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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
commit8daa83a594a2e98f39d764422bfbdbc62c9efd44 (patch)
tree4099e8021376c7d8c05bdf8503093d80e9c7bad0 /source4/dns_server/dns_query.c
parentInitial commit. (diff)
downloadsamba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.tar.xz
samba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.zip
Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'source4/dns_server/dns_query.c')
-rw-r--r--source4/dns_server/dns_query.c1176
1 files changed, 1176 insertions, 0 deletions
diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
new file mode 100644
index 0000000..181beda
--- /dev/null
+++ b/source4/dns_server/dns_query.c
@@ -0,0 +1,1176 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ DNS server handler for queries
+
+ Copyright (C) 2010 Kai Blin <kai@samba.org>
+
+ 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 "includes.h"
+#include "samba/service_task.h"
+#include "libcli/util/werror.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_dns.h"
+#include "librpc/gen_ndr/ndr_dnsp.h"
+#include <ldb.h>
+#include "param/param.h"
+#include "dsdb/samdb/samdb.h"
+#include "dsdb/common/util.h"
+#include "dns_server/dns_server.h"
+#include "libcli/dns/libdns.h"
+#include "lib/util/dlinklist.h"
+#include "lib/util/util_net.h"
+#include "lib/util/tevent_werror.h"
+#include "auth/auth.h"
+#include "auth/credentials/credentials.h"
+#include "auth/gensec/gensec.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_DNS
+#define MAX_Q_RECURSION_DEPTH 20
+
+struct forwarder_string {
+ const char *forwarder;
+ struct forwarder_string *prev, *next;
+};
+
+static WERROR add_response_rr(const char *name,
+ const struct dnsp_DnssrvRpcRecord *rec,
+ struct dns_res_rec **answers)
+{
+ struct dns_res_rec *ans = *answers;
+ uint16_t ai = talloc_array_length(ans);
+ enum ndr_err_code ndr_err;
+
+ if (ai == UINT16_MAX) {
+ return WERR_BUFFER_OVERFLOW;
+ }
+
+ /*
+ * "ans" is always non-NULL and thus its own talloc context
+ */
+ ans = talloc_realloc(ans, ans, struct dns_res_rec, ai+1);
+ if (ans == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ ZERO_STRUCT(ans[ai]);
+
+ switch (rec->wType) {
+ case DNS_QTYPE_CNAME:
+ ans[ai].rdata.cname_record = talloc_strdup(ans, rec->data.cname);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.cname_record);
+ break;
+ case DNS_QTYPE_A:
+ ans[ai].rdata.ipv4_record = talloc_strdup(ans, rec->data.ipv4);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv4_record);
+ break;
+ case DNS_QTYPE_AAAA:
+ ans[ai].rdata.ipv6_record = talloc_strdup(ans, rec->data.ipv6);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv6_record);
+ break;
+ case DNS_TYPE_NS:
+ ans[ai].rdata.ns_record = talloc_strdup(ans, rec->data.ns);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ns_record);
+ break;
+ case DNS_QTYPE_SRV:
+ ans[ai].rdata.srv_record.priority = rec->data.srv.wPriority;
+ ans[ai].rdata.srv_record.weight = rec->data.srv.wWeight;
+ ans[ai].rdata.srv_record.port = rec->data.srv.wPort;
+ ans[ai].rdata.srv_record.target = talloc_strdup(
+ ans, rec->data.srv.nameTarget);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.srv_record.target);
+ break;
+ case DNS_QTYPE_SOA:
+ ans[ai].rdata.soa_record.mname = talloc_strdup(
+ ans, rec->data.soa.mname);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.mname);
+ ans[ai].rdata.soa_record.rname = talloc_strdup(
+ ans, rec->data.soa.rname);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.rname);
+ ans[ai].rdata.soa_record.serial = rec->data.soa.serial;
+ ans[ai].rdata.soa_record.refresh = rec->data.soa.refresh;
+ ans[ai].rdata.soa_record.retry = rec->data.soa.retry;
+ ans[ai].rdata.soa_record.expire = rec->data.soa.expire;
+ ans[ai].rdata.soa_record.minimum = rec->data.soa.minimum;
+ break;
+ case DNS_QTYPE_PTR:
+ ans[ai].rdata.ptr_record = talloc_strdup(ans, rec->data.ptr);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ptr_record);
+ break;
+ case DNS_QTYPE_MX:
+ ans[ai].rdata.mx_record.preference = rec->data.mx.wPriority;
+ ans[ai].rdata.mx_record.exchange = talloc_strdup(
+ ans, rec->data.mx.nameTarget);
+ if (ans[ai].rdata.mx_record.exchange == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_TXT:
+ ndr_err = ndr_dnsp_string_list_copy(ans,
+ &rec->data.txt,
+ &ans[ai].rdata.txt_record.txt);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ default:
+ DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
+ return DNS_ERR(NOT_IMPLEMENTED);
+ }
+
+ ans[ai].name = talloc_strdup(ans, name);
+ W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
+ ans[ai].rr_type = (enum dns_qtype)rec->wType;
+ ans[ai].rr_class = DNS_QCLASS_IN;
+ ans[ai].ttl = rec->dwTtlSeconds;
+ ans[ai].length = UINT16_MAX;
+
+ *answers = ans;
+
+ return WERR_OK;
+}
+
+static WERROR add_dns_res_rec(struct dns_res_rec **pdst,
+ const struct dns_res_rec *src)
+{
+ struct dns_res_rec *dst = *pdst;
+ uint16_t di = talloc_array_length(dst);
+ enum ndr_err_code ndr_err;
+
+ if (di == UINT16_MAX) {
+ return WERR_BUFFER_OVERFLOW;
+ }
+
+ dst = talloc_realloc(dst, dst, struct dns_res_rec, di+1);
+ if (dst == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ ZERO_STRUCT(dst[di]);
+
+ dst[di] = (struct dns_res_rec) {
+ .name = talloc_strdup(dst, src->name),
+ .rr_type = src->rr_type,
+ .rr_class = src->rr_class,
+ .ttl = src->ttl,
+ .length = src->length
+ };
+
+ if (dst[di].name == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ switch (src->rr_type) {
+ case DNS_QTYPE_CNAME:
+ dst[di].rdata.cname_record = talloc_strdup(
+ dst, src->rdata.cname_record);
+ if (dst[di].rdata.cname_record == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_A:
+ dst[di].rdata.ipv4_record = talloc_strdup(
+ dst, src->rdata.ipv4_record);
+ if (dst[di].rdata.ipv4_record == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_AAAA:
+ dst[di].rdata.ipv6_record = talloc_strdup(
+ dst, src->rdata.ipv6_record);
+ if (dst[di].rdata.ipv6_record == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_TYPE_NS:
+ dst[di].rdata.ns_record = talloc_strdup(
+ dst, src->rdata.ns_record);
+ if (dst[di].rdata.ns_record == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_SRV:
+ dst[di].rdata.srv_record = (struct dns_srv_record) {
+ .priority = src->rdata.srv_record.priority,
+ .weight = src->rdata.srv_record.weight,
+ .port = src->rdata.srv_record.port,
+ .target = talloc_strdup(
+ dst, src->rdata.srv_record.target)
+ };
+ if (dst[di].rdata.srv_record.target == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_SOA:
+ dst[di].rdata.soa_record = (struct dns_soa_record) {
+ .mname = talloc_strdup(
+ dst, src->rdata.soa_record.mname),
+ .rname = talloc_strdup(
+ dst, src->rdata.soa_record.rname),
+ .serial = src->rdata.soa_record.serial,
+ .refresh = src->rdata.soa_record.refresh,
+ .retry = src->rdata.soa_record.retry,
+ .expire = src->rdata.soa_record.expire,
+ .minimum = src->rdata.soa_record.minimum
+ };
+
+ if ((dst[di].rdata.soa_record.mname == NULL) ||
+ (dst[di].rdata.soa_record.rname == NULL)) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ break;
+ case DNS_QTYPE_PTR:
+ dst[di].rdata.ptr_record = talloc_strdup(
+ dst, src->rdata.ptr_record);
+ if (dst[di].rdata.ptr_record == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_MX:
+ dst[di].rdata.mx_record = (struct dns_mx_record) {
+ .preference = src->rdata.mx_record.preference,
+ .exchange = talloc_strdup(
+ src, src->rdata.mx_record.exchange)
+ };
+
+ if (dst[di].rdata.mx_record.exchange == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ case DNS_QTYPE_TXT:
+ ndr_err = ndr_dnsp_string_list_copy(dst,
+ &src->rdata.txt_record.txt,
+ &dst[di].rdata.txt_record.txt);
+ if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ break;
+ default:
+ DBG_WARNING("Got unhandled type %u query.\n", src->rr_type);
+ return DNS_ERR(NOT_IMPLEMENTED);
+ }
+
+ *pdst = dst;
+
+ return WERR_OK;
+}
+
+struct ask_forwarder_state {
+ struct dns_name_packet *reply;
+};
+
+static void ask_forwarder_done(struct tevent_req *subreq);
+
+static struct tevent_req *ask_forwarder_send(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ const char *forwarder, struct dns_name_question *question)
+{
+ struct tevent_req *req, *subreq;
+ struct ask_forwarder_state *state;
+
+ req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ subreq = dns_cli_request_send(state, ev, forwarder,
+ question->name, question->question_class,
+ question->question_type);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(subreq, ask_forwarder_done, req);
+ return req;
+}
+
+static void ask_forwarder_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct ask_forwarder_state *state = tevent_req_data(
+ req, struct ask_forwarder_state);
+ int ret;
+
+ ret = dns_cli_request_recv(subreq, state, &state->reply);
+ TALLOC_FREE(subreq);
+
+ if (ret != 0) {
+ tevent_req_werror(req, unix_to_werror(ret));
+ return;
+ }
+
+ tevent_req_done(req);
+}
+
+static WERROR ask_forwarder_recv(
+ struct tevent_req *req, TALLOC_CTX *mem_ctx,
+ struct dns_res_rec **answers, uint16_t *ancount,
+ struct dns_res_rec **nsrecs, uint16_t *nscount,
+ struct dns_res_rec **additional, uint16_t *arcount)
+{
+ struct ask_forwarder_state *state = tevent_req_data(
+ req, struct ask_forwarder_state);
+ struct dns_name_packet *in_packet = state->reply;
+ WERROR err;
+
+ if (tevent_req_is_werror(req, &err)) {
+ return err;
+ }
+
+ *ancount = in_packet->ancount;
+ *answers = talloc_move(mem_ctx, &in_packet->answers);
+
+ *nscount = in_packet->nscount;
+ *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
+
+ *arcount = in_packet->arcount;
+ *additional = talloc_move(mem_ctx, &in_packet->additional);
+
+ return WERR_OK;
+}
+
+static WERROR add_zone_authority_record(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ const struct dns_name_question *question,
+ struct dns_res_rec **nsrecs)
+{
+ const char *zone = NULL;
+ struct dnsp_DnssrvRpcRecord *recs;
+ struct dns_res_rec *ns = *nsrecs;
+ uint16_t rec_count;
+ struct ldb_dn *dn = NULL;
+ unsigned int ri;
+ WERROR werror;
+
+ zone = dns_get_authoritative_zone(dns, question->name);
+ DEBUG(10, ("Creating zone authority record for '%s'\n", zone));
+
+ werror = dns_name2dn(dns, mem_ctx, zone, &dn);
+ if (!W_ERROR_IS_OK(werror)) {
+ return werror;
+ }
+
+ werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
+ if (!W_ERROR_IS_OK(werror)) {
+ return werror;
+ }
+
+ for (ri = 0; ri < rec_count; ri++) {
+ if (recs[ri].wType == DNS_TYPE_SOA) {
+ werror = add_response_rr(zone, &recs[ri], &ns);
+ if (!W_ERROR_IS_OK(werror)) {
+ return werror;
+ }
+ }
+ }
+
+ *nsrecs = ns;
+
+ return WERR_OK;
+}
+
+static struct tevent_req *handle_authoritative_send(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct dns_server *dns, const char *forwarder,
+ struct dns_name_question *question,
+ struct dns_res_rec **answers, struct dns_res_rec **nsrecs,
+ size_t cname_depth);
+static WERROR handle_authoritative_recv(struct tevent_req *req);
+
+struct handle_dnsrpcrec_state {
+ struct dns_res_rec **answers;
+ struct dns_res_rec **nsrecs;
+};
+
+static void handle_dnsrpcrec_gotauth(struct tevent_req *subreq);
+static void handle_dnsrpcrec_gotforwarded(struct tevent_req *subreq);
+
+static struct tevent_req *handle_dnsrpcrec_send(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct dns_server *dns, const char *forwarder,
+ const struct dns_name_question *question,
+ struct dnsp_DnssrvRpcRecord *rec,
+ struct dns_res_rec **answers, struct dns_res_rec **nsrecs,
+ size_t cname_depth)
+{
+ struct tevent_req *req, *subreq;
+ struct handle_dnsrpcrec_state *state;
+ struct dns_name_question *new_q;
+ bool resolve_cname;
+ WERROR werr;
+
+ req = tevent_req_create(mem_ctx, &state,
+ struct handle_dnsrpcrec_state);
+ if (req == NULL) {
+ return NULL;
+ }
+ state->answers = answers;
+ state->nsrecs = nsrecs;
+
+ if (cname_depth >= MAX_Q_RECURSION_DEPTH) {
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ resolve_cname = ((rec->wType == DNS_TYPE_CNAME) &&
+ ((question->question_type == DNS_QTYPE_A) ||
+ (question->question_type == DNS_QTYPE_AAAA)));
+
+ if (!resolve_cname) {
+ if ((question->question_type != DNS_QTYPE_ALL) &&
+ (rec->wType !=
+ (enum dns_record_type) question->question_type)) {
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ werr = add_response_rr(question->name, rec, state->answers);
+ if (tevent_req_werror(req, werr)) {
+ return tevent_req_post(req, ev);
+ }
+
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ werr = add_response_rr(question->name, rec, state->answers);
+ if (tevent_req_werror(req, werr)) {
+ return tevent_req_post(req, ev);
+ }
+
+ new_q = talloc(state, struct dns_name_question);
+ if (tevent_req_nomem(new_q, req)) {
+ return tevent_req_post(req, ev);
+ }
+
+ *new_q = (struct dns_name_question) {
+ .question_type = question->question_type,
+ .question_class = question->question_class,
+ .name = rec->data.cname
+ };
+
+ if (dns_authoritative_for_zone(dns, new_q->name)) {
+ subreq = handle_authoritative_send(
+ state, ev, dns, forwarder, new_q,
+ state->answers, state->nsrecs,
+ cname_depth + 1);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(subreq, handle_dnsrpcrec_gotauth, req);
+ return req;
+ }
+
+ subreq = ask_forwarder_send(state, ev, forwarder, new_q);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(subreq, handle_dnsrpcrec_gotforwarded, req);
+
+ return req;
+}
+
+static void handle_dnsrpcrec_gotauth(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ WERROR werr;
+
+ werr = handle_authoritative_recv(subreq);
+ TALLOC_FREE(subreq);
+ if (tevent_req_werror(req, werr)) {
+ return;
+ }
+ tevent_req_done(req);
+}
+
+static void handle_dnsrpcrec_gotforwarded(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct handle_dnsrpcrec_state *state = tevent_req_data(
+ req, struct handle_dnsrpcrec_state);
+ struct dns_res_rec *answers, *nsrecs, *additional;
+ uint16_t ancount = 0;
+ uint16_t nscount = 0;
+ uint16_t arcount = 0;
+ uint16_t i;
+ WERROR werr;
+
+ werr = ask_forwarder_recv(subreq, state, &answers, &ancount,
+ &nsrecs, &nscount, &additional, &arcount);
+ if (tevent_req_werror(req, werr)) {
+ return;
+ }
+
+ for (i=0; i<ancount; i++) {
+ werr = add_dns_res_rec(state->answers, &answers[i]);
+ if (tevent_req_werror(req, werr)) {
+ return;
+ }
+ }
+
+ for (i=0; i<nscount; i++) {
+ werr = add_dns_res_rec(state->nsrecs, &nsrecs[i]);
+ if (tevent_req_werror(req, werr)) {
+ return;
+ }
+ }
+
+ tevent_req_done(req);
+}
+
+static WERROR handle_dnsrpcrec_recv(struct tevent_req *req)
+{
+ return tevent_req_simple_recv_werror(req);
+}
+
+struct handle_authoritative_state {
+ struct tevent_context *ev;
+ struct dns_server *dns;
+ struct dns_name_question *question;
+ const char *forwarder;
+
+ struct dnsp_DnssrvRpcRecord *recs;
+ uint16_t rec_count;
+ uint16_t recs_done;
+
+ struct dns_res_rec **answers;
+ struct dns_res_rec **nsrecs;
+
+ size_t cname_depth;
+};
+
+static void handle_authoritative_done(struct tevent_req *subreq);
+
+static struct tevent_req *handle_authoritative_send(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct dns_server *dns, const char *forwarder,
+ struct dns_name_question *question,
+ struct dns_res_rec **answers, struct dns_res_rec **nsrecs,
+ size_t cname_depth)
+{
+ struct tevent_req *req, *subreq;
+ struct handle_authoritative_state *state;
+ struct ldb_dn *dn = NULL;
+ WERROR werr;
+
+ req = tevent_req_create(mem_ctx, &state,
+ struct handle_authoritative_state);
+ if (req == NULL) {
+ return NULL;
+ }
+ state->ev = ev;
+ state->dns = dns;
+ state->question = question;
+ state->forwarder = forwarder;
+ state->answers = answers;
+ state->nsrecs = nsrecs;
+ state->cname_depth = cname_depth;
+
+ werr = dns_name2dn(dns, state, question->name, &dn);
+ if (tevent_req_werror(req, werr)) {
+ return tevent_req_post(req, ev);
+ }
+ werr = dns_lookup_records_wildcard(dns, state, dn, &state->recs,
+ &state->rec_count);
+ TALLOC_FREE(dn);
+ if (tevent_req_werror(req, werr)) {
+ return tevent_req_post(req, ev);
+ }
+
+ if (state->rec_count == 0) {
+ tevent_req_werror(req, DNS_ERR(NAME_ERROR));
+ return tevent_req_post(req, ev);
+ }
+
+ subreq = handle_dnsrpcrec_send(
+ state, state->ev, state->dns, state->forwarder,
+ state->question, &state->recs[state->recs_done],
+ state->answers, state->nsrecs,
+ state->cname_depth);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(subreq, handle_authoritative_done, req);
+ return req;
+}
+
+static void handle_authoritative_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct handle_authoritative_state *state = tevent_req_data(
+ req, struct handle_authoritative_state);
+ WERROR werr;
+
+ werr = handle_dnsrpcrec_recv(subreq);
+ TALLOC_FREE(subreq);
+ if (tevent_req_werror(req, werr)) {
+ return;
+ }
+
+ state->recs_done += 1;
+
+ if (state->recs_done == state->rec_count) {
+ tevent_req_done(req);
+ return;
+ }
+
+ subreq = handle_dnsrpcrec_send(
+ state, state->ev, state->dns, state->forwarder,
+ state->question, &state->recs[state->recs_done],
+ state->answers, state->nsrecs,
+ state->cname_depth);
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+ tevent_req_set_callback(subreq, handle_authoritative_done, req);
+}
+
+static WERROR handle_authoritative_recv(struct tevent_req *req)
+{
+ WERROR werr;
+
+ if (tevent_req_is_werror(req, &werr)) {
+ return werr;
+ }
+
+ return WERR_OK;
+}
+
+static NTSTATUS create_tkey(struct dns_server *dns,
+ const char* name,
+ const char* algorithm,
+ const struct tsocket_address *remote_address,
+ const struct tsocket_address *local_address,
+ struct dns_server_tkey **tkey)
+{
+ NTSTATUS status;
+ struct dns_server_tkey_store *store = dns->tkeys;
+ struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
+
+ if (k == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ k->name = talloc_strdup(k, name);
+
+ if (k->name == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ k->algorithm = talloc_strdup(k, algorithm);
+ if (k->algorithm == NULL) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ /*
+ * We only allow SPNEGO/KRB5 currently
+ * and rely on the backend to be RPC/IPC free.
+ *
+ * It allows gensec_update() not to block.
+ */
+ status = samba_server_gensec_krb5_start(k,
+ dns->task->event_ctx,
+ dns->task->msg_ctx,
+ dns->task->lp_ctx,
+ dns->server_credentials,
+ "dns",
+ &k->gensec);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
+ *tkey = NULL;
+ return status;
+ }
+
+ gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
+
+ status = gensec_set_remote_address(k->gensec,
+ remote_address);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(1, ("Failed to set remote address into GENSEC: %s\n",
+ nt_errstr(status)));
+ *tkey = NULL;
+ return status;
+ }
+
+ status = gensec_set_local_address(k->gensec,
+ local_address);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(1, ("Failed to set local address into GENSEC: %s\n",
+ nt_errstr(status)));
+ *tkey = NULL;
+ return status;
+ }
+
+ status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
+
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(1, ("Failed to start GENSEC server code: %s\n",
+ nt_errstr(status)));
+ *tkey = NULL;
+ return status;
+ }
+
+ TALLOC_FREE(store->tkeys[store->next_idx]);
+
+ store->tkeys[store->next_idx] = k;
+ (store->next_idx)++;
+ store->next_idx %= store->size;
+
+ *tkey = k;
+ return NT_STATUS_OK;
+}
+
+static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
+ struct dns_server *dns,
+ struct dns_server_tkey *tkey,
+ const DATA_BLOB *key,
+ DATA_BLOB *reply,
+ uint16_t *dns_auth_error)
+{
+ NTSTATUS status;
+
+ /*
+ * We use samba_server_gensec_krb5_start(),
+ * which only allows SPNEGO/KRB5 currently
+ * and makes sure the backend to be RPC/IPC free.
+ *
+ * See gensec_gssapi_update_internal() as
+ * GENSEC_SERVER.
+ *
+ * It allows gensec_update() not to block.
+ *
+ * If that changes in future we need to use
+ * gensec_update_send/recv here!
+ */
+ status = gensec_update(tkey->gensec, mem_ctx,
+ *key, reply);
+
+ if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
+ *dns_auth_error = DNS_RCODE_OK;
+ return status;
+ }
+
+ if (NT_STATUS_IS_OK(status)) {
+
+ status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
+ if (!NT_STATUS_IS_OK(status)) {
+ *dns_auth_error = DNS_RCODE_BADKEY;
+ return status;
+ }
+ *dns_auth_error = DNS_RCODE_OK;
+ }
+
+ return status;
+}
+
+static WERROR handle_tkey(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ const struct dns_name_packet *in,
+ struct dns_request_state *state,
+ struct dns_res_rec **answers,
+ uint16_t *ancount)
+{
+ struct dns_res_rec *in_tkey = NULL;
+ struct dns_res_rec *ret_tkey;
+ uint16_t i;
+
+ for (i = 0; i < in->arcount; i++) {
+ if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
+ in_tkey = &in->additional[i];
+ break;
+ }
+ }
+
+ /* If this is a TKEY query, it should have a TKEY RR.
+ * Behaviour is not really specified in RFC 2930 or RFC 3645, but
+ * FORMAT_ERROR seems to be what BIND uses .*/
+ if (in_tkey == NULL) {
+ return DNS_ERR(FORMAT_ERROR);
+ }
+
+ ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
+ if (ret_tkey == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
+ if (ret_tkey->name == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ ret_tkey->rr_type = DNS_QTYPE_TKEY;
+ ret_tkey->rr_class = DNS_QCLASS_ANY;
+ ret_tkey->length = UINT16_MAX;
+
+ ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
+ in_tkey->rdata.tkey_record.algorithm);
+ if (ret_tkey->rdata.tkey_record.algorithm == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+
+ ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
+ ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
+ ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
+
+ switch (in_tkey->rdata.tkey_record.mode) {
+ case DNS_TKEY_MODE_DH:
+ /* FIXME: According to RFC 2930, we MUST support this, but we don't.
+ * Still, claim it's a bad key instead of a bad mode */
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
+ break;
+ case DNS_TKEY_MODE_GSSAPI: {
+ NTSTATUS status;
+ struct dns_server_tkey *tkey;
+ DATA_BLOB key;
+ DATA_BLOB reply;
+
+ tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
+ if (tkey != NULL && tkey->complete) {
+ /* TODO: check if the key is still valid */
+ DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
+ break;
+ }
+
+ if (tkey == NULL) {
+ status = create_tkey(dns, in->questions[0].name,
+ in_tkey->rdata.tkey_record.algorithm,
+ state->remote_address,
+ state->local_address,
+ &tkey);
+ if (!NT_STATUS_IS_OK(status)) {
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
+ return ntstatus_to_werror(status);
+ }
+ }
+
+ key.data = in_tkey->rdata.tkey_record.key_data;
+ key.length = in_tkey->rdata.tkey_record.key_size;
+
+ status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
+ &ret_tkey->rdata.tkey_record.error);
+ if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
+ DEBUG(1, ("More processing required\n"));
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
+ } else if (NT_STATUS_IS_OK(status)) {
+ DBG_DEBUG("Tkey handshake completed\n");
+ ret_tkey->rdata.tkey_record.key_size = reply.length;
+ ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
+ reply.data,
+ reply.length);
+ if (ret_tkey->rdata.tkey_record.key_data == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ state->sign = true;
+ state->key_name = talloc_strdup(state->mem_ctx, tkey->name);
+ if (state->key_name == NULL) {
+ return WERR_NOT_ENOUGH_MEMORY;
+ }
+ } else {
+ DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
+ }
+
+ break;
+ }
+ case DNS_TKEY_MODE_DELETE:
+ /* TODO: implement me */
+ DEBUG(1, ("Should delete tkey here\n"));
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
+ break;
+ case DNS_TKEY_MODE_NULL:
+ case DNS_TKEY_MODE_SERVER:
+ case DNS_TKEY_MODE_CLIENT:
+ case DNS_TKEY_MODE_LAST:
+ /* We don't have to implement these, return a mode error */
+ ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
+ break;
+ default:
+ DEBUG(1, ("Unsupported TKEY mode %d\n",
+ in_tkey->rdata.tkey_record.mode));
+ }
+
+ *answers = ret_tkey;
+ *ancount = 1;
+
+ return WERR_OK;
+}
+
+struct dns_server_process_query_state {
+ struct tevent_context *ev;
+ struct dns_server *dns;
+ struct dns_name_question *question;
+
+ struct dns_res_rec *answers;
+ uint16_t ancount;
+ struct dns_res_rec *nsrecs;
+ uint16_t nscount;
+ struct dns_res_rec *additional;
+ uint16_t arcount;
+ struct forwarder_string *forwarders;
+};
+
+static void dns_server_process_query_got_auth(struct tevent_req *subreq);
+static void dns_server_process_query_got_response(struct tevent_req *subreq);
+
+struct tevent_req *dns_server_process_query_send(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct dns_server *dns, struct dns_request_state *req_state,
+ const struct dns_name_packet *in)
+{
+ struct tevent_req *req, *subreq;
+ struct dns_server_process_query_state *state;
+ const char **forwarders = NULL;
+ unsigned int i;
+
+ req = tevent_req_create(mem_ctx, &state,
+ struct dns_server_process_query_state);
+ if (req == NULL) {
+ return NULL;
+ }
+ if (in->qdcount != 1) {
+ tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
+ return tevent_req_post(req, ev);
+ }
+
+ /* Windows returns NOT_IMPLEMENTED on this as well */
+ if (in->questions[0].question_class == DNS_QCLASS_NONE) {
+ tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
+ return tevent_req_post(req, ev);
+ }
+
+ if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
+ WERROR err;
+
+ err = handle_tkey(dns, state, in, req_state,
+ &state->answers, &state->ancount);
+ if (tevent_req_werror(req, err)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_done(req);
+ return tevent_req_post(req, ev);
+ }
+
+ state->dns = dns;
+ state->ev = ev;
+ state->question = &in->questions[0];
+
+ forwarders = lpcfg_dns_forwarder(dns->task->lp_ctx);
+ for (i = 0; forwarders != NULL && forwarders[i] != NULL; i++) {
+ struct forwarder_string *f = talloc_zero(state,
+ struct forwarder_string);
+ f->forwarder = forwarders[i];
+ DLIST_ADD_END(state->forwarders, f);
+ }
+
+ if (dns_authoritative_for_zone(dns, in->questions[0].name)) {
+
+ req_state->flags |= DNS_FLAG_AUTHORITATIVE;
+
+ /*
+ * Initialize the response arrays, so that we can use
+ * them as their own talloc contexts when doing the
+ * realloc
+ */
+ state->answers = talloc_array(state, struct dns_res_rec, 0);
+ if (tevent_req_nomem(state->answers, req)) {
+ return tevent_req_post(req, ev);
+ }
+ state->nsrecs = talloc_array(state, struct dns_res_rec, 0);
+ if (tevent_req_nomem(state->nsrecs, req)) {
+ return tevent_req_post(req, ev);
+ }
+
+ subreq = handle_authoritative_send(
+ state, ev, dns, (forwarders == NULL ? NULL : forwarders[0]),
+ &in->questions[0], &state->answers, &state->nsrecs,
+ 0); /* cname_depth */
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(
+ subreq, dns_server_process_query_got_auth, req);
+ return req;
+ }
+
+ if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
+ (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
+ DEBUG(5, ("Not authoritative for '%s', forwarding\n",
+ in->questions[0].name));
+
+ subreq = ask_forwarder_send(state, ev,
+ (forwarders == NULL ? NULL : forwarders[0]),
+ &in->questions[0]);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+ tevent_req_set_callback(
+ subreq, dns_server_process_query_got_response, req);
+ return req;
+ }
+
+ tevent_req_werror(req, DNS_ERR(NAME_ERROR));
+ return tevent_req_post(req, ev);
+}
+
+static void dns_server_process_query_got_response(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct dns_server_process_query_state *state = tevent_req_data(
+ req, struct dns_server_process_query_state);
+ WERROR werr;
+
+ werr = ask_forwarder_recv(subreq, state,
+ &state->answers, &state->ancount,
+ &state->nsrecs, &state->nscount,
+ &state->additional, &state->arcount);
+ TALLOC_FREE(subreq);
+
+ /* If you get an error, attempt a different forwarder */
+ if (!W_ERROR_IS_OK(werr)) {
+ if (state->forwarders != NULL) {
+ DLIST_REMOVE(state->forwarders, state->forwarders);
+ }
+
+ /* If you have run out of forwarders, simply finish */
+ if (state->forwarders == NULL) {
+ tevent_req_werror(req, werr);
+ return;
+ }
+
+ DEBUG(5, ("DNS query returned %s, trying another forwarder.\n",
+ win_errstr(werr)));
+ subreq = ask_forwarder_send(state, state->ev,
+ state->forwarders->forwarder,
+ state->question);
+
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+
+ tevent_req_set_callback(subreq,
+ dns_server_process_query_got_response,
+ req);
+ return;
+ }
+
+ tevent_req_done(req);
+}
+
+static void dns_server_process_query_got_auth(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct dns_server_process_query_state *state = tevent_req_data(
+ req, struct dns_server_process_query_state);
+ WERROR werr;
+ WERROR werr2;
+
+ werr = handle_authoritative_recv(subreq);
+ TALLOC_FREE(subreq);
+
+ /* If you get an error, attempt a different forwarder */
+ if (!W_ERROR_IS_OK(werr)) {
+ if (state->forwarders != NULL) {
+ DLIST_REMOVE(state->forwarders, state->forwarders);
+ }
+
+ /* If you have run out of forwarders, simply finish */
+ if (state->forwarders == NULL) {
+ werr2 = add_zone_authority_record(state->dns,
+ state,
+ state->question,
+ &state->nsrecs);
+ if (tevent_req_werror(req, werr2)) {
+ DBG_WARNING("Failed to add SOA record: %s\n",
+ win_errstr(werr2));
+ return;
+ }
+
+ state->ancount = talloc_array_length(state->answers);
+ state->nscount = talloc_array_length(state->nsrecs);
+ state->arcount = talloc_array_length(state->additional);
+
+ tevent_req_werror(req, werr);
+ return;
+ }
+
+ DEBUG(5, ("Error: %s, trying a different forwarder.\n",
+ win_errstr(werr)));
+ subreq = handle_authoritative_send(state, state->ev, state->dns,
+ state->forwarders->forwarder,
+ state->question, &state->answers,
+ &state->nsrecs,
+ 0); /* cname_depth */
+
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+
+ tevent_req_set_callback(subreq,
+ dns_server_process_query_got_auth,
+ req);
+ return;
+ }
+
+ werr2 = add_zone_authority_record(state->dns,
+ state,
+ state->question,
+ &state->nsrecs);
+ if (tevent_req_werror(req, werr2)) {
+ DBG_WARNING("Failed to add SOA record: %s\n",
+ win_errstr(werr2));
+ return;
+ }
+
+ state->ancount = talloc_array_length(state->answers);
+ state->nscount = talloc_array_length(state->nsrecs);
+ state->arcount = talloc_array_length(state->additional);
+
+ tevent_req_done(req);
+}
+
+WERROR dns_server_process_query_recv(
+ struct tevent_req *req, TALLOC_CTX *mem_ctx,
+ struct dns_res_rec **answers, uint16_t *ancount,
+ struct dns_res_rec **nsrecs, uint16_t *nscount,
+ struct dns_res_rec **additional, uint16_t *arcount)
+{
+ struct dns_server_process_query_state *state = tevent_req_data(
+ req, struct dns_server_process_query_state);
+ WERROR err = WERR_OK;
+
+ if (tevent_req_is_werror(req, &err)) {
+
+ if ((!W_ERROR_EQUAL(err, DNS_ERR(NAME_ERROR))) &&
+ (!W_ERROR_EQUAL(err, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST))) {
+ return err;
+ }
+ }
+ *answers = talloc_move(mem_ctx, &state->answers);
+ *ancount = state->ancount;
+ *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
+ *nscount = state->nscount;
+ *additional = talloc_move(mem_ctx, &state->additional);
+ *arcount = state->arcount;
+ return err;
+}