On Wed, May 10, 2023 at 2:41 PM Aleksandr Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> wrote: > > On Wed, May 10, 2023 at 11:31 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote: > > > > On Wed, May 10, 2023 at 8:23 AM Alexander Mikhalitsyn > > <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> wrote: > > > > > > We have per struct proto ->bpf_bypass_getsockopt callback > > > to filter out bpf socket cgroup getsockopt hook from being called. > > > > > > It seems worthwhile to add analogical helper for SOL_SOCKET > > > level socket options. First user will be SO_PEERPIDFD. > > > > > > This patch was born as a result of discussion around a new SCM_PIDFD interface: > > > https://lore.kernel.org/all/20230413133355.350571-3-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/ > > > > > > Cc: Alexei Starovoitov <ast@xxxxxxxxxx> > > > Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> > > > Cc: Christian Brauner <brauner@xxxxxxxxxx> > > > Cc: Stanislav Fomichev <sdf@xxxxxxxxxx> > > > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > > > Cc: Eric Dumazet <edumazet@xxxxxxxxxx> > > > Cc: Jakub Kicinski <kuba@xxxxxxxxxx> > > > Cc: Paolo Abeni <pabeni@xxxxxxxxxx> > > > Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> > > > Cc: linux-kernel@xxxxxxxxxxxxxxx > > > Cc: netdev@xxxxxxxxxxxxxxx > > > Cc: bpf@xxxxxxxxxxxxxxx > > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> > > > --- > > > include/linux/bpf-cgroup.h | 8 +++++--- > > > include/net/sock.h | 1 + > > > net/core/sock.c | 5 +++++ > > > 3 files changed, 11 insertions(+), 3 deletions(-) > > > > > > diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h > > > index 57e9e109257e..97d8a49b35bf 100644 > > > --- a/include/linux/bpf-cgroup.h > > > +++ b/include/linux/bpf-cgroup.h > > > @@ -387,10 +387,12 @@ static inline bool cgroup_bpf_sock_enabled(struct sock *sk, > > > int __ret = retval; \ > > > if (cgroup_bpf_enabled(CGROUP_GETSOCKOPT) && \ > > > cgroup_bpf_sock_enabled(sock, CGROUP_GETSOCKOPT)) \ > > > - if (!(sock)->sk_prot->bpf_bypass_getsockopt || \ > > > - !INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \ > > > + if (((level != SOL_SOCKET) || \ > > > + !sock_bpf_bypass_getsockopt(level, optname)) && \ > > > + (!(sock)->sk_prot->bpf_bypass_getsockopt || \ > > > > Any reason we are not putting this into bpf_bypass_getsockopt for > > af_unix struct proto? SO_PEERPIDFD seems relevant only for af_unix? > > Yes, that should work perfectly well. The reason why I'm going this > way is that we are > declaring all SOL_SOCKET-level options in the net/core/sock.c which is > not specific to any address family. > It seems reasonable to have a way to filter out getsockopt for these > options too. > > But I'm not insisting on that way. Yeah, let's move it into af_unix struct proto for now. That should avoid adding extra conditionals for a few places that care about performance (tcp zerocopy fastpath). If we'd ever need to filter out generic SOL_SOCKET level options that apply for all sockets, we might put (and copy-paste) them in the respective {tcp,udp,unix,etc}_bpf_bypass_getsockopt. > Kind regards, > Alex > > > > > > + !INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \ > > > tcp_bpf_bypass_getsockopt, \ > > > - level, optname)) \ > > > + level, optname))) \ > > > __ret = __cgroup_bpf_run_filter_getsockopt( \ > > > sock, level, optname, optval, optlen, \ > > > max_optlen, retval); \ > > > diff --git a/include/net/sock.h b/include/net/sock.h > > > index 8b7ed7167243..530d6d22f42d 100644 > > > --- a/include/net/sock.h > > > +++ b/include/net/sock.h > > > @@ -1847,6 +1847,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname, > > > sockptr_t optval, sockptr_t optlen); > > > int sock_getsockopt(struct socket *sock, int level, int op, > > > char __user *optval, int __user *optlen); > > > +bool sock_bpf_bypass_getsockopt(int level, int optname); > > > int sock_gettstamp(struct socket *sock, void __user *userstamp, > > > bool timeval, bool time32); > > > struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, > > > diff --git a/net/core/sock.c b/net/core/sock.c > > > index 5440e67bcfe3..194a423eb6e5 100644 > > > --- a/net/core/sock.c > > > +++ b/net/core/sock.c > > > @@ -1963,6 +1963,11 @@ int sock_getsockopt(struct socket *sock, int level, int optname, > > > USER_SOCKPTR(optlen)); > > > } > > > > > > +bool sock_bpf_bypass_getsockopt(int level, int optname) > > > +{ > > > + return false; > > > +} > > > + > > > /* > > > * Initialize an sk_lock. > > > * > > > -- > > > 2.34.1 > > >
