[openwrt/openwrt] netifd: relax check in dhcp proto handler

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch openwrt-22.03:
https://git.openwrt.org/7ea412ef5a2871bb42136f914206e15b8cae04e1

commit 7ea412ef5a2871bb42136f914206e15b8cae04e1
Author: Daniel Golle <daniel at makrotopia.org>
AuthorDate: Wed Apr 13 16:51:58 2022 +0100

    netifd: relax check in dhcp proto handler
    
    Checking whether /sbin/udhcpc is a symbolic link breaks using the
    DHCP proto handler inside procd-ujail where bind-mounts are used for
    the resolved link. Check whether /sbin/udhcpc is executable instead
    to allow using the proto handler for DHCP-provisioned containers.
    
    Signed-off-by: Daniel Golle <daniel at makrotopia.org>
    (cherry picked from commit c5f113c43f43c20555298c8500bf91bffbe1f58b)
---
 package/network/config/netifd/files/lib/netifd/proto/dhcp.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/network/config/netifd/files/lib/netifd/proto/dhcp.sh b/package/network/config/netifd/files/lib/netifd/proto/dhcp.sh
index 3034b2ba68..ea6d872eb4 100755
--- a/package/network/config/netifd/files/lib/netifd/proto/dhcp.sh
+++ b/package/network/config/netifd/files/lib/netifd/proto/dhcp.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-[ -L /sbin/udhcpc ] || exit 0
+[ -x /sbin/udhcpc ] || exit 0
 
 . /lib/functions.sh
 . ../netifd-proto.sh