net/smc: Introduce IPPROTO_SMC

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>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index e682ab628dfa66bcbc10f9b4adc08f2a61db377b..d358add1611cd13d034b35d9a19cb3ebcc3e388c 100644 (file)
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -81,6 +81,8 @@ enum {
 #define IPPROTO_ETHERNET       IPPROTO_ETHERNET
   IPPROTO_RAW = 255,           /* Raw IP packets                       */
 #define IPPROTO_RAW            IPPROTO_RAW
+  IPPROTO_SMC = 256,           /* Shared Memory Communications         */
+#define IPPROTO_SMC            IPPROTO_SMC
   IPPROTO_MPTCP = 262,         /* Multipath TCP connection             */
 #define IPPROTO_MPTCP          IPPROTO_MPTCP
   IPPROTO_MAX

diff --git a/net/smc/Makefile b/net/smc/Makefile
index 2c510d5430589851c3c59a2a9031950febf25c38..60f1c87d52126ce85ec83d707417bc4a856b795f 100644 (file)
--- a/net/smc/Makefile
+++ b/net/smc/Makefile
@@ -4,6 +4,6 @@ obj-$(CONFIG_SMC)       += smc.o
 obj-$(CONFIG_SMC_DIAG) += smc_diag.o
 smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o smc_llc.o
 smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o smc_netlink.o smc_stats.o
-smc-y += smc_tracepoint.o
+smc-y += smc_tracepoint.o smc_inet.o
 smc-$(CONFIG_SYSCTL) += smc_sysctl.o
 smc-$(CONFIG_SMC_LO) += smc_loopback.o

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 7ee6f37813d6d7e757adeeca4d1e756c7f864a85..73a875573e7ad5b7a95f7941e33f0d784a91d16d 100644 (file)
--- 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 "smc_inet.h"
 
 static DEFINE_MUTEX(smc_server_lgr_pending);   /* serialize link group
                                                 * creation on server
@@ -3575,10 +3576,15 @@ static int __init smc_init(void)
                pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
                goto out_lo;
        }
-
+       rc = smc_inet_init();
+       if (rc) {
+               pr_err("%s: smc_inet_init fails with %d\n", __func__, rc);
+               goto out_ulp;
+       }
        static_branch_enable(&tcp_have_smc);
        return 0;
-
+out_ulp:
+       tcp_unregister_ulp(&smc_ulp_ops);
 out_lo:
        smc_loopback_exit();
 out_ib:
@@ -3615,6 +3621,7 @@ out_pernet_subsys:
 static void __exit smc_exit(void)
 {
        static_branch_disable(&tcp_have_smc);
+       smc_inet_exit();
        tcp_unregister_ulp(&smc_ulp_ops);
        sock_unregister(PF_SMC);
        smc_core_exit();
@@ -3642,4 +3649,9 @@ MODULE_DESCRIPTION("smc socket address family");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NETPROTO(PF_SMC);
 MODULE_ALIAS_TCP_ULP("smc");
+/* 256 for IPPROTO_SMC and 1 for SOCK_STREAM */
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 256, 1);
+#if IS_ENABLED(CONFIG_IPV6)
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 256, 1);
+#endif /* CONFIG_IPV6 */
 MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);

diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c
new file mode 100644 (file)
index 0000000..bece346
--- /dev/null
+++ b/net/smc/smc_inet.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  Definitions for the IPPROTO_SMC (socket related)
+ *
+ *  Copyright IBM Corp. 2016, 2018
+ *  Copyright (c) 2024, Alibaba Inc.
+ *
+ *  Author: D. Wythe <alibuda@linux.alibaba.com>
+ */
+
+#include <net/protocol.h>
+#include <net/sock.h>
+
+#include "smc_inet.h"
+#include "smc.h"
+
+static int smc_inet_init_sock(struct sock *sk);
+
+static 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,
+};
+
+static 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,
+};
+
+static struct inet_protosw smc_inet_protosw = {
+       .type           = SOCK_STREAM,
+       .protocol       = IPPROTO_SMC,
+       .prot           = &smc_inet_prot,
+       .ops            = &smc_inet_stream_ops,
+       .flags          = INET_PROTOSW_ICSK,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static 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,
+};
+
+static 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,
+};
+
+static 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,
+};
+#endif /* CONFIG_IPV6 */
+
+static int smc_inet_init_sock(struct sock *sk)
+{
+       struct net *net = sock_net(sk);
+
+       /* init common smc sock */
+       smc_sk_init(net, sk, IPPROTO_SMC);
+       /* create clcsock */
+       return smc_create_clcsk(net, sk, sk->sk_family);
+}
+
+int __init smc_inet_init(void)
+{
+       int rc;
+
+       rc = proto_register(&smc_inet_prot, 1);
+       if (rc) {
+               pr_err("%s: proto_register smc_inet_prot fails with %d\n",
+                      __func__, rc);
+               return rc;
+       }
+       /* no return value */
+       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_inet6_prot;
+       }
+       rc = inet6_register_protosw(&smc_inet6_protosw);
+       if (rc) {
+               pr_err("%s: inet6_register_protosw smc_inet6_protosw fails with %d\n",
+                      __func__, rc);
+               goto out_inet6_protosw;
+       }
+       return rc;
+out_inet6_protosw:
+       proto_unregister(&smc_inet6_prot);
+out_inet6_prot:
+       inet_unregister_protosw(&smc_inet_protosw);
+       proto_unregister(&smc_inet_prot);
+#endif /* CONFIG_IPV6 */
+       return rc;
+}
+
+void smc_inet_exit(void)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+       inet6_unregister_protosw(&smc_inet6_protosw);
+       proto_unregister(&smc_inet6_prot);
+#endif /* CONFIG_IPV6 */
+       inet_unregister_protosw(&smc_inet_protosw);
+       proto_unregister(&smc_inet_prot);
+}

diff --git a/net/smc/smc_inet.h b/net/smc/smc_inet.h
new file mode 100644 (file)
index 0000000..a489c8a
--- /dev/null
+++ b/net/smc/smc_inet.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  Definitions for the IPPROTO_SMC (socket related)
+
+ *  Copyright IBM Corp. 2016
+ *  Copyright (c) 2024, Alibaba Inc.
+ *
+ *  Author: D. Wythe <alibuda@linux.alibaba.com>
+ */
+#ifndef __INET_SMC
+#define __INET_SMC
+
+/* Initialize protocol registration on IPPROTO_SMC,
+ * @return 0 on success
+ */
+int smc_inet_init(void);
+
+void smc_inet_exit(void);
+
+#endif /* __INET_SMC */