Experiment with NETLINK socket from Rust

experiments/explore-kobject-uevent/.gitignore

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+target/

experiments/explore-kobject-uevent/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
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+[[package]]
+name = "explore-kobject-uevent"
+version = "0.1.0"
+dependencies = [
+ "nix",
+]
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+dependencies = [
+ "bitflags",
+ "cc",
+ "cfg-if",
+ "libc",
+ "memoffset",
+]

experiments/explore-kobject-uevent/Cargo.toml

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+[package]
+name = "explore-kobject-uevent"
+version = "0.1.0"
+edition = "2018"
+
+[profile.release]
+lto = true
+
+[dependencies]
+nix = "^0.22"

experiments/explore-kobject-uevent/src/main.rs

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+use nix::sys::socket;
+use nix::sys::uio::IoVec;
+
+use std::io;
+
+fn main() -> io::Result<()> {
+    let sock = socket::socket(socket::AddressFamily::Netlink,
+                              socket::SockType::Raw,
+                              socket::SockFlag::SOCK_CLOEXEC,
+                              socket::SockProtocol::NetlinkKObjectUEvent)?;
+
+    let src = socket::SockAddr::new_netlink(0, 1 /* is this the group for kernel-announced events? */);
+    socket::bind(sock, &src)?;
+
+    loop {
+        println!("Waiting...");
+        let mut buf = vec![0u8; 8192];
+        let iov = [IoVec::from_mut_slice(&mut buf)];
+        let mut cmsg = Vec::with_capacity(8192);
+        let r = socket::recvmsg(sock, &iov, Some(&mut cmsg), socket::MsgFlags::MSG_CMSG_CLOEXEC)?;
+        println!("\n{:#?}", r);
+        for i in 0 .. r.bytes {
+            let b = buf[i];
+            if b == 0 {
+                println!();
+            } else if b >= 32 && b < 128 {
+                print!("{}", b as char);
+            } else {
+                print!("\\x{:02x}", b);
+            }
+        }
+        println!();
+    }
+}