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/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file hibernate.c
* \brief Functions to close listeners, stop allowing new circuits,
* etc in preparation for closing down or going dormant; and to track
* bandwidth and time intervals to know when to hibernate and when to
* stop hibernating.
*
* Ordinarily a Tor relay is "Live".
*
* A live relay can stop accepting connections for one of two reasons: either
* it is trying to conserve bandwidth because of bandwidth accounting rules
* ("soft hibernation"), or it is about to shut down ("exiting").
**/
/*
hibernating, phase 1:
- send destroy in response to create cells
- send end (policy failed) in response to begin cells
- close an OR conn when it has no circuits
hibernating, phase 2:
(entered when bandwidth hard limit reached)
- close all OR/AP/exit conns)
*/
#define HIBERNATE_PRIVATE
#include "or.h"
#include "channel.h"
#include "channeltls.h"
#include "config.h"
#include "connection.h"
#include "connection_edge.h"
#include "connection_or.h"
#include "control.h"
#include "crypto_rand.h"
#include "hibernate.h"
#include "main.h"
#include "router.h"
#include "statefile.h"
/** Are we currently awake, asleep, running out of bandwidth, or shutting
* down? */
static hibernate_state_t hibernate_state = HIBERNATE_STATE_INITIAL;
/** If are hibernating, when do we plan to wake up? Set to 0 if we
* aren't hibernating. */
static time_t hibernate_end_time = 0;
/** If we are shutting down, when do we plan finally exit? Set to 0 if
* we aren't shutting down. */
static time_t shutdown_time = 0;
/** A timed event that we'll use when it's time to wake up from
* hibernation. */
static mainloop_event_t *wakeup_event = NULL;
/** Possible accounting periods. */
typedef enum {
UNIT_MONTH=1, UNIT_WEEK=2, UNIT_DAY=3,
} time_unit_t;
/*
* @file hibernate.c
*
* <h4>Accounting</h4>
* Accounting is designed to ensure that no more than N bytes are sent in
* either direction over a given interval (currently, one month, one week, or
* one day) We could
* try to do this by choking our bandwidth to a trickle, but that
* would make our streams useless. Instead, we estimate what our
* bandwidth usage will be, and guess how long we'll be able to
* provide that much bandwidth before hitting our limit. We then
* choose a random time within the accounting interval to come up (so
* that we don't get 50 Tors running on the 1st of the month and none
* on the 30th).
*
* Each interval runs as follows:
*
* <ol>
* <li>We guess our bandwidth usage, based on how much we used
* last time. We choose a "wakeup time" within the interval to come up.
* <li>Until the chosen wakeup time, we hibernate.
* <li> We come up at the wakeup time, and provide bandwidth until we are
* "very close" to running out.
* <li> Then we go into low-bandwidth mode, and stop accepting new
* connections, but provide bandwidth until we run out.
* <li> Then we hibernate until the end of the interval.
*
* If the interval ends before we run out of bandwidth, we go back to
* step one.
*
* Accounting is controlled by the AccountingMax, AccountingRule, and
* AccountingStart options.
*/
/** How many bytes have we read in this accounting interval? */
static uint64_t n_bytes_read_in_interval = 0;
/** How many bytes have we written in this accounting interval? */
static uint64_t n_bytes_written_in_interval = 0;
/** How many seconds have we been running this interval? */
static uint32_t n_seconds_active_in_interval = 0;
/** How many seconds were we active in this interval before we hit our soft
* limit? */
static int n_seconds_to_hit_soft_limit = 0;
/** When in this interval was the soft limit hit. */
static time_t soft_limit_hit_at = 0;
/** How many bytes had we read/written when we hit the soft limit? */
static uint64_t n_bytes_at_soft_limit = 0;
/** When did this accounting interval start? */
static time_t interval_start_time = 0;
/** When will this accounting interval end? */
static time_t interval_end_time = 0;
/** How far into the accounting interval should we hibernate? */
static time_t interval_wakeup_time = 0;
/** How much bandwidth do we 'expect' to use per minute? (0 if we have no
* info from the last period.) */
static uint64_t expected_bandwidth_usage = 0;
/** What unit are we using for our accounting? */
static time_unit_t cfg_unit = UNIT_MONTH;
/** How many days,hours,minutes into each unit does our accounting interval
* start? */
/** @{ */
static int cfg_start_day = 0,
cfg_start_hour = 0,
cfg_start_min = 0;
/** @} */
static const char *hibernate_state_to_string(hibernate_state_t state);
static void reset_accounting(time_t now);
static int read_bandwidth_usage(void);
static time_t start_of_accounting_period_after(time_t now);
static time_t start_of_accounting_period_containing(time_t now);
static void accounting_set_wakeup_time(void);
static void on_hibernate_state_change(hibernate_state_t prev_state);
static void hibernate_schedule_wakeup_event(time_t now, time_t end_time);
static void wakeup_event_callback(mainloop_event_t *ev, void *data);
/**
* Return the human-readable name for the hibernation state <b>state</b>
*/
static const char *
hibernate_state_to_string(hibernate_state_t state)
{
static char buf[64];
switch (state) {
case HIBERNATE_STATE_EXITING: return "EXITING";
case HIBERNATE_STATE_LOWBANDWIDTH: return "SOFT";
case HIBERNATE_STATE_DORMANT: return "HARD";
case HIBERNATE_STATE_INITIAL:
case HIBERNATE_STATE_LIVE:
return "AWAKE";
default:
log_warn(LD_BUG, "unknown hibernate state %d", state);
tor_snprintf(buf, sizeof(buf), "unknown [%d]", state);
return buf;
}
}
/* ************
* Functions for bandwidth accounting.
* ************/
/** Configure accounting start/end time settings based on
* options->AccountingStart. Return 0 on success, -1 on failure. If
* <b>validate_only</b> is true, do not change the current settings. */
int
accounting_parse_options(const or_options_t *options, int validate_only)
{
time_unit_t unit;
int ok, idx;
long d,h,m;
smartlist_t *items;
const char *v = options->AccountingStart;
const char *s;
char *cp;
if (!v) {
if (!validate_only) {
cfg_unit = UNIT_MONTH;
cfg_start_day = 1;
cfg_start_hour = 0;
cfg_start_min = 0;
}
return 0;
}
items = smartlist_new();
smartlist_split_string(items, v, NULL,
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK,0);
if (smartlist_len(items)<2) {
log_warn(LD_CONFIG, "Too few arguments to AccountingStart");
goto err;
}
s = smartlist_get(items,0);
if (0==strcasecmp(s, "month")) {
unit = UNIT_MONTH;
} else if (0==strcasecmp(s, "week")) {
unit = UNIT_WEEK;
} else if (0==strcasecmp(s, "day")) {
unit = UNIT_DAY;
} else {
log_warn(LD_CONFIG,
"Unrecognized accounting unit '%s': only 'month', 'week',"
" and 'day' are supported.", s);
goto err;
}
switch (unit) {
case UNIT_WEEK:
d = tor_parse_long(smartlist_get(items,1), 10, 1, 7, &ok, NULL);
if (!ok) {
log_warn(LD_CONFIG, "Weekly accounting must begin on a day between "
"1 (Monday) and 7 (Sunday)");
goto err;
}
break;
case UNIT_MONTH:
d = tor_parse_long(smartlist_get(items,1), 10, 1, 28, &ok, NULL);
if (!ok) {
log_warn(LD_CONFIG, "Monthly accounting must begin on a day between "
"1 and 28");
goto err;
}
break;
case UNIT_DAY:
d = 0;
break;
/* Coverity dislikes unreachable default cases; some compilers warn on
* switch statements missing a case. Tell Coverity not to worry. */
/* coverity[dead_error_begin] */
default:
tor_assert(0);
}
idx = unit==UNIT_DAY?1:2;
if (smartlist_len(items) != (idx+1)) {
log_warn(LD_CONFIG,"Accounting unit '%s' requires %d argument%s.",
s, idx, (idx>1)?"s":"");
goto err;
}
s = smartlist_get(items, idx);
h = tor_parse_long(s, 10, 0, 23, &ok, &cp);
if (!ok) {
log_warn(LD_CONFIG,"Accounting start time not parseable: bad hour.");
goto err;
}
if (!cp || *cp!=':') {
log_warn(LD_CONFIG,
"Accounting start time not parseable: not in HH:MM format");
goto err;
}
m = tor_parse_long(cp+1, 10, 0, 59, &ok, &cp);
if (!ok) {
log_warn(LD_CONFIG, "Accounting start time not parseable: bad minute");
goto err;
}
if (!cp || *cp!='\0') {
log_warn(LD_CONFIG,
"Accounting start time not parseable: not in HH:MM format");
goto err;
}
if (!validate_only) {
cfg_unit = unit;
cfg_start_day = (int)d;
cfg_start_hour = (int)h;
cfg_start_min = (int)m;
}
SMARTLIST_FOREACH(items, char *, item, tor_free(item));
smartlist_free(items);
return 0;
err:
SMARTLIST_FOREACH(items, char *, item, tor_free(item));
smartlist_free(items);
return -1;
}
/** If we want to manage the accounting system and potentially
* hibernate, return 1, else return 0.
*/
MOCK_IMPL(int,
accounting_is_enabled,(const or_options_t *options))
{
if (options->AccountingMax)
return 1;
return 0;
}
/** If accounting is enabled, return how long (in seconds) this
* interval lasts. */
int
accounting_get_interval_length(void)
{
return (int)(interval_end_time - interval_start_time);
}
/** Return the time at which the current accounting interval will end. */
MOCK_IMPL(time_t,
accounting_get_end_time,(void))
{
return interval_end_time;
}
/** Called from connection.c to tell us that <b>seconds</b> seconds have
* passed, <b>n_read</b> bytes have been read, and <b>n_written</b>
* bytes have been written. */
void
accounting_add_bytes(size_t n_read, size_t n_written, int seconds)
{
n_bytes_read_in_interval += n_read;
n_bytes_written_in_interval += n_written;
/* If we haven't been called in 10 seconds, we're probably jumping
* around in time. */
n_seconds_active_in_interval += (seconds < 10) ? seconds : 0;
}
/** If get_end, return the end of the accounting period that contains
* the time <b>now</b>. Else, return the start of the accounting
* period that contains the time <b>now</b> */
static time_t
edge_of_accounting_period_containing(time_t now, int get_end)
{
int before;
struct tm tm;
tor_localtime_r(&now, &tm);
/* Set 'before' to true iff the current time is before the hh:mm
* changeover time for today. */
before = tm.tm_hour < cfg_start_hour ||
(tm.tm_hour == cfg_start_hour && tm.tm_min < cfg_start_min);
/* Dispatch by unit. First, find the start day of the given period;
* then, if get_end is true, increment to the end day. */
switch (cfg_unit)
{
case UNIT_MONTH: {
/* If this is before the Nth, we want the Nth of last month. */
if (tm.tm_mday < cfg_start_day ||
(tm.tm_mday == cfg_start_day && before)) {
--tm.tm_mon;
}
/* Otherwise, the month is correct. */
tm.tm_mday = cfg_start_day;
if (get_end)
++tm.tm_mon;
break;
}
case UNIT_WEEK: {
/* What is the 'target' day of the week in struct tm format? (We
say Sunday==7; struct tm says Sunday==0.) */
int wday = cfg_start_day % 7;
/* How many days do we subtract from today to get to the right day? */
int delta = (7+tm.tm_wday-wday)%7;
/* If we are on the right day, but the changeover hasn't happened yet,
* then subtract a whole week. */
if (delta == 0 && before)
delta = 7;
tm.tm_mday -= delta;
if (get_end)
tm.tm_mday += 7;
break;
}
case UNIT_DAY:
if (before)
--tm.tm_mday;
if (get_end)
++tm.tm_mday;
break;
default:
tor_assert(0);
}
tm.tm_hour = cfg_start_hour;
tm.tm_min = cfg_start_min;
tm.tm_sec = 0;
tm.tm_isdst = -1; /* Autodetect DST */
return mktime(&tm);
}
/** Return the start of the accounting period containing the time
* <b>now</b>. */
static time_t
start_of_accounting_period_containing(time_t now)
{
return edge_of_accounting_period_containing(now, 0);
}
/** Return the start of the accounting period that comes after the one
* containing the time <b>now</b>. */
static time_t
start_of_accounting_period_after(time_t now)
{
return edge_of_accounting_period_containing(now, 1);
}
/** Return the length of the accounting period containing the time
* <b>now</b>. */
static long
length_of_accounting_period_containing(time_t now)
{
return edge_of_accounting_period_containing(now, 1) -
edge_of_accounting_period_containing(now, 0);
}
/** Initialize the accounting subsystem. */
void
configure_accounting(time_t now)
{
time_t s_now;
/* Try to remember our recorded usage. */
if (!interval_start_time)
read_bandwidth_usage(); /* If we fail, we'll leave values at zero, and
* reset below.*/
s_now = start_of_accounting_period_containing(now);
if (!interval_start_time) {
/* We didn't have recorded usage; Start a new interval. */
log_info(LD_ACCT, "Starting new accounting interval.");
reset_accounting(now);
} else if (s_now == interval_start_time) {
log_info(LD_ACCT, "Continuing accounting interval.");
/* We are in the interval we thought we were in. Do nothing.*/
interval_end_time = start_of_accounting_period_after(interval_start_time);
} else {
long duration =
length_of_accounting_period_containing(interval_start_time);
double delta = ((double)(s_now - interval_start_time)) / duration;
if (-0.50 <= delta && delta <= 0.50) {
/* The start of the period is now a little later or earlier than we
* remembered. That's fine; we might lose some bytes we could otherwise
* have written, but better to err on the side of obeying accounting
* settings. */
log_info(LD_ACCT, "Accounting interval moved by %.02f%%; "
"that's fine.", delta*100);
interval_end_time = start_of_accounting_period_after(now);
} else if (delta >= 0.99) {
/* This is the regular time-moved-forward case; don't be too noisy
* about it or people will complain */
log_info(LD_ACCT, "Accounting interval elapsed; starting a new one");
reset_accounting(now);
} else {
log_warn(LD_ACCT,
"Mismatched accounting interval: moved by %.02f%%. "
"Starting a fresh one.", delta*100);
reset_accounting(now);
}
}
accounting_set_wakeup_time();
}
/** Return the relevant number of bytes sent/received this interval
* based on the set AccountingRule */
uint64_t
get_accounting_bytes(void)
{
if (get_options()->AccountingRule == ACCT_SUM)
return n_bytes_read_in_interval+n_bytes_written_in_interval;
else if (get_options()->AccountingRule == ACCT_IN)
return n_bytes_read_in_interval;
else if (get_options()->AccountingRule == ACCT_OUT)
return n_bytes_written_in_interval;
else
return MAX(n_bytes_read_in_interval, n_bytes_written_in_interval);
}
/** Set expected_bandwidth_usage based on how much we sent/received
* per minute last interval (if we were up for at least 30 minutes),
* or based on our declared bandwidth otherwise. */
static void
update_expected_bandwidth(void)
{
uint64_t expected;
const or_options_t *options= get_options();
uint64_t max_configured = (options->RelayBandwidthRate > 0 ?
options->RelayBandwidthRate :
options->BandwidthRate) * 60;
/* max_configured is the larger of bytes read and bytes written
* If we are accounting based on sum, worst case is both are
* at max, doubling the expected sum of bandwidth */
if (get_options()->AccountingRule == ACCT_SUM)
max_configured *= 2;
#define MIN_TIME_FOR_MEASUREMENT (1800)
if (soft_limit_hit_at > interval_start_time && n_bytes_at_soft_limit &&
(soft_limit_hit_at - interval_start_time) > MIN_TIME_FOR_MEASUREMENT) {
/* If we hit our soft limit last time, only count the bytes up to that
* time. This is a better predictor of our actual bandwidth than
* considering the entirety of the last interval, since we likely started
* using bytes very slowly once we hit our soft limit. */
expected = n_bytes_at_soft_limit /
(soft_limit_hit_at - interval_start_time);
expected /= 60;
} else if (n_seconds_active_in_interval >= MIN_TIME_FOR_MEASUREMENT) {
/* Otherwise, we either measured enough time in the last interval but
* never hit our soft limit, or we're using a state file from a Tor that
* doesn't know to store soft-limit info. Just take rate at which
* we were reading/writing in the last interval as our expected rate.
*/
uint64_t used = get_accounting_bytes();
expected = used / (n_seconds_active_in_interval / 60);
} else {
/* If we haven't gotten enough data last interval, set 'expected'
* to 0. This will set our wakeup to the start of the interval.
* Next interval, we'll choose our starting time based on how much
* we sent this interval.
*/
expected = 0;
}
if (expected > max_configured)
expected = max_configured;
expected_bandwidth_usage = expected;
}
/** Called at the start of a new accounting interval: reset our
* expected bandwidth usage based on what happened last time, set up
* the start and end of the interval, and clear byte/time totals.
*/
static void
reset_accounting(time_t now)
{
log_info(LD_ACCT, "Starting new accounting interval.");
update_expected_bandwidth();
interval_start_time = start_of_accounting_period_containing(now);
interval_end_time = start_of_accounting_period_after(interval_start_time);
n_bytes_read_in_interval = 0;
n_bytes_written_in_interval = 0;
n_seconds_active_in_interval = 0;
n_bytes_at_soft_limit = 0;
soft_limit_hit_at = 0;
n_seconds_to_hit_soft_limit = 0;
}
/** Return true iff we should save our bandwidth usage to disk. */
static inline int
time_to_record_bandwidth_usage(time_t now)
{
/* Note every 600 sec */
#define NOTE_INTERVAL (600)
/* Or every 20 megabytes */
#define NOTE_BYTES 20*(1024*1024)
static uint64_t last_read_bytes_noted = 0;
static uint64_t last_written_bytes_noted = 0;
static time_t last_time_noted = 0;
if (last_time_noted + NOTE_INTERVAL <= now ||
last_read_bytes_noted + NOTE_BYTES <= n_bytes_read_in_interval ||
last_written_bytes_noted + NOTE_BYTES <= n_bytes_written_in_interval ||
(interval_end_time && interval_end_time <= now)) {
last_time_noted = now;
last_read_bytes_noted = n_bytes_read_in_interval;
last_written_bytes_noted = n_bytes_written_in_interval;
return 1;
}
return 0;
}
/** Invoked once per second. Checks whether it is time to hibernate,
* record bandwidth used, etc. */
void
accounting_run_housekeeping(time_t now)
{
if (now >= interval_end_time) {
configure_accounting(now);
}
if (time_to_record_bandwidth_usage(now)) {
if (accounting_record_bandwidth_usage(now, get_or_state())) {
log_warn(LD_FS, "Couldn't record bandwidth usage to disk.");
}
}
}
/** Based on our interval and our estimated bandwidth, choose a
* deterministic (but random-ish) time to wake up. */
static void
accounting_set_wakeup_time(void)
{
char digest[DIGEST_LEN];
crypto_digest_t *d_env;
uint64_t time_to_exhaust_bw;
int time_to_consider;
if (! server_identity_key_is_set()) {
if (init_keys() < 0) {
log_err(LD_BUG, "Error initializing keys");
tor_assert(0);
}
}
if (server_identity_key_is_set()) {
char buf[ISO_TIME_LEN+1];
format_iso_time(buf, interval_start_time);
if (crypto_pk_get_digest(get_server_identity_key(), digest) < 0) {
log_err(LD_BUG, "Error getting our key's digest.");
tor_assert(0);
}
d_env = crypto_digest_new();
crypto_digest_add_bytes(d_env, buf, ISO_TIME_LEN);
crypto_digest_add_bytes(d_env, digest, DIGEST_LEN);
crypto_digest_get_digest(d_env, digest, DIGEST_LEN);
crypto_digest_free(d_env);
} else {
crypto_rand(digest, DIGEST_LEN);
}
if (!expected_bandwidth_usage) {
char buf1[ISO_TIME_LEN+1];
char buf2[ISO_TIME_LEN+1];
format_local_iso_time(buf1, interval_start_time);
format_local_iso_time(buf2, interval_end_time);
interval_wakeup_time = interval_start_time;
log_notice(LD_ACCT,
"Configured hibernation. This interval begins at %s "
"and ends at %s. We have no prior estimate for bandwidth, so "
"we will start out awake and hibernate when we exhaust our quota.",
buf1, buf2);
return;
}
time_to_exhaust_bw =
(get_options()->AccountingMax/expected_bandwidth_usage)*60;
if (time_to_exhaust_bw > INT_MAX) {
time_to_exhaust_bw = INT_MAX;
time_to_consider = 0;
} else {
time_to_consider = accounting_get_interval_length() -
(int)time_to_exhaust_bw;
}
if (time_to_consider<=0) {
interval_wakeup_time = interval_start_time;
} else {
/* XXX can we simplify this just by picking a random (non-deterministic)
* time to be up? If we go down and come up, then we pick a new one. Is
* that good enough? -RD */
/* This is not a perfectly unbiased conversion, but it is good enough:
* in the worst case, the first half of the day is 0.06 percent likelier
* to be chosen than the last half. */
interval_wakeup_time = interval_start_time +
(get_uint32(digest) % time_to_consider);
}
{
char buf1[ISO_TIME_LEN+1];
char buf2[ISO_TIME_LEN+1];
char buf3[ISO_TIME_LEN+1];
char buf4[ISO_TIME_LEN+1];
time_t down_time;
if (interval_wakeup_time+time_to_exhaust_bw > TIME_MAX)
down_time = TIME_MAX;
else
down_time = (time_t)(interval_wakeup_time+time_to_exhaust_bw);
if (down_time>interval_end_time)
down_time = interval_end_time;
format_local_iso_time(buf1, interval_start_time);
format_local_iso_time(buf2, interval_wakeup_time);
format_local_iso_time(buf3, down_time);
format_local_iso_time(buf4, interval_end_time);
log_notice(LD_ACCT,
"Configured hibernation. This interval began at %s; "
"the scheduled wake-up time %s %s; "
"we expect%s to exhaust our quota for this interval around %s; "
"the next interval begins at %s (all times local)",
buf1,
time(NULL)<interval_wakeup_time?"is":"was", buf2,
time(NULL)<down_time?"":"ed", buf3,
buf4);
}
}
/* This rounds 0 up to 1000, but that's actually a feature. */
#define ROUND_UP(x) (((x) + 0x3ff) & ~0x3ff)
/** Save all our bandwidth tracking information to disk. Return 0 on
* success, -1 on failure. */
int
accounting_record_bandwidth_usage(time_t now, or_state_t *state)
{
/* Just update the state */
state->AccountingIntervalStart = interval_start_time;
state->AccountingBytesReadInInterval = ROUND_UP(n_bytes_read_in_interval);
state->AccountingBytesWrittenInInterval =
ROUND_UP(n_bytes_written_in_interval);
state->AccountingSecondsActive = n_seconds_active_in_interval;
state->AccountingExpectedUsage = expected_bandwidth_usage;
state->AccountingSecondsToReachSoftLimit = n_seconds_to_hit_soft_limit;
state->AccountingSoftLimitHitAt = soft_limit_hit_at;
state->AccountingBytesAtSoftLimit = n_bytes_at_soft_limit;
or_state_mark_dirty(state,
now+(get_options()->AvoidDiskWrites ? 7200 : 60));
return 0;
}
#undef ROUND_UP
/** Read stored accounting information from disk. Return 0 on success;
* return -1 and change nothing on failure. */
static int
read_bandwidth_usage(void)
{
or_state_t *state = get_or_state();
{
char *fname = get_datadir_fname("bw_accounting");
int res;
res = unlink(fname);
if (res != 0 && errno != ENOENT) {
log_warn(LD_FS,
"Failed to unlink %s: %s",
fname, strerror(errno));
}
tor_free(fname);
}
if (!state)
return -1;
log_info(LD_ACCT, "Reading bandwidth accounting data from state file");
n_bytes_read_in_interval = state->AccountingBytesReadInInterval;
n_bytes_written_in_interval = state->AccountingBytesWrittenInInterval;
n_seconds_active_in_interval = state->AccountingSecondsActive;
interval_start_time = state->AccountingIntervalStart;
expected_bandwidth_usage = state->AccountingExpectedUsage;
/* Older versions of Tor (before 0.2.2.17-alpha or so) didn't generate these
* fields. If you switch back and forth, you might get an
* AccountingSoftLimitHitAt value from long before the most recent
* interval_start_time. If that's so, then ignore the softlimit-related
* values. */
if (state->AccountingSoftLimitHitAt > interval_start_time) {
soft_limit_hit_at = state->AccountingSoftLimitHitAt;
n_bytes_at_soft_limit = state->AccountingBytesAtSoftLimit;
n_seconds_to_hit_soft_limit = state->AccountingSecondsToReachSoftLimit;
} else {
soft_limit_hit_at = 0;
n_bytes_at_soft_limit = 0;
n_seconds_to_hit_soft_limit = 0;
}
{
char tbuf1[ISO_TIME_LEN+1];
char tbuf2[ISO_TIME_LEN+1];
format_iso_time(tbuf1, state->LastWritten);
format_iso_time(tbuf2, state->AccountingIntervalStart);
log_info(LD_ACCT,
"Successfully read bandwidth accounting info from state written at %s "
"for interval starting at %s. We have been active for %lu seconds in "
"this interval. At the start of the interval, we expected to use "
"about %lu KB per second. ("U64_FORMAT" bytes read so far, "
U64_FORMAT" bytes written so far)",
tbuf1, tbuf2,
(unsigned long)n_seconds_active_in_interval,
(unsigned long)(expected_bandwidth_usage*1024/60),
U64_PRINTF_ARG(n_bytes_read_in_interval),
U64_PRINTF_ARG(n_bytes_written_in_interval));
}
return 0;
}
/** Return true iff we have sent/received all the bytes we are willing
* to send/receive this interval. */
static int
hibernate_hard_limit_reached(void)
{
uint64_t hard_limit = get_options()->AccountingMax;
if (!hard_limit)
return 0;
return get_accounting_bytes() >= hard_limit;
}
/** Return true iff we have sent/received almost all the bytes we are willing
* to send/receive this interval. */
static int
hibernate_soft_limit_reached(void)
{
const uint64_t acct_max = get_options()->AccountingMax;
#define SOFT_LIM_PCT (.95)
#define SOFT_LIM_BYTES (500*1024*1024)
#define SOFT_LIM_MINUTES (3*60)
/* The 'soft limit' is a fair bit more complicated now than once it was.
* We want to stop accepting connections when ALL of the following are true:
* - We expect to use up the remaining bytes in under 3 hours
* - We have used up 95% of our bytes.
* - We have less than 500MB of bytes left.
*/
uint64_t soft_limit = DBL_TO_U64(U64_TO_DBL(acct_max) * SOFT_LIM_PCT);
if (acct_max > SOFT_LIM_BYTES && acct_max - SOFT_LIM_BYTES > soft_limit) {
soft_limit = acct_max - SOFT_LIM_BYTES;
}
if (expected_bandwidth_usage) {
const uint64_t expected_usage =
expected_bandwidth_usage * SOFT_LIM_MINUTES;
if (acct_max > expected_usage && acct_max - expected_usage > soft_limit)
soft_limit = acct_max - expected_usage;
}
if (!soft_limit)
return 0;
return get_accounting_bytes() >= soft_limit;
}
/** Called when we get a SIGINT, or when bandwidth soft limit is
* reached. Puts us into "loose hibernation": we don't accept new
* connections, but we continue handling old ones. */
static void
hibernate_begin(hibernate_state_t new_state, time_t now)
{
const or_options_t *options = get_options();
if (new_state == HIBERNATE_STATE_EXITING &&
hibernate_state != HIBERNATE_STATE_LIVE) {
log_notice(LD_GENERAL,"SIGINT received %s; exiting now.",
hibernate_state == HIBERNATE_STATE_EXITING ?
"a second time" : "while hibernating");
tor_shutdown_event_loop_and_exit(0);
return;
}
if (new_state == HIBERNATE_STATE_LOWBANDWIDTH &&
hibernate_state == HIBERNATE_STATE_LIVE) {
soft_limit_hit_at = now;
n_seconds_to_hit_soft_limit = n_seconds_active_in_interval;
n_bytes_at_soft_limit = get_accounting_bytes();
}
/* close listeners. leave control listener(s). */
connection_mark_all_noncontrol_listeners();
/* XXX kill intro point circs */
/* XXX upload rendezvous service descriptors with no intro points */
if (new_state == HIBERNATE_STATE_EXITING) {
log_notice(LD_GENERAL,"Interrupt: we have stopped accepting new "
"connections, and will shut down in %d seconds. Interrupt "
"again to exit now.", options->ShutdownWaitLength);
shutdown_time = time(NULL) + options->ShutdownWaitLength;
} else { /* soft limit reached */
hibernate_end_time = interval_end_time;
}
hibernate_state = new_state;
accounting_record_bandwidth_usage(now, get_or_state());
or_state_mark_dirty(get_or_state(),
get_options()->AvoidDiskWrites ? now+600 : 0);
}
/** Called when we've been hibernating and our timeout is reached. */
static void
hibernate_end(hibernate_state_t new_state)
{
tor_assert(hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH ||
hibernate_state == HIBERNATE_STATE_DORMANT ||
hibernate_state == HIBERNATE_STATE_INITIAL);
/* listeners will be relaunched in run_scheduled_events() in main.c */
if (hibernate_state != HIBERNATE_STATE_INITIAL)
log_notice(LD_ACCT,"Hibernation period ended. Resuming normal activity.");
hibernate_state = new_state;
hibernate_end_time = 0; /* no longer hibernating */
reset_uptime(); /* reset published uptime */
}
/** A wrapper around hibernate_begin, for when we get SIGINT. */
void
hibernate_begin_shutdown(void)
{
hibernate_begin(HIBERNATE_STATE_EXITING, time(NULL));
}
/**
* Return true iff we are currently hibernating -- that is, if we are in
* any non-live state.
*/
MOCK_IMPL(int,
we_are_hibernating,(void))
{
return hibernate_state != HIBERNATE_STATE_LIVE;
}
/**
* Return true iff we are currently _fully_ hibernating -- that is, if we are
* in a state where we expect to handle no network activity at all.
*/
MOCK_IMPL(int,
we_are_fully_hibernating,(void))
{
return hibernate_state == HIBERNATE_STATE_DORMANT;
}
/** If we aren't currently dormant, close all connections and become
* dormant. */
static void
hibernate_go_dormant(time_t now)
{
connection_t *conn;
if (hibernate_state == HIBERNATE_STATE_DORMANT)
return;
else if (hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH)
hibernate_state = HIBERNATE_STATE_DORMANT;
else
hibernate_begin(HIBERNATE_STATE_DORMANT, now);
log_notice(LD_ACCT,"Going dormant. Blowing away remaining connections.");
/* Close all OR/AP/exit conns. Leave dir conns because we still want
* to be able to upload server descriptors so clients know we're still
* running, and download directories so we can detect if we're obsolete.
* Leave control conns because we still want to be controllable.
*/
while ((conn = connection_get_by_type(CONN_TYPE_OR)) ||
(conn = connection_get_by_type(CONN_TYPE_AP)) ||
(conn = connection_get_by_type(CONN_TYPE_EXIT))) {
if (CONN_IS_EDGE(conn)) {
connection_edge_end(TO_EDGE_CONN(conn), END_STREAM_REASON_HIBERNATING);
}
log_info(LD_NET,"Closing conn type %d", conn->type);
if (conn->type == CONN_TYPE_AP) {
/* send socks failure if needed */
connection_mark_unattached_ap(TO_ENTRY_CONN(conn),
END_STREAM_REASON_HIBERNATING);
} else if (conn->type == CONN_TYPE_OR) {
if (TO_OR_CONN(conn)->chan) {
connection_or_close_normally(TO_OR_CONN(conn), 0);
} else {
connection_mark_for_close(conn);
}
} else {
connection_mark_for_close(conn);
}
}
if (now < interval_wakeup_time)
hibernate_end_time = interval_wakeup_time;
else
hibernate_end_time = interval_end_time;
accounting_record_bandwidth_usage(now, get_or_state());
or_state_mark_dirty(get_or_state(),
get_options()->AvoidDiskWrites ? now+600 : 0);
hibernate_schedule_wakeup_event(now, hibernate_end_time);
}
/**
* Schedule a mainloop event at <b>end_time</b> to wake up from a dormant
* state. We can't rely on this happening from second_elapsed_callback,
* since second_elapsed_callback will be shut down when we're dormant.
*
* (Note that We might immediately go back to sleep after we set the next
* wakeup time.)
*/
static void
hibernate_schedule_wakeup_event(time_t now, time_t end_time)
{
struct timeval delay = { 0, 0 };
if (now >= end_time) {
// In these cases we always wait at least a second, to avoid running
// the callback in a tight loop.
delay.tv_sec = 1;
} else {
delay.tv_sec = (end_time - now);
}
if (!wakeup_event) {
wakeup_event = mainloop_event_postloop_new(wakeup_event_callback, NULL);
}
mainloop_event_schedule(wakeup_event, &delay);
}
/**
* Called at the end of the interval, or at the wakeup time of the current
* interval, to exit the dormant state.
**/
static void
wakeup_event_callback(mainloop_event_t *ev, void *data)
{
(void) ev;
(void) data;
const time_t now = time(NULL);
accounting_run_housekeeping(now);
consider_hibernation(now);
if (hibernate_state != HIBERNATE_STATE_DORMANT) {
/* We woke up, so everything's great here */
return;
}
/* We're still dormant. */
if (now < interval_wakeup_time)
hibernate_end_time = interval_wakeup_time;
else
hibernate_end_time = interval_end_time;
hibernate_schedule_wakeup_event(now, hibernate_end_time);
}
/** Called when hibernate_end_time has arrived. */
static void
hibernate_end_time_elapsed(time_t now)
{
char buf[ISO_TIME_LEN+1];
/* The interval has ended, or it is wakeup time. Find out which. */
accounting_run_housekeeping(now);
if (interval_wakeup_time <= now) {
/* The interval hasn't changed, but interval_wakeup_time has passed.
* It's time to wake up and start being a server. */
hibernate_end(HIBERNATE_STATE_LIVE);
return;
} else {
/* The interval has changed, and it isn't time to wake up yet. */
hibernate_end_time = interval_wakeup_time;
format_iso_time(buf,interval_wakeup_time);
if (hibernate_state != HIBERNATE_STATE_DORMANT) {
/* We weren't sleeping before; we should sleep now. */
log_notice(LD_ACCT,
"Accounting period ended. Commencing hibernation until "
"%s UTC", buf);
hibernate_go_dormant(now);
} else {
log_notice(LD_ACCT,
"Accounting period ended. This period, we will hibernate"
" until %s UTC",buf);
}
}
}
/** Consider our environment and decide if it's time
* to start/stop hibernating.
*/
void
consider_hibernation(time_t now)
{
int accounting_enabled = get_options()->AccountingMax != 0;
char buf[ISO_TIME_LEN+1];
hibernate_state_t prev_state = hibernate_state;
/* If we're in 'exiting' mode, then we just shut down after the interval
* elapses. */
if (hibernate_state == HIBERNATE_STATE_EXITING) {
tor_assert(shutdown_time);
if (shutdown_time <= now) {
log_notice(LD_GENERAL, "Clean shutdown finished. Exiting.");
tor_shutdown_event_loop_and_exit(0);
}
return; /* if exiting soon, don't worry about bandwidth limits */
}
if (hibernate_state == HIBERNATE_STATE_DORMANT) {
/* We've been hibernating because of bandwidth accounting. */
tor_assert(hibernate_end_time);
if (hibernate_end_time > now && accounting_enabled) {
/* If we're hibernating, don't wake up until it's time, regardless of
* whether we're in a new interval. */
return ;
} else {
hibernate_end_time_elapsed(now);
}
}
/* Else, we aren't hibernating. See if it's time to start hibernating, or to
* go dormant. */
if (hibernate_state == HIBERNATE_STATE_LIVE ||
hibernate_state == HIBERNATE_STATE_INITIAL) {
if (hibernate_soft_limit_reached()) {
log_notice(LD_ACCT,
"Bandwidth soft limit reached; commencing hibernation. "
"No new connections will be accepted");
hibernate_begin(HIBERNATE_STATE_LOWBANDWIDTH, now);
} else if (accounting_enabled && now < interval_wakeup_time) {
format_local_iso_time(buf,interval_wakeup_time);
log_notice(LD_ACCT,
"Commencing hibernation. We will wake up at %s local time.",
buf);
hibernate_go_dormant(now);
} else if (hibernate_state == HIBERNATE_STATE_INITIAL) {
hibernate_end(HIBERNATE_STATE_LIVE);
}
}
if (hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH) {
if (!accounting_enabled) {
hibernate_end_time_elapsed(now);
} else if (hibernate_hard_limit_reached()) {
hibernate_go_dormant(now);
} else if (hibernate_end_time <= now) {
/* The hibernation period ended while we were still in lowbandwidth.*/
hibernate_end_time_elapsed(now);
}
}
/* Dispatch a controller event if the hibernation state changed. */
if (hibernate_state != prev_state)
on_hibernate_state_change(prev_state);
}
/** Helper function: called when we get a GETINFO request for an
* accounting-related key on the control connection <b>conn</b>. If we can
* answer the request for <b>question</b>, then set *<b>answer</b> to a newly
* allocated string holding the result. Otherwise, set *<b>answer</b> to
* NULL. */
int
getinfo_helper_accounting(control_connection_t *conn,
const char *question, char **answer,
const char **errmsg)
{
(void) conn;
(void) errmsg;
if (!strcmp(question, "accounting/enabled")) {
*answer = tor_strdup(accounting_is_enabled(get_options()) ? "1" : "0");
} else if (!strcmp(question, "accounting/hibernating")) {
*answer = tor_strdup(hibernate_state_to_string(hibernate_state));
tor_strlower(*answer);
} else if (!strcmp(question, "accounting/bytes")) {
tor_asprintf(answer, U64_FORMAT" "U64_FORMAT,
U64_PRINTF_ARG(n_bytes_read_in_interval),
U64_PRINTF_ARG(n_bytes_written_in_interval));
} else if (!strcmp(question, "accounting/bytes-left")) {
uint64_t limit = get_options()->AccountingMax;
if (get_options()->AccountingRule == ACCT_SUM) {
uint64_t total_left = 0;
uint64_t total_bytes = get_accounting_bytes();
if (total_bytes < limit)
total_left = limit - total_bytes;
tor_asprintf(answer, U64_FORMAT" "U64_FORMAT,
U64_PRINTF_ARG(total_left), U64_PRINTF_ARG(total_left));
} else if (get_options()->AccountingRule == ACCT_IN) {
uint64_t read_left = 0;
if (n_bytes_read_in_interval < limit)
read_left = limit - n_bytes_read_in_interval;
tor_asprintf(answer, U64_FORMAT" "U64_FORMAT,
U64_PRINTF_ARG(read_left), U64_PRINTF_ARG(limit));
} else if (get_options()->AccountingRule == ACCT_OUT) {
uint64_t write_left = 0;
if (n_bytes_written_in_interval < limit)
write_left = limit - n_bytes_written_in_interval;
tor_asprintf(answer, U64_FORMAT" "U64_FORMAT,
U64_PRINTF_ARG(limit), U64_PRINTF_ARG(write_left));
} else {
uint64_t read_left = 0, write_left = 0;
if (n_bytes_read_in_interval < limit)
read_left = limit - n_bytes_read_in_interval;
if (n_bytes_written_in_interval < limit)
write_left = limit - n_bytes_written_in_interval;
tor_asprintf(answer, U64_FORMAT" "U64_FORMAT,
U64_PRINTF_ARG(read_left), U64_PRINTF_ARG(write_left));
}
} else if (!strcmp(question, "accounting/interval-start")) {
*answer = tor_malloc(ISO_TIME_LEN+1);
format_iso_time(*answer, interval_start_time);
} else if (!strcmp(question, "accounting/interval-wake")) {
*answer = tor_malloc(ISO_TIME_LEN+1);
format_iso_time(*answer, interval_wakeup_time);
} else if (!strcmp(question, "accounting/interval-end")) {
*answer = tor_malloc(ISO_TIME_LEN+1);
format_iso_time(*answer, interval_end_time);
} else {
*answer = NULL;
}
return 0;
}
/**
* Helper function: called when the hibernation state changes, and sends a
* SERVER_STATUS event to notify interested controllers of the accounting
* state change.
*/
static void
on_hibernate_state_change(hibernate_state_t prev_state)
{
control_event_server_status(LOG_NOTICE,
"HIBERNATION_STATUS STATUS=%s",
hibernate_state_to_string(hibernate_state));
/* We are changing hibernation state, this can affect the main loop event
* list. Rescan it to update the events state. We do this whatever the new
* hibernation state because they can each possibly affect an event. The
* initial state means we are booting up so we shouldn't scan here because
* at this point the events in the list haven't been initialized. */
if (prev_state != HIBERNATE_STATE_INITIAL) {
rescan_periodic_events(get_options());
}
reschedule_per_second_timer();
}
/** Free all resources held by the accounting module */
void
accounting_free_all(void)
{
mainloop_event_free(wakeup_event);
hibernate_state = HIBERNATE_STATE_INITIAL;
hibernate_end_time = 0;
shutdown_time = 0;
}
#ifdef TOR_UNIT_TESTS
/**
* Manually change the hibernation state. Private; used only by the unit
* tests.
*/
void
hibernate_set_state_for_testing_(hibernate_state_t newstate)
{
hibernate_state = newstate;
}
#endif /* defined(TOR_UNIT_TESTS) */
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