Prime the epan_dissect_t with postdissector wanted fields if necessary.

This makes sure that postdissectors that indicate that they need certain
fields in the first pass will get them.

While we're at it:

Fix the field-fetching code in TRANSUM not to assume it got any
instances of the field being fetched.

Rename process_packet_first_pass() in sharkd to process_packet(), as
it's the only routine in sharkd that processes packets.

Rename process_packet() in tshark and tfshark to
process_packet_single_pass(), as it's what's used if we're only doing
one-pass analysis.

Clean up comments and whitespace.

Change-Id: I3769af952c66f5ca4b68002ad6213858ab9cab9b
Reviewed-on: https://code.wireshark.org/review/21063
Reviewed-by: Guy Harris <guy@alum.mit.edu>

4 files changed, 42 insertions, 3 deletions

diff --git a/epan/epan.c b/epan/epan.c
index 726d2f558c..75ff54214b 100644
--- a/epan/epan.c
+++ b/epan/epan.c
@@ -541,6 +541,17 @@ epan_dissect_prime_with_hfid(epan_dissect_t *edt, int hfid)
 	proto_tree_prime_with_hfid(edt->tree, hfid);
 }
 
+void
+epan_dissect_prime_with_hfid_array(epan_dissect_t *edt, GArray *hfids)
+{
+	guint i;
+
+	for (i = 0; i < hfids->len; i++) {
+		proto_tree_prime_with_hfid(edt->tree,
+		    g_array_index(hfids, int, i));
+	}
+}
+
 /* ----------------------- */
 const gchar *
 epan_custom_set(epan_dissect_t *edt, GSList *field_ids,
diff --git a/epan/epan.h b/epan/epan.h
index 65fca37988..91c7c1c24f 100644
--- a/epan/epan.h
+++ b/epan/epan.h
@@ -225,6 +225,11 @@ WS_DLL_PUBLIC
 void
 epan_dissect_prime_with_hfid(epan_dissect_t *edt, int hfid);
 
+/** Prime an epan_dissect_t's proto_tree with a set of fields/protocols specified by their hfids in a GArray */
+WS_DLL_PUBLIC
+void
+epan_dissect_prime_with_hfid_array(epan_dissect_t *edt, GArray *hfids);
+
 /** fill the dissect run output into the packet list columns */
 WS_DLL_PUBLIC
 void
diff --git a/epan/packet.c b/epan/packet.c
index 4a3b5cbd64..bb43449d7f 100644
--- a/epan/packet.c
+++ b/epan/packet.c
@@ -3350,6 +3350,25 @@ postdissectors_want_fields(void)
 	return FALSE;
 }
 
+void
+prime_epan_dissect_with_postdissector_wanted_fields(epan_dissect_t *edt)
+{
+	guint i;
+
+	if (postdissectors == NULL) {
+		/*
+		 * No postdissector expressed an interest in any fields.
+		 */
+		return;
+	}
+	for (i = 0; i < postdissectors->len; i++) {
+		if (POSTDISSECTORS(i).wanted_fields != NULL &&
+		    POSTDISSECTORS(i).wanted_fields->len != 0)
+			epan_dissect_prime_with_hfid_array(edt,
+			    POSTDISSECTORS(i).wanted_fields);
+	}
+}
+
 /*
  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
  *
diff --git a/epan/packet.h b/epan/packet.h
index 47eed6fe33..e0625ae226 100644
--- a/epan/packet.h
+++ b/epan/packet.h
@@ -25,6 +25,7 @@
 
 #include "proto.h"
 #include "tvbuff.h"
+#include "epan.h"
 #include "value_string.h"
 #include "frame_data.h"
 #include "packet_info.h"
@@ -803,12 +804,15 @@ extern void call_all_postdissectors(tvbuff_t *tvb, packet_info *pinfo, proto_tre
 
 /*
  * Return TRUE if at least one postdissector wants fields, FALSE otherwise.
- * XXX - at some point this should return a bag of all fields requested by
- * all postdissectors, so we can prime the epan_dissect_t with them rather
- * than constructing a bogus tap with a bogus filter.
  */
 WS_DLL_PUBLIC gboolean postdissectors_want_fields(void);
 
+/*
+ * Prime an epan_dissect_t with all the fields wanted by postdissectors.
+ */
+WS_DLL_PUBLIC void
+prime_epan_dissect_with_postdissector_wanted_fields(epan_dissect_t *edt);
+
 /** @} */
 
 #ifdef __cplusplus