luci启动的流程

1、uhttpd Web server的根目录在/etc/config/uhttpd文件中指定为www,主页面为/www/index.html，

2、index.html中指定cgi程序启动脚本为/cgi-bin/luci

3、/cgi-bin/luci脚本，指定缓存路径为/tmp/luci-indexcache，指定cgi启动接口为/usr/lib/lua/luci/sgi/cgi.lua的run()函数

 

注：可以rm -rf /tmp/luci* 来删除luci的备份文件，这样可以清除缓存，执行修改后的操作。

cgi启动流程

run()函数作为CGI程序的启动入口，代码解析如下

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

function run() -- 获取web请求，放于变量r中（包括环境变量，请求数据，出错处理接口）     local r = luci.http.Request(         luci.sys.getenv(),         limitsource(io.stdin, tonumber(luci.sys.getenv("CONTENT_LENGTH"))),         ltn12.sink.file(io.stderr)     )     --创建一个协同程序     local x = coroutine.create(luci.dispatcher.httpdispatch)     local hcache = ""     local active = true     --查看协同程序x的协同状态     while coroutine.status(x) ~= "dead" do         local res, id, data1, data2 = coroutine.resume(x, r)           if not res then             print("Status: 500 Internal Server Error")             print("Content-Type: text/plain\n")             print(id)             break;         end                 -- HTTP的响应报文通过io.write()方式写在stdout上，         -- 在由uhttpd架构将这些数据传递给父进程，         -- 通过tcp连接返回给client端。         if active then             if id == 1 then                         -- 填写HTTP响应状态行                 io.write("Status: " .. tostring(data1) .. " " .. data2 .. "\r\n")             elseif id == 2 then                        -- 准备报文头header                 hcache = hcache .. data1 .. ": " .. data2 .. "\r\n"             elseif id == 3 then                       -- 填写header、blank到stdout上                 io.write(hcache)                 io.write("\r\n")             elseif id == 4 then                           -- 填写body                 io.write(tostring(data1 or ""))             elseif id == 5 then                           -- 关闭io接口，EOF                 io.flush()                 io.close()                 active = false             elseif id == 6 then                 data1:copyz(nixio.stdout, data2)                 data1:close()             end         end     end end

dispatcher启动流程

在上述run()函数中，创建了一个协同程序，调用httpdispatch()函数，而这个函数位于dispatcher.lua中。通过后续的介绍也可以发现，luci真正的主体部分都在dispatcher.lua脚本里，本小节主要对httpdispatch()和dispatch()函数进行介绍。（注：在版本机dispatcher.lua的同目录下有一个dispatcher.luadoc文件，里面介绍dispatcher.lua的参数说明，仅供参考。）

1、httpdispatch()：解析请求，获得HTTP request请求参数

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

//  /usr/lib/lua/luci/dispatch.luafunction httpdispatch(request, prefix)     http.context.request = request       local r = {}     context.request = r       --解析HTTP request，获取请求路径，并传入dispatch()函数进行处理     local pathinfo = http.urldecode(request:getenv("PATH_INFO") or "", true)       if prefix then         for _, node in ipairs(prefix) do             r[#r+1] = node         end     end       local node     for node in pathinfo:gmatch("[^/%z]+") do         r[#r+1] = node     end       determine_request_language()       local stat, err = util.coxpcall(function()         dispatch(context.request)     end, error500)       http.close()       --context._disable_memtrace() end

2、dispatch()：解析请求节点，调度网页显示，分为以下四个部分:

（1）创建节点树node-tree，解析请求路径，获取节点树节点

createtree()函数主要从controller目录下寻找.lua文件，并且调用每个lua文件中的index()函数。这些index函数通过entry(path,target,title,order)函数定义了菜单栏的每个子菜单选项，包括子菜单的节点位置path、调度行为target、页面标题title以及节点顺序order。当解析完index()下的node节点，对应生成一个node-tree。

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

-- Build the index before if it does not exist yet. function createtree()     if not index then         createindex()     end       local ctx  = context     local tree = {nodes={}, inreq=true}       ctx.treecache = setmetatable({}, {__mode="v"})     ctx.tree = tree       local scope = setmetatable({}, {__index = luci.dispatcher})       for k, v in pairs(index) do         scope._NAME = k         setfenv(v, scope)         v()     end       return tree end

（2）认证

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85

if type(auth) == "table" and type(auth.methods) == "table" and #auth.methods > 0 then     local sid, sdat, sacl     for _, method in ipairs(auth.methods) do         sid, sdat, sacl = check_authentication(method)           if sid and sdat and sacl then             break         end     end       if not (sid and sdat and sacl) and auth.login then         local user = http.getenv("HTTP_AUTH_USER")         local pass = http.getenv("HTTP_AUTH_PASS")           if user == nil and pass == nil then             user = http.formvalue("luci_username")             pass = http.formvalue("luci_password")         end           if user and pass then             sid, sdat, sacl = session_setup(user, pass)         end           if not sid then             context.path = {}               http.status(403, "Forbidden")             http.header("X-LuCI-Login-Required", "yes")               local scope = { duser = "root", fuser = user }             local ok, res = util.copcall(tpl.render_string, [[<% include("themes/" .. theme .. "/sysauth") %>]], scope)             if ok then                 return res             end             return tpl.render("sysauth", scope)         end           http.header("Set-Cookie", 'sysauth=%s; path=%s; SameSite=Strict; HttpOnly%s' %{             sid, build_url(), http.getenv("HTTPS") == "on" and "; secure" or ""         })           http.redirect(build_url(unpack(ctx.requestpath)))         return     end       if not sid or not sdat or not sacl then         http.status(403, "Forbidden")         http.header("X-LuCI-Login-Required", "yes")         return     end       ctx.authsession = sid     ctx.authtoken = sdat.token     ctx.authuser = sdat.username     ctx.authacl = sacl end   if #required_path_acls > 0 then     local perm = check_acl_depends(required_path_acls, ctx.authacl and ctx.authacl["access-group"])     if perm == nil then         http.status(403, "Forbidden")         return     end       page.readonly = not perm end   local action = (page and type(page.action) == "table") and page.action or {}   if action.type == "arcombine" then     action = (#requested_path_args > 0) and action.targets[2] or action.targets[1] end   if cors and http.getenv("REQUEST_METHOD") == "OPTIONS" then     luci.http.status(200, "OK")     luci.http.header("Access-Control-Allow-Origin", http.getenv("HTTP_ORIGIN") or "*")     luci.http.header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")     return end   if require_post_security(action) then     if not test_post_security() then         return     end end

　　（3)会根据action.type处理相应的动作，每个controller下的lua文件的index函数会生成页面的菜单栏并定义各个页面的调用方法

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

if action.type == "view" then         tpl.render("view", { view = action.path })       elseif action.type == "call" then         local ok, mod = util.copcall(require, action.module)         if not ok then             error500(mod)             return         end ... elseif action.type == "alias" then ... elseif action.type == "rewrite" then ... elseif action.type == "template" then         tpl.render(action.path, getfenv(1))       elseif action.type == "cbi" then         _cbi({ config = action.config, model = action.path }, unpack(requested_path_args))       elseif action.type == "form" then         _form({ model = action.path }, unpack(requested_path_args)) else         local root = find_subnode(menu, {}, true)         if not root then             error404("No root node was registered, this usually happens if no module was installed.\n" ..                      "Install luci-mod-admin-full and retry. " ..                      "If the module is already installed, try removing the /tmp/luci-indexcache file.")         else             error404("No page is registered at '/" .. table.concat(requested_path_full, "/") .. "'.\n" ..                      "If this url belongs to an extension, make sure it is properly installed.\n" ..                      "If the extension was recently installed, try removing the /tmp/luci-indexcache file.")         end     end end