s4 dns: Add a simple dns lookup helper

3 files changed, 168 insertions, 0 deletions

diff --git a/utils/samba-dig.c b/utils/samba-dig.c
new file mode 100644
index 0000000000..3fd2ecffc4
--- /dev/null
+++ b/utils/samba-dig.c
@@ -0,0 +1,160 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   DNS query too for Samba with socketwrapper support
+
+   Copyright (C) 2012 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 <talloc.h>
+#include <tevent.h>
+#include "lib/util/samba_util.h"
+#include "librpc/ndr/libndr.h"
+#include "librpc/gen_ndr/ndr_dns.h"
+#include "libcli/dns/libdns.h"
+
+static void usage(void)
+{
+	printf("Usage: samba-dig <dns-server-ip> <data> <record-type>\n\n");
+}
+
+static struct dns_name_packet *make_name_packet(TALLOC_CTX *mem_ctx,
+						uint16_t operation)
+{
+	struct dns_name_packet *packet = talloc_zero(mem_ctx,
+						     struct dns_name_packet);
+	if (packet == NULL) {
+		return NULL;
+	}
+
+	packet->id = random();
+	packet->operation |= operation;
+
+	return packet;
+}
+
+#define QTYPE_MAP(type) if (strncmp(type_string, #type , strlen( #type )) == 0) \
+	return DNS_QTYPE_ ## type ;
+
+static enum dns_qtype parse_qtype(const char *type_string)
+{
+	QTYPE_MAP(AAAA);
+	QTYPE_MAP(A);
+	QTYPE_MAP(SOA);
+	QTYPE_MAP(PTR);
+	return -1;
+}
+#undef QTYPE_MAP
+
+static struct dns_name_question *make_question(TALLOC_CTX *mem_ctx,
+					       const char *name,
+					       enum dns_qtype type)
+{
+	struct dns_name_question *question = talloc(mem_ctx,
+			struct dns_name_question);
+	if (question == NULL) {
+		return NULL;
+	}
+
+	question->name = talloc_strdup(question, name);
+	question->question_type = type;
+	question->question_class = DNS_QCLASS_IN;
+
+	return question;
+}
+
+int main(int argc, char **argv)
+{
+	TALLOC_CTX *mem_ctx = talloc_init("samba-dig");
+	struct tevent_context *ev;
+	struct dns_name_packet *dns_packet, *in_packet;
+	struct dns_name_question *question;
+	enum dns_qtype type;
+	enum ndr_err_code ndr_err;
+	struct tevent_req *req;
+	WERROR w_err;
+	DATA_BLOB out, in;
+	int ret = 0;
+
+	if (argc < 4) {
+		usage();
+		exit(1);
+	}
+
+	ev = tevent_context_init(mem_ctx);
+	setup_logging("samba-dig", DEBUG_STDERR);
+	debug_parse_levels("1");
+
+	DEBUG(1,("Querying %s for %s %s\n", argv[1], argv[2], argv[3]));
+
+	dns_packet = make_name_packet(mem_ctx, DNS_OPCODE_QUERY);
+
+	type = parse_qtype(argv[3]);
+	if (type == -1) {
+		DEBUG(0, ("Invalid DNS_QTYPE %s\n", argv[3]));
+		ret = 1;
+		goto error;
+	}
+
+	question = make_question(dns_packet, argv[2], type);
+
+	dns_packet->qdcount = 1;
+	dns_packet->questions = question;
+	NDR_PRINT_DEBUG(dns_name_packet, dns_packet);
+
+	ndr_err = ndr_push_struct_blob(&out, mem_ctx, dns_packet,
+			(ndr_push_flags_fn_t)ndr_push_dns_name_packet);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(0, ("Failed to marshall dns_name_packet: %d\n", ndr_err));
+		ret = 1;
+		goto error;
+	}
+
+	req = dns_udp_request_send(mem_ctx, ev, argv[1], out.data, out.length);
+	if (req == NULL) {
+		DEBUG(0, ("Failed to allocate memory for tevent_req\n"));
+		ret = 1;
+		goto error;
+	}
+	if (!tevent_req_poll(req, ev)) {
+		DEBUG(0, ("Error sending dns request\n"));
+		ret = 1;
+		goto error;
+	}
+	w_err = dns_udp_request_recv(req, mem_ctx, &in.data, &in.length);
+	if (!W_ERROR_IS_OK(w_err)) {
+		DEBUG(0, ("Error receiving dns request: %s\n", win_errstr(w_err)));
+		ret = 1;
+		goto error;
+	}
+
+	in_packet = talloc(mem_ctx, struct dns_name_packet);
+
+	ndr_err = ndr_pull_struct_blob(&in, in_packet, in_packet,
+			(ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(0, ("Failed to unmarshall dns_name_packet: %d\n", ndr_err));
+		ret = 1;
+		goto error;
+	}
+
+	NDR_PRINT_DEBUG(dns_name_packet, in_packet);
+
+error:
+	talloc_free(mem_ctx);
+	return ret;
+}
diff --git a/utils/wscript_build b/utils/wscript_build
new file mode 100644
index 0000000000..3c22ad27ae
--- /dev/null
+++ b/utils/wscript_build
@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+
+bld.SAMBA_BINARY('samba-dig',
+	source='samba-dig.c',
+        deps='samba-util NDR_DNS tevent LIBCLI_DNS'
+	)
+
diff --git a/wscript_build b/wscript_build
index 8dbfd70293..93008a8744 100644
--- a/wscript_build
+++ b/wscript_build
@@ -122,6 +122,7 @@ bld.RECURSE('libds/common')
 bld.RECURSE('source3')
 bld.RECURSE('dfs_server')
 bld.RECURSE('file_server')
+bld.RECURSE('utils')
 
 bld.RECURSE('testsuite/headers')
 bld.RECURSE('testsuite/libsmbclient/src')