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 #include "perms.h" 21 22 struct aa_profile; 23 struct path; 24 25 #define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) 26 27 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ 28 AA_MAY_CREATE | AA_MAY_DELETE | \ 29 AA_MAY_GETATTR | AA_MAY_SETATTR | \ 30 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ 31 AA_EXEC_MMAP | AA_MAY_LINK) 32 33 #define file_ctx(X) ((struct aa_file_ctx *)(X)->f_security) 34 35 /* struct aa_file_ctx - the AppArmor context the file was opened in 36 * @perms: the permission the file was opened with 37 * 38 * The file_ctx could currently be directly stored in file->f_security 39 * as the profile reference is now stored in the f_cred. However the 40 * ctx struct will expand in the future so we keep the struct. 41 */ 42 struct aa_file_ctx { 43 u32 allow; 44 }; 45 46 /** 47 * aa_alloc_file_ctx - allocate file_ctx 48 * @label: initial label of task creating the file 49 * @gfp: gfp flags for allocation 50 * 51 * Returns: file_ctx or NULL on failure 52 */ 53 static inline struct aa_file_ctx *aa_alloc_file_ctx(gfp_t gfp) 54 { 55 struct aa_file_ctx *ctx; 56 57 ctx = kzalloc(sizeof(struct aa_file_ctx), gfp); 58 59 return ctx; 60 } 61 62 /** 63 * aa_free_file_ctx - free a file_ctx 64 * @ctx: file_ctx to free (MAYBE_NULL) 65 */ 66 static inline void aa_free_file_ctx(struct aa_file_ctx *ctx) 67 { 68 if (ctx) 69 kzfree(ctx); 70 } 71 72 /* 73 * The xindex is broken into 3 parts 74 * - index - an index into either the exec name table or the variable table 75 * - exec type - which determines how the executable name and index are used 76 * - flags - which modify how the destination name is applied 77 */ 78 #define AA_X_INDEX_MASK 0x03ff 79 80 #define AA_X_TYPE_MASK 0x0c00 81 #define AA_X_TYPE_SHIFT 10 82 #define AA_X_NONE 0x0000 83 #define AA_X_NAME 0x0400 /* use executable name px */ 84 #define AA_X_TABLE 0x0800 /* use a specified name ->n# */ 85 86 #define AA_X_UNSAFE 0x1000 87 #define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ 88 #define AA_X_INHERIT 0x4000 89 #define AA_X_UNCONFINED 0x8000 90 91 /* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */ 92 #define AA_SECURE_X_NEEDED 0x8000 93 94 /* need to make conditional which ones are being set */ 95 struct path_cond { 96 kuid_t uid; 97 umode_t mode; 98 }; 99 100 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) 101 102 /* FIXME: split perms from dfa and match this to description 103 * also add delegation info. 104 */ 105 static inline u16 dfa_map_xindex(u16 mask) 106 { 107 u16 old_index = (mask >> 10) & 0xf; 108 u16 index = 0; 109 110 if (mask & 0x100) 111 index |= AA_X_UNSAFE; 112 if (mask & 0x200) 113 index |= AA_X_INHERIT; 114 if (mask & 0x80) 115 index |= AA_X_UNCONFINED; 116 117 if (old_index == 1) { 118 index |= AA_X_UNCONFINED; 119 } else if (old_index == 2) { 120 index |= AA_X_NAME; 121 } else if (old_index == 3) { 122 index |= AA_X_NAME | AA_X_CHILD; 123 } else if (old_index) { 124 index |= AA_X_TABLE; 125 index |= old_index - 4; 126 } 127 128 return index; 129 } 130 131 /* 132 * map old dfa inline permissions to new format 133 */ 134 #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ 135 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 136 #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) 137 #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) 138 #define dfa_user_xindex(dfa, state) \ 139 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) 140 141 #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ 142 0x7f) | \ 143 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 144 #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) 145 #define dfa_other_quiet(dfa, state) \ 146 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) 147 #define dfa_other_xindex(dfa, state) \ 148 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) 149 150 int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, 151 const char *op, u32 request, const char *name, 152 const char *target, kuid_t ouid, const char *info, int error); 153 154 /** 155 * struct aa_file_rules - components used for file rule permissions 156 * @dfa: dfa to match path names and conditionals against 157 * @perms: permission table indexed by the matched state accept entry of @dfa 158 * @trans: transition table for indexed by named x transitions 159 * 160 * File permission are determined by matching a path against @dfa and then 161 * then using the value of the accept entry for the matching state as 162 * an index into @perms. If a named exec transition is required it is 163 * looked up in the transition table. 164 */ 165 struct aa_file_rules { 166 unsigned int start; 167 struct aa_dfa *dfa; 168 /* struct perms perms; */ 169 struct aa_domain trans; 170 /* TODO: add delegate table */ 171 }; 172 173 struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, 174 struct path_cond *cond); 175 unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, 176 const char *name, struct path_cond *cond, 177 struct aa_perms *perms); 178 179 int aa_path_perm(const char *op, struct aa_profile *profile, 180 const struct path *path, int flags, u32 request, 181 struct path_cond *cond); 182 183 int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry, 184 const struct path *new_dir, struct dentry *new_dentry); 185 186 int aa_file_perm(const char *op, struct aa_profile *profile, struct file *file, 187 u32 request); 188 189 static inline void aa_free_file_rules(struct aa_file_rules *rules) 190 { 191 aa_put_dfa(rules->dfa); 192 aa_free_domain_entries(&rules->trans); 193 } 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 = file->f_flags; 204 u32 perms = 0; 205 206 if (file->f_mode & FMODE_WRITE) 207 perms |= MAY_WRITE; 208 if (file->f_mode & FMODE_READ) 209 perms |= MAY_READ; 210 211 if ((flags & O_APPEND) && (perms & MAY_WRITE)) 212 perms = (perms & ~MAY_WRITE) | MAY_APPEND; 213 /* trunc implies write permission */ 214 if (flags & O_TRUNC) 215 perms |= MAY_WRITE; 216 if (flags & O_CREAT) 217 perms |= AA_MAY_CREATE; 218 219 return perms; 220 } 221 222 #endif /* __AA_FILE_H */ 223