Re: [PATCH net-next 2/2] net/smc: Introduce IPPROTO_SMC

[Dust Li <dust.li@linux.alibaba.com>]

On 2024-05-10 12:12:13, D. Wythe wrote:
>From: "D. Wythe" <alibuda@linux.alibaba.com>
>
>This patch allows to create smc socket via AF_INET,
>similar to the following code,
>
>/* create v4 smc sock */
>v4 = socket(AF_INET, SOCK_STREAM, IPPROTO_SMC);
>
>/* create v6 smc sock */
>v6 = socket(AF_INET6, SOCK_STREAM, IPPROTO_SMC);
>
>There are several reasons why we believe it is appropriate here:
>
>1. For smc sockets, it actually use IPv4 (AF-INET) or IPv6 (AF-INET6)
>address. There is no AF_SMC address at all.
>
>2. Create smc socket in the AF_INET(6) path, which allows us to reuse
>the infrastructure of AF_INET(6) path, such as common ebpf hooks.
>Otherwise, smc have to implement it again in AF_SMC path.
>
>Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>---
> include/uapi/linux/in.h |   2 +
> net/smc/af_smc.c        | 129 +++++++++++++++++++++++++++++++++++++++++++++++-
> net/smc/inet_smc.h      |  32 ++++++++++++
> 3 files changed, 162 insertions(+), 1 deletion(-)
> create mode 100644 net/smc/inet_smc.h
>
>diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
>index e682ab6..74c12e33 100644
>--- a/include/uapi/linux/in.h
>+++ b/include/uapi/linux/in.h
>@@ -83,6 +83,8 @@ enum {
> #define IPPROTO_RAW		IPPROTO_RAW
>   IPPROTO_MPTCP = 262,		/* Multipath TCP connection		*/
> #define IPPROTO_MPTCP		IPPROTO_MPTCP
>+  IPPROTO_SMC = 263,		/* Shared Memory Communications */
                                                           ^ use tab to align here
>+#define IPPROTO_SMC		IPPROTO_SMC
>   IPPROTO_MAX
> };
> #endif
>diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>index 1f03724..b4557828 100644
>--- a/net/smc/af_smc.c
>+++ b/net/smc/af_smc.c
>@@ -54,6 +54,7 @@
> #include "smc_tracepoint.h"
> #include "smc_sysctl.h"
> #include "smc_loopback.h"
>+#include "inet_smc.h"
> 
> static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
> 						 * creation on server
>@@ -3402,6 +3403,16 @@ static int smc_create(struct net *net, struct socket *sock, int protocol,
> 	.create	= smc_create,
> };
> 

Why not put those whole bunch of inet staff into smc_inet.c ?
Looks like your smc_inet.h is meanless without smc_inet.c

>+int smc_inet_init_sock(struct sock *sk)
>+{
>+	struct net *net = sock_net(sk);
>+
>+	/* init common smc sock */
>+	smc_sock_init(net, sk, IPPROTO_SMC);
>+	/* create clcsock */
>+	return __smc_create_clcsk(net, sk, sk->sk_family);
>+}
>+
> static int smc_ulp_init(struct sock *sk)
> {
> 	struct socket *tcp = sk->sk_socket;
>@@ -3460,6 +3471,90 @@ static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
> 	.clone		= smc_ulp_clone,
> };
> 
>+struct proto smc_inet_prot = {
>+	.name			= "INET_SMC",
>+	.owner			= THIS_MODULE,
>+	.init			= smc_inet_init_sock,
>+	.hash			= smc_hash_sk,
>+	.unhash			= smc_unhash_sk,
>+	.release_cb		= smc_release_cb,
>+	.obj_size		= sizeof(struct smc_sock),
>+	.h.smc_hash	= &smc_v4_hashinfo,
>+	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
                ^
Align please.


>+};
>+
>+const struct proto_ops smc_inet_stream_ops = {
>+	.family		= PF_INET,
>+	.owner		= THIS_MODULE,
>+	.release	= smc_release,
>+	.bind		= smc_bind,
>+	.connect	= smc_connect,
>+	.socketpair	= sock_no_socketpair,
>+	.accept		= smc_accept,
>+	.getname	= smc_getname,
>+	.poll		= smc_poll,
>+	.ioctl		= smc_ioctl,
>+	.listen		= smc_listen,
>+	.shutdown	= smc_shutdown,
>+	.setsockopt	= smc_setsockopt,
>+	.getsockopt	= smc_getsockopt,
>+	.sendmsg	= smc_sendmsg,
>+	.recvmsg	= smc_recvmsg,
>+	.mmap		= sock_no_mmap,
>+	.splice_read	= smc_splice_read,

Ditto

>+};
>+
>+struct inet_protosw smc_inet_protosw = {
>+	.type       = SOCK_STREAM,
>+	.protocol   = IPPROTO_SMC,
>+	.prot   = &smc_inet_prot,
Ditto

>+	.ops    = &smc_inet_stream_ops,
>+	.flags  = INET_PROTOSW_ICSK,
>+};
>+
>+#if IS_ENABLED(CONFIG_IPV6)
>+struct proto smc_inet6_prot = {
>+	.name			= "INET6_SMC",
>+	.owner			= THIS_MODULE,
>+	.init			= smc_inet_init_sock,
>+	.hash			= smc_hash_sk,
>+	.unhash			= smc_unhash_sk,
>+	.release_cb		= smc_release_cb,
>+	.obj_size		= sizeof(struct smc_sock),
>+	.h.smc_hash		= &smc_v6_hashinfo,
>+	.slab_flags		= SLAB_TYPESAFE_BY_RCU,
>+};
>+
>+const struct proto_ops smc_inet6_stream_ops = {
>+	.family		= PF_INET6,
>+	.owner		= THIS_MODULE,
>+	.release	= smc_release,
>+	.bind		= smc_bind,
>+	.connect	= smc_connect,
>+	.socketpair	= sock_no_socketpair,
>+	.accept		= smc_accept,
>+	.getname	= smc_getname,
>+	.poll		= smc_poll,
>+	.ioctl		= smc_ioctl,
>+	.listen		= smc_listen,
>+	.shutdown	= smc_shutdown,
>+	.setsockopt	= smc_setsockopt,
>+	.getsockopt	= smc_getsockopt,
>+	.sendmsg	= smc_sendmsg,
>+	.recvmsg	= smc_recvmsg,
>+	.mmap		= sock_no_mmap,
>+	.splice_read	= smc_splice_read,
Ditto

>+};
>+
>+struct inet_protosw smc_inet6_protosw = {
>+	.type       = SOCK_STREAM,
>+	.protocol   = IPPROTO_SMC,
>+	.prot   = &smc_inet6_prot,
>+	.ops    = &smc_inet6_stream_ops,
>+	.flags  = INET_PROTOSW_ICSK,
Ditto

>+};
>+#endif
>+
> unsigned int smc_net_id;
> 
> static __net_init int smc_net_init(struct net *net)
>@@ -3595,9 +3690,28 @@ static int __init smc_init(void)
> 		goto out_lo;
> 	}
> 
>+	rc = proto_register(&smc_inet_prot, 1);
>+	if (rc) {
>+		pr_err("%s: proto_register smc_inet_prot fails with %d\n", __func__, rc);
>+		goto out_ulp;
>+	}
>+	inet_register_protosw(&smc_inet_protosw);
>+#if IS_ENABLED(CONFIG_IPV6)
>+	rc = proto_register(&smc_inet6_prot, 1);
>+	if (rc) {
>+		pr_err("%s: proto_register smc_inet6_prot fails with %d\n", __func__, rc);
>+		goto out_inet_prot;
>+	}
>+	inet6_register_protosw(&smc_inet6_protosw);
>+#endif
>+
> 	static_branch_enable(&tcp_have_smc);
> 	return 0;
>-
>+out_inet_prot:
>+	inet_unregister_protosw(&smc_inet_protosw);
>+	proto_unregister(&smc_inet_prot);
>+out_ulp:
>+	tcp_unregister_ulp(&smc_ulp_ops);
> out_lo:
> 	smc_loopback_exit();
> out_ib:
>@@ -3634,6 +3748,10 @@ static int __init smc_init(void)
> static void __exit smc_exit(void)
> {
> 	static_branch_disable(&tcp_have_smc);
>+	inet_unregister_protosw(&smc_inet_protosw);
>+#if IS_ENABLED(CONFIG_IPV6)
>+	inet6_unregister_protosw(&smc_inet6_protosw);
>+#endif
> 	tcp_unregister_ulp(&smc_ulp_ops);
> 	sock_unregister(PF_SMC);
> 	smc_core_exit();
>@@ -3645,6 +3763,10 @@ static void __exit smc_exit(void)
> 	destroy_workqueue(smc_hs_wq);
> 	proto_unregister(&smc_proto6);
> 	proto_unregister(&smc_proto);
>+	proto_unregister(&smc_inet_prot);
>+#if IS_ENABLED(CONFIG_IPV6)
>+	proto_unregister(&smc_inet6_prot);
>+#endif
> 	smc_pnet_exit();
> 	smc_nl_exit();
> 	smc_clc_exit();
>@@ -3661,4 +3783,9 @@ static void __exit smc_exit(void)
> MODULE_LICENSE("GPL");
> MODULE_ALIAS_NETPROTO(PF_SMC);
> MODULE_ALIAS_TCP_ULP("smc");
>+/* 263 for IPPROTO_SMC and 1 for SOCK_STREAM */
>+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 263, 1);
>+#if IS_ENABLED(CONFIG_IPV6)
>+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 263, 1);
>+#endif
> MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);
>diff --git a/net/smc/inet_smc.h b/net/smc/inet_smc.h
>new file mode 100644
>index 00000000..fcdcb61
>--- /dev/null
>+++ b/net/smc/inet_smc.h
>@@ -0,0 +1,32 @@
>+/* SPDX-License-Identifier: GPL-2.0 */
>+/*
>+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
>+ *
>+ *  Definitions for the SMC module (socket related)
>+
>+ *  Copyright IBM Corp. 2016

You should update this.

>+ *
>+ */
>+#ifndef __INET_SMC
>+#define __INET_SMC
>+
>+#include <net/protocol.h>
>+#include <net/sock.h>
>+#include <net/tcp.h>
>+
>+extern struct proto smc_inet_prot;
>+extern const struct proto_ops smc_inet_stream_ops;
>+extern struct inet_protosw smc_inet_protosw;
>+
>+#if IS_ENABLED(CONFIG_IPV6)
>+#include <net/ipv6.h>
>+/* MUST after net/tcp.h or warning */
>+#include <net/transp_v6.h>
>+extern struct proto smc_inet6_prot;
>+extern const struct proto_ops smc_inet6_stream_ops;
>+extern struct inet_protosw smc_inet6_protosw;
>+#endif
>+
>+int smc_inet_init_sock(struct sock *sk);
>+
>+#endif // __INET_SMC
         ^
         use /* __INET_SMC */ instead

>-- 
>1.8.3.1
>