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

["D. Wythe" <alibuda@linux.alibaba.com>]

On 5/11/24 10:46 AM, Dust Li wrote:
> On 2024-05-11 10:23:31, D. Wythe wrote:
>>
>> On 5/10/24 5:57 PM, Dust Li wrote:
>>> 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
>> There is a problem here, all previous definitions were aligned with 2 spaces.
> I mean the tab in the annotation in the end, not the space at the beginning.

Oh... that's true.  Thanks for that.

>>>> +#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
>>>
>> This header file was originally reserved for future merging of socks. If
>> nobody likes it, I can move it to the
>> af_smc.c
> I prefer adding a new smc_inet.c, af_smc.c is already very large.
>
> Best regards,
> Dust

Sounds Reasonable. I'll try it in next version.

Thanks,
D. Wythe
>
>>>> +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.
>>>
>> Got it.
>>>> +};
>>>> +
>>>> +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.
>> Got it.
>>>> + *
>>>> + */
>>>> +#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
>>>>