Fix blank Xray Settings page from wrapped xrayTemplateConfig (#4059) (#4069)

`getXraySetting` builds its response as

    { "xraySetting": <db value>, "inboundTags": ..., "outboundTestUrl": ... }

and embeds the raw DB value as the `xraySetting` field without
checking whether the stored value already has that exact shape.

The frontend pulls the textarea content from `result.xraySetting`
and saves it back verbatim. If the DB ever ends up holding the
response-shaped wrapper instead of a real xray config (older
installs where this happened at least once, users who imported a
copy-pasted response into the textarea, a botched migration, etc.),
the next save nests another layer, the one after that nests a
third, and the Vue-side JSON.parse of the resulting blob silently
fails — the Xray Settings page goes blank.

Fix both ends of the round-trip:

* Add `service.UnwrapXrayTemplateConfig`. It peels off any number of
  `xraySetting`-keyed layers, leaving a real xray config behind.
  The check is conservative: if the outer object already contains
  any top-level xray key (`inbounds`, `outbounds`, `routing`, `api`,
  `dns`, `log`, `policy`, `stats`), it is returned unchanged, and
  there is a depth cap to avoid pathological inputs.

* `SaveXraySetting` unwraps before validation so a round-tripped
  wrapper from an already-corrupted page can no longer re-poison
  the DB on save.

* `getXraySetting` unwraps on read and, when it finds a wrapper,
  rewrites the DB with the corrected value. Existing broken installs
  heal themselves on the next visit to the page.

Includes unit tests for the passthrough, single-wrap, multi-wrap,
string-encoded-inner, and false-positive cases.

Co-authored-by: pwnnex <eternxles@gmail.com>

1 files changed, 90 insertions, 0 deletions

diff --git a/web/service/xray_setting_test.go b/web/service/xray_setting_test.go
new file mode 100644
index 00000000..2c165576
--- /dev/null
+++ b/web/service/xray_setting_test.go
@@ -0,0 +1,90 @@
+package service
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+func TestUnwrapXrayTemplateConfig(t *testing.T) {
+	real := `{"log":{},"inbounds":[],"outbounds":[],"routing":{}}`
+
+	t.Run("passes through a clean config", func(t *testing.T) {
+		if got := UnwrapXrayTemplateConfig(real); got != real {
+			t.Fatalf("clean config was modified: %s", got)
+		}
+	})
+
+	t.Run("passes through invalid JSON unchanged", func(t *testing.T) {
+		in := "not json at all"
+		if got := UnwrapXrayTemplateConfig(in); got != in {
+			t.Fatalf("invalid input was modified: %s", got)
+		}
+	})
+
+	t.Run("unwraps one layer of response-shaped wrapper", func(t *testing.T) {
+		wrapper := `{"inboundTags":["tag"],"outboundTestUrl":"x","xraySetting":` + real + `}`
+		got := UnwrapXrayTemplateConfig(wrapper)
+		if !equalJSON(t, got, real) {
+			t.Fatalf("want %s, got %s", real, got)
+		}
+	})
+
+	t.Run("unwraps multiple stacked layers", func(t *testing.T) {
+		lvl1 := `{"xraySetting":` + real + `}`
+		lvl2 := `{"xraySetting":` + lvl1 + `}`
+		lvl3 := `{"xraySetting":` + lvl2 + `}`
+		got := UnwrapXrayTemplateConfig(lvl3)
+		if !equalJSON(t, got, real) {
+			t.Fatalf("want %s, got %s", real, got)
+		}
+	})
+
+	t.Run("handles an xraySetting stored as a JSON-encoded string", func(t *testing.T) {
+		encoded, _ := json.Marshal(real) // becomes a quoted string
+		wrapper := `{"xraySetting":` + string(encoded) + `}`
+		got := UnwrapXrayTemplateConfig(wrapper)
+		if !equalJSON(t, got, real) {
+			t.Fatalf("want %s, got %s", real, got)
+		}
+	})
+
+	t.Run("does not unwrap when top level already has real xray keys", func(t *testing.T) {
+		// Pathological but defensible: if a user's actual config somehow
+		// has both the real keys and an unrelated `xraySetting` key, we
+		// must not strip it.
+		in := `{"inbounds":[],"xraySetting":{"some":"thing"}}`
+		got := UnwrapXrayTemplateConfig(in)
+		if got != in {
+			t.Fatalf("should have left real config alone, got %s", got)
+		}
+	})
+
+	t.Run("stops at a reasonable depth", func(t *testing.T) {
+		// Build a deeper-than-maxDepth chain that ends at something
+		// non-wrapped, and confirm we end up at some valid JSON (we
+		// don't loop forever and we don't blow the stack).
+		s := real
+		for i := 0; i < 16; i++ {
+			s = `{"xraySetting":` + s + `}`
+		}
+		got := UnwrapXrayTemplateConfig(s)
+		if !strings.Contains(got, `"inbounds"`) && !strings.Contains(got, `"xraySetting"`) {
+			t.Fatalf("unexpected tail: %s", got)
+		}
+	})
+}
+
+func equalJSON(t *testing.T, a, b string) bool {
+	t.Helper()
+	var va, vb any
+	if err := json.Unmarshal([]byte(a), &va); err != nil {
+		return false
+	}
+	if err := json.Unmarshal([]byte(b), &vb); err != nil {
+		return false
+	}
+	ja, _ := json.Marshal(va)
+	jb, _ := json.Marshal(vb)
+	return string(ja) == string(jb)
+}