Identify networks via PROXY v2 AUTHORITY; drop default network

papod no longer pre-creates a "default network" at boot.  Instead,
each accepted connection is expected to begin with a PROXY protocol
v2 header (RFC: haproxy.org proxy-protocol.txt) carrying the SNI in
a PP2_TYPE_AUTHORITY (0x02) TLV — exactly what untls now injects.

The authority is used to look up (or create) a network by name, and
the resulting network-id is bound to the client at connect time
rather than at registration time.  Connections that arrive without
a header and without the PAPOD_NETWORK_NAME fallback set are refused
with "ERROR :Closing link: (No network)".

PAPOD_NETWORK_NAME exists for environments where untls is not in
the path (notably the integration test harness, where binder/wscat
speak raw bytes); production deployments should leave it unset and
let untls supply the SNI.

Unit tests cover the parser: a valid header returns the AUTHORITY
and leaves trailing bytes intact; non-PROXY input returns nil and
preserves the stream; PROXY without an AUTHORITY TLV returns "".

1 files changed, 72 insertions, 0 deletions

diff --git a/tests/unit.clj b/tests/unit.clj
index 21833e5..9eda963 100644
--- a/tests/unit.clj
+++ b/tests/unit.clj
@@ -1943,6 +1943,78 @@
         (is (empty?
               (filter #(re-find #" 475 " %) replies)))))))
 
+(def read-proxy-v2-authority! @#'papod/read-proxy-v2-authority!)
+
+(defn- bis-of
+  ^java.io.BufferedInputStream [^bytes b]
+  (java.io.BufferedInputStream.
+    (java.io.ByteArrayInputStream. b)
+    4096))
+
+(defn- proxy-v2-bytes
+  "Construct a PROXY v2 LOCAL/AF_UNSPEC header carrying a single
+  AUTHORITY TLV.  Mirrors what untls writes to the upstream socket."
+  ^bytes [^String authority]
+  (let [auth      (.getBytes authority "UTF-8")
+        sig       (byte-array
+                   [(unchecked-byte 0x0D) (unchecked-byte 0x0A)
+                    (unchecked-byte 0x0D) (unchecked-byte 0x0A)
+                    (unchecked-byte 0x00) (unchecked-byte 0x0D)
+                    (unchecked-byte 0x0A) (unchecked-byte 0x51)
+                    (unchecked-byte 0x55) (unchecked-byte 0x49)
+                    (unchecked-byte 0x54) (unchecked-byte 0x0A)])
+        tlv-len   (+ 3 (alength auth))
+        out       (java.io.ByteArrayOutputStream.)]
+    (.write out sig)
+    (.write out 0x21)
+    (.write out 0x00)
+    (.write out (bit-and (bit-shift-right tlv-len 8) 0xFF))
+    (.write out (bit-and tlv-len 0xFF))
+    (.write out 0x02)
+    (.write out (bit-and (bit-shift-right (alength auth) 8) 0xFF))
+    (.write out (bit-and (alength auth) 0xFF))
+    (.write out auth)
+    (.toByteArray out)))
+
+(deftest test_proxy-v2-parser
+  (testing "valid PROXY v2 with AUTHORITY returns the SNI"
+    (let [hdr  (proxy-v2-bytes "papo.example.com")
+          tail (.getBytes "NICK alice\r\n" "UTF-8")
+          buf  (byte-array (+ (alength hdr) (alength tail)))]
+      (System/arraycopy hdr 0 buf 0 (alength hdr))
+      (System/arraycopy tail 0 buf (alength hdr) (alength tail))
+      (let [bis (bis-of buf)
+            authority (read-proxy-v2-authority! bis)]
+        (is (= authority "papo.example.com"))
+        ;; The trailing IRC bytes should remain readable.
+        (let [out (byte-array (alength tail))
+              _   (.read bis out)]
+          (is (= (String. out "UTF-8") "NICK alice\r\n"))))))
+
+  (testing "no PROXY signature returns nil and preserves bytes"
+    (let [bis (bis-of (.getBytes "NICK alice\r\n" "UTF-8"))]
+      (is (nil? (read-proxy-v2-authority! bis)))
+      (let [out (byte-array 12)
+            _   (.read bis out)]
+        (is (= (String. out "UTF-8") "NICK alice\r\n")))))
+
+  (testing "PROXY v2 without AUTHORITY returns empty string"
+    (let [sig (byte-array
+                [(unchecked-byte 0x0D) (unchecked-byte 0x0A)
+                 (unchecked-byte 0x0D) (unchecked-byte 0x0A)
+                 (unchecked-byte 0x00) (unchecked-byte 0x0D)
+                 (unchecked-byte 0x0A) (unchecked-byte 0x51)
+                 (unchecked-byte 0x55) (unchecked-byte 0x49)
+                 (unchecked-byte 0x54) (unchecked-byte 0x0A)])
+          out (java.io.ByteArrayOutputStream.)]
+      (.write out sig)
+      (.write out 0x21)
+      (.write out 0x00)
+      (.write out 0x00)
+      (.write out 0x00)
+      (let [bis (bis-of (.toByteArray out))]
+        (is (= (read-proxy-v2-authority! bis) ""))))))
+
 (defn -main
   [& _args]
   (binding [*out* *err*]