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/spinlock.h> 19 20 #include "domain.h" 21 #include "match.h" 22 #include "perms.h" 23 24 struct aa_profile; 25 struct path; 26 27 #define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) 28 29 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ 30 AA_MAY_CREATE | AA_MAY_DELETE | \ 31 AA_MAY_GETATTR | AA_MAY_SETATTR | \ 32 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ 33 AA_EXEC_MMAP | AA_MAY_LINK) 34 35 static inline struct aa_file_ctx *file_ctx(struct file *file) 36 { 37 return file->f_security + apparmor_blob_sizes.lbs_file; 38 } 39 40 /* struct aa_file_ctx - the AppArmor context the file was opened in 41 * @lock: lock to update the ctx 42 * @label: label currently cached on the ctx 43 * @perms: the permission the file was opened with 44 */ 45 struct aa_file_ctx { 46 spinlock_t lock; 47 struct aa_label __rcu *label; 48 u32 allow; 49 }; 50 51 /** 52 * aa_alloc_file_ctx - allocate file_ctx 53 * @label: initial label of task creating the file 54 * @gfp: gfp flags for allocation 55 * 56 * Returns: file_ctx or NULL on failure 57 */ 58 static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label, 59 gfp_t gfp) 60 { 61 struct aa_file_ctx *ctx; 62 63 ctx = kzalloc(sizeof(struct aa_file_ctx), gfp); 64 if (ctx) { 65 spin_lock_init(&ctx->lock); 66 rcu_assign_pointer(ctx->label, aa_get_label(label)); 67 } 68 return ctx; 69 } 70 71 /** 72 * aa_free_file_ctx - free a file_ctx 73 * @ctx: file_ctx to free (MAYBE_NULL) 74 */ 75 static inline void aa_free_file_ctx(struct aa_file_ctx *ctx) 76 { 77 if (ctx) { 78 aa_put_label(rcu_access_pointer(ctx->label)); 79 kzfree(ctx); 80 } 81 } 82 83 static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx) 84 { 85 return aa_get_label_rcu(&ctx->label); 86 } 87 88 /* 89 * The xindex is broken into 3 parts 90 * - index - an index into either the exec name table or the variable table 91 * - exec type - which determines how the executable name and index are used 92 * - flags - which modify how the destination name is applied 93 */ 94 #define AA_X_INDEX_MASK 0x03ff 95 96 #define AA_X_TYPE_MASK 0x0c00 97 #define AA_X_TYPE_SHIFT 10 98 #define AA_X_NONE 0x0000 99 #define AA_X_NAME 0x0400 /* use executable name px */ 100 #define AA_X_TABLE 0x0800 /* use a specified name ->n# */ 101 102 #define AA_X_UNSAFE 0x1000 103 #define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ 104 #define AA_X_INHERIT 0x4000 105 #define AA_X_UNCONFINED 0x8000 106 107 /* need to make conditional which ones are being set */ 108 struct path_cond { 109 kuid_t uid; 110 umode_t mode; 111 }; 112 113 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) 114 115 /* FIXME: split perms from dfa and match this to description 116 * also add delegation info. 117 */ 118 static inline u16 dfa_map_xindex(u16 mask) 119 { 120 u16 old_index = (mask >> 10) & 0xf; 121 u16 index = 0; 122 123 if (mask & 0x100) 124 index |= AA_X_UNSAFE; 125 if (mask & 0x200) 126 index |= AA_X_INHERIT; 127 if (mask & 0x80) 128 index |= AA_X_UNCONFINED; 129 130 if (old_index == 1) { 131 index |= AA_X_UNCONFINED; 132 } else if (old_index == 2) { 133 index |= AA_X_NAME; 134 } else if (old_index == 3) { 135 index |= AA_X_NAME | AA_X_CHILD; 136 } else if (old_index) { 137 index |= AA_X_TABLE; 138 index |= old_index - 4; 139 } 140 141 return index; 142 } 143 144 /* 145 * map old dfa inline permissions to new format 146 */ 147 #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ 148 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 149 #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) 150 #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) 151 #define dfa_user_xindex(dfa, state) \ 152 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) 153 154 #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ 155 0x7f) | \ 156 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 157 #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) 158 #define dfa_other_quiet(dfa, state) \ 159 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) 160 #define dfa_other_xindex(dfa, state) \ 161 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) 162 163 int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, 164 const char *op, u32 request, const char *name, 165 const char *target, struct aa_label *tlabel, kuid_t ouid, 166 const char *info, int error); 167 168 /** 169 * struct aa_file_rules - components used for file rule permissions 170 * @dfa: dfa to match path names and conditionals against 171 * @perms: permission table indexed by the matched state accept entry of @dfa 172 * @trans: transition table for indexed by named x transitions 173 * 174 * File permission are determined by matching a path against @dfa and then 175 * then using the value of the accept entry for the matching state as 176 * an index into @perms. If a named exec transition is required it is 177 * looked up in the transition table. 178 */ 179 struct aa_file_rules { 180 unsigned int start; 181 struct aa_dfa *dfa; 182 /* struct perms perms; */ 183 struct aa_domain trans; 184 /* TODO: add delegate table */ 185 }; 186 187 struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, 188 struct path_cond *cond); 189 unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, 190 const char *name, struct path_cond *cond, 191 struct aa_perms *perms); 192 193 int __aa_path_perm(const char *op, struct aa_profile *profile, 194 const char *name, u32 request, struct path_cond *cond, 195 int flags, struct aa_perms *perms); 196 int aa_path_perm(const char *op, struct aa_label *label, 197 const struct path *path, int flags, u32 request, 198 struct path_cond *cond); 199 200 int aa_path_link(struct aa_label *label, struct dentry *old_dentry, 201 const struct path *new_dir, struct dentry *new_dentry); 202 203 int aa_file_perm(const char *op, struct aa_label *label, struct file *file, 204 u32 request); 205 206 void aa_inherit_files(const struct cred *cred, struct files_struct *files); 207 208 static inline void aa_free_file_rules(struct aa_file_rules *rules) 209 { 210 aa_put_dfa(rules->dfa); 211 aa_free_domain_entries(&rules->trans); 212 } 213 214 /** 215 * aa_map_file_perms - map file flags to AppArmor permissions 216 * @file: open file to map flags to AppArmor permissions 217 * 218 * Returns: apparmor permission set for the file 219 */ 220 static inline u32 aa_map_file_to_perms(struct file *file) 221 { 222 int flags = file->f_flags; 223 u32 perms = 0; 224 225 if (file->f_mode & FMODE_WRITE) 226 perms |= MAY_WRITE; 227 if (file->f_mode & FMODE_READ) 228 perms |= MAY_READ; 229 230 if ((flags & O_APPEND) && (perms & MAY_WRITE)) 231 perms = (perms & ~MAY_WRITE) | MAY_APPEND; 232 /* trunc implies write permission */ 233 if (flags & O_TRUNC) 234 perms |= MAY_WRITE; 235 if (flags & O_CREAT) 236 perms |= AA_MAY_CREATE; 237 238 return perms; 239 } 240 241 #endif /* __AA_FILE_H */ 242