1 /*
2  * PTP 1588 support
3  *
4  * This file implements a BPF that recognizes PTP event messages.
5  *
6  * Copyright (C) 2010 OMICRON electronics GmbH
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 #ifndef _PTP_CLASSIFY_H_
24 #define _PTP_CLASSIFY_H_
25 
26 #include <linux/ip.h>
27 #include <linux/skbuff.h>
28 
29 #define PTP_CLASS_NONE  0x00 /* not a PTP event message */
30 #define PTP_CLASS_V1    0x01 /* protocol version 1 */
31 #define PTP_CLASS_V2    0x02 /* protocol version 2 */
32 #define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */
33 #define PTP_CLASS_IPV4  0x10 /* event in an IPV4 UDP packet */
34 #define PTP_CLASS_IPV6  0x20 /* event in an IPV6 UDP packet */
35 #define PTP_CLASS_L2    0x40 /* event in a L2 packet */
36 #define PTP_CLASS_PMASK	0x70 /* mask for the packet type field */
37 #define PTP_CLASS_VLAN	0x80 /* event in a VLAN tagged packet */
38 
39 #define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4)
40 #define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 | PTP_CLASS_IPV6) /* probably DNE */
41 #define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4)
42 #define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 | PTP_CLASS_IPV6)
43 #define PTP_CLASS_V2_L2   (PTP_CLASS_V2 | PTP_CLASS_L2)
44 #define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 | PTP_CLASS_VLAN)
45 #define PTP_CLASS_L4      (PTP_CLASS_IPV4 | PTP_CLASS_IPV6)
46 
47 #define PTP_EV_PORT 319
48 #define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */
49 
50 #define OFF_PTP_SOURCE_UUID	22 /* PTPv1 only */
51 #define OFF_PTP_SEQUENCE_ID	30
52 #define OFF_PTP_CONTROL		32 /* PTPv1 only */
53 
54 /* Below defines should actually be removed at some point in time. */
55 #define IP6_HLEN	40
56 #define UDP_HLEN	8
57 #define OFF_IHL		14
58 #define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)
59 
60 #if defined(CONFIG_NET_PTP_CLASSIFY)
61 /**
62  * ptp_classify_raw - classify a PTP packet
63  * @skb: buffer
64  *
65  * Runs a minimal BPF dissector to classify a network packet to
66  * determine the PTP class. In case the skb does not contain any
67  * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise
68  * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or
69  * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content.
70  */
71 unsigned int ptp_classify_raw(const struct sk_buff *skb);
72 
73 void __init ptp_classifier_init(void);
74 #else
ptp_classifier_init(void)75 static inline void ptp_classifier_init(void)
76 {
77 }
ptp_classify_raw(struct sk_buff * skb)78 static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
79 {
80 	return PTP_CLASS_NONE;
81 }
82 #endif
83 #endif /* _PTP_CLASSIFY_H_ */
84