Developing driver system, fixing random iface bug

Author: brokenCursor

.gitignore

@@ -21,4 +21,5 @@
 go.work
 go.work.sum
 
-.VSCodeCounter
+.VSCodeCounter
+.vscode

config/config.go

@@ -27,11 +27,10 @@ func init() {
 	// -- Defaults -- //
 	config.SetDefault("modem.model", "dummy")
 	config.SetDefault("modem.host", "127.0.0.1")
+	config.SetDefault("modem.cmd_ttl", 10)
 
 	config.SetDefault("logging.general", "error")
 	config.SetDefault("logging.driver", "error")
-
-	config.SetDefault("driver.cmd_ttl", 10)
 	// -- Defaults -- //
 
 	err = config.ReadInConfig()

config/errors.go

@@ -0,0 +1,28 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+)
+
+var ErrNoKey = errors.New("config key does not exist")
+var ErrNilValue = errors.New("config key has no or invalid value")
+var ErrInvalidValue = errors.New("value is invalid")
+
+// -- //
+type ConfigError struct {
+	Key   string
+	Value string
+	Err   error
+}
+
+func (e ConfigError) Error() (err string) {
+	switch {
+	case e.Key != "" && e.Value != "":
+		err = fmt.Sprintf("key=%s value=%s: %s", e.Key, e.Value, e.Err.Error())
+	case e.Key != "":
+		err = fmt.Sprintf("key=%s value=<nil>: %s", e.Key, e.Err.Error())
+	}
+
+	return
+}

drivers/common/common.go renamed to drivers/driver_ctl.go

@@ -1,10 +1,9 @@
-package common
+package drivers
 
 import (
 	"fmt"
 	"log/slog"
 
-	"github.com/brokenCursor/usb-modem-cli/config"
 	"github.com/brokenCursor/usb-modem-cli/logging"
 	"github.com/spf13/viper"
 )
@@ -13,8 +12,6 @@ import (
 
 type (
 	BaseModem interface {
-		SetHost(host string) error
-		GetHost() string
 		GetModel() string
 	}
 
@@ -47,49 +44,45 @@ type (
 )
 
 var (
-	drivers      map[string]func(host string) BaseModem = map[string]func(host string) BaseModem{}
-	driverConfig *viper.Viper
-	logger       *slog.Logger
+	Drivers map[string]func(config *viper.Viper, logger *slog.Logger) (BaseModem, error) = map[string]func(config *viper.Viper, logger *slog.Logger) (BaseModem, error){}
+	logger  *slog.Logger
 )
 
 func init() {
 	logger = logging.GetGeneralLogger()
-	driverConfig = config.Sub("driver")
 }
 
 func IsRegistered(name string) bool {
 	// Check if driver has already been registered
-	_, ok := drivers[name]
+	_, ok := Drivers[name]
 	return ok
 }
 
-func RegisterDriver(name string, generator func(ip string) BaseModem) (*viper.Viper, *slog.Logger) {
+func RegisterDriver(name string, generator func(config *viper.Viper, logger *slog.Logger) (BaseModem, error)) {
 	// Check if driver has already been registered
 	if IsRegistered(name) {
 		panic(fmt.Sprintf("attempted to register %s twice", name))
 	}
 
 	// Register the driver
-	drivers[name] = generator
+	Drivers[name] = generator
 	logger.With("name", name).Debug("driver registered")
-
-	return driverConfig, logging.GetDriverLogger(name)
 }
 
-func GetModemDriver(model string, host string) (BaseModem, error) {
+func GetModemDriver(model string, config *viper.Viper, logger *slog.Logger) (BaseModem, error) {
 	if !IsRegistered(model) {
 		return nil, ErrUnknownModel
 	}
 
-	logger.Debug("driver instance created", "driver", model, "host", host)
-	return drivers[model](host), nil
+	logger.Debug("driver instance created", "driver", model)
+	return Drivers[model](config, logger)
 }
 
 func GetAvailableDrivers() *[]string {
-	keys := make([]string, len(drivers))
+	keys := make([]string, len(Drivers))
 
 	i := 0
-	for k := range drivers {
+	for k := range Drivers {
 		keys[i] = k
 		i++
 	}

drivers/dummy.go

@@ -0,0 +1,28 @@
+package drivers
+
+import (
+	"log/slog"
+
+	"github.com/spf13/viper"
+)
+
+// DO NOT USE DIRECTLY
+type (
+	dummy struct {
+		config *viper.Viper
+		logger *slog.Logger
+	}
+)
+
+func init() {
+	RegisterDriver("dummy", newDummy)
+}
+
+func newDummy(config *viper.Viper, logger *slog.Logger) (BaseModem, error) {
+	logger.With("driver", "dummy").Debug("dummy driver registered")
+	return &dummy{config: config, logger: logger}, nil
+}
+
+func (m *dummy) GetModel() string {
+	return "Dummy"
+}

drivers/dummy/main.go

@@ -1,4 +1,4 @@
-package common
+package drivers
 
 import (
 	"errors"
@@ -24,6 +24,7 @@ func (e ActionError) Error() string {
 	return fmt.Sprintf("action error: %s failed with %e", e.Action, e.Err)
 }
 
+// -- //
 type UnmarshalError struct {
 	RawData *[]byte
 	Err     error

drivers/common/errors.go renamed to drivers/errors.go

@@ -0,0 +1,57 @@
+package drivers
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+)
+
+// Returns this computer's address on the interface
+func GetInterfaceIPv4Addr(iface string) (addr net.IP, err error) {
+	var (
+		ief      *net.Interface
+		addrs    []net.Addr
+		ipv4Addr net.IP
+	)
+
+	// Get interface by name
+	if ief, err = net.InterfaceByName(iface); err != nil { // get interface
+		return
+	}
+
+	// Get all of the addresses on the interface
+	if addrs, err = ief.Addrs(); err != nil {
+		return
+	}
+
+	// Find the first IPv4 address
+	for _, addr := range addrs {
+		if ipv4Addr = addr.(*net.IPNet).IP.To4(); ipv4Addr != nil {
+			break
+		}
+	}
+
+	// If no IPv4 addresses were found on the interface
+	if ipv4Addr == nil {
+		return nil, fmt.Errorf("interface %s don't have an ipv4 address", iface)
+	}
+
+	return ipv4Addr, nil
+}
+
+func GetTransportForIPv4(ifaceIP net.IP) (*http.Transport, error) {
+	addr, err := net.ResolveTCPAddr("tcp", ifaceIP.String()+":0")
+	if err != nil {
+		return nil, err
+	}
+
+	dialer := &net.Dialer{LocalAddr: addr}
+
+	dialContext := func(ctx context.Context, network, addr string) (net.Conn, error) {
+		conn, err := dialer.Dial(network, addr)
+		return conn, err
+	}
+
+	return &http.Transport{DialContext: dialContext}, nil
+}