diff options
Diffstat (limited to 'drivers/net/wireguard/queueing.h')
| -rw-r--r-- | drivers/net/wireguard/queueing.h | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h new file mode 100644 index 000000000000..e49a464238fd --- /dev/null +++ b/drivers/net/wireguard/queueing.h @@ -0,0 +1,197 @@ +/* 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_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) + +/* 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_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; +} + +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 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 */ |