net/core/ptp_classifier.c

   1 /* PTP classifier
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful, but
   8  * WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10  * General Public License for more details.
  11  */
  12
  13 /* The below program is the bpf_asm (tools/net/) representation of
  14  * the opcode array in the ptp_filter structure.
  15  *
  16  * For convenience, this can easily be altered and reviewed with
  17  * bpf_asm and bpf_dbg, e.g. `./bpf_asm -c prog` where prog is a
  18  * simple file containing the below program:
  19  *
  20  * ldh [12]                        ; load ethertype
  21  *
  22  * ; PTP over UDP over IPv4 over Ethernet
  23  * test_ipv4:
  24  *   jneq #0x800, test_ipv6        ; ETH_P_IP ?
  25  *   ldb [23]                      ; load proto
  26  *   jneq #17, drop_ipv4           ; IPPROTO_UDP ?
  27  *   ldh [20]                      ; load frag offset field
  28  *   jset #0x1fff, drop_ipv4       ; don't allow fragments
  29  *   ldxb 4*([14]&0xf)             ; load IP header len
  30  *   ldh [x + 16]                  ; load UDP dst port
  31  *   jneq #319, drop_ipv4          ; is port PTP_EV_PORT ?
  32  *   ldh [x + 22]                  ; load payload
  33  *   and #0xf                      ; mask PTP_CLASS_VMASK
  34  *   or #0x10                      ; PTP_CLASS_IPV4
  35  *   ret a                         ; return PTP class
  36  *   drop_ipv4: ret #0x0           ; PTP_CLASS_NONE
  37  *
  38  * ; PTP over UDP over IPv6 over Ethernet
  39  * test_ipv6:
  40  *   jneq #0x86dd, test_8021q      ; ETH_P_IPV6 ?
  41  *   ldb [20]                      ; load proto
  42  *   jneq #17, drop_ipv6           ; IPPROTO_UDP ?
  43  *   ldh [56]                      ; load UDP dst port
  44  *   jneq #319, drop_ipv6          ; is port PTP_EV_PORT ?
  45  *   ldh [62]                      ; load payload
  46  *   and #0xf                      ; mask PTP_CLASS_VMASK
  47  *   or #0x20                      ; PTP_CLASS_IPV6
  48  *   ret a                         ; return PTP class
  49  *   drop_ipv6: ret #0x0           ; PTP_CLASS_NONE
  50  *
  51  * ; PTP over 802.1Q over Ethernet
  52  * test_8021q:
  53  *   jneq #0x8100, test_ieee1588   ; ETH_P_8021Q ?
  54  *   ldh [16]                      ; load inner type
  55  *   jneq #0x88f7, test_8021q_ipv4 ; ETH_P_1588 ?
  56  *   ldb [18]                      ; load payload
  57  *   and #0x8                      ; as we don't have ports here, test
  58  *   jneq #0x0, drop_ieee1588      ; for PTP_GEN_BIT and drop these
  59  *   ldh [18]                      ; reload payload
  60  *   and #0xf                      ; mask PTP_CLASS_VMASK
  61  *   or #0x70                      ; PTP_CLASS_VLAN|PTP_CLASS_L2
  62  *   ret a                         ; return PTP class
  63  *
  64  * ; PTP over UDP over IPv4 over 802.1Q over Ethernet
  65  * test_8021q_ipv4:
  66  *   jneq #0x800, test_8021q_ipv6  ; ETH_P_IP ?
  67  *   ldb [27]                      ; load proto
  68  *   jneq #17, drop_8021q_ipv4     ; IPPROTO_UDP ?
  69  *   ldh [24]                      ; load frag offset field
  70  *   jset #0x1fff, drop_8021q_ipv4; don't allow fragments
  71  *   ldxb 4*([18]&0xf)             ; load IP header len
  72  *   ldh [x + 20]                  ; load UDP dst port
  73  *   jneq #319, drop_8021q_ipv4    ; is port PTP_EV_PORT ?
  74  *   ldh [x + 26]                  ; load payload
  75  *   and #0xf                      ; mask PTP_CLASS_VMASK
  76  *   or #0x50                      ; PTP_CLASS_VLAN|PTP_CLASS_IPV4
  77  *   ret a                         ; return PTP class
  78  *   drop_8021q_ipv4: ret #0x0     ; PTP_CLASS_NONE
  79  *
  80  * ; PTP over UDP over IPv6 over 802.1Q over Ethernet
  81  * test_8021q_ipv6:
  82  *   jneq #0x86dd, drop_8021q_ipv6 ; ETH_P_IPV6 ?
  83  *   ldb [24]                      ; load proto
  84  *   jneq #17, drop_8021q_ipv6           ; IPPROTO_UDP ?
  85  *   ldh [60]                      ; load UDP dst port
  86  *   jneq #319, drop_8021q_ipv6          ; is port PTP_EV_PORT ?
  87  *   ldh [66]                      ; load payload
  88  *   and #0xf                      ; mask PTP_CLASS_VMASK
  89  *   or #0x60                      ; PTP_CLASS_VLAN|PTP_CLASS_IPV6
  90  *   ret a                         ; return PTP class
  91  *   drop_8021q_ipv6: ret #0x0     ; PTP_CLASS_NONE
  92  *
  93  * ; PTP over Ethernet
  94  * test_ieee1588:
  95  *   jneq #0x88f7, drop_ieee1588   ; ETH_P_1588 ?
  96  *   ldb [14]                      ; load payload
  97  *   and #0x8                      ; as we don't have ports here, test
  98  *   jneq #0x0, drop_ieee1588      ; for PTP_GEN_BIT and drop these
  99  *   ldh [14]                      ; reload payload
 100  *   and #0xf                      ; mask PTP_CLASS_VMASK
 101  *   or #0x30                      ; PTP_CLASS_L2
 102  *   ret a                         ; return PTP class
 103  *   drop_ieee1588: ret #0x0       ; PTP_CLASS_NONE
 104  */
 105
 106 #include <linux/skbuff.h>
 107 #include <linux/filter.h>
 108 #include <linux/ptp_classify.h>
 109
 110 static struct bpf_prog *ptp_insns __read_mostly;
 111
 112 unsigned int ptp_classify_raw(const struct sk_buff *skb)
 113 {
 114         return BPF_PROG_RUN(ptp_insns, skb);
 115 }
 116 EXPORT_SYMBOL_GPL(ptp_classify_raw);
 117
 118 void __init ptp_classifier_init(void)
 119 {
 120         static struct sock_filter ptp_filter[] __initdata = {
 121                 { 0x28,  0,  0, 0x0000000c },
 122                 { 0x15,  0, 12, 0x00000800 },
 123                 { 0x30,  0,  0, 0x00000017 },
 124                 { 0x15,  0,  9, 0x00000011 },
 125                 { 0x28,  0,  0, 0x00000014 },
 126                 { 0x45,  7,  0, 0x00001fff },
 127                 { 0xb1,  0,  0, 0x0000000e },
 128                 { 0x48,  0,  0, 0x00000010 },
 129                 { 0x15,  0,  4, 0x0000013f },
 130                 { 0x48,  0,  0, 0x00000016 },
 131                 { 0x54,  0,  0, 0x0000000f },
 132                 { 0x44,  0,  0, 0x00000010 },
 133                 { 0x16,  0,  0, 0x00000000 },
 134                 { 0x06,  0,  0, 0x00000000 },
 135                 { 0x15,  0,  9, 0x000086dd },
 136                 { 0x30,  0,  0, 0x00000014 },
 137                 { 0x15,  0,  6, 0x00000011 },
 138                 { 0x28,  0,  0, 0x00000038 },
 139                 { 0x15,  0,  4, 0x0000013f },
 140                 { 0x28,  0,  0, 0x0000003e },
 141                 { 0x54,  0,  0, 0x0000000f },
 142                 { 0x44,  0,  0, 0x00000020 },
 143                 { 0x16,  0,  0, 0x00000000 },
 144                 { 0x06,  0,  0, 0x00000000 },
 145                 { 0x15,  0, 32, 0x00008100 },
 146                 { 0x28,  0,  0, 0x00000010 },
 147                 { 0x15,  0,  7, 0x000088f7 },
 148                 { 0x30,  0,  0, 0x00000012 },
 149                 { 0x54,  0,  0, 0x00000008 },
 150                 { 0x15,  0, 35, 0x00000000 },
 151                 { 0x28,  0,  0, 0x00000012 },
 152                 { 0x54,  0,  0, 0x0000000f },
 153                 { 0x44,  0,  0, 0x00000070 },
 154                 { 0x16,  0,  0, 0x00000000 },
 155                 { 0x15,  0, 12, 0x00000800 },
 156                 { 0x30,  0,  0, 0x0000001b },
 157                 { 0x15,  0,  9, 0x00000011 },
 158                 { 0x28,  0,  0, 0x00000018 },
 159                 { 0x45,  7,  0, 0x00001fff },
 160                 { 0xb1,  0,  0, 0x00000012 },
 161                 { 0x48,  0,  0, 0x00000014 },
 162                 { 0x15,  0,  4, 0x0000013f },
 163                 { 0x48,  0,  0, 0x0000001a },
 164                 { 0x54,  0,  0, 0x0000000f },
 165                 { 0x44,  0,  0, 0x00000050 },
 166                 { 0x16,  0,  0, 0x00000000 },
 167                 { 0x06,  0,  0, 0x00000000 },
 168                 { 0x15,  0,  8, 0x000086dd },
 169                 { 0x30,  0,  0, 0x00000018 },
 170                 { 0x15,  0,  6, 0x00000011 },
 171                 { 0x28,  0,  0, 0x0000003c },
 172                 { 0x15,  0,  4, 0x0000013f },
 173                 { 0x28,  0,  0, 0x00000042 },
 174                 { 0x54,  0,  0, 0x0000000f },
 175                 { 0x44,  0,  0, 0x00000060 },
 176                 { 0x16,  0,  0, 0x00000000 },
 177                 { 0x06,  0,  0, 0x00000000 },
 178                 { 0x15,  0,  7, 0x000088f7 },
 179                 { 0x30,  0,  0, 0x0000000e },
 180                 { 0x54,  0,  0, 0x00000008 },
 181                 { 0x15,  0,  4, 0x00000000 },
 182                 { 0x28,  0,  0, 0x0000000e },
 183                 { 0x54,  0,  0, 0x0000000f },
 184                 { 0x44,  0,  0, 0x00000030 },
 185                 { 0x16,  0,  0, 0x00000000 },
 186                 { 0x06,  0,  0, 0x00000000 },
 187         };
 188         struct sock_fprog_kern ptp_prog = {
 189                 .len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter,
 190         };
 191
 192         BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog));
 193 }