Add better error message when ip command is missing

Rose-Rocketry · Jan 29, 2023 · 5d878b8 · 5d878b8
1 parent d2a8a67
commit 5d878b8
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Showing 3 changed files with 34 additions and 29 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -16,7 +16,7 @@
 
 [package]
 name = "xbnet"
-version = "1.2.0"
+version = "1.2.1"
 authors = ["John Goerzen <jgoerzen@complete.org>"]
 edition = "2018"
 license = "GPL-3.0+"

diff --git a/src/tun.rs b/src/tun.rs
@@ -29,6 +29,7 @@ use crossbeam_channel;
 use etherparse::*;
 use log::*;
 use std::collections::HashMap;
+use std::ffi::OsStr;
 use std::io;
 use std::net::IpAddr;
 use std::sync::{Arc, Mutex};
@@ -51,6 +52,22 @@ pub struct XBTun {
     pub dests: Arc<Mutex<HashMap<IpAddr, (u64, Instant)>>>,
 }
 
+fn run_ip_cmd<I, S>(args: I)
+where
+    I: IntoIterator<Item = S>,
+    S: AsRef<OsStr>,
+{
+    assert_eq!(
+        std::process::Command::new("ip")
+            .args(args)
+            .status()
+            .expect("Ensure the 'ip' command from 'iproute2' is available")
+            .code(),
+        Some(0),
+        "ip exited with nonzero exit code"
+    );
+}
+
 impl XBTun {
     pub fn new_tun(
         myxbmac: u64,
@@ -68,27 +85,13 @@ impl XBTun {
         // TODO: This should use ioctl to be more portable
 
         if set_up {
-            assert_eq!(
-                std::process::Command::new("ip")
-                    .args(["link", "set", name, "up"])
-                    .status()
-                    .unwrap()
-                    .code(),
-                Some(0)
-            );
-            info!("Set interface to up")
+            run_ip_cmd(["link", "set", name, "up"]);
+            info!("Set interface to up");
         }
 
         if let Some(ip) = set_ip {
-            assert_eq!(
-                std::process::Command::new("ip")
-                    .args(["addr", "add", &ip, "dev", name])
-                    .status()
-                    .unwrap()
-                    .code(),
-                Some(0)
-            );
-            info!("Set ip to {}", ip)
+            run_ip_cmd(["addr", "add", &ip, "dev", name]);
+            info!("Set ip to {}", ip);
         }
 
         println!("Interface {} (XBee MAC {:x}) ready", name, myxbmac,);
@@ -114,9 +117,7 @@ impl XBTun {
 
         match self.dests.lock().unwrap().get(ipaddr) {
             // Broadcast if we don't know it
-            None => {
-                XB_BROADCAST
-            },
+            None => XB_BROADCAST,
             Some((dest, expiration)) => {
                 if Instant::now() >= *expiration {
                     // Broadcast it if the cache entry has expired
@@ -145,16 +146,18 @@ impl XBTun {
                     let ips = extract_ips(&packet);
                     if let Some((source, destination)) = ips {
                         match destination {
-                            IpAddr::V6(_) =>
+                            IpAddr::V6(_) => {
                                 if self.disable_ipv6 {
                                     debug!("Dropping packet because --disable-ipv6 given");
                                     continue;
-                                },
-                            IpAddr::V4(_) =>
+                                }
+                            }
+                            IpAddr::V4(_) => {
                                 if self.disable_ipv4 {
                                     debug!("Dropping packet because --disable-ipv4 given");
                                     continue;
                                 }
+                            }
                         };
 
                         let destxbmac = self.get_xb_dest_mac(&destination);
@@ -204,16 +207,18 @@ impl XBTun {
                     if let Some((source, destination)) = ips {
                         trace!("SERIN: Packet is {} -> {}", source, destination);
                         match source {
-                            IpAddr::V6(_) =>
+                            IpAddr::V6(_) => {
                                 if self.disable_ipv6 {
                                     debug!("Dropping packet because --disable-ipv6 given");
                                     continue;
-                                },
-                            IpAddr::V4(_) =>
+                                }
+                            }
+                            IpAddr::V4(_) => {
                                 if self.disable_ipv4 {
                                     debug!("Dropping packet because --disable-ipv4 given");
                                     continue;
                                 }
+                            }
                         }
                         if !self.broadcast_everything {
                             self.dests.lock().unwrap().insert(