From d97f32cd52e46c47975f4291ea91e8e42287d5a6 Mon Sep 17 00:00:00 2001
From: Erin Shepherd <erin.shepherd@e43.eu>
Date: Sun, 16 Jul 2023 21:19:07 +0200
Subject: [PATCH] Add support for graceful restart by signal (SIGUSR2)

---
 sysdep/unix/io.c   |  7 +++++++
 sysdep/unix/main.c | 19 +++++++++++++++++++
 sysdep/unix/unix.h |  2 ++
 3 files changed, 28 insertions(+)

diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 6aedcfb6..044b19e2 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -2296,6 +2296,13 @@ io_loop(void)
 	  async_shutdown_flag = 0;
 	  continue;
 	}
+      if (async_graceful_shutdown_flag)
+  {
+	  io_log_event(async_graceful_shutdown, NULL);
+	  async_graceful_shutdown();
+	  async_graceful_shutdown_flag = 0;
+	  continue;
+  }
 
       /* And finally enter poll() to find active sockets */
       watchdog_stop();
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index 0d3ec0c0..16d94e80 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -618,6 +618,14 @@ async_shutdown(void)
   order_shutdown(0);
 }
 
+void
+async_graceful_shutdown(void)
+{
+  DBG("Shutting down for graceful restart...\n");
+  order_shutdown(1);
+}
+
 void
 sysdep_shutdown_done(void)
 {
@@ -645,6 +653,7 @@ cmd_graceful_restart(void)
 volatile sig_atomic_t async_config_flag;
 volatile sig_atomic_t async_dump_flag;
 volatile sig_atomic_t async_shutdown_flag;
+volatile sig_atomic_t async_graceful_shutdown_flag;
 
 static void
 handle_sighup(int sig UNUSED)
@@ -667,6 +676,13 @@ handle_sigterm(int sig UNUSED)
   async_shutdown_flag = 1;
 }
 
+static void
+handle_sigusr2(int sig UNUSED)
+{
+  DBG("Caught SIGUSR2...\n");
+  async_graceful_shutdown_flag = 1;
+}
+
 void watchdog_sigalrm(int sig UNUSED);
 
 static void
@@ -678,6 +694,9 @@ signal_init(void)
   sa.sa_handler = handle_sigusr;
   sa.sa_flags = SA_RESTART;
   sigaction(SIGUSR1, &sa, NULL);
+  sa.sa_handler = handle_sigusr2;
+  sa.sa_flags = SA_RESTART;
+  sigaction(SIGUSR2, &sa, NULL);
   sa.sa_handler = handle_sighup;
   sa.sa_flags = SA_RESTART;
   sigaction(SIGHUP, &sa, NULL);
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index ad85d1ea..df1ad0af 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -24,6 +24,7 @@ extern int parse_and_exit;
 void async_config(void);
 void async_dump(void);
 void async_shutdown(void);
+void async_graceful_shutdown(void);
 char *get_hostname(linpool *lp);
 void cmd_check_config(const char *name);
 void cmd_reconfig(const char *name, int type, uint timeout);
@@ -103,6 +104,7 @@ int sockaddr_read(sockaddr *sa, int af, ip_addr *a, struct iface **ifa, uint *po
 extern volatile sig_atomic_t async_config_flag;
 extern volatile sig_atomic_t async_dump_flag;
 extern volatile sig_atomic_t async_shutdown_flag;
+extern volatile sig_atomic_t async_graceful_shutdown_flag;
 
 void io_init(void);
 void io_loop(void);
-- 
2.39.2