erlang - 在 Yaws 网络服务器上上传进度

Question

我正在测试脚本 upload2.yaws 在 Yaws 2.0 上，但不工作。该脚本是为 Yaws 1.57 开发的。

Yaws 的日志是:

POST /html/upload2.yaws HTTP/1.1
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Host: 192.168.26.10
Referer: http://192.168.26.10/html/upload2.yaws
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36
Cookie: gsScrollPos=0; gsScrollPos=0
Content-Length: 1587
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary5zKIyUtdiK82R4de
Accept-Language: pt,en-US;q=0.8,en;q=0.6,pt-BR;q=0.4
Accept-Encoding: gzip, deflate
Https: 1
Origin: http://192.168.26.10
Cache-Control: max-age=0


upload.yaws:multipart/3 State=filename=undefined rlist=undefined data=undefined
upload.yaws:multipart/3 result
upload.yaws:process_part/4d State=filename=undefined rlist=undefined data=undefined
upload.yaws:multipart/3 done
upload.yaws:result_ehtml/3 error Reason=Error: filename not found in header.
Worker: <0.78.0> 
[2015-07-24 13:50:54.795] ===== SRV -> CLI =====
HTTP/1.1 200 OK
Server: Yaws 2.0
Date: Fri, 24 Jul 2015 13:50:54 GMT
Content-Length: 532
Content-Type: text/html

当我将表单操作更改为使用 netcat 的监听端口时，会收到带有文件名的完整 header :

代码:

show_form(A, Feedback) -> {ehtml,
        [       {form
                ,[{enctype,"multipart/form-data"},{action,"http://192.168.26.10:8800"},{method,"post"}]
                ,       [{p,[],"Choose a file and click Upload."}
                        ,{p,[],{input,[{type,"file"},{name,"file"}],[]}}
                        ,{p,[],{input,[{type,"submit"},{value,"Upload"}],[]}}
                        ]
                }
        ,{p,[],Feedback}
        ]}.

我启动了 nc

$ sudo nc -l 8800

然后显示以下标题:

POST / HTTP/1.1
Host: 192.168.26.10:8800
Connection: keep-alive
Content-Length: 1587
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Origin: http://192.168.26.10
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36
HTTPS: 1
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary9iHQOXBtRE9CyRAZ
Referer: http://192.168.26.10/html/upload2.yaws
Accept-Encoding: gzip, deflate
Accept-Language: pt,en-US;q=0.8,en;q=0.6,pt-BR;q=0.4
Cookie: gsScrollPos=0

------WebKitFormBoundary9iHQOXBtRE9CyRAZ
Content-Disposition: form-data; name="file"; filename="signing_debian_packages.txt"
Content-Type: text/plain

我怀疑错误出在 multipart 函数上，但我是 Erlang 的菜鸟:/

    %%% Process part of a multi-part form post
    %%% returns Ehtml | {get_more, Continuation, NewState}
    multipart(A, State) when is_record(State,upload) ->
            io:fwrite("upload.yaws:multipart/3 State=~s~n", [upload_to_string(State)]),
            case yaws_api:parse_multipart_post(A) of
            {cont, Cont, Part} ->
                    io:fwrite("upload.yaws:multipart/3 cont~n"),
                    case process_part(A, Part, State) of
                    {done, Result} ->
                            io:fwrite("upload.yaws:multipart/3 done~n"),
                            result_ehtml(A, Result);
                    {cont, NewState} ->
                            io:fwrite("upload.yaws:multipart/3 get_more NewState=~s~n", [upload_to_string(NewState)]),
                            {get_more, Cont, NewState}
                    end;
            {result, Part} ->
                    io:fwrite("upload.yaws:multipart/3 result~n"),
                    case process_part(A, Part, State#upload{last=true}) of
                    {done, Result} ->
                            io:fwrite("upload.yaws:multipart/3 done~n"),
                            result_ehtml(A, Result);
                    {cont, _} ->
                            io:fwrite("upload.yaws:multipart/3 error~n"),
                            result_ehtml(A, {error, "Error During Upload"})
                    end;
            [] -> result_ehtml(A, {error,"You must select a file to upload."})
            end.

有人有想法吗？

Answer 1

问题出在处理 header 的 process_part 函数子句中:

%%% Process header
process_part(A, [{head, {"file", Opts}}|Tail], State ) ->
        io:fwrite("upload.yaws:process_part/4d State=~s~n", [upload_to_string(State)]),
        case lists:keysearch(filename, 1, Opts) of
        {value, {_, UncheckedFileName}} ->
                io:fwrite("upload.yaws:process_part/4d UncheckedFileName=~s~n", [UncheckedFileName]),
                FileName = sanitize_filename(UncheckedFileName),
                io:fwrite("upload.yaws:process_part/4d FileName=~s~n", [FileName]),
                process_part(A, Tail, State#upload{filename=FileName,rlist=[]});
        false ->
                {done, {error, "Error: filename not found in header."}}
        end;

调用 lists:keysearch/3 的第一个参数是原子 filename，但它应该是字符串 "filename"反而。修改后的函数为:

%%% Process header
process_part(A, [{head, {"file", Opts}}|Tail], State ) ->
        io:fwrite("upload.yaws:process_part/4d State=~s~n", [upload_to_string(State)]),
        case lists:keysearch("filename", 1, Opts) of
        {value, {_, UncheckedFileName}} ->
                io:fwrite("upload.yaws:process_part/4d UncheckedFileName=~s~n", [UncheckedFileName]),
                FileName = sanitize_filename(UncheckedFileName),
                io:fwrite("upload.yaws:process_part/4d FileName=~s~n", [FileName]),
                process_part(A, Tail, State#upload{filename=FileName,rlist=[]});
        false ->
                {done, {error, "Error: filename not found in header."}}
        end;

有了这个改变，upload2.yaws 对我来说在 Yaws 2.0 和 Erlang 18.0 上工作得很好。