ooni-probe-cli/internal/netxlite/http.go
Simone Basso 2572376fdb
feat(netxlite): implement single use {,tls} dialer (#464)
This basically adapts already existing code inside websteps to
instead be into the netxlite package, where it belongs.

In the process, abstract the TLSDialer but keep a reference to the
previous name to avoid refactoring existing code (just for now).

While there, notice that the right name is CloseIdleConnections (i.e.,
plural not singular) and change the name.

While there, since we abstracted TLSDialer to be an interface, create
suitable factories for making a TLSDialer type from a Dialer and a
TLSHandshaker.

See https://github.com/ooni/probe/issues/1591
2021-09-06 14:12:30 +02:00

120 lines
3.4 KiB
Go

package netxlite
import (
"context"
"crypto/tls"
"net"
"net/http"
"time"
)
// HTTPTransport is an http.Transport-like structure.
type HTTPTransport interface {
// RoundTrip performs the HTTP round trip.
RoundTrip(req *http.Request) (*http.Response, error)
// CloseIdleConnections closes idle connections.
CloseIdleConnections()
}
// httpTransportLogger is an HTTPTransport with logging.
type httpTransportLogger struct {
// HTTPTransport is the underlying HTTP transport.
HTTPTransport HTTPTransport
// Logger is the underlying logger.
Logger Logger
}
var _ HTTPTransport = &httpTransportLogger{}
// RoundTrip implements HTTPTransport.RoundTrip.
func (txp *httpTransportLogger) RoundTrip(req *http.Request) (*http.Response, error) {
host := req.Host
if host == "" {
host = req.URL.Host
}
req.Header.Set("Host", host) // anticipate what Go would do
return txp.logTrip(req)
}
// logTrip is an HTTP round trip with logging.
func (txp *httpTransportLogger) logTrip(req *http.Request) (*http.Response, error) {
txp.Logger.Debugf("> %s %s", req.Method, req.URL.String())
for key, values := range req.Header {
for _, value := range values {
txp.Logger.Debugf("> %s: %s", key, value)
}
}
txp.Logger.Debug(">")
resp, err := txp.HTTPTransport.RoundTrip(req)
if err != nil {
txp.Logger.Debugf("< %s", err)
return nil, err
}
txp.Logger.Debugf("< %d", resp.StatusCode)
for key, values := range resp.Header {
for _, value := range values {
txp.Logger.Debugf("< %s: %s", key, value)
}
}
txp.Logger.Debug("<")
return resp, nil
}
// CloseIdleConnections implement HTTPTransport.CloseIdleConnections.
func (txp *httpTransportLogger) CloseIdleConnections() {
txp.HTTPTransport.CloseIdleConnections()
}
// NewHTTPTransport creates a new HTTP transport using Go stdlib.
func NewHTTPTransport(dialer Dialer, tlsConfig *tls.Config,
handshaker TLSHandshaker) HTTPTransport {
txp := http.DefaultTransport.(*http.Transport).Clone()
dialer = &httpDialerWithReadTimeout{dialer}
txp.DialContext = dialer.DialContext
txp.DialTLSContext = (&tlsDialer{
Config: tlsConfig,
Dialer: dialer,
TLSHandshaker: handshaker,
}).DialTLSContext
// Better for Cloudflare DNS and also better because we have less
// noisy events and we can better understand what happened.
txp.MaxConnsPerHost = 1
// The following (1) reduces the number of headers that Go will
// automatically send for us and (2) ensures that we always receive
// back the true headers, such as Content-Length. This change is
// functional to OONI's goal of observing the network.
txp.DisableCompression = true
return txp
}
// httpDialerWithReadTimeout enforces a read timeout for all HTTP
// connections. See https://github.com/ooni/probe/issues/1609.
type httpDialerWithReadTimeout struct {
Dialer
}
// DialContext implements Dialer.DialContext.
func (d *httpDialerWithReadTimeout) DialContext(
ctx context.Context, network, address string) (net.Conn, error) {
conn, err := d.Dialer.DialContext(ctx, network, address)
if err != nil {
return nil, err
}
return &httpConnWithReadTimeout{conn}, nil
}
// httpConnWithReadTimeout enforces a read timeout for all HTTP
// connections. See https://github.com/ooni/probe/issues/1609.
type httpConnWithReadTimeout struct {
net.Conn
}
// Read implements Conn.Read.
func (c *httpConnWithReadTimeout) Read(b []byte) (int, error) {
c.Conn.SetReadDeadline(time.Now().Add(30 * time.Second))
defer c.Conn.SetReadDeadline(time.Time{})
return c.Conn.Read(b)
}