1 files changed, 68 insertions, 0 deletions
diff --git a/proto_icmpv4.c b/proto_icmpv4.c
new file mode 100644
index 0000000..13f0eda
--- /dev/null
+++ b/proto_icmpv4.c
@@ -0,0 +1,68 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2009, 2010 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <netinet/in.h>    /* for ntohs() */
+
+#include "proto.h"
+#include "protos.h"
+#include "csum.h"
+#include "dissector_eth.h"
+#include "pkt_buff.h"
+#include "built_in.h"
+
+struct icmphdr {
+	uint8_t type;
+	uint8_t code;
+	uint16_t checksum;
+	union {
+		struct {
+			uint16_t id;
+			uint16_t sequence;
+		} echo;
+		uint32_t gateway;
+		struct {
+			uint16_t ____unused;
+			uint16_t mtu;
+		} frag;
+	} un;
+} __packed;
+
+static void icmp(struct pkt_buff *pkt)
+{
+	struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
+	uint16_t csum;
+
+	if (icmp == NULL)
+		return;
+
+	csum = calc_csum(icmp, pkt_len(pkt) + sizeof(*icmp), 0);
+
+	tprintf(" [ ICMP ");
+	tprintf("Type (%u), ", icmp->type);
+	tprintf("Code (%u), ", icmp->code);
+	tprintf("CSum (0x%.4x) is %s", ntohs(icmp->checksum),
+		csum ? colorize_start_full(black, red) "bogus (!)"
+		       colorize_end() : "ok");
+	tprintf(" ]\n");
+}
+
+static void icmp_less(struct pkt_buff *pkt)
+{
+	struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
+
+	if (icmp == NULL)
+		return;
+
+	tprintf(" Type %u Code %u", icmp->type, icmp->code);
+}
+
+struct protocol icmpv4_ops = {
+	.key = 0x01,
+	.print_full = icmp,
+	.print_less = icmp_less,
+};