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

Dust Li
2024-05-10T09:57:21Z

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
>