Parse RPC listen host safely

cmd/rpc/server.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
+	"net"
 	"net/http"
 	"os"
 	"path"
@@ -78,11 +79,11 @@ func NewServer(controller *controller.Controller, config lib.Config, logger lib.
 
 // Start initializes the Canopy RPC servers
 func (s *Server) Start() {
-	hostport := strings.Split(s.config.ListenAddress, ":")
+	host := listenHost(s.config.ListenAddress)
 	// Start the Query and Admin RPC servers concurrently
-	go s.startRPC(createRouter(s), hostport[0], s.config.RPCPort)
-	go s.startRPC(createAdminRouter(s), hostport[0], s.config.AdminPort)
-	go s.startRPC(createDebugRouter(), hostport[0], s.config.ProfilingPort)
+	go s.startRPC(createRouter(s), host, s.config.RPCPort)
+	go s.startRPC(createAdminRouter(s), host, s.config.AdminPort)
+	go s.startRPC(createDebugRouter(), host, s.config.ProfilingPort)
 
 	// Start tasks to update poll results and poll root chain information
 	go s.updatePollResults()
@@ -164,14 +165,22 @@ func (s *Server) updatePollResults() {
 
 // startStaticFileServers starts a file server for the wallet and explorer
 func (s *Server) startStaticFileServers() {
-	hostport := strings.Split(s.config.ListenAddress, ":")
-	s.logger.Infof("Starting Web Wallet 🔑 http://%s:%s ⬅️", hostport[0], s.config.WalletPort)
+	host := listenHost(s.config.ListenAddress)
+	s.logger.Infof("Starting Web Wallet 🔑 http://%s:%s ⬅️", host, s.config.WalletPort)
 
 	s.runStaticFileServer(walletFS, walletStaticDir, s.config.WalletPort, s.config)
-	s.logger.Infof("Starting Block Explorer 🔍️ http://%s:%s ⬅️", hostport[0], s.config.ExplorerPort)
+	s.logger.Infof("Starting Block Explorer 🔍️ http://%s:%s ⬅️", host, s.config.ExplorerPort)
 	s.runStaticFileServer(explorerFS, explorerStaticDir, s.config.ExplorerPort, s.config)
 }
 
+func listenHost(address string) string {
+	host, _, err := net.SplitHostPort(address)
+	if err == nil {
+		return host
+	}
+	return strings.Split(address, colon)[0]
+}
+
 // startHeapProfiler writes periodic heap profiles to the data directory
 // Warning: This calls runtime.GC() which causes pauses and may affect RPC latency
 func (s *Server) startHeapProfiler() {

cmd/rpc/server_test.go

@@ -0,0 +1,24 @@
+package rpc
+
+import "testing"
+
+func TestListenHost(t *testing.T) {
+	tests := []struct {
+		name    string
+		address string
+		want    string
+	}{
+		{name: "ipv4", address: "0.0.0.0:9001", want: "0.0.0.0"},
+		{name: "wildcard", address: ":9001", want: ""},
+		{name: "ipv6", address: "[::]:9001", want: "::"},
+		{name: "host_without_port", address: "localhost", want: "localhost"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := listenHost(tt.address); got != tt.want {
+				t.Fatalf("listenHost(%q) = %q, want %q", tt.address, got, tt.want)
+			}
+		})
+	}
+}