WebSVN – HelenOS – Diff – //trunk/uspace/srv/devmap/devmap.c

 #include <ipc/ns.h>
 #include <async.h>
 #include <stdio.h>
 #include <errno.h>
 #include <bool.h>
-#include <libadt/list.h>
 #include <futex.h>
+#include <stdlib.h>
+#include <string.h>
 #include "devmap.h"
-LIST_INITIALIZE(device_list);
+LIST_INITIALIZE(devices_list);
+LIST_INITIALIZE(drivers_list);
+/* order of locking:
+ * drivers_list_futex
+ * devices_list_futex
+ * (devmap_driver_t *)->devices_futex
+ * create_handle_futex
+ **/
-atomic_t device_list_futex = FUTEX_INITIALIZER;
+static atomic_t devices_list_futex = FUTEX_INITIALIZER;
+static atomic_t drivers_list_futex = FUTEX_INITIALIZER;
+static atomic_t create_handle_futex = FUTEX_INITIALIZER;
+static int devmap_create_handle(void)
+{
+    static int last_handle = 0;
+    int handle;
+    /* TODO: allow reusing old handles after their unregistration
+        and implement some version of LRU algorithm */
+    /* FIXME: overflow */
+    futex_down(&create_handle_futex);
+    last_handle += 1;
+    handle = last_handle;
+    futex_up(&create_handle_futex);
+    return handle;
+}
 /** Initialize device mapper.
+ *
+ *
  */
 static int devmap_init()
+{
-    /* */
+    /* TODO: */
     return EOK;
+}
-static int devmap_register()
+/** Find device with given name.
+ *
+ */
+static devmap_device_t *devmap_device_find_name(const char *name)
+{
+    link_t *item;
+    devmap_device_t *device = NULL;
+    item = devices_list.next;
+    while (item != &devices_list) {
+        device = list_get_instance(item, devmap_device_t, devices);
+        if (0 == strcmp(device->name, name)) {
+            break;
+        }
-    ipc_callid_t callid2;
+        item = item->next;
+    }
+    if (item == &devices_list) {
+        printf("DevMap: no device named %s.\n", name);
+        return NULL;
+    }
+    device = list_get_instance(item, devmap_device_t, devices);
+    return device;
+}
+/** Find device with given handle.
+ * @todo: use hash table
+ */
+static devmap_device_t *devmap_device_find_handle(int handle)
+{
-    size_t size;
+    link_t *item;
+    devmap_device_t *device = NULL;
+    futex_down(&devices_list_futex);
+    item = (&devices_list)->next;
+    while (item != &devices_list) {
+        device = list_get_instance(item, devmap_device_t, devices);
+        if (device->handle == handle) {
+            break;
+        }
+        item = item->next;
+    }
+    if (item == &devices_list) {
-    char buffer[DEVMAP_NAME_MAXLEN + 1];
+        futex_up(&devices_list_futex);
+        return NULL;
+    }
+    device = list_get_instance(item, devmap_device_t, devices);
+    futex_up(&devices_list_futex);
+    return device;
+}
+/** Unregister device and free it. Its assumed that driver's device list
+ * is already locked.
+ *
+ */
+static int devmap_device_unregister_core(devmap_device_t *device)
+{
+    list_remove(&(device->devices));
+    list_remove(&(device->driver_devices));
+    free(device->name);
+    free(device);
+    return EOK;
+}
+/** Read info about new driver and add it into linked list of registered drivers.
+ */
+static void devmap_driver_register(devmap_driver_t **odriver)
+{
+    size_t name_size;
     ipc_callid_t callid;
     ipc_call_t call;
+    devmap_driver_t *driver;
+    ipc_callid_t iid;
-    int retval;
+    ipc_call_t icall;
+    *odriver = NULL;
+    iid = async_get_call(&icall);
-    if (ipc_data_receive(&callid, &call, NULL, &size) != 0) {
+    if (IPC_GET_METHOD(icall) != DEVMAP_DRIVER_REGISTER) {
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    if (NULL == (driver = (devmap_driver_t *)malloc(sizeof(devmap_driver_t)))) {
+        ipc_answer_fast(iid, ENOMEM, 0, 0);
-    //  retval =
+        return;
+    }
-    if (size > DEVMAP_NAME_MAXLEN) {
+    /*
-        retval = ELIMIT;
+     * Get driver name
-    } else {
+     */
-        ipc_data_deliver(callid2, &call, buffer, size);
+    if (!ipc_data_receive(&callid, &call, NULL, &name_size)) {
+        printf("Unexpected request: %u.\n", IPC_GET_METHOD(call));
+        free(driver);
+        ipc_answer_fast(callid, EREFUSED, 0, 0);
-        buffer[DEVMAP_NAME_MAXLEN] = 0;
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    if (name_size > DEVMAP_NAME_MAXLEN) {
+        printf("Too logn name: %u: maximum is %u.\n", name_size, DEVMAP_NAME_MAXLEN);
+        free(driver);
+        ipc_answer_fast(callid, EINVAL, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /*
+     * Allocate buffer for device name.
+     */
+    if (NULL == (driver->name = (char *)malloc(name_size + 1))) {
+        printf("Cannot allocate space for driver name.\n");
+        free(driver);
+        ipc_answer_fast(callid, ENOMEM, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /*
+     * Send confirmation to sender and get data into buffer.
+     */
+    if (EOK != ipc_data_deliver(callid, &call, driver->name, name_size)) {
+        printf("Cannot read driver name.\n");
+        free(driver->name);
+        free(driver);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    driver->name[name_size] = 0;
+    printf("Read driver name: '%s'.\n", driver->name);
+    /* Initialize futex for list of devices owned by this driver */
+    futex_initialize(&(driver->devices_futex) ,1);
+    /*
+     * Initialize list of asociated devices
+     */
+    list_initialize(&(driver->devices));
+    /*
+     * Create connection to the driver
+     */
+    callid = async_get_call(&call);
+    if (IPC_M_CONNECT_TO_ME != IPC_GET_METHOD(call)) {
+        printf("DevMap: Unexpected method: %u.\n", \
+            IPC_GET_METHOD(call));
+        ipc_answer_fast(callid, ENOTSUP, 0, 0);
+        free(driver->name);
+        free(driver);
+        ipc_answer_fast(iid, ENOTSUP, 0, 0);
+        return;
+    }
+    driver->phone = IPC_GET_ARG3(call);
+    ipc_answer_fast(callid, EOK, 0, 0);
+    list_initialize(&(driver->drivers));
+    futex_down(&drivers_list_futex);
+    /* TODO: check that no driver with name equals to driver->name is registered */
+    /*
+     * Insert new driver into list of registered drivers
+     */
+    list_append(&(driver->drivers), &drivers_list);
+    futex_up(&drivers_list_futex);
+    ipc_answer_fast(iid, EOK, 0, 0);
+    printf("Driver registered.\n");
+    *odriver = driver;
-    return EOK;
+    return;
+}
+/** Unregister device driver, unregister all its devices and free driver structure.
+ *
+ */
-static int devmap_unregister()
+static int devmap_driver_unregister(devmap_driver_t *driver)
+{
+    devmap_device_t *device;
+    if (NULL == driver) {
+        printf("Error: driver == NULL.\n");
+        return EEXISTS;
+    }
+    printf("Unregister driver '%s'.\n", driver->name);
+    futex_down(&drivers_list_futex);
+    ipc_hangup(driver->phone);
+    /* remove it from list of drivers */
+    list_remove(&(driver->drivers));
+    /* unregister all its devices */
+    futex_down(&devices_list_futex);
+    futex_down(&(driver->devices_futex));
+    while (!list_empty(&(driver->devices))) {
+        device = list_get_instance(driver->devices.next, devmap_device_t, driver_devices);
+        printf("Unregister device '%s'.\n", device->name);
+        devmap_device_unregister_core(device);
+    }
+    futex_up(&(driver->devices_futex));
+    futex_up(&devices_list_futex);
+    futex_up(&drivers_list_futex);
+    /* free name and driver */
+    if (NULL != driver->name) {
+        free(driver->name);
+    }
+    free(driver);
+    printf("Driver unregistered.\n");
     return EOK;
+}
+/** Register instance of device
+ *
+ */
-static int devmap_forward(int handle, ipc_call_t *call, ipc_callid_t callid)
+static void devmap_device_register(ipc_callid_t iid, ipc_call_t *icall,
+        devmap_driver_t *driver)
+{
-    link_t *item;
+    ipc_callid_t callid;
-    ipcarg_t phone;
+    ipc_call_t call;
+    size_t size;
-    devmap_device_t *dev;
+    devmap_device_t *device;
+    if (NULL == driver) {
+        printf("Invalid driver registration.\n");
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /* Create new device entry */
+    if (NULL == (device = (devmap_device_t *)malloc(sizeof(devmap_device_t)))) {
+        printf("Cannot allocate new device.\n");
+        ipc_answer_fast(iid, ENOMEM, 0, 0);
+        return;
+    }
-    /* FIXME: add futex */
+    /* Get device name */
+    if (!ipc_data_receive(&callid, &call, NULL, &size)) {
+        free(device);
-    futex_down(&device_list_futex);
+        printf("Cannot read device name.\n");
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    if (size > DEVMAP_NAME_MAXLEN) {
+        printf("Too long device name: %u.\n", size);
-    item = (&device_list)->next;
+        free(device);
+        ipc_answer_fast(callid, EINVAL, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+        /* +1 for terminating \0 */
-    while (item != &device_list) {
+    device->name = (char *)malloc(size + 1);
-        dev = list_get_instance(item, devmap_device_t, list);
+    if (NULL == device->name) {
-        if (dev->handle == handle) {
+        printf("Cannot read device name.\n");
-            break;
+        free(device);
-        }
+        ipc_answer_fast(callid, ENOMEM, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
-        item = item->next;
+        return;
+    }
+    ipc_data_deliver(callid, &call, device->name, size);
+    device->name[size] = 0;
+    list_initialize(&(device->devices));
+    list_initialize(&(device->driver_devices));
+    futex_down(&devices_list_futex);
+    /* Check that device with such name is not already registered */
+    if (NULL != devmap_device_find_name(device->name)) {
+        printf("Device '%s' already registered.\n", device->name);
-    if (item == &device_list) {
+        futex_up(&devices_list_futex);
+        free(device->name);
+        free(device);
+        ipc_answer_fast(iid, EEXISTS, 0, 0);
-        return ENOENT;
+        return;
+    }
+    /* Get unique device handle */
-    dev = list_get_instance(item, devmap_device_t, list);
+    device->handle = devmap_create_handle();
-    phone = dev->phone;
+    device->driver = driver;
+    /* Insert device into list of all devices  */
+    list_append(&(device->devices), &devices_list);
+    /* Insert device into list of devices that belog to one driver */
-    futex_up(&device_list_futex);
+    futex_down(&(device->driver->devices_futex));
+    list_append(&(device->driver_devices), &(device->driver->devices));
+    futex_up(&(device->driver->devices_futex));
+    futex_up(&devices_list_futex);
+    printf("Device '%s' registered.\n", device->name);
-    return ipc_forward_fast(callid, phone, 0, 0);
+    ipc_answer_fast(iid, EOK, device->handle, 0);
+    return;
+}
+/**
+ *
+ */
+static int devmap_device_unregister(ipc_callid_t iid, ipc_call_t *icall,
-static int devmap_get_handle()
+    devmap_driver_t *driver)
+{
+    /* TODO */
     return EOK;
+}
+/** Connect client to the device.
+ * Find device driver owning requested device and forward
+ * the message to it.
+ *
+ *
+ */
+static void devmap_forward(ipc_callid_t callid, ipc_call_t *call)
+{
+    devmap_device_t *dev;
+    int handle;
+    /*
+     * Get handle from request
+     */
+    handle = IPC_GET_ARG1(*call);
+    dev = devmap_device_find_handle(handle);
+    if (NULL == dev) {
+        printf("DevMap: No registered device with handle %d.\n", handle);
+        ipc_answer_fast(callid, ENOENT, 0, 0);
+        return;
+    }
+        /* FIXME: is this correct method how to pass argument on forwarding ?*/
+    ipc_forward_fast(callid, dev->driver->phone, (ipcarg_t)(dev->handle), 0);
+    return;
+}
+/** Find handle for device instance identified by name.
+ * In answer will be send EOK and device handle in arg1 or a error
+ * code from errno.h.
+ */
+static void devmap_get_handle(ipc_callid_t iid, ipc_call_t *icall)
+{
+    char *name = NULL;
+    size_t name_size;
+    const devmap_device_t *dev;
+    ipc_callid_t callid;
+    ipc_call_t call;
+    ipcarg_t retval;
+    /*
+     * Wait for incoming message with device name (but do not
+     * read the name itself until the buffer is allocated).
+     */
+    if (!ipc_data_receive(&callid, &call, NULL, &name_size)) {
+        ipc_answer_fast(callid, EREFUSED, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    if (name_size > DEVMAP_NAME_MAXLEN) {
+        ipc_answer_fast(callid, EINVAL, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /*
+     * Allocate buffer for device name.
+     */
+    if (NULL == (name = (char *)malloc(name_size))) {
+        ipc_answer_fast(callid, ENOMEM, 0, 0);
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /*
+     * Send confirmation to sender and get data into buffer.
+     */
+    if (EOK != (retval = ipc_data_deliver(callid, &call, name, name_size))) {
+        ipc_answer_fast(iid, EREFUSED, 0, 0);
+        return;
+    }
+    /*
+     * Find device name in linked list of known devices.
+     */
+    dev = devmap_device_find_name(name);
+    /*
+     * Device was not found.
+     */
+    if (NULL == dev) {
+        printf("DevMap: device %s has not been registered.\n", name);
+        ipc_answer_fast(iid, ENOENT, 0, 0);
+        return;
+    }
+    printf("DevMap: device %s has handler %d.\n", name, dev->handle);
+    ipc_answer_fast(iid, EOK, dev->handle, 0);
+    return;
+}
+/** Find name of device identified by id and send it to caller.
+ *
+ */
+static void devmap_get_name(ipc_callid_t iid, ipc_call_t *icall)
+{
+    const devmap_device_t *device;
+    size_t name_size;
+    device = devmap_device_find_handle(IPC_GET_ARG1(*icall));
+    /*
+     * Device not found.
+     */
+    if (NULL == device) {
+        ipc_answer_fast(iid, ENOENT, 0, 0);
+        return;
+    }
+    ipc_answer_fast(iid, EOK, 0, 0);
+    name_size = strlen(device->name);
+/*  FIXME:
+    we have no channel from DevMap to client ->
+    sending must be initiated by client
+    int rc = ipc_data_send(phone, device->name, name_size);
+    if (rc != EOK) {
+        async_wait_for(req, NULL);
+        return rc;
+    }
+*/
+    /* TODO: send name in response */
+    return;
+}
-/** Function for handling connections to devmap
+/** Handle connection with device driver.
+ *
  */
 static void
-devmap_client_connection(ipc_callid_t iid, ipc_call_t *icall)
+devmap_connection_driver(ipc_callid_t iid, ipc_call_t *icall)
+{
     ipc_callid_t callid;
     ipc_call_t call;
-    int retval;
     bool cont = true;
+    devmap_driver_t *driver = NULL;
-    printf("DevMap: new connection.");
+    ipc_answer_fast(iid, EOK, 0, 0);
-    ipc_answer_fast(iid, EOK, 0, 0); /* Accept connection */
+    devmap_driver_register(&driver);
+    if (NULL == driver) {
+        printf("DevMap: driver registration failed.\n");
+        return;
+    }
     while (cont) {
         callid = async_get_call(&call);
         switch (IPC_GET_METHOD(call)) {
         case IPC_M_PHONE_HUNGUP:
-                /* TODO: if its a device connection, remove it from table */
-            devmap_unregister();
-            printf("DevMap: connection hung up.");
+            printf("DevMap: connection hung up.\n");
             cont = false;
             continue; /* Exit thread */
-        case DEVMAP_REGISTER:
+        case DEVMAP_DRIVER_UNREGISTER:
+            printf("DevMap: unregister driver.\n");
+            if (NULL == driver) {
-            if ((retval = devmap_register()) != EOK) {
+                printf("DevMap: driver was not registered!\n");
+                ipc_answer_fast(callid, ENOENT, 0, 0);
-                cont = false;
+            } else {
+                ipc_answer_fast(callid, EOK, 0, 0);
+            }
             break;
-        case DEVMAP_UNREGISTER:
+        case DEVMAP_DEVICE_REGISTER:
-            /* TODO: remove device (if registred) */
+            /* Register one instance of device */
+            devmap_device_register(callid, &call, driver);
+            break;
+        case DEVMAP_DEVICE_UNREGISTER:
+            /* Remove instance of device identified by handler */
-            retval = devmap_unregister();
+            devmap_device_unregister(callid, &call, driver);
+            break;
+        case DEVMAP_DEVICE_GET_HANDLE:
+            devmap_get_handle(callid, &call);
-            cont = false;
+            break;
+        case DEVMAP_DEVICE_GET_NAME:
+            devmap_get_handle(callid, &call);
             break;
+        default:
+            if (!(callid & IPC_CALLID_NOTIFICATION)) {
+                ipc_answer_fast(callid, ENOENT, 0, 0);
+            }
+        }
+    }
+    if (NULL != driver) {
+            /*
+             * Unregister the device driver and all its devices.
+             */
+        devmap_driver_unregister(driver);
+        driver = NULL;
+    }
+}
+/** Handle connection with device client.
+ *
+ */
+static void
+devmap_connection_client(ipc_callid_t iid, ipc_call_t *icall)
+{
+    ipc_callid_t callid;
+    ipc_call_t call;
+    bool cont = true;
+    ipc_answer_fast(iid, EOK, 0, 0); /* Accept connection */
+    while (cont) {
+        callid = async_get_call(&call);
+        switch (IPC_GET_METHOD(call)) {
-        case DEVMAP_CONNECT_TO_DEVICE:
+        case IPC_M_PHONE_HUNGUP:
-            retval = devmap_forward(IPC_GET_ARG1(call), &call, callid);
+            printf("DevMap: connection hung up.\n");
             cont = false;
+            continue; /* Exit thread */
+        case DEVMAP_DEVICE_CONNECT_ME_TO:
+            /* Connect client to selected device */
+            printf("DevMap: connect to device %d.\n", IPC_GET_ARG1(call));
+            devmap_forward(callid, &call);
+            break;
+        case DEVMAP_DEVICE_GET_HANDLE:
+            devmap_get_handle(callid, &call);
             break;
-        case DEVMAP_GET_HANDLE:
+        case DEVMAP_DEVICE_GET_NAME:
+            /* TODO */
+            devmap_get_name(callid, &call);
             break;
         default:
+            if (!(callid & IPC_CALLID_NOTIFICATION)) {
-            retval = ENOENT;
+                ipc_answer_fast(callid, ENOENT, 0, 0);
+            }
+        }
-        ipc_answer_fast(callid, retval, 0, 0);
+    }
-    printf("DevMap: connection closed.");
-    return;
+}
+/** Function for handling connections to devmap
+ *
+ */
+static void
+devmap_connection(ipc_callid_t iid, ipc_call_t *icall)
+{
+    printf("DevMap: new connection.\n");
+        /* Select interface */
+    switch ((ipcarg_t)(IPC_GET_ARG1(*icall))) {
+        case DEVMAP_DRIVER:
+            devmap_connection_driver(iid, icall);
+            break;
+        case DEVMAP_CLIENT:
+            devmap_connection_client(iid, icall);
+            break;
+        default:
+            ipc_answer_fast(iid, ENOENT, 0, 0); /* No such interface */
+            printf("DevMap: Unknown interface %u.\n", \
+                (ipcarg_t)(IPC_GET_ARG1(*icall)));
+    }
+    /* Cleanup */
+    printf("DevMap: connection closed.\n");
+    return;
+}
+/**
+ *
+ */
 int main(int argc, char *argv[])
+{
     ipcarg_t phonead;
     printf("DevMap: HelenOS device mapper.\n");
     if (devmap_init() != 0) {
-        printf("Error while initializing DevMap service.");
+        printf("Error while initializing DevMap service.\n");
         return -1;
+    }
         /* Set a handler of incomming connections */
-    async_set_client_connection(devmap_client_connection);
+    async_set_client_connection(devmap_connection);
         /* Register device mapper at naming service */
     if (ipc_connect_to_me(PHONE_NS, SERVICE_DEVMAP, 0, &phonead) != 0)
         return -1;

Subversion Repositories HelenOS

(root)//trunk/uspace/srv/devmap/devmap.c – Rev 2555 → 2594