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