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 /* PTP header flag fields */ 47 #define PTP_FLAG_TWOSTEP BIT(1) 48 49 /* Below defines should actually be removed at some point in time. */ 50 #define IP6_HLEN 40 51 #define UDP_HLEN 8 52 #define OFF_IHL 14 53 #define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2) 54 55 struct clock_identity { 56 u8 id[8]; 57 } __packed; 58 59 struct port_identity { 60 struct clock_identity clock_identity; 61 __be16 port_number; 62 } __packed; 63 64 struct ptp_header { 65 u8 tsmt; /* transportSpecific | messageType */ 66 u8 ver; /* reserved | versionPTP */ 67 __be16 message_length; 68 u8 domain_number; 69 u8 reserved1; 70 u8 flag_field[2]; 71 __be64 correction; 72 __be32 reserved2; 73 struct port_identity source_port_identity; 74 __be16 sequence_id; 75 u8 control; 76 u8 log_message_interval; 77 } __packed; 78 79 #if defined(CONFIG_NET_PTP_CLASSIFY) 80 /** 81 * ptp_classify_raw - classify a PTP packet 82 * @skb: buffer 83 * 84 * Runs a minimal BPF dissector to classify a network packet to 85 * determine the PTP class. In case the skb does not contain any 86 * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise 87 * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or 88 * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content. 89 */ 90 unsigned int ptp_classify_raw(const struct sk_buff *skb); 91 92 /** 93 * ptp_parse_header - Get pointer to the PTP v2 header 94 * @skb: packet buffer 95 * @type: type of the packet (see ptp_classify_raw()) 96 * 97 * This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length 98 * is checked. 99 * 100 * Note, internally skb_mac_header() is used. Make sure that the @skb is 101 * initialized accordingly. 102 * 103 * Return: Pointer to the ptp v2 header or NULL if not found 104 */ 105 struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type); 106 107 /** 108 * ptp_get_msgtype - Extract ptp message type from given header 109 * @hdr: ptp header 110 * @type: type of the packet (see ptp_classify_raw()) 111 * 112 * This function returns the message type for a given ptp header. It takes care 113 * of the different ptp header versions (v1 or v2). 114 * 115 * Return: The message type 116 */ 117 static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, 118 unsigned int type) 119 { 120 u8 msgtype; 121 122 if (unlikely(type & PTP_CLASS_V1)) { 123 /* msg type is located at the control field for ptp v1 */ 124 msgtype = hdr->control; 125 } else { 126 msgtype = hdr->tsmt & 0x0f; 127 } 128 129 return msgtype; 130 } 131 132 /** 133 * ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message 134 * @skb: packet buffer 135 * @type: type of the packet (see ptp_classify_raw()) 136 * 137 * This function evaluates whether the given skb is a PTP Sync message. 138 * 139 * Return: true if sync message, false otherwise 140 */ 141 bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type); 142 143 void __init ptp_classifier_init(void); 144 #else 145 static inline void ptp_classifier_init(void) 146 { 147 } 148 static inline unsigned int ptp_classify_raw(struct sk_buff *skb) 149 { 150 return PTP_CLASS_NONE; 151 } 152 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb, 153 unsigned int type) 154 { 155 return NULL; 156 } 157 static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, 158 unsigned int type) 159 { 160 /* The return is meaningless. The stub function would not be 161 * executed since no available header from ptp_parse_header. 162 */ 163 return PTP_MSGTYPE_SYNC; 164 } 165 static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type) 166 { 167 return false; 168 } 169 #endif 170 #endif /* _PTP_CLASSIFY_H_ */ 171