From 6305b2302932f2db091d5bddc11df49f761a1e93 Mon Sep 17 00:00:00 2001
From: Jake Shadle <jake.shadle@embark-studios.com>
Date: Fri, 9 Aug 2024 10:50:20 +0200
Subject: [PATCH] Add missing SAFETY docs

---
 src/components/proxy/io_uring_shared.rs        | 2 ++
 src/components/proxy/sessions/inner_metrics.rs | 1 +
 src/metrics.rs                                 | 1 +
 src/pool.rs                                    | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/src/components/proxy/io_uring_shared.rs b/src/components/proxy/io_uring_shared.rs
index dad2f3bf6..179e38c47 100644
--- a/src/components/proxy/io_uring_shared.rs
+++ b/src/components/proxy/io_uring_shared.rs
@@ -465,6 +465,8 @@ impl<'uring> LoopCtx<'uring> {
             self.sq.sync();
 
             match self.backlog.pop_front() {
+                // SAFETY: Same as Self::push, all memory pointed to in our ops are pinned at
+                // stable locations in memory
                 Some(sqe) => unsafe {
                     let _ = self.sq.push(&sqe);
                 },
diff --git a/src/components/proxy/sessions/inner_metrics.rs b/src/components/proxy/sessions/inner_metrics.rs
index 6ee30c0e2..bc2902ffa 100644
--- a/src/components/proxy/sessions/inner_metrics.rs
+++ b/src/components/proxy/sessions/inner_metrics.rs
@@ -41,6 +41,7 @@ pub(crate) fn active_sessions(asn: Option<&crate::net::maxmind_db::IpNetEntry>)
         let len = crate::metrics::itoa(asnfo.id, &mut asn);
 
         ACTIVE_SESSIONS.with_label_values(&[
+            // SAFETY: itoa only writes ASCII
             unsafe { std::str::from_utf8_unchecked(&asn[..len as _]) },
             &asnfo.as_name,
             &asnfo.as_cc,
diff --git a/src/metrics.rs b/src/metrics.rs
index e07a0369c..f5d9a9892 100644
--- a/src/metrics.rs
+++ b/src/metrics.rs
@@ -86,6 +86,7 @@ pub struct AsnInfo<'a> {
 impl<'a> AsnInfo<'a> {
     #[inline]
     fn asn_str(&self) -> &str {
+        // SAFETY: we only write ASCII in itoa
         unsafe { std::str::from_utf8_unchecked(&self.asn[..self.asn_len as _]) }
     }
 }
diff --git a/src/pool.rs b/src/pool.rs
index 261e5398b..d37bd995e 100644
--- a/src/pool.rs
+++ b/src/pool.rs
@@ -197,6 +197,8 @@ impl PoolBuffer {
     #[inline]
     #[cfg(target_os = "linux")]
     pub(crate) fn set_len(&mut self, len: usize) {
+        // SAFETY: len is the length as returned from the kernel on a successful
+        // recv_from call
         unsafe { self.inner.set_len(len) }
     }
 }