diff --git a/changes/bug4862 b/changes/bug4862
new file mode 100644
index 0000000000..e636395be3
--- /dev/null
+++ b/changes/bug4862
@@ -0,0 +1,8 @@
+ o Major feature (Hidden Service):
+ - Remove the introduction point adaptative algorithm which is leaking
+ popularity by changing the amount of introduction points depending on
+ the amount of traffic the HS sees. With this, we stick to only 3
+ introduction points.
+ - Add the torrc option HiddenServiceNumIntroductionPoints for an
+ operatory to specify a fix amount of introduction points. Maximum
+ value is 10 and default is 3.
diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index e7c08f5046..6cfad56f08 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -2177,6 +2177,10 @@ The following options are used to configure a hidden service.
only owner is able to read the hidden service directory. (Default: 0)
Has no effect on Windows.
+[[HiddenServiceNumIntroductionPoints]] **HiddenServiceNumIntroductionPoints** __NUM__::
+ Number of introduction points the hidden service will have. You can't
+ have more than 10. (Default: 3)
+
TESTING NETWORK OPTIONS
-----------------------
diff --git a/src/or/config.c b/src/or/config.c
index d81bc532b7..0d6c3003ff 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -288,6 +288,7 @@ static config_var_t option_vars_[] = {
VAR("HiddenServiceAllowUnknownPorts",LINELIST_S, RendConfigLines, NULL),
VAR("HiddenServiceMaxStreams",LINELIST_S, RendConfigLines, NULL),
VAR("HiddenServiceMaxStreamsCloseCircuit",LINELIST_S, RendConfigLines, NULL),
+ VAR("HiddenServiceNumIntroductionPoints", LINELIST_S, RendConfigLines, NULL),
V(HiddenServiceStatistics, BOOL, "0"),
V(HidServAuth, LINELIST, NULL),
V(CloseHSClientCircuitsImmediatelyOnTimeout, BOOL, "0"),
diff --git a/src/or/directory.c b/src/or/directory.c
index 549d95a13c..8d7f9f4dea 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -23,6 +23,7 @@
#include "relay.h"
#include "rendclient.h"
#include "rendcommon.h"
+#include "rendservice.h"
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
@@ -2196,6 +2197,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
"Uploading rendezvous descriptor: finished with status "
"200 (%s)", escaped(reason));
control_event_hs_descriptor_uploaded(conn->identity_digest);
+ rend_service_desc_has_uploaded(conn->rend_data);
break;
case 400:
log_warn(LD_REND,"http status 400 (%s) response from dirserver "
diff --git a/src/or/or.h b/src/or/or.h
index 431105b09b..946e7e0def 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -4875,6 +4875,11 @@ typedef struct rend_encoded_v2_service_descriptor_t {
* XXX023 Should this be configurable? */
#define INTRO_POINT_LIFETIME_MAX_SECONDS (24*60*60)
+/** The maximum number of circuit creation retry we do to an intro point
+ * before giving up. We try to reuse intro point that fails during their
+ * lifetime so this is a hard limit on the amount of time we do that. */
+#define MAX_INTRO_POINT_CIRCUIT_RETRIES 3
+
/** Introduction point information. Used both in rend_service_t (on
* the service side) and in rend_service_descriptor_t (on both the
* client and service side). */
@@ -4899,11 +4904,6 @@ typedef struct rend_intro_point_t {
* included in the last HS descriptor we generated. */
unsigned int listed_in_last_desc : 1;
- /** (Service side only) Flag indicating that
- * rend_service_note_removing_intro_point has been called for this
- * intro point. */
- unsigned int rend_service_note_removing_intro_point_called : 1;
-
/** (Service side only) A replay cache recording the RSA-encrypted parts
* of INTRODUCE2 cells this intro point's circuit has received. This is
* used to prevent replay attacks. */
@@ -4930,15 +4930,16 @@ typedef struct rend_intro_point_t {
* point should expire. */
time_t time_to_expire;
- /** (Service side only) The time at which we decided that this intro
- * point should start expiring, or -1 if this intro point is not yet
- * expiring.
- *
- * This field also serves as a flag to indicate that we have decided
- * to expire this intro point, in case intro_point_should_expire_now
- * flaps (perhaps due to a clock jump; perhaps due to other
- * weirdness, or even a (present or future) bug). */
- time_t time_expiring;
+ /** (Service side only) The amount of circuit creation we've made to this
+ * intro point. This is incremented every time we do a circuit relaunch on
+ * this object which is triggered when the circuit dies but the node is
+ * still in the consensus. After MAX_INTRO_POINT_CIRCUIT_RETRIES, we give
+ * up on it. */
+ unsigned int circuit_retries;
+
+ /** (Service side only) Set if this intro point has an established circuit
+ * and unset if it doesn't. */
+ unsigned int circuit_established:1;
} rend_intro_point_t;
#define REND_PROTOCOL_VERSION_BITMASK_WIDTH 16
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index 89f95d7a00..f4fb860078 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -31,9 +31,12 @@
#include "routerparse.h"
#include "routerset.h"
+struct rend_service_t;
static origin_circuit_t *find_intro_circuit(rend_intro_point_t *intro,
const char *pk_digest);
static rend_intro_point_t *find_intro_point(origin_circuit_t *circ);
+static rend_intro_point_t *find_expiring_intro_point(
+ struct rend_service_t *service, origin_circuit_t *circ);
static extend_info_t *find_rp_for_intro(
const rend_intro_cell_t *intro,
@@ -42,7 +45,6 @@ static extend_info_t *find_rp_for_intro(
static int intro_point_accepted_intro_count(rend_intro_point_t *intro);
static int intro_point_should_expire_now(rend_intro_point_t *intro,
time_t now);
-struct rend_service_t;
static int rend_service_derive_key_digests(struct rend_service_t *s);
static int rend_service_load_keys(struct rend_service_t *s);
static int rend_service_load_auth_keys(struct rend_service_t *s,
@@ -87,8 +89,11 @@ struct rend_service_port_config_s {
/** Try to maintain this many intro points per service by default. */
#define NUM_INTRO_POINTS_DEFAULT 3
-/** Maintain no more than this many intro points per hidden service. */
+/** Maximum number of intro points per service. */
#define NUM_INTRO_POINTS_MAX 10
+/** Number of extra intro points we launch if our set of intro nodes is
+ * empty. See proposal 155, section 4. */
+#define NUM_INTRO_POINTS_EXTRA 2
/** If we can't build our intro circuits, don't retry for this long. */
#define INTRO_CIRC_RETRY_PERIOD (60*5)
@@ -102,10 +107,6 @@ struct rend_service_port_config_s {
* rendezvous point before giving up? */
#define MAX_REND_TIMEOUT 30
-/** How many seconds should we wait for new HS descriptors to reach
- * our clients before we close an expiring intro point? */
-#define INTRO_POINT_EXPIRATION_GRACE_PERIOD (5*60)
-
/** Represents a single hidden service running at this OP. */
typedef struct rend_service_t {
/* Fields specified in config file */
@@ -126,6 +127,10 @@ typedef struct rend_service_t {
char pk_digest[DIGEST_LEN]; /**< Hash of permanent hidden-service key. */
smartlist_t *intro_nodes; /**< List of rend_intro_point_t's we have,
* or are trying to establish. */
+ /** List of rend_intro_point_t that are expiring. They are removed once
+ * the new descriptor is successfully uploaded. A node in this list CAN
+ * NOT appear in the intro_nodes list. */
+ smartlist_t *expiring_nodes;
time_t intro_period_started; /**< Start of the current period to build
* introduction points. */
int n_intro_circuits_launched; /**< Count of intro circuits we have
@@ -177,17 +182,6 @@ num_rend_services(void)
return smartlist_len(rend_service_list);
}
-/** Return a string identifying service, suitable for use in a
- * log message. The result does not need to be freed, but may be
- * overwritten by the next call to this function. */
-static const char *
-rend_service_describe_for_log(rend_service_t *service)
-{
- /* XXX024 Use this function throughout rendservice.c. */
- /* XXX024 Return a more useful description? */
- return safe_str_client(service->service_id);
-}
-
/** Helper: free storage held by a single service authorized client entry. */
static void
rend_authorized_client_free(rend_authorized_client_t *client)
@@ -228,6 +222,11 @@ rend_service_free(rend_service_t *service)
rend_intro_point_free(intro););
smartlist_free(service->intro_nodes);
}
+ if (service->expiring_nodes) {
+ SMARTLIST_FOREACH(service->expiring_nodes, rend_intro_point_t *, intro,
+ rend_intro_point_free(intro););
+ smartlist_free(service->expiring_nodes);
+ }
rend_service_descriptor_free(service->desc);
if (service->clients) {
@@ -265,6 +264,7 @@ rend_add_service(rend_service_t *service)
rend_service_port_config_t *p;
service->intro_nodes = smartlist_new();
+ service->expiring_nodes = smartlist_new();
if (service->max_streams_per_circuit < 0) {
log_warn(LD_CONFIG, "Hidden service (%s) configured with negative max "
@@ -590,7 +590,22 @@ rend_config_services(const or_options_t *options, int validate_only)
log_info(LD_CONFIG,
"HiddenServiceMaxStreamsCloseCircuit=%d for %s",
(int)service->max_streams_close_circuit, service->directory);
-
+ } else if (!strcasecmp(line->key, "HiddenServiceNumIntroductionPoints")) {
+ service->n_intro_points_wanted =
+ (unsigned int) tor_parse_long(line->value, 10,
+ NUM_INTRO_POINTS_DEFAULT,
+ NUM_INTRO_POINTS_MAX, &ok, NULL);
+ if (!ok) {
+ log_warn(LD_CONFIG,
+ "HiddenServiceNumIntroductionPoints "
+ "should be between %d and %d, not %s",
+ NUM_INTRO_POINTS_DEFAULT, NUM_INTRO_POINTS_MAX,
+ line->value);
+ rend_service_free(service);
+ return -1;
+ }
+ log_info(LD_CONFIG, "HiddenServiceNumIntroductionPoints=%d for %s",
+ service->n_intro_points_wanted, service->directory);
} else if (!strcasecmp(line->key, "HiddenServiceAuthorizeClient")) {
/* Parse auth type and comma-separated list of client names and add a
* rend_authorized_client_t for each client to the service's list
@@ -765,6 +780,8 @@ rend_config_services(const or_options_t *options, int validate_only)
!strcmp(old->directory, new->directory)) {
smartlist_add_all(new->intro_nodes, old->intro_nodes);
smartlist_clear(old->intro_nodes);
+ smartlist_add_all(new->expiring_nodes, old->expiring_nodes);
+ smartlist_clear(old->expiring_nodes);
smartlist_add(surviving_services, old);
break;
}
@@ -956,11 +973,6 @@ rend_service_update_descriptor(rend_service_t *service)
/* This intro point won't be listed in the descriptor... */
intro_svc->listed_in_last_desc = 0;
- if (intro_svc->time_expiring != -1) {
- /* This intro point is expiring. Don't list it. */
- continue;
- }
-
circ = find_intro_circuit(intro_svc, service->pk_digest);
if (!circ || circ->base_.purpose != CIRCUIT_PURPOSE_S_INTRO) {
/* This intro point's circuit isn't finished yet. Don't list it. */
@@ -1417,107 +1429,6 @@ rend_check_authorization(rend_service_t *service,
return 1;
}
-/** Called when intro will soon be removed from
- * service's list of intro points. */
-static void
-rend_service_note_removing_intro_point(rend_service_t *service,
- rend_intro_point_t *intro)
-{
- time_t now = time(NULL);
-
- /* Don't process an intro point twice here. */
- if (intro->rend_service_note_removing_intro_point_called) {
- return;
- } else {
- intro->rend_service_note_removing_intro_point_called = 1;
- }
-
- /* Update service->n_intro_points_wanted based on how long intro
- * lasted and how many introductions it handled. */
- if (intro->time_published == -1) {
- /* This intro point was never used. Don't change
- * n_intro_points_wanted. */
- } else {
-
- /* We want to increase the number of introduction points service
- * operates if intro was heavily used, or decrease the number of
- * intro points if intro was lightly used.
- *
- * We consider an intro point's target 'usage' to be
- * maximum of INTRODUCE2 cells divided by
- * INTRO_POINT_LIFETIME_MIN_SECONDS seconds. To calculate intro's
- * fraction of target usage, we divide the amount of INTRODUCE2 cells
- * that it has handled by the fraction of _LIFETIME_MIN_SECONDS for
- * which it existed.
- *
- * Then we multiply that fraction of desired usage by a fudge
- * factor of 1.5, to decide how many new introduction points
- * should ideally replace intro (which is now closed or soon to be
- * closed). In theory, assuming that introduction load is
- * distributed equally across all intro points and ignoring the
- * fact that different intro points are established and closed at
- * different times, that number of intro points should bring all
- * of our intro points exactly to our target usage.
- *
- * Then we clamp that number to a number of intro points we might
- * be willing to replace this intro point with and turn it into an
- * integer. then we clamp it again to the number of new intro
- * points we could establish now, then we adjust
- * service->n_intro_points_wanted and let rend_services_introduce
- * create the new intro points we want (if any).
- */
- const double intro_point_usage =
- intro_point_accepted_intro_count(intro) /
- (double)(now - intro->time_published);
- const double intro_point_target_usage =
- intro->max_introductions /
- (double)INTRO_POINT_LIFETIME_MIN_SECONDS;
- const double fractional_n_intro_points_wanted_to_replace_this_one =
- (1.5 * (intro_point_usage / intro_point_target_usage));
- unsigned int n_intro_points_wanted_to_replace_this_one;
- unsigned int n_intro_points_wanted_now;
- unsigned int n_intro_points_really_wanted_now;
- int n_intro_points_really_replacing_this_one;
-
- if (fractional_n_intro_points_wanted_to_replace_this_one >
- NUM_INTRO_POINTS_MAX) {
- n_intro_points_wanted_to_replace_this_one = NUM_INTRO_POINTS_MAX;
- } else if (fractional_n_intro_points_wanted_to_replace_this_one < 0) {
- n_intro_points_wanted_to_replace_this_one = 0;
- } else {
- n_intro_points_wanted_to_replace_this_one = (unsigned)
- fractional_n_intro_points_wanted_to_replace_this_one;
- }
-
- n_intro_points_wanted_now =
- service->n_intro_points_wanted +
- n_intro_points_wanted_to_replace_this_one - 1;
-
- if (n_intro_points_wanted_now < NUM_INTRO_POINTS_DEFAULT) {
- /* XXXX This should be NUM_INTRO_POINTS_MIN instead. Perhaps
- * another use of NUM_INTRO_POINTS_DEFAULT should be, too. */
- n_intro_points_really_wanted_now = NUM_INTRO_POINTS_DEFAULT;
- } else if (n_intro_points_wanted_now > NUM_INTRO_POINTS_MAX) {
- n_intro_points_really_wanted_now = NUM_INTRO_POINTS_MAX;
- } else {
- n_intro_points_really_wanted_now = n_intro_points_wanted_now;
- }
-
- n_intro_points_really_replacing_this_one =
- n_intro_points_really_wanted_now - service->n_intro_points_wanted + 1;
-
- log_info(LD_REND, "Replacing closing intro point for service %s "
- "with %d new intro points (wanted %g replacements); "
- "service will now try to have %u intro points",
- rend_service_describe_for_log(service),
- n_intro_points_really_replacing_this_one,
- fractional_n_intro_points_wanted_to_replace_this_one,
- n_intro_points_really_wanted_now);
-
- service->n_intro_points_wanted = n_intro_points_really_wanted_now;
- }
-}
-
/******
* Handle cells
******/
@@ -1594,12 +1505,15 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
intro_point = find_intro_point(circuit);
if (intro_point == NULL) {
- log_warn(LD_BUG,
- "Internal error: Got an INTRODUCE2 cell on an "
- "intro circ (for service %s) with no corresponding "
- "rend_intro_point_t.",
- escaped(serviceid));
- goto err;
+ intro_point = find_expiring_intro_point(service, circuit);
+ if (intro_point == NULL) {
+ log_warn(LD_BUG,
+ "Internal error: Got an INTRODUCE2 cell on an "
+ "intro circ (for service %s) with no corresponding "
+ "rend_intro_point_t.",
+ escaped(serviceid));
+ goto err;
+ }
}
log_info(LD_REND, "Received INTRODUCE2 cell for service %s on circ %u.",
@@ -2779,12 +2693,27 @@ rend_service_launch_establish_intro(rend_service_t *service,
return 0;
}
-/** Return the number of introduction points that are or have been
- * established for the given service address in query. */
-static int
-count_established_intro_points(const char *query)
+/** Return the number of introduction points that are established for the
+ * given service. */
+static unsigned int
+count_established_intro_points(const rend_service_t *service)
{
- int num_ipos = 0;
+ unsigned int num = 0;
+
+ SMARTLIST_FOREACH(service->intro_nodes, rend_intro_point_t *, intro,
+ num += intro->circuit_established
+ );
+ return num;
+}
+
+/** Return the number of introduction points that are or are being
+ * established for the given service. This function iterates over all
+ * circuit and count those that are linked to the service and are waiting
+ * for the intro point to respond. */
+static unsigned int
+count_intro_point_circuits(const rend_service_t *service)
+{
+ unsigned int num_ipos = 0;
SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
if (!circ->marked_for_close &&
circ->state == CIRCUIT_STATE_OPEN &&
@@ -2792,7 +2721,8 @@ count_established_intro_points(const char *query)
circ->purpose == CIRCUIT_PURPOSE_S_INTRO)) {
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ);
if (oc->rend_data &&
- !rend_cmp_service_ids(query, oc->rend_data->onion_address))
+ !rend_cmp_service_ids(service->service_id,
+ oc->rend_data->onion_address))
num_ipos++;
}
}
@@ -2835,10 +2765,21 @@ rend_service_intro_has_opened(origin_circuit_t *circuit)
}
/* If we already have enough introduction circuits for this service,
- * redefine this one as a general circuit or close it, depending. */
- if (count_established_intro_points(serviceid) >
- (int)service->n_intro_points_wanted) { /* XXX023 remove cast */
+ * redefine this one as a general circuit or close it, depending.
+ * Substract the amount of expiring nodes here since the circuits are
+ * still opened. */
+ if ((count_intro_point_circuits(service) -
+ smartlist_len(service->expiring_nodes)) >
+ service->n_intro_points_wanted) {
const or_options_t *options = get_options();
+ /* Remove the intro point associated with this circuit, it's being
+ * repurposed or closed thus cleanup memory. */
+ rend_intro_point_t *intro = find_intro_point(circuit);
+ if (intro != NULL) {
+ smartlist_remove(service->intro_nodes, intro);
+ rend_intro_point_free(intro);
+ }
+
if (options->ExcludeNodes) {
/* XXXX in some future version, we can test whether the transition is
allowed or not given the actual nodes in the circuit. But for now,
@@ -2937,6 +2878,7 @@ rend_service_intro_established(origin_circuit_t *circuit,
size_t request_len)
{
rend_service_t *service;
+ rend_intro_point_t *intro;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
(void) request;
(void) request_len;
@@ -2954,6 +2896,19 @@ rend_service_intro_established(origin_circuit_t *circuit,
(unsigned)circuit->base_.n_circ_id);
goto err;
}
+ /* We've just successfully established a intro circuit to one of our
+ * introduction point, account for it. */
+ intro = find_intro_point(circuit);
+ if (intro == NULL) {
+ log_warn(LD_REND,
+ "Introduction circuit established without a rend_intro_point_t "
+ "object for service %s on circuit %u",
+ safe_str_client(serviceid), (unsigned)circuit->base_.n_circ_id);
+ goto err;
+ }
+ intro->circuit_established = 1;
+ /* We might not have every introduction point ready but at this point we
+ * know that the descriptor needs to be uploaded. */
service->desc_is_dirty = time(NULL);
circuit_change_purpose(TO_CIRCUIT(circuit), CIRCUIT_PURPOSE_S_INTRO);
@@ -3128,6 +3083,23 @@ find_intro_circuit(rend_intro_point_t *intro, const char *pk_digest)
return NULL;
}
+/** Return the corresponding introdution point using the circuit circ
+ * found in the service. NULL is returned if not found. */
+static rend_intro_point_t *
+find_expiring_intro_point(rend_service_t *service, origin_circuit_t *circ)
+{
+ tor_assert(service);
+ tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
+ TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_INTRO);
+
+ SMARTLIST_FOREACH(service->intro_nodes, rend_intro_point_t *, intro_point,
+ if (crypto_pk_eq_keys(intro_point->intro_key, circ->intro_key)) {
+ return intro_point;
+ });
+
+ return NULL;
+}
+
/** Return a pointer to the rend_intro_point_t corresponding to the
* service-side introduction circuit circ. */
static rend_intro_point_t *
@@ -3194,6 +3166,7 @@ directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
char *hs_dir_ip;
const node_t *node;
+ rend_data_t *rend_data;
hs_dir = smartlist_get(responsible_dirs, j);
if (smartlist_contains_digest(renddesc->successful_uploads,
hs_dir->identity_digest))
@@ -3209,12 +3182,19 @@ directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
continue;
}
/* Send publish request. */
- directory_initiate_command_routerstatus(hs_dir,
- DIR_PURPOSE_UPLOAD_RENDDESC_V2,
- ROUTER_PURPOSE_GENERAL,
- DIRIND_ANONYMOUS, NULL,
- desc->desc_str,
- strlen(desc->desc_str), 0);
+
+ /* We need the service ID to identify which service did the upload
+ * request. Lookup is made in rend_service_desc_has_uploaded(). */
+ rend_data = rend_data_client_create(service_id, desc->desc_id, NULL,
+ REND_NO_AUTH);
+ directory_initiate_command_routerstatus_rend(hs_dir,
+ DIR_PURPOSE_UPLOAD_RENDDESC_V2,
+ ROUTER_PURPOSE_GENERAL,
+ DIRIND_ANONYMOUS, NULL,
+ desc->desc_str,
+ strlen(desc->desc_str),
+ 0, rend_data);
+ rend_data_free(rend_data);
base32_encode(desc_id_base32, sizeof(desc_id_base32),
desc->desc_id, DIGEST_LEN);
hs_dir_ip = tor_dup_ip(hs_dir->addr);
@@ -3397,12 +3377,6 @@ intro_point_should_expire_now(rend_intro_point_t *intro,
return 0;
}
- if (intro->time_expiring != -1) {
- /* We've already started expiring this intro point. *Don't* let
- * this function's result 'flap'. */
- return 1;
- }
-
if (intro_point_accepted_intro_count(intro) >=
intro->max_introductions) {
/* This intro point has been used too many times. Expire it now. */
@@ -3428,48 +3402,162 @@ intro_point_should_expire_now(rend_intro_point_t *intro,
return (now >= intro->time_to_expire);
}
+/** Iterate over intro points in the given service and remove the invalid
+ * ones. For an intro point object to be considered invalid, the circuit
+ * _and_ node need to have disappeared.
+ *
+ * If the intro point should expire, it's placed into the expiring_nodes
+ * list of the service and removed from the active intro nodes list.
+ *
+ * If exclude_nodes is not NULL, add the valid nodes to it.
+ *
+ * If retry_nodes is not NULL, add the valid node to it if the
+ * circuit disappeared but the node is still in the consensus. */
+static void
+remove_invalid_intro_points(rend_service_t *service,
+ smartlist_t *exclude_nodes,
+ smartlist_t *retry_nodes, time_t now)
+{
+ tor_assert(service);
+
+ SMARTLIST_FOREACH_BEGIN(service->intro_nodes, rend_intro_point_t *,
+ intro) {
+ /* Find the introduction point node object. */
+ const node_t *node =
+ node_get_by_id(intro->extend_info->identity_digest);
+ /* Find the intro circuit, this might be NULL. */
+ origin_circuit_t *intro_circ =
+ find_intro_circuit(intro, service->pk_digest);
+
+ /* Add the valid node to the exclusion list so we don't try to establish
+ * an introduction point to it again. */
+ if (node && exclude_nodes) {
+ smartlist_add(exclude_nodes, (void*) node);
+ }
+
+ /* First, make sure we still have a valid circuit for this intro point.
+ * If we dont, we'll give up on it and make a new one. */
+ if (intro_circ == NULL) {
+ log_info(LD_REND, "Attempting to retry on %s as intro point for %s"
+ " (circuit disappeared).",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* We've lost the circuit for this intro point, flag it so it can be
+ * accounted for when considiring uploading a descriptor. */
+ intro->circuit_established = 0;
+
+ /* Node is gone or we've reached our maximum circuit creationg retry
+ * count, clean up everything, we'll find a new one. */
+ if (node == NULL ||
+ intro->circuit_retries >= MAX_INTRO_POINT_CIRCUIT_RETRIES) {
+ rend_intro_point_free(intro);
+ SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
+ /* We've just killed the intro point, nothing left to do. */
+ continue;
+ }
+
+ /* The intro point is still alive so let's try to use it again because
+ * we have a published descriptor containing it. Keep the intro point
+ * in the intro_nodes list because it's still valid, we are rebuilding
+ * a circuit to it. */
+ if (retry_nodes) {
+ smartlist_add(retry_nodes, intro);
+ }
+ }
+ /* else, the circuit is valid so in both cases, node being alive or not,
+ * we leave the circuit and intro point object as is. Closing the
+ * circuit here would leak new consensus timing and freeing the intro
+ * point object would make the intro circuit unusable. */
+
+ /* Now, check if intro point should expire. If it does, queue it so
+ * it can be cleaned up once it has been replaced properly. */
+ if (intro_point_should_expire_now(intro, now)) {
+ log_info(LD_REND, "Expiring %s as intro point for %s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ smartlist_add(service->expiring_nodes, intro);
+ SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
+ /* Intro point is expired, we need a new one thus don't consider it
+ * anymore has a valid established intro point. */
+ intro->circuit_established = 0;
+ }
+ } SMARTLIST_FOREACH_END(intro);
+}
+
+/** A new descriptor has been successfully uploaded for the given
+ * rend_data. Remove and free the expiring nodes from the associated
+ * service. */
+void
+rend_service_desc_has_uploaded(const rend_data_t *rend_data)
+{
+ rend_service_t *service;
+
+ tor_assert(rend_data);
+
+ service = rend_service_get_by_service_id(rend_data->onion_address);
+ if (service == NULL) {
+ log_warn(LD_REND, "Service %s not found after descriptor upload",
+ safe_str_client(rend_data->onion_address));
+ return;
+ }
+
+ SMARTLIST_FOREACH_BEGIN(service->expiring_nodes, rend_intro_point_t *,
+ intro) {
+ origin_circuit_t *intro_circ =
+ find_intro_circuit(intro, service->pk_digest);
+ if (intro_circ != NULL) {
+ circuit_mark_for_close(TO_CIRCUIT(intro_circ),
+ END_CIRC_REASON_FINISHED);
+ }
+ SMARTLIST_DEL_CURRENT(service->expiring_nodes, intro);
+ rend_intro_point_free(intro);
+ } SMARTLIST_FOREACH_END(intro);
+}
+
/** For every service, check how many intro points it currently has, and:
+ * - Invalidate introdution points based on specific criteria, see
+ * remove_invalid_intro_points comments.
* - Pick new intro points as necessary.
* - Launch circuits to any new intro points.
+ *
+ * This is called once a second by the main loop.
*/
void
rend_services_introduce(void)
{
- int i,j,r;
- const node_t *node;
- rend_service_t *service;
- rend_intro_point_t *intro;
- int intro_point_set_changed, prev_intro_nodes;
- unsigned int n_intro_points_unexpired;
- unsigned int n_intro_points_to_open;
+ int i;
time_t now;
const or_options_t *options = get_options();
- /* List of nodes we need to _exclude_ when choosing a new node to establish
- * an intro point to. */
+ /* List of nodes we need to _exclude_ when choosing a new node to
+ * establish an intro point to. */
smartlist_t *exclude_nodes;
+ /* List of nodes we need to retry to build a circuit on them because the
+ * node is valid but circuit died. */
+ smartlist_t *retry_nodes;
if (!have_completed_a_circuit())
return;
exclude_nodes = smartlist_new();
+ retry_nodes = smartlist_new();
now = time(NULL);
- for (i=0; i < smartlist_len(rend_service_list); ++i) {
+ SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, service) {
+ int r;
+ /* Number of intro points we want to open and add to the intro nodes
+ * list of the service. */
+ unsigned int n_intro_points_to_open;
+ /* Have an unsigned len so we can use it to compare values else gcc is
+ * not happy with unmatching signed comparaison. */
+ unsigned int intro_nodes_len;
+ /* Different service are allowed to have the same introduction point as
+ * long as they are on different circuit thus why we clear this list. */
smartlist_clear(exclude_nodes);
- service = smartlist_get(rend_service_list, i);
+ smartlist_clear(retry_nodes);
- tor_assert(service);
-
- /* intro_point_set_changed becomes non-zero iff the set of intro
- * points to be published in service's descriptor has changed. */
- intro_point_set_changed = 0;
-
- /* n_intro_points_unexpired collects the number of non-expiring
- * intro points we have, so that we know how many new intro
- * circuits we need to launch for this service. */
- n_intro_points_unexpired = 0;
-
- if (now > service->intro_period_started+INTRO_CIRC_RETRY_PERIOD) {
+ /* This retry period is important here so we don't stress circuit
+ * creation. */
+ if (now > service->intro_period_started + INTRO_CIRC_RETRY_PERIOD) {
/* One period has elapsed; we can try building circuits again. */
service->intro_period_started = now;
service->n_intro_circuits_launched = 0;
@@ -3480,116 +3568,58 @@ rend_services_introduce(void)
continue;
}
- /* Find out which introduction points we have in progress for this
- service. */
- SMARTLIST_FOREACH_BEGIN(service->intro_nodes, rend_intro_point_t *,
- intro) {
- origin_circuit_t *intro_circ =
- find_intro_circuit(intro, service->pk_digest);
+ /* Cleanup the invalid intro points and save the node objects, if apply,
+ * in the exclude_nodes and retry_nodes list. */
+ remove_invalid_intro_points(service, exclude_nodes, retry_nodes, now);
- if (intro->time_expiring + INTRO_POINT_EXPIRATION_GRACE_PERIOD > now) {
- /* This intro point has completely expired. Remove it, and
- * mark the circuit for close if it's still alive. */
- if (intro_circ != NULL &&
- intro_circ->base_.purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
- circuit_mark_for_close(TO_CIRCUIT(intro_circ),
- END_CIRC_REASON_FINISHED);
- }
+ /* Let's try to rebuild circuit on the nodes we want to retry on. */
+ SMARTLIST_FOREACH_BEGIN(retry_nodes, rend_intro_point_t *, intro) {
+ r = rend_service_launch_establish_intro(service, intro);
+ if (r < 0) {
+ log_warn(LD_REND, "Error launching circuit to node %s for service %s.",
+ safe_str_client(extend_info_describe(intro->extend_info)),
+ safe_str_client(service->service_id));
+ /* Unable to launch a circuit to that intro point, remove it from
+ * the valid list so we can create a new one. */
+ smartlist_remove(service->intro_nodes, intro);
rend_intro_point_free(intro);
- intro = NULL; /* SMARTLIST_DEL_CURRENT takes a name, not a value. */
- SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
- /* We don't need to set intro_point_set_changed here, because
- * this intro point wouldn't have been published in a current
- * descriptor anyway. */
continue;
}
-
- node = node_get_by_id(intro->extend_info->identity_digest);
- if (!node || !intro_circ) {
- int removing_this_intro_point_changes_the_intro_point_set = 1;
- log_info(LD_REND, "Giving up on %s as intro point for %s"
- " (circuit disappeared).",
- safe_str_client(extend_info_describe(intro->extend_info)),
- safe_str_client(service->service_id));
- rend_service_note_removing_intro_point(service, intro);
- if (intro->time_expiring != -1) {
- log_info(LD_REND, "We were already expiring the intro point; "
- "no need to mark the HS descriptor as dirty over this.");
- removing_this_intro_point_changes_the_intro_point_set = 0;
- } else if (intro->listed_in_last_desc) {
- log_info(LD_REND, "The intro point we are giving up on was "
- "included in the last published descriptor. "
- "Marking current descriptor as dirty.");
- service->desc_is_dirty = now;
- }
- rend_intro_point_free(intro);
- intro = NULL; /* SMARTLIST_DEL_CURRENT takes a name, not a value. */
- SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
- if (removing_this_intro_point_changes_the_intro_point_set)
- intro_point_set_changed = 1;
- }
-
- if (intro != NULL && intro_point_should_expire_now(intro, now)) {
- log_info(LD_REND, "Expiring %s as intro point for %s.",
- safe_str_client(extend_info_describe(intro->extend_info)),
- safe_str_client(service->service_id));
-
- rend_service_note_removing_intro_point(service, intro);
-
- /* The polite (and generally Right) way to expire an intro
- * point is to establish a new one to replace it, publish a
- * new descriptor that doesn't list any expiring intro points,
- * and *then*, once our upload attempts for the new descriptor
- * have ended (whether in success or failure), close the
- * expiring intro points.
- *
- * Unfortunately, we can't find out when the new descriptor
- * has actually been uploaded, so we'll have to settle for a
- * five-minute timer. Start it. XXXX024 This sucks. */
- intro->time_expiring = now;
-
- intro_point_set_changed = 1;
- }
-
- if (intro != NULL && intro->time_expiring == -1)
- ++n_intro_points_unexpired;
-
- /* Add the valid node to the exclusion list so we don't try to establish
- * an introduction point to it again. */
- if (node)
- smartlist_add(exclude_nodes, (void*)node);
+ intro->circuit_retries++;
} SMARTLIST_FOREACH_END(intro);
- if (!intro_point_set_changed &&
- (n_intro_points_unexpired >= service->n_intro_points_wanted)) {
+ /* Avoid mismatched signed comparaison below. */
+ intro_nodes_len = (unsigned int) smartlist_len(service->intro_nodes);
+
+ /* Quiescent state, no node expiring and we have more or the amount of
+ * wanted node for this service. Proceed to the next service. Could be
+ * more because we launch two preemptive circuits if our intro nodes
+ * list is empty. */
+ if (smartlist_len(service->expiring_nodes) == 0 &&
+ intro_nodes_len >= service->n_intro_points_wanted) {
continue;
}
- /* Remember how many introduction circuits we started with.
- *
- * prev_intro_nodes serves a different purpose than
- * n_intro_points_unexpired -- this variable tells us where our
- * previously-created intro points end and our new ones begin in
- * the intro-point list, so we don't have to launch the circuits
- * at the same time as we create the intro points they correspond
- * to. XXXX This is daft. */
- prev_intro_nodes = smartlist_len(service->intro_nodes);
+ /* Number of intro points we want to open which is the wanted amount
+ * minus the current amount of valid nodes. */
+ n_intro_points_to_open = service->n_intro_points_wanted - intro_nodes_len;
+ if (intro_nodes_len == 0) {
+ /* We want to end up with n_intro_points_wanted intro points, but if
+ * we have no intro points at all (chances are they all cycled or we
+ * are starting up), we launch NUM_INTRO_POINTS_EXTRA extra circuits
+ * and use the first n_intro_points_wanted that complete. See proposal
+ * #155, section 4 for the rationale of this which is purely for
+ * performance.
+ *
+ * The ones after the first n_intro_points_to_open will be converted
+ * to 'general' internal circuits in rend_service_intro_has_opened(),
+ * and then we'll drop them from the list of intro points. */
+ n_intro_points_to_open += NUM_INTRO_POINTS_EXTRA;
+ }
- /* We have enough directory information to start establishing our
- * intro points. We want to end up with n_intro_points_wanted
- * intro points, but if we're just starting, we launch two extra
- * circuits and use the first n_intro_points_wanted that complete.
- *
- * The ones after the first three will be converted to 'general'
- * internal circuits in rend_service_intro_has_opened(), and then
- * we'll drop them from the list of intro points next time we
- * go through the above "find out which introduction points we have
- * in progress" loop. */
- n_intro_points_to_open = (service->n_intro_points_wanted +
- (prev_intro_nodes == 0 ? 2 : 0));
- for (j = (int)n_intro_points_unexpired;
- j < (int)n_intro_points_to_open;
- ++j) { /* XXXX remove casts */
+ for (i = 0; i < (int) n_intro_points_to_open; i++) {
+ const node_t *node;
+ rend_intro_point_t *intro;
router_crn_flags_t flags = CRN_NEED_UPTIME|CRN_NEED_DESC;
if (get_options()->AllowInvalid_ & ALLOW_INVALID_INTRODUCTION)
flags |= CRN_ALLOW_INVALID;
@@ -3597,16 +3627,15 @@ rend_services_introduce(void)
options->ExcludeNodes, flags);
if (!node) {
log_warn(LD_REND,
- "Could only establish %d introduction points for %s; "
+ "We only have %d introduction points established for %s; "
"wanted %u.",
smartlist_len(service->intro_nodes),
safe_str_client(service->service_id),
n_intro_points_to_open);
break;
}
- intro_point_set_changed = 1;
- /* Add the choosen node to the exclusion list in order to avoid to pick
- * it again in the next iteration. */
+ /* Add the choosen node to the exclusion list in order to avoid to
+ * pick it again in the next iteration. */
smartlist_add(exclude_nodes, (void*)node);
intro = tor_malloc_zero(sizeof(rend_intro_point_t));
intro->extend_info = extend_info_from_node(node, 0);
@@ -3615,7 +3644,6 @@ rend_services_introduce(void)
tor_assert(!fail);
intro->time_published = -1;
intro->time_to_expire = -1;
- intro->time_expiring = -1;
intro->max_introductions =
crypto_rand_int_range(INTRO_POINT_MIN_LIFETIME_INTRODUCTIONS,
INTRO_POINT_MAX_LIFETIME_INTRODUCTIONS);
@@ -3623,24 +3651,20 @@ rend_services_introduce(void)
log_info(LD_REND, "Picked router %s as an intro point for %s.",
safe_str_client(node_describe(node)),
safe_str_client(service->service_id));
- }
-
- /* If there's no need to launch new circuits, stop here. */
- if (!intro_point_set_changed)
- continue;
-
- /* Establish new introduction points. */
- for (j=prev_intro_nodes; j < smartlist_len(service->intro_nodes); ++j) {
- intro = smartlist_get(service->intro_nodes, j);
+ /* Establish new introduction circuit to our chosen intro point. */
r = rend_service_launch_establish_intro(service, intro);
- if (r<0) {
+ if (r < 0) {
log_warn(LD_REND, "Error launching circuit to node %s for service %s.",
safe_str_client(extend_info_describe(intro->extend_info)),
safe_str_client(service->service_id));
+ /* This funcion will be called again by the main loop so this intro
+ * point without a intro circuit will be retried on or removed after
+ * a maximum number of attempts. */
}
}
- }
+ } SMARTLIST_FOREACH_END(service);
smartlist_free(exclude_nodes);
+ smartlist_free(retry_nodes);
}
#define MIN_REND_INITIAL_POST_DELAY (30)
@@ -3675,9 +3699,13 @@ rend_consider_services_upload(time_t now)
service->next_upload_time =
now + rendinitialpostdelay + crypto_rand_int(2*rendpostperiod);
}
- if (service->next_upload_time < now ||
+ /* Does every introduction points have been established? */
+ unsigned int intro_points_ready =
+ count_established_intro_points(service) >= service->n_intro_points_wanted;
+ if (intro_points_ready &&
+ (service->next_upload_time < now ||
(service->desc_is_dirty &&
- service->desc_is_dirty < now-rendinitialpostdelay)) {
+ service->desc_is_dirty < now-rendinitialpostdelay))) {
/* if it's time, or if the directory servers have a wrong service
* descriptor and ours has been stable for rendinitialpostdelay seconds,
* upload a new one of each format. */
diff --git a/src/or/rendservice.h b/src/or/rendservice.h
index b540d2c8ad..35a0bb25e6 100644
--- a/src/or/rendservice.h
+++ b/src/or/rendservice.h
@@ -125,6 +125,7 @@ int rend_service_del_ephemeral(const char *service_id);
void directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
smartlist_t *descs, smartlist_t *hs_dirs,
const char *service_id, int seconds_valid);
+void rend_service_desc_has_uploaded(const rend_data_t *rend_data);
#endif