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
9 struct {
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
18 int ifindex, ingress_ifindex;
19 char name[IFNAMSIZ];
20 unsigned int inum;
21 unsigned int meta_len, frag0_len, kskb_len, kskb2_len;
22
23 SEC("?xdp")
md_xdp(struct xdp_md * ctx)24 int 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
37 SEC("?tc")
md_skb(struct __sk_buff * skb)38 int 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
59 SEC("?tp_btf/sys_enter")
BPF_PROG(untrusted_ptr,struct pt_regs * regs,long id)60 int 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
70 SEC("?tracepoint/syscalls/sys_enter_nanosleep")
kctx_u64(void * ctx)71 int kctx_u64(void *ctx)
72 {
73 u64 *kctx = bpf_core_cast(ctx, u64);
74
75 (void)kctx;
76 return 0;
77 }
78
79 char _license[] SEC("license") = "GPL";
80