78 lines
2.2 KiB
C
78 lines
2.2 KiB
C
/*
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* Copyright (c) 2018-2021 Samsung Electronics Co., Ltd. All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*/
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#include <linux/dsms.h>
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#include <linux/ktime.h>
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#include <linux/math64.h>
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#include <linux/timekeeping.h>
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#include "dsms_kernel_api.h"
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#include "dsms_rate_limit.h"
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#include "dsms_test.h"
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#define ROUND_DURATION_MS ((u64)(1000L))
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#define MAX_MESSAGES_PER_ROUND (50)
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__visible_for_testing int dsms_message_count;
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__visible_for_testing u64 dsms_round_start_ms;
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__visible_for_testing int dsms_get_max_messages_per_round(void)
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{
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return MAX_MESSAGES_PER_ROUND;
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}
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__visible_for_testing u64 round_end_ms(u64 round_start_ms)
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{
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return round_start_ms + ROUND_DURATION_MS;
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}
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__visible_for_testing int is_new_round(u64 now_ms, u64 last_round_start_ms)
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{
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return now_ms >= round_end_ms(last_round_start_ms);
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}
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__visible_for_testing u64 dsms_get_time_ms(void)
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{
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return div_u64(ktime_get_ns(), NSEC_PER_MSEC);
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}
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int __kunit_init dsms_rate_limit_init(void)
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{
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dsms_message_count = 0;
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dsms_round_start_ms = dsms_get_time_ms();
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DSMS_LOG_DEBUG("[rate limit] INIT dsms_round_start_ms=%llu dsms_message_count=%d",
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dsms_round_start_ms, dsms_message_count);
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return 0;
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}
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int dsms_check_message_rate_limit(void)
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{
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int dropped_messages;
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u64 current_time_ms;
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current_time_ms = dsms_get_time_ms();
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if (current_time_ms < dsms_round_start_ms) {
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DSMS_LOG_DEBUG("[rate limit] RESET current_time_ms=%llu dsms_round_start_ms=%llu dsms_message_count=%d",
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current_time_ms, dsms_round_start_ms, dsms_message_count);
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dsms_round_start_ms = current_time_ms;
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dsms_message_count = 0;
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}
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if (is_new_round(current_time_ms, dsms_round_start_ms)) {
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dropped_messages = dsms_message_count - dsms_get_max_messages_per_round();
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if (dropped_messages > 0)
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DSMS_LOG_ERROR("[rate limit] %d of %d messages dropped", dropped_messages, dsms_message_count);
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dsms_round_start_ms = current_time_ms;
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dsms_message_count = 0;
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return DSMS_SUCCESS;
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}
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if (++dsms_message_count > dsms_get_max_messages_per_round())
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return DSMS_DENY;
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return DSMS_SUCCESS;
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}
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