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74ba9207 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
15f0127d RC |
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 | |
15f0127d RC |
8 | */ |
9 | ||
10 | #ifndef _PTP_CLASSIFY_H_ | |
11 | #define _PTP_CLASSIFY_H_ | |
12 | ||
2955762b | 13 | #include <asm/unaligned.h> |
d94ba80e | 14 | #include <linux/ip.h> |
2955762b | 15 | #include <linux/ktime.h> |
408eccce | 16 | #include <linux/skbuff.h> |
2955762b CE |
17 | #include <linux/udp.h> |
18 | #include <net/checksum.h> | |
15f0127d RC |
19 | |
20 | #define PTP_CLASS_NONE 0x00 /* not a PTP event message */ | |
21 | #define PTP_CLASS_V1 0x01 /* protocol version 1 */ | |
22 | #define PTP_CLASS_V2 0x02 /* protocol version 2 */ | |
23 | #define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */ | |
24 | #define PTP_CLASS_IPV4 0x10 /* event in an IPV4 UDP packet */ | |
25 | #define PTP_CLASS_IPV6 0x20 /* event in an IPV6 UDP packet */ | |
5f94c943 SS |
26 | #define PTP_CLASS_L2 0x40 /* event in a L2 packet */ |
27 | #define PTP_CLASS_PMASK 0x70 /* mask for the packet type field */ | |
28 | #define PTP_CLASS_VLAN 0x80 /* event in a VLAN tagged packet */ | |
15f0127d RC |
29 | |
30 | #define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4) | |
408eccce | 31 | #define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 | PTP_CLASS_IPV6) /* probably DNE */ |
15f0127d RC |
32 | #define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4) |
33 | #define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 | PTP_CLASS_IPV6) | |
34 | #define PTP_CLASS_V2_L2 (PTP_CLASS_V2 | PTP_CLASS_L2) | |
35 | #define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 | PTP_CLASS_VLAN) | |
5f94c943 | 36 | #define PTP_CLASS_L4 (PTP_CLASS_IPV4 | PTP_CLASS_IPV6) |
15f0127d | 37 | |
076d38b8 CE |
38 | #define PTP_MSGTYPE_SYNC 0x0 |
39 | #define PTP_MSGTYPE_DELAY_REQ 0x1 | |
40 | #define PTP_MSGTYPE_PDELAY_REQ 0x2 | |
41 | #define PTP_MSGTYPE_PDELAY_RESP 0x3 | |
42 | ||
15f0127d | 43 | #define PTP_EV_PORT 319 |
ec15baec | 44 | #define PTP_GEN_PORT 320 |
f75159e9 | 45 | #define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */ |
15f0127d | 46 | |
d94ba80e RC |
47 | #define OFF_PTP_SOURCE_UUID 22 /* PTPv1 only */ |
48 | #define OFF_PTP_SEQUENCE_ID 30 | |
d94ba80e | 49 | |
5cebb40b HK |
50 | /* PTP header flag fields */ |
51 | #define PTP_FLAG_TWOSTEP BIT(1) | |
52 | ||
408eccce | 53 | /* Below defines should actually be removed at some point in time. */ |
15f0127d RC |
54 | #define IP6_HLEN 40 |
55 | #define UDP_HLEN 8 | |
408eccce | 56 | #define OFF_IHL 14 |
408eccce | 57 | #define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2) |
15f0127d | 58 | |
bdfbb63c KK |
59 | struct clock_identity { |
60 | u8 id[8]; | |
61 | } __packed; | |
62 | ||
63 | struct port_identity { | |
64 | struct clock_identity clock_identity; | |
65 | __be16 port_number; | |
66 | } __packed; | |
67 | ||
68 | struct ptp_header { | |
69 | u8 tsmt; /* transportSpecific | messageType */ | |
70 | u8 ver; /* reserved | versionPTP */ | |
71 | __be16 message_length; | |
72 | u8 domain_number; | |
73 | u8 reserved1; | |
74 | u8 flag_field[2]; | |
75 | __be64 correction; | |
76 | __be32 reserved2; | |
77 | struct port_identity source_port_identity; | |
78 | __be16 sequence_id; | |
79 | u8 control; | |
80 | u8 log_message_interval; | |
81 | } __packed; | |
82 | ||
408eccce DB |
83 | #if defined(CONFIG_NET_PTP_CLASSIFY) |
84 | /** | |
85 | * ptp_classify_raw - classify a PTP packet | |
86 | * @skb: buffer | |
87 | * | |
88 | * Runs a minimal BPF dissector to classify a network packet to | |
89 | * determine the PTP class. In case the skb does not contain any | |
90 | * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise | |
91 | * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or | |
92 | * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content. | |
93 | */ | |
164d8c66 DB |
94 | unsigned int ptp_classify_raw(const struct sk_buff *skb); |
95 | ||
bdfbb63c KK |
96 | /** |
97 | * ptp_parse_header - Get pointer to the PTP v2 header | |
98 | * @skb: packet buffer | |
99 | * @type: type of the packet (see ptp_classify_raw()) | |
100 | * | |
101 | * This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length | |
102 | * is checked. | |
103 | * | |
104 | * Note, internally skb_mac_header() is used. Make sure that the @skb is | |
105 | * initialized accordingly. | |
106 | * | |
107 | * Return: Pointer to the ptp v2 header or NULL if not found | |
108 | */ | |
109 | struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type); | |
110 | ||
036c508b KK |
111 | /** |
112 | * ptp_get_msgtype - Extract ptp message type from given header | |
113 | * @hdr: ptp header | |
114 | * @type: type of the packet (see ptp_classify_raw()) | |
115 | * | |
116 | * This function returns the message type for a given ptp header. It takes care | |
117 | * of the different ptp header versions (v1 or v2). | |
118 | * | |
119 | * Return: The message type | |
120 | */ | |
121 | static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, | |
122 | unsigned int type) | |
123 | { | |
124 | u8 msgtype; | |
125 | ||
126 | if (unlikely(type & PTP_CLASS_V1)) { | |
127 | /* msg type is located at the control field for ptp v1 */ | |
128 | msgtype = hdr->control; | |
129 | } else { | |
130 | msgtype = hdr->tsmt & 0x0f; | |
131 | } | |
132 | ||
133 | return msgtype; | |
134 | } | |
135 | ||
2955762b CE |
136 | /** |
137 | * ptp_check_diff8 - Computes new checksum (when altering a 64-bit field) | |
138 | * @old: old field value | |
139 | * @new: new field value | |
140 | * @oldsum: previous checksum | |
141 | * | |
142 | * This function can be used to calculate a new checksum when only a single | |
143 | * field is changed. Similar as ip_vs_check_diff*() in ip_vs.h. | |
144 | * | |
145 | * Return: Updated checksum | |
146 | */ | |
147 | static inline __wsum ptp_check_diff8(__be64 old, __be64 new, __wsum oldsum) | |
148 | { | |
149 | __be64 diff[2] = { ~old, new }; | |
150 | ||
151 | return csum_partial(diff, sizeof(diff), oldsum); | |
152 | } | |
153 | ||
154 | /** | |
155 | * ptp_header_update_correction - Update PTP header's correction field | |
156 | * @skb: packet buffer | |
157 | * @type: type of the packet (see ptp_classify_raw()) | |
158 | * @hdr: ptp header | |
159 | * @correction: new correction value | |
160 | * | |
161 | * This updates the correction field of a PTP header and updates the UDP | |
162 | * checksum (if UDP is used as transport). It is needed for hardware capable of | |
163 | * one-step P2P that does not already modify the correction field of Pdelay_Req | |
164 | * event messages on ingress. | |
165 | */ | |
166 | static inline | |
167 | void ptp_header_update_correction(struct sk_buff *skb, unsigned int type, | |
168 | struct ptp_header *hdr, s64 correction) | |
169 | { | |
170 | __be64 correction_old; | |
171 | struct udphdr *uhdr; | |
172 | ||
173 | /* previous correction value is required for checksum update. */ | |
174 | memcpy(&correction_old, &hdr->correction, sizeof(correction_old)); | |
175 | ||
176 | /* write new correction value */ | |
177 | put_unaligned_be64((u64)correction, &hdr->correction); | |
178 | ||
179 | switch (type & PTP_CLASS_PMASK) { | |
180 | case PTP_CLASS_IPV4: | |
181 | case PTP_CLASS_IPV6: | |
182 | /* locate udp header */ | |
183 | uhdr = (struct udphdr *)((char *)hdr - sizeof(struct udphdr)); | |
184 | break; | |
185 | default: | |
186 | return; | |
187 | } | |
188 | ||
189 | /* update checksum */ | |
190 | uhdr->check = csum_fold(ptp_check_diff8(correction_old, | |
191 | hdr->correction, | |
192 | ~csum_unfold(uhdr->check))); | |
193 | if (!uhdr->check) | |
194 | uhdr->check = CSUM_MANGLED_0; | |
195 | ||
196 | skb->ip_summed = CHECKSUM_NONE; | |
197 | } | |
198 | ||
f72de02e KK |
199 | /** |
200 | * ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message | |
201 | * @skb: packet buffer | |
202 | * @type: type of the packet (see ptp_classify_raw()) | |
203 | * | |
204 | * This function evaluates whether the given skb is a PTP Sync message. | |
205 | * | |
206 | * Return: true if sync message, false otherwise | |
207 | */ | |
208 | bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type); | |
209 | ||
408eccce DB |
210 | void __init ptp_classifier_init(void); |
211 | #else | |
212 | static inline void ptp_classifier_init(void) | |
213 | { | |
214 | } | |
052fddfb AL |
215 | static inline unsigned int ptp_classify_raw(struct sk_buff *skb) |
216 | { | |
217 | return PTP_CLASS_NONE; | |
218 | } | |
bdfbb63c KK |
219 | static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb, |
220 | unsigned int type) | |
221 | { | |
222 | return NULL; | |
223 | } | |
e6221295 YL |
224 | static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, |
225 | unsigned int type) | |
226 | { | |
227 | /* The return is meaningless. The stub function would not be | |
228 | * executed since no available header from ptp_parse_header. | |
229 | */ | |
076d38b8 | 230 | return PTP_MSGTYPE_SYNC; |
e6221295 | 231 | } |
f72de02e KK |
232 | static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type) |
233 | { | |
234 | return false; | |
235 | } | |
2955762b CE |
236 | |
237 | static inline | |
238 | void ptp_header_update_correction(struct sk_buff *skb, unsigned int type, | |
239 | struct ptp_header *hdr, s64 correction) | |
240 | { | |
241 | } | |
15f0127d | 242 | #endif |
408eccce | 243 | #endif /* _PTP_CLASSIFY_H_ */ |