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 <net/netlabel.h> 19 20 /* 21 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is 22 * bigger than can be used, and 24 is the next lower multiple 23 * of 8, and there are too many issues if there isn't space set 24 * aside for the terminating null byte. 25 */ 26 #define SMK_MAXLEN 23 27 #define SMK_LABELLEN (SMK_MAXLEN+1) 28 29 /* 30 * How many kinds of access are there? 31 * Here's your answer. 32 */ 33 #define SMK_ACCESSDASH '-' 34 #define SMK_ACCESSLOW "rwxa" 35 #define SMK_ACCESSKINDS (sizeof(SMK_ACCESSLOW) - 1) 36 37 struct superblock_smack { 38 char *smk_root; 39 char *smk_floor; 40 char *smk_hat; 41 char *smk_default; 42 int smk_initialized; 43 spinlock_t smk_sblock; /* for initialization */ 44 }; 45 46 struct socket_smack { 47 char *smk_out; /* outbound label */ 48 char *smk_in; /* inbound label */ 49 char smk_packet[SMK_LABELLEN]; /* TCP peer label */ 50 }; 51 52 /* 53 * Inode smack data 54 */ 55 struct inode_smack { 56 char *smk_inode; /* label of the fso */ 57 struct mutex smk_lock; /* initialization lock */ 58 int smk_flags; /* smack inode flags */ 59 }; 60 61 #define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ 62 63 /* 64 * A label access rule. 65 */ 66 struct smack_rule { 67 char *smk_subject; 68 char *smk_object; 69 int smk_access; 70 }; 71 72 /* 73 * An entry in the table of permitted label accesses. 74 */ 75 struct smk_list_entry { 76 struct smk_list_entry *smk_next; 77 struct smack_rule smk_rule; 78 }; 79 80 /* 81 * An entry in the table mapping smack values to 82 * CIPSO level/category-set values. 83 */ 84 struct smack_cipso { 85 int smk_level; 86 char smk_catset[SMK_LABELLEN]; 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 smack_known *smk_next; 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 /* 127 * xattr names 128 */ 129 #define XATTR_SMACK_SUFFIX "SMACK64" 130 #define XATTR_SMACK_IPIN "SMACK64IPIN" 131 #define XATTR_SMACK_IPOUT "SMACK64IPOUT" 132 #define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX 133 #define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN 134 #define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT 135 136 /* 137 * smackfs macic number 138 */ 139 #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ 140 141 /* 142 * A limit on the number of entries in the lists 143 * makes some of the list administration easier. 144 */ 145 #define SMACK_LIST_MAX 10000 146 147 /* 148 * CIPSO defaults. 149 */ 150 #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ 151 #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ 152 #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ 153 #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ 154 #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ 155 156 /* 157 * Just to make the common cases easier to deal with 158 */ 159 #define MAY_ANY (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) 160 #define MAY_ANYREAD (MAY_READ | MAY_EXEC) 161 #define MAY_ANYWRITE (MAY_WRITE | MAY_APPEND) 162 #define MAY_READWRITE (MAY_READ | MAY_WRITE) 163 #define MAY_NOT 0 164 165 /* 166 * These functions are in smack_lsm.c 167 */ 168 struct inode_smack *new_inode_smack(char *); 169 170 /* 171 * These functions are in smack_access.c 172 */ 173 int smk_access(char *, char *, int); 174 int smk_curacc(char *, u32); 175 int smack_to_cipso(const char *, struct smack_cipso *); 176 void smack_from_cipso(u32, char *, char *); 177 char *smack_from_secid(const u32); 178 char *smk_import(const char *, int); 179 struct smack_known *smk_import_entry(const char *, int); 180 u32 smack_to_secid(const char *); 181 182 /* 183 * Shared data. 184 */ 185 extern int smack_cipso_direct; 186 extern int smack_net_nltype; 187 extern char *smack_net_ambient; 188 189 extern struct smack_known *smack_known; 190 extern struct smack_known smack_known_floor; 191 extern struct smack_known smack_known_hat; 192 extern struct smack_known smack_known_huh; 193 extern struct smack_known smack_known_invalid; 194 extern struct smack_known smack_known_star; 195 extern struct smack_known smack_known_unset; 196 197 extern struct smk_list_entry *smack_list; 198 199 /* 200 * Stricly for CIPSO level manipulation. 201 * Set the category bit number in a smack label sized buffer. 202 */ 203 static inline void smack_catset_bit(int cat, char *catsetp) 204 { 205 if (cat > SMK_LABELLEN * 8) 206 return; 207 208 catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); 209 } 210 211 /* 212 * Present a pointer to the smack label in an inode blob. 213 */ 214 static inline char *smk_of_inode(const struct inode *isp) 215 { 216 struct inode_smack *sip = isp->i_security; 217 return sip->smk_inode; 218 } 219 220 #endif /* _SECURITY_SMACK_H */ 221