Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | /* * (C) 2005 Andreas Gruenbacher <agruen@suse.de> * * This file is released under the GPL. * * Generic ACL support for in-memory filesystems. */ #include <linux/sched.h> #include <linux/gfp.h> #include <linux/fs.h> #include <linux/generic_acl.h> #include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> static size_t generic_acl_list(struct dentry *dentry, char *list, size_t list_size, const char *name, size_t name_len, int type) { struct posix_acl *acl; const char *xname; size_t size; acl = get_cached_acl(dentry->d_inode, type); if (!acl) return 0; posix_acl_release(acl); switch (type) { case ACL_TYPE_ACCESS: xname = POSIX_ACL_XATTR_ACCESS; break; case ACL_TYPE_DEFAULT: xname = POSIX_ACL_XATTR_DEFAULT; break; default: return 0; } size = strlen(xname) + 1; if (list && size <= list_size) memcpy(list, xname, size); return size; } static int generic_acl_get(struct dentry *dentry, const char *name, void *buffer, size_t size, int type) { struct posix_acl *acl; int error; if (strcmp(name, "") != 0) return -EINVAL; acl = get_cached_acl(dentry->d_inode, type); if (!acl) return -ENODATA; error = posix_acl_to_xattr(acl, buffer, size); posix_acl_release(acl); return error; } static int generic_acl_set(struct dentry *dentry, const char *name, const void *value, size_t size, int flags, int type) { struct inode *inode = dentry->d_inode; struct posix_acl *acl = NULL; int error; if (strcmp(name, "") != 0) return -EINVAL; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; if (!inode_owner_or_capable(inode)) return -EPERM; if (value) { acl = posix_acl_from_xattr(value, size); if (IS_ERR(acl)) return PTR_ERR(acl); } if (acl) { error = posix_acl_valid(acl); if (error) goto failed; switch (type) { case ACL_TYPE_ACCESS: error = posix_acl_equiv_mode(acl, &inode->i_mode); if (error < 0) goto failed; inode->i_ctime = CURRENT_TIME; if (error == 0) { posix_acl_release(acl); acl = NULL; } break; case ACL_TYPE_DEFAULT: if (!S_ISDIR(inode->i_mode)) { error = -EINVAL; goto failed; } break; } } set_cached_acl(inode, type, acl); error = 0; failed: posix_acl_release(acl); return error; } /** * generic_acl_init - Take care of acl inheritance at @inode create time * * Files created inside a directory with a default ACL inherit the * directory's default ACL. */ int generic_acl_init(struct inode *inode, struct inode *dir) { struct posix_acl *acl = NULL; int error; if (!S_ISLNK(inode->i_mode)) acl = get_cached_acl(dir, ACL_TYPE_DEFAULT); if (acl) { if (S_ISDIR(inode->i_mode)) set_cached_acl(inode, ACL_TYPE_DEFAULT, acl); error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode); if (error < 0) return error; if (error > 0) set_cached_acl(inode, ACL_TYPE_ACCESS, acl); } else { inode->i_mode &= ~current_umask(); } error = 0; posix_acl_release(acl); return error; } /** * generic_acl_chmod - change the access acl of @inode upon chmod() * * A chmod also changes the permissions of the owner, group/mask, and * other ACL entries. */ int generic_acl_chmod(struct inode *inode) { struct posix_acl *acl; int error = 0; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; acl = get_cached_acl(inode, ACL_TYPE_ACCESS); if (acl) { error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); if (error) return error; set_cached_acl(inode, ACL_TYPE_ACCESS, acl); posix_acl_release(acl); } return error; } const struct xattr_handler generic_acl_access_handler = { .prefix = POSIX_ACL_XATTR_ACCESS, .flags = ACL_TYPE_ACCESS, .list = generic_acl_list, .get = generic_acl_get, .set = generic_acl_set, }; const struct xattr_handler generic_acl_default_handler = { .prefix = POSIX_ACL_XATTR_DEFAULT, .flags = ACL_TYPE_DEFAULT, .list = generic_acl_list, .get = generic_acl_get, .set = generic_acl_set, }; |