include/linux/ptp_classify.h

   1 /*
   2  * PTP 1588 support
   3  *
   4  * This file implements a BPF that recognizes PTP event messages.
   5  *
   6  * Copyright (C) 2010 OMICRON electronics GmbH
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #ifndef _PTP_CLASSIFY_H_
  24 #define _PTP_CLASSIFY_H_
  25
  26 #include <linux/if_ether.h>
  27 #include <linux/if_vlan.h>
  28 #include <linux/filter.h>
  29 #ifdef __KERNEL__
  30 #include <linux/in.h>
  31 #else
  32 #include <netinet/in.h>
  33 #endif
  34
  35 #define PTP_CLASS_NONE  0x00 /* not a PTP event message */
  36 #define PTP_CLASS_V1    0x01 /* protocol version 1 */
  37 #define PTP_CLASS_V2    0x02 /* protocol version 2 */
  38 #define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */
  39 #define PTP_CLASS_IPV4  0x10 /* event in an IPV4 UDP packet */
  40 #define PTP_CLASS_IPV6  0x20 /* event in an IPV6 UDP packet */
  41 #define PTP_CLASS_L2    0x30 /* event in a L2 packet */
  42 #define PTP_CLASS_VLAN  0x40 /* event in a VLAN tagged L2 packet */
  43 #define PTP_CLASS_PMASK 0xf0 /* mask for the packet type field */
  44
  45 #define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4)
  46 #define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 | PTP_CLASS_IPV6) /*probably DNE*/
  47 #define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4)
  48 #define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 | PTP_CLASS_IPV6)
  49 #define PTP_CLASS_V2_L2   (PTP_CLASS_V2 | PTP_CLASS_L2)
  50 #define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 | PTP_CLASS_VLAN)
  51
  52 #define PTP_EV_PORT 319
  53
  54 #define OFF_ETYPE       12
  55 #define OFF_IHL         14
  56 #define OFF_FRAG        20
  57 #define OFF_PROTO4      23
  58 #define OFF_NEXT        6
  59 #define OFF_UDP_DST     2
  60
  61 #define IP6_HLEN        40
  62 #define UDP_HLEN        8
  63
  64 #define RELOFF_DST4     (ETH_HLEN + OFF_UDP_DST)
  65 #define OFF_DST6        (ETH_HLEN + IP6_HLEN + OFF_UDP_DST)
  66 #define OFF_PTP6        (ETH_HLEN + IP6_HLEN + UDP_HLEN)
  67
  68 #define OP_AND  (BPF_ALU | BPF_AND  | BPF_K)
  69 #define OP_JEQ  (BPF_JMP | BPF_JEQ  | BPF_K)
  70 #define OP_JSET (BPF_JMP | BPF_JSET | BPF_K)
  71 #define OP_LDB  (BPF_LD  | BPF_B    | BPF_ABS)
  72 #define OP_LDH  (BPF_LD  | BPF_H    | BPF_ABS)
  73 #define OP_LDHI (BPF_LD  | BPF_H    | BPF_IND)
  74 #define OP_LDX  (BPF_LDX | BPF_B    | BPF_MSH)
  75 #define OP_OR   (BPF_ALU | BPF_OR   | BPF_K)
  76 #define OP_RETA (BPF_RET | BPF_A)
  77 #define OP_RETK (BPF_RET | BPF_K)
  78
  79 static inline int ptp_filter_init(struct sock_filter *f, int len)
  80 {
  81         if (OP_LDH == f[0].code)
  82                 return sk_chk_filter(f, len);
  83         else
  84                 return 0;
  85 }
  86
  87 #define PTP_FILTER \
  88         {OP_LDH,        0,   0, OFF_ETYPE               }, /*              */ \
  89         {OP_JEQ,        0,  12, ETH_P_IP                }, /* f goto L20   */ \
  90         {OP_LDB,        0,   0, OFF_PROTO4              }, /*              */ \
  91         {OP_JEQ,        0,   9, IPPROTO_UDP             }, /* f goto L10   */ \
  92         {OP_LDH,        0,   0, OFF_FRAG                }, /*              */ \
  93         {OP_JSET,       7,   0, 0x1fff                  }, /* t goto L11   */ \
  94         {OP_LDX,        0,   0, OFF_IHL                 }, /*              */ \
  95         {OP_LDHI,       0,   0, RELOFF_DST4             }, /*              */ \
  96         {OP_JEQ,        0,   4, PTP_EV_PORT             }, /* f goto L12   */ \
  97         {OP_LDHI,       0,   0, ETH_HLEN + UDP_HLEN     }, /*              */ \
  98         {OP_AND,        0,   0, PTP_CLASS_VMASK         }, /*              */ \
  99         {OP_OR,         0,   0, PTP_CLASS_IPV4          }, /*              */ \
 100         {OP_RETA,       0,   0, 0                       }, /*              */ \
 101 /*L1x*/ {OP_RETK,       0,   0, PTP_CLASS_NONE          }, /*              */ \
 102 /*L20*/ {OP_JEQ,        0,   9, ETH_P_IPV6              }, /* f goto L40   */ \
 103         {OP_LDB,        0,   0, ETH_HLEN + OFF_NEXT     }, /*              */ \
 104         {OP_JEQ,        0,   6, IPPROTO_UDP             }, /* f goto L30   */ \
 105         {OP_LDH,        0,   0, OFF_DST6                }, /*              */ \
 106         {OP_JEQ,        0,   4, PTP_EV_PORT             }, /* f goto L31   */ \
 107         {OP_LDH,        0,   0, OFF_PTP6                }, /*              */ \
 108         {OP_AND,        0,   0, PTP_CLASS_VMASK         }, /*              */ \
 109         {OP_OR,         0,   0, PTP_CLASS_IPV6          }, /*              */ \
 110         {OP_RETA,       0,   0, 0                       }, /*              */ \
 111 /*L3x*/ {OP_RETK,       0,   0, PTP_CLASS_NONE          }, /*              */ \
 112 /*L40*/ {OP_JEQ,        0,   6, ETH_P_8021Q             }, /* f goto L50   */ \
 113         {OP_LDH,        0,   0, OFF_ETYPE + 4           }, /*              */ \
 114         {OP_JEQ,        0,   9, ETH_P_1588              }, /* f goto L60   */ \
 115         {OP_LDH,        0,   0, ETH_HLEN + VLAN_HLEN    }, /*              */ \
 116         {OP_AND,        0,   0, PTP_CLASS_VMASK         }, /*              */ \
 117         {OP_OR,         0,   0, PTP_CLASS_VLAN          }, /*              */ \
 118         {OP_RETA,       0,   0, 0                       }, /*              */ \
 119 /*L50*/ {OP_JEQ,        0,   4, ETH_P_1588              }, /* f goto L61   */ \
 120         {OP_LDH,        0,   0, ETH_HLEN                }, /*              */ \
 121         {OP_AND,        0,   0, PTP_CLASS_VMASK         }, /*              */ \
 122         {OP_OR,         0,   0, PTP_CLASS_L2            }, /*              */ \
 123         {OP_RETA,       0,   0, 0                       }, /*              */ \
 124 /*L6x*/ {OP_RETK,       0,   0, PTP_CLASS_NONE          },
 125
 126 #endif