Netavark: nftables support

Adds an nftables firewall backend and tests for said backend.
Implements basic forwarding, port forwarding, and teardown for
all relevant rules. Heavily based on our existing iptables driver
but with a number of improvements (we live in a dedicated table,
so this should play much more nicely with other tools using the
firewall; IPv4 and IPv6 share a table and almost all code; and
rule structure is a bit simpler because we do have our own table
and don't have to worry about cluttering up the FORWARD chain,
we'll the the only ones using it.

This implementation presently does not support isolation; that
will be added in a followon.

Fixes #816

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

Author: mheon

Cargo.lock

@@ -49,6 +49,7 @@ sha2 = "0.10.8"
 netlink-packet-utils = "0.5.2"
 netlink-packet-route = "0.18.1"
 netlink-packet-core = "0.7.0"
+nftables = "0.2.4"
 fs2 = "0.4.3"
 netlink-sys = "0.8.5"
 tokio = { version = "1.35", features = ["rt", "rt-multi-thread", "signal", "fs"] }

Cargo.toml

@@ -81,6 +81,11 @@ pub enum NetavarkError {
     DHCPProxy(tonic::Status),
 
     List(NetavarkErrorList),
+
+    Nftables(nftables::helper::NftablesError),
+
+    SubnetParse(ipnet::AddrParseError),
+    AddrParse(std::net::AddrParseError),
 }
 
 /// Internal struct for JSON output
@@ -160,6 +165,9 @@ impl fmt::Display for NetavarkError {
                     Ok(())
                 }
             }
+            NetavarkError::Nftables(e) => write!(f, "nftables error: {e}"),
+            NetavarkError::SubnetParse(e) => write!(f, "parsing IP subnet error: {e}"),
+            NetavarkError::AddrParse(e) => write!(f, "parsing IP address error: {e}"),
         }
     }
 }
@@ -213,3 +221,21 @@ impl From<tonic::Status> for NetavarkError {
         NetavarkError::DHCPProxy(err)
     }
 }
+
+impl From<nftables::helper::NftablesError> for NetavarkError {
+    fn from(err: nftables::helper::NftablesError) -> Self {
+        NetavarkError::Nftables(err)
+    }
+}
+
+impl From<ipnet::AddrParseError> for NetavarkError {
+    fn from(err: ipnet::AddrParseError) -> Self {
+        NetavarkError::SubnetParse(err)
+    }
+}
+
+impl From<std::net::AddrParseError> for NetavarkError {
+    fn from(err: std::net::AddrParseError) -> Self {
+        NetavarkError::AddrParse(err)
+    }
+}

src/error/mod.rs

@@ -4,7 +4,7 @@ use crate::network::internal_types;
 use crate::network::internal_types::{PortForwardConfig, TearDownNetwork, TeardownPortForward};
 use crate::network::types::PortMapping;
 use core::convert::TryFrom;
-use log::{debug, info};
+use log::{debug, info, warn};
 use std::collections::HashMap;
 use std::vec::Vec;
 use zbus::{
@@ -679,3 +679,70 @@ fn make_port_tuple(port: &PortMapping, addr: &str) -> (String, String, String, S
         to_return
     }
 }
+
+/// Check if firewalld is running.
+/// Not used within the firewalld driver, but by other drivers that may need to
+/// interact with firewalld.
+pub fn is_firewalld_running(conn: &Connection) -> bool {
+    conn.call_method(
+        Some("org.freedesktop.DBus"),
+        "/org/freedesktop/DBus",
+        Some("org.freedesktop.DBus"),
+        "GetNameOwner",
+        &"org.fedoraproject.FirewallD1",
+    )
+    .is_ok()
+}
+
+/// If possible, add a firewalld rule to allow traffic.
+/// Ignore all errors, beyond possibly logging them.
+/// Not used within the firewalld driver, but by other drivers that may need to
+/// interact with firewalld.
+pub fn add_firewalld_if_possible(net: &ipnet::IpNet) {
+    let conn = match Connection::system() {
+        Ok(conn) => conn,
+        Err(_) => return,
+    };
+    if !is_firewalld_running(&conn) {
+        return;
+    }
+    debug!("Adding firewalld rules for network {}", net.to_string());
+
+    match add_source_subnets_to_zone(&conn, "trusted", &[*net]) {
+        Ok(_) => {}
+        Err(e) => warn!(
+            "Error adding subnet {} from firewalld trusted zone: {}",
+            net.to_string(),
+            e
+        ),
+    }
+}
+
+/// If possible, remove a firewalld rule to allow traffic.
+/// Ignore all errors, beyond possibly logging them.
+/// Not used within the firewalld driver, but by other drivers that may need to
+/// interact with firewalld.
+pub fn rm_firewalld_if_possible(net: &ipnet::IpNet) {
+    let conn = match Connection::system() {
+        Ok(conn) => conn,
+        Err(_) => return,
+    };
+    if !is_firewalld_running(&conn) {
+        return;
+    }
+    debug!("Removing firewalld rules for IPs {}", net.to_string());
+    match conn.call_method(
+        Some("org.fedoraproject.FirewallD1"),
+        "/org/fedoraproject/FirewallD1",
+        Some("org.fedoraproject.FirewallD1.zone"),
+        "removeSource",
+        &("trusted", net.to_string()),
+    ) {
+        Ok(_) => {}
+        Err(e) => warn!(
+            "Error removing subnet {} from firewalld trusted zone: {}",
+            net.to_string(),
+            e
+        ),
+    };
+}

src/firewall/firewalld.rs

@@ -10,8 +10,6 @@ use crate::network::internal_types::{
 };
 use iptables;
 use iptables::IPTables;
-use log::{debug, warn};
-use zbus::blocking::Connection;
 
 pub(crate) const MAX_HASH_SIZE: usize = 13;
 
@@ -64,7 +62,7 @@ impl firewall::FirewallDriver for IptablesDriver {
 
                 create_network_chains(chains)?;
 
-                add_firewalld_if_possible(&network);
+                firewalld::add_firewalld_if_possible(&network);
             }
         }
         Ok(())
@@ -106,7 +104,7 @@ impl firewall::FirewallDriver for IptablesDriver {
                 }
 
                 if tear.complete_teardown {
-                    rm_firewalld_if_possible(&network)
+                    firewalld::rm_firewalld_if_possible(&network)
                 }
             }
         }
@@ -216,64 +214,3 @@ impl firewall::FirewallDriver for IptablesDriver {
         Result::Ok(())
     }
 }
-
-/// Check if firewalld is running
-fn is_firewalld_running(conn: &Connection) -> bool {
-    conn.call_method(
-        Some("org.freedesktop.DBus"),
-        "/org/freedesktop/DBus",
-        Some("org.freedesktop.DBus"),
-        "GetNameOwner",
-        &"org.fedoraproject.FirewallD1",
-    )
-    .is_ok()
-}
-
-/// If possible, add a firewalld rule to allow traffic.
-/// Ignore all errors, beyond possibly logging them.
-fn add_firewalld_if_possible(net: &ipnet::IpNet) {
-    let conn = match Connection::system() {
-        Ok(conn) => conn,
-        Err(_) => return,
-    };
-    if !is_firewalld_running(&conn) {
-        return;
-    }
-    debug!("Adding firewalld rules for network {}", net.to_string());
-
-    match firewalld::add_source_subnets_to_zone(&conn, "trusted", &[*net]) {
-        Ok(_) => {}
-        Err(e) => warn!(
-            "Error adding subnet {} from firewalld trusted zone: {}",
-            net.to_string(),
-            e
-        ),
-    }
-}
-
-// If possible, remove a firewalld rule to allow traffic.
-// Ignore all errors, beyond possibly logging them.
-fn rm_firewalld_if_possible(net: &ipnet::IpNet) {
-    let conn = match Connection::system() {
-        Ok(conn) => conn,
-        Err(_) => return,
-    };
-    if !is_firewalld_running(&conn) {
-        return;
-    }
-    debug!("Removing firewalld rules for IPs {}", net.to_string());
-    match conn.call_method(
-        Some("org.fedoraproject.FirewallD1"),
-        "/org/fedoraproject/FirewallD1",
-        Some("org.fedoraproject.FirewallD1.zone"),
-        "removeSource",
-        &("trusted", net.to_string()),
-    ) {
-        Ok(_) => {}
-        Err(e) => warn!(
-            "Error removing subnet {} from firewalld trusted zone: {}",
-            net.to_string(),
-            e
-        ),
-    };
-}

src/firewall/iptables.rs

@@ -8,6 +8,7 @@ use zbus::blocking::Connection;
 pub mod firewalld;
 pub mod fwnone;
 pub mod iptables;
+pub mod nft;
 pub mod state;
 mod varktables;
 
@@ -108,9 +109,7 @@ pub fn get_supported_firewall_driver(
             }
             FirewallImpl::Nftables => {
                 info!("Using nftables firewall driver");
-                Err(NetavarkError::msg(
-                    "nftables support presently not available",
-                ))
+                nft::new()
             }
             FirewallImpl::Fwnone => {
                 info!("Not using firewall");