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
110static struct bpf_prog *ptp_insns __read_mostly;
111
112unsigned int ptp_classify_raw(const struct sk_buff *skb)
113{
114	return BPF_PROG_RUN(ptp_insns, skb);
115}
116EXPORT_SYMBOL_GPL(ptp_classify_raw);
117
118void __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