1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. 4 */ 5 6 #ifndef _WG_QUEUEING_H 7 #define _WG_QUEUEING_H 8 9 #include "peer.h" 10 #include <linux/types.h> 11 #include <linux/skbuff.h> 12 #include <linux/ip.h> 13 #include <linux/ipv6.h> 14 #include <net/ip_tunnels.h> 15 16 struct wg_device; 17 struct wg_peer; 18 struct multicore_worker; 19 struct crypt_queue; 20 struct prev_queue; 21 struct sk_buff; 22 23 /* queueing.c APIs: */ 24 int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function, 25 unsigned int len); 26 void wg_packet_queue_free(struct crypt_queue *queue, bool purge); 27 struct multicore_worker __percpu * 28 wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr); 29 30 /* receive.c APIs: */ 31 void wg_packet_receive(struct wg_device *wg, struct sk_buff *skb); 32 void wg_packet_handshake_receive_worker(struct work_struct *work); 33 /* NAPI poll function: */ 34 int wg_packet_rx_poll(struct napi_struct *napi, int budget); 35 /* Workqueue worker: */ 36 void wg_packet_decrypt_worker(struct work_struct *work); 37 38 /* send.c APIs: */ 39 void wg_packet_send_queued_handshake_initiation(struct wg_peer *peer, 40 bool is_retry); 41 void wg_packet_send_handshake_response(struct wg_peer *peer); 42 void wg_packet_send_handshake_cookie(struct wg_device *wg, 43 struct sk_buff *initiating_skb, 44 __le32 sender_index); 45 void wg_packet_send_keepalive(struct wg_peer *peer); 46 void wg_packet_purge_staged_packets(struct wg_peer *peer); 47 void wg_packet_send_staged_packets(struct wg_peer *peer); 48 /* Workqueue workers: */ 49 void wg_packet_handshake_send_worker(struct work_struct *work); 50 void wg_packet_tx_worker(struct work_struct *work); 51 void wg_packet_encrypt_worker(struct work_struct *work); 52 53 enum packet_state { 54 PACKET_STATE_UNCRYPTED, 55 PACKET_STATE_CRYPTED, 56 PACKET_STATE_DEAD 57 }; 58 59 struct packet_cb { 60 u64 nonce; 61 struct noise_keypair *keypair; 62 atomic_t state; 63 u32 mtu; 64 u8 ds; 65 }; 66 67 #define PACKET_CB(skb) ((struct packet_cb *)((skb)->cb)) 68 #define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer) 69 70 static inline bool wg_check_packet_protocol(struct sk_buff *skb) 71 { 72 __be16 real_protocol = ip_tunnel_parse_protocol(skb); 73 return real_protocol && skb->protocol == real_protocol; 74 } 75 76 static inline void wg_reset_packet(struct sk_buff *skb, bool encapsulating) 77 { 78 u8 l4_hash = skb->l4_hash; 79 u8 sw_hash = skb->sw_hash; 80 u32 hash = skb->hash; 81 skb_scrub_packet(skb, true); 82 memset(&skb->headers, 0, sizeof(skb->headers)); 83 if (encapsulating) { 84 skb->l4_hash = l4_hash; 85 skb->sw_hash = sw_hash; 86 skb->hash = hash; 87 } 88 skb->queue_mapping = 0; 89 skb->nohdr = 0; 90 skb->peeked = 0; 91 skb->mac_len = 0; 92 skb->dev = NULL; 93 #ifdef CONFIG_NET_SCHED 94 skb->tc_index = 0; 95 #endif 96 skb_reset_redirect(skb); 97 skb->hdr_len = skb_headroom(skb); 98 skb_reset_mac_header(skb); 99 skb_reset_network_header(skb); 100 skb_reset_transport_header(skb); 101 skb_probe_transport_header(skb); 102 skb_reset_inner_headers(skb); 103 } 104 105 static inline int wg_cpumask_choose_online(int *stored_cpu, unsigned int id) 106 { 107 unsigned int cpu = *stored_cpu; 108 109 while (unlikely(cpu >= nr_cpu_ids || !cpu_online(cpu))) 110 cpu = *stored_cpu = cpumask_nth(id % num_online_cpus(), cpu_online_mask); 111 112 return cpu; 113 } 114 115 /* This function is racy, in the sense that it's called while last_cpu is 116 * unlocked, so it could return the same CPU twice. Adding locking or using 117 * atomic sequence numbers is slower though, and the consequences of racing are 118 * harmless, so live with it. 119 */ 120 static inline int wg_cpumask_next_online(int *last_cpu) 121 { 122 int cpu = cpumask_next(READ_ONCE(*last_cpu), cpu_online_mask); 123 if (cpu >= nr_cpu_ids) 124 cpu = cpumask_first(cpu_online_mask); 125 WRITE_ONCE(*last_cpu, cpu); 126 return cpu; 127 } 128 129 void wg_prev_queue_init(struct prev_queue *queue); 130 131 /* Multi producer */ 132 bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb); 133 134 /* Single consumer */ 135 struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue); 136 137 /* Single consumer */ 138 static inline struct sk_buff *wg_prev_queue_peek(struct prev_queue *queue) 139 { 140 if (queue->peeked) 141 return queue->peeked; 142 queue->peeked = wg_prev_queue_dequeue(queue); 143 return queue->peeked; 144 } 145 146 /* Single consumer */ 147 static inline void wg_prev_queue_drop_peeked(struct prev_queue *queue) 148 { 149 queue->peeked = NULL; 150 } 151 152 static inline int wg_queue_enqueue_per_device_and_peer( 153 struct crypt_queue *device_queue, struct prev_queue *peer_queue, 154 struct sk_buff *skb, struct workqueue_struct *wq) 155 { 156 int cpu; 157 158 atomic_set_release(&PACKET_CB(skb)->state, PACKET_STATE_UNCRYPTED); 159 /* We first queue this up for the peer ingestion, but the consumer 160 * will wait for the state to change to CRYPTED or DEAD before. 161 */ 162 if (unlikely(!wg_prev_queue_enqueue(peer_queue, skb))) 163 return -ENOSPC; 164 165 /* Then we queue it up in the device queue, which consumes the 166 * packet as soon as it can. 167 */ 168 cpu = wg_cpumask_next_online(&device_queue->last_cpu); 169 if (unlikely(ptr_ring_produce_bh(&device_queue->ring, skb))) 170 return -EPIPE; 171 queue_work_on(cpu, wq, &per_cpu_ptr(device_queue->worker, cpu)->work); 172 return 0; 173 } 174 175 static inline void wg_queue_enqueue_per_peer_tx(struct sk_buff *skb, enum packet_state state) 176 { 177 /* We take a reference, because as soon as we call atomic_set, the 178 * peer can be freed from below us. 179 */ 180 struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb)); 181 182 atomic_set_release(&PACKET_CB(skb)->state, state); 183 queue_work_on(wg_cpumask_choose_online(&peer->serial_work_cpu, peer->internal_id), 184 peer->device->packet_crypt_wq, &peer->transmit_packet_work); 185 wg_peer_put(peer); 186 } 187 188 static inline void wg_queue_enqueue_per_peer_rx(struct sk_buff *skb, enum packet_state state) 189 { 190 /* We take a reference, because as soon as we call atomic_set, the 191 * peer can be freed from below us. 192 */ 193 struct wg_peer *peer = wg_peer_get(PACKET_PEER(skb)); 194 195 atomic_set_release(&PACKET_CB(skb)->state, state); 196 napi_schedule(&peer->napi); 197 wg_peer_put(peer); 198 } 199 200 #ifdef DEBUG 201 bool wg_packet_counter_selftest(void); 202 #endif 203 204 #endif /* _WG_QUEUEING_H */ 205