Add --overview and --no-print options to tcpdump

CHANGES

@@ -29,6 +29,8 @@ DayOfTheWeek, Month DD, YYYY / The Tcpdump Group
       Add --print-sampling to print every Nth packet instead of all.
       Print the supported time stamp types (-J) to stdout instead of stderr.
       Print the list of data link types (-L) to stdout instead of stderr.
+      Add --overview to print an overview of the contents of the capture
+      Add --no-print to suppress printing of individual packets (useful with --overview)
     Source code:
       Use %zu when printing a sizeof to squelch compiler warnings
       Remove unused missing/snprintf.c.

ethertype.h

@@ -216,4 +216,11 @@
 #define	ETHERTYPE_ARISTA        0xd28b /*  Arista Networks vendor specific EtherType */
 #endif
 
+/*
+ * Length of an Ethernet header; note that some compilers may pad
+ * "struct ether_header" to a multiple of 4 bytes, for example, so
+ * "sizeof (struct ether_header)" may not give the right answer.
+ */
+#define ETHER_HDRLEN		14
+
 extern const struct tok ethertype_values[];

netdissect.h

@@ -238,6 +238,9 @@ struct netdissect_options {
   const u_char *ndo_packetp;
   const u_char *ndo_snapend;
 
+  int ndo_dlt; /* datalink type */
+  int ndo_length_type; /*  */
+
   /* stack of saved packet boundary and buffer information */
   struct netdissect_saved_packet_info *ndo_packet_info_stack;
 

print-ether.c

@@ -42,13 +42,6 @@ struct	ether_header {
 	nd_uint16_t	ether_length_type;
 };
 
-/*
- * Length of an Ethernet header; note that some compilers may pad
- * "struct ether_header" to a multiple of 4 bytes, for example, so
- * "sizeof (struct ether_header)" may not give the right answer.
- */
-#define ETHER_HDRLEN		14
-
 const struct tok ethertype_values[] = {
     { ETHERTYPE_IP,		"IPv4" },
     { ETHERTYPE_MPLS,		"MPLS unicast" },
@@ -200,6 +193,7 @@ ether_common_print(netdissect_options *ndo, const u_char *p, u_int length,
 	 */
 recurse:
 	length_type = GET_BE_U_2(p);
+	ndo->ndo_length_type = length_type;
 
 	length -= 2;
 	caplen -= 2;
@@ -237,6 +231,7 @@ ether_common_print(netdissect_options *ndo, const u_char *p, u_int length,
 			 * Keep processing type/length fields.
 			 */
 			length_type = GET_BE_U_2(p);
+			ndo->ndo_length_type = length_type;
 
 			ND_ICHECK_U(caplen, <, 2);
 			length -= 2;
@@ -281,6 +276,8 @@ ether_common_print(netdissect_options *ndo, const u_char *p, u_int length,
 		}
 
 		length_type = GET_BE_U_2(p + 2);
+		ndo->ndo_length_type = length_type;
+
 		p += 4;
 		length -= 4;
 		caplen -= 4;