hw/9pfs/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 "hw/virtio.h"
  15 #include "virtio-9p.h"
  16 #include "fsdev/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     char buffer[PATH_MAX];
  70     void *ovalue = value;
  71     XattrOperations *xops;
  72     char *orig_value, *orig_value_start;
  73     ssize_t xattr_len, parsed_len = 0, attr_len;
  74
  75     /* Get the actual len */
  76     xattr_len = llistxattr(rpath(ctx, path, buffer), value, 0);
  77     if (xattr_len <= 0) {
  78         return xattr_len;
  79     }
  80
  81     /* Now fetch the xattr and find the actual size */
  82     orig_value = qemu_malloc(xattr_len);
  83     xattr_len = llistxattr(rpath(ctx, path, buffer), orig_value, xattr_len);
  84
  85     /* store the orig pointer */
  86     orig_value_start = orig_value;
  87     while (xattr_len > parsed_len) {
  88         xops = get_xattr_operations(ctx->xops, orig_value);
  89         if (!xops) {
  90             goto next_entry;
  91         }
  92
  93         if (!value) {
  94             size += xops->listxattr(ctx, path, orig_value, value, vsize);
  95         } else {
  96             size = xops->listxattr(ctx, path, orig_value, value, vsize);
  97             if (size < 0) {
  98                 goto err_out;
  99             }
 100             value += size;
 101             vsize -= size;
 102         }
 103 next_entry:
 104         /* Got the next entry */
 105         attr_len = strlen(orig_value) + 1;
 106         parsed_len += attr_len;
 107         orig_value += attr_len;
 108     }
 109     if (value) {
 110         size = value - ovalue;
 111     }
 112
 113 err_out:
 114     qemu_free(orig_value_start);
 115     return size;
 116 }
 117
 118 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
 119                    void *value, size_t size, int flags)
 120 {
 121     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 122     if (xops) {
 123         return xops->setxattr(ctx, path, name, value, size, flags);
 124     }
 125     errno = -EOPNOTSUPP;
 126     return -1;
 127
 128 }
 129
 130 int v9fs_remove_xattr(FsContext *ctx,
 131                       const char *path, const char *name)
 132 {
 133     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 134     if (xops) {
 135         return xops->removexattr(ctx, path, name);
 136     }
 137     errno = -EOPNOTSUPP;
 138     return -1;
 139
 140 }
 141
 142 XattrOperations *mapped_xattr_ops[] = {
 143     &mapped_user_xattr,
 144     &mapped_pacl_xattr,
 145     &mapped_dacl_xattr,
 146     NULL,
 147 };
 148
 149 XattrOperations *passthrough_xattr_ops[] = {
 150     &passthrough_user_xattr,
 151     &passthrough_acl_xattr,
 152     NULL,
 153 };
 154
 155 /* for .user none model should be same as passthrough */
 156 XattrOperations *none_xattr_ops[] = {
 157     &passthrough_user_xattr,
 158     &none_acl_xattr,
 159     NULL,
 160 };