linux-stable/kernel/bpf/preload/bpf_preload.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BPF_PRELOAD_H
#define _BPF_PRELOAD_H

struct bpf_preload_info {
	char link_name[16];
	struct bpf_link *link;
};

struct bpf_preload_ops {
	int (*preload)(struct bpf_preload_info *);
	struct module *owner;
};
extern struct bpf_preload_ops *bpf_preload_ops;
#define BPF_PRELOAD_LINKS 2
#endif
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com 2020-08-19 04:27:58 +00:00			`/* SPDX-License-Identifier: GPL-2.0 */`
			`#ifndef _BPF_PRELOAD_H`
			`#define _BPF_PRELOAD_H`

bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com 2022-02-09 23:20:01 +00:00			`struct bpf_preload_info {`
			`char link_name[16];`
			`struct bpf_link *link;`
			`};`
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com 2020-08-19 04:27:58 +00:00
			`struct bpf_preload_ops {`
			`int (preload)(struct bpf_preload_info );`
			`struct module *owner;`
			`};`
			`extern struct bpf_preload_ops *bpf_preload_ops;`
			`#define BPF_PRELOAD_LINKS 2`
			`#endif`