1 files changed, 623 insertions, 0 deletions

diff --git a/source4/kdc/kdc-server.c b/source4/kdc/kdc-server.c
new file mode 100644
index 0000000..297d91e
--- /dev/null
+++ b/source4/kdc/kdc-server.c
@@ -0,0 +1,623 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   KDC related functions
+
+   Copyright (c) 2005-2008 Andrew Bartlett <abartlet@samba.org>
+   Copyright (c) 2005      Andrew Tridgell <tridge@samba.org>
+   Copyright (c) 2005      Stefan Metzmacher <metze@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 "param/param.h"
+#include "samba/process_model.h"
+#include "lib/tsocket/tsocket.h"
+#include "libcli/util/tstream.h"
+#include "kdc/kdc-server.h"
+#include "kdc/kdc-proxy.h"
+#include "lib/stream/packet.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_KERBEROS
+
+/*
+ * State of an open tcp connection
+ */
+struct kdc_tcp_connection {
+	/* stream connection we belong to */
+	struct stream_connection *conn;
+
+	/* the kdc_server the connection belongs to */
+	struct kdc_socket *kdc_socket;
+
+	struct tstream_context *tstream;
+
+	struct tevent_queue *send_queue;
+};
+
+struct kdc_tcp_call {
+	struct kdc_tcp_connection *kdc_conn;
+	DATA_BLOB in;
+	DATA_BLOB out;
+	uint8_t out_hdr[4];
+	struct iovec out_iov[2];
+};
+
+struct kdc_udp_call {
+	struct kdc_udp_socket *sock;
+	struct tsocket_address *src;
+	DATA_BLOB in;
+	DATA_BLOB out;
+};
+
+static void kdc_udp_call_proxy_done(struct tevent_req *subreq);
+static void kdc_udp_call_sendto_done(struct tevent_req *subreq);
+
+static void kdc_tcp_call_writev_done(struct tevent_req *subreq);
+static void kdc_tcp_call_proxy_done(struct tevent_req *subreq);
+
+static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdc_conn,
+					 const char *reason)
+{
+	stream_terminate_connection(kdc_conn->conn, reason);
+}
+
+static NTSTATUS kdc_proxy_unavailable_error(struct kdc_server *kdc,
+					    TALLOC_CTX *mem_ctx,
+					    DATA_BLOB *out)
+{
+	krb5_error_code code;
+	krb5_data enc_error;
+
+	code = smb_krb5_mk_error(kdc->smb_krb5_context->krb5_context,
+				 KRB5KDC_ERR_SVC_UNAVAILABLE,
+				 NULL,
+				 NULL,
+				 NULL,
+				 NULL,
+				 &enc_error);
+	if (code != 0) {
+		DBG_WARNING("Unable to form krb5 error reply\n");
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	*out = data_blob_talloc(mem_ctx, enc_error.data, enc_error.length);
+	smb_krb5_free_data_contents(kdc->smb_krb5_context->krb5_context,
+				    &enc_error);
+	if (!out->data) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static void kdc_udp_call_loop(struct tevent_req *subreq)
+{
+	struct kdc_udp_socket *sock = tevent_req_callback_data(subreq,
+				      struct kdc_udp_socket);
+	struct kdc_udp_call *call;
+	uint8_t *buf;
+	ssize_t len;
+	int sys_errno;
+	kdc_code ret;
+
+	call = talloc(sock, struct kdc_udp_call);
+	if (call == NULL) {
+		talloc_free(call);
+		goto done;
+	}
+	call->sock = sock;
+
+	len = tdgram_recvfrom_recv(subreq, &sys_errno,
+				   call, &buf, &call->src);
+	TALLOC_FREE(subreq);
+	if (len == -1) {
+		talloc_free(call);
+		goto done;
+	}
+
+	call->in.data = buf;
+	call->in.length = len;
+
+	DBG_DEBUG("Received krb5 UDP packet of length %zu from %s\n",
+		  call->in.length,
+		  tsocket_address_string(call->src, call));
+
+	/* Call krb5 */
+	ret = sock->kdc_socket->process(sock->kdc_socket->kdc,
+				       call,
+				       &call->in,
+				       &call->out,
+				       call->src,
+				       sock->kdc_socket->local_address,
+				       1 /* Datagram */);
+	if (ret == KDC_ERROR) {
+		talloc_free(call);
+		goto done;
+	}
+
+	if (ret == KDC_PROXY_REQUEST) {
+		uint16_t port;
+
+		if (!sock->kdc_socket->kdc->am_rodc) {
+			DBG_ERR("proxying requested when not RODC\n");
+			talloc_free(call);
+			goto done;
+		}
+
+		port = tsocket_address_inet_port(sock->kdc_socket->local_address);
+
+		subreq = kdc_udp_proxy_send(call,
+					    sock->kdc_socket->kdc->task->event_ctx,
+					    sock->kdc_socket->kdc,
+					    port,
+					    call->in);
+		if (subreq == NULL) {
+			talloc_free(call);
+			goto done;
+		}
+		tevent_req_set_callback(subreq, kdc_udp_call_proxy_done, call);
+		goto done;
+	}
+
+	subreq = tdgram_sendto_queue_send(call,
+					  sock->kdc_socket->kdc->task->event_ctx,
+					  sock->dgram,
+					  sock->send_queue,
+					  call->out.data,
+					  call->out.length,
+					  call->src);
+	if (subreq == NULL) {
+		talloc_free(call);
+		goto done;
+	}
+	tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
+
+done:
+	subreq = tdgram_recvfrom_send(sock,
+				      sock->kdc_socket->kdc->task->event_ctx,
+				      sock->dgram);
+	if (subreq == NULL) {
+		task_server_terminate(sock->kdc_socket->kdc->task,
+				      "no memory for tdgram_recvfrom_send",
+				      true);
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_udp_call_loop, sock);
+}
+
+static void kdc_udp_call_proxy_done(struct tevent_req *subreq)
+{
+	struct kdc_udp_call *call =
+		tevent_req_callback_data(subreq,
+		struct kdc_udp_call);
+	NTSTATUS status;
+
+	status = kdc_udp_proxy_recv(subreq, call, &call->out);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		/* generate an error packet */
+		status = kdc_proxy_unavailable_error(call->sock->kdc_socket->kdc,
+						     call, &call->out);
+	}
+
+	if (!NT_STATUS_IS_OK(status)) {
+		talloc_free(call);
+		return;
+	}
+
+	subreq = tdgram_sendto_queue_send(call,
+					  call->sock->kdc_socket->kdc->task->event_ctx,
+					  call->sock->dgram,
+					  call->sock->send_queue,
+					  call->out.data,
+					  call->out.length,
+					  call->src);
+	if (subreq == NULL) {
+		talloc_free(call);
+		return;
+	}
+
+	tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
+}
+
+static void kdc_udp_call_sendto_done(struct tevent_req *subreq)
+{
+	struct kdc_udp_call *call = tevent_req_callback_data(subreq,
+				       struct kdc_udp_call);
+	int sys_errno;
+
+	tdgram_sendto_queue_recv(subreq, &sys_errno);
+
+	/* We don't care about errors */
+
+	talloc_free(call);
+}
+
+static void kdc_tcp_call_loop(struct tevent_req *subreq)
+{
+	struct kdc_tcp_connection *kdc_conn = tevent_req_callback_data(subreq,
+				      struct kdc_tcp_connection);
+	struct kdc_tcp_call *call;
+	NTSTATUS status;
+	kdc_code ret;
+
+	call = talloc(kdc_conn, struct kdc_tcp_call);
+	if (call == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
+				"no memory for kdc_tcp_call");
+		return;
+	}
+	call->kdc_conn = kdc_conn;
+
+	status = tstream_read_pdu_blob_recv(subreq,
+					    call,
+					    &call->in);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		const char *reason;
+
+		reason = talloc_asprintf(call, "kdc_tcp_call_loop: "
+					 "tstream_read_pdu_blob_recv() - %s",
+					 nt_errstr(status));
+		if (!reason) {
+			reason = nt_errstr(status);
+		}
+
+		kdc_tcp_terminate_connection(kdc_conn, reason);
+		return;
+	}
+
+	DBG_DEBUG("Received krb5 TCP packet of length %zu from %s\n",
+		  call->in.length,
+		  tsocket_address_string(kdc_conn->conn->remote_address, call));
+
+	/* skip length header */
+	call->in.data +=4;
+	call->in.length -= 4;
+
+	/* Call krb5 */
+	ret = kdc_conn->kdc_socket->process(kdc_conn->kdc_socket->kdc,
+					   call,
+					   &call->in,
+					   &call->out,
+					   kdc_conn->conn->remote_address,
+					   kdc_conn->conn->local_address,
+					   0 /* Stream */);
+	if (ret == KDC_ERROR) {
+		kdc_tcp_terminate_connection(kdc_conn,
+				"kdc_tcp_call_loop: process function failed");
+		return;
+	}
+
+	if (ret == KDC_PROXY_REQUEST) {
+		uint16_t port;
+
+		if (!kdc_conn->kdc_socket->kdc->am_rodc) {
+			kdc_tcp_terminate_connection(kdc_conn,
+						     "kdc_tcp_call_loop: proxying requested when not RODC");
+			return;
+		}
+		port = tsocket_address_inet_port(kdc_conn->conn->local_address);
+
+		subreq = kdc_tcp_proxy_send(call,
+					    kdc_conn->conn->event.ctx,
+					    kdc_conn->kdc_socket->kdc,
+					    port,
+					    call->in);
+		if (subreq == NULL) {
+			kdc_tcp_terminate_connection(kdc_conn,
+				"kdc_tcp_call_loop: kdc_tcp_proxy_send failed");
+			return;
+		}
+		tevent_req_set_callback(subreq, kdc_tcp_call_proxy_done, call);
+		return;
+	}
+
+	/* First add the length of the out buffer */
+	RSIVAL(call->out_hdr, 0, call->out.length);
+	call->out_iov[0].iov_base = (char *) call->out_hdr;
+	call->out_iov[0].iov_len = 4;
+
+	call->out_iov[1].iov_base = (char *) call->out.data;
+	call->out_iov[1].iov_len = call->out.length;
+
+	subreq = tstream_writev_queue_send(call,
+					   kdc_conn->conn->event.ctx,
+					   kdc_conn->tstream,
+					   kdc_conn->send_queue,
+					   call->out_iov, 2);
+	if (subreq == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
+				"no memory for tstream_writev_queue_send");
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
+
+	/*
+	 * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
+	 * tstream_full_request_u32 provides the pdu length then.
+	 */
+	subreq = tstream_read_pdu_blob_send(kdc_conn,
+					    kdc_conn->conn->event.ctx,
+					    kdc_conn->tstream,
+					    4, /* initial_read_size */
+					    tstream_full_request_u32,
+					    kdc_conn);
+	if (subreq == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
+				"no memory for tstream_read_pdu_blob_send");
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
+}
+
+static void kdc_tcp_call_proxy_done(struct tevent_req *subreq)
+{
+	struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
+			struct kdc_tcp_call);
+	struct kdc_tcp_connection *kdc_conn = call->kdc_conn;
+	NTSTATUS status;
+
+	status = kdc_tcp_proxy_recv(subreq, call, &call->out);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		/* generate an error packet */
+		status = kdc_proxy_unavailable_error(kdc_conn->kdc_socket->kdc,
+						     call, &call->out);
+	}
+
+	if (!NT_STATUS_IS_OK(status)) {
+		const char *reason;
+
+		reason = talloc_asprintf(call, "kdc_tcp_call_proxy_done: "
+					 "kdc_proxy_unavailable_error - %s",
+					 nt_errstr(status));
+		if (!reason) {
+			reason = "kdc_tcp_call_proxy_done: kdc_proxy_unavailable_error() failed";
+		}
+
+		kdc_tcp_terminate_connection(call->kdc_conn, reason);
+		return;
+	}
+
+	/* First add the length of the out buffer */
+	RSIVAL(call->out_hdr, 0, call->out.length);
+	call->out_iov[0].iov_base = (char *) call->out_hdr;
+	call->out_iov[0].iov_len = 4;
+
+	call->out_iov[1].iov_base = (char *) call->out.data;
+	call->out_iov[1].iov_len = call->out.length;
+
+	subreq = tstream_writev_queue_send(call,
+					   kdc_conn->conn->event.ctx,
+					   kdc_conn->tstream,
+					   kdc_conn->send_queue,
+					   call->out_iov, 2);
+	if (subreq == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_proxy_done: "
+				"no memory for tstream_writev_queue_send");
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
+
+	/*
+	 * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
+	 * tstream_full_request_u32 provides the pdu length then.
+	 */
+	subreq = tstream_read_pdu_blob_send(kdc_conn,
+					    kdc_conn->conn->event.ctx,
+					    kdc_conn->tstream,
+					    4, /* initial_read_size */
+					    tstream_full_request_u32,
+					    kdc_conn);
+	if (subreq == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_proxy_done: "
+				"no memory for tstream_read_pdu_blob_send");
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
+}
+
+static void kdc_tcp_call_writev_done(struct tevent_req *subreq)
+{
+	struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
+			struct kdc_tcp_call);
+	int sys_errno;
+	int rc;
+
+	rc = tstream_writev_queue_recv(subreq, &sys_errno);
+	TALLOC_FREE(subreq);
+	if (rc == -1) {
+		const char *reason;
+
+		reason = talloc_asprintf(call, "kdc_tcp_call_writev_done: "
+					 "tstream_writev_queue_recv() - %d:%s",
+					 sys_errno, strerror(sys_errno));
+		if (!reason) {
+			reason = "kdc_tcp_call_writev_done: tstream_writev_queue_recv() failed";
+		}
+
+		kdc_tcp_terminate_connection(call->kdc_conn, reason);
+		return;
+	}
+
+	/* We don't care about errors */
+
+	talloc_free(call);
+}
+
+/*
+  called when we get a new connection
+*/
+static void kdc_tcp_accept(struct stream_connection *conn)
+{
+	struct kdc_socket *kdc_socket;
+	struct kdc_tcp_connection *kdc_conn;
+	struct tevent_req *subreq;
+	int rc;
+
+	kdc_conn = talloc_zero(conn, struct kdc_tcp_connection);
+	if (kdc_conn == NULL) {
+		stream_terminate_connection(conn,
+				"kdc_tcp_accept: out of memory");
+		return;
+	}
+
+	kdc_conn->send_queue = tevent_queue_create(conn, "kdc_tcp_accept");
+	if (kdc_conn->send_queue == NULL) {
+		stream_terminate_connection(conn,
+				"kdc_tcp_accept: out of memory");
+		return;
+	}
+
+	kdc_socket = talloc_get_type(conn->private_data, struct kdc_socket);
+
+	TALLOC_FREE(conn->event.fde);
+
+	rc = tstream_bsd_existing_socket(kdc_conn,
+			socket_get_fd(conn->socket),
+			&kdc_conn->tstream);
+	if (rc < 0) {
+		stream_terminate_connection(conn,
+				"kdc_tcp_accept: out of memory");
+		return;
+	}
+	/* as server we want to fail early */
+	tstream_bsd_fail_readv_first_error(kdc_conn->tstream, true);
+
+	kdc_conn->conn = conn;
+	kdc_conn->kdc_socket = kdc_socket;
+	conn->private_data = kdc_conn;
+
+	/*
+	 * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
+	 * tstream_full_request_u32 provides the pdu length then.
+	 */
+	subreq = tstream_read_pdu_blob_send(kdc_conn,
+					    kdc_conn->conn->event.ctx,
+					    kdc_conn->tstream,
+					    4, /* initial_read_size */
+					    tstream_full_request_u32,
+					    kdc_conn);
+	if (subreq == NULL) {
+		kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_accept: "
+				"no memory for tstream_read_pdu_blob_send");
+		return;
+	}
+	tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
+}
+
+static void kdc_tcp_recv(struct stream_connection *conn, uint16_t flags)
+{
+	struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
+							     struct kdc_tcp_connection);
+	/* this should never be triggered! */
+	kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_recv: called");
+}
+
+static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
+{
+	struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
+							     struct kdc_tcp_connection);
+	/* this should never be triggered! */
+	kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_send: called");
+}
+
+static const struct stream_server_ops kdc_tcp_stream_ops = {
+	.name			= "kdc_tcp",
+	.accept_connection	= kdc_tcp_accept,
+	.recv_handler		= kdc_tcp_recv,
+	.send_handler		= kdc_tcp_send
+};
+
+/*
+ * Start listening on the given address
+ */
+NTSTATUS kdc_add_socket(struct kdc_server *kdc,
+			const struct model_ops *model_ops,
+			const char *name,
+			const char *address,
+			uint16_t port,
+			kdc_process_fn_t process,
+			bool udp_only)
+{
+	struct kdc_socket *kdc_socket;
+	struct kdc_udp_socket *kdc_udp_socket;
+	struct tevent_req *udpsubreq;
+	NTSTATUS status;
+	int ret;
+
+	kdc_socket = talloc(kdc, struct kdc_socket);
+	NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
+
+	kdc_socket->kdc = kdc;
+	kdc_socket->process = process;
+
+	ret = tsocket_address_inet_from_strings(kdc_socket, "ip",
+						address, port,
+						&kdc_socket->local_address);
+	if (ret != 0) {
+		status = map_nt_error_from_unix_common(errno);
+		return status;
+	}
+
+	if (!udp_only) {
+		status = stream_setup_socket(kdc->task,
+					     kdc->task->event_ctx,
+					     kdc->task->lp_ctx,
+					     model_ops,
+					     &kdc_tcp_stream_ops,
+					     "ip", address, &port,
+					     lpcfg_socket_options(kdc->task->lp_ctx),
+					     kdc_socket,
+					     kdc->task->process_context);
+		if (!NT_STATUS_IS_OK(status)) {
+			DBG_ERR("Failed to bind to %s:%u TCP - %s\n",
+				address, port, nt_errstr(status));
+			talloc_free(kdc_socket);
+			return status;
+		}
+	}
+
+	kdc_udp_socket = talloc(kdc_socket, struct kdc_udp_socket);
+	NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket);
+
+	kdc_udp_socket->kdc_socket = kdc_socket;
+
+	ret = tdgram_inet_udp_socket(kdc_socket->local_address,
+				     NULL,
+				     kdc_udp_socket,
+				     &kdc_udp_socket->dgram);
+	if (ret != 0) {
+		status = map_nt_error_from_unix_common(errno);
+		DBG_ERR("Failed to bind to %s:%u UDP - %s\n",
+			address, port, nt_errstr(status));
+		return status;
+	}
+
+	kdc_udp_socket->send_queue = tevent_queue_create(kdc_udp_socket,
+							 "kdc_udp_send_queue");
+	NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket->send_queue);
+
+	udpsubreq = tdgram_recvfrom_send(kdc_udp_socket,
+					 kdc->task->event_ctx,
+					 kdc_udp_socket->dgram);
+	NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
+	tevent_req_set_callback(udpsubreq, kdc_udp_call_loop, kdc_udp_socket);
+
+	return NT_STATUS_OK;
+}