Fix Go agent packet loss parsing

agent/go/cmd/rmm-agent/main.go

@@ -1484,7 +1484,7 @@ func connectivityChecks(targets []string) []map[string]any {
 func parsePacketLoss(output string) float64 {
 	for _, part := range strings.Split(output, ",") {
 		if strings.Contains(part, "packet loss") {
-			clean := strings.TrimSpace(strings.ReplaceAll(part, "% packet loss", ""))
+			clean := packetLossNumber(part)
 			value, err := strconv.ParseFloat(clean, 64)
 			if err == nil {
 				return value
@@ -1494,6 +1494,24 @@ func parsePacketLoss(output string) float64 {
 	return 100
 }
 
+func packetLossNumber(value string) string {
+	percent := strings.IndexByte(value, '%')
+	if percent < 0 {
+		return ""
+	}
+	value = strings.TrimSpace(value[:percent])
+	start := len(value)
+	for start > 0 {
+		r := rune(value[start-1])
+		if (r >= '0' && r <= '9') || r == '.' {
+			start--
+			continue
+		}
+		break
+	}
+	return value[start:]
+}
+
 func parseLatency(output string) float64 {
 	for _, line := range strings.Split(output, "\n") {
 		if !strings.Contains(line, "min/avg/max") && !strings.Contains(line, "round-trip") {

agent/go/cmd/rmm-agent/main_test.go

@@ -47,3 +47,34 @@ func TestLooksLikeMAC(t *testing.T) {
 		}
 	}
 }
+
+func TestParsePacketLossBusyBox(t *testing.T) {
+	output := `PING 10.10.10.10 (10.10.10.10): 56 data bytes
+64 bytes from 10.10.10.10: seq=0 ttl=64 time=1.157 ms
+64 bytes from 10.10.10.10: seq=1 ttl=64 time=0.883 ms
+64 bytes from 10.10.10.10: seq=2 ttl=64 time=0.952 ms
+
+--- 10.10.10.10 ping statistics ---
+3 packets transmitted, 3 packets received, 0% packet loss
+round-trip min/avg/max = 0.883/0.997/1.157 ms`
+
+	if loss := parsePacketLoss(output); loss != 0 {
+		t.Fatalf("expected 0%% packet loss, got %v", loss)
+	}
+	if latency := parseLatency(output); latency != 0.997 {
+		t.Fatalf("expected avg latency 0.997, got %v", latency)
+	}
+}
+
+func TestParsePacketLossGNU(t *testing.T) {
+	output := `--- 1.1.1.1 ping statistics ---
+3 packets transmitted, 2 received, 33.3333% packet loss, time 2002ms
+rtt min/avg/max/mdev = 10.100/11.200/12.300/0.100 ms`
+
+	if loss := parsePacketLoss(output); loss != 33.3333 {
+		t.Fatalf("expected 33.3333%% packet loss, got %v", loss)
+	}
+	if latency := parseLatency(output); latency != 11.2 {
+		t.Fatalf("expected avg latency 11.2, got %v", latency)
+	}
+}