source: mainline/uspace/srv/logger/main.c@ 76d92db1

/*
 * Copyright (c) 2012 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup logger Logging service.
 * @brief HelenOS logging service.
 * @{
 */

/** @file
 */

#include <ipc/services.h>
#include <ipc/logger.h>
#include <io/log.h>
#include <ns.h>
#include <async.h>
#include <stdio.h>
#include <errno.h>
#include <str_error.h>
#include <malloc.h>
#include "logger.h"

static logging_namespace_t *find_namespace_and_attach_writer(void)
{
        ipc_call_t call;
        ipc_callid_t callid = async_get_call(&call);

        if (IPC_GET_IMETHOD(call) != LOGGER_REGISTER) {
                async_answer_0(callid, EINVAL);
                return NULL;
        }

        void *name;
        int rc = async_data_write_accept(&name, true, 1, MAX_NAMESPACE_LENGTH, 0, NULL);
        async_answer_0(callid, rc);

        if (rc != EOK) {
                return NULL;
        }

        logging_namespace_t *result = namespace_writer_attach((const char *) name);

        free(name);

        return result;
}

static int handle_receive_message(logging_namespace_t *namespace, int level)
{
        bool skip_message = (level > DEFAULT_LOGGING_LEVEL) && !namespace_has_reader(namespace, level);
        if (skip_message) {
                /* Abort the actual message buffer transfer. */
                ipc_callid_t callid;
                size_t size;
                int rc = ENAK;
                if (!async_data_write_receive(&callid, &size))
                        rc = EINVAL;

                async_answer_0(callid, rc);
                return rc;
        }

        void *message;
        int rc = async_data_write_accept(&message, true, 0, 0, 0, NULL);
        if (rc != EOK) {
                return rc;
        }

        namespace_add_message(namespace, message, level);

        free(message);

        return EOK;
}

static void connection_handler_sink(logging_namespace_t *namespace)
{
        printf(NAME "/sink: new client %s.\n", namespace_get_name(namespace));

        while (true) {
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);

                if (!IPC_GET_IMETHOD(call))
                        break;

                int rc;

                switch (IPC_GET_IMETHOD(call)) {
                case LOGGER_MESSAGE:
                        rc = handle_receive_message(namespace, IPC_GET_ARG1(call));
                        async_answer_0(callid, rc);
                        break;
                default:
                        async_answer_0(callid, EINVAL);
                        break;
                }
        }

        printf(NAME "/sink: client %s terminated.\n", namespace_get_name(namespace));
        namespace_writer_detach(namespace);
}


static logging_namespace_t *find_namespace_and_attach_reader(void)
{
        ipc_call_t call;
        ipc_callid_t callid = async_get_call(&call);

        if (IPC_GET_IMETHOD(call) != LOGGER_CONNECT) {
                async_answer_0(callid, EINVAL);
                return NULL;
        }

        void *name;
        int rc = async_data_write_accept(&name, true, 1, MAX_NAMESPACE_LENGTH, 0, NULL);

        if (rc != EOK) {
                async_answer_0(callid, rc);
                return NULL;
        }

        logging_namespace_t *result = namespace_reader_attach((const char *) name);
        if (result == NULL) {
                rc = ENOENT;
        }

        async_answer_0(callid, rc);

        free(name);

        return result;
}


static int handle_send_message(logging_namespace_t *namespace, int *level)
{
        ipc_callid_t callid;
        size_t size;
        bool expects_data_read = async_data_read_receive(&callid, &size);
        if (!expects_data_read) {
                return EINVAL;
        }

        log_message_t *message = namespace_get_next_message(namespace);
        size_t message_len = str_size(message->message) + 1;

        if (size > message_len) {
                size = message_len;
        }

        async_data_read_finalize(callid, message->message, size);

        *level = (int) message->level;
        message_destroy(message);

        return EOK;
}


static void connection_handler_source(logging_namespace_t *namespace)
{
        printf(NAME "/source: new client for %s.\n", namespace_get_name(namespace));

        while (true) {
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);

                if (!IPC_GET_IMETHOD(call))
                        break;

                int rc;
                int message_level = 0;

                switch (IPC_GET_IMETHOD(call)) {
                case LOGGER_GET_MESSAGE:
                        rc = handle_send_message(namespace, &message_level);
                        async_answer_1(callid, rc, message_level);
                        break;
                default:
                        async_answer_0(callid, EINVAL);
                        break;
                }
        }

        printf(NAME "/source: client %s terminated.\n", namespace_get_name(namespace));
        namespace_reader_detach(namespace);
}

static void connection_handler(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        logger_interface_t iface = IPC_GET_ARG1(*icall);

        logging_namespace_t *namespace = NULL;

        switch (iface) {
        case LOGGER_INTERFACE_SINK:
                /* First call has to be the registration. */
                async_answer_0(iid, EOK);
                namespace = find_namespace_and_attach_writer();
                if (namespace == NULL) {
                        fprintf(stderr, NAME ": failed to register namespace.\n");
                        break;
                }
                connection_handler_sink(namespace);
                break;
        case LOGGER_INTERFACE_SOURCE:
                async_answer_0(iid, EOK);
                /* First call has to find existing namespace. */
                namespace = find_namespace_and_attach_reader();
                if (namespace == NULL) {
                        fprintf(stderr, NAME ": failed to attach client.\n");
                        break;
                }
                connection_handler_source(namespace);
                break;
        default:
                async_answer_0(iid, EINVAL);
                break;
        }
}

int main(int argc, char *argv[])
{
        printf(NAME ": HelenOS Logging Service\n");
        
        async_set_client_connection(connection_handler);
        
        int rc = service_register(SERVICE_LOGGER);
        if (rc != EOK) {
                printf(NAME ": failed to register: %s.\n", str_error(rc));
                return -1;
        }
        
        printf(NAME ": Accepting connections\n");
        async_manager();
        
        /* Never reached */
        return 0;
}

/**
 * @}
 */