From 4a0ee78890699706f59cc9bdf8283ecaa4e0a141 Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Fri, 18 Aug 2023 18:01:13 +0900 Subject: samples/bpf: unify bpf program suffix to .bpf with tracing programs Currently, BPF programs typically have a suffix of .bpf.c. However, some programs still utilize a mixture of _kern.c suffix alongside the naming convention. In order to achieve consistency in the naming of these programs, this commit unifies the inconsistency in the naming convention of BPF kernel programs. Signed-off-by: Daniel T. Lee Link: https://lore.kernel.org/r/20230818090119.477441-4-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov --- samples/bpf/tracex1.bpf.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 samples/bpf/tracex1.bpf.c (limited to 'samples/bpf/tracex1.bpf.c') diff --git a/samples/bpf/tracex1.bpf.c b/samples/bpf/tracex1.bpf.c new file mode 100644 index 000000000000..bb78bdbffa87 --- /dev/null +++ b/samples/bpf/tracex1.bpf.c @@ -0,0 +1,53 @@ +/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com + * + * 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. + */ +#include "vmlinux.h" +#include "net_shared.h" +#include +#include +#include + +#define _(P) \ + ({ \ + typeof(P) val = 0; \ + bpf_probe_read_kernel(&val, sizeof(val), &(P)); \ + val; \ + }) + +/* kprobe is NOT a stable ABI + * kernel functions can be removed, renamed or completely change semantics. + * Number of arguments and their positions can change, etc. + * In such case this bpf+kprobe example will no longer be meaningful + */ +SEC("kprobe/__netif_receive_skb_core") +int bpf_prog1(struct pt_regs *ctx) +{ + /* attaches to kprobe __netif_receive_skb_core, + * looks for packets on loobpack device and prints them + */ + char devname[IFNAMSIZ]; + struct net_device *dev; + struct sk_buff *skb; + int len; + + /* non-portable! works for the given kernel only */ + bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx)); + dev = _(skb->dev); + len = _(skb->len); + + bpf_probe_read_kernel(devname, sizeof(devname), dev->name); + + if (devname[0] == 'l' && devname[1] == 'o') { + char fmt[] = "skb %p len %d\n"; + /* using bpf_trace_printk() for DEBUG ONLY */ + bpf_trace_printk(fmt, sizeof(fmt), skb, len); + } + + return 0; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; -- cgit v1.2.3