1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3#include "vmlinux.h"
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6#include <bpf/bpf_core_read.h>
7#include "bpf_kfuncs.h"
8
9struct {
10	__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
11	__uint(map_flags, BPF_F_NO_PREALLOC);
12	__type(key, int);
13	__type(value, long);
14} enter_id SEC(".maps");
15
16#define	IFNAMSIZ 16
17
18int ifindex, ingress_ifindex;
19char name[IFNAMSIZ];
20unsigned int inum;
21unsigned int meta_len, frag0_len, kskb_len, kskb2_len;
22
23SEC("?xdp")
24int md_xdp(struct xdp_md *ctx)
25{
26	struct xdp_buff *kctx = bpf_cast_to_kern_ctx(ctx);
27	struct net_device *dev;
28
29	dev = kctx->rxq->dev;
30	ifindex = dev->ifindex;
31	inum = dev->nd_net.net->ns.inum;
32	__builtin_memcpy(name, dev->name, IFNAMSIZ);
33	ingress_ifindex = ctx->ingress_ifindex;
34	return XDP_PASS;
35}
36
37SEC("?tc")
38int md_skb(struct __sk_buff *skb)
39{
40	struct sk_buff *kskb = bpf_cast_to_kern_ctx(skb);
41	struct skb_shared_info *shared_info;
42	struct sk_buff *kskb2;
43
44	kskb_len = kskb->len;
45
46	/* Simulate the following kernel macro:
47	 *   #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
48	 */
49	shared_info = bpf_core_cast(kskb->head + kskb->end, struct skb_shared_info);
50	meta_len = shared_info->meta_len;
51	frag0_len = shared_info->frag_list->len;
52
53	/* kskb2 should be equal to kskb */
54	kskb2 = bpf_core_cast(kskb, typeof(*kskb2));
55	kskb2_len = kskb2->len;
56	return 0;
57}
58
59SEC("?tp_btf/sys_enter")
60int BPF_PROG(untrusted_ptr, struct pt_regs *regs, long id)
61{
62	struct task_struct *task, *task_dup;
63
64	task = bpf_get_current_task_btf();
65	task_dup = bpf_core_cast(task, struct task_struct);
66	(void)bpf_task_storage_get(&enter_id, task_dup, 0, 0);
67	return 0;
68}
69
70SEC("?tracepoint/syscalls/sys_enter_nanosleep")
71int kctx_u64(void *ctx)
72{
73	u64 *kctx = bpf_core_cast(ctx, u64);
74
75	(void)kctx;
76	return 0;
77}
78
79char _license[] SEC("license") = "GPL";
80