add "dig +qid" option to set QID to desired value

bin/dig/dig.c

@@ -1489,6 +1489,24 @@ plus_option(char *option, bool is_batchfile, dig_lookup_t *lookup) {
 		break;
 	case 'q':
 		switch (cmd[1]) {
+		case 'i': /* qid */
+			FULLCHECK("qid");
+			if (!state) {
+				lookup->setqid = false;
+				lookup->qid = 0;
+				break;
+			}
+			if (value == NULL) {
+				goto need_value;
+			}
+			result = parse_uint(&num, value, MAXQID, "qid");
+			if (result != ISC_R_SUCCESS) {
+				warn("Couldn't parse qid");
+				goto exit_or_usage;
+			}
+			lookup->setqid = true;
+			lookup->qid = num;
+			break;
 		case 'r': /* qr */
 			FULLCHECK("qr");
 			lookup->qr = state;

bin/dig/dig.rst

@@ -426,6 +426,10 @@ abbreviation is unambiguous; for example, ``+cd`` is equivalent to
    mandatory. Responses to padded queries may also be padded, but only
    if the query uses TCP or DNS COOKIE.
 
+``+qid=value``
+ 
+   Specify the query ID to use when sending queries.
+
 ``+[no]qr``
    Toggles the display of the query message as it is sent. By default, the query
    is not printed.

bin/dig/dighost.c

@@ -677,6 +677,8 @@ make_empty_lookup(void) {
 	looknew->tcflag = false;
 	looknew->print_unknown_format = false;
 	looknew->zflag = false;
+	looknew->setqid = false;
+	looknew->qid = 0;
 	looknew->ns_search_only = false;
 	looknew->origin = NULL;
 	looknew->tsigctx = NULL;
@@ -820,6 +822,8 @@ clone_lookup(dig_lookup_t *lookold, bool servers) {
 	looknew->tcflag = lookold->tcflag;
 	looknew->print_unknown_format = lookold->print_unknown_format;
 	looknew->zflag = lookold->zflag;
+	looknew->setqid = lookold->setqid;
+	looknew->qid = lookold->qid;
 	looknew->ns_search_only = lookold->ns_search_only;
 	looknew->tcp_mode = lookold->tcp_mode;
 	looknew->tcp_mode_set = lookold->tcp_mode_set;
@@ -2298,6 +2302,11 @@ setup_lookup(dig_lookup_t *lookup) {
 		lookup->sendmsg->flags |= 0x0040U;
 	}
 
+	if (lookup->setqid) {
+		debug("set QID");
+		lookup->sendmsg->id = lookup->qid;
+	}
+
 	dns_message_addname(lookup->sendmsg, lookup->name,
 			    DNS_SECTION_QUESTION);
 

bin/dig/dighost.h

@@ -60,6 +60,8 @@
 #define MAXPORT 0xffff
 /*% Max serial number */
 #define MAXSERIAL 0xffffffff
+/*% Max query ID */
+#define MAXQID 0xffff
 
 /*% Default TCP Timeout */
 #define TCP_TIMEOUT 10
@@ -108,9 +110,10 @@ struct dig_lookup {
 		tcp_keepalive, header_only, ednsneg, mapped,
 		print_unknown_format, multiline, nottl, noclass, onesoa,
 		use_usec, nocrypto, ttlunits, idnin, idnout, expandaaaa, qr,
-		accept_reply_unexpected_src; /*%  print replies from
+		accept_reply_unexpected_src, /*%  print replies from
 					      * unexpected
 					      *   sources. */
+		setqid;			     /*% use a speciied query ID */
 	char textname[MXNAME];		     /*% Name we're going to be
 					      * looking up */
 	char cmdline[MXNAME];
@@ -157,6 +160,7 @@ struct dig_lookup {
 	dns_opcode_t opcode;
 	int rrcomments;
 	unsigned int eoferr;
+	uint16_t qid;
 };
 
 /*% The dig_query structure */

bin/dig/nslookup.c

@@ -788,6 +788,8 @@ addlookup(char *opt) {
 	lookup->aaonly = aaonly;
 	lookup->retries = tries;
 	lookup->udpsize = 0;
+	lookup->setqid = false;
+	lookup->qid = 0;
 	lookup->comments = comments;
 	if (lookup->rdtype == dns_rdatatype_any && !tcpmode_set) {
 		lookup->tcp_mode = true;