source: mainline/uspace/srv/devman/main.c@ c47e1a8

/*
 * 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 <ipc/ns.h>
#include <async.h>
#include <stdio.h>
#include <errno.h>
#include <bool.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include <str.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <ctype.h>
#include <ipc/devman.h>
#include <ipc/driver.h>
#include <thread.h>

#include "devman.h"

#define DRIVER_DEFAULT_STORE  "/srv/drivers"

static driver_list_t drivers_list;
static dev_tree_t device_tree;

/** Wrapper for receiving strings
 *
 * This wrapper only makes it more comfortable to use async_data_write_*
 * functions to receive strings.
 *
 * @param str      Pointer to string pointer (which should be later disposed
 *                 by free()). If the operation fails, the pointer is not
 *                 touched.
 * @param max_size Maximum size (in bytes) of the string to receive. 0 means
 *                 no limit.
 * @param received If not NULL, the size of the received data is stored here.
 *
 * @return Zero on success or a value from @ref errno.h on failure.
 *
 */
static int async_string_receive(char **str, const size_t max_size, size_t *received)
{
        ipc_callid_t callid;
        size_t size;
        if (!async_data_write_receive(&callid, &size)) {
                ipc_answer_0(callid, EINVAL);
                return EINVAL;
        }
        
        if ((max_size > 0) && (size > max_size)) {
                ipc_answer_0(callid, EINVAL);
                return EINVAL;
        }
        
        char *data = (char *) malloc(size + 1);
        if (data == NULL) {
                ipc_answer_0(callid, ENOMEM);
                return ENOMEM;
        }
        
        int rc = async_data_write_finalize(callid, data, size);
        if (rc != EOK) {
                free(data);
                return rc;
        }
        
        data[size] = 0;
        *str = data;
        if (received != NULL)
                *received = size;
        
        return EOK;
}

/**
 * Register running driver.
 */
static driver_t * devman_driver_register(void)
{       
        printf(NAME ": devman_driver_register \n");
        
        ipc_call_t icall;
        ipc_callid_t iid = async_get_call(&icall);
        driver_t *driver = NULL;
        
        if (IPC_GET_METHOD(icall) != DEVMAN_DRIVER_REGISTER) {
                ipc_answer_0(iid, EREFUSED);
                return NULL;
        }
        
        char *drv_name = NULL;
        
        // Get driver name
        int rc = async_string_receive(&drv_name, DEVMAN_NAME_MAXLEN, NULL);     
        if (rc != EOK) {
                ipc_answer_0(iid, rc);
                return NULL;
        }
        printf(NAME ": the %s driver is trying to register by the service.\n", drv_name);
        
        // Find driver structure
        driver = find_driver(&drivers_list, drv_name);
        
        if (NULL == driver) {
                printf(NAME ": no driver named %s was found.\n", drv_name);
                free(drv_name);
                drv_name = NULL;
                ipc_answer_0(iid, ENOENT);
                return NULL;
        }
        
        free(drv_name);
        drv_name = NULL;
        
        // Create connection to the driver
        printf(NAME ":  creating connection to the %s driver.\n", driver->name);        
        ipc_call_t call;
        ipc_callid_t callid = async_get_call(&call);            
        if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
                ipc_answer_0(callid, ENOTSUP);
                ipc_answer_0(iid, ENOTSUP);
                return NULL;
        }
        
        // remember driver's phone
        set_driver_phone(driver, IPC_GET_ARG5(call));
        
        printf(NAME ":  the %s driver was successfully registered as running.\n", driver->name);
        
        ipc_answer_0(callid, EOK);      
        
        ipc_answer_0(iid, EOK);
        
        return driver;
}

/**
 * Receive device match ID from the device's parent driver and add it to the list of devices match ids.
 * 
 * @param match_ids the list of the device's match ids.
 * 
 * @return 0 on success, negative error code otherwise. 
 */
static int devman_receive_match_id(match_id_list_t *match_ids) {
        
        match_id_t *match_id = create_match_id();
        ipc_callid_t callid;
        ipc_call_t call;
        int rc = 0;
        
        callid = async_get_call(&call);
        if (DEVMAN_ADD_MATCH_ID != IPC_GET_METHOD(call)) {
                printf(NAME ": ERROR: devman_receive_match_id - invalid protocol.\n");
                ipc_answer_0(callid, EINVAL); 
                delete_match_id(match_id);
                return EINVAL;
        }
        
        if (NULL == match_id) {
                printf(NAME ": ERROR: devman_receive_match_id - failed to allocate match id.\n");
                ipc_answer_0(callid, ENOMEM);
                return ENOMEM;
        }
        
        ipc_answer_0(callid, EOK);
        
        match_id->score = IPC_GET_ARG1(call);
        
        char *match_id_str;
        rc = async_string_receive(&match_id_str, DEVMAN_NAME_MAXLEN, NULL);     
        match_id->id = match_id_str;
        if (EOK != rc) {
                delete_match_id(match_id);
                printf(NAME ": devman_receive_match_id - failed to receive match id string.\n");
                return rc;
        }
        
        list_append(&match_id->link, &match_ids->ids);
        
        printf(NAME ": received match id '%s', score = %d \n", match_id->id, match_id->score);
        return rc;
}

/**
 * Receive device match IDs from the device's parent driver 
 * and add them to the list of devices match ids.
 * 
 * @param match_count the number of device's match ids to be received.
 * @param match_ids the list of the device's match ids.
 * 
 * @return 0 on success, negative error code otherwise.
 */
static int devman_receive_match_ids(ipcarg_t match_count, match_id_list_t *match_ids) 
{       
        int ret = EOK;
        size_t i;
        for (i = 0; i < match_count; i++) {
                if (EOK != (ret = devman_receive_match_id(match_ids))) {
                        return ret;
                }
        }
        return ret;
}

/** Handle child device registration. 
 * 
 * Child devices are registered by their parent's device driver.
 */
static void devman_add_child(ipc_callid_t callid, ipc_call_t *call)
{
        // printf(NAME ": devman_add_child\n");
        
        device_handle_t parent_handle = IPC_GET_ARG1(*call);
        ipcarg_t match_count = IPC_GET_ARG2(*call);
        
        node_t *parent =  find_dev_node(&device_tree, parent_handle);
        
        if (NULL == parent) {
                ipc_answer_0(callid, ENOENT);
                return;
        }       
        
        char *dev_name = NULL;
        int rc = async_string_receive(&dev_name, DEVMAN_NAME_MAXLEN, NULL);     
        if (EOK != rc) {
                ipc_answer_0(callid, rc);
                return;
        }
        // printf(NAME ": newly added child device's name is '%s'.\n", dev_name);
        
        node_t *node = create_dev_node();
        if (!insert_dev_node(&device_tree, node, dev_name, parent)) {
                delete_dev_node(node);
                ipc_answer_0(callid, ENOMEM);
                return;
        }       
        
        printf(NAME ": devman_add_child %s\n", node->pathname);
        
        devman_receive_match_ids(match_count, &node->match_ids);
        
        // return device handle to parent's driver
        ipc_answer_1(callid, EOK, node->handle);
        
        // try to find suitable driver and assign it to the device      
        assign_driver(node, &drivers_list);
}

/**
 * Initialize driver which has registered itself as running and ready.
 * 
 * The initialization is done in a separate fibril to avoid deadlocks 
 * (if the driver needed to be served by devman during the driver's initialization). 
 */
static int init_running_drv(void *drv)
{
        driver_t *driver = (driver_t *)drv;
        initialize_running_driver(driver);      
        printf(NAME ": the %s driver was successfully initialized. \n", driver->name);
        return 0;
}

/** Function for handling connections from a driver to the device manager.
 */
static void devman_connection_driver(ipc_callid_t iid, ipc_call_t *icall)
{       
        /* Accept the connection */
        ipc_answer_0(iid, EOK);
        
        driver_t *driver = devman_driver_register();
        if (NULL == driver)
                return;
        
        // Initialize the driver as running (e.g. pass assigned devices to it) in a separate fibril;
        // the separate fibril is used to enable the driver 
        // to use devman service during the driver's initialization.
        fid_t fid = fibril_create(init_running_drv, driver);
        if (fid == 0) {
                printf(NAME ": Error creating fibril for the initialization of the newly registered running driver.\n");
                return;
        }
        fibril_add_ready(fid);
        
        /*thread_id_t tid;
        if (0 != thread_create(init_running_drv, driver, "init_running_drv", &tid)) {
                printf(NAME ": failed to start the initialization of the newly registered running driver.\n");
        }*/
        
        ipc_callid_t callid;
        ipc_call_t call;
        bool cont = true;
        while (cont) {
                callid = async_get_call(&call);
                
                switch (IPC_GET_METHOD(call)) {
                case IPC_M_PHONE_HUNGUP:
                        cont = false;
                        continue;
                case DEVMAN_ADD_CHILD_DEVICE:
                        devman_add_child(callid, &call);
                        break;
                default:
                        ipc_answer_0(callid, EINVAL); 
                        break;
                }
        }
}

/** Find handle for the device instance identified by the device's path in the device tree.
 */
static void devman_device_get_handle(ipc_callid_t iid, ipc_call_t *icall)
{
        char *pathname;
        
        /* Get fqdn */
        int rc = async_string_receive(&pathname, 0, NULL);
        if (rc != EOK) {
                ipc_answer_0(iid, rc);
                return;
        }
        
        node_t * dev = find_dev_node_by_path(&device_tree, pathname); 
        
        free(pathname);

        if (NULL == dev) {
                ipc_answer_0(iid, ENOENT);
                return;
        }
        
        ipc_answer_1(iid, EOK, dev->handle);
}


/** Function for handling connections from a client to the device manager.
 */
static void devman_connection_client(ipc_callid_t iid, ipc_call_t *icall)
{
        /* Accept connection */
        ipc_answer_0(iid, EOK);
        
        bool cont = true;
        while (cont) {
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);
                
                switch (IPC_GET_METHOD(call)) {
                case IPC_M_PHONE_HUNGUP:
                        cont = false;
                        continue;
                case DEVMAN_DEVICE_GET_HANDLE:
                        devman_device_get_handle(callid, &call);
                        break;
                default:
                        if (!(callid & IPC_CALLID_NOTIFICATION))
                                ipc_answer_0(callid, ENOENT);
                }
        }       
}

static void devman_forward(ipc_callid_t iid, ipc_call_t *icall, bool drv_to_parent) {   
        
        device_handle_t handle = IPC_GET_ARG2(*icall);
        // printf(NAME ": devman_forward - trying to forward connection to device with handle %x.\n", handle);
        
        node_t *dev = find_dev_node(&device_tree, handle);
        if (NULL == dev) {
                printf(NAME ": devman_forward error - no device with handle %x was found.\n", handle);
                ipc_answer_0(iid, ENOENT);
                return;
        }
        
        driver_t *driver = NULL;
        
        if (drv_to_parent) {
                if (NULL != dev->parent) {
                        driver = dev->parent->drv;              
                }
        } else if (DEVICE_USABLE == dev->state) {
                driver = dev->drv;              
                assert(NULL != driver);
        }
        
        if (NULL == driver) {   
                printf(NAME ": devman_forward error - the device is not in usable state.\n", handle);
                ipc_answer_0(iid, ENOENT);
                return; 
        }
        
        int method;     
        if (drv_to_parent) {
                method = DRIVER_DRIVER;
        } else {
                method = DRIVER_CLIENT;
        }
        
        if (driver->phone <= 0) {
                printf(NAME ": devman_forward: cound not forward to driver %s ", driver->name);
                printf("the driver's phone is %x).\n", driver->phone);
                return;
        }
        printf(NAME ": devman_forward: forward connection to device %s to driver %s.\n", dev->pathname, driver->name);
        ipc_forward_fast(iid, driver->phone, method, dev->handle, 0, IPC_FF_NONE);      
}

/** Function for handling connections to device manager.
 *
 */
static void devman_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        // Select interface 
        switch ((ipcarg_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_TO_PARENTS_DEVICE:
                // Connect client to selected device
                devman_forward(iid, icall, true);
                break;          
        default:
                /* No such interface */
                ipc_answer_0(iid, ENOENT);
        }
}

/** Initialize device manager internal structures.
 */
static bool devman_init()
{
        printf(NAME ": devman_init - looking for available drivers. \n");       
        
        // initialize list of available drivers
        init_driver_list(&drivers_list);
        if (0 == lookup_available_drivers(&drivers_list, DRIVER_DEFAULT_STORE)) {
                printf(NAME " no drivers found.");
                return false;
        }
        printf(NAME ": devman_init  - list of drivers has been initialized. \n");

        // create root device node 
        if (!init_device_tree(&device_tree, &drivers_list)) {
                printf(NAME " failed to initialize device tree.");
                return false;           
        }

        return true;
}

int main(int argc, char *argv[])
{
        printf(NAME ": HelenOS Device Manager\n");

        if (!devman_init()) {
                printf(NAME ": Error while initializing service\n");
                return -1;
        }
        
        // Set a handler of incomming connections
        async_set_client_connection(devman_connection);

        // Register device manager at naming service
        ipcarg_t phonead;
        if (ipc_connect_to_me(PHONE_NS, SERVICE_DEVMAN, 0, 0, &phonead) != 0)
                return -1;

        printf(NAME ": Accepting connections\n");
        async_manager();

        // Never reached
        return 0;
}

/** @}
 */