iface;
 	
 	addr32_t sa_netnum  = addr32_in(addr->sa_netnum);
 	addr48_t sa_nodenum = addr48_in(addr->sa_nodenum);
@@ -356,7 +356,7 @@ static int router_bind(struct router_vars *router, SOCKET control, SOCKET sock,
 	if(!iface) {
 		log_printf(LOG_ERROR, "bind failed: no such address");
 		
-		free_ipx_interfaces(&ifaces);
+		free_ipx_interface_list(&ifaces);
 		
 		WSASetLastError(WSAEADDRNOTAVAIL);
 		return -1;
@@ -372,7 +372,7 @@ static int router_bind(struct router_vars *router, SOCKET control, SOCKET sock,
 	uint32_t iface_ipaddr  = iface->ipaddr->ipaddr;
 	uint32_t iface_netmask = iface->ipaddr->netmask;
 	
-	free_ipx_interfaces(&ifaces);
+	free_ipx_interface_list(&ifaces);
 	
 	EnterCriticalSection(&(router->crit_sec));
 	

src/winsock.c

@@ -524,7 +524,7 @@ int WSAAPI getsockopt(SOCKET fd, int level, int optname, char FAR *optval, int F
 				
 				IPX_ADDRESS_DATA *ipxdata = (IPX_ADDRESS_DATA*)optval;
 				
-				struct ipx_interface *nic = get_interfaces(ipxdata->adapternum);
+				struct ipx_interface *nic = ipx_interface_by_index(ipxdata->adapternum);
 				
 				if(!nic) {
 					RETURN_WSA(ERROR_NO_DATA, -1);
@@ -552,16 +552,7 @@ int WSAAPI getsockopt(SOCKET fd, int level, int optname, char FAR *optval, int F
 			if(optname == IPX_MAX_ADAPTER_NUM) {
 				CHECK_OPTLEN(sizeof(int));
 				
-				*intval = 0;
+				*intval = ipx_interface_count();
-				
-				struct ipx_interface *ifaces = get_interfaces(-1), *nic;
-				
-				for(nic = ifaces; nic;) {
-					(*intval)++;
-					nic = nic->next;
-				}
-				
-				free_ipx_interfaces(&ifaces);
 				
 				RETURN(0);
 			}