mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
34f79502bb
SK_SKB BPF programs are run from the socket/tcp context but early in the stack before much of the TCP metadata is needed in tcp_skb_cb. So we can use some unused fields to place BPF metadata needed for SK_SKB programs when implementing the redirect function. This allows us to drop the preempt disable logic. It does however require an API change so sk_redirect_map() has been updated to additionally provide ctx_ptr to skb. Note, we do however continue to disable/enable preemption around actual BPF program running to account for map updates. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
109 lines
2.7 KiB
C
109 lines
2.7 KiB
C
/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
|
|
*
|
|
* 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.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*/
|
|
#include <uapi/linux/bpf.h>
|
|
#include <uapi/linux/if_ether.h>
|
|
#include <uapi/linux/if_packet.h>
|
|
#include <uapi/linux/ip.h>
|
|
#include "../../tools/testing/selftests/bpf/bpf_helpers.h"
|
|
#include "../../tools/testing/selftests/bpf/bpf_endian.h"
|
|
|
|
/* Sockmap sample program connects a client and a backend together
|
|
* using cgroups.
|
|
*
|
|
* client:X <---> frontend:80 client:X <---> backend:80
|
|
*
|
|
* For simplicity we hard code values here and bind 1:1. The hard
|
|
* coded values are part of the setup in sockmap.sh script that
|
|
* is associated with this BPF program.
|
|
*
|
|
* The bpf_printk is verbose and prints information as connections
|
|
* are established and verdicts are decided.
|
|
*/
|
|
|
|
#define bpf_printk(fmt, ...) \
|
|
({ \
|
|
char ____fmt[] = fmt; \
|
|
bpf_trace_printk(____fmt, sizeof(____fmt), \
|
|
##__VA_ARGS__); \
|
|
})
|
|
|
|
struct bpf_map_def SEC("maps") sock_map = {
|
|
.type = BPF_MAP_TYPE_SOCKMAP,
|
|
.key_size = sizeof(int),
|
|
.value_size = sizeof(int),
|
|
.max_entries = 20,
|
|
};
|
|
|
|
SEC("sk_skb1")
|
|
int bpf_prog1(struct __sk_buff *skb)
|
|
{
|
|
return skb->len;
|
|
}
|
|
|
|
SEC("sk_skb2")
|
|
int bpf_prog2(struct __sk_buff *skb)
|
|
{
|
|
__u32 lport = skb->local_port;
|
|
__u32 rport = skb->remote_port;
|
|
int ret = 0;
|
|
|
|
if (lport == 10000)
|
|
ret = 10;
|
|
else
|
|
ret = 1;
|
|
|
|
bpf_printk("sockmap: %d -> %d @ %d\n", lport, bpf_ntohl(rport), ret);
|
|
return bpf_sk_redirect_map(skb, &sock_map, ret, 0);
|
|
}
|
|
|
|
SEC("sockops")
|
|
int bpf_sockmap(struct bpf_sock_ops *skops)
|
|
{
|
|
__u32 lport, rport;
|
|
int op, err = 0, index, key, ret;
|
|
|
|
|
|
op = (int) skops->op;
|
|
|
|
switch (op) {
|
|
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
|
|
lport = skops->local_port;
|
|
rport = skops->remote_port;
|
|
|
|
if (lport == 10000) {
|
|
ret = 1;
|
|
err = bpf_sock_map_update(skops, &sock_map, &ret,
|
|
BPF_NOEXIST);
|
|
bpf_printk("passive(%i -> %i) map ctx update err: %d\n",
|
|
lport, bpf_ntohl(rport), err);
|
|
}
|
|
break;
|
|
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
|
|
lport = skops->local_port;
|
|
rport = skops->remote_port;
|
|
|
|
if (bpf_ntohl(rport) == 10001) {
|
|
ret = 10;
|
|
err = bpf_sock_map_update(skops, &sock_map, &ret,
|
|
BPF_NOEXIST);
|
|
bpf_printk("active(%i -> %i) map ctx update err: %d\n",
|
|
lport, bpf_ntohl(rport), err);
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
char _license[] SEC("license") = "GPL";
|