lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 28 Apr 2022 15:18:29 -0700 From: Jakub Kicinski <kuba@...nel.org> To: Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com> Cc: Jens Axboe <axboe@...nel.dk>, netdev <netdev@...r.kernel.org> Subject: Re: [PATCH] net: pass back data left in socket after receive On Wed, 27 Apr 2022 13:49:34 -0600 Jens Axboe wrote: > This is currently done for CMSG_INQ, add an ability to do so via struct > msghdr as well and have CMSG_INQ use that too. If the caller sets > msghdr->msg_get_inq, then we'll pass back the hint in msghdr->msg_inq. > > Rearrange struct msghdr a bit so we can add this member while shrinking > it at the same time. On a 64-bit build, it was 96 bytes before this > change and 88 bytes afterwards. > > Signed-off-by: Jens Axboe <axboe@...nel.dk> LGTM, but I said that once before.. Eric? FWIW the io_uring patch that uses it is here: https://git.kernel.dk/cgit/linux-block/commit/?h=io_uring-flags2 > diff --git a/include/linux/socket.h b/include/linux/socket.h > index 6f85f5d957ef..12085c9a8544 100644 > --- a/include/linux/socket.h > +++ b/include/linux/socket.h > @@ -50,6 +50,9 @@ struct linger { > struct msghdr { > void *msg_name; /* ptr to socket address structure */ > int msg_namelen; /* size of socket address structure */ > + > + int msg_inq; /* output, data left in socket */ > + > struct iov_iter msg_iter; /* data */ > > /* > @@ -62,8 +65,9 @@ struct msghdr { > void __user *msg_control_user; > }; > bool msg_control_is_user : 1; > - __kernel_size_t msg_controllen; /* ancillary data buffer length */ > + bool msg_get_inq : 1;/* return INQ after receive */ > unsigned int msg_flags; /* flags on received message */ > + __kernel_size_t msg_controllen; /* ancillary data buffer length */ > struct kiocb *msg_iocb; /* ptr to iocb for async requests */ > }; > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index cf18fbcbf123..78d79e26fb4d 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2335,8 +2335,10 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len, > if (sk->sk_state == TCP_LISTEN) > goto out; > > - if (tp->recvmsg_inq) > + if (tp->recvmsg_inq) { > *cmsg_flags = TCP_CMSG_INQ; > + msg->msg_get_inq = 1; > + } > timeo = sock_rcvtimeo(sk, nonblock); > > /* Urgent data needs to be handled specially. */ > @@ -2559,7 +2561,7 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len, > int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, > int flags, int *addr_len) > { > - int cmsg_flags = 0, ret, inq; > + int cmsg_flags = 0, ret; > struct scm_timestamping_internal tss; > > if (unlikely(flags & MSG_ERRQUEUE)) > @@ -2576,12 +2578,14 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, > release_sock(sk); > sk_defer_free_flush(sk); > > - if (cmsg_flags && ret >= 0) { > + if ((cmsg_flags || msg->msg_get_inq) && ret >= 0) { > if (cmsg_flags & TCP_CMSG_TS) > tcp_recv_timestamp(msg, sk, &tss); > + if (msg->msg_get_inq) > + msg->msg_inq = tcp_inq_hint(sk); > if (cmsg_flags & TCP_CMSG_INQ) { > - inq = tcp_inq_hint(sk); > - put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); > + put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(msg->msg_inq), > + &msg->msg_inq); > } > } > return ret; >
Powered by blists - more mailing lists