Failover: Initial implementation

3 files changed, 43 insertions, 4 deletions

diff --git a/client/client.go b/client/client.go
index a31334a..b37c506 100644
--- a/client/client.go
+++ b/client/client.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/eduvpn/eduvpn-common/internal/config"
 	"github.com/eduvpn/eduvpn-common/internal/discovery"
+	"github.com/eduvpn/eduvpn-common/internal/failover"
 	"github.com/eduvpn/eduvpn-common/internal/fsm"
 	"github.com/eduvpn/eduvpn-common/internal/log"
 	"github.com/eduvpn/eduvpn-common/internal/server"
@@ -62,6 +63,9 @@ type Client struct {
 
 	// Whether to enable debugging
 	Debug bool `json:"-"`
+
+	// The Failover monitor for the current VPN connection
+	Failover *failover.DroppedConMon
 }
 
 // Register initializes the clientwith the following parameters:
diff --git a/client/fsm.go b/client/fsm.go
index c156fba..76dee05 100644
--- a/client/fsm.go
+++ b/client/fsm.go
@@ -212,7 +212,7 @@ func (c *Client) SetSearchServer() error {
 		return err
 	}
 
-	// TODO(jwijenbergh): Should we handle `false` returned value here?
+	//TODO(jwijenbergh): Should we handle `false` returned value here?
 	c.FSM.GoTransition(StateSearchServer)
 	return nil
 }
@@ -325,7 +325,7 @@ func (c *Client) SetDisconnected(cleanup bool) error {
 func (c *Client) goBackInternal() {
 	err := c.GoBack()
 	if err != nil {
-		// TODO(jwijenbergh): Bit suspicious - logging level INFO, yet stacktrace logged.
+		//TODO(jwijenbergh): Bit suspicious - logging level INFO, yet stacktrace logged.
 		c.Logger.Infof("failed going back: %s\nstacktrace:\n%s", err.Error(), err.(*errors.Error).ErrorStack())
 	}
 }
diff --git a/client/server.go b/client/server.go
index 4c00986..6802a47 100644
--- a/client/server.go
+++ b/client/server.go
@@ -1,6 +1,7 @@
 package client
 
 import (
+	"github.com/eduvpn/eduvpn-common/internal/failover"
 	"github.com/eduvpn/eduvpn-common/internal/oauth"
 	"github.com/eduvpn/eduvpn-common/internal/server"
 	"github.com/eduvpn/eduvpn-common/internal/util"
@@ -84,8 +85,8 @@ func (c *Client) getConfig(srv server.Server, preferTCP bool) (string, string, e
 
 	// Save the config
 	if err = c.Config.Save(&c); err != nil {
-		// TODO(jwijenbergh): Not sure why INFO level, yet stacktrace...
-		// TODO(jwijenbergh): Even worse, why logging it but then return nil? The calling code will think that everything went well.
+		//TODO(jwijenbergh): Not sure why INFO level, yet stacktrace...
+		//TODO(jwijenbergh): Even worse, why logging it but then return nil? The calling code will think that everything went well.
 		c.Logger.Infof("c.Config.Save failed: %s\nstacktrace:\n%s",
 			err.Error(), err.(*errors.Error).ErrorStack())
 	}
@@ -584,3 +585,37 @@ func (c *Client) SetProfileID(profileID string) (err error) {
 	b.Profiles.Current = profileID
 	return nil
 }
+
+func (c *Client) StartFailover(gateway string, wgMTU int, readRxBytes func() (int64, error)) (bool, error) {
+	currentServer, currentServerErr := c.Servers.GetCurrentServer()
+	if currentServerErr != nil {
+		return false, currentServerErr
+	}
+
+	// Check if the current profile supports OpenVPN
+	profile, profileErr := server.CurrentProfile(currentServer)
+	if profileErr != nil {
+		return false, profileErr
+	}
+
+	if !profile.SupportsOpenVPN() {
+		return false, errors.New("Profile does not support OpenVPN fallback")
+	}
+
+	monitor, monitorErr := failover.New(readRxBytes)
+	if monitorErr != nil {
+		return false, monitorErr
+	}
+	// Initialize the client's monitor
+	c.Failover = monitor
+
+	return c.Failover.Start(gateway, wgMTU)
+}
+
+func (c *Client) CancelFailover() error {
+	if c.Failover == nil {
+		return errors.New("No failover process")
+	}
+	c.Failover.Cancel()
+	return nil
+}