Tor  0.4.7.0-alpha-dev
selftest.c
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1 /* Copyright (c) 2001 Matej Pfajfar.
2  * Copyright (c) 2001-2004, Roger Dingledine.
3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
4  * Copyright (c) 2007-2021, The Tor Project, Inc. */
5 /* See LICENSE for licensing information */
6 
7 /**
8  * \file selftest.c
9  * \brief Relay self-testing
10  *
11  * Relays need to make sure that their own ports are reachable, and estimate
12  * their own bandwidth, before publishing.
13  */
14 
15 #include "core/or/or.h"
16 
17 #include "app/config/config.h"
18 
20 #include "core/mainloop/mainloop.h"
22 
23 #include "core/or/circuitbuild.h"
24 #include "core/or/circuitlist.h"
25 #include "core/or/circuituse.h"
26 #include "core/or/crypt_path_st.h"
27 #include "core/or/extendinfo.h"
28 #include "core/or/extend_info_st.h"
30 #include "core/or/relay.h"
31 
33 
35 
38 
42 #include "feature/nodelist/routerlist.h" // but...
45 
47 #include "feature/relay/router.h"
48 #include "feature/relay/selftest.h"
49 
50 static bool have_orport_for_family(int family);
51 static void inform_testing_reachability(const tor_addr_t *addr,
52  uint16_t port);
53 
54 /** Whether we can reach our IPv4 ORPort from the outside. */
55 static bool can_reach_or_port_ipv4 = false;
56 /** Whether we can reach our IPv6 ORPort from the outside. */
57 static bool can_reach_or_port_ipv6 = false;
58 
59 /** Has informed_testing_reachable logged a message about testing our IPv4
60  * ORPort? */
62 /** Has informed_testing_reachable logged a message about testing our IPv6
63  * ORPort? */
65 
66 /** Forget what we have learned about our reachability status. */
67 void
69 {
73 }
74 
75 /** Return 1 if we won't do reachability checks, because:
76  * - AssumeReachable is set, or
77  * - the network is disabled.
78  * Otherwise, return 0.
79  */
80 static int
82 {
83  return options->AssumeReachable ||
85 }
86 
87 /** Return 0 if we need to do an ORPort reachability check, because:
88  * - no reachability check has been done yet, or
89  * - we've initiated reachability checks, but none have succeeded.
90  * Return 1 if we don't need to do an ORPort reachability check, because:
91  * - we've seen a successful reachability check, or
92  * - AssumeReachable is set, or
93  * - the network is disabled.
94 
95  * If `family'`is AF_INET or AF_INET6, return true only when we should skip
96  * the given family's orport check (Because it's been checked, or because we
97  * aren't checking it.) If `family` is 0, return true if we can skip _all_
98  * orport checks.
99  */
100 int
102  int family)
103 {
104  tor_assert_nonfatal(family == AF_INET || family == AF_INET6 || family == 0);
105  int reach_checks_disabled = router_reachability_checks_disabled(options);
106  if (reach_checks_disabled) {
107  return true;
108  }
109 
110  // Note that we do a == 1 here, not just a boolean check. This value
111  // is also an autobool, so CFG_AUTO does not mean that we should
112  // assume IPv6 ports are reachable.
113  const bool ipv6_assume_reachable = (options->AssumeReachableIPv6 == 1);
114 
115  // Which reachability flags should we look at?
116  const bool checking_ipv4 = (family == AF_INET || family == 0);
117  const bool checking_ipv6 = (family == AF_INET6 || family == 0);
118 
119  if (checking_ipv4) {
121  return false;
122  }
123  }
124  if (checking_ipv6 && !ipv6_assume_reachable) {
126  return false;
127  }
128  }
129 
130  return true;
131 }
132 
133 /** Relay DirPorts are no longer used (though authorities are). In either case,
134  * reachability self test is done anymore, since network re-entry towards an
135  * authority DirPort is not allowed. Thus, consider it always reachable. */
136 int
138 {
139  (void) options;
140  return 1;
141 }
142 
143 /** See if we currently believe our ORPort to be unreachable. If so, return 1
144  * else return 0. */
145 static int
147 {
149  const or_options_t *options = get_options();
150 
151  if (!me)
152  return 0;
153 
154  /* Doesn't check our IPv6 address, see #34065. */
155  if (routerset_contains_router(options->ExcludeNodes, me, -1) &&
156  options->StrictNodes) {
157  /* If we've excluded ourself, and StrictNodes is set, we can't test
158  * ourself. */
159 #define SELF_EXCLUDED_WARN_INTERVAL 3600
160  static ratelim_t warning_limit=RATELIM_INIT(SELF_EXCLUDED_WARN_INTERVAL);
161  log_fn_ratelim(&warning_limit, LOG_WARN, LD_CIRC,
162  "Can't perform self-tests for this relay: we have "
163  "listed ourself in ExcludeNodes, and StrictNodes is set. "
164  "We cannot learn whether we are usable, and will not "
165  "be able to advertise ourself.");
166  return 0;
167  }
168  return 1;
169 }
170 
171 /**
172  * Return true if we have configured an ORPort for the given family that
173  * we would like to advertise.
174  *
175  * Like other self-testing functions, this function looks at our most
176  * recently built descriptor.
177  **/
178 static bool
180 {
182 
183  if (!me)
184  return false;
185 
186  tor_addr_port_t ap;
187  if (router_get_orport(me, &ap, family) < 0) {
188  return false;
189  }
190  return true;
191 }
192 
193 /** Allocate and return a new extend_info_t that can be used to build
194  * a circuit to or through the router <b>r</b>, using an address from
195  * <b>family</b> (if available).
196  *
197  * Clients don't have routerinfos, so this function should only be called on a
198  * server.
199  *
200  * If the requested address is not available, returns NULL. */
201 static extend_info_t *
203 {
204  crypto_pk_t *rsa_pubkey;
205  extend_info_t *info;
206  tor_addr_port_t ap;
207 
208  if (BUG(!r)) {
209  return NULL;
210  }
211 
212  /* Relays always assume that the first hop is reachable. They ignore
213  * ReachableAddresses. */
214  tor_assert_nonfatal(router_or_conn_should_skip_reachable_address_check(
215  get_options(), 0));
216 
217  const ed25519_public_key_t *ed_id_key;
218  if (r->cache_info.signing_key_cert)
219  ed_id_key = &r->cache_info.signing_key_cert->signing_key;
220  else
221  ed_id_key = NULL;
222 
223  if (router_get_orport(r, &ap, family) < 0) {
224  /* We don't have an ORPort for the requested family. */
225  return NULL;
226  }
227  rsa_pubkey = router_get_rsa_onion_pkey(r->onion_pkey, r->onion_pkey_len);
228  info = extend_info_new(r->nickname, r->cache_info.identity_digest,
229  ed_id_key,
230  rsa_pubkey, r->onion_curve25519_pkey,
231  &ap.addr, ap.port);
232  crypto_pk_free(rsa_pubkey);
233  return info;
234 }
235 
236 /** Launch a self-testing circuit to one of our ORPorts, using an address from
237  * <b>family</b> (if available). The circuit can be used to test reachability
238  * or bandwidth. <b>me</b> is our own routerinfo.
239  *
240  * Logs an info-level status message. If <b>orport_reachable</b> is false,
241  * call it a reachability circuit. Otherwise, call it a bandwidth circuit.
242  *
243  * See router_do_reachability_checks() for details. */
244 static void
246  int family,
247  int orport_reachable)
248 {
249  extend_info_t *ei = extend_info_from_router(me, family);
250  int ipv6_flags = (family == AF_INET6 ? CIRCLAUNCH_IS_IPV6_SELFTEST : 0);
251 
252  /* If we're trying to test IPv6, but we don't have an IPv6 ORPort, ei will
253  * be NULL. */
254  if (ei) {
255  const char *family_name = fmt_af_family(family);
256  const tor_addr_port_t *ap = extend_info_get_orport(ei, family);
257  log_info(LD_CIRC, "Testing %s of my %s ORPort: %s.",
258  !orport_reachable ? "reachability" : "bandwidth",
259  family_name, fmt_addrport_ap(ap));
260 
261  if (!orport_reachable) {
262  /* Only log if we are actually doing a reachability test to learn if our
263  * ORPort is reachable. Else, this prints a log notice if we are simply
264  * opening a bandwidth testing circuit even though we are reachable. */
265  inform_testing_reachability(&ap->addr, ap->port);
266  }
267 
271  ipv6_flags);
272  extend_info_free(ei);
273  }
274 }
275 
276 /** Some time has passed, or we just got new directory information. See if we
277  * currently believe our ORPort to be unreachable. If so, launch a new test
278  * for it.
279  *
280  * For ORPort, we simply try making a circuit that ends at ourselves. Success
281  * is noticed in onionskin_answer().
282  */
283 void
285 {
287  const or_options_t *options = get_options();
288  int orport_reachable_v4 =
289  router_orport_seems_reachable(options, AF_INET);
290  int orport_reachable_v6 =
291  router_orport_seems_reachable(options, AF_INET6);
292 
294  bool need_testing = !circuit_enough_testing_circs();
295  /* At the moment, tor relays believe that they are reachable when they
296  * receive any create cell on an inbound connection, if the address
297  * family is correct.
298  */
299  if (!orport_reachable_v4 || need_testing) {
300  router_do_orport_reachability_checks(me, AF_INET, orport_reachable_v4);
301  }
302  if (!orport_reachable_v6 || need_testing) {
303  router_do_orport_reachability_checks(me, AF_INET6, orport_reachable_v6);
304  }
305  }
306 }
307 
308 /** Log a message informing the user that we are testing a port for
309  * reachability, if we have not already logged such a message.
310  *
311  * Calls to router_reset_reachability() will reset our view of whether we have
312  * logged this message for a given port. */
313 static void
314 inform_testing_reachability(const tor_addr_t *addr, uint16_t port)
315 {
317  return;
318 
319  bool *have_informed_ptr;
320  if (tor_addr_family(addr) == AF_INET) {
321  have_informed_ptr = &have_informed_testing_or_port_ipv4;
322  } else {
323  have_informed_ptr = &have_informed_testing_or_port_ipv6;
324  }
325 
326  if (*have_informed_ptr) {
327  /* We already told the user that we're testing this port; no need to
328  * do it again. */
329  return;
330  }
331 
332  char addr_buf[TOR_ADDRPORT_BUF_LEN];
333  strlcpy(addr_buf, fmt_addrport(addr, port), sizeof(addr_buf));
334 
335  const char *afname = fmt_af_family(tor_addr_family(addr));
336 
338  "CHECKING_REACHABILITY ORADDRESS=%s",
339  addr_buf);
340 
341  log_notice(LD_OR, "Now checking whether %s ORPort %s is reachable... "
342  "(this may take up to %d minutes -- look for log "
343  "messages indicating success)",
344  afname, addr_buf,
346 
347  *have_informed_ptr = true;
348 }
349 
350 /**
351  * Return true if this module knows of no reason why we shouldn't publish
352  * a server descriptor.
353  **/
354 static bool
356 {
357  return options->PublishServerDescriptor_ != NO_DIRINFO &&
358  router_all_orports_seem_reachable(options);
359 }
360 
361 /** Annotate that we found our ORPort reachable with a given address
362  * family. */
363 void
365 {
367  const or_options_t *options = get_options();
368  const char *reachable_reason = "ORPort found reachable";
369  bool *can_reach_ptr;
370  if (family == AF_INET) {
371  can_reach_ptr = &can_reach_or_port_ipv4;
372  } else if (family == AF_INET6) {
373  can_reach_ptr = &can_reach_or_port_ipv6;
374  } else {
376  return;
377  }
378  if (!*can_reach_ptr && me) {
379  tor_addr_port_t ap;
380  if (router_get_orport(me, &ap, family) < 0) {
381  return;
382  }
383  char *address = tor_strdup(fmt_addrport_ap(&ap));
384 
385  *can_reach_ptr = true;
386 
387  log_notice(LD_OR,"Self-testing indicates your ORPort %s is reachable from "
388  "the outside. Excellent.%s",
389  address,
390  ready_to_publish(options) ?
391  " Publishing server descriptor." : "");
392 
393  /* Make sure our descriptor is marked to publish the IPv6 if it is now
394  * reachable. This can change at runtime. */
395  if (family == AF_INET6) {
396  mark_my_descriptor_if_omit_ipv6_changes(reachable_reason, false);
397  } else {
398  mark_my_descriptor_dirty(reachable_reason);
399  }
400  /* This is a significant enough change to upload immediately,
401  * at least in a test network */
402  if (options->TestingTorNetwork == 1) {
404  }
406  "REACHABILITY_SUCCEEDED ORADDRESS=%s",
407  address);
408  tor_free(address);
409  }
410 }
411 
412 /** We have enough testing circuits open. Send a bunch of "drop"
413  * cells down each of them, to exercise our bandwidth.
414  *
415  * May use IPv4 and IPv6 testing circuits (if available). */
416 void
417 router_perform_bandwidth_test(int num_circs, time_t now)
418 {
419  int num_cells = (int)(get_options()->BandwidthRate * 10 /
421  int max_cells = num_cells < CIRCWINDOW_START ?
422  num_cells : CIRCWINDOW_START;
423  int cells_per_circuit = max_cells / num_circs;
424  origin_circuit_t *circ = NULL;
425 
426  log_notice(LD_OR,"Performing bandwidth self-test...done.");
427  while ((circ = circuit_get_next_by_purpose(circ,
429  /* dump cells_per_circuit drop cells onto this circ */
430  int i = cells_per_circuit;
431  if (circ->base_.state != CIRCUIT_STATE_OPEN)
432  continue;
433  circ->base_.timestamp_dirty = now;
434  while (i-- > 0) {
435  if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
436  RELAY_COMMAND_DROP,
437  NULL, 0, circ->cpath->prev)<0) {
438  return; /* stop if error */
439  }
440  }
441  }
442 }
const char * fmt_addrport(const tor_addr_t *addr, uint16_t port)
Definition: address.c:1199
const char * fmt_af_family(sa_family_t family)
Definition: address.c:1246
static sa_family_t tor_addr_family(const tor_addr_t *a)
Definition: address.h:187
#define TOR_ADDRPORT_BUF_LEN
Definition: address.h:233
Header file for directory authority mode.
Authority certificate structure.
Header file for circuitbuild.c.
origin_circuit_t * circuit_get_next_by_purpose(origin_circuit_t *start, uint8_t purpose)
Definition: circuitlist.c:1769
Header file for circuitlist.c.
#define CIRCUIT_STATE_OPEN
Definition: circuitlist.h:32
#define CIRCUIT_PURPOSE_TESTING
Definition: circuitlist.h:118
int circuit_enough_testing_circs(void)
Definition: circuituse.c:1613
origin_circuit_t * circuit_launch_by_extend_info(uint8_t purpose, extend_info_t *extend_info, int flags)
Definition: circuituse.c:2100
Header file for circuituse.c.
#define CIRCLAUNCH_NEED_CAPACITY
Definition: circuituse.h:43
#define CIRCLAUNCH_IS_IPV6_SELFTEST
Definition: circuituse.h:54
#define CIRCLAUNCH_IS_INTERNAL
Definition: circuituse.h:46
const or_options_t * get_options(void)
Definition: config.c:919
Header file for config.c.
Header file for connection.c.
int control_event_server_status(int severity, const char *format,...)
Header file for control_events.c.
Path structures for origin circuits.
Header file for dirclient.c.
Header file for directory.c.
Extend-info structure.
const tor_addr_port_t * extend_info_get_orport(const extend_info_t *ei, int family)
Definition: extendinfo.c:263
extend_info_t * extend_info_new(const char *nickname, const char *rsa_id_digest, const ed25519_public_key_t *ed_id, crypto_pk_t *onion_key, const curve25519_public_key_t *ntor_key, const tor_addr_t *addr, uint16_t port)
Definition: extendinfo.c:33
Header for core/or/extendinfo.c.
#define log_fn_ratelim(ratelim, severity, domain, args,...)
Definition: log.h:288
#define LD_OR
Definition: log.h:92
#define LOG_NOTICE
Definition: log.h:50
#define LD_CIRC
Definition: log.h:82
#define LOG_WARN
Definition: log.h:53
Header file for mainloop.c.
#define tor_free(p)
Definition: malloc.h:52
int net_is_disabled(void)
Definition: netstatus.c:25
Header for netstatus.c.
Master header file for Tor-specific functionality.
#define CELL_MAX_NETWORK_SIZE
Definition: or.h:460
#define TO_CIRCUIT(x)
Definition: or.h:845
#define TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT
Definition: or.h:430
#define CIRCWINDOW_START
Definition: or.h:382
Origin circuit structure.
Header file for relay.c.
void reschedule_descriptor_update_check(void)
Header for feature/relay/relay_periodic.c.
void mark_my_descriptor_if_omit_ipv6_changes(const char *reason, bool omit_ipv6)
Definition: router.c:2506
const routerinfo_t * router_get_my_routerinfo(void)
Definition: router.c:1801
void mark_my_descriptor_dirty(const char *reason)
Definition: router.c:2569
Header file for router.c.
int router_get_orport(const routerinfo_t *router, tor_addr_port_t *ap_out, int family)
Definition: routerinfo.c:27
Header file for routerinfo.c.
Router descriptor structure.
Header file for routerlist.c.
int routerset_contains_router(const routerset_t *set, const routerinfo_t *ri, country_t country)
Definition: routerset.c:328
Header file for routerset.c.
static bool can_reach_or_port_ipv6
Definition: selftest.c:57
static int router_should_check_reachability(void)
Definition: selftest.c:146
static bool ready_to_publish(const or_options_t *options)
Definition: selftest.c:355
static bool have_informed_testing_or_port_ipv4
Definition: selftest.c:61
int router_orport_seems_reachable(const or_options_t *options, int family)
Definition: selftest.c:101
static bool have_orport_for_family(int family)
Definition: selftest.c:179
static bool have_informed_testing_or_port_ipv6
Definition: selftest.c:64
static bool can_reach_or_port_ipv4
Definition: selftest.c:55
void router_do_reachability_checks(void)
Definition: selftest.c:284
void router_orport_found_reachable(int family)
Definition: selftest.c:364
void router_perform_bandwidth_test(int num_circs, time_t now)
Definition: selftest.c:417
static int router_reachability_checks_disabled(const or_options_t *options)
Definition: selftest.c:81
static void inform_testing_reachability(const tor_addr_t *addr, uint16_t port)
Definition: selftest.c:314
void router_reset_reachability(void)
Definition: selftest.c:68
static extend_info_t * extend_info_from_router(const routerinfo_t *r, int family)
Definition: selftest.c:202
int router_dirport_seems_reachable(const or_options_t *options)
Definition: selftest.c:137
static void router_do_orport_reachability_checks(const routerinfo_t *me, int family, int orport_reachable)
Definition: selftest.c:245
Header file for selftest.c.
uint8_t state
Definition: circuit_st.h:110
time_t timestamp_dirty
Definition: circuit_st.h:187
struct crypt_path_t * prev
Definition: crypt_path_st.h:75
dirinfo_type_t PublishServerDescriptor_
uint64_t BandwidthRate
struct routerset_t * ExcludeNodes
int AssumeReachableIPv6
crypt_path_t * cpath
char * onion_pkey
Definition: routerinfo_st.h:37
size_t onion_pkey_len
Definition: routerinfo_st.h:39
struct curve25519_public_key_t * onion_curve25519_pkey
Definition: routerinfo_st.h:43
char * nickname
Definition: routerinfo_st.h:22
char identity_digest[DIGEST_LEN]
struct tor_cert_st * signing_key_cert
Header for torcert.c.
#define tor_assert_nonfatal_unreached()
Definition: util_bug.h:176