From d0ca944b9c25c8e1afbc9071633457bcef1dbf67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=80=9A=E6=B4=B2?= <zhangsongcui3371@sina.com>
Date: Tue, 1 Apr 2025 10:48:30 +0800
Subject: [PATCH] Netif (Linux): support default route detection for ipv6

---
 src/common/netif/netif_linux.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/common/netif/netif_linux.c b/src/common/netif/netif_linux.c
index 1845ee0e2..6c0dbd1e6 100644
--- a/src/common/netif/netif_linux.c
+++ b/src/common/netif/netif_linux.c
@@ -7,7 +7,7 @@
 #define FF_STR_INDIR(x) #x
 #define FF_STR(x) FF_STR_INDIR(x)
 
-bool ffNetifGetDefaultRouteImpl(char iface[IF_NAMESIZE + 1], uint32_t* ifIndex)
+static bool getDefaultRouteIPv4(char iface[IF_NAMESIZE + 1], uint32_t* ifIndex)
 {
     FILE* FF_AUTO_CLOSE_FILE netRoute = fopen("/proc/net/route", "r");
     if (!netRoute) return false;
@@ -15,12 +15,38 @@ bool ffNetifGetDefaultRouteImpl(char iface[IF_NAMESIZE + 1], uint32_t* ifIndex)
     // skip first line
     FF_UNUSED(fscanf(netRoute, "%*[^\n]\n"));
 
-    unsigned long long destination; //, gateway, flags, refCount, use, metric, mask, mtu,
+    unsigned long long destination; //, gateway, flags, refCount, use, metric, mask, mtu, ...
     while (fscanf(netRoute, "%" FF_STR(IF_NAMESIZE) "s%llx%*[^\n]", iface, &destination) == 2)
     {
         if (destination != 0) continue;
         *ifIndex = if_nametoindex(iface);
         return true;
     }
+    iface[0] = '\0';
     return false;
 }
+
+static bool getDefaultRouteIPv6(char iface[IF_NAMESIZE + 1], uint32_t* ifIndex)
+{
+    FILE* FF_AUTO_CLOSE_FILE netRoute = fopen("/proc/net/ipv6_route", "r");
+    if (!netRoute) return false;
+
+    uint32_t prefixLen;
+    //destination, dest_prefix_len, source, src_prefix_len, next hop, metric, ref counter, use counter, flags, iface
+    while (fscanf(netRoute, "%*s %x %*s %*s %*s %*s %*s %*s %*s %" FF_STR(IF_NAMESIZE) "s", &prefixLen, iface) == 2)
+    {
+        if (prefixLen != 0) continue;
+        *ifIndex = if_nametoindex(iface);
+        return true;
+    }
+    iface[0] = '\0';
+    return false;
+}
+
+bool ffNetifGetDefaultRouteImpl(char iface[IF_NAMESIZE + 1], uint32_t* ifIndex)
+{
+    if (getDefaultRouteIPv4(iface, ifIndex))
+        return true;
+
+    return getDefaultRouteIPv6(iface, ifIndex);
+}