Commit ab14fd4e authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Daniel Borkmann
Browse files

bpf: Add bpf_sk_storage support to bpf_tcp_ca 



This patch adds bpf_sk_storage_get() and bpf_sk_storage_delete()
helper to the bpf_tcp_ca's struct_ops.  That would allow
bpf-tcp-cc to:
1) share sk private data with other bpf progs.
2) use bpf_sk_storage as a private storage for a bpf-tcp-cc
   if the existing icsk_ca_priv is not big enough.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200320152101.2169498-1-kafai@fb.com
parent 1440e792

net/ipv4/bpf_tcp_ca.c

+33 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/btf.h>

#include <linux/filter.h>

#include <net/tcp.h>

#include <net/bpf_sk_storage.h>



static u32 optional_ops[] = {

	offsetof(struct tcp_congestion_ops, init),
@@ -27,6 +28,27 @@ static u32 unsupported_ops[] = { 
static const struct btf_type *tcp_sock_type;

static u32 tcp_sock_id, sock_id;



static int btf_sk_storage_get_ids[5];

static struct bpf_func_proto btf_sk_storage_get_proto __read_mostly;



static int btf_sk_storage_delete_ids[5];

static struct bpf_func_proto btf_sk_storage_delete_proto __read_mostly;



static void convert_sk_func_proto(struct bpf_func_proto *to, int *to_btf_ids,

				  const struct bpf_func_proto *from)

{

	int i;



	*to = *from;

	to->btf_id = to_btf_ids;

	for (i = 0; i < ARRAY_SIZE(to->arg_type); i++) {

		if (to->arg_type[i] == ARG_PTR_TO_SOCKET) {

			to->arg_type[i] = ARG_PTR_TO_BTF_ID;

			to->btf_id[i] = tcp_sock_id;

		}

	}

}



static int bpf_tcp_ca_init(struct btf *btf)

{

	s32 type_id;
@@ -42,6 +64,13 @@ static int bpf_tcp_ca_init(struct btf *btf) 
	tcp_sock_id = type_id;

	tcp_sock_type = btf_type_by_id(btf, tcp_sock_id);



	convert_sk_func_proto(&btf_sk_storage_get_proto,

			      btf_sk_storage_get_ids,

			      &bpf_sk_storage_get_proto);

	convert_sk_func_proto(&btf_sk_storage_delete_proto,

			      btf_sk_storage_delete_ids,

			      &bpf_sk_storage_delete_proto);



	return 0;

}
@@ -167,6 +196,10 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id, 
	switch (func_id) {

	case BPF_FUNC_tcp_send_ack:

		return &bpf_tcp_send_ack_proto;

	case BPF_FUNC_sk_storage_get:

		return &btf_sk_storage_get_proto;

	case BPF_FUNC_sk_storage_delete:

		return &btf_sk_storage_delete_proto;

	default:

		return bpf_base_func_proto(func_id);

	}

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