1/* SPDX-License-Identifier: GPL-2.0-only */
2
3#ifndef __NET_PSP_H
4#define __NET_PSP_H
5
6#include <linux/mutex.h>
7#include <linux/refcount.h>
8
9struct netlink_ext_ack;
10
11#define PSP_DEFAULT_UDP_PORT 1000
12
13struct psphdr {
14 u8 nexthdr;
15 u8 hdrlen;
16 u8 crypt_offset;
17 u8 verfl;
18 __be32 spi;
19 __be64 iv;
20 __be64 vc[]; /* optional */
21};
22
23#define PSP_ENCAP_HLEN (sizeof(struct udphdr) + sizeof(struct psphdr))
24
25#define PSP_SPI_KEY_ID GENMASK(30, 0)
26#define PSP_SPI_KEY_PHASE BIT(31)
27
28#define PSPHDR_CRYPT_OFFSET GENMASK(5, 0)
29
30#define PSPHDR_VERFL_SAMPLE BIT(7)
31#define PSPHDR_VERFL_DROP BIT(6)
32#define PSPHDR_VERFL_VERSION GENMASK(5, 2)
33#define PSPHDR_VERFL_VIRT BIT(1)
34#define PSPHDR_VERFL_ONE BIT(0)
35
36#define PSP_HDRLEN_NOOPT ((sizeof(struct psphdr) - 8) / 8)
37
38/**
39 * struct psp_dev_config - PSP device configuration
40 * @versions: PSP versions enabled on the device
41 */
42struct psp_dev_config {
43 u32 versions;
44};
45
46/**
47 * struct psp_dev - PSP device struct
48 * @main_netdev: original netdevice of this PSP device
49 * @ops: driver callbacks
50 * @caps: device capabilities
51 * @drv_priv: driver priv pointer
52 * @lock: instance lock, protects all fields
53 * @refcnt: reference count for the instance
54 * @id: instance id
55 * @generation: current generation of the device key
56 * @config: current device configuration
57 * @active_assocs: list of registered associations
58 * @prev_assocs: associations which use old (but still usable)
59 * device key
60 * @stale_assocs: associations which use a rotated out key
61 *
62 * @rcu: RCU head for freeing the structure
63 */
64struct psp_dev {
65 struct net_device *main_netdev;
66
67 struct psp_dev_ops *ops;
68 struct psp_dev_caps *caps;
69 void *drv_priv;
70
71 struct mutex lock;
72 refcount_t refcnt;
73
74 u32 id;
75
76 u8 generation;
77
78 struct psp_dev_config config;
79
80 struct list_head active_assocs;
81 struct list_head prev_assocs;
82 struct list_head stale_assocs;
83
84 struct rcu_head rcu;
85};
86
87#define PSP_GEN_VALID_MASK 0x7f
88
89/**
90 * struct psp_dev_caps - PSP device capabilities
91 */
92struct psp_dev_caps {
93 /**
94 * @versions: mask of supported PSP versions
95 * Set this field to 0 to indicate PSP is not supported at all.
96 */
97 u32 versions;
98
99 /**
100 * @assoc_drv_spc: size of driver-specific state in Tx assoc
101 * Determines the size of struct psp_assoc::drv_data
102 */
103 u32 assoc_drv_spc;
104};
105
106#define PSP_MAX_KEY 32
107
108#define PSP_HDR_SIZE 16 /* We don't support optional fields, yet */
109#define PSP_TRL_SIZE 16 /* AES-GCM/GMAC trailer size */
110
111struct psp_skb_ext {
112 __be32 spi;
113 u16 dev_id;
114 u8 generation;
115 u8 version;
116};
117
118struct psp_key_parsed {
119 __be32 spi;
120 u8 key[PSP_MAX_KEY];
121};
122
123struct psp_assoc {
124 struct psp_dev *psd;
125
126 u16 dev_id;
127 u8 generation;
128 u8 version;
129 u8 peer_tx;
130
131 u32 upgrade_seq;
132
133 struct psp_key_parsed tx;
134 struct psp_key_parsed rx;
135
136 refcount_t refcnt;
137 struct rcu_head rcu;
138 struct work_struct work;
139 struct list_head assocs_list;
140
141 u8 drv_data[] __aligned(8);
142};
143
144/**
145 * struct psp_dev_ops - netdev driver facing PSP callbacks
146 */
147struct psp_dev_ops {
148 /**
149 * @set_config: set configuration of a PSP device
150 * Driver can inspect @psd->config for the previous configuration.
151 * Core will update @psd->config with @config on success.
152 */
153 int (*set_config)(struct psp_dev *psd, struct psp_dev_config *conf,
154 struct netlink_ext_ack *extack);
155
156 /**
157 * @key_rotate: rotate the device key
158 */
159 int (*key_rotate)(struct psp_dev *psd, struct netlink_ext_ack *extack);
160
161 /**
162 * @rx_spi_alloc: allocate an Rx SPI+key pair
163 * Allocate an Rx SPI and resulting derived key.
164 * This key should remain valid until key rotation.
165 */
166 int (*rx_spi_alloc)(struct psp_dev *psd, u32 version,
167 struct psp_key_parsed *assoc,
168 struct netlink_ext_ack *extack);
169
170 /**
171 * @tx_key_add: add a Tx key to the device
172 * Install an association in the device. Core will allocate space
173 * for the driver to use at drv_data.
174 */
175 int (*tx_key_add)(struct psp_dev *psd, struct psp_assoc *pas,
176 struct netlink_ext_ack *extack);
177 /**
178 * @tx_key_del: remove a Tx key from the device
179 * Remove an association from the device.
180 */
181 void (*tx_key_del)(struct psp_dev *psd, struct psp_assoc *pas);
182};
183
184#endif /* __NET_PSP_H */
185