samba-mirror/source3/smbd/smb1_process.c

/* 
   Unix SMB/CIFS implementation.
   process incoming packets - main loop
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Volker Lendecke 2005-2007

   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 "../lib/tsocket/tsocket.h"
#include "system/filesys.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "smbd/smbXsrv_open.h"
#include "librpc/gen_ndr/netlogon.h"
#include "../lib/async_req/async_sock.h"
#include "ctdbd_conn.h"
#include "../lib/util/select.h"
#include "printing/queue_process.h"
#include "system/select.h"
#include "passdb.h"
#include "auth.h"
#include "messages.h"
#include "lib/messages_ctdb.h"
#include "smbprofile.h"
#include "rpc_server/spoolss/srv_spoolss_nt.h"
#include "../lib/util/tevent_ntstatus.h"
#include "../libcli/security/dom_sid.h"
#include "../libcli/security/security_token.h"
#include "lib/id_cache.h"
#include "lib/util/sys_rw_data.h"
#include "system/threads.h"
#include "lib/pthreadpool/pthreadpool_tevent.h"
#include "util_event.h"
#include "libcli/smb/smbXcli_base.h"
#include "lib/util/time_basic.h"
#include "source3/lib/substitute.h"

/* Internal message queue for deferred opens. */
struct pending_message_list {
	struct pending_message_list *next, *prev;
	struct timeval request_time; /* When was this first issued? */
	struct smbd_server_connection *sconn;
	struct smbXsrv_connection *xconn;
	struct tevent_timer *te;
	struct smb_perfcount_data pcd;
	uint32_t seqnum;
	bool encrypted;
	bool processed;
	DATA_BLOB buf;
	struct deferred_open_record *open_rec;
};

static bool smb_splice_chain(uint8_t **poutbuf, const uint8_t *andx_buf);

void smbd_echo_init(struct smbXsrv_connection *xconn)
{
	xconn->smb1.echo_handler.trusted_fd = -1;
	xconn->smb1.echo_handler.socket_lock_fd = -1;
#ifdef HAVE_ROBUST_MUTEXES
	xconn->smb1.echo_handler.socket_mutex = NULL;
#endif
}

static bool smbd_echo_active(struct smbXsrv_connection *xconn)
{
	if (xconn->smb1.echo_handler.socket_lock_fd != -1) {
		return true;
	}

#ifdef HAVE_ROBUST_MUTEXES
	if (xconn->smb1.echo_handler.socket_mutex != NULL) {
		return true;
	}
#endif

	return false;
}

static bool smbd_lock_socket_internal(struct smbXsrv_connection *xconn)
{
	if (!smbd_echo_active(xconn)) {
		return true;
	}

	xconn->smb1.echo_handler.ref_count++;

	if (xconn->smb1.echo_handler.ref_count > 1) {
		return true;
	}

	DEBUG(10,("pid[%d] wait for socket lock\n", (int)getpid()));

#ifdef HAVE_ROBUST_MUTEXES
	if (xconn->smb1.echo_handler.socket_mutex != NULL) {
		int ret = EINTR;

		while (ret == EINTR) {
			ret = pthread_mutex_lock(
				xconn->smb1.echo_handler.socket_mutex);
			if (ret == 0) {
				break;
			}
		}
		if (ret != 0) {
			DEBUG(1, ("pthread_mutex_lock failed: %s\n",
				  strerror(ret)));
			return false;
		}
	}
#endif

	if (xconn->smb1.echo_handler.socket_lock_fd != -1) {
		bool ok;

		do {
			ok = fcntl_lock(
				xconn->smb1.echo_handler.socket_lock_fd,
				F_SETLKW, 0, 0, F_WRLCK);
		} while (!ok && (errno == EINTR));

		if (!ok) {
			DEBUG(1, ("fcntl_lock failed: %s\n", strerror(errno)));
			return false;
		}
	}

	DEBUG(10,("pid[%d] got socket lock\n", (int)getpid()));

	return true;
}

void smbd_lock_socket(struct smbXsrv_connection *xconn)
{
	if (!smbd_lock_socket_internal(xconn)) {
		exit_server_cleanly("failed to lock socket");
	}
}

static bool smbd_unlock_socket_internal(struct smbXsrv_connection *xconn)
{
	if (!smbd_echo_active(xconn)) {
		return true;
	}

	xconn->smb1.echo_handler.ref_count--;

	if (xconn->smb1.echo_handler.ref_count > 0) {
		return true;
	}

#ifdef HAVE_ROBUST_MUTEXES
	if (xconn->smb1.echo_handler.socket_mutex != NULL) {
		int ret;
		ret = pthread_mutex_unlock(
			xconn->smb1.echo_handler.socket_mutex);
		if (ret != 0) {
			DEBUG(1, ("pthread_mutex_unlock failed: %s\n",
				  strerror(ret)));
			return false;
		}
	}
#endif

	if (xconn->smb1.echo_handler.socket_lock_fd != -1) {
		bool ok;

		do {
			ok = fcntl_lock(
				xconn->smb1.echo_handler.socket_lock_fd,
				F_SETLKW, 0, 0, F_UNLCK);
		} while (!ok && (errno == EINTR));

		if (!ok) {
			DEBUG(1, ("fcntl_lock failed: %s\n", strerror(errno)));
			return false;
		}
	}

	DEBUG(10,("pid[%d] unlocked socket\n", (int)getpid()));

	return true;
}

void smbd_unlock_socket(struct smbXsrv_connection *xconn)
{
	if (!smbd_unlock_socket_internal(xconn)) {
		exit_server_cleanly("failed to unlock socket");
	}
}

/* Accessor function for smb_read_error for smbd functions. */

/****************************************************************************
 Send an smb to a fd.
****************************************************************************/

bool smb1_srv_send(struct smbXsrv_connection *xconn, char *buffer,
		   bool do_signing, uint32_t seqnum,
		   bool do_encrypt,
		   struct smb_perfcount_data *pcd)
{
	size_t len = 0;
	ssize_t ret;
	char *buf_out = buffer;

	if (!NT_STATUS_IS_OK(xconn->transport.status)) {
		/*
		 * we're not supposed to do any io
		 */
		return true;
	}

	smbd_lock_socket(xconn);

	if (do_signing) {
		NTSTATUS status;

		/* Sign the outgoing packet if required. */
		status = smb1_srv_calculate_sign_mac(xconn, buf_out, seqnum);
		if (!NT_STATUS_IS_OK(status)) {
			DBG_ERR("Failed to calculate signing mac: %s\n",
				nt_errstr(status));
			return false;
		}
	}

	if (do_encrypt) {
		NTSTATUS status = srv_encrypt_buffer(xconn, buffer, &buf_out);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0, ("send_smb: SMB encryption failed "
				"on outgoing packet! Error %s\n",
				nt_errstr(status) ));
			ret = -1;
			goto out;
		}
	}

	len = smb_len_large(buf_out) + 4;

	ret = write_data(xconn->transport.sock, buf_out, len);
	if (ret <= 0) {
		int saved_errno = errno;
		/*
		 * Try and give an error message saying what
		 * client failed.
		 */
		DEBUG(1,("pid[%d] Error writing %d bytes to client %s. %d. (%s)\n",
			 (int)getpid(), (int)len,
			 smbXsrv_connection_dbg(xconn),
			 (int)ret, strerror(saved_errno)));
		errno = saved_errno;

		srv_free_enc_buffer(xconn, buf_out);
		goto out;
	}

	SMB_PERFCOUNT_SET_MSGLEN_OUT(pcd, len);
	srv_free_enc_buffer(xconn, buf_out);
out:
	SMB_PERFCOUNT_END(pcd);

	smbd_unlock_socket(xconn);
	return (ret > 0);
}

/* Socket functions for smbd packet processing. */

static bool valid_packet_size(size_t len)
{
	/*
	 * A WRITEX with CAP_LARGE_WRITEX can be 64k worth of data plus 65 bytes
	 * of header. Don't print the error if this fits.... JRA.
	 */

	if (len > (LARGE_WRITEX_BUFFER_SIZE + LARGE_WRITEX_HDR_SIZE)) {
		DEBUG(0,("Invalid packet length! (%lu bytes).\n",
					(unsigned long)len));
		return false;
	}
	return true;
}

/****************************************************************************
 Attempt a zerocopy writeX read. We know here that len > smb_size-4
****************************************************************************/

/*
 * Unfortunately, earlier versions of smbclient/libsmbclient
 * don't send this "standard" writeX header. I've fixed this
 * for 3.2 but we'll use the old method with earlier versions.
 * Windows and CIFSFS at least use this standard size. Not
 * sure about MacOSX.
 */

#define STANDARD_WRITE_AND_X_HEADER_SIZE (smb_size - 4 + /* basic header */ \
				(2*14) + /* word count (including bcc) */ \
				1 /* pad byte */)

static NTSTATUS receive_smb_raw_talloc_partial_read(TALLOC_CTX *mem_ctx,
						    const char lenbuf[4],
						    struct smbXsrv_connection *xconn,
						    int sock,
						    char **buffer,
						    unsigned int timeout,
						    size_t *p_unread,
						    size_t *len_ret)
{
	/* Size of a WRITEX call (+4 byte len). */
	char writeX_header[4 + STANDARD_WRITE_AND_X_HEADER_SIZE];
	ssize_t len = smb_len_large(lenbuf); /* Could be a UNIX large writeX. */
	ssize_t toread;
	NTSTATUS status;

	memcpy(writeX_header, lenbuf, 4);

	status = read_fd_with_timeout(
		sock, writeX_header + 4,
		STANDARD_WRITE_AND_X_HEADER_SIZE,
		STANDARD_WRITE_AND_X_HEADER_SIZE,
		timeout, NULL);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("read_fd_with_timeout failed for client %s read "
			  "error = %s.\n",
			  smbXsrv_connection_dbg(xconn),
			  nt_errstr(status)));
		return status;
	}

	/*
	 * Ok - now try and see if this is a possible
	 * valid writeX call.
	 */

	if (is_valid_writeX_buffer(xconn, (uint8_t *)writeX_header)) {
		/*
		 * If the data offset is beyond what
		 * we've read, drain the extra bytes.
		 */
		uint16_t doff = SVAL(writeX_header,smb_vwv11);
		ssize_t newlen;

		if (doff > STANDARD_WRITE_AND_X_HEADER_SIZE) {
			size_t drain = doff - STANDARD_WRITE_AND_X_HEADER_SIZE;
			if (drain_socket(sock, drain) != drain) {
	                        smb_panic("receive_smb_raw_talloc_partial_read:"
					" failed to drain pending bytes");
	                }
		} else {
			doff = STANDARD_WRITE_AND_X_HEADER_SIZE;
		}

		/* Spoof down the length and null out the bcc. */
		set_message_bcc(writeX_header, 0);
		newlen = smb_len(writeX_header);

		/* Copy the header we've written. */

		*buffer = (char *)talloc_memdup(mem_ctx,
				writeX_header,
				sizeof(writeX_header));

		if (*buffer == NULL) {
			DEBUG(0, ("Could not allocate inbuf of length %d\n",
				  (int)sizeof(writeX_header)));
			return NT_STATUS_NO_MEMORY;
		}

		/* Work out the remaining bytes. */
		*p_unread = len - STANDARD_WRITE_AND_X_HEADER_SIZE;
		*len_ret = newlen + 4;
		return NT_STATUS_OK;
	}

	if (!valid_packet_size(len)) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	/*
	 * Not a valid writeX call. Just do the standard
	 * talloc and return.
	 */

	*buffer = talloc_array(mem_ctx, char, len+4);

	if (*buffer == NULL) {
		DEBUG(0, ("Could not allocate inbuf of length %d\n",
			  (int)len+4));
		return NT_STATUS_NO_MEMORY;
	}

	/* Copy in what we already read. */
	memcpy(*buffer,
		writeX_header,
		4 + STANDARD_WRITE_AND_X_HEADER_SIZE);
	toread = len - STANDARD_WRITE_AND_X_HEADER_SIZE;

	if(toread > 0) {
		status = read_packet_remainder(
			sock,
			(*buffer) + 4 + STANDARD_WRITE_AND_X_HEADER_SIZE,
			timeout, toread);

		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(10, ("receive_smb_raw_talloc_partial_read: %s\n",
				   nt_errstr(status)));
			return status;
		}
	}

	*len_ret = len + 4;
	return NT_STATUS_OK;
}

static NTSTATUS receive_smb_raw_talloc(TALLOC_CTX *mem_ctx,
				       struct smbXsrv_connection *xconn,
				       int sock,
				       char **buffer, unsigned int timeout,
				       size_t *p_unread, size_t *plen)
{
	char lenbuf[4];
	size_t len;
	int min_recv_size = lp_min_receive_file_size();
	NTSTATUS status;

	*p_unread = 0;

	status = read_smb_length_return_keepalive(sock, lenbuf, timeout,
						  &len);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	if (CVAL(lenbuf,0) == 0 && min_recv_size &&
	    (smb_len_large(lenbuf) > /* Could be a UNIX large writeX. */
		(min_recv_size + STANDARD_WRITE_AND_X_HEADER_SIZE)) &&
	    !smb1_srv_is_signing_active(xconn) &&
	    xconn->smb1.echo_handler.trusted_fde == NULL) {

		return receive_smb_raw_talloc_partial_read(
			mem_ctx, lenbuf, xconn, sock, buffer, timeout,
			p_unread, plen);
	}

	if (!valid_packet_size(len)) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	/*
	 * The +4 here can't wrap, we've checked the length above already.
	 */

	*buffer = talloc_array(mem_ctx, char, len+4);

	if (*buffer == NULL) {
		DEBUG(0, ("Could not allocate inbuf of length %d\n",
			  (int)len+4));
		return NT_STATUS_NO_MEMORY;
	}

	memcpy(*buffer, lenbuf, sizeof(lenbuf));

	status = read_packet_remainder(sock, (*buffer)+4, timeout, len);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	*plen = len + 4;
	return NT_STATUS_OK;
}

NTSTATUS smb1_receive_talloc(TALLOC_CTX *mem_ctx,
			     struct smbXsrv_connection *xconn,
			     int sock,
			     char **buffer, unsigned int timeout,
			     size_t *p_unread, bool *p_encrypted,
			     size_t *p_len,
			     uint32_t *seqnum,
			     bool trusted_channel)
{
	size_t len = 0;
	NTSTATUS status;

	*p_encrypted = false;

	status = receive_smb_raw_talloc(mem_ctx, xconn, sock, buffer, timeout,
					p_unread, &len);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)?5:1,
		      ("receive_smb_raw_talloc failed for client %s "
		       "read error = %s.\n",
		       smbXsrv_connection_dbg(xconn),
		       nt_errstr(status)) );
		return status;
	}

	if (is_encrypted_packet((uint8_t *)*buffer)) {
		status = srv_decrypt_buffer(xconn, *buffer);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0, ("receive_smb_talloc: SMB decryption failed on "
				"incoming packet! Error %s\n",
				nt_errstr(status) ));
			return status;
		}
		*p_encrypted = true;
	}

	/* Check the incoming SMB signature. */
	if (!smb1_srv_check_sign_mac(xconn, *buffer, seqnum, trusted_channel)) {
		DEBUG(0, ("receive_smb: SMB Signature verification failed on "
			  "incoming packet!\n"));
		return NT_STATUS_INVALID_NETWORK_RESPONSE;
	}

	*p_len = len;
	return NT_STATUS_OK;
}

/****************************************************************************
 Function to push a message onto the tail of a linked list of smb messages ready
 for processing.
****************************************************************************/

static bool push_queued_message(struct smb_request *req,
				struct timeval request_time,
				struct timeval end_time,
				struct deferred_open_record *open_rec)
{
	int msg_len = smb_len(req->inbuf) + 4;
	struct pending_message_list *msg;

	msg = talloc_zero(NULL, struct pending_message_list);

	if(msg == NULL) {
		DEBUG(0,("push_message: malloc fail (1)\n"));
		return False;
	}
	msg->sconn = req->sconn;
	msg->xconn = req->xconn;

	msg->buf = data_blob_talloc(msg, req->inbuf, msg_len);
	if(msg->buf.data == NULL) {
		DEBUG(0,("push_message: malloc fail (2)\n"));
		TALLOC_FREE(msg);
		return False;
	}

	msg->request_time = request_time;
	msg->seqnum = req->seqnum;
	msg->encrypted = req->encrypted;
	msg->processed = false;
	SMB_PERFCOUNT_DEFER_OP(&req->pcd, &msg->pcd);

	if (open_rec) {
		msg->open_rec = talloc_move(msg, &open_rec);
	}

#if 0
	msg->te = tevent_add_timer(msg->sconn->ev_ctx,
				   msg,
				   end_time,
				   smbd_deferred_open_timer,
				   msg);
	if (!msg->te) {
		DEBUG(0,("push_message: event_add_timed failed\n"));
		TALLOC_FREE(msg);
		return false;
	}
#endif

	DLIST_ADD_END(req->sconn->deferred_open_queue, msg);

	DEBUG(10,("push_message: pushed message length %u on "
		  "deferred_open_queue\n", (unsigned int)msg_len));

	return True;
}

/****************************************************************************
 Function to push a deferred open smb message onto a linked list of local smb
 messages ready for processing.
****************************************************************************/

bool push_deferred_open_message_smb1(struct smb_request *req,
				     struct timeval timeout,
				     struct file_id id,
				     struct deferred_open_record *open_rec)
{
	struct timeval_buf tvbuf;
	struct timeval end_time;

	if (req->unread_bytes) {
		DEBUG(0,("push_deferred_open_message_smb: logic error ! "
			"unread_bytes = %u\n",
			(unsigned int)req->unread_bytes ));
		smb_panic("push_deferred_open_message_smb: "
			"logic error unread_bytes != 0" );
	}

	end_time = timeval_sum(&req->request_time, &timeout);

	DBG_DEBUG("pushing message len %u mid %"PRIu64" timeout time [%s]\n",
		  (unsigned int) smb_len(req->inbuf)+4,
		  req->mid,
		  timeval_str_buf(&end_time, false, true, &tvbuf));

	return push_queued_message(req, req->request_time, end_time, open_rec);
}

/*
 * Only allow 5 outstanding trans requests. We're allocating memory, so
 * prevent a DoS.
 */

NTSTATUS allow_new_trans(struct trans_state *list, uint64_t mid)
{
	int count = 0;
	for (; list != NULL; list = list->next) {

		if (list->mid == mid) {
			return NT_STATUS_INVALID_PARAMETER;
		}

		count += 1;
	}
	if (count > 5) {
		return NT_STATUS_INSUFFICIENT_RESOURCES;
	}

	return NT_STATUS_OK;
}

/*
These flags determine some of the permissions required to do an operation 

Note that I don't set NEED_WRITE on some write operations because they
are used by some brain-dead clients when printing, and I don't want to
force write permissions on print services.
*/
#define AS_USER (1<<0)
#define NEED_WRITE (1<<1) /* Must be paired with AS_USER */
#define TIME_INIT (1<<2)
#define CAN_IPC (1<<3) /* Must be paired with AS_USER */
#define AS_GUEST (1<<5) /* Must *NOT* be paired with AS_USER */
#define DO_CHDIR (1<<6)

/* 
   define a list of possible SMB messages and their corresponding
   functions. Any message that has a NULL function is unimplemented -
   please feel free to contribute implementations!
*/
static const struct smb_message_struct {
	const char *name;
	void (*fn)(struct smb_request *req);
	int flags;
} smb_messages[256] = {

/* 0x00 */ { "SMBmkdir",reply_mkdir,AS_USER | NEED_WRITE},
/* 0x01 */ { "SMBrmdir",reply_rmdir,AS_USER | NEED_WRITE},
/* 0x02 */ { "SMBopen",reply_open,AS_USER },
/* 0x03 */ { "SMBcreate",reply_mknew,AS_USER},
/* 0x04 */ { "SMBclose",reply_close,AS_USER | CAN_IPC },
/* 0x05 */ { "SMBflush",reply_flush,AS_USER},
/* 0x06 */ { "SMBunlink",reply_unlink,AS_USER | NEED_WRITE },
/* 0x07 */ { "SMBmv",reply_mv,AS_USER | NEED_WRITE },
/* 0x08 */ { "SMBgetatr",reply_getatr,AS_USER},
/* 0x09 */ { "SMBsetatr",reply_setatr,AS_USER | NEED_WRITE},
/* 0x0a */ { "SMBread",reply_read,AS_USER},
/* 0x0b */ { "SMBwrite",reply_write,AS_USER | CAN_IPC },
/* 0x0c */ { "SMBlock",reply_lock,AS_USER},
/* 0x0d */ { "SMBunlock",reply_unlock,AS_USER},
/* 0x0e */ { "SMBctemp",reply_ctemp,AS_USER },
/* 0x0f */ { "SMBmknew",reply_mknew,AS_USER},
/* 0x10 */ { "SMBcheckpath",reply_checkpath,AS_USER},
/* 0x11 */ { "SMBexit",reply_exit,DO_CHDIR},
/* 0x12 */ { "SMBlseek",reply_lseek,AS_USER},
/* 0x13 */ { "SMBlockread",reply_lockread,AS_USER},
/* 0x14 */ { "SMBwriteunlock",reply_writeunlock,AS_USER},
/* 0x15 */ { NULL, NULL, 0 },
/* 0x16 */ { NULL, NULL, 0 },
/* 0x17 */ { NULL, NULL, 0 },
/* 0x18 */ { NULL, NULL, 0 },
/* 0x19 */ { NULL, NULL, 0 },
/* 0x1a */ { "SMBreadbraw",reply_readbraw,AS_USER},
/* 0x1b */ { "SMBreadBmpx",reply_readbmpx,AS_USER},
/* 0x1c */ { "SMBreadBs",reply_readbs,AS_USER },
/* 0x1d */ { "SMBwritebraw",reply_writebraw,AS_USER},
/* 0x1e */ { "SMBwriteBmpx",reply_writebmpx,AS_USER},
/* 0x1f */ { "SMBwriteBs",reply_writebs,AS_USER},
/* 0x20 */ { "SMBwritec", NULL,0},
/* 0x21 */ { NULL, NULL, 0 },
/* 0x22 */ { "SMBsetattrE",reply_setattrE,AS_USER | NEED_WRITE },
/* 0x23 */ { "SMBgetattrE",reply_getattrE,AS_USER },
/* 0x24 */ { "SMBlockingX",reply_lockingX,AS_USER },
/* 0x25 */ { "SMBtrans",reply_trans,AS_USER | CAN_IPC },
/* 0x26 */ { "SMBtranss",reply_transs,AS_USER | CAN_IPC},
/* 0x27 */ { "SMBioctl",reply_ioctl,0},
/* 0x28 */ { "SMBioctls", NULL,AS_USER},
/* 0x29 */ { "SMBcopy",reply_copy,AS_USER | NEED_WRITE },
/* 0x2a */ { "SMBmove", NULL,AS_USER | NEED_WRITE },
/* 0x2b */ { "SMBecho",reply_echo,0},
/* 0x2c */ { "SMBwriteclose",reply_writeclose,AS_USER},
/* 0x2d */ { "SMBopenX",reply_open_and_X,AS_USER | CAN_IPC },
/* 0x2e */ { "SMBreadX",reply_read_and_X,AS_USER | CAN_IPC },
/* 0x2f */ { "SMBwriteX",reply_write_and_X,AS_USER | CAN_IPC },
/* 0x30 */ { NULL, NULL, 0 },
/* 0x31 */ { NULL, NULL, 0 },
/* 0x32 */ { "SMBtrans2",reply_trans2, AS_USER | CAN_IPC },
/* 0x33 */ { "SMBtranss2",reply_transs2, AS_USER | CAN_IPC },
/* 0x34 */ { "SMBfindclose",reply_findclose,AS_USER},
/* 0x35 */ { "SMBfindnclose",reply_findnclose,AS_USER},
/* 0x36 */ { NULL, NULL, 0 },
/* 0x37 */ { NULL, NULL, 0 },
/* 0x38 */ { NULL, NULL, 0 },
/* 0x39 */ { NULL, NULL, 0 },
/* 0x3a */ { NULL, NULL, 0 },
/* 0x3b */ { NULL, NULL, 0 },
/* 0x3c */ { NULL, NULL, 0 },
/* 0x3d */ { NULL, NULL, 0 },
/* 0x3e */ { NULL, NULL, 0 },
/* 0x3f */ { NULL, NULL, 0 },
/* 0x40 */ { NULL, NULL, 0 },
/* 0x41 */ { NULL, NULL, 0 },
/* 0x42 */ { NULL, NULL, 0 },
/* 0x43 */ { NULL, NULL, 0 },
/* 0x44 */ { NULL, NULL, 0 },
/* 0x45 */ { NULL, NULL, 0 },
/* 0x46 */ { NULL, NULL, 0 },
/* 0x47 */ { NULL, NULL, 0 },
/* 0x48 */ { NULL, NULL, 0 },
/* 0x49 */ { NULL, NULL, 0 },
/* 0x4a */ { NULL, NULL, 0 },
/* 0x4b */ { NULL, NULL, 0 },
/* 0x4c */ { NULL, NULL, 0 },
/* 0x4d */ { NULL, NULL, 0 },
/* 0x4e */ { NULL, NULL, 0 },
/* 0x4f */ { NULL, NULL, 0 },
/* 0x50 */ { NULL, NULL, 0 },
/* 0x51 */ { NULL, NULL, 0 },
/* 0x52 */ { NULL, NULL, 0 },
/* 0x53 */ { NULL, NULL, 0 },
/* 0x54 */ { NULL, NULL, 0 },
/* 0x55 */ { NULL, NULL, 0 },
/* 0x56 */ { NULL, NULL, 0 },
/* 0x57 */ { NULL, NULL, 0 },
/* 0x58 */ { NULL, NULL, 0 },
/* 0x59 */ { NULL, NULL, 0 },
/* 0x5a */ { NULL, NULL, 0 },
/* 0x5b */ { NULL, NULL, 0 },
/* 0x5c */ { NULL, NULL, 0 },
/* 0x5d */ { NULL, NULL, 0 },
/* 0x5e */ { NULL, NULL, 0 },
/* 0x5f */ { NULL, NULL, 0 },
/* 0x60 */ { NULL, NULL, 0 },
/* 0x61 */ { NULL, NULL, 0 },
/* 0x62 */ { NULL, NULL, 0 },
/* 0x63 */ { NULL, NULL, 0 },
/* 0x64 */ { NULL, NULL, 0 },
/* 0x65 */ { NULL, NULL, 0 },
/* 0x66 */ { NULL, NULL, 0 },
/* 0x67 */ { NULL, NULL, 0 },
/* 0x68 */ { NULL, NULL, 0 },
/* 0x69 */ { NULL, NULL, 0 },
/* 0x6a */ { NULL, NULL, 0 },
/* 0x6b */ { NULL, NULL, 0 },
/* 0x6c */ { NULL, NULL, 0 },
/* 0x6d */ { NULL, NULL, 0 },
/* 0x6e */ { NULL, NULL, 0 },
/* 0x6f */ { NULL, NULL, 0 },
/* 0x70 */ { "SMBtcon",reply_tcon,0},
/* 0x71 */ { "SMBtdis",reply_tdis,DO_CHDIR},
/* 0x72 */ { "SMBnegprot",reply_negprot,0},
/* 0x73 */ { "SMBsesssetupX",reply_sesssetup_and_X,0},
/* 0x74 */ { "SMBulogoffX",reply_ulogoffX, 0}, /* ulogoff doesn't give a valid TID */
/* 0x75 */ { "SMBtconX",reply_tcon_and_X,0},
/* 0x76 */ { NULL, NULL, 0 },
/* 0x77 */ { NULL, NULL, 0 },
/* 0x78 */ { NULL, NULL, 0 },
/* 0x79 */ { NULL, NULL, 0 },
/* 0x7a */ { NULL, NULL, 0 },
/* 0x7b */ { NULL, NULL, 0 },
/* 0x7c */ { NULL, NULL, 0 },
/* 0x7d */ { NULL, NULL, 0 },
/* 0x7e */ { NULL, NULL, 0 },
/* 0x7f */ { NULL, NULL, 0 },
/* 0x80 */ { "SMBdskattr",reply_dskattr,AS_USER},
/* 0x81 */ { "SMBsearch",reply_search,AS_USER},
/* 0x82 */ { "SMBffirst",reply_search,AS_USER},
/* 0x83 */ { "SMBfunique",reply_search,AS_USER},
/* 0x84 */ { "SMBfclose",reply_fclose,AS_USER},
/* 0x85 */ { NULL, NULL, 0 },
/* 0x86 */ { NULL, NULL, 0 },
/* 0x87 */ { NULL, NULL, 0 },
/* 0x88 */ { NULL, NULL, 0 },
/* 0x89 */ { NULL, NULL, 0 },
/* 0x8a */ { NULL, NULL, 0 },
/* 0x8b */ { NULL, NULL, 0 },
/* 0x8c */ { NULL, NULL, 0 },
/* 0x8d */ { NULL, NULL, 0 },
/* 0x8e */ { NULL, NULL, 0 },
/* 0x8f */ { NULL, NULL, 0 },
/* 0x90 */ { NULL, NULL, 0 },
/* 0x91 */ { NULL, NULL, 0 },
/* 0x92 */ { NULL, NULL, 0 },
/* 0x93 */ { NULL, NULL, 0 },
/* 0x94 */ { NULL, NULL, 0 },
/* 0x95 */ { NULL, NULL, 0 },
/* 0x96 */ { NULL, NULL, 0 },
/* 0x97 */ { NULL, NULL, 0 },
/* 0x98 */ { NULL, NULL, 0 },
/* 0x99 */ { NULL, NULL, 0 },
/* 0x9a */ { NULL, NULL, 0 },
/* 0x9b */ { NULL, NULL, 0 },
/* 0x9c */ { NULL, NULL, 0 },
/* 0x9d */ { NULL, NULL, 0 },
/* 0x9e */ { NULL, NULL, 0 },
/* 0x9f */ { NULL, NULL, 0 },
/* 0xa0 */ { "SMBnttrans",reply_nttrans, AS_USER | CAN_IPC },
/* 0xa1 */ { "SMBnttranss",reply_nttranss, AS_USER | CAN_IPC },
/* 0xa2 */ { "SMBntcreateX",reply_ntcreate_and_X, AS_USER | CAN_IPC },
/* 0xa3 */ { NULL, NULL, 0 },
/* 0xa4 */ { "SMBntcancel",reply_ntcancel, 0 },
/* 0xa5 */ { "SMBntrename",reply_ntrename, AS_USER | NEED_WRITE },
/* 0xa6 */ { NULL, NULL, 0 },
/* 0xa7 */ { NULL, NULL, 0 },
/* 0xa8 */ { NULL, NULL, 0 },
/* 0xa9 */ { NULL, NULL, 0 },
/* 0xaa */ { NULL, NULL, 0 },
/* 0xab */ { NULL, NULL, 0 },
/* 0xac */ { NULL, NULL, 0 },
/* 0xad */ { NULL, NULL, 0 },
/* 0xae */ { NULL, NULL, 0 },
/* 0xaf */ { NULL, NULL, 0 },
/* 0xb0 */ { NULL, NULL, 0 },
/* 0xb1 */ { NULL, NULL, 0 },
/* 0xb2 */ { NULL, NULL, 0 },
/* 0xb3 */ { NULL, NULL, 0 },
/* 0xb4 */ { NULL, NULL, 0 },
/* 0xb5 */ { NULL, NULL, 0 },
/* 0xb6 */ { NULL, NULL, 0 },
/* 0xb7 */ { NULL, NULL, 0 },
/* 0xb8 */ { NULL, NULL, 0 },
/* 0xb9 */ { NULL, NULL, 0 },
/* 0xba */ { NULL, NULL, 0 },
/* 0xbb */ { NULL, NULL, 0 },
/* 0xbc */ { NULL, NULL, 0 },
/* 0xbd */ { NULL, NULL, 0 },
/* 0xbe */ { NULL, NULL, 0 },
/* 0xbf */ { NULL, NULL, 0 },
/* 0xc0 */ { "SMBsplopen",reply_printopen,AS_USER},
/* 0xc1 */ { "SMBsplwr",reply_printwrite,AS_USER},
/* 0xc2 */ { "SMBsplclose",reply_printclose,AS_USER},
/* 0xc3 */ { "SMBsplretq",reply_printqueue,AS_USER},
/* 0xc4 */ { NULL, NULL, 0 },
/* 0xc5 */ { NULL, NULL, 0 },
/* 0xc6 */ { NULL, NULL, 0 },
/* 0xc7 */ { NULL, NULL, 0 },
/* 0xc8 */ { NULL, NULL, 0 },
/* 0xc9 */ { NULL, NULL, 0 },
/* 0xca */ { NULL, NULL, 0 },
/* 0xcb */ { NULL, NULL, 0 },
/* 0xcc */ { NULL, NULL, 0 },
/* 0xcd */ { NULL, NULL, 0 },
/* 0xce */ { NULL, NULL, 0 },
/* 0xcf */ { NULL, NULL, 0 },
/* 0xd0 */ { "SMBsends",reply_sends,AS_GUEST},
/* 0xd1 */ { "SMBsendb", NULL,AS_GUEST},
/* 0xd2 */ { "SMBfwdname", NULL,AS_GUEST},
/* 0xd3 */ { "SMBcancelf", NULL,AS_GUEST},
/* 0xd4 */ { "SMBgetmac", NULL,AS_GUEST},
/* 0xd5 */ { "SMBsendstrt",reply_sendstrt,AS_GUEST},
/* 0xd6 */ { "SMBsendend",reply_sendend,AS_GUEST},
/* 0xd7 */ { "SMBsendtxt",reply_sendtxt,AS_GUEST},
/* 0xd8 */ { NULL, NULL, 0 },
/* 0xd9 */ { NULL, NULL, 0 },
/* 0xda */ { NULL, NULL, 0 },
/* 0xdb */ { NULL, NULL, 0 },
/* 0xdc */ { NULL, NULL, 0 },
/* 0xdd */ { NULL, NULL, 0 },
/* 0xde */ { NULL, NULL, 0 },
/* 0xdf */ { NULL, NULL, 0 },
/* 0xe0 */ { NULL, NULL, 0 },
/* 0xe1 */ { NULL, NULL, 0 },
/* 0xe2 */ { NULL, NULL, 0 },
/* 0xe3 */ { NULL, NULL, 0 },
/* 0xe4 */ { NULL, NULL, 0 },
/* 0xe5 */ { NULL, NULL, 0 },
/* 0xe6 */ { NULL, NULL, 0 },
/* 0xe7 */ { NULL, NULL, 0 },
/* 0xe8 */ { NULL, NULL, 0 },
/* 0xe9 */ { NULL, NULL, 0 },
/* 0xea */ { NULL, NULL, 0 },
/* 0xeb */ { NULL, NULL, 0 },
/* 0xec */ { NULL, NULL, 0 },
/* 0xed */ { NULL, NULL, 0 },
/* 0xee */ { NULL, NULL, 0 },
/* 0xef */ { NULL, NULL, 0 },
/* 0xf0 */ { NULL, NULL, 0 },
/* 0xf1 */ { NULL, NULL, 0 },
/* 0xf2 */ { NULL, NULL, 0 },
/* 0xf3 */ { NULL, NULL, 0 },
/* 0xf4 */ { NULL, NULL, 0 },
/* 0xf5 */ { NULL, NULL, 0 },
/* 0xf6 */ { NULL, NULL, 0 },
/* 0xf7 */ { NULL, NULL, 0 },
/* 0xf8 */ { NULL, NULL, 0 },
/* 0xf9 */ { NULL, NULL, 0 },
/* 0xfa */ { NULL, NULL, 0 },
/* 0xfb */ { NULL, NULL, 0 },
/* 0xfc */ { NULL, NULL, 0 },
/* 0xfd */ { NULL, NULL, 0 },
/* 0xfe */ { NULL, NULL, 0 },
/* 0xff */ { NULL, NULL, 0 }

};


/*******************************************************************
 Dump a packet to a file.
********************************************************************/

static void smb_dump(const char *name, int type, const char *data)
{
	size_t len;
	int fd, i;
	char *fname = NULL;
	if (DEBUGLEVEL < 50) {
		return;
	}

	len = smb_len_tcp(data)+4;
	for (i=1;i<100;i++) {
		fname = talloc_asprintf(talloc_tos(),
				"/tmp/%s.%d.%s",
				name,
				i,
				type ? "req" : "resp");
		if (fname == NULL) {
			return;
		}
		fd = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0644);
		if (fd != -1 || errno != EEXIST) break;
		TALLOC_FREE(fname);
	}
	if (fd != -1) {
		ssize_t ret = write(fd, data, len);
		if (ret != len)
			DEBUG(0,("smb_dump: problem: write returned %d\n", (int)ret ));
		close(fd);
		DEBUG(0,("created %s len %lu\n", fname, (unsigned long)len));
	}
	TALLOC_FREE(fname);
}

static void smb1srv_update_crypto_flags(struct smbXsrv_session *session,
					struct smb_request *req,
					uint8_t type,
					bool *update_session_globalp,
					bool *update_tcon_globalp)
{
	connection_struct *conn = req->conn;
	struct smbXsrv_tcon *tcon = conn ? conn->tcon : NULL;
	uint8_t encrypt_flag = SMBXSRV_PROCESSED_UNENCRYPTED_PACKET;
	uint8_t sign_flag = SMBXSRV_PROCESSED_UNSIGNED_PACKET;
	bool update_session = false;
	bool update_tcon = false;

	if (req->encrypted) {
		encrypt_flag = SMBXSRV_PROCESSED_ENCRYPTED_PACKET;
	}

	if (smb1_srv_is_signing_active(req->xconn)) {
		sign_flag = SMBXSRV_PROCESSED_SIGNED_PACKET;
	} else if ((type == SMBecho) || (type == SMBsesssetupX)) {
		/*
		 * echo can be unsigned. Sesssion setup except final
		 * session setup response too
		 */
		sign_flag &= ~SMBXSRV_PROCESSED_UNSIGNED_PACKET;
	}

	update_session |= smbXsrv_set_crypto_flag(
		&session->global->encryption_flags, encrypt_flag);
	update_session |= smbXsrv_set_crypto_flag(
		&session->global->signing_flags, sign_flag);

	if (tcon) {
		update_tcon |= smbXsrv_set_crypto_flag(
			&tcon->global->encryption_flags, encrypt_flag);
		update_tcon |= smbXsrv_set_crypto_flag(
			&tcon->global->signing_flags, sign_flag);
	}

	if (update_session) {
		session->global->channels[0].encryption_cipher = SMB_ENCRYPTION_GSSAPI;
	}

	*update_session_globalp = update_session;
	*update_tcon_globalp = update_tcon;
	return;
}

/****************************************************************************
 Prepare everything for calling the actual request function, and potentially
 call the request function via the "new" interface.

 Return False if the "legacy" function needs to be called, everything is
 prepared.

 Return True if we're done.

 I know this API sucks, but it is the one with the least code change I could
 find.
****************************************************************************/

static connection_struct *switch_message(uint8_t type, struct smb_request *req)
{
	const struct loadparm_substitution *lp_sub =
		loadparm_s3_global_substitution();
	int flags;
	uint64_t session_tag;
	connection_struct *conn = NULL;
	struct smbXsrv_connection *xconn = req->xconn;
	NTTIME now = timeval_to_nttime(&req->request_time);
	struct smbXsrv_session *session = NULL;
	NTSTATUS status;

	errno = 0;

	if (!xconn->smb1.negprot.done) {
		switch (type) {
			/*
			 * Without a negprot the request must
			 * either be a negprot, or one of the
			 * evil old SMB mailslot messaging types.
			 */
			case SMBnegprot:
			case SMBsendstrt:
			case SMBsendend:
			case SMBsendtxt:
				break;
			default:
				exit_server_cleanly("The first request "
					"should be a negprot");
		}
	}

	if (smb_messages[type].fn == NULL) {
		DEBUG(0,("Unknown message type %d!\n",type));
		smb_dump("Unknown", 1, (const char *)req->inbuf);
		reply_unknown_new(req, type);
		return NULL;
	}

	flags = smb_messages[type].flags;

	/* In share mode security we must ignore the vuid. */
	session_tag = req->vuid;
	conn = req->conn;

	DEBUG(3,("switch message %s (pid %d) conn 0x%lx\n", smb_fn_name(type),
		 (int)getpid(), (unsigned long)conn));

	smb_dump(smb_fn_name(type), 1, (const char *)req->inbuf);

	/* Ensure this value is replaced in the incoming packet. */
	SSVAL(discard_const_p(uint8_t, req->inbuf),smb_uid,session_tag);

	/*
	 * Ensure the correct username is in current_user_info.  This is a
	 * really ugly bugfix for problems with multiple session_setup_and_X's
	 * being done and allowing %U and %G substitutions to work correctly.
	 * There is a reason this code is done here, don't move it unless you
	 * know what you're doing... :-).
	 * JRA.
	 */

	/*
	 * lookup an existing session
	 *
	 * Note: for now we only check for NT_STATUS_NETWORK_SESSION_EXPIRED
	 * here, the main check is still in change_to_user()
	 */
	status = smb1srv_session_lookup(xconn,
					session_tag,
					now,
					&session);
	if (NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_SESSION_EXPIRED)) {
		switch (type) {
		case SMBsesssetupX:
			status = NT_STATUS_OK;
			break;
		default:
			DEBUG(1,("Error: session %llu is expired, mid=%llu.\n",
				 (unsigned long long)session_tag,
				 (unsigned long long)req->mid));
			reply_nterror(req, NT_STATUS_NETWORK_SESSION_EXPIRED);
			return conn;
		}
	}

	if (session != NULL &&
	    session->global->auth_session_info != NULL &&
	    !(flags & AS_USER))
	{
		/*
		 * change_to_user() implies set_current_user_info()
		 * and chdir_connect_service().
		 *
		 * So we only call set_current_user_info if
		 * we don't have AS_USER specified.
		 */
		set_current_user_info(
			session->global->auth_session_info->unix_info->sanitized_username,
			session->global->auth_session_info->unix_info->unix_name,
			session->global->auth_session_info->info->domain_name);
	}

	/* Does this call need to be run as the connected user? */
	if (flags & AS_USER) {

		/* Does this call need a valid tree connection? */
		if (!conn) {
			/*
			 * Amazingly, the error code depends on the command
			 * (from Samba4).
			 */
			if (type == SMBntcreateX) {
				reply_nterror(req, NT_STATUS_INVALID_HANDLE);
			} else {
				reply_nterror(req, NT_STATUS_NETWORK_NAME_DELETED);
			}
			return NULL;
		}

		set_current_case_sensitive(conn, SVAL(req->inbuf,smb_flg));

		/*
		 * change_to_user() implies set_current_user_info()
		 * and chdir_connect_service().
		 */
		if (!change_to_user_and_service(conn,session_tag)) {
			DEBUG(0, ("Error: Could not change to user. Removing "
				"deferred open, mid=%llu.\n",
				(unsigned long long)req->mid));
			reply_force_doserror(req, ERRSRV, ERRbaduid);
			return conn;
		}

		/* All NEED_WRITE and CAN_IPC flags must also have AS_USER. */

		/* Does it need write permission? */
		if ((flags & NEED_WRITE) && !CAN_WRITE(conn)) {
			reply_nterror(req, NT_STATUS_MEDIA_WRITE_PROTECTED);
			return conn;
		}

		/* IPC services are limited */
		if (IS_IPC(conn) && !(flags & CAN_IPC)) {
			reply_nterror(req, NT_STATUS_ACCESS_DENIED);
			return conn;
		}
	} else if (flags & AS_GUEST) {
		/*
		 * Does this protocol need to be run as guest? (Only archane
		 * messenger service requests have this...)
		 */
		if (!change_to_guest()) {
			reply_nterror(req, NT_STATUS_ACCESS_DENIED);
			return conn;
		}
	} else {
		/* This call needs to be run as root */
		change_to_root_user();
	}

	/* load service specific parameters */
	if (conn) {
		if (req->encrypted) {
			conn->encrypted_tid = true;
			/* encrypted required from now on. */
			conn->encrypt_level = SMB_SIGNING_REQUIRED;
		} else if (ENCRYPTION_REQUIRED(conn)) {
			if (req->cmd != SMBtrans2 && req->cmd != SMBtranss2) {
				DEBUG(1,("service[%s] requires encryption"
					"%s ACCESS_DENIED. mid=%llu\n",
					lp_servicename(talloc_tos(), lp_sub, SNUM(conn)),
					smb_fn_name(type),
					(unsigned long long)req->mid));
				reply_nterror(req, NT_STATUS_ACCESS_DENIED);
				return conn;
			}
		}

		if (flags & DO_CHDIR) {
			bool ok;

			ok = chdir_current_service(conn);
			if (!ok) {
				reply_nterror(req, NT_STATUS_ACCESS_DENIED);
				return conn;
			}
		}
		conn->num_smb_operations++;
	}

	/*
	 * Update encryption and signing state tracking flags that are
	 * used by smbstatus to display signing and encryption status.
	 */
	if (session != NULL) {
		bool update_session_global = false;
		bool update_tcon_global = false;

		req->session = session;

		smb1srv_update_crypto_flags(session, req, type,
					    &update_session_global,
					    &update_tcon_global);

		if (update_session_global) {
			status = smbXsrv_session_update(session);
			if (!NT_STATUS_IS_OK(status)) {
				reply_nterror(req, NT_STATUS_UNSUCCESSFUL);
				return conn;
			}
		}

		if (update_tcon_global) {
			status = smbXsrv_tcon_update(req->conn->tcon);
			if (!NT_STATUS_IS_OK(status)) {
				reply_nterror(req, NT_STATUS_UNSUCCESSFUL);
				return conn;
			}
		}
	}

	smb_messages[type].fn(req);
	return req->conn;
}

/****************************************************************************
 Construct a reply to the incoming packet.
****************************************************************************/

void construct_reply(struct smbXsrv_connection *xconn,
		     char *inbuf, int size, size_t unread_bytes,
		     uint32_t seqnum, bool encrypted,
		     struct smb_perfcount_data *deferred_pcd)
{
	struct smbd_server_connection *sconn = xconn->client->sconn;
	struct smb_request *req;

	if (!(req = talloc(talloc_tos(), struct smb_request))) {
		smb_panic("could not allocate smb_request");
	}

	if (!init_smb_request(req, sconn, xconn, (uint8_t *)inbuf, unread_bytes,
			      encrypted, seqnum)) {
		exit_server_cleanly("Invalid SMB request");
	}

	req->inbuf  = (uint8_t *)talloc_move(req, &inbuf);

	/* we popped this message off the queue - keep original perf data */
	if (deferred_pcd)
		req->pcd = *deferred_pcd;
	else {
		SMB_PERFCOUNT_START(&req->pcd);
		SMB_PERFCOUNT_SET_OP(&req->pcd, req->cmd);
		SMB_PERFCOUNT_SET_MSGLEN_IN(&req->pcd, size);
	}

	req->conn = switch_message(req->cmd, req);

	if (req->outbuf == NULL) {
		/*
		 * Request has suspended itself, will come
		 * back here.
		 */
		return;
	}
	if (CVAL(req->outbuf,0) == 0) {
		show_msg((char *)req->outbuf);
	}
	smb_request_done(req);
}

static void construct_reply_chain(struct smbXsrv_connection *xconn,
				  char *inbuf, int size, uint32_t seqnum,
				  bool encrypted,
				  struct smb_perfcount_data *deferred_pcd)
{
	struct smb_request **reqs = NULL;
	struct smb_request *req;
	unsigned num_reqs;
	bool ok;

	ok = smb1_parse_chain(xconn, (uint8_t *)inbuf, xconn, encrypted,
			      seqnum, &reqs, &num_reqs);
	if (!ok) {
		char errbuf[smb_size];
		error_packet(errbuf, 0, 0, NT_STATUS_INVALID_PARAMETER,
			     __LINE__, __FILE__);
		if (!smb1_srv_send(xconn, errbuf, true, seqnum, encrypted,
				  NULL)) {
			exit_server_cleanly("construct_reply_chain: "
					    "smb1_srv_send failed.");
		}
		return;
	}

	req = reqs[0];
	req->inbuf = (uint8_t *)talloc_move(reqs, &inbuf);

	req->conn = switch_message(req->cmd, req);

	if (req->outbuf == NULL) {
		/*
		 * Request has suspended itself, will come
		 * back here.
		 */
		return;
	}
	smb_request_done(req);
}

/*
 * To be called from an async SMB handler that is potentially chained
 * when it is finished for shipping.
 */

void smb_request_done(struct smb_request *req)
{
	struct smb_request **reqs = NULL;
	struct smb_request *first_req;
	size_t i, num_reqs, next_index;
	NTSTATUS status;

	if (req->chain == NULL) {
		first_req = req;
		goto shipit;
	}

	reqs = req->chain;
	num_reqs = talloc_array_length(reqs);

	for (i=0; i<num_reqs; i++) {
		if (reqs[i] == req) {
			break;
		}
	}
	if (i == num_reqs) {
		/*
		 * Invalid chain, should not happen
		 */
		status = NT_STATUS_INTERNAL_ERROR;
		goto error;
	}
	next_index = i+1;

	while ((next_index < num_reqs) && (IVAL(req->outbuf, smb_rcls) == 0)) {
		struct smb_request *next = reqs[next_index];
		struct smbXsrv_tcon *tcon;
		NTTIME now = timeval_to_nttime(&req->request_time);

		next->vuid = SVAL(req->outbuf, smb_uid);
		next->tid  = SVAL(req->outbuf, smb_tid);
		status = smb1srv_tcon_lookup(req->xconn, next->tid,
					     now, &tcon);

		if (NT_STATUS_IS_OK(status)) {
			next->conn = tcon->compat;
		} else {
			next->conn = NULL;
		}
		next->chain_fsp = req->chain_fsp;
		next->inbuf = req->inbuf;

		req = next;
		req->conn = switch_message(req->cmd, req);

		if (req->outbuf == NULL) {
			/*
			 * Request has suspended itself, will come
			 * back here.
			 */
			return;
		}
		next_index += 1;
	}

	first_req = reqs[0];

	for (i=1; i<next_index; i++) {
		bool ok;

		ok = smb_splice_chain(&first_req->outbuf, reqs[i]->outbuf);
		if (!ok) {
			status = NT_STATUS_INTERNAL_ERROR;
			goto error;
		}
	}

	SSVAL(first_req->outbuf, smb_uid, SVAL(req->outbuf, smb_uid));
	SSVAL(first_req->outbuf, smb_tid, SVAL(req->outbuf, smb_tid));

	/*
	 * This scary statement intends to set the
	 * FLAGS2_32_BIT_ERROR_CODES flg2 field in first_req->outbuf
	 * to the value last_req->outbuf carries
	 */
	SSVAL(first_req->outbuf, smb_flg2,
	      (SVAL(first_req->outbuf, smb_flg2) & ~FLAGS2_32_BIT_ERROR_CODES)
	      |(SVAL(req->outbuf, smb_flg2) & FLAGS2_32_BIT_ERROR_CODES));

	/*
	 * Transfer the error codes from the subrequest to the main one
	 */
	SSVAL(first_req->outbuf, smb_rcls, SVAL(req->outbuf, smb_rcls));
	SSVAL(first_req->outbuf, smb_err,  SVAL(req->outbuf, smb_err));

	_smb_setlen_large(
		first_req->outbuf, talloc_get_size(first_req->outbuf) - 4);

shipit:
	if (!smb1_srv_send(first_req->xconn,
			  (char *)first_req->outbuf,
			  true, first_req->seqnum+1,
			  IS_CONN_ENCRYPTED(req->conn)||first_req->encrypted,
			  &first_req->pcd)) {
		exit_server_cleanly("construct_reply_chain: smb1_srv_send "
				    "failed.");
	}
	TALLOC_FREE(req);	/* non-chained case */
	TALLOC_FREE(reqs);	/* chained case */
	return;

error:
	{
		char errbuf[smb_size];
		error_packet(errbuf, 0, 0, status, __LINE__, __FILE__);
		if (!smb1_srv_send(req->xconn, errbuf, true,
				  req->seqnum+1, req->encrypted,
				  NULL)) {
			exit_server_cleanly("construct_reply_chain: "
					    "smb1_srv_send failed.");
		}
	}
	TALLOC_FREE(req);	/* non-chained case */
	TALLOC_FREE(reqs);	/* chained case */
}

/****************************************************************************
 Process an smb from the client
****************************************************************************/

void process_smb1(struct smbXsrv_connection *xconn,
		  uint8_t *inbuf, size_t nread, size_t unread_bytes,
		  uint32_t seqnum, bool encrypted,
		  struct smb_perfcount_data *deferred_pcd)
{
	struct smbd_server_connection *sconn = xconn->client->sconn;

	/* Make sure this is an SMB packet. smb_size contains NetBIOS header
	 * so subtract 4 from it. */
	if ((nread < (smb_size - 4)) || !valid_smb1_header(inbuf)) {
		DEBUG(2,("Non-SMB packet of length %d. Terminating server\n",
			 smb_len(inbuf)));

		/* special magic for immediate exit */
		if ((nread == 9) &&
		    (IVAL(inbuf, 4) == SMB_SUICIDE_PACKET) &&
		    lp_parm_bool(-1, "smbd", "suicide mode", false)) {
			uint8_t exitcode = CVAL(inbuf, 8);
			DBG_WARNING("SUICIDE: Exiting immediately with code %d\n",
				    (int)exitcode);
			exit(exitcode);
		}

		exit_server_cleanly("Non-SMB packet");
	}

	show_msg((char *)inbuf);

	if ((unread_bytes == 0) && smb1_is_chain(inbuf)) {
		construct_reply_chain(xconn, (char *)inbuf, nread,
				      seqnum, encrypted, deferred_pcd);
	} else {
		construct_reply(xconn, (char *)inbuf, nread, unread_bytes,
				seqnum,	encrypted, deferred_pcd);
	}

	sconn->trans_num++;
}

/****************************************************************************
 Return a string containing the function name of a SMB command.
****************************************************************************/

const char *smb_fn_name(int type)
{
	const char *unknown_name = "SMBunknown";

	if (smb_messages[type].name == NULL)
		return(unknown_name);

	return(smb_messages[type].name);
}

/****************************************************************************
 Helper functions for contruct_reply.
****************************************************************************/

void add_to_common_flags2(uint32_t v)
{
	common_flags2 |= v;
}

void remove_from_common_flags2(uint32_t v)
{
	common_flags2 &= ~v;
}

/**
 * @brief Find the smb_cmd offset of the last command pushed
 * @param[in] buf	The buffer we're building up
 * @retval		Where can we put our next andx cmd?
 *
 * While chaining requests, the "next" request we're looking at needs to put
 * its SMB_Command before the data the previous request already built up added
 * to the chain. Find the offset to the place where we have to put our cmd.
 */

static bool find_andx_cmd_ofs(uint8_t *buf, size_t *pofs)
{
	uint8_t cmd;
	size_t ofs;

	cmd = CVAL(buf, smb_com);

	if (!smb1cli_is_andx_req(cmd)) {
		return false;
	}

	ofs = smb_vwv0;

	while (CVAL(buf, ofs) != 0xff) {

		if (!smb1cli_is_andx_req(CVAL(buf, ofs))) {
			return false;
		}

		/*
		 * ofs is from start of smb header, so add the 4 length
		 * bytes. The next cmd is right after the wct field.
		 */
		ofs = SVAL(buf, ofs+2) + 4 + 1;

		if (ofs+4 >= talloc_get_size(buf)) {
			return false;
		}
	}

	*pofs = ofs;
	return true;
}

/**
 * @brief Do the smb chaining at a buffer level
 * @param[in] poutbuf		Pointer to the talloc'ed buffer to be modified
 * @param[in] andx_buf		Buffer to be appended
 */

static bool smb_splice_chain(uint8_t **poutbuf, const uint8_t *andx_buf)
{
	uint8_t smb_command	= CVAL(andx_buf, smb_com);
	uint8_t wct		= CVAL(andx_buf, smb_wct);
	const uint16_t *vwv	= (const uint16_t *)(andx_buf + smb_vwv);
	uint32_t num_bytes	= smb_buflen(andx_buf);
	const uint8_t *bytes	= (const uint8_t *)smb_buf_const(andx_buf);

	uint8_t *outbuf;
	size_t old_size, new_size;
	size_t ofs;
	size_t chain_padding = 0;
	size_t andx_cmd_ofs;


	old_size = talloc_get_size(*poutbuf);

	if ((old_size % 4) != 0) {
		/*
		 * Align the wct field of subsequent requests to a 4-byte
		 * boundary
		 */
		chain_padding = 4 - (old_size % 4);
	}

	/*
	 * After the old request comes the new wct field (1 byte), the vwv's
	 * and the num_bytes field.
	 */

	new_size = old_size + chain_padding + 1 + wct * sizeof(uint16_t) + 2;
	new_size += num_bytes;

	if ((smb_command != SMBwriteX) && (new_size > 0xffff)) {
		DEBUG(1, ("smb_splice_chain: %u bytes won't fit\n",
			  (unsigned)new_size));
		return false;
	}

	outbuf = talloc_realloc(NULL, *poutbuf, uint8_t, new_size);
	if (outbuf == NULL) {
		DEBUG(0, ("talloc failed\n"));
		return false;
	}
	*poutbuf = outbuf;

	if (!find_andx_cmd_ofs(outbuf, &andx_cmd_ofs)) {
		DEBUG(1, ("invalid command chain\n"));
		*poutbuf = talloc_realloc(NULL, *poutbuf, uint8_t, old_size);
		return false;
	}

	if (chain_padding != 0) {
		memset(outbuf + old_size, 0, chain_padding);
		old_size += chain_padding;
	}

	SCVAL(outbuf, andx_cmd_ofs, smb_command);
	SSVAL(outbuf, andx_cmd_ofs + 2, old_size - 4);

	ofs = old_size;

	/*
	 * Push the chained request:
	 *
	 * wct field
	 */

	SCVAL(outbuf, ofs, wct);
	ofs += 1;

	/*
	 * vwv array
	 */

	memcpy(outbuf + ofs, vwv, sizeof(uint16_t) * wct);

	/*
	 * HACK ALERT
	 *
	 * Read&X has an offset into its data buffer at
	 * vwv[6]. reply_read_andx has no idea anymore that it's
	 * running from within a chain, so we have to fix up the
	 * offset here.
	 *
	 * Although it looks disgusting at this place, I want to keep
	 * it here. The alternative would be to push knowledge about
	 * the andx chain down into read&x again.
	 */

	if (smb_command == SMBreadX) {
		uint8_t *bytes_addr;

		if (wct < 7) {
			/*
			 * Invalid read&x response
			 */
			return false;
		}

		bytes_addr = outbuf + ofs	 /* vwv start */
			+ sizeof(uint16_t) * wct /* vwv array */
			+ sizeof(uint16_t)	 /* bcc */
			+ 1;			 /* padding byte */

		SSVAL(outbuf + ofs, 6 * sizeof(uint16_t),
		      bytes_addr - outbuf - 4);
	}

	ofs += sizeof(uint16_t) * wct;

	/*
	 * bcc (byte count)
	 */

	SSVAL(outbuf, ofs, num_bytes);
	ofs += sizeof(uint16_t);

	/*
	 * The bytes field
	 */

	memcpy(outbuf + ofs, bytes, num_bytes);

	return true;
}

bool smb1_is_chain(const uint8_t *buf)
{
	uint8_t cmd, wct, andx_cmd;

	cmd = CVAL(buf, smb_com);
	if (!smb1cli_is_andx_req(cmd)) {
		return false;
	}
	wct = CVAL(buf, smb_wct);
	if (wct < 2) {
		return false;
	}
	andx_cmd = CVAL(buf, smb_vwv);
	return (andx_cmd != 0xFF);
}

bool smb1_walk_chain(const uint8_t *buf,
		     bool (*fn)(uint8_t cmd,
				uint8_t wct, const uint16_t *vwv,
				uint16_t num_bytes, const uint8_t *bytes,
				void *private_data),
		     void *private_data)
{
	size_t smblen = smb_len(buf);
	const char *smb_buf = smb_base(buf);
	uint8_t cmd, chain_cmd;
	uint8_t wct;
	const uint16_t *vwv;
	uint16_t num_bytes;
	const uint8_t *bytes;

	cmd = CVAL(buf, smb_com);
	wct = CVAL(buf, smb_wct);
	vwv = (const uint16_t *)(buf + smb_vwv);
	num_bytes = smb_buflen(buf);
	bytes = (const uint8_t *)smb_buf_const(buf);

	if (!fn(cmd, wct, vwv, num_bytes, bytes, private_data)) {
		return false;
	}

	if (!smb1cli_is_andx_req(cmd)) {
		return true;
	}
	if (wct < 2) {
		return false;
	}

	chain_cmd = CVAL(vwv, 0);

	while (chain_cmd != 0xff) {
		uint32_t chain_offset;	/* uint32_t to avoid overflow */
		size_t length_needed;
		ptrdiff_t vwv_offset;

		chain_offset = SVAL(vwv+1, 0);

		/*
		 * Check if the client tries to fool us. The chain
		 * offset needs to point beyond the current request in
		 * the chain, it needs to strictly grow. Otherwise we
		 * might be tricked into an endless loop always
		 * processing the same request over and over again. We
		 * used to assume that vwv and the byte buffer array
		 * in a chain are always attached, but OS/2 the
		 * Write&X/Read&X chain puts the Read&X vwv array
		 * right behind the Write&X vwv chain. The Write&X bcc
		 * array is put behind the Read&X vwv array. So now we
		 * check whether the chain offset points strictly
		 * behind the previous vwv array. req->buf points
		 * right after the vwv array of the previous
		 * request. See
		 * https://bugzilla.samba.org/show_bug.cgi?id=8360 for
		 * more information.
		 */

		vwv_offset = ((const char *)vwv - smb_buf);
		if (chain_offset <= vwv_offset) {
			return false;
		}

		/*
		 * Next check: Make sure the chain offset does not
		 * point beyond the overall smb request length.
		 */

		length_needed = chain_offset+1;	/* wct */
		if (length_needed > smblen) {
			return false;
		}

		/*
		 * Now comes the pointer magic. Goal here is to set up
		 * vwv and buf correctly again. The chain offset (the
		 * former vwv[1]) points at the new wct field.
		 */

		wct = CVAL(smb_buf, chain_offset);

		if (smb1cli_is_andx_req(chain_cmd) && (wct < 2)) {
			return false;
		}

		/*
		 * Next consistency check: Make the new vwv array fits
		 * in the overall smb request.
		 */

		length_needed += (wct+1)*sizeof(uint16_t); /* vwv+buflen */
		if (length_needed > smblen) {
			return false;
		}
		vwv = (const uint16_t *)(smb_buf + chain_offset + 1);

		/*
		 * Now grab the new byte buffer....
		 */

		num_bytes = SVAL(vwv+wct, 0);

		/*
		 * .. and check that it fits.
		 */

		length_needed += num_bytes;
		if (length_needed > smblen) {
			return false;
		}
		bytes = (const uint8_t *)(vwv+wct+1);

		if (!fn(chain_cmd, wct, vwv, num_bytes, bytes, private_data)) {
			return false;
		}

		if (!smb1cli_is_andx_req(chain_cmd)) {
			return true;
		}
		chain_cmd = CVAL(vwv, 0);
	}
	return true;
}

static bool smb1_chain_length_cb(uint8_t cmd,
				 uint8_t wct, const uint16_t *vwv,
				 uint16_t num_bytes, const uint8_t *bytes,
				 void *private_data)
{
	unsigned *count = (unsigned *)private_data;
	*count += 1;
	return true;
}

unsigned smb1_chain_length(const uint8_t *buf)
{
	unsigned count = 0;

	if (!smb1_walk_chain(buf, smb1_chain_length_cb, &count)) {
		return 0;
	}
	return count;
}

struct smb1_parse_chain_state {
	TALLOC_CTX *mem_ctx;
	const uint8_t *buf;
	struct smbd_server_connection *sconn;
	struct smbXsrv_connection *xconn;
	bool encrypted;
	uint32_t seqnum;

	struct smb_request **reqs;
	unsigned num_reqs;
};

static bool smb1_parse_chain_cb(uint8_t cmd,
				uint8_t wct, const uint16_t *vwv,
				uint16_t num_bytes, const uint8_t *bytes,
				void *private_data)
{
	struct smb1_parse_chain_state *state =
		(struct smb1_parse_chain_state *)private_data;
	struct smb_request **reqs;
	struct smb_request *req;
	bool ok;

	reqs = talloc_realloc(state->mem_ctx, state->reqs,
			      struct smb_request *, state->num_reqs+1);
	if (reqs == NULL) {
		return false;
	}
	state->reqs = reqs;

	req = talloc(reqs, struct smb_request);
	if (req == NULL) {
		return false;
	}

	ok = init_smb_request(req, state->sconn, state->xconn, state->buf, 0,
			      state->encrypted, state->seqnum);
	if (!ok) {
		return false;
	}
	req->cmd = cmd;
	req->wct = wct;
	req->vwv = vwv;
	req->buflen = num_bytes;
	req->buf = bytes;

	reqs[state->num_reqs] = req;
	state->num_reqs += 1;
	return true;
}

bool smb1_parse_chain(TALLOC_CTX *mem_ctx, const uint8_t *buf,
		      struct smbXsrv_connection *xconn,
		      bool encrypted, uint32_t seqnum,
		      struct smb_request ***reqs, unsigned *num_reqs)
{
	struct smbd_server_connection *sconn = NULL;
	struct smb1_parse_chain_state state;
	unsigned i;

	if (xconn != NULL) {
		sconn = xconn->client->sconn;
	}

	state.mem_ctx = mem_ctx;
	state.buf = buf;
	state.sconn = sconn;
	state.xconn = xconn;
	state.encrypted = encrypted;
	state.seqnum = seqnum;
	state.reqs = NULL;
	state.num_reqs = 0;

	if (!smb1_walk_chain(buf, smb1_parse_chain_cb, &state)) {
		TALLOC_FREE(state.reqs);
		return false;
	}
	for (i=0; i<state.num_reqs; i++) {
		state.reqs[i]->chain = state.reqs;
	}
	*reqs = state.reqs;
	*num_reqs = state.num_reqs;
	return true;
}

static bool fd_is_readable(int fd)
{
	int ret, revents;

	ret = poll_one_fd(fd, POLLIN|POLLHUP, 0, &revents);

	return ((ret > 0) && ((revents & (POLLIN|POLLHUP|POLLERR)) != 0));

}

static void smbd_server_connection_write_handler(
	struct smbXsrv_connection *xconn)
{
	/* TODO: make write nonblocking */
}

void smbd_smb1_server_connection_read_handler(struct smbXsrv_connection *xconn,
					      int fd)
{
	uint8_t *inbuf = NULL;
	size_t inbuf_len = 0;
	size_t unread_bytes = 0;
	bool encrypted = false;
	TALLOC_CTX *mem_ctx = talloc_tos();
	NTSTATUS status;
	uint32_t seqnum;

	bool async_echo = lp_async_smb_echo_handler();
	bool from_client = false;

	if (async_echo) {
		if (fd_is_readable(xconn->smb1.echo_handler.trusted_fd)) {
			/*
			 * This is the super-ugly hack to prefer the packets
			 * forwarded by the echo handler over the ones by the
			 * client directly
			 */
			fd = xconn->smb1.echo_handler.trusted_fd;
		}
	}

	from_client = (xconn->transport.sock == fd);

	if (async_echo && from_client) {
		smbd_lock_socket(xconn);

		if (!fd_is_readable(fd)) {
			DEBUG(10,("the echo listener was faster\n"));
			smbd_unlock_socket(xconn);
			return;
		}
	}

	/* TODO: make this completely nonblocking */
	status = receive_smb_talloc(mem_ctx, xconn, fd,
				    (char **)(void *)&inbuf,
				    0, /* timeout */
				    &unread_bytes,
				    &encrypted,
				    &inbuf_len, &seqnum,
				    !from_client /* trusted channel */);

	if (async_echo && from_client) {
		smbd_unlock_socket(xconn);
	}

	if (NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
		goto process;
	}
	if (NT_STATUS_IS_ERR(status)) {
		exit_server_cleanly("failed to receive smb request");
	}
	if (!NT_STATUS_IS_OK(status)) {
		return;
	}

process:
	process_smb(xconn, inbuf, inbuf_len, unread_bytes,
		    seqnum, encrypted, NULL);
}

static void smbd_server_echo_handler(struct tevent_context *ev,
				     struct tevent_fd *fde,
				     uint16_t flags,
				     void *private_data)
{
	struct smbXsrv_connection *xconn =
		talloc_get_type_abort(private_data,
		struct smbXsrv_connection);

	if (!NT_STATUS_IS_OK(xconn->transport.status)) {
		/*
		 * we're not supposed to do any io
		 */
		TEVENT_FD_NOT_READABLE(xconn->smb1.echo_handler.trusted_fde);
		TEVENT_FD_NOT_WRITEABLE(xconn->smb1.echo_handler.trusted_fde);
		return;
	}

	if (flags & TEVENT_FD_WRITE) {
		smbd_server_connection_write_handler(xconn);
		return;
	}
	if (flags & TEVENT_FD_READ) {
		smbd_smb1_server_connection_read_handler(
			xconn, xconn->smb1.echo_handler.trusted_fd);
		return;
	}
}

/*
 * Send keepalive packets to our client
 */
bool keepalive_fn(const struct timeval *now, void *private_data)
{
	struct smbd_server_connection *sconn = talloc_get_type_abort(
		private_data, struct smbd_server_connection);
	struct smbXsrv_connection *xconn = NULL;
	bool ret;

	if (sconn->using_smb2) {
		/* Don't do keepalives on an SMB2 connection. */
		return false;
	}

	/*
	 * With SMB1 we only have 1 connection
	 */
	xconn = sconn->client->connections;
	smbd_lock_socket(xconn);
	ret = send_keepalive(xconn->transport.sock);
	smbd_unlock_socket(xconn);

	if (!ret) {
		int saved_errno = errno;
		/*
		 * Try and give an error message saying what
		 * client failed.
		 */
		DEBUG(0, ("send_keepalive failed for client %s. "
			  "Error %s - exiting\n",
			  smbXsrv_connection_dbg(xconn),
			  strerror(saved_errno)));
		errno = saved_errno;
		return False;
	}
	return True;
}

/*
 * Read an smb packet in the echo handler child, giving the parent
 * smbd one second to react once the socket becomes readable.
 */

struct smbd_echo_read_state {
	struct tevent_context *ev;
	struct smbXsrv_connection *xconn;

	char *buf;
	size_t buflen;
	uint32_t seqnum;
};

static void smbd_echo_read_readable(struct tevent_req *subreq);
static void smbd_echo_read_waited(struct tevent_req *subreq);

static struct tevent_req *smbd_echo_read_send(
	TALLOC_CTX *mem_ctx, struct tevent_context *ev,
	struct smbXsrv_connection *xconn)
{
	struct tevent_req *req, *subreq;
	struct smbd_echo_read_state *state;

	req = tevent_req_create(mem_ctx, &state,
				struct smbd_echo_read_state);
	if (req == NULL) {
		return NULL;
	}
	state->ev = ev;
	state->xconn = xconn;

	subreq = wait_for_read_send(state, ev, xconn->transport.sock, false);
	if (tevent_req_nomem(subreq, req)) {
		return tevent_req_post(req, ev);
	}
	tevent_req_set_callback(subreq, smbd_echo_read_readable, req);
	return req;
}

static void smbd_echo_read_readable(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(
		subreq, struct tevent_req);
	struct smbd_echo_read_state *state = tevent_req_data(
		req, struct smbd_echo_read_state);
	bool ok;
	int err;

	ok = wait_for_read_recv(subreq, &err);
	TALLOC_FREE(subreq);
	if (!ok) {
		tevent_req_nterror(req, map_nt_error_from_unix(err));
		return;
	}

	/*
	 * Give the parent smbd one second to step in
	 */

	subreq = tevent_wakeup_send(
		state, state->ev, timeval_current_ofs(1, 0));
	if (tevent_req_nomem(subreq, req)) {
		return;
	}
	tevent_req_set_callback(subreq, smbd_echo_read_waited, req);
}

static void smbd_echo_read_waited(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(
		subreq, struct tevent_req);
	struct smbd_echo_read_state *state = tevent_req_data(
		req, struct smbd_echo_read_state);
	struct smbXsrv_connection *xconn = state->xconn;
	bool ok;
	NTSTATUS status;
	size_t unread = 0;
	bool encrypted;

	ok = tevent_wakeup_recv(subreq);
	TALLOC_FREE(subreq);
	if (!ok) {
		tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
		return;
	}

	ok = smbd_lock_socket_internal(xconn);
	if (!ok) {
		tevent_req_nterror(req, map_nt_error_from_unix(errno));
		DEBUG(0, ("%s: failed to lock socket\n", __location__));
		return;
	}

	if (!fd_is_readable(xconn->transport.sock)) {
		DEBUG(10,("echo_handler[%d] the parent smbd was faster\n",
			  (int)getpid()));

		ok = smbd_unlock_socket_internal(xconn);
		if (!ok) {
			tevent_req_nterror(req, map_nt_error_from_unix(errno));
			DEBUG(1, ("%s: failed to unlock socket\n",
				__location__));
			return;
		}

		subreq = wait_for_read_send(state, state->ev,
					    xconn->transport.sock, false);
		if (tevent_req_nomem(subreq, req)) {
			return;
		}
		tevent_req_set_callback(subreq, smbd_echo_read_readable, req);
		return;
	}

	status = receive_smb_talloc(state, xconn,
				    xconn->transport.sock,
				    &state->buf,
				    0 /* timeout */,
				    &unread,
				    &encrypted,
				    &state->buflen,
				    &state->seqnum,
				    false /* trusted_channel*/);

	if (tevent_req_nterror(req, status)) {
		tevent_req_nterror(req, status);
		DEBUG(1, ("echo_handler[%d]: receive_smb_raw_talloc failed: %s\n",
			  (int)getpid(), nt_errstr(status)));
		return;
	}

	ok = smbd_unlock_socket_internal(xconn);
	if (!ok) {
		tevent_req_nterror(req, map_nt_error_from_unix(errno));
		DEBUG(1, ("%s: failed to unlock socket\n", __location__));
		return;
	}
	tevent_req_done(req);
}

static NTSTATUS smbd_echo_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
				    char **pbuf, size_t *pbuflen, uint32_t *pseqnum)
{
	struct smbd_echo_read_state *state = tevent_req_data(
		req, struct smbd_echo_read_state);
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		return status;
	}
	*pbuf = talloc_move(mem_ctx, &state->buf);
	*pbuflen = state->buflen;
	*pseqnum = state->seqnum;
	return NT_STATUS_OK;
}

struct smbd_echo_state {
	struct tevent_context *ev;
	struct iovec *pending;
	struct smbd_server_connection *sconn;
	struct smbXsrv_connection *xconn;
	int parent_pipe;

	struct tevent_fd *parent_fde;

	struct tevent_req *write_req;
};

static void smbd_echo_writer_done(struct tevent_req *req);

static void smbd_echo_activate_writer(struct smbd_echo_state *state)
{
	int num_pending;

	if (state->write_req != NULL) {
		return;
	}

	num_pending = talloc_array_length(state->pending);
	if (num_pending == 0) {
		return;
	}

	state->write_req = writev_send(state, state->ev, NULL,
				       state->parent_pipe, false,
				       state->pending, num_pending);
	if (state->write_req == NULL) {
		DEBUG(1, ("writev_send failed\n"));
		exit(1);
	}

	talloc_steal(state->write_req, state->pending);
	state->pending = NULL;

	tevent_req_set_callback(state->write_req, smbd_echo_writer_done,
				state);
}

static void smbd_echo_writer_done(struct tevent_req *req)
{
	struct smbd_echo_state *state = tevent_req_callback_data(
		req, struct smbd_echo_state);
	ssize_t written;
	int err;

	written = writev_recv(req, &err);
	TALLOC_FREE(req);
	state->write_req = NULL;
	if (written == -1) {
		DEBUG(1, ("writev to parent failed: %s\n", strerror(err)));
		exit(1);
	}
	DEBUG(10,("echo_handler[%d]: forwarded pdu to main\n", (int)getpid()));
	smbd_echo_activate_writer(state);
}

static bool smbd_echo_reply(struct smbd_echo_state *state,
			    uint8_t *inbuf, size_t inbuf_len,
			    uint32_t seqnum)
{
	struct smb_request req;
	uint16_t num_replies;
	char *outbuf;
	bool ok;

	if ((inbuf_len == 4) && (CVAL(inbuf, 0) == NBSSkeepalive)) {
		DEBUG(10, ("Got netbios keepalive\n"));
		/*
		 * Just swallow it
		 */
		return true;
	}

	if (inbuf_len < smb_size) {
		DEBUG(10, ("Got short packet: %d bytes\n", (int)inbuf_len));
		return false;
	}
	if (!valid_smb1_header(inbuf)) {
		DEBUG(10, ("Got invalid SMB header\n"));
		return false;
	}

	if (!init_smb_request(&req, state->sconn, state->xconn, inbuf, 0, false,
			      seqnum)) {
		return false;
	}
	req.inbuf = inbuf;

	DEBUG(10, ("smbecho handler got cmd %d (%s)\n", (int)req.cmd,
		   smb_messages[req.cmd].name
		   ? smb_messages[req.cmd].name : "unknown"));

	if (req.cmd != SMBecho) {
		return false;
	}
	if (req.wct < 1) {
		return false;
	}

	num_replies = SVAL(req.vwv+0, 0);
	if (num_replies != 1) {
		/* Not a Windows "Hey, you're still there?" request */
		return false;
	}

	if (!create_outbuf(talloc_tos(), &req, req.inbuf, &outbuf,
			   1, req.buflen)) {
		DEBUG(10, ("create_outbuf failed\n"));
		return false;
	}
	req.outbuf = (uint8_t *)outbuf;

	SSVAL(req.outbuf, smb_vwv0, num_replies);

	if (req.buflen > 0) {
		memcpy(smb_buf(req.outbuf), req.buf, req.buflen);
	}

	ok = smb1_srv_send(req.xconn,
			  (char *)outbuf,
			  true, seqnum+1,
			  false, &req.pcd);
	TALLOC_FREE(outbuf);
	if (!ok) {
		exit(1);
	}

	return true;
}

static void smbd_echo_exit(struct tevent_context *ev,
			   struct tevent_fd *fde, uint16_t flags,
			   void *private_data)
{
	DEBUG(2, ("smbd_echo_exit: lost connection to parent\n"));
	exit(0);
}

static void smbd_echo_got_packet(struct tevent_req *req);

static void smbd_echo_loop(struct smbXsrv_connection *xconn,
			   int parent_pipe)
{
	struct smbd_echo_state *state;
	struct tevent_req *read_req;

	state = talloc_zero(xconn, struct smbd_echo_state);
	if (state == NULL) {
		DEBUG(1, ("talloc failed\n"));
		return;
	}
	state->xconn = xconn;
	state->parent_pipe = parent_pipe;
	state->ev = samba_tevent_context_init(state);
	if (state->ev == NULL) {
		DEBUG(1, ("samba_tevent_context_init failed\n"));
		TALLOC_FREE(state);
		return;
	}
	state->parent_fde = tevent_add_fd(state->ev, state, parent_pipe,
					TEVENT_FD_READ, smbd_echo_exit,
					state);
	if (state->parent_fde == NULL) {
		DEBUG(1, ("tevent_add_fd failed\n"));
		TALLOC_FREE(state);
		return;
	}

	read_req = smbd_echo_read_send(state, state->ev, xconn);
	if (read_req == NULL) {
		DEBUG(1, ("smbd_echo_read_send failed\n"));
		TALLOC_FREE(state);
		return;
	}
	tevent_req_set_callback(read_req, smbd_echo_got_packet, state);

	while (true) {
		if (tevent_loop_once(state->ev) == -1) {
			DEBUG(1, ("tevent_loop_once failed: %s\n",
				  strerror(errno)));
			break;
		}
	}
	TALLOC_FREE(state);
}

static void smbd_echo_got_packet(struct tevent_req *req)
{
	struct smbd_echo_state *state = tevent_req_callback_data(
		req, struct smbd_echo_state);
	NTSTATUS status;
	char *buf = NULL;
	size_t buflen = 0;
	uint32_t seqnum = 0;
	bool reply;

	status = smbd_echo_read_recv(req, state, &buf, &buflen, &seqnum);
	TALLOC_FREE(req);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("smbd_echo_read_recv returned %s\n",
			  nt_errstr(status)));
		exit(1);
	}

	reply = smbd_echo_reply(state, (uint8_t *)buf, buflen, seqnum);
	if (!reply) {
		size_t num_pending;
		struct iovec *tmp;
		struct iovec *iov;

		num_pending = talloc_array_length(state->pending);
		tmp = talloc_realloc(state, state->pending, struct iovec,
				     num_pending+1);
		if (tmp == NULL) {
			DEBUG(1, ("talloc_realloc failed\n"));
			exit(1);
		}
		state->pending = tmp;

		if (buflen >= smb_size) {
			/*
			 * place the seqnum in the packet so that the main process
			 * can reply with signing
			 */
			SIVAL(buf, smb_ss_field, seqnum);
			SIVAL(buf, smb_ss_field+4, NT_STATUS_V(NT_STATUS_OK));
		}

		iov = &state->pending[num_pending];
		iov->iov_base = talloc_move(state->pending, &buf);
		iov->iov_len = buflen;

		DEBUG(10,("echo_handler[%d]: forward to main\n",
			  (int)getpid()));
		smbd_echo_activate_writer(state);
	}

	req = smbd_echo_read_send(state, state->ev, state->xconn);
	if (req == NULL) {
		DEBUG(1, ("smbd_echo_read_send failed\n"));
		exit(1);
	}
	tevent_req_set_callback(req, smbd_echo_got_packet, state);
}


/*
 * Handle SMBecho requests in a forked child process
 */
bool fork_echo_handler(struct smbXsrv_connection *xconn)
{
	int listener_pipe[2];
	int res;
	pid_t child;
	bool use_mutex = false;

	res = pipe(listener_pipe);
	if (res == -1) {
		DEBUG(1, ("pipe() failed: %s\n", strerror(errno)));
		return false;
	}

#ifdef HAVE_ROBUST_MUTEXES
	use_mutex = tdb_runtime_check_for_robust_mutexes();

	if (use_mutex) {
		pthread_mutexattr_t a;

		xconn->smb1.echo_handler.socket_mutex =
			anonymous_shared_allocate(sizeof(pthread_mutex_t));
		if (xconn->smb1.echo_handler.socket_mutex == NULL) {
			DEBUG(1, ("Could not create mutex shared memory: %s\n",
				  strerror(errno)));
			goto fail;
		}

		res = pthread_mutexattr_init(&a);
		if (res != 0) {
			DEBUG(1, ("pthread_mutexattr_init failed: %s\n",
				  strerror(res)));
			goto fail;
		}
		res = pthread_mutexattr_settype(&a, PTHREAD_MUTEX_ERRORCHECK);
		if (res != 0) {
			DEBUG(1, ("pthread_mutexattr_settype failed: %s\n",
				  strerror(res)));
			pthread_mutexattr_destroy(&a);
			goto fail;
		}
		res = pthread_mutexattr_setpshared(&a, PTHREAD_PROCESS_SHARED);
		if (res != 0) {
			DEBUG(1, ("pthread_mutexattr_setpshared failed: %s\n",
				  strerror(res)));
			pthread_mutexattr_destroy(&a);
			goto fail;
		}
		res = pthread_mutexattr_setrobust(&a, PTHREAD_MUTEX_ROBUST);
		if (res != 0) {
			DEBUG(1, ("pthread_mutexattr_setrobust failed: "
				  "%s\n", strerror(res)));
			pthread_mutexattr_destroy(&a);
			goto fail;
		}
		res = pthread_mutex_init(xconn->smb1.echo_handler.socket_mutex,
					 &a);
		pthread_mutexattr_destroy(&a);
		if (res != 0) {
			DEBUG(1, ("pthread_mutex_init failed: %s\n",
				  strerror(res)));
			goto fail;
		}
	}
#endif

	if (!use_mutex) {
		xconn->smb1.echo_handler.socket_lock_fd =
			create_unlink_tmp(lp_lock_directory());
		if (xconn->smb1.echo_handler.socket_lock_fd == -1) {
			DEBUG(1, ("Could not create lock fd: %s\n",
				  strerror(errno)));
			goto fail;
		}
	}

	child = fork();
	if (child == 0) {
		NTSTATUS status;

		close(listener_pipe[0]);
		set_blocking(listener_pipe[1], false);

		status = smbd_reinit_after_fork(xconn->client->msg_ctx,
						xconn->client->raw_ev_ctx,
						true,
						"smbd-echo");
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(1, ("reinit_after_fork failed: %s\n",
				  nt_errstr(status)));
			exit(1);
		}
		initialize_password_db(true, xconn->client->raw_ev_ctx);
		smbd_echo_loop(xconn, listener_pipe[1]);
		exit(0);
	}
	close(listener_pipe[1]);
	listener_pipe[1] = -1;
	xconn->smb1.echo_handler.trusted_fd = listener_pipe[0];

	DEBUG(10,("fork_echo_handler: main[%d] echo_child[%d]\n", (int)getpid(), (int)child));

	/*
	 * Without smb signing this is the same as the normal smbd
	 * listener. This needs to change once signing comes in.
	 */
	xconn->smb1.echo_handler.trusted_fde = tevent_add_fd(
					xconn->client->raw_ev_ctx,
					xconn,
					xconn->smb1.echo_handler.trusted_fd,
					TEVENT_FD_READ,
					smbd_server_echo_handler,
					xconn);
	if (xconn->smb1.echo_handler.trusted_fde == NULL) {
		DEBUG(1, ("event_add_fd failed\n"));
		goto fail;
	}

	return true;

fail:
	if (listener_pipe[0] != -1) {
		close(listener_pipe[0]);
	}
	if (listener_pipe[1] != -1) {
		close(listener_pipe[1]);
	}
	if (xconn->smb1.echo_handler.socket_lock_fd != -1) {
		close(xconn->smb1.echo_handler.socket_lock_fd);
	}
#ifdef HAVE_ROBUST_MUTEXES
	if (xconn->smb1.echo_handler.socket_mutex != NULL) {
		pthread_mutex_destroy(xconn->smb1.echo_handler.socket_mutex);
		anonymous_shared_free(xconn->smb1.echo_handler.socket_mutex);
	}
#endif
	smbd_echo_init(xconn);

	return false;
}

bool req_is_in_chain(const struct smb_request *req)
{
	if (req->vwv != (const uint16_t *)(req->inbuf+smb_vwv)) {
		/*
		 * We're right now handling a subsequent request, so we must
		 * be in a chain
		 */
		return true;
	}

	if (!smb1cli_is_andx_req(req->cmd)) {
		return false;
	}

	if (req->wct < 2) {
		/*
		 * Okay, an illegal request, but definitely not chained :-)
		 */
		return false;
	}

	return (CVAL(req->vwv+0, 0) != 0xFF);
}