chore(errors): review all errors in codebase

internal/firewall/enable.go

@@ -2,16 +2,9 @@ package firewall
 
 import (
 	"context"
-	"errors"
 	"fmt"
 )
 
-var (
-	ErrEnable        = errors.New("failed enabling firewall")
-	ErrDisable       = errors.New("failed disabling firewall")
-	ErrUserPostRules = errors.New("cannot run user post firewall rules")
-)
-
 type Enabler interface {
 	SetEnabled(ctx context.Context, enabled bool) (err error)
 }
@@ -32,7 +25,7 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {
 	if !enabled {
 		c.logger.Info("disabling...")
 		if err = c.disable(ctx); err != nil {
-			return err
+			return fmt.Errorf("cannot disable firewall: %w", err)
 		}
 		c.enabled = false
 		c.logger.Info("disabled successfully")
@@ -42,7 +35,7 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {
 	c.logger.Info("enabling...")
 
 	if err := c.enable(ctx); err != nil {
-		return fmt.Errorf("%w: %s", ErrEnable, err)
+		return fmt.Errorf("cannot enable firewall: %w", err)
 	}
 	c.enabled = true
 	c.logger.Info("enabled successfully")
@@ -52,13 +45,13 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {
 
 func (c *Config) disable(ctx context.Context) (err error) {
 	if err = c.clearAllRules(ctx); err != nil {
-		return fmt.Errorf("cannot disable firewall: %w", err)
+		return fmt.Errorf("cannot clear all rules: %w", err)
 	}
 	if err = c.setIPv4AllPolicies(ctx, "ACCEPT"); err != nil {
-		return fmt.Errorf("cannot disable firewall: %w", err)
+		return fmt.Errorf("cannot set ipv4 policies: %w", err)
 	}
 	if err = c.setIPv6AllPolicies(ctx, "ACCEPT"); err != nil {
-		return fmt.Errorf("cannot disable firewall: %w", err)
+		return fmt.Errorf("cannot set ipv6 policies: %w", err)
 	}
 	return nil
 }
@@ -76,12 +69,12 @@ func (c *Config) fallbackToDisabled(ctx context.Context) {
 func (c *Config) enable(ctx context.Context) (err error) {
 	touched := false
 	if err = c.setIPv4AllPolicies(ctx, "DROP"); err != nil {
-		return fmt.Errorf("cannot enable firewall: %w", err)
+		return err
 	}
 	touched = true
 
 	if err = c.setIPv6AllPolicies(ctx, "DROP"); err != nil {
-		return fmt.Errorf("cannot enable firewall: %w", err)
+		return err
 	}
 
 	const remove = false
@@ -94,33 +87,33 @@ func (c *Config) enable(ctx context.Context) (err error) {
 
 	// Loopback traffic
 	if err = c.acceptInputThroughInterface(ctx, "lo", remove); err != nil {
-		return fmt.Errorf("cannot enable firewall: %w", err)
+		return err
 	}
 	if err = c.acceptOutputThroughInterface(ctx, "lo", remove); err != nil {
-		return fmt.Errorf("cannot enable firewall: %w", err)
+		return err
 	}
 
 	if err = c.acceptEstablishedRelatedTraffic(ctx, remove); err != nil {
-		return fmt.Errorf("cannot enable firewall: %w", err)
+		return err
 	}
 	if c.vpnConnection.IP != nil {
 		if err = c.acceptOutputTrafficToVPN(ctx, c.defaultInterface, c.vpnConnection, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 		if err = c.acceptOutputThroughInterface(ctx, c.vpnIntf, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 	}
 
 	for _, network := range c.localNetworks {
 		if err := c.acceptOutputFromIPToSubnet(ctx, network.InterfaceName, network.IP, *network.IPNet, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 	}
 
 	for _, subnet := range c.outboundSubnets {
 		if err := c.acceptOutputFromIPToSubnet(ctx, c.defaultInterface, c.localIP, subnet, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 	}
 
@@ -128,18 +121,18 @@ func (c *Config) enable(ctx context.Context) (err error) {
 	// to reach Gluetun.
 	for _, network := range c.localNetworks {
 		if err := c.acceptInputToSubnet(ctx, network.InterfaceName, *network.IPNet, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 	}
 
 	for port, intf := range c.allowedInputPorts {
 		if err := c.acceptInputToPort(ctx, intf, port, remove); err != nil {
-			return fmt.Errorf("cannot enable firewall: %w", err)
+			return err
 		}
 	}
 
 	if err := c.runUserPostRules(ctx, c.customRulesPath, remove); err != nil {
-		return fmt.Errorf("%w: %s", ErrUserPostRules, err)
+		return fmt.Errorf("cannot run user defined post firewall rules: %w", err)
 	}
 
 	return nil