basic file descriptor passing

3 files changed, 85 insertions, 10 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f9a0b2e..3a0e669 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,6 +5,7 @@ dependencies = [
  "env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nix 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -16,6 +17,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "bitflags"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "env_logger"
 version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -57,6 +68,19 @@ dependencies = [
 ]
 
 [[package]]
+name = "nix"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "semver 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "regex"
 version = "0.1.77"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -74,6 +98,19 @@ version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "rustc_version"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "thread-id"
 version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -96,6 +133,11 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "winapi"
 version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index e8cd7e6..be7fd7f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["bnewbold <bnewbold@robocracy.org>"]
 
 [dependencies]
+nix = "0.7"
 log = "0.3"
 env_logger = "0.3"
 getopts = "^0.2"
diff --git a/src/main.rs b/src/main.rs
index d87f037..d4221dc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -19,28 +19,45 @@
 extern crate getopts;
 extern crate log;
 extern crate env_logger;
+extern crate nix;
 
 use std::env;
 use std::u64;
 use std::str::FromStr;
-use std::{time, thread};
 use std::process::exit;
 use std::process::Command;
+use std::process::Child;
+use std::net::SocketAddr;
+use std::net::TcpListener;
+use std::net::ToSocketAddrs;
 use getopts::Options;
 
-fn run(prog: Vec<String>, number: u64) {
+use std::os::unix::io::IntoRawFd;
 
+fn run(binds: Vec<TcpListener>, mut prog: Command, number: u64) {
 
+    prog.env("EINHORN_FD_COUNT", binds.len().to_string());
+    // This iterator destroys the TcpListeners
+    for (i, b) in binds.into_iter().enumerate() {
+        let orig_fd = b.into_raw_fd();
+        // Duplicate, which also clears the CLOEXEC flag
+        //let fd = nix::fcntl::fcntl(nix::fcntl::FcntlArg::F_DUPFD(orig_fd)).unwrap();
+        let fd = nix::unistd::dup(orig_fd).unwrap();
+        println!("fd={} FD_CLOEXEC={}", fd, nix::fcntl::fcntl(fd, nix::fcntl::FcntlArg::F_GETFD).unwrap());
+        prog.env(format!("EINHORN_FD_{}", i), fd.to_string());
+        // NB: is fd getting destroyed here?
+    }
+
+    let mut children: Vec<Child> = vec![];
     for _ in 0..number {
         println!("Running!");
-        Command::new(&prog[0])
-                .args(&prog[1..])
-                .spawn()
-                .expect("command failed");
+        children.push(prog.spawn().expect("error spawning"));
     }
 
-    println!("Sleeping for 1sec");
-    thread::sleep(time::Duration::from_secs(1));
+    println!("Waiting for all children to die");
+    for mut c in children {
+        c.wait().unwrap();
+    }
 }
 
 fn print_usage(opts: Options) {
@@ -54,6 +71,7 @@ fn main() {
     let args: Vec<String> = env::args().collect();
 
     let mut opts = Options::new();
+    opts.parsing_style(getopts::ParsingStyle::StopAtFirstFree);
     opts.optflag("h", "help", "print this help menu");
     opts.optflag("v", "verbose", "more debugging messages");
     opts.optopt("n", "number", "how many program copies to spawn", "COUNT");
@@ -70,10 +88,16 @@ fn main() {
     }
 
     let number: u64 = match matches.opt_str("number") {
-        Some(n) => u64::from_str(&n).unwrap(),
+        Some(n) => u64::from_str(&n).expect("number arg should be an integer"),
         None => 1
     };
 
+    let sock_addrs: Vec<SocketAddr> = matches.opt_strs("bind").iter().map(|b| {
+        //let sa: SocketAddr = b.to_socket_addrs().unwrap().next().unwrap();
+        //sa
+        b.to_socket_addrs().unwrap().next().unwrap()
+    }).collect();
+
     let program_and_args = if !matches.free.is_empty() {
         matches.free
     } else {
@@ -88,5 +112,13 @@ fn main() {
     }
     builder.init().unwrap();
 
-    run(program_and_args, number);
+    let binds: Vec<TcpListener> = sock_addrs.iter().map(|sa| {
+        TcpListener::bind(sa).unwrap()
+    }).collect();
+
+    let mut prog = Command::new(&program_and_args[0]);
+    prog.args(&program_and_args[1..]);
+
+    run(binds, prog, number);
+    exit(0);
 }