/* SPDX-License-Identifier: GPL-2.0 *//* * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ #ifndef _WG_QUEUEING_H#define _WG_QUEUEING_H #include "peer.h"#include <linux/types.h>#include <linux/skbuff.h>#include <linux/ip.h>#include <linux/ipv6.h>#include <net/ip_tunnels.h> struct wg_device;struct wg_peer;struct multicore_worker;struct crypt_queue;struct prev_queue;struct sk_buff; /* queueing.c APIs: */int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,			 unsigned int len);void wg_packet_queue_free(struct crypt_queue *queue);struct multicore_worker __percpu *wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr); /* receive.c APIs: */void wg_packet_receive(struct wg_device *wg, struct sk_buff *skb);void wg_packet_handshake_receive_worker(struct work_struct *work);/* NAPI poll function: */int wg_packet_rx_poll(struct napi_struct *napi, int budget);/* Workqueue worker: */void wg_packet_decrypt_worker(struct work_struct *work); /* send.c APIs: */void wg_packet_send_queued_handshake_initiation(struct wg_peer *peer,						bool is_retry);void wg_packet_send_handshake_response(struct wg_peer *peer);void wg_packet_send_handshake_cookie(struct wg_device *wg,				     struct sk_buff *initiating_skb,				     __le32 sender_index);void wg_packet_send_keepalive(struct wg_peer *peer);void wg_packet_purge_staged_packets(struct wg_peer *peer);void wg_packet_send_staged_packets(struct wg_peer *peer);/* Workqueue workers: */void wg_packet_handshake_send_worker(struct work_struct *work);void wg_packet_tx_worker(struct work_struct *work);void wg_packet_encrypt_worker(struct work_struct *work); enum packet_state {	PACKET_STATE_UNCRYPTED,	PACKET_STATE_CRYPTED,	PACKET_STATE_DEAD}; struct packet_cb {	u64 nonce;	struct noise_keypair *keypair;	atomic_t state;	u32 mtu;	u8 ds;}; #define PACKET_CB(skb) ((struct packet_cb *)((skb)->cb))#define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer) static inline bool wg_check_packet_protocol(struct sk_buff *skb){	__be16 real_protocol = ip_tunnel_parse_protocol(skb);	return real_protocol && skb->protocol == real_protocol;} static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating){	u8 l4_hash = skb->l4_hash;	u8 sw_hash = skb->sw_hash;	u32 hash = skb->hash;	skb_scrub_packet(skb, true);	memset(&skb->headers_start, 0,	       offsetof(struct sk_buff, headers_end) -		       offsetof(struct sk_buff, headers_start));	if (encapsulating) {		skb->l4_hash = l4_hash;		skb->sw_hash = sw_hash;		skb->hash = hash;	}	skb->queue_mapping = 0;	skb->nohdr = 0;	skb->peeked = 0;	skb->mac_len = 0;	skb->dev = NULL;#ifdef CONFIG_NET_SCHED	skb->tc_index = 0;#endif	skb_reset_redirect(skb);	skb->hdr_len = skb_headroom(skb);	skb_reset_mac_header(skb);	skb_reset_network_header(skb);	skb_reset_transport_header(skb);	skb_probe_transport_header(skb);	skb_reset_inner_headers(skb);} static inline int wg_cpumask_choose_online(int *stored_cpu, unsigned int id){	unsigned int cpu = *stored_cpu, cpu_index, i; 	if (unlikely(cpu == nr_cpumask_bits ||		     !cpumask_test_cpu(cpu, cpu_online_mask))) {		cpu_index = id % cpumask_weight(cpu_online_mask);		cpu = cpumask_first(cpu_online_mask);		for (i = 0; i < cpu_index; ++i)			cpu = cpumask_next(cpu, cpu_online_mask);		*stored_cpu = cpu;	}	return cpu;} /* This function is racy, in the sense that next is unlocked, so it could return * the same CPU twice. A race-free version of this would be to instead store an * atomic sequence number, do an increment-and-return, and then iterate through * every possible CPU until we get to that index -- choose_cpu. However that's * a bit slower, and it doesn't seem like this potential race actually * introduces any performance loss, so we live with it. */static inline int wg_cpumask_next_online(int *next){	int cpu = *next; 	while (unlikely(!cpumask_test_cpu(cpu, cpu_online_mask)))		cpu = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;	*next = cpumask_next(cpu, cpu_online_mask) % nr_cpumask_bits;	return cpu;} void wg_prev_queue_init(struct prev_queue *queue); /* Multi producer */bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb); /* Single consumer */struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue); /* Single consumer */static inline struct sk_buff *wg_prev_queue_peek(struct prev_queue *queue){	if (queue->peeked)		return queue->peeked;	queue->peeked = wg_prev_queue_dequeue(queue);	return queue->peeked;} /* Single consumer */static inline void wg_prev_queue_drop_peeked(struct prev_queue *queue){	queue->peeked = NULL;} static inline int wg_queue_enqueue_per_device_and_peer(	struct crypt_queue *device_queue, struct prev_queue *peer_queue,	struct sk_buff *skb, struct workqueue_struct *wq, int *next_cpu){	int cpu; 	atomic_set_release(&PACKET_CB(skb)->state, PACKET_STATE_UNCRYPTED);	/* We first queue this up for the peer ingestion, but the consumer	 * will wait for the state to change to CRYPTED or DEAD before.	 */	if (unlikely(!wg_prev_queue_enqueue(peer_queue, skb)))		return -ENOSPC; 	/* Then we queue it up in the device queue, which consumes the	 * packet as soon as it can.	 */	cpu = wg_cpumask_next_online(next_cpu);	if (unlikely(ptr_ring_produce_bh(&device_queue->ring, skb)))		return -EPIPE;	queue_work_on(cpu, wq, &per_cpu_ptr(device_queue->worker, cpu)->work);	return 0;} static inline void wg_queue_enqueue_per_peer_tx(struct sk_buff *skb, enum packet_state state){	/* We take a reference, because as soon as we call atomic_set, the	 * peer can be freed from below us.	 */	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb)); 	atomic_set_release(&PACKET_CB(skb)->state, state);	queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu, peer->internal_id),		      peer->device->packet_crypt_wq, &peer->transmit_packet_work);	wg_peer_put(peer);} static inline void wg_queue_enqueue_per_peer_rx(struct sk_buff *skb, enum packet_state state){	/* We take a reference, because as soon as we call atomic_set, the	 * peer can be freed from below us.	 */	struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb)); 	atomic_set_release(&PACKET_CB(skb)->state, state);	napi_schedule(&peer->napi);	wg_peer_put(peer);} #ifdef DEBUGbool wg_packet_counter_selftest(void);#endif #endif /* _WG_QUEUEING_H */