From: "D. Wythe" <alibuda@xxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxx>
Reviewed-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>
Reviewed-by: Dust Li <dust.li@xxxxxxxxxxxxxxxxx>
Tested-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Tested-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>
---
include/uapi/linux/in.h | 2 +
net/smc/Makefile | 2 +-
net/smc/af_smc.c | 16 ++++-
net/smc/smc_inet.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++
net/smc/smc_inet.h | 22 +++++++
5 files changed, 198 insertions(+), 3 deletions(-)
create mode 100644 net/smc/smc_inet.c
create mode 100644 net/smc/smc_inet.h
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index e682ab6..d358add 100644
--- 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 2c510d54..60f1c87 100644
--- 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 8e3ce76..435f38b 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 "smc_inet.h"
static DEFINE_MUTEX(smc_server_lgr_pending); /* serialize link group
* creation on server
@@ -3593,10 +3594,15 @@ 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:
@@ -3633,6 +3639,7 @@ static int __init smc_init(void)
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();
@@ -3660,4 +3667,9 @@ static void __exit smc_exit(void)
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
index 00000000..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@xxxxxxxxxxxxxxxxx>
+ */
+
+#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,
