move network config to pbs_config workspace

pbs-config/Cargo.toml

@@ -6,12 +6,14 @@ edition = "2018"
 description = "Configuration file management for PBS"
 
 [dependencies]
+libc = "0.2"
 anyhow = "1.0"
 lazy_static = "1.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 openssl = "0.10"
 nix = "0.19.1"
+regex = "1.2"
 
 
 proxmox = { version = "0.13.0", default-features = false, features = [ "cli" ] }

pbs-config/src/lib.rs

@@ -2,6 +2,7 @@ pub mod domains;
 pub mod drive;
 pub mod key_config;
 pub mod media_pool;
+pub mod network;
 pub mod remote;
 pub mod sync;
 pub mod tape_encryption_keys;

pbs-config/src/network/helper.rs

@@ -0,0 +1,217 @@
+use std::path::Path;
+use std::process::Command;
+use std::collections::HashMap;
+use std::os::unix::io::{AsRawFd, FromRawFd};
+
+use anyhow::{Error, bail, format_err};
+use lazy_static::lazy_static;
+use nix::ioctl_read_bad;
+use nix::sys::socket::{socket, AddressFamily, SockType, SockFlag};
+use regex::Regex;
+
+use proxmox::*; // for IP macros
+use proxmox::tools::fd::Fd;
+
+pub static IPV4_REVERSE_MASK: &[&str] = &[
+    "0.0.0.0",
+    "128.0.0.0",
+    "192.0.0.0",
+    "224.0.0.0",
+    "240.0.0.0",
+    "248.0.0.0",
+    "252.0.0.0",
+    "254.0.0.0",
+    "255.0.0.0",
+    "255.128.0.0",
+    "255.192.0.0",
+    "255.224.0.0",
+    "255.240.0.0",
+    "255.248.0.0",
+    "255.252.0.0",
+    "255.254.0.0",
+    "255.255.0.0",
+    "255.255.128.0",
+    "255.255.192.0",
+    "255.255.224.0",
+    "255.255.240.0",
+    "255.255.248.0",
+    "255.255.252.0",
+    "255.255.254.0",
+    "255.255.255.0",
+    "255.255.255.128",
+    "255.255.255.192",
+    "255.255.255.224",
+    "255.255.255.240",
+    "255.255.255.248",
+    "255.255.255.252",
+    "255.255.255.254",
+    "255.255.255.255",
+];
+
+lazy_static! {
+    pub static ref IPV4_MASK_HASH_LOCALNET: HashMap<&'static str, u8> = {
+        let mut map = HashMap::new();
+        #[allow(clippy::needless_range_loop)]
+        for i in 8..32 {
+            map.insert(IPV4_REVERSE_MASK[i], i as u8);
+        }
+        map
+    };
+}
+
+pub fn parse_cidr(cidr: &str) -> Result<(String, u8, bool), Error> {
+    let (address, mask, is_v6) = parse_address_or_cidr(cidr)?;
+    if let Some(mask) = mask {
+        Ok((address, mask, is_v6))
+    } else {
+        bail!("missing netmask in '{}'", cidr);
+    }
+}
+
+pub fn check_netmask(mask: u8, is_v6: bool) -> Result<(), Error> {
+    let (ver, min, max) = if is_v6 {
+        ("IPv6", 1, 128)
+    } else {
+        ("IPv4", 1, 32)
+    };
+
+    if !(mask >= min && mask <= max) {
+        bail!("{} mask '{}' is out of range ({}..{}).", ver, mask, min, max);
+    }
+
+    Ok(())
+}
+
+// parse ip address with optional cidr mask
+pub fn parse_address_or_cidr(cidr: &str) -> Result<(String, Option<u8>, bool), Error> {
+
+    lazy_static! {
+        pub static ref CIDR_V4_REGEX: Regex = Regex::new(
+            concat!(r"^(", IPV4RE!(), r")(?:/(\d{1,2}))?$")
+        ).unwrap();
+        pub static ref CIDR_V6_REGEX: Regex = Regex::new(
+            concat!(r"^(", IPV6RE!(), r")(?:/(\d{1,3}))?$")
+        ).unwrap();
+    }
+
+    if let Some(caps) = CIDR_V4_REGEX.captures(&cidr) {
+        let address = &caps[1];
+        if let Some(mask) = caps.get(2) {
+            let mask = u8::from_str_radix(mask.as_str(), 10)?;
+            check_netmask(mask, false)?;
+            Ok((address.to_string(), Some(mask), false))
+        } else {
+            Ok((address.to_string(), None, false))
+        }
+    } else if let Some(caps) = CIDR_V6_REGEX.captures(&cidr) {
+        let address = &caps[1];
+        if let Some(mask) = caps.get(2) {
+            let mask = u8::from_str_radix(mask.as_str(), 10)?;
+            check_netmask(mask, true)?;
+            Ok((address.to_string(), Some(mask), true))
+        } else {
+            Ok((address.to_string(), None, true))
+        }
+    } else {
+        bail!("invalid address/mask '{}'", cidr);
+    }
+}
+
+pub fn get_network_interfaces() -> Result<HashMap<String, bool>, Error> {
+
+    const PROC_NET_DEV: &str = "/proc/net/dev";
+
+    #[repr(C)]
+    pub struct ifreq {
+        ifr_name: [libc::c_uchar; libc::IFNAMSIZ],
+        ifru_flags: libc::c_short,
+    }
+
+    ioctl_read_bad!(get_interface_flags, libc::SIOCGIFFLAGS, ifreq);
+
+    lazy_static!{
+        static ref IFACE_LINE_REGEX: Regex = Regex::new(r"^\s*([^:\s]+):").unwrap();
+    }
+    let raw = std::fs::read_to_string(PROC_NET_DEV)
+        .map_err(|err| format_err!("unable to read {} - {}", PROC_NET_DEV, err))?;
+
+    let lines = raw.lines();
+
+    let sock = unsafe {
+        Fd::from_raw_fd(
+            socket(
+                AddressFamily::Inet,
+                SockType::Datagram,
+                SockFlag::empty(),
+                None,
+            )
+            .or_else(|_| {
+                socket(
+                    AddressFamily::Inet6,
+                    SockType::Datagram,
+                    SockFlag::empty(),
+                    None,
+                )
+            })?,
+        )
+    };
+
+    let mut interface_list = HashMap::new();
+
+    for line in lines {
+        if let Some(cap) = IFACE_LINE_REGEX.captures(line) {
+            let ifname = &cap[1];
+
+            let mut req = ifreq { ifr_name: *b"0000000000000000", ifru_flags: 0 };
+            for (i, b) in std::ffi::CString::new(ifname)?.as_bytes_with_nul().iter().enumerate() {
+                if i < (libc::IFNAMSIZ-1) { req.ifr_name[i] = *b as libc::c_uchar; }
+            }
+            let res = unsafe { get_interface_flags(sock.as_raw_fd(), &mut req)? };
+            if res != 0 {
+                bail!("ioctl get_interface_flags for '{}' failed ({})", ifname, res);
+            }
+            let is_up = (req.ifru_flags & (libc::IFF_UP as libc::c_short)) != 0;
+            interface_list.insert(ifname.to_string(), is_up);
+        }
+    }
+
+    Ok(interface_list)
+}
+
+pub fn compute_file_diff(filename: &str, shadow: &str) -> Result<String, Error> {
+
+    let output = Command::new("diff")
+        .arg("-b")
+        .arg("-u")
+        .arg(filename)
+        .arg(shadow)
+        .output()
+        .map_err(|err| format_err!("failed to execute diff - {}", err))?;
+
+    let diff = pbs_tools::command_output_as_string(output, Some(|c| c == 0 || c == 1))
+        .map_err(|err| format_err!("diff failed: {}", err))?;
+
+    Ok(diff)
+}
+
+pub fn assert_ifupdown2_installed() -> Result<(), Error> {
+    if !Path::new("/usr/share/ifupdown2").exists() {
+        bail!("ifupdown2 is not installed.");
+    }
+
+    Ok(())
+}
+
+pub fn network_reload() -> Result<(), Error> {
+
+    let output = Command::new("ifreload")
+        .arg("-a")
+        .output()
+        .map_err(|err| format_err!("failed to execute 'ifreload' - {}", err))?;
+
+    pbs_tools::command_output(output, None)
+        .map_err(|err| format_err!("ifreload failed: {}", err))?;
+
+
+    Ok(())
+}

pbs-config/src/network/lexer.rs

@@ -0,0 +1,128 @@
+use std::io::BufRead;
+use std::iter::Iterator;
+use std::collections::{HashMap, VecDeque};
+
+use lazy_static::lazy_static;
+
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum Token {
+    Text,
+    Comment,
+    DHCP,
+    Newline,
+    Address,
+    Auto,
+    Gateway,
+    Inet,
+    Inet6,
+    Iface,
+    Loopback,
+    Manual,
+    Netmask,
+    Static,
+    Attribute,
+    MTU,
+    BridgePorts,
+    BridgeVlanAware,
+    BondSlaves,
+    BondMode,
+    BondPrimary,
+    BondXmitHashPolicy,
+    EOF,
+}
+
+lazy_static! {
+    static ref KEYWORDS: HashMap<&'static str, Token> = {
+        let mut map = HashMap::new();
+        map.insert("address", Token::Address);
+        map.insert("auto", Token::Auto);
+        map.insert("dhcp", Token::DHCP);
+        map.insert("gateway", Token::Gateway);
+        map.insert("inet", Token::Inet);
+        map.insert("inet6", Token::Inet6);
+        map.insert("iface", Token::Iface);
+        map.insert("loopback", Token::Loopback);
+        map.insert("manual", Token::Manual);
+        map.insert("netmask", Token::Netmask);
+        map.insert("static", Token::Static);
+        map.insert("mtu", Token::MTU);
+        map.insert("bridge-ports", Token::BridgePorts);
+        map.insert("bridge_ports", Token::BridgePorts);
+        map.insert("bridge-vlan-aware", Token::BridgeVlanAware);
+        map.insert("bridge_vlan_aware", Token::BridgeVlanAware);
+        map.insert("bond-slaves", Token::BondSlaves);
+        map.insert("bond_slaves", Token::BondSlaves);
+        map.insert("bond-mode", Token::BondMode);
+        map.insert("bond-primary", Token::BondPrimary);
+        map.insert("bond_primary", Token::BondPrimary);
+        map.insert("bond_xmit_hash_policy", Token::BondXmitHashPolicy);
+        map.insert("bond-xmit-hash-policy", Token::BondXmitHashPolicy);
+        map
+    };
+}
+
+pub struct Lexer<R> {
+    input: R,
+    eof_count: usize,
+    cur_line: Option<VecDeque<(Token, String)>>,
+}
+
+impl <R: BufRead> Lexer<R> {
+
+    pub fn new(input: R) -> Self {
+        Self { input, eof_count: 0, cur_line: None }
+    }
+
+    fn split_line(line: &str) -> VecDeque<(Token, String)> {
+        if let Some(comment) = line.strip_prefix('#') {
+            let mut res = VecDeque::new();
+            res.push_back((Token::Comment, comment.trim().to_string()));
+            return res;
+        }
+        let mut list: VecDeque<(Token, String)> = line.split_ascii_whitespace().map(|text| {
+            let token = KEYWORDS.get(text).unwrap_or(&Token::Text);
+            (*token, text.to_string())
+        }).collect();
+
+        if line.starts_with(|c: char| c.is_ascii_whitespace() && c != '\n') {
+            list.push_front((Token::Attribute, String::from("\t")));
+        }
+        list
+    }
+}
+
+impl <R: BufRead> Iterator for Lexer<R> {
+
+    type Item = Result<(Token, String), std::io::Error>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.cur_line.is_none() {
+            let mut line = String::new();
+            match self.input.read_line(&mut line) {
+                Err(err) => return Some(Err(err)),
+                Ok(0) => {
+                    self.eof_count += 1;
+                    if self.eof_count == 1 { return Some(Ok((Token::EOF, String::new()))); }
+                    return None;
+                }
+                _ => {}
+            }
+            self.cur_line = Some(Self::split_line(&line));
+        }
+
+        match self.cur_line {
+            Some(ref mut  cur_line) => {
+                if cur_line.is_empty() {
+                    self.cur_line = None;
+                    Some(Ok((Token::Newline, String::from("\n"))))
+                } else {
+                    let (token, text) = cur_line.pop_front().unwrap();
+                    Some(Ok((token, text)))
+                }
+            }
+            None => {
+                None
+            }
+        }
+    }
+}

pbs-config/src/network/mod.rs

@@ -0,0 +1,630 @@
+use std::io::{Write};
+use std::collections::{HashSet, HashMap, BTreeMap};
+
+use anyhow::{Error, format_err, bail};
+use serde::de::{value, IntoDeserializer, Deserialize};
+use lazy_static::lazy_static;
+use regex::Regex;
+
+use proxmox::tools::{fs::replace_file, fs::CreateOptions};
+
+mod helper;
+pub use helper::*;
+
+mod lexer;
+pub use lexer::*;
+
+mod parser;
+pub use parser::*;
+
+use pbs_api_types::{Interface, NetworkConfigMethod, NetworkInterfaceType, LinuxBondMode, BondXmitHashPolicy};
+
+use crate::{open_backup_lockfile, BackupLockGuard};
+
+lazy_static!{
+    static ref PHYSICAL_NIC_REGEX: Regex = Regex::new(r"^(?:eth\d+|en[^:.]+|ib\d+)$").unwrap();
+}
+
+pub fn is_physical_nic(iface: &str) -> bool {
+    PHYSICAL_NIC_REGEX.is_match(iface)
+}
+
+pub fn bond_mode_from_str(s: &str) -> Result<LinuxBondMode, Error> {
+    LinuxBondMode::deserialize(s.into_deserializer())
+        .map_err(|_: value::Error| format_err!("invalid bond_mode '{}'", s))
+}
+
+pub fn bond_mode_to_str(mode: LinuxBondMode) -> &'static str {
+    match mode {
+        LinuxBondMode::balance_rr => "balance-rr",
+        LinuxBondMode::active_backup => "active-backup",
+        LinuxBondMode::balance_xor => "balance-xor",
+        LinuxBondMode::broadcast => "broadcast",
+        LinuxBondMode::ieee802_3ad => "802.3ad",
+        LinuxBondMode::balance_tlb => "balance-tlb",
+        LinuxBondMode::balance_alb => "balance-alb",
+    }
+}
+
+pub fn bond_xmit_hash_policy_from_str(s: &str) -> Result<BondXmitHashPolicy, Error> {
+    BondXmitHashPolicy::deserialize(s.into_deserializer())
+        .map_err(|_: value::Error| format_err!("invalid bond_xmit_hash_policy '{}'", s))
+}
+
+pub fn bond_xmit_hash_policy_to_str(policy: &BondXmitHashPolicy) -> &'static str {
+    match policy {
+        BondXmitHashPolicy::layer2 => "layer2",
+        BondXmitHashPolicy::layer2_3 => "layer2+3",
+        BondXmitHashPolicy::layer3_4 => "layer3+4",
+    }
+}
+
+// Write attributes not depending on address family
+fn write_iface_attributes(iface: &Interface, w: &mut dyn Write) -> Result<(), Error> {
+
+    static EMPTY_LIST: Vec<String> = Vec::new();
+
+    match iface.interface_type {
+        NetworkInterfaceType::Bridge => {
+            if let Some(true) = iface.bridge_vlan_aware {
+                writeln!(w, "\tbridge-vlan-aware yes")?;
+            }
+            let ports = iface.bridge_ports.as_ref().unwrap_or(&EMPTY_LIST);
+            if ports.is_empty() {
+                writeln!(w, "\tbridge-ports none")?;
+            } else {
+                writeln!(w, "\tbridge-ports {}", ports.join(" "))?;
+            }
+        }
+        NetworkInterfaceType::Bond => {
+            let mode = iface.bond_mode.unwrap_or(LinuxBondMode::balance_rr);
+            writeln!(w, "\tbond-mode {}", bond_mode_to_str(mode))?;
+            if let Some(primary) = &iface.bond_primary {
+                if mode == LinuxBondMode::active_backup {
+                    writeln!(w, "\tbond-primary {}", primary)?;
+                }
+            }
+
+            if let Some(xmit_policy) = &iface.bond_xmit_hash_policy {
+                if mode == LinuxBondMode::ieee802_3ad ||
+                    mode == LinuxBondMode::balance_xor
+                {
+                    writeln!(w, "\tbond_xmit_hash_policy {}", bond_xmit_hash_policy_to_str(xmit_policy))?;
+                }
+            }
+
+            let slaves = iface.slaves.as_ref().unwrap_or(&EMPTY_LIST);
+            if slaves.is_empty() {
+                writeln!(w, "\tbond-slaves none")?;
+            } else {
+                writeln!(w, "\tbond-slaves {}", slaves.join(" "))?;
+            }
+        }
+        _ => {}
+    }
+
+    if let Some(mtu) = iface.mtu {
+        writeln!(w, "\tmtu {}", mtu)?;
+    }
+
+    Ok(())
+}
+
+// Write attributes depending on address family inet (IPv4)
+fn write_iface_attributes_v4(iface: &Interface, w: &mut dyn Write, method: NetworkConfigMethod) -> Result<(), Error> {
+    if method == NetworkConfigMethod::Static {
+        if let Some(address) = &iface.cidr {
+            writeln!(w, "\taddress {}", address)?;
+        }
+        if let Some(gateway) = &iface.gateway {
+            writeln!(w, "\tgateway {}", gateway)?;
+        }
+    }
+
+    for option in &iface.options {
+        writeln!(w, "\t{}", option)?;
+    }
+
+    if let Some(ref comments) = iface.comments {
+        for comment in comments.lines() {
+            writeln!(w, "#{}", comment)?;
+        }
+    }
+
+    Ok(())
+}
+
+/// Write attributes depending on address family inet6 (IPv6)
+fn write_iface_attributes_v6(iface: &Interface, w: &mut dyn Write, method: NetworkConfigMethod) -> Result<(), Error> {
+    if method == NetworkConfigMethod::Static {
+        if let Some(address) = &iface.cidr6 {
+            writeln!(w, "\taddress {}", address)?;
+        }
+        if let Some(gateway) = &iface.gateway6 {
+            writeln!(w, "\tgateway {}", gateway)?;
+        }
+    }
+
+    for option in &iface.options6 {
+        writeln!(w, "\t{}", option)?;
+    }
+
+    if let Some(ref comments) = iface.comments6 {
+        for comment in comments.lines() {
+            writeln!(w, "#{}", comment)?;
+        }
+    }
+
+    Ok(())
+}
+
+fn write_iface(iface: &Interface, w: &mut dyn Write) -> Result<(), Error> {
+
+    fn method_to_str(method: NetworkConfigMethod) -> &'static str {
+        match method {
+            NetworkConfigMethod::Static => "static",
+            NetworkConfigMethod::Loopback => "loopback",
+            NetworkConfigMethod::Manual => "manual",
+            NetworkConfigMethod::DHCP => "dhcp",
+        }
+    }
+
+    if iface.method.is_none() && iface.method6.is_none() { return Ok(()); }
+
+    if iface.autostart {
+        writeln!(w, "auto {}", iface.name)?;
+    }
+
+    if let Some(method) = iface.method {
+        writeln!(w, "iface {} inet {}", iface.name, method_to_str(method))?;
+        write_iface_attributes_v4(iface, w, method)?;
+        write_iface_attributes(iface, w)?;
+        writeln!(w)?;
+    }
+
+    if let Some(method6) = iface.method6 {
+        let mut skip_v6 = false; // avoid empty inet6 manual entry
+        if iface.method.is_some()
+            && method6 == NetworkConfigMethod::Manual
+            && iface.comments6.is_none()
+            && iface.options6.is_empty()
+        {
+            skip_v6 = true;
+        }
+
+        if !skip_v6 {
+            writeln!(w, "iface {} inet6 {}", iface.name, method_to_str(method6))?;
+            write_iface_attributes_v6(iface, w, method6)?;
+            if iface.method.is_none() { // only write common attributes once
+                write_iface_attributes(iface, w)?;
+            }
+            writeln!(w)?;
+        }
+    }
+
+    Ok(())
+}
+
+#[derive(Debug)]
+enum NetworkOrderEntry {
+    Iface(String),
+    Comment(String),
+    Option(String),
+}
+
+#[derive(Debug, Default)]
+pub struct NetworkConfig {
+    pub interfaces: BTreeMap<String, Interface>,
+    order: Vec<NetworkOrderEntry>,
+}
+
+use std::convert::TryFrom;
+
+impl TryFrom<NetworkConfig> for String  {
+
+    type Error = Error;
+
+    fn try_from(config: NetworkConfig) -> Result<Self, Self::Error> {
+        let mut output = Vec::new();
+        config.write_config(&mut output)?;
+        let res = String::from_utf8(output)?;
+        Ok(res)
+    }
+}
+
+impl NetworkConfig {
+
+    pub fn new() -> Self {
+        Self {
+            interfaces: BTreeMap::new(),
+            order: Vec::new(),
+        }
+    }
+
+    pub fn lookup(&self, name: &str) -> Result<&Interface, Error> {
+        let interface = self.interfaces.get(name).ok_or_else(|| {
+            format_err!("interface '{}' does not exist.", name)
+        })?;
+        Ok(interface)
+    }
+
+    pub fn lookup_mut(&mut self, name: &str) -> Result<&mut Interface, Error> {
+        let interface = self.interfaces.get_mut(name).ok_or_else(|| {
+            format_err!("interface '{}' does not exist.", name)
+        })?;
+        Ok(interface)
+    }
+
+    /// Check if ports are used only once
+    pub fn check_port_usage(&self) -> Result<(), Error> {
+        let mut used_ports = HashMap::new();
+        let mut check_port_usage = |iface, ports: &Vec<String>| {
+            for port in ports.iter() {
+                if let Some(prev_iface) = used_ports.get(port) {
+                    bail!("iface '{}' port '{}' is already used on interface '{}'",
+                          iface, port, prev_iface);
+                }
+                used_ports.insert(port.to_string(), iface);
+            }
+            Ok(())
+        };
+
+        for (iface, interface) in self.interfaces.iter() {
+            if let Some(ports) = &interface.bridge_ports { check_port_usage(iface, ports)?; }
+            if let Some(slaves) = &interface.slaves { check_port_usage(iface, slaves)?; }
+        }
+        Ok(())
+    }
+
+    /// Check if child mtu is less or equal than parent mtu
+    pub fn check_mtu(&self, parent_name: &str, child_name: &str) -> Result<(), Error> {
+
+        let parent = self.interfaces.get(parent_name)
+            .ok_or_else(|| format_err!("check_mtu - missing parent interface '{}'", parent_name))?;
+        let child = self.interfaces.get(child_name)
+            .ok_or_else(|| format_err!("check_mtu - missing child interface '{}'", child_name))?;
+
+        let child_mtu = match child.mtu {
+            Some(mtu) => mtu,
+            None => return Ok(()),
+        };
+
+        let parent_mtu = match parent.mtu {
+            Some(mtu) => mtu,
+            None => {
+                if parent.interface_type == NetworkInterfaceType::Bond {
+                    child_mtu
+                } else {
+                    1500
+                }
+            }
+        };
+
+        if parent_mtu < child_mtu {
+            bail!("interface '{}' - mtu {} is lower than '{}' - mtu {}\n",
+                  parent_name, parent_mtu, child_name, child_mtu);
+        }
+
+        Ok(())
+    }
+
+    /// Check if bond slaves exists
+    pub fn check_bond_slaves(&self) -> Result<(), Error> {
+        for (iface, interface) in self.interfaces.iter() {
+            if let Some(slaves) = &interface.slaves {
+                for slave in slaves.iter() {
+                    match self.interfaces.get(slave) {
+                        Some(entry) => {
+                            if entry.interface_type != NetworkInterfaceType::Eth {
+                                bail!("bond '{}' - wrong interface type on slave '{}' ({:?} != {:?})",
+                                      iface, slave, entry.interface_type, NetworkInterfaceType::Eth);
+                            }
+                        }
+                        None => {
+                            bail!("bond '{}' - unable to find slave '{}'", iface, slave);
+                        }
+                    }
+                    self.check_mtu(iface, slave)?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// Check if bridge ports exists
+    pub fn check_bridge_ports(&self) -> Result<(), Error> {
+        lazy_static!{
+            static ref VLAN_INTERFACE_REGEX: Regex = Regex::new(r"^(\S+)\.(\d+)$").unwrap();
+        }
+
+        for (iface, interface) in self.interfaces.iter() {
+            if let Some(ports) = &interface.bridge_ports {
+                for port in ports.iter() {
+                    let captures = VLAN_INTERFACE_REGEX.captures(port);
+                    let port = if let Some(ref caps) = captures { &caps[1] } else { port.as_str() };
+                    if !self.interfaces.contains_key(port) {
+                        bail!("bridge '{}' - unable to find port '{}'", iface, port);
+                    }
+                    self.check_mtu(iface, port)?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    pub fn write_config(&self, w: &mut dyn Write) -> Result<(), Error> {
+
+        self.check_port_usage()?;
+        self.check_bond_slaves()?;
+        self.check_bridge_ports()?;
+
+        let mut done = HashSet::new();
+
+        let mut last_entry_was_comment = false;
+
+        for entry in self.order.iter() {
+             match entry {
+                NetworkOrderEntry::Comment(comment) => {
+                    writeln!(w, "#{}", comment)?;
+                    last_entry_was_comment = true;
+                }
+                NetworkOrderEntry::Option(option) => {
+                    if last_entry_was_comment {  writeln!(w)?; }
+                    last_entry_was_comment = false;
+                    writeln!(w, "{}", option)?;
+                    writeln!(w)?;
+                }
+                NetworkOrderEntry::Iface(name) => {
+                    let interface = match self.interfaces.get(name) {
+                        Some(interface) => interface,
+                        None => continue,
+                    };
+
+                    if last_entry_was_comment {  writeln!(w)?; }
+                    last_entry_was_comment = false;
+
+                    if done.contains(name) { continue; }
+                    done.insert(name);
+
+                    write_iface(interface, w)?;
+                }
+            }
+        }
+
+        for (name, interface) in &self.interfaces {
+            if done.contains(name) { continue; }
+            write_iface(interface, w)?;
+        }
+        Ok(())
+    }
+}
+
+pub const NETWORK_INTERFACES_FILENAME: &str = "/etc/network/interfaces";
+pub const NETWORK_INTERFACES_NEW_FILENAME: &str = "/etc/network/interfaces.new";
+pub const NETWORK_LOCKFILE: &str = "/var/lock/pve-network.lck";
+
+pub fn lock_config() -> Result<BackupLockGuard, Error> {
+    open_backup_lockfile(NETWORK_LOCKFILE, None, true)
+}
+
+pub fn config() -> Result<(NetworkConfig, [u8;32]), Error> {
+
+    let content = match proxmox::tools::fs::file_get_optional_contents(NETWORK_INTERFACES_NEW_FILENAME)? {
+        Some(content) => content,
+        None => {
+            let content = proxmox::tools::fs::file_get_optional_contents(NETWORK_INTERFACES_FILENAME)?;
+            content.unwrap_or_default()
+        }
+    };
+
+    let digest = openssl::sha::sha256(&content);
+
+    let existing_interfaces = get_network_interfaces()?;
+    let mut parser = NetworkParser::new(&content[..]);
+    let data = parser.parse_interfaces(Some(&existing_interfaces))?;
+
+    Ok((data, digest))
+}
+
+pub fn changes() -> Result<String, Error> {
+
+    if !std::path::Path::new(NETWORK_INTERFACES_NEW_FILENAME).exists() {
+        return Ok(String::new());
+    }
+
+    compute_file_diff(NETWORK_INTERFACES_FILENAME, NETWORK_INTERFACES_NEW_FILENAME)
+}
+
+pub fn save_config(config: &NetworkConfig) -> Result<(), Error> {
+
+    let mut raw = Vec::new();
+    config.write_config(&mut raw)?;
+
+    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0644);
+    // set the correct owner/group/permissions while saving file
+    // owner(rw) = root, group(r)=root, others(r)
+    let options = CreateOptions::new()
+        .perm(mode)
+        .owner(nix::unistd::ROOT)
+        .group(nix::unistd::Gid::from_raw(0));
+
+    replace_file(NETWORK_INTERFACES_NEW_FILENAME, &raw, options)?;
+
+    Ok(())
+}
+
+// shell completion helper
+pub fn complete_interface_name(_arg: &str, _param: &HashMap<String, String>) -> Vec<String> {
+    match config() {
+        Ok((data, _digest)) => data.interfaces.keys().map(|id| id.to_string()).collect(),
+        Err(_) => return vec![],
+    }
+}
+
+
+pub fn complete_port_list(arg: &str, _param: &HashMap<String, String>) -> Vec<String> {
+    let mut ports = Vec::new();
+    match config() {
+        Ok((data, _digest)) => {
+            for (iface, interface) in data.interfaces.iter() {
+                if interface.interface_type == NetworkInterfaceType::Eth {
+                    ports.push(iface.to_string());
+                }
+            }
+        }
+        Err(_) => return vec![],
+    };
+
+    let arg = arg.trim();
+    let prefix = if let Some(idx) = arg.rfind(',') { &arg[..idx+1] } else { "" };
+    ports.iter().map(|port| format!("{}{}", prefix, port)).collect()
+}
+
+#[cfg(test)]
+mod test {
+
+    use anyhow::{Error};
+
+    use super::*;
+
+    #[test]
+    fn test_network_config_create_lo_1() -> Result<(), Error> {
+
+        let input = "";
+
+        let mut parser = NetworkParser::new(&input.as_bytes()[..]);
+
+        let config = parser.parse_interfaces(None)?;
+
+        let output = String::try_from(config)?;
+
+        let expected = "auto lo\niface lo inet loopback\n\n";
+        assert_eq!(output, expected);
+
+        // run again using output as input
+        let mut parser = NetworkParser::new(&output.as_bytes()[..]);
+
+        let config = parser.parse_interfaces(None)?;
+
+        let output = String::try_from(config)?;
+
+        assert_eq!(output, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_network_config_create_lo_2() -> Result<(), Error> {
+
+        let input = "#c1\n\n#c2\n\niface test inet manual\n";
+
+        let mut parser = NetworkParser::new(&input.as_bytes()[..]);
+
+        let config = parser.parse_interfaces(None)?;
+
+        let output = String::try_from(config)?;
+
+        // Note: loopback should be added in front of other interfaces
+        let expected = "#c1\n#c2\n\nauto lo\niface lo inet loopback\n\niface test inet manual\n\n";
+        assert_eq!(output, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_network_config_parser_no_blank_1() -> Result<(), Error> {
+        let input = "auto lo\n\
+                     iface lo inet loopback\n\
+                     iface lo inet6 loopback\n\
+                     auto ens18\n\
+                     iface ens18 inet static\n\
+                     \taddress 192.168.20.144/20\n\
+                     \tgateway 192.168.16.1\n\
+                     # comment\n\
+                     iface ens20 inet static\n\
+                     \taddress 192.168.20.145/20\n\
+                     iface ens21 inet manual\n\
+                     iface ens22 inet manual\n";
+
+        let mut parser = NetworkParser::new(&input.as_bytes()[..]);
+
+        let config = parser.parse_interfaces(None)?;
+
+        let output = String::try_from(config)?;
+
+        let expected = "auto lo\n\
+                        iface lo inet loopback\n\
+                        \n\
+                        iface lo inet6 loopback\n\
+                        \n\
+                        auto ens18\n\
+                        iface ens18 inet static\n\
+                        \taddress 192.168.20.144/20\n\
+                        \tgateway 192.168.16.1\n\
+                        #comment\n\
+                        \n\
+                        iface ens20 inet static\n\
+                        \taddress 192.168.20.145/20\n\
+                        \n\
+                        iface ens21 inet manual\n\
+                        \n\
+                        iface ens22 inet manual\n\
+                        \n";
+        assert_eq!(output, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_network_config_parser_no_blank_2() -> Result<(), Error> {
+        // Adapted from bug 2926
+        let input = "### Hetzner Online GmbH installimage\n\
+                     \n\
+                     source /etc/network/interfaces.d/*\n\
+                     \n\
+                     auto lo\n\
+                     iface lo inet loopback\n\
+                     iface lo inet6 loopback\n\
+                     \n\
+                     auto enp4s0\n\
+                     iface enp4s0 inet static\n\
+                     \taddress 10.10.10.10/24\n\
+                     \tgateway 10.10.10.1\n\
+                     \t# route 10.10.20.10/24 via 10.10.20.1\n\
+                     \tup route add -net 10.10.20.10 netmask 255.255.255.0 gw 10.10.20.1 dev enp4s0\n\
+                     \n\
+                     iface enp4s0 inet6 static\n\
+                     \taddress fe80::5496:35ff:fe99:5a6a/64\n\
+                     \tgateway fe80::1\n";
+
+        let mut parser = NetworkParser::new(&input.as_bytes()[..]);
+
+        let config = parser.parse_interfaces(None)?;
+
+        let output = String::try_from(config)?;
+
+        let expected = "### Hetzner Online GmbH installimage\n\
+                        \n\
+                        source /etc/network/interfaces.d/*\n\
+                        \n\
+                        auto lo\n\
+                        iface lo inet loopback\n\
+                        \n\
+                        iface lo inet6 loopback\n\
+                        \n\
+                        auto enp4s0\n\
+                        iface enp4s0 inet static\n\
+                        \taddress 10.10.10.10/24\n\
+                        \tgateway 10.10.10.1\n\
+                        \t# route 10.10.20.10/24 via 10.10.20.1\n\
+                        \tup route add -net 10.10.20.10 netmask 255.255.255.0 gw 10.10.20.1 dev enp4s0\n\
+                        \n\
+                        iface enp4s0 inet6 static\n\
+                        \taddress fe80::5496:35ff:fe99:5a6a/64\n\
+                        \tgateway fe80::1\n\
+                        \n";
+        assert_eq!(output, expected);
+
+        Ok(())
+    }
+}

pbs-config/src/network/parser.rs

@@ -0,0 +1,568 @@
+use std::io::{BufRead};
+use std::iter::{Peekable, Iterator};
+use std::collections::{HashMap, HashSet};
+
+use anyhow::{Error, bail, format_err};
+use lazy_static::lazy_static;
+use regex::Regex;
+
+use super::helper::*;
+use super::lexer::*;
+
+use super::{NetworkConfig, NetworkOrderEntry, Interface, NetworkConfigMethod, NetworkInterfaceType, bond_mode_from_str, bond_xmit_hash_policy_from_str};
+
+fn set_method_v4(iface: &mut Interface, method: NetworkConfigMethod) -> Result<(), Error> {
+    if iface.method.is_none() {
+        iface.method = Some(method);
+    } else {
+        bail!("inet configuration method already set.");
+    }
+    Ok(())
+}
+
+fn set_method_v6(iface: &mut Interface, method: NetworkConfigMethod) -> Result<(), Error> {
+    if iface.method6.is_none() {
+        iface.method6 = Some(method);
+    } else {
+        bail!("inet6 configuration method already set.");
+    }
+    Ok(())
+}
+
+fn set_cidr_v4(iface: &mut Interface, address: String) -> Result<(), Error> {
+    if iface.cidr.is_none() {
+        iface.cidr = Some(address);
+    } else {
+        bail!("duplicate IPv4 address.");
+    }
+    Ok(())
+}
+
+fn set_gateway_v4(iface: &mut Interface, gateway: String) -> Result<(), Error> {
+    if iface.gateway.is_none() {
+        iface.gateway = Some(gateway);
+    } else {
+        bail!("duplicate IPv4 gateway.");
+    }
+    Ok(())
+}
+
+fn set_cidr_v6(iface: &mut Interface, address: String) -> Result<(), Error> {
+    if iface.cidr6.is_none() {
+        iface.cidr6 = Some(address);
+    } else {
+        bail!("duplicate IPv6 address.");
+    }
+    Ok(())
+}
+
+fn set_gateway_v6(iface: &mut Interface, gateway: String) -> Result<(), Error> {
+    if iface.gateway6.is_none() {
+        iface.gateway6 = Some(gateway);
+    } else {
+        bail!("duplicate IPv4 gateway.");
+    }
+    Ok(())
+}
+
+fn set_interface_type(iface: &mut Interface, interface_type: NetworkInterfaceType) -> Result<(), Error> {
+    if iface.interface_type == NetworkInterfaceType::Unknown {
+        iface.interface_type = interface_type;
+    } else if iface.interface_type != interface_type {
+        bail!("interface type already defined - cannot change from {:?} to {:?}", iface.interface_type, interface_type);
+    }
+    Ok(())
+}
+
+pub struct NetworkParser<R: BufRead> {
+    input: Peekable<Lexer<R>>,
+    line_nr: usize,
+}
+
+impl <R: BufRead> NetworkParser<R> {
+
+    pub fn new(reader: R) -> Self {
+        let input = Lexer::new(reader).peekable();
+        Self { input, line_nr: 1 }
+    }
+
+    fn peek(&mut self) -> Result<Token, Error> {
+        match self.input.peek() {
+            Some(Err(err)) => {
+                bail!("input error - {}", err);
+            }
+            Some(Ok((token, _))) => {
+                Ok(*token)
+            }
+            None => {
+                bail!("got unexpected end of stream (inside peek)");
+            }
+        }
+    }
+
+    fn next(&mut self) -> Result<(Token, String), Error> {
+        match self.input.next() {
+            Some(Err(err)) => {
+                bail!("input error - {}", err);
+            }
+            Some(Ok((token, text))) => {
+                if token == Token::Newline { self.line_nr += 1; }
+                Ok((token, text))
+            }
+            None => {
+                bail!("got unexpected end of stream (inside peek)");
+            }
+        }
+    }
+
+    fn next_text(&mut self) -> Result<String, Error> {
+        match self.next()? {
+            (Token::Text, text) => Ok(text),
+            (unexpected, _) => bail!("got unexpected token {:?} (expecting Text)", unexpected),
+        }
+    }
+
+    fn eat(&mut self, expected: Token) -> Result<String, Error> {
+        let (next, text) = self.next()?;
+        if next != expected {
+            bail!("expected {:?}, got {:?}", expected, next);
+        }
+        Ok(text)
+    }
+
+    fn parse_auto(&mut self, auto_flag: &mut HashSet<String>) -> Result<(), Error> {
+        self.eat(Token::Auto)?;
+
+        loop {
+            match self.next()? {
+                (Token::Text, iface) => {
+                     auto_flag.insert(iface.to_string());
+                }
+                (Token::Newline, _) => break,
+                unexpected => {
+                    bail!("expected {:?}, got {:?}", Token::Text, unexpected);
+                }
+            }
+
+        }
+
+        Ok(())
+    }
+
+    fn parse_netmask(&mut self) -> Result<u8, Error> {
+        self.eat(Token::Netmask)?;
+        let netmask = self.next_text()?;
+
+        let mask = if let Some(mask) = IPV4_MASK_HASH_LOCALNET.get(netmask.as_str())  {
+            *mask
+        } else {
+            match u8::from_str_radix(netmask.as_str(), 10) {
+                Ok(mask) => mask,
+                Err(err) => {
+                    bail!("unable to parse netmask '{}' - {}", netmask, err);
+                }
+            }
+        };
+
+        self.eat(Token::Newline)?;
+
+        Ok(mask)
+    }
+
+    fn parse_iface_address(&mut self) -> Result<(String, Option<u8>, bool), Error> {
+        self.eat(Token::Address)?;
+        let cidr = self.next_text()?;
+
+        let (_address, mask, ipv6) = parse_address_or_cidr(&cidr)?;
+
+        self.eat(Token::Newline)?;
+
+        Ok((cidr, mask, ipv6))
+    }
+
+    fn parse_iface_gateway(&mut self, interface: &mut Interface) -> Result<(), Error> {
+        self.eat(Token::Gateway)?;
+        let gateway = self.next_text()?;
+
+        if proxmox::tools::common_regex::IP_REGEX.is_match(&gateway) {
+            if gateway.contains(':') {
+                set_gateway_v6(interface, gateway)?;
+            } else {
+                set_gateway_v4(interface, gateway)?;
+            }
+        } else {
+            bail!("unable to parse gateway address");
+        }
+
+        self.eat(Token::Newline)?;
+
+        Ok(())
+    }
+
+    fn parse_iface_mtu(&mut self) -> Result<u64, Error> {
+        self.eat(Token::MTU)?;
+
+        let mtu = self.next_text()?;
+        let mtu = match u64::from_str_radix(&mtu, 10) {
+            Ok(mtu) => mtu,
+            Err(err) => {
+                bail!("unable to parse mtu value '{}' - {}", mtu, err);
+            }
+        };
+
+        self.eat(Token::Newline)?;
+
+        Ok(mtu)
+    }
+
+    fn parse_yes_no(&mut self) -> Result<bool, Error> {
+        let text = self.next_text()?;
+        let value = match text.to_lowercase().as_str() {
+            "yes" => true,
+            "no" => false,
+            _ => {
+                bail!("unable to bool value '{}' - (expected yes/no)", text);
+            }
+        };
+
+        self.eat(Token::Newline)?;
+
+        Ok(value)
+    }
+
+    fn parse_to_eol(&mut self) -> Result<String, Error> {
+        let mut line = String::new();
+        loop {
+            match self.next()? {
+                (Token::Newline, _) => return Ok(line),
+                (_, text) => {
+                    if !line.is_empty() { line.push(' '); }
+                    line.push_str(&text);
+                }
+            }
+        }
+    }
+
+    fn parse_iface_list(&mut self) -> Result<Vec<String>, Error> {
+        let mut list = Vec::new();
+
+        loop {
+            let (token, text) = self.next()?;
+            match token {
+                Token::Newline => break,
+                Token::Text => {
+                    if &text != "none" {
+                        list.push(text);
+                    }
+                }
+                _ => bail!("unable to parse interface list - unexpected token '{:?}'", token),
+            }
+        }
+
+        Ok(list)
+    }
+
+    fn parse_iface_attributes(
+        &mut self,
+        interface: &mut Interface,
+        address_family_v4: bool,
+        address_family_v6: bool,
+    ) -> Result<(), Error> {
+
+        let mut netmask = None;
+        let mut address_list = Vec::new();
+
+        loop {
+            match self.peek()? {
+                Token::Attribute => { self.eat(Token::Attribute)?; },
+                Token::Comment => {
+                    let comment = self.eat(Token::Comment)?;
+                    if !address_family_v4 && address_family_v6 {
+                        let mut comments = interface.comments6.take().unwrap_or_default();
+                        if !comments.is_empty() { comments.push('\n'); }
+                        comments.push_str(&comment);
+                        interface.comments6 = Some(comments);
+                    } else {
+                        let mut comments = interface.comments.take().unwrap_or_default();
+                        if !comments.is_empty() { comments.push('\n'); }
+                        comments.push_str(&comment);
+                        interface.comments = Some(comments);
+                    }
+                    self.eat(Token::Newline)?;
+                    continue;
+                }
+                _ => break,
+            }
+
+            match self.peek()? {
+                Token::Address => {
+                    let (cidr, mask, is_v6) = self.parse_iface_address()?;
+                    address_list.push((cidr, mask, is_v6));
+                }
+                Token::Gateway => self.parse_iface_gateway(interface)?,
+                Token::Netmask => {
+                    //Note: netmask is deprecated, but we try to do our best
+                    netmask = Some(self.parse_netmask()?);
+                }
+                Token::MTU => {
+                    let mtu = self.parse_iface_mtu()?;
+                    interface.mtu = Some(mtu);
+                }
+                Token::BridgeVlanAware => {
+                    self.eat(Token::BridgeVlanAware)?;
+                    let bridge_vlan_aware = self.parse_yes_no()?;
+                    interface.bridge_vlan_aware = Some(bridge_vlan_aware);
+                }
+                Token::BridgePorts => {
+                    self.eat(Token::BridgePorts)?;
+                    let ports = self.parse_iface_list()?;
+                    interface.bridge_ports = Some(ports);
+                    set_interface_type(interface, NetworkInterfaceType::Bridge)?;
+                }
+                Token::BondSlaves => {
+                    self.eat(Token::BondSlaves)?;
+                    let slaves = self.parse_iface_list()?;
+                    interface.slaves = Some(slaves);
+                    set_interface_type(interface, NetworkInterfaceType::Bond)?;
+                }
+                Token::BondMode => {
+                    self.eat(Token::BondMode)?;
+                    let mode = self.next_text()?;
+                    interface.bond_mode = Some(bond_mode_from_str(&mode)?);
+                    self.eat(Token::Newline)?;
+                }
+                Token::BondPrimary => {
+                    self.eat(Token::BondPrimary)?;
+                    let primary = self.next_text()?;
+                    interface.bond_primary = Some(primary);
+                    self.eat(Token::Newline)?;
+                }
+                Token::BondXmitHashPolicy => {
+                    self.eat(Token::BondXmitHashPolicy)?;
+                    let policy = bond_xmit_hash_policy_from_str(&self.next_text()?)?;
+                    interface.bond_xmit_hash_policy = Some(policy);
+                    self.eat(Token::Newline)?;
+                }
+                _ => { // parse addon attributes
+                    let option = self.parse_to_eol()?;
+                    if !option.is_empty() {
+                        if !address_family_v4 && address_family_v6 {
+                            interface.options6.push(option);
+                        } else {
+                            interface.options.push(option);
+                        }
+                   };
+                 },
+            }
+        }
+
+        #[allow(clippy::comparison_chain)]
+        if let Some(netmask) = netmask {
+            if address_list.len() > 1 {
+                bail!("unable to apply netmask to multiple addresses (please use cidr notation)");
+            } else if address_list.len() == 1 {
+                let (mut cidr, mask, is_v6) = address_list.pop().unwrap();
+                if mask.is_some()  {
+                    // address already has a mask  - ignore netmask
+                } else {
+                    check_netmask(netmask, is_v6)?;
+                    cidr.push_str(&format!("/{}", netmask));
+                }
+                if is_v6 {
+                    set_cidr_v6(interface, cidr)?;
+                } else {
+                    set_cidr_v4(interface, cidr)?;
+                }
+            } else {
+                // no address - simply ignore useless netmask
+            }
+        } else {
+            for (cidr, mask, is_v6) in address_list {
+                if mask.is_none() {
+                    bail!("missing netmask in '{}'", cidr);
+                }
+                if is_v6 {
+                    set_cidr_v6(interface, cidr)?;
+                } else {
+                    set_cidr_v4(interface, cidr)?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn parse_iface(&mut self, config: &mut NetworkConfig) -> Result<(), Error> {
+        self.eat(Token::Iface)?;
+        let iface = self.next_text()?;
+
+        let mut address_family_v4 = false;
+        let mut address_family_v6 = false;
+        let mut config_method = None;
+
+        loop {
+            let (token, text) = self.next()?;
+            match token {
+                Token::Newline => break,
+                Token::Inet => address_family_v4 = true,
+                Token::Inet6 => address_family_v6 = true,
+                Token::Loopback => config_method = Some(NetworkConfigMethod::Loopback),
+                Token::Static => config_method = Some(NetworkConfigMethod::Static),
+                Token::Manual => config_method = Some(NetworkConfigMethod::Manual),
+                Token::DHCP => config_method = Some(NetworkConfigMethod::DHCP),
+                _ => bail!("unknown iface option {}", text),
+            }
+        }
+
+        let config_method = config_method.unwrap_or(NetworkConfigMethod::Static);
+
+        if !(address_family_v4 || address_family_v6) {
+            address_family_v4 = true;
+            address_family_v6 = true;
+        }
+
+        if let Some(mut interface) = config.interfaces.get_mut(&iface) {
+            if address_family_v4 {
+                set_method_v4(interface, config_method)?;
+            }
+            if address_family_v6 {
+                set_method_v6(interface, config_method)?;
+            }
+
+            self.parse_iface_attributes(&mut interface, address_family_v4, address_family_v6)?;
+        } else {
+            let mut interface = Interface::new(iface.clone());
+            if address_family_v4 {
+                set_method_v4(&mut interface, config_method)?;
+            }
+            if address_family_v6 {
+                set_method_v6(&mut interface, config_method)?;
+            }
+
+            self.parse_iface_attributes(&mut interface, address_family_v4, address_family_v6)?;
+
+            config.interfaces.insert(interface.name.clone(), interface);
+
+            config.order.push(NetworkOrderEntry::Iface(iface));
+        }
+
+        Ok(())
+    }
+
+    pub fn parse_interfaces(&mut self, existing_interfaces: Option<&HashMap<String, bool>>) -> Result<NetworkConfig, Error> {
+        self._parse_interfaces(existing_interfaces)
+            .map_err(|err| format_err!("line {}: {}", self.line_nr, err))
+    }
+
+    pub fn _parse_interfaces(&mut self, existing_interfaces: Option<&HashMap<String, bool>>) -> Result<NetworkConfig, Error> {
+        let mut config = NetworkConfig::new();
+
+        let mut auto_flag: HashSet<String> = HashSet::new();
+
+        loop {
+            match self.peek()? {
+                Token::EOF => {
+                    break;
+                }
+                Token::Newline => {
+                    // skip empty lines
+                    self.eat(Token::Newline)?;
+                }
+                Token::Comment => {
+                    let (_, text) = self.next()?;
+                    config.order.push(NetworkOrderEntry::Comment(text));
+                    self.eat(Token::Newline)?;
+                }
+                Token::Auto => {
+                    self.parse_auto(&mut auto_flag)?;
+                }
+                Token::Iface => {
+                    self.parse_iface(&mut config)?;
+                }
+                _ => {
+                    let option = self.parse_to_eol()?;
+                    if !option.is_empty() {
+                        config.order.push(NetworkOrderEntry::Option(option));
+                    }
+                }
+            }
+        }
+
+        for iface in auto_flag.iter() {
+            if let Some(interface) = config.interfaces.get_mut(iface) {
+                interface.autostart = true;
+            }
+        }
+
+        lazy_static!{
+            static ref INTERFACE_ALIAS_REGEX: Regex = Regex::new(r"^\S+:\d+$").unwrap();
+            static ref VLAN_INTERFACE_REGEX: Regex = Regex::new(r"^\S+\.\d+$").unwrap();
+        }
+
+        if let Some(existing_interfaces) = existing_interfaces {
+            for (iface, active) in existing_interfaces.iter()  {
+                if let Some(interface) = config.interfaces.get_mut(iface) {
+                    interface.active = *active;
+                    if interface.interface_type == NetworkInterfaceType::Unknown && super::is_physical_nic(iface) {
+                        interface.interface_type = NetworkInterfaceType::Eth;
+                    }
+                } else if super::is_physical_nic(iface) { // also add all physical NICs
+                    let mut interface = Interface::new(iface.clone());
+                    set_method_v4(&mut interface, NetworkConfigMethod::Manual)?;
+                    interface.interface_type = NetworkInterfaceType::Eth;
+                    interface.active = *active;
+                    config.interfaces.insert(interface.name.clone(), interface);
+                    config.order.push(NetworkOrderEntry::Iface(iface.to_string()));
+                }
+            }
+        }
+
+        for (name, interface) in config.interfaces.iter_mut() {
+            if interface.interface_type != NetworkInterfaceType::Unknown { continue; }
+            if name == "lo" {
+                interface.interface_type = NetworkInterfaceType::Loopback;
+                continue;
+            }
+            if INTERFACE_ALIAS_REGEX.is_match(name) {
+                interface.interface_type = NetworkInterfaceType::Alias;
+                continue;
+            }
+            if VLAN_INTERFACE_REGEX.is_match(name) {
+                interface.interface_type = NetworkInterfaceType::Vlan;
+                continue;
+            }
+            if super::is_physical_nic(name) {
+                interface.interface_type = NetworkInterfaceType::Eth;
+                continue;
+            }
+        }
+
+        if config.interfaces.get("lo").is_none() {
+            let mut interface = Interface::new(String::from("lo"));
+            set_method_v4(&mut interface, NetworkConfigMethod::Loopback)?;
+            interface.interface_type = NetworkInterfaceType::Loopback;
+            interface.autostart = true;
+            config.interfaces.insert(interface.name.clone(), interface);
+
+            // Note: insert 'lo' as first interface after initial comments
+            let mut new_order = Vec::new();
+            let mut added_lo = false;
+            for entry in config.order {
+                if added_lo { new_order.push(entry); continue; } // copy the rest
+                match entry {
+                    NetworkOrderEntry::Comment(_) => {
+                        new_order.push(entry);
+                     }
+                    _ => {
+                        new_order.push(NetworkOrderEntry::Iface(String::from("lo")));
+                        added_lo = true;
+                        new_order.push(entry);
+                    }
+                }
+            }
+            config.order = new_order;
+        }
+
+        Ok(config)
+    }
+}