[PATCH for-next 08/12] io_uring: recv/recvmsg retarget_rsrc support

Dylan Yudaken
2022-10-31T13:41:58Z

Add can_retarget_rsrc handler for recv/recvmsg

Signed-off-by: Dylan Yudaken <dylany@meta.com>
---
io_uring/net.c | 22 +++++++++++++++++++++-
io_uring/net.h | 1 +
io_uring/opdef.c | 2 ++
3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index f4638e79a022..0fa05ef52dd3 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -70,6 +70,11 @@ struct io_send_zc_msg {
struct io_kiocb *notif;
};

+struct io_recv_msg {
+ struct io_sr_msg sr;
+ int retarget_fd;
+};
+

#define IO_APOLL_MULTI_POLLED (REQ_F_APOLL_MULTISHOT | REQ_F_POLLED)

@@ -547,7 +552,8 @@ int io_recvmsg_prep_async(struct io_kiocb *req)

int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
- struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+ struct io_recv_msg *rcv = io_kiocb_to_cmd(req, struct io_recv_msg);
+ struct io_sr_msg *sr = &rcv->sr;

if (unlikely(sqe->file_index || sqe->addr2))
return -EINVAL;
@@ -572,6 +578,11 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
req->flags |= REQ_F_APOLL_MULTISHOT;
}

+ if (req->flags & REQ_F_FIXED_FILE)
+ rcv->retarget_fd = req->cqe.fd;
+ else
+ rcv->retarget_fd = -1;
+
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
@@ -709,6 +720,15 @@ static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
kmsg->controllen + err;
}

+bool io_recv_can_retarget_rsrc(struct io_kiocb *req)
+{
+ struct io_recv_msg *rcv = io_kiocb_to_cmd(req, struct io_recv_msg);
+
+ if (rcv->retarget_fd < 0)
+ return false;
+ return io_file_peek_fixed(req, rcv->retarget_fd) == req->file;
+}
+
int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
diff --git a/io_uring/net.h b/io_uring/net.h
index 5ffa11bf5d2e..6b5719084494 100644
--- a/io_uring/net.h
+++ b/io_uring/net.h
@@ -43,6 +43,7 @@ int io_recvmsg_prep_async(struct io_kiocb *req);
int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags);
int io_recv(struct io_kiocb *req, unsigned int issue_flags);
+bool io_recv_can_retarget_rsrc(struct io_kiocb *req);

void io_sendrecv_fail(struct io_kiocb *req);

diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 83dc0f9ad3b2..1a0be5681c7b 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -178,6 +178,7 @@ const struct io_op_def io_op_defs[] = {
.prep_async = io_recvmsg_prep_async,
.cleanup = io_sendmsg_recvmsg_cleanup,
.fail = io_sendrecv_fail,
+ .can_retarget_rsrc = io_recv_can_retarget_rsrc,
#else
.prep = io_eopnotsupp_prep,
#endif
@@ -340,6 +341,7 @@ const struct io_op_def io_op_defs[] = {
.prep = io_recvmsg_prep,
.issue = io_recv,
.fail = io_sendrecv_fail,
+ .can_retarget_rsrc = io_recv_can_retarget_rsrc,
#else
.prep = io_eopnotsupp_prep,
#endif
--
2.30.2