commit 14e83e626be84c4f311b8e8f0d80ca141675fa9e Author: George Kadianakis desnacked@riseup.net Date: Tue Dec 2 12:20:35 2014 +0000
Add two hidden-service related statistics.
The two statistics are: 1. number of RELAY cells observed on successfully established rendezvous circuits; and 2. number of .onion addresses observed as hidden-service directory.
Both statistics are accumulated over 24 hours, obfuscated by rounding up to the next multiple of a given number and adding random noise, and written to local file stats/hidserv-stats.
Notably, no statistics will be gathered on clients or services, but only on relays. --- doc/tor.1.txt | 5 ++ src/or/command.c | 9 +++ src/or/config.c | 13 ++++ src/or/main.c | 5 ++ src/or/or.h | 8 ++ src/or/rendcommon.c | 7 ++ src/or/rendmid.c | 7 ++ src/or/rephist.c | 216 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/or/rephist.h | 7 ++ src/or/router.c | 5 ++ 10 files changed, 282 insertions(+)
diff --git a/doc/tor.1.txt b/doc/tor.1.txt index e876829..b09f322 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -1764,6 +1764,11 @@ is non-zero): When this option is enabled, Tor writes statistics on the bidirectional use of connections to disk every 24 hours. (Default: 0)
+[[HiddenServiceStatistics]] **HiddenServiceStatistics** **0**|**1**:: + When this option is enabled, a Tor relay writes statistics on its role as + hidden-service directory, introduction point, or rendezvous point to disk + every 24 hours. (Default: 0) + [[ExtraInfoStatistics]] **ExtraInfoStatistics** **0**|**1**:: When this option is enabled, Tor includes previously gathered statistics in its extra-info documents that it uploads to the directory authorities. diff --git a/src/or/command.c b/src/or/command.c index 268c495..8e214bf 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -438,6 +438,7 @@ command_process_created_cell(cell_t *cell, channel_t *chan) static void command_process_relay_cell(cell_t *cell, channel_t *chan) { + const or_options_t *options = get_options(); circuit_t *circ; int reason, direction;
@@ -511,6 +512,14 @@ command_process_relay_cell(cell_t *cell, channel_t *chan) direction==CELL_DIRECTION_OUT?"forward":"backward"); circuit_mark_for_close(circ, -reason); } + + /* If this is a cell in an RP circuit, count it as part of the + hidden service stats */ + if (options->HiddenServiceStatistics && + !CIRCUIT_IS_ORIGIN(circ) && + TO_OR_CIRCUIT(circ)->circuit_carries_hs_traffic_stats) { + rep_hist_seen_new_rp_cell(); + } }
/** Process a 'destroy' <b>cell</b> that just arrived from diff --git a/src/or/config.c b/src/or/config.c index 28f1df0..9a6f952 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -268,6 +268,7 @@ static config_var_t option_vars_[] = { VAR("HiddenServicePort", LINELIST_S, RendConfigLines, NULL), VAR("HiddenServiceVersion",LINELIST_S, RendConfigLines, NULL), VAR("HiddenServiceAuthorizeClient",LINELIST_S,RendConfigLines, NULL), + V(HiddenServiceStatistics, BOOL, "0"), V(HidServAuth, LINELIST, NULL), V(CloseHSClientCircuitsImmediatelyOnTimeout, BOOL, "0"), V(CloseHSServiceRendCircuitsImmediatelyOnTimeout, BOOL, "0"), @@ -1714,6 +1715,7 @@ options_act(const or_options_t *old_options) if (options->CellStatistics || options->DirReqStatistics || options->EntryStatistics || options->ExitPortStatistics || options->ConnDirectionStatistics || + options->HiddenServiceStatistics || options->BridgeAuthoritativeDir) { time_t now = time(NULL); int print_notice = 0; @@ -1722,6 +1724,7 @@ options_act(const or_options_t *old_options) if (!public_server_mode(options)) { options->CellStatistics = 0; options->EntryStatistics = 0; + options->HiddenServiceStatistics = 0; options->ExitPortStatistics = 0; }
@@ -1767,6 +1770,11 @@ options_act(const or_options_t *old_options) options->ConnDirectionStatistics) { rep_hist_conn_stats_init(now); } + if ((!old_options || !old_options->HiddenServiceStatistics) && + options->HiddenServiceStatistics) { + log_info(LD_CONFIG, "Configured to measure hidden service statistics."); + rep_hist_hs_stats_init(now); + } if ((!old_options || !old_options->BridgeAuthoritativeDir) && options->BridgeAuthoritativeDir) { rep_hist_desc_stats_init(now); @@ -1778,6 +1786,8 @@ options_act(const or_options_t *old_options) "data directory in 24 hours from now."); }
+ /* If we used to have statistics enabled but we just disabled them, + stop gathering them. */ if (old_options && old_options->CellStatistics && !options->CellStatistics) rep_hist_buffer_stats_term(); @@ -1787,6 +1797,9 @@ options_act(const or_options_t *old_options) if (old_options && old_options->EntryStatistics && !options->EntryStatistics) geoip_entry_stats_term(); + if (old_options && old_options->HiddenServiceStatistics && + !options->HiddenServiceStatistics) + rep_hist_hs_stats_term(); if (old_options && old_options->ExitPortStatistics && !options->ExitPortStatistics) rep_hist_exit_stats_term(); diff --git a/src/or/main.c b/src/or/main.c index e78e9bf..160bfa0 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -1384,6 +1384,11 @@ run_scheduled_events(time_t now) if (next_write && next_write < next_time_to_write_stats_files) next_time_to_write_stats_files = next_write; } + if (options->HiddenServiceStatistics) { + time_t next_write = rep_hist_hs_stats_write(time_to_write_stats_files); + if (next_write && next_write < next_time_to_write_stats_files) + next_time_to_write_stats_files = next_write; + } if (options->ExitPortStatistics) { time_t next_write = rep_hist_exit_stats_write(time_to_write_stats_files); if (next_write && next_write < next_time_to_write_stats_files) diff --git a/src/or/or.h b/src/or/or.h index 0de3745..ee86697 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3204,6 +3204,10 @@ typedef struct or_circuit_t { /** True iff this circuit was made with a CREATE_FAST cell. */ unsigned int is_first_hop : 1;
+ /** If set, this circuit carries HS traffic. Consider it in any HS + * statistics. */ + unsigned int circuit_carries_hs_traffic_stats : 1; + /** Number of cells that were removed from circuit queue; reset every * time when writing buffer stats to disk. */ uint32_t processed_cells; @@ -3961,6 +3965,10 @@ typedef struct { /** If true, the user wants us to collect statistics as entry node. */ int EntryStatistics;
+ /** If true, the user wants us to collect statistics as hidden service + * directory, introduction point, or rendezvous point. */ + int HiddenServiceStatistics; + /** If true, include statistics file contents in extra-info documents. */ int ExtraInfoStatistics;
diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c index df74b74..e779ecf 100644 --- a/src/or/rendcommon.c +++ b/src/or/rendcommon.c @@ -924,6 +924,7 @@ rend_cache_lookup_v2_desc_as_dir(const char *desc_id, const char **desc) rend_cache_store_status_t rend_cache_store_v2_desc_as_dir(const char *desc) { + const or_options_t *options = get_options(); rend_service_descriptor_t *parsed; char desc_id[DIGEST_LEN]; char *intro_content; @@ -1003,6 +1004,12 @@ rend_cache_store_v2_desc_as_dir(const char *desc) log_info(LD_REND, "Successfully stored service descriptor with desc ID " "'%s' and len %d.", safe_str(desc_id_base32), (int)encoded_size); + + /* Statistics: Note down this potentially new HS. */ + if (options->HiddenServiceStatistics) { + rep_hist_stored_maybe_new_hs(e->parsed->pk); + } + number_stored++; goto advance; skip: diff --git a/src/or/rendmid.c b/src/or/rendmid.c index 6a701e7..1c56471 100644 --- a/src/or/rendmid.c +++ b/src/or/rendmid.c @@ -281,6 +281,7 @@ int rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request, size_t request_len) { + const or_options_t *options = get_options(); or_circuit_t *rend_circ; char hexid[9]; int reason = END_CIRC_REASON_INTERNAL; @@ -316,6 +317,12 @@ rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request, goto err; }
+ /* Statistics: Mark this circuit as an RP circuit so that we collect + stats from it. */ + if (options->HiddenServiceStatistics) { + circ->circuit_carries_hs_traffic_stats = 1; + } + /* Send the RENDEZVOUS2 cell to Alice. */ if (relay_send_command_from_edge(0, TO_CIRCUIT(rend_circ), RELAY_COMMAND_RENDEZVOUS2, diff --git a/src/or/rephist.c b/src/or/rephist.c index f1e8827..a190fc8 100644 --- a/src/or/rephist.c +++ b/src/or/rephist.c @@ -2908,11 +2908,227 @@ rep_hist_log_circuit_handshake_stats(time_t now) memset(onion_handshakes_requested, 0, sizeof(onion_handshakes_requested)); }
+/* Hidden service statistics section */ + +/** Start of the current hidden service stats interval or 0 if we're + * not collecting hidden service statistics. */ +static time_t start_of_hs_stats_interval; + +/** Carries the various hidden service statistics, and any other + * information needed. */ +typedef struct hs_stats_t { + /** How many relay cells have we seen as rendezvous points? */ + int64_t rp_relay_cells_seen; + + /** Set of unique public key digests we've seen this stat period + * (could also be implemented as sorted smartlist). */ + digestmap_t *onions_seen_this_period; +} hs_stats_t; + +/** Our statistics structure singleton. */ +static hs_stats_t *hs_stats = NULL; + +/** Allocate, initialize and return an hs_stats_t structure. */ +static hs_stats_t * +hs_stats_new(void) +{ + hs_stats_t * hs_stats = tor_malloc_zero(sizeof(hs_stats_t)); + hs_stats->onions_seen_this_period = digestmap_new(); + + return hs_stats; +} + +/** Free an hs_stats_t structure. */ +static void +hs_stats_free(hs_stats_t *hs_stats) +{ + if (!hs_stats) { + return; + } + + digestmap_free(hs_stats->onions_seen_this_period, NULL); + tor_free(hs_stats); +} + +/** Initialize hidden service statistics. */ +void +rep_hist_hs_stats_init(time_t now) +{ + if (!hs_stats) { + hs_stats = hs_stats_new(); + } + + start_of_hs_stats_interval = now; +} + +/** Clear history of hidden service statistics and set the measurement + * interval start to <b>now</b>. */ +static void +rep_hist_reset_hs_stats(time_t now) +{ + if (!hs_stats) { + hs_stats = hs_stats_new(); + } + + hs_stats->rp_relay_cells_seen = 0; + + digestmap_free(hs_stats->onions_seen_this_period, NULL); + hs_stats->onions_seen_this_period = digestmap_new(); + + start_of_hs_stats_interval = now; +} + +/** Stop collecting hidden service stats in a way that we can re-start + * doing so in rep_hist_buffer_stats_init(). */ +void +rep_hist_hs_stats_term(void) +{ + rep_hist_reset_hs_stats(0); +} + +/** We saw a new HS relay cell, Count it! */ +void +rep_hist_seen_new_rp_cell(void) +{ + if (!hs_stats) { + return; // We're not collecting stats + } + + hs_stats->rp_relay_cells_seen++; +} + +/** As HSDirs, we saw another hidden service with public key + * <b>pubkey</b>. Check whether we have counted it before, if not + * count it now! */ +void +rep_hist_stored_maybe_new_hs(const crypto_pk_t *pubkey) +{ + char pubkey_hash[DIGEST_LEN]; + + if (!hs_stats) { + return; // We're not collecting stats + } + + /* Get the digest of the pubkey which will be used to detect whether + we've seen this hidden service before or not. */ + if (crypto_pk_get_digest(pubkey, pubkey_hash) < 0) { + /* This fail should not happen; key has been validated by + descriptor parsing code first. */ + return; + } + + /* Check if this is the first time we've seen this hidden + service. If it is, count it as new. */ + if (!digestmap_get(hs_stats->onions_seen_this_period, + pubkey_hash)) { + digestmap_set(hs_stats->onions_seen_this_period, + pubkey_hash, (void*)(uintptr_t)1); + } +} + +/* The number of cells that are supposed to be hidden from the adversary + * by adding noise from the Laplace distribution. This value, divided by + * EPSILON, is Laplace parameter b. */ +#define REND_CELLS_DELTA_F 2048 +/* Security parameter for obfuscating number of cells with a value between + * 0 and 1. Smaller values obfuscate observations more, but at the same + * time make statistics less usable. */ +#define REND_CELLS_EPSILON 0.3 +/* The number of cells that are supposed to be hidden from the adversary + * by rounding up to the next multiple of this number. */ +#define REND_CELLS_BIN_SIZE 1024 +/* The number of service identities that are supposed to be hidden from + * the adversary by adding noise from the Laplace distribution. This + * value, divided by EPSILON, is Laplace parameter b. */ +#define ONIONS_SEEN_DELTA_F 8 +/* Security parameter for obfuscating number of service identities with a + * value between 0 and 1. Smaller values obfuscate observations more, but + * at the same time make statistics less usable. */ +#define ONIONS_SEEN_EPSILON 0.3 +/* The number of service identities that are supposed to be hidden from + * the adversary by rounding up to the next multiple of this number. */ +#define ONIONS_SEEN_BIN_SIZE 8 + +/** Allocate and return a string containing hidden service stats that + * are meant to be placed in the extra-info descriptor. */ +static char * +rep_hist_format_hs_stats(time_t now) +{ + char t[ISO_TIME_LEN+1]; + char *hs_stats_string; + int64_t obfuscated_cells_seen; + int64_t obfuscated_onions_seen; + + obfuscated_cells_seen = round_int64_to_next_multiple_of( + hs_stats->rp_relay_cells_seen, + REND_CELLS_BIN_SIZE); + obfuscated_cells_seen = add_laplace_noise(obfuscated_cells_seen, + crypto_rand_double(), + REND_CELLS_DELTA_F, REND_CELLS_EPSILON); + obfuscated_onions_seen = round_int64_to_next_multiple_of(digestmap_size( + hs_stats->onions_seen_this_period), + ONIONS_SEEN_BIN_SIZE); + obfuscated_onions_seen = add_laplace_noise(obfuscated_onions_seen, + crypto_rand_double(), ONIONS_SEEN_DELTA_F, + ONIONS_SEEN_EPSILON); + + format_iso_time(t, now); + tor_asprintf(&hs_stats_string, "hidserv-stats-end %s (%d s)\n" + "hidserv-rend-relayed-cells "I64_FORMAT" delta_f=%d " + "epsilon=%.2f bin_size=%d\n" + "hidserv-dir-onions-seen "I64_FORMAT" delta_f=%d " + "epsilon=%.2f bin_size=%d\n", + t, (unsigned) (now - start_of_hs_stats_interval), + I64_PRINTF_ARG(obfuscated_cells_seen), REND_CELLS_DELTA_F, + REND_CELLS_EPSILON, REND_CELLS_BIN_SIZE, + I64_PRINTF_ARG(obfuscated_onions_seen), + ONIONS_SEEN_DELTA_F, + ONIONS_SEEN_EPSILON, ONIONS_SEEN_BIN_SIZE); + + return hs_stats_string; +} + +/** If 24 hours have passed since the beginning of the current HS + * stats period, write buffer stats to $DATADIR/stats/hidserv-stats + * (possibly overwriting an existing file) and reset counters. Return + * when we would next want to write buffer stats or 0 if we never want to + * write. */ +time_t +rep_hist_hs_stats_write(time_t now) +{ + char *str = NULL; + + if (!start_of_hs_stats_interval) { + return 0; /* Not initialized. */ + } + + if (start_of_hs_stats_interval + WRITE_STATS_INTERVAL > now) { + goto done; /* Not ready to write */ + } + + /* Generate history string. */ + str = rep_hist_format_hs_stats(now); + + /* Reset HS history. */ + rep_hist_reset_hs_stats(now); + + /* Try to write to disk. */ + if (!check_or_create_data_subdir("stats")) { + write_to_data_subdir("stats", "hidserv-stats", str, + "hidden service stats"); + } + + done: + tor_free(str); + return start_of_hs_stats_interval + WRITE_STATS_INTERVAL; +} + /** Free all storage held by the OR/link history caches, by the * bandwidth history arrays, by the port history, or by statistics . */ void rep_hist_free_all(void) { + hs_stats_free(hs_stats); digestmap_free(history_map, free_or_history); tor_free(read_array); tor_free(write_array); diff --git a/src/or/rephist.h b/src/or/rephist.h index d853fe2..8fd1599 100644 --- a/src/or/rephist.h +++ b/src/or/rephist.h @@ -99,6 +99,13 @@ void rep_hist_note_circuit_handshake_requested(uint16_t type); void rep_hist_note_circuit_handshake_assigned(uint16_t type); void rep_hist_log_circuit_handshake_stats(time_t now);
+void rep_hist_hs_stats_init(time_t now); +void rep_hist_hs_stats_term(void); +time_t rep_hist_hs_stats_write(time_t now); +char *rep_hist_get_hs_stats_string(void); +void rep_hist_seen_new_rp_cell(void); +void rep_hist_stored_maybe_new_hs(const crypto_pk_t *pubkey); + void rep_hist_free_all(void);
#endif diff --git a/src/or/router.c b/src/or/router.c index 01838b4..3e60880 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -2654,6 +2654,11 @@ extrainfo_dump_to_string(char **s_out, extrainfo_t *extrainfo, "dirreq-stats-end", now, &contents) > 0) { smartlist_add(chunks, contents); } + if (options->HiddenServiceStatistics && + load_stats_file("stats"PATH_SEPARATOR"hidserv-stats", + "hidserv-stats-end", now, &contents) > 0) { + smartlist_add(chunks, contents); + } if (options->EntryStatistics && load_stats_file("stats"PATH_SEPARATOR"entry-stats", "entry-stats-end", now, &contents) > 0) {