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 */ 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 /** 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 */ 138 bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type); 139 140 void __init ptp_classifier_init(void); 141 #else 142 static inline void ptp_classifier_init(void) 143 { 144 } 145 static inline unsigned int ptp_classify_raw(struct sk_buff *skb) 146 { 147 return PTP_CLASS_NONE; 148 } 149 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb, 150 unsigned int type) 151 { 152 return NULL; 153 } 154 static 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 } 162 static 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_ */ 168