Allow multiple bypass IP addresses/CIDRs in routing setup

See issue #73.

Dockerfile

@@ -12,18 +12,9 @@ RUN cargo build --release --target x86_64-unknown-linux-gnu
 ## Final image
 ####################################################################################################
 FROM ubuntu:latest
-WORKDIR /app
 
-ENV TUN=tun0
-ENV PROXY=
-ENV DNS=virtual
-ENV MODE=auto
-ENV BYPASS_IP=
-ENV VERBOSITY=info
-
-RUN apt update && apt install -y iproute2 curl && apt clean all
+RUN apt update && apt install -y iproute2 && apt clean all
 
 COPY --from=builder /worker/target/x86_64-unknown-linux-gnu/release/tun2proxy /usr/bin/tun2proxy
-COPY --from=builder /worker/docker/entrypoint.sh /app
 
-ENTRYPOINT ["/app/entrypoint.sh"]
+ENTRYPOINT ["/usr/bin/tun2proxy", "--setup", "auto"]

README.md

@@ -99,7 +99,7 @@ Options:
       --dns-addr <IP>      DNS resolver address [default: 8.8.8.8]
   -6, --ipv6-enabled       IPv6 enabled
   -s, --setup <method>     Routing and system setup [default: none] [possible values: none, auto]
-  -b, --bypass <IP>        Public proxy IP used in routing setup which should bypassing the tunnel
+  -b, --bypass <IP|CIDR>   IPs and CIDRs used in routing setup which should bypass the tunnel
   -v, --verbosity <level>  Verbosity level [default: info] [possible values: off, error, warn, info, debug, trace]
   -h, --help               Print help
   -V, --version            Print version
@@ -119,31 +119,17 @@ Next, start a container from the tun2proxy image:
 
 ```bash
 docker run -d \
-	-e PROXY=proto://[username[:password]@]host:port \
 	-v /dev/net/tun:/dev/net/tun \
 	--sysctl net.ipv6.conf.default.disable_ipv6=0 \
 	--cap-add NET_ADMIN \
 	--name tun2proxy \
-	tun2proxy
+	tun2proxy --proxy proto://[username[:password]@]host:port
 ```
 
-container env list
-
-| container env | Default | program option          | mean                                                         |
-| ------------- | ------- | ----------------------- | ------------------------------------------------------------ |
-| TUN           | tun0    | -t, --tun <name>        | Name of the tun interface [default: tun0]                    |
-| PROXY         | None    | -p, --proxy <URL>       | Proxy URL in the form proto://[username[:password]@]host:port |
-| DNS           | virtual | -d, --dns <strategy>    | DNS handling strategy [default: virtual] [possible values: virtual, over-tcp, direct] |
-| MODE          | auto    | -s, --setup <method>    | Routing and system setup [default: none] [possible values: none, auto] |
-| BYPASS_IP     | None    | -b, --bypass <IP>       | Public proxy IP used in routing setup which should bypassing the tunnel |
-| VERBOSITY     | info    | -v, --verbosity <level> | Verbosity level [default: info] [possible values: off, error, warn, info, debug, trace] |
-|               |         |                         |                                                              |
-
 You can then provide the running container's network to another worker container by sharing the network namespace (like kubernetes sidecar):
 
 ```bash
 docker run -it \
-	-d \
 	--network "container:tun2proxy" \
 	ubuntu:latest
 ```

docker/entrypoint.sh

@@ -1,35 +0,0 @@
-#!/bin/bash
-
-
-run() {
-  if [ -n "$TUN" ]; then
-    TUN="--tun $TUN"
-  fi
-
-  if [ -n "$PROXY" ]; then
-    PROXY="--proxy $PROXY"
-  fi
-
-  if [ -n "$DNS" ]; then
-    DNS="--dns $DNS"
-  fi
-
-  if [ -n "$BYPASS_IP" ]; then
-    BYPASS_IP="--bypass $BYPASS_IP"
-  fi
-
-  if [ -n "$VERBOSITY" ]; then
-    VERBOSITY="-v $VERBOSITY"
-  fi
-
-  if [ -n "$MODE" ]; then
-    MODE="--setup $MODE"
-  fi
-
-  echo "Bootstrap ready!! Exec Command: tun2proxy $TUN $PROXY $DNS $VERBOSITY $MODE $BYPASS_IP $@"
-
-  exec tun2proxy $TUN $PROXY $DNS $VERBOSITY $MODE $BYPASS_IP $@
-}
-
-
-run $@ || echo "Runing ERROR!!"

src/lib.rs

@@ -4,6 +4,7 @@ use crate::{
     socks::SocksProxyManager,
     tun2proxy::{ConnectionManager, TunToProxy},
 };
+use smoltcp::wire::IpCidr;
 use socks5_impl::protocol::UserKey;
 use std::{
     net::{SocketAddr, ToSocketAddrs},
@@ -17,6 +18,7 @@ mod http;
 pub mod setup;
 mod socks;
 mod tun2proxy;
+pub mod util;
 mod virtdevice;
 mod virtdns;
 #[cfg(target_os = "windows")]
@@ -104,8 +106,8 @@ pub struct Options {
     dns_over_tcp: bool,
     dns_addr: Option<std::net::IpAddr>,
     ipv6_enabled: bool,
-    bypass: Option<std::net::IpAddr>,
     pub setup: bool,
+    bypass: Vec<IpCidr>,
 }
 
 impl Options {
@@ -140,8 +142,10 @@ impl Options {
         self
     }
 
-    pub fn with_bypass(mut self, ip: Option<std::net::IpAddr>) -> Self {
-        self.bypass = ip;
+    pub fn with_bypass_ips<'a>(mut self, bypass_ips: impl IntoIterator<Item = &'a IpCidr>) -> Self {
+        for bypass_ip in bypass_ips {
+            self.bypass.push(*bypass_ip);
+        }
         self
     }
 }

src/main.rs

@@ -1,5 +1,7 @@
 use clap::Parser;
+use smoltcp::wire::IpCidr;
 use std::{net::IpAddr, process::ExitCode};
+use tun2proxy::util::str_to_cidr;
 use tun2proxy::{error::Error, main_entry, NetworkInterface, Options, Proxy};
 
 #[cfg(target_os = "linux")]
@@ -41,9 +43,9 @@ struct Args {
     #[arg(short, long, value_name = "method", value_enum, default_value = if cfg!(target_os = "linux") { "none" } else { "auto" })]
     setup: Option<ArgSetup>,
 
-    /// Public proxy IP used in routing setup which should bypassing the tunnel
-    #[arg(short, long, value_name = "IP")]
-    bypass: Option<IpAddr>,
+    /// IPs used in routing setup which should bypass the tunnel
+    #[arg(short, long, value_name = "IP|CIDR")]
+    bypass: Vec<String>,
 
     /// Verbosity level
     #[arg(short, long, value_name = "level", value_enum, default_value = "info")]
@@ -53,7 +55,7 @@ struct Args {
 /// DNS query handling strategy
 /// - Virtual: Intercept DNS queries and resolve them locally with a fake IP address
 /// - OverTcp: Use TCP to send DNS queries to the DNS server
-/// - Direct: Looks as general UDP traffic but change the destination to the DNS server
+/// - Direct: Do not handle DNS by relying on DNS server bypassing
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, clap::ValueEnum)]
 enum ArgDns {
     Virtual,
@@ -117,20 +119,28 @@ fn main() -> ExitCode {
         }
     };
 
-    let bypass_tun_ip = match args.bypass {
-        Some(addr) => addr,
-        None => args.proxy.addr.ip(),
-    };
-    options = options.with_bypass(Some(bypass_tun_ip));
-
     options.setup = args.setup.map(|s| s == ArgSetup::Auto).unwrap_or(false);
 
     let block = || -> Result<(), Error> {
+        let mut bypass_ips = Vec::<IpCidr>::new();
+        for cidr_str in args.bypass {
+            bypass_ips.push(str_to_cidr(&cidr_str)?);
+        }
+        if bypass_ips.is_empty() {
+            let prefix_len = if args.proxy.addr.ip().is_ipv6() { 128 } else { 32 };
+            bypass_ips.push(IpCidr::new(args.proxy.addr.ip().into(), prefix_len))
+        }
+
+        options = options.with_bypass_ips(&bypass_ips);
+
         #[cfg(target_os = "linux")]
-        if options.setup {
-            let mut setup = Setup::new(&args.tun, &bypass_tun_ip, get_default_cidrs(), args.bypass.is_some());
-            setup.configure()?;
-            setup.drop_privileges()?;
+        {
+            let mut setup: Setup;
+            if options.setup {
+                setup = Setup::new(&args.tun, bypass_ips, get_default_cidrs());
+                setup.configure()?;
+                setup.drop_privileges()?;
+            }
         }
 
         main_entry(&interface, &args.proxy, options)?;

src/setup.rs

@@ -8,7 +8,7 @@ use std::{
     ffi::OsStr,
     fs,
     io::BufRead,
-    net::{IpAddr, Ipv4Addr, Ipv6Addr},
+    net::{Ipv4Addr, Ipv6Addr},
     os::unix::io::RawFd,
     process::{Command, Output},
     str::FromStr,
@@ -17,11 +17,10 @@ use std::{
 #[derive(Clone)]
 pub struct Setup {
     routes: Vec<IpCidr>,
-    tunnel_bypass_addr: IpAddr,
-    allow_private: bool,
+    tunnel_bypass_addrs: Vec<IpCidr>,
     tun: String,
     set_up: bool,
-    delete_proxy_route: bool,
+    delete_proxy_routes: Vec<IpCidr>,
     child: libc::pid_t,
     unmount_resolvconf: bool,
     restore_resolvconf_data: Option<Vec<u8>>,
@@ -76,35 +75,41 @@ where
 impl Setup {
     pub fn new(
         tun: impl Into<String>,
-        tunnel_bypass_addr: &IpAddr,
+        tunnel_bypass_addrs: impl IntoIterator<Item = IpCidr>,
         routes: impl IntoIterator<Item = IpCidr>,
-        allow_private: bool,
     ) -> Self {
         let routes_cidr = routes.into_iter().collect();
+        let bypass_cidrs = tunnel_bypass_addrs.into_iter().collect();
         Self {
             tun: tun.into(),
-            tunnel_bypass_addr: *tunnel_bypass_addr,
-            allow_private,
+            tunnel_bypass_addrs: bypass_cidrs,
             routes: routes_cidr,
             set_up: false,
-            delete_proxy_route: false,
+            delete_proxy_routes: Vec::<IpCidr>::new(),
             child: 0,
             unmount_resolvconf: false,
             restore_resolvconf_data: None,
         }
     }
 
-    fn route_proxy_address(&mut self) -> Result<bool, Error> {
-        let route_show_args = if self.tunnel_bypass_addr.is_ipv6() {
+    fn bypass_cidr(cidr: &IpCidr) -> Result<bool, Error> {
+        let is_ipv6 = match cidr {
+            IpCidr::Ipv4(_) => false,
+            IpCidr::Ipv6(_) => true,
+        };
+        let route_show_args = if is_ipv6 {
             ["ip", "-6", "route", "show"]
         } else {
             ["ip", "-4", "route", "show"]
         };
 
-        let routes = run_iproute(route_show_args, "failed to get routing table", true)?;
+        let routes = run_iproute(
+            route_show_args,
+            "failed to get routing table through the ip command",
+            true,
+        )?;
 
         let mut route_info = Vec::<(IpCidr, Vec<String>)>::new();
-
         for line in routes.stdout.lines() {
             if line.is_err() {
                 break;
@@ -117,15 +122,11 @@ impl Setup {
             let mut split = line.split_whitespace();
             let mut dst_str = split.next().unwrap();
             if dst_str == "default" {
-                dst_str = if self.tunnel_bypass_addr.is_ipv6() {
-                    "::/0"
-                } else {
-                    "0.0.0.0/0"
-                }
+                dst_str = if is_ipv6 { "::/0" } else { "0.0.0.0/0" }
             }
 
             let (addr_str, prefix_len_str) = match dst_str.split_once(['/']) {
-                None => (dst_str, if self.tunnel_bypass_addr.is_ipv6() { "128" } else { "32" }),
+                None => (dst_str, if is_ipv6 { "128" } else { "32" }),
                 Some((addr_str, prefix_len_str)) => (addr_str, prefix_len_str),
             };
 
@@ -140,19 +141,19 @@ impl Setup {
         // Sort routes by prefix length, the most specific route comes first.
         route_info.sort_by(|entry1, entry2| entry2.0.prefix_len().cmp(&entry1.0.prefix_len()));
 
-        for (cidr, route_components) in route_info {
-            if !cidr.contains_addr(&smoltcp::wire::IpAddress::from(self.tunnel_bypass_addr)) {
+        for (route_cidr, route_components) in route_info {
+            if !route_cidr.contains_subnet(cidr) {
                 continue;
             }
 
             // The IP address is routed through a more specific route than the default route.
             // In this case, there is nothing to do.
-            if cidr.prefix_len() != 0 {
+            if route_cidr.prefix_len() != 0 {
                 break;
             }
 
             let mut proxy_route = vec!["ip".into(), "route".into(), "add".into()];
-            proxy_route.push(self.tunnel_bypass_addr.to_string());
+            proxy_route.push(cidr.to_string());
             proxy_route.extend(route_components.into_iter());
             run_iproute(proxy_route, "failed to clone route for proxy", false)?;
             return Ok(true);
@@ -235,14 +236,17 @@ impl Setup {
         self.set_up = false;
         log::info!("[{}] Restoring network configuration", nix::unistd::getpid());
         let _ = Command::new("ip").args(["link", "del", self.tun.as_str()]).output();
-        if self.delete_proxy_route {
+
+        for cidr in &self.delete_proxy_routes {
             let _ = Command::new("ip")
-                .args(["route", "del", self.tunnel_bypass_addr.to_string().as_str()])
+                .args(["route", "del", cidr.to_string().as_str()])
                 .output();
         }
+
         if self.unmount_resolvconf {
             nix::mount::umount("/etc/resolv.conf")?;
         }
+
         if let Some(data) = &self.restore_resolvconf_data {
             fs::write("/etc/resolv.conf", data)?;
         }
@@ -259,8 +263,6 @@ impl Setup {
             )?;
 
             self.set_up = true;
-            let _tun_name = self.tun.clone();
-            let _proxy_ip = self.tunnel_bypass_addr;
 
             run_iproute(
                 ["ip", "link", "set", self.tun.as_str(), "up"],
@@ -268,8 +270,13 @@ impl Setup {
                 true,
             )?;
 
-            let delete_proxy_route = self.route_proxy_address()?;
-            self.delete_proxy_route = delete_proxy_route;
+            let mut delete_proxy_route = Vec::<IpCidr>::new();
+            for cidr in &self.tunnel_bypass_addrs {
+                if Self::bypass_cidr(cidr)? {
+                    delete_proxy_route.push(*cidr);
+                }
+            }
+            self.delete_proxy_routes = delete_proxy_route;
             self.setup_resolv_conf()?;
             self.add_tunnel_routes()?;
 
@@ -321,14 +328,6 @@ impl Setup {
             return Err("Automatic setup requires root privileges".into());
         }
 
-        if self.tunnel_bypass_addr.is_loopback() && !self.allow_private {
-            log::warn!(
-                "The proxy address {} is a loopback address. You may need to manually \
-                provide --bypass-ip to specify the server IP bypassing the tunnel",
-                self.tunnel_bypass_addr
-            )
-        }
-
         let (read_from_child, write_to_parent) = nix::unistd::pipe()?;
         match fork::fork() {
             Ok(Fork::Child) => {

src/tun2proxy.rs

@@ -259,7 +259,7 @@ impl<'a> TunToProxy<'a> {
 
         #[cfg(target_os = "windows")]
         if options.setup {
-            tun.setup_config(options.bypass, options.dns_addr)?;
+            tun.setup_config(&options.bypass, options.dns_addr)?;
         }
 
         let poll = Poll::new()?;

src/util.rs

@@ -0,0 +1,22 @@
+use crate::error::Error;
+use smoltcp::wire::IpCidr;
+use std::net::IpAddr;
+use std::str::FromStr;
+
+pub fn str_to_cidr(s: &str) -> Result<IpCidr, Error> {
+    // IpCidr's FromString implementation requires the netmask to be specified.
+    // Try to parse as IP address without netmask before falling back.
+    match IpAddr::from_str(s) {
+        Err(_) => (),
+        Ok(cidr) => {
+            let prefix_len = if cidr.is_ipv4() { 32 } else { 128 };
+            return Ok(IpCidr::new(cidr.into(), prefix_len));
+        }
+    };
+
+    let cidr = IpCidr::from_str(s);
+    match cidr {
+        Err(()) => Err("Invalid CIDR: ".into()),
+        Ok(cidr) => Ok(cidr),
+    }
+}

src/wintuninterface.rs

@@ -1,4 +1,5 @@
 use mio::{event, windows::NamedPipe, Interest, Registry, Token};
+use smoltcp::wire::IpCidr;
 use smoltcp::{
     phy::{self, Device, DeviceCapabilities, Medium},
     time::Instant,
@@ -225,7 +226,11 @@ impl WinTunInterface {
         Ok(())
     }
 
-    pub fn setup_config(&mut self, bypass_ip: Option<IpAddr>, dns_addr: Option<IpAddr>) -> Result<(), io::Error> {
+    pub fn setup_config<'a>(
+        &mut self,
+        bypass_ips: impl IntoIterator<Item = &'a IpCidr>,
+        dns_addr: Option<IpAddr>,
+    ) -> Result<(), io::Error> {
         let adapter = self.wintun_session.get_adapter();
 
         // Setup the adapter's address/mask/gateway
@@ -261,7 +266,7 @@ impl WinTunInterface {
 
         // 3. route the bypass ip to the old gateway
         // command: `route add bypass_ip old_gateway metric 1`
-        if let Some(bypass_ip) = bypass_ip {
+        for bypass_ip in bypass_ips {
             let args = &["add", &bypass_ip.to_string(), &old_gateway.to_string(), "metric", "1"];
             run_command("route", args)?;
             log::info!("route {:?}", args);

tests/proxy.rs

@@ -11,8 +11,10 @@ mod tests {
     use nix::sys::signal;
     use nix::unistd::Pid;
     use serial_test::serial;
+    use smoltcp::wire::IpCidr;
 
     use tun2proxy::setup::{get_default_cidrs, Setup};
+    use tun2proxy::util::str_to_cidr;
     use tun2proxy::{main_entry, NetworkInterface, Options, Proxy, ProxyType};
 
     #[derive(Clone, Debug)]
@@ -66,12 +68,17 @@ mod tests {
                         continue;
                     }
 
-                    let bypass_ip = match env::var("BYPASS_IP") {
-                        Err(_) => test.proxy.addr.ip(),
-                        Ok(ip_str) => IpAddr::from_str(ip_str.as_str()).unwrap(),
+                    let mut bypass_ips = Vec::<IpCidr>::new();
+
+                    match env::var("BYPASS_IP") {
+                        Err(_) => {
+                            let prefix_len = if test.proxy.addr.ip().is_ipv6() { 128 } else { 32 };
+                            bypass_ips.push(IpCidr::new(test.proxy.addr.ip().into(), prefix_len));
+                        }
+                        Ok(ip_str) => bypass_ips.push(str_to_cidr(&ip_str).expect("Invalid bypass IP")),
                     };
 
-                    let mut setup = Setup::new(TUN_TEST_DEVICE, &bypass_ip, get_default_cidrs(), false);
+                    let mut setup = Setup::new(TUN_TEST_DEVICE, bypass_ips, get_default_cidrs());
                     setup.configure().unwrap();
 
                     match fork::fork() {