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

 /*
  * Copyright (c) 2007 Jakub Jermar
  * 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.
  */
 /** @addtogroup fs
  * @{
  */
 /**
  * @file    vfs.c
  * @brief   VFS multiplexer for HelenOS.
  */
 #include <ipc/ipc.h>
 #include <ipc/services.h>
 #include <async.h>
 #include <errno.h>
 #include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
 #include <bool.h>
-#include <futex.h>
 #include <libadt/list.h>
 #include "vfs.h"
 #define dprintf(...)    printf(__VA_ARGS__)
-atomic_t fs_head_futex = FUTEX_INITIALIZER;
-link_t fs_head;
-/** Verify the VFS info structure.
- *
- * @param info      Info structure to be verified.
- *
- * @return      Non-zero if the info structure is sane, zero otherwise.
- */
-static bool vfs_info_sane(vfs_info_t *info)
-{
-    int i;
-    /*
-     * Check if the name is non-empty and is composed solely of ASCII
-     * characters [a-z]+[a-z0-9_-]*.
-     */
-    if (!islower(info->name[0])) {
-        dprintf("The name doesn't start with a lowercase character.\n");
-        return false;
-    }
-    for (i = 1; i < FS_NAME_MAXLEN; i++) {
-        if (!(islower(info->name[i]) || isdigit(info->name[i])) &&
-            (info->name[i] != '-') && (info->name[i] != '_')) {
-            if (info->name[i] == '\0') {
-                break;
-            } else {
-                dprintf("The name contains illegal "
-                    "characters.\n");
-                return false;
-            }
-        }
-    }
-    /*
-     * Check if the FS implements mandatory VFS operations.
-     */
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_REGISTER not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_MOUNT not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_UNMOUNT not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_LOOKUP not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_OPEN not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_CLOSE not defined by the client.\n");
-        return false;
-    }
-    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED) {
-        dprintf("Operation VFS_READ not defined by the client.\n");
-        return false;
-    }
-    /*
-     * Check if each operation is either not defined, defined or default.
-     */
-    for (i = VFS_FIRST; i < VFS_LAST; i++) {
-        if ((info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_NULL) &&
-            (info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFAULT) &&
-            (info->ops[IPC_METHOD_TO_VFS_OP(i)] != VFS_OP_DEFINED)) {
-            dprintf("Operation info not understood.\n");
-            return false;
-        }
-    }
-    return true;
-}
-/** VFS_REGISTER protocol function.
- *
- * @param rid       Hash of the call with the request.
- * @param request   Call structure with the request.
- */
-static void vfs_register(ipc_callid_t rid, ipc_call_t *request)
-{
-    ipc_callid_t callid;
-    ipc_call_t call;
-    int rc;
-    size_t size;
-    dprintf("Processing VFS_REGISTER request received from %p.\n",
-        request->in_phone_hash);
-    /*
-     * The first call has to be IPC_M_DATA_SEND in which we receive the
-     * VFS info structure from the client FS.
-     */
-    if (!ipc_data_receive(&callid, &call, NULL, &size)) {
-        /*
-         * The client doesn't obey the same protocol as we do.
-         */
-        dprintf("Receiving of VFS info failed.\n");
-        ipc_answer_fast(callid, EINVAL, 0, 0);
-        ipc_answer_fast(rid, EINVAL, 0, 0);
-        return;
-    }
-    dprintf("VFS info received, size = %d\n", size);
-    /*
-     * We know the size of the VFS info structure. See if the client
-     * understands this easy concept too.
-     */
-    if (size != sizeof(vfs_info_t)) {
-        /*
-         * The client is sending us something, which cannot be
-         * the info structure.
-         */
-        dprintf("Received VFS info has bad size.\n");
-        ipc_answer_fast(callid, EINVAL, 0, 0);
-        ipc_answer_fast(rid, EINVAL, 0, 0);
-        return;
-    }
-    fs_info_t *fs_info;
-    /*
-     * Allocate and initialize a buffer for the fs_info structure.
-     */
-    fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
-    if (!fs_info) {
-        dprintf("Could not allocate memory for FS info.\n");
-        ipc_answer_fast(callid, ENOMEM, 0, 0);
-        ipc_answer_fast(rid, ENOMEM, 0, 0);
-        return;
-    }
-    link_initialize(&fs_info->fs_link);
-    rc = ipc_data_deliver(callid, &call, &fs_info->vfs_info, size);
-    if (rc != EOK) {
-        dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
-            rc);
-        free(fs_info);
-        ipc_answer_fast(callid, rc, 0, 0);
-        ipc_answer_fast(rid, rc, 0, 0);
-        return;
-    }
-    dprintf("VFS info delivered.\n");
-    if (!vfs_info_sane(&fs_info->vfs_info)) {
-        free(fs_info);
-        ipc_answer_fast(callid, EINVAL, 0, 0);
-        ipc_answer_fast(rid, EINVAL, 0, 0);
-        return;
-    }
-    futex_down(&fs_head_futex);
-    /*
-     * Check for duplicit registrations.
-     */
-    link_t *cur;
-    for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
-        fs_info_t *fi = list_get_instance(cur, fs_info_t,
-            fs_link);
-        /* TODO: replace strcmp with strncmp once we have it */
-        if (strcmp(fs_info->vfs_info.name, fi->vfs_info.name) == 0) {
-            /*
-             * We already register a fs like this.
-             */
-            dprintf("FS is already registered.\n");
-            futex_up(&fs_head_futex);
-            free(fs_info);
-            ipc_answer_fast(callid, EEXISTS, 0, 0);
-            ipc_answer_fast(rid, EEXISTS, 0, 0);
-            return;
-        }
-    }
-    /*
-     * Add fs_info to the list of registered FS's.
-     */
-    dprintf("Adding FS into the registered list.\n");
-    list_append(&fs_info->fs_link, &fs_head);
-    /*
-     * ACK receiving a properly formatted, non-duplicit vfs_info.
-     */
-    ipc_answer_fast(callid, EOK, 0, 0);
-    /*
-     * Now we want the client to send us the IPC_M_CONNECT_TO_ME call so
-     * that a callback connection is created and we have a phone through
-     * which to forward VFS requests to it.
-     */
-    callid = async_get_call(&call);
-    if (IPC_GET_METHOD(call) != IPC_M_CONNECT_TO_ME) {
-        dprintf("Unexpected call, method = %d\n", IPC_GET_METHOD(call));
-        list_remove(&fs_info->fs_link);
-        futex_up(&fs_head_futex);
-        free(fs_info);
-        ipc_answer_fast(callid, EINVAL, 0, 0);
-        ipc_answer_fast(rid, EINVAL, 0, 0);
-        return;
-    }
-    fs_info->phone = IPC_GET_ARG3(call);
-    ipc_answer_fast(callid, EOK, 0, 0);
-    dprintf("Callback connection to FS created.\n");
-    futex_up(&fs_head_futex);
-    /*
-     * That was it. The FS has been registered.
-     */
-    ipc_answer_fast(rid, EOK, 0, 0);
-    dprintf("\"%s\" filesystem successfully registered.\n",
-        fs_info->vfs_info.name);
-}
 static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)
+{
     bool keep_on_going = 1;
     printf("Connection opened from %p\n", icall->in_phone_hash);
     /*
      * The connection was opened via the IPC_CONNECT_ME_TO call.
      * This call needs to be answered.
      */
     ipc_answer_fast(iid, EOK, 0, 0);
     /*
      * Here we enter the main connection fibril loop.
      * The logic behind this loop and the protocol is that we'd like to keep
      * each connection open for a while before we close it. The benefit of
      * this is that the client doesn't have to establish a new connection
      * upon each request.  On the other hand, the client must be ready to
      * re-establish a connection if we hang it up due to reaching of maximum
      * number of requests per connection or due to the client timing out.
      */
     while (keep_on_going) {
         ipc_callid_t callid;
         ipc_call_t call;
         callid = async_get_call(&call);
         printf("Received call, method=%d\n", IPC_GET_METHOD(call));
         switch (IPC_GET_METHOD(call)) {
         case IPC_M_PHONE_HUNGUP:
             keep_on_going = false;
             break;
         case VFS_REGISTER:
             vfs_register(callid, &call);
             keep_on_going = false;
             break;
         case VFS_MOUNT:
         case VFS_UNMOUNT:
         case VFS_OPEN:
         case VFS_CREATE:
         case VFS_CLOSE:
         case VFS_READ:
         case VFS_WRITE:
         case VFS_SEEK:
         default:
             ipc_answer_fast(callid, ENOTSUP, 0, 0);
             break;
+        }
+    }
     /* TODO: cleanup after the client */
+}
 int main(int argc, char **argv)
+{
     ipcarg_t phonead;
     printf("VFS: HelenOS VFS server\n");
     list_initialize(&fs_head);
     async_set_client_connection(vfs_connection);
     ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, &phonead);
     async_manager();
     return 0;
+}
 /**
  * @}
  */

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/vfs/vfs.c – Rev 2532 → 2535