let the kernel pick my UDP ports

Cargo.lock

@@ -18,15 +18,6 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "130aac562c0dd69c56b3b1cc8ffd2e17be31d0b6c25b61c96b76231aa23e39e1"
 
-[[package]]
-name = "c2-chacha"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "214238caa1bf3a496ec3392968969cab8549f96ff30652c9e56885329315f6bb"
-dependencies = [
- "ppv-lite86",
-]
-
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
@@ -60,23 +51,11 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
-[[package]]
-name = "getrandom"
-version = "0.1.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
-dependencies = [
- "cfg-if",
- "libc",
- "wasi",
-]
-
 [[package]]
 name = "hptp"
 version = "0.1.0"
 dependencies = [
  "chrono",
- "rand",
  "thiserror",
  "tokio",
 ]
@@ -212,12 +191,6 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "237844750cfbb86f67afe27eee600dfbbcb6188d734139b534cbfbf4f96792ae"
 
-[[package]]
-name = "ppv-lite86"
-version = "0.2.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.9"
@@ -236,47 +209,6 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "rand"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
-dependencies = [
- "getrandom",
- "libc",
- "rand_chacha",
- "rand_core",
- "rand_hc",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"
-dependencies = [
- "c2-chacha",
- "rand_core",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
-dependencies = [
- "getrandom",
-]
-
-[[package]]
-name = "rand_hc"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
-dependencies = [
- "rand_core",
-]
-
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
@@ -350,12 +282,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 
-[[package]]
-name = "wasi"
-version = "0.9.0+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
-
 [[package]]
 name = "winapi"
 version = "0.2.8"

hptp-recv/src/main.rs

@@ -17,8 +17,6 @@ enum Error {
         source: tokio::io::Error,
         backtrace: std::backtrace::Backtrace,
     },
-    #[error("no UDP port available for listening")]
-    NoPortAvail,
 }
 
 fn entry() -> Result<(), Error> {
@@ -38,9 +36,7 @@ fn main() {
 }
 
 async fn start(log: &mut Logger) -> Result<(), Error> {
-    let sock = hptp::udp_retrying_bind(16, hptp::random_port)
+    let sock = tokio::net::UdpSocket::bind((std::net::Ipv4Addr::LOCALHOST, 0)).await?;
-        .await
-        .map_err(|_| Error::NoPortAvail)?;
     log.bound(sock.local_addr()?.port()).await;
     let mut out = tokio::io::stdout();
     let mut peer = Peer::new(sock);

hptp-send/src/main.rs

@@ -21,8 +21,6 @@ enum Error {
     },
     #[error("invalid command-line arguments")]
     InvalidArgs,
-    #[error("did not find an available local port")]
-    NoAvailPort,
 }
 
 fn main() {
@@ -51,9 +49,7 @@ fn entry() -> Result<(), Error> {
 
 async fn start(log: &mut Logger) -> Result<(), Error> {
     let targ_addr = parse_args(std::env::args())?;
-    let sock = hptp::udp_retrying_bind(16, hptp::random_port)
+    let sock = tokio::net::UdpSocket::bind((std::net::Ipv4Addr::LOCALHOST, 0)).await?;
-        .await
-        .map_err(|_| Error::NoAvailPort)?;
     log.debug_msg(format!("bound on {}", sock.local_addr()?))
         .await;
     let mut out = tokio::io::stdin();

hptp/Cargo.toml

@@ -9,6 +9,5 @@ edition = "2018"
 
 [dependencies]
 tokio = {version = "0.2.*", features = ["io-std", "io-util", "udp"]}
-rand = "0.7.*"
 thiserror = "*"
 chrono = "0.4.*"

hptp/src/lib.rs

@@ -1,4 +1,3 @@
-extern crate rand;
 #[macro_use]
 extern crate thiserror;
 extern crate chrono;
@@ -6,24 +5,3 @@ extern crate chrono;
 pub mod logger;
 pub mod msg;
 pub mod peer;
-
-use std::net::Ipv4Addr;
-use tokio::net::UdpSocket;
-
-pub async fn udp_retrying_bind<F>(max_tries: usize, mut pick_port: F) -> Result<UdpSocket, ()>
-where
-    F: FnMut() -> u16,
-{
-    for _ in 0..max_tries {
-        let port = pick_port();
-        if let Ok(sock) = UdpSocket::bind((Ipv4Addr::LOCALHOST, port)).await {
-            return Ok(sock);
-        }
-    }
-    Err(())
-}
-
-pub fn random_port() -> u16 {
-    use rand::distributions::{Distribution, Uniform};
-    Uniform::new(1025, 65535u16).sample(&mut rand::thread_rng())
-}