[PATCH 1/2] idl: Add support for parsing OPT records

[Kai Blin]

Signed-off-by: Kai Blin <k...@samba.org>
---
librpc/idl/dns.idl | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/librpc/idl/dns.idl b/librpc/idl/dns.idl
index 984f2b3..5b86f7e 100644
--- a/librpc/idl/dns.idl
+++ b/librpc/idl/dns.idl
@@ -106,6 +106,7 @@ interface dns
DNS_QTYPE_ATMA = 0x0022,
DNS_QTYPE_NAPTR = 0x0023,
DNS_QTYPE_DNAME = 0x0027,
+ DNS_QTYPE_OPT = 0x0029,
DNS_QTYPE_DS = 0x002B,
DNS_QTYPE_RRSIG = 0x002E,
DNS_QTYPE_NSEC = 0x002F,
@@ -168,6 +169,12 @@ interface dns
} dns_srv_record;

typedef [public] struct {
+ uint16 option_code;
+ uint16 option_length;
+ uint8 option_data[option_length];
+ } dns_opt_record;
+
+ typedef [public] struct {
dns_string algorithm;
uint32 inception;
uint32 expiration;
@@ -216,6 +223,7 @@ interface dns
[case(DNS_QTYPE_TXT)] dns_txt_record txt_record;
[case(DNS_QTYPE_AAAA)] ipv6address ipv6_record;
[case(DNS_QTYPE_SRV)] dns_srv_record srv_record;
+ [case(DNS_QTYPE_OPT)] dns_opt_record opt_record;
[case(DNS_QTYPE_TSIG)] dns_tsig_record tsig_record;
[case(DNS_QTYPE_TKEY)] dns_tkey_record tkey_record;
[default];
--
1.8.1.2

[Kai Blin]

This should fix bug #9632

Signed-off-by: Kai Blin <k...@samba.org>
---

source4/dns_server/dns_query.c | 13 +++++++++++++
source4/dns_server/dns_server.c | 2 ++
source4/dns_server/dns_server.h | 4 ++++
source4/dns_server/dns_utils.c | 21 +++++++++++++++++++++
4 files changed, 40 insertions(+)

diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
index 4ad14b9..5414e1d 100644
--- a/source4/dns_server/dns_query.c
+++ b/source4/dns_server/dns_query.c
@@ -138,14 +138,17 @@ struct ask_forwarder_state {
static void ask_forwarder_done(struct tevent_req *subreq);

static struct tevent_req *ask_forwarder_send(
+ struct dns_server *dns,
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;
+ struct dns_res_rec *options;
struct dns_name_packet out_packet = { 0, };
DATA_BLOB out_blob;
enum ndr_err_code ndr_err;
+ WERROR werr;

req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
if (req == NULL) {
@@ -166,6 +169,15 @@ static struct tevent_req *ask_forwarder_send(
out_packet.qdcount = 1;
out_packet.questions = question;

+ werr = dns_generate_options(dns, state, &options);
+ if (!W_ERROR_IS_OK(werr)) {
+ tevent_req_werror(req, werr);
+ return tevent_req_post(req, ev);
+ }
+
+ out_packet.arcount = 1;
+ out_packet.additional = options;
+
ndr_err = ndr_push_struct_blob(
&out_blob, state, &out_packet,
(ndr_push_flags_fn_t)ndr_push_dns_name_packet);
@@ -615,6 +627,7 @@ struct tevent_req *dns_server_process_query_send(
in->questions[0].name));

subreq = ask_forwarder_send(
+ dns,
state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
&in->questions[0]);
if (tevent_req_nomem(subreq, req)) {
diff --git a/source4/dns_server/dns_server.c b/source4/dns_server/dns_server.c
index bb4605f..7ad4aca 100644
--- a/source4/dns_server/dns_server.c
+++ b/source4/dns_server/dns_server.c
@@ -791,6 +791,8 @@ static void dns_task_init(struct task_server *task)
}

dns->task = task;
+ /*FIXME: Make this a configurable option */
+ dns->max_payload = 4096;

dns->server_credentials = cli_credentials_init(dns);
if (!dns->server_credentials) {
diff --git a/source4/dns_server/dns_server.h b/source4/dns_server/dns_server.h
index ef85730..efe4db8 100644
--- a/source4/dns_server/dns_server.h
+++ b/source4/dns_server/dns_server.h
@@ -56,6 +56,7 @@ struct dns_server {
struct dns_server_zone *zones;
struct dns_server_tkey_store *tkeys;
struct cli_credentials *server_credentials;
+ uint16_t max_payload;
};

struct dns_request_state {
@@ -107,6 +108,9 @@ WERROR dns_name2dn(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
const char *name,
struct ldb_dn **_dn);
+WERROR dns_generate_options(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ struct dns_res_rec **options);
struct dns_server_tkey *dns_find_tkey(struct dns_server_tkey_store *store,
const char *name);
WERROR dns_verify_tsig(struct dns_server *dns,
diff --git a/source4/dns_server/dns_utils.c b/source4/dns_server/dns_utils.c
index e03a409..21c7f5a 100644
--- a/source4/dns_server/dns_utils.c
+++ b/source4/dns_server/dns_utils.c
@@ -378,3 +378,24 @@ WERROR dns_name2dn(struct dns_server *dns,
*_dn = dn;
return WERR_OK;
}
+
+WERROR dns_generate_options(struct dns_server *dns,
+ TALLOC_CTX *mem_ctx,
+ struct dns_res_rec **options)
+{
+ struct dns_res_rec *o;
+
+ o = talloc_zero(mem_ctx, struct dns_res_rec);
+ if (o == NULL) {
+ return WERR_NOMEM;
+ }
+ o->name = '\0';
+ o->rr_type = DNS_QTYPE_OPT;
+ /* This is ugly, but RFC2671 wants the payload size in this field */
+ o->rr_class = (enum dns_qclass) dns->max_payload;
+ o->ttl = 0;
+ o->length = 0;
+
+ *options = o;
+ return WERR_OK;
+}
--
1.8.1.2