February 2018 - tor-commits - lists.torproject.org

[tor/maint-0.3.1] geoip: Increment and decrement functions for the geoip client cache
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 4d812e29b9b1ec88fe268c150a826466b23a8762 Author: David Goulet <dgoulet(a)torproject.org> Date: Fri Feb 2 13:14:50 2018 -0500 geoip: Increment and decrement functions for the geoip client cache These functions protect againts over and underflow. They BUG() in case we overflow the counter. Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/geoip.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/src/or/geoip.c b/src/or/geoip.c index c5e8cdab9..92db9742e 100644 --- a/src/or/geoip.c +++ b/src/or/geoip.c @@ -76,6 +76,34 @@ static char geoip6_digest[DIGEST_LEN]; * handler. */ static size_t geoip_client_history_cache_size; +/* Increment the geoip client history cache size counter with the given bytes. + * This prevents an overflow and set it to its maximum in that case. */ +static inline void +geoip_increment_client_history_cache_size(size_t bytes) +{ + /* This is shockingly high, lets log it so it can be reported. */ + IF_BUG_ONCE(geoip_client_history_cache_size > (SIZE_MAX - bytes)) { + geoip_client_history_cache_size = SIZE_MAX; + return; + } + geoip_client_history_cache_size += bytes; +} + +/* Decrement the geoip client history cache size counter with the given bytes. + * This prevents an underflow and set it to 0 in that case. */ +static inline void +geoip_decrement_client_history_cache_size(size_t bytes) +{ + /* Going below 0 means that we either allocated an entry without + * incrementing the counter or we have different sizes when allocating and + * freeing. It shouldn't happened so log it. */ + IF_BUG_ONCE(geoip_client_history_cache_size < bytes) { + geoip_client_history_cache_size = 0; + return; + } + geoip_client_history_cache_size -= bytes; +} + /** Return the index of the country's entry in the GeoIP * country list if it is a valid 2-letter country code, otherwise * return -1. */ @@ -546,7 +574,7 @@ clientmap_entry_free(clientmap_entry_t *ent) if (!ent) return; - geoip_client_history_cache_size -= clientmap_entry_size(ent); + geoip_decrement_client_history_cache_size(clientmap_entry_size(ent)); tor_free(ent->transport_name); tor_free(ent); @@ -610,7 +638,7 @@ geoip_note_client_seen(geoip_client_action_t action, ent->transport_name = tor_strdup(transport_name); ent->action = (int)action; HT_INSERT(clientmap, &client_history, ent); - geoip_client_history_cache_size += clientmap_entry_size(ent); + geoip_increment_client_history_cache_size(clientmap_entry_size(ent)); } if (now / 60 <= (int)MAX_LAST_SEEN_IN_MINUTES && now >= 0) ent->last_seen_in_minutes = (unsigned)(now/60);

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[tor/maint-0.3.1] channel_tls_get_remote_addr_method now returns real_addr.
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 33d9889a2bdd611bcc255c68c43d60b8919ab663 Author: Fernando Fernandez Mancera <ffmancera(a)riseup.net> Date: Mon Jan 22 15:20:17 2018 +0100 channel_tls_get_remote_addr_method now returns real_addr. The accurate address of a connection is real_addr, not the addr member. channel_tls_get_remote_addr_method() now returns real_addr instead. Fixes #24952; bugfix on 707c1e2 in 0.2.4.11-alpha. Signed-off-by: Fernando Fernandez Mancera <ffmancera(a)riseup.net> --- changes/bug24952 | 5 +++++ src/or/channeltls.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/changes/bug24952 b/changes/bug24952 new file mode 100644 index 000000000..93174c04f --- /dev/null +++ b/changes/bug24952 @@ -0,0 +1,5 @@ + o Minor bugfix (channel connection): + - The accurate address of a connection is real_addr, not the addr member. + TLS Channel remote address is now real_addr content instead of addr + member. Fixes bug 24952; bugfix on 707c1e2e26 in 0.2.4.11-alpha. + Patch by "ffmancera". diff --git a/src/or/channeltls.c b/src/or/channeltls.c index 09cca95b6..890646989 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -514,7 +514,7 @@ channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out) tor_assert(addr_out); if (tlschan->conn) { - tor_addr_copy(addr_out, &(TO_CONN(tlschan->conn)->addr)); + tor_addr_copy(addr_out, &(tlschan->conn->real_addr)); rv = 1; } else tor_addr_make_unspec(addr_out);

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[tor/maint-0.3.1] dos: Make sure cc_stats_refill_bucket can't overflow while calculating
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit a09d5f5735abe2e1d16cf0ee9389ae096d5e7ef1 Author: teor <teor2345(a)gmail.com> Date: Wed Jan 31 11:13:17 2018 +1100 dos: Make sure cc_stats_refill_bucket can't overflow while calculating Debug log the elapsed time in cc_stats_refill_bucket Part of #25094. Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/dos.c | 82 +++++++++++++++++++++++++++++++++++++---------------- src/or/dos.h | 2 +- src/test/test_dos.c | 2 +- 3 files changed, 59 insertions(+), 27 deletions(-) diff --git a/src/or/dos.c b/src/or/dos.c index a614d1231..c221e5ecd 100644 --- a/src/or/dos.c +++ b/src/or/dos.c @@ -222,7 +222,7 @@ cc_consensus_has_changed(const networkstatus_t *ns) /** Return the number of circuits we allow per second under the current * configuration. */ -STATIC uint32_t +STATIC uint64_t get_circuit_rate_per_second(void) { return dos_cc_circuit_rate; @@ -234,31 +234,40 @@ get_circuit_rate_per_second(void) STATIC void cc_stats_refill_bucket(cc_client_stats_t *stats, const tor_addr_t *addr) { - uint32_t new_circuit_bucket_count, circuit_rate = 0, num_token; - time_t now, elapsed_time_last_refill; + uint32_t new_circuit_bucket_count; + uint64_t num_token, elapsed_time_last_refill = 0, circuit_rate = 0; + time_t now; + int64_t last_refill_ts; tor_assert(stats); tor_assert(addr); now = approx_time(); + last_refill_ts = (int64_t)stats->last_circ_bucket_refill_ts; - /* We've never filled the bucket so fill it with the maximum being the burst - * and we are done. */ - if (stats->last_circ_bucket_refill_ts == 0) { - num_token = dos_cc_circuit_burst; - goto end; + /* If less than a second has elapsed, don't add any tokens. + * Note: If a relay's clock is ever 0, any new clients won't get a refill + * until the next second. But a relay that thinks it is 1970 will never + * validate the public consensus. */ + if ((int64_t)now == last_refill_ts) { + goto done; } /* At this point, we know we might need to add token to the bucket. We'll - * first compute the circuit rate that is how many circuit are we allowed to - * do per second. */ + * first get the circuit rate that is how many circuit are we allowed to do + * per second. */ circuit_rate = get_circuit_rate_per_second(); - /* How many seconds have elapsed between now and the last refill? */ - elapsed_time_last_refill = now - stats->last_circ_bucket_refill_ts; + /* We've never filled the bucket so fill it with the maximum being the burst + * and we are done. + * Note: If a relay's clock is ever 0, all clients that were last refilled + * in that zero second will get a full refill here. */ + if (last_refill_ts == 0) { + num_token = dos_cc_circuit_burst; + goto end; + } - /* If the elapsed time is below 0 it means our clock jumped backward so in - * that case, lets be safe and fill it up to the maximum. Not filling it + /* Our clock jumped backward so fill it up to the maximum. Not filling it * could trigger a detection for a valid client. Also, if the clock jumped * negative but we didn't notice until the elapsed time became positive * again, then we potentially spent many seconds not refilling the bucket @@ -266,28 +275,51 @@ cc_stats_refill_bucket(cc_client_stats_t *stats, const tor_addr_t *addr) * until now means that no circuit creation requests came in during that * time, so the client doesn't end up punished that much from this hopefully * rare situation.*/ - if (elapsed_time_last_refill < 0) { - /* Dividing the burst by the circuit rate gives us the time span that will - * give us the maximum allowed value of token. */ - elapsed_time_last_refill = (dos_cc_circuit_burst / circuit_rate); + if ((int64_t)now < last_refill_ts) { + /* Use the maximum allowed value of token. */ + num_token = dos_cc_circuit_burst; + goto end; + } + + /* How many seconds have elapsed between now and the last refill? + * This subtraction can't underflow, because now >= last_refill_ts. + * And it can't overflow, because INT64_MAX - (-INT64_MIN) == UINT64_MAX. */ + elapsed_time_last_refill = (uint64_t)now - last_refill_ts; + + /* If the elapsed time is very large, it means our clock jumped forward. + * If the multiplication would overflow, use the maximum allowed value. */ + if (elapsed_time_last_refill > UINT32_MAX) { + num_token = dos_cc_circuit_burst; + goto end; } /* Compute how many circuits we are allowed in that time frame which we'll - * add to the bucket. This can be big but it is cap to a maximum after. */ + * add to the bucket. This can't overflow, because both multiplicands + * are less than or equal to UINT32_MAX, and num_token is uint64_t. */ num_token = elapsed_time_last_refill * circuit_rate; end: - /* We cap the bucket to the burst value else this could grow to infinity - * over time. */ - new_circuit_bucket_count = MIN(stats->circuit_bucket + num_token, - dos_cc_circuit_burst); + /* If the sum would overflow, use the maximum allowed value. */ + if (num_token > UINT32_MAX - stats->circuit_bucket) { + new_circuit_bucket_count = dos_cc_circuit_burst; + } else { + /* We cap the bucket to the burst value else this could overflow uint32_t + * over time. */ + new_circuit_bucket_count = MIN(stats->circuit_bucket + (uint32_t)num_token, + dos_cc_circuit_burst); + } + /* This function is not allowed to make the bucket count smaller */ + tor_assert_nonfatal(new_circuit_bucket_count >= stats->circuit_bucket); log_debug(LD_DOS, "DoS address %s has its circuit bucket value: %" PRIu32 - ". Filling it to %" PRIu32 ". Circuit rate is %" PRIu32, + ". Filling it to %" PRIu32 ". Circuit rate is %" PRIu64 + ". Elapsed time is %" PRIi64, fmt_addr(addr), stats->circuit_bucket, new_circuit_bucket_count, - circuit_rate); + circuit_rate, (int64_t)elapsed_time_last_refill); stats->circuit_bucket = new_circuit_bucket_count; stats->last_circ_bucket_refill_ts = now; + + done: return; } diff --git a/src/or/dos.h b/src/or/dos.h index 8695512ea..5d35a2b12 100644 --- a/src/or/dos.h +++ b/src/or/dos.h @@ -125,7 +125,7 @@ STATIC uint32_t get_param_cc_circuit_burst(const networkstatus_t *ns); STATIC uint32_t get_param_cc_min_concurrent_connection( const networkstatus_t *ns); -STATIC uint32_t get_circuit_rate_per_second(void); +STATIC uint64_t get_circuit_rate_per_second(void); STATIC void cc_stats_refill_bucket(cc_client_stats_t *stats, const tor_addr_t *addr); diff --git a/src/test/test_dos.c b/src/test/test_dos.c index 80abc1937..7fe549560 100644 --- a/src/test/test_dos.c +++ b/src/test/test_dos.c @@ -176,7 +176,7 @@ test_dos_bucket_refill(void *arg) /* Initialize DoS subsystem and get relevant limits */ dos_init(); uint32_t max_circuit_count = get_param_cc_circuit_burst(NULL); - int circ_rate = get_circuit_rate_per_second(); + uint64_t circ_rate = get_circuit_rate_per_second(); /* Check that the circuit rate is a positive number and smaller than the max * circuit count */ tt_int_op(circ_rate, OP_GT, 1);

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[tor/maint-0.3.1] dos: Add the connection DoS mitigation subsystem
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit acf7ea77d8d76830924a14145afbcf3c95a06b0e Author: David Goulet <dgoulet(a)torproject.org> Date: Thu Jan 25 16:28:54 2018 -0500 dos: Add the connection DoS mitigation subsystem Defend against an address that has reached the concurrent connection count threshold. Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/connection.c | 8 ++++++++ src/or/dos.c | 34 ++++++++++++++++++++++++++++++++++ src/or/dos.h | 2 ++ 3 files changed, 44 insertions(+) diff --git a/src/or/connection.c b/src/or/connection.c index 15f489c6b..791fd95c2 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -1600,6 +1600,14 @@ connection_handle_listener_read(connection_t *conn, int new_type) return 0; } } + if (new_type == CONN_TYPE_OR) { + /* Assess with the connection DoS mitigation subsystem if this address + * can open a new connection. */ + if (dos_conn_addr_get_defense_type(&addr) == DOS_CONN_DEFENSE_CLOSE) { + tor_close_socket(news); + return 0; + } + } newconn = connection_new(new_type, conn->socket_family); newconn->s = news; diff --git a/src/or/dos.c b/src/or/dos.c index 8c00a2f31..7e3a2ab7f 100644 --- a/src/or/dos.c +++ b/src/or/dos.c @@ -53,6 +53,9 @@ static unsigned int dos_conn_enabled = 0; static uint32_t dos_conn_max_concurrent_count; static dos_conn_defense_type_t dos_conn_defense_type; +/* Keep some stats for the heartbeat so we can report out. */ +static uint64_t conn_num_addr_rejected; + /* * General interface of the denial of service mitigation subsystem. */ @@ -488,6 +491,37 @@ dos_cc_get_defense_type(channel_t *chan) /* Concurrent connection detection public API. */ +/* Return true iff the given address is permitted to open another connection. + * A defense value is returned for the caller to take appropriate actions. */ +dos_conn_defense_type_t +dos_conn_addr_get_defense_type(const tor_addr_t *addr) +{ + clientmap_entry_t *entry; + + tor_assert(addr); + + /* Skip everything if not enabled. */ + if (!dos_conn_enabled) { + goto end; + } + + /* We are only interested in client connection from the geoip cache. */ + entry = geoip_lookup_client(addr, NULL, GEOIP_CLIENT_CONNECT); + if (entry == NULL) { + goto end; + } + + /* Need to be above the maximum concurrent connection count to trigger a + * defense. */ + if (entry->dos_stats.concurrent_count > dos_conn_max_concurrent_count) { + conn_num_addr_rejected++; + return dos_conn_defense_type; + } + + end: + return DOS_CONN_DEFENSE_NONE; +} + /* General API */ /* Called when a new client connection has been established on the given diff --git a/src/or/dos.h b/src/or/dos.h index fa86295cf..cc7749836 100644 --- a/src/or/dos.h +++ b/src/or/dos.h @@ -107,6 +107,8 @@ typedef enum dos_conn_defense_type_t { DOS_CONN_DEFENSE_MAX = 2, } dos_conn_defense_type_t; +dos_conn_defense_type_t dos_conn_addr_get_defense_type(const tor_addr_t *addr); + #ifdef DOS_PRIVATE STATIC uint32_t get_param_conn_max_concurrent_count(

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[tor/maint-0.3.1] test: Add unit tests for overflows and underflows in cc_stats_refill_bucket
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 1f4a73133cf864774c017e2c50b347727519c18f Author: teor <teor2345(a)gmail.com> Date: Wed Jan 31 11:22:20 2018 +1100 test: Add unit tests for overflows and underflows in cc_stats_refill_bucket Closes #25094. Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/test/test_dos.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) diff --git a/src/test/test_dos.c b/src/test/test_dos.c index 7fe549560..071926c28 100644 --- a/src/test/test_dos.c +++ b/src/test/test_dos.c @@ -234,6 +234,152 @@ test_dos_bucket_refill(void *arg) current_circ_count += max_circuit_count; tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now use a very large time, and check that the token bucket does not have + * more than max_circs allowance, even tho we let it simmer for so long. */ + now = INT32_MAX; /* 2038? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now use a very small time, and check that the token bucket has exactly + * the max_circs allowance, because backward clock jumps are rare. */ + now = INT32_MIN; /* 19?? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Progress time forward one sec again, refill the bucket and check that the + * refill happened correctly. */ + now += 1; + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + /* check refill */ + current_circ_count += circ_rate; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now use a very large time (again), and check that the token bucket does + * not have more than max_circs allowance, even tho we let it simmer for so + * long. */ + now = INT32_MAX; /* 2038? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* This code resets the time to zero with 32-bit time_t, which triggers the + * code that initialises the bucket. */ +#if SIZEOF_TIME_T == 8 + /* Now use a very very small time, and check that the token bucket has + * exactly the max_circs allowance, because backward clock jumps are rare. + */ + now = (time_t)INT64_MIN; /* ???? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Progress time forward one sec again, refill the bucket and check that the + * refill happened correctly. */ + now += 1; + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + /* check refill */ + current_circ_count += circ_rate; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now use a very very small time, and check that the token bucket has + * exactly the max_circs allowance, because backward clock jumps are rare. + */ + now = (time_t)INT64_MIN; /* ???? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now use a very very large time, and check that the token bucket does not + * have more than max_circs allowance, even tho we let it simmer for so + * long. */ + now = (time_t)INT64_MAX; /* ???? */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); +#endif + done: tor_free(chan); dos_free_all();

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[tor/maint-0.3.1] dos: We can put less token than the current amount
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 78d6cb58707ff46464c591e45d81e83388427e2c Author: David Goulet <dgoulet(a)torproject.org> Date: Fri Feb 2 17:04:12 2018 -0500 dos: We can put less token than the current amount Becasue the circuit creation burst and rate can change at runtime it is possible that between two refill of a bucket, we end up setting the bucket value to less than there currently is. Fixes #25128 Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/dos.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/src/or/dos.c b/src/or/dos.c index c221e5ecd..88f1351a3 100644 --- a/src/or/dos.c +++ b/src/or/dos.c @@ -308,8 +308,6 @@ cc_stats_refill_bucket(cc_client_stats_t *stats, const tor_addr_t *addr) new_circuit_bucket_count = MIN(stats->circuit_bucket + (uint32_t)num_token, dos_cc_circuit_burst); } - /* This function is not allowed to make the bucket count smaller */ - tor_assert_nonfatal(new_circuit_bucket_count >= stats->circuit_bucket); log_debug(LD_DOS, "DoS address %s has its circuit bucket value: %" PRIu32 ". Filling it to %" PRIu32 ". Circuit rate is %" PRIu64 ". Elapsed time is %" PRIi64,

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[tor/maint-0.3.1] test: Add unit tests for the DoS subsystem
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit c3c2b55decc80028728780422fe2766ec6517246 Author: George Kadianakis <desnacked(a)riseup.net> Date: Thu Jan 25 16:38:59 2018 -0500 test: Add unit tests for the DoS subsystem Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/channel.c | 4 +- src/or/channel.h | 3 +- src/test/include.am | 1 + src/test/test.c | 1 + src/test/test.h | 1 + src/test/test_dos.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 255 insertions(+), 3 deletions(-) diff --git a/src/or/channel.c b/src/or/channel.c index fdd3f81e8..54e10666d 100644 --- a/src/or/channel.c +++ b/src/or/channel.c @@ -3845,8 +3845,8 @@ channel_get_canonical_remote_descr(channel_t *chan) * supports this operation, and return 1. Return 0 if the underlying transport * doesn't let us do this. */ -int -channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out) +MOCK_IMPL(int, +channel_get_addr_if_possible,(channel_t *chan, tor_addr_t *addr_out)) { tor_assert(chan); tor_assert(addr_out); diff --git a/src/or/channel.h b/src/or/channel.h index a711b56d4..bcd345e8d 100644 --- a/src/or/channel.h +++ b/src/or/channel.h @@ -550,7 +550,8 @@ MOCK_DECL(void, channel_dump_statistics, (channel_t *chan, int severity)); void channel_dump_transport_statistics(channel_t *chan, int severity); const char * channel_get_actual_remote_descr(channel_t *chan); const char * channel_get_actual_remote_address(channel_t *chan); -int channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out); +MOCK_DECL(int, channel_get_addr_if_possible, (channel_t *chan, + tor_addr_t *addr_out)); const char * channel_get_canonical_remote_descr(channel_t *chan); int channel_has_queued_writes(channel_t *chan); int channel_is_bad_for_new_circs(channel_t *chan); diff --git a/src/test/include.am b/src/test/include.am index 8ecfaf10c..91b0a5910 100644 --- a/src/test/include.am +++ b/src/test/include.am @@ -87,6 +87,7 @@ src_test_test_SOURCES = \ src/test/test_controller.c \ src/test/test_controller_events.c \ src/test/test_crypto.c \ + src/test/test_dos.c \ src/test/test_data.c \ src/test/test_dir.c \ src/test/test_dir_common.c \ diff --git a/src/test/test.c b/src/test/test.c index 9a41b976b..f66dee2d0 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -1197,6 +1197,7 @@ struct testgroup_t testgroups[] = { { "control/", controller_tests }, { "control/event/", controller_event_tests }, { "crypto/", crypto_tests }, + { "dos/", dos_tests }, { "dir/", dir_tests }, { "dir_handle_get/", dir_handle_get_tests }, { "dir/md/", microdesc_tests }, diff --git a/src/test/test.h b/src/test/test.h index 25336ac83..41df6b134 100644 --- a/src/test/test.h +++ b/src/test/test.h @@ -190,6 +190,7 @@ extern struct testcase_t container_tests[]; extern struct testcase_t controller_tests[]; extern struct testcase_t controller_event_tests[]; extern struct testcase_t crypto_tests[]; +extern struct testcase_t dos_tests[]; extern struct testcase_t dir_tests[]; extern struct testcase_t dir_handle_get_tests[]; extern struct testcase_t entryconn_tests[]; diff --git a/src/test/test_dos.c b/src/test/test_dos.c new file mode 100644 index 000000000..5a8474ad8 --- /dev/null +++ b/src/test/test_dos.c @@ -0,0 +1,248 @@ +/* Copyright (c) 2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#define DOS_PRIVATE +#define TOR_CHANNEL_INTERNAL_ +#define CIRCUITLIST_PRIVATE + +#include "or.h" +#include "dos.h" +#include "circuitlist.h" +#include "geoip.h" +#include "channel.h" +#include "test.h" +#include "log_test_helpers.h" + +static unsigned int +mock_enable_dos_protection(const networkstatus_t *ns) +{ + (void) ns; + return 1; +} + +/** Test that the connection tracker of the DoS subsystem will block clients + * who try to establish too many connections */ +static void +test_dos_conn_creation(void *arg) +{ + (void) arg; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + + /* Initialize test data */ + or_connection_t or_conn; + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Get DoS subsystem limits */ + dos_init(); + uint32_t max_concurrent_conns = get_param_conn_max_concurrent_count(NULL); + + /* Introduce new client */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + { /* Register many conns from this client but not enough to get it blocked */ + unsigned int i; + for (i = 0; i < max_concurrent_conns; i++) { + dos_new_client_conn(&or_conn); + } + } + + /* Check that new conns are still permitted */ + tt_int_op(DOS_CONN_DEFENSE_NONE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Register another conn and check that new conns are not allowed anymore */ + dos_new_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Close a client conn and see that a new conn will be permitted again */ + dos_close_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_NONE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Register another conn and see that defense measures get reactivated */ + dos_new_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + done: + dos_free_all(); +} + +/** Helper mock: Place a fake IP addr for this channel in addr_out */ +static int +mock_channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out) +{ + (void)chan; + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(addr_out, "18.0.0.1"));; + return 1; + + done: + return 0; +} + +/** Test that the circuit tracker of the DoS subsystem will block clients who + * try to establish too many circuits. */ +static void +test_dos_circuit_creation(void *arg) +{ + (void) arg; + unsigned int i; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + MOCK(channel_get_addr_if_possible, + mock_channel_get_addr_if_possible); + + /* Initialize channels/conns/circs that will be used */ + channel_t *chan = tor_malloc_zero(sizeof(channel_t)); + channel_init(chan); + chan->is_client = 1; + + /* Initialize test data */ + or_connection_t or_conn; + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Get DoS subsystem limits */ + dos_init(); + uint32_t max_circuit_count = get_param_cc_circuit_burst(NULL); + uint32_t min_conc_conns_for_cc = + get_param_cc_min_concurrent_connection(NULL); + + /* Introduce new client and establish enough connections to activate the + * circuit counting subsystem */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + for (i = 0; i < min_conc_conns_for_cc ; i++) { + dos_new_client_conn(&or_conn); + } + + /* Register new circuits for this client and conn, but not enough to get + * detected as dos */ + for (i=0; i < max_circuit_count-1; i++) { + dos_cc_new_create_cell(chan); + } + /* see that we didn't get detected for dosing */ + tt_int_op(DOS_CC_DEFENSE_NONE, OP_EQ, dos_cc_get_defense_type(chan)); + + /* Register another CREATE cell that will push us over the limit. Check that + * the cell gets refused. */ + dos_cc_new_create_cell(chan); + tt_int_op(DOS_CC_DEFENSE_REFUSE_CELL, OP_EQ, dos_cc_get_defense_type(chan)); + + /* TODO: Wait a few seconds before sending the cell, and check that the + buckets got refilled properly. */ + /* TODO: Actually send a Tor cell (instead of calling the DoS function) and + * check that it will get refused */ + + done: + tor_free(chan); + dos_free_all(); +} + +/** Test that the DoS subsystem properly refills the circuit token buckets. */ +static void +test_dos_bucket_refill(void *arg) +{ + (void) arg; + int i; + /* For this test, this variable is set to the current circ count of the token + * bucket. */ + uint32_t current_circ_count; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + MOCK(channel_get_addr_if_possible, + mock_channel_get_addr_if_possible); + + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + update_approx_time(now); + + /* Initialize channels/conns/circs that will be used */ + channel_t *chan = tor_malloc_zero(sizeof(channel_t)); + channel_init(chan); + chan->is_client = 1; + or_connection_t or_conn; + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Initialize DoS subsystem and get relevant limits */ + dos_init(); + uint32_t max_circuit_count = get_param_cc_circuit_burst(NULL); + int circ_rate = tor_lround(get_circuit_rate_per_second()); + /* Check that the circuit rate is a positive number and smaller than the max + * circuit count */ + tt_int_op(circ_rate, OP_GT, 1); + tt_int_op(circ_rate, OP_LT, max_circuit_count); + + /* Register this client */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + dos_new_client_conn(&or_conn); + + /* Fetch this client from the geoip cache and get its DoS structs */ + clientmap_entry_t *entry = geoip_lookup_client(addr, NULL, + GEOIP_CLIENT_CONNECT); + tt_assert(entry); + dos_client_stats_t* dos_stats = &entry->dos_stats; + /* Check that the circuit bucket is still uninitialized */ + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, 0); + + /* Send a create cell: then check that the circ token bucket got initialized + * and one circ was subtracted. */ + dos_cc_new_create_cell(chan); + current_circ_count = max_circuit_count - 1; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send 29 more CREATEs and ensure that the bucket is missing 30 + * tokens */ + for (i=0; i < 29; i++) { + dos_cc_new_create_cell(chan); + current_circ_count--; + } + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* OK! Progress time forward one sec, refill the bucket and check that the + * refill happened correctly. */ + now += 1; + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + /* check refill */ + current_circ_count += circ_rate; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now progress time a week forward, and check that the token bucket does not + * have more than max_circs allowance, even tho we let it simmer for so + * long. */ + now += 604800; /* a week */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + done: + tor_free(chan); + dos_free_all(); +} + +struct testcase_t dos_tests[] = { + { "conn_creation", test_dos_conn_creation, TT_FORK, NULL, NULL }, + { "circuit_creation", test_dos_circuit_creation, TT_FORK, NULL, NULL }, + { "bucket_refill", test_dos_bucket_refill, TT_FORK, NULL, NULL }, + END_OF_TESTCASES +}; +

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[tor/maint-0.3.1] geoip: Hook the client history cache into the OOM handler
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 51839f47650463f59bd2cc84da05d5bc535d699d Author: David Goulet <dgoulet(a)torproject.org> Date: Fri Feb 2 10:15:28 2018 -0500 geoip: Hook the client history cache into the OOM handler If the cache is using 20% of our maximum allowed memory, clean 10% of it. Same behavior as the HS descriptor cache. Closes #25122 Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- changes/ticket25122 | 4 +++ src/or/geoip.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++ src/or/geoip.h | 2 ++ src/or/relay.c | 16 ++++++++-- src/test/test.c | 18 +++++++++++ 5 files changed, 128 insertions(+), 3 deletions(-) diff --git a/changes/ticket25122 b/changes/ticket25122 new file mode 100644 index 000000000..2921811b2 --- /dev/null +++ b/changes/ticket25122 @@ -0,0 +1,4 @@ + o Minor feature (geoip cache): + - Make our OOM handler aware of the geoip client history cache so it + doesn't fill up the memory which is especially important for IPv6 and + our DoS mitigation subsystem. Closes ticket 25122. diff --git a/src/or/geoip.c b/src/or/geoip.c index 00c055bbe..c5e8cdab9 100644 --- a/src/or/geoip.c +++ b/src/or/geoip.c @@ -72,6 +72,10 @@ static smartlist_t *geoip_ipv4_entries = NULL, *geoip_ipv6_entries = NULL; static char geoip_digest[DIGEST_LEN]; static char geoip6_digest[DIGEST_LEN]; +/* Total size in bytes of the geoip client history cache. Used by the OOM + * handler. */ +static size_t geoip_client_history_cache_size; + /** Return the index of the country's entry in the GeoIP * country list if it is a valid 2-letter country code, otherwise * return -1. */ @@ -526,6 +530,15 @@ HT_PROTOTYPE(clientmap, clientmap_entry_t, node, clientmap_entry_hash, HT_GENERATE2(clientmap, clientmap_entry_t, node, clientmap_entry_hash, clientmap_entries_eq, 0.6, tor_reallocarray_, tor_free_) +/** Return the size of a client map entry. */ +static inline size_t +clientmap_entry_size(const clientmap_entry_t *ent) +{ + tor_assert(ent); + return (sizeof(clientmap_entry_t) + + (ent->transport_name ? strlen(ent->transport_name) : 0)); +} + /** Free all storage held by ent. */ static void clientmap_entry_free(clientmap_entry_t *ent) @@ -533,6 +546,8 @@ clientmap_entry_free(clientmap_entry_t *ent) if (!ent) return; + geoip_client_history_cache_size -= clientmap_entry_size(ent); + tor_free(ent->transport_name); tor_free(ent); } @@ -595,6 +610,7 @@ geoip_note_client_seen(geoip_client_action_t action, ent->transport_name = tor_strdup(transport_name); ent->action = (int)action; HT_INSERT(clientmap, &client_history, ent); + geoip_client_history_cache_size += clientmap_entry_size(ent); } if (now / 60 <= (int)MAX_LAST_SEEN_IN_MINUTES && now >= 0) ent->last_seen_in_minutes = (unsigned)(now/60); @@ -635,6 +651,81 @@ geoip_remove_old_clients(time_t cutoff) &cutoff); } +/* Cleanup client entries older than the cutoff. Used for the OOM. Return the + * number of bytes freed. If 0 is returned, nothing was freed. */ +static size_t +oom_clean_client_entries(time_t cutoff) +{ + size_t bytes = 0; + clientmap_entry_t **ent, **ent_next; + + for (ent = HT_START(clientmap, &client_history); ent; ent = ent_next) { + clientmap_entry_t *entry = *ent; + if (entry->last_seen_in_minutes < (cutoff / 60)) { + ent_next = HT_NEXT_RMV(clientmap, &client_history, ent); + bytes += clientmap_entry_size(entry); + clientmap_entry_free(entry); + } else { + ent_next = HT_NEXT(clientmap, &client_history, ent); + } + } + return bytes; +} + +/* Below this minimum lifetime, the OOM won't cleanup any entries. */ +#define GEOIP_CLIENT_CACHE_OOM_MIN_CUTOFF (4 * 60 * 60) +/* The OOM moves the cutoff by that much every run. */ +#define GEOIP_CLIENT_CACHE_OOM_STEP (15 * 50) + +/* Cleanup the geoip client history cache called from the OOM handler. Return + * the amount of bytes removed. This can return a value below or above + * min_remove_bytes but will stop as oon as the min_remove_bytes has been + * reached. */ +size_t +geoip_client_cache_handle_oom(time_t now, size_t min_remove_bytes) +{ + time_t k; + size_t bytes_removed = 0; + + /* Our OOM handler called with 0 bytes to remove is a code flow error. */ + tor_assert(min_remove_bytes != 0); + + /* Set k to the initial cutoff of an entry. We then going to move it by step + * to try to remove as much as we can. */ + k = WRITE_STATS_INTERVAL; + + do { + time_t cutoff; + + /* If k has reached the minimum lifetime, we have to stop else we might + * remove every single entries which would be pretty bad for the DoS + * mitigation subsystem if by just filling the geoip cache, it was enough + * to trigger the OOM and clean every single entries. */ + if (k <= GEOIP_CLIENT_CACHE_OOM_MIN_CUTOFF) { + break; + } + + cutoff = now - k; + bytes_removed += oom_clean_client_entries(cutoff); + k -= GEOIP_CLIENT_CACHE_OOM_STEP; + } while (bytes_removed < min_remove_bytes); + + return bytes_removed; +} + +/* Return the total size in bytes of the client history cache. */ +size_t +geoip_client_cache_total_allocation(void) +{ + size_t bytes = 0; + clientmap_entry_t **ent; + + HT_FOREACH(ent, clientmap, &client_history) { + bytes += clientmap_entry_size(*ent); + } + return bytes; +} + /** How many responses are we giving to clients requesting v3 network * statuses? */ static uint32_t ns_v3_responses[GEOIP_NS_RESPONSE_NUM]; diff --git a/src/or/geoip.h b/src/or/geoip.h index 070296dd0..42d0c1cfd 100644 --- a/src/or/geoip.h +++ b/src/or/geoip.h @@ -33,6 +33,8 @@ void geoip_note_client_seen(geoip_client_action_t action, const tor_addr_t *addr, const char *transport_name, time_t now); void geoip_remove_old_clients(time_t cutoff); +size_t geoip_client_cache_total_allocation(void); +size_t geoip_client_cache_handle_oom(time_t now, size_t min_remove_bytes); void geoip_note_ns_response(geoip_ns_response_t response); char *geoip_get_transport_history(void); diff --git a/src/or/relay.c b/src/or/relay.c index 29f34ca03..22ce76752 100644 --- a/src/or/relay.c +++ b/src/or/relay.c @@ -2469,24 +2469,34 @@ static time_t last_time_under_memory_pressure = 0; STATIC int cell_queues_check_size(void) { + time_t now = time(NULL); size_t alloc = cell_queues_get_total_allocation(); alloc += buf_get_total_allocation(); alloc += tor_zlib_get_total_allocation(); const size_t rend_cache_total = rend_cache_get_total_allocation(); alloc += rend_cache_total; + const size_t geoip_client_cache_total = + geoip_client_cache_total_allocation(); + alloc += geoip_client_cache_total; if (alloc >= get_options()->MaxMemInQueues_low_threshold) { last_time_under_memory_pressure = approx_time(); if (alloc >= get_options()->MaxMemInQueues) { /* If we're spending over 20% of the memory limit on hidden service - * descriptors, free them until we're down to 10%. - */ + * descriptors, free them until we're down to 10%. Do the same for geoip + * client cache. */ if (rend_cache_total > get_options()->MaxMemInQueues / 5) { const size_t bytes_to_remove = rend_cache_total - (size_t)(get_options()->MaxMemInQueues / 10); - rend_cache_clean_v2_descs_as_dir(time(NULL), bytes_to_remove); + rend_cache_clean_v2_descs_as_dir(now, bytes_to_remove); alloc -= rend_cache_total; alloc += rend_cache_get_total_allocation(); } + if (geoip_client_cache_total > get_options()->MaxMemInQueues / 5) { + const size_t bytes_to_remove = + geoip_client_cache_total - + (size_t)(get_options()->MaxMemInQueues / 10); + alloc -= geoip_client_cache_handle_oom(now, bytes_to_remove); + } circuits_handle_oom(alloc); return 1; } diff --git a/src/test/test.c b/src/test/test.c index 9a41b976b..e2fbfd21b 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -912,6 +912,24 @@ test_geoip(void *arg) tt_str_op(entry_stats_2,OP_EQ, s); tor_free(s); + /* Test the OOM handler. Add a client, run the OOM. */ + geoip_entry_stats_init(now); + SET_TEST_ADDRESS(100); + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, &addr, NULL, + now - (12 * 60 * 60)); + /* We've seen this 12 hours ago. Run the OOM, it should clean the entry + * because it is above the minimum cutoff of 4 hours. */ + size_t bytes_removed = geoip_client_cache_handle_oom(now, 1000); + tt_size_op(bytes_removed, OP_GT, 0); + + /* Do it again but this time with an entry with a lower cutoff. */ + geoip_entry_stats_init(now); + SET_TEST_ADDRESS(100); + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, &addr, NULL, + now - (3 * 60 * 60)); + bytes_removed = geoip_client_cache_handle_oom(now, 1000); + tt_size_op(bytes_removed, OP_EQ, 0); + /* Stop collecting entry statistics. */ geoip_entry_stats_term(); get_options_mutable()->EntryStatistics = 0;

1 0

[tor/maint-0.3.1] Merge branch 'ticket25122_029_02' into ticket24902_029_05
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 475218c108ad84aa302f0daec013faab9ff778f2 Merge: 33d9889a2 e758d659a Author: David Goulet <dgoulet(a)torproject.org> Date: Fri Feb 2 14:55:01 2018 -0500 Merge branch 'ticket25122_029_02' into ticket24902_029_05 changes/ticket25122 | 4 ++ src/or/geoip.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++-- src/or/geoip.h | 2 + src/or/relay.c | 16 ++++-- src/test/test.c | 18 +++++++ 5 files changed, 180 insertions(+), 8 deletions(-) diff --cc src/or/geoip.c index 4e4f6e639,76fca43f6..20dad5f15 --- a/src/or/geoip.c +++ b/src/or/geoip.c @@@ -516,9 -574,7 +557,10 @@@ clientmap_entry_free(clientmap_entry_t if (!ent) return; + /* This entry is about to be freed so pass it to the DoS subsystem to see if + * any actions can be taken about it. */ + dos_geoip_entry_about_to_free(ent); + geoip_decrement_client_history_cache_size(clientmap_entry_size(ent)); tor_free(ent->transport_name); tor_free(ent); @@@ -573,13 -651,13 +640,9 @@@ geoip_note_client_seen(geoip_client_act safe_str_client(fmt_addr((addr))), transport_name ? transport_name : "<no transport>"); - tor_addr_copy(&lookup.addr, addr); - lookup.action = (int)action; - lookup.transport_name = (char*) transport_name; - ent = HT_FIND(clientmap, &client_history, &lookup); - + ent = geoip_lookup_client(addr, transport_name, action); if (! ent) { - ent = tor_malloc_zero(sizeof(clientmap_entry_t)); - tor_addr_copy(&ent->addr, addr); - if (transport_name) - ent->transport_name = tor_strdup(transport_name); - ent->action = (int)action; + ent = clientmap_entry_new(action, addr, transport_name); HT_INSERT(clientmap, &client_history, ent); } if (now / 60 <= (int)MAX_LAST_SEEN_IN_MINUTES && now >= 0) @@@ -621,25 -699,81 +684,100 @@@ geoip_remove_old_clients(time_t cutoff &cutoff); } +/* Return a client entry object matching the given address, transport name and + * geoip action from the clientmap. NULL if not found. The transport_name can + * be NULL. */ +clientmap_entry_t * +geoip_lookup_client(const tor_addr_t *addr, const char *transport_name, + geoip_client_action_t action) +{ + clientmap_entry_t lookup; + + tor_assert(addr); + + /* We always look for a client connection with no transport. */ + tor_addr_copy(&lookup.addr, addr); + lookup.action = action; + lookup.transport_name = (char *) transport_name; + + return HT_FIND(clientmap, &client_history, &lookup); +} + + /* Cleanup client entries older than the cutoff. Used for the OOM. Return the + * number of bytes freed. If 0 is returned, nothing was freed. */ + static size_t + oom_clean_client_entries(time_t cutoff) + { + size_t bytes = 0; + clientmap_entry_t **ent, **ent_next; + + for (ent = HT_START(clientmap, &client_history); ent; ent = ent_next) { + clientmap_entry_t *entry = *ent; + if (entry->last_seen_in_minutes < (cutoff / 60)) { + ent_next = HT_NEXT_RMV(clientmap, &client_history, ent); + bytes += clientmap_entry_size(entry); + clientmap_entry_free(entry); + } else { + ent_next = HT_NEXT(clientmap, &client_history, ent); + } + } + return bytes; + } + + /* Below this minimum lifetime, the OOM won't cleanup any entries. */ + #define GEOIP_CLIENT_CACHE_OOM_MIN_CUTOFF (4 * 60 * 60) + /* The OOM moves the cutoff by that much every run. */ + #define GEOIP_CLIENT_CACHE_OOM_STEP (15 * 50) + + /* Cleanup the geoip client history cache called from the OOM handler. Return + * the amount of bytes removed. This can return a value below or above + * min_remove_bytes but will stop as oon as the min_remove_bytes has been + * reached. */ + size_t + geoip_client_cache_handle_oom(time_t now, size_t min_remove_bytes) + { + time_t k; + size_t bytes_removed = 0; + + /* Our OOM handler called with 0 bytes to remove is a code flow error. */ + tor_assert(min_remove_bytes != 0); + + /* Set k to the initial cutoff of an entry. We then going to move it by step + * to try to remove as much as we can. */ + k = WRITE_STATS_INTERVAL; + + do { + time_t cutoff; + + /* If k has reached the minimum lifetime, we have to stop else we might + * remove every single entries which would be pretty bad for the DoS + * mitigation subsystem if by just filling the geoip cache, it was enough + * to trigger the OOM and clean every single entries. */ + if (k <= GEOIP_CLIENT_CACHE_OOM_MIN_CUTOFF) { + break; + } + + cutoff = now - k; + bytes_removed += oom_clean_client_entries(cutoff); + k -= GEOIP_CLIENT_CACHE_OOM_STEP; + } while (bytes_removed < min_remove_bytes); + + return bytes_removed; + } + + /* Return the total size in bytes of the client history cache. */ + size_t + geoip_client_cache_total_allocation(void) + { + size_t bytes = 0; + clientmap_entry_t **ent; + + HT_FOREACH(ent, clientmap, &client_history) { + bytes += clientmap_entry_size(*ent); + } + return bytes; + } + /** How many responses are we giving to clients requesting v3 network * statuses? */ static uint32_t ns_v3_responses[GEOIP_NS_RESPONSE_NUM]; diff --cc src/or/geoip.h index aa0fca50f,42d0c1cfd..c8ea9f85e --- a/src/or/geoip.h +++ b/src/or/geoip.h @@@ -57,9 -33,8 +57,11 @@@ void geoip_note_client_seen(geoip_clien const tor_addr_t *addr, const char *transport_name, time_t now); void geoip_remove_old_clients(time_t cutoff); +clientmap_entry_t *geoip_lookup_client(const tor_addr_t *addr, + const char *transport_name, + geoip_client_action_t action); + size_t geoip_client_cache_total_allocation(void); + size_t geoip_client_cache_handle_oom(time_t now, size_t min_remove_bytes); void geoip_note_ns_response(geoip_ns_response_t response); char *geoip_get_transport_history(void);

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[tor/maint-0.3.1] dos: Add a heartbeat log
by nickm＠torproject.org 16 Feb '18

16 Feb '18

commit 14a8b87852887f8c20a424ff32a2b6746105dd6c Author: David Goulet <dgoulet(a)torproject.org> Date: Thu Jan 25 16:36:05 2018 -0500 dos: Add a heartbeat log Signed-off-by: David Goulet <dgoulet(a)torproject.org> --- src/or/dos.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ src/or/dos.h | 1 + src/or/status.c | 2 ++ 3 files changed, 48 insertions(+) diff --git a/src/or/dos.c b/src/or/dos.c index d98d3db16..40e88aead 100644 --- a/src/or/dos.c +++ b/src/or/dos.c @@ -555,6 +555,51 @@ dos_should_refuse_single_hop_client(void) 0 /* default */, 0, 1); } +/* Log a heartbeat message with some statistics. */ +void +dos_log_heartbeat(void) +{ + char *conn_msg = NULL; + char *cc_msg = NULL; + char *single_hop_client_msg = NULL; + + if (!dos_is_enabled()) { + goto end; + } + + if (dos_cc_enabled) { + tor_asprintf(&cc_msg, + " %" PRIu64 " circuits rejected," + " %" PRIu32 " marked addresses.", + cc_num_rejected_cells, cc_num_marked_addrs); + } + + if (dos_conn_enabled) { + tor_asprintf(&conn_msg, + " %" PRIu64 " connections closed.", + conn_num_addr_rejected); + } + + if (dos_should_refuse_single_hop_client()) { + tor_asprintf(&single_hop_client_msg, + " %" PRIu64 " single hop clients refused.", + num_single_hop_client_refused); + } + + log_notice(LD_HEARTBEAT, + "DoS mitigation since startup:%s%s%s", + (cc_msg != NULL) ? cc_msg : " [cc not enabled]", + (conn_msg != NULL) ? conn_msg : " [conn not enabled]", + (single_hop_client_msg != NULL) ? single_hop_client_msg : ""); + + tor_free(conn_msg); + tor_free(cc_msg); + tor_free(single_hop_client_msg); + + end: + return; +} + /* Called when a new client connection has been established on the given * address. */ void diff --git a/src/or/dos.h b/src/or/dos.h index ec4c033ae..56835169d 100644 --- a/src/or/dos.h +++ b/src/or/dos.h @@ -47,6 +47,7 @@ void dos_init(void); void dos_free_all(void); void dos_consensus_has_changed(const networkstatus_t *ns); int dos_enabled(void); +void dos_log_heartbeat(void); void dos_new_client_conn(or_connection_t *or_conn); void dos_close_client_conn(const or_connection_t *or_conn); diff --git a/src/or/status.c b/src/or/status.c index fce6a1015..fa2238b9f 100644 --- a/src/or/status.c +++ b/src/or/status.c @@ -27,6 +27,7 @@ #include "hibernate.h" #include "rephist.h" #include "statefile.h" +#include "dos.h" static void log_accounting(const time_t now, const or_options_t *options); #include "geoip.h" @@ -145,6 +146,7 @@ log_heartbeat(time_t now) if (public_server_mode(options)) { rep_hist_log_circuit_handshake_stats(now); rep_hist_log_link_protocol_counts(); + dos_log_heartbeat(); } circuit_log_ancient_one_hop_circuits(1800);

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