1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * Copyright IBM Corporation, 2010 4 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> 5 */ 6 7 #include <linux/module.h> 8 #include <linux/fs.h> 9 #include <linux/fs_struct.h> 10 #include <net/9p/9p.h> 11 #include <net/9p/client.h> 12 #include <linux/slab.h> 13 #include <linux/sched.h> 14 #include <linux/posix_acl_xattr.h> 15 #include "xattr.h" 16 #include "acl.h" 17 #include "v9fs.h" 18 #include "v9fs_vfs.h" 19 #include "fid.h" 20 21 static struct posix_acl *v9fs_fid_get_acl(struct p9_fid *fid, const char *name) 22 { 23 ssize_t size; 24 void *value = NULL; 25 struct posix_acl *acl = NULL; 26 27 size = v9fs_fid_xattr_get(fid, name, NULL, 0); 28 if (size < 0) 29 return ERR_PTR(size); 30 if (size == 0) 31 return ERR_PTR(-ENODATA); 32 33 value = kzalloc(size, GFP_NOFS); 34 if (!value) 35 return ERR_PTR(-ENOMEM); 36 37 size = v9fs_fid_xattr_get(fid, name, value, size); 38 if (size < 0) 39 acl = ERR_PTR(size); 40 else if (size == 0) 41 acl = ERR_PTR(-ENODATA); 42 else 43 acl = posix_acl_from_xattr(&init_user_ns, value, size); 44 kfree(value); 45 return acl; 46 } 47 48 static struct posix_acl *v9fs_acl_get(struct dentry *dentry, const char *name) 49 { 50 struct p9_fid *fid; 51 struct posix_acl *acl = NULL; 52 53 fid = v9fs_fid_lookup(dentry); 54 if (IS_ERR(fid)) 55 return ERR_CAST(fid); 56 57 acl = v9fs_fid_get_acl(fid, name); 58 p9_fid_put(fid); 59 return acl; 60 } 61 62 static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, const char *name) 63 { 64 int retval; 65 struct posix_acl *acl = NULL; 66 67 acl = v9fs_fid_get_acl(fid, name); 68 if (!IS_ERR(acl)) 69 return acl; 70 71 retval = PTR_ERR(acl); 72 if (retval == -ENODATA || retval == -ENOSYS || retval == -EOPNOTSUPP) 73 return NULL; 74 75 /* map everything else to -EIO */ 76 return ERR_PTR(-EIO); 77 } 78 79 int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) 80 { 81 int retval = 0; 82 struct posix_acl *pacl, *dacl; 83 struct v9fs_session_info *v9ses; 84 85 v9ses = v9fs_inode2v9ses(inode); 86 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || 87 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { 88 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL); 89 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL); 90 return 0; 91 } 92 /* get the default/access acl values and cache them */ 93 dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT); 94 pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS); 95 96 if (!IS_ERR(dacl) && !IS_ERR(pacl)) { 97 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); 98 set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); 99 } else 100 retval = -EIO; 101 102 if (!IS_ERR(dacl)) 103 posix_acl_release(dacl); 104 105 if (!IS_ERR(pacl)) 106 posix_acl_release(pacl); 107 108 return retval; 109 } 110 111 static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) 112 { 113 struct posix_acl *acl; 114 /* 115 * 9p Always cache the acl value when 116 * instantiating the inode (v9fs_inode_from_fid) 117 */ 118 acl = get_cached_acl(inode, type); 119 BUG_ON(is_uncached_acl(acl)); 120 return acl; 121 } 122 123 struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type, bool rcu) 124 { 125 struct v9fs_session_info *v9ses; 126 127 if (rcu) 128 return ERR_PTR(-ECHILD); 129 130 v9ses = v9fs_inode2v9ses(inode); 131 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || 132 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { 133 /* 134 * On access = client and acl = on mode get the acl 135 * values from the server 136 */ 137 return NULL; 138 } 139 return v9fs_get_cached_acl(inode, type); 140 141 } 142 143 struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap, 144 struct dentry *dentry, int type) 145 { 146 struct v9fs_session_info *v9ses; 147 148 v9ses = v9fs_dentry2v9ses(dentry); 149 /* We allow set/get/list of acl when access=client is not specified. */ 150 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) 151 return v9fs_acl_get(dentry, posix_acl_xattr_name(type)); 152 return v9fs_get_cached_acl(d_inode(dentry), type); 153 } 154 155 int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 156 struct posix_acl *acl, int type) 157 { 158 int retval; 159 size_t size = 0; 160 void *value = NULL; 161 const char *acl_name; 162 struct v9fs_session_info *v9ses; 163 struct inode *inode = d_inode(dentry); 164 165 if (acl) { 166 retval = posix_acl_valid(inode->i_sb->s_user_ns, acl); 167 if (retval) 168 goto err_out; 169 170 value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS); 171 if (!value) { 172 retval = -ENOMEM; 173 goto err_out; 174 } 175 } 176 177 /* 178 * set the attribute on the remote. Without even looking at the 179 * xattr value. We leave it to the server to validate 180 */ 181 acl_name = posix_acl_xattr_name(type); 182 v9ses = v9fs_dentry2v9ses(dentry); 183 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) { 184 retval = v9fs_xattr_set(dentry, acl_name, value, size, 0); 185 goto err_out; 186 } 187 188 if (S_ISLNK(inode->i_mode)) { 189 retval = -EOPNOTSUPP; 190 goto err_out; 191 } 192 193 if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) { 194 retval = -EPERM; 195 goto err_out; 196 } 197 198 switch (type) { 199 case ACL_TYPE_ACCESS: 200 if (acl) { 201 struct iattr iattr = {}; 202 struct posix_acl *acl_mode = acl; 203 204 retval = posix_acl_update_mode(&nop_mnt_idmap, inode, 205 &iattr.ia_mode, 206 &acl_mode); 207 if (retval) 208 goto err_out; 209 if (!acl_mode) { 210 /* 211 * ACL can be represented by the mode bits. 212 * So don't update ACL below. 213 */ 214 kfree(value); 215 value = NULL; 216 size = 0; 217 } 218 iattr.ia_valid = ATTR_MODE; 219 /* 220 * FIXME should we update ctime ? 221 * What is the following setxattr update the mode ? 222 */ 223 v9fs_vfs_setattr_dotl(&nop_mnt_idmap, dentry, &iattr); 224 } 225 break; 226 case ACL_TYPE_DEFAULT: 227 if (!S_ISDIR(inode->i_mode)) { 228 retval = acl ? -EINVAL : 0; 229 goto err_out; 230 } 231 break; 232 } 233 234 retval = v9fs_xattr_set(dentry, acl_name, value, size, 0); 235 if (!retval) 236 set_cached_acl(inode, type, acl); 237 238 err_out: 239 kfree(value); 240 return retval; 241 } 242 243 static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl) 244 { 245 int retval; 246 char *name; 247 size_t size; 248 void *buffer; 249 250 if (!acl) 251 return 0; 252 253 /* Set a setxattr request to server */ 254 buffer = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_KERNEL); 255 if (!buffer) 256 return -ENOMEM; 257 258 switch (type) { 259 case ACL_TYPE_ACCESS: 260 name = XATTR_NAME_POSIX_ACL_ACCESS; 261 break; 262 case ACL_TYPE_DEFAULT: 263 name = XATTR_NAME_POSIX_ACL_DEFAULT; 264 break; 265 default: 266 BUG(); 267 } 268 retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0); 269 kfree(buffer); 270 return retval; 271 } 272 273 int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid) 274 { 275 int retval = 0; 276 struct posix_acl *acl; 277 278 if (S_ISLNK(inode->i_mode)) 279 return -EOPNOTSUPP; 280 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); 281 if (acl) { 282 retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); 283 if (retval) 284 return retval; 285 set_cached_acl(inode, ACL_TYPE_ACCESS, acl); 286 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl); 287 posix_acl_release(acl); 288 } 289 return retval; 290 } 291 292 int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid, 293 struct posix_acl *dacl, struct posix_acl *acl) 294 { 295 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); 296 set_cached_acl(inode, ACL_TYPE_ACCESS, acl); 297 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl); 298 v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl); 299 return 0; 300 } 301 302 void v9fs_put_acl(struct posix_acl *dacl, 303 struct posix_acl *acl) 304 { 305 posix_acl_release(dacl); 306 posix_acl_release(acl); 307 } 308 309 int v9fs_acl_mode(struct inode *dir, umode_t *modep, 310 struct posix_acl **dpacl, struct posix_acl **pacl) 311 { 312 int retval = 0; 313 umode_t mode = *modep; 314 struct posix_acl *acl = NULL; 315 316 if (!S_ISLNK(mode)) { 317 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT); 318 if (IS_ERR(acl)) 319 return PTR_ERR(acl); 320 if (!acl) 321 mode &= ~current_umask(); 322 } 323 if (acl) { 324 if (S_ISDIR(mode)) 325 *dpacl = posix_acl_dup(acl); 326 retval = __posix_acl_create(&acl, GFP_NOFS, &mode); 327 if (retval < 0) 328 return retval; 329 if (retval > 0) 330 *pacl = acl; 331 else 332 posix_acl_release(acl); 333 } 334 *modep = mode; 335 return 0; 336 } 337