1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
// SPDX-License-Identifier: GPL-2.0-only
/* PTP classifier
*/
/* The below program is the bpf_asm (tools/net/) representation of
* the opcode array in the ptp_filter structure.
*
* For convenience, this can easily be altered and reviewed with
* bpf_asm and bpf_dbg, e.g. `./bpf_asm -c prog` where prog is a
* simple file containing the below program:
*
* ldh [12] ; load ethertype
*
* ; PTP over UDP over IPv4 over Ethernet
* test_ipv4:
* jneq #0x800, test_ipv6 ; ETH_P_IP ?
* ldb [23] ; load proto
* jneq #17, drop_ipv4 ; IPPROTO_UDP ?
* ldh [20] ; load frag offset field
* jset #0x1fff, drop_ipv4 ; don't allow fragments
* ldxb 4*([14]&0xf) ; load IP header len
* ldh [x + 16] ; load UDP dst port
* jneq #319, drop_ipv4 ; is port PTP_EV_PORT ?
* ldh [x + 22] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x10 ; PTP_CLASS_IPV4
* ret a ; return PTP class
* drop_ipv4: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over UDP over IPv6 over Ethernet
* test_ipv6:
* jneq #0x86dd, test_8021q ; ETH_P_IPV6 ?
* ldb [20] ; load proto
* jneq #17, drop_ipv6 ; IPPROTO_UDP ?
* ldh [56] ; load UDP dst port
* jneq #319, drop_ipv6 ; is port PTP_EV_PORT ?
* ldh [62] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x20 ; PTP_CLASS_IPV6
* ret a ; return PTP class
* drop_ipv6: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over 802.1Q over Ethernet
* test_8021q:
* jneq #0x8100, test_ieee1588 ; ETH_P_8021Q ?
* ldh [16] ; load inner type
* jneq #0x88f7, test_8021q_ipv4 ; ETH_P_1588 ?
* ldb [18] ; load payload
* and #0x8 ; as we don't have ports here, test
* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
* ldh [18] ; reload payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0xc0 ; PTP_CLASS_VLAN|PTP_CLASS_L2
* ret a ; return PTP class
*
* ; PTP over UDP over IPv4 over 802.1Q over Ethernet
* test_8021q_ipv4:
* jneq #0x800, test_8021q_ipv6 ; ETH_P_IP ?
* ldb [27] ; load proto
* jneq #17, drop_8021q_ipv4 ; IPPROTO_UDP ?
* ldh [24] ; load frag offset field
* jset #0x1fff, drop_8021q_ipv4; don't allow fragments
* ldxb 4*([18]&0xf) ; load IP header len
* ldh [x + 20] ; load UDP dst port
* jneq #319, drop_8021q_ipv4 ; is port PTP_EV_PORT ?
* ldh [x + 26] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x90 ; PTP_CLASS_VLAN|PTP_CLASS_IPV4
* ret a ; return PTP class
* drop_8021q_ipv4: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over UDP over IPv6 over 802.1Q over Ethernet
* test_8021q_ipv6:
* jneq #0x86dd, drop_8021q_ipv6 ; ETH_P_IPV6 ?
* ldb [24] ; load proto
* jneq #17, drop_8021q_ipv6 ; IPPROTO_UDP ?
* ldh [60] ; load UDP dst port
* jneq #319, drop_8021q_ipv6 ; is port PTP_EV_PORT ?
* ldh [66] ; load payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0xa0 ; PTP_CLASS_VLAN|PTP_CLASS_IPV6
* ret a ; return PTP class
* drop_8021q_ipv6: ret #0x0 ; PTP_CLASS_NONE
*
* ; PTP over Ethernet
* test_ieee1588:
* jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
* ldb [14] ; load payload
* and #0x8 ; as we don't have ports here, test
* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
* ldh [14] ; reload payload
* and #0xf ; mask PTP_CLASS_VMASK
* or #0x40 ; PTP_CLASS_L2
* ret a ; return PTP class
* drop_ieee1588: ret #0x0 ; PTP_CLASS_NONE
*/
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/ptp_classify.h>
static struct bpf_prog *ptp_insns __read_mostly;
unsigned int ptp_classify_raw(const struct sk_buff *skb)
{
return BPF_PROG_RUN(ptp_insns, skb);
}
EXPORT_SYMBOL_GPL(ptp_classify_raw);
struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type)
{
u8 *ptr = skb_mac_header(skb);
if (type & PTP_CLASS_VLAN)
ptr += VLAN_HLEN;
switch (type & PTP_CLASS_PMASK) {
case PTP_CLASS_IPV4:
ptr += IPV4_HLEN(ptr) + UDP_HLEN;
break;
case PTP_CLASS_IPV6:
ptr += IP6_HLEN + UDP_HLEN;
break;
case PTP_CLASS_L2:
break;
default:
return NULL;
}
ptr += ETH_HLEN;
/* Ensure that the entire header is present in this packet. */
if (ptr + sizeof(struct ptp_header) > skb->data + skb->len)
return NULL;
return (struct ptp_header *)ptr;
}
EXPORT_SYMBOL_GPL(ptp_parse_header);
void __init ptp_classifier_init(void)
{
static struct sock_filter ptp_filter[] __initdata = {
{ 0x28, 0, 0, 0x0000000c },
{ 0x15, 0, 12, 0x00000800 },
{ 0x30, 0, 0, 0x00000017 },
{ 0x15, 0, 9, 0x00000011 },
{ 0x28, 0, 0, 0x00000014 },
{ 0x45, 7, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x0000000e },
{ 0x48, 0, 0, 0x00000010 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x48, 0, 0, 0x00000016 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000010 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 9, 0x000086dd },
{ 0x30, 0, 0, 0x00000014 },
{ 0x15, 0, 6, 0x00000011 },
{ 0x28, 0, 0, 0x00000038 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x28, 0, 0, 0x0000003e },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000020 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 32, 0x00008100 },
{ 0x28, 0, 0, 0x00000010 },
{ 0x15, 0, 7, 0x000088f7 },
{ 0x30, 0, 0, 0x00000012 },
{ 0x54, 0, 0, 0x00000008 },
{ 0x15, 0, 35, 0x00000000 },
{ 0x28, 0, 0, 0x00000012 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x000000c0 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x15, 0, 12, 0x00000800 },
{ 0x30, 0, 0, 0x0000001b },
{ 0x15, 0, 9, 0x00000011 },
{ 0x28, 0, 0, 0x00000018 },
{ 0x45, 7, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x00000012 },
{ 0x48, 0, 0, 0x00000014 },
{ 0x15, 0, 4, 0x0000013f },
{ 0x48, 0, 0, 0x0000001a },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000090 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 8, 0x000086dd },
{ 0x30, 0, 0, 0x00000018 },
{ 0x15, 0, 6, 0x00000011 },
{ 0x28, 0, 0, 0x0000003c },
{ 0x15, 0, 4, 0x0000013f },
{ 0x28, 0, 0, 0x00000042 },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x000000a0 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
{ 0x15, 0, 7, 0x000088f7 },
{ 0x30, 0, 0, 0x0000000e },
{ 0x54, 0, 0, 0x00000008 },
{ 0x15, 0, 4, 0x00000000 },
{ 0x28, 0, 0, 0x0000000e },
{ 0x54, 0, 0, 0x0000000f },
{ 0x44, 0, 0, 0x00000040 },
{ 0x16, 0, 0, 0x00000000 },
{ 0x06, 0, 0, 0x00000000 },
};
struct sock_fprog_kern ptp_prog;
ptp_prog.len = ARRAY_SIZE(ptp_filter);
ptp_prog.filter = ptp_filter;
BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog));
}
|
