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From:   Pavel Begunkov <asml.silence@gmail.com>
To:     io-uring@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Jonathan Lemon <jonathan.lemon@gmail.com>,
        Willem de Bruijn <willemb@google.com>,
        Jens Axboe <axboe@kernel.dk>, David Ahern <dsahern@kernel.org>,
        kernel-team@fb.com, Pavel Begunkov <asml.silence@gmail.com>
Subject: [PATCH net-next v5 05/27] skbuff: carry external ubuf_info in msghdr
Date:   Tue, 12 Jul 2022 21:52:29 +0100
Message-Id: <2c3ce22ec6939856cef4329d8c95e4c8dfb355d8.1657643355.git.asml.silence@gmail.com>
In-Reply-To: <cover.1657643355.git.asml.silence@gmail.com>
References: <cover.1657643355.git.asml.silence@gmail.com>
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Make possible for network in-kernel callers like io_uring to pass in a
custom ubuf_info by setting it in a new field of struct msghdr.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 include/linux/socket.h | 1 +
 net/compat.c           | 1 +
 net/socket.c           | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 17311ad9f9af..7bac9fc1cee0 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -69,6 +69,7 @@ struct msghdr {
 	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 */
+	struct ubuf_info *msg_ubuf;
 };
 
 struct user_msghdr {
diff --git a/net/compat.c b/net/compat.c
index 210fc3b4d0d8..6cd2e7683dd0 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -80,6 +80,7 @@ int __get_compat_msghdr(struct msghdr *kmsg,
 		return -EMSGSIZE;
 
 	kmsg->msg_iocb = NULL;
+	kmsg->msg_ubuf = NULL;
 	*ptr = msg.msg_iov;
 	*len = msg.msg_iovlen;
 	return 0;
diff --git a/net/socket.c b/net/socket.c
index 2bc8773d9dc5..ed061609265e 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2106,6 +2106,7 @@ int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
 	msg.msg_control = NULL;
 	msg.msg_controllen = 0;
 	msg.msg_namelen = 0;
+	msg.msg_ubuf = NULL;
 	if (addr) {
 		err = move_addr_to_kernel(addr, addr_len, &address);
 		if (err < 0)
@@ -2171,6 +2172,7 @@ int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
 	msg.msg_namelen = 0;
 	msg.msg_iocb = NULL;
 	msg.msg_flags = 0;
+	msg.msg_ubuf = NULL;
 	if (sock->file->f_flags & O_NONBLOCK)
 		flags |= MSG_DONTWAIT;
 	err = sock_recvmsg(sock, &msg, flags);
@@ -2409,6 +2411,7 @@ int __copy_msghdr_from_user(struct msghdr *kmsg,
 		return -EMSGSIZE;
 
 	kmsg->msg_iocb = NULL;
+	kmsg->msg_ubuf = NULL;
 	*uiov = msg.msg_iov;
 	*nsegs = msg.msg_iovlen;
 	return 0;
-- 
2.37.0