1 files changed, 109 insertions, 0 deletions
diff --git a/proto_mpls_unicast.c b/proto_mpls_unicast.c
new file mode 100644
index 0000000..113c10f
--- /dev/null
+++ b/proto_mpls_unicast.c
@@ -0,0 +1,109 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2012 Markus Amend <markus@netsniff-ng.org>, Deutsche Flugsicherung GmbH
+ * Subject to the GPL, version 2.
+ *
+ * http://tools.ietf.org/html/rfc3032
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <netinet/in.h>    /* for ntohs() */
+#include <errno.h>
+
+#include "proto.h"
+#include "protos.h"
+#include "dissector_eth.h"
+#include "built_in.h"
+#include "pkt_buff.h"
+
+struct mpls_uchdr {
+	uint32_t mpls_uc_hdr;
+} __packed;
+
+static int mpls_uc_next_proto(struct pkt_buff *pkt)
+{
+	uint8_t proto;
+	uint16_t key = 0;
+
+	if (pkt_len(pkt))
+		proto = *(pkt->data);
+	else
+		return -EIO;
+
+	/* FIXME: Right now only test for IP Version field */
+	switch (proto >> 4) {
+	case 4:
+		key = 0x0800; /* IPv4*/
+		break;
+	case 6:
+		key = 0x86DD; /* IPv6*/
+		break;
+	default:
+		/* Nothing detected ... */
+		return -ENOENT;
+	}
+
+	return key;
+}
+
+static void mpls_uc_full(struct pkt_buff *pkt)
+{
+	int next;
+	uint32_t mpls_uc_data;
+	struct mpls_uchdr *mpls_uc;
+	uint8_t s = 0;
+
+	do {
+		mpls_uc = (struct mpls_uchdr *) pkt_pull(pkt, sizeof(*mpls_uc));
+		if (mpls_uc == NULL)
+			return;
+
+		mpls_uc_data = ntohl(mpls_uc->mpls_uc_hdr);
+		s = (mpls_uc_data >> 8) & 0x1;
+
+		tprintf(" [ MPLS ");
+		tprintf("Label (%u), ", mpls_uc_data >> 12);
+		tprintf("Exp (%u), ", (mpls_uc_data >> 9) & 0x7);
+		tprintf("S (%u), ", s);
+		tprintf("TTL (%u)", (mpls_uc_data & 0xFF));
+		tprintf(" ]\n");
+	} while (!s);
+
+	next = mpls_uc_next_proto(pkt);
+	if (next < 0)
+		return;
+
+	pkt_set_proto(pkt, &eth_lay2, (uint16_t) next);
+}
+
+static void mpls_uc_less(struct pkt_buff *pkt)
+{
+	int next;
+	uint32_t mpls_uc_data;
+	struct mpls_uchdr *mpls_uc;
+	uint8_t s = 0;
+
+	do {
+		mpls_uc = (struct mpls_uchdr *) pkt_pull(pkt, sizeof(*mpls_uc));
+		if (mpls_uc == NULL)
+			return;
+
+		mpls_uc_data = ntohl(mpls_uc->mpls_uc_hdr);
+		s = (mpls_uc_data >> 8) & 0x1;
+
+		tprintf(" MPLS/%u", mpls_uc_data >> 12);
+	} while (!s);
+
+	next = mpls_uc_next_proto(pkt);
+	if (next < 0)
+		return;
+
+	pkt_set_proto(pkt, &eth_lay2, (uint16_t) next);
+}
+
+struct protocol mpls_uc_ops = {
+	.key = 0x8847,
+	.print_full = mpls_uc_full,
+	.print_less = mpls_uc_less,
+};