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-rw-r--r--net/core/ptp_classifier.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/net/core/ptp_classifier.c b/net/core/ptp_classifier.c
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+/* 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, drop_ieee1588 ; 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 #0x40 ; PTP_CLASS_V2_VLAN
+ * ret a ; return PTP class
+ *
+ * ; 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 #0x30 ; 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 sk_filter *ptp_insns __read_mostly;
+
+unsigned int ptp_classify_raw(const struct sk_buff *skb)
+{
+ return SK_RUN_FILTER(ptp_insns, skb);
+}
+EXPORT_SYMBOL_GPL(ptp_classify_raw);
+
+void __init ptp_classifier_init(void)
+{
+ static struct sock_filter ptp_filter[] = {
+ { 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, 9, 0x00008100 },
+ { 0x28, 0, 0, 0x00000010 },
+ { 0x15, 0, 15, 0x000088f7 },
+ { 0x30, 0, 0, 0x00000012 },
+ { 0x54, 0, 0, 0x00000008 },
+ { 0x15, 0, 12, 0x00000000 },
+ { 0x28, 0, 0, 0x00000012 },
+ { 0x54, 0, 0, 0x0000000f },
+ { 0x44, 0, 0, 0x00000040 },
+ { 0x16, 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, 0x00000030 },
+ { 0x16, 0, 0, 0x00000000 },
+ { 0x06, 0, 0, 0x00000000 },
+ };
+ struct sock_fprog ptp_prog = {
+ .len = ARRAY_SIZE(ptp_filter), .filter = ptp_filter,
+ };
+
+ BUG_ON(sk_unattached_filter_create(&ptp_insns, &ptp_prog));
+}