feat(agent): preserve approved SIP route in ARI originate request

internal/asterisk/originate.go

@@ -0,0 +1,30 @@
+package asterisk
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/CyCoreSystems/ari/v5"
+)
+
+var dialedRoute = regexp.MustCompile(`^[a-zA-Z0-9]+$`)
+
+// approvedOriginateRequest binds an already-approved Agent instruction to one
+// native ARI channel. The Dispatcher, not the Agent, selected the trunk,
+// caller and complete dialed number (including any trunk-specific prefix).
+func approvedOriginateRequest(executionID, trunkID, dialedCallee, callerID string, answerTimeout time.Duration) (ari.OriginateRequest, error) {
+	if !trunkName.MatchString(executionID) || !trunkName.MatchString(trunkID) || !dialedRoute.MatchString(dialedCallee) || strings.TrimSpace(callerID) == "" || strings.ContainsAny(callerID, "\r\n") {
+		return ari.OriginateRequest{}, errors.New("approved ARI channel identity or route is incomplete")
+	}
+	seconds := int(answerTimeout / time.Second)
+	if seconds < 1 {
+		return ari.OriginateRequest{}, fmt.Errorf("approved ARI answer window is shorter than one second: %s", answerTimeout)
+	}
+	return ari.OriginateRequest{
+		ChannelID: executionID, Endpoint: "PJSIP/" + dialedCallee + "@" + trunkID,
+		CallerID: callerID, App: "go-sip-agent", Timeout: seconds,
+	}, nil
+}

internal/asterisk/originate_test.go

@@ -0,0 +1,41 @@
+package asterisk
+
+import (
+	"testing"
+	"time"
+)
+
+func TestOriginatePreservesApprovedRouteAndCaller(t *testing.T) {
+	for _, tc := range []struct {
+		trunk, dialed, caller, expected string
+	}{
+		{"shuqi", "708915000000001", "BD1234", "PJSIP/708915000000001@shuqi"},
+		{"zhongding", "15000000001", "mbkq", "PJSIP/15000000001@zhongding"},
+		{"baiying", "mka75515000000001", "KQ1234", "PJSIP/mka75515000000001@baiying"},
+	} {
+		request, err := approvedOriginateRequest("execution-123", tc.trunk, tc.dialed, tc.caller, 7*time.Second+900*time.Millisecond)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if request.Endpoint != tc.expected || request.CallerID != tc.caller || request.ChannelID != "execution-123" || request.Timeout != 7 || request.App != "go-sip-agent" {
+			t.Fatalf("Agent changed approved SIP route/caller or exceeded answer deadline: %+v", request)
+		}
+	}
+}
+
+func TestOriginateRejectsMissingOrUnrepresentableSignedRoute(t *testing.T) {
+	for _, tc := range []struct {
+		executionID, trunk, dialed, caller string
+		answer                             time.Duration
+	}{
+		{"", "shuqi", "708915000000001", "BD1234", time.Second},
+		{"execution-123", "../shuqi", "708915000000001", "BD1234", time.Second},
+		{"execution-123", "shuqi", "7089/15000000001", "BD1234", time.Second},
+		{"execution-123", "shuqi", "708915000000001", "BD1234\n", time.Second},
+		{"execution-123", "shuqi", "708915000000001", "BD1234", 900 * time.Millisecond},
+	} {
+		if _, err := approvedOriginateRequest(tc.executionID, tc.trunk, tc.dialed, tc.caller, tc.answer); err == nil {
+			t.Fatal("invalid signed route or subsecond answer timeout cannot create a channel")
+		}
+	}
+}