When constructing a *Listener socket, check that it's actually listening

Depends on nix-rust/nix#2263

Cargo.toml

@@ -24,13 +24,12 @@ default = []
 capsicum = { version = "0.3.0", features = ["casper"] }
 casper-sys = { version = "0.1.1" }
 cstr = "0.2.0"
-libc = "0.2.147"
-nix = { version = "0.27.0", features = [ "net", "socket" ] }
+libc = "0.2.150"
+nix = { version = "0.27.1", features = [ "net", "socket" ] }
 tokio = { version = "1.27.0", default-features = false, features = ["net"], optional = true}
 
 [dev-dependencies]
 ctor = "0.2.3"
-libc = "0.2.147"
 tempfile = "3.4"
 tokio = { version = "1.27.0", features = ["macros", "rt"] }
 
@@ -41,3 +40,5 @@ path = "tests/functional/mod.rs"
 [patch.crates-io]
 capsicum = { git = "https://github.com/asomers/capsicum-rs", rev = "f5fd1e6"}
 casper-sys = { git = "https://github.com/asomers/capsicum-rs", rev = "f5fd1e6"}
+libc = { git = "https://github.com/rust-lang/libc", rev = "f37806e499409eab8cfa897280a869bc5e2623a9" }
+nix = { git = "https://github.com/asomers/nix", rev = "34eec97" }

tests/functional/std.rs

@@ -12,6 +12,7 @@ use capsicum_net::{
     UnixDatagramExt,
     UnixListenerExt,
 };
+use nix::sys::socket::{getsockopt, sockopt::ListenQLimit};
 use tempfile::TempDir;
 
 use crate::CASPER;
@@ -65,6 +66,7 @@ mod bind {
             let socket = TcpListener::cap_bind(&mut cap_net, want).unwrap();
             let bound = socket.local_addr().unwrap();
             assert_eq!(want, bound);
+            assert!(getsockopt(&socket, ListenQLimit).unwrap() > 0);
         }
 
         #[test]
@@ -76,6 +78,7 @@ mod bind {
             let socket = TcpListener::cap_bind(&mut cap_net, want).unwrap();
             let bound = socket.local_addr().unwrap();
             assert_eq!(want, bound);
+            assert!(getsockopt(&socket, ListenQLimit).unwrap() > 0);
         }
     }
 
@@ -172,6 +175,7 @@ mod bind {
             let bound: nix::sys::socket::UnixAddr =
                 nix::sys::socket::getsockname(socket.as_raw_fd()).unwrap();
             assert_eq!(path, bound.path().unwrap());
+            assert!(getsockopt(&socket, ListenQLimit).unwrap() > 0);
         }
     }
 }