dnsniff

commit c0f18fb9b102ddd67183da5f0e6f16dc1c866ad9
parent 30d8a9904de544ba14e5cc92b41244867e4c848e
Author: Louis Burda <quent.burda@gmail.com>
Date:   Thu, 16 Feb 2023 20:23:13 +0100

Small fixes

Diffstat:
M
dnsniff.c
 | 
7
++++---

1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/dnsniff.c b/dnsniff.c
@@ -18,6 +18,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#define PACKETBUFLEN (1024 * 1024)
 #define HDRLEN (sizeof(struct ethhdr) + sizeof(struct iphdr) + sizeof(struct udphdr))
 
 struct dnshdr {
@@ -74,7 +75,7 @@ static int sock, ifid;
 void
 usage(void)
 {
-	printf("Usage: dnsniff INTERFACE\n");
+	printf("Usage: dnsniff IFACE\n");
 	exit(0);
 }
 
@@ -238,7 +239,7 @@ main(int argc, const char **argv)
 	if (argc != 2) usage();
 	ifname = argv[1];
 
-	buf = malloc(1024 * 1024);
+	buf = malloc(PACKETBUFLEN);
 	if (!buf) err(1, "malloc");
 
 	sniff_init(ifname);
@@ -246,7 +247,7 @@ main(int argc, const char **argv)
 	flt.dst_ip = 0;
 	flt.src_ip = 0;
 	flt.dst_port = htons(53);
-	while (sniff(&pkt, &flt, buf, 1024 * 1024)) {
+	while (sniff(&pkt, &flt, buf, PACKETBUFLEN)) {
 		inet_ntop(AF_INET, (struct in_addr *) &pkt.ip->saddr,
 			src_ip, INET_ADDRSTRLEN);
 		inet_ntop(AF_INET, (struct in_addr *) &pkt.ip->daddr,