linux/samples/bpf/sock_flags_kern.c
David Ahern 554ae6e792 samples/bpf: add userspace example for prohibiting sockets
Add examples preventing a process in a cgroup from opening a socket
based family, protocol and type.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02 13:46:09 -05:00

45 lines
986 B
C

#include <uapi/linux/bpf.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <uapi/linux/in.h>
#include <uapi/linux/in6.h>
#include "bpf_helpers.h"
SEC("cgroup/sock1")
int bpf_prog1(struct bpf_sock *sk)
{
char fmt[] = "socket: family %d type %d protocol %d\n";
bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
/* block PF_INET6, SOCK_RAW, IPPROTO_ICMPV6 sockets
* ie., make ping6 fail
*/
if (sk->family == PF_INET6 &&
sk->type == SOCK_RAW &&
sk->protocol == IPPROTO_ICMPV6)
return 0;
return 1;
}
SEC("cgroup/sock2")
int bpf_prog2(struct bpf_sock *sk)
{
char fmt[] = "socket: family %d type %d protocol %d\n";
bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
/* block PF_INET, SOCK_RAW, IPPROTO_ICMP sockets
* ie., make ping fail
*/
if (sk->family == PF_INET &&
sk->type == SOCK_RAW &&
sk->protocol == IPPROTO_ICMP)
return 0;
return 1;
}
char _license[] SEC("license") = "GPL";