hw/virtio-9p-xattr.c

   1 /*
   2  * Virtio 9p  xattr callback
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "virtio.h"
  15 #include "virtio-9p.h"
  16 #include "file-op-9p.h"
  17 #include "virtio-9p-xattr.h"
  18
  19
  20 static XattrOperations *get_xattr_operations(XattrOperations **h,
  21                                              const char *name)
  22 {
  23     XattrOperations *xops;
  24     for (xops = *(h)++; xops != NULL; xops = *(h)++) {
  25         if (!strncmp(name, xops->name, strlen(xops->name))) {
  26             return xops;
  27         }
  28     }
  29     return NULL;
  30 }
  31
  32 ssize_t v9fs_get_xattr(FsContext *ctx, const char *path,
  33                        const char *name, void *value, size_t size)
  34 {
  35     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
  36     if (xops) {
  37         return xops->getxattr(ctx, path, name, value, size);
  38     }
  39     errno = -EOPNOTSUPP;
  40     return -1;
  41 }
  42
  43 ssize_t pt_listxattr(FsContext *ctx, const char *path,
  44                      char *name, void *value, size_t size)
  45 {
  46     int name_size = strlen(name) + 1;
  47     if (!value) {
  48         return name_size;
  49     }
  50
  51     if (size < name_size) {
  52         errno = ERANGE;
  53         return -1;
  54     }
  55
  56     strncpy(value, name, name_size);
  57     return name_size;
  58 }
  59
  60
  61 /*
  62  * Get the list and pass to each layer to find out whether
  63  * to send the data or not
  64  */
  65 ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
  66                         void *value, size_t vsize)
  67 {
  68     ssize_t size = 0;
  69     void *ovalue = value;
  70     XattrOperations *xops;
  71     char *orig_value, *orig_value_start;
  72     ssize_t xattr_len, parsed_len = 0, attr_len;
  73
  74     /* Get the actual len */
  75     xattr_len = llistxattr(rpath(ctx, path), value, 0);
  76
  77     /* Now fetch the xattr and find the actual size */
  78     orig_value = qemu_malloc(xattr_len);
  79     xattr_len = llistxattr(rpath(ctx, path), orig_value, xattr_len);
  80
  81     /* store the orig pointer */
  82     orig_value_start = orig_value;
  83     while (xattr_len > parsed_len) {
  84         xops = get_xattr_operations(ctx->xops, orig_value);
  85         if (!xops) {
  86             goto next_entry;
  87         }
  88
  89         if (!value) {
  90             size += xops->listxattr(ctx, path, orig_value, value, vsize);
  91         } else {
  92             size = xops->listxattr(ctx, path, orig_value, value, vsize);
  93             if (size < 0) {
  94                 goto err_out;
  95             }
  96             value += size;
  97             vsize -= size;
  98         }
  99 next_entry:
 100         /* Got the next entry */
 101         attr_len = strlen(orig_value) + 1;
 102         parsed_len += attr_len;
 103         orig_value += attr_len;
 104     }
 105     if (value) {
 106         size = value - ovalue;
 107     }
 108
 109 err_out:
 110     qemu_free(orig_value_start);
 111     return size;
 112 }
 113
 114 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
 115                    void *value, size_t size, int flags)
 116 {
 117     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 118     if (xops) {
 119         return xops->setxattr(ctx, path, name, value, size, flags);
 120     }
 121     errno = -EOPNOTSUPP;
 122     return -1;
 123
 124 }
 125
 126 int v9fs_remove_xattr(FsContext *ctx,
 127                       const char *path, const char *name)
 128 {
 129     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 130     if (xops) {
 131         return xops->removexattr(ctx, path, name);
 132     }
 133     errno = -EOPNOTSUPP;
 134     return -1;
 135
 136 }
 137
 138 XattrOperations *mapped_xattr_ops[] = {
 139     &mapped_user_xattr,
 140     &mapped_pacl_xattr,
 141     &mapped_dacl_xattr,
 142     NULL,
 143 };
 144
 145 XattrOperations *passthrough_xattr_ops[] = {
 146     &passthrough_user_xattr,
 147     &passthrough_acl_xattr,
 148     NULL,
 149 };
 150
 151 /* for .user none model should be same as passthrough */
 152 XattrOperations *none_xattr_ops[] = {
 153     &passthrough_user_xattr,
 154     &none_acl_xattr,
 155     NULL,
 156 };