1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * AppArmor security module 4 * 5 * This file contains AppArmor file mediation function definitions. 6 * 7 * Copyright (C) 1998-2008 Novell/SUSE 8 * Copyright 2009-2010 Canonical Ltd. 9 */ 10 11 #ifndef __AA_FILE_H 12 #define __AA_FILE_H 13 14 #include <linux/spinlock.h> 15 16 #include "domain.h" 17 #include "match.h" 18 #include "perms.h" 19 20 struct aa_profile; 21 struct path; 22 23 #define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) 24 25 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ 26 AA_MAY_CREATE | AA_MAY_DELETE | \ 27 AA_MAY_GETATTR | AA_MAY_SETATTR | \ 28 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ 29 AA_EXEC_MMAP | AA_MAY_LINK) 30 31 static inline struct aa_file_ctx *file_ctx(struct file *file) 32 { 33 return file->f_security + apparmor_blob_sizes.lbs_file; 34 } 35 36 /* struct aa_file_ctx - the AppArmor context the file was opened in 37 * @lock: lock to update the ctx 38 * @label: label currently cached on the ctx 39 * @perms: the permission the file was opened with 40 */ 41 struct aa_file_ctx { 42 spinlock_t lock; 43 struct aa_label __rcu *label; 44 u32 allow; 45 }; 46 47 /** 48 * aa_alloc_file_ctx - allocate file_ctx 49 * @label: initial label of task creating the file 50 * @gfp: gfp flags for allocation 51 * 52 * Returns: file_ctx or NULL on failure 53 */ 54 static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label, 55 gfp_t gfp) 56 { 57 struct aa_file_ctx *ctx; 58 59 ctx = kzalloc(sizeof(struct aa_file_ctx), gfp); 60 if (ctx) { 61 spin_lock_init(&ctx->lock); 62 rcu_assign_pointer(ctx->label, aa_get_label(label)); 63 } 64 return ctx; 65 } 66 67 /** 68 * aa_free_file_ctx - free a file_ctx 69 * @ctx: file_ctx to free (MAYBE_NULL) 70 */ 71 static inline void aa_free_file_ctx(struct aa_file_ctx *ctx) 72 { 73 if (ctx) { 74 aa_put_label(rcu_access_pointer(ctx->label)); 75 kfree_sensitive(ctx); 76 } 77 } 78 79 static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx) 80 { 81 return aa_get_label_rcu(&ctx->label); 82 } 83 84 /* 85 * The xindex is broken into 3 parts 86 * - index - an index into either the exec name table or the variable table 87 * - exec type - which determines how the executable name and index are used 88 * - flags - which modify how the destination name is applied 89 */ 90 #define AA_X_INDEX_MASK 0x03ff 91 92 #define AA_X_TYPE_MASK 0x0c00 93 #define AA_X_TYPE_SHIFT 10 94 #define AA_X_NONE 0x0000 95 #define AA_X_NAME 0x0400 /* use executable name px */ 96 #define AA_X_TABLE 0x0800 /* use a specified name ->n# */ 97 98 #define AA_X_UNSAFE 0x1000 99 #define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ 100 #define AA_X_INHERIT 0x4000 101 #define AA_X_UNCONFINED 0x8000 102 103 /* need to make conditional which ones are being set */ 104 struct path_cond { 105 kuid_t uid; 106 umode_t mode; 107 }; 108 109 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) 110 111 /* FIXME: split perms from dfa and match this to description 112 * also add delegation info. 113 */ 114 static inline u16 dfa_map_xindex(u16 mask) 115 { 116 u16 old_index = (mask >> 10) & 0xf; 117 u16 index = 0; 118 119 if (mask & 0x100) 120 index |= AA_X_UNSAFE; 121 if (mask & 0x200) 122 index |= AA_X_INHERIT; 123 if (mask & 0x80) 124 index |= AA_X_UNCONFINED; 125 126 if (old_index == 1) { 127 index |= AA_X_UNCONFINED; 128 } else if (old_index == 2) { 129 index |= AA_X_NAME; 130 } else if (old_index == 3) { 131 index |= AA_X_NAME | AA_X_CHILD; 132 } else if (old_index) { 133 index |= AA_X_TABLE; 134 index |= old_index - 4; 135 } 136 137 return index; 138 } 139 140 /* 141 * map old dfa inline permissions to new format 142 */ 143 #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ 144 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 145 #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) 146 #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) 147 #define dfa_user_xindex(dfa, state) \ 148 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) 149 150 #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ 151 0x7f) | \ 152 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) 153 #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) 154 #define dfa_other_quiet(dfa, state) \ 155 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) 156 #define dfa_other_xindex(dfa, state) \ 157 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) 158 159 int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, 160 const char *op, u32 request, const char *name, 161 const char *target, struct aa_label *tlabel, kuid_t ouid, 162 const char *info, int error); 163 164 /** 165 * struct aa_file_rules - components used for file rule permissions 166 * @dfa: dfa to match path names and conditionals against 167 * @perms: permission table indexed by the matched state accept entry of @dfa 168 * @trans: transition table for indexed by named x transitions 169 * 170 * File permission are determined by matching a path against @dfa and 171 * then using the value of the accept entry for the matching state as 172 * an index into @perms. If a named exec transition is required it is 173 * looked up in the transition table. 174 */ 175 struct aa_file_rules { 176 unsigned int start; 177 struct aa_dfa *dfa; 178 /* struct perms perms; */ 179 struct aa_domain trans; 180 /* TODO: add delegate table */ 181 }; 182 183 struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, 184 struct path_cond *cond); 185 unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, 186 const char *name, struct path_cond *cond, 187 struct aa_perms *perms); 188 189 int __aa_path_perm(const char *op, struct aa_profile *profile, 190 const char *name, u32 request, struct path_cond *cond, 191 int flags, struct aa_perms *perms); 192 int aa_path_perm(const char *op, struct aa_label *label, 193 const struct path *path, int flags, u32 request, 194 struct path_cond *cond); 195 196 int aa_path_link(struct aa_label *label, struct dentry *old_dentry, 197 const struct path *new_dir, struct dentry *new_dentry); 198 199 int aa_file_perm(const char *op, struct aa_label *label, struct file *file, 200 u32 request, bool in_atomic); 201 202 void aa_inherit_files(const struct cred *cred, struct files_struct *files); 203 204 static inline void aa_free_file_rules(struct aa_file_rules *rules) 205 { 206 aa_put_dfa(rules->dfa); 207 aa_free_domain_entries(&rules->trans); 208 } 209 210 /** 211 * aa_map_file_perms - map file flags to AppArmor permissions 212 * @file: open file to map flags to AppArmor permissions 213 * 214 * Returns: apparmor permission set for the file 215 */ 216 static inline u32 aa_map_file_to_perms(struct file *file) 217 { 218 int flags = file->f_flags; 219 u32 perms = 0; 220 221 if (file->f_mode & FMODE_WRITE) 222 perms |= MAY_WRITE; 223 if (file->f_mode & FMODE_READ) 224 perms |= MAY_READ; 225 226 if ((flags & O_APPEND) && (perms & MAY_WRITE)) 227 perms = (perms & ~MAY_WRITE) | MAY_APPEND; 228 /* trunc implies write permission */ 229 if (flags & O_TRUNC) 230 perms |= MAY_WRITE; 231 if (flags & O_CREAT) 232 perms |= AA_MAY_CREATE; 233 234 return perms; 235 } 236 237 #endif /* __AA_FILE_H */ 238