[Networking] GetBestRoute refactor (#13553)

Refactor to support UWP.

libretro-common/include/net/net_ifinfo.h

@@ -1,4 +1,4 @@
-/* Copyright  (C) 2010-2020 The RetroArch team
+/* Copyright  (C) 2010-2022 The RetroArch team
  *
  * ---------------------------------------------------------------------------------------
  * The following license statement only applies to this file (net_ifinfo.h).
@@ -50,6 +50,8 @@ void net_ifinfo_free(net_ifinfo_t *list);
 
 bool net_ifinfo_new(net_ifinfo_t *list);
 
+bool net_ifinfo_best(const char *dst, void *src, bool ipv6);
+
 RETRO_END_DECLS
 
 #endif

libretro-common/net/net_ifinfo.c

@@ -1,4 +1,4 @@
-/* Copyright  (C) 2010-2020 The RetroArch team
+/* Copyright  (C) 2010-2022 The RetroArch team
  *
  * ---------------------------------------------------------------------------------------
  * The following license statement only applies to this file (net_ifinfo.c).
@@ -27,6 +27,10 @@
 #include <retro_miscellaneous.h>
 
 #if defined(_WIN32) && !defined(_XBOX)
+#ifdef _MSC_VER
+#pragma comment(lib, "Iphlpapi")
+#endif
+
 #include <winsock2.h>
 #include <iphlpapi.h>
 #include <ws2tcpip.h>
@@ -256,3 +260,94 @@ error:
 
    return false;
 }
+
+bool net_ifinfo_best(const char *dst, void *src, bool ipv6)
+{
+   bool ret = false;
+
+/* TODO/FIXME: Implement for other platforms, if necessary. */
+#if defined(_WIN32) && !defined(_XBOX)
+   if (!ipv6)
+   {
+      /* Courtesy of MiniUPnP: https://github.com/miniupnp/miniupnp */
+      DWORD index;
+      unsigned long udst          = inet_addr(dst);
+#ifdef __WINRT__
+      struct sockaddr_in addr_dst = {0};
+#endif
+
+      if (udst == INADDR_NONE || udst == INADDR_ANY)
+         return ret;
+
+      if (!src)
+         return ret;
+
+#ifdef __WINRT__
+      addr_dst.sin_family      = AF_INET;
+      addr_dst.sin_addr.s_addr = udst;
+      if (GetBestInterfaceEx((struct sockaddr *) &addr_dst, &index)
+         == NO_ERROR)
+#else
+      if (GetBestInterface(udst, &index) == NO_ERROR)
+#endif
+      {
+         /* Microsoft docs recommend doing it this way. */
+         ULONG len                       = 15 * 1024;
+         PIP_ADAPTER_ADDRESSES addresses = calloc(1, len);
+
+         if (addresses)
+         {
+            ULONG flags  = GAA_FLAG_SKIP_ANYCAST |
+               GAA_FLAG_SKIP_MULTICAST |
+               GAA_FLAG_SKIP_DNS_SERVER |
+               GAA_FLAG_SKIP_FRIENDLY_NAME;
+            ULONG result = GetAdaptersAddresses(AF_INET, flags, NULL,
+               addresses, &len);
+
+            if (result == ERROR_BUFFER_OVERFLOW)
+            {
+               PIP_ADAPTER_ADDRESSES new_addresses = realloc(addresses, len);
+
+               if (new_addresses)
+               {
+                  memset(new_addresses, 0, len);
+
+                  addresses = new_addresses;
+                  result    = GetAdaptersAddresses(AF_INET, flags, NULL,
+                     addresses, &len);
+               }
+            }
+
+            if (result == NO_ERROR)
+            {
+               PIP_ADAPTER_ADDRESSES addr = addresses;
+
+               do
+               {
+                  if (addr->IfIndex == index)
+                  {
+                     if (addr->FirstUnicastAddress)
+                     {
+                        struct sockaddr_in *addr_unicast =
+                           (struct sockaddr_in *)
+                           addr->FirstUnicastAddress->Address.lpSockaddr;
+
+                        memcpy(src, &addr_unicast->sin_addr,
+                           sizeof(addr_unicast->sin_addr));
+
+                        ret = true;
+                     }
+
+                     break;
+                  }
+               } while ((addr = addr->Next));
+            }
+
+            free(addresses);
+         }
+      }
+   }
+#endif
+
+   return ret;
+}

libretro-common/net/net_natt.c

@@ -20,10 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#if defined(_WIN32) && !defined(__WINRT__) && defined(_MSC_VER)
-#pragma comment(lib, "Iphlpapi")
-#endif
-
 #include <stdlib.h>
 #include <stdio.h>
 
@@ -33,14 +29,14 @@
 
 #include <string/stdstring.h>
 
+#ifndef HAVE_SOCKET_LEGACY
+#include <net/net_ifinfo.h>
+#endif
+
 #include "../../tasks/tasks_internal.h"
 
 #include <net/net_natt.h>
 
-#if defined(_WIN32) && !defined(__WINRT__)
-#include <iphlpapi.h>
-#endif
-
 static bool translate_addr(struct sockaddr_in *addr,
    char *host, size_t hostlen, char *port, size_t portlen)
 {
@@ -85,9 +81,6 @@ bool natt_init(struct natt_discovery *discovery)
       "ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1\r\n"
       "MX: 5\r\n"
       "\r\n";
-#if defined(_WIN32) && !defined(__WINRT__)
-   MIB_IPFORWARDROW ip_forward;
-#endif
    bool ret;
    int fd                        = -1;
    struct addrinfo *msearch_addr = NULL;
@@ -110,51 +103,16 @@ bool natt_init(struct natt_discovery *discovery)
    if (!bind_addr)
       goto failure;
 
-#if defined(_WIN32) && !defined(__WINRT__)
+#ifndef HAVE_SOCKET_LEGACY
-   if (GetBestRoute(inet_addr("223.255.255.255"),
-      0, &ip_forward) == NO_ERROR)
    {
-      DWORD            index = ip_forward.dwForwardIfIndex;
+      struct sockaddr_in *addr = (struct sockaddr_in *) bind_addr->ai_addr;
-      PMIB_IPADDRTABLE table = malloc(sizeof(*table));
 
-      if (table)
+      if (net_ifinfo_best("223.255.255.255", &addr->sin_addr, false))
       {
-         DWORD len    = sizeof(*table);
-         DWORD result = GetIpAddrTable(table, &len, FALSE);
-
-         if (result == ERROR_INSUFFICIENT_BUFFER)
-         {
-            PMIB_IPADDRTABLE new_table = realloc(table, len);
-
-            if (new_table) 
-            {
-               table  = new_table;
-               result = GetIpAddrTable(table, &len, FALSE);
-            }
-         }
-
-         if (result == NO_ERROR)
-         {
-            DWORD i;
-
-            for (i = 0; i < table->dwNumEntries; i++)
-            {
-               PMIB_IPADDRROW ip_addr = &table->table[i];
-
-               if (ip_addr->dwIndex == index)
-               {
 #ifdef IP_MULTICAST_IF
-                  setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
+         setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
-                     (const char *) &ip_addr->dwAddr, sizeof(ip_addr->dwAddr));
+            (const char *) &addr->sin_addr, sizeof(addr->sin_addr));
 #endif
-                  ((struct sockaddr_in *) bind_addr->ai_addr)->sin_addr.s_addr =
-                     ip_addr->dwAddr;
-                  break;
-               }
-            }
-         }
-
-         free(table);
       }
    }
 #endif

network/netplay/netplay_frontend.c

@@ -2,7 +2,7 @@
  *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
  *  Copyright (C) 2011-2021 - Daniel De Matteis
  *  Copyright (C) 2016-2017 - Gregor Richards
- *  Copyright (C) 2021-2021 - Roberto V. Rampim
+ *  Copyright (C) 2021-2022 - Roberto V. Rampim
  *
  *  RetroArch is free software: you can redistribute it and/or modify it under the terms
  *  of the GNU General Public License as published by the Free Software Found-
@@ -20,10 +20,6 @@
 #pragma comment(lib, "ws2_32")
 #endif
 
-#if defined(_WIN32) && !defined(__WINRT__) && defined(_MSC_VER)
-#pragma comment(lib, "Iphlpapi")
-#endif
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
@@ -41,14 +37,14 @@
 #include <lrc_hash.h>
 #include <retro_timers.h>
 
+#ifndef HAVE_SOCKET_LEGACY
+#include <net/net_ifinfo.h>
+#endif
+
 #include <math/float_minmax.h>
 #include <string/stdstring.h>
 #include <file/file_path.h>
 
-#if defined(_WIN32) && !defined(__WINRT__)
-#include <iphlpapi.h>
-#endif
-
 #ifdef HAVE_DISCORD
 #include "../discord.h"
 #endif
@@ -247,55 +243,9 @@ bool init_netplay_discovery(void)
 
    if (ret)
    {
-#if defined(_WIN32) && !defined(__WINRT__)
+#ifndef HAVE_SOCKET_LEGACY
-      MIB_IPFORWARDROW ip_forward;
+      net_ifinfo_best("223.255.255.255",
-
+         &((struct sockaddr_in *) addr->ai_addr)->sin_addr, false);
-      if (GetBestRoute(inet_addr("223.255.255.255"),
-         0, &ip_forward) == NO_ERROR)
-      {
-         DWORD            index = ip_forward.dwForwardIfIndex;
-         PMIB_IPADDRTABLE table = malloc(sizeof(*table));
-
-         if (table)
-         {
-            DWORD len    = sizeof(*table);
-            DWORD result = GetIpAddrTable(table, &len, FALSE);
-
-            if (result == ERROR_INSUFFICIENT_BUFFER)
-            {
-               PMIB_IPADDRTABLE new_table = realloc(table, len);
-
-               if (new_table) 
-               {
-                  table  = new_table;
-                  result = GetIpAddrTable(table, &len, FALSE);
-               }
-            }
-
-            if (result == NO_ERROR)
-            {
-               DWORD i;
-
-               for (i = 0; i < table->dwNumEntries; i++)
-               {
-                  PMIB_IPADDRROW ip_addr = &table->table[i];
-
-                  if (ip_addr->dwIndex == index)
-                  {
-#ifdef IP_MULTICAST_IF
-                     setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
-                        (const char *) &ip_addr->dwAddr, sizeof(ip_addr->dwAddr));
-#endif
-                     ((struct sockaddr_in *) addr->ai_addr)->sin_addr.s_addr =
-                        ip_addr->dwAddr;
-                     break;
-                  }
-               }
-            }
-
-            free(table);
-         }
-      }
 #endif
 
 #ifdef SO_BROADCAST