[PATCH net-next v4 05/27] skbuff: carry external ubuf_info in msghdr

Pavel Begunkov
2022-07-07T11:52:34Z

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;
--
2.36.1