libknot+kdig: support for EDNS DE flag (DELEG-aware signal)

doc/man_kdig.rst

@@ -177,6 +177,9 @@ Options
 **+**\ [\ **no**\ ]\ **dnssec**
   Same as **+**\ [\ **no**\ ]\ **doflag**
 
+**+**\ [\ **no**\ ]\ **deflag**
+  Set the DE flag.
+
 **+**\ [\ **no**\ ]\ **all**
   Show all packet sections.
 

src/knot/nameserver/process_query.c

@@ -261,7 +261,7 @@ static int answer_edns_init(const knot_pkt_t *query, knot_pkt_t *resp,
 	/* Set DO bit if set (DNSSEC requested). */
 	if (knot_pkt_has_dnssec(query)) {
 		knot_edns_set_do(&qdata->opt_rr);
-	}
+	} // TODO: also echo back DE bit if we are DELEG-aware?
 
 	/* Append NSID if requested and available. */
 	if (knot_pkt_edns_option(query, KNOT_EDNS_OPTION_NSID) != NULL) {

src/libknot/packet/pkt.h

@@ -364,6 +364,15 @@ static inline bool knot_pkt_has_dnssec(const knot_pkt_t *pkt)
 	return knot_pkt_has_edns(pkt) && knot_edns_do(pkt->opt_rr);
 }
 
+/*!
+ * \brief Checks if DE bit is set in the packet's OPT RR.
+ */
+static inline bool knot_pkt_has_deleg_aware(const knot_pkt_t *pkt)
+{
+	assert(pkt);
+	return knot_pkt_has_edns(pkt) && knot_edns_de(pkt->opt_rr);
+}
+
 /*!
  * \brief Get specific EDNS option from a parsed packet.
  */

src/libknot/probe/data.c

@@ -85,6 +85,7 @@ int knot_probe_data_set(knot_probe_data_t *data, knot_probe_proto_t proto,
 		data->query_edns.version = knot_edns_get_version(query->opt_rr);
 		data->query_edns.present = 1;
 		data->query_edns.flag_do = knot_edns_do(query->opt_rr);
+		data->query_edns.flag_de = knot_edns_de(query->opt_rr);
 		if (query->edns_opts != NULL) {
 			for (int i = 0; i <= KNOT_EDNS_MAX_OPTION_CODE; i++) {
 				if (query->edns_opts->ptr[i] != NULL) {

src/libknot/probe/data.h

@@ -72,7 +72,8 @@ typedef struct {
 		uint8_t version;  /*!< EDNS version. */
 		uint8_t present  : 1; /*!< EDNS presence indication. */
 		uint8_t flag_do  : 1; /*!< DO flag indication. */
-		uint8_t reserved : 6; /*!< Unused. */
+		uint8_t flag_de  : 1; /*!< DE flag indication. */
+		uint8_t reserved : 5; /*!< Unused. */
 	} query_edns;
 
 	struct {

src/libknot/rrset-dump.c

@@ -987,6 +987,8 @@ static void wire_ednsflags_to_str(rrset_dump_params_t *p)
 
 			if ((mask & KNOT_EDNS_DO_MASK)) {
 				dump_string(p, "DO");
+			} else if ((mask & KNOT_EDNS_DE_MASK)) {
+				dump_string(p, "DE");
 			} else {
 				dump_str_uint(p, "BIT", i);
 			}

src/libknot/rrtype/opt.h

@@ -28,6 +28,7 @@ enum {
 
 	/*! \brief Bit mask for DO bit. */
 	KNOT_EDNS_DO_MASK = (uint32_t)(1 << 15),
+	KNOT_EDNS_DE_MASK = (uint32_t)(1 << 13),
 
 	/*! \brief Minimal UDP payload with EDNS enabled. */
 	KNOT_EDNS_MIN_UDP_PAYLOAD    = 512,
@@ -259,6 +260,12 @@ bool knot_edns_do(const knot_rrset_t *opt_rr)
 	assert(opt_rr != NULL);
 	return opt_rr->ttl & KNOT_EDNS_DO_MASK;
 }
+static inline
+bool knot_edns_de(const knot_rrset_t *opt_rr)
+{
+	assert(opt_rr != NULL);
+	return opt_rr->ttl & KNOT_EDNS_DE_MASK;
+}
 
 /*!
  * \brief Sets the DO bit in the OPT RR.
@@ -274,6 +281,12 @@ void knot_edns_set_do(knot_rrset_t *opt_rr)
 	assert(opt_rr != NULL);
 	opt_rr->ttl |= KNOT_EDNS_DO_MASK;
 }
+static inline
+void knot_edns_set_de(knot_rrset_t *opt_rr)
+{
+	assert(opt_rr != NULL);
+	opt_rr->ttl |= KNOT_EDNS_DE_MASK;
+}
 
 /*!
  * \brief Add EDNS option into the package with empty (zeroed) content.

src/utils/common/exec.c

@@ -336,9 +336,22 @@ static void print_section_opt(const knot_pkt_t *packet, const style_t *style)
 		ercode_str = unknown_ercode;
 	}
 
-	printf(";; Version: %u; flags: %s; UDP size: %u B; ext-rcode: %s\n",
+	char flags[96] = " ", *flend = flags;
+	for (uint32_t mask = 1 << 15, bit = 1; mask; mask >>= 1, bit++) {
+		if (packet->opt_rr->ttl & mask) {
+			if (mask & KNOT_EDNS_DO_MASK) {
+				flend += snprintf(flend, 4, " do");
+			} else if (mask & KNOT_EDNS_DE_MASK) {
+				flend += snprintf(flend, 4, " de");
+			} else {
+				flend += snprintf(flend, 7, " bit%u", bit);
+			}
+		}
+	}
+
+	printf(";; Version: %u; flags:%s; UDP size: %u B; ext-rcode: %s\n",
 	       knot_edns_get_version(packet->opt_rr),
-	       (knot_edns_do(packet->opt_rr) != 0) ? "do" : "",
+	       flags,
 	       knot_edns_get_payload(packet->opt_rr),
 	       ercode_str);
 
@@ -851,6 +864,8 @@ static void json_print_edns(jsonw_t *w, const knot_pkt_t *pkt)
 		if ((flags & mask)) {
 			if ((mask & KNOT_EDNS_DO_MASK)) {
 				jsonw_str(w, NULL, "DO");
+			} else if ((mask & KNOT_EDNS_DE_MASK)) {
+				jsonw_str(w, NULL, "DE");
 			} else {
 				(void)snprintf(tmp, sizeof(tmp), "BIT%d", i);
 				jsonw_str(w, NULL, tmp);

src/utils/kdig/kdig_exec.c

@@ -242,6 +242,9 @@ static int add_query_edns(knot_pkt_t *packet, const query_t *query, uint16_t max
 	if (query->flags.do_flag) {
 		knot_edns_set_do(&opt_rr);
 	}
+	if (query->flags.de_flag) {
+		knot_edns_set_de(&opt_rr);
+	}
 
 	/* Append NSID. */
 	if (query->nsid) {
@@ -356,7 +359,7 @@ static bool use_edns(const query_t *query)
 	return query->edns > -1 || query->udp_size > -1 || query->nsid ||
 	       query->zoneversion || query->subnet.family != AF_UNSPEC ||
 	       query->flags.do_flag || query->cc.len > 0 || do_padding(query) ||
-	       !ednsopt_list_empty(&query->edns_opts);
+	       query->flags.de_flag || !ednsopt_list_empty(&query->edns_opts);
 }
 
 static knot_pkt_t *create_query_packet(const query_t *query)

src/utils/kdig/kdig_params.c

@@ -40,7 +40,8 @@ static const flags_t DEFAULT_FLAGS_DIG = {
 	.z_flag  = false,
 	.ad_flag = true,
 	.cd_flag = false,
-	.do_flag = false
+	.do_flag = false,
+	.de_flag = false,
 };
 
 static const style_t DEFAULT_STYLE_DIG = {
@@ -275,6 +276,24 @@ static int opt_nodoflag(const char *arg, void *query)
 	return KNOT_EOK;
 }
 
+static int opt_deflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.de_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nodeflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.de_flag = false;
+
+	return KNOT_EOK;
+}
+
 static int opt_all(const char *arg, void *query)
 {
 	query_t *q = query;
@@ -1550,6 +1569,9 @@ static const param_t kdig_opts2[] = {
 	{ "dnssec",         ARG_NONE,     opt_doflag },   // Alias.
 	{ "nodnssec",       ARG_NONE,     opt_nodoflag },
 
+	{ "deflag",         ARG_NONE,     opt_deflag },
+	{ "nodeflag",       ARG_NONE,     opt_nodeflag },
+
 	{ "all",            ARG_NONE,     opt_all },
 	{ "noall",          ARG_NONE,     opt_noall },
 
@@ -2377,6 +2399,7 @@ static void print_help(void)
 	       "       +[no]cdflag                Set CD flag.\n"
 	       "       +[no]doflag                Set DO flag.\n"
 	       "       +[no]dnssec                Same as +[no]doflag.\n"
+	       "       +[no]deflag                Set DE flag.\n"
 	       "       +[no]all                   Show all packet sections.\n"
 	       "       +[no]qr                    Show query packet.\n"
 	       "       +[no]header              * Show packet header.\n"

src/utils/kdig/kdig_params.h

@@ -48,6 +48,8 @@ typedef struct {
 	bool	cd_flag;
 	/*!< DNSSEC OK flag. */
 	bool	do_flag;
+	/*!< DELEG-aware flag. */
+	bool	de_flag;
 } flags_t;
 
 /*! \brief Basic parameters for DNS query. */