1 /* 2 * AppArmor security module 3 * 4 * This file contains AppArmor file mediation function definitions. 5 * 6 * Copyright (C) 1998-2008 Novell/SUSE 7 * Copyright 2009-2010 Canonical Ltd. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation, version 2 of the 12 * License. 13 */ 14 15 #ifndef __AA_FILE_H 16 #define __AA_FILE_H 17 18 #include "domain.h" 19 #include "match.h" 20 21 struct aa_profile; 22 struct path; 23 24 /* 25 * We use MAY_EXEC, MAY_WRITE, MAY_READ, MAY_APPEND and the following flags 26 * for profile permissions 27 */ 28 #define AA_MAY_CREATE 0x0010 29 #define AA_MAY_DELETE 0x0020 30 #define AA_MAY_META_WRITE 0x0040 31 #define AA_MAY_META_READ 0x0080 32 33 #define AA_MAY_CHMOD 0x0100 34 #define AA_MAY_CHOWN 0x0200 35 #define AA_MAY_LOCK 0x0400 36 #define AA_EXEC_MMAP 0x0800 37 38 #define AA_MAY_LINK 0x1000 39 #define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */ 40 #define AA_MAY_ONEXEC 0x40000000 /* exec allows onexec */ 41 #define AA_MAY_CHANGE_PROFILE 0x80000000 42 #define AA_MAY_CHANGEHAT 0x80000000 /* ctrl auditing only */ 43 44 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ 45 AA_MAY_CREATE | AA_MAY_DELETE | \ 46 AA_MAY_META_READ | AA_MAY_META_WRITE | \ 47 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ 48 AA_EXEC_MMAP | AA_MAY_LINK) 49 50 /* 51 * The xindex is broken into 3 parts 52 * - index - an index into either the exec name table or the variable table 53 * - exec type - which determines how the executable name and index are used 54 * - flags - which modify how the destination name is applied 55 */ 56 #define AA_X_INDEX_MASK 0x03ff 57 58 #define AA_X_TYPE_MASK 0x0c00 59 #define AA_X_TYPE_SHIFT 10 60 #define AA_X_NONE 0x0000 61 #define AA_X_NAME 0x0400 /* use executable name px */ 62 #define AA_X_TABLE 0x0800 /* use a specified name ->n# */ 63 64 #define AA_X_UNSAFE 0x1000 65 #define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ 66 #define AA_X_INHERIT 0x4000 67 #define AA_X_UNCONFINED 0x8000 68 69 /* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */ 70 #define AA_SECURE_X_NEEDED 0x8000 71 72 /* need to make conditional which ones are being set */ 73 struct path_cond { 74 kuid_t uid; 75 umode_t mode; 76 }; 77 78 /* struct file_perms - file permission 79 * @allow: mask of permissions that are allowed 80 * @audit: mask of permissions to force an audit message for 81 * @quiet: mask of permissions to quiet audit messages for 82 * @kill: mask of permissions that when matched will kill the task 83 * @xindex: exec transition index if @allow contains MAY_EXEC 84 * 85 * The @audit and @queit mask should be mutually exclusive. 86 */ 87 struct file_perms { 88 u32 allow; 89 u32 audit; 90 u32 quiet; 91 u32 kill; 92 u16 xindex; 93 }; 94 95 extern struct file_perms nullperms; 96 97 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) 98 99 /* FIXME: split perms from dfa and match this to description 100 * also add delegation info. 101 */ 102 static inline u16 dfa_map_xindex(u16 mask) 103 { 104 u16 old_index = (mask >> 10) & 0xf; 105 u16 index = 0; 106 107 if (mask & 0x100) 108 index |= AA_X_UNSAFE; 109 if (mask & 0x200) 110 index |= AA_X_INHERIT; 111 if (mask & 0x80) 112 index |= AA_X_UNCONFINED; 113 114 if (old_index == 1) { 115 index |= AA_X_UNCONFINED; 116 } else if (old_index == 2) { 117 index |= AA_X_NAME; 118 } else if (old_index == 3) { 119 index |= AA_X_NAME | AA_X_CHILD; 120 } else if (old_index) { 121 index |= AA_X_TABLE; 122 index |= old_index - 4; 123 } 124 125 return index; 126 } 127 128 /* 129 * map old dfa inline permissions to new format 130 */ 131 #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ 132 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 133 #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) 134 #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) 135 #define dfa_user_xindex(dfa, state) \ 136 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) 137 138 #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ 139 0x7f) | \ 140 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 141 #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) 142 #define dfa_other_quiet(dfa, state) \ 143 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) 144 #define dfa_other_xindex(dfa, state) \ 145 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) 146 147 int aa_audit_file(struct aa_profile *profile, struct file_perms *perms, 148 const char *op, u32 request, const char *name, 149 const char *target, kuid_t ouid, const char *info, int error); 150 151 /** 152 * struct aa_file_rules - components used for file rule permissions 153 * @dfa: dfa to match path names and conditionals against 154 * @perms: permission table indexed by the matched state accept entry of @dfa 155 * @trans: transition table for indexed by named x transitions 156 * 157 * File permission are determined by matching a path against @dfa and then 158 * then using the value of the accept entry for the matching state as 159 * an index into @perms. If a named exec transition is required it is 160 * looked up in the transition table. 161 */ 162 struct aa_file_rules { 163 unsigned int start; 164 struct aa_dfa *dfa; 165 /* struct perms perms; */ 166 struct aa_domain trans; 167 /* TODO: add delegate table */ 168 }; 169 170 unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, 171 const char *name, struct path_cond *cond, 172 struct file_perms *perms); 173 174 int aa_path_perm(const char *op, struct aa_profile *profile, 175 const struct path *path, int flags, u32 request, 176 struct path_cond *cond); 177 178 int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry, 179 const struct path *new_dir, struct dentry *new_dentry); 180 181 int aa_file_perm(const char *op, struct aa_profile *profile, struct file *file, 182 u32 request); 183 184 static inline void aa_free_file_rules(struct aa_file_rules *rules) 185 { 186 aa_put_dfa(rules->dfa); 187 aa_free_domain_entries(&rules->trans); 188 } 189 190 /** 191 * aa_map_file_perms - map file flags to AppArmor permissions 192 * @file: open file to map flags to AppArmor permissions 193 * 194 * Returns: apparmor permission set for the file 195 */ 196 static inline u32 aa_map_file_to_perms(struct file *file) 197 { 198 int flags = file->f_flags; 199 u32 perms = 0; 200 201 if (file->f_mode & FMODE_WRITE) 202 perms |= MAY_WRITE; 203 if (file->f_mode & FMODE_READ) 204 perms |= MAY_READ; 205 206 if ((flags & O_APPEND) && (perms & MAY_WRITE)) 207 perms = (perms & ~MAY_WRITE) | MAY_APPEND; 208 /* trunc implies write permission */ 209 if (flags & O_TRUNC) 210 perms |= MAY_WRITE; 211 if (flags & O_CREAT) 212 perms |= AA_MAY_CREATE; 213 214 return perms; 215 } 216 217 #endif /* __AA_FILE_H */ 218