[PATCH net-next v2 0/3] Introduce IPPROTO_SMC

[PATCH net-next v2 0/3] Introduce IPPROTO_SMC

[D. Wythe]

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. Such as:
  1. Replace IPPROTO_TCP with IPPROTO_SMC in the socket() syscall
     initiated by the user, without the use of LD-PRELOAD.
  2. Select whether immediate fallback is required based on peer's port/ip
     before connect().

A very significant result is that we can now use eBPF to implement smc_run
instead of LD_PRELOAD, who is completely ineffective in scenarios of static
linking.

Another potential value is that we are attempting to optimize the performance of
fallback socks, where merging socks is an important part, and it relies on the
creation of SMC sockets under the AF_INET path. (More information :
https://lore.kernel.org/netdev/1699442703-25015-1-git-send-email-alibuda@linux.alibaba.com/T/)

v1 -> v2 :

- Code formatting, mainly including alignment and annotation repair.
- move inet_smc proto ops to inet_smc.c, avoiding af_smc.c becoming too bulky.
- Fix the issue where refactoring affects the initialization order.
- Fix compile warning (unused out_inet_prot) while CONFIG_IPV6 was not set.

D. Wythe (3):
  net/smc: refatoring initialization of smc sock
  net/smc: expose smc proto operations
  net/smc: Introduce IPPROTO_SMC

 include/uapi/linux/in.h |   2 +
 net/smc/Makefile        |   2 +-
 net/smc/af_smc.c        | 183 ++++++++++++++++++++++++++++++------------------
 net/smc/inet_smc.c      | 107 ++++++++++++++++++++++++++++
 net/smc/inet_smc.h      |  32 +++++++++
 net/smc/smc.h           |  38 ++++++++++
 6 files changed, 294 insertions(+), 70 deletions(-)
 create mode 100644 net/smc/inet_smc.c
 create mode 100644 net/smc/inet_smc.h

-- 
1.8.3.1

[PATCH net-next v2 1/3] net/smc: refatoring initialization of smc sock

[D. Wythe]

From: "D. Wythe" <alibuda@linux.alibaba.com>

This patch aims to isolate the shared components of SMC socket
allocation by introducing smc_sock_init() for sock initialization
and __smc_create_clcsk() for the initialization of clcsock.

This is in preparation for the subsequent implementation of the
AF_INET version of SMC.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
---
 net/smc/af_smc.c | 86 +++++++++++++++++++++++++++++++-------------------------
 net/smc/smc.h    |  5 ++++
 2 files changed, 53 insertions(+), 38 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 9389f0c..d8c116e 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -361,25 +361,15 @@ static void smc_destruct(struct sock *sk)
 		return;
 }
 
-static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
-				   int protocol)
+void smc_sock_init(struct net *net, struct sock *sk, int protocol)
 {
-	struct smc_sock *smc;
-	struct proto *prot;
-	struct sock *sk;
-
-	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
-	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
-	if (!sk)
-		return NULL;
+	struct smc_sock *smc = smc_sk(sk);
 
-	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
 	sk->sk_state = SMC_INIT;
 	sk->sk_destruct = smc_destruct;
 	sk->sk_protocol = protocol;
 	WRITE_ONCE(sk->sk_sndbuf, 2 * READ_ONCE(net->smc.sysctl_wmem));
 	WRITE_ONCE(sk->sk_rcvbuf, 2 * READ_ONCE(net->smc.sysctl_rmem));
-	smc = smc_sk(sk);
 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 	INIT_WORK(&smc->connect_work, smc_connect_work);
 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
@@ -389,6 +379,24 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
 	sk->sk_prot->hash(sk);
 	mutex_init(&smc->clcsock_release_lock);
 	smc_init_saved_callbacks(smc);
+	smc->limit_smc_hs = net->smc.limit_smc_hs;
+	smc->use_fallback = false; /* assume rdma capability first */
+	smc->fallback_rsn = 0;
+}
+
+static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
+				   int protocol)
+{
+	struct proto *prot;
+	struct sock *sk;
+
+	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
+	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
+	if (!sk)
+		return NULL;
+
+	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
+	smc_sock_init(net, sk, protocol);
 
 	return sk;
 }
@@ -3321,6 +3329,31 @@ static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
 	.splice_read	= smc_splice_read,
 };
 
+int smc_create_clcsk(struct net *net, struct sock *sk, int family)
+{
+	struct smc_sock *smc = smc_sk(sk);
+	int rc;
+
+	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
+			      &smc->clcsock);
+	if (rc) {
+		sk_common_release(sk);
+		return rc;
+	}
+
+	/* smc_clcsock_release() does not wait smc->clcsock->sk's
+	 * destruction;  its sk_state might not be TCP_CLOSE after
+	 * smc->sk is close()d, and TCP timers can be fired later,
+	 * which need net ref.
+	 */
+	sk = smc->clcsock->sk;
+	__netns_tracker_free(net, &sk->ns_tracker, false);
+	sk->sk_net_refcnt = 1;
+	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
+	sock_inuse_add(net, 1);
+	return 0;
+}
+
 static int __smc_create(struct net *net, struct socket *sock, int protocol,
 			int kern, struct socket *clcsock)
 {
@@ -3346,35 +3379,12 @@ static int __smc_create(struct net *net, struct socket *sock, int protocol,
 
 	/* create internal TCP socket for CLC handshake and fallback */
 	smc = smc_sk(sk);
-	smc->use_fallback = false; /* assume rdma capability first */
-	smc->fallback_rsn = 0;
-
-	/* default behavior from limit_smc_hs in every net namespace */
-	smc->limit_smc_hs = net->smc.limit_smc_hs;
 
 	rc = 0;
-	if (!clcsock) {
-		rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
-				      &smc->clcsock);
-		if (rc) {
-			sk_common_release(sk);
-			goto out;
-		}
-
-		/* smc_clcsock_release() does not wait smc->clcsock->sk's
-		 * destruction;  its sk_state might not be TCP_CLOSE after
-		 * smc->sk is close()d, and TCP timers can be fired later,
-		 * which need net ref.
-		 */
-		sk = smc->clcsock->sk;
-		__netns_tracker_free(net, &sk->ns_tracker, false);
-		sk->sk_net_refcnt = 1;
-		get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
-		sock_inuse_add(net, 1);
-	} else {
+	if (!clcsock)
+		rc = smc_create_clcsk(net, sk, family);
+	else
 		smc->clcsock = clcsock;
-	}
-
 out:
 	return rc;
 }
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 18c8b78..a0accb5 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -34,6 +34,11 @@
 extern struct proto smc_proto;
 extern struct proto smc_proto6;
 
+/* smc sock initialization */
+void smc_sock_init(struct net *net, struct sock *sk, int protocol);
+/* clcsock initialization */
+int smc_create_clcsk(struct net *net, struct sock *sk, int family);
+
 #ifdef ATOMIC64_INIT
 #define KERNEL_HAS_ATOMIC64
 #endif
-- 
1.8.3.1

[PATCH net-next v2 2/3] net/smc: expose smc proto operations

[D. Wythe]

From: "D. Wythe" <alibuda@linux.alibaba.com>

Externalize smc proto operations (smc_xxx) to allow
access from files other that af_smc.c

This is in preparation for the subsequent implementation
of the AF_INET version of SMC.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
---
 net/smc/af_smc.c | 60 ++++++++++++++++++++++++++++----------------------------
 net/smc/smc.h    | 33 +++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 30 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index d8c116e..5b7a194 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -170,15 +170,15 @@ static bool smc_hs_congested(const struct sock *sk)
 	return false;
 }
 
-static struct smc_hashinfo smc_v4_hashinfo = {
+struct smc_hashinfo smc_v4_hashinfo = {
 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
 };
 
-static struct smc_hashinfo smc_v6_hashinfo = {
+struct smc_hashinfo smc_v6_hashinfo = {
 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
 };
 
-static int smc_hash_sk(struct sock *sk)
+int smc_hash_sk(struct sock *sk)
 {
 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
 	struct hlist_head *head;
@@ -193,7 +193,7 @@ static int smc_hash_sk(struct sock *sk)
 	return 0;
 }
 
-static void smc_unhash_sk(struct sock *sk)
+void smc_unhash_sk(struct sock *sk)
 {
 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
 
@@ -207,7 +207,7 @@ static void smc_unhash_sk(struct sock *sk)
  * work which we didn't do because of user hold the sock_lock in the
  * BH context
  */
-static void smc_release_cb(struct sock *sk)
+void smc_release_cb(struct sock *sk)
 {
 	struct smc_sock *smc = smc_sk(sk);
 
@@ -307,7 +307,7 @@ static int __smc_release(struct smc_sock *smc)
 	return rc;
 }
 
-static int smc_release(struct socket *sock)
+int smc_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -401,8 +401,8 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
 	return sk;
 }
 
-static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
-		    int addr_len)
+int smc_bind(struct socket *sock, struct sockaddr *uaddr,
+	     int addr_len)
 {
 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 	struct sock *sk = sock->sk;
@@ -1649,8 +1649,8 @@ static void smc_connect_work(struct work_struct *work)
 	release_sock(&smc->sk);
 }
 
-static int smc_connect(struct socket *sock, struct sockaddr *addr,
-		       int alen, int flags)
+int smc_connect(struct socket *sock, struct sockaddr *addr,
+		int alen, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -2631,7 +2631,7 @@ static void smc_clcsock_data_ready(struct sock *listen_clcsock)
 	read_unlock_bh(&listen_clcsock->sk_callback_lock);
 }
 
-static int smc_listen(struct socket *sock, int backlog)
+int smc_listen(struct socket *sock, int backlog)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -2696,8 +2696,8 @@ static int smc_listen(struct socket *sock, int backlog)
 	return rc;
 }
 
-static int smc_accept(struct socket *sock, struct socket *new_sock,
-		      int flags, bool kern)
+int smc_accept(struct socket *sock, struct socket *new_sock,
+	       int flags, bool kern)
 {
 	struct sock *sk = sock->sk, *nsk;
 	DECLARE_WAITQUEUE(wait, current);
@@ -2766,8 +2766,8 @@ static int smc_accept(struct socket *sock, struct socket *new_sock,
 	return rc;
 }
 
-static int smc_getname(struct socket *sock, struct sockaddr *addr,
-		       int peer)
+int smc_getname(struct socket *sock, struct sockaddr *addr,
+		int peer)
 {
 	struct smc_sock *smc;
 
@@ -2780,7 +2780,7 @@ static int smc_getname(struct socket *sock, struct sockaddr *addr,
 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
 }
 
-static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -2818,8 +2818,8 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 	return rc;
 }
 
-static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
-		       int flags)
+int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		int flags)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -2868,8 +2868,8 @@ static __poll_t smc_accept_poll(struct sock *parent)
 	return mask;
 }
 
-static __poll_t smc_poll(struct file *file, struct socket *sock,
-			     poll_table *wait)
+__poll_t smc_poll(struct file *file, struct socket *sock,
+		  poll_table *wait)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -2921,7 +2921,7 @@ static __poll_t smc_poll(struct file *file, struct socket *sock,
 	return mask;
 }
 
-static int smc_shutdown(struct socket *sock, int how)
+int smc_shutdown(struct socket *sock, int how)
 {
 	struct sock *sk = sock->sk;
 	bool do_shutdown = true;
@@ -3061,8 +3061,8 @@ static int __smc_setsockopt(struct socket *sock, int level, int optname,
 	return rc;
 }
 
-static int smc_setsockopt(struct socket *sock, int level, int optname,
-			  sockptr_t optval, unsigned int optlen)
+int smc_setsockopt(struct socket *sock, int level, int optname,
+		   sockptr_t optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
@@ -3148,8 +3148,8 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
 	return rc;
 }
 
-static int smc_getsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int __user *optlen)
+int smc_getsockopt(struct socket *sock, int level, int optname,
+		   char __user *optval, int __user *optlen)
 {
 	struct smc_sock *smc;
 	int rc;
@@ -3174,8 +3174,8 @@ static int smc_getsockopt(struct socket *sock, int level, int optname,
 	return rc;
 }
 
-static int smc_ioctl(struct socket *sock, unsigned int cmd,
-		     unsigned long arg)
+int smc_ioctl(struct socket *sock, unsigned int cmd,
+	      unsigned long arg)
 {
 	union smc_host_cursor cons, urg;
 	struct smc_connection *conn;
@@ -3261,9 +3261,9 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
  * Note that subsequent recv() calls have to wait till all splice() processing
  * completed.
  */
-static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
-			       struct pipe_inode_info *pipe, size_t len,
-			       unsigned int flags)
+ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
+			struct pipe_inode_info *pipe, size_t len,
+			unsigned int flags)
 {
 	struct sock *sk = sock->sk;
 	struct smc_sock *smc;
diff --git a/net/smc/smc.h b/net/smc/smc.h
index a0accb5..ad755ee 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -34,6 +34,39 @@
 extern struct proto smc_proto;
 extern struct proto smc_proto6;
 
+extern struct smc_hashinfo smc_v4_hashinfo;
+extern struct smc_hashinfo smc_v6_hashinfo;
+
+int smc_hash_sk(struct sock *sk);
+void smc_unhash_sk(struct sock *sk);
+void smc_release_cb(struct sock *sk);
+
+int smc_release(struct socket *sock);
+int smc_bind(struct socket *sock, struct sockaddr *uaddr,
+	     int addr_len);
+int smc_connect(struct socket *sock, struct sockaddr *addr,
+		int alen, int flags);
+int smc_accept(struct socket *sock, struct socket *new_sock,
+	       int flags, bool kern);
+int smc_getname(struct socket *sock, struct sockaddr *addr,
+		int peer);
+__poll_t smc_poll(struct file *file, struct socket *sock,
+		  poll_table *wait);
+int smc_ioctl(struct socket *sock, unsigned int cmd,
+	      unsigned long arg);
+int smc_listen(struct socket *sock, int backlog);
+int smc_shutdown(struct socket *sock, int how);
+int smc_setsockopt(struct socket *sock, int level, int optname,
+		   sockptr_t optval, unsigned int optlen);
+int smc_getsockopt(struct socket *sock, int level, int optname,
+		   char __user *optval, int __user *optlen);
+int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len);
+int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		int flags);
+ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
+			struct pipe_inode_info *pipe, size_t len,
+			unsigned int flags);
+
 /* smc sock initialization */
 void smc_sock_init(struct net *net, struct sock *sk, int protocol);
 /* clcsock initialization */
-- 
1.8.3.1

[PATCH net-next v2 3/3] net/smc: Introduce IPPROTO_SMC

[D. Wythe]

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/Makefile        |   2 +-
 net/smc/af_smc.c        |  37 ++++++++++++++++-
 net/smc/inet_smc.c      | 107 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/smc/inet_smc.h      |  32 +++++++++++++++
 5 files changed, 178 insertions(+), 2 deletions(-)
 create mode 100644 net/smc/inet_smc.c
 create mode 100644 net/smc/inet_smc.h

diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index e682ab6..0c6322b 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		*/
+#define IPPROTO_SMC		IPPROTO_SMC
   IPPROTO_MAX
 };
 #endif
diff --git a/net/smc/Makefile b/net/smc/Makefile
index 2c510d54..472b9ee 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 inet_smc.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 5b7a194..6a26d29 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
@@ -3594,9 +3595,30 @@ 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;
-
+#if IS_ENABLED(CONFIG_IPV6)
+out_inet_prot:
+	inet_unregister_protosw(&smc_inet_protosw);
+	proto_unregister(&smc_inet_prot);
+#endif
+out_ulp:
+	tcp_unregister_ulp(&smc_ulp_ops);
 out_lo:
 	smc_loopback_exit();
 out_ib:
@@ -3633,6 +3655,10 @@ 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();
@@ -3644,6 +3670,10 @@ 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();
@@ -3660,4 +3690,9 @@ 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.c b/net/smc/inet_smc.c
new file mode 100644
index 00000000..ba270da
--- /dev/null
+++ b/net/smc/inet_smc.c
@@ -0,0 +1,107 @@
+// 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
+ *
+ *  Author(s):  D. Wythe <alibuda@linux.alibaba.com>
+ */
+
+#include "inet_smc.h"
+#include "smc.h"
+
+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,
+};
+
+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,
+};
+
+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)
+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,
+};
+
+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
+
+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);
+}
diff --git a/net/smc/inet_smc.h b/net/smc/inet_smc.h
new file mode 100644
index 00000000..23803cd
--- /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 IPPROTO_SMC (socket related)
+
+ *  Copyright IBM Corp. 2016
+ *
+ */
+#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 */
-- 
1.8.3.1

Re: [PATCH net-next v2 0/3] Introduce IPPROTO_SMC

[Jakub Kicinski]

On Wed, 15 May 2024 14:41:43 +0800 D. Wythe wrote:
> 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);

## Form letter - net-next-closed

The merge window for v6.10 has begun and we have already posted our pull
request. Therefore net-next is closed for new drivers, features, code
refactoring and optimizations. We are currently accepting bug fixes only.

Please repost when net-next reopens after May 26th.

RFC patches sent for review only are obviously welcome at any time.

See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
-- 
pw-bot: defer