src/or/shared_random_state.h

   1 /* Copyright (c) 2016-2017, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 #ifndef TOR_SHARED_RANDOM_STATE_H
   5 #define TOR_SHARED_RANDOM_STATE_H
   6
   7 #include "shared_random.h"
   8
   9 /* Action that can be performed on the state for any objects. */
  10 typedef enum {
  11   SR_STATE_ACTION_GET     = 1,
  12   SR_STATE_ACTION_PUT     = 2,
  13   SR_STATE_ACTION_DEL     = 3,
  14   SR_STATE_ACTION_DEL_ALL = 4,
  15   SR_STATE_ACTION_SAVE    = 5,
  16 } sr_state_action_t;
  17
  18 /* Object in the state that can be queried through the state API. */
  19 typedef enum {
  20   /* Will return a single commit using an authority identity key. */
  21   SR_STATE_OBJ_COMMIT,
  22   /* Returns the entire list of commits from the state. */
  23   SR_STATE_OBJ_COMMITS,
  24   /* Return the current SRV object pointer. */
  25   SR_STATE_OBJ_CURSRV,
  26   /* Return the previous SRV object pointer. */
  27   SR_STATE_OBJ_PREVSRV,
  28   /* Return the phase. */
  29   SR_STATE_OBJ_PHASE,
  30   /* Get or Put the valid after time. */
  31   SR_STATE_OBJ_VALID_AFTER,
  32 } sr_state_object_t;
  33
  34 /* State of the protocol. It's also saved on disk in fname. This data
  35  * structure MUST be synchronized at all time with the one on disk. */
  36 typedef struct sr_state_t {
  37   /* Filename of the state file on disk. */
  38   char *fname;
  39   /* Version of the protocol. */
  40   uint32_t version;
  41   /* The valid-after of the voting period we have prepared the state for. */
  42   time_t valid_after;
  43   /* Until when is this state valid? */
  44   time_t valid_until;
  45   /* Protocol phase. */
  46   sr_phase_t phase;
  47
  48   /* Number of runs completed. */
  49   uint64_t n_protocol_runs;
  50   /* The number of commitment rounds we've performed in this protocol run. */
  51   unsigned int n_commit_rounds;
  52   /* The number of reveal rounds we've performed in this protocol run. */
  53   unsigned int n_reveal_rounds;
  54
  55   /* A map of all the received commitments for this protocol run. This is
  56    * indexed by authority RSA identity digest. */
  57   digestmap_t *commits;
  58
  59   /* Current and previous shared random value. */
  60   sr_srv_t *previous_srv;
  61   sr_srv_t *current_srv;
  62
  63   /* Indicate if the state contains an SRV that was _just_ generated. This is
  64    * used during voting so that we know whether to use the super majority rule
  65    * or not when deciding on keeping it for the consensus. It is _always_ set
  66    * to 0 post consensus.
  67    *
  68    * EDGE CASE: if an authority computes a new SRV then immediately reboots
  69    * and, once back up, votes for the current round, it won't know if the
  70    * SRV is fresh or not ultimately making it _NOT_ use the super majority
  71    * when deciding to put or not the SRV in the consensus. This is for now
  72    * an acceptable very rare edge case. */
  73   unsigned int is_srv_fresh:1;
  74 } sr_state_t;
  75
  76 /* Persistent state of the protocol, as saved to disk. */
  77 typedef struct sr_disk_state_t {
  78   uint32_t magic_;
  79   /* Version of the protocol. */
  80   int Version;
  81   /* Version of our running tor. */
  82   char *TorVersion;
  83   /* Creation time of this state */
  84   time_t ValidAfter;
  85   /* State valid until? */
  86   time_t ValidUntil;
  87   /* All commits seen that are valid. */
  88   config_line_t *Commit;
  89   /* Previous and current shared random value. */
  90   config_line_t *SharedRandValues;
  91   /* Extra Lines for configuration we might not know. */
  92   config_line_t *ExtraLines;
  93 } sr_disk_state_t;
  94
  95 /* API */
  96
  97 /* Public methods: */
  98
  99 void sr_state_update(time_t valid_after);
 100
 101 /* Private methods (only used by shared-random.c): */
 102
 103 void sr_state_set_valid_after(time_t valid_after);
 104 sr_phase_t sr_state_get_phase(void);
 105 const sr_srv_t *sr_state_get_previous_srv(void);
 106 const sr_srv_t *sr_state_get_current_srv(void);
 107 void sr_state_set_previous_srv(const sr_srv_t *srv);
 108 void sr_state_set_current_srv(const sr_srv_t *srv);
 109 void sr_state_clean_srvs(void);
 110 digestmap_t *sr_state_get_commits(void);
 111 sr_commit_t *sr_state_get_commit(const char *rsa_fpr);
 112 void sr_state_add_commit(sr_commit_t *commit);
 113 void sr_state_delete_commits(void);
 114 void sr_state_copy_reveal_info(sr_commit_t *saved_commit,
 115                                const sr_commit_t *commit);
 116 unsigned int sr_state_srv_is_fresh(void);
 117 void sr_state_set_fresh_srv(void);
 118 void sr_state_unset_fresh_srv(void);
 119 int sr_state_init(int save_to_disk, int read_from_disk);
 120 int sr_state_is_initialized(void);
 121 void sr_state_save(void);
 122 void sr_state_free(void);
 123
 124 time_t sr_state_get_start_time_of_current_protocol_run(time_t now);
 125 unsigned int sr_state_get_phase_duration(void);
 126 unsigned int sr_state_get_protocol_run_duration(void);
 127
 128 #ifdef SHARED_RANDOM_STATE_PRIVATE
 129
 130 STATIC int disk_state_load_from_disk_impl(const char *fname);
 131
 132 STATIC sr_phase_t get_sr_protocol_phase(time_t valid_after);
 133 STATIC time_t get_start_time_of_current_round(void);
 134
 135 STATIC time_t get_state_valid_until_time(time_t now);
 136 STATIC const char *get_phase_str(sr_phase_t phase);
 137 STATIC void reset_state_for_new_protocol_run(time_t valid_after);
 138 STATIC void new_protocol_run(time_t valid_after);
 139 STATIC void state_rotate_srv(void);
 140 STATIC int is_phase_transition(sr_phase_t next_phase);
 141
 142 #endif /* defined(SHARED_RANDOM_STATE_PRIVATE) */
 143
 144 #ifdef TOR_UNIT_TESTS
 145
 146 STATIC void set_sr_phase(sr_phase_t phase);
 147 STATIC sr_state_t *get_sr_state(void);
 148
 149 #endif /* defined(TOR_UNIT_TESTS) */
 150
 151 #endif /* !defined(TOR_SHARED_RANDOM_STATE_H) */
 152