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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * PTP 1588 support
4 *
5 * This file implements a BPF that recognizes PTP event messages.
6 *
7 * Copyright (C) 2010 OMICRON electronics GmbH
8 */
9
10#ifndef _PTP_CLASSIFY_H_
11#define _PTP_CLASSIFY_H_
12
13#include <linux/ip.h>
14#include <linux/skbuff.h>
15
16#define PTP_CLASS_NONE 0x00 /* not a PTP event message */
17#define PTP_CLASS_V1 0x01 /* protocol version 1 */
18#define PTP_CLASS_V2 0x02 /* protocol version 2 */
19#define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */
20#define PTP_CLASS_IPV4 0x10 /* event in an IPV4 UDP packet */
21#define PTP_CLASS_IPV6 0x20 /* event in an IPV6 UDP packet */
22#define PTP_CLASS_L2 0x40 /* event in a L2 packet */
23#define PTP_CLASS_PMASK 0x70 /* mask for the packet type field */
24#define PTP_CLASS_VLAN 0x80 /* event in a VLAN tagged packet */
25
26#define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4)
27#define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 | PTP_CLASS_IPV6) /* probably DNE */
28#define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4)
29#define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 | PTP_CLASS_IPV6)
30#define PTP_CLASS_V2_L2 (PTP_CLASS_V2 | PTP_CLASS_L2)
31#define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 | PTP_CLASS_VLAN)
32#define PTP_CLASS_L4 (PTP_CLASS_IPV4 | PTP_CLASS_IPV6)
33
34#define PTP_MSGTYPE_SYNC 0x0
35#define PTP_MSGTYPE_DELAY_REQ 0x1
36#define PTP_MSGTYPE_PDELAY_REQ 0x2
37#define PTP_MSGTYPE_PDELAY_RESP 0x3
38
39#define PTP_EV_PORT 319
40#define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */
41
42#define OFF_PTP_SOURCE_UUID 22 /* PTPv1 only */
43#define OFF_PTP_SEQUENCE_ID 30
44
45/* Below defines should actually be removed at some point in time. */
46#define IP6_HLEN 40
47#define UDP_HLEN 8
48#define OFF_IHL 14
49#define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)
50
51struct clock_identity {
52 u8 id[8];
53} __packed;
54
55struct port_identity {
56 struct clock_identity clock_identity;
57 __be16 port_number;
58} __packed;
59
60struct ptp_header {
61 u8 tsmt; /* transportSpecific | messageType */
62 u8 ver; /* reserved | versionPTP */
63 __be16 message_length;
64 u8 domain_number;
65 u8 reserved1;
66 u8 flag_field[2];
67 __be64 correction;
68 __be32 reserved2;
69 struct port_identity source_port_identity;
70 __be16 sequence_id;
71 u8 control;
72 u8 log_message_interval;
73} __packed;
74
75#if defined(CONFIG_NET_PTP_CLASSIFY)
76/**
77 * ptp_classify_raw - classify a PTP packet
78 * @skb: buffer
79 *
80 * Runs a minimal BPF dissector to classify a network packet to
81 * determine the PTP class. In case the skb does not contain any
82 * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise
83 * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or
84 * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content.
85 */
86unsigned int ptp_classify_raw(const struct sk_buff *skb);
87
88/**
89 * ptp_parse_header - Get pointer to the PTP v2 header
90 * @skb: packet buffer
91 * @type: type of the packet (see ptp_classify_raw())
92 *
93 * This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length
94 * is checked.
95 *
96 * Note, internally skb_mac_header() is used. Make sure that the @skb is
97 * initialized accordingly.
98 *
99 * Return: Pointer to the ptp v2 header or NULL if not found
100 */
101struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type);
102
103/**
104 * ptp_get_msgtype - Extract ptp message type from given header
105 * @hdr: ptp header
106 * @type: type of the packet (see ptp_classify_raw())
107 *
108 * This function returns the message type for a given ptp header. It takes care
109 * of the different ptp header versions (v1 or v2).
110 *
111 * Return: The message type
112 */
113static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
114 unsigned int type)
115{
116 u8 msgtype;
117
118 if (unlikely(type & PTP_CLASS_V1)) {
119 /* msg type is located at the control field for ptp v1 */
120 msgtype = hdr->control;
121 } else {
122 msgtype = hdr->tsmt & 0x0f;
123 }
124
125 return msgtype;
126}
127
128void __init ptp_classifier_init(void);
129#else
130static inline void ptp_classifier_init(void)
131{
132}
133static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
134{
135 return PTP_CLASS_NONE;
136}
137static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb,
138 unsigned int type)
139{
140 return NULL;
141}
142static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
143 unsigned int type)
144{
145 /* The return is meaningless. The stub function would not be
146 * executed since no available header from ptp_parse_header.
147 */
148 return PTP_MSGTYPE_SYNC;
149}
150#endif
151#endif /* _PTP_CLASSIFY_H_ */