| // 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); |
| |
| 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)); |
| } |
