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
51 struct clock_identity {
52 u8 id[8];
53 } __packed;
54
55 struct port_identity {
56 struct clock_identity clock_identity;
57 __be16 port_number;
58 } __packed;
59
60 struct 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 */
86 unsigned 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 */
101 struct 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 */
ptp_get_msgtype(const struct ptp_header * hdr,unsigned int type)113 static 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
128 void __init ptp_classifier_init(void);
129 #else
ptp_classifier_init(void)130 static inline void ptp_classifier_init(void)
131 {
132 }
ptp_classify_raw(struct sk_buff * skb)133 static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
134 {
135 return PTP_CLASS_NONE;
136 }
ptp_parse_header(struct sk_buff * skb,unsigned int type)137 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb,
138 unsigned int type)
139 {
140 return NULL;
141 }
ptp_get_msgtype(const struct ptp_header * hdr,unsigned int type)142 static 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_ */
152
