go-gemini/request.go
2021-02-28 22:20:59 -05:00

130 lines
3.3 KiB
Go

package gemini
import (
"bufio"
"crypto/tls"
"io"
"net"
"net/url"
)
// A Request represents a Gemini request received by a server or to be sent
// by a client.
type Request struct {
// URL specifies the URL being requested.
URL *url.URL
// For client requests, Host optionally specifies the server to
// connect to. It may be of the form "host" or "host:port".
// If empty, the value of URL.Host is used.
// For international domain names, Host may be in Punycode or
// Unicode form. Use golang.org/x/net/idna to convert it to
// either format if needed.
// This field is ignored by the Gemini server.
Host string
// For client requests, Certificate optionally specifies the
// TLS certificate to present to the other side of the connection.
// This field is ignored by the Gemini server.
Certificate *tls.Certificate
conn net.Conn
tls *tls.ConnectionState
}
// NewRequest returns a new request.
// The returned Request is suitable for use with Client.Do.
//
// Callers should be careful that the URL query is properly escaped.
// See the documentation for QueryEscape for more information.
func NewRequest(rawurl string) (*Request, error) {
u, err := url.Parse(rawurl)
if err != nil {
return nil, err
}
return &Request{URL: u}, nil
}
// ReadRequest reads and parses an incoming request from r.
//
// ReadRequest is a low-level function and should only be used
// for specialized applications; most code should use the Server
// to read requests and handle them via the Handler interface.
func ReadRequest(r io.Reader) (*Request, error) {
// Read URL
r = io.LimitReader(r, 1026)
br := bufio.NewReaderSize(r, 1026)
rawurl, err := br.ReadString('\r')
if err != nil {
return nil, err
}
// Read terminating line feed
if b, err := br.ReadByte(); err != nil {
return nil, err
} else if b != '\n' {
return nil, ErrInvalidRequest
}
// Trim carriage return
rawurl = rawurl[:len(rawurl)-1]
// Validate URL
if len(rawurl) > 1024 {
return nil, ErrInvalidRequest
}
u, err := url.Parse(rawurl)
if err != nil {
return nil, err
}
return &Request{URL: u}, nil
}
// WriteTo writes r to w in the Gemini request format.
// This method consults the request URL only.
func (r *Request) WriteTo(w io.Writer) (int64, error) {
bw := bufio.NewWriterSize(w, 1026)
url := r.URL.String()
if len(url) > 1024 {
return 0, ErrInvalidRequest
}
var wrote int64
n, err := bw.WriteString(url)
wrote += int64(n)
if err != nil {
return wrote, err
}
n, err = bw.Write(crlf)
wrote += int64(n)
if err != nil {
return wrote, err
}
return wrote, bw.Flush()
}
// Conn returns the network connection on which the request was received.
// Conn returns nil for client requests.
func (r *Request) Conn() net.Conn {
return r.conn
}
// TLS returns information about the TLS connection on which the
// request was received.
// TLS returns nil for client requests.
func (r *Request) TLS() *tls.ConnectionState {
if r.tls == nil {
if tlsConn, ok := r.conn.(*tls.Conn); ok {
state := tlsConn.ConnectionState()
r.tls = &state
}
}
return r.tls
}
// ServerName returns the value of the TLS Server Name Indication extension
// sent by the client.
// ServerName returns an empty string for client requests.
func (r *Request) ServerName() string {
if tls := r.TLS(); tls != nil {
return tls.ServerName
}
return ""
}