mtu: minor fixups; try harder to traverse nat boxes in mtu inject

2 files changed, 10 insertions, 6 deletions

diff --git a/icmp.c b/icmp.c
index bb5db3f..8c27a8e 100644
--- a/icmp.c
+++ b/icmp.c
@@ -260,8 +260,7 @@ int icmp_send_frag_needed(int fd, struct sockaddr *to, int tolen,
 	icp->un.frag.mtu = htons(newmtu);
 
 	/* copy ip header + 64-bits of original packet */
-	memcpy(&packet[sizeof(struct icmphdr)], iph,
-	       sizeof(struct iphdr) + 8);
+	memcpy(icp + 1, iph, sizeof(struct iphdr) + 8);
 
 	icp->checksum = in_cksum((u_short *) icp, len, 0);
 
@@ -275,7 +274,7 @@ int icmp_send_ping(int fd, struct sockaddr *to, int tolen,
 		   int seq, int total_size)
 {
 	struct sockaddr_in *to_in = (struct sockaddr_in *) to;
-	char packet[1500];
+	__u8 packet[1500];
 	struct icmphdr *icp;
 	int len;
 
@@ -285,6 +284,7 @@ int icmp_send_ping(int fd, struct sockaddr *to, int tolen,
 		total_size = sizeof(struct iphdr) + sizeof(struct icmphdr);
 
 	len = total_size - sizeof(struct iphdr);
+	memset(packet, 0, sizeof(packet));
 
 	icp = (struct icmphdr *) packet;
 	icp->type = ICMP_ECHO;
diff --git a/mtu.c b/mtu.c
index 1a3c42c..01af3ed 100644
--- a/mtu.c
+++ b/mtu.c
@@ -93,9 +93,9 @@ static void do_inject(void)
 	struct sockaddr_in from;
 	int len, seq = 0;
 
+	icmp_send_ping(fd, (struct sockaddr *) &to, sizeof(to),
+		       ++seq, mtu_size);
 	for (;;) {
-		icmp_send_ping(fd, (struct sockaddr *) &to, sizeof(to),
-			       ++seq, mtu_size);
 		if ((len = icmp_read_reply(fd, (struct sockaddr *) &from,
 					   sizeof(from),
 					   buf, sizeof(buf))) <= 0)
@@ -106,9 +106,13 @@ static void do_inject(void)
 				     (struct sockaddr *) &to))
 			continue;
 
+		if (seq != 1)
+			sleep(1);
+
+		icmp_send_ping(fd, (struct sockaddr *) &to, sizeof(to),
+			       ++seq, mtu_size);
 		icmp_send_frag_needed(fd, (struct sockaddr *) &to, sizeof(to),
 				      (struct iphdr *) buf, mtu_size - 2);
-		sleep(1);
 	}
 }