src/feature/rend/rendcache.h

   1 /* Copyright (c) 2015-2019, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * \file rendcache.h
   6  * \brief Header file for rendcache.c
   7  **/
   8
   9 #ifndef TOR_RENDCACHE_H
  10 #define TOR_RENDCACHE_H
  11
  12 #include "core/or/or.h"
  13 #include "feature/rend/rendcommon.h"
  14
  15 /** How old do we let hidden service descriptors get before discarding
  16  * them as too old? */
  17 #define REND_CACHE_MAX_AGE (2*24*60*60)
  18 /** How wrong do we assume our clock may be when checking whether hidden
  19  * services are too old or too new? */
  20 #define REND_CACHE_MAX_SKEW (24*60*60)
  21 /** How old do we keep an intro point failure entry in the failure cache? */
  22 #define REND_CACHE_FAILURE_MAX_AGE (5*60)
  23
  24 /* Do not allow more than this many introduction points in a hidden service
  25  * descriptor */
  26 #define MAX_INTRO_POINTS 10
  27
  28 /** A cached rendezvous descriptor. */
  29 typedef struct rend_cache_entry_t {
  30   size_t len; /**< Length of <b>desc</b> */
  31   time_t last_served; /**< When did we last write this one to somebody?
  32                        * (HSDir only) */
  33   char *desc; /**< Service descriptor */
  34   rend_service_descriptor_t *parsed; /**< Parsed value of 'desc' */
  35 } rend_cache_entry_t;
  36
  37 /* Introduction point failure type. */
  38 typedef struct rend_cache_failure_intro_t {
  39   /* When this intro point failure occurred thus we allocated this object and
  40    * cache it. */
  41   time_t created_ts;
  42   rend_intro_point_failure_t failure_type;
  43 } rend_cache_failure_intro_t;
  44
  45 /** Cache failure object indexed by service ID. */
  46 typedef struct rend_cache_failure_t {
  47   /* Contains rend_cache_failure_intro_t indexed by identity digest. */
  48   digestmap_t *intro_failures;
  49 } rend_cache_failure_t;
  50
  51 typedef enum {
  52   REND_CACHE_TYPE_CLIENT  = 1,
  53   REND_CACHE_TYPE_SERVICE = 2,
  54 } rend_cache_type_t;
  55
  56 /* Return maximum lifetime in seconds of a cache entry. */
  57 static inline time_t
  58 rend_cache_max_entry_lifetime(void)
  59 {
  60   return REND_CACHE_MAX_AGE + REND_CACHE_MAX_SKEW;
  61 }
  62
  63 void rend_cache_init(void);
  64 void rend_cache_clean(time_t now, rend_cache_type_t cache_type);
  65 void rend_cache_failure_clean(time_t now);
  66 size_t rend_cache_clean_v2_descs_as_dir(time_t cutoff);
  67 void rend_cache_purge(void);
  68 void rend_cache_free_all(void);
  69 int rend_cache_lookup_entry(const char *query, int version,
  70                             rend_cache_entry_t **entry_out);
  71 int rend_cache_lookup_v2_desc_as_service(const char *query,
  72                                          rend_cache_entry_t **entry_out);
  73 int rend_cache_lookup_v2_desc_as_dir(const char *query, const char **desc);
  74
  75 int rend_cache_store_v2_desc_as_dir(const char *desc);
  76 int rend_cache_store_v2_desc_as_service(const char *desc);
  77 int rend_cache_store_v2_desc_as_client(const char *desc,
  78                                        const char *desc_id_base32,
  79                                        const rend_data_t *rend_query,
  80                                        rend_cache_entry_t **entry);
  81 size_t rend_cache_get_total_allocation(void);
  82
  83 void rend_cache_intro_failure_note(rend_intro_point_failure_t failure,
  84                                    const uint8_t *identity,
  85                                    const char *service_id);
  86 void rend_cache_failure_purge(void);
  87 void rend_cache_decrement_allocation(size_t n);
  88 void rend_cache_increment_allocation(size_t n);
  89
  90 #ifdef RENDCACHE_PRIVATE
  91
  92 STATIC size_t rend_cache_entry_allocation(const rend_cache_entry_t *e);
  93 STATIC void rend_cache_entry_free_(rend_cache_entry_t *e);
  94 #define rend_cache_entry_free(e) \
  95   FREE_AND_NULL(rend_cache_entry_t, rend_cache_entry_free_, (e))
  96 STATIC void rend_cache_failure_intro_entry_free_(rend_cache_failure_intro_t
  97                                                  *entry);
  98 #define rend_cache_failure_intro_entry_free(e)                          \
  99   FREE_AND_NULL(rend_cache_failure_intro_t,                   \
 100                           rend_cache_failure_intro_entry_free_, (e))
 101 STATIC void rend_cache_failure_entry_free_(rend_cache_failure_t *entry);
 102 #define rend_cache_failure_entry_free(e)                        \
 103   FREE_AND_NULL(rend_cache_failure_t,                 \
 104                           rend_cache_failure_entry_free_, (e))
 105 STATIC int cache_failure_intro_lookup(const uint8_t *identity,
 106                                       const char *service_id,
 107                                       rend_cache_failure_intro_t
 108                                       **intro_entry);
 109 STATIC rend_cache_failure_intro_t *rend_cache_failure_intro_entry_new(
 110                                       rend_intro_point_failure_t failure);
 111 STATIC rend_cache_failure_t *rend_cache_failure_entry_new(void);
 112 STATIC void rend_cache_failure_remove(rend_service_descriptor_t *desc);
 113 STATIC void cache_failure_intro_add(const uint8_t *identity,
 114                                     const char *service_id,
 115                                     rend_intro_point_failure_t failure);
 116 STATIC void validate_intro_point_failure(const rend_service_descriptor_t *desc,
 117                                         const char *service_id);
 118
 119 STATIC void rend_cache_failure_entry_free_void(void *entry);
 120
 121 #ifdef TOR_UNIT_TESTS
 122 extern strmap_t *rend_cache;
 123 extern strmap_t *rend_cache_failure;
 124 extern digestmap_t *rend_cache_v2_dir;
 125 extern size_t rend_cache_total_allocation;
 126 #endif /* defined(TOR_UNIT_TESTS) */
 127 #endif /* defined(RENDCACHE_PRIVATE) */
 128
 129 #endif /* !defined(TOR_RENDCACHE_H) */
 130