[RFC 02/12] skbuff: pass a struct ubuf_info in msghdr

[Pavel Begunkov <asml.silence@gmail.com>]

Instead of the net stack managing ubuf_info, allow to pass it in from
outside in a struct msghdr (in-kernel structure), so io_uring can make
use of it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c          | 2 ++
 include/linux/socket.h | 1 +
 net/compat.c           | 1 +
 net/socket.c           | 3 +++
 4 files changed, 7 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 72da3a75521a..59380e3454ad 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4911,6 +4911,7 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags)
 	msg.msg_control = NULL;
 	msg.msg_controllen = 0;
 	msg.msg_namelen = 0;
+	msg.msg_ubuf = NULL;
 
 	flags = req->sr_msg.msg_flags;
 	if (issue_flags & IO_URING_F_NONBLOCK)
@@ -5157,6 +5158,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 	msg.msg_namelen = 0;
 	msg.msg_iocb = NULL;
 	msg.msg_flags = 0;
+	msg.msg_ubuf = NULL;
 
 	flags = req->sr_msg.msg_flags;
 	if (force_nonblock)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 8ef26d89ef49..6bd2c6b0c6f2 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -65,6 +65,7 @@ struct msghdr {
 	__kernel_size_t	msg_controllen;	/* ancillary data buffer length */
 	unsigned int	msg_flags;	/* flags on received message */
 	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 7f64a6eccf63..0a29b616a38c 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2023,6 +2023,7 @@ 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)
@@ -2088,6 +2089,7 @@ 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);
@@ -2326,6 +2328,7 @@ 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;
-- 
2.34.0