Provide a lua script that uses alfred to propagate and collect all interface mac + names, then generate a /tmp/bat-hosts file. If there's already a (probably hand-made) /etc/bat-hosts it won't overwrite it, but if there's none, it will symlink /etc/bat-hosts -> /tmp/bat-hosts

Signed-off-by: Gui Iribarren gui@altermundi.net Thanks-to: Joshua Head joshua.head@outlook.com ---

ChangeLog v2: make the script selectable through menuconfig, disabled by default

alfred/Config.in | 9 ++++ alfred/Makefile | 3 ++ alfred/files/bat-hosts.lua | 107 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 119 insertions(+) create mode 100644 alfred/files/bat-hosts.lua

diff --git a/alfred/Config.in b/alfred/Config.in index 1791949..97f9ea2 100644 --- a/alfred/Config.in +++ b/alfred/Config.in @@ -1,3 +1,6 @@ +config ALFRED_NEEDS_lua + bool + config ALFRED_NEEDS_libgps bool

@@ -6,6 +9,12 @@ config PACKAGE_ALFRED_VIS depends on PACKAGE_alfred default y

+config PACKAGE_ALFRED_BATHOSTS + bool "enable autogeneration of /etc/bat-hosts" + depends on PACKAGE_alfred + select ALFRED_NEEDS_lua + default n + config PACKAGE_ALFRED_GPSD bool "enable gpsd service for alfred" depends on PACKAGE_alfred diff --git a/alfred/Makefile b/alfred/Makefile index 67be82f..b6d8255 100644 --- a/alfred/Makefile +++ b/alfred/Makefile @@ -28,6 +28,7 @@ define Package/alfred CATEGORY:=Network TITLE:=A.L.F.R.E.D. - Almighty Lightweight Fact Remote Exchange Daemon DEPENDS:= +libc +IPV6:kmod-ipv6 +librt \ + +ALFRED_NEEDS_lua:lua \ +ALFRED_NEEDS_libgps:libgps endef

@@ -77,6 +78,8 @@ define Package/alfred/install $(INSTALL_BIN) ./files/alfred.init $(1)/etc/init.d/alfred $(INSTALL_DIR) $(1)/etc/config $(INSTALL_DATA) ./files/alfred.config $(1)/etc/config/alfred + $(INSTALL_DIR) $(1)/etc/alfred + [ "x$(CONFIG_PACKAGE_ALFRED_BATHOSTS)" == "xy" ] && $(INSTALL_BIN) ./files/bat-hosts.lua $(1)/etc/alfred/bat-hosts.lua ; true endef

$(eval $(call BuildPackage,alfred)) diff --git a/alfred/files/bat-hosts.lua b/alfred/files/bat-hosts.lua new file mode 100644 index 0000000..8648caf --- /dev/null +++ b/alfred/files/bat-hosts.lua @@ -0,0 +1,107 @@ +#!/usr/bin/lua + +local type_id = 64 -- bat-hosts + +function get_hostname() + local hostfile = io.open("/proc/sys/kernel/hostname", "r") + local ret_string = hostfile:read() + hostfile:close() + return ret_string +end + +function get_interfaces_names() + local ret = {} + + for name in io.popen("ls -1 /sys/class/net/"):lines() do + table.insert(ret, name) + end + + return ret +end + +function get_interface_address(name) + local addressfile = io.open("/sys/class/net/"..name.."/address", "r") + local ret_string = addressfile:read() + addressfile:close() + return ret_string +end + + +local function generate_bat_hosts() +-- get hostname and interface macs/names +-- then return a table containing valid bat-hosts lines + local n, i + local ifaces, ret = {}, {} + + local hostname = get_hostname() + + for n, i in ipairs(get_interfaces_names()) do + local address = get_interface_address(i) + if not ifaces[address] then ifaces[address] = i end + end + + for mac, iname in pairs(ifaces) do + if mac:match("^%x%x:%x%x:%x%x:%x%x:%x%x:%x%x$") and not mac:match("00:00:00:00:00:00") then + table.insert(ret, mac.." "..hostname.."_"..iname.."\n") + end + end + + return ret +end + +local function publish_bat_hosts() +-- pass a raw chunk of data to alfred + local fd = io.popen("alfred -s " .. type_id, "w") + if fd then + local ret = generate_bat_hosts() + if ret then + fd:write(table.concat(ret)) + end + fd:close() + end +end + +local function write_bat_hosts(rows) + local content = { "### /tmp/bat-hosts generated by alfred-bat-hosts\n", + "### /!\ This file is overwritten every 5 minutes /!\\n", + "### (To keep manual changes, replace /etc/bat-hosts symlink with a static file)\n" } + + -- merge the chunks from all nodes, de-escaping newlines + for _, row in ipairs(rows) do + local node, value = unpack(row) + table.insert(content, "# Node ".. node .. "\n") + table.insert(content, value:gsub("\x0a", "\n") .. "\n") + end + + -- write parsed content down to disk + local fd = io.open("/tmp/bat-hosts", "w") + if fd then + fd:write(table.concat(content)) + fd:close() + end + + -- try to make a symlink in /etc pointing to /tmp, + -- if it exists, ln will do nothing. + os.execute("ln -ns /tmp/bat-hosts /etc/bat-hosts 2>/dev/null") +end + +local function receive_bat_hosts() +-- read raw chunks from alfred, convert them to a nested table and call write_bat_hosts + local fd = io.popen("alfred -r " .. type_id) + --[[ this command returns something like + { "54:e6:fc:b9:cb:37", "00:11:22:33:44:55 ham_wlan0\x0a00:22:33:22:33:22 ham_eth0\x0a" }, + { "90:f6:52:bb:ec:57", "00:22:33:22:33:23 spam\x0a" }, + ]]-- + + if fd then + local output = fd:read("*a") + if output then + assert(loadstring("rows = {" .. output .. "}"))() + write_bat_hosts(rows) + end + fd:close() + end +end + +publish_bat_hosts() +receive_bat_hosts()