feat(app/client): expose socket bind options

Cargo.lock

@@ -251,6 +251,15 @@ dependencies = [
  "clap_derive",
 ]
 
+[[package]]
+name = "clap-num"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "822c4000301ac390e65995c62207501e3ef800a1fc441df913a5e8e4dc374816"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "clap_builder"
 version = "4.6.7"
@@ -819,6 +828,7 @@ version = "0.8.0"
 dependencies = [
  "chrono",
  "clap",
+ "clap-num",
  "crossterm",
  "ctrlc",
  "futures-core",

crates/irtt-app/Cargo.toml

@@ -49,6 +49,7 @@ tui =["dep:tokio", "dep:futures-core", "dep:irtt-client", "irtt-client/ancillary
 [dependencies]
 chrono = { version = "0.4.45", default-features = false, features = ["clock"], optional = true }
 clap = { version = "4.6.7", features = ["derive", "env"] }
+clap-num = "=1.2.0"
 crossterm = { version = "0.29.0", features = ["event-stream"], optional = true }
 futures-core = { version = "0.3.34", default-features = false, optional = true }
 ctrlc = { version = "3.5.2", features = ["termination"] }

crates/irtt-app/src/shared/client/args.rs

@@ -1,4 +1,4 @@
-use std::{fmt, time::Duration};
+use std::{fmt, net::IpAddr, net::SocketAddr, time::Duration};
 
 use clap::ValueEnum;
 use irtt_client::{MAX_DSCP_CODEPOINT, MAX_SERVER_FILL_BYTES, MAX_TTL, MAX_UDP_PAYLOAD_LENGTH};
@@ -70,6 +70,38 @@ pub struct CommonClientArgs {
     #[arg(long, value_name = "1..=255", value_parser = parse_ttl)]
     pub ttl: Option<u32>,
 
+    #[arg(
+        long = "bind-addr",
+        value_name = "IP[:PORT]",
+        value_parser = parse_bind_addr,
+        long_help = "Local IP address and optional UDP port to bind. \
+                     If no port is specified, the operating system selects \
+                     an ephemeral port. IPv6 addresses with an explicit \
+                     port must use [ADDR]:PORT syntax."
+    )]
+    pub bind_addr: Option<SocketAddr>,
+
+    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+    #[arg(
+        long = "bind-device",
+        value_name = "DEVICE",
+        help = "Bind the socket to a network device"
+    )]
+    pub bind_to_device: Option<String>,
+
+    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+    #[arg(
+        long,
+        value_name = "MARK",
+        value_parser = clap_num::maybe_hex::<u32>,
+        help = "Set the outgoing socket firewall mark"
+    )]
+    pub mark: Option<u32>,
+
+    #[cfg(target_os = "freebsd")]
+    #[arg(long, value_name = "FIB", help = "Set the socket routing table (FIB)")]
+    pub fib: Option<u32>,
+
     /// Accept safe server restrictions during negotiation.
     #[arg(long)]
     pub loose: bool,
@@ -77,7 +109,8 @@ pub struct CommonClientArgs {
 
 impl fmt::Debug for CommonClientArgs {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("CommonClientArgs")
+        let mut debug = f.debug_struct("CommonClientArgs");
+        debug
             .field("ipv4", &self.ipv4)
             .field("ipv6", &self.ipv6)
             .field("dual_stack", &self.dual_stack)
@@ -90,8 +123,14 @@ impl fmt::Debug for CommonClientArgs {
             .field("server_fill", &self.server_fill)
             .field("dscp", &self.dscp)
             .field("ttl", &self.ttl)
-            .field("loose", &self.loose)
-            .finish()
+            .field("bind_addr", &self.bind_addr);
+        #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+        debug
+            .field("bind_to_device", &self.bind_to_device)
+            .field("mark", &self.mark);
+        #[cfg(target_os = "freebsd")]
+        debug.field("fib", &self.fib);
+        debug.field("loose", &self.loose).finish()
     }
 }
 
@@ -152,6 +191,13 @@ impl From<ReceivedStatsArg> for ReceivedStats {
     }
 }
 
+fn parse_bind_addr(input: &str) -> Result<SocketAddr, String> {
+    input
+        .parse::<SocketAddr>()
+        .or_else(|_| input.parse::<IpAddr>().map(|ip| SocketAddr::new(ip, 0)))
+        .map_err(|_| "expected an IP address, optionally with a port".to_owned())
+}
+
 pub fn parse_duration(input: &str) -> Result<Duration, String> {
     let (number, unit) = split_duration(input)?;
     let value: u64 = number

crates/irtt-app/src/shared/client/config.rs

@@ -50,6 +50,13 @@ impl CommonClientArgs {
                     Authentication::Hmac(HmacKey::new(key.as_bytes()))
                 }),
             socket: SocketConfig {
+                bind_addr: self.bind_addr,
+                #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+                bind_to_device: self.bind_to_device.clone(),
+                #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+                mark: self.mark,
+                #[cfg(target_os = "freebsd")]
+                fib: self.fib,
                 ttl: self.ttl,
                 ..SocketConfig::default()
             },

docs/irtt-client.md

@@ -93,6 +93,25 @@ labels; choose another alias if one collides with an explicit label.
 ordinary multi-target pacing and each sends its own probes, so dual-stack can
 double the number of probes per interval compared with one target per hostname.
 
+## LOCAL SOCKET CONFIGURATION
+
+The client supports configuring its local UDP sockets using the following options:
+
+- `--bind-addr IP[:PORT]` binds sockets to the specified local IP address and optional port. If no port is specified, or the port is `0`, the operating system assigns an ephemeral port. IPv6 addresses with an explicit port must use `[ADDR]:PORT` syntax. The address family must match the target's resolved address family.
+- `--bind-device DEVICE` (Linux, Android, Fuchsia) binds sockets to a network interface using `SO_BINDTODEVICE`.
+- `--mark MARK` (Linux, Android, Fuchsia) sets the socket's firewall mark using `SO_MARK`, allowing traffic to be selected by policy routing or firewall rules. Accepts a decimal or 0x-prefixed hexadecimal unsigned 32-bit integer.
+- `--fib FIB` (FreeBSD) selects a routing table using `SO_SETFIB`. The FIB is specified as a decimal unsigned 32-bit integer.
+
+For example, bind IPv4 probes to a specific source address and interface, with a firewall mark:
+
+```sh
+irtt-client -4 --bind-addr 192.0.2.10 --bind-device wan0 --mark 1234 host.example
+```
+
+Setting a firewall mark or binding to a network device may require elevated privileges or appropriate capabilities. If the operating system rejects a socket option, socket setup fails.
+
+A fixed local port may cause binding conflicts when multiple target sockets are created. Use an ephemeral port unless a specific source port is required. A family-specific bind address is also incompatible with targets using the other address family.
+
 ## DYNAMIC TARGET SETS FROM STANDARD INPUT
 
 `--targets-stdin` is available only with continuous mode (`--duration 0`).