add ALLOWED_NETS, use netip, small linting fixes

README.md

@@ -26,6 +26,7 @@ Simple socks5 server using go-socks5 with authentication, allowed ips list and d
 |PROXY_PORT|String|1080|Set listen port for application inside docker container|
 |ALLOWED_DEST_FQDN|String|EMPTY|Allowed destination address regular expression pattern. Default allows all.|
 |ALLOWED_IPS|String|Empty|Set allowed IP's that can connect to proxy, separator `,`|
+|ALLOWED_NETS|String|Empty|Set allowed networks that can connect to proxy, separator `,`|
 
 
 # Build your own image:

ruleset.go

@@ -3,8 +3,9 @@ package main
 import (
 	"regexp"
 
+	"context"
+
 	"github.com/armon/go-socks5"
-	"golang.org/x/net/context"
 )
 
 // PermitDestAddrPattern returns a RuleSet which selectively allows addresses

server.go

@@ -2,11 +2,11 @@ package main
 
 import (
 	"log"
-	"net"
+	"net/netip"
 	"os"
 
 	"github.com/armon/go-socks5"
-	"github.com/caarlos0/env/v6"
+	env "github.com/caarlos0/env/v6"
 )
 
 type params struct {
@@ -15,6 +15,7 @@ type params struct {
 	Port            string   `env:"PROXY_PORT" envDefault:"1080"`
 	AllowedDestFqdn string   `env:"ALLOWED_DEST_FQDN" envDefault:""`
 	AllowedIPs      []string `env:"ALLOWED_IPS" envSeparator:"," envDefault:""`
+	AllowedNets     []string `env:"ALLOWED_NETS" envSeparator:"," envDefault:""`
 }
 
 func main() {
@@ -48,15 +49,25 @@ func main() {
 	}
 
 	// Set IP whitelist
+	if len(cfg.AllowedIPs) > 0 || len(cfg.AllowedNets) > 0 {
+		whitelist := make([]netip.Addr, len(cfg.AllowedIPs))
+		whitelistnet := make([]netip.Prefix, len(cfg.AllowedNets))
+
 		if len(cfg.AllowedIPs) > 0 {
-		whitelist := make([]net.IP, len(cfg.AllowedIPs))
 			for i, ip := range cfg.AllowedIPs {
-			whitelist[i] = net.ParseIP(ip)
+				whitelist[i], _ = netip.ParseAddr(ip)
+			}
+		}
+		if len(cfg.AllowedNets) > 0 {
+			for i, inet := range cfg.AllowedNets {
+				whitelistnet[i], _ = netip.ParsePrefix(inet)
 			}
-		server.SetIPWhitelist(whitelist)
 		}
 
-	log.Printf("Start listening proxy service on port %s\n", cfg.Port)
+		server.SetIPWhitelist(whitelist, whitelistnet)
+	}
+
+	log.Printf("Started proxy service listening on port %s\n", cfg.Port)
 	if err := server.ListenAndServe("tcp", ":"+cfg.Port); err != nil {
 		log.Fatal(err)
 	}

vendor/github.com/armon/go-socks5/auth.go

@@ -15,8 +15,8 @@ const (
 )
 
 var (
-	UserAuthFailed  = fmt.Errorf("User authentication failed")
+	UserAuthFailed  = fmt.Errorf("user authentication failed")
-	NoSupportedAuth = fmt.Errorf("No supported authentication mechanism")
+	NoSupportedAuth = fmt.Errorf("no supported authentication mechanism")
 )
 
 // A Request encapsulates authentication state provided
@@ -71,7 +71,7 @@ func (a UserPassAuthenticator) Authenticate(reader io.Reader, writer io.Writer)
 
 	// Ensure we are compatible
 	if header[0] != userAuthVersion {
-		return nil, fmt.Errorf("Unsupported auth version: %v", header[0])
+		return nil, fmt.Errorf("unsupported auth version: %v", header[0])
 	}
 
 	// Get the user name
@@ -114,7 +114,7 @@ func (s *Server) authenticate(conn io.Writer, bufConn io.Reader) (*AuthContext,
 	// Get the methods
 	methods, err := readMethods(bufConn)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to get auth methods: %v", err)
+		return nil, fmt.Errorf("failed to get auth methods: %v", err)
 	}
 
 	// Select a usable method

vendor/github.com/armon/go-socks5/request.go

@@ -1,13 +1,13 @@
 package socks5
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"net"
+	"net/netip"
 	"strconv"
 	"strings"
-
-	"golang.org/x/net/context"
 )
 
 const (
@@ -32,7 +32,7 @@ const (
 )
 
 var (
-	unrecognizedAddrType = fmt.Errorf("Unrecognized address type")
+	unrecognizedAddrType = fmt.Errorf("unrecognized address type")
 )
 
 // AddressRewriter is used to rewrite a destination transparently
@@ -44,7 +44,7 @@ type AddressRewriter interface {
 // which may be specified as IPv4, IPv6, or a FQDN
 type AddrSpec struct {
 	FQDN string
-	IP   net.IP
+	IP   netip.Addr
 	Port int
 }
 
@@ -58,7 +58,7 @@ func (a *AddrSpec) String() string {
 // Address returns a string suitable to dial; prefer returning IP-based
 // address, fallback to FQDN
 func (a AddrSpec) Address() string {
-	if 0 != len(a.IP) {
+	if len(a.String()) != 0 {
 		return net.JoinHostPort(a.IP.String(), strconv.Itoa(a.Port))
 	}
 	return net.JoinHostPort(a.FQDN, strconv.Itoa(a.Port))
@@ -91,12 +91,12 @@ func NewRequest(bufConn io.Reader) (*Request, error) {
 	// Read the version byte
 	header := []byte{0, 0, 0}
 	if _, err := io.ReadAtLeast(bufConn, header, 3); err != nil {
-		return nil, fmt.Errorf("Failed to get command version: %v", err)
+		return nil, fmt.Errorf("failed to get command version: %v", err)
 	}
 
 	// Ensure we are compatible
 	if header[0] != socks5Version {
-		return nil, fmt.Errorf("Unsupported command version: %v", header[0])
+		return nil, fmt.Errorf("unsupported command version: %v", header[0])
 	}
 
 	// Read in the destination address
@@ -125,9 +125,9 @@ func (s *Server) handleRequest(req *Request, conn conn) error {
 		ctx_, addr, err := s.config.Resolver.Resolve(ctx, dest.FQDN)
 		if err != nil {
 			if err := sendReply(conn, hostUnreachable, nil); err != nil {
-				return fmt.Errorf("Failed to send reply: %v", err)
+				return fmt.Errorf("failed to send reply: %v", err)
 			}
-			return fmt.Errorf("Failed to resolve destination '%v': %v", dest.FQDN, err)
+			return fmt.Errorf("failed to resolve destination '%v': %v", dest.FQDN, err)
 		}
 		ctx = ctx_
 		dest.IP = addr
@@ -149,9 +149,9 @@ func (s *Server) handleRequest(req *Request, conn conn) error {
 		return s.handleAssociate(ctx, conn, req)
 	default:
 		if err := sendReply(conn, commandNotSupported, nil); err != nil {
-			return fmt.Errorf("Failed to send reply: %v", err)
+			return fmt.Errorf("failed to send reply: %v", err)
 		}
-		return fmt.Errorf("Unsupported command: %v", req.Command)
+		return fmt.Errorf("unsupported command: %v", req.Command)
 	}
 }
 
@@ -160,9 +160,9 @@ func (s *Server) handleConnect(ctx context.Context, conn conn, req *Request) err
 	// Check if this is allowed
 	if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
 		if err := sendReply(conn, ruleFailure, nil); err != nil {
-			return fmt.Errorf("Failed to send reply: %v", err)
+			return fmt.Errorf("failed to send reply: %v", err)
 		}
-		return fmt.Errorf("Connect to %v blocked by rules", req.DestAddr)
+		return fmt.Errorf("connect to %v blocked by rules", req.DestAddr)
 	} else {
 		ctx = ctx_
 	}
@@ -184,17 +184,18 @@ func (s *Server) handleConnect(ctx context.Context, conn conn, req *Request) err
 			resp = networkUnreachable
 		}
 		if err := sendReply(conn, resp, nil); err != nil {
-			return fmt.Errorf("Failed to send reply: %v", err)
+			return fmt.Errorf("failed to send reply: %v", err)
 		}
-		return fmt.Errorf("Connect to %v failed: %v", req.DestAddr, err)
+		return fmt.Errorf("connect to %v failed: %v", req.DestAddr, err)
 	}
 	defer target.Close()
 
 	// Send success
 	local := target.LocalAddr().(*net.TCPAddr)
-	bind := AddrSpec{IP: local.IP, Port: local.Port}
+	localAddr, _ := netip.AddrFromSlice(local.IP)
+	bind := AddrSpec{IP: localAddr, Port: local.Port}
 	if err := sendReply(conn, successReply, &bind); err != nil {
-		return fmt.Errorf("Failed to send reply: %v", err)
+		return fmt.Errorf("failed to send reply: %v", err)
 	}
 
 	// Start proxying
@@ -218,16 +219,16 @@ func (s *Server) handleBind(ctx context.Context, conn conn, req *Request) error
 	// Check if this is allowed
 	if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
 		if err := sendReply(conn, ruleFailure, nil); err != nil {
-			return fmt.Errorf("Failed to send reply: %v", err)
+			return fmt.Errorf("failed to send reply: %v", err)
 		}
-		return fmt.Errorf("Bind to %v blocked by rules", req.DestAddr)
+		return fmt.Errorf("bind to %v blocked by rules", req.DestAddr)
 	} else {
 		ctx = ctx_
 	}
 
 	// TODO: Support bind
 	if err := sendReply(conn, commandNotSupported, nil); err != nil {
-		return fmt.Errorf("Failed to send reply: %v", err)
+		return fmt.Errorf("failed to send reply: %v", err)
 	}
 	return nil
 }
@@ -237,16 +238,16 @@ func (s *Server) handleAssociate(ctx context.Context, conn conn, req *Request) e
 	// Check if this is allowed
 	if ctx_, ok := s.config.Rules.Allow(ctx, req); !ok {
 		if err := sendReply(conn, ruleFailure, nil); err != nil {
-			return fmt.Errorf("Failed to send reply: %v", err)
+			return fmt.Errorf("failed to send reply: %v", err)
 		}
-		return fmt.Errorf("Associate to %v blocked by rules", req.DestAddr)
+		return fmt.Errorf("associate to %v blocked by rules", req.DestAddr)
 	} else {
 		ctx = ctx_
 	}
 
 	// TODO: Support associate
 	if err := sendReply(conn, commandNotSupported, nil); err != nil {
-		return fmt.Errorf("Failed to send reply: %v", err)
+		return fmt.Errorf("failed to send reply: %v", err)
 	}
 	return nil
 }
@@ -269,14 +270,14 @@ func readAddrSpec(r io.Reader) (*AddrSpec, error) {
 		if _, err := io.ReadAtLeast(r, addr, len(addr)); err != nil {
 			return nil, err
 		}
-		d.IP = net.IP(addr)
+		d.IP, _ = netip.AddrFromSlice(addr)
 
 	case ipv6Address:
 		addr := make([]byte, 16)
 		if _, err := io.ReadAtLeast(r, addr, len(addr)); err != nil {
 			return nil, err
 		}
-		d.IP = net.IP(addr)
+		d.IP, _ = netip.AddrFromSlice(addr)
 
 	case fqdnAddress:
 		if _, err := r.Read(addrType); err != nil {
@@ -320,18 +321,18 @@ func sendReply(w io.Writer, resp uint8, addr *AddrSpec) error {
 		addrBody = append([]byte{byte(len(addr.FQDN))}, addr.FQDN...)
 		addrPort = uint16(addr.Port)
 
-	case addr.IP.To4() != nil:
+	case addr.IP.As4() != [4]byte{}:
 		addrType = ipv4Address
-		addrBody = []byte(addr.IP.To4())
+		addrBody = addr.IP.AsSlice()
 		addrPort = uint16(addr.Port)
 
-	case addr.IP.To16() != nil:
+	case addr.IP.As16() != [16]byte{}:
 		addrType = ipv6Address
-		addrBody = []byte(addr.IP.To16())
+		addrBody = addr.IP.AsSlice()
 		addrPort = uint16(addr.Port)
 
 	default:
-		return fmt.Errorf("Failed to format address: %v", addr)
+		return fmt.Errorf("failed to format address: %v", addr)
 	}
 
 	// Format the message

vendor/github.com/armon/go-socks5/resolver.go

@@ -1,23 +1,23 @@
 package socks5
 
 import (
-	"net"
+	"context"
-
+	"net/netip"
-	"golang.org/x/net/context"
 )
 
 // NameResolver is used to implement custom name resolution
 type NameResolver interface {
-	Resolve(ctx context.Context, name string) (context.Context, net.IP, error)
+	Resolve(ctx context.Context, name string) (context.Context, netip.Addr, error)
 }
 
 // DNSResolver uses the system DNS to resolve host names
 type DNSResolver struct{}
 
-func (d DNSResolver) Resolve(ctx context.Context, name string) (context.Context, net.IP, error) {
+func (d DNSResolver) Resolve(ctx context.Context, name string) (context.Context, netip.Addr, error) {
-	addr, err := net.ResolveIPAddr("ip", name)
+	addr, err := netip.ParseAddr(name)
+
 	if err != nil {
-		return ctx, nil, err
+		return ctx, netip.Addr{}, err
 	}
-	return ctx, addr.IP, err
+	return ctx, addr, err
 }

vendor/github.com/armon/go-socks5/ruleset.go

@@ -1,7 +1,7 @@
 package socks5
 
 import (
-	"golang.org/x/net/context"
+	"context"
 )
 
 // RuleSet is used to provide custom rules to allow or prohibit actions

vendor/github.com/armon/go-socks5/socks5.go

@@ -2,12 +2,12 @@ package socks5
 
 import (
 	"bufio"
+	"context"
 	"fmt"
 	"log"
 	"net"
+	"net/netip"
 	"os"
-
-	"golang.org/x/net/context"
 )
 
 const (
@@ -40,7 +40,7 @@ type Config struct {
 	Rewriter AddressRewriter
 
 	// BindIP is used for bind or udp associate
-	BindIP net.IP
+	BindIP netip.Addr
 
 	// Logger can be used to provide a custom log target.
 	// Defaults to stdout.
@@ -55,7 +55,8 @@ type Config struct {
 type Server struct {
 	config       *Config
 	authMethods  map[uint8]Authenticator
-	isIPAllowed func(net.IP) bool
+	isIPAllowed  func(netip.Addr) bool
+	isNetAllowed func(netip.Addr) bool
 }
 
 // New creates a new Server and potentially returns an error
@@ -95,7 +96,7 @@ func New(conf *Config) (*Server, error) {
 	}
 
 	// Set default IP whitelist function
-	server.isIPAllowed = func(ip net.IP) bool {
+	server.isIPAllowed = func(ip netip.Addr) bool {
 		return true // default allow all IPs
 	}
 
@@ -120,14 +121,18 @@ func (s *Server) Serve(l net.Listener) error {
 		}
 		go s.ServeConn(conn)
 	}
-	return nil
 }
 
 // SetIPWhitelist sets the function to check if a given IP is allowed
-func (s *Server) SetIPWhitelist(allowedIPs []net.IP) {
+func (s *Server) SetIPWhitelist(allowedIPs []netip.Addr, allowedNets []netip.Prefix) {
-	s.isIPAllowed = func(ip net.IP) bool {
+	s.isIPAllowed = func(ip netip.Addr) bool {
 		for _, allowedIP := range allowedIPs {
-			if ip.Equal(allowedIP) {
+			if ip.Compare(allowedIP) == 0 {
+				return true
+			}
+		}
+		for _, allowedNet := range allowedNets {
+			if allowedNet.Contains(ip) {
 				return true
 			}
 		}
@@ -146,7 +151,7 @@ func (s *Server) ServeConn(conn net.Conn) error {
 		s.config.Logger.Printf("[ERR] socks: Failed to get client IP address: %v", err)
 		return err
 	}
-	ip := net.ParseIP(clientIP)
+	ip, _ := netip.ParseAddr(string(clientIP))
 	if s.isIPAllowed(ip) {
 		s.config.Logger.Printf("[INFO] socks: Connection from allowed IP address: %s", clientIP)
 	} else {
@@ -163,7 +168,7 @@ func (s *Server) ServeConn(conn net.Conn) error {
 
 	// Ensure we are compatible
 	if version[0] != socks5Version {
-		err := fmt.Errorf("Unsupported SOCKS version: %v", version)
+		err := fmt.Errorf("unsupported SOCKS version: %v", version)
 		s.config.Logger.Printf("[ERR] socks: %v", err)
 		return err
 	}
@@ -171,7 +176,7 @@ func (s *Server) ServeConn(conn net.Conn) error {
 	// Authenticate the connection
 	authContext, err := s.authenticate(conn, bufConn)
 	if err != nil {
-		err = fmt.Errorf("Failed to authenticate: %v", err)
+		err = fmt.Errorf("failed to authenticate: %v", err)
 		s.config.Logger.Printf("[ERR] socks: %v", err)
 		return err
 	}
@@ -180,19 +185,20 @@ func (s *Server) ServeConn(conn net.Conn) error {
 	if err != nil {
 		if err == unrecognizedAddrType {
 			if err := sendReply(conn, addrTypeNotSupported, nil); err != nil {
-				return fmt.Errorf("Failed to send reply: %v", err)
+				return fmt.Errorf("failed to send reply: %v", err)
 			}
 		}
-		return fmt.Errorf("Failed to read destination address: %v", err)
+		return fmt.Errorf("failed to read destination address: %v", err)
 	}
 	request.AuthContext = authContext
 	if client, ok := conn.RemoteAddr().(*net.TCPAddr); ok {
-		request.RemoteAddr = &AddrSpec{IP: client.IP, Port: client.Port}
+		addr, _ := netip.ParseAddr(string(client.IP))
+		request.RemoteAddr = &AddrSpec{IP: addr, Port: client.Port}
 	}
 
 	// Process the client request
 	if err := s.handleRequest(request, conn); err != nil {
-		err = fmt.Errorf("Failed to handle request: %v", err)
+		err = fmt.Errorf("failed to handle request: %v", err)
 		s.config.Logger.Printf("[ERR] socks: %v", err)
 		return err
 	}