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
52 struct clock_identity {
53 u8 id[8];
54 } __packed;
55
56 struct port_identity {
57 struct clock_identity clock_identity;
58 __be16 port_number;
59 } __packed;
60
61 struct 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 */
87 unsigned 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 */
102 struct 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 */
ptp_get_msgtype(const struct ptp_header * hdr,unsigned int type)114 static 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 void __init ptp_classifier_init(void);
130 #else
ptp_classifier_init(void)131 static inline void ptp_classifier_init(void)
132 {
133 }
ptp_classify_raw(struct sk_buff * skb)134 static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
135 {
136 return PTP_CLASS_NONE;
137 }
ptp_parse_header(struct sk_buff * skb,unsigned int type)138 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb,
139 unsigned int type)
140 {
141 return NULL;
142 }
ptp_get_msgtype(const struct ptp_header * hdr,unsigned int type)143 static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
144 unsigned int type)
145 {
146 /* The return is meaningless. The stub function would not be
147 * executed since no available header from ptp_parse_header.
148 */
149 return PTP_MSGTYPE_SYNC;
150 }
151 #endif
152 #endif /* _PTP_CLASSIFY_H_ */
153