wireguard: switch from gcfg to asciigoat.org/ini/basic

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/wireguard/config_parser.go

@@ -0,0 +1,169 @@
+package wireguard
+
+import (
+	"io/fs"
+	"strconv"
+
+	"asciigoat.org/ini/basic"
+	"darvaza.org/core"
+)
+
+type sectionHandler func(*Config, *basic.Section) error
+
+var sectionMap = map[string]func(*Config, *basic.Section) error{
+	"Interface": loadInterfaceConfSection,
+	"Peer":      loadPeerConfSection,
+}
+
+func loadConfSection(out *Config, src *basic.Section) error {
+	h, ok := sectionMap[src.Key]
+	if !ok {
+		return core.Wrap(fs.ErrInvalid, "unknown section %q", src.Key)
+	}
+
+	return h(out, src)
+}
+
+func loadInterfaceConfSection(out *Config, src *basic.Section) error {
+	var cfg InterfaceConfig
+
+	for _, field := range src.Fields {
+		if err := loadInterfaceConfField(&cfg, field); err != nil {
+			return core.Wrap(err, "Interface")
+		}
+	}
+
+	out.Interface = cfg
+	return nil
+}
+
+func loadPeerConfSection(out *Config, src *basic.Section) error {
+	var cfg PeerConfig
+
+	for _, field := range src.Fields {
+		if err := loadPeerConfField(&cfg, field); err != nil {
+			return core.Wrap(err, "Peer[%v]", len(out.Peer))
+		}
+	}
+
+	out.Peer = append(out.Peer, cfg)
+	return nil
+}
+
+// revive:disable:cyclomatic
+// revive:disable:cognitive-complexity
+
+func loadInterfaceConfField(cfg *InterfaceConfig, field basic.Field) error {
+	// revive:enable:cyclomatic
+	// revive:enable:cognitive-complexity
+
+	// TODO: refactor when asciigoat's ini parser learns to do reflection
+	switch field.Key {
+	case "Address":
+		if !core.IsZero(cfg.Address) {
+			return core.Wrap(fs.ErrInvalid, "duplicate field %q", field.Key)
+		}
+
+		err := cfg.Address.UnmarshalText([]byte(field.Value))
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		default:
+			return nil
+		}
+	case "PrivateKey":
+		if !core.IsZero(cfg.PrivateKey) {
+			return core.Wrap(fs.ErrInvalid, "duplicate field %q", field.Key)
+		}
+
+		err := cfg.PrivateKey.UnmarshalText([]byte(field.Value))
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		default:
+			return nil
+		}
+	case "ListenPort":
+		if cfg.ListenPort > 0 {
+			return core.Wrap(fs.ErrInvalid, "duplicate field %q", field.Key)
+		}
+
+		u64, err := strconv.ParseUint(field.Value, 10, 16)
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		case u64 == 0:
+			return core.Wrap(fs.ErrInvalid, "invalid %q value", field.Key)
+		default:
+			cfg.ListenPort = uint16(u64)
+			return nil
+		}
+	default:
+		return core.Wrap(fs.ErrInvalid, "unknown field %q", field.Key)
+	}
+}
+
+// revive:disable:cyclomatic
+// revive:disable:cognitive-complexity
+
+func loadPeerConfField(cfg *PeerConfig, field basic.Field) error {
+	// revive:enable:cyclomatic
+	// revive:enable:cognitive-complexity
+
+	switch field.Key {
+	case "PublicKey":
+		if !core.IsZero(cfg.PublicKey) {
+			return core.Wrap(fs.ErrInvalid, "duplicate field %q", field.Key)
+		}
+
+		err := cfg.PublicKey.UnmarshalText([]byte(field.Value))
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		default:
+			return nil
+		}
+	case "Endpoint":
+		if cfg.Endpoint.String() != "" {
+			return core.Wrap(fs.ErrInvalid, "duplicate field %q", field.Key)
+		}
+
+		err := cfg.Endpoint.UnmarshalText([]byte(field.Value))
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		default:
+			return nil
+		}
+	case "AllowedIPs":
+		s, err := parseAllowedIPs(field.Value)
+		switch {
+		case err != nil:
+			return core.Wrap(err, field.Key)
+		case len(s) > 0:
+			cfg.AllowedIPs = append(cfg.AllowedIPs, s...)
+			return nil
+		}
+	default:
+		return core.Wrap(fs.ErrInvalid, "unknown field %q", field.Key)
+	}
+	return nil
+}
+
+func newConfigFromDocument(doc *basic.Document) (*Config, error) {
+	var out Config
+
+	if len(doc.Global) > 0 {
+		err := core.Wrap(fs.ErrInvalid, "fields before the first section")
+		return nil, err
+	}
+
+	for i := range doc.Sections {
+		src := &doc.Sections[i]
+		if err := loadConfSection(&out, src); err != nil {
+			return nil, err
+		}
+	}
+
+	return &out, nil
+}