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 */ 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 130 static inline void ptp_classifier_init(void) 131 { 132 } 133 static inline unsigned int ptp_classify_raw(struct sk_buff *skb) 134 { 135 return PTP_CLASS_NONE; 136 } 137 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb, 138 unsigned int type) 139 { 140 return NULL; 141 } 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