From: David Ahern > Sent: 01 December 2016 15:14 > On 11/30/16 10:59 PM, Alexei Starovoitov wrote: > > On Wed, Nov 30, 2016 at 10:16:50AM -0800, David Ahern wrote: > >> Add examples preventing a process in a cgroup from opening a socket > >> based family, protocol and type. > >> > >> Signed-off-by: David Ahern <d...@cumulusnetworks.com> > > ... > >> +++ b/samples/bpf/sock_flags_kern.c > >> @@ -0,0 +1,37 @@ > >> +#include <uapi/linux/bpf.h> > >> +#include <linux/socket.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 == 3 && sk->protocol == 58) > >> + return 0; > > > > why not to use SOCK_RAW and IPPROTO_ICMPV6 instead of constants? > > header file hell.
You can at least improve the comment. Or add: #ifndef SOCK_RAW #define SPCK_RAW 3 #endif (etc) at the top of the file. David