textproto: parse RFC 959 multiline responses correctly

Fixes #2218

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5037041

diff --git a/src/pkg/net/textproto/reader.go b/src/pkg/net/textproto/reader.go
index ce0ddc73f8403a2583d7a5cc50b52904c6d0f2d4..a404f4758a8082ea7ace1daf2cb5e3859870f5fb 100644 (file)
--- a/src/pkg/net/textproto/reader.go
+++ b/src/pkg/net/textproto/reader.go
@@ -11,6 +11,7 @@ import (
        "io/ioutil"
        "os"
        "strconv"
+       "strings"
 )
 
 // BUG(rsc): To let callers manage exposure to denial of service
@@ -182,6 +183,10 @@ func (r *Reader) readCodeLine(expectCode int) (code int, continued bool, message
        if err != nil {
                return
        }
+       return parseCodeLine(line, expectCode)
+}
+
+func parseCodeLine(line string, expectCode int) (code int, continued bool, message string, err os.Error) {
        if len(line) < 4 || line[3] != ' ' && line[3] != '-' {
                err = ProtocolError("short response: " + line)
                return
@@ -224,15 +229,20 @@ func (r *Reader) ReadCodeLine(expectCode int) (code int, message string, err os.
        return
 }
 
-// ReadResponse reads a multi-line response of the form
+// ReadResponse reads a multi-line response of the form:
+//
 //     code-message line 1
 //     code-message line 2
 //     ...
 //     code message line n
-// where code is a 3-digit status code. Each line should have the same code.
-// The response is terminated by a line that uses a space between the code and
-// the message line rather than a dash. Each line in message is separated by
-// a newline (\n).
+//
+// where code is a 3-digit status code. The first line starts with the
+// code and a hyphen. The response is terminated by a line that starts
+// with the same code followed by a space. Each line in message is
+// separated by a newline (\n).
+//
+// See page 36 of RFC 959 (http://www.ietf.org/rfc/rfc959.txt) for
+// details.
 //
 // If the prefix of the status does not match the digits in expectCode,
 // ReadResponse returns with err set to &Error{code, message}.
@@ -244,11 +254,18 @@ func (r *Reader) ReadCodeLine(expectCode int) (code int, message string, err os.
 func (r *Reader) ReadResponse(expectCode int) (code int, message string, err os.Error) {
        code, continued, message, err := r.readCodeLine(expectCode)
        for err == nil && continued {
+               line, err := r.ReadLine()
+               if err != nil {
+                       return
+               }
+
                var code2 int
                var moreMessage string
-               code2, continued, moreMessage, err = r.readCodeLine(expectCode)
-               if code != code2 {
-                       err = ProtocolError("status code mismatch: " + strconv.Itoa(code) + ", " + strconv.Itoa(code2))
+               code2, continued, moreMessage, err = parseCodeLine(line, expectCode)
+               if err != nil || code2 != code {
+                       message += "\n" + strings.TrimRight(line, "\r\n")
+                       continued = true
+                       continue
                }
                message += "\n" + moreMessage
        }

diff --git a/src/pkg/net/textproto/reader_test.go b/src/pkg/net/textproto/reader_test.go
index 0658e58b82dedc373b5e8ce175baf4049595ce40..23ebc3f61e87e10f371a1eeae58ddc2ad0725443 100644 (file)
--- a/src/pkg/net/textproto/reader_test.go
+++ b/src/pkg/net/textproto/reader_test.go
@@ -138,3 +138,56 @@ func TestReadMIMEHeader(t *testing.T) {
                t.Fatalf("ReadMIMEHeader: %v, %v; want %v", m, err, want)
        }
 }
+
+type readResponseTest struct {
+       in       string
+       inCode   int
+       wantCode int
+       wantMsg  string
+}
+
+var readResponseTests = []readResponseTest{
+       {"230-Anonymous access granted, restrictions apply\n" +
+               "Read the file README.txt,\n" +
+               "230  please",
+               23,
+               230,
+               "Anonymous access granted, restrictions apply\nRead the file README.txt,\n please",
+       },
+
+       {"230 Anonymous access granted, restrictions apply\n",
+               23,
+               230,
+               "Anonymous access granted, restrictions apply",
+       },
+
+       {"400-A\n400-B\n400 C",
+               4,
+               400,
+               "A\nB\nC",
+       },
+
+       {"400-A\r\n400-B\r\n400 C\r\n",
+               4,
+               400,
+               "A\nB\nC",
+       },
+}
+
+// See http://www.ietf.org/rfc/rfc959.txt page 36.
+func TestRFC959Lines(t *testing.T) {
+       for i, tt := range readResponseTests {
+               r := reader(tt.in + "\nFOLLOWING DATA")
+               code, msg, err := r.ReadResponse(tt.inCode)
+               if err != nil {
+                       t.Errorf("#%d: ReadResponse: %v", i, err)
+                       continue
+               }
+               if code != tt.wantCode {
+                       t.Errorf("#%d: code=%d, want %d", i, code, tt.wantCode)
+               }
+               if msg != tt.wantMsg {
+                       t.Errorf("%#d: msg=%q, want %q", i, msg, tt.wantMsg)
+               }
+       }
+}