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package sshd
import (
"context"
"errors"
"sync"
"testing"
"time"
"github.com/prometheus/client_golang/prometheus/testutil"
"github.com/stretchr/testify/require"
"golang.org/x/crypto/ssh"
"golang.org/x/sync/semaphore"
grpccodes "google.golang.org/grpc/codes"
grpcstatus "google.golang.org/grpc/status"
"gitlab.com/gitlab-org/gitlab-shell/v14/client"
"gitlab.com/gitlab-org/gitlab-shell/v14/internal/command/shared/disallowedcommand"
"gitlab.com/gitlab-org/gitlab-shell/v14/internal/config"
"gitlab.com/gitlab-org/gitlab-shell/v14/internal/metrics"
)
type rejectCall struct {
reason ssh.RejectionReason
message string
}
type fakeNewChannel struct {
channelType string
extraData []byte
acceptErr error
acceptCh chan struct{}
rejectCh chan rejectCall
}
func (f *fakeNewChannel) Accept() (ssh.Channel, <-chan *ssh.Request, error) {
if f.acceptCh != nil {
f.acceptCh <- struct{}{}
}
return nil, nil, f.acceptErr
}
func (f *fakeNewChannel) Reject(reason ssh.RejectionReason, message string) error {
if f.rejectCh != nil {
f.rejectCh <- rejectCall{reason: reason, message: message}
}
return nil
}
func (f *fakeNewChannel) ChannelType() string {
return f.channelType
}
func (f *fakeNewChannel) ExtraData() []byte {
return f.extraData
}
type fakeConn struct {
ssh.Conn
sentRequestName string
mu sync.Mutex
}
func (f *fakeConn) SentRequestName() string {
f.mu.Lock()
defer f.mu.Unlock()
return f.sentRequestName
}
func (f *fakeConn) SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error) {
f.mu.Lock()
defer f.mu.Unlock()
f.sentRequestName = name
return true, nil, nil
}
func setup(sessionsNum int64, newChannel *fakeNewChannel) (*connection, chan ssh.NewChannel) {
cfg := &config.Config{Server: config.ServerConfig{ConcurrentSessionsLimit: sessionsNum}}
conn := &connection{cfg: cfg, concurrentSessions: semaphore.NewWeighted(sessionsNum)}
chans := make(chan ssh.NewChannel, 1)
chans <- newChannel
return conn, chans
}
func TestPanicDuringSessionIsRecovered(t *testing.T) {
newChannel := &fakeNewChannel{channelType: "session"}
conn, chans := setup(1, newChannel)
numSessions := 0
require.NotPanics(t, func() {
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
numSessions += 1
close(chans)
panic("This is a panic")
})
})
require.Equal(t, numSessions, 1)
}
func TestUnknownChannelType(t *testing.T) {
rejectCh := make(chan rejectCall)
defer close(rejectCh)
newChannel := &fakeNewChannel{channelType: "unknown session", rejectCh: rejectCh}
conn, chans := setup(1, newChannel)
go func() {
conn.handleRequests(context.Background(), nil, chans, nil)
}()
rejectionData := <-rejectCh
expectedRejection := rejectCall{reason: ssh.UnknownChannelType, message: "unknown channel type"}
require.Equal(t, expectedRejection, rejectionData)
}
func TestTooManySessions(t *testing.T) {
rejectCh := make(chan rejectCall)
defer close(rejectCh)
newChannel := &fakeNewChannel{channelType: "session", rejectCh: rejectCh}
conn, chans := setup(1, newChannel)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
go func() {
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
<-ctx.Done() // Keep the accepted channel open until the end of the test
return nil
})
}()
chans <- newChannel
require.Equal(t, <-rejectCh, rejectCall{reason: ssh.ResourceShortage, message: "too many concurrent sessions"})
}
func TestAcceptSessionSucceeds(t *testing.T) {
newChannel := &fakeNewChannel{channelType: "session"}
conn, chans := setup(1, newChannel)
channelHandled := false
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
channelHandled = true
close(chans)
return nil
})
require.True(t, channelHandled)
}
func TestAcceptSessionFails(t *testing.T) {
acceptCh := make(chan struct{})
defer close(acceptCh)
acceptErr := errors.New("some failure")
newChannel := &fakeNewChannel{channelType: "session", acceptCh: acceptCh, acceptErr: acceptErr}
conn, chans := setup(1, newChannel)
channelHandled := false
go func() {
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
channelHandled = true
return nil
})
}()
require.Equal(t, <-acceptCh, struct{}{})
// Waits until the number of sessions is back to 0, since we can only have 1
conn.concurrentSessions.Acquire(context.Background(), 1)
defer conn.concurrentSessions.Release(1)
require.False(t, channelHandled)
}
func TestClientAliveInterval(t *testing.T) {
f := &fakeConn{}
ticker := time.NewTicker(time.Millisecond)
defer ticker.Stop()
conn := &connection{}
go conn.sendKeepAliveMsg(context.Background(), &ssh.ServerConn{f, nil}, ticker)
require.Eventually(t, func() bool { return KeepAliveMsg == f.SentRequestName() }, time.Second, time.Millisecond)
}
func TestSessionsMetrics(t *testing.T) {
// Unfortunately, there is no working way to reset Counter (not CounterVec)
// https://pkg.go.dev/github.com/prometheus/client_golang/prometheus#pkg-index
initialSessionsTotal := testutil.ToFloat64(metrics.SliSshdSessionsTotal)
initialSessionsErrorTotal := testutil.ToFloat64(metrics.SliSshdSessionsErrorsTotal)
newChannel := &fakeNewChannel{channelType: "session"}
conn, chans := setup(1, newChannel)
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
close(chans)
return errors.New("custom error")
})
require.InDelta(t, initialSessionsTotal+1, testutil.ToFloat64(metrics.SliSshdSessionsTotal), 0.1)
require.InDelta(t, initialSessionsErrorTotal+1, testutil.ToFloat64(metrics.SliSshdSessionsErrorsTotal), 0.1)
for i, ignoredError := range []struct {
desc string
err error
}{
{"canceled requests", grpcstatus.Error(grpccodes.Canceled, "canceled")},
{"unavailable Gitaly", grpcstatus.Error(grpccodes.Unavailable, "unavailable")},
{"api error", &client.ApiError{"api error"}},
{"disallowed command", disallowedcommand.Error},
{"not our ref", grpcstatus.Error(grpccodes.Internal, `rpc error: code = Internal desc = cmd wait: exit status 128, stderr: "fatal: git upload-pack: not our ref 9106d18f6a1b8022f6517f479696f3e3ea5e68c1"`)},
} {
t.Run(ignoredError.desc, func(t *testing.T) {
conn, chans = setup(1, newChannel)
ignored := ignoredError.err
conn.handleRequests(context.Background(), nil, chans, func(*ssh.ServerConn, ssh.Channel, <-chan *ssh.Request) error {
close(chans)
return ignored
})
require.InDelta(t, initialSessionsTotal+2+float64(i), testutil.ToFloat64(metrics.SliSshdSessionsTotal), 0.1)
require.InDelta(t, initialSessionsErrorTotal+1, testutil.ToFloat64(metrics.SliSshdSessionsErrorsTotal), 0.1)
})
}
}
|
