security/apparmor/include/policy_unpack.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * AppArmor security module
   4  *
   5  * This file contains AppArmor policy loading interface function definitions.
   6  *
   7  * Copyright (C) 1998-2008 Novell/SUSE
   8  * Copyright 2009-2010 Canonical Ltd.
   9  */
  10
  11 #ifndef __POLICY_INTERFACE_H
  12 #define __POLICY_INTERFACE_H
  13
  14 #include <linux/list.h>
  15 #include <linux/kref.h>
  16 #include <linux/dcache.h>
  17 #include <linux/workqueue.h>
  18
  19
  20 struct aa_load_ent {
  21         struct list_head list;
  22         struct aa_profile *new;
  23         struct aa_profile *old;
  24         struct aa_profile *rename;
  25         const char *ns_name;
  26 };
  27
  28 void aa_load_ent_free(struct aa_load_ent *ent);
  29 struct aa_load_ent *aa_load_ent_alloc(void);
  30
  31 #define PACKED_FLAG_HAT         1
  32 #define PACKED_FLAG_DEBUG1      2
  33 #define PACKED_FLAG_DEBUG2      4
  34
  35 #define PACKED_MODE_ENFORCE     0
  36 #define PACKED_MODE_COMPLAIN    1
  37 #define PACKED_MODE_KILL        2
  38 #define PACKED_MODE_UNCONFINED  3
  39 #define PACKED_MODE_USER        4
  40
  41 struct aa_ns;
  42
  43 enum {
  44         AAFS_LOADDATA_ABI = 0,
  45         AAFS_LOADDATA_REVISION,
  46         AAFS_LOADDATA_HASH,
  47         AAFS_LOADDATA_DATA,
  48         AAFS_LOADDATA_COMPRESSED_SIZE,
  49         AAFS_LOADDATA_DIR,              /* must be last actual entry */
  50         AAFS_LOADDATA_NDENTS            /* count of entries */
  51 };
  52
  53 /*
  54  * The AppArmor interface treats data as a type byte followed by the
  55  * actual data.  The interface has the notion of a named entry
  56  * which has a name (AA_NAME typecode followed by name string) followed by
  57  * the entries typecode and data.  Named types allow for optional
  58  * elements and extensions to be added and tested for without breaking
  59  * backwards compatibility.
  60  */
  61
  62 enum aa_code {
  63         AA_U8,
  64         AA_U16,
  65         AA_U32,
  66         AA_U64,
  67         AA_NAME,                /* same as string except it is items name */
  68         AA_STRING,
  69         AA_BLOB,
  70         AA_STRUCT,
  71         AA_STRUCTEND,
  72         AA_LIST,
  73         AA_LISTEND,
  74         AA_ARRAY,
  75         AA_ARRAYEND,
  76 };
  77
  78 /*
  79  * aa_ext is the read of the buffer containing the serialized profile.  The
  80  * data is copied into a kernel buffer in apparmorfs and then handed off to
  81  * the unpack routines.
  82  */
  83 struct aa_ext {
  84         void *start;
  85         void *end;
  86         void *pos;              /* pointer to current position in the buffer */
  87         u32 version;
  88 };
  89
  90 /*
  91  * struct aa_loaddata - buffer of policy raw_data set
  92  *
  93  * there is no loaddata ref for being on ns list, nor a ref from
  94  * d_inode(@dentry) when grab a ref from these, @ns->lock must be held
  95  * && __aa_get_loaddata() needs to be used, and the return value
  96  * checked, if NULL the loaddata is already being reaped and should be
  97  * considered dead.
  98  */
  99 struct aa_loaddata {
 100         struct kref count;
 101         struct list_head list;
 102         struct work_struct work;
 103         struct dentry *dents[AAFS_LOADDATA_NDENTS];
 104         struct aa_ns *ns;
 105         char *name;
 106         size_t size;                    /* the original size of the payload */
 107         size_t compressed_size;         /* the compressed size of the payload */
 108         long revision;                  /* the ns policy revision this caused */
 109         int abi;
 110         unsigned char *hash;
 111
 112         /* Pointer to payload. If @compressed_size > 0, then this is the
 113          * compressed version of the payload, else it is the uncompressed
 114          * version (with the size indicated by @size).
 115          */
 116         char *data;
 117 };
 118
 119 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, const char **ns);
 120
 121 /**
 122  * __aa_get_loaddata - get a reference count to uncounted data reference
 123  * @data: reference to get a count on
 124  *
 125  * Returns: pointer to reference OR NULL if race is lost and reference is
 126  *          being repeated.
 127  * Requires: @data->ns->lock held, and the return code MUST be checked
 128  *
 129  * Use only from inode->i_private and @data->list found references
 130  */
 131 static inline struct aa_loaddata *
 132 __aa_get_loaddata(struct aa_loaddata *data)
 133 {
 134         if (data && kref_get_unless_zero(&(data->count)))
 135                 return data;
 136
 137         return NULL;
 138 }
 139
 140 /**
 141  * aa_get_loaddata - get a reference count from a counted data reference
 142  * @data: reference to get a count on
 143  *
 144  * Returns: point to reference
 145  * Requires: @data to have a valid reference count on it. It is a bug
 146  *           if the race to reap can be encountered when it is used.
 147  */
 148 static inline struct aa_loaddata *
 149 aa_get_loaddata(struct aa_loaddata *data)
 150 {
 151         struct aa_loaddata *tmp = __aa_get_loaddata(data);
 152
 153         AA_BUG(data && !tmp);
 154
 155         return tmp;
 156 }
 157
 158 void __aa_loaddata_update(struct aa_loaddata *data, long revision);
 159 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r);
 160 void aa_loaddata_kref(struct kref *kref);
 161 struct aa_loaddata *aa_loaddata_alloc(size_t size);
 162 static inline void aa_put_loaddata(struct aa_loaddata *data)
 163 {
 164         if (data)
 165                 kref_put(&data->count, aa_loaddata_kref);
 166 }
 167
 168 #if IS_ENABLED(CONFIG_KUNIT)
 169 bool aa_inbounds(struct aa_ext *e, size_t size);
 170 size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk);
 171 bool aa_unpack_X(struct aa_ext *e, enum aa_code code);
 172 bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name);
 173 bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name);
 174 bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name);
 175 bool aa_unpack_array(struct aa_ext *e, const char *name, u16 *size);
 176 size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name);
 177 int aa_unpack_str(struct aa_ext *e, const char **string, const char *name);
 178 int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name);
 179 #endif
 180
 181 #endif /* __POLICY_INTERFACE_H */