liminix-fork/examples/acquire-wan-address.fnl
2023-07-08 23:08:25 +01:00

60 lines
2.1 KiB
Fennel

(local { : merge : split : file-exists? : system } (require :anoia))
(local svc (require :anoia.svc))
;; structurally this is remarkably similar to
;; acquire-lan-prefix.fnl. maybe they should be merged: if not then
;; we could at least extract some common code
;; (alternatively we could move all the parsing code into the thing in
;; the odhcp service that *writes* this stuff)
; (parse-address "2001:8b0:1111:1111:0:ffff:51bb:4cf2/128,3600,7200")
(fn parse-address [str]
(fn parse-extra [s]
(let [out {}]
(each [name val (string.gmatch s ",(.-)=([^,]+)")]
(tset out name val))
out))
(let [(address len preferred valid extra)
(string.match str "(.-)/(%d+),(%d+),(%d+)(.*)$")]
(merge {: address : len : preferred : valid} (parse-extra extra))))
(local bound-states
{ :bound true
:rebound true
:informed true
:updated true
:ra-updated true
})
(fn changes [old-addresses new-addresses]
(let [added {}
deleted {}
old-set (collect [_ v (ipairs old-addresses)] (values v true))
new-set (collect [_ v (ipairs new-addresses)] (values v true))]
(each [_ address (ipairs new-addresses)]
(if (not (. old-set address))
(table.insert added (parse-address address))))
(each [_ address (ipairs old-addresses)]
(if (not (. new-set address))
(table.insert deleted (parse-address address))))
(values added deleted)))
(let [[state-directory wan-device] arg
dir (svc.open state-directory)]
(var addresses [])
(while true
(while (not (dir:ready?)) (dir:wait))
(if (. bound-states (dir:output "state"))
(let [new-addresses (split " " (dir:output "/addresses"))
(added deleted) (changes addresses new-addresses)]
(each [_ p (ipairs added)]
(system
(.. "ip address add " p.address "/" p.len " dev " wan-device)))
(each [_ p (ipairs deleted)]
(system
(.. "ip address del " p.address "/" p.len " dev " wan-device)))
(set addresses new-addresses)))
(dir:wait)))