229 lines
7.7 KiB
C
229 lines
7.7 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/* PTP classifier
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*/
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/* The below program is the bpf_asm (tools/net/) representation of
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* the opcode array in the ptp_filter structure.
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*
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* For convenience, this can easily be altered and reviewed with
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* bpf_asm and bpf_dbg, e.g. `./bpf_asm -c prog` where prog is a
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* simple file containing the below program:
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*
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* ldh [12] ; load ethertype
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*
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* ; PTP over UDP over IPv4 over Ethernet
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* test_ipv4:
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* jneq #0x800, test_ipv6 ; ETH_P_IP ?
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* ldb [23] ; load proto
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* jneq #17, drop_ipv4 ; IPPROTO_UDP ?
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* ldh [20] ; load frag offset field
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* jset #0x1fff, drop_ipv4 ; don't allow fragments
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* ldxb 4*([14]&0xf) ; load IP header len
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* ldh [x + 16] ; load UDP dst port
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* jneq #319, drop_ipv4 ; is port PTP_EV_PORT ?
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* ldh [x + 22] ; load payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0x10 ; PTP_CLASS_IPV4
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* ret a ; return PTP class
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* drop_ipv4: ret #0x0 ; PTP_CLASS_NONE
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*
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* ; PTP over UDP over IPv6 over Ethernet
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* test_ipv6:
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* jneq #0x86dd, test_8021q ; ETH_P_IPV6 ?
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* ldb [20] ; load proto
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* jneq #17, drop_ipv6 ; IPPROTO_UDP ?
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* ldh [56] ; load UDP dst port
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* jneq #319, drop_ipv6 ; is port PTP_EV_PORT ?
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* ldh [62] ; load payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0x20 ; PTP_CLASS_IPV6
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* ret a ; return PTP class
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* drop_ipv6: ret #0x0 ; PTP_CLASS_NONE
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*
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* ; PTP over 802.1Q over Ethernet
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* test_8021q:
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* jneq #0x8100, test_ieee1588 ; ETH_P_8021Q ?
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* ldh [16] ; load inner type
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* jneq #0x88f7, test_8021q_ipv4 ; ETH_P_1588 ?
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* ldb [18] ; load payload
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* and #0x8 ; as we don't have ports here, test
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* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
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* ldh [18] ; reload payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0xc0 ; PTP_CLASS_VLAN|PTP_CLASS_L2
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* ret a ; return PTP class
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*
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* ; PTP over UDP over IPv4 over 802.1Q over Ethernet
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* test_8021q_ipv4:
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* jneq #0x800, test_8021q_ipv6 ; ETH_P_IP ?
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* ldb [27] ; load proto
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* jneq #17, drop_8021q_ipv4 ; IPPROTO_UDP ?
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* ldh [24] ; load frag offset field
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* jset #0x1fff, drop_8021q_ipv4; don't allow fragments
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* ldxb 4*([18]&0xf) ; load IP header len
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* ldh [x + 20] ; load UDP dst port
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* jneq #319, drop_8021q_ipv4 ; is port PTP_EV_PORT ?
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* ldh [x + 26] ; load payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0x90 ; PTP_CLASS_VLAN|PTP_CLASS_IPV4
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* ret a ; return PTP class
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* drop_8021q_ipv4: ret #0x0 ; PTP_CLASS_NONE
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*
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* ; PTP over UDP over IPv6 over 802.1Q over Ethernet
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* test_8021q_ipv6:
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* jneq #0x86dd, drop_8021q_ipv6 ; ETH_P_IPV6 ?
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* ldb [24] ; load proto
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* jneq #17, drop_8021q_ipv6 ; IPPROTO_UDP ?
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* ldh [60] ; load UDP dst port
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* jneq #319, drop_8021q_ipv6 ; is port PTP_EV_PORT ?
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* ldh [66] ; load payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0xa0 ; PTP_CLASS_VLAN|PTP_CLASS_IPV6
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* ret a ; return PTP class
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* drop_8021q_ipv6: ret #0x0 ; PTP_CLASS_NONE
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*
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* ; PTP over Ethernet
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* test_ieee1588:
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* jneq #0x88f7, drop_ieee1588 ; ETH_P_1588 ?
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* ldb [14] ; load payload
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* and #0x8 ; as we don't have ports here, test
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* jneq #0x0, drop_ieee1588 ; for PTP_GEN_BIT and drop these
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* ldh [14] ; reload payload
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* and #0xf ; mask PTP_CLASS_VMASK
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* or #0x40 ; PTP_CLASS_L2
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* ret a ; return PTP class
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* drop_ieee1588: ret #0x0 ; PTP_CLASS_NONE
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*/
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#include <linux/skbuff.h>
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#include <linux/filter.h>
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#include <linux/ptp_classify.h>
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static struct bpf_prog *ptp_insns __read_mostly;
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unsigned int ptp_classify_raw(const struct sk_buff *skb)
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{
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return bpf_prog_run(ptp_insns, skb);
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}
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EXPORT_SYMBOL_GPL(ptp_classify_raw);
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struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type)
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{
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u8 *ptr = skb_mac_header(skb);
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if (type & PTP_CLASS_VLAN)
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ptr += VLAN_HLEN;
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switch (type & PTP_CLASS_PMASK) {
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case PTP_CLASS_IPV4:
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ptr += IPV4_HLEN(ptr) + UDP_HLEN;
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break;
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case PTP_CLASS_IPV6:
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ptr += IP6_HLEN + UDP_HLEN;
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break;
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case PTP_CLASS_L2:
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break;
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default:
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return NULL;
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}
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ptr += ETH_HLEN;
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/* Ensure that the entire header is present in this packet. */
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if (ptr + sizeof(struct ptp_header) > skb->data + skb->len)
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return NULL;
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return (struct ptp_header *)ptr;
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}
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EXPORT_SYMBOL_GPL(ptp_parse_header);
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bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type)
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{
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struct ptp_header *hdr;
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hdr = ptp_parse_header(skb, type);
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if (!hdr)
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return false;
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return ptp_get_msgtype(hdr, type) == PTP_MSGTYPE_SYNC;
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}
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EXPORT_SYMBOL_GPL(ptp_msg_is_sync);
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void __init ptp_classifier_init(void)
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{
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static struct sock_filter ptp_filter[] __initdata = {
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{ 0x28, 0, 0, 0x0000000c },
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{ 0x15, 0, 12, 0x00000800 },
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{ 0x30, 0, 0, 0x00000017 },
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{ 0x15, 0, 9, 0x00000011 },
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{ 0x28, 0, 0, 0x00000014 },
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{ 0x45, 7, 0, 0x00001fff },
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{ 0xb1, 0, 0, 0x0000000e },
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{ 0x48, 0, 0, 0x00000010 },
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{ 0x15, 0, 4, 0x0000013f },
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{ 0x48, 0, 0, 0x00000016 },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x00000010 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x06, 0, 0, 0x00000000 },
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{ 0x15, 0, 9, 0x000086dd },
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{ 0x30, 0, 0, 0x00000014 },
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{ 0x15, 0, 6, 0x00000011 },
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{ 0x28, 0, 0, 0x00000038 },
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{ 0x15, 0, 4, 0x0000013f },
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{ 0x28, 0, 0, 0x0000003e },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x00000020 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x06, 0, 0, 0x00000000 },
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{ 0x15, 0, 32, 0x00008100 },
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{ 0x28, 0, 0, 0x00000010 },
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{ 0x15, 0, 7, 0x000088f7 },
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{ 0x30, 0, 0, 0x00000012 },
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{ 0x54, 0, 0, 0x00000008 },
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{ 0x15, 0, 35, 0x00000000 },
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{ 0x28, 0, 0, 0x00000012 },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x000000c0 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x15, 0, 12, 0x00000800 },
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{ 0x30, 0, 0, 0x0000001b },
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{ 0x15, 0, 9, 0x00000011 },
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{ 0x28, 0, 0, 0x00000018 },
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{ 0x45, 7, 0, 0x00001fff },
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{ 0xb1, 0, 0, 0x00000012 },
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{ 0x48, 0, 0, 0x00000014 },
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{ 0x15, 0, 4, 0x0000013f },
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{ 0x48, 0, 0, 0x0000001a },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x00000090 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x06, 0, 0, 0x00000000 },
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{ 0x15, 0, 8, 0x000086dd },
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{ 0x30, 0, 0, 0x00000018 },
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{ 0x15, 0, 6, 0x00000011 },
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{ 0x28, 0, 0, 0x0000003c },
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{ 0x15, 0, 4, 0x0000013f },
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{ 0x28, 0, 0, 0x00000042 },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x000000a0 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x06, 0, 0, 0x00000000 },
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{ 0x15, 0, 7, 0x000088f7 },
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{ 0x30, 0, 0, 0x0000000e },
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{ 0x54, 0, 0, 0x00000008 },
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{ 0x15, 0, 4, 0x00000000 },
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{ 0x28, 0, 0, 0x0000000e },
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{ 0x54, 0, 0, 0x0000000f },
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{ 0x44, 0, 0, 0x00000040 },
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{ 0x16, 0, 0, 0x00000000 },
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{ 0x06, 0, 0, 0x00000000 },
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};
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struct sock_fprog_kern ptp_prog;
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ptp_prog.len = ARRAY_SIZE(ptp_filter);
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ptp_prog.filter = ptp_filter;
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BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog));
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}
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