WebSVN – HelenOS – Diff – /branches/sparc/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 <stdlib.h>
+#include <string.h>
+#include <ctype.h>
 #include <bool.h>
+#include <futex.h>
+#include <libadt/list.h>
 #include "vfs.h"
+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 int vfs_info_sane(vfs_info_t *info)
+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]))
+        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
+                return false;
+        }
+    }
+    /*
+     * Check if the FS implements mandatory VFS operations.
+     */
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_REGISTER)] != VFS_OP_DEFINED)
+        return false;
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] != VFS_OP_DEFINED)
+        return false;
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] != VFS_OP_DEFINED)
+        return false;
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_OPEN)] != VFS_OP_DEFINED)
+        return false;
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_CLOSE)] != VFS_OP_DEFINED)
+        return false;
+    if (info->ops[IPC_METHOD_TO_VFS_OP(VFS_READ)] != VFS_OP_DEFINED)
+        return false;
+    /*
+     * Check if each operation is either not defined, defined or default.
+     */
+    for (i = VFS_FIRST; i < VFS_LAST; i++) {
+        if ((IPC_METHOD_TO_VFS_OP(i) != VFS_OP_NULL) &&
+            (IPC_METHOD_TO_VFS_OP(i) != VFS_OP_DEFAULT) &&
+            (IPC_METHOD_TO_VFS_OP(i) != VFS_OP_DEFINED))
+            return false;
+    }
-    return 1;   /* XXX */
+    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;
     /*
      * 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_send_accept(&callid, &call, NULL, &size)) {
         /*
          * The client doesn't obey the same protocol as we do.
          */
         ipc_answer_fast(callid, EINVAL, 0, 0);
         ipc_answer_fast(rid, EINVAL, 0, 0);
         return;
+    }
     /*
-     * We know the size of the info structure. See if the client understands
+     * We know the size of the VFS info structure. See if the client
-     * this easy concept too.
+     * understands this easy concept too.
      */
     if (size != sizeof(vfs_info_t)) {
         /*
          * The client is sending us something, which cannot be
          * the info structure.
          */
         ipc_answer_fast(callid, EINVAL, 0, 0);
         ipc_answer_fast(rid, EINVAL, 0, 0);
         return;
+    }
-    vfs_info_t *info;
+    fs_info_t *fs_info;
     /*
-     * Allocate a buffer for the info structure.
+     * Allocate and initialize a buffer for the fs_info structure.
      */
-    info = (vfs_info_t *) malloc(sizeof(vfs_info_t));
+    fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
-    if (!info) {
+    if (!fs_info) {
         ipc_answer_fast(callid, ENOMEM, 0, 0);
         ipc_answer_fast(rid, ENOMEM, 0, 0);
         return;
+    }
+    link_initialize(&fs_info->fs_link);
-    rc = ipc_data_send_answer(callid, &call, info, size);
+    rc = ipc_data_send_answer(callid, &call, &fs_info->vfs_info, size);
     if (!rc) {
-        free(info);
+        free(fs_info);
         ipc_answer_fast(callid, rc, 0, 0);
         ipc_answer_fast(rid, rc, 0, 0);
         return;
+    }
-    if (!vfs_info_sane(info)) {
+    if (!vfs_info_sane(&fs_info->vfs_info)) {
-        free(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.
+             */
+            futex_up(&fs_head_futex);
+            free(fs_info);
+            ipc_answer_fast(callid, EEXISTS, 0, 0);
+            ipc_answer_fast(rid, EEXISTS, 0, 0);
+            return;
+        }
+    }
+    /*
+     * TODO:
+     * 1. send the client the IPC_M_CONNECT_TO_ME call so that it makes a
+     *    callback connection.
+     * 2. add the fs_info into fs_head
+     */
+    futex_up(&fs_head_futex);
+}
 static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)
+{
     bool keep_on_going = 1;
     /*
      * 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);
         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;
+    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)/branches/sparc/uspace/srv/vfs/vfs.c @ 3606 – Rev 2523 → 2526