// 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); bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type){	struct ptp_header *hdr; 	hdr = ptp_parse_header(skb, type);	if (!hdr)		return false; 	return ptp_get_msgtype(hdr, type) == PTP_MSGTYPE_SYNC;}EXPORT_SYMBOL_GPL(ptp_msg_is_sync); 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));}