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