|
|
@@ -0,0 +1,311 @@
|
|
|
+
|
|
|
+local dhcpsrv = {}
|
|
|
+
|
|
|
+local udpsrv = require("udpsrv")
|
|
|
+
|
|
|
+local TAG = "dhcpsrv"
|
|
|
+
|
|
|
+----
|
|
|
+-- 参考地址
|
|
|
+-- https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
|
|
|
+
|
|
|
+local function dhcp_decode(buff)
|
|
|
+ -- buff:seek(0)
|
|
|
+ local dst = {}
|
|
|
+ -- 开始解析dhcp
|
|
|
+ dst.op = buff[0]
|
|
|
+ dst.htype = buff[1]
|
|
|
+ dst.hlen = buff[2]
|
|
|
+ dst.hops = buff[3]
|
|
|
+ buff:seek(4)
|
|
|
+ dst.xid = buff:read(4)
|
|
|
+
|
|
|
+ _, dst.secs = buff:unpack(">H")
|
|
|
+ _, dst.flags = buff:unpack(">H")
|
|
|
+ dst.ciaddr = buff:read(4)
|
|
|
+ dst.yiaddr = buff:read(4)
|
|
|
+ dst.siaddr = buff:read(4)
|
|
|
+ dst.giaddr = buff:read(4)
|
|
|
+ dst.chaddr = buff:read(16)
|
|
|
+
|
|
|
+ -- 跳过192字节
|
|
|
+ buff:seek(192, zbuff.SEEK_CUR)
|
|
|
+
|
|
|
+ -- 解析magic
|
|
|
+ _, dst.magic = buff:unpack(">I")
|
|
|
+
|
|
|
+ -- 解析option
|
|
|
+ local opt = {}
|
|
|
+ while buff:len() > buff:used() do
|
|
|
+ local tag = buff:read(1):byte()
|
|
|
+ if tag ~= 0 then
|
|
|
+ local len = buff:read(1):byte()
|
|
|
+ if tag == 0xFF or len == 0 then
|
|
|
+ break
|
|
|
+ end
|
|
|
+ local data = buff:read(len)
|
|
|
+ if tag == 53 then
|
|
|
+ -- 53: DHCP Message Type
|
|
|
+ dst.msgtype = data:byte()
|
|
|
+ end
|
|
|
+ table.insert(opt, {tag, data})
|
|
|
+ -- log.info(TAG, "tag", tag, "data", data:toHex())
|
|
|
+ end
|
|
|
+ end
|
|
|
+ if dst.msgtype == nil then
|
|
|
+ return -- 没有解析到msgtype,直接返回
|
|
|
+ end
|
|
|
+ dst.opts = opt
|
|
|
+ return dst
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_buff2ip(buff)
|
|
|
+ return string.format("%d.%d.%d.%d", buff:byte(1), buff:byte(2), buff:byte(3), buff:byte(4))
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_print_pkg(pkg)
|
|
|
+ log.info(TAG, "XID", pkg.xid:toHex())
|
|
|
+ log.info(TAG, "secs", pkg.secs)
|
|
|
+ log.info(TAG, "flags", pkg.flags)
|
|
|
+ log.info(TAG, "chaddr", pkg.chaddr:sub(1, pkg.hlen):toHex())
|
|
|
+ log.info(TAG, "yiaddr", dhcp_buff2ip(pkg.yiaddr))
|
|
|
+ log.info(TAG, "siaddr", dhcp_buff2ip(pkg.siaddr))
|
|
|
+ log.info(TAG, "giaddr", dhcp_buff2ip(pkg.giaddr))
|
|
|
+ log.info(TAG, "ciaddr", dhcp_buff2ip(pkg.ciaddr))
|
|
|
+ log.info(TAG, "magic", string.format("%08X", pkg.magic))
|
|
|
+ for _, opt in pairs(pkg.opts) do
|
|
|
+ if opt[1] == 53 then
|
|
|
+ log.info(TAG, "msgtype", opt[2]:byte())
|
|
|
+ elseif opt[1] == 60 then
|
|
|
+ log.info(TAG, "auth", opt[2])
|
|
|
+ elseif opt[1] == 57 then
|
|
|
+ log.info(TAG, "Maximum DHCP message size", opt[2]:byte() * 256 + opt[2]:byte(2))
|
|
|
+ elseif opt[1] == 61 then
|
|
|
+ log.info(TAG, "Client-identifier", opt[2]:toHex())
|
|
|
+ elseif opt[1] == 55 then
|
|
|
+ log.info(TAG, "Parameter request list", opt[2]:toHex())
|
|
|
+ elseif opt[1] == 12 then
|
|
|
+ log.info(TAG, "Host name", opt[2])
|
|
|
+ -- elseif opt[1] == 58 then
|
|
|
+ -- log.info(TAG, "Renewal (T1) time value", opt[2]:unpack(">I"))
|
|
|
+ end
|
|
|
+ end
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_encode(pkg, buff)
|
|
|
+ -- 合成DHCP包
|
|
|
+ buff:seek(0)
|
|
|
+ buff[0] = pkg.op
|
|
|
+ buff[1] = pkg.htype
|
|
|
+ buff[2] = pkg.hlen
|
|
|
+ buff[3] = pkg.hops
|
|
|
+ buff:seek(4)
|
|
|
+ -- 写入XID
|
|
|
+ buff:write(pkg.xid)
|
|
|
+ -- 几个重要的参数
|
|
|
+ buff:pack(">H", pkg.secs)
|
|
|
+ buff:pack(">H", pkg.flags)
|
|
|
+ buff:write(pkg.ciaddr)
|
|
|
+ buff:write(pkg.yiaddr)
|
|
|
+ buff:write(pkg.siaddr)
|
|
|
+ buff:write(pkg.giaddr)
|
|
|
+ -- 写入MAC地址
|
|
|
+ buff:write(pkg.chaddr)
|
|
|
+ -- 跳过192字节
|
|
|
+ buff:seek(192, zbuff.SEEK_CUR)
|
|
|
+ -- 写入magic
|
|
|
+ buff:pack(">I", pkg.magic)
|
|
|
+ -- 写入option
|
|
|
+ for _, opt in pairs(pkg.opts) do
|
|
|
+ buff:write(opt[1])
|
|
|
+ buff:write(#opt[2])
|
|
|
+ buff:write(opt[2])
|
|
|
+ end
|
|
|
+ buff:write(0xFF, 0x00)
|
|
|
+end
|
|
|
+
|
|
|
+----
|
|
|
+
|
|
|
+local function dhcp_send_x(srv, pkg, client, msgtype)
|
|
|
+ local buff = zbuff.create(300)
|
|
|
+ pkg.op = 2
|
|
|
+ pkg.ciaddr = "\0\0\0\0"
|
|
|
+ pkg.yiaddr = string.char(srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], client.ip)
|
|
|
+ pkg.siaddr = string.char(srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], srv.opts.gw[4])
|
|
|
+ pkg.giaddr = "\0\0\0\0"
|
|
|
+ pkg.secs = 0
|
|
|
+
|
|
|
+ pkg.opts = {} -- 复位option
|
|
|
+ table.insert(pkg.opts, {53, string.char(msgtype)})
|
|
|
+ table.insert(pkg.opts, {1, string.char(srv.opts.mark[1], srv.opts.mark[2], srv.opts.mark[3], srv.opts.mark[4])})
|
|
|
+ table.insert(pkg.opts, {3, string.char(srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], srv.opts.gw[4])})
|
|
|
+ table.insert(pkg.opts, {51, "\x00\x00\x1E\x00"}) -- 7200秒, 大概
|
|
|
+ table.insert(pkg.opts, {54, string.char(srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], srv.opts.gw[4])})
|
|
|
+ table.insert(pkg.opts, {6, string.char(223, 5, 5, 5)})
|
|
|
+ table.insert(pkg.opts, {6, string.char(119, 29, 29, 29)})
|
|
|
+ table.insert(pkg.opts, {6, string.char(srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], srv.opts.gw[4])})
|
|
|
+
|
|
|
+ dhcp_encode(pkg, buff)
|
|
|
+
|
|
|
+ local dst = "255.255.255.255"
|
|
|
+ if 4 == msgtype then
|
|
|
+ dst = string.format("%d.%d.%d.%d", srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], client.ip)
|
|
|
+ end
|
|
|
+ -- log.info(TAG, "发送", msgtype, dst, buff:query():toHex())
|
|
|
+ srv.udp:send(buff, dst, 68)
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_send_offer(srv, pkg, client)
|
|
|
+ dhcp_send_x(srv, pkg, client, 2)
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_send_ack(srv, pkg, client)
|
|
|
+ dhcp_send_x(srv, pkg, client, 5)
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_send_nack(srv, pkg, client)
|
|
|
+ dhcp_send_x(srv, pkg, client, 6)
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_handle_discover(srv, pkg)
|
|
|
+ local mac = pkg.chaddr:sub(1, pkg.hlen)
|
|
|
+ -- 看看是不是已经分配了ip
|
|
|
+ for _, client in pairs(srv.clients) do
|
|
|
+ if client.mac == mac then
|
|
|
+ log.info(TAG, "发现已经分配的mac地址, send offer")
|
|
|
+ dhcp_send_offer(srv, pkg, client)
|
|
|
+ return
|
|
|
+ end
|
|
|
+ end
|
|
|
+ -- TODO 清理已经过期的IP分配记录
|
|
|
+ -- 分配一个新的ip
|
|
|
+ if #srv.clients >= (srv.opts.ip_end - srv.opts.ip_start) then
|
|
|
+ log.info(TAG, "没有可分配的ip了")
|
|
|
+ return
|
|
|
+ end
|
|
|
+ local ip = nil
|
|
|
+ for i = srv.opts.ip_start, srv.opts.ip_end, 1 do
|
|
|
+ if srv.clients[i] == nil then
|
|
|
+ ip = i
|
|
|
+ break
|
|
|
+ end
|
|
|
+ end
|
|
|
+ if ip == nil then
|
|
|
+ log.info(TAG, "没有可分配的ip了")
|
|
|
+ return
|
|
|
+ end
|
|
|
+ log.info(TAG, "分配ip", mac:toHex(), string.format("%d.%d.%d.%d", srv.opts.gw[1], srv.opts.gw[2], srv.opts.gw[3], ip))
|
|
|
+ local client = {
|
|
|
+ mac = mac,
|
|
|
+ ip = ip,
|
|
|
+ tm = mcu.ticks() // mcu.hz(),
|
|
|
+ stat = 1
|
|
|
+ }
|
|
|
+ srv.clients[ip] = client
|
|
|
+ log.info(TAG, "send offer")
|
|
|
+ dhcp_send_offer(srv, pkg, client)
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_handle_request(srv, pkg)
|
|
|
+ local mac = pkg.chaddr:sub(1, pkg.hlen)
|
|
|
+ -- 看看是不是已经分配了ip
|
|
|
+ for _, client in pairs(srv.clients) do
|
|
|
+ if client.mac == mac then
|
|
|
+ log.info(TAG, "request,发现已经分配的mac地址, send ack")
|
|
|
+ client.tm = mcu.ticks() // mcu.hz()
|
|
|
+ stat = 3
|
|
|
+ dhcp_send_ack(srv, pkg, client)
|
|
|
+ return
|
|
|
+ end
|
|
|
+ end
|
|
|
+ -- 没有找到, 那应该返回NACK
|
|
|
+ log.info(TAG, "request,没有分配的mac地址, send nack")
|
|
|
+ dhcp_send_nack(srv, pkg, {ip=pkg.yiaddr:byte(1)})
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_pkg_handle(srv, pkg)
|
|
|
+ -- 进行基本的检查
|
|
|
+ if pkg.magic ~= 0x63825363 then
|
|
|
+ log.warn(TAG, "dhcp数据包的magic不对劲,忽略该数据包", pkg.magic)
|
|
|
+ return
|
|
|
+ end
|
|
|
+ if pkg.op ~= 1 then
|
|
|
+ log.info(TAG, "op不对,忽略该数据包", pkg.op)
|
|
|
+ return
|
|
|
+ end
|
|
|
+ if pkg.htype ~= 1 or pkg.hlen ~= 6 then
|
|
|
+ log.warn(TAG, "htype/hlen 不认识, 忽略该数据包")
|
|
|
+ return
|
|
|
+ end
|
|
|
+ -- 看看是不是能处理的类型, 当前只处理discover/request
|
|
|
+ if pkg.msgtype == 1 or pkg.msgtype == 3 then
|
|
|
+ else
|
|
|
+ log.warn(TAG, "msgtype不是discover/request, 忽略该数据包", pkg.msgtype)
|
|
|
+ return
|
|
|
+ end
|
|
|
+ -- 检查一下mac地址是否合法
|
|
|
+ local mac = pkg.chaddr:sub(1, pkg.hlen)
|
|
|
+ if mac == "\0\0\0\0\0\0" or mac == "\xFF\xFF\xFF\xFF\xFF\xFF" then
|
|
|
+ log.warn(TAG, "mac地址为空, 忽略该数据包")
|
|
|
+ return
|
|
|
+ end
|
|
|
+
|
|
|
+ -- 处理discover包
|
|
|
+ if pkg.msgtype == 1 then
|
|
|
+ log.info(TAG, "是discover包")
|
|
|
+ dhcp_handle_discover(srv, pkg)
|
|
|
+ elseif pkg.msgtype == 3 then
|
|
|
+ log.info(TAG, "是request包")
|
|
|
+ dhcp_handle_request(srv, pkg)
|
|
|
+ end
|
|
|
+ -- TODO 处理结束, 打印一下客户的列表?
|
|
|
+end
|
|
|
+
|
|
|
+local function dhcp_task(srv)
|
|
|
+ while 1 do
|
|
|
+ -- log.info("ulwip", "等待DHCP数据")
|
|
|
+ local result, data = sys.waitUntil(srv.udp_topic, 1000)
|
|
|
+ if result then
|
|
|
+ -- log.info("ulwip", "收到dhcp数据包", data:toHex())
|
|
|
+ -- 解析DHCP数据包
|
|
|
+ local pkg = dhcp_decode(zbuff.create(#data, data))
|
|
|
+ if pkg then
|
|
|
+ -- dhcp_print_pkg(pkg)
|
|
|
+ dhcp_pkg_handle(srv, pkg)
|
|
|
+ end
|
|
|
+ end
|
|
|
+ end
|
|
|
+end
|
|
|
+function dhcpsrv.create(opts)
|
|
|
+ local srv = {}
|
|
|
+ if not opts then
|
|
|
+ opts = {}
|
|
|
+ end
|
|
|
+ srv.udp_topic = "dhcpd_inc"
|
|
|
+ -- 补充参数
|
|
|
+ if not opts.mark then
|
|
|
+ opts.mark = {255, 255, 255, 0}
|
|
|
+ end
|
|
|
+ if not opts.gw then
|
|
|
+ opts.gw = {192, 168, 4, 1}
|
|
|
+ end
|
|
|
+ if not opts.dns then
|
|
|
+ opts.dns = opts.gw
|
|
|
+ end
|
|
|
+ if not opts.ip_start then
|
|
|
+ opts.ip_start = 100
|
|
|
+ end
|
|
|
+ if not opts.ip_end then
|
|
|
+ opts.ip_end = 200
|
|
|
+ end
|
|
|
+
|
|
|
+ srv.clients = {}
|
|
|
+ srv.opts = opts
|
|
|
+
|
|
|
+ srv.udp = udpsrv.create(67, srv.udp_topic, opts.adapter)
|
|
|
+ srv.task = sys.taskInit(dhcp_task, srv)
|
|
|
+ return srv
|
|
|
+end
|
|
|
+
|
|
|
+
|
|
|
+return dhcpsrv
|