1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Isovalent */
3 #include <stdbool.h>
4
5 #include <linux/bpf.h>
6 #include <linux/if_ether.h>
7 #include <linux/stddef.h>
8 #include <linux/if_packet.h>
9 #include <bpf/bpf_endian.h>
10 #include <bpf/bpf_helpers.h>
11 #include <bpf/bpf_core_read.h>
12
13 char LICENSE[] SEC("license") = "GPL";
14
15 bool seen_tc1;
16 bool seen_tc2;
17 bool seen_tc3;
18 bool seen_tc4;
19 bool seen_tc5;
20 bool seen_tc6;
21 bool seen_tc7;
22 bool seen_tc8;
23
24 bool set_type;
25
26 bool seen_eth;
27 bool seen_host;
28 bool seen_mcast;
29
30 int mark, prio;
31 unsigned short headroom, tailroom;
32
33 SEC("tc/ingress")
tc1(struct __sk_buff * skb)34 int tc1(struct __sk_buff *skb)
35 {
36 struct ethhdr eth = {};
37
38 if (skb->protocol != __bpf_constant_htons(ETH_P_IP))
39 goto out;
40 if (bpf_skb_load_bytes(skb, 0, ð, sizeof(eth)))
41 goto out;
42 seen_eth = eth.h_proto == bpf_htons(ETH_P_IP);
43 seen_host = skb->pkt_type == PACKET_HOST;
44 if (seen_host && set_type) {
45 eth.h_dest[0] = 4;
46 if (bpf_skb_store_bytes(skb, 0, ð, sizeof(eth), 0))
47 goto fail;
48 bpf_skb_change_type(skb, PACKET_MULTICAST);
49 }
50 out:
51 seen_tc1 = true;
52 fail:
53 return TCX_NEXT;
54 }
55
56 SEC("tc/egress")
tc2(struct __sk_buff * skb)57 int tc2(struct __sk_buff *skb)
58 {
59 seen_tc2 = true;
60 return TCX_NEXT;
61 }
62
63 SEC("tc/egress")
tc3(struct __sk_buff * skb)64 int tc3(struct __sk_buff *skb)
65 {
66 seen_tc3 = true;
67 return TCX_NEXT;
68 }
69
70 SEC("tc/egress")
tc4(struct __sk_buff * skb)71 int tc4(struct __sk_buff *skb)
72 {
73 seen_tc4 = true;
74 return TCX_NEXT;
75 }
76
77 SEC("tc/egress")
tc5(struct __sk_buff * skb)78 int tc5(struct __sk_buff *skb)
79 {
80 seen_tc5 = true;
81 return TCX_PASS;
82 }
83
84 SEC("tc/egress")
tc6(struct __sk_buff * skb)85 int tc6(struct __sk_buff *skb)
86 {
87 seen_tc6 = true;
88 return TCX_PASS;
89 }
90
91 SEC("tc/ingress")
tc7(struct __sk_buff * skb)92 int tc7(struct __sk_buff *skb)
93 {
94 struct ethhdr eth = {};
95
96 if (skb->protocol != __bpf_constant_htons(ETH_P_IP))
97 goto out;
98 if (bpf_skb_load_bytes(skb, 0, ð, sizeof(eth)))
99 goto out;
100 if (eth.h_dest[0] == 4 && set_type) {
101 seen_mcast = skb->pkt_type == PACKET_MULTICAST;
102 bpf_skb_change_type(skb, PACKET_HOST);
103 }
104 out:
105 seen_tc7 = true;
106 return TCX_PASS;
107 }
108
109 struct sk_buff {
110 struct net_device *dev;
111 };
112
113 struct net_device {
114 unsigned short needed_headroom;
115 unsigned short needed_tailroom;
116 };
117
118 SEC("tc/egress")
tc8(struct __sk_buff * skb)119 int tc8(struct __sk_buff *skb)
120 {
121 struct net_device *dev = BPF_CORE_READ((struct sk_buff *)skb, dev);
122
123 seen_tc8 = true;
124 mark = skb->mark;
125 prio = skb->priority;
126 headroom = BPF_CORE_READ(dev, needed_headroom);
127 tailroom = BPF_CORE_READ(dev, needed_tailroom);
128 return TCX_PASS;
129 }
130