diff --git a/Knot.files b/Knot.files
index 423b38c38fab3153b20ba59f492bdab708559527..1025dd5c25869e814b0216e7dcfd30a5f89f511d 100644
--- a/Knot.files
+++ b/Knot.files
@@ -266,6 +266,8 @@ src/knot/modules/rosedb.h
src/knot/modules/rosedb_tool.c
src/knot/modules/synth_record.c
src/knot/modules/synth_record.h
+src/knot/modules/whoami.c
+src/knot/modules/whoami.h
src/knot/nameserver/axfr.c
src/knot/nameserver/axfr.h
src/knot/nameserver/chaos.c
diff --git a/src/Makefile.am b/src/Makefile.am
index 2ddd23146e5b7411fe9bc2983c91b26e90991102..ad1c2a55b3a12058ffc6446c8b518314c730d899 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -282,6 +282,8 @@ libknotd_la_SOURCES = \
knot/modules/online_sign/nsec_next.h \
knot/modules/synth_record.c \
knot/modules/synth_record.h \
+ knot/modules/whoami.c \
+ knot/modules/whoami.h \
knot/nameserver/axfr.c \
knot/nameserver/axfr.h \
knot/nameserver/chaos.c \
diff --git a/src/knot/conf/scheme.c b/src/knot/conf/scheme.c
index 5226f47651842527c55f886a09c0c010f3aade41..8046cd5bb9a5f94695ef93041abcae57db5830f2 100644
--- a/src/knot/conf/scheme.c
+++ b/src/knot/conf/scheme.c
@@ -37,6 +37,7 @@
#if USE_DNSTAP
#include "knot/modules/dnstap.h"
#endif
+#include "knot/modules/whoami.h"
#define HOURS(x) ((x) * 3600)
#define DAYS(x) ((x) * HOURS(24))
@@ -260,6 +261,7 @@ const yp_item_t conf_scheme[] = {
{ check_mod_dnstap } },
#endif
{ C_MOD_ONLINE_SIGN, YP_TGRP, YP_VGRP = { scheme_mod_online_sign }, YP_FMULTI },
+ { C_MOD_WHOAMI, YP_TGRP, YP_VGRP = { scheme_mod_whoami }, YP_FMULTI },
/***********/
{ C_TPL, YP_TGRP, YP_VGRP = { desc_template }, YP_FMULTI, { check_template } },
{ C_ZONE, YP_TGRP, YP_VGRP = { desc_zone }, YP_FMULTI, { check_zone } },
diff --git a/src/knot/modules/whoami.c b/src/knot/modules/whoami.c
new file mode 100644
index 0000000000000000000000000000000000000000..c7c5dda5fea21f3c646d0a1f3292ea72b0775c65
--- /dev/null
+++ b/src/knot/modules/whoami.c
@@ -0,0 +1,154 @@
+/* Copyright (C) 2016 Fastly, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "knot/modules/whoami.h"
+#include "knot/nameserver/process_query.h"
+#include "knot/nameserver/internet.h"
+#include "libknot/libknot.h"
+
+const yp_item_t scheme_mod_whoami[] = {
+ { C_ID, YP_TSTR, YP_VNONE },
+ { C_COMMENT, YP_TSTR, YP_VNONE },
+ { NULL }
+};
+
+static int whoami_query(int state, knot_pkt_t *pkt, struct query_data *qdata, void *ctx)
+{
+ knot_rrset_t *rrset = NULL;
+
+ /* Sanity checks. */
+ if (pkt == NULL ||
+ qdata == NULL ||
+ qdata->query == NULL ||
+ qdata->param == NULL || qdata->param->remote == NULL ||
+ qdata->zone == NULL || qdata->zone->name == NULL ||
+ qdata->zone->contents == NULL || qdata->zone->contents->apex == NULL)
+ {
+ return ERROR;
+ }
+
+ /* Retrieve the query tuple. */
+ const knot_dname_t *qname = knot_pkt_qname(qdata->query);
+ const uint16_t qtype = knot_pkt_qtype(qdata->query);
+ const uint16_t qclass = knot_pkt_qclass(qdata->query);
+
+ /* We only generate A and AAAA records, which are Internet class. */
+ if (qclass != KNOT_CLASS_IN) {
+ return state;
+ }
+
+ /* Only handle queries with qname set to the zone name. */
+ if (!knot_dname_is_equal(qname, qdata->zone->name)) {
+ return state;
+ }
+
+ /* Only handle A and AAAA queries. */
+ if (qtype != KNOT_RRTYPE_A && qtype != KNOT_RRTYPE_AAAA) {
+ return state;
+ }
+
+ /* Retrieve the IP address that sent the query. */
+ const struct sockaddr_storage *query_source = qdata->param->remote;
+ if (query_source == NULL) {
+ return ERROR;
+ }
+
+ /* If the socket address family corresponds to the query type (i.e.,
+ * AF_INET <-> A and AF_INET6 <-> AAAA), put the socket address and
+ * length into 'rdata' and 'len_rdata'.
+ */
+ const void *rdata = NULL;
+ size_t len_rdata = 0;
+ if (query_source->ss_family == AF_INET && qtype == KNOT_RRTYPE_A) {
+ const struct sockaddr_in *sai = (struct sockaddr_in *)query_source;
+ rdata = &sai->sin_addr.s_addr;
+ len_rdata = sizeof(sai->sin_addr.s_addr);
+ } else if (query_source->ss_family == AF_INET6 && qtype == KNOT_RRTYPE_AAAA) {
+ const struct sockaddr_in6 *sai6 = (struct sockaddr_in6 *)query_source;
+ rdata = &sai6->sin6_addr;
+ len_rdata = sizeof(sai6->sin6_addr);
+ } else {
+ /* Query type didn't match address family. */
+ return state;
+ }
+
+ /* Sanity check, since knot_rrset_add_rdata() takes a uint16_t length
+ * parameter.
+ */
+ if (len_rdata > UINT16_MAX) {
+ return state;
+ }
+
+ /* Synthesize the response RRset. */
+
+ /* Owner name, type, and class are taken from the question. */
+ rrset = knot_rrset_new(qname, qtype, qclass, &pkt->mm);
+ if (rrset == NULL) {
+ return ERROR;
+ }
+
+ /* TTL is taken from the TTL of the SOA record. */
+ uint32_t ttl = 0;
+ const zone_node_t *apex = qdata->zone->contents->apex;
+ for (uint16_t i = 0; apex != NULL && i < apex->rrset_count; i++) {
+ const struct rr_data *rr_data = &apex->rrs[i];
+ if (rr_data->type == KNOT_RRTYPE_SOA) {
+ ttl = knot_rdataset_ttl(&rr_data->rrs);
+ break;
+ }
+ }
+
+ /* Record data is the query source address. */
+ int ret = knot_rrset_add_rdata(rrset, rdata, len_rdata, ttl, &pkt->mm);
+ if (ret != KNOT_EOK) {
+ knot_rrset_free(&rrset, &pkt->mm);
+ return ERROR;
+ }
+
+ /* Add the new RRset to the response packet. */
+ ret = knot_pkt_put(pkt, KNOT_COMPR_HINT_QNAME, rrset, KNOT_PF_FREE);
+ if (ret != KNOT_EOK) {
+ knot_rrset_free(&rrset, &pkt->mm);
+ return ERROR;
+ }
+
+ /* Success. */
+ return HIT;
+}
+
+int whoami_load(struct query_plan *plan, struct query_module *self,
+ const knot_dname_t *zone)
+{
+ /* Sanity checks. */
+ if (plan == NULL || self == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ /* Hook to the query plan. */
+ query_plan_step(plan, QPLAN_ANSWER, whoami_query, NULL);
+
+ return KNOT_EOK;
+}
+
+int whoami_unload(struct query_module *self)
+{
+ /* Sanity check. */
+ if (self == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ return KNOT_EOK;
+}
diff --git a/src/knot/modules/whoami.h b/src/knot/modules/whoami.h
new file mode 100644
index 0000000000000000000000000000000000000000..5b922e76af9f84864fdaa822c771e49e17d08cb4
--- /dev/null
+++ b/src/knot/modules/whoami.h
@@ -0,0 +1,39 @@
+/* Copyright (C) 2016 Fastly, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*!
+ * \file
+ *
+ * \brief whoami module
+ *
+ * \addtogroup query_processing
+ * @{
+ */
+
+#pragma once
+
+#include "knot/nameserver/query_module.h"
+
+/*! \brief Module scheme. */
+#define C_MOD_WHOAMI "\x0A""mod-whoami"
+extern const yp_item_t scheme_mod_whoami[];
+
+/*! \brief Module interface. */
+int whoami_load(struct query_plan *plan, struct query_module *self,
+ const knot_dname_t *zone);
+int whoami_unload(struct query_module *self);
+
+/*! @} */
diff --git a/src/knot/nameserver/query_module.c b/src/knot/nameserver/query_module.c
index 04caa2e15f6330e2a33a4ec8e0d5bd9164983106..5011c3111f7dfb435d1a4cc43145c76fedcba8b9 100644
--- a/src/knot/nameserver/query_module.c
+++ b/src/knot/nameserver/query_module.c
@@ -29,6 +29,7 @@
#if USE_DNSTAP
#include "knot/modules/dnstap.h"
#endif
+#include "knot/modules/whoami.h"
typedef struct static_module {
const yp_name_t *name;
@@ -48,6 +49,7 @@ static_module_t MODULES[] = {
#if USE_DNSTAP
{ C_MOD_DNSTAP, &dnstap_load, &dnstap_unload, MOD_SCOPE_ANY },
#endif
+ { C_MOD_WHOAMI, &whoami_load, &whoami_unload, MOD_SCOPE_ANY },
{ NULL }
};