Re: [B.A.T.M.A.N.] [PATCH 2/2] alfred: Bundle a lua script for autogenerating bat-hosts file

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

Thanks a lot, this sounds like a really good idea! As this will be part of the openwrt package, I'd like to ask to make the bat-hosts.lua script optional and selectable (like you can turn on/off vis). I'll do the same for other (optional) services like gps.

Also, do you need any additional dependencies for lua?

Thanks, Simon

---

alfred/Makefile | 2 + alfred/files/bat-hosts.lua | 107 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 109 insertions(+) create mode 100644 alfred/files/bat-hosts.lua

diff --git a/alfred/Makefile b/alfred/Makefile index db9c71f..7027192 100644 --- a/alfred/Makefile +++ b/alfred/Makefile @@ -74,6 +74,8 @@ 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
• $(INSTALL_BIN) ./files/bat-hosts.lua $(1)/etc/alfred/bat-hosts.lua

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..19f2cad --- /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("*a")
• ret_string = string.gsub(ret_string, "\n", "")
• 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("*a")
• ret_string = string.gsub(ret_string, "\n", "")
• 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)
• ifaces[address] = i
• 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 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

+local function write_bat_hosts(rows)

• local content = { "### File generated by alfred-bat-hosts\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

+publish_bat_hosts() +receive_bat_hosts()