pub mod error;
use error::IptablesError;
use lazy_static::lazy_static;
use nix::fcntl::{flock, FlockArg};
use regex::{Match, Regex};
use std::convert::From;
use std::error::Error;
use std::ffi::OsStr;
use std::fs::File;
use std::os::unix::io::AsRawFd;
use std::process::{Command, Output};
use std::vec::Vec;
const BUILTIN_CHAINS_FILTER: &[&str] = &["INPUT", "FORWARD", "OUTPUT"];
const BUILTIN_CHAINS_MANGLE: &[&str] = &["PREROUTING", "OUTPUT", "INPUT", "FORWARD", "POSTROUTING"];
const BUILTIN_CHAINS_NAT: &[&str] = &["PREROUTING", "POSTROUTING", "OUTPUT"];
const BUILTIN_CHAINS_RAW: &[&str] = &["PREROUTING", "OUTPUT"];
const BUILTIN_CHAINS_SECURITY: &[&str] = &["INPUT", "OUTPUT", "FORWARD"];
lazy_static! {
static ref RE_SPLIT: Regex = Regex::new(r#"["'].+?["']|[^ ]+"#).unwrap();
}
trait SplitQuoted {
fn split_quoted(&self) -> Vec<&str>;
}
impl SplitQuoted for str {
fn split_quoted(&self) -> Vec<&str> {
RE_SPLIT
.find_iter(self)
.map(|m| Match::as_str(&m))
.map(|s| s.trim_matches(|c| c == '"' || c == '\''))
.collect::<Vec<_>>()
}
}
fn error_from_str(msg: &str) -> Box<dyn Error> {
msg.into()
}
fn output_to_result(output: Output) -> Result<(), Box<dyn Error>> {
if !output.status.success() {
return Err(Box::new(IptablesError::from(output)));
}
Ok(())
}
fn get_builtin_chains(table: &str) -> Result<&[&str], Box<dyn Error>> {
match table {
"filter" => Ok(BUILTIN_CHAINS_FILTER),
"mangle" => Ok(BUILTIN_CHAINS_MANGLE),
"nat" => Ok(BUILTIN_CHAINS_NAT),
"raw" => Ok(BUILTIN_CHAINS_RAW),
"security" => Ok(BUILTIN_CHAINS_SECURITY),
_ => Err(error_from_str("given table is not supported by iptables")),
}
}
pub struct IPTables {
pub cmd: &'static str,
pub has_check: bool,
pub has_wait: bool,
pub is_numeric: bool,
}
#[cfg(not(target_os = "linux"))]
pub fn new(is_ipv6: bool) -> Result<IPTables, Box<dyn Error>> {
Err(error_from_str("iptables only works on Linux"))
}
#[cfg(target_os = "linux")]
pub fn new(is_ipv6: bool) -> Result<IPTables, Box<dyn Error>> {
let cmd = if is_ipv6 { "ip6tables" } else { "iptables" };
let version_output = Command::new(cmd).arg("--version").output()?;
let re = Regex::new(r"v(\d+)\.(\d+)\.(\d+)")?;
let version_string = String::from_utf8_lossy(version_output.stdout.as_slice());
let versions = re
.captures(&version_string)
.ok_or("invalid version number")?;
let v_major = versions
.get(1)
.ok_or("unable to get major version number")?
.as_str()
.parse::<i32>()?;
let v_minor = versions
.get(2)
.ok_or("unable to get minor version number")?
.as_str()
.parse::<i32>()?;
let v_patch = versions
.get(3)
.ok_or("unable to get patch version number")?
.as_str()
.parse::<i32>()?;
Ok(IPTables {
cmd,
has_check: (v_major > 1)
|| (v_major == 1 && v_minor > 4)
|| (v_major == 1 && v_minor == 4 && v_patch > 10),
has_wait: (v_major > 1)
|| (v_major == 1 && v_minor > 4)
|| (v_major == 1 && v_minor == 4 && v_patch > 19),
is_numeric: false,
})
}
impl IPTables {
pub fn get_policy(&self, table: &str, chain: &str) -> Result<String, Box<dyn Error>> {
let builtin_chains = get_builtin_chains(table)?;
if !builtin_chains.iter().as_slice().contains(&chain) {
return Err(error_from_str(
"given chain is not a default chain in the given table, can't get policy",
));
}
let stdout = match self.is_numeric {
false => self.run(&["-t", table, "-L", chain])?.stdout,
true => self.run(&["-t", table, "-L", chain, "-n"])?.stdout,
};
let output = String::from_utf8_lossy(stdout.as_slice());
for item in output.trim().split('\n') {
let fields = item.split(' ').collect::<Vec<&str>>();
if fields.len() > 1 && fields[0] == "Chain" && fields[1] == chain {
return Ok(fields[3].replace(")", ""));
}
}
Err(error_from_str(
"could not find the default policy for table and chain",
))
}
pub fn set_policy(&self, table: &str, chain: &str, policy: &str) -> Result<(), Box<dyn Error>> {
let builtin_chains = get_builtin_chains(table)?;
if !builtin_chains.iter().as_slice().contains(&chain) {
return Err(error_from_str(
"given chain is not a default chain in the given table, can't set policy",
));
}
self.run(&["-t", table, "-P", chain, policy])
.and_then(output_to_result)
}
pub fn execute(&self, table: &str, command: &str) -> Result<Output, Box<dyn Error>> {
self.run(&[&["-t", table], command.split_quoted().as_slice()].concat())
}
#[cfg(target_os = "linux")]
pub fn exists(&self, table: &str, chain: &str, rule: &str) -> Result<bool, Box<dyn Error>> {
if !self.has_check {
return self.exists_old_version(table, chain, rule);
}
self.run(&[&["-t", table, "-C", chain], rule.split_quoted().as_slice()].concat())
.map(|output| output.status.success())
}
#[cfg(target_os = "linux")]
pub fn chain_exists(&self, table: &str, chain: &str) -> Result<bool, Box<dyn Error>> {
match self.is_numeric {
false => self
.run(&["-t", table, "-L", chain])
.map(|output| output.status.success()),
true => self
.run(&["-t", table, "-L", chain, "-n"])
.map(|output| output.status.success()),
}
}
fn exists_old_version(
&self,
table: &str,
chain: &str,
rule: &str,
) -> Result<bool, Box<dyn Error>> {
match self.is_numeric {
false => self.run(&["-t", table, "-S"]).map(|output| {
String::from_utf8_lossy(&output.stdout).contains(&format!("-A {} {}", chain, rule))
}),
true => self.run(&["-t", table, "-S", "-n"]).map(|output| {
String::from_utf8_lossy(&output.stdout).contains(&format!("-A {} {}", chain, rule))
}),
}
}
pub fn insert(
&self,
table: &str,
chain: &str,
rule: &str,
position: i32,
) -> Result<(), Box<dyn Error>> {
self.run(
&[
&["-t", table, "-I", chain, &position.to_string()],
rule.split_quoted().as_slice(),
]
.concat(),
)
.and_then(output_to_result)
}
pub fn insert_unique(
&self,
table: &str,
chain: &str,
rule: &str,
position: i32,
) -> Result<(), Box<dyn Error>> {
if self.exists(table, chain, rule)? {
return Err(error_from_str("the rule exists in the table/chain"));
}
self.insert(table, chain, rule, position)
}
pub fn replace(
&self,
table: &str,
chain: &str,
rule: &str,
position: i32,
) -> Result<(), Box<dyn Error>> {
self.run(
&[
&["-t", table, "-R", chain, &position.to_string()],
rule.split_quoted().as_slice(),
]
.concat(),
)
.and_then(output_to_result)
}
pub fn append(&self, table: &str, chain: &str, rule: &str) -> Result<(), Box<dyn Error>> {
self.run(&[&["-t", table, "-A", chain], rule.split_quoted().as_slice()].concat())
.and_then(output_to_result)
}
pub fn append_unique(
&self,
table: &str,
chain: &str,
rule: &str,
) -> Result<(), Box<dyn Error>> {
if self.exists(table, chain, rule)? {
return Err(error_from_str("the rule exists in the table/chain"));
}
self.append(table, chain, rule)
}
pub fn append_replace(
&self,
table: &str,
chain: &str,
rule: &str,
) -> Result<(), Box<dyn Error>> {
if self.exists(table, chain, rule)? {
self.delete(table, chain, rule)?;
}
self.append(table, chain, rule)
}
pub fn delete(&self, table: &str, chain: &str, rule: &str) -> Result<(), Box<dyn Error>> {
self.run(&[&["-t", table, "-D", chain], rule.split_quoted().as_slice()].concat())
.and_then(output_to_result)
}
pub fn delete_all(&self, table: &str, chain: &str, rule: &str) -> Result<(), Box<dyn Error>> {
while self.exists(table, chain, rule)? {
self.delete(table, chain, rule)?;
}
Ok(())
}
pub fn list(&self, table: &str, chain: &str) -> Result<Vec<String>, Box<dyn Error>> {
match self.is_numeric {
false => self.get_list(&["-t", table, "-S", chain]),
true => self.get_list(&["-t", table, "-S", chain, "-n"]),
}
}
pub fn list_table(&self, table: &str) -> Result<Vec<String>, Box<dyn Error>> {
match self.is_numeric {
false => self.get_list(&["-t", table, "-S"]),
true => self.get_list(&["-t", table, "-S", "-n"]),
}
}
pub fn list_chains(&self, table: &str) -> Result<Vec<String>, Box<dyn Error>> {
let mut list = Vec::new();
let stdout = self.run(&["-t", table, "-S"])?.stdout;
let output = String::from_utf8_lossy(stdout.as_slice());
for item in output.trim().split('\n') {
let fields = item.split(' ').collect::<Vec<&str>>();
if fields.len() > 1 && (fields[0] == "-P" || fields[0] == "-N") {
list.push(fields[1].to_string());
}
}
Ok(list)
}
pub fn new_chain(&self, table: &str, chain: &str) -> Result<(), Box<dyn Error>> {
self.run(&["-t", table, "-N", chain])
.and_then(output_to_result)
}
pub fn flush_chain(&self, table: &str, chain: &str) -> Result<(), Box<dyn Error>> {
self.run(&["-t", table, "-F", chain])
.and_then(output_to_result)
}
pub fn rename_chain(
&self,
table: &str,
old_chain: &str,
new_chain: &str,
) -> Result<(), Box<dyn Error>> {
self.run(&["-t", table, "-E", old_chain, new_chain])
.and_then(output_to_result)
}
pub fn delete_chain(&self, table: &str, chain: &str) -> Result<(), Box<dyn Error>> {
self.run(&["-t", table, "-X", chain])
.and_then(output_to_result)
}
pub fn flush_table(&self, table: &str) -> Result<(), Box<dyn Error>> {
self.run(&["-t", table, "-F"]).and_then(output_to_result)
}
fn get_list<S: AsRef<OsStr>>(&self, args: &[S]) -> Result<Vec<String>, Box<dyn Error>> {
let stdout = self.run(args)?.stdout;
Ok(String::from_utf8_lossy(stdout.as_slice())
.trim()
.split('\n')
.map(String::from)
.collect())
}
pub fn set_numeric(&mut self, numeric: bool) {
self.is_numeric = numeric;
}
fn run<S: AsRef<OsStr>>(&self, args: &[S]) -> Result<Output, Box<dyn Error>> {
let mut file_lock = None;
let mut output_cmd = Command::new(self.cmd);
let output;
if self.has_wait {
output = output_cmd.args(args).arg("--wait").output()?;
} else {
file_lock = Some(File::create("/var/run/xtables_old.lock")?);
let mut need_retry = true;
while need_retry {
match flock(
file_lock.as_ref().unwrap().as_raw_fd(),
FlockArg::LockExclusiveNonblock,
) {
Ok(_) => need_retry = false,
Err(e) if e == nix::errno::Errno::EAGAIN => {
need_retry = true;
}
Err(e) => {
return Err(Box::new(e));
}
}
}
output = output_cmd.args(args).output()?;
}
if let Some(f) = file_lock {
drop(f)
}
Ok(output)
}
}