diff mbox series

[1/8] io_uring/net: unify how recvmsg and sendmsg copy in the msghdr

Message ID 20240225003941.129030-2-axboe@kernel.dk (mailing list archive)
State New
Headers show
Series Support for provided buffers for send | expand

Commit Message

Jens Axboe Feb. 25, 2024, 12:35 a.m. UTC 
For recvmsg, we roll our own since we support buffer selections. This
isn't the case for sendmsg right now, but in preparation for doing so,
make the recvmsg copy helpers generic so we can call them from the
sendmsg side as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/net.c | 275 +++++++++++++++++++++++++------------------------
 1 file changed, 140 insertions(+), 135 deletions(-)

Comments

Pavel Begunkov Feb. 26, 2024, 2:41 p.m. UTC | #1 
On 2/25/24 00:35, Jens Axboe wrote:
> For recvmsg, we roll our own since we support buffer selections. This
> isn't the case for sendmsg right now, but in preparation for doing so,
> make the recvmsg copy helpers generic so we can call them from the
> sendmsg side as well.

I thought about it before, definitely like the idea, I think
patches 1-2 can probably get merged first.
Jens Axboe Feb. 26, 2024, 3:03 p.m. UTC | #2 
On 2/26/24 7:41 AM, Pavel Begunkov wrote:
> On 2/25/24 00:35, Jens Axboe wrote:
>> For recvmsg, we roll our own since we support buffer selections. This
>> isn't the case for sendmsg right now, but in preparation for doing so,
>> make the recvmsg copy helpers generic so we can call them from the
>> sendmsg side as well.
> 
> I thought about it before, definitely like the idea, I think
> patches 1-2 can probably get merged first.

Yep, I'll queue 1 right now, and then just send patch 2 to netdev once
patch 1 lands upstream. There's no rush on patch 2, half of it could
have gone in months ago in fact.
diff mbox series

Patch

diff --git a/io_uring/net.c b/io_uring/net.c
index 161622029147..fcbaeb7cc045 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -204,16 +204,148 @@  static int io_setup_async_msg(struct io_kiocb *req,
 	return -EAGAIN;
 }
 
+static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
+{
+	int hdr;
+
+	if (iomsg->namelen < 0)
+		return true;
+	if (check_add_overflow((int)sizeof(struct io_uring_recvmsg_out),
+			       iomsg->namelen, &hdr))
+		return true;
+	if (check_add_overflow(hdr, (int)iomsg->controllen, &hdr))
+		return true;
+
+	return false;
+}
+
+#ifdef CONFIG_COMPAT
+static int __io_compat_msg_copy_hdr(struct io_kiocb *req,
+				    struct io_async_msghdr *iomsg,
+				    struct sockaddr __user **addr, int ddir)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct compat_msghdr msg;
+	struct compat_iovec __user *uiov;
+	int ret;
+
+	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
+		return -EFAULT;
+
+	ret = __get_compat_msghdr(&iomsg->msg, &msg, addr);
+	if (ret)
+		return ret;
+
+	uiov = compat_ptr(msg.msg_iov);
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		compat_ssize_t clen;
+
+		iomsg->free_iov = NULL;
+		if (msg.msg_iovlen == 0) {
+			sr->len = 0;
+		} else if (msg.msg_iovlen > 1) {
+			return -EINVAL;
+		} else {
+			if (!access_ok(uiov, sizeof(*uiov)))
+				return -EFAULT;
+			if (__get_user(clen, &uiov->iov_len))
+				return -EFAULT;
+			if (clen < 0)
+				return -EINVAL;
+			sr->len = clen;
+		}
+
+		if (ddir == ITER_DEST && req->flags & REQ_F_APOLL_MULTISHOT) {
+			iomsg->namelen = msg.msg_namelen;
+			iomsg->controllen = msg.msg_controllen;
+			if (io_recvmsg_multishot_overflow(iomsg))
+				return -EOVERFLOW;
+		}
+	} else {
+		iomsg->free_iov = iomsg->fast_iov;
+		ret = __import_iovec(ddir, (struct iovec __user *)uiov,
+				     msg.msg_iovlen, UIO_FASTIOV,
+				     &iomsg->free_iov, &iomsg->msg.msg_iter,
+				     true);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static int __io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
+			     struct sockaddr __user **addr, int ddir)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct user_msghdr msg;
+	int ret;
+
+	if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
+		return -EFAULT;
+
+	ret = __copy_msghdr(&iomsg->msg, &msg, addr);
+	if (ret)
+		return ret;
+
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		if (msg.msg_iovlen == 0) {
+			sr->len = iomsg->fast_iov[0].iov_len = 0;
+			iomsg->fast_iov[0].iov_base = NULL;
+			iomsg->free_iov = NULL;
+		} else if (msg.msg_iovlen > 1) {
+			return -EINVAL;
+		} else {
+			if (copy_from_user(iomsg->fast_iov, msg.msg_iov,
+					   sizeof(*msg.msg_iov)))
+				return -EFAULT;
+			sr->len = iomsg->fast_iov[0].iov_len;
+			iomsg->free_iov = NULL;
+		}
+
+		if (ddir == ITER_DEST && req->flags & REQ_F_APOLL_MULTISHOT) {
+			iomsg->namelen = msg.msg_namelen;
+			iomsg->controllen = msg.msg_controllen;
+			if (io_recvmsg_multishot_overflow(iomsg))
+				return -EOVERFLOW;
+		}
+	} else {
+		iomsg->free_iov = iomsg->fast_iov;
+		ret = __import_iovec(ddir, msg.msg_iov, msg.msg_iovlen,
+				     UIO_FASTIOV, &iomsg->free_iov,
+				     &iomsg->msg.msg_iter, false);
+		if (ret > 0)
+			ret = 0;
+	}
+
+	return ret;
+}
+
+static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
+			   struct sockaddr __user **addr, int ddir)
+{
+	iomsg->msg.msg_name = &iomsg->addr;
+	iomsg->msg.msg_iter.nr_segs = 0;
+
+#ifdef CONFIG_COMPAT
+	if (req->ctx->compat)
+		return __io_compat_msg_copy_hdr(req, iomsg, addr, ddir);
+#endif
+
+	return __io_msg_copy_hdr(req, iomsg, addr, ddir);
+}
+
 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
 			       struct io_async_msghdr *iomsg)
 {
 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 	int ret;
 
-	iomsg->msg.msg_name = &iomsg->addr;
-	iomsg->free_iov = iomsg->fast_iov;
-	ret = sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags,
-					&iomsg->free_iov);
+	ret = io_msg_copy_hdr(req, iomsg, NULL, ITER_SOURCE);
+	if (ret)
+		return ret;
+
 	/* save msg_control as sys_sendmsg() overwrites it */
 	sr->msg_control = iomsg->msg.msg_control_user;
 	return ret;
@@ -435,142 +567,15 @@  int io_send(struct io_kiocb *req, unsigned int issue_flags)
 	return IOU_OK;
 }
 
-static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
-{
-	int hdr;
-
-	if (iomsg->namelen < 0)
-		return true;
-	if (check_add_overflow((int)sizeof(struct io_uring_recvmsg_out),
-			       iomsg->namelen, &hdr))
-		return true;
-	if (check_add_overflow(hdr, (int)iomsg->controllen, &hdr))
-		return true;
-
-	return false;
-}
-
-static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
-				 struct io_async_msghdr *iomsg)
-{
-	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
-	struct user_msghdr msg;
-	int ret;
-
-	if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
-		return -EFAULT;
-
-	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
-	if (ret)
-		return ret;
-
-	if (req->flags & REQ_F_BUFFER_SELECT) {
-		if (msg.msg_iovlen == 0) {
-			sr->len = iomsg->fast_iov[0].iov_len = 0;
-			iomsg->fast_iov[0].iov_base = NULL;
-			iomsg->free_iov = NULL;
-		} else if (msg.msg_iovlen > 1) {
-			return -EINVAL;
-		} else {
-			if (copy_from_user(iomsg->fast_iov, msg.msg_iov, sizeof(*msg.msg_iov)))
-				return -EFAULT;
-			sr->len = iomsg->fast_iov[0].iov_len;
-			iomsg->free_iov = NULL;
-		}
-
-		if (req->flags & REQ_F_APOLL_MULTISHOT) {
-			iomsg->namelen = msg.msg_namelen;
-			iomsg->controllen = msg.msg_controllen;
-			if (io_recvmsg_multishot_overflow(iomsg))
-				return -EOVERFLOW;
-		}
-	} else {
-		iomsg->free_iov = iomsg->fast_iov;
-		ret = __import_iovec(ITER_DEST, msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV,
-				     &iomsg->free_iov, &iomsg->msg.msg_iter,
-				     false);
-		if (ret > 0)
-			ret = 0;
-	}
-
-	return ret;
-}
-
-#ifdef CONFIG_COMPAT
-static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
-					struct io_async_msghdr *iomsg)
-{
-	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
-	struct compat_msghdr msg;
-	struct compat_iovec __user *uiov;
-	int ret;
-
-	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
-		return -EFAULT;
-
-	ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
-	if (ret)
-		return ret;
-
-	uiov = compat_ptr(msg.msg_iov);
-	if (req->flags & REQ_F_BUFFER_SELECT) {
-		compat_ssize_t clen;
-
-		iomsg->free_iov = NULL;
-		if (msg.msg_iovlen == 0) {
-			sr->len = 0;
-		} else if (msg.msg_iovlen > 1) {
-			return -EINVAL;
-		} else {
-			if (!access_ok(uiov, sizeof(*uiov)))
-				return -EFAULT;
-			if (__get_user(clen, &uiov->iov_len))
-				return -EFAULT;
-			if (clen < 0)
-				return -EINVAL;
-			sr->len = clen;
-		}
-
-		if (req->flags & REQ_F_APOLL_MULTISHOT) {
-			iomsg->namelen = msg.msg_namelen;
-			iomsg->controllen = msg.msg_controllen;
-			if (io_recvmsg_multishot_overflow(iomsg))
-				return -EOVERFLOW;
-		}
-	} else {
-		iomsg->free_iov = iomsg->fast_iov;
-		ret = __import_iovec(ITER_DEST, (struct iovec __user *)uiov, msg.msg_iovlen,
-				   UIO_FASTIOV, &iomsg->free_iov,
-				   &iomsg->msg.msg_iter, true);
-		if (ret < 0)
-			return ret;
-	}
-
-	return 0;
-}
-#endif
-
-static int io_recvmsg_copy_hdr(struct io_kiocb *req,
-			       struct io_async_msghdr *iomsg)
-{
-	iomsg->msg.msg_name = &iomsg->addr;
-	iomsg->msg.msg_iter.nr_segs = 0;
-
-#ifdef CONFIG_COMPAT
-	if (req->ctx->compat)
-		return __io_compat_recvmsg_copy_hdr(req, iomsg);
-#endif
-
-	return __io_recvmsg_copy_hdr(req, iomsg);
-}
-
 int io_recvmsg_prep_async(struct io_kiocb *req)
 {
+	struct io_async_msghdr *iomsg;
 	int ret;
 
 	if (!io_msg_alloc_async_prep(req))
 		return -ENOMEM;
-	ret = io_recvmsg_copy_hdr(req, req->async_data);
+	iomsg = req->async_data;
+	ret = io_msg_copy_hdr(req, iomsg, &iomsg->uaddr, ITER_DEST);
 	if (!ret)
 		req->flags |= REQ_F_NEED_CLEANUP;
 	return ret;
@@ -793,7 +798,7 @@  int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 	if (req_has_async_data(req)) {
 		kmsg = req->async_data;
 	} else {
-		ret = io_recvmsg_copy_hdr(req, &iomsg);
+		ret = io_msg_copy_hdr(req, &iomsg, &iomsg.uaddr, ITER_DEST);
 		if (ret)
 			return ret;
 		kmsg = &iomsg;