From c90e2998f6ddb225efba3538f3e06b8a79f2c023 Mon Sep 17 00:00:00 2001
From: netblue30 <netblue30@protonmail.com>
Date: Tue, 25 Oct 2022 14:34:17 -0400
Subject: nettrace: various fixes

---
 src/fnettrace-icmp/main.c | 35 ++++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)

(limited to 'src/fnettrace-icmp/main.c')

diff --git a/src/fnettrace-icmp/main.c b/src/fnettrace-icmp/main.c
index 47d61a326..e1e5daa48 100644
--- a/src/fnettrace-icmp/main.c
+++ b/src/fnettrace-icmp/main.c
@@ -22,6 +22,8 @@
 #include <time.h>
 #include <linux/filter.h>
 #include <linux/if_ether.h>
+#include <sys/prctl.h>
+#include <signal.h>
 #define MAX_BUF_SIZE (64 * 1024)
 
 char *type_description[19] = {
@@ -139,6 +141,19 @@ static void custom_bpf(int sock) {
 	}
 }
 
+static void print_date(void) {
+	static int day = -1;
+	time_t now = time(NULL);
+	struct tm *t = localtime(&now);
+
+	if (day != t->tm_yday) {
+		printf("\nICMP trace for %s", ctime(&now));
+		day = t->tm_yday;
+	}
+
+	fflush(0);
+}
+
 static void run_trace(void) {
 	// grab all Ethernet packets and use a custom BPF filter to get TLS/SNI packets
 	int s = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
@@ -146,19 +161,24 @@ static void run_trace(void) {
 		errExit("socket");
 	custom_bpf(s);
 
+	struct timeval tv;
+	tv.tv_sec = 10;
+	tv.tv_usec = 0;
 	unsigned char buf[MAX_BUF_SIZE];
 	while (1) {
 		fd_set rfds;
 		FD_ZERO(&rfds);
 		FD_SET(s, &rfds);
-		struct timeval tv;
-		tv.tv_sec = 1;
-		tv.tv_usec = 0;
 		int rv = select(s + 1, &rfds, NULL, NULL, &tv);
 		if (rv < 0)
 			errExit("select");
-		else if (rv == 0)
+		else if (rv == 0) {
+			print_date();
+			tv.tv_sec = 10;
+			tv.tv_usec = 0;
 			continue;
+		}
+
 		unsigned bytes = recvfrom(s, buf, MAX_BUF_SIZE, 0, NULL, NULL);
 
 		if (bytes >= (14 + 20 + 2)) { // size of  MAC + IP + ICMP code and type fields
@@ -180,7 +200,6 @@ static void run_trace(void) {
 	close(s);
 }
 
-
 static void usage(void) {
 	printf("Usage: fnettrace-icmp [OPTIONS]\n");
 	printf("Options:\n");
@@ -207,8 +226,10 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
-	time_t now = time(NULL);
-	printf("ICMP trace for %s\n", ctime(&now));
+	// kill the process if the parent died
+	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
+
+	print_date();
 	run_trace();
 
 	return 0;
-- 
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