110 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
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|  */
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| 
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| #include "queueing.h"
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| #include <linux/skb_array.h>
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| 
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| struct multicore_worker __percpu *
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| wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr)
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| {
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| 	int cpu;
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| 	struct multicore_worker __percpu *worker = alloc_percpu(struct multicore_worker);
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| 
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| 	if (!worker)
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| 		return NULL;
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| 
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| 	for_each_possible_cpu(cpu) {
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| 		per_cpu_ptr(worker, cpu)->ptr = ptr;
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| 		INIT_WORK(&per_cpu_ptr(worker, cpu)->work, function);
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| 	}
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| 	return worker;
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| }
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| 
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| int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
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| 			 unsigned int len)
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| {
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| 	int ret;
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| 
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| 	memset(queue, 0, sizeof(*queue));
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| 	queue->last_cpu = -1;
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| 	ret = ptr_ring_init(&queue->ring, len, GFP_KERNEL);
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| 	if (ret)
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| 		return ret;
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| 	queue->worker = wg_packet_percpu_multicore_worker_alloc(function, queue);
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| 	if (!queue->worker) {
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| 		ptr_ring_cleanup(&queue->ring, NULL);
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| 		return -ENOMEM;
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| 	}
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| 	return 0;
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| }
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| 
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| void wg_packet_queue_free(struct crypt_queue *queue, bool purge)
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| {
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| 	free_percpu(queue->worker);
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| 	WARN_ON(!purge && !__ptr_ring_empty(&queue->ring));
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| 	ptr_ring_cleanup(&queue->ring, purge ? __skb_array_destroy_skb : NULL);
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| }
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| 
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| #define NEXT(skb) ((skb)->prev)
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| #define STUB(queue) ((struct sk_buff *)&queue->empty)
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| 
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| void wg_prev_queue_init(struct prev_queue *queue)
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| {
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| 	NEXT(STUB(queue)) = NULL;
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| 	queue->head = queue->tail = STUB(queue);
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| 	queue->peeked = NULL;
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| 	atomic_set(&queue->count, 0);
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| 	BUILD_BUG_ON(
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| 		offsetof(struct sk_buff, next) != offsetof(struct prev_queue, empty.next) -
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| 							offsetof(struct prev_queue, empty) ||
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| 		offsetof(struct sk_buff, prev) != offsetof(struct prev_queue, empty.prev) -
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| 							 offsetof(struct prev_queue, empty));
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| }
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| 
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| static void __wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
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| {
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| 	WRITE_ONCE(NEXT(skb), NULL);
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| 	WRITE_ONCE(NEXT(xchg_release(&queue->head, skb)), skb);
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| }
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| 
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| bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
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| {
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| 	if (!atomic_add_unless(&queue->count, 1, MAX_QUEUED_PACKETS))
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| 		return false;
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| 	__wg_prev_queue_enqueue(queue, skb);
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| 	return true;
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| }
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| 
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| struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue)
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| {
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| 	struct sk_buff *tail = queue->tail, *next = smp_load_acquire(&NEXT(tail));
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| 
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| 	if (tail == STUB(queue)) {
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| 		if (!next)
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| 			return NULL;
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| 		queue->tail = next;
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| 		tail = next;
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| 		next = smp_load_acquire(&NEXT(next));
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| 	}
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| 	if (next) {
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| 		queue->tail = next;
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| 		atomic_dec(&queue->count);
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| 		return tail;
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| 	}
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| 	if (tail != READ_ONCE(queue->head))
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| 		return NULL;
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| 	__wg_prev_queue_enqueue(queue, STUB(queue));
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| 	next = smp_load_acquire(&NEXT(tail));
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| 	if (next) {
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| 		queue->tail = next;
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| 		atomic_dec(&queue->count);
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| 		return tail;
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| 	}
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| 	return NULL;
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| }
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| 
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| #undef NEXT
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| #undef STUB
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