Commit e0610476 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Daniel Borkmann
Browse files

bpf: Support BPF_FUNC_get_socket_cookie() for BPF_PROG_TYPE_SK_REUSEPORT. 



We will call sock_reuseport.prog for socket migration in the next commit,
so the eBPF program has to know which listener is closing to select a new
listener.

We can currently get a unique ID of each listener in the userspace by
calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map.

This patch makes the pointer of sk available in sk_reuseport_md so that we
can get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program.

Suggested-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f7zc@kafai-mbp.dhcp.thefacebook.com/
Link: https://lore.kernel.org/bpf/20210612123224.12525-9-kuniyu@amazon.co.jp
parent d4f2c86b

include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -5416,6 +5416,7 @@ struct sk_reuseport_md { 
	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */

	__u32 bind_inany;	/* Is sock bound to an INANY address? */

	__u32 hash;		/* A hash of the packet 4 tuples */

	__bpf_md_ptr(struct bpf_sock *, sk);

};



#define BPF_TAG_SIZE	8

net/core/filter.c

+10 −0
Original line number Diff line number Diff line
@@ -10172,6 +10172,8 @@ sk_reuseport_func_proto(enum bpf_func_id func_id, 
		return &sk_reuseport_load_bytes_proto;

	case BPF_FUNC_skb_load_bytes_relative:

		return &sk_reuseport_load_bytes_relative_proto;

	case BPF_FUNC_get_socket_cookie:

		return &bpf_get_socket_ptr_cookie_proto;

	default:

		return bpf_base_func_proto(func_id);

	}
@@ -10201,6 +10203,10 @@ sk_reuseport_is_valid_access(int off, int size, 
	case offsetof(struct sk_reuseport_md, hash):

		return size == size_default;



	case offsetof(struct sk_reuseport_md, sk):

		info->reg_type = PTR_TO_SOCKET;

		return size == sizeof(__u64);



	/* Fields that allow narrowing */

	case bpf_ctx_range(struct sk_reuseport_md, eth_protocol):

		if (size < sizeof_field(struct sk_buff, protocol))
@@ -10273,6 +10279,10 @@ static u32 sk_reuseport_convert_ctx_access(enum bpf_access_type type, 
	case offsetof(struct sk_reuseport_md, bind_inany):

		SK_REUSEPORT_LOAD_FIELD(bind_inany);

		break;



	case offsetof(struct sk_reuseport_md, sk):

		SK_REUSEPORT_LOAD_FIELD(sk);

		break;

	}



	return insn - insn_buf;

tools/include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -5416,6 +5416,7 @@ struct sk_reuseport_md { 
	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */

	__u32 bind_inany;	/* Is sock bound to an INANY address? */

	__u32 hash;		/* A hash of the packet 4 tuples */

	__bpf_md_ptr(struct bpf_sock *, sk);

};



#define BPF_TAG_SIZE	8