.github/workflows/check.yml

@@ -41,6 +41,7 @@ jobs:
       - name: Run cargo-tarpaulin
         uses: actions-rs/tarpaulin@v0.1
         with:
+          version: '0.9.0'
           args: '-o Html -- --test-threads=1'
       - name: Archive code coverage results
         uses: actions/upload-artifact@v1

src/device.rs

@@ -6,7 +6,7 @@ use libc::{c_short, c_ulong, ioctl, IFF_NO_PI, IFF_TAP, IFF_TUN, IF_NAMESIZE};
 use std::{
     collections::VecDeque,
     fmt, fs,
-    io::{self, Cursor, Error as IoError, ErrorKind, Read, Write},
+    io::{self, Error as IoError, ErrorKind, Read, Write},
     os::unix::io::{AsRawFd, RawFd},
     str,
     str::FromStr
@@ -150,10 +150,8 @@ impl TunTapDevice {
         let res = unsafe { ioctl(fd.as_raw_fd(), TUNSETIFF, &mut ifreq) };
         match res {
             0 => {
-                let mut ifname = String::with_capacity(32);
+                let nul_range_end = ifreq.ifr_name.iter().position(|&c| c == b'\0').unwrap_or(ifreq.ifr_name.len());
-                let mut cursor = Cursor::new(ifreq.ifr_name);
+                let ifname = unsafe { str::from_utf8_unchecked(&ifreq.ifr_name[0..nul_range_end]) }.to_string();
-                cursor.read_to_string(&mut ifname)?;
-                ifname = ifname.trim_end_matches('\0').to_owned();
                 Ok(Self { fd, ifname, type_ })
             }
             _ => Err(IoError::last_os_error())