liminix/examples/acquire-delegated-prefix.fnl
2023-06-18 17:41:09 +01:00

70 lines
2.1 KiB
Fennel

(local inotify (require :inotify))
(fn watch-fsevents [directory-name]
(let [handle (inotify.init)]
(handle:addwatch directory-name
inotify.IN_CREATE
inotify.IN_MOVE
inotify.IN_DELETE
inotify.IN_DELETE_SELF
inotify.IN_MOVED_FROM
inotify.IN_MOVED_TO
inotify.IN_CLOSE_WRITE)
handle))
(fn merge [table1 table2]
(collect [k v (pairs table2) &into table1]
k v))
(fn parse-extra [s]
(let [out {}]
(each [name val (string.gmatch s ",(.-)=([^,]+)")]
(tset out name val))
out))
(fn parse-prefixes [prefixes]
(icollect [val (string.gmatch prefixes "([^ ]+)")]
(let [(prefix len preferred valid extra)
(string.match val "(.-)::/(%d+),(%d+),(%d+)(.*)$")]
(merge {: prefix : len : preferred : valid} (parse-extra extra))
)))
;; Format: <prefix>/<length>,preferred,valid[,excluded=<excluded-prefix>/<length>][,class=<prefix class #>]
;; (parse-prefixes "2001:8b0:de3a:40dc::/64,7198,7198 2001:8b0:de3a:1001::/64,7198,7188,excluded=1/2,thi=10")
(fn file-exists? [name]
(match (io.open name :r)
f (do (f:close) true)
_ false))
(fn read-line [name]
(with-open [f (assert (io.open name :r) (.. "can't open file " name))]
(f:read "*l")))
(var last-update 0)
(fn event-time [directory]
(if (file-exists? (.. directory "/state"))
(tonumber (read-line (.. directory "/last-update")))
nil))
(fn wait-for-update [directory fsevents]
(while (<= (or (event-time directory) 0) last-update)
(fsevents:read))
(set last-update (event-time directory))
true)
(let [[state-directory lan-device] arg
fsevents (watch-fsevents state-directory)]
(while (wait-for-update state-directory fsevents)
(match (read-line (.. state-directory "/state"))
(where (or :bound :rebound :informed :updated :ra-updated))
(let [[{ : prefix : len : preferred : valid }]
(parse-prefixes (read-line (.. state-directory "/prefixes")))]
(os.execute (.. "ip address add " prefix "::1/" len
" dev " lan-device)))
_ (os.exit 1))))