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Daniel Borkmann408eccc2014-04-01 16:20:23 +02001/* PTP classifier
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
11 */
12
13/* The below program is the bpf_asm (tools/net/) representation of
14 * the opcode array in the ptp_filter structure.
15 *
16 * For convenience, this can easily be altered and reviewed with
17 * bpf_asm and bpf_dbg, e.g. `./bpf_asm -c prog` where prog is a
18 * simple file containing the below program:
19 *
20 * ldh [12] ; load ethertype
21 *
22 * ; PTP over UDP over IPv4 over Ethernet
23 * test_ipv4:
24 * jneq #0x800, test_ipv6 ; ETH_P_IP ?
25 * ldb [23] ; load proto
26 * jneq #17, drop_ipv4 ; IPPROTO_UDP ?
27 * ldh [20] ; load frag offset field
28 * jset #0x1fff, drop_ipv4 ; don't allow fragments
29 * ldxb 4*([14]&0xf) ; load IP header len
30 * ldh [x + 16] ; load UDP dst port
31 * jneq #319, drop_ipv4 ; is port PTP_EV_PORT ?
32 * ldh [x + 22] ; load payload
33 * and #0xf ; mask PTP_CLASS_VMASK
34 * or #0x10 ; PTP_CLASS_IPV4
35 * ret a ; return PTP class
36 * drop_ipv4: ret #0x0 ; PTP_CLASS_NONE
37 *
38 * ; PTP over UDP over IPv6 over Ethernet
39 * test_ipv6:
40 * jneq #0x86dd, test_8021q ; ETH_P_IPV6 ?
41 * ldb [20] ; load proto
42 * jneq #17, drop_ipv6 ; IPPROTO_UDP ?
43 * ldh [56] ; load UDP dst port
44 * jneq #319, drop_ipv6 ; is port PTP_EV_PORT ?
45 * ldh [62] ; load payload
46 * and #0xf ; mask PTP_CLASS_VMASK
47 * or #0x20 ; PTP_CLASS_IPV6
48 * ret a ; return PTP class
49 * drop_ipv6: ret #0x0 ; PTP_CLASS_NONE
50 *
51 * ; PTP over 802.1Q over Ethernet
52 * test_8021q:
53 * jneq #0x8100, test_ieee1588 ; ETH_P_8021Q ?
54 * ldh [16] ; load inner type
55 * jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
56 * ldb [18] ; load payload
57 * and #0x8 ; as we don't have ports here, test
58 * jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
59 * ldh [18] ; reload payload
60 * and #0xf ; mask PTP_CLASS_VMASK
61 * or #0x40 ; PTP_CLASS_V2_VLAN
62 * ret a ; return PTP class
63 *
64 * ; PTP over Ethernet
65 * test_ieee1588:
66 * jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
67 * ldb [14] ; load payload
68 * and #0x8 ; as we don't have ports here, test
69 * jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
70 * ldh [14] ; reload payload
71 * and #0xf ; mask PTP_CLASS_VMASK
72 * or #0x30 ; PTP_CLASS_L2
73 * ret a ; return PTP class
74 * drop_ieee1588: ret #0x0 ; PTP_CLASS_NONE
75 */
76
77#include <linux/skbuff.h>
78#include <linux/filter.h>
79#include <linux/ptp_classify.h>
80
81static struct sk_filter *ptp_insns __read_mostly;
82
83unsigned int ptp_classify_raw(const struct sk_buff *skb)
84{
85 return SK_RUN_FILTER(ptp_insns, skb);
86}
87EXPORT_SYMBOL_GPL(ptp_classify_raw);
88
89void __init ptp_classifier_init(void)
90{
Mathias Krause0f49ff02014-05-10 22:23:28 +020091 static struct sock_filter ptp_filter[] __initdata = {
Daniel Borkmann408eccc2014-04-01 16:20:23 +020092 { 0x28, 0, 0, 0x0000000c },
93 { 0x15, 0, 12, 0x00000800 },
94 { 0x30, 0, 0, 0x00000017 },
95 { 0x15, 0, 9, 0x00000011 },
96 { 0x28, 0, 0, 0x00000014 },
97 { 0x45, 7, 0, 0x00001fff },
98 { 0xb1, 0, 0, 0x0000000e },
99 { 0x48, 0, 0, 0x00000010 },
100 { 0x15, 0, 4, 0x0000013f },
101 { 0x48, 0, 0, 0x00000016 },
102 { 0x54, 0, 0, 0x0000000f },
103 { 0x44, 0, 0, 0x00000010 },
104 { 0x16, 0, 0, 0x00000000 },
105 { 0x06, 0, 0, 0x00000000 },
106 { 0x15, 0, 9, 0x000086dd },
107 { 0x30, 0, 0, 0x00000014 },
108 { 0x15, 0, 6, 0x00000011 },
109 { 0x28, 0, 0, 0x00000038 },
110 { 0x15, 0, 4, 0x0000013f },
111 { 0x28, 0, 0, 0x0000003e },
112 { 0x54, 0, 0, 0x0000000f },
113 { 0x44, 0, 0, 0x00000020 },
114 { 0x16, 0, 0, 0x00000000 },
115 { 0x06, 0, 0, 0x00000000 },
116 { 0x15, 0, 9, 0x00008100 },
117 { 0x28, 0, 0, 0x00000010 },
118 { 0x15, 0, 15, 0x000088f7 },
119 { 0x30, 0, 0, 0x00000012 },
120 { 0x54, 0, 0, 0x00000008 },
121 { 0x15, 0, 12, 0x00000000 },
122 { 0x28, 0, 0, 0x00000012 },
123 { 0x54, 0, 0, 0x0000000f },
124 { 0x44, 0, 0, 0x00000040 },
125 { 0x16, 0, 0, 0x00000000 },
126 { 0x15, 0, 7, 0x000088f7 },
127 { 0x30, 0, 0, 0x0000000e },
128 { 0x54, 0, 0, 0x00000008 },
129 { 0x15, 0, 4, 0x00000000 },
130 { 0x28, 0, 0, 0x0000000e },
131 { 0x54, 0, 0, 0x0000000f },
132 { 0x44, 0, 0, 0x00000030 },
133 { 0x16, 0, 0, 0x00000000 },
134 { 0x06, 0, 0, 0x00000000 },
135 };
Daniel Borkmannb1fcd352014-05-23 18:43:58 +0200136 struct sock_fprog_kern ptp_prog = {
Daniel Borkmann408eccc2014-04-01 16:20:23 +0200137 .len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter,
138 };
139
140 BUG_ON(sk_unattached_filter_create(&ptp_insns, &ptp_prog));
141}