1 /* 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, test_8021q_ipv4 ; 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 #0xc0 ; PTP_CLASS_VLAN|PTP_CLASS_L2
62 * ret a ; return PTP class
63 *
64 * ; PTP over UDP over IPv4 over 802.1Q over Ethernet
65 * test_8021q_ipv4:
66 * jneq #0x800, test_8021q_ipv6 ; ETH_P_IP ?
67 * ldb [27] ; load proto
68 * jneq #17, drop_8021q_ipv4 ; IPPROTO_UDP ?
69 * ldh [24] ; load frag offset field
70 * jset #0x1fff, drop_8021q_ipv4; don't allow fragments
71 * ldxb 4*([18]&0xf) ; load IP header len
72 * ldh [x + 20] ; load UDP dst port
73 * jneq #319, drop_8021q_ipv4 ; is port PTP_EV_PORT ?
74 * ldh [x + 26] ; load payload
75 * and #0xf ; mask PTP_CLASS_VMASK
76 * or #0x90 ; PTP_CLASS_VLAN|PTP_CLASS_IPV4
77 * ret a ; return PTP class
78 * drop_8021q_ipv4: ret #0x0 ; PTP_CLASS_NONE
79 *
80 * ; PTP over UDP over IPv6 over 802.1Q over Ethernet
81 * test_8021q_ipv6:
82 * jneq #0x86dd, drop_8021q_ipv6 ; ETH_P_IPV6 ?
83 * ldb [24] ; load proto
84 * jneq #17, drop_8021q_ipv6 ; IPPROTO_UDP ?
85 * ldh [60] ; load UDP dst port
86 * jneq #319, drop_8021q_ipv6 ; is port PTP_EV_PORT ?
87 * ldh [66] ; load payload
88 * and #0xf ; mask PTP_CLASS_VMASK
89 * or #0xa0 ; PTP_CLASS_VLAN|PTP_CLASS_IPV6
90 * ret a ; return PTP class
91 * drop_8021q_ipv6: ret #0x0 ; PTP_CLASS_NONE
92 *
93 * ; PTP over Ethernet
94 * test_ieee1588:
95 * jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
96 * ldb [14] ; load payload
97 * and #0x8 ; as we don't have ports here, test
98 * jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
99 * ldh [14] ; reload payload
100 * and #0xf ; mask PTP_CLASS_VMASK
101 * or #0x40 ; PTP_CLASS_L2
102 * ret a ; return PTP class
103 * drop_ieee1588: ret #0x0 ; PTP_CLASS_NONE
104 */
105
106 #include <linux/skbuff.h>
107 #include <linux/filter.h>
108 #include <linux/ptp_classify.h>
109
110 static struct bpf_prog *ptp_insns __read_mostly;
111
ptp_classify_raw(const struct sk_buff * skb)112 unsigned int ptp_classify_raw(const struct sk_buff *skb)
113 {
114 return BPF_PROG_RUN(ptp_insns, skb);
115 }
116 EXPORT_SYMBOL_GPL(ptp_classify_raw);
117
ptp_classifier_init(void)118 void __init ptp_classifier_init(void)
119 {
120 static struct sock_filter ptp_filter[] __initdata = {
121 { 0x28, 0, 0, 0x0000000c },
122 { 0x15, 0, 12, 0x00000800 },
123 { 0x30, 0, 0, 0x00000017 },
124 { 0x15, 0, 9, 0x00000011 },
125 { 0x28, 0, 0, 0x00000014 },
126 { 0x45, 7, 0, 0x00001fff },
127 { 0xb1, 0, 0, 0x0000000e },
128 { 0x48, 0, 0, 0x00000010 },
129 { 0x15, 0, 4, 0x0000013f },
130 { 0x48, 0, 0, 0x00000016 },
131 { 0x54, 0, 0, 0x0000000f },
132 { 0x44, 0, 0, 0x00000010 },
133 { 0x16, 0, 0, 0x00000000 },
134 { 0x06, 0, 0, 0x00000000 },
135 { 0x15, 0, 9, 0x000086dd },
136 { 0x30, 0, 0, 0x00000014 },
137 { 0x15, 0, 6, 0x00000011 },
138 { 0x28, 0, 0, 0x00000038 },
139 { 0x15, 0, 4, 0x0000013f },
140 { 0x28, 0, 0, 0x0000003e },
141 { 0x54, 0, 0, 0x0000000f },
142 { 0x44, 0, 0, 0x00000020 },
143 { 0x16, 0, 0, 0x00000000 },
144 { 0x06, 0, 0, 0x00000000 },
145 { 0x15, 0, 32, 0x00008100 },
146 { 0x28, 0, 0, 0x00000010 },
147 { 0x15, 0, 7, 0x000088f7 },
148 { 0x30, 0, 0, 0x00000012 },
149 { 0x54, 0, 0, 0x00000008 },
150 { 0x15, 0, 35, 0x00000000 },
151 { 0x28, 0, 0, 0x00000012 },
152 { 0x54, 0, 0, 0x0000000f },
153 { 0x44, 0, 0, 0x000000c0 },
154 { 0x16, 0, 0, 0x00000000 },
155 { 0x15, 0, 12, 0x00000800 },
156 { 0x30, 0, 0, 0x0000001b },
157 { 0x15, 0, 9, 0x00000011 },
158 { 0x28, 0, 0, 0x00000018 },
159 { 0x45, 7, 0, 0x00001fff },
160 { 0xb1, 0, 0, 0x00000012 },
161 { 0x48, 0, 0, 0x00000014 },
162 { 0x15, 0, 4, 0x0000013f },
163 { 0x48, 0, 0, 0x0000001a },
164 { 0x54, 0, 0, 0x0000000f },
165 { 0x44, 0, 0, 0x00000090 },
166 { 0x16, 0, 0, 0x00000000 },
167 { 0x06, 0, 0, 0x00000000 },
168 { 0x15, 0, 8, 0x000086dd },
169 { 0x30, 0, 0, 0x00000018 },
170 { 0x15, 0, 6, 0x00000011 },
171 { 0x28, 0, 0, 0x0000003c },
172 { 0x15, 0, 4, 0x0000013f },
173 { 0x28, 0, 0, 0x00000042 },
174 { 0x54, 0, 0, 0x0000000f },
175 { 0x44, 0, 0, 0x000000a0 },
176 { 0x16, 0, 0, 0x00000000 },
177 { 0x06, 0, 0, 0x00000000 },
178 { 0x15, 0, 7, 0x000088f7 },
179 { 0x30, 0, 0, 0x0000000e },
180 { 0x54, 0, 0, 0x00000008 },
181 { 0x15, 0, 4, 0x00000000 },
182 { 0x28, 0, 0, 0x0000000e },
183 { 0x54, 0, 0, 0x0000000f },
184 { 0x44, 0, 0, 0x00000040 },
185 { 0x16, 0, 0, 0x00000000 },
186 { 0x06, 0, 0, 0x00000000 },
187 };
188 struct sock_fprog_kern ptp_prog = {
189 .len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter,
190 };
191
192 BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog));
193 }
194