14b8df3702
Instead of keeping one pair of RX and TX timestamp for each address, add a separate RX->TX map using an ordered circular buffer. Save the RX timestamps as 64-bit integers and search them with a combined linear interpolation and binary algorithm. This enables the server to support multiple interleaved clients sharing the same IP address (e.g. NAT) and it will allow other improvements to be implemented later. A drawback is that a single broken client sending interleaved requests at a high rate (without spoofing the source address) can now prevent clients on other addresses from getting interleaved responses. The total number of saved timestamps does not change. It's still determined by the clientloglimit directive. A new option may be added later if needed. The whole buffer is allocated at once, but only on first use to not waste memory on client-only configurations.
1030 lines
26 KiB
C
1030 lines
26 KiB
C
/*
|
|
chronyd/chronyc - Programs for keeping computer clocks accurate.
|
|
|
|
**********************************************************************
|
|
* Copyright (C) Richard P. Curnow 1997-2003
|
|
* Copyright (C) Miroslav Lichvar 2009, 2015-2017
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of version 2 of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
**********************************************************************
|
|
|
|
=======================================================================
|
|
|
|
This module keeps a count of the number of successful accesses by
|
|
clients, and the times of the last accesses.
|
|
|
|
This can be used for status reporting, and (in the case of a
|
|
server), if it needs to know which clients have made use of its data
|
|
recently.
|
|
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include "sysincl.h"
|
|
|
|
#include "array.h"
|
|
#include "clientlog.h"
|
|
#include "conf.h"
|
|
#include "memory.h"
|
|
#include "ntp.h"
|
|
#include "reports.h"
|
|
#include "util.h"
|
|
#include "logging.h"
|
|
|
|
#define MAX_SERVICES 3
|
|
|
|
typedef struct {
|
|
IPAddr ip_addr;
|
|
uint32_t last_hit[MAX_SERVICES];
|
|
uint32_t hits[MAX_SERVICES];
|
|
uint16_t drops[MAX_SERVICES];
|
|
uint16_t tokens[MAX_SERVICES];
|
|
int8_t rate[MAX_SERVICES];
|
|
int8_t ntp_timeout_rate;
|
|
uint8_t drop_flags;
|
|
} Record;
|
|
|
|
/* Hash table of records, there is a fixed number of records per slot */
|
|
static ARR_Instance records;
|
|
|
|
#define SLOT_BITS 4
|
|
|
|
/* Number of records in one slot of the hash table */
|
|
#define SLOT_SIZE (1U << SLOT_BITS)
|
|
|
|
/* Minimum number of slots */
|
|
#define MIN_SLOTS 1
|
|
|
|
/* Maximum number of slots, this is a hard limit */
|
|
#define MAX_SLOTS (1U << (24 - SLOT_BITS))
|
|
|
|
/* Number of slots in the hash table */
|
|
static unsigned int slots;
|
|
|
|
/* Maximum number of slots given memory allocation limit */
|
|
static unsigned int max_slots;
|
|
|
|
/* Times of last hits are saved as 32-bit fixed point values */
|
|
#define TS_FRAC 4
|
|
#define INVALID_TS 0
|
|
|
|
/* Static offset included in conversion to the fixed-point timestamps to
|
|
randomise their alignment */
|
|
static uint32_t ts_offset;
|
|
|
|
/* Request rates are saved in the record as 8-bit scaled log2 values */
|
|
#define RATE_SCALE 4
|
|
#define MIN_RATE (-14 * RATE_SCALE)
|
|
#define INVALID_RATE -128
|
|
|
|
/* Response rates are controlled by token buckets. The capacity and
|
|
number of tokens spent on response are determined from configured
|
|
minimum inverval between responses (in log2) and burst length. */
|
|
|
|
#define MIN_LIMIT_INTERVAL (-15 - TS_FRAC)
|
|
#define MAX_LIMIT_INTERVAL 12
|
|
#define MIN_LIMIT_BURST 1
|
|
#define MAX_LIMIT_BURST 255
|
|
|
|
static uint16_t max_tokens[MAX_SERVICES];
|
|
static uint16_t tokens_per_hit[MAX_SERVICES];
|
|
|
|
/* Reduction of token rates to avoid overflow of 16-bit counters. Negative
|
|
shift is used for coarse limiting with intervals shorter than -TS_FRAC. */
|
|
static int token_shift[MAX_SERVICES];
|
|
|
|
/* Rates at which responses are randomly allowed (in log2) when the
|
|
buckets don't have enough tokens. This is necessary in order to
|
|
prevent an attacker sending requests with spoofed source address
|
|
from blocking responses to the address completely. */
|
|
|
|
#define MIN_LEAK_RATE 1
|
|
#define MAX_LEAK_RATE 4
|
|
|
|
static int leak_rate[MAX_SERVICES];
|
|
|
|
/* Limit intervals in log2 */
|
|
static int limit_interval[MAX_SERVICES];
|
|
|
|
/* Flag indicating whether facility is turned on or not */
|
|
static int active;
|
|
|
|
/* RX and TX timestamp saved for clients using interleaved mode */
|
|
typedef struct {
|
|
uint64_t rx_ts;
|
|
uint32_t flags;
|
|
int32_t tx_ts_offset;
|
|
} NtpTimestamps;
|
|
|
|
/* Flags for NTP timestamps */
|
|
#define NTPTS_DISABLED 1
|
|
#define NTPTS_VALID_TX 2
|
|
|
|
/* RX->TX map using a circular buffer with ordered timestamps */
|
|
typedef struct {
|
|
ARR_Instance timestamps;
|
|
uint32_t first;
|
|
uint32_t size;
|
|
uint32_t max_size;
|
|
uint32_t cached_index;
|
|
uint64_t cached_rx_ts;
|
|
} NtpTimestampMap;
|
|
|
|
static NtpTimestampMap ntp_ts_map;
|
|
|
|
/* Maximum interval of NTP timestamps in future after a backward step */
|
|
#define NTPTS_FUTURE_LIMIT (1LL << 32) /* 1 second */
|
|
|
|
/* Maximum number of timestamps moved in the array to insert a new timestamp */
|
|
#define NTPTS_INSERT_LIMIT 64
|
|
|
|
/* Global statistics */
|
|
static uint32_t total_hits[MAX_SERVICES];
|
|
static uint32_t total_drops[MAX_SERVICES];
|
|
static uint32_t total_ntp_auth_hits;
|
|
static uint32_t total_record_drops;
|
|
|
|
#define NSEC_PER_SEC 1000000000U
|
|
|
|
/* ================================================== */
|
|
|
|
static int expand_hashtable(void);
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
compare_ts(uint32_t x, uint32_t y)
|
|
{
|
|
if (x == y)
|
|
return 0;
|
|
if (y == INVALID_TS)
|
|
return 1;
|
|
return (int32_t)(x - y) > 0 ? 1 : -1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
compare_total_hits(Record *x, Record *y)
|
|
{
|
|
uint32_t x_hits, y_hits;
|
|
int i;
|
|
|
|
for (i = 0, x_hits = y_hits = 0; i < MAX_SERVICES; i++) {
|
|
x_hits += x->hits[i];
|
|
y_hits += y->hits[i];
|
|
}
|
|
|
|
return x_hits > y_hits ? 1 : -1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static Record *
|
|
get_record(IPAddr *ip)
|
|
{
|
|
uint32_t last_hit = 0, oldest_hit = 0;
|
|
Record *record, *oldest_record;
|
|
unsigned int first, i, j;
|
|
|
|
if (!active || (ip->family != IPADDR_INET4 && ip->family != IPADDR_INET6))
|
|
return NULL;
|
|
|
|
while (1) {
|
|
/* Get index of the first record in the slot */
|
|
first = UTI_IPToHash(ip) % slots * SLOT_SIZE;
|
|
|
|
for (i = 0, oldest_record = NULL; i < SLOT_SIZE; i++) {
|
|
record = ARR_GetElement(records, first + i);
|
|
|
|
if (!UTI_CompareIPs(ip, &record->ip_addr, NULL))
|
|
return record;
|
|
|
|
if (record->ip_addr.family == IPADDR_UNSPEC)
|
|
break;
|
|
|
|
for (j = 0; j < MAX_SERVICES; j++) {
|
|
if (j == 0 || compare_ts(last_hit, record->last_hit[j]) < 0)
|
|
last_hit = record->last_hit[j];
|
|
}
|
|
|
|
if (!oldest_record || compare_ts(oldest_hit, last_hit) > 0 ||
|
|
(oldest_hit == last_hit && compare_total_hits(oldest_record, record) > 0)) {
|
|
oldest_record = record;
|
|
oldest_hit = last_hit;
|
|
}
|
|
}
|
|
|
|
/* If the slot still has an empty record, use it */
|
|
if (record->ip_addr.family == IPADDR_UNSPEC)
|
|
break;
|
|
|
|
/* Resize the table if possible and try again as the new slot may
|
|
have some empty records */
|
|
if (expand_hashtable())
|
|
continue;
|
|
|
|
/* There is no other option, replace the oldest record */
|
|
record = oldest_record;
|
|
total_record_drops++;
|
|
break;
|
|
}
|
|
|
|
record->ip_addr = *ip;
|
|
for (i = 0; i < MAX_SERVICES; i++)
|
|
record->last_hit[i] = INVALID_TS;
|
|
for (i = 0; i < MAX_SERVICES; i++)
|
|
record->hits[i] = 0;
|
|
for (i = 0; i < MAX_SERVICES; i++)
|
|
record->drops[i] = 0;
|
|
for (i = 0; i < MAX_SERVICES; i++)
|
|
record->tokens[i] = max_tokens[i];
|
|
for (i = 0; i < MAX_SERVICES; i++)
|
|
record->rate[i] = INVALID_RATE;
|
|
record->ntp_timeout_rate = INVALID_RATE;
|
|
record->drop_flags = 0;
|
|
|
|
return record;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
expand_hashtable(void)
|
|
{
|
|
ARR_Instance old_records;
|
|
Record *old_record, *new_record;
|
|
unsigned int i;
|
|
|
|
old_records = records;
|
|
|
|
if (2 * slots > max_slots)
|
|
return 0;
|
|
|
|
records = ARR_CreateInstance(sizeof (Record));
|
|
|
|
slots = MAX(MIN_SLOTS, 2 * slots);
|
|
assert(slots <= max_slots);
|
|
|
|
ARR_SetSize(records, slots * SLOT_SIZE);
|
|
|
|
/* Mark all new records as empty */
|
|
for (i = 0; i < slots * SLOT_SIZE; i++) {
|
|
new_record = ARR_GetElement(records, i);
|
|
new_record->ip_addr.family = IPADDR_UNSPEC;
|
|
}
|
|
|
|
if (!old_records)
|
|
return 1;
|
|
|
|
/* Copy old records to the new hash table */
|
|
for (i = 0; i < ARR_GetSize(old_records); i++) {
|
|
old_record = ARR_GetElement(old_records, i);
|
|
if (old_record->ip_addr.family == IPADDR_UNSPEC)
|
|
continue;
|
|
|
|
new_record = get_record(&old_record->ip_addr);
|
|
|
|
assert(new_record);
|
|
*new_record = *old_record;
|
|
}
|
|
|
|
ARR_DestroyInstance(old_records);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
set_bucket_params(int interval, int burst, uint16_t *max_tokens,
|
|
uint16_t *tokens_per_packet, int *token_shift)
|
|
{
|
|
interval = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
|
|
burst = CLAMP(MIN_LIMIT_BURST, burst, MAX_LIMIT_BURST);
|
|
|
|
if (interval >= -TS_FRAC) {
|
|
/* Find the smallest shift with which the maximum number fits in 16 bits */
|
|
for (*token_shift = 0; *token_shift < interval + TS_FRAC; (*token_shift)++) {
|
|
if (burst << (TS_FRAC + interval - *token_shift) < 1U << 16)
|
|
break;
|
|
}
|
|
} else {
|
|
/* Coarse rate limiting */
|
|
*token_shift = interval + TS_FRAC;
|
|
*tokens_per_packet = 1;
|
|
burst = MAX(1U << -*token_shift, burst);
|
|
}
|
|
|
|
*tokens_per_packet = 1U << (TS_FRAC + interval - *token_shift);
|
|
*max_tokens = *tokens_per_packet * burst;
|
|
|
|
DEBUG_LOG("Tokens max %d packet %d shift %d",
|
|
*max_tokens, *tokens_per_packet, *token_shift);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_Initialise(void)
|
|
{
|
|
int i, interval, burst, lrate, slots2;
|
|
|
|
for (i = 0; i < MAX_SERVICES; i++) {
|
|
max_tokens[i] = 0;
|
|
tokens_per_hit[i] = 0;
|
|
token_shift[i] = 0;
|
|
leak_rate[i] = 0;
|
|
limit_interval[i] = MIN_LIMIT_INTERVAL;
|
|
|
|
switch (i) {
|
|
case CLG_NTP:
|
|
if (!CNF_GetNTPRateLimit(&interval, &burst, &lrate))
|
|
continue;
|
|
break;
|
|
case CLG_NTSKE:
|
|
if (!CNF_GetNtsRateLimit(&interval, &burst, &lrate))
|
|
continue;
|
|
break;
|
|
case CLG_CMDMON:
|
|
if (!CNF_GetCommandRateLimit(&interval, &burst, &lrate))
|
|
continue;
|
|
break;
|
|
default:
|
|
assert(0);
|
|
}
|
|
|
|
set_bucket_params(interval, burst, &max_tokens[i], &tokens_per_hit[i], &token_shift[i]);
|
|
leak_rate[i] = CLAMP(MIN_LEAK_RATE, lrate, MAX_LEAK_RATE);
|
|
limit_interval[i] = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
|
|
}
|
|
|
|
active = !CNF_GetNoClientLog();
|
|
if (!active) {
|
|
for (i = 0; i < MAX_SERVICES; i++) {
|
|
if (leak_rate[i] != 0)
|
|
LOG_FATAL("Rate limiting cannot be enabled with noclientlog");
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* Calculate the maximum number of slots that can be allocated in the
|
|
configured memory limit. Take into account expanding of the hash
|
|
table where two copies exist at the same time. */
|
|
max_slots = CNF_GetClientLogLimit() /
|
|
((sizeof (Record) + sizeof (NtpTimestamps)) * SLOT_SIZE * 3 / 2);
|
|
max_slots = CLAMP(MIN_SLOTS, max_slots, MAX_SLOTS);
|
|
for (slots2 = 0; 1U << (slots2 + 1) <= max_slots; slots2++)
|
|
;
|
|
|
|
DEBUG_LOG("Max records %u", 1U << (slots2 + SLOT_BITS));
|
|
|
|
slots = 0;
|
|
records = NULL;
|
|
|
|
expand_hashtable();
|
|
|
|
UTI_GetRandomBytes(&ts_offset, sizeof (ts_offset));
|
|
ts_offset %= NSEC_PER_SEC / (1U << TS_FRAC);
|
|
|
|
ntp_ts_map.timestamps = NULL;
|
|
ntp_ts_map.first = 0;
|
|
ntp_ts_map.size = 0;
|
|
ntp_ts_map.max_size = 1U << (slots2 + SLOT_BITS);
|
|
ntp_ts_map.cached_index = 0;
|
|
ntp_ts_map.cached_rx_ts = 0ULL;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_Finalise(void)
|
|
{
|
|
if (!active)
|
|
return;
|
|
|
|
ARR_DestroyInstance(records);
|
|
if (ntp_ts_map.timestamps)
|
|
ARR_DestroyInstance(ntp_ts_map.timestamps);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static uint32_t
|
|
get_ts_from_timespec(struct timespec *ts)
|
|
{
|
|
uint32_t sec = ts->tv_sec, nsec = ts->tv_nsec;
|
|
|
|
nsec += ts_offset;
|
|
if (nsec >= NSEC_PER_SEC) {
|
|
nsec -= NSEC_PER_SEC;
|
|
sec++;
|
|
}
|
|
|
|
/* This is fast and accurate enough */
|
|
return sec << TS_FRAC | (140740U * (nsec >> 15)) >> (32 - TS_FRAC);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
update_record(CLG_Service service, Record *record, struct timespec *now)
|
|
{
|
|
uint32_t interval, now_ts, prev_hit, tokens;
|
|
int interval2, tshift, mtokens;
|
|
int8_t *rate;
|
|
|
|
now_ts = get_ts_from_timespec(now);
|
|
|
|
prev_hit = record->last_hit[service];
|
|
record->last_hit[service] = now_ts;
|
|
record->hits[service]++;
|
|
|
|
interval = now_ts - prev_hit;
|
|
|
|
if (prev_hit == INVALID_TS || (int32_t)interval < 0)
|
|
return;
|
|
|
|
tshift = token_shift[service];
|
|
mtokens = max_tokens[service];
|
|
|
|
if (tshift >= 0)
|
|
tokens = (now_ts >> tshift) - (prev_hit >> tshift);
|
|
else if (now_ts - prev_hit > mtokens)
|
|
tokens = mtokens;
|
|
else
|
|
tokens = (now_ts - prev_hit) << -tshift;
|
|
record->tokens[service] = MIN(record->tokens[service] + tokens, mtokens);
|
|
|
|
/* Convert the interval to scaled and rounded log2 */
|
|
if (interval) {
|
|
interval += interval >> 1;
|
|
for (interval2 = -RATE_SCALE * TS_FRAC; interval2 < -MIN_RATE;
|
|
interval2 += RATE_SCALE) {
|
|
if (interval <= 1)
|
|
break;
|
|
interval >>= 1;
|
|
}
|
|
} else {
|
|
interval2 = -RATE_SCALE * (TS_FRAC + 1);
|
|
}
|
|
|
|
/* For the NTP service, update one of the two rates depending on whether
|
|
the previous request of the client had a reply or it timed out */
|
|
rate = service == CLG_NTP && record->drop_flags & (1U << service) ?
|
|
&record->ntp_timeout_rate : &record->rate[service];
|
|
|
|
/* Update the rate in a rough approximation of exponential moving average */
|
|
if (*rate == INVALID_RATE) {
|
|
*rate = -interval2;
|
|
} else {
|
|
if (*rate < -interval2) {
|
|
(*rate)++;
|
|
} else if (*rate > -interval2) {
|
|
if (*rate > RATE_SCALE * 5 / 2 - interval2)
|
|
*rate = RATE_SCALE * 5 / 2 - interval2;
|
|
else
|
|
*rate = (*rate - interval2 - 1) / 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
get_index(Record *record)
|
|
{
|
|
return record - (Record *)ARR_GetElements(records);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_GetClientIndex(IPAddr *client)
|
|
{
|
|
Record *record;
|
|
|
|
record = get_record(client);
|
|
if (record == NULL)
|
|
return -1;
|
|
|
|
return get_index(record);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
check_service_number(CLG_Service service)
|
|
{
|
|
assert(service >= 0 && service <= MAX_SERVICES);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_LogServiceAccess(CLG_Service service, IPAddr *client, struct timespec *now)
|
|
{
|
|
Record *record;
|
|
|
|
check_service_number(service);
|
|
|
|
total_hits[service]++;
|
|
|
|
record = get_record(client);
|
|
if (record == NULL)
|
|
return -1;
|
|
|
|
update_record(service, record, now);
|
|
|
|
DEBUG_LOG("service %d hits %"PRIu32" rate %d trate %d tokens %d",
|
|
(int)service, record->hits[service], record->rate[service],
|
|
service == CLG_NTP ? record->ntp_timeout_rate : INVALID_RATE,
|
|
record->tokens[service]);
|
|
|
|
return get_index(record);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
limit_response_random(int leak_rate)
|
|
{
|
|
static uint32_t rnd;
|
|
static int bits_left = 0;
|
|
int r;
|
|
|
|
if (bits_left < leak_rate) {
|
|
UTI_GetRandomBytes(&rnd, sizeof (rnd));
|
|
bits_left = 8 * sizeof (rnd);
|
|
}
|
|
|
|
/* Return zero on average once per 2^leak_rate */
|
|
r = rnd % (1U << leak_rate) ? 1 : 0;
|
|
rnd >>= leak_rate;
|
|
bits_left -= leak_rate;
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_LimitServiceRate(CLG_Service service, int index)
|
|
{
|
|
Record *record;
|
|
int drop;
|
|
|
|
check_service_number(service);
|
|
|
|
if (tokens_per_hit[service] == 0)
|
|
return 0;
|
|
|
|
record = ARR_GetElement(records, index);
|
|
record->drop_flags &= ~(1U << service);
|
|
|
|
if (record->tokens[service] >= tokens_per_hit[service]) {
|
|
record->tokens[service] -= tokens_per_hit[service];
|
|
return 0;
|
|
}
|
|
|
|
drop = limit_response_random(leak_rate[service]);
|
|
|
|
/* Poorly implemented NTP clients can send requests at a higher rate
|
|
when they are not getting replies. If the request rate seems to be more
|
|
than twice as much as when replies are sent, give up on rate limiting to
|
|
reduce the amount of traffic. Invert the sense of the leak to respond to
|
|
most of the requests, but still keep the estimated rate updated. */
|
|
if (service == CLG_NTP && record->ntp_timeout_rate != INVALID_RATE &&
|
|
record->ntp_timeout_rate > record->rate[service] + RATE_SCALE)
|
|
drop = !drop;
|
|
|
|
if (!drop) {
|
|
record->tokens[service] = 0;
|
|
return 0;
|
|
}
|
|
|
|
record->drop_flags |= 1U << service;
|
|
record->drops[service]++;
|
|
total_drops[service]++;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_LogAuthNtpRequest(void)
|
|
{
|
|
total_ntp_auth_hits++;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_GetNtpMinPoll(void)
|
|
{
|
|
return limit_interval[CLG_NTP];
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static NtpTimestamps *
|
|
get_ntp_tss(uint32_t index)
|
|
{
|
|
return ARR_GetElement(ntp_ts_map.timestamps,
|
|
(ntp_ts_map.first + index) & (ntp_ts_map.max_size - 1));
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
find_ntp_rx_ts(uint64_t rx_ts, uint32_t *index)
|
|
{
|
|
uint64_t rx_x, rx_lo, rx_hi, step;
|
|
uint32_t i, x, lo, hi;
|
|
|
|
if (ntp_ts_map.cached_rx_ts == rx_ts && rx_ts != 0ULL) {
|
|
*index = ntp_ts_map.cached_index;
|
|
return 1;
|
|
}
|
|
|
|
if (ntp_ts_map.size == 0) {
|
|
*index = 0;
|
|
return 0;
|
|
}
|
|
|
|
lo = 0;
|
|
hi = ntp_ts_map.size - 1;
|
|
rx_lo = get_ntp_tss(lo)->rx_ts;
|
|
rx_hi = get_ntp_tss(hi)->rx_ts;
|
|
|
|
/* Check for ts < lo before ts > hi to trim timestamps from "future" later
|
|
if both conditions are true to not break the order of the endpoints.
|
|
Compare timestamps by their difference to allow adjacent NTP eras. */
|
|
if ((int64_t)(rx_ts - rx_lo) < 0) {
|
|
*index = 0;
|
|
return 0;
|
|
} else if ((int64_t)(rx_ts - rx_hi) > 0) {
|
|
*index = ntp_ts_map.size;
|
|
return 0;
|
|
}
|
|
|
|
/* Perform a combined linear interpolation and binary search */
|
|
|
|
for (i = 0; ; i++) {
|
|
if (rx_ts == rx_hi) {
|
|
*index = ntp_ts_map.cached_index = hi;
|
|
ntp_ts_map.cached_rx_ts = rx_ts;
|
|
return 1;
|
|
} else if (rx_ts == rx_lo) {
|
|
*index = ntp_ts_map.cached_index = lo;
|
|
ntp_ts_map.cached_rx_ts = rx_ts;
|
|
return 1;
|
|
} else if (lo + 1 == hi) {
|
|
*index = hi;
|
|
return 0;
|
|
}
|
|
|
|
if (hi - lo > 3 && i % 2 == 0) {
|
|
step = (rx_hi - rx_lo) / (hi - lo);
|
|
if (step == 0)
|
|
step = 1;
|
|
x = lo + (rx_ts - rx_lo) / step;
|
|
} else {
|
|
x = lo + (hi - lo) / 2;
|
|
}
|
|
|
|
if (x <= lo)
|
|
x = lo + 1;
|
|
else if (x >= hi)
|
|
x = hi - 1;
|
|
|
|
rx_x = get_ntp_tss(x)->rx_ts;
|
|
|
|
if ((int64_t)(rx_x - rx_ts) <= 0) {
|
|
lo = x;
|
|
rx_lo = rx_x;
|
|
} else {
|
|
hi = x;
|
|
rx_hi = rx_x;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static uint64_t
|
|
ntp64_to_int64(NTP_int64 *ts)
|
|
{
|
|
return (uint64_t)ntohl(ts->hi) << 32 | ntohl(ts->lo);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
int64_to_ntp64(uint64_t ts, NTP_int64 *ntp_ts)
|
|
{
|
|
ntp_ts->hi = htonl(ts >> 32);
|
|
ntp_ts->lo = htonl(ts & ((1ULL << 32) - 1));
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static uint32_t
|
|
push_ntp_tss(uint32_t index)
|
|
{
|
|
if (ntp_ts_map.size < ntp_ts_map.max_size) {
|
|
ntp_ts_map.size++;
|
|
} else {
|
|
ntp_ts_map.first = (ntp_ts_map.first + 1) % (ntp_ts_map.max_size);
|
|
if (index > 0)
|
|
index--;
|
|
}
|
|
|
|
return index;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
set_ntp_tx_offset(NtpTimestamps *tss, NTP_int64 *rx_ts, struct timespec *tx_ts)
|
|
{
|
|
struct timespec ts;
|
|
|
|
if (!tx_ts) {
|
|
tss->flags &= ~NTPTS_VALID_TX;
|
|
return;
|
|
}
|
|
|
|
UTI_Ntp64ToTimespec(rx_ts, &ts);
|
|
UTI_DiffTimespecs(&ts, tx_ts, &ts);
|
|
|
|
if (ts.tv_sec < -2 || ts.tv_sec > 1) {
|
|
tss->flags &= ~NTPTS_VALID_TX;
|
|
return;
|
|
}
|
|
|
|
tss->tx_ts_offset = (int32_t)ts.tv_nsec + (int32_t)ts.tv_sec * (int32_t)NSEC_PER_SEC;
|
|
tss->flags |= NTPTS_VALID_TX;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static void
|
|
get_ntp_tx(NtpTimestamps *tss, struct timespec *tx_ts)
|
|
{
|
|
int32_t offset = tss->tx_ts_offset;
|
|
NTP_int64 ntp_ts;
|
|
|
|
if (tss->flags & NTPTS_VALID_TX) {
|
|
int64_to_ntp64(tss->rx_ts, &ntp_ts);
|
|
UTI_Ntp64ToTimespec(&ntp_ts, tx_ts);
|
|
if (offset >= (int32_t)NSEC_PER_SEC) {
|
|
offset -= NSEC_PER_SEC;
|
|
tx_ts->tv_sec++;
|
|
}
|
|
tx_ts->tv_nsec += offset;
|
|
UTI_NormaliseTimespec(tx_ts);
|
|
} else {
|
|
UTI_ZeroTimespec(tx_ts);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_SaveNtpTimestamps(NTP_int64 *rx_ts, struct timespec *tx_ts)
|
|
{
|
|
NtpTimestamps *tss;
|
|
uint32_t i, index;
|
|
uint64_t rx;
|
|
|
|
if (!active)
|
|
return;
|
|
|
|
/* Allocate the array on first use */
|
|
if (!ntp_ts_map.timestamps) {
|
|
ntp_ts_map.timestamps = ARR_CreateInstance(sizeof (NtpTimestamps));
|
|
ARR_SetSize(ntp_ts_map.timestamps, ntp_ts_map.max_size);
|
|
}
|
|
|
|
rx = ntp64_to_int64(rx_ts);
|
|
|
|
if (rx == 0ULL)
|
|
return;
|
|
|
|
/* Disable the RX timestamp if it already exists to avoid responding
|
|
with a wrong TX timestamp */
|
|
if (find_ntp_rx_ts(rx, &index)) {
|
|
get_ntp_tss(index)->flags |= NTPTS_DISABLED;
|
|
return;
|
|
}
|
|
|
|
assert(index <= ntp_ts_map.size);
|
|
|
|
if (index == ntp_ts_map.size) {
|
|
/* Increase the size or drop the oldest timestamp to make room for
|
|
the new timestamp */
|
|
index = push_ntp_tss(index);
|
|
} else {
|
|
/* Trim timestamps in distant future after backward step */
|
|
while (index < ntp_ts_map.size &&
|
|
get_ntp_tss(ntp_ts_map.size - 1)->rx_ts - rx > NTPTS_FUTURE_LIMIT)
|
|
ntp_ts_map.size--;
|
|
|
|
/* Insert the timestamp if it is close to the latest timestamp.
|
|
Otherwise, replace the closest older or the oldest timestamp. */
|
|
if (index + NTPTS_INSERT_LIMIT >= ntp_ts_map.size) {
|
|
index = push_ntp_tss(index);
|
|
for (i = ntp_ts_map.size - 1; i > index; i--)
|
|
*get_ntp_tss(i) = *get_ntp_tss(i - 1);
|
|
} else {
|
|
if (index > 0)
|
|
index--;
|
|
}
|
|
}
|
|
|
|
ntp_ts_map.cached_index = index;
|
|
ntp_ts_map.cached_rx_ts = rx;
|
|
|
|
tss = get_ntp_tss(index);
|
|
tss->rx_ts = rx;
|
|
tss->flags = 0;
|
|
set_ntp_tx_offset(tss, rx_ts, tx_ts);
|
|
|
|
DEBUG_LOG("Saved RX+TX index=%"PRIu32" first=%"PRIu32" size=%"PRIu32,
|
|
index, ntp_ts_map.first, ntp_ts_map.size);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_UpdateNtpTxTimestamp(NTP_int64 *rx_ts, struct timespec *tx_ts)
|
|
{
|
|
uint32_t index;
|
|
|
|
if (!ntp_ts_map.timestamps)
|
|
return;
|
|
|
|
if (!find_ntp_rx_ts(ntp64_to_int64(rx_ts), &index))
|
|
return;
|
|
|
|
set_ntp_tx_offset(get_ntp_tss(index), rx_ts, tx_ts);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_GetNtpTxTimestamp(NTP_int64 *rx_ts, struct timespec *tx_ts)
|
|
{
|
|
NtpTimestamps *tss;
|
|
uint32_t index;
|
|
|
|
if (!ntp_ts_map.timestamps)
|
|
return 0;
|
|
|
|
if (!find_ntp_rx_ts(ntp64_to_int64(rx_ts), &index))
|
|
return 0;
|
|
|
|
tss = get_ntp_tss(index);
|
|
|
|
if (tss->flags & NTPTS_DISABLED)
|
|
return 0;
|
|
|
|
get_ntp_tx(tss, tx_ts);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_DisableNtpTimestamps(NTP_int64 *rx_ts)
|
|
{
|
|
uint32_t index;
|
|
|
|
if (!ntp_ts_map.timestamps)
|
|
return;
|
|
|
|
if (find_ntp_rx_ts(ntp64_to_int64(rx_ts), &index))
|
|
get_ntp_tss(index)->flags |= NTPTS_DISABLED;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_GetNumberOfIndices(void)
|
|
{
|
|
if (!active)
|
|
return -1;
|
|
|
|
return ARR_GetSize(records);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int get_interval(int rate)
|
|
{
|
|
if (rate == INVALID_RATE)
|
|
return 127;
|
|
|
|
rate += rate > 0 ? RATE_SCALE / 2 : -RATE_SCALE / 2;
|
|
|
|
return rate / -RATE_SCALE;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static uint32_t get_last_ago(uint32_t x, uint32_t y)
|
|
{
|
|
if (y == INVALID_TS || (int32_t)(x - y) < 0)
|
|
return -1;
|
|
|
|
return (x - y) >> TS_FRAC;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
CLG_GetClientAccessReportByIndex(int index, int reset, uint32_t min_hits,
|
|
RPT_ClientAccessByIndex_Report *report, struct timespec *now)
|
|
{
|
|
Record *record;
|
|
uint32_t now_ts;
|
|
int i, r;
|
|
|
|
if (!active || index < 0 || index >= ARR_GetSize(records))
|
|
return 0;
|
|
|
|
record = ARR_GetElement(records, index);
|
|
|
|
if (record->ip_addr.family == IPADDR_UNSPEC)
|
|
return 0;
|
|
|
|
if (min_hits == 0) {
|
|
r = 1;
|
|
} else {
|
|
for (i = r = 0; i < MAX_SERVICES; i++) {
|
|
if (record->hits[i] >= min_hits) {
|
|
r = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (r) {
|
|
now_ts = get_ts_from_timespec(now);
|
|
|
|
report->ip_addr = record->ip_addr;
|
|
report->ntp_hits = record->hits[CLG_NTP];
|
|
report->nke_hits = record->hits[CLG_NTSKE];
|
|
report->cmd_hits = record->hits[CLG_CMDMON];
|
|
report->ntp_drops = record->drops[CLG_NTP];
|
|
report->nke_drops = record->drops[CLG_NTSKE];
|
|
report->cmd_drops = record->drops[CLG_CMDMON];
|
|
report->ntp_interval = get_interval(record->rate[CLG_NTP]);
|
|
report->nke_interval = get_interval(record->rate[CLG_NTSKE]);
|
|
report->cmd_interval = get_interval(record->rate[CLG_CMDMON]);
|
|
report->ntp_timeout_interval = get_interval(record->ntp_timeout_rate);
|
|
report->last_ntp_hit_ago = get_last_ago(now_ts, record->last_hit[CLG_NTP]);
|
|
report->last_nke_hit_ago = get_last_ago(now_ts, record->last_hit[CLG_NTSKE]);
|
|
report->last_cmd_hit_ago = get_last_ago(now_ts, record->last_hit[CLG_CMDMON]);
|
|
}
|
|
|
|
if (reset) {
|
|
for (i = 0; i < MAX_SERVICES; i++) {
|
|
record->hits[i] = 0;
|
|
record->drops[i] = 0;
|
|
}
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
CLG_GetServerStatsReport(RPT_ServerStatsReport *report)
|
|
{
|
|
report->ntp_hits = total_hits[CLG_NTP];
|
|
report->nke_hits = total_hits[CLG_NTSKE];
|
|
report->cmd_hits = total_hits[CLG_CMDMON];
|
|
report->ntp_drops = total_drops[CLG_NTP];
|
|
report->nke_drops = total_drops[CLG_NTSKE];
|
|
report->cmd_drops = total_drops[CLG_CMDMON];
|
|
report->log_drops = total_record_drops;
|
|
report->ntp_auth_hits = total_ntp_auth_hits;
|
|
}
|