[openwrt/openwrt] base-files: introduce a function to generate IAID

[LEDE Commits]

noltari pushed a commit to openwrt/openwrt.git, branch openwrt-25.12:
https://git.openwrt.org/b5d094635118ba1e9cc89abbbabd7e267bd7af3a

commit b5d094635118ba1e9cc89abbbabd7e267bd7af3a
Author: Álvaro Fernández Rojas <noltari at gmail.com>
AuthorDate: Tue Jan 13 18:19:48 2026 +0100

    base-files: introduce a function to generate IAID
    
    Add new function "network_generate_iface_iaid()" to generate a stable IAID
    from an interface name.
    
    (cherry picked from commit e1f2b666ff94f2b8a50ca000d69f5b5f0b89a27c)
    Link: https://github.com/openwrt/openwrt/pull/21489
    Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
---
 package/base-files/files/lib/functions/network.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/package/base-files/files/lib/functions/network.sh b/package/base-files/files/lib/functions/network.sh
index 4851a5817a..54ca7b00d4 100644
--- a/package/base-files/files/lib/functions/network.sh
+++ b/package/base-files/files/lib/functions/network.sh
@@ -24,6 +24,17 @@ __network_ifstatus() {
 	eval "$__tmp"
 }
 
+# determine the IAID of the given logical interface
+# 1: destination variable
+# 2: interface
+network_generate_iface_iaid() {
+	local __iaid
+
+	__iaid=$(printf '%s' "$2" | md5sum | cut -c 1-8)
+
+	export "$1=$__iaid"
+}
+
 # determine first IPv4 address of given logical interface
 # 1: destination variable
 # 2: interface