/* 
   Unix SMB/CIFS implementation.
   default IPC$ NTVFS backend

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) Stefan (metze) Metzmacher 2004-2005
   Copyright (C) Jelmer Vernooij 2005

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
  this implements the IPC$ backend, called by the NTVFS subsystem to
  handle requests on IPC$ shares
*/


#include "includes.h"
#include "dlinklist.h"
#include "smb_server/smb_server.h"
#include "ntvfs/ipc/ipc.h"
#include "ntvfs/ntvfs.h"
#include "rpc_server/dcerpc_server.h"
#include "smb_build.h"

#define IPC_BASE_FNUM 0x400

/* this is the private structure used to keep the state of an open
   ipc$ connection. It needs to keep information about all open
   pipes */
struct ipc_private {
	struct idr_context *idtree_fnum;

	struct dcesrv_context *dcesrv;

	/* a list of open pipes */
	struct pipe_state {
		struct pipe_state *next, *prev;
		struct ipc_private *private;
		const char *pipe_name;
		const struct named_pipe_ops *ops;
		void *private_data;
		uint16_t fnum;
		uint16_t ipc_state;
		/* we need to remember the session it was opened on,
		   as it is illegal to operate on someone elses fnum */
		struct smbsrv_session *session;

		/* we need to remember the client pid that 
		   opened the file so SMBexit works */
		uint16_t smbpid;
	} *pipe_list;

};


/*
  find a open pipe give a file descriptor
*/
static struct pipe_state *pipe_state_find(struct ipc_private *private, uint16_t fnum)
{
	return idr_find(private->idtree_fnum, fnum);
}


/*
  connect to a share - always works 
*/
static NTSTATUS ipc_connect(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, const char *sharename)
{
	struct smbsrv_tcon *tcon = req->tcon;
	struct ipc_private *private;

	tcon->fs_type = talloc_strdup(tcon, "IPC");
	NT_STATUS_HAVE_NO_MEMORY(tcon->fs_type);

	tcon->dev_type = talloc_strdup(tcon, "IPC");
	NT_STATUS_HAVE_NO_MEMORY(tcon->dev_type);

	/* prepare the private state for this connection */
	private = talloc(ntvfs, struct ipc_private);
	NT_STATUS_HAVE_NO_MEMORY(private);

	ntvfs->private_data = private;

	private->pipe_list = NULL;

	private->idtree_fnum = idr_init(private);
	NT_STATUS_HAVE_NO_MEMORY(private->idtree_fnum);

	return NT_STATUS_OK;
}

/*
  disconnect from a share
*/
static NTSTATUS ipc_disconnect(struct ntvfs_module_context *ntvfs,
			       struct smbsrv_tcon *tcon)
{
	return NT_STATUS_OK;
}

/*
  delete a file
*/
static NTSTATUS ipc_unlink(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req, struct smb_unlink *unl)
{
	return NT_STATUS_ACCESS_DENIED;
}


/*
  ioctl interface - we don't do any
*/
static NTSTATUS ipc_ioctl(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_ioctl *io)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  check if a directory exists
*/
static NTSTATUS ipc_chkpath(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, struct smb_chkpath *cp)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  return info on a pathname
*/
static NTSTATUS ipc_qpathinfo(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req, union smb_fileinfo *info)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  set info on a pathname
*/
static NTSTATUS ipc_setpathinfo(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, union smb_setfileinfo *st)
{
	return NT_STATUS_ACCESS_DENIED;
}


/*
  destroy a open pipe structure
*/
static int ipc_fd_destructor(void *ptr)
{
	struct pipe_state *p = ptr;
	idr_remove(p->private->idtree_fnum, p->fnum);
	DLIST_REMOVE(p->private->pipe_list, p);
	return 0;
}

static struct named_pipe {
	struct named_pipe *prev, *next;
	const char *name;
	const struct named_pipe_ops *ops;
	void *context_data;
} *named_pipes = NULL;

static NTSTATUS find_pipe_ops(const char *fname, const struct named_pipe_ops **ops, void **context_data)
{
	struct named_pipe *np;

	for (np = named_pipes; np; np = np->next) {
		if (strcasecmp_m(np->name, fname) == 0) {
			if (ops) *ops = np->ops;
			if (context_data) *context_data = np->context_data;
			return NT_STATUS_OK;
		}
	}

	return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}

NTSTATUS named_pipe_listen(const char *name, const struct named_pipe_ops *ops, void *context_data)
{
	NTSTATUS status;
	struct named_pipe *np;
	DEBUG(3, ("Registering named pipe `%s'\n", name));

	status = find_pipe_ops(name, NULL, NULL);
	if (NT_STATUS_IS_OK(status)) {
		return NT_STATUS_OBJECT_NAME_COLLISION;
	}

	if (!NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
		return status;
	}

	np = talloc(talloc_autofree_context(), struct named_pipe);
	np->name = talloc_strdup(np, name);
	np->ops = ops;
	np->context_data = context_data;
	np->prev = np->next = NULL;

	DLIST_ADD(named_pipes, np);

	return NT_STATUS_OK;
}



/*
  open a file backend - used for MSRPC pipes
*/
static NTSTATUS ipc_open_generic(struct ntvfs_module_context *ntvfs,
				 struct smbsrv_request *req, const char *fname, 
				 struct pipe_state **ps)
{
	struct pipe_state *p;
	NTSTATUS status;
	struct ipc_private *private = ntvfs->private_data;
	void *context_data;
	int fnum;

	if (!req->session || !req->session->session_info) {
		return NT_STATUS_ACCESS_DENIED;
	}

	p = talloc(req, struct pipe_state);
	NT_STATUS_HAVE_NO_MEMORY(p);

	while (fname[0] == '\\') fname++;
	
	p->pipe_name = talloc_asprintf(p, "\\pipe\\%s", fname);
	NT_STATUS_HAVE_NO_MEMORY(p->pipe_name);

	status = find_pipe_ops(p->pipe_name, &p->ops, &context_data);

	/* FIXME: Perhaps fall back to opening /var/lib/samba/ipc/<pipename> ? */
	if (NT_STATUS_IS_ERR(status)) {
		DEBUG(0, ("Unable to find pipe ops for `%s'\n", p->pipe_name));
		return status;
	}

	status = p->ops->open(context_data, p->pipe_name, req->session->session_info, req->smb_conn->connection, p, &p->private_data);
	if (NT_STATUS_IS_ERR(status)) {
		return status;
	}

	fnum = idr_get_new_above(private->idtree_fnum, p, IPC_BASE_FNUM, UINT16_MAX);
	if (fnum == -1) {
		return NT_STATUS_TOO_MANY_OPENED_FILES;
	}

	p->fnum = fnum;
	p->ipc_state = 0x5ff;

	DLIST_ADD(private->pipe_list, p);

	p->smbpid = req->smbpid;
	p->session = req->session;
	p->private = private;

	*ps = p;

	talloc_steal(private, p);

	talloc_set_destructor(p, ipc_fd_destructor);

	return NT_STATUS_OK;
}

/*
  open a file with ntcreatex - used for MSRPC pipes
*/
static NTSTATUS ipc_open_ntcreatex(struct ntvfs_module_context *ntvfs,
				   struct smbsrv_request *req, union smb_open *oi)
{
	struct pipe_state *p;
	NTSTATUS status;

	status = ipc_open_generic(ntvfs, req, oi->ntcreatex.in.fname, &p);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	ZERO_STRUCT(oi->ntcreatex.out);
	oi->ntcreatex.out.fnum = p->fnum;
	oi->ntcreatex.out.ipc_state = p->ipc_state;
	oi->ntcreatex.out.file_type = FILE_TYPE_MESSAGE_MODE_PIPE;

	return status;
}

/*
  open a file with openx - used for MSRPC pipes
*/
static NTSTATUS ipc_open_openx(struct ntvfs_module_context *ntvfs,
			       struct smbsrv_request *req, union smb_open *oi)
{
	struct pipe_state *p;
	NTSTATUS status;
	const char *fname = oi->openx.in.fname;

	status = ipc_open_generic(ntvfs, req, fname, &p);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	ZERO_STRUCT(oi->openx.out);
	oi->openx.out.fnum = p->fnum;
	oi->openx.out.ftype = 2;
	oi->openx.out.devstate = p->ipc_state;
	
	return status;
}

/*
  open a file - used for MSRPC pipes
*/
static NTSTATUS ipc_open(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, union smb_open *oi)
{
	NTSTATUS status;

	switch (oi->generic.level) {
	case RAW_OPEN_NTCREATEX:
		status = ipc_open_ntcreatex(ntvfs, req, oi);
		break;
	case RAW_OPEN_OPENX:
		status = ipc_open_openx(ntvfs, req, oi);
		break;
	default:
		status = NT_STATUS_NOT_SUPPORTED;
		break;
	}

	return status;
}

/*
  create a directory
*/
static NTSTATUS ipc_mkdir(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_mkdir *md)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  remove a directory
*/
static NTSTATUS ipc_rmdir(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, struct smb_rmdir *rd)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  rename a set of files
*/
static NTSTATUS ipc_rename(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req, union smb_rename *ren)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  copy a set of files
*/
static NTSTATUS ipc_copy(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req, struct smb_copy *cp)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  read from a file
*/
static NTSTATUS ipc_read(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req, union smb_read *rd)
{
	struct ipc_private *private = ntvfs->private_data;
	DATA_BLOB data;
	uint16_t fnum;
	struct pipe_state *p;
	NTSTATUS status = NT_STATUS_OK;

	if (rd->generic.level != RAW_READ_GENERIC) {
		return ntvfs_map_read(req, rd, ntvfs);
	}

	fnum = rd->readx.in.fnum;

	p = pipe_state_find(private, fnum);
	if (!p) {
		return NT_STATUS_INVALID_HANDLE;
	}

	data.length = rd->readx.in.maxcnt;
	data.data = rd->readx.out.data;
	if (data.length > UINT16_MAX) {
		data.length = UINT16_MAX;
	}

	if (data.length != 0) {
		status = p->ops->read(p->private_data, &data);
		if (NT_STATUS_IS_ERR(status)) {
			return status;
		}
	}

	rd->readx.out.remaining = 0;
	rd->readx.out.compaction_mode = 0;
	rd->readx.out.nread = data.length;

	return status;
}

/*
  write to a file
*/
static NTSTATUS ipc_write(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_write *wr)
{
	struct ipc_private *private = ntvfs->private_data;
	DATA_BLOB data;
	uint16_t fnum;
	struct pipe_state *p;
	NTSTATUS status;

	if (wr->generic.level != RAW_WRITE_GENERIC) {
		return ntvfs_map_write(req, wr, ntvfs);
	}

	fnum = wr->writex.in.fnum;
	data.data = discard_const_p(void, wr->writex.in.data);
	data.length = wr->writex.in.count;

	p = pipe_state_find(private, fnum);
	if (!p) {
		return NT_STATUS_INVALID_HANDLE;
	}

	status = p->ops->write(p->private_data, &data);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	wr->writex.out.nwritten = data.length;
	wr->writex.out.remaining = 0;

	return NT_STATUS_OK;
}

/*
  seek in a file
*/
static NTSTATUS ipc_seek(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req, struct smb_seek *io)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  flush a file
*/
static NTSTATUS ipc_flush(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, struct smb_flush *io)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  close a file
*/
static NTSTATUS ipc_close(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_close *io)
{
	struct ipc_private *private = ntvfs->private_data;
	struct pipe_state *p;

	if (io->generic.level != RAW_CLOSE_CLOSE) {
		return ntvfs_map_close(req, io, ntvfs);
	}

	p = pipe_state_find(private, io->close.in.fnum);
	if (!p) {
		return NT_STATUS_INVALID_HANDLE;
	}

	talloc_free(p);

	return NT_STATUS_OK;
}

/*
  exit - closing files
*/
static NTSTATUS ipc_exit(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req)
{
	struct ipc_private *private = ntvfs->private_data;
	struct pipe_state *p, *next;
	
	for (p=private->pipe_list; p; p=next) {
		next = p->next;
		if (p->smbpid == req->smbpid) {
			talloc_free(p);
		}
	}

	return NT_STATUS_OK;
}

/*
  logoff - closing files open by the user
*/
static NTSTATUS ipc_logoff(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req)
{
	struct ipc_private *private = ntvfs->private_data;
	struct pipe_state *p, *next;
	
	for (p=private->pipe_list; p; p=next) {
		next = p->next;
		if (p->session == req->session) {
			talloc_free(p);
		}
	}

	return NT_STATUS_OK;
}

/*
  setup for an async call
*/
static NTSTATUS ipc_async_setup(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req,
				void *private)
{
	return NT_STATUS_OK;
}

/*
  cancel an async call
*/
static NTSTATUS ipc_cancel(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req)
{
	return NT_STATUS_UNSUCCESSFUL;
}

/*
  lock a byte range
*/
static NTSTATUS ipc_lock(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req, union smb_lock *lck)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  set info on a open file
*/
static NTSTATUS ipc_setfileinfo(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, union smb_setfileinfo *info)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  query info on a open file
*/
static NTSTATUS ipc_qfileinfo(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req, union smb_fileinfo *info)
{
	return NT_STATUS_ACCESS_DENIED;
}


/*
  return filesystem info
*/
static NTSTATUS ipc_fsinfo(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req, union smb_fsinfo *fs)
{
	return NT_STATUS_ACCESS_DENIED;
}

/*
  return print queue info
*/
static NTSTATUS ipc_lpq(struct ntvfs_module_context *ntvfs,
			struct smbsrv_request *req, union smb_lpq *lpq)
{
	return NT_STATUS_ACCESS_DENIED;
}

/* 
   list files in a directory matching a wildcard pattern
*/
static NTSTATUS ipc_search_first(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_search_first *io,
			  void *search_private, 
			  BOOL (*callback)(void *, union smb_search_data *))
{
	return NT_STATUS_ACCESS_DENIED;
}

/* 
   continue listing files in a directory 
*/
static NTSTATUS ipc_search_next(struct ntvfs_module_context *ntvfs,
			 struct smbsrv_request *req, union smb_search_next *io,
			 void *search_private, 
			 BOOL (*callback)(void *, union smb_search_data *))
{
	return NT_STATUS_ACCESS_DENIED;
}

/* 
   end listing files in a directory 
*/
static NTSTATUS ipc_search_close(struct ntvfs_module_context *ntvfs,
			  struct smbsrv_request *req, union smb_search_close *io)
{
	return NT_STATUS_ACCESS_DENIED;
}

/* SMBtrans - set named pipe state */
static NTSTATUS ipc_np_set_nm_state(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, struct smb_trans2 *trans)
{
	struct ipc_private *private = ntvfs->private_data;
	struct pipe_state *p;

	/* the fnum is in setup[1] */
	p = pipe_state_find(private, trans->in.setup[1]);
	if (!p) {
		return NT_STATUS_INVALID_HANDLE;
	}

	if (trans->in.params.length != 2) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	p->ipc_state = SVAL(trans->in.params.data, 0);

	trans->out.setup_count = 0;
	trans->out.setup = NULL;
	trans->out.params = data_blob(NULL, 0);
	trans->out.data = data_blob(NULL, 0);

	return NT_STATUS_OK;
}

/* SMBtrans - named pipe transaction */
static NTSTATUS ipc_np_trans(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, struct smb_trans2 *trans)
{
	struct ipc_private *private = ntvfs->private_data;
	NTSTATUS status;
	struct pipe_state *p;

	/* the fnum is in setup[1] */
	p = pipe_state_find(private, trans->in.setup[1]);
	if (!p) {
		return NT_STATUS_INVALID_HANDLE;
	}

   	if (trans->in.setup_count != 2) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	trans->out.data = data_blob_talloc(req, NULL, trans->in.max_data);
	if (!trans->out.data.data) {
		return NT_STATUS_NO_MEMORY;
	}
	
	status = p->ops->trans(p->private_data, &trans->in.data, &trans->out.data);
	if (NT_STATUS_IS_ERR(status)) {
		return status;
	}

	trans->out.setup_count = 0;
	trans->out.setup = NULL;
	trans->out.params = data_blob(NULL, 0);

	return NT_STATUS_OK;
}

/* SMBtrans - used to provide access to SMB pipes */
static NTSTATUS ipc_trans(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, struct smb_trans2 *trans)
{
	NTSTATUS status;

	if (strequal(trans->in.trans_name, "\\PIPE\\")) { /* Named pipe */
		switch (trans->in.setup[0]) {
		case NAMED_PIPE_SETHANDLESTATE:
			status = ipc_np_set_nm_state(ntvfs, req, trans);
			break;
		case NAMED_PIPE_TRANSACT:
			status = ipc_np_trans(ntvfs, req, trans);
			break;
		default:
			status = NT_STATUS_INVALID_PARAMETER;
			break;
		}
	} else if (strequal(trans->in.trans_name, "\\PIPE\\LANMAN")) { /* RAP */
		status = ipc_rap_call(req, trans);
	} else {
		DEBUG(1, ("Unknown transaction name `%s'\n", trans->in.trans_name));
		status = NT_STATUS_NOT_SUPPORTED;
	}

	return status;
}

/*
  initialialise the IPC backend, registering ourselves with the ntvfs subsystem
 */
NTSTATUS ntvfs_ipc_init(void)
{
	NTSTATUS ret;
	struct ntvfs_ops ops;
	init_module_fn static_init[] = STATIC_ntvfs_ipc_MODULES;
	init_module_fn *shared_init;
	
	ZERO_STRUCT(ops);
	
	/* fill in the name and type */
	ops.name = "default";
	ops.type = NTVFS_IPC;

	/* fill in all the operations */
	ops.connect = ipc_connect;
	ops.disconnect = ipc_disconnect;
	ops.unlink = ipc_unlink;
	ops.chkpath = ipc_chkpath;
	ops.qpathinfo = ipc_qpathinfo;
	ops.setpathinfo = ipc_setpathinfo;
	ops.openfile = ipc_open;
	ops.mkdir = ipc_mkdir;
	ops.rmdir = ipc_rmdir;
	ops.rename = ipc_rename;
	ops.copy = ipc_copy;
	ops.ioctl = ipc_ioctl;
	ops.read = ipc_read;
	ops.write = ipc_write;
	ops.seek = ipc_seek;
	ops.flush = ipc_flush;	
	ops.close = ipc_close;
	ops.exit = ipc_exit;
	ops.lock = ipc_lock;
	ops.setfileinfo = ipc_setfileinfo;
	ops.qfileinfo = ipc_qfileinfo;
	ops.fsinfo = ipc_fsinfo;
	ops.lpq = ipc_lpq;
	ops.search_first = ipc_search_first;
	ops.search_next = ipc_search_next;
	ops.search_close = ipc_search_close;
	ops.trans = ipc_trans;
	ops.logoff = ipc_logoff;
	ops.async_setup = ipc_async_setup;
	ops.cancel = ipc_cancel;

	/* register ourselves with the NTVFS subsystem. */
	ret = ntvfs_register(&ops);

	if (!NT_STATUS_IS_OK(ret)) {
		DEBUG(0,("Failed to register IPC backend!\n"));
		return ret;
	}

	/* load available named pipe backends */
	shared_init = load_samba_modules(NULL, "np");

	run_init_functions(static_init);
	run_init_functions(shared_init);

	talloc_free(shared_init);

	return ret;
}