Disable rp filter atomically

wwqgtxx · wwqgtxx · commit 42b6218e50f5 · 2026-02-01T13:08:15.000+08:00
diff --git a/tun_linux.go b/tun_linux.go
@@ -73,6 +73,7 @@ func New(options Options) (Tun, error) {
 			options: options,
 		}
 	}
+	nativeTun.disableReversePathFilter()
 	return nativeTun, nil
 }
 
@@ -1049,3 +1050,10 @@ func (t *NativeTun) setSearchDomainForSystemdResolved() {
 		_ = shell.Exec(ctlPath, append([]string{"dns", t.options.Name}, common.Map(dnsServer, netip.Addr.String)...)...).Run()
 	}()
 }
+
+func (t *NativeTun) disableReversePathFilter() {
+	_ = os.WriteFile("/proc/sys/net/ipv4/conf/all/rp_filter", []byte{'0'}, 0o644)
+	if t.options.Name != "" {
+		_ = os.WriteFile("/proc/sys/net/ipv4/conf/"+t.options.Name+"/rp_filter", []byte{'0'}, 0o644)
+	}
+}

Original file line number	Diff line number	Diff line change
`@@ -73,6 +73,7 @@ func New(options Options) (Tun, error) {`
`73`	`73`	`options: options,`
`74`	`74`	`}`
`75`	`75`	`}`
	`76`	`+ nativeTun.disableReversePathFilter()`
`76`	`77`	`return nativeTun, nil`
`77`	`78`	`}`
`78`	`79`
`@@ -1049,3 +1050,10 @@ func (t *NativeTun) setSearchDomainForSystemdResolved() {`
`1049`	`1050`	`_ = shell.Exec(ctlPath, append([]string{"dns", t.options.Name}, common.Map(dnsServer, netip.Addr.String)...)...).Run()`
`1050`	`1051`	`}()`
`1051`	`1052`	`}`
	`1053`	`+`
	`1054`	`+func (t *NativeTun) disableReversePathFilter() {`
	`1055`	`+ _ = os.WriteFile("/proc/sys/net/ipv4/conf/all/rp_filter", []byte{'0'}, 0o644)`
	`1056`	`+ if t.options.Name != "" {`
	`1057`	`+ _ = os.WriteFile("/proc/sys/net/ipv4/conf/"+t.options.Name+"/rp_filter", []byte{'0'}, 0o644)`
	`1058`	`+ }`
	`1059`	`+}`