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 24 /* 25 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 26 * bigger than can be used, and 24 is the next lower multiple 27 * of 8, and there are too many issues if there isn't space set 28 * aside for the terminating null byte. 29 */ 30 #define SMK_MAXLEN 23 31 #define SMK_LABELLEN (SMK_MAXLEN+1) 32 33 struct superblock_smack { 34 char *smk_root; 35 char *smk_floor; 36 char *smk_hat; 37 char *smk_default; 38 int smk_initialized; 39 spinlock_t smk_sblock; /* for initialization */ 40 }; 41 42 struct socket_smack { 43 char *smk_out; /* outbound label */ 44 char *smk_in; /* inbound label */ 45 char smk_packet[SMK_LABELLEN]; /* TCP peer label */ 46 }; 47 48 /* 49 * Inode smack data 50 */ 51 struct inode_smack { 52 char *smk_inode; /* label of the fso */ 53 struct mutex smk_lock; /* initialization lock */ 54 int smk_flags; /* smack inode flags */ 55 }; 56 57 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 58 59 /* 60 * A label access rule. 61 */ 62 struct smack_rule { 63 struct list_head list; 64 char *smk_subject; 65 char *smk_object; 66 int smk_access; 67 }; 68 69 /* 70 * An entry in the table mapping smack values to 71 * CIPSO level/category-set values. 72 */ 73 struct smack_cipso { 74 int smk_level; 75 char smk_catset[SMK_LABELLEN]; 76 }; 77 78 /* 79 * An entry in the table identifying hosts. 80 */ 81 struct smk_netlbladdr { 82 struct list_head list; 83 struct sockaddr_in smk_host; /* network address */ 84 struct in_addr smk_mask; /* network mask */ 85 char *smk_label; /* label */ 86 }; 87 88 /* 89 * This is the repository for labels seen so that it is 90 * not necessary to keep allocating tiny chuncks of memory 91 * and so that they can be shared. 92 * 93 * Labels are never modified in place. Anytime a label 94 * is imported (e.g. xattrset on a file) the list is checked 95 * for it and it is added if it doesn't exist. The address 96 * is passed out in either case. Entries are added, but 97 * never deleted. 98 * 99 * Since labels are hanging around anyway it doesn't 100 * hurt to maintain a secid for those awkward situations 101 * where kernel components that ought to use LSM independent 102 * interfaces don't. The secid should go away when all of 103 * these components have been repaired. 104 * 105 * If there is a cipso value associated with the label it 106 * gets stored here, too. This will most likely be rare as 107 * the cipso direct mapping in used internally. 108 */ 109 struct smack_known { 110 struct list_head list; 111 char smk_known[SMK_LABELLEN]; 112 u32 smk_secid; 113 struct smack_cipso *smk_cipso; 114 spinlock_t smk_cipsolock; /* for changing cipso map */ 115 }; 116 117 /* 118 * Mount options 119 */ 120 #define SMK_FSDEFAULT "smackfsdef=" 121 #define SMK_FSFLOOR "smackfsfloor=" 122 #define SMK_FSHAT "smackfshat=" 123 #define SMK_FSROOT "smackfsroot=" 124 125 /* 126 * xattr names 127 */ 128 #define XATTR_SMACK_SUFFIX "SMACK64" 129 #define XATTR_SMACK_IPIN "SMACK64IPIN" 130 #define XATTR_SMACK_IPOUT "SMACK64IPOUT" 131 #define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX 132 #define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN 133 #define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT 134 135 #define SMACK_CIPSO_OPTION "-CIPSO" 136 137 /* 138 * How communications on this socket are treated. 139 * Usually it's determined by the underlying netlabel code 140 * but there are certain cases, including single label hosts 141 * and potentially single label interfaces for which the 142 * treatment can not be known in advance. 143 * 144 * The possibility of additional labeling schemes being 145 * introduced in the future exists as well. 146 */ 147 #define SMACK_UNLABELED_SOCKET 0 148 #define SMACK_CIPSO_SOCKET 1 149 150 /* 151 * smackfs magic number 152 * smackfs macic number 153 */ 154 #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ 155 156 /* 157 * A limit on the number of entries in the lists 158 * makes some of the list administration easier. 159 */ 160 #define SMACK_LIST_MAX 10000 161 162 /* 163 * CIPSO defaults. 164 */ 165 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 166 #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ 167 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 168 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 169 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 170 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 171 172 /* 173 * Just to make the common cases easier to deal with 174 */ 175 #define MAY_ANY (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) 176 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 177 #define MAY_ANYWRITE (MAY_WRITE | MAY_APPEND) 178 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 179 #define MAY_NOT 0 180 181 /* 182 * These functions are in smack_lsm.c 183 */ 184 struct inode_smack *new_inode_smack(char *); 185 186 /* 187 * These functions are in smack_access.c 188 */ 189 int smk_access(char *, char *, int); 190 int smk_curacc(char *, u32); 191 int smack_to_cipso(const char *, struct smack_cipso *); 192 void smack_from_cipso(u32, char *, char *); 193 char *smack_from_secid(const u32); 194 char *smk_import(const char *, int); 195 struct smack_known *smk_import_entry(const char *, int); 196 u32 smack_to_secid(const char *); 197 198 /* 199 * Shared data. 200 */ 201 extern int smack_cipso_direct; 202 extern char *smack_net_ambient; 203 extern char *smack_onlycap; 204 extern const char *smack_cipso_option; 205 206 extern struct smack_known smack_known_floor; 207 extern struct smack_known smack_known_hat; 208 extern struct smack_known smack_known_huh; 209 extern struct smack_known smack_known_invalid; 210 extern struct smack_known smack_known_star; 211 extern struct smack_known smack_known_web; 212 213 extern struct list_head smack_known_list; 214 extern struct list_head smack_rule_list; 215 extern struct list_head smk_netlbladdr_list; 216 217 extern struct security_operations smack_ops; 218 219 /* 220 * Stricly for CIPSO level manipulation. 221 * Set the category bit number in a smack label sized buffer. 222 */ 223 static inline void smack_catset_bit(int cat, char *catsetp) 224 { 225 if (cat > SMK_LABELLEN * 8) 226 return; 227 228 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 229 } 230 231 /* 232 * Present a pointer to the smack label in an inode blob. 233 */ 234 static inline char *smk_of_inode(const struct inode *isp) 235 { 236 struct inode_smack *sip = isp->i_security; 237 return sip->smk_inode; 238 } 239 240 #endif /* _SECURITY_SMACK_H */ 241