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 <linux/path.h> 19 20 #include "domain.h" 21 #include "match.h" 22 23 struct aa_profile; 24 25 /* 26 * We use MAY_EXEC, MAY_WRITE, MAY_READ, MAY_APPEND and the following flags 27 * for profile permissions 28 */ 29 #define AA_MAY_CREATE 0x0010 30 #define AA_MAY_DELETE 0x0020 31 #define AA_MAY_META_WRITE 0x0040 32 #define AA_MAY_META_READ 0x0080 33 34 #define AA_MAY_CHMOD 0x0100 35 #define AA_MAY_CHOWN 0x0200 36 #define AA_MAY_LOCK 0x0400 37 #define AA_EXEC_MMAP 0x0800 38 39 #define AA_MAY_LINK 0x1000 40 #define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */ 41 #define AA_MAY_ONEXEC 0x40000000 /* exec allows onexec */ 42 #define AA_MAY_CHANGE_PROFILE 0x80000000 43 #define AA_MAY_CHANGEHAT 0x80000000 /* ctrl auditing only */ 44 45 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ 46 AA_MAY_CREATE | AA_MAY_DELETE | \ 47 AA_MAY_META_READ | AA_MAY_META_WRITE | \ 48 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ 49 AA_EXEC_MMAP | AA_MAY_LINK) 50 51 /* 52 * The xindex is broken into 3 parts 53 * - index - an index into either the exec name table or the variable table 54 * - exec type - which determines how the executable name and index are used 55 * - flags - which modify how the destination name is applied 56 */ 57 #define AA_X_INDEX_MASK 0x03ff 58 59 #define AA_X_TYPE_MASK 0x0c00 60 #define AA_X_TYPE_SHIFT 10 61 #define AA_X_NONE 0x0000 62 #define AA_X_NAME 0x0400 /* use executable name px */ 63 #define AA_X_TABLE 0x0800 /* use a specified name ->n# */ 64 65 #define AA_X_UNSAFE 0x1000 66 #define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ 67 #define AA_X_INHERIT 0x4000 68 #define AA_X_UNCONFINED 0x8000 69 70 /* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */ 71 #define AA_SECURE_X_NEEDED 0x8000 72 73 /* need to make conditional which ones are being set */ 74 struct path_cond { 75 uid_t uid; 76 umode_t mode; 77 }; 78 79 /* struct file_perms - file permission 80 * @allow: mask of permissions that are allowed 81 * @audit: mask of permissions to force an audit message for 82 * @quiet: mask of permissions to quiet audit messages for 83 * @kill: mask of permissions that when matched will kill the task 84 * @xindex: exec transition index if @allow contains MAY_EXEC 85 * 86 * The @audit and @queit mask should be mutually exclusive. 87 */ 88 struct file_perms { 89 u32 allow; 90 u32 audit; 91 u32 quiet; 92 u32 kill; 93 u16 xindex; 94 }; 95 96 extern struct file_perms nullperms; 97 98 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) 99 100 /* FIXME: split perms from dfa and match this to description 101 * also add delegation info. 102 */ 103 static inline u16 dfa_map_xindex(u16 mask) 104 { 105 u16 old_index = (mask >> 10) & 0xf; 106 u16 index = 0; 107 108 if (mask & 0x100) 109 index |= AA_X_UNSAFE; 110 if (mask & 0x200) 111 index |= AA_X_INHERIT; 112 if (mask & 0x80) 113 index |= AA_X_UNCONFINED; 114 115 if (old_index == 1) { 116 index |= AA_X_UNCONFINED; 117 } else if (old_index == 2) { 118 index |= AA_X_NAME; 119 } else if (old_index == 3) { 120 index |= AA_X_NAME | AA_X_CHILD; 121 } else { 122 index |= AA_X_TABLE; 123 index |= old_index - 4; 124 } 125 126 return index; 127 } 128 129 /* 130 * map old dfa inline permissions to new format 131 */ 132 #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ 133 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 134 #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) 135 #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) 136 #define dfa_user_xindex(dfa, state) \ 137 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) 138 139 #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ 140 0x7f) | \ 141 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 142 #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) 143 #define dfa_other_quiet(dfa, state) \ 144 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) 145 #define dfa_other_xindex(dfa, state) \ 146 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) 147 148 int aa_audit_file(struct aa_profile *profile, struct file_perms *perms, 149 gfp_t gfp, int op, u32 request, const char *name, 150 const char *target, uid_t ouid, const char *info, int error); 151 152 /** 153 * struct aa_file_rules - components used for file rule permissions 154 * @dfa: dfa to match path names and conditionals against 155 * @perms: permission table indexed by the matched state accept entry of @dfa 156 * @trans: transition table for indexed by named x transitions 157 * 158 * File permission are determined by matching a path against @dfa and then 159 * then using the value of the accept entry for the matching state as 160 * an index into @perms. If a named exec transition is required it is 161 * looked up in the transition table. 162 */ 163 struct aa_file_rules { 164 unsigned int start; 165 struct aa_dfa *dfa; 166 /* struct perms perms; */ 167 struct aa_domain trans; 168 /* TODO: add delegate table */ 169 }; 170 171 unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, 172 const char *name, struct path_cond *cond, 173 struct file_perms *perms); 174 175 int aa_path_perm(int op, struct aa_profile *profile, struct path *path, 176 int flags, u32 request, struct path_cond *cond); 177 178 int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry, 179 struct path *new_dir, struct dentry *new_dentry); 180 181 int aa_file_perm(int 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 #define ACC_FMODE(x) (("\000\004\002\006"[(x)&O_ACCMODE]) | (((x) << 1) & 0x40)) 191 192 /* from namei.c */ 193 #define MAP_OPEN_FLAGS(x) ((((x) + 1) & O_ACCMODE) ? (x) + 1 : (x)) 194 195 /** 196 * aa_map_file_perms - map file flags to AppArmor permissions 197 * @file: open file to map flags to AppArmor permissions 198 * 199 * Returns: apparmor permission set for the file 200 */ 201 static inline u32 aa_map_file_to_perms(struct file *file) 202 { 203 int flags = MAP_OPEN_FLAGS(file->f_flags); 204 u32 perms = ACC_FMODE(file->f_mode); 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