cregit-Linux how code gets into the kernel

Release 4.11 net/core/ptp_classifier.c

Directory: net/core
/* PTP classifier
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */

/* 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); }

Contributors

PersonTokensPropCommitsCommitProp
Daniel Borkmann1995.00%150.00%
Alexei Starovoitov15.00%150.00%
Total20100.00%2100.00%

EXPORT_SYMBOL_GPL(ptp_classify_raw);
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 = { .len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter, }; BUG_ON(bpf_prog_create(&ptp_insns, &ptp_prog)); }

Contributors

PersonTokensPropCommitsCommitProp
Daniel Borkmann47166.53%233.33%
Stefan Sörensen23533.19%233.33%
Mathias Krause10.14%116.67%
Alexei Starovoitov10.14%116.67%
Total708100.00%6100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Daniel Borkmann51168.04%233.33%
Stefan Sörensen23631.42%233.33%
Alexei Starovoitov30.40%116.67%
Mathias Krause10.13%116.67%
Total751100.00%6100.00%
Directory: net/core
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