1 files changed, 82 insertions, 0 deletions
diff --git a/vendor/tempfile/src/util.rs b/vendor/tempfile/src/util.rs
new file mode 100644
index 00000000..2ac9bea4
--- /dev/null
+++ b/vendor/tempfile/src/util.rs
@@ -0,0 +1,82 @@
+use std::ffi::{OsStr, OsString};
+use std::path::{Path, PathBuf};
+use std::{io, iter::repeat_with};
+
+use crate::error::IoResultExt;
+
+fn tmpname(rng: &mut fastrand::Rng, prefix: &OsStr, suffix: &OsStr, rand_len: usize) -> OsString {
+    let capacity = prefix
+        .len()
+        .saturating_add(suffix.len())
+        .saturating_add(rand_len);
+    let mut buf = OsString::with_capacity(capacity);
+    buf.push(prefix);
+    let mut char_buf = [0u8; 4];
+    for c in repeat_with(|| rng.alphanumeric()).take(rand_len) {
+        buf.push(c.encode_utf8(&mut char_buf));
+    }
+    buf.push(suffix);
+    buf
+}
+
+pub fn create_helper<R>(
+    base: &Path,
+    prefix: &OsStr,
+    suffix: &OsStr,
+    random_len: usize,
+    mut f: impl FnMut(PathBuf) -> io::Result<R>,
+) -> io::Result<R> {
+    // Make the path absolute. Otherwise, changing the current directory can invalidate a stored
+    // path (causing issues when cleaning up temporary files.
+    let mut base = base; // re-borrow to shrink lifetime
+    let base_path_storage; // slot to store the absolute path, if necessary.
+    if !base.is_absolute() {
+        let cur_dir = std::env::current_dir()?;
+        base_path_storage = cur_dir.join(base);
+        base = &base_path_storage;
+    }
+
+    let num_retries = if random_len != 0 {
+        crate::NUM_RETRIES
+    } else {
+        1
+    };
+
+    // We fork the fastrand rng.
+    let mut rng = fastrand::Rng::new();
+    for i in 0..num_retries {
+        // If we fail to create the file the first three times, re-seed from system randomness in
+        // case an attacker is predicting our randomness (fastrand is predictable). If re-seeding
+        // doesn't help, either:
+        //
+        // 1. We have lots of temporary files, possibly created by an attacker but not necessarily.
+        //    Re-seeding the randomness won't help here.
+        // 2. We're failing to create random files for some other reason. This shouldn't be the case
+        //    given that we're checking error kinds, but it could happen.
+        #[cfg(all(
+            feature = "getrandom",
+            any(windows, unix, target_os = "redox", target_os = "wasi")
+        ))]
+        if i == 3 {
+            if let Ok(seed) = getrandom::u64() {
+                rng.seed(seed);
+            }
+        }
+        let _ = i; // avoid unused variable warning for the above.
+
+        let path = base.join(tmpname(&mut rng, prefix, suffix, random_len));
+        return match f(path) {
+            Err(ref e) if e.kind() == io::ErrorKind::AlreadyExists && num_retries > 1 => continue,
+            // AddrInUse can happen if we're creating a UNIX domain socket and
+            // the path already exists.
+            Err(ref e) if e.kind() == io::ErrorKind::AddrInUse && num_retries > 1 => continue,
+            res => res,
+        };
+    }
+
+    Err(io::Error::new(
+        io::ErrorKind::AlreadyExists,
+        "too many temporary files exist",
+    ))
+    .with_err_path(|| base)
+}