Basic HTTP POST support.

R=rsc
APPROVED=rsc
DELTA=45  (37 added, 1 deleted, 7 changed)
OCL=29964
CL=29990

src/lib/http/request.go

@@ -13,10 +13,12 @@ package http
 
 import (
 	"bufio";
+	"fmt";
 	"http";
 	"io";
 	"os";
-	"strings"
+	"strconv";
+	"strings";
 )
 
 const (
@@ -33,6 +35,8 @@ var (
 	LineTooLong = &ProtocolError{"http header line too long"};
 	ValueTooLong = &ProtocolError{"http header value too long"};
 	HeaderTooLong = &ProtocolError{"http header too long"};
+	BadContentLength = &ProtocolError{"invalid content length"};
+	ShortEntityBody = &ProtocolError{"entity body too short"};
 	BadHeader = &ProtocolError{"malformed http header"};
 	BadRequest = &ProtocolError{"invalid http request"};
 	BadHTTPVersion = &ProtocolError{"unsupported http version"};
@@ -40,9 +44,9 @@ var (
 
 // A Request represents a parsed HTTP request header.
 type Request struct {
-	Method string;		// GET, PUT,etc.
+	Method string;		// GET, POST, PUT, etc.
 	RawUrl string;		// The raw URL given in the request.
-	Url *URL;		// URL after GET, PUT etc.
+	Url *URL;		// Parsed URL.
 	Proto string;	// "HTTP/1.0"
 	ProtoMajor int;	// 1
 	ProtoMinor int;	// 0
@@ -68,6 +72,9 @@ type Request struct {
 	// following a hyphen uppercase and the rest lowercase.
 	Header map[string] string;
 
+	// The message body.
+	Body io.Reader;
+
 	// Whether to close the connection after replying to this request.
 	Close bool;
 
@@ -386,5 +393,21 @@ func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
 	//	Via
 	//	Warning
 
-	return req, nil;
+	// A message body exists when either Content-Length or Transfer-Encoding
+	// headers are present. TODO: Handle Transfer-Encoding.
+	if v, present := req.Header["Content-Length"]; present {
+		length, err := strconv.Btoui64(v, 10);
+		if err != nil {
+			return nil, BadContentLength
+		}
+		// TODO: limit the Content-Length. This is an easy DoS vector.
+		raw := make([]byte, length);
+		n, err := b.Read(raw);
+		if err != nil || uint64(n) < length {
+			return nil, ShortEntityBody
+		}
+		req.Body = io.NewByteReader(raw);
+	}
+
+	return req, nil
 }

src/lib/http/triv.go

@@ -14,6 +14,7 @@ import (
 	"log";
 	"net";
 	"os";
+	"strconv";
 )
 
 
@@ -24,7 +25,7 @@ func HelloServer(c *http.Conn, req *http.Request) {
 	io.WriteString(c, "hello, world!\n");
 }
 
-// simple counter server
+// Simple counter server. POSTing to it will set the value.
 type Counter struct {
 	n int;
 }
@@ -36,8 +37,21 @@ func (ctr *Counter) String() string {
 }
 
 func (ctr *Counter) ServeHTTP(c *http.Conn, req *http.Request) {
+	switch req.Method {
+	case "GET":
+		ctr.n++;
+	case "POST":
+		buf := new(io.ByteBuffer);
+		io.Copy(req.Body, buf);
+		body := string(buf.Data());
+		if n, err := strconv.Atoi(body); err != nil {
+			fmt.Fprintf(c, "bad POST: %v\nbody: [%v]\n", err, body);
+		} else {
+			ctr.n = n;
+			fmt.Fprint(c, "counter reset\n");
+		}
+	}
 	fmt.Fprintf(c, "counter = %d\n", ctr.n);
-	ctr.n++;
 }
 
 // simple file server