/*
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/xprt.h>
#include <linux/sunrpc/bc_xprt.h>
#include "internal.h"
#include "callback.h"

#define NFSDBG_FACILITY		NFSDBG_CLIENT

/*
 * Initialize the NFS4 callback service
 */
static int nfs4_init_callback(struct nfs_client *clp)
{
	int error;

	if (clp->rpc_ops->version == 4) {
		struct rpc_xprt *xprt;

		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);

		if (nfs4_has_session(clp)) {
			error = xprt_setup_backchannel(xprt,
						NFS41_BC_MIN_CALLBACKS);
			if (error < 0)
				return error;
		}

		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
		if (error < 0) {
			dprintk("%s: failed to start callback. Error = %d\n",
				__func__, error);
			return error;
		}
		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
	}
	return 0;
}

/*
 * Initialize the minor version specific parts of an NFS4 client record
 */
static int nfs4_init_client_minor_version(struct nfs_client *clp)
{
#if defined(CONFIG_NFS_V4_1)
	if (clp->cl_mvops->minor_version) {
		struct nfs4_session *session = NULL;
		/*
		 * Create the session and mark it expired.
		 * When a SEQUENCE operation encounters the expired session
		 * it will do session recovery to initialize it.
		 */
		session = nfs4_alloc_session(clp);
		if (!session)
			return -ENOMEM;

		clp->cl_session = session;
		/*
		 * The create session reply races with the server back
		 * channel probe. Mark the client NFS_CS_SESSION_INITING
		 * so that the client back channel can find the
		 * nfs_client struct
		 */
		nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
	}
#endif /* CONFIG_NFS_V4_1 */

	return nfs4_init_callback(clp);
}

/**
 * nfs4_init_client - Initialise an NFS4 client record
 *
 * @clp: nfs_client to initialise
 * @timeparms: timeout parameters for underlying RPC transport
 * @ip_addr: callback IP address in presentation format
 * @authflavor: authentication flavor for underlying RPC transport
 *
 * Returns pointer to an NFS client, or an ERR_PTR value.
 */
struct nfs_client *nfs4_init_client(struct nfs_client *clp,
				    const struct rpc_timeout *timeparms,
				    const char *ip_addr,
				    rpc_authflavor_t authflavour)
{
	char buf[INET6_ADDRSTRLEN + 1];
	int error;

	if (clp->cl_cons_state == NFS_CS_READY) {
		/* the client is initialised already */
		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
		return clp;
	}

	/* Check NFS protocol revision and initialize RPC op vector */
	clp->rpc_ops = &nfs_v4_clientops;

	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
	error = nfs_create_rpc_client(clp, timeparms, authflavour);
	if (error < 0)
		goto error;

	/* If no clientaddr= option was specified, find a usable cb address */
	if (ip_addr == NULL) {
		struct sockaddr_storage cb_addr;
		struct sockaddr *sap = (struct sockaddr *)&cb_addr;

		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
		if (error < 0)
			goto error;
		error = rpc_ntop(sap, buf, sizeof(buf));
		if (error < 0)
			goto error;
		ip_addr = (const char *)buf;
	}
	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));

	error = nfs_idmap_new(clp);
	if (error < 0) {
		dprintk("%s: failed to create idmapper. Error = %d\n",
			__func__, error);
		goto error;
	}
	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);

	error = nfs4_init_client_minor_version(clp);
	if (error < 0)
		goto error;

	if (!nfs4_has_session(clp))
		nfs_mark_client_ready(clp, NFS_CS_READY);
	return clp;

error:
	nfs_mark_client_ready(clp, error);
	nfs_put_client(clp);
	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
	return ERR_PTR(error);
}