source: vendor/current/ctdb/client/client_control.c

/*
   CTDB client code

   Copyright (C) Amitay Isaacs  2015

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "replace.h"
#include "system/network.h"
#include "system/filesys.h"

#include <talloc.h>
#include <tevent.h>
#include <tdb.h>

#include "lib/util/tevent_unix.h"

#include "common/reqid.h"
#include "common/srvid.h"
#include "common/comm.h"

#include "protocol/protocol.h"
#include "protocol/protocol_api.h"

#include "client/client_private.h"
#include "client/client.h"


/*
 * Handle REQ_CONTROL and REPLY_CONTROL
 */

struct ctdb_client_control_state {
        struct ctdb_client_context *client;
        uint32_t opcode;
        uint32_t flags;
        uint32_t reqid;
        struct ctdb_reply_control *reply;
        struct tevent_req *req;
};

static int ctdb_client_control_state_destructor(
        struct ctdb_client_control_state *state);
static void ctdb_client_control_done(struct tevent_req *subreq);

struct tevent_req *ctdb_client_control_send(TALLOC_CTX *mem_ctx,
                                            struct tevent_context *ev,
                                            struct ctdb_client_context *client,
                                            uint32_t destnode,
                                            struct timeval timeout,
                                            struct ctdb_req_control *request)
{
        struct ctdb_req_header h;
        struct tevent_req *req, *subreq;
        struct ctdb_client_control_state *state;
        uint32_t reqid;
        uint8_t *buf;
        size_t buflen;
        int ret;

        req = tevent_req_create(mem_ctx, &state,
                                struct ctdb_client_control_state);
        if (req == NULL) {
                return NULL;
        }

        reqid = reqid_new(client->idr, state);
        if (reqid == REQID_INVALID) {
                talloc_free(req);
                return NULL;
        }

        state->client = client;
        state->flags = request->flags;
        state->opcode = request->opcode;
        state->reqid = reqid;
        state->req = req;
        state->reply = talloc_zero(state, struct ctdb_reply_control);
        if (tevent_req_nomem(state->reply, req)) {
                return tevent_req_post(req, ev);
        }

        talloc_set_destructor(state, ctdb_client_control_state_destructor);

        ctdb_req_header_fill(&h, 0, CTDB_REQ_CONTROL, destnode,
                             client->pnn, reqid);

        ret = ctdb_req_control_push(&h, request, state, &buf, &buflen);
        if (ret != 0) {
                tevent_req_error(req, ret);
                return tevent_req_post(req, ev);
        }

        if (!tevent_timeval_is_zero(&timeout)) {
                tevent_req_set_endtime(req, ev, timeout);
        }

        subreq = comm_write_send(state, ev, client->comm, buf, buflen);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, ctdb_client_control_done, req);

        return req;
}

static int ctdb_client_control_state_destructor(
        struct ctdb_client_control_state *state)
{
        reqid_remove(state->client->idr, state->reqid);
        return 0;
}

static void ctdb_client_control_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct ctdb_client_control_state *state = tevent_req_data(
                req, struct ctdb_client_control_state);
        bool status;
        int ret;

        status = comm_write_recv(subreq, &ret);
        TALLOC_FREE(subreq);
        if (! status) {
                tevent_req_error(req, ret);
                return;
        }

        /* Daemon will not reply, so we set status to 0 */
        if (state->flags & CTDB_CTRL_FLAG_NOREPLY) {
                state->reply->status = 0;
                tevent_req_done(req);
        }

        /* wait for the reply or timeout */
}

void ctdb_client_reply_control(struct ctdb_client_context *client,
                               uint8_t *buf, size_t buflen, uint32_t reqid)
{
        struct ctdb_req_header h;
        struct ctdb_client_control_state *state;
        int ret;

        state = reqid_find(client->idr, reqid,
                           struct ctdb_client_control_state);
        if (state == NULL) {
                return;
        }

        if (reqid != state->reqid) {
                return;
        }

        ret = ctdb_reply_control_pull(buf, buflen, state->opcode, &h,
                                      state->reply, state->reply);
        if (ret != 0) {
                tevent_req_error(state->req, ret);
                return;
        }

        tevent_req_done(state->req);
}

bool ctdb_client_control_recv(struct tevent_req *req, int *perr,
                              TALLOC_CTX *mem_ctx,
                              struct ctdb_reply_control **reply)
{
        struct ctdb_client_control_state *state = tevent_req_data(
                req, struct ctdb_client_control_state);
        int err;

        if (tevent_req_is_unix_error(req, &err)) {
                if (perr != NULL) {
                        *perr = err;
                }
                return false;
        }

        if (reply != NULL) {
                *reply = talloc_steal(mem_ctx, state->reply);
        }

        return true;
}

/*
 * Handle multiple nodes - there cannot be any return data
 */

struct ctdb_client_control_multi_state {
        uint32_t *pnn_list;
        int count;
        int done;
        int err;
        int *err_list;
        struct ctdb_reply_control **reply;
};

struct control_index_state {
        struct tevent_req *req;
        int index;
};

static void ctdb_client_control_multi_done(struct tevent_req *subreq);

struct tevent_req *ctdb_client_control_multi_send(
                                TALLOC_CTX *mem_ctx,
                                struct tevent_context *ev,
                                struct ctdb_client_context *client,
                                uint32_t *pnn_list, int count,
                                struct timeval timeout,
                                struct ctdb_req_control *request)
{
        struct tevent_req *req, *subreq;
        struct ctdb_client_control_multi_state *state;
        int i;

        if (pnn_list == NULL || count == 0) {
                return NULL;
        }

        req = tevent_req_create(mem_ctx, &state,
                                struct ctdb_client_control_multi_state);
        if (req == NULL) {
                return NULL;
        }

        state->pnn_list = pnn_list;
        state->count = count;
        state->done = 0;
        state->err = 0;
        state->err_list = talloc_zero_array(state, int, count);
        if (tevent_req_nomem(state->err_list, req)) {
                return tevent_req_post(req, ev);
        }
        state->reply = talloc_zero_array(state, struct ctdb_reply_control *,
                                         count);
        if (tevent_req_nomem(state->reply, req)) {
                return tevent_req_post(req, ev);
        }

        for (i=0; i<count; i++) {
                struct control_index_state *substate;

                subreq = ctdb_client_control_send(state, ev, client,
                                                  pnn_list[i], timeout,
                                                  request);
                if (tevent_req_nomem(subreq, req)) {
                        return tevent_req_post(req, ev);
                }

                substate = talloc(subreq, struct control_index_state);
                if (tevent_req_nomem(substate, req)) {
                        return tevent_req_post(req, ev);
                }

                substate->req = req;
                substate->index = i;

                tevent_req_set_callback(subreq, ctdb_client_control_multi_done,
                                        substate);
        }

        return req;
}

static void ctdb_client_control_multi_done(struct tevent_req *subreq)
{
        struct control_index_state *substate = tevent_req_callback_data(
                subreq, struct control_index_state);
        struct tevent_req *req = substate->req;
        int idx = substate->index;
        struct ctdb_client_control_multi_state *state = tevent_req_data(
                req, struct ctdb_client_control_multi_state);
        bool status;
        int ret;

        status = ctdb_client_control_recv(subreq, &ret, state->reply,
                                          &state->reply[idx]);
        TALLOC_FREE(subreq);
        if (! status) {
                if (state->err == 0) {
                        state->err = ret;
                        state->err_list[idx] = state->err;
                }
        } else {
                if (state->reply[idx]->status != 0) {
                        if (state->err == 0) {
                                state->err = state->reply[idx]->status;
                                state->err_list[idx] = state->err;
                        }
                }
        }

        state->done += 1;

        if (state->done == state->count) {
                tevent_req_done(req);
        }
}

bool ctdb_client_control_multi_recv(struct tevent_req *req, int *perr,
                                    TALLOC_CTX *mem_ctx, int **perr_list,
                                    struct ctdb_reply_control ***preply)
{
        struct ctdb_client_control_multi_state *state = tevent_req_data(
                req, struct ctdb_client_control_multi_state);
        int err;

        if (tevent_req_is_unix_error(req, &err)) {
                if (perr != NULL) {
                        *perr = err;
                }
                if (perr_list != NULL) {
                        *perr_list = talloc_steal(mem_ctx, state->err_list);
                }
                return false;
        }

        if (perr != NULL) {
                *perr = state->err;
        }

        if (perr_list != NULL) {
                *perr_list = talloc_steal(mem_ctx, state->err_list);
        }

        if (preply != NULL) {
                *preply = talloc_steal(mem_ctx, state->reply);
        }

        if (state->err != 0) {
                return false;
        }

        return true;
}

int ctdb_client_control_multi_error(uint32_t *pnn_list, int count,
                                    int *err_list, uint32_t *pnn)
{
        int ret = 0, i;

        for (i=0; i<count; i++) {
                if (err_list[i] != 0) {
                        ret = err_list[i];
                        *pnn = pnn_list[i];
                }
        }

        return ret;
}

/*
 * Sync version of control send/recv
 */

int ctdb_client_control(TALLOC_CTX *mem_ctx,
                        struct tevent_context *ev,
                        struct ctdb_client_context *client,
                        uint32_t destnode,
                        struct timeval timeout,
                        struct ctdb_req_control *request,
                        struct ctdb_reply_control **reply)
{
        struct tevent_req *req;
        int ret;
        bool status;

        req = ctdb_client_control_send(mem_ctx, ev, client, destnode, timeout,
                                       request);
        if (req == NULL) {
                return ENOMEM;
        }

        tevent_req_poll(req, ev);

        status = ctdb_client_control_recv(req, &ret, mem_ctx, reply);
        if (! status) {
                return ret;
        }

        return 0;
}

int ctdb_client_control_multi(TALLOC_CTX *mem_ctx,
                              struct tevent_context *ev,
                              struct ctdb_client_context *client,
                              uint32_t *pnn_list, int count,
                              struct timeval timeout,
                              struct ctdb_req_control *request,
                              int **perr_list,
                              struct ctdb_reply_control ***preply)
{
        struct tevent_req *req;
        bool status;
        int ret;

        req = ctdb_client_control_multi_send(mem_ctx, ev, client,
                                             pnn_list, count,
                                             timeout, request);
        if (req == NULL) {
                return ENOMEM;
        }

        tevent_req_poll(req, ev);

        status = ctdb_client_control_multi_recv(req, &ret, mem_ctx, perr_list,
                                                preply);
        if (! status) {
                return ret;
        }

        return 0;
}