ooni-probe-cli/internal/measurex/quic.go
Simone Basso 399d2f65da
feat(measurex): refactored measurement library (#528)
This commit introduce a measurement library that consists of
refactored code from earlier websteps experiments.

I am not going to add tests for the time being, because this library
is still a bit in flux, as we finalize websteps.

I will soon though commit documentation explaining in detail how
to use it, which currrently is at https://github.com/ooni/probe-cli/pull/506
and adds a new directory to internal/tutorial.

The core idea of this measurement library is to allow two
measurement modes:

1. tracing, which is what we're currently doing now, and the
tutorial shows how we can rewrite the measurement part of web
connectivity with measurex using less code. Under a tracing
approach, we construct a normal http.Client that however has
tracing configured, we gather events for resolve, connect, TLS
handshake, QUIC handshake, HTTP round trip, etc. and then we
try to make sense of what happened from the events stream;

2. step-by-step, which is what websteps does, and basically
means that after each operation you immediately write into
a Measurement structure its results and immediately draw the
conclusions on what seems odd (which later may become an
anomaly if we see what the test helper measured).

This library is also such that it produces a data format
compatible with the current OONI spec.

This work is part of https://github.com/ooni/probe/issues/1733.
2021-09-30 01:24:08 +02:00

176 lines
4.7 KiB
Go

package measurex
//
// QUIC
//
// Wrappers for QUIC to store events into a WritableDB.
//
import (
"context"
"crypto/tls"
"net"
"time"
"github.com/lucas-clemente/quic-go"
"github.com/ooni/probe-cli/v3/internal/netxlite"
"github.com/ooni/probe-cli/v3/internal/netxlite/quicx"
)
// QUICConn is the kind of conn used by QUIC.
type QUICConn = quicx.UDPLikeConn
// QUICDialer creates QUICSesssions.
type QUICDialer = netxlite.QUICDialer
// QUICListener creates listening connections for QUIC.
type QUICListener = netxlite.QUICListener
type quicListenerDB struct {
netxlite.QUICListener
begin time.Time
db WritableDB
}
func (ql *quicListenerDB) Listen(addr *net.UDPAddr) (QUICConn, error) {
pconn, err := ql.QUICListener.Listen(addr)
if err != nil {
return nil, err
}
return &udpLikeConnDB{
UDPLikeConn: pconn,
begin: ql.begin,
db: ql.db,
}, nil
}
type udpLikeConnDB struct {
quicx.UDPLikeConn
begin time.Time
db WritableDB
}
func (c *udpLikeConnDB) WriteTo(p []byte, addr net.Addr) (int, error) {
started := time.Since(c.begin).Seconds()
count, err := c.UDPLikeConn.WriteTo(p, addr)
finished := time.Since(c.begin).Seconds()
c.db.InsertIntoReadWrite(&NetworkEvent{
Operation: "write_to",
Network: "quic",
RemoteAddr: addr.String(),
Started: started,
Finished: finished,
Failure: NewArchivalFailure(err),
Count: count,
})
return count, err
}
func (c *udpLikeConnDB) ReadFrom(b []byte) (int, net.Addr, error) {
started := time.Since(c.begin).Seconds()
count, addr, err := c.UDPLikeConn.ReadFrom(b)
finished := time.Since(c.begin).Seconds()
c.db.InsertIntoReadWrite(&NetworkEvent{
Operation: "read_from",
Network: "quic",
RemoteAddr: addrStringIfNotNil(addr),
Started: started,
Finished: finished,
Failure: NewArchivalFailure(err),
Count: count,
})
return count, addr, err
}
func (c *udpLikeConnDB) Close() error {
started := time.Since(c.begin).Seconds()
err := c.UDPLikeConn.Close()
finished := time.Since(c.begin).Seconds()
c.db.InsertIntoClose(&NetworkEvent{
Operation: "close",
Network: "quic",
RemoteAddr: "",
Started: started,
Finished: finished,
Failure: NewArchivalFailure(err),
Count: 0,
})
return err
}
// QUICHandshakeEvent is the result of QUICHandshake.
type QUICHandshakeEvent = TLSHandshakeEvent
// NewQUICDialerWithoutResolver creates a new QUICDialer that is not
// attached to any resolver. This means that every attempt to dial any
// address containing a domain name will fail. This QUICDialer will
// save any event into the WritableDB. Any QUICConn created by it will
// likewise save any event into the WritableDB.
func (mx *Measurer) NewQUICDialerWithoutResolver(db WritableDB, logger Logger) QUICDialer {
return &quicDialerDB{db: db, logger: logger, begin: mx.Begin}
}
type quicDialerDB struct {
netxlite.QUICDialer
begin time.Time
db WritableDB
logger Logger
}
func (qh *quicDialerDB) DialContext(ctx context.Context, network, address string,
tlsConfig *tls.Config, quicConfig *quic.Config) (quic.EarlySession, error) {
started := time.Since(qh.begin).Seconds()
var state tls.ConnectionState
listener := &quicListenerDB{
QUICListener: netxlite.NewQUICListener(),
begin: qh.begin,
db: qh.db,
}
dialer := netxlite.NewQUICDialerWithoutResolver(listener, qh.logger)
defer dialer.CloseIdleConnections()
sess, err := dialer.DialContext(ctx, network, address, tlsConfig, quicConfig)
if err == nil {
select {
case <-sess.HandshakeComplete().Done():
state = sess.ConnectionState().TLS.ConnectionState
case <-ctx.Done():
sess, err = nil, ctx.Err()
}
}
finished := time.Since(qh.begin).Seconds()
qh.db.InsertIntoQUICHandshake(&QUICHandshakeEvent{
Network: "quic",
RemoteAddr: address,
SNI: tlsConfig.ServerName,
ALPN: tlsConfig.NextProtos,
SkipVerify: tlsConfig.InsecureSkipVerify,
Started: started,
Finished: finished,
Failure: NewArchivalFailure(err),
Oddity: qh.computeOddity(err),
TLSVersion: netxlite.TLSVersionString(state.Version),
CipherSuite: netxlite.TLSCipherSuiteString(state.CipherSuite),
NegotiatedProto: state.NegotiatedProtocol,
PeerCerts: NewArchivalTLSCerts(peerCerts(nil, &state)),
})
return sess, err
}
func (qh *quicDialerDB) computeOddity(err error) Oddity {
if err == nil {
return ""
}
switch err.Error() {
case netxlite.FailureGenericTimeoutError:
return OddityQUICHandshakeTimeout
case netxlite.FailureHostUnreachable:
return OddityQUICHandshakeHostUnreachable
default:
return OddityQUICHandshakeOther
}
}
func (qh *quicDialerDB) CloseIdleConnections() {
// nothing to do
}