[RFC PATCH 2/4] net: add uring_cmd callback to UDP

Breno Leitao
2023-04-06T14:46:13Z

This is the implementation of uring_cmd for the udp protocol. It
basically encompasses SOCKET_URING_OP_SIOCOUTQ and
SOCKET_URING_OP_SIOCINQ, which is similar to the SIOCOUTQ and SIOCINQ
ioctls.

The return value is exactly the same as the regular ioctl (udp_ioctl()).

Signed-off-by: Breno Leitao <leitao@debian.org>
---
include/net/udp.h | 2 ++
include/uapi/linux/net.h | 5 +++++
net/ipv4/udp.c | 16 ++++++++++++++++
3 files changed, 23 insertions(+)

diff --git a/include/net/udp.h b/include/net/udp.h
index de4b528522bb..c0e829dacc2f 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -283,6 +283,8 @@ void udp_flush_pending_frames(struct sock *sk);
int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size);
void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
int udp_rcv(struct sk_buff *skb);
+int udp_uring_cmd(struct sock *sk, struct io_uring_cmd *cmd,
+ unsigned int issue_flags);
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
int udp_init_sock(struct sock *sk);
int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
diff --git a/include/uapi/linux/net.h b/include/uapi/linux/net.h
index 4dabec6bd957..dd8e7ced7d24 100644
--- a/include/uapi/linux/net.h
+++ b/include/uapi/linux/net.h
@@ -55,4 +55,9 @@ typedef enum {

#define __SO_ACCEPTCON (1 << 16) /* performed a listen */

+enum {
+ SOCKET_URING_OP_SIOCINQ = 0,
+ SOCKET_URING_OP_SIOCOUTQ,
+};
+
#endif /* _UAPI_LINUX_NET_H */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c605d171eb2d..d6d60600831b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -113,6 +113,7 @@
#include <net/sock_reuseport.h>
#include <net/addrconf.h>
#include <net/udp_tunnel.h>
+#include <linux/io_uring.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6_stubs.h>
#endif
@@ -1711,6 +1712,20 @@ static int first_packet_length(struct sock *sk)
return res;
}

+int udp_uring_cmd(struct sock *sk, struct io_uring_cmd *cmd,
+ unsigned int issue_flags)
+{
+ switch (cmd->sqe->cmd_op) {
+ case SOCKET_URING_OP_SIOCOUTQ:
+ return sk_wmem_alloc_get(sk);
+ case SOCKET_URING_OP_SIOCINQ:
+ return max_t(int, 0, first_packet_length(sk));
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+EXPORT_SYMBOL_GPL(udp_uring_cmd);
+
/*
* IOCTL requests applicable to the UDP protocol
*/
@@ -2952,6 +2967,7 @@ struct proto udp_prot = {
.connect = ip4_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
+ .uring_cmd = udp_uring_cmd,
.init = udp_init_sock,
.destroy = udp_destroy_sock,
.setsockopt = udp_setsockopt,
--
2.34.1