[openwrt/openwrt] 6rd: delete tunnel on interface teardown

[LEDE Commits]

stintel pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/6a2f516d55a7782dd6882fa163e31a0ead70f70f

commit 6a2f516d55a7782dd6882fa163e31a0ead70f70f
Author: David Lam <david at thedavid.net>
AuthorDate: Sun Sep 19 22:42:14 2021 -0700

    6rd: delete tunnel on interface teardown
    
    Delete tunnel on 6rd interface teardown.
    Should solve problem related to tunnel stuck on restart loop
    with "Unknown Command" on tunnel restart due to wan connection drop.
    
    This patch is similar to the one written by Ansuel on Aug 2, 2021
    but the 6rd teardown produces the same symptoms when the network
    service is restarted.
    
    Signed-off-by: David Lam <david at thedavid.net>
---
 package/network/ipv6/6rd/Makefile     | 2 +-
 package/network/ipv6/6rd/files/6rd.sh | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/package/network/ipv6/6rd/Makefile b/package/network/ipv6/6rd/Makefile
index 9836ae9361..f9c4c6f7a5 100644
--- a/package/network/ipv6/6rd/Makefile
+++ b/package/network/ipv6/6rd/Makefile
@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=6rd
-PKG_RELEASE:=10
+PKG_RELEASE:=11
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk
diff --git a/package/network/ipv6/6rd/files/6rd.sh b/package/network/ipv6/6rd/files/6rd.sh
index 62a20314d9..3c913e54f1 100644
--- a/package/network/ipv6/6rd/files/6rd.sh
+++ b/package/network/ipv6/6rd/files/6rd.sh
@@ -82,6 +82,8 @@ proto_6rd_setup() {
 
 proto_6rd_teardown() {
 	local cfg="$1"
+	local link="6rd-$cfg"
+	ip link del $link
 }
 
 proto_6rd_init_config() {