1 /* 2 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, version 2. 7 * 8 * Author: 9 * Casey Schaufler <casey@schaufler-ca.com> 10 * 11 */ 12 13 #ifndef _SECURITY_SMACK_H 14 #define _SECURITY_SMACK_H 15 16 #include <linux/capability.h> 17 #include <linux/spinlock.h> 18 #include <linux/security.h> 19 #include <linux/in.h> 20 #include <net/netlabel.h> 21 #include <linux/list.h> 22 #include <linux/rculist.h> 23 #include <linux/lsm_audit.h> 24 25 /* 26 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 27 * bigger than can be used, and 24 is the next lower multiple 28 * of 8, and there are too many issues if there isn't space set 29 * aside for the terminating null byte. 30 */ 31 #define SMK_MAXLEN 23 32 #define SMK_LABELLEN (SMK_MAXLEN+1) 33 34 struct superblock_smack { 35 char *smk_root; 36 char *smk_floor; 37 char *smk_hat; 38 char *smk_default; 39 int smk_initialized; 40 spinlock_t smk_sblock; /* for initialization */ 41 }; 42 43 struct socket_smack { 44 char *smk_out; /* outbound label */ 45 char *smk_in; /* inbound label */ 46 char smk_packet[SMK_LABELLEN]; /* TCP peer label */ 47 }; 48 49 /* 50 * Inode smack data 51 */ 52 struct inode_smack { 53 char *smk_inode; /* label of the fso */ 54 struct mutex smk_lock; /* initialization lock */ 55 int smk_flags; /* smack inode flags */ 56 }; 57 58 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 59 60 /* 61 * A label access rule. 62 */ 63 struct smack_rule { 64 struct list_head list; 65 char *smk_subject; 66 char *smk_object; 67 int smk_access; 68 }; 69 70 /* 71 * An entry in the table mapping smack values to 72 * CIPSO level/category-set values. 73 */ 74 struct smack_cipso { 75 int smk_level; 76 char smk_catset[SMK_LABELLEN]; 77 }; 78 79 /* 80 * An entry in the table identifying hosts. 81 */ 82 struct smk_netlbladdr { 83 struct list_head list; 84 struct sockaddr_in smk_host; /* network address */ 85 struct in_addr smk_mask; /* network mask */ 86 char *smk_label; /* label */ 87 }; 88 89 /* 90 * This is the repository for labels seen so that it is 91 * not necessary to keep allocating tiny chuncks of memory 92 * and so that they can be shared. 93 * 94 * Labels are never modified in place. Anytime a label 95 * is imported (e.g. xattrset on a file) the list is checked 96 * for it and it is added if it doesn't exist. The address 97 * is passed out in either case. Entries are added, but 98 * never deleted. 99 * 100 * Since labels are hanging around anyway it doesn't 101 * hurt to maintain a secid for those awkward situations 102 * where kernel components that ought to use LSM independent 103 * interfaces don't. The secid should go away when all of 104 * these components have been repaired. 105 * 106 * If there is a cipso value associated with the label it 107 * gets stored here, too. This will most likely be rare as 108 * the cipso direct mapping in used internally. 109 */ 110 struct smack_known { 111 struct list_head list; 112 char smk_known[SMK_LABELLEN]; 113 u32 smk_secid; 114 struct smack_cipso *smk_cipso; 115 spinlock_t smk_cipsolock; /* for changing cipso map */ 116 }; 117 118 /* 119 * Mount options 120 */ 121 #define SMK_FSDEFAULT "smackfsdef=" 122 #define SMK_FSFLOOR "smackfsfloor=" 123 #define SMK_FSHAT "smackfshat=" 124 #define SMK_FSROOT "smackfsroot=" 125 126 #define SMACK_CIPSO_OPTION "-CIPSO" 127 128 /* 129 * How communications on this socket are treated. 130 * Usually it's determined by the underlying netlabel code 131 * but there are certain cases, including single label hosts 132 * and potentially single label interfaces for which the 133 * treatment can not be known in advance. 134 * 135 * The possibility of additional labeling schemes being 136 * introduced in the future exists as well. 137 */ 138 #define SMACK_UNLABELED_SOCKET 0 139 #define SMACK_CIPSO_SOCKET 1 140 141 /* 142 * smackfs magic number 143 * smackfs macic number 144 */ 145 #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ 146 147 /* 148 * A limit on the number of entries in the lists 149 * makes some of the list administration easier. 150 */ 151 #define SMACK_LIST_MAX 10000 152 153 /* 154 * CIPSO defaults. 155 */ 156 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 157 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 158 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 159 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 160 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 161 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 162 163 /* 164 * Just to make the common cases easier to deal with 165 */ 166 #define MAY_ANY (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) 167 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 168 #define MAY_ANYWRITE (MAY_WRITE | MAY_APPEND) 169 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 170 #define MAY_NOT 0 171 172 /* 173 * Number of access types used by Smack (rwxa) 174 */ 175 #define SMK_NUM_ACCESS_TYPE 4 176 177 /* 178 * Smack audit data; is empty if CONFIG_AUDIT not set 179 * to save some stack 180 */ 181 struct smk_audit_info { 182 #ifdef CONFIG_AUDIT 183 struct common_audit_data a; 184 #endif 185 }; 186 /* 187 * These functions are in smack_lsm.c 188 */ 189 struct inode_smack *new_inode_smack(char *); 190 191 /* 192 * These functions are in smack_access.c 193 */ 194 int smk_access(char *, char *, int, struct smk_audit_info *); 195 int smk_curacc(char *, u32, struct smk_audit_info *); 196 int smack_to_cipso(const char *, struct smack_cipso *); 197 void smack_from_cipso(u32, char *, char *); 198 char *smack_from_secid(const u32); 199 char *smk_import(const char *, int); 200 struct smack_known *smk_import_entry(const char *, int); 201 u32 smack_to_secid(const char *); 202 203 /* 204 * Shared data. 205 */ 206 extern int smack_cipso_direct; 207 extern char *smack_net_ambient; 208 extern char *smack_onlycap; 209 extern const char *smack_cipso_option; 210 211 extern struct smack_known smack_known_floor; 212 extern struct smack_known smack_known_hat; 213 extern struct smack_known smack_known_huh; 214 extern struct smack_known smack_known_invalid; 215 extern struct smack_known smack_known_star; 216 extern struct smack_known smack_known_web; 217 218 extern struct list_head smack_known_list; 219 extern struct list_head smack_rule_list; 220 extern struct list_head smk_netlbladdr_list; 221 222 extern struct security_operations smack_ops; 223 224 /* 225 * Stricly for CIPSO level manipulation. 226 * Set the category bit number in a smack label sized buffer. 227 */ 228 static inline void smack_catset_bit(int cat, char *catsetp) 229 { 230 if (cat > SMK_LABELLEN * 8) 231 return; 232 233 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 234 } 235 236 /* 237 * Present a pointer to the smack label in an inode blob. 238 */ 239 static inline char *smk_of_inode(const struct inode *isp) 240 { 241 struct inode_smack *sip = isp->i_security; 242 return sip->smk_inode; 243 } 244 245 /* 246 * logging functions 247 */ 248 #define SMACK_AUDIT_DENIED 0x1 249 #define SMACK_AUDIT_ACCEPT 0x2 250 extern int log_policy; 251 252 void smack_log(char *subject_label, char *object_label, 253 int request, 254 int result, struct smk_audit_info *auditdata); 255 256 #ifdef CONFIG_AUDIT 257 258 /* 259 * some inline functions to set up audit data 260 * they do nothing if CONFIG_AUDIT is not set 261 * 262 */ 263 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 264 char type) 265 { 266 memset(a, 0, sizeof(*a)); 267 a->a.type = type; 268 a->a.smack_audit_data.function = func; 269 } 270 271 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 272 struct task_struct *t) 273 { 274 a->a.u.tsk = t; 275 } 276 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 277 struct dentry *d) 278 { 279 a->a.u.fs.path.dentry = d; 280 } 281 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 282 struct vfsmount *m) 283 { 284 a->a.u.fs.path.mnt = m; 285 } 286 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 287 struct inode *i) 288 { 289 a->a.u.fs.inode = i; 290 } 291 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 292 struct path p) 293 { 294 a->a.u.fs.path = p; 295 } 296 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 297 struct sock *sk) 298 { 299 a->a.u.net.sk = sk; 300 } 301 302 #else /* no AUDIT */ 303 304 static inline void smk_ad_init(struct smk_audit_info *a, const char *func, 305 char type) 306 { 307 } 308 static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, 309 struct task_struct *t) 310 { 311 } 312 static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, 313 struct dentry *d) 314 { 315 } 316 static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, 317 struct vfsmount *m) 318 { 319 } 320 static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, 321 struct inode *i) 322 { 323 } 324 static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, 325 struct path p) 326 { 327 } 328 static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, 329 struct sock *sk) 330 { 331 } 332 #endif 333 334 #endif /* _SECURITY_SMACK_H */ 335