or.h

关于tor匿名通信的源代码

  char identity_digest[DIGEST_LEN];
  /** Declared publication time of the descriptor. */
  time_t published_on;
  /** For routerdescs only: digest of the corresponding extrainfo. */
  char extra_info_digest[DIGEST_LEN];
  /** For routerdescs only: Status of downloading the corresponding
   * extrainfo. */
  download_status_t ei_dl_status;
  /** Where is the descriptor saved? */
  saved_location_t saved_location;
  /** If saved_location is SAVED_IN_CACHE or SAVED_IN_JOURNAL, the offset of
   * this descriptor in the corresponding file. */
  off_t saved_offset;
  /** What position is this descriptor within routerlist->routers or
   * routerlist->old_routers? -1 for none. */
  int routerlist_index;
  /** The valid-until time of the most recent consensus that listed this
   * descriptor, or a bit after the publication time of the most recent v2
   * networkstatus that listed it.  0 for "never listed in a consensus or
   * status, so far as we know." */
  time_t last_listed_as_valid_until;
#ifdef TRACK_SERVED_TIME
  /** DOCDOC */
  time_t last_served_at; /*XXXX021 remove if not useful. */
#endif
  /* If true, we do not ever try to save this object in the cache. */
  unsigned int do_not_cache : 1;
  /* If true, this item is meant to represent an extrainfo. */
  unsigned int is_extrainfo : 1;
  /* If true, we got an extrainfo for this item, and the digest was right,
   * but it was incompatible. */
  unsigned int extrainfo_is_bogus : 1;
  /* If true, we are willing to transmit this item unencrypted. */
  unsigned int send_unencrypted : 1;
} signed_descriptor_t;

/** Information about another onion router in the network. */
typedef struct {
  signed_descriptor_t cache_info;
  char *address; /**< Location of OR: either a hostname or an IP address. */
  char *nickname; /**< Human-readable OR name. */

  uint32_t addr; /**< IPv4 address of OR, in host order. */
  uint16_t or_port; /**< Port for TLS connections. */
  uint16_t dir_port; /**< Port for HTTP directory connections. */

  crypto_pk_env_t *onion_pkey; /**< Public RSA key for onions. */
  crypto_pk_env_t *identity_pkey;  /**< Public RSA key for signing. */

  char *platform; /**< What software/operating system is this OR using? */

  /* link info */
  uint32_t bandwidthrate; /**< How many bytes does this OR add to its token
                           * bucket per second? */
  uint32_t bandwidthburst; /**< How large is this OR's token bucket? */
  /** How many bytes/s is this router known to handle? */
  uint32_t bandwidthcapacity;
  smartlist_t *exit_policy; /**< What streams will this OR permit
                             * to exit?  NULL for 'reject *:*'. */
  long uptime; /**< How many seconds the router claims to have been up */
  smartlist_t *declared_family; /**< Nicknames of router which this router
                                 * claims are its family. */
  char *contact_info; /**< Declared contact info for this router. */
  unsigned int is_hibernating:1; /**< Whether the router claims to be
                                  * hibernating */
  unsigned int has_old_dnsworkers:1; /**< Whether the router is using
                                      * dnsworker code. */
  unsigned int caches_extra_info:1; /**< Whether the router caches and serves
                                     * extrainfo documents. */

  /* local info */
  unsigned int is_running:1; /**< As far as we know, is this OR currently
                              * running? */
  unsigned int is_valid:1; /**< Has a trusted dirserver validated this OR?
                               *  (For Authdir: Have we validated this OR?)
                               */
  unsigned int is_named:1; /**< Do we believe the nickname that this OR gives
                            * us? */
  unsigned int is_fast:1; /** Do we think this is a fast OR? */
  unsigned int is_stable:1; /** Do we think this is a stable OR? */
  unsigned int is_possible_guard:1; /**< Do we think this is an OK guard? */
  unsigned int is_exit:1; /**< Do we think this is an OK exit? */
  unsigned int is_bad_exit:1; /**< Do we think this exit is censored, borked,
                               * or otherwise nasty? */
  unsigned int is_bad_directory:1; /**< Do we think this directory is junky,
                                    * underpowered, or otherwise useless? */
  unsigned int wants_to_be_hs_dir:1; /**< True iff this router claims to be
                                      * a hidden service directory. */
  unsigned int is_hs_dir:1; /**< True iff this router is a hidden service
                             * directory according to the authorities. */

/** Tor can use this router for general positions in circuits. */
#define ROUTER_PURPOSE_GENERAL 0
/** Tor should avoid using this router for circuit-building. */
#define ROUTER_PURPOSE_CONTROLLER 1
/** Tor should use this router only for bridge positions in circuits. */
#define ROUTER_PURPOSE_BRIDGE 2
/** Tor should not use this router; it was marked in cached-descriptors with
 * a purpose we didn't recognize. */
#define ROUTER_PURPOSE_UNKNOWN 255

  uint8_t purpose; /** What positions in a circuit is this router good for? */

  /* The below items are used only by authdirservers for
   * reachability testing. */
  /** When was the last time we could reach this OR? */
  time_t last_reachable;
  /** When did we start testing reachability for this OR? */
  time_t testing_since;

} routerinfo_t;

/** Information needed to keep and cache a signed extra-info document. */
typedef struct extrainfo_t {
  signed_descriptor_t cache_info;
  /** The router's nickname. */
  char nickname[MAX_NICKNAME_LEN+1];
  /** True iff we found the right key for this extra-info, verified the
   * signature, and found it to be bad. */
  unsigned int bad_sig : 1;
  /** If present, we didn't have the right key to verify this extra-info,
   * so this is a copy of the signature in the document. */
  char *pending_sig;
  /** Length of pending_sig. */
  size_t pending_sig_len;
} extrainfo_t;

/** Contents of a single router entry in a network status object.
 */
typedef struct routerstatus_t {
  time_t published_on; /**< When was this router published? */
  char nickname[MAX_NICKNAME_LEN+1]; /**< The nickname this router says it
                                      * has. */
  char identity_digest[DIGEST_LEN]; /**< Digest of the router's identity
                                     * key. */
  char descriptor_digest[DIGEST_LEN]; /**< Digest of the router's most recent
                                       * descriptor. */
  uint32_t addr; /**< IPv4 address for this router. */
  uint16_t or_port; /**< OR port for this router. */
  uint16_t dir_port; /**< Directory port for this router. */
  unsigned int is_authority:1; /**< True iff this router is an authority. */
  unsigned int is_exit:1; /**< True iff this router is a good exit. */
  unsigned int is_stable:1; /**< True iff this router stays up a long time. */
  unsigned int is_fast:1; /**< True iff this router has good bandwidth. */
  unsigned int is_running:1; /**< True iff this router is up. */
  unsigned int is_named:1; /**< True iff "nickname" belongs to this router. */
  unsigned int is_unnamed:1; /**< True iff "nickname" belongs to another
                              * router. */
  unsigned int is_valid:1; /**< True iff this router isn't invalid. */
  unsigned int is_v2_dir:1; /**< True iff this router can serve directory
                             * information with v2 of the directory
                             * protocol. (All directory caches cache v1
                             * directories.)  */
  unsigned int is_possible_guard:1; /**< True iff this router would be a good
                                     * choice as an entry guard. */
  unsigned int is_bad_exit:1; /**< True iff this node is a bad choice for
                               * an exit node. */
  unsigned int is_bad_directory:1; /**< Do we think this directory is junky,
                                    * underpowered, or otherwise useless? */
  unsigned int is_hs_dir:1; /** True iff this router is a v2-or-later hidden
                             * service directory. */
  /** True iff we know version info for this router. (i.e., a "v" entry was
   * included.)  We'll replace all these with a big tor_version_t or a char[]
   * if the number of traits we care about ever becomes incredibly big. */
  unsigned int version_known:1;
  /** True iff this router is a version that supports BEGIN_DIR cells. */
  unsigned int version_supports_begindir:1;
  /** True iff this router is a version that supports conditional consensus
   *  downloads (signed by list of authorities). */
  unsigned int version_supports_conditional_consensus:1;
  /** True iff this router is a version that we can post extrainfo docs to. */
  unsigned int version_supports_extrainfo_upload:1;
  /** True iff this router is a version that, if it caches directory info,
   * we can get v3 downloads from. */
  unsigned int version_supports_v3_dir:1;

  /* ---- The fields below aren't derived from the networkstatus; they
   * hold local information only. */

  /** True if we, as a directory mirror, want to download the corresponding
   * routerinfo from the authority who gave us this routerstatus.  (That is,
   * if we don't have the routerinfo, and if we haven't already tried to get it
   * from this authority.)  Applies in v2 networkstatus document only.
   */
  unsigned int need_to_mirror:1;
  unsigned int name_lookup_warned:1; /**< Have we warned the user for referring
                                      * to this (unnamed) router by nickname?
                                      */
  time_t last_dir_503_at; /**< When did this router last tell us that it
                           * was too busy to serve directory info? */
  download_status_t dl_status;

} routerstatus_t;

/** How many times will we try to download a router's descriptor before giving
 * up? */
#define MAX_ROUTERDESC_DOWNLOAD_FAILURES 8

/** Contents of a v2 (non-consensus, non-vote) network status object. */
typedef struct networkstatus_v2_t {
  /** When did we receive the network-status document? */
  time_t received_on;

  /** What was the digest of the document? */
  char networkstatus_digest[DIGEST_LEN];

  unsigned int is_recent; /**< Is this recent enough to influence running
                           * status? */

  /* These fields come from the actual network-status document.*/
  time_t published_on; /**< Declared publication date. */

  char *source_address; /**< Canonical directory server hostname. */
  uint32_t source_addr; /**< Canonical directory server IP. */
  uint16_t source_dirport; /**< Canonical directory server dirport. */

  unsigned int binds_names:1; /**< True iff this directory server binds
                               * names. */
  unsigned int recommends_versions:1; /**< True iff this directory server
                                       * recommends client and server software
                                       * versions. */
  unsigned int lists_bad_exits:1; /**< True iff this directory server marks
                                   * malfunctioning exits as bad. */
  /** True iff this directory server marks malfunctioning directories as
   * bad. */
  unsigned int lists_bad_directories:1;

  char identity_digest[DIGEST_LEN]; /**< Digest of signing key. */
  char *contact; /**< How to contact directory admin? (may be NULL). */
  crypto_pk_env_t *signing_key; /**< Key used to sign this directory. */
  char *client_versions; /**< comma-separated list of recommended client
                          * versions. */
  char *server_versions; /**< comma-separated list of recommended server
                          * versions. */

  smartlist_t *entries; /**< List of routerstatus_t*.   This list is kept
                         * sorted by identity_digest. */
} networkstatus_v2_t;

/** The claim about a single router, make in a vote. */
typedef struct vote_routerstatus_t {
  routerstatus_t status; /**< Underlying 'status' object for this router.
                          * Flags are redundant. */
  uint64_t flags; /**< Bit-field for all recognized flags; index into
                   * networkstatus_t.known_flags. */
  char *version; /**< The version that the authority says this router is
                  * running. */
} vote_routerstatus_t;

/** Information about a single voter in a vote or a consensus. */
typedef struct networkstatus_voter_info_t {
  char *nickname; /**< Nickname of this voter */
  char identity_digest[DIGEST_LEN]; /**< Digest of this voter's identity key */
  char *address; /**< Address of this voter, in string format. */
  uint32_t addr; /**< Address of this voter, in IPv4, in host order. */
  uint16_t dir_port; /**< Directory port of this voter */
  uint16_t or_port; /**< OR port of this voter */
  char *contact; /**< Contact information for this voter. */
  char vote_digest[DIGEST_LEN]; /**< Digest of this voter's vote, as signed. */

  /* Nothing from here on is signed. */
  char signing_key_digest[DIGEST_LEN]; /**< Declared digest of signing key
                                        * used by this voter. */
  char *signature; /**< Signature from this voter. */
  int signature_len; /**< Length of <b>signature</b> */
  unsigned int bad_signature : 1; /**< Set to true if we've tried to verify
                                   * the sig, and we know it's bad. */
  unsigned int good_signature : 1; /**< Set to true if we've verified the sig
                                     * as good. */
} networkstatus_voter_info_t;

/** A common structure to hold a v3 network status vote, or a v3 network
 * status consensus. */
typedef struct networkstatus_t {
  int is_vote; /**< True if this is a vote; false if it is a consensus. */
  time_t published; /**< Vote only: Tiem when vote was written. */
  time_t valid_after; /**< Time after which this vote or consensus applies. */
  time_t fresh_until; /**< Time before which this is the most recent vote or
                       * consensus. */
  time_t valid_until; /**< Time after which this vote or consensus should not
                       * be used. */

  /** Consensus only: what method was used to produce this consensus? */
  int consensus_method;
  /** Vote only: what methods is this voter willing to use? */
  smartlist_t *supported_methods;

  /** How long does this vote/consensus claim that authorities take to
   * distribute their votes to one another? */
  int vote_seconds;
  /** How long does this vote/consensus claim that authorites take to
   * distribute their consensus signatures to one another? */
  int dist_seconds;

  /** Comma-separated list of recommended client software, or NULL if this
   * voter has no opinion. */
  char *client_versions;
  char *server_versions;
  /** List of flags that this vote/consensus applies to routers.  If a flag is
   * not listed here, the voter h