Commit 32e76b18 authored by Joe Stringer's avatar Joe Stringer Committed by Alexei Starovoitov
Browse files

bpf: Document BPF_PROG_ATTACH syscall command 



Document the prog attach command in more detail, based on git commits:
* commit f4324551 ("bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH
  commands")
* commit 4f738adb ("bpf: create tcp_bpf_ulp allowing BPF to monitor
  socket TX/RX data")
* commit f4364dcf ("media: rc: introduce BPF_PROG_LIRC_MODE2")
* commit d58e468b ("flow_dissector: implements flow dissector BPF
  hook")

Signed-off-by: default avatarJoe Stringer <joe@cilium.io>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Reviewed-by: default avatarQuentin Monnet <quentin@isovalent.com>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-6-joe@cilium.io
parent 8aacb3c8

include/uapi/linux/bpf.h

+37 −0
Original line number Diff line number Diff line
@@ -253,6 +253,43 @@ union bpf_iter_link_info { 
 *		Attach an eBPF program to a *target_fd* at the specified

 *		*attach_type* hook.

 *

 *		The *attach_type* specifies the eBPF attachment point to

 *		attach the program to, and must be one of *bpf_attach_type*

 *		(see below).

 *

 *		The *attach_bpf_fd* must be a valid file descriptor for a

 *		loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap

 *		or sock_ops type corresponding to the specified *attach_type*.

 *

 *		The *target_fd* must be a valid file descriptor for a kernel

 *		object which depends on the attach type of *attach_bpf_fd*:

 *

 *		**BPF_PROG_TYPE_CGROUP_DEVICE**,

 *		**BPF_PROG_TYPE_CGROUP_SKB**,

 *		**BPF_PROG_TYPE_CGROUP_SOCK**,

 *		**BPF_PROG_TYPE_CGROUP_SOCK_ADDR**,

 *		**BPF_PROG_TYPE_CGROUP_SOCKOPT**,

 *		**BPF_PROG_TYPE_CGROUP_SYSCTL**,

 *		**BPF_PROG_TYPE_SOCK_OPS**

 *

 *			Control Group v2 hierarchy with the eBPF controller

 *			enabled. Requires the kernel to be compiled with

 *			**CONFIG_CGROUP_BPF**.

 *

 *		**BPF_PROG_TYPE_FLOW_DISSECTOR**

 *

 *			Network namespace (eg /proc/self/ns/net).

 *

 *		**BPF_PROG_TYPE_LIRC_MODE2**

 *

 *			LIRC device path (eg /dev/lircN). Requires the kernel

 *			to be compiled with **CONFIG_BPF_LIRC_MODE2**.

 *

 *		**BPF_PROG_TYPE_SK_SKB**,

 *		**BPF_PROG_TYPE_SK_MSG**

 *

 *			eBPF map of socket type (eg **BPF_MAP_TYPE_SOCKHASH**).

 *

 *	Return

 *		Returns zero on success. On error, -1 is returned and *errno*

 *		is set appropriately.