重构：模块化 RRPP Lite 并更新入口

lite/rrpp_core/forwarder_primitives.py

@@ -0,0 +1,91 @@
+"""本地转发器的无状态报文解析与改写函数。"""
+
+from urllib.parse import urlsplit
+
+
+HTTP_METHODS = (
+    b"CONNECT ", b"GET ", b"POST ", b"PUT ", b"DELETE ",
+    b"HEAD ", b"OPTIONS ", b"PATCH ",
+)
+
+
+def starts_with_http_method(data: bytes) -> bool:
+    return any(data.startswith(method) for method in HTTP_METHODS)
+
+
+def inject_proxy_auth(data: bytes, basic_auth: str) -> bytes:
+    """为完整 HTTP 代理请求注入上游 Basic Authorization。"""
+    if not starts_with_http_method(data):
+        return data
+    end = data.find(b"\r\n\r\n")
+    if end == -1:
+        return data
+    head = data[:end]
+    first_end = head.find(b"\r\n")
+    request_line = head if first_end == -1 else head[:first_end]
+    headers = b"" if first_end == -1 else head[first_end + 2:]
+    for line in headers.split(b"\r\n"):
+        if b":" not in line:
+            continue
+        name = line[:line.index(b":")].strip().lower()
+        if name == b"authorization":
+            return data
+    auth_line = f"Authorization: Basic {basic_auth}\r\n".encode()
+    return request_line + b"\r\n" + auth_line + headers + data[end:]
+
+
+def parse_connect_authority(first_line: str):
+    """从 CONNECT 首行提取 ``(host, port)``，失败时返回 ``None``。"""
+    parts = first_line.split(" ")
+    if len(parts) < 2:
+        return None
+    authority = parts[1]
+    if authority.startswith("[") and "]" in authority:
+        try:
+            host = authority[1:authority.index("]")]
+            tail = authority[authority.index("]") + 1:]
+            if tail.startswith(":") and tail[1:].isdigit():
+                return host, int(tail[1:])
+        except ValueError:
+            pass
+    if ":" not in authority:
+        return None
+    host, _, port_s = authority.rpartition(":")
+    if not host or not port_s.isdigit():
+        return None
+    return host, int(port_s)
+
+
+def parse_http_absolute(first_line: str):
+    """从明文 HTTP 代理首行提取 ``(host, port)``，失败时返回 ``None``。"""
+    parts = first_line.split(" ")
+    if len(parts) < 2 or not parts[1].lower().startswith(("http://", "https://")):
+        return None
+    parsed = urlsplit(parts[1])
+    if not parsed.hostname:
+        return None
+    port = parsed.port or (443 if parsed.scheme == "https" else 80)
+    return parsed.hostname, port
+
+
+def force_http_close(buffer: bytes) -> bytes:
+    """直连明文 HTTP 时强制 Connection: close，避免错复用连接。"""
+    end = buffer.find(b"\r\n\r\n")
+    if end == -1:
+        return buffer
+    head, tail = buffer[:end], buffer[end:]
+    lines = head.split(b"\r\n")
+    out = [lines[0]]
+    conn_seen = False
+    for line in lines[1:]:
+        low = line.lower()
+        if low.startswith(b"connection:"):
+            out.append(b"Connection: close")
+            conn_seen = True
+        elif low.startswith(b"proxy-connection:"):
+            continue
+        else:
+            out.append(line)
+    if not conn_seen:
+        out.append(b"Connection: close")
+    return b"\r\n".join(out) + tail