--- zzzz-none-000/linux-3.10.107/fs/posix_acl.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/fs/posix_acl.c 2021-02-04 17:41:59.000000000 +0000 @@ -1,10 +1,8 @@ /* - * linux/fs/posix_acl.c + * Copyright (C) 2002,2003 by Andreas Gruenbacher * - * Copyright (C) 2002 by Andreas Gruenbacher - * - * Fixes from William Schumacher incorporated on 15 March 2001. - * (Reported by Charles Bertsch, ). + * Fixes from William Schumacher incorporated on 15 March 2001. + * (Reported by Charles Bertsch, ). */ /* @@ -18,15 +16,112 @@ #include #include #include +#include +#include #include +#include -#include +struct posix_acl **acl_by_type(struct inode *inode, int type) +{ + switch (type) { + case ACL_TYPE_ACCESS: + return &inode->i_acl; + case ACL_TYPE_DEFAULT: + return &inode->i_default_acl; + default: + BUG(); + } +} +EXPORT_SYMBOL(acl_by_type); -EXPORT_SYMBOL(posix_acl_init); -EXPORT_SYMBOL(posix_acl_alloc); -EXPORT_SYMBOL(posix_acl_valid); -EXPORT_SYMBOL(posix_acl_equiv_mode); -EXPORT_SYMBOL(posix_acl_from_mode); +struct posix_acl *get_cached_acl(struct inode *inode, int type) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *acl = ACCESS_ONCE(*p); + if (acl) { + spin_lock(&inode->i_lock); + acl = *p; + if (acl != ACL_NOT_CACHED) + acl = posix_acl_dup(acl); + spin_unlock(&inode->i_lock); + } + return acl; +} +EXPORT_SYMBOL(get_cached_acl); + +struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) +{ + return rcu_dereference(*acl_by_type(inode, type)); +} +EXPORT_SYMBOL(get_cached_acl_rcu); + +void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; + spin_lock(&inode->i_lock); + old = *p; + rcu_assign_pointer(*p, posix_acl_dup(acl)); + spin_unlock(&inode->i_lock); + if (old != ACL_NOT_CACHED) + posix_acl_release(old); +} +EXPORT_SYMBOL(set_cached_acl); + +void forget_cached_acl(struct inode *inode, int type) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; + spin_lock(&inode->i_lock); + old = *p; + *p = ACL_NOT_CACHED; + spin_unlock(&inode->i_lock); + if (old != ACL_NOT_CACHED) + posix_acl_release(old); +} +EXPORT_SYMBOL(forget_cached_acl); + +void forget_all_cached_acls(struct inode *inode) +{ + struct posix_acl *old_access, *old_default; + spin_lock(&inode->i_lock); + old_access = inode->i_acl; + old_default = inode->i_default_acl; + inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; + spin_unlock(&inode->i_lock); + if (old_access != ACL_NOT_CACHED) + posix_acl_release(old_access); + if (old_default != ACL_NOT_CACHED) + posix_acl_release(old_default); +} +EXPORT_SYMBOL(forget_all_cached_acls); + +struct posix_acl *get_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + + acl = get_cached_acl(inode, type); + if (acl != ACL_NOT_CACHED) + return acl; + + if (!IS_POSIXACL(inode)) + return NULL; + + /* + * A filesystem can force a ACL callback by just never filling the + * ACL cache. But normally you'd fill the cache either at inode + * instantiation time, or on the first ->get_acl call. + * + * If the filesystem doesn't have a get_acl() function at all, we'll + * just create the negative cache entry. + */ + if (!inode->i_op->get_acl) { + set_cached_acl(inode, type, NULL); + return NULL; + } + return inode->i_op->get_acl(inode, type); +} +EXPORT_SYMBOL(get_acl); /* * Init a fresh posix_acl @@ -37,6 +132,7 @@ atomic_set(&acl->a_refcount, 1); acl->a_count = count; } +EXPORT_SYMBOL(posix_acl_init); /* * Allocate a new ACL with the specified number of entries. @@ -51,6 +147,7 @@ posix_acl_init(acl, count); return acl; } +EXPORT_SYMBOL(posix_acl_alloc); /* * Clone an ACL. @@ -78,8 +175,6 @@ { const struct posix_acl_entry *pa, *pe; int state = ACL_USER_OBJ; - kuid_t prev_uid = INVALID_UID; - kgid_t prev_gid = INVALID_GID; int needs_mask = 0; FOREACH_ACL_ENTRY(pa, acl, pe) { @@ -98,10 +193,6 @@ return -EINVAL; if (!uid_valid(pa->e_uid)) return -EINVAL; - if (uid_valid(prev_uid) && - uid_lte(pa->e_uid, prev_uid)) - return -EINVAL; - prev_uid = pa->e_uid; needs_mask = 1; break; @@ -117,10 +208,6 @@ return -EINVAL; if (!gid_valid(pa->e_gid)) return -EINVAL; - if (gid_valid(prev_gid) && - gid_lte(pa->e_gid, prev_gid)) - return -EINVAL; - prev_gid = pa->e_gid; needs_mask = 1; break; @@ -146,6 +233,7 @@ return 0; return -EINVAL; } +EXPORT_SYMBOL(posix_acl_valid); /* * Returns 0 if the acl can be exactly represented in the traditional @@ -192,6 +280,7 @@ *mode_p = (*mode_p & ~S_IRWXUGO) | mode; return not_equiv; } +EXPORT_SYMBOL(posix_acl_equiv_mode); /* * Create an ACL representing the file mode permission bits of an inode. @@ -213,6 +302,7 @@ acl->a_entries[2].e_perm = (mode & S_IRWXO); return acl; } +EXPORT_SYMBOL(posix_acl_from_mode); /* * Return 0 if current is granted want access to the inode @@ -344,7 +434,7 @@ /* * Modify the ACL for the chmod syscall. */ -static int posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) +static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) { struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; struct posix_acl_entry *pa, *pe; @@ -390,7 +480,7 @@ } int -posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) +__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) { struct posix_acl *clone = posix_acl_clone(*acl, gfp); int err = -ENOMEM; @@ -405,7 +495,102 @@ *acl = clone; return err; } -EXPORT_SYMBOL(posix_acl_create); +EXPORT_SYMBOL(__posix_acl_create); + +int +__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) +{ + struct posix_acl *clone = posix_acl_clone(*acl, gfp); + int err = -ENOMEM; + if (clone) { + err = __posix_acl_chmod_masq(clone, mode); + if (err) { + posix_acl_release(clone); + clone = NULL; + } + } + posix_acl_release(*acl); + *acl = clone; + return err; +} +EXPORT_SYMBOL(__posix_acl_chmod); + +int +posix_acl_chmod(struct inode *inode, umode_t mode) +{ + struct posix_acl *acl; + int ret = 0; + + if (!IS_POSIXACL(inode)) + return 0; + if (!inode->i_op->set_acl) + return -EOPNOTSUPP; + + acl = get_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR_OR_NULL(acl)) { + if (acl == ERR_PTR(-EOPNOTSUPP)) + return 0; + return PTR_ERR(acl); + } + + ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); + if (ret) + return ret; + ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); + posix_acl_release(acl); + return ret; +} +EXPORT_SYMBOL(posix_acl_chmod); + +int +posix_acl_create(struct inode *dir, umode_t *mode, + struct posix_acl **default_acl, struct posix_acl **acl) +{ + struct posix_acl *p; + struct posix_acl *clone; + int ret; + + *acl = NULL; + *default_acl = NULL; + + if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) + return 0; + + p = get_acl(dir, ACL_TYPE_DEFAULT); + if (!p || p == ERR_PTR(-EOPNOTSUPP)) { + *mode &= ~current_umask(); + return 0; + } + if (IS_ERR(p)) + return PTR_ERR(p); + + clone = posix_acl_clone(p, GFP_NOFS); + if (!clone) + goto no_mem; + + ret = posix_acl_create_masq(clone, mode); + if (ret < 0) + goto no_mem_clone; + + if (ret == 0) + posix_acl_release(clone); + else + *acl = clone; + + if (!S_ISDIR(*mode)) + posix_acl_release(p); + else + *default_acl = p; + + return 0; + +no_mem_clone: + posix_acl_release(clone); +no_mem: + posix_acl_release(p); + return -ENOMEM; +} +EXPORT_SYMBOL_GPL(posix_acl_create); /** * posix_acl_update_mode - update mode in set_acl @@ -420,38 +605,330 @@ * Called from set_acl inode operations. */ int posix_acl_update_mode(struct inode *inode, umode_t *mode_p, - struct posix_acl **acl) + struct posix_acl **acl) { - umode_t mode = inode->i_mode; - int error; + umode_t mode = inode->i_mode; + int error; - error = posix_acl_equiv_mode(*acl, &mode); - if (error < 0) - return error; - if (error == 0) - *acl = NULL; - if (!in_group_p(inode->i_gid) && - !capable_wrt_inode_uidgid(inode, CAP_FSETID)) - mode &= ~S_ISGID; - *mode_p = mode; - return 0; + error = posix_acl_equiv_mode(*acl, &mode); + if (error < 0) + return error; + if (error == 0) + *acl = NULL; + if (!in_group_p(inode->i_gid) && + !capable_wrt_inode_uidgid(inode, CAP_FSETID)) + mode &= ~S_ISGID; + *mode_p = mode; + return 0; } EXPORT_SYMBOL(posix_acl_update_mode); +/* + * Fix up the uids and gids in posix acl extended attributes in place. + */ +static void posix_acl_fix_xattr_userns( + struct user_namespace *to, struct user_namespace *from, + void *value, size_t size) +{ + posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; + posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; + int count; + kuid_t uid; + kgid_t gid; + + if (!value) + return; + if (size < sizeof(posix_acl_xattr_header)) + return; + if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) + return; + + count = posix_acl_xattr_count(size); + if (count < 0) + return; + if (count == 0) + return; + + for (end = entry + count; entry != end; entry++) { + switch(le16_to_cpu(entry->e_tag)) { + case ACL_USER: + uid = make_kuid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kuid(to, uid)); + break; + case ACL_GROUP: + gid = make_kgid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kgid(to, gid)); + break; + default: + break; + } + } +} + +void posix_acl_fix_xattr_from_user(void *value, size_t size) +{ + struct user_namespace *user_ns = current_user_ns(); + if (user_ns == &init_user_ns) + return; + posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size); +} + +void posix_acl_fix_xattr_to_user(void *value, size_t size) +{ + struct user_namespace *user_ns = current_user_ns(); + if (user_ns == &init_user_ns) + return; + posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size); +} + +/* + * Convert from extended attribute to in-memory representation. + */ +struct posix_acl * +posix_acl_from_xattr(struct user_namespace *user_ns, + const void *value, size_t size) +{ + posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; + posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; + int count; + struct posix_acl *acl; + struct posix_acl_entry *acl_e; + + if (!value) + return NULL; + if (size < sizeof(posix_acl_xattr_header)) + return ERR_PTR(-EINVAL); + if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) + return ERR_PTR(-EOPNOTSUPP); + + count = posix_acl_xattr_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + + acl = posix_acl_alloc(count, GFP_NOFS); + if (!acl) + return ERR_PTR(-ENOMEM); + acl_e = acl->a_entries; + + for (end = entry + count; entry != end; acl_e++, entry++) { + acl_e->e_tag = le16_to_cpu(entry->e_tag); + acl_e->e_perm = le16_to_cpu(entry->e_perm); + + switch(acl_e->e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + break; + + case ACL_USER: + acl_e->e_uid = + make_kuid(user_ns, + le32_to_cpu(entry->e_id)); + if (!uid_valid(acl_e->e_uid)) + goto fail; + break; + case ACL_GROUP: + acl_e->e_gid = + make_kgid(user_ns, + le32_to_cpu(entry->e_id)); + if (!gid_valid(acl_e->e_gid)) + goto fail; + break; + + default: + goto fail; + } + } + return acl; + +fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL (posix_acl_from_xattr); + +/* + * Convert from in-memory to extended attribute representation. + */ int -posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) +posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, + void *buffer, size_t size) { - struct posix_acl *clone = posix_acl_clone(*acl, gfp); - int err = -ENOMEM; - if (clone) { - err = posix_acl_chmod_masq(clone, mode); - if (err) { - posix_acl_release(clone); - clone = NULL; + posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer; + posix_acl_xattr_entry *ext_entry; + int real_size, n; + + real_size = posix_acl_xattr_size(acl->a_count); + if (!buffer) + return real_size; + if (real_size > size) + return -ERANGE; + + ext_entry = ext_acl->a_entries; + ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); + + for (n=0; n < acl->a_count; n++, ext_entry++) { + const struct posix_acl_entry *acl_e = &acl->a_entries[n]; + ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); + ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); + switch(acl_e->e_tag) { + case ACL_USER: + ext_entry->e_id = + cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); + break; + case ACL_GROUP: + ext_entry->e_id = + cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); + break; + default: + ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); + break; } } - posix_acl_release(*acl); - *acl = clone; - return err; + return real_size; +} +EXPORT_SYMBOL (posix_acl_to_xattr); + +static int +posix_acl_xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, const char *name, + void *value, size_t size) +{ + struct posix_acl *acl; + int error; + + if (strcmp(name, "") != 0) + return -EINVAL; + if (!IS_POSIXACL(d_backing_inode(dentry))) + return -EOPNOTSUPP; + if (d_is_symlink(dentry)) + return -EOPNOTSUPP; + + acl = get_acl(d_backing_inode(dentry), handler->flags); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + + error = posix_acl_to_xattr(&init_user_ns, acl, value, size); + posix_acl_release(acl); + + return error; +} + +int +set_posix_acl(struct inode *inode, int type, struct posix_acl *acl) +{ + if (!IS_POSIXACL(inode)) + return -EOPNOTSUPP; + if (!inode->i_op->set_acl) + return -EOPNOTSUPP; + + if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + if (!inode_owner_or_capable(inode)) + return -EPERM; + + if (acl) { + int ret = posix_acl_valid(acl); + if (ret) + return ret; + } + return inode->i_op->set_acl(inode, acl, type); +} +EXPORT_SYMBOL(set_posix_acl); + +static int +posix_acl_xattr_set(const struct xattr_handler *handler, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct inode *inode = d_backing_inode(dentry); + struct posix_acl *acl = NULL; + int ret; + + if (strcmp(name, "") != 0) + return -EINVAL; + + if (value) { + acl = posix_acl_from_xattr(&init_user_ns, value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + } + ret = set_posix_acl(inode, handler->flags, acl); + posix_acl_release(acl); + return ret; +} + +static size_t +posix_acl_xattr_list(const struct xattr_handler *handler, + struct dentry *dentry, char *list, size_t list_size, + const char *name, size_t name_len) +{ + const char *xname = handler->prefix; + size_t size; + + if (!IS_POSIXACL(d_backing_inode(dentry))) + return 0; + + size = strlen(xname) + 1; + if (list && size <= list_size) + memcpy(list, xname, size); + return size; +} + +const struct xattr_handler posix_acl_access_xattr_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .flags = ACL_TYPE_ACCESS, + .list = posix_acl_xattr_list, + .get = posix_acl_xattr_get, + .set = posix_acl_xattr_set, +}; +EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler); + +const struct xattr_handler posix_acl_default_xattr_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .flags = ACL_TYPE_DEFAULT, + .list = posix_acl_xattr_list, + .get = posix_acl_xattr_get, + .set = posix_acl_xattr_set, +}; +EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler); + +int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + int error; + + if (type == ACL_TYPE_ACCESS) { + error = posix_acl_update_mode(inode, + &inode->i_mode, &acl); + if (error) + return error; + } + + inode->i_ctime = CURRENT_TIME; + set_cached_acl(inode, type, acl); + return 0; +} + +int simple_acl_create(struct inode *dir, struct inode *inode) +{ + struct posix_acl *default_acl, *acl; + int error; + + error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); + if (error) + return error; + + set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); + set_cached_acl(inode, ACL_TYPE_ACCESS, acl); + + if (default_acl) + posix_acl_release(default_acl); + if (acl) + posix_acl_release(acl); + return 0; } -EXPORT_SYMBOL(posix_acl_chmod);