/* 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> struct wg_device; struct wg_peer; struct multicore_worker; struct crypt_queue; struct sk_buff; /* queueing.c APIs: */ int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function, bool multicore, unsigned int len); void wg_packet_queue_free(struct crypt_queue *queue, bool multicore); struct multicore_worker __percpu * wg_packet_alloc_percpu_multicore_worker(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) /* Returns either the correct skb->protocol value, or 0 if invalid. */ static inline __be16 wg_skb_examine_untrusted_ip_hdr(struct sk_buff *skb) { if (skb_network_header(skb) >= skb->head && (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) && ip_hdr(skb)->version == 4) return htons(ETH_P_IP); if (skb_network_header(skb) >= skb->head && (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) && ipv6_hdr(skb)->version == 6) return htons(ETH_P_IPV6); return 0; } static inline void wg_reset_packet(struct sk_buff *skb) { const int pfmemalloc = skb->pfmemalloc; skb_scrub_packet(skb, true); memset(&skb->headers_start, 0, offsetof(struct sk_buff, headers_end) - offsetof(struct sk_buff, headers_start)); skb->pfmemalloc = pfmemalloc; 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; skb_reset_tc(skb); #endif skb->hdr_len = skb_headroom(skb); skb_reset_mac_header(skb); skb_reset_network_header(skb); skb_probe_transport_header(skb, 0); 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; } static inline int wg_queue_enqueue_per_device_and_peer( struct crypt_queue *device_queue, struct crypt_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(ptr_ring_produce_bh(&peer_queue->ring, 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(struct crypt_queue *queue, 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, &queue->work); wg_peer_put(peer); } static inline void wg_queue_enqueue_per_peer_napi(struct crypt_queue *queue, 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 DEBUG bool wg_packet_counter_selftest(void); #endif #endif /* _WG_QUEUEING_H */