hw/9pfs/9p-xattr.c

   1 /*
   2  * 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-9p.h"
  15 #include "fsdev/file-op-9p.h"
  16 #include "9p-xattr.h"
  17
  18
  19 static XattrOperations *get_xattr_operations(XattrOperations **h,
  20                                              const char *name)
  21 {
  22     XattrOperations *xops;
  23     for (xops = *(h)++; xops != NULL; xops = *(h)++) {
  24         if (!strncmp(name, xops->name, strlen(xops->name))) {
  25             return xops;
  26         }
  27     }
  28     return NULL;
  29 }
  30
  31 ssize_t v9fs_get_xattr(FsContext *ctx, const char *path,
  32                        const char *name, void *value, size_t size)
  33 {
  34     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
  35     if (xops) {
  36         return xops->getxattr(ctx, path, name, value, size);
  37     }
  38     errno = EOPNOTSUPP;
  39     return -1;
  40 }
  41
  42 ssize_t pt_listxattr(FsContext *ctx, const char *path,
  43                      char *name, void *value, size_t size)
  44 {
  45     int name_size = strlen(name) + 1;
  46     if (!value) {
  47         return name_size;
  48     }
  49
  50     if (size < name_size) {
  51         errno = ERANGE;
  52         return -1;
  53     }
  54
  55     /* no need for strncpy: name_size is strlen(name)+1 */
  56     memcpy(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;
  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     buffer = rpath(ctx, path);
  77     xattr_len = llistxattr(buffer, value, 0);
  78     if (xattr_len <= 0) {
  79         g_free(buffer);
  80         return xattr_len;
  81     }
  82
  83     /* Now fetch the xattr and find the actual size */
  84     orig_value = g_malloc(xattr_len);
  85     xattr_len = llistxattr(buffer, orig_value, xattr_len);
  86     g_free(buffer);
  87
  88     /* store the orig pointer */
  89     orig_value_start = orig_value;
  90     while (xattr_len > parsed_len) {
  91         xops = get_xattr_operations(ctx->xops, orig_value);
  92         if (!xops) {
  93             goto next_entry;
  94         }
  95
  96         if (!value) {
  97             size += xops->listxattr(ctx, path, orig_value, value, vsize);
  98         } else {
  99             size = xops->listxattr(ctx, path, orig_value, value, vsize);
 100             if (size < 0) {
 101                 goto err_out;
 102             }
 103             value += size;
 104             vsize -= size;
 105         }
 106 next_entry:
 107         /* Got the next entry */
 108         attr_len = strlen(orig_value) + 1;
 109         parsed_len += attr_len;
 110         orig_value += attr_len;
 111     }
 112     if (value) {
 113         size = value - ovalue;
 114     }
 115
 116 err_out:
 117     g_free(orig_value_start);
 118     return size;
 119 }
 120
 121 int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
 122                    void *value, size_t size, int flags)
 123 {
 124     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 125     if (xops) {
 126         return xops->setxattr(ctx, path, name, value, size, flags);
 127     }
 128     errno = EOPNOTSUPP;
 129     return -1;
 130
 131 }
 132
 133 int v9fs_remove_xattr(FsContext *ctx,
 134                       const char *path, const char *name)
 135 {
 136     XattrOperations *xops = get_xattr_operations(ctx->xops, name);
 137     if (xops) {
 138         return xops->removexattr(ctx, path, name);
 139     }
 140     errno = EOPNOTSUPP;
 141     return -1;
 142
 143 }
 144
 145 XattrOperations *mapped_xattr_ops[] = {
 146     &mapped_user_xattr,
 147     &mapped_pacl_xattr,
 148     &mapped_dacl_xattr,
 149     NULL,
 150 };
 151
 152 XattrOperations *passthrough_xattr_ops[] = {
 153     &passthrough_user_xattr,
 154     &passthrough_acl_xattr,
 155     NULL,
 156 };
 157
 158 /* for .user none model should be same as passthrough */
 159 XattrOperations *none_xattr_ops[] = {
 160     &passthrough_user_xattr,
 161     &none_acl_xattr,
 162     NULL,
 163 };