From 6f2d1c5b1589295249e7b4548657374bfe11f909 Mon Sep 17 00:00:00 2001
From: Andy Fiddaman <andy@oxidecomputer.com>
Date: Mon, 4 Dec 2023 16:55:29 +0000
Subject: [PATCH] Improve wtmp record mangling. (#4501)

This fixes two problems with the current wtmp/utmp record mangling.
First it is not idempotent, the system's notion of boot time is set to
the current time of day whenever sled agent confirms that time is
synchronised. Secondly, this is only approximate even for the first sled
agent start, but it's plain wrong if sled agent restarts later.

In conjunction with changes to stlouis, the `tmpx` utility is now able
to process all zones itself, and uses the true system boot time for each
zone when updating records.

Fixes: https://github.com/oxidecomputer/omicron/issues/3514
---
 sled-agent/src/services.rs             | 45 ++++++--------------------
 tools/install_builder_prerequisites.sh |  2 ++
 2 files changed, 12 insertions(+), 35 deletions(-)

diff --git a/sled-agent/src/services.rs b/sled-agent/src/services.rs
index 88f79e7064..dc309e8423 100644
--- a/sled-agent/src/services.rs
+++ b/sled-agent/src/services.rs
@@ -101,13 +101,11 @@ use sled_storage::manager::StorageHandle;
 use slog::Logger;
 use std::collections::BTreeMap;
 use std::collections::HashSet;
-use std::iter;
 use std::iter::FromIterator;
 use std::net::{IpAddr, Ipv6Addr, SocketAddr};
 use std::str::FromStr;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
-use std::time::{SystemTime, UNIX_EPOCH};
 use tokio::io::AsyncWriteExt;
 use tokio::sync::Mutex;
 use tokio::sync::{oneshot, MutexGuard};
@@ -2931,10 +2929,7 @@ impl ServiceManager {
         Ok(())
     }
 
-    pub fn boottime_rewrite<'a>(
-        &self,
-        zones: impl Iterator<Item = &'a RunningZone>,
-    ) {
+    pub fn boottime_rewrite(&self) {
         if self
             .inner
             .time_synced
@@ -2945,33 +2940,13 @@ impl ServiceManager {
             return;
         }
 
-        let now = SystemTime::now()
-            .duration_since(UNIX_EPOCH)
-            .expect("SystemTime before UNIX EPOCH");
-
-        info!(self.inner.log, "Setting boot time to {:?}", now);
-
-        let files: Vec<Utf8PathBuf> = zones
-            .map(|z| z.root())
-            .chain(iter::once(Utf8PathBuf::from("/")))
-            .flat_map(|r| [r.join("var/adm/utmpx"), r.join("var/adm/wtmpx")])
-            .collect();
-
-        for file in files {
-            let mut command = std::process::Command::new(PFEXEC);
-            let cmd = command.args(&[
-                "/usr/platform/oxide/bin/tmpx",
-                &format!("{}", now.as_secs()),
-                &file.as_str(),
-            ]);
-            match execute(cmd) {
-                Err(e) => {
-                    warn!(self.inner.log, "Updating {} failed: {}", &file, e);
-                }
-                Ok(_) => {
-                    info!(self.inner.log, "Updated {}", &file);
-                }
-            }
+        // Call out to the 'tmpx' utility program which will rewrite the wtmpx
+        // and utmpx databases in every zone, including the global zone, to
+        // reflect the adjusted system boot time.
+        let mut command = std::process::Command::new(PFEXEC);
+        let cmd = command.args(&["/usr/platform/oxide/bin/tmpx", "-Z"]);
+        if let Err(e) = execute(cmd) {
+            warn!(self.inner.log, "Updating [wu]tmpx databases failed: {}", e);
         }
     }
 
@@ -2980,7 +2955,7 @@ impl ServiceManager {
 
         if let Some(true) = self.inner.skip_timesync {
             info!(self.inner.log, "Configured to skip timesync checks");
-            self.boottime_rewrite(existing_zones.values());
+            self.boottime_rewrite();
             return Ok(TimeSync {
                 sync: true,
                 ref_id: 0,
@@ -3034,7 +3009,7 @@ impl ServiceManager {
                         && correction.abs() <= 0.05;
 
                     if sync {
-                        self.boottime_rewrite(existing_zones.values());
+                        self.boottime_rewrite();
                     }
 
                     Ok(TimeSync {
diff --git a/tools/install_builder_prerequisites.sh b/tools/install_builder_prerequisites.sh
index d3ecd8eaa8..1ce133dff3 100755
--- a/tools/install_builder_prerequisites.sh
+++ b/tools/install_builder_prerequisites.sh
@@ -131,6 +131,8 @@ function install_packages {
       "library/libxmlsec1"
       # "bindgen leverages libclang to preprocess, parse, and type check C and C++ header files."
       "pkg:/ooce/developer/clang-$CLANGVER"
+      "system/library/gcc-runtime"
+      "system/library/g++-runtime"
     )
 
     # Install/update the set of packages.