Re-araranged stack subsystems

Author: ccie18643

examples/run_stack.py

@@ -50,7 +50,7 @@
     Ip6Host,
     MacAddress,
 )
-from pytcp import TcpIpStack, initialize_interface
+from pytcp import stack
 
 
 @click.command()
@@ -104,17 +104,14 @@ def cli(
     Start PyTCP stack and stop it when user presses Ctrl-C.
     """
 
-    fd, mtu = initialize_interface(interface)
-
     if ip6_host:
         ip6_host.gateway = ip6_gateway
 
     if ip4_host:
         ip4_host.gateway = ip4_gateway
 
-    stack = TcpIpStack(
-        fd=fd,
-        mtu=mtu,
+    stack.init(
+        *stack.initialize_interface(interface),
         mac_address=mac_address,
         ip6_host=ip6_host,
         ip4_host=ip4_host,

pyproject.toml

@@ -87,4 +87,5 @@ disable = """
     no-member,
     too-many-ancestors,
     redefined-outer-name,
+    global-statement,
 """

pytcp/__init__.py

@@ -27,142 +27,9 @@
 
 
 """
-Module contains the main PyTCP stack class.
+Package contains the PyTCP stack modules.
 
 pytcp/__init__.py
 
 ver 3.0.2
 """
-
-
-import fcntl
-import os
-import struct
-import sys
-
-from net_addr.ip4_host import Ip4HostOrigin
-from net_addr.ip6_host import Ip6HostOrigin
-
-from net_addr import Ip4Host, Ip6Host, MacAddress
-from pytcp import config, stack
-from pytcp.lib.logger import log
-from pytcp.socket.socket import (  # noqa: F401
-    AddressFamily,
-    IpProto,
-    ReceiveTimeout,
-    Socket,
-    SocketType,
-    gaierror,
-)
-
-TUNSETIFF = 0x400454CA
-IFF_TUN = 0x0001
-IFF_TAP = 0x0002
-IFF_NO_PI = 0x1000
-
-
-def initialize_interface(if_name: str, /) -> tuple[int, int]:
-    """
-    Initialize the TAP/TUN interface.
-    """
-
-    match if_name[0:3].lower():
-        case "tap":
-            if_type = IFF_TAP
-            mtu = config.INTERFACE__TAP__MTU
-        case "tun":
-            if_type = IFF_TUN
-            mtu = config.INTERFACE__TUN__MTU
-        case _:
-            log(
-                "stack",
-                "<CRIT>Interface name must start with 'tap' or 'tun'</>",
-            )
-            sys.exit(-1)
-
-    try:
-        fd = os.open("/dev/net/tun", os.O_RDWR)
-
-    except FileNotFoundError:
-        log("stack", "<CRIT>Unable to access '/dev/net/tun' device</>")
-        sys.exit(-1)
-
-    fcntl.ioctl(
-        fd,
-        TUNSETIFF,
-        struct.pack("16sH", if_name.encode(), if_type | IFF_NO_PI),
-    )
-
-    return fd, mtu
-
-
-class TcpIpStack:
-    """
-    Main PyTCP library class.
-    """
-
-    def __init__(
-        self,
-        fd: int,
-        mtu: int,
-        *,
-        mac_address: MacAddress | None = None,
-        ip4_host: Ip4Host | None = None,
-        ip6_host: Ip6Host | None = None,
-    ):
-        """
-        Initialize stack on the provided interface.
-        """
-
-        self._fd = fd
-        self._mtu = mtu
-
-        # Set the MAC address.
-        if mac_address is not None:
-            stack.packet_handler._assign_mac_address(
-                mac_unicast=MacAddress(mac_address)
-            )
-
-        # Set the IPv4 address.
-        if config.IP4__SUPPORT_ENABLED is True:
-            if ip4_host is None:
-                config.IP4__HOST_DHCP = True
-            else:
-                ip4_host.origin = Ip4HostOrigin.STATIC
-                stack.packet_handler._assign_ip4_address(ip4_host=ip4_host)
-                config.IP4__HOST_DHCP = False
-
-        # Set the IPv6 address.
-        if config.IP6__SUPPORT_ENABLED is True:
-            if ip6_host is None:
-                config.IP6__LLA_AUTOCONFIG = True
-                config.IP6__GUA_AUTOCONFIG = True
-            else:
-                ip6_host.origin = Ip6HostOrigin.STATIC
-                stack.packet_handler._assign_ip6_address(ip6_host=ip6_host)
-                config.IP6__LLA_AUTOCONFIG = True
-                config.IP6__GUA_AUTOCONFIG = False
-
-    def start(self) -> None:
-        """
-        Start stack components.
-        """
-
-        stack.timer.start()
-        stack.arp_cache.start()
-        stack.nd_cache.start()
-        stack.rx_ring.start(fd=self._fd)
-        stack.tx_ring.start(fd=self._fd, mtu=self._mtu)
-        stack.packet_handler.start()
-
-    def stop(self) -> None:
-        """
-        Stop stack components.
-        """
-
-        stack.packet_handler.stop()
-        stack.tx_ring.stop()
-        stack.rx_ring.stop()
-        stack.arp_cache.stop()
-        stack.nd_cache.stop()
-        stack.timer.stop()

pytcp/config.py

@@ -39,16 +39,6 @@
 
 assert version_info >= (3, 12), "PyTCP requires Python version 3.12 or higher."
 
-# TAP interface MTU, describes how much payload Ethernet packet can carry.
-INTERFACE__TAP__MTU = 1500
-
-# TUN interface MTU..
-INTERFACE__TUN__MTU = 1500
-
-
-# Support for IPv6 and IPv4, at least one should be anabled.
-IP6__SUPPORT_ENABLED = True
-IP4__SUPPORT_ENABLED = True
 
 # Logger configuration - LOG__CHANNEL sets which subsystems of stack log to the
 # console, LOG__DEBUG adds info about class/method caller.
@@ -78,16 +68,6 @@
 }
 LOG__DEBUG = False
 
-# Unicast MAC addresses assigned to stack, currently there is not any kind of
-# duplicate MAC detection performed. This can be overridden when stack object
-# is created.
-ETHERNET__MAC_ADDRESS = "02:00:00:77:77:77"
-
-# IPv6 address auto configuration is implemented using EUI64 addressing and
-# ICMPv6 Router Advertisement messages.
-IP6__LLA_AUTOCONFIG = True
-IP6__GUA_AUTOCONFIG = True
-
 # IPv6 default Hop Limit value.
 IP6__DEFAULT_HOP_LIMIT = 64
 
@@ -104,19 +84,6 @@
 IP4__FRAG_FLOW_TIMEOUT = 5
 IP6__FRAG_FLOW_TIMEOUT = 5
 
-# IPv4 DHCP based address configuration.
-IP4__HOST_DHCP = True
-
-# ARP cache configuration.
-ARP__CACHE__ENTRY_MAX_AGE = 3600
-ARP__CACHE__ENTRY_REFRESH_TIME = 300
-ARP__CACHE__UPDATE_FROM_DIRECT_REQUEST = True
-ARP__CACHE__UPDATE_FROM_GRATUITIOUS_REPLY = True
-
-# ICMPv6 ND cache configuration.
-ICMP6__ND__CACHE__ENTRY_MAX_AGE = 3600
-ICMP6__ND__CACHE__ENTRY_REFRESH_TIME = 300
-
 # TCP/UDP ephemeral port range to be used by outbound connections.
 EPHEMERAL_PORT_RANGE = range(32168, 60700, 2)
 

pytcp/socket/tcp__session.py

@@ -49,7 +49,7 @@
 from enum import auto
 from typing import TYPE_CHECKING, Any
 
-from pytcp import config, stack
+from pytcp import stack
 from pytcp.lib.logger import log
 from pytcp.lib.name_enum import NameEnum
 
@@ -68,6 +68,8 @@
     100  # Delay between consecutive delayed ACK outbound packets
 )
 
+INTERFACE__TAP__MTU = 1500
+
 
 class TcpSessionError(Exception):
     """
@@ -209,7 +211,7 @@ def __init__(
         self._rcv_una: int = 0
 
         # Maximum segment size
-        self._rcv_mss: int = config.INTERFACE__TAP__MTU - 40
+        self._rcv_mss: int = INTERFACE__TAP__MTU - 40
 
         # Window size
         self._rcv_wnd: int = 65535
@@ -883,7 +885,7 @@ def _tcp_fsm_listen(
                 )
                 # Initialize session parameters
                 self._snd_mss = min(
-                    packet_rx_md.tcp__mss, config.INTERFACE__TAP__MTU - 40
+                    packet_rx_md.tcp__mss, INTERFACE__TAP__MTU - 40
                 )
                 self._snd_wnd = (
                     packet_rx_md.tcp__win << self._snd_wsc
@@ -940,7 +942,7 @@ def _tcp_fsm_syn_sent(
             ):
                 # Initialize session parameters
                 self._snd_mss = min(
-                    packet_rx_md.tcp__mss, config.INTERFACE__TAP__MTU - 40
+                    packet_rx_md.tcp__mss, INTERFACE__TAP__MTU - 40
                 )
                 self._snd_wnd = (
                     packet_rx_md.tcp__win << self._snd_wsc