// 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)); }