source: mainline/uspace/srv/devman/main.c@ 613d644

/*
 * Copyright (c) 2010 Lenka Trochtova
 * 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 devman Device manager.
 * @brief HelenOS device manager.
 * @{
 */

/** @file
 */

#include <assert.h>
#include <ipc/services.h>
#include <ns.h>
#include <async.h>
#include <stdio.h>
#include <errno.h>
#include <stdbool.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include <str.h>
#include <ctype.h>
#include <io/log.h>
#include <ipc/devman.h>
#include <ipc/driver.h>
#include <loc.h>

#include "client_conn.h"
#include "dev.h"
#include "devman.h"
#include "devtree.h"
#include "drv_conn.h"
#include "driver.h"
#include "fun.h"
#include "loc.h"

#define DRIVER_DEFAULT_STORE  "/drv"

driver_list_t drivers_list;
dev_tree_t device_tree;

static void devman_forward(ipc_callid_t iid, ipc_call_t *icall,
    bool drv_to_parent)
{
        devman_handle_t handle = IPC_GET_ARG2(*icall);
        devman_handle_t fwd_h;
        fun_node_t *fun = NULL;
        dev_node_t *dev = NULL;
        
        fun = find_fun_node(&device_tree, handle);
        if (fun == NULL)
                dev = find_dev_node(&device_tree, handle);
        else {
                fibril_rwlock_read_lock(&device_tree.rwlock);
                dev = fun->dev;
                if (dev != NULL)
                        dev_add_ref(dev);
                fibril_rwlock_read_unlock(&device_tree.rwlock);
        }

        /*
         * For a valid function to connect to we need a device. The root
         * function, for example, has no device and cannot be connected to.
         * This means @c dev needs to be valid regardless whether we are
         * connecting to a device or to a function.
         */
        if (dev == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "IPC forwarding failed - no device or "
                    "function with handle %" PRIun " was found.", handle);
                async_answer_0(iid, ENOENT);
                goto cleanup;
        }

        if (fun == NULL && !drv_to_parent) {
                log_msg(LOG_DEFAULT, LVL_ERROR, NAME ": devman_forward error - cannot "
                    "connect to handle %" PRIun ", refers to a device.",
                    handle);
                async_answer_0(iid, ENOENT);
                goto cleanup;
        }
        
        driver_t *driver = NULL;
        
        fibril_rwlock_read_lock(&device_tree.rwlock);
        
        if (drv_to_parent) {
                /* Connect to parent function of a device (or device function). */
                if (dev->pfun->dev != NULL)
                        driver = dev->pfun->dev->drv;
                
                fwd_h = dev->pfun->handle;
        } else {
                /* Connect to the specified function */
                driver = dev->drv;
                fwd_h = handle;
        }
        
        fibril_rwlock_read_unlock(&device_tree.rwlock);
        
        if (driver == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "IPC forwarding refused - " \
                    "the device %" PRIun " is not in usable state.", handle);
                async_answer_0(iid, ENOENT);
                goto cleanup;
        }
        
        int method;
        if (drv_to_parent)
                method = DRIVER_DRIVER;
        else
                method = DRIVER_CLIENT;
        
        if (!driver->sess) {
                log_msg(LOG_DEFAULT, LVL_ERROR,
                    "Could not forward to driver `%s'.", driver->name);
                async_answer_0(iid, EINVAL);
                goto cleanup;
        }

        if (fun != NULL) {
                log_msg(LOG_DEFAULT, LVL_DEBUG,
                    "Forwarding request for `%s' function to driver `%s'.",
                    fun->pathname, driver->name);
        } else {
                log_msg(LOG_DEFAULT, LVL_DEBUG,
                    "Forwarding request for `%s' device to driver `%s'.",
                    dev->pfun->pathname, driver->name);
        }
        
        async_exch_t *exch = async_exchange_begin(driver->sess);
        async_forward_fast(iid, exch, method, fwd_h, 0, IPC_FF_NONE);
        async_exchange_end(exch);
        
cleanup:
        if (dev != NULL)
                dev_del_ref(dev);
        
        if (fun != NULL)
                fun_del_ref(fun);
}

/** Function for handling connections from a client forwarded by the location
 * service to the device manager. */
static void devman_connection_loc(ipc_callid_t iid, ipc_call_t *icall)
{
        service_id_t service_id = IPC_GET_ARG2(*icall);
        fun_node_t *fun;
        dev_node_t *dev;
        devman_handle_t handle;
        driver_t *driver;

        fun = find_loc_tree_function(&device_tree, service_id);
        
        fibril_rwlock_read_lock(&device_tree.rwlock);
        
        if (fun == NULL || fun->dev == NULL || fun->dev->drv == NULL) {
                log_msg(LOG_DEFAULT, LVL_WARN, "devman_connection_loc(): function "
                    "not found.\n");
                fibril_rwlock_read_unlock(&device_tree.rwlock);
                async_answer_0(iid, ENOENT);
                return;
        }
        
        dev = fun->dev;
        driver = dev->drv;
        handle = fun->handle;
        
        fibril_rwlock_read_unlock(&device_tree.rwlock);
        
        async_exch_t *exch = async_exchange_begin(driver->sess);
        async_forward_fast(iid, exch, DRIVER_CLIENT, handle, 0,
            IPC_FF_NONE);
        async_exchange_end(exch);
        
        log_msg(LOG_DEFAULT, LVL_DEBUG,
            "Forwarding loc service request for `%s' function to driver `%s'.",
            fun->pathname, driver->name);

        fun_del_ref(fun);
}

/** Function for handling connections to device manager. */
static void devman_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        /* Select port. */
        switch ((sysarg_t) (IPC_GET_ARG1(*icall))) {
        case DEVMAN_DRIVER:
                devman_connection_driver(iid, icall);
                break;
        case DEVMAN_CLIENT:
                devman_connection_client(iid, icall);
                break;
        case DEVMAN_CONNECT_TO_DEVICE:
                /* Connect client to selected device. */
                devman_forward(iid, icall, false);
                break;
        case DEVMAN_CONNECT_FROM_LOC:
                /* Someone connected through loc node. */
                devman_connection_loc(iid, icall);
                break;
        case DEVMAN_CONNECT_TO_PARENTS_DEVICE:
                /* Connect client to selected device. */
                devman_forward(iid, icall, true);
                break;
        default:
                /* No such interface */
                async_answer_0(iid, ENOENT);
        }
}

static void *devman_client_data_create(void)
{
        client_t *client;
        
        client = calloc(1, sizeof(client_t));
        if (client == NULL)
                return NULL;
        
        fibril_mutex_initialize(&client->mutex);
        return client;
}

static void devman_client_data_destroy(void *data)
{
        free(data);
}

/** Initialize device manager internal structures. */
static bool devman_init(void)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "devman_init - looking for available drivers.");
        
        /* Initialize list of available drivers. */
        init_driver_list(&drivers_list);
        if (lookup_available_drivers(&drivers_list,
            DRIVER_DEFAULT_STORE) == 0) {
                log_msg(LOG_DEFAULT, LVL_FATAL, "No drivers found.");
                return false;
        }
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "devman_init - list of drivers has been initialized.");
        
        /* Create root device node. */
        if (!init_device_tree(&device_tree, &drivers_list)) {
                log_msg(LOG_DEFAULT, LVL_FATAL, "Failed to initialize device tree.");
                return false;
        }
        
        /*
         * Caution: As the device manager is not a real loc
         * driver (it uses a completely different IPC protocol
         * than an ordinary loc driver), forwarding a connection
         * from client to the devman by location service will
         * not work.
         */
        loc_server_register(NAME);
        
        return true;
}

int main(int argc, char *argv[])
{
        printf("%s: HelenOS Device Manager\n", NAME);
        
        int rc = log_init(NAME);
        if (rc != EOK) {
                printf("%s: Error initializing logging subsystem.\n", NAME);
                return rc;
        }
        
        /* Set handlers for incoming connections. */
        async_set_client_data_constructor(devman_client_data_create);
        async_set_client_data_destructor(devman_client_data_destroy);
        async_set_client_connection(devman_connection);
        
        if (!devman_init()) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Error while initializing service.");
                return -1;
        }
        
        /* Register device manager at naming service. */
        rc = service_register(SERVICE_DEVMAN);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering as a service.");
                return rc;
        }
        
        printf("%s: Accepting connections.\n", NAME);
        task_retval(0);
        async_manager();
        
        /* Never reached. */
        return 0;
}

/** @}
 */