Small fixes

1 files changed, 4 insertions, 3 deletions

diff --git a/dnsniff.c b/dnsniff.c
index 4a1e3f2..319bd83 100644
--- 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,