linux/tools/testing/selftests/bpf/progs/bind_perm.c
Stanislav Fomichev 8259fdeb30 selftests/bpf: Verify that rebinding to port < 1024 from BPF works
Return 3 to indicate that permission check for port 111
should be skipped.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210127193140.3170382-2-sdf@google.com
2021-01-27 18:18:15 -08:00

46 lines
840 B
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/stddef.h>
#include <linux/bpf.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
static __always_inline int bind_prog(struct bpf_sock_addr *ctx, int family)
{
struct bpf_sock *sk;
sk = ctx->sk;
if (!sk)
return 0;
if (sk->family != family)
return 0;
if (ctx->type != SOCK_STREAM)
return 0;
/* Return 1 OR'ed with the first bit set to indicate
* that CAP_NET_BIND_SERVICE should be bypassed.
*/
if (ctx->user_port == bpf_htons(111))
return (1 | 2);
return 1;
}
SEC("cgroup/bind4")
int bind_v4_prog(struct bpf_sock_addr *ctx)
{
return bind_prog(ctx, AF_INET);
}
SEC("cgroup/bind6")
int bind_v6_prog(struct bpf_sock_addr *ctx)
{
return bind_prog(ctx, AF_INET6);
}
char _license[] SEC("license") = "GPL";