/*
 * Copyright (C) Joerg Lenneis 2003
 * Copyright (C) Frank Lahm 2010
 * All Rights Reserved.  See COPYING.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */

#ifdef CNID_BACKEND_DBD

#include <stdlib.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <errno.h>
#include <netinet/in.h>
#include <net/if.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <time.h>
#include <arpa/inet.h>

#include <atalk/logger.h>
#include <atalk/adouble.h>
#include <atalk/cnid.h>
#include <atalk/cnid_dbd_private.h>
#include <atalk/util.h>

#include "cnid_dbd.h"

#ifndef SOL_TCP
#define SOL_TCP IPPROTO_TCP
#endif /* ! SOL_TCP */

/* Wait MAX_DELAY seconds before a request to the CNID server times out */
#define MAX_DELAY 20
#define ONE_DELAY 5

static void RQST_RESET(struct cnid_dbd_rqst  *r)
{
    memset(r, 0, sizeof(struct cnid_dbd_rqst ));
}

static void delay(int sec)
{
    struct timeval tv;

    tv.tv_usec = 0;
    tv.tv_sec  = sec;
    select(0, NULL, NULL, NULL, &tv);
}

static int tsock_getfd(const char *host, const char *port)
{
    int sock = -1;
    int attr;
    int err;
    struct addrinfo hints, *servinfo, *p;
    int optval;
    socklen_t optlen = sizeof(optval);

    /* Prepare hint for getaddrinfo */
    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
#ifdef AI_NUMERICSERV
    hints.ai_flags = AI_NUMERICSERV;
#endif

    if ((err = getaddrinfo(host, port, &hints, &servinfo)) != 0) {
        LOG(log_error, logtype_default, "tsock_getfd: getaddrinfo: CNID server %s:%s : %s\n",
            host, port, gai_strerror(err));
        return -1;
    }

    /* loop through all the results and bind to the first we can */
    for (p = servinfo; p != NULL; p = p->ai_next) {
        if ((sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
            LOG(log_info, logtype_default, "tsock_getfd: socket CNID server %s:: %s",
                host, strerror(errno));
            continue;
        }

        attr = 1;
        if (setsockopt(sock, SOL_TCP, TCP_NODELAY, &attr, sizeof(attr)) == -1) {
            LOG(log_error, logtype_cnid, "getfd: set TCP_NODELAY CNID server %s: %s",
                host, strerror(errno));
            close(sock);
            sock = -1;
            return -1;
        }

        if (setnonblock(sock, 1) != 0) {
            LOG(log_error, logtype_cnid, "getfd: setnonblock: %s", strerror(errno));
            close(sock);
            sock = -1;
            return -1;
        }

        if (connect(sock, p->ai_addr, p->ai_addrlen) == -1) {
            if (errno == EINPROGRESS) {
                struct timeval tv;
                tv.tv_usec = 0;
                tv.tv_sec  = 5; /* give it five seconds ... */
                fd_set wfds;
                FD_ZERO(&wfds);
                FD_SET(sock, &wfds);

                if ((err = select(sock + 1, NULL, &wfds, NULL, &tv)) == 0) {
                    /* timeout */
                    LOG(log_error, logtype_cnid, "getfd: select timed out for CNID server %s",
                        host);
                    close(sock);
                    sock = -1;
                    continue;
                }
                if (err == -1) {
                    /* select failed */
                    LOG(log_error, logtype_cnid, "getfd: select failed for CNID server %s",
                        host);
                    close(sock);
                    sock = -1;
                    continue;
                }

                if ( ! FD_ISSET(sock, &wfds)) {
                    /* give up */
                    LOG(log_error, logtype_cnid, "getfd: socket not ready connecting to %s",
                        host);
                    close(sock);
                    sock = -1;
                    continue;
                }

                if ((err = getsockopt(sock, SOL_SOCKET, SO_ERROR, &optval, &optlen)) != 0 || optval != 0) {
                    if (err != 0) {
                        /* somethings very wrong */
                        LOG(log_error, logtype_cnid, "getfd: getsockopt error with CNID server %s: %s",
                            host, strerror(errno));
                    } else {
                        errno = optval;
                        LOG(log_error, logtype_cnid, "getfd: getsockopt says: %s",
                            strerror(errno));
                    }
                    close(sock);
                    sock = -1;
                    continue;
                }
            } else {
                LOG(log_error, logtype_cnid, "getfd: connect CNID server %s: %s",
                    host, strerror(errno));
                close(sock);
                sock = -1;
                continue;
            }
        }

        /* We've got a socket */
        break;
    }

    freeaddrinfo(servinfo);

    if (p == NULL) {
        errno = optval;
        LOG(log_error, logtype_cnid, "tsock_getfd: no suitable network config from CNID server (%s:%s): %s",
            host, port, strerror(errno));
        return -1;
    }

    return(sock);
}

/*!
 * Write "towrite" bytes using writev on non-blocking fd
 *
 * Every short write is considered an error, transmit can handle that.
 *
 * @param fd      (r) socket fd which must be non-blocking
 * @param iov     (r) iovec for writev
 * @param towrite (r) number of bytes in all iovec elements
 * @param vecs    (r) number of iovecs in array
 *
 * @returns "towrite" bytes written or -1 on error
 */
static int write_vec(int fd, struct iovec *iov, ssize_t towrite, int vecs)
{
    ssize_t len;
    int slept = 0;
    int sleepsecs;

    while (1) {
        if (((len = writev(fd, iov, vecs)) == -1 && errno == EINTR))
            continue;

        if ((! slept) && len == -1 && errno == EAGAIN) {
            sleepsecs = 2;
            while ((sleepsecs = sleep(sleepsecs)));
            slept = 1;
            continue;
        }

        if (len == towrite) /* wrote everything out */
            break;

        if (len == -1)
            LOG(log_error, logtype_cnid, "write_vec: %s", strerror(errno));
        else
            LOG(log_error, logtype_cnid, "write_vec: short write: %d", len);
        return len;
    }

    LOG(log_maxdebug, logtype_cnid, "write_vec: wrote %d bytes", len);

    return len;
}

/* --------------------- */
static int init_tsock(CNID_private *db)
{
    int fd;
    int len;
    struct iovec iov[2];

    LOG(log_debug, logtype_cnid, "init_tsock: BEGIN. Opening volume '%s', CNID Server: %s/%s",
        db->db_dir, db->cnidserver, db->cnidport);

    if ((fd = tsock_getfd(db->cnidserver, db->cnidport)) < 0)
        return -1;

    len = strlen(db->db_dir);

    iov[0].iov_base = &len;
    iov[0].iov_len  = sizeof(int);

    iov[1].iov_base = db->db_dir;
    iov[1].iov_len  = len;

    if (write_vec(fd, iov, len + sizeof(int), 2) != len + sizeof(int)) {
        LOG(log_error, logtype_cnid, "init_tsock: Error/short write: %s", strerror(errno));
        close(fd);
        return -1;
    }

    LOG(log_debug, logtype_cnid, "init_tsock: ok");

    return fd;
}

/* --------------------- */
static int send_packet(CNID_private *db, struct cnid_dbd_rqst *rqst)
{
    struct iovec iov[2];
    size_t towrite;
    int vecs;

    iov[0].iov_base = rqst;
    iov[0].iov_len  = sizeof(struct cnid_dbd_rqst);
    towrite = sizeof(struct cnid_dbd_rqst);
    vecs = 1;

    if (rqst->namelen) {
        iov[1].iov_base = (char *)rqst->name;
        iov[1].iov_len  = rqst->namelen;
        towrite += rqst->namelen;
        vecs++;
    }

    if (write_vec(db->fd, iov, towrite, vecs) != towrite) {
        LOG(log_warning, logtype_cnid, "send_packet: Error writev rqst (db_dir %s): %s",
            db->db_dir, strerror(errno));
        return -1;
    }

    LOG(log_maxdebug, logtype_cnid, "send_packet: {done}");
    return 0;
}

/* ------------------- */
static void dbd_initstamp(struct cnid_dbd_rqst *rqst)
{
    RQST_RESET(rqst);
    rqst->op = CNID_DBD_OP_GETSTAMP;
}

/* ------------------- */
static int dbd_reply_stamp(struct cnid_dbd_rply *rply)
{
    switch (rply->result) {
    case CNID_DBD_RES_OK:
        break;
    case CNID_DBD_RES_NOTFOUND:
        return -1;
    case CNID_DBD_RES_ERR_DB:
    default:
        errno = CNID_ERR_DB;
        return -1;
    }
    return 0;
}

/* ---------------------
 * send a request and get reply
 * assume send is non blocking
 * if no answer after sometime (at least MAX_DELAY secondes) return an error
 */
static int dbd_rpc(CNID_private *db, struct cnid_dbd_rqst *rqst, struct cnid_dbd_rply *rply)
{
    ssize_t ret;
    char *nametmp;
    size_t len;

    if (send_packet(db, rqst) < 0) {
        return -1;
    }
    len = rply->namelen;
    nametmp = rply->name;

    ret = readt(db->fd, rply, sizeof(struct cnid_dbd_rply), 0, ONE_DELAY);

    if (ret != sizeof(struct cnid_dbd_rply)) {
        LOG(log_debug, logtype_cnid, "dbd_rpc: Error reading header from fd (db_dir %s): %s",
            db->db_dir, ret == -1 ? strerror(errno) : "closed");
        rply->name = nametmp;
        return -1;
    }
    rply->name = nametmp;
    if (rply->namelen && rply->namelen > len) {
        LOG(log_error, logtype_cnid,
            "dbd_rpc: Error reading name (db_dir %s): %s name too long: %d. only wanted %d, garbage?",
            db->db_dir, rply->name, rply->namelen, len);
        return -1;
    }
    if (rply->namelen && (ret = readt(db->fd, rply->name, rply->namelen, 0, ONE_DELAY)) != (ssize_t)rply->namelen) {
        LOG(log_error, logtype_cnid, "dbd_rpc: Error reading name from fd (db_dir %s): %s",
            db->db_dir, ret == -1?strerror(errno):"closed");
        return -1;
    }

    LOG(log_maxdebug, logtype_cnid, "dbd_rpc: {done}");

    return 0;
}

/* -------------------- */
static int transmit(CNID_private *db, struct cnid_dbd_rqst *rqst, struct cnid_dbd_rply *rply)
{
    time_t orig, t;
    int clean = 1; /* no errors so far - to prevent sleep on first try */

    while (1) {
        if (db->fd == -1) {
            LOG(log_maxdebug, logtype_cnid, "transmit: connecting to cnid_dbd ...");
            if ((db->fd = init_tsock(db)) < 0) {
                goto transmit_fail;
            }
            if (db->notfirst) {
                LOG(log_debug7, logtype_cnid, "transmit: reconnected to cnid_dbd");
            } else { /* db->notfirst == 0 */
                db->notfirst = 1;
            }
            LOG(log_debug, logtype_cnid, "transmit: attached to '%s'", db->db_dir);
        }
        if (!dbd_rpc(db, rqst, rply)) {
            LOG(log_maxdebug, logtype_cnid, "transmit: {done}");
            return 0;
        }
    transmit_fail:
        if (db->fd != -1) {
            close(db->fd);
            db->fd = -1; /* FD not valid... will need to reconnect */
        }

        if (errno == ECONNREFUSED) { /* errno carefully injected in tsock_getfd */
            /* give up */
            LOG(log_error, logtype_cnid, "transmit: connection refused (db_dir %s)", db->db_dir);
            return -1;
        }

        if (!clean) { /* don't sleep if just got disconnected by cnid server */
            time(&t);
            if (t - orig > MAX_DELAY) {
                LOG(log_error, logtype_cnid, "transmit: Request to dbd daemon (db_dir %s) timed out.", db->db_dir);
                return -1;
            }
            /* sleep a little before retry */
            delay(1);
        } else {
            clean = 0; /* false... next time sleep */
            time(&orig);
        }
    }
    return -1;
}

/* ---------------------- */
static struct _cnid_db *cnid_dbd_new(const char *volpath)
{
    struct _cnid_db *cdb;

    if ((cdb = (struct _cnid_db *)calloc(1, sizeof(struct _cnid_db))) == NULL)
        return NULL;

    if ((cdb->volpath = strdup(volpath)) == NULL) {
        free(cdb);
        return NULL;
    }

    cdb->flags = CNID_FLAG_PERSISTENT | CNID_FLAG_LAZY_INIT;

    cdb->cnid_add = cnid_dbd_add;
    cdb->cnid_delete = cnid_dbd_delete;
    cdb->cnid_get = cnid_dbd_get;
    cdb->cnid_lookup = cnid_dbd_lookup;
    cdb->cnid_find = cnid_dbd_find;
    cdb->cnid_nextid = NULL;
    cdb->cnid_resolve = cnid_dbd_resolve;
    cdb->cnid_getstamp = cnid_dbd_getstamp;
    cdb->cnid_update = cnid_dbd_update;
    cdb->cnid_rebuild_add = cnid_dbd_rebuild_add;
    cdb->cnid_close = cnid_dbd_close;
    cdb->cnid_wipe = cnid_dbd_wipe;
    return cdb;
}

/* ---------------------- */
struct _cnid_db *cnid_dbd_open(struct cnid_open_args *args)
{
    CNID_private *db = NULL;
    struct _cnid_db *cdb = NULL;

    if (!args->dir) {
        return NULL;
    }

    if ((cdb = cnid_dbd_new(args->dir)) == NULL) {
        LOG(log_error, logtype_cnid, "cnid_open: Unable to allocate memory for database");
        return NULL;
    }

    if ((db = (CNID_private *)calloc(1, sizeof(CNID_private))) == NULL) {
        LOG(log_error, logtype_cnid, "cnid_open: Unable to allocate memory for database");
        goto cnid_dbd_open_fail;
    }

    cdb->_private = db;

    /* We keep a copy of the directory in the db structure so that we can
       transparently reconnect later. */
    strcpy(db->db_dir, args->dir);
    db->magic = CNID_DB_MAGIC;
    db->fd = -1;
    db->cnidserver = strdup(args->cnidserver);
    db->cnidport = strdup(args->cnidport);

    LOG(log_debug, logtype_cnid, "cnid_dbd_open: Finished initializing cnid dbd module for volume '%s'", db->db_dir);

    return cdb;

cnid_dbd_open_fail:
    if (cdb != NULL) {
        if (cdb->volpath != NULL) {
            free(cdb->volpath);
        }
        free(cdb);
    }
    if (db != NULL)
        free(db);

    return NULL;
}

/* ---------------------- */
void cnid_dbd_close(struct _cnid_db *cdb)
{
    CNID_private *db;

    if (!cdb) {
        LOG(log_error, logtype_cnid, "cnid_close called with NULL argument !");
        return;
    }

    if ((db = cdb->_private) != NULL) {
        LOG(log_debug, logtype_cnid, "closing database connection for volume '%s'", db->db_dir);

        if (db->fd >= 0)
            close(db->fd);
        free(db);
    }

    free(cdb->volpath);
    free(cdb);

    return;
}

/**
 * Get the db stamp
 **/
static int cnid_dbd_stamp(CNID_private *db)
{
    struct cnid_dbd_rqst rqst_stamp;
    struct cnid_dbd_rply rply_stamp;
    char  stamp[ADEDLEN_PRIVSYN];

    dbd_initstamp(&rqst_stamp);
    memset(stamp, 0, ADEDLEN_PRIVSYN);
    rply_stamp.name = stamp;
    rply_stamp.namelen = ADEDLEN_PRIVSYN;

    if (transmit(db, &rqst_stamp, &rply_stamp) < 0)
        return -1;
    if (dbd_reply_stamp(&rply_stamp ) < 0)
        return -1;

    if (db->client_stamp)
        memcpy(db->client_stamp, stamp, ADEDLEN_PRIVSYN);
    memcpy(db->stamp, stamp, ADEDLEN_PRIVSYN);

    return 0;
}

/* ---------------------- */
cnid_t cnid_dbd_add(struct _cnid_db *cdb, const struct stat *st,
                    cnid_t did, const char *name, size_t len, cnid_t hint)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    cnid_t id;

    if (!cdb || !(db = cdb->_private) || !st || !name) {
        LOG(log_error, logtype_cnid, "cnid_add: Parameter error");
        errno = CNID_ERR_PARAM;
        return CNID_INVALID;
    }

    if (len > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_add: Path name is too long");
        errno = CNID_ERR_PATH;
        return CNID_INVALID;
    }

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_ADD;

    if (!(cdb->flags & CNID_FLAG_NODEV)) {
        rqst.dev = st->st_dev;
    }

    rqst.ino = st->st_ino;
    rqst.type = S_ISDIR(st->st_mode)?1:0;
    rqst.cnid = hint;
    rqst.did = did;
    rqst.name = name;
    rqst.namelen = len;

    LOG(log_debug, logtype_cnid, "cnid_dbd_add: CNID: %u, name: '%s', dev: 0x%llx, inode: 0x%llx, type: %s",
        ntohl(did), name, (long long)rqst.dev, (long long)st->st_ino, rqst.type ? "dir" : "file");

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return CNID_INVALID;
    }

    switch(rply.result) {
    case CNID_DBD_RES_OK:
        id = rply.cnid;
        LOG(log_debug, logtype_cnid, "cnid_dbd_add: got CNID: %u", ntohl(id));
        break;
    case CNID_DBD_RES_ERR_MAX:
        errno = CNID_ERR_MAX;
        id = CNID_INVALID;
        break;
    case CNID_DBD_RES_ERR_DB:
    case CNID_DBD_RES_ERR_DUPLCNID:
        errno = CNID_ERR_DB;
        id = CNID_INVALID;
        break;
    default:
        abort();
    }

    return id;
}

/* ---------------------- */
cnid_t cnid_dbd_get(struct _cnid_db *cdb, cnid_t did, const char *name, size_t len)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    cnid_t id;

    if (!cdb || !(db = cdb->_private) || !name) {
        LOG(log_error, logtype_cnid, "cnid_dbd_get: Parameter error");
        errno = CNID_ERR_PARAM;
        return CNID_INVALID;
    }

    if (len > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_dbd_get: Path name is too long");
        errno = CNID_ERR_PATH;
        return CNID_INVALID;
    }

    LOG(log_debug, logtype_cnid, "cnid_dbd_get: DID: %u, name: '%s'", ntohl(did), name);

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_GET;
    rqst.did = did;
    rqst.name = name;
    rqst.namelen = len;

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return CNID_INVALID;
    }

    switch(rply.result) {
    case CNID_DBD_RES_OK:
        id = rply.cnid;
        LOG(log_debug, logtype_cnid, "cnid_dbd_get: got CNID: %u", ntohl(id));
        break;
    case CNID_DBD_RES_NOTFOUND:
        id = CNID_INVALID;
        break;
    case CNID_DBD_RES_ERR_DB:
        id = CNID_INVALID;
        errno = CNID_ERR_DB;
        break;
    default:
        abort();
    }

    return id;
}

/* ---------------------- */
char *cnid_dbd_resolve(struct _cnid_db *cdb, cnid_t *id, void *buffer, size_t len)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    char *name;

    if (!cdb || !(db = cdb->_private) || !id || !(*id)) {
        LOG(log_error, logtype_cnid, "cnid_resolve: Parameter error");
        errno = CNID_ERR_PARAM;
        return NULL;
    }

    LOG(log_debug, logtype_cnid, "cnid_dbd_resolve: resolving CNID: %u", ntohl(*id));

    /* TODO: We should maybe also check len. At the moment we rely on the caller
       to provide a buffer that is large enough for MAXPATHLEN plus
       CNID_HEADER_LEN plus 1 byte, which is large enough for the maximum that
       can come from the database. */

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_RESOLVE;
    rqst.cnid = *id;

    /* Pass buffer to transmit so it can stuff the reply data there */
    rply.name = (char *)buffer;
    rply.namelen = len;

    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        *id = CNID_INVALID;
        return NULL;
    }

    switch (rply.result) {
    case CNID_DBD_RES_OK:
        *id = rply.did;
        name = rply.name + CNID_NAME_OFS;
        LOG(log_debug, logtype_cnid, "cnid_dbd_resolve: resolved did: %u, name: '%s'", ntohl(*id), name);
        break;
    case CNID_DBD_RES_NOTFOUND:
        *id = CNID_INVALID;
        name = NULL;
        break;
    case CNID_DBD_RES_ERR_DB:
        errno = CNID_ERR_DB;
        *id = CNID_INVALID;
        name = NULL;
        break;
    default:
        abort();
    }

    return name;
}

/**
 * Caller passes buffer where we will store the db stamp
 **/
int cnid_dbd_getstamp(struct _cnid_db *cdb, void *buffer, const size_t len)
{
    CNID_private *db;

    if (!cdb || !(db = cdb->_private) || len != ADEDLEN_PRIVSYN) {
        LOG(log_error, logtype_cnid, "cnid_getstamp: Parameter error");
        errno = CNID_ERR_PARAM;
        return -1;
    }
    db->client_stamp = buffer;
    db->stamp_size = len;

    return cnid_dbd_stamp(db);
}

/* ---------------------- */
cnid_t cnid_dbd_lookup(struct _cnid_db *cdb, const struct stat *st, cnid_t did,
                       const char *name, size_t len)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    cnid_t id;

    if (!cdb || !(db = cdb->_private) || !st || !name) {
        LOG(log_error, logtype_cnid, "cnid_lookup: Parameter error");
        errno = CNID_ERR_PARAM;
        return CNID_INVALID;
    }

    if (len > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_lookup: Path name is too long");
        errno = CNID_ERR_PATH;
        return CNID_INVALID;
    }

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_LOOKUP;

    if (!(cdb->flags & CNID_FLAG_NODEV)) {
        rqst.dev = st->st_dev;
    }

    rqst.ino = st->st_ino;
    rqst.type = S_ISDIR(st->st_mode)?1:0;
    rqst.did = did;
    rqst.name = name;
    rqst.namelen = len;

    LOG(log_debug, logtype_cnid, "cnid_dbd_lookup: CNID: %u, name: '%s', inode: 0x%llx, type: %d (0=file, 1=dir)",
        ntohl(did), name, (long long)st->st_ino, rqst.type);

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return CNID_INVALID;
    }

    switch (rply.result) {
    case CNID_DBD_RES_OK:
        id = rply.cnid;
        LOG(log_debug, logtype_cnid, "cnid_dbd_lookup: got CNID: %u", ntohl(id));
        break;
    case CNID_DBD_RES_NOTFOUND:
        id = CNID_INVALID;
        break;
    case CNID_DBD_RES_ERR_DB:
        errno = CNID_ERR_DB;
        id = CNID_INVALID;
        break;
    default:
        abort();
    }

    return id;
}

/* ---------------------- */
int cnid_dbd_find(struct _cnid_db *cdb, const char *name, size_t namelen, void *buffer, size_t buflen)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    int count;

    if (!cdb || !(db = cdb->_private) || !name) {
        LOG(log_error, logtype_cnid, "cnid_find: Parameter error");
        errno = CNID_ERR_PARAM;
        return CNID_INVALID;
    }

    if (namelen > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_find: Path name is too long");
        errno = CNID_ERR_PATH;
        return CNID_INVALID;
    }

    LOG(log_debug, logtype_cnid, "cnid_find(\"%s\")", name);

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_SEARCH;

    rqst.name = name;
    rqst.namelen = namelen;

    rply.name = buffer;
    rply.namelen = buflen;

    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return CNID_INVALID;
    }

    switch (rply.result) {
    case CNID_DBD_RES_OK:
        count = rply.namelen / sizeof(cnid_t);
        LOG(log_debug, logtype_cnid, "cnid_find: got %d matches", count);
        break;
    case CNID_DBD_RES_NOTFOUND:
        count = 0;
        break;
    case CNID_DBD_RES_ERR_DB:
        errno = CNID_ERR_DB;
        count = -1;
        break;
    default:
        abort();
    }

    return count;
}

/* ---------------------- */
int cnid_dbd_update(struct _cnid_db *cdb, cnid_t id, const struct stat *st,
                    cnid_t did, const char *name, size_t len)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;

    if (!cdb || !(db = cdb->_private) || !id || !st || !name) {
        LOG(log_error, logtype_cnid, "cnid_update: Parameter error");
        errno = CNID_ERR_PARAM;
        return -1;
    }

    if (len > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_update: Path name is too long");
        errno = CNID_ERR_PATH;
        return -1;
    }

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_UPDATE;
    rqst.cnid = id;
    if (!(cdb->flags & CNID_FLAG_NODEV)) {
        rqst.dev = st->st_dev;
    }
    rqst.ino = st->st_ino;
    rqst.type = S_ISDIR(st->st_mode)?1:0;
    rqst.did = did;
    rqst.name = name;
    rqst.namelen = len;

    LOG(log_debug, logtype_cnid, "cnid_dbd_update: CNID: %u, name: '%s', inode: 0x%llx, type: %d (0=file, 1=dir)",
        ntohl(id), name, (long long)st->st_ino, rqst.type);

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return -1;
    }

    switch (rply.result) {
    case CNID_DBD_RES_OK:
        LOG(log_debug, logtype_cnid, "cnid_dbd_update: updated");
    case CNID_DBD_RES_NOTFOUND:
        return 0;
    case CNID_DBD_RES_ERR_DB:
        errno = CNID_ERR_DB;
        return -1;
    default:
        abort();
    }
}

/* ---------------------- */
cnid_t cnid_dbd_rebuild_add(struct _cnid_db *cdb, const struct stat *st,
                            cnid_t did, const char *name, size_t len, cnid_t hint)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;
    cnid_t id;

    if (!cdb || !(db = cdb->_private) || !st || !name || hint == CNID_INVALID) {
        LOG(log_error, logtype_cnid, "cnid_rebuild_add: Parameter error");
        errno = CNID_ERR_PARAM;
        return CNID_INVALID;
    }

    if (len > MAXPATHLEN) {
        LOG(log_error, logtype_cnid, "cnid_rebuild_add: Path name is too long");
        errno = CNID_ERR_PATH;
        return CNID_INVALID;
    }

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_REBUILD_ADD;

    if (!(cdb->flags & CNID_FLAG_NODEV)) {
        rqst.dev = st->st_dev;
    }

    rqst.ino = st->st_ino;
    rqst.type = S_ISDIR(st->st_mode)?1:0;
    rqst.did = did;
    rqst.name = name;
    rqst.namelen = len;
    rqst.cnid = hint;

    LOG(log_debug, logtype_cnid, "cnid_dbd_rebuild_add: CNID: %u, name: '%s', inode: 0x%llx, type: %d (0=file, 1=dir), hint: %u",
        ntohl(did), name, (long long)st->st_ino, rqst.type, hint);

    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return CNID_INVALID;
    }

    switch(rply.result) {
    case CNID_DBD_RES_OK:
        id = rply.cnid;
        LOG(log_debug, logtype_cnid, "cnid_dbd_rebuild_add: got CNID: %u", ntohl(id));
        break;
    case CNID_DBD_RES_ERR_MAX:
        errno = CNID_ERR_MAX;
        id = CNID_INVALID;
        break;
    case CNID_DBD_RES_ERR_DB:
    case CNID_DBD_RES_ERR_DUPLCNID:
        errno = CNID_ERR_DB;
        id = CNID_INVALID;
        break;
    default:
        abort();
    }
    return id;
}

/* ---------------------- */
int cnid_dbd_delete(struct _cnid_db *cdb, const cnid_t id)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;

    if (!cdb || !(db = cdb->_private) || !id) {
        LOG(log_error, logtype_cnid, "cnid_delete: Parameter error");
        errno = CNID_ERR_PARAM;
        return -1;
    }

    LOG(log_debug, logtype_cnid, "cnid_dbd_delete: delete CNID: %u", ntohl(id));

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_DELETE;
    rqst.cnid = id;

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return -1;
    }

    switch (rply.result) {
    case CNID_DBD_RES_OK:
        LOG(log_debug, logtype_cnid, "cnid_dbd_delete: deleted CNID: %u", ntohl(id));
    case CNID_DBD_RES_NOTFOUND:
        return 0;
    case CNID_DBD_RES_ERR_DB:
        errno = CNID_ERR_DB;
        return -1;
    default:
        abort();
    }
}

int cnid_dbd_wipe(struct _cnid_db *cdb)
{
    CNID_private *db;
    struct cnid_dbd_rqst rqst;
    struct cnid_dbd_rply rply;

    if (!cdb || !(db = cdb->_private)) {
        LOG(log_error, logtype_cnid, "cnid_wipe: Parameter error");
        errno = CNID_ERR_PARAM;
        return -1;
    }

    LOG(log_debug, logtype_cnid, "cnid_dbd_wipe");

    RQST_RESET(&rqst);
    rqst.op = CNID_DBD_OP_WIPE;
    rqst.cnid = 0;

    rply.namelen = 0;
    if (transmit(db, &rqst, &rply) < 0) {
        errno = CNID_ERR_DB;
        return -1;
    }

    if (rply.result != CNID_DBD_RES_OK) {
        errno = CNID_ERR_DB;
        return -1;
    }
    LOG(log_debug, logtype_cnid, "cnid_dbd_wipe: ok");

    return cnid_dbd_stamp(db);
}


struct _cnid_module cnid_dbd_module = {
    "dbd",
    {NULL, NULL},
    cnid_dbd_open,
    0
};

#endif /* CNID_DBD */