demo: remove workarounds that have been upstreamed to nemu

Nemu previously had an issue with PIDs above 4 hex digits (> 65535)
where created network interfaces would have names of length
exceeding IFNAMSIZ. These fixes have been upstreamed in nemu3.

Problems around the @ notation used by iproute have also been fixed
and/or upstreamed in nemu3.

This reverts the following commits:
  cfb2c159
  06f33ff2
  27a27263

demo/demo

@@ -74,8 +74,6 @@ if args.duration:
     signal.signal(signal.SIGALRM, handler)
     signal.alarm(args.duration)
 
-with open('fixnemu.py') as f:
-    exec(compile(f.read(), 'fixnemu.py', 'exec'))
 
 class Re6stNode(nemu.Node):
     name: str

demo/fixnemu.py

-# -*- coding: utf-8 -*-
-
-# Copyright 2010, 2011 INRIA
-# Copyright 2011 Martín Ferrari <martin.ferrari@gmail.com>
-#
-# This file is contains patches to Nemu.
-#
-# Nemu is free software: you can redistribute it and/or modify it under the
-# terms of the GNU General Public License version 2, as published by the Free
-# Software Foundation.
-#
-# Nemu is distributed in the hope that it will be useful, but WITHOUT ANY
-# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with
-# Nemu.  If not, see <http://www.gnu.org/licenses/>.
-
-import re
-import os
-from nemu.iproute import backticks, get_if_data, route, \
-    get_addr_data, get_all_route_data, interface
-from nemu.interface import Switch, Interface
-from types import FunctionType
-
-def _get_all_route_data():
-    ipdata = backticks([IP_PATH, "-o", "route", "list"]) # "table", "all"
-    ipdata += backticks([IP_PATH, "-o", "-f", "inet6", "route", "list"])
-
-    ifdata = get_if_data()[1]
-    ret = []
-    for line in ipdata.split("\n"):
-        if line == "":
-            continue
-        # PATCH: parse 'from'
-        # PATCH: 'dev' is missing on 'unreachable' ipv4 routes
-        match = re.match('(?:(unicast|local|broadcast|multicast|throw|'
-            r'unreachable|prohibit|blackhole|nat) )?(\S+)(?: from (\S+))?'
-            r'(?: via (\S+))?(?: dev (\S+))?.*(?: metric (\d+))?', line)
-        if not match:
-            raise RuntimeError("Invalid output from `ip route': `%s'" % line)
-        tipe = match.group(1) or "unicast"
-        prefix = match.group(2)
-        #src = match.group(3)
-        nexthop = match.group(4)
-        interface = ifdata[match.group(5) or "lo"]
-        metric = match.group(6)
-        if prefix == "default" or re.search(r'/0$', prefix):
-            prefix = None
-            prefix_len = 0
-        else:
-            match = re.match(r'([0-9a-f:.]+)(?:/(\d+))?$', prefix)
-            prefix = match.group(1)
-            prefix_len = int(match.group(2) or 32)
-        ret.append(route(tipe, prefix, prefix_len, nexthop, interface.index,
-            metric))
-    return ret
-
-get_all_route_data.__code__ = _get_all_route_data.__code__
-
-interface__init__ = interface.__init__
-def __init__(self, *args, **kw):
-    interface__init__(self, *args, **kw)
-    if self.name:
-        self.name = self.name.split('@',1)[0]
-interface.__init__ = __init__
-
-get_addr_data.orig = FunctionType(get_addr_data.__code__,
-                              get_addr_data.__globals__)
-def _get_addr_data():
-    byidx, bynam = get_addr_data.orig()
-    return byidx, {name.split('@',1)[0]: a for name, a in bynam.items()}
-get_addr_data.__code__ = _get_addr_data.__code__
-
-@staticmethod
-def _gen_if_name():
-    n = Interface._gen_next_id()
-    # Max 15 chars
-    # XXX: We truncate pid to not exceed IFNAMSIZ on systems with 32-bits pids
-    #      but we should find something better to avoid possible collision.
-    return "NETNSif-%.4x%.3x" % (os.getpid() % 0xffff, n)
-Interface._gen_if_name = _gen_if_name
-
-@staticmethod
-def _gen_br_name():
-    n = Switch._gen_next_id()
-     # XXX: same as for _gen_if_name
-    return "NETNSbr-%.4x%.3x" % (os.getpid() % 0xffff, n)
-Switch._gen_br_name = _gen_br_name

re6st/tests/test_network/network_build.py

@@ -6,11 +6,6 @@ import weakref
 from subprocess import DEVNULL, PIPE
 from pathlib import Path
 
-from re6st.tests import DEMO_PATH
-
-fix_file = DEMO_PATH / "fixnemu.py"
-# execfile(str(fix_file)) Removed in python3
-exec(open(str(fix_file)).read())
 IPTABLES = 'iptables-nft'
 
 class ConnectableError(Exception):