/*
  Copyright (c) 2008-2013 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

#include "glusterfs/dict.h"
#include "glusterfs/statedump.h"
#include "glusterfs/client_t.h"
#include "glusterfs/list.h"
#include "glusterfs/libglusterfs-messages.h"

static int
gf_client_chain_client_entries(cliententry_t *entries, uint32_t startidx,
                               uint32_t endcount)
{
    uint32_t i = 0;

    if (!entries) {
        gf_msg_callingfn("client_t", GF_LOG_WARNING, EINVAL, LG_MSG_INVALID_ARG,
                         "!entries");
        return -1;
    }

    /* Chain only till the second to last entry because we want to
     * ensure that the last entry has GF_CLIENTTABLE_END.
     */
    for (i = startidx; i < (endcount - 1); i++)
        entries[i].next_free = i + 1;

    /* i has already been incremented up to the last entry. */
    entries[i].next_free = GF_CLIENTTABLE_END;

    return 0;
}

static int
gf_client_clienttable_expand(clienttable_t *clienttable, uint32_t nr)
{
    cliententry_t *oldclients = NULL;
    uint32_t oldmax_clients = -1;
    int ret = -1;

    if (clienttable == NULL || nr <= clienttable->max_clients) {
        gf_msg_callingfn("client_t", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
                         "invalid argument");
        ret = EINVAL;
        goto out;
    }

    oldclients = clienttable->cliententries;
    oldmax_clients = clienttable->max_clients;

    clienttable->cliententries = GF_CALLOC(nr, sizeof(cliententry_t),
                                           gf_common_mt_cliententry_t);
    if (!clienttable->cliententries) {
        clienttable->cliententries = oldclients;
        ret = 0;
        goto out;
    }
    clienttable->max_clients = nr;

    if (oldclients) {
        uint32_t cpy = oldmax_clients * sizeof(cliententry_t);
        memcpy(clienttable->cliententries, oldclients, cpy);
    }

    gf_client_chain_client_entries(clienttable->cliententries, oldmax_clients,
                                   clienttable->max_clients);

    /* Now that expansion is done, we must update the client list
     * head pointer so that the client allocation functions can continue
     * using the expanded table.
     */
    clienttable->first_free = oldmax_clients;
    GF_FREE(oldclients);
    ret = 0;
out:
    return ret;
}

clienttable_t *
gf_clienttable_alloc(void)
{
    clienttable_t *clienttable = NULL;
    int result = 0;

    clienttable = GF_CALLOC(1, sizeof(clienttable_t),
                            gf_common_mt_clienttable_t);
    if (!clienttable)
        return NULL;

    LOCK_INIT(&clienttable->lock);

    result = gf_client_clienttable_expand(clienttable,
                                          GF_CLIENTTABLE_INITIAL_SIZE);
    if (result != 0) {
        gf_msg("client_t", GF_LOG_ERROR, 0, LG_MSG_EXPAND_CLIENT_TABLE_FAILED,
               "gf_client_clienttable_expand failed");
        GF_FREE(clienttable);
        return NULL;
    }

    return clienttable;
}

/*
 * Increments ref.bind if the client is already present or creates a new
 * client with ref.bind = 1,ref.count = 1 it signifies that
 * as long as ref.bind is > 0 client should be alive.
 */
client_t *
gf_client_get(xlator_t *this, client_auth_data_t *cred, char *client_uid,
              char *subdir_mount)
{
    client_t *client = NULL;
    cliententry_t *cliententry = NULL;
    clienttable_t *clienttable = NULL;
    unsigned int i = 0;
    unsigned int client_uid_len = 0;

    if (this == NULL || client_uid == NULL) {
        gf_msg_callingfn("client_t", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
                         "invalid argument");
        errno = EINVAL;
        return NULL;
    }

    clienttable = this->ctx->clienttable;

    LOCK(&clienttable->lock);
    {
        for (; i < clienttable->max_clients; i++) {
            client = clienttable->cliententries[i].client;
            if (client == NULL)
                continue;
            /*
             * look for matching client_uid, _and_
             * if auth was used, matching auth flavour and data
             */
            if (strcmp(client_uid, client->client_uid) == 0 &&
                (cred->flavour && (cred->flavour == client->auth.flavour &&
                                   (size_t)cred->datalen == client->auth.len &&
                                   memcmp(cred->authdata, client->auth.data,
                                          client->auth.len) == 0))) {
                GF_ATOMIC_INC(client->bind);
                goto unlock;
            }
        }

        client_uid_len = strlen(client_uid) + 1;
        client = GF_CALLOC(1, sizeof(client_t) + client_uid_len,
                           gf_common_mt_client_t);
        if (client == NULL) {
            errno = ENOMEM;
            goto unlock;
        }

        GF_ATOMIC_INIT(client->bind, 1);
        GF_ATOMIC_INIT(client->count, 1);
        client->this = this;
        client->tbl_index = clienttable->first_free;

        client->auth.flavour = cred->flavour;
        if (cred->flavour) {
            client->auth.data = GF_MALLOC(cred->datalen, gf_common_mt_client_t);
            if (client->auth.data == NULL) {
                GF_FREE(client);
                client = NULL;
                errno = ENOMEM;
                goto unlock;
            }
            memcpy(client->auth.data, cred->authdata, cred->datalen);
            client->auth.len = cred->datalen;
        }

        if (subdir_mount != NULL)
            client->subdir_mount = gf_strdup(subdir_mount);

        GF_ATOMIC_INIT(client->fd_cnt, 0);
        LOCK_INIT(&client->scratch_ctx_lock);
        memcpy(client->client_uid, client_uid, client_uid_len);

        cliententry = &clienttable->cliententries[clienttable->first_free];
        if (cliententry->next_free == GF_CLIENTTABLE_END) {
            int result = gf_client_clienttable_expand(
                clienttable,
                clienttable->max_clients + GF_CLIENTTABLE_INITIAL_SIZE);
            if (result != 0) {
                GF_FREE(client);
                client = NULL;
                errno = result;
                goto unlock;
            }
            cliententry = &clienttable->cliententries[client->tbl_index];
            cliententry->next_free = clienttable->first_free;
        }
        cliententry->client = client;
        clienttable->first_free = cliententry->next_free;
        cliententry->next_free = GF_CLIENTENTRY_ALLOCATED;
    }
unlock:
    UNLOCK(&clienttable->lock);

    if (client)
        gf_msg_callingfn("client_t", GF_LOG_DEBUG, 0, LG_MSG_BIND_REF,
                         "%s: bind_ref: %" GF_PRI_ATOMIC
                         ", ref: "
                         "%" GF_PRI_ATOMIC,
                         client->client_uid, GF_ATOMIC_GET(client->bind),
                         GF_ATOMIC_GET(client->count));
    return client;
}

void
gf_client_put(client_t *client, gf_boolean_t *detached)
{
    gf_boolean_t unref = _gf_false;
    int bind_ref;

    if (client == NULL)
        goto out;

    if (detached)
        *detached = _gf_false;

    bind_ref = GF_ATOMIC_DEC(client->bind);
    if (bind_ref == 0)
        unref = _gf_true;

    gf_msg_callingfn("client_t", GF_LOG_DEBUG, 0, LG_MSG_BIND_REF,
                     "%s: "
                     "bind_ref: %" GF_PRI_ATOMIC ", ref: %" GF_PRI_ATOMIC
                     ", "
                     "unref: %d",
                     client->client_uid, GF_ATOMIC_GET(client->bind),
                     GF_ATOMIC_GET(client->count), unref);
    if (unref) {
        if (detached)
            *detached = _gf_true;
        gf_client_unref(client);
    }

out:
    return;
}

client_t *
gf_client_ref(client_t *client)
{
    if (!client) {
        gf_msg_callingfn("client_t", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
                         "null client");
        return NULL;
    }

    GF_ATOMIC_INC(client->count);
    gf_msg_callingfn("client_t", GF_LOG_DEBUG, 0, LG_MSG_REF_COUNT,
                     "%s: "
                     "ref-count %" GF_PRI_ATOMIC,
                     client->client_uid, GF_ATOMIC_GET(client->count));
    return client;
}

static void
gf_client_destroy_recursive(xlator_t *xl, client_t *client)
{
    xlator_list_t *trav;

    if (!xl->call_cleanup && xl->cbks->client_destroy) {
        xl->cbks->client_destroy(xl, client);
    }

    for (trav = xl->children; trav; trav = trav->next) {
        gf_client_destroy_recursive(trav->xlator, client);
    }
}

static void
client_destroy(client_t *client)
{
    clienttable_t *clienttable = NULL;
    glusterfs_graph_t *gtrav = NULL;

    if (client == NULL) {
        gf_msg_callingfn("xlator", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
                         "invalid argument");
        goto out;
    }

    clienttable = client->this->ctx->clienttable;

    LOCK(&clienttable->lock);
    {
        clienttable->cliententries[client->tbl_index].client = NULL;
        clienttable->cliententries[client->tbl_index]
            .next_free = clienttable->first_free;
        clienttable->first_free = client->tbl_index;
    }
    UNLOCK(&clienttable->lock);

    list_for_each_entry(gtrav, &client->this->ctx->graphs, list)
    {
        gf_client_destroy_recursive(gtrav->top, client);
    }

    if (client->subdir_inode)
        inode_unref(client->subdir_inode);

    LOCK_DESTROY(&client->scratch_ctx_lock);

    GF_FREE(client->auth.data);
    GF_FREE(client->auth.username);
    GF_FREE(client->auth.passwd);
    GF_FREE(client->subdir_mount);
    GF_FREE(client->client_name);
    GF_FREE(client);
out:
    return;
}

static int
gf_client_disconnect_recursive(xlator_t *xl, client_t *client)
{
    int ret = 0;
    xlator_list_t *trav;

    if (!xl->call_cleanup && xl->cbks->client_disconnect) {
        ret = xl->cbks->client_disconnect(xl, client);
    }

    for (trav = xl->children; trav; trav = trav->next) {
        ret |= gf_client_disconnect_recursive(trav->xlator, client);
    }

    return ret;
}

int
gf_client_disconnect(client_t *client)
{
    int ret = 0;
    glusterfs_graph_t *gtrav = NULL;

    list_for_each_entry(gtrav, &client->this->ctx->graphs, list)
    {
        ret |= gf_client_disconnect_recursive(gtrav->top, client);
    }

    return ret;
}

void
gf_client_unref(client_t *client)
{
    uint64_t refcount;

    if (!client) {
        gf_msg_callingfn("client_t", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
                         "client is NULL");
        return;
    }

    refcount = GF_ATOMIC_DEC(client->count);
    gf_msg_callingfn("client_t", GF_LOG_DEBUG, 0, LG_MSG_REF_COUNT,
                     "%s: "
                     "ref-count %" GF_PRI_ATOMIC,
                     client->client_uid, refcount);
    if (refcount == 0) {
        gf_msg(THIS->name, GF_LOG_INFO, 0, LG_MSG_DISCONNECT_CLIENT,
               "Shutting down connection %s", client->client_uid);
        client_destroy(client);
    }
}

/* value (assumed to be passed NULL) is returned if the key was found.
   ret value >= 0 - the location it is found (value is non NULL)
   or the 1st free slot (in case value is NULL)
   or -1 in case no free slots found
*/
static int
__client_ctx_get_int(client_t *client, void *key, void **value)
{
    int index = 0;
    int set_idx = -1;

    for (index = 0; index < GF_CLIENTCTX_INITIAL_SIZE; index++) {
        if (!client->scratch_ctx[index].ctx_key) {
            if (set_idx == -1)
                set_idx = index;
            /* don't break, check if key already exists
               further on */
        } else if (client->scratch_ctx[index].ctx_key == key) {
            *value = client->scratch_ctx[index].ctx_value;
            return index;
        }
    }

    // if the value was not found, return -1 or the 1st free slot.
    return set_idx;
}

/*will return success with old value if exist*/
void *
client_ctx_set(client_t *client, void *key, void *value)
{
    int ret = 0;
    void *ret_value = NULL;

    if (!client || !key || !value)
        return NULL;

    LOCK(&client->scratch_ctx_lock);
    {
        ret = __client_ctx_get_int(client, key, &ret_value);
        if (!ret_value && ret >= 0) {
            // key was not found and ret is the location of the 1st free slot
            client->scratch_ctx[ret].ctx_key = key;
            client->scratch_ctx[ret].ctx_value = value;
            ret_value = value;
        }
    }
    UNLOCK(&client->scratch_ctx_lock);

    return ret_value;
}

void *
client_ctx_get(client_t *client, void *key)
{
    void *ret_value = NULL;

    if (!client || !key)
        return NULL;

    LOCK(&client->scratch_ctx_lock);
    {
        (void)__client_ctx_get_int(client, key, &ret_value);
    }
    UNLOCK(&client->scratch_ctx_lock);

    return ret_value;
}

void *
client_ctx_del(client_t *client, void *key)
{
    int ret = 0;
    void *ret_value = NULL;

    if (!client || !key)
        goto out;

    LOCK(&client->scratch_ctx_lock);
    {
        ret = __client_ctx_get_int(client, key, &ret_value);
        if (ret_value) {
            client->scratch_ctx[ret].ctx_key = 0;
            client->scratch_ctx[ret].ctx_value = 0;
        }
    }
    UNLOCK(&client->scratch_ctx_lock);

out:
    return ret_value;
}

void
client_ctx_dump(client_t *client, char *prefix)
{
#if 0 /* TBD, FIXME */
        struct client_ctx   *client_ctx = NULL;
        xlator_t            *xl = NULL;
        int                  i = 0;

        if ((client == NULL) || (client->ctx == NULL)) {
                goto out;
        }

        LOCK (&client->ctx_lock);
        if (client->ctx != NULL) {
                client_ctx = GF_CALLOC (client->inode->table->xl->graph->ctx_count,
                                        sizeof (*client_ctx),
                                        gf_common_mt_client_ctx);
                if (client_ctx == NULL) {
                        goto unlock;
                }

                for (i = 0; i < client->inode->table->xl->graph->ctx_count; i++) {
                        client_ctx[i] = client->ctx[i];
                }
        }
unlock:
        UNLOCK (&client->ctx_lock);

        if (client_ctx == NULL) {
                goto out;
        }

        for (i = 0; i < client->inode->table->xl->graph->ctx_count; i++) {
                if (client_ctx[i].xl_key) {
                        xl = (xlator_t *)(long)client_ctx[i].xl_key;
                        if (xl->dumpops && xl->dumpops->clientctx)
                                xl->dumpops->clientctx (xl, client);
                }
        }
out:
        GF_FREE (client_ctx);
#endif
}

/*
 * the following functions are here to preserve legacy behavior of the
 * protocol/server xlator dump, but perhaps they should just be folded
 * into the client dump instead?
 */
int
gf_client_dump_fdtables_to_dict(xlator_t *this, dict_t *dict)
{
    clienttable_t *clienttable = NULL;
    int count = 0;
    int ret = -1;
#ifdef NOTYET
    client_t *client = NULL;
    char key[GF_DUMP_MAX_BUF_LEN] = {
        0,
    };
#endif

    GF_VALIDATE_OR_GOTO(THIS->name, this, out);
    GF_VALIDATE_OR_GOTO(this->name, dict, out);

    clienttable = this->ctx->clienttable;

    if (!clienttable)
        return -1;

#ifdef NOTYET
    ret = TRY_LOCK(&clienttable->lock);
    {
        if (ret) {
            gf_msg("client_t", GF_LOG_WARNING, 0, LG_MSG_LOCK_FAILED,
                   "Unable to acquire lock");
            return -1;
        }
        for (; count < clienttable->max_clients; count++) {
            if (GF_CLIENTENTRY_ALLOCATED !=
                clienttable->cliententries[count].next_free)
                continue;
            client = clienttable->cliententries[count].client;
            if (client->bound_xl &&
                !strcmp(client->bound_xl->name, this->name)) {
                snprintf(key, sizeof(key), "conn%d", count++);
                fdtable_dump_to_dict(client->server_ctx.fdtable, key, dict);
            }
        }
    }
    UNLOCK(&clienttable->lock);
#endif

    ret = dict_set_int32(dict, "conncount", count);
out:
    return ret;
}

int
gf_client_dump_fdtables(xlator_t *this)
{
    client_t *client = NULL;
    clienttable_t *clienttable = NULL;
    int count = 1;
    int ret = -1;
    char key[GF_DUMP_MAX_BUF_LEN] = {
        0,
    };

    GF_VALIDATE_OR_GOTO(THIS->name, this, out);

    clienttable = this->ctx->clienttable;

    if (!clienttable)
        return -1;

    ret = TRY_LOCK(&clienttable->lock);
    {
        if (ret) {
            gf_msg("client_t", GF_LOG_WARNING, 0, LG_MSG_LOCK_FAILED,
                   "Unable to acquire lock");
            return -1;
        }

        for (; count < clienttable->max_clients; count++) {
            if (GF_CLIENTENTRY_ALLOCATED !=
                clienttable->cliententries[count].next_free)
                continue;
            client = clienttable->cliententries[count].client;
            if (client->client_uid) {
                gf_proc_dump_build_key(key, "conn", "%d.id", count);
                gf_proc_dump_write(key, "%s", client->client_uid);
            }

            if (client->subdir_mount) {
                gf_proc_dump_build_key(key, "conn", "%d.subdir", count);
                gf_proc_dump_write(key, "%s", client->subdir_mount);
            }
            gf_proc_dump_build_key(key, "conn", "%d.ref", count);
            gf_proc_dump_write(key, "%" GF_PRI_ATOMIC,
                               GF_ATOMIC_GET(client->count));
            if (client->bound_xl) {
                gf_proc_dump_build_key(key, "conn", "%d.bound_xl", count);
                gf_proc_dump_write(key, "%s", client->bound_xl->name);
            }

#ifdef NOTYET
            gf_proc_dump_build_key(key, "conn", "%d.id", count);
            fdtable_dump(client->server_ctx.fdtable, key);
#endif
        }
    }

    UNLOCK(&clienttable->lock);

    ret = 0;
out:
    return ret;
}

int
gf_client_dump_inodes_to_dict(xlator_t *this, dict_t *dict)
{
    client_t *client = NULL;
    clienttable_t *clienttable = NULL;
    xlator_t *prev_bound_xl = NULL;
    char key[32] = {
        0,
    };
    int count = 0;
    int ret = -1;

    GF_VALIDATE_OR_GOTO(THIS->name, this, out);
    GF_VALIDATE_OR_GOTO(this->name, dict, out);

    clienttable = this->ctx->clienttable;

    if (!clienttable)
        return -1;

    ret = LOCK(&clienttable->lock);
    {
        if (ret) {
            gf_msg("client_t", GF_LOG_WARNING, 0, LG_MSG_LOCK_FAILED,
                   "Unable to acquire lock");
            return -1;
        }
        for (; count < clienttable->max_clients; count++) {
            if (GF_CLIENTENTRY_ALLOCATED !=
                clienttable->cliententries[count].next_free)
                continue;
            client = clienttable->cliententries[count].client;
            if (client->bound_xl &&
                !strcmp(client->bound_xl->name, this->name)) {
                if (client->bound_xl->itable) {
                    /* Presently every brick contains only
                     * one bound_xl for all connections.
                     * This will lead to duplicating of
                     *  the inode lists, if listing is
                     * done for every connection. This
                     * simple check prevents duplication
                     * in the present case. If need arises
                     * the check can be improved.
                     */
                    if (client->bound_xl == prev_bound_xl)
                        continue;
                    prev_bound_xl = client->bound_xl;

                    snprintf(key, sizeof(key), "conn%d", count);
                    inode_table_dump_to_dict(client->bound_xl->itable, key,
                                             dict);
                }
            }
        }
    }
    UNLOCK(&clienttable->lock);

    ret = dict_set_int32(dict, "conncount", count);

out:
    if (prev_bound_xl)
        prev_bound_xl = NULL;
    return ret;
}

int
gf_client_dump_inodes(xlator_t *this)
{
    client_t *client = NULL;
    clienttable_t *clienttable = NULL;
    xlator_t *prev_bound_xl = NULL;
    int count = 0;
    int ret = -1;
    char key[GF_DUMP_MAX_BUF_LEN] = {
        0,
    };

    GF_VALIDATE_OR_GOTO(THIS->name, this, out);

    clienttable = this->ctx->clienttable;

    if (!clienttable)
        goto out;

    ret = TRY_LOCK(&clienttable->lock);
    {
        if (ret) {
            gf_msg("client_t", GF_LOG_WARNING, 0, LG_MSG_LOCK_FAILED,
                   "Unable to acquire lock");
            goto out;
        }

        for (; count < clienttable->max_clients; count++) {
            if (GF_CLIENTENTRY_ALLOCATED !=
                clienttable->cliententries[count].next_free)
                continue;
            client = clienttable->cliententries[count].client;
            if (client->bound_xl && client->bound_xl->itable) {
                /* Presently every brick contains only
                 * one bound_xl for all connections.
                 * This will lead to duplicating of
                 * the inode lists, if listing is
                 * done for every connection. This
                 * simple check prevents duplication
                 * in the present case. If need arises
                 * the check can be improved.
                 */
                if (client->bound_xl == prev_bound_xl)
                    continue;
                prev_bound_xl = client->bound_xl;

                gf_proc_dump_build_key(key, "conn", "%d.bound_xl.%s", count,
                                       client->bound_xl->name);
                inode_table_dump(client->bound_xl->itable, key);
            }
        }
    }
    UNLOCK(&clienttable->lock);

    ret = 0;
out:
    return ret;
}