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-rw-r--r--drivers/net/wireguard/queueing.h198
1 files changed, 198 insertions, 0 deletions
diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h
new file mode 100644
index 000000000000..f8de703dff97
--- /dev/null
+++ b/drivers/net/wireguard/queueing.h
@@ -0,0 +1,198 @@
+/* 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 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 */