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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_PORT 320
41#define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */
42
43#define OFF_PTP_SOURCE_UUID 22 /* PTPv1 only */
44#define OFF_PTP_SEQUENCE_ID 30
45
46/* Below defines should actually be removed at some point in time. */
47#define IP6_HLEN 40
48#define UDP_HLEN 8
49#define OFF_IHL 14
50#define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)
51
52struct clock_identity {
53 u8 id[8];
54} __packed;
55
56struct port_identity {
57 struct clock_identity clock_identity;
58 __be16 port_number;
59} __packed;
60
61struct ptp_header {
62 u8 tsmt; /* transportSpecific | messageType */
63 u8 ver; /* reserved | versionPTP */
64 __be16 message_length;
65 u8 domain_number;
66 u8 reserved1;
67 u8 flag_field[2];
68 __be64 correction;
69 __be32 reserved2;
70 struct port_identity source_port_identity;
71 __be16 sequence_id;
72 u8 control;
73 u8 log_message_interval;
74} __packed;
75
76#if defined(CONFIG_NET_PTP_CLASSIFY)
77/**
78 * ptp_classify_raw - classify a PTP packet
79 * @skb: buffer
80 *
81 * Runs a minimal BPF dissector to classify a network packet to
82 * determine the PTP class. In case the skb does not contain any
83 * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise
84 * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or
85 * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content.
86 */
87unsigned int ptp_classify_raw(const struct sk_buff *skb);
88
89/**
90 * ptp_parse_header - Get pointer to the PTP v2 header
91 * @skb: packet buffer
92 * @type: type of the packet (see ptp_classify_raw())
93 *
94 * This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length
95 * is checked.
96 *
97 * Note, internally skb_mac_header() is used. Make sure that the @skb is
98 * initialized accordingly.
99 *
100 * Return: Pointer to the ptp v2 header or NULL if not found
101 */
102struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type);
103
104/**
105 * ptp_get_msgtype - Extract ptp message type from given header
106 * @hdr: ptp header
107 * @type: type of the packet (see ptp_classify_raw())
108 *
109 * This function returns the message type for a given ptp header. It takes care
110 * of the different ptp header versions (v1 or v2).
111 *
112 * Return: The message type
113 */
114static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
115 unsigned int type)
116{
117 u8 msgtype;
118
119 if (unlikely(type & PTP_CLASS_V1)) {
120 /* msg type is located at the control field for ptp v1 */
121 msgtype = hdr->control;
122 } else {
123 msgtype = hdr->tsmt & 0x0f;
124 }
125
126 return msgtype;
127}
128
129/**
130 * ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message
131 * @skb: packet buffer
132 * @type: type of the packet (see ptp_classify_raw())
133 *
134 * This function evaluates whether the given skb is a PTP Sync message.
135 *
136 * Return: true if sync message, false otherwise
137 */
138bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type);
139
140void __init ptp_classifier_init(void);
141#else
142static inline void ptp_classifier_init(void)
143{
144}
145static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
146{
147 return PTP_CLASS_NONE;
148}
149static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb,
150 unsigned int type)
151{
152 return NULL;
153}
154static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
155 unsigned int type)
156{
157 /* The return is meaningless. The stub function would not be
158 * executed since no available header from ptp_parse_header.
159 */
160 return PTP_MSGTYPE_SYNC;
161}
162static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type)
163{
164 return false;
165}
166#endif
167#endif /* _PTP_CLASSIFY_H_ */