Have all TCP flags in the structure that is passed to subdissectors.

Have subdissectors do the bit math checking for particular flag bits.

Change-Id: Ie6350e316f79af879be9fc512ce215f24449a7e5
Reviewed-on: https://code.wireshark.org/review/13071
Reviewed-by: Michael Mann <mmann78@netscape.net>
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

4 files changed, 9 insertions, 10 deletions

diff --git a/epan/dissectors/packet-http.c b/epan/dissectors/packet-http.c
index 0cfe31a704..d024dd52f0 100644
--- a/epan/dissectors/packet-http.c
+++ b/epan/dissectors/packet-http.c
@@ -824,7 +824,7 @@ dissect_http_message(tvbuff_t *tvb, int offset, packet_info *pinfo,
 		 */
 		gboolean try_desegment_body = (http_desegment_body &&
 			(!(conv_data->request_method && g_str_equal(conv_data->request_method, "HEAD"))) &&
-			((tcpinfo == NULL) || (tcpinfo->fin == FALSE)));
+			((tcpinfo == NULL) || (!IS_TH_FIN(tcpinfo->flags))));
 		if (!req_resp_hdrs_do_reassembly(tvb, offset, pinfo,
 		    http_desegment_headers, try_desegment_body)) {
 			/*
diff --git a/epan/dissectors/packet-rlogin.c b/epan/dissectors/packet-rlogin.c
index c20fcea2eb..feebee70ff 100644
--- a/epan/dissectors/packet-rlogin.c
+++ b/epan/dissectors/packet-rlogin.c
@@ -204,7 +204,7 @@ static void rlogin_display(rlogin_hash_entry_t *hash_info,
 	 * to something past this segment, we'd have to remember the urgent
 	 * pointer setting for this conversation.
 	 */
-	if (tcpinfo && tcpinfo->urgent &&      /* if urgent pointer set */
+	if (tcpinfo && IS_TH_URG(tcpinfo->flags) &&      /* if urgent pointer set */
 	    length >= tcpinfo->urgent_pointer) /* and it's in this frame */
 	{
 		/* Get urgent byte into Temp */
@@ -428,7 +428,7 @@ dissect_rlogin(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
 				                   "Startup info received");
 		}
 		else
-		if (tcpinfo && tcpinfo->urgent && length >= tcpinfo->urgent_pointer)
+		if (tcpinfo && IS_TH_URG(tcpinfo->flags) && length >= tcpinfo->urgent_pointer)
 		{
 			/* Urgent pointer inside current data represents a control message */
 			col_append_str(pinfo->cinfo, COL_INFO, "Control Message");
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c
index 7386eda7f3..fa124015a3 100644
--- a/epan/dissectors/packet-tcp.c
+++ b/epan/dissectors/packet-tcp.c
@@ -4946,7 +4946,7 @@ dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
     tcph->th_seq = tvb_get_ntohl(tvb, offset + 4);
     tcph->th_ack = tvb_get_ntohl(tvb, offset + 8);
     th_off_x2 = tvb_get_guint8(tvb, offset + 12);
-    tcph->th_flags = tvb_get_ntohs(tvb, offset + 12) & 0x0FFF;
+    tcpinfo.flags = tcph->th_flags = tvb_get_ntohs(tvb, offset + 12) & TH_MASK;
     tcph->th_win = tvb_get_ntohs(tvb, offset + 14);
     real_window = tcph->th_win;
     tcph->th_hlen = hi_nibble(th_off_x2) * 4;  /* TCP header length, in bytes */
@@ -5216,7 +5216,6 @@ dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
     if(tcph->th_flags & TH_FIN) {
         /* XXX - find a way to know the server port and output only that one */
         expert_add_info(pinfo, tf_fin, &ei_tcp_connection_fin);
-        tcpinfo.fin = TRUE;
     }
     if(tcph->th_flags & TH_RST)
         /* XXX - find a way to know the server port and output only that one */
@@ -5396,14 +5395,12 @@ dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 
     item = proto_tree_add_item_ret_uint(tcp_tree, hf_tcp_urgent_pointer, tvb, offset + 18, 2, ENC_BIG_ENDIAN, &th_urp);
 
-    if (tcph->th_flags & TH_URG) {
+    if (IS_TH_URG(tcph->th_flags)) {
         /* Export the urgent pointer, for the benefit of protocols such as
            rlogin. */
-        tcpinfo.urgent = TRUE;
         tcpinfo.urgent_pointer = (guint16)th_urp;
         tcp_info_append_uint(pinfo, "Urg", th_urp);
     } else {
-        tcpinfo.urgent = FALSE;
          if (th_urp) {
             /* Note if the urgent pointer field is non-zero */
             expert_add_info(pinfo, item, &ei_tcp_urgent_pointer_non_zero);
diff --git a/epan/dissectors/packet-tcp.h b/epan/dissectors/packet-tcp.h
index 55711f0291..876a4b68ed 100644
--- a/epan/dissectors/packet-tcp.h
+++ b/epan/dissectors/packet-tcp.h
@@ -44,6 +44,9 @@ extern "C" {
 #define TH_RES  0x0E00 /* 3 reserved bits */
 #define TH_MASK 0x0FFF
 
+#define IS_TH_FIN(x) (x & TH_FIN)
+#define IS_TH_URG(x) (x & TH_URG)
+
 /* Idea for gt: either x > y, or y is much bigger (assume wrap) */
 #define GT_SEQ(x, y) ((gint32)((y) - (x)) < 0)
 #define LT_SEQ(x, y) ((gint32)((x) - (y)) < 0)
@@ -106,8 +109,7 @@ struct tcpinfo {
 	guint32 nxtseq;          /* Sequence number of first byte after data */
 	guint32 lastackseq;      /* Sequence number of last ack */
 	gboolean is_reassembled; /* This is reassembled data. */
-	gboolean fin;            /* TRUE if FIN flag bit is set */
-	gboolean urgent;         /* TRUE if "urgent_pointer" is valid */
+	guint16	flags;           /* TCP flags */
 	guint16	urgent_pointer;  /* Urgent pointer value for the current packet. */
 };