Handle SIGTERM and SIGINT for graceful shutdown

impl/src/main.c

@@ -1,9 +1,7 @@
 #include <linux/if.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <ctype.h>
-#include <time.h>
 
 #include <liquid/liquid.h>
 
@@ -11,6 +9,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <signal.h>
 
 #include "utils.h"
 #include "layer1/tx.h"
@@ -42,6 +41,17 @@ static struct {
 } m_stats;
 
 
+static void signal_handler(int signal, siginfo_t *info, void *ctx)
+{
+	(void)signal;
+	(void)info;
+	(void)ctx;
+
+	fprintf(stderr, "\nGracefully shutting down on signal %d.\n", signal);
+
+	m_running = false;
+}
+
 static void block_tx_for(unsigned offset_ms)
 {
 	next_tx_switch_time = get_hires_time() + (double)offset_ms * 0.001;
@@ -210,6 +220,21 @@ int main(void)
 	RESULT_CHECK(layer1_tx_init(&tx));
 	RESULT_CHECK(layer1_rx_init(&rx, cb_rx));
 
+	// ** Set up signal handling
+
+	struct sigaction term_action = {0};
+	term_action.sa_sigaction = signal_handler;
+
+	if(sigaction(SIGTERM, &term_action, NULL) < 0) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	if(sigaction(SIGINT, &term_action, NULL) < 0) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
 	// ** Process packets **
 
 	struct pollfd pfd;