1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (c) 2008, Christoph Hellwig 4 * All Rights Reserved. 5 */ 6#include "xfs.h" 7#include "xfs_shared.h" 8#include "xfs_format.h" 9#include "xfs_log_format.h" 10#include "xfs_trans_resv.h" 11#include "xfs_mount.h" 12#include "xfs_inode.h" 13#include "xfs_attr.h" 14#include "xfs_trace.h" 15#include "xfs_error.h" 16#include "xfs_acl.h" 17#include "xfs_da_format.h" 18#include "xfs_da_btree.h" 19 20#include <linux/posix_acl_xattr.h> 21 22/* 23 * Locking scheme: 24 * - all ACL updates are protected by inode->i_mutex, which is taken before 25 * calling into this file. 26 */ 27 28STATIC struct posix_acl * 29xfs_acl_from_disk( 30 struct xfs_mount *mp, 31 const struct xfs_acl *aclp, 32 int len, 33 int max_entries) 34{ 35 struct posix_acl_entry *acl_e; 36 struct posix_acl *acl; 37 const struct xfs_acl_entry *ace; 38 unsigned int count, i; 39 40 if (len < sizeof(*aclp)) { 41 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp, 42 len); 43 return ERR_PTR(-EFSCORRUPTED); 44 } 45 46 count = be32_to_cpu(aclp->acl_cnt); 47 if (count > max_entries || XFS_ACL_SIZE(count) != len) { 48 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp, 49 len); 50 return ERR_PTR(-EFSCORRUPTED); 51 } 52 53 acl = posix_acl_alloc(count, GFP_KERNEL); 54 if (!acl) 55 return ERR_PTR(-ENOMEM); 56 57 for (i = 0; i < count; i++) { 58 acl_e = &acl->a_entries[i]; 59 ace = &aclp->acl_entry[i]; 60 61 /* 62 * The tag is 32 bits on disk and 16 bits in core. 63 * 64 * Because every access to it goes through the core 65 * format first this is not a problem. 66 */ 67 acl_e->e_tag = be32_to_cpu(ace->ae_tag); 68 acl_e->e_perm = be16_to_cpu(ace->ae_perm); 69 70 switch (acl_e->e_tag) { 71 case ACL_USER: 72 acl_e->e_uid = make_kuid(&init_user_ns, 73 be32_to_cpu(ace->ae_id)); 74 break; 75 case ACL_GROUP: 76 acl_e->e_gid = make_kgid(&init_user_ns, 77 be32_to_cpu(ace->ae_id)); 78 break; 79 case ACL_USER_OBJ: 80 case ACL_GROUP_OBJ: 81 case ACL_MASK: 82 case ACL_OTHER: 83 break; 84 default: 85 goto fail; 86 } 87 } 88 return acl; 89 90fail: 91 posix_acl_release(acl); 92 return ERR_PTR(-EINVAL); 93} 94 95STATIC void 96xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) 97{ 98 const struct posix_acl_entry *acl_e; 99 struct xfs_acl_entry *ace; 100 int i; 101 102 aclp->acl_cnt = cpu_to_be32(acl->a_count); 103 for (i = 0; i < acl->a_count; i++) { 104 ace = &aclp->acl_entry[i]; 105 acl_e = &acl->a_entries[i]; 106 107 ace->ae_tag = cpu_to_be32(acl_e->e_tag); 108 switch (acl_e->e_tag) { 109 case ACL_USER: 110 ace->ae_id = cpu_to_be32( 111 from_kuid(&init_user_ns, acl_e->e_uid)); 112 break; 113 case ACL_GROUP: 114 ace->ae_id = cpu_to_be32( 115 from_kgid(&init_user_ns, acl_e->e_gid)); 116 break; 117 default: 118 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID); 119 break; 120 } 121 122 ace->ae_perm = cpu_to_be16(acl_e->e_perm); 123 } 124} 125 126struct posix_acl * 127xfs_get_acl(struct inode *inode, int type) 128{ 129 struct xfs_inode *ip = XFS_I(inode); 130 struct xfs_mount *mp = ip->i_mount; 131 struct posix_acl *acl = NULL; 132 struct xfs_da_args args = { 133 .dp = ip, 134 .attr_filter = XFS_ATTR_ROOT, 135 .valuelen = XFS_ACL_MAX_SIZE(mp), 136 }; 137 int error; 138 139 trace_xfs_get_acl(ip); 140 141 switch (type) { 142 case ACL_TYPE_ACCESS: 143 args.name = SGI_ACL_FILE; 144 break; 145 case ACL_TYPE_DEFAULT: 146 args.name = SGI_ACL_DEFAULT; 147 break; 148 default: 149 BUG(); 150 } 151 args.namelen = strlen(args.name); 152 153 /* 154 * If the attribute doesn't exist make sure we have a negative cache 155 * entry, for any other error assume it is transient. 156 */ 157 error = xfs_attr_get(&args); 158 if (!error) { 159 acl = xfs_acl_from_disk(mp, args.value, args.valuelen, 160 XFS_ACL_MAX_ENTRIES(mp)); 161 } else if (error != -ENOATTR) { 162 acl = ERR_PTR(error); 163 } 164 165 kmem_free(args.value); 166 return acl; 167} 168 169int 170__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 171{ 172 struct xfs_inode *ip = XFS_I(inode); 173 struct xfs_da_args args = { 174 .dp = ip, 175 .attr_filter = XFS_ATTR_ROOT, 176 }; 177 int error; 178 179 switch (type) { 180 case ACL_TYPE_ACCESS: 181 args.name = SGI_ACL_FILE; 182 break; 183 case ACL_TYPE_DEFAULT: 184 if (!S_ISDIR(inode->i_mode)) 185 return acl ? -EACCES : 0; 186 args.name = SGI_ACL_DEFAULT; 187 break; 188 default: 189 return -EINVAL; 190 } 191 args.namelen = strlen(args.name); 192 193 if (acl) { 194 args.valuelen = XFS_ACL_SIZE(acl->a_count); 195 args.value = kvzalloc(args.valuelen, GFP_KERNEL); 196 if (!args.value) 197 return -ENOMEM; 198 xfs_acl_to_disk(args.value, acl); 199 } 200 201 error = xfs_attr_set(&args); 202 kmem_free(args.value); 203 204 /* 205 * If the attribute didn't exist to start with that's fine. 206 */ 207 if (!acl && error == -ENOATTR) 208 error = 0; 209 if (!error) 210 set_cached_acl(inode, type, acl); 211 return error; 212} 213 214static int 215xfs_set_mode(struct inode *inode, umode_t mode) 216{ 217 int error = 0; 218 219 if (mode != inode->i_mode) { 220 struct iattr iattr; 221 222 iattr.ia_valid = ATTR_MODE | ATTR_CTIME; 223 iattr.ia_mode = mode; 224 iattr.ia_ctime = current_time(inode); 225 226 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL); 227 } 228 229 return error; 230} 231 232int 233xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) 234{ 235 umode_t mode; 236 bool set_mode = false; 237 int error = 0; 238 239 if (!acl) 240 goto set_acl; 241 242 error = -E2BIG; 243 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb))) 244 return error; 245 246 if (type == ACL_TYPE_ACCESS) { 247 error = posix_acl_update_mode(inode, &mode, &acl); 248 if (error) 249 return error; 250 set_mode = true; 251 } 252 253 set_acl: 254 error = __xfs_set_acl(inode, acl, type); 255 if (error) 256 return error; 257 258 /* 259 * We set the mode after successfully updating the ACL xattr because the 260 * xattr update can fail at ENOSPC and we don't want to change the mode 261 * if the ACL update hasn't been applied. 262 */ 263 if (set_mode) 264 error = xfs_set_mode(inode, mode); 265 266 return error; 267} 268 269/* 270 * Invalidate any cached ACLs if the user has bypassed the ACL interface. 271 * We don't validate the content whatsoever so it is caller responsibility to 272 * provide data in valid format and ensure i_mode is consistent. 273 */ 274void 275xfs_forget_acl( 276 struct inode *inode, 277 const char *name) 278{ 279 if (!strcmp(name, SGI_ACL_FILE)) 280 forget_cached_acl(inode, ACL_TYPE_ACCESS); 281 else if (!strcmp(name, SGI_ACL_DEFAULT)) 282 forget_cached_acl(inode, ACL_TYPE_DEFAULT); 283} 284