1/* 2 * Copyright (C) 2008 Christoph Hellwig. 3 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19#include "xfs.h" 20#include "xfs_da_btree.h" 21#include "xfs_bmap_btree.h" 22#include "xfs_inode.h" 23#include "xfs_attr.h" 24#include "xfs_attr_leaf.h" 25#include "xfs_acl.h" 26#include "xfs_vnodeops.h" 27 28#include <linux/posix_acl_xattr.h> 29#include <linux/xattr.h> 30 31 32static int 33xfs_xattr_get(struct dentry *dentry, const char *name, 34 void *value, size_t size, int xflags) 35{ 36 struct xfs_inode *ip = XFS_I(dentry->d_inode); 37 int error, asize = size; 38 39 if (strcmp(name, "") == 0) 40 return -EINVAL; 41 42 /* Convert Linux syscall to XFS internal ATTR flags */ 43 if (!size) { 44 xflags |= ATTR_KERNOVAL; 45 value = NULL; 46 } 47 48 error = -xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags); 49 if (error) 50 return error; 51 return asize; 52} 53 54static int 55xfs_xattr_set(struct dentry *dentry, const char *name, const void *value, 56 size_t size, int flags, int xflags) 57{ 58 struct xfs_inode *ip = XFS_I(dentry->d_inode); 59 60 if (strcmp(name, "") == 0) 61 return -EINVAL; 62 63 /* Convert Linux syscall to XFS internal ATTR flags */ 64 if (flags & XATTR_CREATE) 65 xflags |= ATTR_CREATE; 66 if (flags & XATTR_REPLACE) 67 xflags |= ATTR_REPLACE; 68 69 if (!value) 70 return -xfs_attr_remove(ip, (unsigned char *)name, xflags); 71 return -xfs_attr_set(ip, (unsigned char *)name, 72 (void *)value, size, xflags); 73} 74 75static const struct xattr_handler xfs_xattr_user_handler = { 76 .prefix = XATTR_USER_PREFIX, 77 .flags = 0, /* no flags implies user namespace */ 78 .get = xfs_xattr_get, 79 .set = xfs_xattr_set, 80}; 81 82static const struct xattr_handler xfs_xattr_trusted_handler = { 83 .prefix = XATTR_TRUSTED_PREFIX, 84 .flags = ATTR_ROOT, 85 .get = xfs_xattr_get, 86 .set = xfs_xattr_set, 87}; 88 89static const struct xattr_handler xfs_xattr_security_handler = { 90 .prefix = XATTR_SECURITY_PREFIX, 91 .flags = ATTR_SECURE, 92 .get = xfs_xattr_get, 93 .set = xfs_xattr_set, 94}; 95 96const struct xattr_handler *xfs_xattr_handlers[] = { 97 &xfs_xattr_user_handler, 98 &xfs_xattr_trusted_handler, 99 &xfs_xattr_security_handler, 100#ifdef CONFIG_XFS_POSIX_ACL 101 &xfs_xattr_acl_access_handler, 102 &xfs_xattr_acl_default_handler, 103#endif 104 NULL 105}; 106 107static unsigned int xfs_xattr_prefix_len(int flags) 108{ 109 if (flags & XFS_ATTR_SECURE) 110 return sizeof("security"); 111 else if (flags & XFS_ATTR_ROOT) 112 return sizeof("trusted"); 113 else 114 return sizeof("user"); 115} 116 117static const char *xfs_xattr_prefix(int flags) 118{ 119 if (flags & XFS_ATTR_SECURE) 120 return xfs_xattr_security_handler.prefix; 121 else if (flags & XFS_ATTR_ROOT) 122 return xfs_xattr_trusted_handler.prefix; 123 else 124 return xfs_xattr_user_handler.prefix; 125} 126 127static int 128xfs_xattr_put_listent( 129 struct xfs_attr_list_context *context, 130 int flags, 131 unsigned char *name, 132 int namelen, 133 int valuelen, 134 unsigned char *value) 135{ 136 unsigned int prefix_len = xfs_xattr_prefix_len(flags); 137 char *offset; 138 int arraytop; 139 140 ASSERT(context->count >= 0); 141 142 /* 143 * Only show root namespace entries if we are actually allowed to 144 * see them. 145 */ 146 if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN)) 147 return 0; 148 149 arraytop = context->count + prefix_len + namelen + 1; 150 if (arraytop > context->firstu) { 151 context->count = -1; /* insufficient space */ 152 return 1; 153 } 154 offset = (char *)context->alist + context->count; 155 strncpy(offset, xfs_xattr_prefix(flags), prefix_len); 156 offset += prefix_len; 157 strncpy(offset, (char *)name, namelen); /* real name */ 158 offset += namelen; 159 *offset = '\0'; 160 context->count += prefix_len + namelen + 1; 161 return 0; 162} 163 164static int 165xfs_xattr_put_listent_sizes( 166 struct xfs_attr_list_context *context, 167 int flags, 168 unsigned char *name, 169 int namelen, 170 int valuelen, 171 unsigned char *value) 172{ 173 context->count += xfs_xattr_prefix_len(flags) + namelen + 1; 174 return 0; 175} 176 177static int 178list_one_attr(const char *name, const size_t len, void *data, 179 size_t size, ssize_t *result) 180{ 181 char *p = data + *result; 182 183 *result += len; 184 if (!size) 185 return 0; 186 if (*result > size) 187 return -ERANGE; 188 189 strcpy(p, name); 190 return 0; 191} 192 193ssize_t 194xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size) 195{ 196 struct xfs_attr_list_context context; 197 struct attrlist_cursor_kern cursor = { 0 }; 198 struct inode *inode = dentry->d_inode; 199 int error; 200 201 /* 202 * First read the regular on-disk attributes. 203 */ 204 memset(&context, 0, sizeof(context)); 205 context.dp = XFS_I(inode); 206 context.cursor = &cursor; 207 context.resynch = 1; 208 context.alist = data; 209 context.bufsize = size; 210 context.firstu = context.bufsize; 211 212 if (size) 213 context.put_listent = xfs_xattr_put_listent; 214 else 215 context.put_listent = xfs_xattr_put_listent_sizes; 216 217 xfs_attr_list_int(&context); 218 if (context.count < 0) 219 return -ERANGE; 220 221 /* 222 * Then add the two synthetic ACL attributes. 223 */ 224 if (posix_acl_access_exists(inode)) { 225 error = list_one_attr(POSIX_ACL_XATTR_ACCESS, 226 strlen(POSIX_ACL_XATTR_ACCESS) + 1, 227 data, size, &context.count); 228 if (error) 229 return error; 230 } 231 232 if (posix_acl_default_exists(inode)) { 233 error = list_one_attr(POSIX_ACL_XATTR_DEFAULT, 234 strlen(POSIX_ACL_XATTR_DEFAULT) + 1, 235 data, size, &context.count); 236 if (error) 237 return error; 238 } 239 240 return context.count; 241} 242