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authorJoe Groocock <me@frebib.net>2023-08-20 14:40:38 +0100
committerViacheslav Hletenko <v.gletenko@vyos.io>2023-12-06 06:55:31 +0000
commit7d49f7079f1129c2fadc7f38ceb230804d89e177 (patch)
treeab142ba5a5f9dcd0fc1994be0bc0f17852f0d368 /src/conf_mode/nat64.py
parent99c674cdf6147a69fd57b4151886ff42917caeec (diff)
downloadvyos-1x-7d49f7079f1129c2fadc7f38ceb230804d89e177.tar.gz
vyos-1x-7d49f7079f1129c2fadc7f38ceb230804d89e177.zip
nat64: T160: Implement Jool-based NAT64 translator
Signed-off-by: Joe Groocock <me@frebib.net>
Diffstat (limited to 'src/conf_mode/nat64.py')
-rwxr-xr-xsrc/conf_mode/nat64.py226
1 files changed, 226 insertions, 0 deletions
diff --git a/src/conf_mode/nat64.py b/src/conf_mode/nat64.py
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+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+# pylint: disable=empty-docstring,missing-module-docstring
+
+import csv
+import os
+import re
+
+from ipaddress import IPv6Network
+
+from vyos import ConfigError
+from vyos import airbag
+from vyos.config import Config
+from vyos.configdict import dict_merge
+from vyos.configdict import is_node_changed
+from vyos.utils.dict import dict_search
+from vyos.utils.file import write_json
+from vyos.utils.kernel import check_kmod
+from vyos.utils.process import cmd
+from vyos.utils.process import run
+
+airbag.enable()
+
+INSTANCE_REGEX = re.compile(r"instance-(\d+)")
+JOOL_CONFIG_DIR = "/run/jool"
+
+
+def get_config(config: Config | None = None) -> None:
+ """ """
+ if config is None:
+ config = Config()
+
+ base = ["nat64"]
+ nat64 = config.get_config_dict(base, key_mangling=("-", "_"), get_first_key=True)
+
+ # T2665: we must add the tagNode defaults individually until this is
+ # moved to the base class
+ for direction in ["source"]:
+ if direction in nat64:
+ default_values = defaults(base + [direction, "rule"])
+ if "rule" in nat64[direction]:
+ for rule in nat64[direction]["rule"]:
+ nat64[direction]["rule"][rule] = dict_merge(
+ default_values, nat64[direction]["rule"][rule]
+ )
+
+ # Only support netfilter for now
+ nat64[direction]["rule"][rule]["mode"] = "netfilter"
+
+ base_src = base + ["source", "rule"]
+
+ # Load in existing instances so we can destroy any unknown
+ lines = cmd("jool instance display --csv").splitlines()
+ for _, instance, _ in csv.reader(lines):
+ match = INSTANCE_REGEX.fullmatch(instance)
+ if not match:
+ # FIXME: Instances that don't match should be ignored but WARN'ed to the user
+ continue
+ num = match.group(1)
+
+ rules = nat64.setdefault("source", {}).setdefault("rule", {})
+ # Mark it for deletion
+ if num not in rules:
+ rules[num] = {"deleted": True}
+ continue
+
+ # If the user changes the mode, recreate the instance else Jool fails with:
+ # Jool error: Sorry; you can't change an instance's framework for now.
+ if is_node_changed(config, base_src + [f"instance-{num}", "mode"]):
+ rules[num]["recreate"] = True
+
+ # If the user changes the pool6, recreate the instance else Jool fails with:
+ # Jool error: Sorry; you can't change a NAT64 instance's pool6 for now.
+ if dict_search("source.prefix", rules[num]) and is_node_changed(
+ config,
+ base_src + [num, "source", "prefix"],
+ ):
+ rules[num]["recreate"] = True
+
+ return nat64
+
+
+def verify(nat64) -> None:
+ """ """
+ if not nat64:
+ # no need to verify the CLI as nat64 is going to be deactivated
+ return
+
+ if dict_search("source.rule", nat64):
+ # Ensure only 1 netfilter instance per namespace
+ nf_rules = filter(
+ lambda i: "deleted" not in i and i["mode"] == "netfilter",
+ nat64["source"]["rule"].values(),
+ )
+ next(nf_rules, None) # Discard the first element
+ if next(nf_rules, None) is not None:
+ raise ConfigError(
+ "Jool permits only 1 NAT64 netfilter instance (per network namespace)"
+ )
+
+ for rule, instance in nat64["source"]["rule"].items():
+ if "deleted" in instance:
+ continue
+
+ # Verify that source.prefix is set and is a /96
+ if not dict_search("source.prefix", instance):
+ raise ConfigError(f"Source NAT64 rule {rule} missing source prefix")
+ if IPv6Network(instance["source"]["prefix"]).prefixlen != 96:
+ raise ConfigError(f"Source NAT64 rule {rule} source prefix must be /96")
+
+ pools = dict_search("translation.pool", instance)
+ if pools:
+ for num, pool in pools.items():
+ if "address" not in pool:
+ raise ConfigError(
+ f"Source NAT64 rule {rule} translation pool "
+ f"{num} missing address/prefix"
+ )
+ if "port" not in pool:
+ raise ConfigError(
+ f"Source NAT64 rule {rule} translation pool "
+ f"{num} missing port(-range)"
+ )
+
+
+def generate(nat64) -> None:
+ """ """
+ os.makedirs(JOOL_CONFIG_DIR, exist_ok=True)
+
+ if dict_search("source.rule", nat64):
+ for rule, instance in nat64["source"]["rule"].items():
+ if "deleted" in instance:
+ # Delete the unused instance file
+ os.unlink(os.path.join(JOOL_CONFIG_DIR, f"instance-{rule}.json"))
+ continue
+
+ name = f"instance-{rule}"
+ config = {
+ "instance": name,
+ "framework": "netfilter",
+ "global": {
+ "pool6": instance["source"]["prefix"],
+ "manually-enabled": "disable" not in instance,
+ },
+ # "bib": [],
+ }
+
+ if "description" in instance:
+ config["comment"] = instance["description"]
+
+ if dict_search("translation.pool", instance):
+ pool4 = []
+ for pool in instance["translation"]["pool"].values():
+ if "disable" in pool:
+ continue
+
+ protos = pool.get("protocol", {}).keys() or ("tcp", "udp", "icmp")
+ for proto in protos:
+ obj = {
+ "protocol": proto.upper(),
+ "prefix": pool["address"],
+ "port range": pool["port"],
+ }
+ if "description" in pool:
+ obj["comment"] = pool["description"]
+
+ pool4.append(obj)
+
+ if pool4:
+ config["pool4"] = pool4
+
+ write_json(f"{JOOL_CONFIG_DIR}/{name}.json", config)
+
+
+def apply(nat64) -> None:
+ """ """
+ if not nat64:
+ return
+
+ if dict_search("source.rule", nat64):
+ # Deletions first to avoid conflicts
+ for rule, instance in nat64["source"]["rule"].items():
+ if not any(k in instance for k in ("deleted", "recreate")):
+ continue
+
+ ret = run(f"jool instance remove instance-{rule}")
+ if ret != 0:
+ raise ConfigError(
+ f"Failed to remove nat64 source rule {rule} (jool instance instance-{rule})"
+ )
+
+ # Now creations
+ for rule, instance in nat64["source"]["rule"].items():
+ if "deleted" in instance:
+ continue
+
+ name = f"instance-{rule}"
+ ret = run(f"jool -i {name} file handle {JOOL_CONFIG_DIR}/{name}.json")
+ if ret != 0:
+ raise ConfigError(f"Failed to set jool instance {name}")
+
+
+if __name__ == "__main__":
+ try:
+ check_kmod(["jool"])
+ c = get_config()
+ verify(c)
+ generate(c)
+ apply(c)
+ except ConfigError as e:
+ print(e)
+ exit(1)