(* OCaml HTTP - do it yourself (fully OCaml) HTTP daemon Copyright (C) <2002> Stefano Zacchiroli This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *) open Neturl;; open Printf;; let debug = false let debug_print str = prerr_endline ("DEBUG: " ^ str); flush stderr let default_addr = "0.0.0.0" let default_port = 80 let default_timeout = 300 (* type url_syntax_option = Url_part_not_recognized | Url_part_allowed | Url_part_required * (1) scheme://user:password@host:port/path;params?query#fragment *) let request_uri_syntax = { url_enable_scheme = Url_part_not_recognized; url_enable_user = Url_part_not_recognized; url_enable_password = Url_part_not_recognized; url_enable_host = Url_part_not_recognized; url_enable_port = Url_part_not_recognized; url_enable_path = Url_part_required; url_enable_param = Url_part_not_recognized; url_enable_query = Url_part_allowed; url_enable_fragment = Url_part_not_recognized; url_enable_other = Url_part_not_recognized; url_accepts_8bits = false; url_is_valid = (fun _ -> true); } let crlf = "\r\n" exception Malformed_request of string exception Unsupported_method of string exception Malformed_request_URI of string exception Unsupported_HTTP_version of string exception Malformed_query of string exception Malformed_query_binding of string * string (** given a list of length 2 @return a pair formed by the elements of the list @raise Assert_failure if the list length isn't 2 *) let pair_of_2_sized_list = function | [a;b] -> (a,b) | _ -> assert false (** given an HTTP like query string (e.g. "name1=value1&name2=value2&...") @return a list of pairs [("name1", "value1"); ("name2", "value2")] @raise Malformed_query if the string isn't a valid query string @raise Malformed_query_binding if some piece of the query isn't valid *) let split_query_params = let (bindings_sep, binding_sep) = (Pcre.regexp "&", Pcre.regexp "=") in fun ~query -> let bindings = Pcre.split ~rex:bindings_sep query in if List.length bindings < 1 then raise (Malformed_query query); List.map (fun binding -> let pieces = Pcre.split ~rex:binding_sep binding in if List.length pieces <> 2 then raise (Malformed_query_binding (binding, query)); pair_of_2_sized_list pieces) bindings (** given an input channel and a separator @return a line read from it (like Pervasives.input_line) line is returned only after reading a separator string; separator string isn't included in the returned value FIXME what about efficiency?, input is performed char-by-char *) let generic_input_line ~sep ~ic = let sep_len = String.length sep in if sep_len < 1 then failwith ("Separator '" ^ sep ^ "' is too short!") else (* valid separator *) let line = ref "" in let sep_pointer = ref 0 in try while true do if !sep_pointer >= String.length sep then (* line completed *) raise End_of_file else begin (* incomplete line: need to read more *) let ch = input_char ic in if ch = String.get sep !sep_pointer then (* next piece of sep *) incr sep_pointer else begin (* useful char *) for i = 0 to !sep_pointer - 1 do line := !line ^ (String.make 1 (String.get sep i)) done; sep_pointer := 0; line := !line ^ (String.make 1 ch) end end done; assert false (* unreacheable statement *) with End_of_file -> if !line = "" then raise End_of_file else !line (** given an input channel, reads from it a GET HTTP request and @return a pair where path is a string representing the requested path and query_params is a list of pairs (the GET parameters) *) let parse_http_request = let patch_empty_path s = (if s = "" then "/" else s) in let pieces_sep = Pcre.regexp " " in fun ~ic -> let request_line = generic_input_line ~sep:crlf ~ic in if debug then debug_print ("request_line: '" ^ request_line ^ "'"); match Pcre.split ~rex:pieces_sep request_line with | [meth; request_uri_raw; http_version] -> if meth <> "GET" then raise (Unsupported_method meth); (match http_version with | "HTTP/1.0" | "HTTP/1.1" -> () | _ -> raise (Unsupported_HTTP_version http_version)); let request_uri = try url_of_string request_uri_syntax request_uri_raw with Malformed_URL -> raise (Malformed_request_URI request_uri_raw) in let path = patch_empty_path (String.concat "/" (url_path request_uri)) in let query_params = try split_query_params (url_query request_uri) with Not_found -> [] in (path, query_params) | _ -> raise (Malformed_request request_line) (** send raw data on outchan, flushing it afterwards *) let send_raw ~data outchan = output_string outchan data; flush outchan let send_CRLF = send_raw ~data:crlf (** TODO perform some sanity test on header and value *) let send_header ~header ~value = send_raw ~data:(header ^ ": " ^ value ^ crlf) let send_headers ~headers outchan = List.iter (fun (header, value) -> send_header ~header ~value outchan) headers (** internal: parse a code argument from a function which have two optional arguments "code" and "status" *) let get_code_argument func_name = fun ~code ~status -> (match code, status with | Some c, None -> c | None, Some s -> Http_common.code_of_status s | Some _, Some _ -> failwith (func_name ^ " you must give 'code' or 'status', not both") | None, None -> failwith (func_name ^ " you must give 'code' or 'status', not none")) (** internal: low level for send_status_line *) let send_status_line' ~version ~code = let status_line = String.concat " " [ Http_common.string_of_version version; string_of_int code; Http_common.reason_phrase_of_code code ] in send_raw ~data:(status_line ^ crlf) let send_status_line ?(version = Http_common.http_version) ?code ?status outchan = send_status_line' ~version ~code:(get_code_argument "Daemon.send_status_line" ~code ~status) outchan let send_basic_headers ?(version = Http_common.http_version) ?code ?status outchan = send_status_line' ~version ~code:(get_code_argument "Daemon.send_basic_headers" ~code ~status) outchan; send_headers ~headers:["Date", Http_misc.date_822 (); "Server", "OCaml HTTP Daemon"] outchan (** internal: send a fooish body explaining in HTML form the 'reason phrase' of an HTTP response; body, if given, will be appended to the body *) let send_foo_body ~code ~body = let reason_phrase = Http_common.reason_phrase_of_code code in let body = sprintf " %d %s

%d - %s

%s " code reason_phrase code reason_phrase (match body with None -> "" | Some text -> "\n" ^ text) in send_raw ~data:body (** internal: low level for respond_redirect, respond_error, ... This function send a status line corresponding to a given code, some basic headers, the additional headers (if given) and an HTML page containing the reason phrase; if body is given it will be included in the body of the HTML page *) let send_empty_response f_name ?(is_valid_status = fun _ -> true) ?(headers = []) ~body () = fun ?(version = Http_common.http_version) ?code ?status outchan -> let code = get_code_argument f_name ~code ~status in if not (is_valid_status code) then failwith (sprintf "'%d' isn't a valid status code for %s" code f_name) else begin (* status code suitable for answering *) send_basic_headers ~version ~code outchan; send_header ~header:"Connection" ~value:"close" outchan; send_header ~header:"Content-Type" ~value:"text/html; charset=iso-8859-1" outchan; send_headers ~headers outchan; send_CRLF outchan; send_foo_body ~code ~body outchan end (* TODO sanity tests on location *) let respond_redirect ~location ?body ?(version = Http_common.http_version) ?(code = 301) ?status outchan = let code = match status with | None -> code | Some (s: Http_types.redirection_status) -> Http_common.code_of_status s in send_empty_response "Daemon.respond_redirect" ~is_valid_status:Http_common.is_redirection ~headers:["Location", location] ~body () ~version ~code outchan let respond_error ?body ?(version = Http_common.http_version) ?(code = 400) ?status outchan = let code = match status with | None -> code | Some s -> Http_common.code_of_status s in send_empty_response "Daemon.respond_error" ~is_valid_status:Http_common.is_error ~body () ~version ~code outchan let respond_not_found ~url ?(version = Http_common.http_version) outchan = send_empty_response "Daemon.respond_not_found" ~body:None () ~version ~code:404 outchan let respond_forbidden ~url ?(version = Http_common.http_version) outchan = send_empty_response "Daemon.respond_permission_denied" ~body:None () ~version ~code:403 outchan let send_file ?name ?file outchan = let buflen = 1024 in let buf = String.make buflen ' ' in let (file, cleanup) = (match (name, file) with | Some n, None -> (* if we open the file, we close it before returning *) let f = open_in n in f, (fun () -> close_in f) | None, Some f -> (f, (fun () -> ())) | _ -> failwith "Daemon.send_file: either name or file must be given") in try while true do let bytes = input file buf 0 buflen in if bytes = 0 then raise End_of_file else output outchan buf 0 bytes done; assert false with End_of_file -> begin flush outchan; cleanup () end (* TODO interface is too ugly to advertise this function in .mli *) (** create a minimal HTML directory listing of a given directory and send it over an out_channel, directory is passed as a dir_handle; name is the directory name, used for pretty printing purposes; path is the opened dir path, used to test its contents with stat *) let send_dir_listing ~dir ~name ~path outchan = fprintf outchan "\n%s\n\n" name; let (dirs, files) = List.partition (fun e -> Http_misc.is_directory (path ^ e)) (Http_misc.ls dir) in List.iter (fun d -> fprintf outchan "%s/
\n" d d) (List.sort compare dirs); List.iter (fun f -> fprintf outchan "%s
\n" f f) (List.sort compare files); fprintf outchan "\n"; flush outchan let respond_file ~fname ?(version = Http_common.http_version) outchan = (** ASSUMPTION: 'fname' doesn't begin with a "/"; it's relative to the current document root (usually the daemon's cwd) *) let droot = Sys.getcwd () in (* document root *) let path = droot ^ "/" ^ fname in (* full path to the desired file *) if not (Sys.file_exists path) then (* file not found *) respond_not_found ~url:fname outchan else begin try if Http_misc.is_directory path then begin (* file found, is a dir *) let dir = Unix.opendir path in send_basic_headers ~version ~code:200 outchan; send_header "Content-Type" "text/html" outchan; send_CRLF outchan; send_dir_listing ~dir ~name:fname ~path outchan; Unix.closedir dir end else begin (* file found, is something else *) let file = open_in fname in send_basic_headers ~version ~code:200 outchan; send_header ~header:"Content-Length" ~value:(string_of_int (Http_misc.filesize fname)) outchan; send_CRLF outchan; send_file ~file outchan; close_in file end with | Unix.Unix_error (Unix.EACCES, s, _) when (s = fname) -> respond_forbidden ~url:fname ~version outchan | Sys_error s when (Pcre.pmatch ~rex:(Pcre.regexp (fname ^ ": Permission denied")) s) -> respond_forbidden ~url:fname ~version outchan end let respond_with (res: Http_types.response) outchan = res#serialize outchan; flush outchan let start ?(addr = default_addr) ?(port = default_port) ?(timeout = Some default_timeout) callback = let sockaddr = Unix.ADDR_INET (Unix.inet_addr_of_string addr, port) in let timeout_callback signo = if signo = Sys.sigalrm then begin debug_print "TIMEOUT, exiting ..."; exit 2 end in let daemon_callback inchan outchan = (match timeout with | Some timeout -> ignore (Sys.signal Sys.sigalrm (Sys.Signal_handle timeout_callback)); ignore (Unix.alarm timeout) | None -> ()); try let (path, parameters) = parse_http_request inchan in callback path parameters outchan; flush outchan with | End_of_file -> respond_error ~code:400 ~body:"Unexpected End Of File" outchan | Malformed_request req -> respond_error ~code:400 ~body:( "request 1st line format should be: ' '" ^ "
\nwhile received request 1st line was:
\n" ^ req) outchan | Unsupported_method meth -> respond_error ~code:501 ~body:("Method '" ^ meth ^ "' isn't supported (yet)") outchan | Malformed_request_URI uri -> respond_error ~code:400 ~body:("Malformed URL: '" ^ uri ^ "'") outchan | Unsupported_HTTP_version version -> respond_error ~code:505 ~body:("HTTP version '" ^ version ^ "' isn't supported (yet)") outchan | Malformed_query query -> respond_error ~code:400 ~body:("Malformed query string '" ^ query ^ "'") outchan | Malformed_query_binding (binding, query) -> respond_error ~code:400 ~body:( sprintf "Malformed query element '%s' in query '%s'" binding query) outchan in Unix.establish_server daemon_callback sockaddr let start' ?(addr = default_addr) ?(port = default_port) ?(timeout = Some default_timeout) (callback: (Http_types.request -> out_channel -> unit)) = let wrapper path params outchan = let req = new Http_request.request ~path ~params in callback req outchan in start ~addr ~port ~timeout wrapper module Trivial = struct let callback path _ outchan = if not (Pcre.pmatch ~rex:(Pcre.regexp "^/") path) then respond_error ~code:400 outchan else respond_file ~fname:(Http_misc.strip_heading_slash path) outchan let start ?(addr = default_addr) ?(port = default_port) () = start ~addr ~port callback end