1d8a0af5ee
This adds a new selftest that tests the ability to attach an freplace program to a program type that relies on the expected_attach_type of the target program to pass verification. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/158773526831.293902.16011743438619684815.stgit@toke.dk
77 lines
1.7 KiB
C
77 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// Copyright (c) 2018 Facebook
|
|
|
|
#include <string.h>
|
|
|
|
#include <linux/stddef.h>
|
|
#include <linux/bpf.h>
|
|
#include <linux/in.h>
|
|
#include <linux/in6.h>
|
|
#include <sys/socket.h>
|
|
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_endian.h>
|
|
|
|
#define SRC_REWRITE_IP4 0x7f000004U
|
|
#define DST_REWRITE_IP4 0x7f000001U
|
|
#define DST_REWRITE_PORT4 4444
|
|
|
|
int _version SEC("version") = 1;
|
|
|
|
__attribute__ ((noinline))
|
|
int do_bind(struct bpf_sock_addr *ctx)
|
|
{
|
|
struct sockaddr_in sa = {};
|
|
|
|
sa.sin_family = AF_INET;
|
|
sa.sin_port = bpf_htons(0);
|
|
sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4);
|
|
|
|
if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
SEC("cgroup/connect4")
|
|
int connect_v4_prog(struct bpf_sock_addr *ctx)
|
|
{
|
|
struct bpf_sock_tuple tuple = {};
|
|
struct bpf_sock *sk;
|
|
|
|
/* Verify that new destination is available. */
|
|
memset(&tuple.ipv4.saddr, 0, sizeof(tuple.ipv4.saddr));
|
|
memset(&tuple.ipv4.sport, 0, sizeof(tuple.ipv4.sport));
|
|
|
|
tuple.ipv4.daddr = bpf_htonl(DST_REWRITE_IP4);
|
|
tuple.ipv4.dport = bpf_htons(DST_REWRITE_PORT4);
|
|
|
|
if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
|
|
return 0;
|
|
else if (ctx->type == SOCK_STREAM)
|
|
sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof(tuple.ipv4),
|
|
BPF_F_CURRENT_NETNS, 0);
|
|
else
|
|
sk = bpf_sk_lookup_udp(ctx, &tuple, sizeof(tuple.ipv4),
|
|
BPF_F_CURRENT_NETNS, 0);
|
|
|
|
if (!sk)
|
|
return 0;
|
|
|
|
if (sk->src_ip4 != tuple.ipv4.daddr ||
|
|
sk->src_port != DST_REWRITE_PORT4) {
|
|
bpf_sk_release(sk);
|
|
return 0;
|
|
}
|
|
|
|
bpf_sk_release(sk);
|
|
|
|
/* Rewrite destination. */
|
|
ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4);
|
|
ctx->user_port = bpf_htons(DST_REWRITE_PORT4);
|
|
|
|
return do_bind(ctx) ? 1 : 0;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|