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-rw-r--r--src/pkg/http/request.go745
1 files changed, 745 insertions, 0 deletions
diff --git a/src/pkg/http/request.go b/src/pkg/http/request.go
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+++ b/src/pkg/http/request.go
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+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP Request reading and parsing.
+
+// Package http implements parsing of HTTP requests, replies, and URLs and
+// provides an extensible HTTP server and a basic HTTP client.
+package http
+
+import (
+ "bufio"
+ "bytes"
+ "crypto/tls"
+ "encoding/base64"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "mime"
+ "mime/multipart"
+ "net/textproto"
+ "os"
+ "strconv"
+ "strings"
+ "url"
+)
+
+const (
+ maxLineLength = 4096 // assumed <= bufio.defaultBufSize
+ maxValueLength = 4096
+ maxHeaderLines = 1024
+ chunkSize = 4 << 10 // 4 KB chunks
+ defaultMaxMemory = 32 << 20 // 32 MB
+)
+
+// ErrMissingFile is returned by FormFile when the provided file field name
+// is either not present in the request or not a file field.
+var ErrMissingFile = os.NewError("http: no such file")
+
+// HTTP request parsing errors.
+type ProtocolError struct {
+ ErrorString string
+}
+
+func (err *ProtocolError) String() string { return err.ErrorString }
+
+var (
+ ErrLineTooLong = &ProtocolError{"header line too long"}
+ ErrHeaderTooLong = &ProtocolError{"header too long"}
+ ErrShortBody = &ProtocolError{"entity body too short"}
+ ErrNotSupported = &ProtocolError{"feature not supported"}
+ ErrUnexpectedTrailer = &ProtocolError{"trailer header without chunked transfer encoding"}
+ ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"}
+ ErrNotMultipart = &ProtocolError{"request Content-Type isn't multipart/form-data"}
+ ErrMissingBoundary = &ProtocolError{"no multipart boundary param Content-Type"}
+)
+
+type badStringError struct {
+ what string
+ str string
+}
+
+func (e *badStringError) String() string { return fmt.Sprintf("%s %q", e.what, e.str) }
+
+// Headers that Request.Write handles itself and should be skipped.
+var reqWriteExcludeHeader = map[string]bool{
+ "Host": true,
+ "User-Agent": true,
+ "Content-Length": true,
+ "Transfer-Encoding": true,
+ "Trailer": true,
+}
+
+// A Request represents a parsed HTTP request header.
+type Request struct {
+ Method string // GET, POST, PUT, etc.
+ RawURL string // The raw URL given in the request.
+ URL *url.URL // Parsed URL.
+
+ // The protocol version for incoming requests.
+ // Outgoing requests always use HTTP/1.1.
+ Proto string // "HTTP/1.0"
+ ProtoMajor int // 1
+ ProtoMinor int // 0
+
+ // A header maps request lines to their values.
+ // If the header says
+ //
+ // accept-encoding: gzip, deflate
+ // Accept-Language: en-us
+ // Connection: keep-alive
+ //
+ // then
+ //
+ // Header = map[string][]string{
+ // "Accept-Encoding": {"gzip, deflate"},
+ // "Accept-Language": {"en-us"},
+ // "Connection": {"keep-alive"},
+ // }
+ //
+ // HTTP defines that header names are case-insensitive.
+ // The request parser implements this by canonicalizing the
+ // name, making the first character and any characters
+ // following a hyphen uppercase and the rest lowercase.
+ Header Header
+
+ // The message body.
+ Body io.ReadCloser
+
+ // ContentLength records the length of the associated content.
+ // The value -1 indicates that the length is unknown.
+ // Values >= 0 indicate that the given number of bytes may be read from Body.
+ ContentLength int64
+
+ // TransferEncoding lists the transfer encodings from outermost to innermost.
+ // An empty list denotes the "identity" encoding.
+ TransferEncoding []string
+
+ // Whether to close the connection after replying to this request.
+ Close bool
+
+ // The host on which the URL is sought.
+ // Per RFC 2616, this is either the value of the Host: header
+ // or the host name given in the URL itself.
+ Host string
+
+ // The parsed form. Only available after ParseForm is called.
+ Form url.Values
+
+ // The parsed multipart form, including file uploads.
+ // Only available after ParseMultipartForm is called.
+ MultipartForm *multipart.Form
+
+ // Trailer maps trailer keys to values. Like for Header, if the
+ // response has multiple trailer lines with the same key, they will be
+ // concatenated, delimited by commas.
+ Trailer Header
+
+ // RemoteAddr allows HTTP servers and other software to record
+ // the network address that sent the request, usually for
+ // logging. This field is not filled in by ReadRequest and
+ // has no defined format. The HTTP server in this package
+ // sets RemoteAddr to an "IP:port" address before invoking a
+ // handler.
+ RemoteAddr string
+
+ // TLS allows HTTP servers and other software to record
+ // information about the TLS connection on which the request
+ // was received. This field is not filled in by ReadRequest.
+ // The HTTP server in this package sets the field for
+ // TLS-enabled connections before invoking a handler;
+ // otherwise it leaves the field nil.
+ TLS *tls.ConnectionState
+}
+
+// ProtoAtLeast returns whether the HTTP protocol used
+// in the request is at least major.minor.
+func (r *Request) ProtoAtLeast(major, minor int) bool {
+ return r.ProtoMajor > major ||
+ r.ProtoMajor == major && r.ProtoMinor >= minor
+}
+
+// UserAgent returns the client's User-Agent, if sent in the request.
+func (r *Request) UserAgent() string {
+ return r.Header.Get("User-Agent")
+}
+
+// Cookies parses and returns the HTTP cookies sent with the request.
+func (r *Request) Cookies() []*Cookie {
+ return readCookies(r.Header, "")
+}
+
+var ErrNoCookie = os.NewError("http: named cookied not present")
+
+// Cookie returns the named cookie provided in the request or
+// ErrNoCookie if not found.
+func (r *Request) Cookie(name string) (*Cookie, os.Error) {
+ for _, c := range readCookies(r.Header, name) {
+ return c, nil
+ }
+ return nil, ErrNoCookie
+}
+
+// AddCookie adds a cookie to the request. Per RFC 6265 section 5.4,
+// AddCookie does not attach more than one Cookie header field. That
+// means all cookies, if any, are written into the same line,
+// separated by semicolon.
+func (r *Request) AddCookie(c *Cookie) {
+ s := fmt.Sprintf("%s=%s", sanitizeName(c.Name), sanitizeValue(c.Value))
+ if c := r.Header.Get("Cookie"); c != "" {
+ r.Header.Set("Cookie", c+"; "+s)
+ } else {
+ r.Header.Set("Cookie", s)
+ }
+}
+
+// Referer returns the referring URL, if sent in the request.
+//
+// Referer is misspelled as in the request itself, a mistake from the
+// earliest days of HTTP. This value can also be fetched from the
+// Header map as Header["Referer"]; the benefit of making it available
+// as a method is that the compiler can diagnose programs that use the
+// alternate (correct English) spelling req.Referrer() but cannot
+// diagnose programs that use Header["Referrer"].
+func (r *Request) Referer() string {
+ return r.Header.Get("Referer")
+}
+
+// multipartByReader is a sentinel value.
+// Its presence in Request.MultipartForm indicates that parsing of the request
+// body has been handed off to a MultipartReader instead of ParseMultipartFrom.
+var multipartByReader = &multipart.Form{
+ Value: make(map[string][]string),
+ File: make(map[string][]*multipart.FileHeader),
+}
+
+// MultipartReader returns a MIME multipart reader if this is a
+// multipart/form-data POST request, else returns nil and an error.
+// Use this function instead of ParseMultipartForm to
+// process the request body as a stream.
+func (r *Request) MultipartReader() (*multipart.Reader, os.Error) {
+ if r.MultipartForm == multipartByReader {
+ return nil, os.NewError("http: MultipartReader called twice")
+ }
+ if r.MultipartForm != nil {
+ return nil, os.NewError("http: multipart handled by ParseMultipartForm")
+ }
+ r.MultipartForm = multipartByReader
+ return r.multipartReader()
+}
+
+func (r *Request) multipartReader() (*multipart.Reader, os.Error) {
+ v := r.Header.Get("Content-Type")
+ if v == "" {
+ return nil, ErrNotMultipart
+ }
+ d, params := mime.ParseMediaType(v)
+ if d != "multipart/form-data" {
+ return nil, ErrNotMultipart
+ }
+ boundary, ok := params["boundary"]
+ if !ok {
+ return nil, ErrMissingBoundary
+ }
+ return multipart.NewReader(r.Body, boundary), nil
+}
+
+// Return value if nonempty, def otherwise.
+func valueOrDefault(value, def string) string {
+ if value != "" {
+ return value
+ }
+ return def
+}
+
+const defaultUserAgent = "Go http package"
+
+// Write writes an HTTP/1.1 request -- header and body -- in wire format.
+// This method consults the following fields of req:
+// Host
+// RawURL, if non-empty, or else URL
+// Method (defaults to "GET")
+// Header
+// ContentLength
+// TransferEncoding
+// Body
+//
+// If Body is present, Content-Length is <= 0 and TransferEncoding
+// hasn't been set to "identity", Write adds "Transfer-Encoding:
+// chunked" to the header. Body is closed after it is sent.
+func (req *Request) Write(w io.Writer) os.Error {
+ return req.write(w, false)
+}
+
+// WriteProxy is like Write but writes the request in the form
+// expected by an HTTP proxy. It includes the scheme and host
+// name in the URI instead of using a separate Host: header line.
+// If req.RawURL is non-empty, WriteProxy uses it unchanged
+// instead of URL but still omits the Host: header.
+func (req *Request) WriteProxy(w io.Writer) os.Error {
+ return req.write(w, true)
+}
+
+func (req *Request) write(w io.Writer, usingProxy bool) os.Error {
+ host := req.Host
+ if host == "" {
+ if req.URL == nil {
+ return os.NewError("http: Request.Write on Request with no Host or URL set")
+ }
+ host = req.URL.Host
+ }
+
+ urlStr := req.RawURL
+ if urlStr == "" {
+ urlStr = valueOrDefault(req.URL.EncodedPath(), "/")
+ if req.URL.RawQuery != "" {
+ urlStr += "?" + req.URL.RawQuery
+ }
+ if usingProxy {
+ if urlStr == "" || urlStr[0] != '/' {
+ urlStr = "/" + urlStr
+ }
+ urlStr = req.URL.Scheme + "://" + host + urlStr
+ }
+ }
+
+ bw := bufio.NewWriter(w)
+ fmt.Fprintf(bw, "%s %s HTTP/1.1\r\n", valueOrDefault(req.Method, "GET"), urlStr)
+
+ // Header lines
+ fmt.Fprintf(bw, "Host: %s\r\n", host)
+
+ // Use the defaultUserAgent unless the Header contains one, which
+ // may be blank to not send the header.
+ userAgent := defaultUserAgent
+ if req.Header != nil {
+ if ua := req.Header["User-Agent"]; len(ua) > 0 {
+ userAgent = ua[0]
+ }
+ }
+ if userAgent != "" {
+ fmt.Fprintf(bw, "User-Agent: %s\r\n", userAgent)
+ }
+
+ // Process Body,ContentLength,Close,Trailer
+ tw, err := newTransferWriter(req)
+ if err != nil {
+ return err
+ }
+ err = tw.WriteHeader(bw)
+ if err != nil {
+ return err
+ }
+
+ // TODO: split long values? (If so, should share code with Conn.Write)
+ err = req.Header.WriteSubset(bw, reqWriteExcludeHeader)
+ if err != nil {
+ return err
+ }
+
+ io.WriteString(bw, "\r\n")
+
+ // Write body and trailer
+ err = tw.WriteBody(bw)
+ if err != nil {
+ return err
+ }
+ bw.Flush()
+ return nil
+}
+
+// Read a line of bytes (up to \n) from b.
+// Give up if the line exceeds maxLineLength.
+// The returned bytes are a pointer into storage in
+// the bufio, so they are only valid until the next bufio read.
+func readLineBytes(b *bufio.Reader) (p []byte, err os.Error) {
+ if p, err = b.ReadSlice('\n'); err != nil {
+ // We always know when EOF is coming.
+ // If the caller asked for a line, there should be a line.
+ if err == os.EOF {
+ err = io.ErrUnexpectedEOF
+ } else if err == bufio.ErrBufferFull {
+ err = ErrLineTooLong
+ }
+ return nil, err
+ }
+ if len(p) >= maxLineLength {
+ return nil, ErrLineTooLong
+ }
+
+ // Chop off trailing white space.
+ var i int
+ for i = len(p); i > 0; i-- {
+ if c := p[i-1]; c != ' ' && c != '\r' && c != '\t' && c != '\n' {
+ break
+ }
+ }
+ return p[0:i], nil
+}
+
+// readLineBytes, but convert the bytes into a string.
+func readLine(b *bufio.Reader) (s string, err os.Error) {
+ p, e := readLineBytes(b)
+ if e != nil {
+ return "", e
+ }
+ return string(p), nil
+}
+
+// Convert decimal at s[i:len(s)] to integer,
+// returning value, string position where the digits stopped,
+// and whether there was a valid number (digits, not too big).
+func atoi(s string, i int) (n, i1 int, ok bool) {
+ const Big = 1000000
+ if i >= len(s) || s[i] < '0' || s[i] > '9' {
+ return 0, 0, false
+ }
+ n = 0
+ for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+ n = n*10 + int(s[i]-'0')
+ if n > Big {
+ return 0, 0, false
+ }
+ }
+ return n, i, true
+}
+
+// ParseHTTPVersion parses a HTTP version string.
+// "HTTP/1.0" returns (1, 0, true).
+func ParseHTTPVersion(vers string) (major, minor int, ok bool) {
+ if len(vers) < 5 || vers[0:5] != "HTTP/" {
+ return 0, 0, false
+ }
+ major, i, ok := atoi(vers, 5)
+ if !ok || i >= len(vers) || vers[i] != '.' {
+ return 0, 0, false
+ }
+ minor, i, ok = atoi(vers, i+1)
+ if !ok || i != len(vers) {
+ return 0, 0, false
+ }
+ return major, minor, true
+}
+
+type chunkedReader struct {
+ r *bufio.Reader
+ n uint64 // unread bytes in chunk
+ err os.Error
+}
+
+func (cr *chunkedReader) beginChunk() {
+ // chunk-size CRLF
+ var line string
+ line, cr.err = readLine(cr.r)
+ if cr.err != nil {
+ return
+ }
+ cr.n, cr.err = strconv.Btoui64(line, 16)
+ if cr.err != nil {
+ return
+ }
+ if cr.n == 0 {
+ // trailer CRLF
+ for {
+ line, cr.err = readLine(cr.r)
+ if cr.err != nil {
+ return
+ }
+ if line == "" {
+ break
+ }
+ }
+ cr.err = os.EOF
+ }
+}
+
+func (cr *chunkedReader) Read(b []uint8) (n int, err os.Error) {
+ if cr.err != nil {
+ return 0, cr.err
+ }
+ if cr.n == 0 {
+ cr.beginChunk()
+ if cr.err != nil {
+ return 0, cr.err
+ }
+ }
+ if uint64(len(b)) > cr.n {
+ b = b[0:cr.n]
+ }
+ n, cr.err = cr.r.Read(b)
+ cr.n -= uint64(n)
+ if cr.n == 0 && cr.err == nil {
+ // end of chunk (CRLF)
+ b := make([]byte, 2)
+ if _, cr.err = io.ReadFull(cr.r, b); cr.err == nil {
+ if b[0] != '\r' || b[1] != '\n' {
+ cr.err = os.NewError("malformed chunked encoding")
+ }
+ }
+ }
+ return n, cr.err
+}
+
+// NewRequest returns a new Request given a method, URL, and optional body.
+func NewRequest(method, urlStr string, body io.Reader) (*Request, os.Error) {
+ u, err := url.Parse(urlStr)
+ if err != nil {
+ return nil, err
+ }
+ rc, ok := body.(io.ReadCloser)
+ if !ok && body != nil {
+ rc = ioutil.NopCloser(body)
+ }
+ req := &Request{
+ Method: method,
+ URL: u,
+ Proto: "HTTP/1.1",
+ ProtoMajor: 1,
+ ProtoMinor: 1,
+ Header: make(Header),
+ Body: rc,
+ Host: u.Host,
+ }
+ if body != nil {
+ switch v := body.(type) {
+ case *strings.Reader:
+ req.ContentLength = int64(v.Len())
+ case *bytes.Buffer:
+ req.ContentLength = int64(v.Len())
+ }
+ }
+
+ return req, nil
+}
+
+// SetBasicAuth sets the request's Authorization header to use HTTP
+// Basic Authentication with the provided username and password.
+//
+// With HTTP Basic Authentication the provided username and password
+// are not encrypted.
+func (r *Request) SetBasicAuth(username, password string) {
+ s := username + ":" + password
+ r.Header.Set("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(s)))
+}
+
+// ReadRequest reads and parses a request from b.
+func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
+
+ tp := textproto.NewReader(b)
+ req = new(Request)
+
+ // First line: GET /index.html HTTP/1.0
+ var s string
+ if s, err = tp.ReadLine(); err != nil {
+ if err == os.EOF {
+ err = io.ErrUnexpectedEOF
+ }
+ return nil, err
+ }
+
+ var f []string
+ if f = strings.SplitN(s, " ", 3); len(f) < 3 {
+ return nil, &badStringError{"malformed HTTP request", s}
+ }
+ req.Method, req.RawURL, req.Proto = f[0], f[1], f[2]
+ var ok bool
+ if req.ProtoMajor, req.ProtoMinor, ok = ParseHTTPVersion(req.Proto); !ok {
+ return nil, &badStringError{"malformed HTTP version", req.Proto}
+ }
+
+ if req.URL, err = url.ParseRequest(req.RawURL); err != nil {
+ return nil, err
+ }
+
+ // Subsequent lines: Key: value.
+ mimeHeader, err := tp.ReadMIMEHeader()
+ if err != nil {
+ return nil, err
+ }
+ req.Header = Header(mimeHeader)
+
+ // RFC2616: Must treat
+ // GET /index.html HTTP/1.1
+ // Host: www.google.com
+ // and
+ // GET http://www.google.com/index.html HTTP/1.1
+ // Host: doesntmatter
+ // the same. In the second case, any Host line is ignored.
+ req.Host = req.URL.Host
+ if req.Host == "" {
+ req.Host = req.Header.Get("Host")
+ }
+ req.Header.Del("Host")
+
+ fixPragmaCacheControl(req.Header)
+
+ // TODO: Parse specific header values:
+ // Accept
+ // Accept-Encoding
+ // Accept-Language
+ // Authorization
+ // Cache-Control
+ // Connection
+ // Date
+ // Expect
+ // From
+ // If-Match
+ // If-Modified-Since
+ // If-None-Match
+ // If-Range
+ // If-Unmodified-Since
+ // Max-Forwards
+ // Proxy-Authorization
+ // Referer [sic]
+ // TE (transfer-codings)
+ // Trailer
+ // Transfer-Encoding
+ // Upgrade
+ // User-Agent
+ // Via
+ // Warning
+
+ err = readTransfer(req, b)
+ if err != nil {
+ return nil, err
+ }
+
+ return req, nil
+}
+
+// ParseForm parses the raw query.
+// For POST requests, it also parses the request body as a form.
+// ParseMultipartForm calls ParseForm automatically.
+// It is idempotent.
+func (r *Request) ParseForm() (err os.Error) {
+ if r.Form != nil {
+ return
+ }
+
+ if r.URL != nil {
+ r.Form, err = url.ParseQuery(r.URL.RawQuery)
+ }
+ if r.Method == "POST" {
+ if r.Body == nil {
+ return os.NewError("missing form body")
+ }
+ ct := r.Header.Get("Content-Type")
+ switch strings.SplitN(ct, ";", 2)[0] {
+ case "text/plain", "application/x-www-form-urlencoded", "":
+ const maxFormSize = int64(10 << 20) // 10 MB is a lot of text.
+ b, e := ioutil.ReadAll(io.LimitReader(r.Body, maxFormSize+1))
+ if e != nil {
+ if err == nil {
+ err = e
+ }
+ break
+ }
+ if int64(len(b)) > maxFormSize {
+ return os.NewError("http: POST too large")
+ }
+ var newValues url.Values
+ newValues, e = url.ParseQuery(string(b))
+ if err == nil {
+ err = e
+ }
+ if r.Form == nil {
+ r.Form = make(url.Values)
+ }
+ // Copy values into r.Form. TODO: make this smoother.
+ for k, vs := range newValues {
+ for _, value := range vs {
+ r.Form.Add(k, value)
+ }
+ }
+ case "multipart/form-data":
+ // handled by ParseMultipartForm
+ default:
+ return &badStringError{"unknown Content-Type", ct}
+ }
+ }
+ return err
+}
+
+// ParseMultipartForm parses a request body as multipart/form-data.
+// The whole request body is parsed and up to a total of maxMemory bytes of
+// its file parts are stored in memory, with the remainder stored on
+// disk in temporary files.
+// ParseMultipartForm calls ParseForm if necessary.
+// After one call to ParseMultipartForm, subsequent calls have no effect.
+func (r *Request) ParseMultipartForm(maxMemory int64) os.Error {
+ if r.MultipartForm == multipartByReader {
+ return os.NewError("http: multipart handled by MultipartReader")
+ }
+ if r.Form == nil {
+ err := r.ParseForm()
+ if err != nil {
+ return err
+ }
+ }
+ if r.MultipartForm != nil {
+ return nil
+ }
+
+ mr, err := r.multipartReader()
+ if err == ErrNotMultipart {
+ return nil
+ } else if err != nil {
+ return err
+ }
+
+ f, err := mr.ReadForm(maxMemory)
+ if err != nil {
+ return err
+ }
+ for k, v := range f.Value {
+ r.Form[k] = append(r.Form[k], v...)
+ }
+ r.MultipartForm = f
+
+ return nil
+}
+
+// FormValue returns the first value for the named component of the query.
+// FormValue calls ParseMultipartForm and ParseForm if necessary.
+func (r *Request) FormValue(key string) string {
+ if r.Form == nil {
+ r.ParseMultipartForm(defaultMaxMemory)
+ }
+ if vs := r.Form[key]; len(vs) > 0 {
+ return vs[0]
+ }
+ return ""
+}
+
+// FormFile returns the first file for the provided form key.
+// FormFile calls ParseMultipartForm and ParseForm if necessary.
+func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, os.Error) {
+ if r.MultipartForm == multipartByReader {
+ return nil, nil, os.NewError("http: multipart handled by MultipartReader")
+ }
+ if r.MultipartForm == nil {
+ err := r.ParseMultipartForm(defaultMaxMemory)
+ if err != nil {
+ return nil, nil, err
+ }
+ }
+ if r.MultipartForm != nil && r.MultipartForm.File != nil {
+ if fhs := r.MultipartForm.File[key]; len(fhs) > 0 {
+ f, err := fhs[0].Open()
+ return f, fhs[0], err
+ }
+ }
+ return nil, nil, ErrMissingFile
+}
+
+func (r *Request) expectsContinue() bool {
+ return strings.ToLower(r.Header.Get("Expect")) == "100-continue"
+}
+
+func (r *Request) wantsHttp10KeepAlive() bool {
+ if r.ProtoMajor != 1 || r.ProtoMinor != 0 {
+ return false
+ }
+ return strings.Contains(strings.ToLower(r.Header.Get("Connection")), "keep-alive")
+}