first init

sni_spoofing/utils/__init__.py

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+"""Network utility functions.
+
+Cross-platform network interface detection and helpers.
+"""
+
+import socket
+import sys
+import platform
+from typing import Optional
+
+
+def get_default_interface_ipv4(dest: str = "8.8.8.8") -> Optional[str]:
+    """Get the IPv4 address of the default network interface.
+
+    Creates a UDP socket and connects to a public address to determine
+    which local IP would be used for outgoing connections.
+
+    Args:
+        dest: Destination IP to determine route (not actually contacted)
+
+    Returns:
+        Local IPv4 address string, or None on failure
+    """
+    try:
+        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        s.connect((dest, 53))
+        addr = s.getsockname()[0]
+        s.close()
+        return addr
+    except OSError:
+        return None
+
+
+def get_default_interface_ipv6(dest: str = "2001:4860:4860::8888") -> Optional[str]:
+    """Get the IPv6 address of the default network interface.
+
+    Args:
+        dest: Destination IPv6 to determine route
+
+    Returns:
+        Local IPv6 address string, or None on failure
+    """
+    try:
+        s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
+        s.connect((dest, 53))
+        addr = s.getsockname()[0]
+        s.close()
+        return addr
+    except OSError:
+        return None
+
+
+def check_platform_capabilities() -> dict:
+    """Check what DPI bypass capabilities are available on this platform.
+
+    Returns:
+        Dictionary of available features
+    """
+    caps = {
+        "platform": platform.system(),
+        "python_version": sys.version,
+        "fragment_support": True,  # Always available (userspace TCP)
+        "tls_record_frag": True,   # Always available (application layer)
+        "fake_sni": True,          # Always available (application layer)
+        "tcp_nodelay": True,       # Always available
+        "raw_socket": False,       # Platform-dependent
+        "ip_ttl_trick": False,     # Platform-dependent
+    }
+
+    # Check raw socket support (needed for advanced tricks)
+    try:
+        if platform.system() != "Windows":
+            s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)
+            s.close()
+            caps["raw_socket"] = True
+            caps["ip_ttl_trick"] = True
+        else:
+            # Windows raw sockets are limited
+            caps["raw_socket"] = False
+    except (PermissionError, OSError):
+        pass
+
+    # Check AF_PACKET support (Linux only, needed for seq_id injection)
+    try:
+        if platform.system() == "Linux":
+            s = socket.socket(
+                socket.AF_PACKET, socket.SOCK_RAW, socket.htons(0x0003)
+            )
+            s.close()
+            caps["af_packet"] = True
+            caps["raw_injection"] = True
+        else:
+            caps["af_packet"] = False
+            caps["raw_injection"] = False
+    except (PermissionError, OSError, AttributeError):
+        caps["af_packet"] = False
+        caps["raw_injection"] = False
+
+    return caps
+
+
+def resolve_host(host: str) -> str:
+    """Resolve hostname to IP address.
+
+    Args:
+        host: Hostname or IP address
+
+    Returns:
+        IP address string
+    """
+    try:
+        return socket.gethostbyname(host)
+    except socket.gaierror:
+        return host
+
+
+def is_valid_ip(addr: str) -> bool:
+    """Check if string is a valid IPv4 or IPv6 address."""
+    for family in (socket.AF_INET, socket.AF_INET6):
+        try:
+            socket.inet_pton(family, addr)
+            return True
+        except (socket.error, OSError):
+            continue
+    return False
+
+
+def is_valid_port(port: int) -> bool:
+    """Check if port number is valid."""
+    return isinstance(port, int) and 1 <= port <= 65535