diff --git a/bin/yunomdns b/bin/yunomdns index 862a1f477..0aee28195 100755 --- a/bin/yunomdns +++ b/bin/yunomdns @@ -4,160 +4,152 @@ Pythonic declaration of mDNS .local domains for YunoHost """ -import subprocess -import re import sys import yaml - -import socket from time import sleep from typing import List, Dict -from zeroconf import Zeroconf, ServiceInfo +import ifaddr +from ipaddress import ip_address +from zeroconf import Zeroconf, ServiceInfo, ServiceBrowser -# Helper command taken from Moulinette -def check_output(args, stderr=subprocess.STDOUT, shell=True, **kwargs): - """Run command with arguments and return its output as a byte string - Overwrite some of the arguments to capture standard error in the result - and use shell by default before calling subprocess.check_output. + +def get_network_local_interfaces() -> Dict[str, Dict[str, List[str]]]: """ - return ( - subprocess.check_output(args, stderr=stderr, shell=shell, **kwargs) - .decode("utf-8") - .strip() - ) - -# Helper command taken from Moulinette -def _extract_inet(string, skip_netmask=False, skip_loopback=True): + Returns interfaces with their associated local IPs """ - Extract IP addresses (v4 and/or v6) from a string limited to one - address by protocol - Keyword argument: - string -- String to search in - skip_netmask -- True to skip subnet mask extraction - skip_loopback -- False to include addresses reserved for the - loopback interface - - Returns: - A dict of {protocol: address} with protocol one of 'ipv4' or 'ipv6' - - """ - ip4_pattern = ( - r"((25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}" - ) - ip6_pattern = r"(((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)::?((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)" - ip4_pattern += r"/[0-9]{1,2})" if not skip_netmask else ")" - ip6_pattern += r"/[0-9]{1,3})" if not skip_netmask else ")" - result = {} - - for m in re.finditer(ip4_pattern, string): - addr = m.group(1) - if skip_loopback and addr.startswith("127."): - continue - - # Limit to only one result - result["ipv4"] = addr - break - - for m in re.finditer(ip6_pattern, string): - addr = m.group(1) - if skip_loopback and addr == "::1": - continue - - # Limit to only one result - result["ipv6"] = addr - break - - return result - -# Helper command taken from Moulinette -def get_network_interfaces(): - - # Get network devices and their addresses (raw infos from 'ip addr') - devices_raw = {} - output = check_output("ip --brief a").split("\n") - for line in output: - line = line.split() - iname = line[0] - ips = ' '.join(line[2:]) - - devices_raw[iname] = ips - - # Parse relevant informations for each of them - devices = { - name: _extract_inet(addrs) - for name, addrs in devices_raw.items() - if name != "lo" + interfaces = { + adapter.name: { + "ipv4": [ip.ip for ip in adapter.ips if ip.is_IPv4 and ip_address(ip.ip).is_private], + "ipv6": [ip.ip[0] for ip in adapter.ips if ip.is_IPv6 and ip_address(ip.ip[0]).is_private and not ip_address(ip.ip[0]).is_link_local], + } + for adapter in ifaddr.get_adapters() + if adapter.name != "lo" } + return interfaces - return devices -if __name__ == '__main__': +# Listener class, to detect duplicates on the network +# Stores the list of servers in its list property +class Listener: + def __init__(self): + self.list = [] + + def remove_service(self, zeroconf, type, name): + info = zeroconf.get_service_info(type, name) + self.list.remove(info.server) + + def update_service(self, zeroconf, type, name): + pass + + def add_service(self, zeroconf, type, name): + info = zeroconf.get_service_info(type, name) + self.list.append(info.server[:-1]) + + +def main() -> bool: ### # CONFIG ### - with open('/etc/yunohost/mdns.yml', 'r') as f: + with open("/etc/yunohost/mdns.yml", "r") as f: config = yaml.safe_load(f) or {} - updated = False - required_fields = ["interfaces", "domains"] + required_fields = ["domains"] missing_fields = [field for field in required_fields if field not in config] + interfaces = get_network_local_interfaces() if missing_fields: - print("The fields %s are required" % ', '.join(missing_fields)) + print(f"The fields {missing_fields} are required in mdns.yml") + return False - if config['interfaces'] is None: - print('No interface listed for broadcast.') - sys.exit(0) + if "interfaces" not in config: + config["interfaces"] = [interface + for interface, local_ips in interfaces.items() + if local_ips["ipv4"]] - if 'yunohost.local' not in config['domains']: - config['domains'].append('yunohost.local') + if "ban_interfaces" in config: + config["interfaces"] = [interface + for interface in config["interfaces"] + if interface not in config["ban_interfaces"]] - zcs = {} - interfaces = get_network_interfaces() - for interface in config['interfaces']: - infos = [] # List of ServiceInfo objects, to feed Zeroconf - ips = [] # Human-readable IPs - b_ips = [] # Binary-convered IPs + # Let's discover currently published .local domains accross the network + zc = Zeroconf() + listener = Listener() + browser = ServiceBrowser(zc, "_device-info._tcp.local.", listener) + sleep(2) + browser.cancel() + zc.close() - ipv4 = interfaces[interface]['ipv4'].split('/')[0] - if ipv4: - ips.append(ipv4) - b_ips.append(socket.inet_pton(socket.AF_INET, ipv4)) + # Always attempt to publish yunohost.local + if "yunohost.local" not in config["domains"]: + config["domains"].append("yunohost.local") - ipv6 = interfaces[interface]['ipv6'].split('/')[0] - if ipv6: - ips.append(ipv6) - b_ips.append(socket.inet_pton(socket.AF_INET6, ipv6)) + def find_domain_not_already_published(domain): + + # Try domain.local ... but if it's already published by another entity, + # try domain-2.local, domain-3.local, ... + + i = 1 + domain_i = domain + + while domain_i in listener.list: + print(f"Uh oh, {domain_i} already exists on the network...") + + i += 1 + domain_i = domain.replace(".local", f"-{i}.local") + + return domain_i + + config['domains'] = [find_domain_not_already_published(domain) for domain in config['domains']] + + zcs: Dict[Zeroconf, List[ServiceInfo]] = {} + + for interface in config["interfaces"]: + + if interface not in interfaces: + print(f"Interface {interface} listed in config file is not present on system.") + continue + + # Only broadcast IPv4 because IPv6 is buggy ... because we ain't using python3-ifaddr >= 0.1.7 + # Buster only ships 0.1.6 + # Bullseye ships 0.1.7 + # To be re-enabled once we're on bullseye... + # ips: List[str] = interfaces[interface]["ipv4"] + interfaces[interface]["ipv6"] + ips: List[str] = interfaces[interface]["ipv4"] # If at least one IP is listed - if ips: - # Create a Zeroconf object, and store the ServiceInfos - zc = Zeroconf(interfaces=ips) - zcs[zc]=[] - for d in config['domains']: - d_domain=d.replace('.local','') - if '.' in d_domain: - print(d_domain+'.local: subdomains are not supported.') - else: - # Create a ServiceInfo object for each .local domain - zcs[zc].append(ServiceInfo( - type_='_device-info._tcp.local.', - name=interface+': '+d_domain+'._device-info._tcp.local.', - addresses=b_ips, - port=80, - server=d+'.', - )) - print('Adding '+d+' with addresses '+str(ips)+' on interface '+interface) + if not ips: + continue + + # Create a Zeroconf object, and store the ServiceInfos + zc = Zeroconf(interfaces=ips) # type: ignore + zcs[zc] = [] + + for d in config["domains"]: + d_domain = d.replace(".local", "") + if "." in d_domain: + print(f"{d_domain}.local: subdomains are not supported.") + continue + # Create a ServiceInfo object for each .local domain + zcs[zc].append( + ServiceInfo( + type_="_device-info._tcp.local.", + name=f"{interface}: {d_domain}._device-info._tcp.local.", + parsed_addresses=ips, + port=80, + server=f"{d}.", + ) + ) + print(f"Adding {d} with addresses {ips} on interface {interface}") # Run registration print("Registering...") for zc, infos in zcs.items(): for info in infos: - zc.register_service(info) + zc.register_service(info, allow_name_change=True, cooperating_responders=True) try: print("Registered. Press Ctrl+C or stop service to stop.") @@ -168,6 +160,11 @@ if __name__ == '__main__': finally: print("Unregistering...") for zc, infos in zcs.items(): - for info in infos: - zc.unregister_service(info) + zc.unregister_all_services() zc.close() + + return True + + +if __name__ == "__main__": + sys.exit(0 if main() else 1) diff --git a/data/hooks/conf_regen/37-mdns b/data/hooks/conf_regen/37-mdns index 17f7bb8e2..b8112a6c1 100755 --- a/data/hooks/conf_regen/37-mdns +++ b/data/hooks/conf_regen/37-mdns @@ -12,13 +12,6 @@ _generate_config() { [[ "$domain" =~ ^[^.]+\.local$ ]] || continue echo " - $domain" done - - echo "interfaces:" - local_network_interfaces="$(ip --brief a | grep ' 10\.\| 192\.168\.' | awk '{print $1}')" - for interface in $local_network_interfaces - do - echo " - $interface" - done } do_init_regen() { diff --git a/data/templates/mdns/yunomdns.service b/data/templates/mdns/yunomdns.service index ce2641b5d..c1f1b7b06 100644 --- a/data/templates/mdns/yunomdns.service +++ b/data/templates/mdns/yunomdns.service @@ -6,6 +6,7 @@ After=network.target User=mdns Group=mdns Type=simple +Environment=PYTHONUNBUFFERED=1 ExecStart=/usr/bin/yunomdns StandardOutput=syslog