1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2015-2018 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 wireguard_device;
struct wireguard_peer;
struct multicore_worker;
struct crypt_queue;
struct sk_buff;
/* queueing.c APIs: */
int packet_queue_init(struct crypt_queue *queue, work_func_t function,
bool multicore, unsigned int len);
void packet_queue_free(struct crypt_queue *queue, bool multicore);
struct multicore_worker __percpu *
packet_alloc_percpu_multicore_worker(work_func_t function, void *ptr);
/* receive.c APIs: */
void packet_receive(struct wireguard_device *wg, struct sk_buff *skb);
void packet_handshake_receive_worker(struct work_struct *work);
/* NAPI poll function: */
int packet_rx_poll(struct napi_struct *napi, int budget);
/* Workqueue worker: */
void packet_decrypt_worker(struct work_struct *work);
/* send.c APIs: */
void packet_send_queued_handshake_initiation(struct wireguard_peer *peer,
bool is_retry);
void packet_send_handshake_response(struct wireguard_peer *peer);
void packet_send_handshake_cookie(struct wireguard_device *wg,
struct sk_buff *initiating_skb,
__le32 sender_index);
void packet_send_keepalive(struct wireguard_peer *peer);
void packet_send_staged_packets(struct wireguard_peer *peer);
/* Workqueue workers: */
void packet_handshake_send_worker(struct work_struct *work);
void packet_tx_worker(struct work_struct *work);
void 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_PEER(skb) (((struct packet_cb *)skb->cb)->keypair->entry.peer)
#define PACKET_CB(skb) ((struct packet_cb *)skb->cb)
/* Returns either the correct skb->protocol value, or 0 if invalid. */
static inline __be16 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 skb_reset(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 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 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 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 = 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 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 wireguard_peer *peer = peer_get(PACKET_PEER(skb));
atomic_set_release(&PACKET_CB(skb)->state, state);
queue_work_on(cpumask_choose_online(&peer->serial_work_cpu,
peer->internal_id),
peer->device->packet_crypt_wq, &queue->work);
peer_put(peer);
}
static inline void 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 wireguard_peer *peer = peer_get(PACKET_PEER(skb));
atomic_set_release(&PACKET_CB(skb)->state, state);
napi_schedule(&peer->napi);
peer_put(peer);
}
#ifdef DEBUG
bool packet_counter_selftest(void);
#endif
#endif /* _WG_QUEUEING_H */
|
