/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 * 
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 *
 * Portions Copyright (c) 2006,2008 Sine Nomine Associates
 */

/*
	System:		VICE-TWO
	Module:		fssync.c
	Institution:	The Information Technology Center, Carnegie-Mellon University

 */

#ifndef AFS_PTHREAD_ENV
#define USUAL_PRIORITY (LWP_MAX_PRIORITY - 2)

/*
 * stack size increased from 8K because the HP machine seemed to have trouble
 * with the smaller stack
 */
#define USUAL_STACK_SIZE	(24 * 1024)
#endif /* !AFS_PTHREAD_ENV */

/*
   fssync-client.c
   File server synchronization with external volume utilities.
   client-side implementation
 */

#include <afsconfig.h>
#include <afs/param.h>


#include <sys/types.h>
#include <stdio.h>
#ifdef AFS_NT40_ENV
#include <winsock2.h>
#include <time.h>
#else
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/time.h>
#endif
#include <errno.h>
#ifdef AFS_PTHREAD_ENV
#include <assert.h>
#else /* AFS_PTHREAD_ENV */
#include <afs/assert.h>
#endif /* AFS_PTHREAD_ENV */
#include <signal.h>
#include <string.h>

#include <rx/xdr.h>
#include <afs/afsint.h>
#include "nfs.h"
#include <afs/errors.h>
#include "daemon_com.h"
#include "fssync.h"
#include "lwp.h"
#include "lock.h"
#include <afs/afssyscalls.h>
#include "ihandle.h"
#include "vnode.h"
#include "volume.h"
#include "partition.h"

#ifdef FSSYNC_BUILD_CLIENT

/*@printflike@*/ extern void Log(const char *format, ...);

extern int LogLevel;

static SYNC_client_state fssync_state = 
    { -1,                    /* file descriptor */
      FSSYNC_ENDPOINT_DECL,  /* server endpoint */
      FSYNC_PROTO_VERSION,   /* protocol version */
      5,                     /* connect retry limit */
      120,                   /* hard timeout */
      "FSSYNC",              /* protocol name string */
    };

#ifdef AFS_PTHREAD_ENV
static pthread_mutex_t vol_fsync_mutex;
static volatile int vol_fsync_mutex_init = 0;
#define VFSYNC_LOCK \
    assert(pthread_mutex_lock(&vol_fsync_mutex) == 0)
#define VFSYNC_UNLOCK \
    assert(pthread_mutex_unlock(&vol_fsync_mutex) == 0)
#else
#define VFSYNC_LOCK
#define VFSYNC_UNLOCK
#endif

int
FSYNC_clientInit(void)
{
#ifdef AFS_PTHREAD_ENV
    /* this is safe since it gets called with VOL_LOCK held, or before we go multithreaded */
    if (!vol_fsync_mutex_init) {
	assert(pthread_mutex_init(&vol_fsync_mutex, NULL) == 0);
	vol_fsync_mutex_init = 1;
    }
#endif
    return SYNC_connect(&fssync_state);
}

void
FSYNC_clientFinis(void)
{
    SYNC_closeChannel(&fssync_state);
}

int
FSYNC_clientChildProcReconnect(void)
{
    return SYNC_reconnect(&fssync_state);
}

/* fsync client interface */
afs_int32
FSYNC_askfs(SYNC_command * com, SYNC_response * res)
{
    afs_int32 code;

    VFSYNC_LOCK;
    code = SYNC_ask(&fssync_state, com, res);
    VFSYNC_UNLOCK;

    switch (code) {
    case SYNC_OK:
    case SYNC_FAILED:
	break;
    case SYNC_COM_ERROR:
    case SYNC_BAD_COMMAND:
	Log("FSYNC_askfs: fatal FSSYNC protocol error; volume management functionality disabled until next fileserver restart\n");
	break;
    case SYNC_DENIED:
	Log("FSYNC_askfs: FSSYNC request denied for reason=%d\n", res->hdr.reason);
	break;
    default:
	Log("FSYNC_askfs: unknown protocol response %d\n", code);
	break;
    }
    return code;
}


/**
 *  FSSYNC volume operations client interface.
 *
 * @param[in]    volume     volume id
 * @param[in]    partName   partition name string
 * @param[in]    com        FSSYNC command code
 * @param[in]    reason     FSSYNC reason sub-code
 * @param[out]   res        response message
 *
 * @return operation status
 *    @retval SYNC_OK  success
 */
afs_int32
FSYNC_GenericOp(void * ext_hdr, size_t ext_len,
	      int command, int reason,
	      SYNC_response * res_in)
{
    SYNC_response res_l, *res;
    SYNC_command com;

    if (res_in) {
	res = res_in;
    } else {
	res = &res_l;
	res_l.payload.buf = NULL;
	res_l.payload.len = 0;
    }

    memset(&com, 0, sizeof(com));

    com.hdr.programType = programType;
    com.hdr.command = command;
    com.hdr.reason = reason;
    com.hdr.command_len = sizeof(com.hdr) + ext_len;
    com.payload.buf = ext_hdr;
    com.payload.len = ext_len;

    return FSYNC_askfs(&com, res);
}

afs_int32
FSYNC_VolOp(VolumeId volume, char * partition, 
	    int command, int reason,
	    SYNC_response * res)
{
    FSSYNC_VolOp_hdr vcom;

    memset(&vcom, 0, sizeof(vcom));

    vcom.volume = volume;
    if (partition)
	strlcpy(vcom.partName, partition, sizeof(vcom.partName));

    return FSYNC_GenericOp(&vcom, sizeof(vcom), command, reason, res);
}

afs_int32
FSYNC_StatsOp(FSSYNC_StatsOp_hdr * scom, int command, int reason,
	      SYNC_response * res)
{
    return FSYNC_GenericOp(scom, sizeof(*scom), command, reason, res);
}

/**
 * query the volume group cache.
 *
 * @param[in]  part     vice partition path
 * @param[in]  volid    volume id
 * @param[out] qry      query response object
 * @param[out] res      SYNC response message
 *
 * @return operation status
 *    @retval SYNC_OK success
 */
afs_int32
FSYNC_VGCQuery(char * part,
	     VolumeId volid,
	     FSSYNC_VGQry_response_t * qry,
	     SYNC_response *res)
{
    SYNC_response lres;

    if (!res) {
	res = &lres;
    }

    res->hdr.response_len = sizeof(res->hdr);
    res->payload.buf = qry;
    res->payload.len = sizeof(*qry);

    return FSYNC_VolOp(volid, part, FSYNC_VG_QUERY, 0, res);
}

/**
 * perform an update operation on the VGC.
 *
 * @param[in] parent    rw volume
 * @param[in] child     volume id to add
 * @param[in] partition name of vice partition on which this VG resides
 * @param[in] opcode    FSSYNC VG cache opcode
 * @param[in] reason    FSSYNC reason code
 * @param[out] res      SYNC response message
 *
 * @return operation status
 *    @retval SYNC_OK success
 *
 * @internal
 */
static afs_int32
_FSYNC_VGCUpdate(char * partition,
		 VolumeId parent,
		 VolumeId child,
		 int opcode,
		 int reason,
		 SYNC_response *res)
{
    FSSYNC_VGUpdate_command_t vcom;

    memset(&vcom, 0, sizeof(vcom));

    vcom.parent = parent;
    vcom.child = child;
    if (partition)
	strlcpy(vcom.partName, partition, sizeof(vcom.partName));

    return FSYNC_GenericOp(&vcom, sizeof(vcom), opcode, reason, res);
}

/**
 * Add volume to volume group cache.
 *
 * @param[in] parent    rw volume
 * @param[in] child     volume id to add
 * @param[in] partition name of vice partition on which this VG resides
 * @param[in] reason    FSSYNC reason code
 * @param[out] res      SYNC response message
 *
 * @return operation status
 *    @retval SYNC_OK success
 */
afs_int32
FSYNC_VGCAdd(char * partition,
	     VolumeId parent,
	     VolumeId child,
	     int reason,
	     SYNC_response *res)
{
    return _FSYNC_VGCUpdate(partition, parent, child, FSYNC_VG_ADD, reason, res);
}

/**
 * Delete volume from volume group cache.
 *
 * @param[in] parent    rw volume
 * @param[in] child     volume id to add
 * @param[in] partition name of vice partition on which this VG resides
 * @param[in] reason    FSSYNC reason code
 * @param[out] res      SYNC response message
 *
 * @return operation status
 *    @retval SYNC_OK success
 */
afs_int32
FSYNC_VGCDel(char * partition,
	     VolumeId parent,
	     VolumeId child,
	     int reason,
	     SYNC_response *res)
{
    return _FSYNC_VGCUpdate(partition, parent, child, FSYNC_VG_DEL, reason, res);
}

/**
 * perform an asynchronous volume group scan.
 *
 * @param[in] partition   vice partition string
 * @param[in] reason      FSSYNC reason code
 *
 * @note if partition is NULL, all vice partitions will be scanned.
 *
 * @return operation status
 *    @retval SYNC_OK success
 */
afs_int32
FSYNC_VGCScan(char * partition, int reason)
{
    int command;

    if (partition == NULL) {
	command = FSYNC_VG_SCAN_ALL;
	partition = "";
    } else {
	command = FSYNC_VG_SCAN;
    }

    return FSYNC_VolOp(0, partition, command, reason, NULL);
}

#endif /* FSSYNC_BUILD_CLIENT */