1 files changed, 235 insertions, 0 deletions
diff --git a/ops/mq_cli/src/main.rs b/ops/mq_cli/src/main.rs
new file mode 100644
index 000000000000..927993b486ad
--- /dev/null
+++ b/ops/mq_cli/src/main.rs
@@ -0,0 +1,235 @@
+extern crate clap;
+extern crate libc;
+extern crate nix;
+extern crate posix_mq;
+
+use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
+use posix_mq::{Message, Name, Queue};
+use std::fs::{read_dir, File};
+use std::io::{self, Read, Write};
+use std::process::exit;
+
+fn run_ls() {
+    let mqueues = read_dir("/dev/mqueue").expect("Could not read message queues");
+
+    for queue in mqueues {
+        let path = queue.unwrap().path();
+        let status = {
+            let mut file = File::open(&path).expect("Could not open queue file");
+
+            let mut content = String::new();
+            file.read_to_string(&mut content)
+                .expect("Could not read queue file");
+
+            content
+        };
+
+        let queue_name = path
+            .components()
+            .last()
+            .unwrap()
+            .as_os_str()
+            .to_string_lossy();
+
+        println!("/{}: {}", queue_name, status)
+    }
+}
+
+fn run_inspect(queue_name: &str) {
+    let name = Name::new(queue_name).expect("Invalid queue name");
+    let queue = Queue::open(name).expect("Could not open queue");
+
+    println!("Queue {}:\n", queue_name);
+    println!("Max. message size: {} bytes", queue.max_size());
+    println!("Max. # of pending messages: {}", queue.max_pending());
+}
+
+fn run_create(cmd: &ArgMatches) {
+    if let Some(rlimit) = cmd.value_of("rlimit") {
+        set_rlimit(rlimit.parse().expect("Invalid rlimit value"));
+    }
+
+    let name = Name::new(cmd.value_of("queue").unwrap()).expect("Invalid queue name");
+
+    let max_pending: i64 = cmd.value_of("max-pending").unwrap().parse().unwrap();
+    let max_size: i64 = cmd.value_of("max-size").unwrap().parse().unwrap();
+
+    let queue = Queue::create(name, max_pending, max_size * 1024);
+
+    match queue {
+        Ok(_) => println!("Queue created successfully"),
+        Err(e) => {
+            writeln!(io::stderr(), "Could not create queue: {}", e).ok();
+            exit(1);
+        }
+    };
+}
+
+fn run_receive(queue_name: &str) {
+    let name = Name::new(queue_name).expect("Invalid queue name");
+    let queue = Queue::open(name).expect("Could not open queue");
+
+    let message = match queue.receive() {
+        Ok(msg) => msg,
+        Err(e) => {
+            writeln!(io::stderr(), "Failed to receive message: {}", e).ok();
+            exit(1);
+        }
+    };
+
+    // Attempt to write the message out as a string, but write out raw bytes if it turns out to not
+    // be UTF-8 encoded data.
+    match String::from_utf8(message.data.clone()) {
+        Ok(string) => println!("{}", string),
+        Err(_) => {
+            writeln!(io::stderr(), "Message not UTF-8 encoded!").ok();
+            io::stdout().write(message.data.as_ref()).ok();
+        }
+    };
+}
+
+fn run_send(queue_name: &str, content: &str) {
+    let name = Name::new(queue_name).expect("Invalid queue name");
+    let queue = Queue::open(name).expect("Could not open queue");
+
+    let message = Message {
+        data: content.as_bytes().to_vec(),
+        priority: 0,
+    };
+
+    match queue.send(&message) {
+        Ok(_) => (),
+        Err(e) => {
+            writeln!(io::stderr(), "Could not send message: {}", e).ok();
+            exit(1);
+        }
+    }
+}
+
+fn run_rlimit() {
+    let mut rlimit = libc::rlimit {
+        rlim_cur: 0,
+        rlim_max: 0,
+    };
+
+    let mut errno = 0;
+    unsafe {
+        let res = libc::getrlimit(libc::RLIMIT_MSGQUEUE, &mut rlimit);
+        if res != 0 {
+            errno = nix::errno::errno();
+        }
+    };
+
+    if errno != 0 {
+        writeln!(
+            io::stderr(),
+            "Could not get message queue rlimit: {}",
+            errno
+        )
+        .ok();
+    } else {
+        println!("Message queue rlimit:");
+        println!("Current limit: {}", rlimit.rlim_cur);
+        println!("Maximum limit: {}", rlimit.rlim_max);
+    }
+}
+
+fn set_rlimit(new_limit: u64) {
+    let rlimit = libc::rlimit {
+        rlim_cur: new_limit,
+        rlim_max: new_limit,
+    };
+
+    let mut errno: i32 = 0;
+    unsafe {
+        let res = libc::setrlimit(libc::RLIMIT_MSGQUEUE, &rlimit);
+        if res != 0 {
+            errno = nix::errno::errno();
+        }
+    }
+
+    match errno {
+        0 => println!("Set RLIMIT_MSGQUEUE hard limit to {}", new_limit),
+        _ => {
+            // Not mapping these error codes to messages for now, the user can
+            // look up the meaning in setrlimit(2).
+            panic!("Could not set hard limit: {}", errno);
+        }
+    };
+}
+
+fn main() {
+    let ls = SubCommand::with_name("ls").about("list message queues");
+
+    let queue_arg = Arg::with_name("queue").required(true).takes_value(true);
+
+    let rlimit_arg = Arg::with_name("rlimit")
+        .help("RLIMIT_MSGQUEUE to set for this command")
+        .long("rlimit")
+        .takes_value(true);
+
+    let inspect = SubCommand::with_name("inspect")
+        .about("inspect details about a queue")
+        .arg(&queue_arg);
+
+    let create = SubCommand::with_name("create")
+        .about("Create a new queue")
+        .arg(&queue_arg)
+        .arg(&rlimit_arg)
+        .arg(
+            Arg::with_name("max-size")
+                .help("maximum message size (in kB)")
+                .long("max-size")
+                .required(true)
+                .takes_value(true),
+        )
+        .arg(
+            Arg::with_name("max-pending")
+                .help("maximum # of pending messages")
+                .long("max-pending")
+                .required(true)
+                .takes_value(true),
+        );
+
+    let receive = SubCommand::with_name("receive")
+        .about("Receive a message from a queue")
+        .arg(&queue_arg);
+
+    let send = SubCommand::with_name("send")
+        .about("Send a message to a queue")
+        .arg(&queue_arg)
+        .arg(
+            Arg::with_name("message")
+                .help("the message to send")
+                .required(true),
+        );
+
+    let rlimit = SubCommand::with_name("rlimit")
+        .about("Get the message queue rlimit")
+        .setting(AppSettings::SubcommandRequiredElseHelp);
+
+    let matches = App::new("mq")
+        .setting(AppSettings::SubcommandRequiredElseHelp)
+        .version("1.0.0")
+        .about("Administrate and inspect POSIX message queues")
+        .subcommand(ls)
+        .subcommand(inspect)
+        .subcommand(create)
+        .subcommand(receive)
+        .subcommand(send)
+        .subcommand(rlimit)
+        .get_matches();
+
+    match matches.subcommand() {
+        ("ls", _) => run_ls(),
+        ("inspect", Some(cmd)) => run_inspect(cmd.value_of("queue").unwrap()),
+        ("create", Some(cmd)) => run_create(cmd),
+        ("receive", Some(cmd)) => run_receive(cmd.value_of("queue").unwrap()),
+        ("send", Some(cmd)) => run_send(
+            cmd.value_of("queue").unwrap(),
+            cmd.value_of("message").unwrap(),
+        ),
+        ("rlimit", _) => run_rlimit(),
+        _ => unimplemented!(),
+    }
+}