/*
   Unix SMB/Netbios implementation.
   Generic infrstructure for RPC Daemons
   Copyright (C) Simo Sorce 2010

   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 "rpc_server/rpc_server.h"
#include "rpc_dce.h"
#include "librpc/gen_ndr/netlogon.h"
#include "librpc/gen_ndr/auth.h"
#include "registry/reg_parse_prs.h"
#include "lib/tsocket/tsocket.h"
#include "libcli/named_pipe_auth/npa_tstream.h"
#include "../auth/auth_sam_reply.h"

#define SERVER_TCP_LOW_PORT  1024
#define SERVER_TCP_HIGH_PORT 1300

static NTSTATUS auth_anonymous_session_info(TALLOC_CTX *mem_ctx,
					    struct auth_session_info_transport **session_info)
{
	struct auth_session_info_transport *i;
	struct auth_serversupplied_info *s;
	struct auth_user_info_dc *u;
	union netr_Validation val;
	NTSTATUS status;

	i = talloc_zero(mem_ctx, struct auth_session_info_transport);
	if (i == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	status = make_server_info_guest(i, &s);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	i->security_token = s->security_token;
	i->session_key    = s->user_session_key;

	val.sam3 = s->info3;

	status = make_user_info_dc_netlogon_validation(mem_ctx,
						       "",
						       3,
						       &val,
						       &u);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("conversion of info3 into user_info_dc failed!\n"));
		return status;
	}
	i->info = talloc_move(i, &u->info);
	talloc_free(u);

	*session_info = i;

	return NT_STATUS_OK;
}

/* Creates a pipes_struct and initializes it with the information
 * sent from the client */
static int make_server_pipes_struct(TALLOC_CTX *mem_ctx,
				    const char *pipe_name,
				    const struct ndr_syntax_id id,
				    enum dcerpc_transport_t transport,
				    const char *client_address,
				    const char *server_address,
				    struct auth_session_info_transport *session_info,
				    struct pipes_struct **_p,
				    int *perrno)
{
	struct netr_SamInfo3 *info3;
	struct auth_user_info_dc *auth_user_info_dc;
	struct pipes_struct *p;
	NTSTATUS status;
	bool ok;

	p = talloc_zero(mem_ctx, struct pipes_struct);
	if (!p) {
		*perrno = ENOMEM;
		return -1;
	}
	p->syntax = id;
	p->transport = transport;

	p->mem_ctx = talloc_named(p, 0, "pipe %s %p", pipe_name, p);
	if (!p->mem_ctx) {
		TALLOC_FREE(p);
		*perrno = ENOMEM;
		return -1;
	}

	ok = init_pipe_handles(p, &id);
	if (!ok) {
		DEBUG(1, ("Failed to init handles\n"));
		TALLOC_FREE(p);
		*perrno = EINVAL;
		return -1;
	}


	data_blob_free(&p->in_data.data);
	data_blob_free(&p->in_data.pdu);

	p->endian = RPC_LITTLE_ENDIAN;

	/* Fake up an auth_user_info_dc for now, to make an info3, to make the session_info structure */
	auth_user_info_dc = talloc_zero(p, struct auth_user_info_dc);
	if (!auth_user_info_dc) {
		TALLOC_FREE(p);
		*perrno = ENOMEM;
		return -1;
	}

	auth_user_info_dc->num_sids = session_info->security_token->num_sids;
	auth_user_info_dc->sids = session_info->security_token->sids;
	auth_user_info_dc->info = session_info->info;
	auth_user_info_dc->user_session_key = session_info->session_key;

	/* This creates the input structure that make_server_info_info3 is looking for */
	status = auth_convert_user_info_dc_saminfo3(p, auth_user_info_dc,
						    &info3);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to convert auth_user_info_dc into netr_SamInfo3\n"));
		TALLOC_FREE(p);
		*perrno = EINVAL;
		return -1;
	}

	status = make_server_info_info3(p,
					info3->base.account_name.string,
					info3->base.domain.string,
					&p->session_info, info3);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to init server info\n"));
		TALLOC_FREE(p);
		*perrno = EINVAL;
		return -1;
	}

	/*
	 * Some internal functions need a local token to determine access to
	 * resoutrces.
	 */
	status = create_local_token(p->session_info);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to init local auth token\n"));
		TALLOC_FREE(p);
		*perrno = EINVAL;
		return -1;
	}

	/* Now override the session_info->security_token with the exact
	 * security_token we were given from the other side,
	 * regardless of what we just calculated */
	p->session_info->security_token = talloc_move(p->session_info, &session_info->security_token);

	/* Also set the session key to the correct value */
	p->session_info->user_session_key = session_info->session_key;
	p->session_info->user_session_key.data = talloc_move(p->session_info, &session_info->session_key.data);

	p->client_id = talloc_zero(p, struct client_address);
	if (!p->client_id) {
		TALLOC_FREE(p);
		*perrno = ENOMEM;
		return -1;
	}
	strlcpy(p->client_id->addr,
		client_address, sizeof(p->client_id->addr));
	p->client_id->name = talloc_strdup(p->client_id, client_address);
	if (p->client_id->name == NULL) {
		TALLOC_FREE(p);
		*perrno = ENOMEM;
		return -1;
	}

	if (server_address != NULL) {
		p->server_id = talloc_zero(p, struct client_address);
		if (p->client_id == NULL) {
			TALLOC_FREE(p);
			*perrno = ENOMEM;
			return -1;
		}

		strlcpy(p->server_id->addr,
			server_address,
			sizeof(p->server_id->addr));

		p->server_id->name = talloc_strdup(p->server_id,
						   server_address);
		if (p->server_id->name == NULL) {
			TALLOC_FREE(p);
			*perrno = ENOMEM;
			return -1;
		}
	}

	talloc_set_destructor(p, close_internal_rpc_pipe_hnd);

	*_p = p;
	return 0;
}

/* Add some helper functions to wrap the common ncacn packet reading functions
 * until we can share more dcerpc code */
struct dcerpc_ncacn_read_packet_state {
	struct ncacn_packet *pkt;
	DATA_BLOB buffer;
};

static void dcerpc_ncacn_read_packet_done(struct tevent_req *subreq);

static struct tevent_req *dcerpc_ncacn_read_packet_send(TALLOC_CTX *mem_ctx,
					struct tevent_context *ev,
					struct tstream_context *tstream)
{
	struct dcerpc_ncacn_read_packet_state *state;
	struct tevent_req *req, *subreq;

	req = tevent_req_create(mem_ctx, &state,
				struct dcerpc_ncacn_read_packet_state);
	if (!req) {
		return NULL;
	}
	ZERO_STRUCTP(state);

	subreq = dcerpc_read_ncacn_packet_send(state, ev, tstream);
	if (!subreq) {
		tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
		tevent_req_post(req, ev);
		return req;
	}
	tevent_req_set_callback(subreq, dcerpc_ncacn_read_packet_done, req);

	return req;
}

static void dcerpc_ncacn_read_packet_done(struct tevent_req *subreq)
{
	struct tevent_req *req =
		tevent_req_callback_data(subreq, struct tevent_req);
	struct dcerpc_ncacn_read_packet_state *state =
		tevent_req_data(req, struct dcerpc_ncacn_read_packet_state);
	NTSTATUS status;

	status = dcerpc_read_ncacn_packet_recv(subreq, state,
						&state->pkt,
						&state->buffer);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(3, ("Failed to receive dceprc packet!\n"));
		tevent_req_nterror(req, status);
		return;
	}

	tevent_req_done(req);
}

static NTSTATUS dcerpc_ncacn_read_packet_recv(struct tevent_req *req,
						TALLOC_CTX *mem_ctx,
						DATA_BLOB *buffer)
{
	struct dcerpc_ncacn_read_packet_state *state =
		tevent_req_data(req, struct dcerpc_ncacn_read_packet_state);
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		tevent_req_received(req);
		return status;
	}

	buffer->data = talloc_move(mem_ctx, &state->buffer.data);
	buffer->length = state->buffer.length;

	tevent_req_received(req);
	return NT_STATUS_OK;
}



/* Start listening on the appropriate unix socket and setup all is needed to
 * dispatch requests to the pipes rpc implementation */

struct dcerpc_ncacn_listen_state {
	struct ndr_syntax_id syntax_id;

	int fd;
	union {
		char *name;
		uint16_t port;
	} ep;

	struct tevent_context *ev_ctx;
	struct messaging_context *msg_ctx;
};

static void named_pipe_listener(struct tevent_context *ev,
				struct tevent_fd *fde,
				uint16_t flags,
				void *private_data);

bool setup_named_pipe_socket(const char *pipe_name,
			     struct tevent_context *ev_ctx)
{
	struct dcerpc_ncacn_listen_state *state;
	struct tevent_fd *fde;
	char *np_dir;

	state = talloc(ev_ctx, struct dcerpc_ncacn_listen_state);
	if (!state) {
		DEBUG(0, ("Out of memory\n"));
		return false;
	}
	state->ep.name = talloc_strdup(state, pipe_name);
	if (state->ep.name == NULL) {
		DEBUG(0, ("Out of memory\n"));
		goto out;
	}
	state->fd = -1;

	np_dir = talloc_asprintf(state, "%s/np", lp_ncalrpc_dir());
	if (!np_dir) {
		DEBUG(0, ("Out of memory\n"));
		goto out;
	}

	if (!directory_create_or_exist(np_dir, geteuid(), 0700)) {
		DEBUG(0, ("Failed to create pipe directory %s - %s\n",
			  np_dir, strerror(errno)));
		goto out;
	}

	state->fd = create_pipe_sock(np_dir, pipe_name, 0700);
	if (state->fd == -1) {
		DEBUG(0, ("Failed to create pipe socket! [%s/%s]\n",
			  np_dir, pipe_name));
		goto out;
	}

	DEBUG(10, ("Openened pipe socket fd %d for %s\n",
		   state->fd, pipe_name));

	fde = tevent_add_fd(ev_ctx,
			    state, state->fd, TEVENT_FD_READ,
			    named_pipe_listener, state);
	if (!fde) {
		DEBUG(0, ("Failed to add event handler!\n"));
		goto out;
	}

	tevent_fd_set_auto_close(fde);
	return true;

out:
	if (state->fd != -1) {
		close(state->fd);
	}
	TALLOC_FREE(state);
	return false;
}

static void named_pipe_accept_function(const char *pipe_name, int fd);

static void named_pipe_listener(struct tevent_context *ev,
				struct tevent_fd *fde,
				uint16_t flags,
				void *private_data)
{
	struct dcerpc_ncacn_listen_state *state =
			talloc_get_type_abort(private_data,
					      struct dcerpc_ncacn_listen_state);
	struct sockaddr_un sunaddr;
	socklen_t len;
	int sd = -1;

	/* TODO: should we have a limit to the number of clients ? */

	len = sizeof(sunaddr);

	while (sd == -1) {
		sd = accept(state->fd,
			    (struct sockaddr *)(void *)&sunaddr, &len);
		if (errno != EINTR) break;
	}

	if (sd == -1) {
		DEBUG(6, ("Failed to get a valid socket [%s]\n",
			  strerror(errno)));
		return;
	}

	DEBUG(6, ("Accepted socket %d\n", sd));

	named_pipe_accept_function(state->ep.name, sd);
}


/* This is the core of the rpc server.
 * Accepts connections from clients and process requests using the appropriate
 * dispatcher table. */

struct named_pipe_client {
	const char *pipe_name;
	struct ndr_syntax_id pipe_id;

	struct tevent_context *ev;
	struct messaging_context *msg_ctx;

	uint16_t file_type;
	uint16_t device_state;
	uint64_t allocation_size;

	struct tstream_context *tstream;

	struct tsocket_address *client;
	char *client_name;
	struct tsocket_address *server;
	char *server_name;
	struct auth_session_info_transport *session_info;

	struct pipes_struct *p;

	struct tevent_queue *write_queue;

	struct iovec *iov;
	size_t count;
};

static void named_pipe_accept_done(struct tevent_req *subreq);

static void named_pipe_accept_function(const char *pipe_name, int fd)
{
	struct ndr_syntax_id syntax;
	struct named_pipe_client *npc;
	struct tstream_context *plain;
	struct tevent_req *subreq;
	bool ok;
	int ret;

	ok = is_known_pipename(pipe_name, &syntax);
	if (!ok) {
		DEBUG(1, ("Unknown pipe [%s]\n", pipe_name));
		close(fd);
		return;
	}

	npc = talloc_zero(NULL, struct named_pipe_client);
	if (!npc) {
		DEBUG(0, ("Out of memory!\n"));
		close(fd);
		return;
	}
	npc->pipe_name = pipe_name;
	npc->pipe_id = syntax;
	npc->ev = server_event_context();
	npc->msg_ctx = server_messaging_context();

	/* make sure socket is in NON blocking state */
	ret = set_blocking(fd, false);
	if (ret != 0) {
		DEBUG(2, ("Failed to make socket non-blocking\n"));
		TALLOC_FREE(npc);
		close(fd);
		return;
	}

	ret = tstream_bsd_existing_socket(npc, fd, &plain);
	if (ret != 0) {
		DEBUG(2, ("Failed to create tstream socket\n"));
		TALLOC_FREE(npc);
		close(fd);
		return;
	}

	npc->file_type = FILE_TYPE_MESSAGE_MODE_PIPE;
	npc->device_state = 0xff | 0x0400 | 0x0100;
	npc->allocation_size = 4096;

	subreq = tstream_npa_accept_existing_send(npc, npc->ev, plain,
						  npc->file_type,
						  npc->device_state,
						  npc->allocation_size);
	if (!subreq) {
		DEBUG(2, ("Failed to start async accept procedure\n"));
		TALLOC_FREE(npc);
		close(fd);
		return;
	}
	tevent_req_set_callback(subreq, named_pipe_accept_done, npc);
}

static void named_pipe_packet_process(struct tevent_req *subreq);
static void named_pipe_packet_done(struct tevent_req *subreq);

static void named_pipe_accept_done(struct tevent_req *subreq)
{
	struct named_pipe_client *npc =
		tevent_req_callback_data(subreq, struct named_pipe_client);
	const char *cli_addr;
	int error;
	int ret;

	ret = tstream_npa_accept_existing_recv(subreq, &error, npc,
						&npc->tstream,
						&npc->client,
						&npc->client_name,
						&npc->server,
						&npc->server_name,
						&npc->session_info);
	TALLOC_FREE(subreq);
	if (ret != 0) {
		DEBUG(2, ("Failed to accept named pipe connection! (%s)\n",
			  strerror(error)));
		TALLOC_FREE(npc);
		return;
	}

	if (tsocket_address_is_inet(npc->client, "ip")) {
		cli_addr = tsocket_address_inet_addr_string(npc->client,
							    subreq);
		if (cli_addr == NULL) {
			TALLOC_FREE(npc);
			return;
		}
	} else {
		cli_addr = "";
	}

	ret = make_server_pipes_struct(npc,
					npc->pipe_name, npc->pipe_id, NCACN_NP,
					cli_addr, NULL, npc->session_info,
					&npc->p, &error);
	if (ret != 0) {
		DEBUG(2, ("Failed to create pipes_struct! (%s)\n",
			  strerror(error)));
		goto fail;
	}
	npc->p->msg_ctx = npc->msg_ctx;

	npc->write_queue = tevent_queue_create(npc, "np_server_write_queue");
	if (!npc->write_queue) {
		DEBUG(2, ("Failed to set up write queue!\n"));
		goto fail;
	}

	/* And now start receaving and processing packets */
	subreq = dcerpc_ncacn_read_packet_send(npc, npc->ev, npc->tstream);
	if (!subreq) {
		DEBUG(2, ("Failed to start receving packets\n"));
		goto fail;
	}
	tevent_req_set_callback(subreq, named_pipe_packet_process, npc);
	return;

fail:
	DEBUG(2, ("Fatal error. Terminating client(%s) connection!\n",
		  npc->client_name));
	/* terminate client connection */
	talloc_free(npc);
	return;
}

static void named_pipe_packet_process(struct tevent_req *subreq)
{
	struct named_pipe_client *npc =
		tevent_req_callback_data(subreq, struct named_pipe_client);
	struct _output_data *out = &npc->p->out_data;
	DATA_BLOB recv_buffer = data_blob_null;
	NTSTATUS status;
	ssize_t data_left;
	ssize_t data_used;
	char *data;
	uint32_t to_send;
	bool ok;

	status = dcerpc_ncacn_read_packet_recv(subreq, npc, &recv_buffer);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		goto fail;
	}

	data_left = recv_buffer.length;
	data = (char *)recv_buffer.data;

	while (data_left) {

		data_used = process_incoming_data(npc->p, data, data_left);
		if (data_used < 0) {
			DEBUG(3, ("Failed to process dceprc request!\n"));
			status = NT_STATUS_UNEXPECTED_IO_ERROR;
			goto fail;
		}

		data_left -= data_used;
		data += data_used;
	}

	/* Do not leak this buffer, npc is a long lived context */
	talloc_free(recv_buffer.data);

	/* this is needed because of the way DCERPC Binds work in
	 * the RPC marshalling code */
	to_send = out->frag.length - out->current_pdu_sent;
	if (to_send > 0) {

		DEBUG(10, ("Current_pdu_len = %u, "
			   "current_pdu_sent = %u "
			   "Returning %u bytes\n",
			   (unsigned int)out->frag.length,
			   (unsigned int)out->current_pdu_sent,
			   (unsigned int)to_send));

		npc->iov = talloc_zero(npc, struct iovec);
		if (!npc->iov) {
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}
		npc->count = 1;

		npc->iov[0].iov_base = out->frag.data
					+ out->current_pdu_sent;
		npc->iov[0].iov_len = to_send;

		out->current_pdu_sent += to_send;
	}

	/* this condition is false for bind packets, or when we haven't
	 * yet got a full request, and need to wait for more data from
	 * the client */
	while (out->data_sent_length < out->rdata.length) {

		ok = create_next_pdu(npc->p);
		if (!ok) {
			DEBUG(3, ("Failed to create next PDU!\n"));
			status = NT_STATUS_UNEXPECTED_IO_ERROR;
			goto fail;
		}

		npc->iov = talloc_realloc(npc, npc->iov,
					    struct iovec, npc->count + 1);
		if (!npc->iov) {
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}

		npc->iov[npc->count].iov_base = out->frag.data;
		npc->iov[npc->count].iov_len = out->frag.length;

		DEBUG(10, ("PDU number: %d, PDU Length: %u\n",
			   (unsigned int)npc->count,
			   (unsigned int)npc->iov[npc->count].iov_len));
		dump_data(11, (const uint8_t *)npc->iov[npc->count].iov_base,
				npc->iov[npc->count].iov_len);
		npc->count++;
	}

	/* we still don't have a complete request, go back and wait for more
	 * data */
	if (npc->count == 0) {
		/* Wait for the next packet */
		subreq = dcerpc_ncacn_read_packet_send(npc, npc->ev, npc->tstream);
		if (!subreq) {
			DEBUG(2, ("Failed to start receving packets\n"));
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}
		tevent_req_set_callback(subreq, named_pipe_packet_process, npc);
		return;
	}

	DEBUG(10, ("Sending a total of %u bytes\n",
		   (unsigned int)npc->p->out_data.data_sent_length));

	subreq = tstream_writev_queue_send(npc, npc->ev,
					   npc->tstream,
					   npc->write_queue,
					   npc->iov, npc->count);
	if (!subreq) {
		DEBUG(2, ("Failed to send packet\n"));
		status = NT_STATUS_NO_MEMORY;
		goto fail;
	}
	tevent_req_set_callback(subreq, named_pipe_packet_done, npc);
	return;

fail:
	DEBUG(2, ("Fatal error(%s). "
		  "Terminating client(%s) connection!\n",
		  nt_errstr(status), npc->client_name));
	/* terminate client connection */
	talloc_free(npc);
	return;
}

static void named_pipe_packet_done(struct tevent_req *subreq)
{
	struct named_pipe_client *npc =
		tevent_req_callback_data(subreq, struct named_pipe_client);
	int sys_errno;
	int ret;

	ret = tstream_writev_queue_recv(subreq, &sys_errno);
	TALLOC_FREE(subreq);
	if (ret == -1) {
		DEBUG(2, ("Writev failed!\n"));
		goto fail;
	}

	/* clear out any data that may have been left around */
	npc->count = 0;
	TALLOC_FREE(npc->iov);
	data_blob_free(&npc->p->in_data.data);
	data_blob_free(&npc->p->out_data.frag);
	data_blob_free(&npc->p->out_data.rdata);

	/* Wait for the next packet */
	subreq = dcerpc_ncacn_read_packet_send(npc, npc->ev, npc->tstream);
	if (!subreq) {
		DEBUG(2, ("Failed to start receving packets\n"));
		sys_errno = ENOMEM;
		goto fail;
	}
	tevent_req_set_callback(subreq, named_pipe_packet_process, npc);
	return;

fail:
	DEBUG(2, ("Fatal error(%s). "
		  "Terminating client(%s) connection!\n",
		  strerror(sys_errno), npc->client_name));
	/* terminate client connection */
	talloc_free(npc);
	return;
}

static void dcerpc_ncacn_accept(struct tevent_context *ev_ctx,
				struct messaging_context *msg_ctx,
				struct ndr_syntax_id syntax_id,
				enum dcerpc_transport_t transport,
				const char *name,
				uint16_t port,
				struct tsocket_address *cli_addr,
				struct tsocket_address *srv_addr,
				int s);

/********************************************************************
 * Start listening on the tcp/ip socket
 ********************************************************************/

static void dcerpc_ncacn_tcpip_listener(struct tevent_context *ev,
					struct tevent_fd *fde,
					uint16_t flags,
					void *private_data);

uint16_t setup_dcerpc_ncacn_tcpip_socket(struct tevent_context *ev_ctx,
					 struct messaging_context *msg_ctx,
					 struct ndr_syntax_id syntax_id,
					 const struct sockaddr_storage *ifss,
					 uint16_t port)
{
	struct dcerpc_ncacn_listen_state *state;
	struct tevent_fd *fde;
	int rc;

	state = talloc(ev_ctx, struct dcerpc_ncacn_listen_state);
	if (state == NULL) {
		DEBUG(0, ("setup_dcerpc_ncacn_tcpip_socket: Out of memory\n"));
		return 0;
	}

	state->syntax_id = syntax_id;
	state->fd = -1;
	state->ep.port = port;

	if (state->ep.port == 0) {
		uint16_t i;

		for (i = SERVER_TCP_LOW_PORT; i <= SERVER_TCP_HIGH_PORT; i++) {
			state->fd = open_socket_in(SOCK_STREAM,
						   i,
						   0,
						   ifss,
						   false);
			if (state->fd > 0) {
				state->ep.port = i;
				break;
			}
		}
	} else {
		state->fd = open_socket_in(SOCK_STREAM,
					   state->ep.port,
					   0,
					   ifss,
					   true);
	}
	if (state->fd == -1) {
		DEBUG(0, ("setup_dcerpc_ncacn_tcpip_socket: Failed to create "
			  "socket on port %u!\n", state->ep.port));
		goto out;
	}

	state->ev_ctx = ev_ctx;
	state->msg_ctx = msg_ctx;

	/* ready to listen */
	set_socket_options(state->fd, "SO_KEEPALIVE");
	set_socket_options(state->fd, lp_socket_options());

	/* Set server socket to non-blocking for the accept. */
	set_blocking(state->fd, false);

	rc = listen(state->fd, SMBD_LISTEN_BACKLOG);
	if (rc == -1) {
		DEBUG(0,("setup_tcpip_socket: listen - %s\n", strerror(errno)));
		goto out;
	}

	DEBUG(10, ("setup_tcpip_socket: openened socket fd %d for port %u\n",
		   state->fd, state->ep.port));

	fde = tevent_add_fd(state->ev_ctx,
			    state,
			    state->fd,
			    TEVENT_FD_READ,
			    dcerpc_ncacn_tcpip_listener,
			    state);
	if (fde == NULL) {
		DEBUG(0, ("setup_tcpip_socket: Failed to add event handler!\n"));
		goto out;
	}

	tevent_fd_set_auto_close(fde);

	return state->ep.port;
out:
	if (state->fd != -1) {
		close(state->fd);
	}
	TALLOC_FREE(state);

	return 0;
}

static void dcerpc_ncacn_tcpip_listener(struct tevent_context *ev,
					struct tevent_fd *fde,
					uint16_t flags,
					void *private_data)
{
	struct dcerpc_ncacn_listen_state *state =
			talloc_get_type_abort(private_data,
					      struct dcerpc_ncacn_listen_state);
	struct tsocket_address *cli_addr = NULL;
	struct tsocket_address *srv_addr = NULL;
	struct sockaddr_storage addr;
	socklen_t in_addrlen = sizeof(addr);
	int s = -1;
	int rc;

	while (s == -1) {
		s = accept(state->fd, (struct sockaddr *)(void *) &addr, &in_addrlen);
		if (s == -1 && errno != EINTR) {
			break;
		}
	}

	if (s == -1) {
		DEBUG(0,("tcpip_listener accept: %s\n",
			 strerror(errno)));
		return;
	}

	rc = tsocket_address_bsd_from_sockaddr(state,
					       (struct sockaddr *)(void *) &addr,
					       in_addrlen,
					       &cli_addr);
	if (rc < 0) {
		close(s);
		return;
	}

	rc = getsockname(s, (struct sockaddr *)(void *) &addr, &in_addrlen);
	if (rc < 0) {
		close(s);
		return;
	}

	rc = tsocket_address_bsd_from_sockaddr(state,
					       (struct sockaddr *)(void *) &addr,
					       in_addrlen,
					       &srv_addr);
	if (rc < 0) {
		close(s);
		return;
	}

	DEBUG(6, ("tcpip_listener: Accepted socket %d\n", s));

	dcerpc_ncacn_accept(state->ev_ctx,
			    state->msg_ctx,
			    state->syntax_id,
			    NCACN_IP_TCP,
			    NULL,
			    state->ep.port,
			    cli_addr,
			    srv_addr,
			    s);
}

/********************************************************************
 * Start listening on the ncalrpc socket
 ********************************************************************/

static void dcerpc_ncalrpc_listener(struct tevent_context *ev,
				    struct tevent_fd *fde,
				    uint16_t flags,
				    void *private_data);

bool setup_dcerpc_ncalrpc_socket(struct tevent_context *ev_ctx,
				 struct messaging_context *msg_ctx,
				 struct ndr_syntax_id syntax_id,
				 const char *name)
{
	struct dcerpc_ncacn_listen_state *state;
	struct tevent_fd *fde;

	state = talloc(ev_ctx, struct dcerpc_ncacn_listen_state);
	if (state == NULL) {
		DEBUG(0, ("Out of memory\n"));
		return false;
	}

	state->syntax_id = syntax_id;
	state->fd = -1;

	if (name == NULL) {
		name = "DEFAULT";
	}
	state->ep.name = talloc_strdup(state, name);

	if (state->ep.name == NULL) {
		DEBUG(0, ("Out of memory\n"));
		talloc_free(state);
		return false;
	}

	if (!directory_create_or_exist(lp_ncalrpc_dir(), geteuid(), 0700)) {
		DEBUG(0, ("Failed to create pipe directory %s - %s\n",
			  lp_ncalrpc_dir(), strerror(errno)));
		goto out;
	}

	state->fd = create_pipe_sock(lp_ncalrpc_dir(), name, 0700);
	if (state->fd == -1) {
		DEBUG(0, ("Failed to create pipe socket! [%s/%s]\n",
			  lp_ncalrpc_dir(), name));
		goto out;
	}

	DEBUG(10, ("Openened pipe socket fd %d for %s\n", state->fd, name));

	state->ev_ctx = ev_ctx;
	state->msg_ctx = msg_ctx;

	/* Set server socket to non-blocking for the accept. */
	set_blocking(state->fd, false);

	fde = tevent_add_fd(state->ev_ctx,
			    state,
			    state->fd,
			    TEVENT_FD_READ,
			    dcerpc_ncalrpc_listener,
			    state);
	if (fde == NULL) {
		DEBUG(0, ("Failed to add event handler for ncalrpc!\n"));
		goto out;
	}

	tevent_fd_set_auto_close(fde);

	return true;
out:
	if (state->fd != -1) {
		close(state->fd);
	}
	TALLOC_FREE(state);

	return 0;
}

static void dcerpc_ncalrpc_listener(struct tevent_context *ev,
					struct tevent_fd *fde,
					uint16_t flags,
					void *private_data)
{
	struct dcerpc_ncacn_listen_state *state =
			talloc_get_type_abort(private_data,
					      struct dcerpc_ncacn_listen_state);
	struct tsocket_address *cli_addr = NULL;
	struct sockaddr_un sunaddr;
	struct sockaddr *addr = (struct sockaddr *)(void *)&sunaddr;
	socklen_t len;
	int sd = -1;
	int rc;

	while (sd == -1) {
		sd = accept(state->fd, addr, &len);
		if (sd == -1 && errno != EINTR) {
			break;
		}
	}

	if (sd == -1) {
		DEBUG(0, ("ncalrpc accept() failed: %s\n", strerror(errno)));
		return;
	}

	rc = tsocket_address_bsd_from_sockaddr(state,
					       addr, len,
					       &cli_addr);
	if (rc < 0) {
		close(sd);
		return;
	}

	DEBUG(10, ("Accepted ncalrpc socket %d\n", sd));

	dcerpc_ncacn_accept(state->ev_ctx,
			    state->msg_ctx,
			    state->syntax_id, NCALRPC,
			    state->ep.name, 0,
			    cli_addr, NULL, sd);
}

struct dcerpc_ncacn_conn {
	struct ndr_syntax_id syntax_id;

	enum dcerpc_transport_t transport;

	union {
		const char *name;
		uint16_t port;
	} ep;

	int sock;

	struct pipes_struct *p;

	struct tevent_context *ev_ctx;
	struct messaging_context *msg_ctx;

	struct tstream_context *tstream;
	struct tevent_queue *send_queue;

	struct tsocket_address *client;
	char *client_name;
	struct tsocket_address *server;
	char *server_name;
	struct auth_session_info_transport *session_info;

	struct iovec *iov;
	size_t count;
};

static void dcerpc_ncacn_packet_process(struct tevent_req *subreq);
static void dcerpc_ncacn_packet_done(struct tevent_req *subreq);

static void dcerpc_ncacn_accept(struct tevent_context *ev_ctx,
				struct messaging_context *msg_ctx,
				struct ndr_syntax_id syntax_id,
				enum dcerpc_transport_t transport,
				const char *name,
				uint16_t port,
				struct tsocket_address *cli_addr,
				struct tsocket_address *srv_addr,
				int s) {
	struct dcerpc_ncacn_conn *ncacn_conn;
	struct tevent_req *subreq;
	const char *cli_str;
	const char *srv_str = NULL;
	char *pipe_name;
	NTSTATUS status;
	int sys_errno;
	int rc;

	DEBUG(10, ("dcerpc_ncacn_accept\n"));

	ncacn_conn = talloc_zero(ev_ctx, struct dcerpc_ncacn_conn);
	if (ncacn_conn == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		close(s);
		return;
	}

	switch (transport) {
		case NCACN_IP_TCP:
			ncacn_conn->ep.port = port;
			break;
		case NCALRPC:
		case NCACN_NP:
			ncacn_conn->ep.name = talloc_strdup(ncacn_conn, name);
			break;
		default:
			DEBUG(0, ("unknown dcerpc transport: %u!\n",
				  transport));
			talloc_free(ncacn_conn);
			close(s);
			return;
	}
	ncacn_conn->transport = transport;
	ncacn_conn->syntax_id = syntax_id;
	ncacn_conn->ev_ctx = ev_ctx;
	ncacn_conn->msg_ctx = msg_ctx;
	ncacn_conn->sock = s;

	ncacn_conn->client = talloc_move(ncacn_conn, &cli_addr);
	if (tsocket_address_is_inet(ncacn_conn->client, "ip")) {
		ncacn_conn->client_name =
			tsocket_address_inet_addr_string(ncacn_conn->client,
							 ncacn_conn);
	} else {
		ncacn_conn->client_name =
			tsocket_address_unix_path(ncacn_conn->client,
						  ncacn_conn);
	}
	if (ncacn_conn->client_name == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		talloc_free(ncacn_conn);
		close(s);
		return;
	}

	if (srv_addr != NULL) {
		ncacn_conn->server = talloc_move(ncacn_conn, &srv_addr);

		ncacn_conn->server_name =
			tsocket_address_inet_addr_string(ncacn_conn->server,
							 ncacn_conn);
		if (ncacn_conn->server_name == NULL) {
			DEBUG(0, ("Out of memory!\n"));
			talloc_free(ncacn_conn);
			close(s);
			return;
		}
	}

	rc = set_blocking(s, false);
	if (rc < 0) {
		DEBUG(2, ("Failed to set dcerpc socket to non-blocking\n"));
		talloc_free(ncacn_conn);
		close(s);
		return;
	}

	/*
	 * As soon as we have tstream_bsd_existing_socket set up it will
	 * take care of closing the socket.
	 */
	rc = tstream_bsd_existing_socket(ncacn_conn, s, &ncacn_conn->tstream);
	if (rc < 0) {
		DEBUG(2, ("Failed to create tstream socket for dcerpc\n"));
		talloc_free(ncacn_conn);
		close(s);
		return;
	}

	switch (ncacn_conn->transport) {
		case NCACN_IP_TCP:
			pipe_name = tsocket_address_string(ncacn_conn->client,
							   ncacn_conn);
			break;
		case NCALRPC:
			pipe_name = talloc_strdup(ncacn_conn,
						  ncacn_conn->ep.name);
			break;
		default:
			talloc_free(ncacn_conn);
			return;
	}

	if (tsocket_address_is_inet(ncacn_conn->client, "ip")) {
		cli_str = ncacn_conn->client_name;
	} else {
		cli_str = "";
	}

	if (ncacn_conn->server != NULL) {
		if (tsocket_address_is_inet(ncacn_conn->server, "ip")) {
			srv_str = ncacn_conn->server_name;
		} else {
			srv_str = NULL;
		}
	}

	if (ncacn_conn->session_info == NULL) {
		status = auth_anonymous_session_info(ncacn_conn,
						     &ncacn_conn->session_info);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(2, ("Failed to create "
				  "auth_anonymous_session_info - %s\n",
				  nt_errstr(status)));
			talloc_free(ncacn_conn);
			return;
		}
	}

	rc = make_server_pipes_struct(ncacn_conn,
				      pipe_name,
				      ncacn_conn->syntax_id,
				      ncacn_conn->transport,
				      cli_str,
				      srv_str,
				      ncacn_conn->session_info,
				      &ncacn_conn->p,
				      &sys_errno);
	if (rc < 0) {
		DEBUG(2, ("Failed to create pipe struct - %s",
			  strerror(sys_errno)));
		talloc_free(ncacn_conn);
		return;
	}

	ncacn_conn->send_queue = tevent_queue_create(ncacn_conn,
							"dcerpc send queue");
	if (ncacn_conn->send_queue == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		talloc_free(ncacn_conn);
		return;
	}

	subreq = dcerpc_ncacn_read_packet_send(ncacn_conn,
					       ncacn_conn->ev_ctx,
					       ncacn_conn->tstream);
	if (subreq == NULL) {
		DEBUG(2, ("Failed to send ncacn packet\n"));
		talloc_free(ncacn_conn);
		return;
	}

	tevent_req_set_callback(subreq, dcerpc_ncacn_packet_process, ncacn_conn);

	DEBUG(10, ("dcerpc_ncacn_accept done\n"));

	return;
}

static void dcerpc_ncacn_packet_process(struct tevent_req *subreq)
{
	struct dcerpc_ncacn_conn *ncacn_conn =
		tevent_req_callback_data(subreq, struct dcerpc_ncacn_conn);

	struct _output_data *out = &ncacn_conn->p->out_data;
	DATA_BLOB recv_buffer = data_blob_null;
	ssize_t data_left;
	ssize_t data_used;
	uint32_t to_send;
	char *data;
	NTSTATUS status;
	bool ok;

	status = dcerpc_ncacn_read_packet_recv(subreq, ncacn_conn, &recv_buffer);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		goto fail;
	}

	data_left = recv_buffer.length;
	data = (char *) recv_buffer.data;

	while (data_left) {
		data_used = process_incoming_data(ncacn_conn->p, data, data_left);
		if (data_used < 0) {
			DEBUG(3, ("Failed to process dcerpc request!\n"));
			status = NT_STATUS_UNEXPECTED_IO_ERROR;
			goto fail;
		}

		data_left -= data_used;
		data += data_used;
	}

	/* Do not leak this buffer */
	talloc_free(recv_buffer.data);

	/*
	 * This is needed because of the way DCERPC binds work in the RPC
	 * marshalling code
	 */
	to_send = out->frag.length - out->current_pdu_sent;
	if (to_send > 0) {

		DEBUG(10, ("Current_pdu_len = %u, "
			   "current_pdu_sent = %u "
			   "Returning %u bytes\n",
			   (unsigned int)out->frag.length,
			   (unsigned int)out->current_pdu_sent,
			   (unsigned int)to_send));

		ncacn_conn->iov = talloc_zero(ncacn_conn, struct iovec);
		if (ncacn_conn->iov == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}
		ncacn_conn->count = 1;

		ncacn_conn->iov[0].iov_base = out->frag.data
					    + out->current_pdu_sent;
		ncacn_conn->iov[0].iov_len = to_send;

		out->current_pdu_sent += to_send;
	}

	/*
	 * This condition is false for bind packets, or when we haven't yet got
	 * a full request, and need to wait for more data from the client
	 */
	while (out->data_sent_length < out->rdata.length) {
		ok = create_next_pdu(ncacn_conn->p);
		if (!ok) {
			DEBUG(3, ("Failed to create next PDU!\n"));
			status = NT_STATUS_UNEXPECTED_IO_ERROR;
			goto fail;
		}

		ncacn_conn->iov = talloc_realloc(ncacn_conn,
						 ncacn_conn->iov,
						 struct iovec,
						 ncacn_conn->count + 1);
		if (ncacn_conn->iov == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}

		ncacn_conn->iov[ncacn_conn->count].iov_base = out->frag.data;
		ncacn_conn->iov[ncacn_conn->count].iov_len = out->frag.length;

		DEBUG(10, ("PDU number: %d, PDU Length: %u\n",
			   (unsigned int) ncacn_conn->count,
			   (unsigned int) ncacn_conn->iov[ncacn_conn->count].iov_len));
		dump_data(11, (const uint8_t *) ncacn_conn->iov[ncacn_conn->count].iov_base,
			      ncacn_conn->iov[ncacn_conn->count].iov_len);
		ncacn_conn->count++;
	}

	/*
	 * We still don't have a complete request, go back and wait for more
	 * data.
	 */
	if (ncacn_conn->count == 0) {
		/* Wait for the next packet */
		subreq = dcerpc_ncacn_read_packet_send(ncacn_conn,
						       ncacn_conn->ev_ctx,
						       ncacn_conn->tstream);
		if (subreq == NULL) {
			DEBUG(2, ("Failed to start receving packets\n"));
			status = NT_STATUS_NO_MEMORY;
			goto fail;
		}
		tevent_req_set_callback(subreq, dcerpc_ncacn_packet_process, ncacn_conn);
		return;
	}

	DEBUG(10, ("Sending a total of %u bytes\n",
		   (unsigned int)ncacn_conn->p->out_data.data_sent_length));

	subreq = tstream_writev_queue_send(ncacn_conn,
					   ncacn_conn->ev_ctx,
					   ncacn_conn->tstream,
					   ncacn_conn->send_queue,
					   ncacn_conn->iov,
					   ncacn_conn->count);
	if (subreq == NULL) {
		DEBUG(2, ("Failed to send packet\n"));
		status = NT_STATUS_NO_MEMORY;
		goto fail;
	}

	tevent_req_set_callback(subreq, dcerpc_ncacn_packet_done, ncacn_conn);
	return;

fail:
	DEBUG(2, ("Fatal error(%s). "
		  "Terminating client(%s) connection!\n",
		  nt_errstr(status), ncacn_conn->client_name));

	/* Terminate client connection */
	talloc_free(ncacn_conn);
	return;
}

static void dcerpc_ncacn_packet_done(struct tevent_req *subreq)
{
	struct dcerpc_ncacn_conn *ncacn_conn =
		tevent_req_callback_data(subreq, struct dcerpc_ncacn_conn);
	int sys_errno;
	int rc;

	rc = tstream_writev_queue_recv(subreq, &sys_errno);
	TALLOC_FREE(subreq);
	if (rc < 0) {
		DEBUG(2, ("Writev failed!\n"));
		goto fail;
	}

	/* clear out any data that may have been left around */
	ncacn_conn->count = 0;
	TALLOC_FREE(ncacn_conn->iov);
	data_blob_free(&ncacn_conn->p->in_data.data);
	data_blob_free(&ncacn_conn->p->out_data.frag);
	data_blob_free(&ncacn_conn->p->out_data.rdata);

	/* Wait for the next packet */
	subreq = dcerpc_ncacn_read_packet_send(ncacn_conn,
					       ncacn_conn->ev_ctx,
					       ncacn_conn->tstream);
	if (subreq == NULL) {
		DEBUG(2, ("Failed to start receving packets\n"));
		sys_errno = ENOMEM;
		goto fail;
	}

	tevent_req_set_callback(subreq, dcerpc_ncacn_packet_process, ncacn_conn);
	return;

fail:
	DEBUG(2, ("Fatal error(%s). Terminating client(%s) connection!\n",
		  strerror(sys_errno), ncacn_conn->client_name));

	/* Terminate client connection */
	talloc_free(ncacn_conn);
	return;
}

/* vim: set ts=8 sw=8 noet cindent syntax=c.doxygen: */