Add hard fileno (#366)

* increase the fileno limit

This allows wstunnel to use fds>1024.
Otherwise heavy use can easily run out of file descriptors on connection
attempts.
While there will still be a limit, it is significantly higher (~500
times on my system) which provides enough headroom for connections to be
torn down and fds to be closed.

Cargo.lock

@@ -765,6 +765,16 @@ dependencies = [
  "utf-8",
 ]
 
+[[package]]
+name = "fdlimit"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e182f7dbc2ef73d9ef67351c5fbbea084729c48362d3ce9dd44c28e32e277fe5"
+dependencies = [
+ "libc",
+ "thiserror",
+]
+
 [[package]]
 name = "filetime"
 version = "0.2.25"
@@ -3128,6 +3138,7 @@ dependencies = [
  "crossterm",
  "fast-socks5",
  "fastwebsockets",
+ "fdlimit",
  "futures-util",
  "hickory-resolver",
  "http-body-util",

Cargo.toml

@@ -23,6 +23,8 @@ ppp = { version = "2.2.0", features = [] }
 async-channel = { version = "2.3.1", features = [] }
 arc-swap = { version = "1.7.1", features = [] }
 
+fdlimit = "0.3.0"
+
 # For config file parsing
 regex = { version = "1.11.0", default-features = false, features = ["std", "perf"] }
 serde_regex = "1.1.0"

src/main.rs

@@ -19,7 +19,7 @@ use base64::Engine;
 use clap::Parser;
 use hyper::header::HOST;
 use hyper::http::{HeaderName, HeaderValue};
-use log::debug;
+use log::{debug, warn};
 use parking_lot::{Mutex, RwLock};
 use std::collections::BTreeMap;
 use std::fmt::Debug;
@@ -727,6 +727,9 @@ async fn main() -> anyhow::Result<()> {
     } else {
         logger.init();
     };
+    if let Err(err) = fdlimit::raise_fd_limit() {
+        warn!("Failed to set soft filelimit to hard file limit: {}", err)
+    }
 
     match args.commands {
         Commands::Client(args) => {