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2ad36f68c8
tor/src/or/main.c
Nick Mathewson 2ad36f68c8 Rename ServerDNSAllowBrokenResolvConf to ServerDNSAllowBrokenConfig. 
(Many users have no idea what a resolv.conf is, and shouldn't be forced to learn.  The old option will keep working for now.)
Also, document it.

svn:r17661
2008-12-17 22:58:14 +00:00

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/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2008, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/* $Id$ */
const char main_c_id[] =
"$Id$";
/**
* \file main.c
* \brief Toplevel module. Handles signals, multiplexes between
* connections, implements main loop, and drives scheduled events.
**/
#define MAIN_PRIVATE
#include "or.h"
#ifdef USE_DMALLOC
#include <dmalloc.h>
#include <openssl/crypto.h>
#endif
#include "memarea.h"
void evdns_shutdown(int);
/********* PROTOTYPES **********/
static void dumpmemusage(int severity);
static void dumpstats(int severity); /* log stats */
static void conn_read_callback(int fd, short event, void *_conn);
static void conn_write_callback(int fd, short event, void *_conn);
static void signal_callback(int fd, short events, void *arg);
static void second_elapsed_callback(int fd, short event, void *args);
static int conn_close_if_marked(int i);
static void connection_start_reading_from_linked_conn(connection_t *conn);
static int connection_should_read_from_linked_conn(connection_t *conn);
/********* START VARIABLES **********/
int global_read_bucket; /**< Max number of bytes I can read this second. */
int global_write_bucket; /**< Max number of bytes I can write this second. */
/** Max number of relayed (bandwidth class 1) bytes I can read this second. */
int global_relayed_read_bucket;
/** Max number of relayed (bandwidth class 1) bytes I can write this second. */
int global_relayed_write_bucket;
/** What was the read bucket before the last second_elapsed_callback() call?
* (used to determine how many bytes we've read). */
static int stats_prev_global_read_bucket;
/** What was the write bucket before the last second_elapsed_callback() call?
* (used to determine how many bytes we've written). */
static int stats_prev_global_write_bucket;
/* XXX we might want to keep stats about global_relayed_*_bucket too. Or not.*/
/** How many bytes have we read/written since we started the process? */
static uint64_t stats_n_bytes_read = 0;
static uint64_t stats_n_bytes_written = 0;
/** What time did this process start up? */
time_t time_of_process_start = 0;
/** How many seconds have we been running? */
long stats_n_seconds_working = 0;
/** When do we next launch DNS wildcarding checks? */
static time_t time_to_check_for_correct_dns = 0;
/** How often will we honor SIGNEWNYM requests? */
#define MAX_SIGNEWNYM_RATE 10
/** When did we last process a SIGNEWNYM request? */
static time_t time_of_last_signewnym = 0;
/** Is there a signewnym request we're currently waiting to handle? */
static int signewnym_is_pending = 0;
/** Smartlist of all open connections. */
static smartlist_t *connection_array = NULL;
/** List of connections that have been marked for close and need to be freed
* and removed from connection_array. */
static smartlist_t *closeable_connection_lst = NULL;
/** List of linked connections that are currently reading data into their
* inbuf from their partner's outbuf. */
static smartlist_t *active_linked_connection_lst = NULL;
/** Flag: Set to true iff we entered the current libevent main loop via
* <b>loop_once</b>. If so, there's no need to trigger a loopexit in order
* to handle linked connections. */
static int called_loop_once = 0;
/** We set this to 1 when we've opened a circuit, so we can print a log
* entry to inform the user that Tor is working. */
int has_completed_circuit=0;
/** How often do we check for router descriptors that we should download
* when we have too little directory info? */
#define GREEDY_DESCRIPTOR_RETRY_INTERVAL (10)
/** How often do we check for router descriptors that we should download
* when we have enough directory info? */
#define LAZY_DESCRIPTOR_RETRY_INTERVAL (60)
/** How often do we 'forgive' undownloadable router descriptors and attempt
* to download them again? */
#define DESCRIPTOR_FAILURE_RESET_INTERVAL (60*60)
/** How long do we let a directory connection stall before expiring it? */
#define DIR_CONN_MAX_STALL (5*60)
/** How old do we let a connection to an OR get before deciding it's
* too old for new circuits? */
#define TIME_BEFORE_OR_CONN_IS_TOO_OLD (60*60*24*7)
/** How long do we let OR connections handshake before we decide that
* they are obsolete? */
#define TLS_HANDSHAKE_TIMEOUT (60)
/********* END VARIABLES ************/
/****************************************************************************
*
* This section contains accessors and other methods on the connection_array
* variables (which are global within this file and unavailable outside it).
*
****************************************************************************/
/** Add <b>conn</b> to the array of connections that we can poll on. The
* connection's socket must be set; the connection starts out
* non-reading and non-writing.
*/
int
connection_add(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->s >= 0 ||
conn->linked ||
(conn->type == CONN_TYPE_AP &&
TO_EDGE_CONN(conn)->is_dns_request));
tor_assert(conn->conn_array_index == -1); /* can only connection_add once */
conn->conn_array_index = smartlist_len(connection_array);
smartlist_add(connection_array, conn);
if (conn->s >= 0 || conn->linked) {
conn->read_event = tor_malloc_zero(sizeof(struct event));
conn->write_event = tor_malloc_zero(sizeof(struct event));
event_set(conn->read_event, conn->s, EV_READ|EV_PERSIST,
conn_read_callback, conn);
event_set(conn->write_event, conn->s, EV_WRITE|EV_PERSIST,
conn_write_callback, conn);
}
log_debug(LD_NET,"new conn type %s, socket %d, address %s, n_conns %d.",
conn_type_to_string(conn->type), conn->s, conn->address,
smartlist_len(connection_array));
return 0;
}
/** Remove the connection from the global list, and remove the
* corresponding poll entry. Calling this function will shift the last
* connection (if any) into the position occupied by conn.
*/
int
connection_remove(connection_t *conn)
{
int current_index;
connection_t *tmp;
tor_assert(conn);
log_debug(LD_NET,"removing socket %d (type %s), n_conns now %d",
conn->s, conn_type_to_string(conn->type),
smartlist_len(connection_array));
tor_assert(conn->conn_array_index >= 0);
current_index = conn->conn_array_index;
connection_unregister_events(conn); /* This is redundant, but cheap. */
if (current_index == smartlist_len(connection_array)-1) { /* at the end */
smartlist_del(connection_array, current_index);
return 0;
}
/* replace this one with the one at the end */
smartlist_del(connection_array, current_index);
tmp = smartlist_get(connection_array, current_index);
tmp->conn_array_index = current_index;
return 0;
}
/** If <b>conn</b> is an edge conn, remove it from the list
* of conn's on this circuit. If it's not on an edge,
* flush and send destroys for all circuits on this conn.
*
* Remove it from connection_array (if applicable) and
* from closeable_connection_list.
*
* Then free it.
*/
static void
connection_unlink(connection_t *conn)
{
connection_about_to_close_connection(conn);
if (conn->conn_array_index >= 0) {
connection_remove(conn);
}
if (conn->linked_conn) {
conn->linked_conn->linked_conn = NULL;
if (! conn->linked_conn->marked_for_close &&
conn->linked_conn->reading_from_linked_conn)
connection_start_reading(conn->linked_conn);
conn->linked_conn = NULL;
}
smartlist_remove(closeable_connection_lst, conn);
smartlist_remove(active_linked_connection_lst, conn);
if (conn->type == CONN_TYPE_EXIT) {
assert_connection_edge_not_dns_pending(TO_EDGE_CONN(conn));
}
if (conn->type == CONN_TYPE_OR) {
if (!tor_digest_is_zero(TO_OR_CONN(conn)->identity_digest))
connection_or_remove_from_identity_map(TO_OR_CONN(conn));
}
connection_free(conn);
}
/** Schedule <b>conn</b> to be closed. **/
void
add_connection_to_closeable_list(connection_t *conn)
{
tor_assert(!smartlist_isin(closeable_connection_lst, conn));
tor_assert(conn->marked_for_close);
assert_connection_ok(conn, time(NULL));
smartlist_add(closeable_connection_lst, conn);
}
/** Return 1 if conn is on the closeable list, else return 0. */
int
connection_is_on_closeable_list(connection_t *conn)
{
return smartlist_isin(closeable_connection_lst, conn);
}
/** Return true iff conn is in the current poll array. */
int
connection_in_array(connection_t *conn)
{
return smartlist_isin(connection_array, conn);
}
/** Set <b>*array</b> to an array of all connections, and <b>*n</b>
* to the length of the array. <b>*array</b> and <b>*n</b> must not
* be modified.
*/
smartlist_t *
get_connection_array(void)
{
if (!connection_array)
connection_array = smartlist_create();
return connection_array;
}
/** Set the event mask on <b>conn</b> to <b>events</b>. (The event
* mask is a bitmask whose bits are EV_READ and EV_WRITE.)
*/
void
connection_watch_events(connection_t *conn, short events)
{
if (events & EV_READ)
connection_start_reading(conn);
else
connection_stop_reading(conn);
if (events & EV_WRITE)
connection_start_writing(conn);
else
connection_stop_writing(conn);
}
/** Return true iff <b>conn</b> is listening for read events. */
int
connection_is_reading(connection_t *conn)
{
tor_assert(conn);
return conn->reading_from_linked_conn ||
(conn->read_event && event_pending(conn->read_event, EV_READ, NULL));
}
/** Tell the main loop to stop notifying <b>conn</b> of any read events. */
void
connection_stop_reading(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->read_event);
if (conn->linked) {
conn->reading_from_linked_conn = 0;
connection_stop_reading_from_linked_conn(conn);
} else {
if (event_del(conn->read_event))
log_warn(LD_NET, "Error from libevent setting read event state for %d "
"to unwatched: %s",
conn->s,
tor_socket_strerror(tor_socket_errno(conn->s)));
}
}
/** Tell the main loop to start notifying <b>conn</b> of any read events. */
void
connection_start_reading(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->read_event);
if (conn->linked) {
conn->reading_from_linked_conn = 1;
if (connection_should_read_from_linked_conn(conn))
connection_start_reading_from_linked_conn(conn);
} else {
if (event_add(conn->read_event, NULL))
log_warn(LD_NET, "Error from libevent setting read event state for %d "
"to watched: %s",
conn->s,
tor_socket_strerror(tor_socket_errno(conn->s)));
}
}
/** Return true iff <b>conn</b> is listening for write events. */
int
connection_is_writing(connection_t *conn)
{
tor_assert(conn);
return conn->writing_to_linked_conn ||
(conn->write_event && event_pending(conn->write_event, EV_WRITE, NULL));
}
/** Tell the main loop to stop notifying <b>conn</b> of any write events. */
void
connection_stop_writing(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->write_event);
if (conn->linked) {
conn->writing_to_linked_conn = 0;
if (conn->linked_conn)
connection_stop_reading_from_linked_conn(conn->linked_conn);
} else {
if (event_del(conn->write_event))
log_warn(LD_NET, "Error from libevent setting write event state for %d "
"to unwatched: %s",
conn->s,
tor_socket_strerror(tor_socket_errno(conn->s)));
}
}
/** Tell the main loop to start notifying <b>conn</b> of any write events. */
void
connection_start_writing(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->write_event);
if (conn->linked) {
conn->writing_to_linked_conn = 1;
if (conn->linked_conn &&
connection_should_read_from_linked_conn(conn->linked_conn))
connection_start_reading_from_linked_conn(conn->linked_conn);
} else {
if (event_add(conn->write_event, NULL))
log_warn(LD_NET, "Error from libevent setting write event state for %d "
"to watched: %s",
conn->s,
tor_socket_strerror(tor_socket_errno(conn->s)));
}
}
/** Return true iff <b>conn</b> is linked conn, and reading from the conn
* linked to it would be good and feasible. (Reading is "feasible" if the
* other conn exists and has data in its outbuf, and is "good" if we have our
* reading_from_linked_conn flag set and the other conn has its
* writing_to_linked_conn flag set.)*/
static int
connection_should_read_from_linked_conn(connection_t *conn)
{
if (conn->linked && conn->reading_from_linked_conn) {
if (! conn->linked_conn ||
(conn->linked_conn->writing_to_linked_conn &&
buf_datalen(conn->linked_conn->outbuf)))
return 1;
}
return 0;
}
/** Helper: Tell the main loop to begin reading bytes into <b>conn</b> from
* its linked connection, if it is not doing so already. Called by
* connection_start_reading and connection_start_writing as appropriate. */
static void
connection_start_reading_from_linked_conn(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->linked == 1);
if (!conn->active_on_link) {
conn->active_on_link = 1;
smartlist_add(active_linked_connection_lst, conn);
if (!called_loop_once) {
/* This is the first event on the list; we won't be in LOOP_ONCE mode,
* so we need to make sure that the event_loop() actually exits at the
* end of its run through the current connections and
* lets us activate read events for linked connections. */
struct timeval tv = { 0, 0 };
event_loopexit(&tv);
}
} else {
tor_assert(smartlist_isin(active_linked_connection_lst, conn));
}
}
/** Tell the main loop to stop reading bytes into <b>conn</b> from its linked
* connection, if is currently doing so. Called by connection_stop_reading,
* connection_stop_writing, and connection_read. */
void
connection_stop_reading_from_linked_conn(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->linked == 1);
if (conn->active_on_link) {
conn->active_on_link = 0;
/* FFFF We could keep an index here so we can smartlist_del
* cleanly. On the other hand, this doesn't show up on profiles,
* so let's leave it alone for now. */
smartlist_remove(active_linked_connection_lst, conn);
} else {
tor_assert(!smartlist_isin(active_linked_connection_lst, conn));
}
}
/** Close all connections that have been scheduled to get closed. */
static void
close_closeable_connections(void)
{
int i;
for (i = 0; i < smartlist_len(closeable_connection_lst); ) {
connection_t *conn = smartlist_get(closeable_connection_lst, i);
if (conn->conn_array_index < 0) {
connection_unlink(conn); /* blow it away right now */
} else {
if (!conn_close_if_marked(conn->conn_array_index))
++i;
}
}
}
/** Libevent callback: this gets invoked when (connection_t*)<b>conn</b> has
* some data to read. */
static void
conn_read_callback(int fd, short event, void *_conn)
{
connection_t *conn = _conn;
(void)fd;
(void)event;
log_debug(LD_NET,"socket %d wants to read.",conn->s);
assert_connection_ok(conn, time(NULL));
if (connection_handle_read(conn) < 0) {
if (!conn->marked_for_close) {
#ifndef MS_WINDOWS
log_warn(LD_BUG,"Unhandled error on read for %s connection "
"(fd %d); removing",
conn_type_to_string(conn->type), conn->s);
tor_fragile_assert();
#endif
if (CONN_IS_EDGE(conn))
connection_edge_end_errno(TO_EDGE_CONN(conn));
connection_mark_for_close(conn);
}
}
assert_connection_ok(conn, time(NULL));
if (smartlist_len(closeable_connection_lst))
close_closeable_connections();
}
/** Libevent callback: this gets invoked when (connection_t*)<b>conn</b> has
* some data to write. */
static void
conn_write_callback(int fd, short events, void *_conn)
{
connection_t *conn = _conn;
(void)fd;
(void)events;
LOG_FN_CONN(conn, (LOG_DEBUG, LD_NET, "socket %d wants to write.",conn->s));
assert_connection_ok(conn, time(NULL));
if (connection_handle_write(conn, 0) < 0) {
if (!conn->marked_for_close) {
/* this connection is broken. remove it. */
log_fn(LOG_WARN,LD_BUG,
"unhandled error on write for %s connection (fd %d); removing",
conn_type_to_string(conn->type), conn->s);
tor_fragile_assert();
if (CONN_IS_EDGE(conn)) {
/* otherwise we cry wolf about duplicate close */
edge_connection_t *edge_conn = TO_EDGE_CONN(conn);
if (!edge_conn->end_reason)
edge_conn->end_reason = END_STREAM_REASON_INTERNAL;
edge_conn->edge_has_sent_end = 1;
}
connection_close_immediate(conn); /* So we don't try to flush. */
connection_mark_for_close(conn);
}
}
assert_connection_ok(conn, time(NULL));
if (smartlist_len(closeable_connection_lst))
close_closeable_connections();
}
/** If the connection at connection_array[i] is marked for close, then:
* - If it has data that it wants to flush, try to flush it.
* - If it _still_ has data to flush, and conn->hold_open_until_flushed is
* true, then leave the connection open and return.
* - Otherwise, remove the connection from connection_array and from
* all other lists, close it, and free it.
* Returns 1 if the connection was closed, 0 otherwise.
*/
static int
conn_close_if_marked(int i)
{
connection_t *conn;
int retval;
time_t now;
conn = smartlist_get(connection_array, i);
if (!conn->marked_for_close)
return 0; /* nothing to see here, move along */
now = time(NULL);
assert_connection_ok(conn, now);
assert_all_pending_dns_resolves_ok();
log_debug(LD_NET,"Cleaning up connection (fd %d).",conn->s);
if ((conn->s >= 0 || conn->linked_conn) && connection_wants_to_flush(conn)) {
/* s == -1 means it's an incomplete edge connection, or that the socket
* has already been closed as unflushable. */
ssize_t sz = connection_bucket_write_limit(conn, now);
if (!conn->hold_open_until_flushed)
log_info(LD_NET,
"Conn (addr %s, fd %d, type %s, state %d) marked, but wants "
"to flush %d bytes. (Marked at %s:%d)",
escaped_safe_str(conn->address),
conn->s, conn_type_to_string(conn->type), conn->state,
(int)conn->outbuf_flushlen,
conn->marked_for_close_file, conn->marked_for_close);
if (conn->linked_conn) {
retval = move_buf_to_buf(conn->linked_conn->inbuf, conn->outbuf,
&conn->outbuf_flushlen);
if (retval >= 0) {
/* The linked conn will notice that it has data when it notices that
* we're gone. */
connection_start_reading_from_linked_conn(conn->linked_conn);
}
log_debug(LD_GENERAL, "Flushed last %d bytes from a linked conn; "
"%d left; flushlen %d; wants-to-flush==%d", retval,
(int)buf_datalen(conn->outbuf),
(int)conn->outbuf_flushlen,
connection_wants_to_flush(conn));
} else if (connection_speaks_cells(conn)) {
if (conn->state == OR_CONN_STATE_OPEN) {
retval = flush_buf_tls(TO_OR_CONN(conn)->tls, conn->outbuf, sz,
&conn->outbuf_flushlen);
} else
retval = -1; /* never flush non-open broken tls connections */
} else {
retval = flush_buf(conn->s, conn->outbuf, sz, &conn->outbuf_flushlen);
}
if (retval >= 0 && /* Technically, we could survive things like
TLS_WANT_WRITE here. But don't bother for now. */
conn->hold_open_until_flushed && connection_wants_to_flush(conn)) {
if (retval > 0) {
LOG_FN_CONN(conn, (LOG_INFO,LD_NET,
"Holding conn (fd %d) open for more flushing.",
conn->s));
conn->timestamp_lastwritten = now; /* reset so we can flush more */
}
return 0;
}
if (connection_wants_to_flush(conn)) {
int severity;
if (conn->type == CONN_TYPE_EXIT ||
(conn->type == CONN_TYPE_OR && server_mode(get_options())) ||
(conn->type == CONN_TYPE_DIR && conn->purpose == DIR_PURPOSE_SERVER))
severity = LOG_INFO;
else
severity = LOG_NOTICE;
/* XXXX Maybe allow this to happen a certain amount per hour; it usually
* is meaningless. */
log_fn(severity, LD_NET, "We stalled too much while trying to write %d "
"bytes to address %s. If this happens a lot, either "
"something is wrong with your network connection, or "
"something is wrong with theirs. "
"(fd %d, type %s, state %d, marked at %s:%d).",
(int)buf_datalen(conn->outbuf),
escaped_safe_str(conn->address), conn->s,
conn_type_to_string(conn->type), conn->state,
conn->marked_for_close_file,
conn->marked_for_close);
}
}
connection_unlink(conn); /* unlink, remove, free */
return 1;
}
/** We've just tried every dirserver we know about, and none of
* them were reachable. Assume the network is down. Change state
* so next time an application connection arrives we'll delay it
* and try another directory fetch. Kill off all the circuit_wait
* streams that are waiting now, since they will all timeout anyway.
*/
void
directory_all_unreachable(time_t now)
{
connection_t *conn;
(void)now;
stats_n_seconds_working=0; /* reset it */
while ((conn = connection_get_by_type_state(CONN_TYPE_AP,
AP_CONN_STATE_CIRCUIT_WAIT))) {
edge_connection_t *edge_conn = TO_EDGE_CONN(conn);
log_notice(LD_NET,
"Is your network connection down? "
"Failing connection to '%s:%d'.",
safe_str(edge_conn->socks_request->address),
edge_conn->socks_request->port);
connection_mark_unattached_ap(edge_conn,
END_STREAM_REASON_NET_UNREACHABLE);
}
control_event_general_status(LOG_ERR, "DIR_ALL_UNREACHABLE");
}
/** This function is called whenever we successfully pull down some new
* network statuses or server descriptors. */
void
directory_info_has_arrived(time_t now, int from_cache)
{
or_options_t *options = get_options();
if (!router_have_minimum_dir_info()) {
int quiet = directory_too_idle_to_fetch_descriptors(options, now);
log(quiet ? LOG_INFO : LOG_NOTICE, LD_DIR,
"I learned some more directory information, but not enough to "
"build a circuit: %s", get_dir_info_status_string());
update_router_descriptor_downloads(now);
return;
} else {
if (directory_fetches_from_authorities(options))
update_router_descriptor_downloads(now);
/* if we have enough dir info, then update our guard status with
* whatever we just learned. */
entry_guards_compute_status();
/* Don't even bother trying to get extrainfo until the rest of our
* directory info is up-to-date */
if (options->DownloadExtraInfo)
update_extrainfo_downloads(now);
}
if (server_mode(options) && !we_are_hibernating() && !from_cache &&
(has_completed_circuit || !any_predicted_circuits(now)))
consider_testing_reachability(1, 1);
}
/** Perform regular maintenance tasks for a single connection. This
* function gets run once per second per connection by run_scheduled_events.
*/
static void
run_connection_housekeeping(int i, time_t now)
{
cell_t cell;
connection_t *conn = smartlist_get(connection_array, i);
or_options_t *options = get_options();
or_connection_t *or_conn;
if (conn->outbuf && !buf_datalen(conn->outbuf) && conn->type == CONN_TYPE_OR)
TO_OR_CONN(conn)->timestamp_lastempty = now;
if (conn->marked_for_close) {
/* nothing to do here */
return;
}
/* Expire any directory connections that haven't been active (sent
* if a server or received if a client) for 5 min */
if (conn->type == CONN_TYPE_DIR &&
((DIR_CONN_IS_SERVER(conn) &&
conn->timestamp_lastwritten + DIR_CONN_MAX_STALL < now) ||
(!DIR_CONN_IS_SERVER(conn) &&
conn->timestamp_lastread + DIR_CONN_MAX_STALL < now))) {
log_info(LD_DIR,"Expiring wedged directory conn (fd %d, purpose %d)",
conn->s, conn->purpose);
/* This check is temporary; it's to let us know whether we should consider
* parsing partial serverdesc responses. */
if (conn->purpose == DIR_PURPOSE_FETCH_SERVERDESC &&
buf_datalen(conn->inbuf)>=1024) {
log_info(LD_DIR,"Trying to extract information from wedged server desc "
"download.");
connection_dir_reached_eof(TO_DIR_CONN(conn));
} else {
connection_mark_for_close(conn);
}
return;
}
if (!connection_speaks_cells(conn))
return; /* we're all done here, the rest is just for OR conns */
or_conn = TO_OR_CONN(conn);
if (!or_conn->is_bad_for_new_circs) {
if (conn->timestamp_created + TIME_BEFORE_OR_CONN_IS_TOO_OLD < now) {
log_info(LD_OR,
"Marking OR conn to %s:%d as too old for new circuits "
"(fd %d, %d secs old).",
conn->address, conn->port, conn->s,
(int)(now - conn->timestamp_created));
or_conn->is_bad_for_new_circs = 1;
} else {
or_connection_t *best =
connection_or_get_by_identity_digest(or_conn->identity_digest);
if (best && best != or_conn &&
(conn->state == OR_CONN_STATE_OPEN ||
now > conn->timestamp_created + TLS_HANDSHAKE_TIMEOUT)) {
/* We only mark as obsolete connections that already are in
* OR_CONN_STATE_OPEN, i.e. that have finished their TLS handshaking.
* This is necessary because authorities judge whether a router is
* reachable based on whether they were able to TLS handshake with it
* recently. Without this check we would expire connections too
* early for router->last_reachable to be updated.
*/
log_info(LD_OR,
"Marking duplicate conn to %s:%d as too old for new circuits "
"(fd %d, %d secs old).",
conn->address, conn->port, conn->s,
(int)(now - conn->timestamp_created));
or_conn->is_bad_for_new_circs = 1;
}
}
}
if (or_conn->is_bad_for_new_circs && !or_conn->n_circuits) {
/* no unmarked circs -- mark it now */
log_info(LD_OR,
"Expiring non-used OR connection to fd %d (%s:%d) [Too old].",
conn->s, conn->address, conn->port);
if (conn->state == OR_CONN_STATE_CONNECTING)
connection_or_connect_failed(TO_OR_CONN(conn),
END_OR_CONN_REASON_TIMEOUT,
"Tor gave up on the connection");
connection_mark_for_close(conn);
conn->hold_open_until_flushed = 1;
return;
}
/* If we haven't written to an OR connection for a while, then either nuke
the connection or send a keepalive, depending. */
if (now >= conn->timestamp_lastwritten + options->KeepalivePeriod) {
routerinfo_t *router = router_get_by_digest(or_conn->identity_digest);
int maxCircuitlessPeriod = options->MaxCircuitDirtiness*3/2;
if (!connection_state_is_open(conn)) {
/* We never managed to actually get this connection open and happy. */
log_info(LD_OR,"Expiring non-open OR connection to fd %d (%s:%d).",
conn->s,conn->address, conn->port);
connection_mark_for_close(conn);
conn->hold_open_until_flushed = 1;
} else if (we_are_hibernating() && !or_conn->n_circuits &&
!buf_datalen(conn->outbuf)) {
/* We're hibernating, there's no circuits, and nothing to flush.*/
log_info(LD_OR,"Expiring non-used OR connection to fd %d (%s:%d) "
"[Hibernating or exiting].",
conn->s,conn->address, conn->port);
connection_mark_for_close(conn);
conn->hold_open_until_flushed = 1;
} else if (!clique_mode(options) && !or_conn->n_circuits &&
now >= or_conn->timestamp_last_added_nonpadding +
maxCircuitlessPeriod &&
(!router || !server_mode(options) ||
!router_is_clique_mode(router))) {
log_info(LD_OR,"Expiring non-used OR connection to fd %d (%s:%d) "
"[Not in clique mode].",
conn->s,conn->address, conn->port);
connection_mark_for_close(conn);
conn->hold_open_until_flushed = 1;
} else if (
now >= or_conn->timestamp_lastempty + options->KeepalivePeriod*10 &&
now >= conn->timestamp_lastwritten + options->KeepalivePeriod*10) {
log_fn(LOG_PROTOCOL_WARN,LD_PROTOCOL,
"Expiring stuck OR connection to fd %d (%s:%d). (%d bytes to "
"flush; %d seconds since last write)",
conn->s, conn->address, conn->port,
(int)buf_datalen(conn->outbuf),
(int)(now-conn->timestamp_lastwritten));
connection_mark_for_close(conn);
} else if (!buf_datalen(conn->outbuf)) {
/* either in clique mode, or we've got a circuit. send a padding cell. */
log_fn(LOG_DEBUG,LD_OR,"Sending keepalive to (%s:%d)",
conn->address, conn->port);
memset(&cell,0,sizeof(cell_t));
cell.command = CELL_PADDING;
connection_or_write_cell_to_buf(&cell, or_conn);
}
}
}
/** Honor a NEWNYM request: make future requests unlinkability to past
* requests. */
static void
signewnym_impl(time_t now)
{
circuit_expire_all_dirty_circs();
addressmap_clear_transient();
time_of_last_signewnym = now;
signewnym_is_pending = 0;
}
/** Perform regular maintenance tasks. This function gets run once per
* second by second_elapsed_callback().
*/
static void
run_scheduled_events(time_t now)
{
static time_t last_rotated_x509_certificate = 0;
static time_t time_to_check_v3_certificate = 0;
static time_t time_to_check_listeners = 0;
static time_t time_to_check_descriptor = 0;
static time_t time_to_check_ipaddress = 0;
static time_t time_to_shrink_memory = 0;
static time_t time_to_try_getting_descriptors = 0;
static time_t time_to_reset_descriptor_failures = 0;
static time_t time_to_add_entropy = 0;
static time_t time_to_write_hs_statistics = 0;
static time_t time_to_write_bridge_status_file = 0;
static time_t time_to_downrate_stability = 0;
static time_t time_to_save_stability = 0;
static time_t time_to_clean_caches = 0;
static time_t time_to_recheck_bandwidth = 0;
static time_t time_to_check_for_expired_networkstatus = 0;
static time_t time_to_dump_geoip_stats = 0;
static time_t time_to_retry_dns_init = 0;
or_options_t *options = get_options();
int i;
int have_dir_info;
/** 0. See if we've been asked to shut down and our timeout has
* expired; or if our bandwidth limits are exhausted and we
* should hibernate; or if it's time to wake up from hibernation.
*/
consider_hibernation(now);
/* 0b. If we've deferred a signewnym, make sure it gets handled
* eventually. */
if (signewnym_is_pending &&
time_of_last_signewnym + MAX_SIGNEWNYM_RATE <= now) {
log(LOG_INFO, LD_CONTROL, "Honoring delayed NEWNYM request");
signewnym_impl(now);
}
/** 1a. Every MIN_ONION_KEY_LIFETIME seconds, rotate the onion keys,
* shut down and restart all cpuworkers, and update the directory if
* necessary.
*/
if (server_mode(options) &&
get_onion_key_set_at()+MIN_ONION_KEY_LIFETIME < now) {
log_info(LD_GENERAL,"Rotating onion key.");
rotate_onion_key();
cpuworkers_rotate();
if (router_rebuild_descriptor(1)<0) {
log_info(LD_CONFIG, "Couldn't rebuild router descriptor");
}
if (advertised_server_mode())
router_upload_dir_desc_to_dirservers(0);
}
if (time_to_try_getting_descriptors < now) {
update_router_descriptor_downloads(now);
update_extrainfo_downloads(now);
if (options->UseBridges)
fetch_bridge_descriptors(now);
if (router_have_minimum_dir_info())
time_to_try_getting_descriptors = now + LAZY_DESCRIPTOR_RETRY_INTERVAL;
else
time_to_try_getting_descriptors = now + GREEDY_DESCRIPTOR_RETRY_INTERVAL;
}
if (time_to_reset_descriptor_failures < now) {
router_reset_descriptor_download_failures();
time_to_reset_descriptor_failures =
now + DESCRIPTOR_FAILURE_RESET_INTERVAL;
}
/** 1b. Every MAX_SSL_KEY_LIFETIME seconds, we change our TLS context. */
if (!last_rotated_x509_certificate)
last_rotated_x509_certificate = now;
if (last_rotated_x509_certificate+MAX_SSL_KEY_LIFETIME < now) {
log_info(LD_GENERAL,"Rotating tls context.");
if (tor_tls_context_new(get_identity_key(), MAX_SSL_KEY_LIFETIME) < 0) {
log_warn(LD_BUG, "Error reinitializing TLS context");
/* XXX is it a bug here, that we just keep going? -RD */
}
last_rotated_x509_certificate = now;
/* We also make sure to rotate the TLS connections themselves if they've
* been up for too long -- but that's done via is_bad_for_new_circs in
* connection_run_housekeeping() above. */
}
if (time_to_add_entropy < now) {
if (time_to_add_entropy) {
/* We already seeded once, so don't die on failure. */
crypto_seed_rng(0);
}
/** How often do we add more entropy to OpenSSL's RNG pool? */
#define ENTROPY_INTERVAL (60*60)
time_to_add_entropy = now + ENTROPY_INTERVAL;
}
/** 1c. If we have to change the accounting interval or record
* bandwidth used in this accounting interval, do so. */
if (accounting_is_enabled(options))
accounting_run_housekeeping(now);
if (now % 10 == 0 && (authdir_mode_tests_reachability(options)) &&
!we_are_hibernating()) {
/* try to determine reachability of the other Tor relays */
dirserv_test_reachability(now, 0);
}
/** 1d. Periodically, we discount older stability information so that new
* stability info counts more, and save the stability information to disk as
* appropriate. */
if (time_to_downrate_stability < now)
time_to_downrate_stability = rep_hist_downrate_old_runs(now);
if (authdir_mode_tests_reachability(options)) {
if (time_to_save_stability < now) {
if (time_to_save_stability && rep_hist_record_mtbf_data()<0) {
log_warn(LD_GENERAL, "Couldn't store mtbf data.");
}
#define SAVE_STABILITY_INTERVAL (30*60)
time_to_save_stability = now + SAVE_STABILITY_INTERVAL;
}
}
/* 1e. Periodicaly, if we're a v3 authority, we check whether our cert is
* close to expiring and warn the admin if it is. */
if (time_to_check_v3_certificate < now) {
v3_authority_check_key_expiry();
#define CHECK_V3_CERTIFICATE_INTERVAL (5*60)
time_to_check_v3_certificate = now + CHECK_V3_CERTIFICATE_INTERVAL;
}
/* 1f. Check whether our networkstatus has expired.
*/
if (time_to_check_for_expired_networkstatus < now) {
networkstatus_t *ns = networkstatus_get_latest_consensus();
/*XXXX020 this value needs to be the same as REASONABLY_LIVE_TIME in
* networkstatus_get_reasonably_live_consensus(), but that value is way
* way too high. Arma: is the bridge issue there resolved yet? -NM */
#define NS_EXPIRY_SLOP (24*60*60)
if (ns && ns->valid_until < now+NS_EXPIRY_SLOP &&
router_have_minimum_dir_info()) {
router_dir_info_changed();
}
#define CHECK_EXPIRED_NS_INTERVAL (2*60)
time_to_check_for_expired_networkstatus = now + CHECK_EXPIRED_NS_INTERVAL;
}
if (time_to_dump_geoip_stats < now) {
#define DUMP_GEOIP_STATS_INTERVAL (60*60);
if (time_to_dump_geoip_stats)
dump_geoip_stats();
time_to_dump_geoip_stats = now + DUMP_GEOIP_STATS_INTERVAL;
}
/* Remove old information from rephist and the rend cache. */
if (time_to_clean_caches < now) {
rep_history_clean(now - options->RephistTrackTime);
rend_cache_clean();
rend_cache_clean_v2_descs_as_dir();
#define CLEAN_CACHES_INTERVAL (30*60)
time_to_clean_caches = now + CLEAN_CACHES_INTERVAL;
}
#define RETRY_DNS_INTERVAL (10*60)
/* If we're a server and initializing dns failed, retry periodically. */
if (time_to_retry_dns_init < now) {
time_to_retry_dns_init = now + RETRY_DNS_INTERVAL;
if (server_mode(options) && has_dns_init_failed())
dns_init();
}
/** 2. Periodically, we consider force-uploading our descriptor
* (if we've passed our internal checks). */
/** How often do we check whether part of our router info has changed in a way
* that would require an upload? */
#define CHECK_DESCRIPTOR_INTERVAL (60)
/** How often do we (as a router) check whether our IP address has changed? */
#define CHECK_IPADDRESS_INTERVAL (15*60)
/* 2b. Once per minute, regenerate and upload the descriptor if the old
* one is inaccurate. */
if (time_to_check_descriptor < now) {
static int dirport_reachability_count = 0;
time_to_check_descriptor = now + CHECK_DESCRIPTOR_INTERVAL;
check_descriptor_bandwidth_changed(now);
if (time_to_check_ipaddress < now) {
time_to_check_ipaddress = now + CHECK_IPADDRESS_INTERVAL;
check_descriptor_ipaddress_changed(now);
}
/** If our router descriptor ever goes this long without being regenerated
* because something changed, we force an immediate regenerate-and-upload. */
#define FORCE_REGENERATE_DESCRIPTOR_INTERVAL (18*60*60)
mark_my_descriptor_dirty_if_older_than(
now - FORCE_REGENERATE_DESCRIPTOR_INTERVAL);
consider_publishable_server(0);
/* also, check religiously for reachability, if it's within the first
* 20 minutes of our uptime. */
if (server_mode(options) &&
(has_completed_circuit || !any_predicted_circuits(now)) &&
!we_are_hibernating()) {
if (stats_n_seconds_working < TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT) {
consider_testing_reachability(1, dirport_reachability_count==0);
if (++dirport_reachability_count > 5)
dirport_reachability_count = 0;
} else if (time_to_recheck_bandwidth < now) {
/* If we haven't checked for 12 hours and our bandwidth estimate is
* low, do another bandwidth test. This is especially important for
* bridges, since they might go long periods without much use. */
routerinfo_t *me = router_get_my_routerinfo();
if (time_to_recheck_bandwidth && me &&
me->bandwidthcapacity < me->bandwidthrate &&
me->bandwidthcapacity < 51200) {
reset_bandwidth_test();
}
#define BANDWIDTH_RECHECK_INTERVAL (12*60*60)
time_to_recheck_bandwidth = now + BANDWIDTH_RECHECK_INTERVAL;
}
}
/* If any networkstatus documents are no longer recent, we need to
* update all the descriptors' running status. */
/* purge obsolete entries */
networkstatus_v2_list_clean(now);
/* Remove dead routers. */
routerlist_remove_old_routers();
/* Also, once per minute, check whether we want to download any
* networkstatus documents.
*/
update_networkstatus_downloads(now);
}
/** 2c. Let directory voting happen. */
if (authdir_mode_v3(options))
dirvote_act(options, now);
/** 3a. Every second, we examine pending circuits and prune the
* ones which have been pending for more than a few seconds.
* We do this before step 4, so it can try building more if
* it's not comfortable with the number of available circuits.
*/
circuit_expire_building(now);
/** 3b. Also look at pending streams and prune the ones that 'began'
* a long time ago but haven't gotten a 'connected' yet.
* Do this before step 4, so we can put them back into pending
* state to be picked up by the new circuit.
*/
connection_ap_expire_beginning();
/** 3c. And expire connections that we've held open for too long.
*/
connection_expire_held_open();
/** 3d. And every 60 seconds, we relaunch listeners if any died. */
if (!we_are_hibernating() && time_to_check_listeners < now) {
retry_all_listeners(NULL, NULL);
time_to_check_listeners = now+60;
}
/** 4. Every second, we try a new circuit if there are no valid
* circuits. Every NewCircuitPeriod seconds, we expire circuits
* that became dirty more than MaxCircuitDirtiness seconds ago,
* and we make a new circ if there are no clean circuits.
*/
have_dir_info = router_have_minimum_dir_info();
if (have_dir_info && !we_are_hibernating())
circuit_build_needed_circs(now);
/** 5. We do housekeeping for each connection... */
for (i=0;i<smartlist_len(connection_array);i++) {
run_connection_housekeeping(i, now);
}
if (time_to_shrink_memory < now) {
SMARTLIST_FOREACH(connection_array, connection_t *, conn, {
if (conn->outbuf)
buf_shrink(conn->outbuf);
if (conn->inbuf)
buf_shrink(conn->inbuf);
});
clean_cell_pool();
buf_shrink_freelists(0);
/** How often do we check buffers and pools for empty space that can be
* deallocated? */
#define MEM_SHRINK_INTERVAL (60)
time_to_shrink_memory = now + MEM_SHRINK_INTERVAL;
}
/** 6. And remove any marked circuits... */
circuit_close_all_marked();
/** 7. And upload service descriptors if necessary. */
if (has_completed_circuit && !we_are_hibernating()) {
rend_consider_services_upload(now);
rend_consider_descriptor_republication();
}
/** 8. and blow away any connections that need to die. have to do this now,
* because if we marked a conn for close and left its socket -1, then
* we'll pass it to poll/select and bad things will happen.
*/
close_closeable_connections();
/** 8b. And if anything in our state is ready to get flushed to disk, we
* flush it. */
or_state_save(now);
/** 9. and if we're a server, check whether our DNS is telling stories to
* us. */
if (server_mode(options) && time_to_check_for_correct_dns < now) {
if (!time_to_check_for_correct_dns) {
time_to_check_for_correct_dns = now + 60 + crypto_rand_int(120);
} else {
dns_launch_correctness_checks();
time_to_check_for_correct_dns = now + 12*3600 +
crypto_rand_int(12*3600);
}
}
/** 10. write hidden service usage statistic to disk */
if (options->HSAuthorityRecordStats && time_to_write_hs_statistics < now) {
hs_usage_write_statistics_to_file(now);
#define WRITE_HSUSAGE_INTERVAL (30*60)
time_to_write_hs_statistics = now+WRITE_HSUSAGE_INTERVAL;
}
/** 10b. write bridge networkstatus file to disk */
if (options->BridgeAuthoritativeDir &&
time_to_write_bridge_status_file < now) {
networkstatus_dump_bridge_status_to_file(now);
#define BRIDGE_STATUSFILE_INTERVAL (30*60)
time_to_write_bridge_status_file = now+BRIDGE_STATUSFILE_INTERVAL;
}
}
/** Libevent timer: used to invoke second_elapsed_callback() once per
* second. */
static struct event *timeout_event = NULL;
/** Number of libevent errors in the last second: we die if we get too many. */
static int n_libevent_errors = 0;
/** Libevent callback: invoked once every second. */
static void
second_elapsed_callback(int fd, short event, void *args)
{
/* XXXX This could be sensibly refactored into multiple callbacks, and we
* could use libevent's timers for this rather than checking the current
* time against a bunch of timeouts every second. */
static struct timeval one_second;
static long current_second = 0;
struct timeval now;
size_t bytes_written;
size_t bytes_read;
int seconds_elapsed;
or_options_t *options = get_options();
(void)fd;
(void)event;
(void)args;
if (!timeout_event) {
timeout_event = tor_malloc_zero(sizeof(struct event));
evtimer_set(timeout_event, second_elapsed_callback, NULL);
one_second.tv_sec = 1;
one_second.tv_usec = 0;
}
n_libevent_errors = 0;
/* log_fn(LOG_NOTICE, "Tick."); */
tor_gettimeofday(&now);
/* the second has rolled over. check more stuff. */
bytes_written = stats_prev_global_write_bucket - global_write_bucket;
bytes_read = stats_prev_global_read_bucket - global_read_bucket;
seconds_elapsed = current_second ? (int)(now.tv_sec - current_second) : 0;
stats_n_bytes_read += bytes_read;
stats_n_bytes_written += bytes_written;
if (accounting_is_enabled(options) && seconds_elapsed >= 0)
accounting_add_bytes(bytes_read, bytes_written, seconds_elapsed);
control_event_bandwidth_used((uint32_t)bytes_read,(uint32_t)bytes_written);
control_event_stream_bandwidth_used();
if (seconds_elapsed > 0)
connection_bucket_refill(seconds_elapsed, now.tv_sec);
stats_prev_global_read_bucket = global_read_bucket;
stats_prev_global_write_bucket = global_write_bucket;
if (server_mode(options) &&
!we_are_hibernating() &&
seconds_elapsed > 0 &&
has_completed_circuit &&
stats_n_seconds_working / TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT !=
(stats_n_seconds_working+seconds_elapsed) /
TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT) {
/* every 20 minutes, check and complain if necessary */
routerinfo_t *me = router_get_my_routerinfo();
if (me && !check_whether_orport_reachable())
log_warn(LD_CONFIG,"Your server (%s:%d) has not managed to confirm that "
"its ORPort is reachable. Please check your firewalls, ports, "
"address, /etc/hosts file, etc.",
me->address, me->or_port);
if (me && !check_whether_dirport_reachable())
log_warn(LD_CONFIG,
"Your server (%s:%d) has not managed to confirm that its "
"DirPort is reachable. Please check your firewalls, ports, "
"address, /etc/hosts file, etc.",
me->address, me->dir_port);
}
/** If more than this many seconds have elapsed, probably the clock
* jumped: doesn't count. */
#define NUM_JUMPED_SECONDS_BEFORE_WARN 100
if (seconds_elapsed < -NUM_JUMPED_SECONDS_BEFORE_WARN ||
seconds_elapsed >= NUM_JUMPED_SECONDS_BEFORE_WARN) {
circuit_note_clock_jumped(seconds_elapsed);
/* XXX if the time jumps *back* many months, do our events in
* run_scheduled_events() recover? I don't think they do. -RD */
} else if (seconds_elapsed > 0)
stats_n_seconds_working += seconds_elapsed;
run_scheduled_events(now.tv_sec);
current_second = now.tv_sec; /* remember which second it is, for next time */
#if 0
if (current_second % 300 == 0) {
rep_history_clean(current_second - options->RephistTrackTime);
dumpmemusage(get_min_log_level()<LOG_INFO ?
get_min_log_level() : LOG_INFO);
}
#endif
if (evtimer_add(timeout_event, &one_second))
log_err(LD_NET,
"Error from libevent when setting one-second timeout event");
}
#ifndef MS_WINDOWS
/** Called when a possibly ignorable libevent error occurs; ensures that we
* don't get into an infinite loop by ignoring too many errors from
* libevent. */
static int
got_libevent_error(void)
{
if (++n_libevent_errors > 8) {
log_err(LD_NET, "Too many libevent errors in one second; dying");
return -1;
}
return 0;
}
#endif
#define UPTIME_CUTOFF_FOR_NEW_BANDWIDTH_TEST (6*60*60)
/** Called when our IP address seems to have changed. <b>at_interface</b>
* should be true if we detected a change in our interface, and false if we
* detected a change in our published address. */
void
ip_address_changed(int at_interface)
{
int server = server_mode(get_options());
if (at_interface) {
if (! server) {
/* Okay, change our keys. */
init_keys();
}
} else {
if (server) {
if (stats_n_seconds_working > UPTIME_CUTOFF_FOR_NEW_BANDWIDTH_TEST)
reset_bandwidth_test();
stats_n_seconds_working = 0;
router_reset_reachability();
mark_my_descriptor_dirty();
}
}
dns_servers_relaunch_checks();
}
/** Forget what we've learned about the correctness of our DNS servers, and
* start learning again. */
void
dns_servers_relaunch_checks(void)
{
if (server_mode(get_options())) {
dns_reset_correctness_checks();
time_to_check_for_correct_dns = 0;
}
}
/** Called when we get a SIGHUP: reload configuration files and keys,
* retry all connections, and so on. */
static int
do_hup(void)
{
or_options_t *options = get_options();
#ifdef USE_DMALLOC
dmalloc_log_stats();
dmalloc_log_changed(0, 1, 0, 0);
#endif
log_notice(LD_GENERAL,"Received reload signal (hup). Reloading config and "
"resetting internal state.");
if (accounting_is_enabled(options))
accounting_record_bandwidth_usage(time(NULL), get_or_state());
router_reset_warnings();
routerlist_reset_warnings();
addressmap_clear_transient();
/* first, reload config variables, in case they've changed */
if (options->ReloadTorrcOnSIGHUP) {
/* no need to provide argc/v, they've been cached in init_from_config */
if (options_init_from_torrc(0, NULL) < 0) {
log_err(LD_CONFIG,"Reading config failed--see warnings above. "
"For usage, try -h.");
return -1;
}
options = get_options(); /* they have changed now */
} else {
log_notice(LD_GENERAL, "Not reloading config file: the controller told "
"us not to.");
}
if (authdir_mode_handles_descs(options, -1)) {
/* reload the approved-routers file */
if (dirserv_load_fingerprint_file() < 0) {
/* warnings are logged from dirserv_load_fingerprint_file() directly */
log_info(LD_GENERAL, "Error reloading fingerprints. "
"Continuing with old list.");
}
}
/* Rotate away from the old dirty circuits. This has to be done
* after we've read the new options, but before we start using
* circuits for directory fetches. */
circuit_expire_all_dirty_circs();
/* retry appropriate downloads */
router_reset_status_download_failures();
router_reset_descriptor_download_failures();
update_networkstatus_downloads(time(NULL));
/* We'll retry routerstatus downloads in about 10 seconds; no need to
* force a retry there. */
if (server_mode(options)) {
/* Restart cpuworker and dnsworker processes, so they get up-to-date
* configuration options. */
cpuworkers_rotate();
dns_reset();
}
return 0;
}
/** Tor main loop. */
/* static */ int
do_main_loop(void)
{
int loop_result;
time_t now;
/* initialize dns resolve map, spawn workers if needed */
if (dns_init() < 0) {
if (get_options()->ServerDNSAllowBrokenConfig)
log_warn(LD_GENERAL, "Couldn't set up any working nameservers. "
"Network not up yet? Will try again soon.");
else {
log_err(LD_GENERAL,"Error initializing dns subsystem; exiting. To "
"retry instead, set the ServerDNSAllowBrokenResolvConf option.");
}
}
handle_signals(1);
/* load the private keys, if we're supposed to have them, and set up the
* TLS context. */
if (! identity_key_is_set()) {
if (init_keys() < 0) {
log_err(LD_BUG,"Error initializing keys; exiting");
return -1;
}
}
/* Set up the packed_cell_t memory pool. */
init_cell_pool();
/* Set up our buckets */
connection_bucket_init();
stats_prev_global_read_bucket = global_read_bucket;
stats_prev_global_write_bucket = global_write_bucket;
/* initialize the bootstrap status events to know we're starting up */
control_event_bootstrap(BOOTSTRAP_STATUS_STARTING, 0);
if (trusted_dirs_reload_certs())
return -1;
if (router_reload_v2_networkstatus()) {
return -1;
}
if (router_reload_consensus_networkstatus()) {
return -1;
}
/* load the routers file, or assign the defaults. */
if (router_reload_router_list()) {
return -1;
}
/* load the networkstatuses. (This launches a download for new routers as
* appropriate.)
*/
now = time(NULL);
directory_info_has_arrived(now, 1);
if (authdir_mode_tests_reachability(get_options())) {
/* the directory is already here, run startup things */
dirserv_test_reachability(now, 1);
}
if (server_mode(get_options())) {
/* launch cpuworkers. Need to do this *after* we've read the onion key. */
cpu_init();
}
/* set up once-a-second callback. */
second_elapsed_callback(0,0,NULL);
for (;;) {
if (nt_service_is_stopping())
return 0;
#ifndef MS_WINDOWS
/* Make it easier to tell whether libevent failure is our fault or not. */
errno = 0;
#endif
/* All active linked conns should get their read events activated. */
SMARTLIST_FOREACH(active_linked_connection_lst, connection_t *, conn,
event_active(conn->read_event, EV_READ, 1));
called_loop_once = smartlist_len(active_linked_connection_lst) ? 1 : 0;
/* poll until we have an event, or the second ends, or until we have
* some active linked connections to trigger events for. */
loop_result = event_loop(called_loop_once ? EVLOOP_ONCE : 0);
/* let catch() handle things like ^c, and otherwise don't worry about it */
if (loop_result < 0) {
int e = tor_socket_errno(-1);
/* let the program survive things like ^z */
if (e != EINTR && !ERRNO_IS_EINPROGRESS(e)) {
#ifdef HAVE_EVENT_GET_METHOD
log_err(LD_NET,"libevent call with %s failed: %s [%d]",
event_get_method(), tor_socket_strerror(e), e);
#else
log_err(LD_NET,"libevent call failed: %s [%d]",
tor_socket_strerror(e), e);
#endif
return -1;
#ifndef MS_WINDOWS
} else if (e == EINVAL) {
log_warn(LD_NET, "EINVAL from libevent: should you upgrade libevent?");
if (got_libevent_error())
return -1;
#endif
} else {
if (ERRNO_IS_EINPROGRESS(e))
log_warn(LD_BUG,
"libevent call returned EINPROGRESS? Please report.");
log_debug(LD_NET,"libevent call interrupted.");
/* You can't trust the results of this poll(). Go back to the
* top of the big for loop. */
continue;
}
}
}
}
/** Used to implement the SIGNAL control command: if we accept
* <b>the_signal</b> as a remote pseudo-signal, act on it. */
/* We don't re-use catch() here because:
* 1. We handle a different set of signals than those allowed in catch.
* 2. Platforms without signal() are unlikely to define SIGfoo.
* 3. The control spec is defined to use fixed numeric signal values
* which just happen to match the unix values.
*/
void
control_signal_act(int the_signal)
{
switch (the_signal)
{
case 1:
signal_callback(0,0,(void*)(uintptr_t)SIGHUP);
break;
case 2:
signal_callback(0,0,(void*)(uintptr_t)SIGINT);
break;
case 10:
signal_callback(0,0,(void*)(uintptr_t)SIGUSR1);
break;
case 12:
signal_callback(0,0,(void*)(uintptr_t)SIGUSR2);
break;
case 15:
signal_callback(0,0,(void*)(uintptr_t)SIGTERM);
break;
case SIGNEWNYM:
signal_callback(0,0,(void*)(uintptr_t)SIGNEWNYM);
break;
case SIGCLEARDNSCACHE:
signal_callback(0,0,(void*)(uintptr_t)SIGCLEARDNSCACHE);
break;
default:
log_warn(LD_BUG, "Unrecognized signal number %d.", the_signal);
break;
}
}
/** Libevent callback: invoked when we get a signal.
*/
static void
signal_callback(int fd, short events, void *arg)
{
uintptr_t sig = (uintptr_t)arg;
(void)fd;
(void)events;
switch (sig)
{
case SIGTERM:
log_notice(LD_GENERAL,"Catching signal TERM, exiting cleanly.");
tor_cleanup();
exit(0);
break;
case SIGINT:
if (!server_mode(get_options())) { /* do it now */
log_notice(LD_GENERAL,"Interrupt: exiting cleanly.");
tor_cleanup();
exit(0);
}
hibernate_begin_shutdown();
break;
#ifdef SIGPIPE
case SIGPIPE:
log_debug(LD_GENERAL,"Caught sigpipe. Ignoring.");
break;
#endif
case SIGUSR1:
/* prefer to log it at INFO, but make sure we always see it */
dumpstats(get_min_log_level()<LOG_INFO ? get_min_log_level() : LOG_INFO);
break;
case SIGUSR2:
switch_logs_debug();
log_debug(LD_GENERAL,"Caught USR2, going to loglevel debug. "
"Send HUP to change back.");
break;
case SIGHUP:
if (do_hup() < 0) {
log_warn(LD_CONFIG,"Restart failed (config error?). Exiting.");
tor_cleanup();
exit(1);
}
break;
#ifdef SIGCHLD
case SIGCHLD:
while (waitpid(-1,NULL,WNOHANG) > 0) ; /* keep reaping until no more
zombies */
break;
#endif
case SIGNEWNYM: {
time_t now = time(NULL);
if (time_of_last_signewnym + MAX_SIGNEWNYM_RATE > now) {
signewnym_is_pending = 1;
log(LOG_NOTICE, LD_CONTROL,
"Rate limiting NEWNYM request: delaying by %d second(s)",
(int)(MAX_SIGNEWNYM_RATE+time_of_last_signewnym-now));
} else {
signewnym_impl(now);
}
break;
}
case SIGCLEARDNSCACHE:
addressmap_clear_transient();
break;
}
}
extern uint64_t rephist_total_alloc;
extern uint32_t rephist_total_num;
/**
* Write current memory usage information to the log.
*/
static void
dumpmemusage(int severity)
{
connection_dump_buffer_mem_stats(severity);
log(severity, LD_GENERAL, "In rephist: "U64_FORMAT" used by %d Tors.",
U64_PRINTF_ARG(rephist_total_alloc), rephist_total_num);
dump_routerlist_mem_usage(severity);
dump_cell_pool_usage(severity);
buf_dump_freelist_sizes(severity);
tor_log_mallinfo(severity);
}
/** Write all statistics to the log, with log level 'severity'. Called
* in response to a SIGUSR1. */
static void
dumpstats(int severity)
{
time_t now = time(NULL);
time_t elapsed;
int rbuf_cap, wbuf_cap, rbuf_len, wbuf_len;
log(severity, LD_GENERAL, "Dumping stats:");
SMARTLIST_FOREACH(connection_array, connection_t *, conn,
{
int i = conn_sl_idx;
log(severity, LD_GENERAL,
"Conn %d (socket %d) type %d (%s), state %d (%s), created %d secs ago",
i, conn->s, conn->type, conn_type_to_string(conn->type),
conn->state, conn_state_to_string(conn->type, conn->state),
(int)(now - conn->timestamp_created));
if (!connection_is_listener(conn)) {
log(severity,LD_GENERAL,
"Conn %d is to %s:%d.", i,
safe_str(conn->address), conn->port);
log(severity,LD_GENERAL,
"Conn %d: %d bytes waiting on inbuf (len %d, last read %d secs ago)",
i,
(int)buf_datalen(conn->inbuf),
(int)buf_allocation(conn->inbuf),
(int)(now - conn->timestamp_lastread));
log(severity,LD_GENERAL,
"Conn %d: %d bytes waiting on outbuf "
"(len %d, last written %d secs ago)",i,
(int)buf_datalen(conn->outbuf),
(int)buf_allocation(conn->outbuf),
(int)(now - conn->timestamp_lastwritten));
if (conn->type == CONN_TYPE_OR) {
or_connection_t *or_conn = TO_OR_CONN(conn);
if (or_conn->tls) {
tor_tls_get_buffer_sizes(or_conn->tls, &rbuf_cap, &rbuf_len,
&wbuf_cap, &wbuf_len);
log(severity, LD_GENERAL,
"Conn %d: %d/%d bytes used on openssl read buffer; "
"%d/%d bytes used on write buffer.",
i, rbuf_len, rbuf_cap, wbuf_len, wbuf_cap);
}
}
}
circuit_dump_by_conn(conn, severity); /* dump info about all the circuits
* using this conn */
});
log(severity, LD_NET,
"Cells processed: "U64_FORMAT" padding\n"
" "U64_FORMAT" create\n"
" "U64_FORMAT" created\n"
" "U64_FORMAT" relay\n"
" ("U64_FORMAT" relayed)\n"
" ("U64_FORMAT" delivered)\n"
" "U64_FORMAT" destroy",
U64_PRINTF_ARG(stats_n_padding_cells_processed),
U64_PRINTF_ARG(stats_n_create_cells_processed),
U64_PRINTF_ARG(stats_n_created_cells_processed),
U64_PRINTF_ARG(stats_n_relay_cells_processed),
U64_PRINTF_ARG(stats_n_relay_cells_relayed),
U64_PRINTF_ARG(stats_n_relay_cells_delivered),
U64_PRINTF_ARG(stats_n_destroy_cells_processed));
if (stats_n_data_cells_packaged)
log(severity,LD_NET,"Average packaged cell fullness: %2.3f%%",
100*(U64_TO_DBL(stats_n_data_bytes_packaged) /
U64_TO_DBL(stats_n_data_cells_packaged*RELAY_PAYLOAD_SIZE)) );
if (stats_n_data_cells_received)
log(severity,LD_NET,"Average delivered cell fullness: %2.3f%%",
100*(U64_TO_DBL(stats_n_data_bytes_received) /
U64_TO_DBL(stats_n_data_cells_received*RELAY_PAYLOAD_SIZE)) );
if (now - time_of_process_start >= 0)
elapsed = now - time_of_process_start;
else
elapsed = 0;
if (elapsed) {
log(severity, LD_NET,
"Average bandwidth: "U64_FORMAT"/%d = %d bytes/sec reading",
U64_PRINTF_ARG(stats_n_bytes_read),
(int)elapsed,
(int) (stats_n_bytes_read/elapsed));
log(severity, LD_NET,
"Average bandwidth: "U64_FORMAT"/%d = %d bytes/sec writing",
U64_PRINTF_ARG(stats_n_bytes_written),
(int)elapsed,
(int) (stats_n_bytes_written/elapsed));
}
log(severity, LD_NET, "--------------- Dumping memory information:");
dumpmemusage(severity);
rep_hist_dump_stats(now,severity);
rend_service_dump_stats(severity);
dump_pk_ops(severity);
dump_distinct_digest_count(severity);
}
/** Called by exit() as we shut down the process.
*/
static void
exit_function(void)
{
/* NOTE: If we ever daemonize, this gets called immediately. That's
* okay for now, because we only use this on Windows. */
#ifdef MS_WINDOWS
WSACleanup();
#endif
}
/** Set up the signal handlers for either parent or child. */
void
handle_signals(int is_parent)
{
#ifndef MS_WINDOWS /* do signal stuff only on unix */
int i;
static int signals[] = {
SIGINT, /* do a controlled slow shutdown */
SIGTERM, /* to terminate now */
SIGPIPE, /* otherwise sigpipe kills us */
SIGUSR1, /* dump stats */
SIGUSR2, /* go to loglevel debug */
SIGHUP, /* to reload config, retry conns, etc */
#ifdef SIGXFSZ
SIGXFSZ, /* handle file-too-big resource exhaustion */
#endif
SIGCHLD, /* handle dns/cpu workers that exit */
-1 };
static struct event signal_events[16]; /* bigger than it has to be. */
if (is_parent) {
for (i = 0; signals[i] >= 0; ++i) {
signal_set(&signal_events[i], signals[i], signal_callback,
(void*)(uintptr_t)signals[i]);
if (signal_add(&signal_events[i], NULL))
log_warn(LD_BUG, "Error from libevent when adding event for signal %d",
signals[i]);
}
} else {
struct sigaction action;
action.sa_flags = 0;
sigemptyset(&action.sa_mask);
action.sa_handler = SIG_IGN;
sigaction(SIGINT, &action, NULL);
sigaction(SIGTERM, &action, NULL);
sigaction(SIGPIPE, &action, NULL);
sigaction(SIGUSR1, &action, NULL);
sigaction(SIGUSR2, &action, NULL);
sigaction(SIGHUP, &action, NULL);
#ifdef SIGXFSZ
sigaction(SIGXFSZ, &action, NULL);
#endif
}
#else /* MS windows */
(void)is_parent;
#endif /* signal stuff */
}
/** Main entry point for the Tor command-line client.
*/
/* static */ int
tor_init(int argc, char *argv[])
{
char buf[256];
int i, quiet = 0;
time_of_process_start = time(NULL);
if (!connection_array)
connection_array = smartlist_create();
if (!closeable_connection_lst)
closeable_connection_lst = smartlist_create();
if (!active_linked_connection_lst)
active_linked_connection_lst = smartlist_create();
/* Have the log set up with our application name. */
tor_snprintf(buf, sizeof(buf), "Tor %s", get_version());
log_set_application_name(buf);
/* Initialize the history structures. */
rep_hist_init();
/* Initialize the service cache. */
rend_cache_init();
addressmap_init(); /* Init the client dns cache. Do it always, since it's
* cheap. */
/* We search for the "quiet" option first, since it decides whether we
* will log anything at all to the command line. */
for (i=1;i<argc;++i) {
if (!strcmp(argv[i], "--hush"))
quiet = 1;
if (!strcmp(argv[i], "--quiet"))
quiet = 2;
}
/* give it somewhere to log to initially */
switch (quiet) {
case 2:
/* no initial logging */
break;
case 1:
add_temp_log(LOG_WARN);
break;
default:
add_temp_log(LOG_NOTICE);
}
log(LOG_NOTICE, LD_GENERAL, "Tor v%s. This is experimental software. "
"Do not rely on it for strong anonymity. (Running on %s)",get_version(),
get_uname());
if (network_init()<0) {
log_err(LD_BUG,"Error initializing network; exiting.");
return -1;
}
atexit(exit_function);
if (options_init_from_torrc(argc,argv) < 0) {
log_err(LD_CONFIG,"Reading config failed--see warnings above.");
return -1;
}
#ifndef MS_WINDOWS
if (geteuid()==0)
log_warn(LD_GENERAL,"You are running Tor as root. You don't need to, "
"and you probably shouldn't.");
#endif
crypto_global_init(get_options()->HardwareAccel);
if (crypto_seed_rng(1)) {
log_err(LD_BUG, "Unable to seed random number generator. Exiting.");
return -1;
}
return 0;
}
static tor_lockfile_t *lockfile = NULL;
/** Try to grab the lock file described in <b>options</b>, if we do not
* already have it. If <b>err_if_locked</b> is true, warn if somebody else is
* holding the lock, and exit if we can't get it after waiting. Otherwise,
* return -1 if we can't get the lockfile. Return 0 on success.
*/
int
try_locking(or_options_t *options, int err_if_locked)
{
if (lockfile)
return 0;
else {
char *fname = options_get_datadir_fname2_suffix(options, "lock",NULL,NULL);
int already_locked = 0;
tor_lockfile_t *lf = tor_lockfile_lock(fname, 0, &already_locked);
tor_free(fname);
if (!lf) {
if (err_if_locked && already_locked) {
int r;
log_warn(LD_GENERAL, "It looks like another Tor process is running "
"with the same data directory. Waiting 5 seconds to see "
"if it goes away.");
#ifndef WIN32
sleep(5);
#else
Sleep(5000);
#endif
r = try_locking(options, 0);
if (r<0) {
log_err(LD_GENERAL, "No, it's still there. Exiting.");
exit(0);
}
return r;
}
return -1;
}
lockfile = lf;
return 0;
}
}
int
have_lockfile(void)
{
return lockfile != NULL;
}
void
release_lockfile(void)
{
if (lockfile) {
tor_lockfile_unlock(lockfile);
lockfile = NULL;
}
}
/** Free all memory that we might have allocated somewhere.
* If <b>postfork</b>, we are a worker process and we want to free
* only the parts of memory that we won't touch. If !<b>postfork</b>,
* Tor is shutting down and we should free everything.
*
* Helps us find the real leaks with dmalloc and the like. Also valgrind
* should then report 0 reachable in its leak report (in an ideal world --
* in practice libevent, ssl, libc etc never quite free everything). */
void
tor_free_all(int postfork)
{
if (!postfork) {
evdns_shutdown(1);
}
geoip_free_all();
dirvote_free_all();
routerlist_free_all();
networkstatus_free_all();
addressmap_free_all();
set_exit_redirects(NULL); /* free the registered exit redirects */
dirserv_free_all();
rend_service_free_all();
rend_cache_free_all();
rend_service_authorization_free_all();
rep_hist_free_all();
hs_usage_free_all();
dns_free_all();
clear_pending_onions();
circuit_free_all();
entry_guards_free_all();
connection_free_all();
buf_shrink_freelists(1);
memarea_clear_freelist();
if (!postfork) {
config_free_all();
router_free_all();
policies_free_all();
}
free_cell_pool();
if (!postfork) {
tor_tls_free_all();
}
/* stuff in main.c */
if (connection_array)
smartlist_free(connection_array);
if (closeable_connection_lst)
smartlist_free(closeable_connection_lst);
if (active_linked_connection_lst)
smartlist_free(active_linked_connection_lst);
tor_free(timeout_event);
/* Stuff in util.c and address.c*/
if (!postfork) {
escaped(NULL);
esc_router_info(NULL);
logs_free_all(); /* free log strings. do this last so logs keep working. */
}
}
/** Do whatever cleanup is necessary before shutting Tor down. */
void
tor_cleanup(void)
{
or_options_t *options = get_options();
/* Remove our pid file. We don't care if there was an error when we
* unlink, nothing we could do about it anyways. */
if (options->command == CMD_RUN_TOR) {
if (options->PidFile)
unlink(options->PidFile);
if (accounting_is_enabled(options))
accounting_record_bandwidth_usage(time(NULL), get_or_state());
or_state_mark_dirty(get_or_state(), 0); /* force an immediate save. */
or_state_save(time(NULL));
if (authdir_mode_tests_reachability(options))
rep_hist_record_mtbf_data();
}
#ifdef USE_DMALLOC
dmalloc_log_stats();
#endif
tor_free_all(0); /* We could move tor_free_all back into the ifdef below
later, if it makes shutdown unacceptably slow. But for
now, leave it here: it's helped us catch bugs in the
past. */
crypto_global_cleanup();
#ifdef USE_DMALLOC
dmalloc_log_unfreed();
dmalloc_shutdown();
#endif
}
/** Read/create keys as needed, and echo our fingerprint to stdout. */
/* static */ int
do_list_fingerprint(void)
{
char buf[FINGERPRINT_LEN+1];
crypto_pk_env_t *k;
const char *nickname = get_options()->Nickname;
if (!server_mode(get_options())) {
log_err(LD_GENERAL,
"Clients don't have long-term identity keys. Exiting.\n");
return -1;
}
tor_assert(nickname);
if (init_keys() < 0) {
log_err(LD_BUG,"Error initializing keys; can't display fingerprint");
return -1;
}
if (!(k = get_identity_key())) {
log_err(LD_GENERAL,"Error: missing identity key.");
return -1;
}
if (crypto_pk_get_fingerprint(k, buf, 1)<0) {
log_err(LD_BUG, "Error computing fingerprint");
return -1;
}
printf("%s %s\n", nickname, buf);
return 0;
}
/** Entry point for password hashing: take the desired password from
* the command line, and print its salted hash to stdout. **/
/* static */ void
do_hash_password(void)
{
char output[256];
char key[S2K_SPECIFIER_LEN+DIGEST_LEN];
crypto_rand(key, S2K_SPECIFIER_LEN-1);
key[S2K_SPECIFIER_LEN-1] = (uint8_t)96; /* Hash 64 K of data. */
secret_to_key(key+S2K_SPECIFIER_LEN, DIGEST_LEN,
get_options()->command_arg, strlen(get_options()->command_arg),
key);
base16_encode(output, sizeof(output), key, sizeof(key));
printf("16:%s\n",output);
}
/** Main entry point for the Tor process. Called from main(). */
/* This function is distinct from main() only so we can link main.c into
* the unittest binary without conflicting with the unittests' main. */
int
tor_main(int argc, char *argv[])
{
int result = 0;
tor_threads_init();
init_logging();
#ifdef USE_DMALLOC
{
/* Instruct OpenSSL to use our internal wrappers for malloc,
realloc and free. */
int r = CRYPTO_set_mem_ex_functions(_tor_malloc, _tor_realloc, _tor_free);
tor_assert(r);
}
#endif
#ifdef NT_SERVICE
{
int done = 0;
result = nt_service_parse_options(argc, argv, &done);
if (done) return result;
}
#endif
if (tor_init(argc, argv)<0)
return -1;
switch (get_options()->command) {
case CMD_RUN_TOR:
#ifdef NT_SERVICE
nt_service_set_state(SERVICE_RUNNING);
#endif
result = do_main_loop();
break;
case CMD_LIST_FINGERPRINT:
result = do_list_fingerprint();
break;
case CMD_HASH_PASSWORD:
do_hash_password();
result = 0;
break;
case CMD_VERIFY_CONFIG:
printf("Configuration was valid\n");
result = 0;
break;
case CMD_RUN_UNITTESTS: /* only set by test.c */
default:
log_warn(LD_BUG,"Illegal command number %d: internal error.",
get_options()->command);
result = -1;
}
tor_cleanup();
return result;
}
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