X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/e0787e5d8ce80ea53f447057c466a65759c4d56c..c50f3934dacc4bd3fe16a900d4c63c05acb50ce3:/print-erspan.c

diff --git a/print-erspan.c b/print-erspan.c
index 3bcf0acd..1f8c9f00 100644
--- a/print-erspan.c
+++ b/print-erspan.c
@@ -32,16 +32,18 @@
  * Specifications: I-D draft-foschiano-erspan-03.
  */
 
-#ifdef HAVE_CONFIG_H
 #include <config.h>
-#endif
 
 #include "netdissect-stdinc.h"
 
 #define ND_LONGJMP_FROM_TCHECK
 #include "netdissect.h"
 #include "extract.h"
+#include "gre.h"
 
+/*
+ * ERSPAN Type II.
+ */
 #define ERSPAN2_VER_SHIFT	28
 #define ERSPAN2_VER_MASK	(0xfU << ERSPAN2_VER_SHIFT)
 #define ERSPAN2_VER		(0x1U << ERSPAN2_VER_SHIFT)
@@ -63,13 +65,8 @@
 #define ERSPAN2_INDEX_SHIFT	0
 #define ERSPAN2_INDEX_MASK	(0xfffffU << ERSPAN2_INDEX_SHIFT)
 
-/*
- * XXX - eh?
- */
-#define	GRE_SP		0x1000		/* sequence# present */
-
 void
-erspan_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int len)
+erspan_i_ii_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int len)
 {
 	uint32_t hdr, ver, vlan, cos, en, sid, index;
 
@@ -77,11 +74,17 @@ erspan_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int le
 	nd_print_protocol(ndo);
 
 	if (!(flags & GRE_SP)) {
-		ND_PRINT(" I: ");
+		/*
+		 * ERSPAN Type I; no header, just a raw Ethernet frame.
+		 */
+		ND_PRINT(" type1: ");
 		ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
 		return;
 	}
 
+	/*
+	 * ERSPAN Type II.
+	 */
 	ND_ICHECK_U(len, <, 4);
 	hdr = GET_BE_U_4(bp);
 	bp += 4;
@@ -89,13 +92,16 @@ erspan_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int le
 
 	ver = hdr & ERSPAN2_VER_MASK;
 	if (ver != ERSPAN2_VER) {
+		/*
+		 * Not Type II.
+		 */
 		ver >>= ERSPAN2_VER_SHIFT;
 		ND_PRINT(" erspan-unknown-version-%x", ver);
 		return;
 	}
 
 	if (ndo->ndo_vflag)
-		ND_PRINT(" II");
+		ND_PRINT(" type2");
 
 	sid = (hdr & ERSPAN2_SID_MASK) >> ERSPAN2_SID_SHIFT;
 	ND_PRINT(" session %u", sid);
@@ -141,3 +147,147 @@ erspan_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int le
 invalid:
 	nd_print_invalid(ndo);
 }
+
+/*
+ * ERSPAN Type III.
+ */
+#define ERSPAN3_VER_SHIFT		28
+#define ERSPAN3_VER_MASK		(0xfU << ERSPAN3_VER_SHIFT)
+#define ERSPAN3_VER			(0x2U << ERSPAN3_VER_SHIFT)
+#define ERSPAN3_VLAN_SHIFT		16
+#define ERSPAN3_VLAN_MASK		(0xfffU << ERSPAN3_VLAN_SHIFT)
+#define ERSPAN3_COS_SHIFT		13
+#define ERSPAN3_COS_MASK		(0x7U << ERSPAN3_COS_SHIFT)
+#define ERSPAN3_BSO_SHIFT		11
+#define ERSPAN3_BSO_MASK		(0x3U << ERSPAN3_BSO_SHIFT)
+#define ERSPAN3_BSO_GOOD_UNKNOWN	0x0U
+#define ERSPAN3_BSO_BAD			0x3U
+#define ERSPAN3_BSO_SHORT		0x1U
+#define ERSPAN3_BSO_OVERSIZED		0x2U
+#define ERSPAN3_T_SHIFT			10
+#define ERSPAN3_T_MASK			(0x1U << ERSPAN3_T_SHIFT)
+#define ERSPAN3_SID_SHIFT		0
+#define ERSPAN3_SID_MASK		(0x3ffU << ERSPAN3_SID_SHIFT)
+#define ERSPAN3_P_SHIFT			15
+#define ERSPAN3_P_MASK			(0x1U << ERSPAN3_P_SHIFT)
+#define ERSPAN3_FT_SHIFT		10
+#define ERSPAN3_FT_MASK			(0x1fU << ERSPAN3_FT_SHIFT)
+#define ERSPAN3_FT_ETHERNET		0
+#define ERSPAN3_FT_IP			2
+#define ERSPAN3_HW_ID_SHIFT		4
+#define ERSPAN3_HW_ID_MASK		(0x3fU << ERSPAN3_HW_ID_SHIFT)
+#define ERSPAN3_D_SHIFT			3
+#define ERSPAN3_D_MASK			(0x1U << ERSPAN3_D_SHIFT)
+#define ERSPAN3_GRA_SHIFT		1
+#define ERSPAN3_GRA_MASK		(0x3U << ERSPAN3_GRA_SHIFT)
+#define ERSPAN3_O_SHIFT			0
+#define ERSPAN3_O_MASK			(0x1U << ERSPAN3_O_SHIFT)
+
+static const struct tok erspan3_bso_values[] = {
+	{ ERSPAN3_BSO_GOOD_UNKNOWN, "Good/unknown" },
+	{ ERSPAN3_BSO_BAD,          "Bad" },
+	{ ERSPAN3_BSO_SHORT,        "Short" },
+	{ ERSPAN3_BSO_OVERSIZED,    "Oversized" },
+	{ 0, NULL }
+};
+
+static const struct tok erspan3_ft_values[] = {
+	{ ERSPAN3_FT_ETHERNET, "Ethernet" },
+	{ ERSPAN3_FT_IP, "IP" },
+	{ 0, NULL }
+};
+
+void
+erspan_iii_print(netdissect_options *ndo, const u_char *bp, u_int len)
+{
+	uint32_t hdr, hdr2, ver, cos, sid, ft;
+
+	ndo->ndo_protocol = "erspan";
+	nd_print_protocol(ndo);
+
+	/*
+	 * We do not check the GRE flags; ERSPAN Type III always
+	 * has an ERSPAN header.
+	 */
+	ND_ICHECK_U(len, <, 4);
+	hdr = GET_BE_U_4(bp);
+	bp += 4;
+	len -= 4;
+
+	ver = hdr & ERSPAN3_VER_MASK;
+	if (ver != ERSPAN3_VER) {
+		/*
+		 * Not Type III.
+		 */
+		ver >>= ERSPAN3_VER_SHIFT;
+		ND_PRINT(" erspan-unknown-version-%x", ver);
+		return;
+	}
+
+	if (ndo->ndo_vflag)
+		ND_PRINT(" type3");
+
+	sid = (hdr & ERSPAN3_SID_MASK) >> ERSPAN3_SID_SHIFT;
+	ND_PRINT(" session %u", sid);
+
+	ND_PRINT(" bso %s",
+		 tok2str(erspan3_bso_values, "unknown %x",
+			 (hdr & ERSPAN3_BSO_MASK) >> ERSPAN3_BSO_SHIFT));
+
+	if (ndo->ndo_vflag) {
+		cos = (hdr & ERSPAN3_COS_MASK) >> ERSPAN3_COS_SHIFT;
+		ND_PRINT(" cos %u", cos);
+
+		if (hdr & ERSPAN3_T_MASK)
+			ND_PRINT(" truncated");
+	}
+
+	/* Skip timestamp */
+	ND_ICHECK_U(len, <, 4);
+	ND_TCHECK_LEN(bp, 4);
+	bp += 4;
+	len -= 4;
+
+	/* Skip SGT */
+	ND_ICHECK_U(len, <, 2);
+	ND_TCHECK_LEN(bp, 2);
+	bp += 2;
+	len -= 2;
+
+	/* Additional fields */
+	ND_ICHECK_U(len, <, 2);
+	hdr2 = GET_BE_U_2(bp);
+	bp += 2;
+	len -= 2;
+
+	ft = (hdr2 & ERSPAN3_FT_MASK) >> ERSPAN3_FT_SHIFT;
+	ND_PRINT(" ft %s",
+		 tok2str(erspan3_ft_values, "unknown %x", ft));
+
+
+	/* Do we have the platform-specific header? */
+	if (hdr2 & ERSPAN3_O_MASK) {
+		/* Yes.  Skip it. */
+		ND_ICHECK_U(len, <, 8);
+		ND_TCHECK_LEN(bp, 8);
+		bp += 8;
+		len -= 8;
+	}
+
+	ND_PRINT(": ");
+
+	switch (ft) {
+
+	case ERSPAN3_FT_ETHERNET:
+		ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+		break;
+
+	default:
+		ND_PRINT("Frame type unknown");
+		break;
+	}
+	return;
+
+invalid:
+	nd_print_invalid(ndo);
+}