Re: [PATCH v1 net-next] net: Deprecate SO_DEBUG and reclaim SOCK_DBG bit.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

From: Gerd Bayer <gbayer@linux.ibm.com>
Date: Wed, 14 Feb 2024 09:14:33 +0100
> On Tue, 2024-02-13 at 14:31 -0800, Kuniyuki Iwashima wrote:
> 
> Hi Kuniyuki,
> 
> I'm adding the newly appointed SMC maintainers to chime in.
> 
> > Recently, commit 8e5443d2b866 ("net: remove SOCK_DEBUG leftovers")
> > removed the last users of SOCK_DEBUG(), and commit b1dffcf0da22
> > ("net:
> > remove SOCK_DEBUG macro") removed the macro.
> > 
> > Now is the time to deprecate the oldest socket option.
> > 
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> > ---
> >  include/net/sock.h  | 1 -
> >  net/core/sock.c     | 6 +++---
> >  net/mptcp/sockopt.c | 4 +---
> >  net/smc/af_smc.c    | 5 ++---
> >  4 files changed, 6 insertions(+), 10 deletions(-)
> > 
> > diff --git a/net/core/sock.c b/net/core/sock.c
> > index 88bf810394a5..0a58dc861908 100644
> > --- a/net/core/sock.c
> > +++ b/net/core/sock.c
> > @@ -1194,10 +1194,9 @@ int sk_setsockopt(struct sock *sk, int level,
> > int optname,
> >  
> >         switch (optname) {
> >         case SO_DEBUG:
> > +               /* deprecated, but kept for compatibility. */
> Not 100% sure about the language - but isn't the DEBUG feature
> *removed* rather than just *deprecated*?

SO_DEBUG is still here, and the user won't get -ENOPROTOOPT.
That's why I wrote deprecated, no strong preference though.

> 
> >                 if (val && !sockopt_capable(CAP_NET_ADMIN))
> >                         ret = -EACCES;
> > -               else
> > -                       sock_valbool_flag(sk, SOCK_DBG, valbool);
> >                 break;
> >         case SO_REUSEADDR:
> >                 sk->sk_reuse = (valbool ? SK_CAN_REUSE :
> > SK_NO_REUSE);
> > @@ -1619,7 +1618,8 @@ int sk_getsockopt(struct sock *sk, int level,
> > int optname,
> >  
> >         switch (optname) {
> >         case SO_DEBUG:
> > -               v.val = sock_flag(sk, SOCK_DBG);
> > +               /* deprecated. */
> Same here.
> 
> > +               v.val = 0;
> >                 break;
> >  
> >         case SO_DONTROUTE:
> > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> > index da37e4541a5d..f6d90eef3d7c 100644
> > --- a/net/mptcp/sockopt.c
> > +++ b/net/mptcp/sockopt.c
> > @@ -81,7 +81,7 @@ static void mptcp_sol_socket_sync_intval(struct
> > mptcp_sock *msk, int optname, in
> >  
> >                 switch (optname) {
> >                 case SO_DEBUG:
> > -                       sock_valbool_flag(ssk, SOCK_DBG, !!val);
> > +                       /* deprecated. */
> and here.
> 
> >                         break;
> >                 case SO_KEEPALIVE:
> >                         if (ssk->sk_prot->keepalive)
> > @@ -1458,8 +1458,6 @@ static void sync_socket_options(struct
> > mptcp_sock *msk, struct sock *ssk)
> >                 sk_dst_reset(ssk);
> >         }
> >  
> > -       sock_valbool_flag(ssk, SOCK_DBG, sock_flag(sk, SOCK_DBG));
> > -
> >         if (inet_csk(sk)->icsk_ca_ops != inet_csk(ssk)->icsk_ca_ops)
> >                 tcp_set_congestion_control(ssk, msk->ca_name, false,
> > true);
> >         __tcp_sock_set_cork(ssk, !!msk->cork);
> > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> > index 66763c74ab76..062e16a2766a 100644
> > --- a/net/smc/af_smc.c
> > +++ b/net/smc/af_smc.c
> > @@ -445,7 +445,6 @@ static int smc_bind(struct socket *sock, struct
> > sockaddr *uaddr,
> >                              (1UL << SOCK_LINGER) | \
> >                              (1UL << SOCK_BROADCAST) | \
> >                              (1UL << SOCK_TIMESTAMP) | \
> > -                            (1UL << SOCK_DBG) | \
> >                              (1UL << SOCK_RCVTSTAMP) | \
> >                              (1UL << SOCK_RCVTSTAMPNS) | \
> >                              (1UL << SOCK_LOCALROUTE) | \
> > @@ -511,8 +510,8 @@ static void smc_copy_sock_settings_to_clc(struct
> > smc_sock *smc)
> >  
> >  #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
> >                              (1UL << SOCK_KEEPOPEN) | \
> > -                            (1UL << SOCK_LINGER) | \
> > -                            (1UL << SOCK_DBG))
> > +                            (1UL << SOCK_LINGER))
> > +
> >  /* copy only settings and flags relevant for smc from clc to smc
> > socket */
> >  static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
> >  {
> The SMC changes look good to me, so feel free to add my
> Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>

Thanks!