From 0e81cfd971dc4833c699dcd8924e54a5021bc4e8 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 19 May 2025 13:57:57 -0700 Subject: af_unix: Move SOCK_PASS{CRED,PIDFD,SEC} to struct sock. As explained in the next patch, SO_PASSRIGHTS would have a problem if we assigned a corresponding bit to socket->flags, so it must be managed in struct sock. Mixing socket->flags and sk->sk_flags for similar options will look confusing, and sk->sk_flags does not have enough space on 32bit system. Also, as mentioned in commit 16e572626961 ("af_unix: dont send SCM_CREDENTIALS by default"), SOCK_PASSCRED and SOCK_PASSPID handling is known to be slow, and managing the flags in struct socket cannot avoid that for embryo sockets. Let's move SOCK_PASS{CRED,PIDFD,SEC} to struct sock. While at it, other SOCK_XXX flags in net.h are grouped as enum. Note that assign_bit() was atomic, so the writer side is moved down after lock_sock() in setsockopt(), but the bit is only read once in sendmsg() and recvmsg(), so lock_sock() is not needed there. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/net.h | 15 +++++++-------- include/net/sock.h | 16 +++++++++++++++- 2 files changed, 22 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/linux/net.h b/include/linux/net.h index 0ff950eecc6b..f8418d6e33e0 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -36,14 +36,13 @@ struct net; * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected. * Eventually all flags will be in sk->sk_wq->flags. */ -#define SOCKWQ_ASYNC_NOSPACE 0 -#define SOCKWQ_ASYNC_WAITDATA 1 -#define SOCK_NOSPACE 2 -#define SOCK_PASSCRED 3 -#define SOCK_PASSSEC 4 -#define SOCK_SUPPORT_ZC 5 -#define SOCK_CUSTOM_SOCKOPT 6 -#define SOCK_PASSPIDFD 7 +enum socket_flags { + SOCKWQ_ASYNC_NOSPACE, + SOCKWQ_ASYNC_WAITDATA, + SOCK_NOSPACE, + SOCK_SUPPORT_ZC, + SOCK_CUSTOM_SOCKOPT, +}; #ifndef ARCH_HAS_SOCKET_TYPES /** diff --git a/include/net/sock.h b/include/net/sock.h index 483522377955..d90a71f66ab8 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -337,6 +337,11 @@ struct sk_filter; * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME * @sk_txtime_report_errors: set report errors mode for SO_TXTIME * @sk_txtime_unused: unused txtime flags + * @sk_scm_recv_flags: all flags used by scm_recv() + * @sk_scm_credentials: flagged by SO_PASSCRED to recv SCM_CREDENTIALS + * @sk_scm_security: flagged by SO_PASSSEC to recv SCM_SECURITY + * @sk_scm_pidfd: flagged by SO_PASSPIDFD to recv SCM_PIDFD + * @sk_scm_unused: unused flags for scm_recv() * @ns_tracker: tracker for netns reference * @sk_user_frags: xarray of pages the user is holding a reference on. * @sk_owner: reference to the real owner of the socket that calls @@ -523,7 +528,16 @@ struct sock { #endif int sk_disconnects; - u8 sk_txrehash; + union { + u8 sk_txrehash; + u8 sk_scm_recv_flags; + struct { + u8 sk_scm_credentials : 1, + sk_scm_security : 1, + sk_scm_pidfd : 1, + sk_scm_unused : 5; + }; + }; u8 sk_clockid; u8 sk_txtime_deadline_mode : 1, sk_txtime_report_errors : 1, -- cgit v1.2.3