HTTP is now generic, with function http_request.

RFC is more strictly followed.

src/http.lua

@@ -1,5 +1,6 @@
 -----------------------------------------------------------------------------
--- Simple HTTP/1.1 support for the Lua language using the LuaSocket toolkit.
+-- Full HTTP/1.1 client support for the Lua language using the 
+-- LuaSocket 1.2 toolkit.
 -- Author: Diego Nehab
 -- Date: 26/12/2000
 -- Conforming to: RFC 2068
@@ -13,127 +14,123 @@ local TIMEOUT = 60
 -- default port for document retrieval
 local PORT = 80
 -- user agent field sent in request
-local USERAGENT = "LuaSocket/HTTP 1.0"
+local USERAGENT = "LuaSocket 1.2 HTTP 1.1"
 
 -----------------------------------------------------------------------------
--- Tries to get a line from the server or close socket if error
+-- Tries to get a pattern from the server and closes socket on error
 --   sock: socket connected to the server
+--   pattern: pattern to receive
 -- Returns
---   line: line received or nil in case of error
+--   data: line received or nil in case of error
 --   err: error message if any
 -----------------------------------------------------------------------------
-local try_getline = function(sock)
+local try_get = function(...)
-	line, err = sock:receive()
+    local sock = arg[1]
+	local data, err = call(sock.receive,  arg)
     if err then
         sock:close()
         return nil, err
     end
-	return line
+    return data
 end
 
 -----------------------------------------------------------------------------
--- Tries to send a line to the server or close socket if error
+-- Tries to send data to the server and closes socket on error
 --   sock: socket connected to the server
---   line: line to send
+--   data: data to send
 -- Returns
---   err: error message if any
+--   err: error message if any, nil if successfull
 -----------------------------------------------------------------------------
-local try_sendline = function(sock, line)
+local try_send = function(sock, data)
-	err = sock:send(line)
+    err = sock:send(data)
     if err then sock:close() end
     return err
 end
 
 -----------------------------------------------------------------------------
--- Retrieves status from http reply
+-- Retrieves status code from http status line
 -- Input
---   reply: http reply string
+--   line: http status line
 -- Returns
---   status: integer with status code
+--   code: integer with status code
 -----------------------------------------------------------------------------
-local get_status = function(reply)
+local get_statuscode = function(line)
-	local _,_, status = strfind(reply, " (%d%d%d) ")
+    local _,_, code = strfind(line, " (%d%d%d) ")
-	return tonumber(status)
+    return tonumber(code)
 end
 
 -----------------------------------------------------------------------------
 -- Receive server reply messages
 -- Input
---   sock: server socket
+--   sock: socket connected to the server
 -- Returns
---   status: server reply status code or nil if error
+--   code: server status code or nil if error
---   reply: full server reply
+--   line: full http status line
 --   err: error message if any
 -----------------------------------------------------------------------------
-local get_reply = function(sock)
+local get_status = function(sock)
-    local reply, err
+    local line, err
-    reply, err = %try_getline(sock)
+    line, err = %try_get(sock)
-    if not err then return %get_status(reply), reply
+    if not err then return %get_statuscode(line), line
     else return nil, nil, err end
 end
 
 -----------------------------------------------------------------------------
--- Receive and parse mime headers
+-- Receive and parse responce header fields
 -- Input
---   sock: server socket
+--   sock: socket connected to the server
---     mime: a table that might already contain mime headers
+--   headers: a table that might already contain headers
 -- Returns
---   mime: a table with all mime headers in the form
+--   headers: a table with all headers fields in the form
 --        {name_1 = "value_1", name_2 = "value_2" ... name_n = "value_n"} 
 --        all name_i are lowercase
 --   nil and error message in case of error
 -----------------------------------------------------------------------------
-local get_mime = function(sock, mime)
+local get_headers = function(sock, headers)
     local line, err
     local name, value
     -- get first line
-    line, err = %try_getline(sock)
+    line, err = %try_get(sock)
     if err then return nil, err end
     -- headers go until a blank line is found
     while line ~= "" do
         -- get field-name and value
         _,_, name, value = strfind(line, "(.-):%s*(.*)")
+        if not name or not value then 
+            sock:close()
+            return nil, "malformed reponse headers" 
+        end
         name = strlower(name)
         -- get next line (value might be folded)
-        line, err = %try_getline(sock)
+        line, err = %try_get(sock)
         if err then return nil, err end
         -- unfold any folded values
-        while not err and line ~= "" and (strsub(line, 1, 1) == " ") do
+        while not err and strfind(line, "^%s") do
             value = value .. line
-            line, err = %try_getline(sock)
+            line, err = %try_get(sock)
             if err then return nil, err end
         end
         -- save pair in table
-        if mime[name] then
+        if headers[name] then headers[name] = headers[name] .. ", " .. value
-            -- join any multiple field
+        else headers[name] = value end
-            mime[name] = mime[name] .. ", " .. value
-        else
-            -- new field
-            mime[name] = value
     end
-    end
+    return headers
-    return mime
 end
 
 -----------------------------------------------------------------------------
--- Receives http body
+-- Receives a chunked message body
 -- Input
---   sock: server socket
+--   sock: socket connected to the server
---   mime: initial mime headers
 -- Returns
---    body: a string containing the body of the document
+--   body: a string containing the body of the message
 --   nil and error message in case of error
--- Obs:
---    mime: headers might be modified by chunked transfer
 -----------------------------------------------------------------------------
-local get_body = function(sock, mime)
+local try_getchunked = function(sock)
-    local body, err
+    local chunk_size, line, err
-    if mime["transfer-encoding"] == "chunked" then
+    local body = ""
-		local chunk_size, line
-    	body = ""
     repeat 
         -- get chunk size, skip extention
-            line, err = %try_getline(sock)
+        line, err = %try_get(sock)
         if err then return nil, err end
         chunk_size = tonumber(gsub(line, ";.*", ""), 16)
         if not chunk_size then 
@@ -141,33 +138,43 @@ local get_body = function(sock, mime)
             return nil, "invalid chunk size"
         end
         -- get chunk
-			line, err = sock:receive(chunk_size) 
+        line, err = %try_get(sock, chunk_size) 
-			if err then 
+        if err then return nil, err end
-				sock:close()
-				return nil, err 
-			end
         -- concatenate new chunk
         body = body .. line
         -- skip blank line
-            _, err = %try_getline(sock)
+        _, err = %try_get(sock)
         if err then return nil, err end
     until chunk_size <= 0
-        -- store extra mime headers
+	return body
-        --_, err = %get_mime(sock, mime)
+end
+
+-----------------------------------------------------------------------------
+-- Receives http body
+-- Input
+--   sock: socket connected to the server
+--   headers: response header fields
+-- Returns
+--    body: a string containing the body of the document
+--    nil and error message in case of error
+-- Obs:
+--    headers: headers might be modified by chunked transfer
+-----------------------------------------------------------------------------
+local get_body = function(sock, headers)
+    local body, err
+    if headers["transfer-encoding"] == "chunked" then
+		body, err = %try_getchunked(sock)
+		if err then return nil, err end
+        -- store extra entity headers
+        --_, err = %get_headers(sock, headers)
         --if err then return nil, err end
-    elseif mime["content-length"] then
+    elseif headers["content-length"] then
-        body, err = sock:receive(tonumber(mime["content-length"]))
+        body, err = %try_get(sock, tonumber(headers["content-length"]))
-		if err then 
+        if err then return nil, err end
-			sock:close()
-			return nil, err 
-		end
     else 
         -- get it all until connection closes!
-        body, err = sock:receive("*a") 
+        body, err = %try_get(sock, "*a") 
-		if err then 
+        if err then return nil, err end
-			sock:close()
-			return nil, err 
-		end
     end
     -- return whole body
     return body
@@ -175,10 +182,9 @@ end
 
 -----------------------------------------------------------------------------
 -- Parses a url and returns its scheme, user, password, host, port 
--- and path components, according to RFC 1738, Uniform Resource Locators (URL),
+-- and path components, according to RFC 1738
--- of December 1994
 -- Input
---   url: unique resource locator desired
+--   url: uniform resource locator of request
 --   default: table containing default values to be returned
 -- Returns
 --   table with the following fields:
@@ -213,47 +219,99 @@ local split_url = function(url, default)
 end
 
 -----------------------------------------------------------------------------
--- Sends a GET message through socket
+-- Tries to send request body, using chunked transfer-encoding
+-- Apache, for instance, accepts only 8kb of body in a post to a CGI script
+-- if we use only the content-length header field...
 -- Input
---   socket: http connection socket
+--   sock: socket connected to the server
---   path: path requested
+--   body: body to be sent in request
---   mime: mime headers to send in request
 -- Returns
 --   err: nil in case of success, error message otherwise
 -----------------------------------------------------------------------------
-local send_get = function(sock, path, mime)
+local try_sendchunked = function(sock, body)
-	local err = %try_sendline(sock, "GET " .. path .. " HTTP/1.1\r\n")
+    local wanted = strlen(body)
+    local first = 1
+    local chunk_size
+    local err
+    while wanted > 0 do
+        chunk_size = min(wanted, 1024)
+        err = %try_send(sock, format("%x\r\n", chunk_size))
         if err then return err end
-	for i, v in mime do
+        err = %try_send(sock, strsub(body, first, first + chunk_size - 1))
-    	err = %try_sendline(sock, i .. ": " .. v .. "\r\n")
         if err then return err end
+        err = %try_send(sock, "\r\n")
+        if err then return err end
+        wanted = wanted - chunk_size
+        first = first + chunk_size
     end
-    err = %try_sendline(sock, "\r\n")
+    err = %try_send(sock, "0\r\n")
     return err
 end
 
 -----------------------------------------------------------------------------
--- Converts field names to lowercase
+-- Sends a http request message through socket
 -- Input
---   headers: user header fields
+--   sock: socket connected to the server
---   parsed: parsed url components
+--   method: request method to  be used
+--   path: url path
+--   headers: request headers to be sent
+--   body: request message body, if any
 -- Returns
---   mime: a table with the same headers, but with lowercase field names
+--   err: nil in case of success, error message otherwise
 -----------------------------------------------------------------------------
-local fill_headers = function(headers, parsed)
+local send_request = function(sock, method, path, headers, body)
-	local mime = {}
+    local err = %try_send(sock, method .. " " .. path .. " HTTP/1.1\r\n")
+    if err then return err end
+    for i, v in headers do
+        err = %try_send(sock, i .. ": " .. v .. "\r\n")
+        if err then return err end
+    end
+    err = %try_send(sock, "\r\n")
+    --if not err and body then err = %try_sendchunked(sock, body) end
+    if not err and body then err = %try_send(sock, body) end
+    return err
+end
+
+-----------------------------------------------------------------------------
+-- Determines if we should read a message body from the server response
+-- Input
+--   method: method used in request
+--   code: server response status code
+-- Returns
+--   1 if a message body should be processed, nil otherwise
+-----------------------------------------------------------------------------
+function has_responsebody(method, code)
+    if method == "HEAD" then return nil end
+    if code == 204 or code == 304 then return nil end
+    if code >= 100 and code < 200 then return nil end
+    return 1
+end
+
+-----------------------------------------------------------------------------
+-- Converts field names to lowercase and add message body size specification
+-- Input
+--   headers: request header fields
+--   parsed: parsed url components
+--   body: request message body, if any
+-- Returns
+--   lower: a table with the same headers, but with lowercase field names
+-----------------------------------------------------------------------------
+local fill_headers = function(headers, parsed, body)
+    local lower = {}
     headers = headers or {}
     for i,v in headers do
-		mime[strlower(i)] = v
+        lower[strlower(i)] = v
     end
-	mime["connection"] = "close"
+    --if body then lower["transfer-encoding"] = "chunked" end
-	mime["host"] = parsed.host
+    if body then lower["content-length"] = tostring(strlen(body)) end
-	mime["user-agent"] = %USERAGENT
+    lower["connection"] = "close"
+    lower["host"] = parsed.host
+    lower["user-agent"] = %USERAGENT
     if parsed.user and parsed.pass then -- Basic Authentication
-		mime["authorization"] = "Basic ".. 
+        lower["authorization"] = "Basic ".. 
             base64(parsed.user .. ":" .. parsed.pass)
     end
-	return mime
+    return lower
 end
 
 -----------------------------------------------------------------------------
@@ -262,51 +320,84 @@ end
 dofile("base64.lua")
 
 -----------------------------------------------------------------------------
--- Downloads and receives a http url, with its mime headers
+-- Sends a HTTP request and retrieves the server reply
 -- Input
---   url: unique resource locator desired
+--   method: "GET", "PUT", "POST" etc
---   headers: headers to send with request
+--   url: target uniform resource locator
---   tried: is this an authentication retry?
+--   headers: request headers to send
+--   body: request message body
 -- Returns
---   body: document body, if successfull
+--   resp_body: response message body, if successfull
---   mime: headers received with document, if sucessfull
+--   resp_hdrs: response header fields received, if sucessfull
---   reply: server reply, if successfull
+--   line: server response status line, if successfull
---   err: error message, if any
+--   err: error message if any
 -----------------------------------------------------------------------------
-function http_get(url, headers)
+function http_request(method, url, headers, body)
-    local sock, err, mime, body, status, reply
+    local sock, err
+    local resp_hdrs, response_body
+    local line, code
     -- get url components
     local parsed = %split_url(url, {port = %PORT, path ="/"})
+    -- methods are case sensitive
+    method = strupper(method)
     -- fill default headers
-	headers = %fill_headers(headers, parsed)
+    headers = %fill_headers(headers, parsed, body)
     -- try connection
     sock, err = connect(parsed.host, parsed.port)
     if not sock then return nil, nil, nil, err end
     -- set connection timeout
     sock:timeout(%TIMEOUT)
     -- send request
-	err = %send_get(sock, parsed.path, headers)
+    err = %send_request(sock, method, parsed.path, headers, body)
     if err then return nil, nil, nil, err end
     -- get server message
-    status, reply, err = %get_reply(sock)
+    code, line, err = %get_status(sock)
     if err then return nil, nil, nil, err end
-    -- get url accordingly
+    -- deal with reply
-    if status == 200 then -- ok, go on and get it
+    resp_hdrs, err = %get_headers(sock, {})
-        mime, err = %get_mime(sock, {})
+    if err then return nil, nil, line, err end
-		if err then return nil, nil, reply, err end
+    -- get body if status and method allow one
-        body, err = %get_body(sock, mime)
+    if has_responsebody(method, code) then
-		if err then return nil, mime, reply, err end
+        resp_body, err = %get_body(sock, resp_hdrs)
-        sock:close()
+        if err then return nil, resp_hdrs, line, err end
-    	return body, mime, reply
-    elseif status == 301 then -- moved permanently, try again
-        mime = %get_mime(sock, {})
-        sock:close()
-        if mime["location"] then return http_get(mime["location"], headers)
-        else return nil, mime, reply end
-	elseif status == 401 then 
-        mime, err = %get_mime(sock, {})
-		if err then return nil, nil, reply, err end
-		return nil, mime, reply
     end
-	return nil, nil, reply
+    sock:close()
+    -- should we automatically retry?
+    if (code == 301 or code == 302) then
+        if (method == "GET" or method == "HEAD") and resp_hdrs["location"] then 
+            return http_request(method, resp_hdrs["location"], headers, body)
+        else return nil, resp_hdrs, line end
+    end
+    return resp_body, resp_hdrs, line
+end
+
+-----------------------------------------------------------------------------
+-- Retrieves a URL by the method "GET"
+-- Input
+--   url: target uniform resource locator
+--   headers: request headers to send
+-- Returns
+--   body: response message body, if successfull
+--   headers: response header fields, if sucessfull
+--   line: response status line, if successfull
+--   err: error message, if any
+-----------------------------------------------------------------------------
+function http_get(url, headers)
+    return http_request("GET", url, headers)
+end
+
+-----------------------------------------------------------------------------
+-- Retrieves a URL by the method "GET"
+-- Input
+--   url: target uniform resource locator
+--   body: request message body
+--   headers: request headers to send
+-- Returns
+--   body: response message body, if successfull
+--   headers: response header fields, if sucessfull
+--   line: response status line, if successfull
+--   err: error message, if any
+-----------------------------------------------------------------------------
+function http_post(url, body, headers)
+    return http_request("POST", url, headers, body)
 end