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

D. Wythe
2024-05-11T03:02:56Z

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
>>>>