Get rid of the pkt_encap field in struct packet_info.

pinfo->pkt_encap is jsut a copy of pinfo->phdr->pkt_encap; no need for
the copy.

Expand a comment while we're at it.

Change-Id: I5fcfe694ecba42507f1d629d01440da0a0989501
Reviewed-on: https://code.wireshark.org/review/25643
Reviewed-by: Guy Harris <guy@alum.mit.edu>

4 files changed, 18 insertions, 12 deletions

diff --git a/epan/dissectors/file-file.c b/epan/dissectors/file-file.c
index f926a75077..f336494f5c 100644
--- a/epan/dissectors/file-file.c
+++ b/epan/dissectors/file-file.c
@@ -121,7 +121,7 @@ dissect_file_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
 
 		fh_tree = proto_item_add_subtree(ti, ett_file);
 
-		proto_tree_add_int(fh_tree, hf_file_ftap_encap, tvb, 0, 0, pinfo->pkt_encap);
+		proto_tree_add_int(fh_tree, hf_file_ftap_encap, tvb, 0, 0, pinfo->phdr->pkt_encap);
 
 		proto_tree_add_uint(fh_tree, hf_file_record_number, tvb, 0, 0, pinfo->num);
 
@@ -177,12 +177,12 @@ dissect_file_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
 		*/
 		__try {
 #endif
-			if (!dissector_try_uint(file_encap_dissector_table, pinfo->pkt_encap,
+			if (!dissector_try_uint(file_encap_dissector_table, pinfo->phdr->pkt_encap,
 						tvb, pinfo, parent_tree)) {
 
 				col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
 				col_add_fstr(pinfo->cinfo, COL_INFO, "FTAP_ENCAP = %d",
-					     pinfo->pkt_encap);
+					     pinfo->phdr->pkt_encap);
 				call_data_dissector(tvb, pinfo, parent_tree);
 			}
 #ifdef _MSC_VER
diff --git a/epan/dissectors/packet-frame.c b/epan/dissectors/packet-frame.c
index bfce974f17..e9cd5a8f0e 100644
--- a/epan/dissectors/packet-frame.c
+++ b/epan/dissectors/packet-frame.c
@@ -245,7 +245,7 @@ dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void*
 		 * overrides the packet record.
 		 */
 		if (pinfo->pseudo_header != NULL) {
-			switch (pinfo->pkt_encap) {
+			switch (pinfo->phdr->pkt_encap) {
 
 			case WTAP_ENCAP_WFLEET_HDLC:
 			case WTAP_ENCAP_CHDLC_WITH_PHDR:
@@ -432,7 +432,7 @@ dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void*
 		}
 
 		if (pinfo->phdr->rec_type == REC_TYPE_PACKET)
-			proto_tree_add_int(fh_tree, hf_frame_wtap_encap, tvb, 0, 0, pinfo->pkt_encap);
+			proto_tree_add_int(fh_tree, hf_frame_wtap_encap, tvb, 0, 0, pinfo->phdr->pkt_encap);
 
 		if (pinfo->presence_flags & PINFO_HAS_TS) {
 			proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
@@ -519,7 +519,7 @@ dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void*
 		}
 
 		/* Check for existences of MTP2 link number */
-		if ((pinfo->pseudo_header != NULL ) && (pinfo->pkt_encap == WTAP_ENCAP_MTP2_WITH_PHDR)) {
+		if ((pinfo->pseudo_header != NULL ) && (pinfo->phdr->pkt_encap == WTAP_ENCAP_MTP2_WITH_PHDR)) {
 			proto_tree_add_uint(fh_tree, hf_link_number, tvb,
 					    0, 0, pinfo->link_number);
 		}
@@ -561,12 +561,12 @@ dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void*
 					    (void *)pinfo->pseudo_header);
 				} else {
 					if (!dissector_try_uint_new(wtap_encap_dissector_table,
-					    pinfo->pkt_encap, tvb, pinfo,
+					    pinfo->phdr->pkt_encap, tvb, pinfo,
 					    parent_tree, TRUE,
 					    (void *)pinfo->pseudo_header)) {
 						col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
 						col_add_fstr(pinfo->cinfo, COL_INFO, "WTAP_ENCAP = %d",
-							     pinfo->pkt_encap);
+							     pinfo->phdr->pkt_encap);
 						call_data_dissector(tvb, pinfo, parent_tree);
 					}
 				}
diff --git a/epan/dissectors/packet-nettl.c b/epan/dissectors/packet-nettl.c
index 52b4ab0362..13ef003b0f 100644
--- a/epan/dissectors/packet-nettl.c
+++ b/epan/dissectors/packet-nettl.c
@@ -227,7 +227,7 @@ dissect_nettl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U
                            0, 0, pinfo->pseudo_header->nettl.uid);
     }
 
-    switch (pinfo->pkt_encap) {
+    switch (pinfo->phdr->pkt_encap) {
         case WTAP_ENCAP_NETTL_ETHERNET:
             call_dissector(eth_withoutfcs_handle, tvb, pinfo, tree);
             break;
diff --git a/epan/dissectors/packet-snort.c b/epan/dissectors/packet-snort.c
index 616f38bd00..6da2a4b7e8 100644
--- a/epan/dissectors/packet-snort.c
+++ b/epan/dissectors/packet-snort.c
@@ -1166,11 +1166,18 @@ snort_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
 
                 /* Older versions of Snort don't support capture file with several encapsulations (like pcapng),
                  * so write in pcap format and hope we have just one encap.
-                 * Newer versions of Snort can read pcapng now, but still write in pcap format.
+                 * Newer versions of Snort can read pcapng now, but still
+                 * write in pcap format; if "newer versions of Snort" really
+                 * means "Snort, when using newer versions of libpcap", then,
+                 * yes, they can read pcapng, but they can't read pcapng
+                 * files with more than one encapsulation type, as libpcap's
+                 * API currently can't handle that, so even those "newer
+                 * versions of Snort" wouldn't handle multiple encapsulation
+                 * types.
                  */
                 current_session.pdh = wtap_dump_fdopen(current_session.in,
                                                        WTAP_FILE_TYPE_SUBTYPE_PCAP,
-                                                       pinfo->pkt_encap,
+                                                       pinfo->phdr->pkt_encap,
                                                        WTAP_MAX_PACKET_SIZE_STANDARD,
                                                        FALSE,                 /* compressed */
                                                        &open_err);
@@ -1193,7 +1200,6 @@ snort_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
 
             wtp.caplen = tvb_captured_length(tvb);
             wtp.len = tvb_reported_length(tvb);
-            wtp.pkt_encap = pinfo->pkt_encap;
             if (current_session.pdh->encap != wtp.pkt_encap) {
                 /* XXX, warning! convert? */
             }