[PATCH V2 net-next 02/15] smc: establish new socket family

Ursula Braun
2016-09-27T16:41:43Z

* enable smc module loading and unloading
* register new socket family
* basic smc socket creation and deletion
* use backing TCP socket to run CLC (Connection Layer Control)
handshake of SMC protocol
* Setup for infiniband traffic is implemented in follow-on patches.
For now fallback to TCP socket is always used.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Utz Bacher <utz.bacher@de.ibm.com>
---
MAINTAINERS | 7 +
include/linux/socket.h | 7 +-
net/Kconfig | 1 +
net/Makefile | 1 +
net/core/sock.c | 6 +-
net/smc/Kconfig | 11 +
net/smc/Makefile | 2 +
net/smc/af_smc.c | 623 +++++++++++++++++++++++++++++++++++++++++++++++++
net/smc/smc.h | 36 +++
9 files changed, 690 insertions(+), 4 deletions(-)
create mode 100644 net/smc/Kconfig
create mode 100644 net/smc/Makefile
create mode 100644 net/smc/af_smc.c
create mode 100644 net/smc/smc.h

diff --git a/MAINTAINERS b/MAINTAINERS
index efd69c76..fdf5cc6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10331,6 +10331,13 @@ S: Maintained
F: Documentation/devicetree/bindings/serial/
F: drivers/tty/serial/

+SHARED MEMORY COMMUNICATIONS (SMC) SOCKETS
+M: Ursula Braun <ursula.braun@linux.vnet.ibm.com>
+L: linux-s390@vger.kernel.org
+W: http://www.ibm.com/developerworks/linux/linux390/
+S: Supported
+F: net/smc/
+
SYNOPSYS DESIGNWARE DMAC DRIVER
M: Viresh Kumar <vireshk@kernel.org>
M: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/include/linux/socket.h b/include/linux/socket.h
index b5cc5a6..a4a1cc7 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -202,8 +202,12 @@ struct ucred {
#define AF_VSOCK 40 /* vSockets */
#define AF_KCM 41 /* Kernel Connection Multiplexor*/
#define AF_QIPCRTR 42 /* Qualcomm IPC Router */
+#define AF_SMC 43 /* smc sockets: reserve number for
+ * PF_SMC protocol family that
+ * reuses AF_INET address family
+ */

-#define AF_MAX 43 /* For now.. */
+#define AF_MAX 44 /* For now.. */

/* Protocol families, same as address families. */
#define PF_UNSPEC AF_UNSPEC
@@ -251,6 +255,7 @@ struct ucred {
#define PF_VSOCK AF_VSOCK
#define PF_KCM AF_KCM
#define PF_QIPCRTR AF_QIPCRTR
+#define PF_SMC AF_SMC
#define PF_MAX AF_MAX

/* Maximum queue length specifiable by listen. */
diff --git a/net/Kconfig b/net/Kconfig
index 7b6cd34..c6f611e 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -57,6 +57,7 @@ source "net/packet/Kconfig"
source "net/unix/Kconfig"
source "net/xfrm/Kconfig"
source "net/iucv/Kconfig"
+source "net/smc/Kconfig"

config INET
bool "TCP/IP networking"
diff --git a/net/Makefile b/net/Makefile
index 4cafaa2..5d6e0e5f 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_MAC80211) += mac80211/
obj-$(CONFIG_TIPC) += tipc/
obj-$(CONFIG_NETLABEL) += netlabel/
obj-$(CONFIG_IUCV) += iucv/
+obj-$(CONFIG_SMC) += smc/
obj-$(CONFIG_RFKILL) += rfkill/
obj-$(CONFIG_NET_9P) += 9p/
obj-$(CONFIG_CAIF) += caif/
diff --git a/net/core/sock.c b/net/core/sock.c
index ce31244..d275d04 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -222,7 +222,7 @@ static const char *const af_family_key_strings[AF_MAX+1] = {
"sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN" , "sk_lock-AF_PHONET" ,
"sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG" ,
"sk_lock-AF_NFC" , "sk_lock-AF_VSOCK" , "sk_lock-AF_KCM" ,
- "sk_lock-AF_MAX"
+ "sk_lock-AF_SMC" , "sk_lock-AF_MAX"
};
static const char *const af_family_slock_key_strings[AF_MAX+1] = {
"slock-AF_UNSPEC", "slock-AF_UNIX" , "slock-AF_INET" ,
@@ -239,7 +239,7 @@ static const char *const af_family_slock_key_strings[AF_MAX+1] = {
"slock-AF_RXRPC" , "slock-AF_ISDN" , "slock-AF_PHONET" ,
"slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG" ,
"slock-AF_NFC" , "slock-AF_VSOCK" ,"slock-AF_KCM" ,
- "slock-AF_MAX"
+ "slock-AF_SMC" , "slock-AF_MAX"
};
static const char *const af_family_clock_key_strings[AF_MAX+1] = {
"clock-AF_UNSPEC", "clock-AF_UNIX" , "clock-AF_INET" ,
@@ -256,7 +256,7 @@ static const char *const af_family_clock_key_strings[AF_MAX+1] = {
"clock-AF_RXRPC" , "clock-AF_ISDN" , "clock-AF_PHONET" ,
"clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG" ,
"clock-AF_NFC" , "clock-AF_VSOCK" , "clock-AF_KCM" ,
- "clock-AF_MAX"
+ "closck-AF_smc" , "clock-AF_MAX"
};

/*
diff --git a/net/smc/Kconfig b/net/smc/Kconfig
new file mode 100644
index 0000000..bc02980
--- /dev/null
+++ b/net/smc/Kconfig
@@ -0,0 +1,11 @@
+config SMC
+ tristate "SMC socket protocol family"
+ depends on INET && INFINIBAND
+ ---help---
+ SMC-R provides a "sockets over RDMA" solution making use of
+ RDMA over Converged Ethernet (RoCE) technology to upgrade
+ AF_INET TCP connections transparently.
+ The Linux implementation of the SMC-R solution is designed as
+ a separate socket family SMC.
+
+ Select this option if you want to run SMC socket applications
diff --git a/net/smc/Makefile b/net/smc/Makefile
new file mode 100644
index 0000000..c285c86
--- /dev/null
+++ b/net/smc/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_SMC) += smc.o
+smc-y := af_smc.o
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
new file mode 100644
index 0000000..ae3332c
--- /dev/null
+++ b/net/smc/af_smc.c
@@ -0,0 +1,623 @@
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * AF_SMC protocol family socket handler keeping the AF_INET sock address type
+ * applies to SOCK_STREAM sockets only
+ * offers an alternative communication option for TCP-protocol sockets
+ * applicable with RoCE-cards only
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ * based on prototype from Frank Blaschka
+ */
+
+#define KMSG_COMPONENT "smc"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+
+#include "smc.h"
+
+static void smc_set_keepalive(struct sock *sk, int val)
+{
+ struct smc_sock *smc = smc_sk(sk);
+
+ smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
+}
+
+static struct proto smc_proto = {
+ .name = "SMC",
+ .owner = THIS_MODULE,
+ .keepalive = smc_set_keepalive,
+ .obj_size = sizeof(struct smc_sock),
+ .slab_flags = SLAB_DESTROY_BY_RCU,
+};
+
+static int smc_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+
+ if (!sk)
+ goto out;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+
+ sk->sk_state = SMC_CLOSED;
+ if (smc->clcsock) {
+ sock_release(smc->clcsock);
+ smc->clcsock = NULL;
+ }
+
+ /* detach socket */
+ sock_set_flag(sk, SOCK_ZAPPED);
+ sock_orphan(sk);
+ sock->sk = NULL;
+ release_sock(sk);
+
+ sock_put(sk);
+out:
+ return 0;
+}
+
+static void smc_destruct(struct sock *sk)
+{
+ if (sk->sk_state != SMC_CLOSED)
+ return;
+ if (!sock_flag(sk, SOCK_DEAD))
+ return;
+
+ sk_refcnt_debug_dec(sk);
+}
+
+static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
+{
+ struct smc_sock *smc;
+ struct sock *sk;
+
+ sk = sk_alloc(net, PF_SMC, GFP_KERNEL, &smc_proto, 0);
+ if (!sk)
+ return NULL;
+
+ sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
+ sk->sk_state = SMC_INIT;
+ sk->sk_destruct = smc_destruct;
+ sk->sk_protocol = SMCPROTO_SMC;
+ sk_refcnt_debug_inc(sk);
+
+ smc = smc_sk(sk);
+ smc->clcsock = NULL;
+ smc->use_fallback = 0;
+
+ return sk;
+}
+
+static 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;
+ struct smc_sock *smc;
+ int rc;
+
+ smc = smc_sk(sk);
+
+ /* replicate tests from inet_bind(), to be safe wrt. future changes */
+ rc = -EINVAL;
+ if (addr_len < sizeof(struct sockaddr_in))
+ goto out;
+
+ rc = -EAFNOSUPPORT;
+ /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
+ if ((addr->sin_family != AF_INET) &&
+ ((addr->sin_family != AF_UNSPEC) ||
+ (addr->sin_addr.s_addr != htonl(INADDR_ANY))))
+ goto out;
+
+ lock_sock(sk);
+
+ /* Check if socket is already active */
+ rc = -EINVAL;
+ if (sk->sk_state != SMC_INIT)
+ goto out_rel;
+
+ smc->clcsock->sk->sk_reuse = sk->sk_reuse;
+ rc = kernel_bind(smc->clcsock, uaddr, addr_len);
+
+out_rel:
+ release_sock(sk);
+out:
+ return rc;
+}
+
+static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
+ unsigned long mask)
+{
+ /* options we don't get control via setsockopt for */
+ nsk->sk_type = osk->sk_type;
+ nsk->sk_sndbuf = osk->sk_sndbuf;
+ nsk->sk_rcvbuf = osk->sk_rcvbuf;
+ nsk->sk_sndtimeo = osk->sk_sndtimeo;
+ nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
+ nsk->sk_mark = osk->sk_mark;
+ nsk->sk_priority = osk->sk_priority;
+ nsk->sk_rcvlowat = osk->sk_rcvlowat;
+ nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
+ nsk->sk_err = osk->sk_err;
+
+ nsk->sk_flags &= ~mask;
+ nsk->sk_flags |= osk->sk_flags & mask;
+}
+
+#define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
+ (1UL << SOCK_KEEPOPEN) | \
+ (1UL << SOCK_LINGER) | \
+ (1UL << SOCK_BROADCAST) | \
+ (1UL << SOCK_TIMESTAMP) | \
+ (1UL << SOCK_DBG) | \
+ (1UL << SOCK_RCVTSTAMP) | \
+ (1UL << SOCK_RCVTSTAMPNS) | \
+ (1UL << SOCK_LOCALROUTE) | \
+ (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
+ (1UL << SOCK_RXQ_OVFL) | \
+ (1UL << SOCK_WIFI_STATUS) | \
+ (1UL << SOCK_NOFCS) | \
+ (1UL << SOCK_FILTER_LOCKED))
+/* copy only relevant settings and flags of SOL_SOCKET level from smc to
+ * clc socket (since smc is not called for these options from net/core)
+ */
+static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
+{
+ smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
+}
+
+#define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
+ (1UL << SOCK_KEEPOPEN) | \
+ (1UL << SOCK_LINGER) | \
+ (1UL << SOCK_DBG))
+/* copy only settings and flags relevant for smc from clc to smc socket */
+static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
+{
+ smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
+}
+
+static int smc_connect(struct socket *sock, struct sockaddr *addr,
+ int alen, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc = -EINVAL;
+
+ smc = smc_sk(sk);
+
+ /* separate smc parameter checking to be safe */
+ if (alen < sizeof(addr->sa_family))
+ goto out_err;
+ if (addr->sa_family != AF_INET)
+ goto out_err;
+
+ lock_sock(sk);
+ switch (sk->sk_state) {
+ default:
+ goto out;
+ case SMC_ACTIVE:
+ rc = -EISCONN;
+ goto out;
+ case SMC_INIT:
+ rc = 0;
+ break;
+ }
+
+ smc_copy_sock_settings_to_clc(smc);
+ rc = kernel_connect(smc->clcsock, addr, alen, flags);
+ if (rc)
+ goto out;
+
+ sk->sk_state = SMC_ACTIVE;
+
+ /* always use TCP fallback as transport mechanism for now;
+ * This will change once RDMA transport is implemented
+ */
+ smc->use_fallback = 1;
+
+out:
+ release_sock(sk);
+out_err:
+ return rc;
+}
+
+static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
+{
+ struct sock *sk = &lsmc->sk;
+ struct socket *new_clcsock;
+ struct sock *new_sk;
+ int rc;
+
+ new_sk = smc_sock_alloc(sock_net(sk), NULL);
+ if (!new_sk) {
+ rc = -ENOMEM;
+ lsmc->sk.sk_err = ENOMEM;
+ *new_smc = NULL;
+ goto out;
+ }
+ *new_smc = smc_sk(new_sk);
+
+ rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
+ if (rc) {
+ sock_put(new_sk);
+ *new_smc = NULL;
+ goto out;
+ }
+
+ (*new_smc)->clcsock = new_clcsock;
+out:
+ return rc;
+}
+
+static int smc_listen(struct socket *sock, int backlog)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+
+ rc = -EINVAL;
+ if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
+ goto out;
+
+ rc = 0;
+ if (sk->sk_state == SMC_LISTEN) {
+ sk->sk_max_ack_backlog = backlog;
+ goto out;
+ }
+ /* some socket options are handled in core, so we could not apply
+ * them to the clc socket -- copy smc socket options to clc socket
+ */
+ smc_copy_sock_settings_to_clc(smc);
+
+ rc = kernel_listen(smc->clcsock, backlog);
+ if (rc)
+ goto out;
+ sk->sk_max_ack_backlog = backlog;
+ sk->sk_ack_backlog = 0;
+ sk->sk_state = SMC_LISTEN;
+
+out:
+ release_sock(sk);
+ return rc;
+}
+
+static int smc_accept(struct socket *sock, struct socket *new_sock,
+ int flags)
+{
+ struct smc_sock *new_smc;
+ struct sock *sk = sock->sk;
+ struct smc_sock *lsmc;
+ int rc;
+
+ lsmc = smc_sk(sk);
+ lock_sock(sk);
+
+ if (lsmc->sk.sk_state != SMC_LISTEN) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ rc = smc_clcsock_accept(lsmc, &new_smc);
+ if (rc)
+ goto out;
+ sock_graft(&new_smc->sk, new_sock);
+ new_smc->sk.sk_state = SMC_ACTIVE;
+
+ smc_copy_sock_settings_to_smc(new_smc);
+
+ /* always use TCP fallback as transport mechanism for now;
+ * This will change once RDMA transport is implemented
+ */
+ new_smc->use_fallback = 1;
+
+out:
+ release_sock(sk);
+ return rc;
+}
+
+static int smc_getname(struct socket *sock, struct sockaddr *addr,
+ int *len, int peer)
+{
+ struct smc_sock *smc;
+
+ if (peer && (sock->sk->sk_state != SMC_ACTIVE))
+ return -ENOTCONN;
+
+ smc = smc_sk(sock->sk);
+
+ return smc->clcsock->ops->getname(smc->clcsock, addr, len, peer);
+}
+
+static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc = -EPIPE;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+ if (sk->sk_state != SMC_ACTIVE)
+ goto out;
+ if (smc->use_fallback)
+ rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
+ else
+ rc = sock_no_sendmsg(sock, msg, len);
+out:
+ release_sock(sk);
+ return rc;
+}
+
+static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc = -ENOTCONN;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+ if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
+ goto out;
+
+ if (smc->use_fallback)
+ rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
+ else
+ rc = sock_no_recvmsg(sock, msg, len, flags);
+out:
+ release_sock(sk);
+ return rc;
+}
+
+static unsigned int smc_poll(struct file *file, struct socket *sock,
+ poll_table *wait)
+{
+ struct sock *sk = sock->sk;
+ unsigned int mask = 0;
+ struct smc_sock *smc;
+
+ smc = smc_sk(sock->sk);
+ if ((sk->sk_state == SMC_INIT) || (sk->sk_state == SMC_LISTEN) ||
+ smc->use_fallback) {
+ mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
+ /* if non-blocking connect finished ... */
+ lock_sock(sk);
+ if ((sk->sk_state == SMC_INIT) && (mask & POLLOUT)) {
+ sk->sk_state = SMC_ACTIVE;
+ /* always use TCP fallback as transport mechanism;
+ * This will change once RDMA transport is implemented
+ */
+ smc->use_fallback = 1;
+ }
+ release_sock(sk);
+ } else {
+ mask = sock_no_poll(file, sock, wait);
+ }
+
+ return mask;
+}
+
+static int smc_shutdown(struct socket *sock, int how)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc = -EINVAL;
+
+ smc = smc_sk(sk);
+
+ if ((how < SHUT_RD) || (how > SHUT_RDWR))
+ goto out_err;
+
+ lock_sock(sk);
+
+ rc = -ENOTCONN;
+ if (sk->sk_state == SMC_CLOSED)
+ goto out;
+ if (smc->use_fallback) {
+ rc = kernel_sock_shutdown(smc->clcsock, how);
+ sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
+ if (sk->sk_shutdown == SHUTDOWN_MASK)
+ sk->sk_state = SMC_CLOSED;
+ } else {
+ rc = sock_no_shutdown(sock, how);
+ }
+
+out:
+ release_sock(sk);
+
+out_err:
+ return rc;
+}
+
+static int smc_setsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, unsigned int optlen)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+
+ smc = smc_sk(sk);
+
+ /* generic setsockopts reaching us here always apply to the
+ * CLC socket
+ */
+ return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
+ optval, optlen);
+}
+
+static int smc_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct smc_sock *smc;
+
+ smc = smc_sk(sock->sk);
+ /* socket options apply to the CLC socket */
+ return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
+ optval, optlen);
+}
+
+static int smc_ioctl(struct socket *sock, unsigned int cmd,
+ unsigned long arg)
+{
+ struct smc_sock *smc;
+
+ smc = smc_sk(sock->sk);
+ if (smc->use_fallback)
+ return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
+ else
+ return sock_no_ioctl(sock, cmd, arg);
+}
+
+static ssize_t smc_sendpage(struct socket *sock, struct page *page,
+ int offset, size_t size, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct smc_sock *smc;
+ int rc = -EPIPE;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+ if (sk->sk_state != SMC_ACTIVE)
+ goto out;
+ if (smc->use_fallback)
+ rc = kernel_sendpage(smc->clcsock, page, offset,
+ size, flags);
+ else
+ rc = sock_no_sendpage(sock, page, offset, size, flags);
+
+out:
+ release_sock(sk);
+ return rc;
+}
+
+static 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;
+ int rc = -ENOTCONN;
+
+ smc = smc_sk(sk);
+ lock_sock(sk);
+ if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
+ goto out;
+ if (smc->use_fallback) {
+ rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
+ pipe, len, flags);
+ } else {
+ rc = -EOPNOTSUPP;
+ }
+out:
+ release_sock(sk);
+ return rc;
+}
+
+/* must look like tcp */
+static const struct proto_ops smc_sock_ops = {
+ .family = PF_SMC,
+ .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,
+ .sendpage = smc_sendpage,
+ .splice_read = smc_splice_read,
+};
+
+static int smc_create(struct net *net, struct socket *sock, int protocol,
+ int kern)
+{
+ struct smc_sock *smc;
+ struct sock *sk;
+ int rc;
+
+ rc = -ESOCKTNOSUPPORT;
+ if (sock->type != SOCK_STREAM)
+ goto out;
+
+ rc = -EPROTONOSUPPORT;
+ if ((protocol != IPPROTO_IP) && (protocol != IPPROTO_TCP))
+ goto out;
+
+ rc = -ENOBUFS;
+ sock->ops = &smc_sock_ops;
+ sk = smc_sock_alloc(net, sock);
+ if (!sk)
+ goto out;
+
+ /* create internal TCP socket for CLC handshake and fallback */
+ smc = smc_sk(sk);
+ rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
+ IPPROTO_TCP, &smc->clcsock);
+ if (rc)
+ sk_common_release(sk);
+
+out:
+ return rc;
+}
+
+static const struct net_proto_family smc_sock_family_ops = {
+ .family = PF_SMC,
+ .owner = THIS_MODULE,
+ .create = smc_create,
+};
+
+static int __init smc_init(void)
+{
+ int rc;
+
+ rc = proto_register(&smc_proto, 1);
+ if (rc) {
+ pr_err("%s: proto_register fails with %d\n", __func__, rc);
+ goto out;
+ }
+
+ rc = sock_register(&smc_sock_family_ops);
+ if (rc) {
+ pr_err("%s: sock_register fails with %d\n", __func__, rc);
+ goto out_proto;
+ }
+
+ return 0;
+
+out_proto:
+ proto_unregister(&smc_proto);
+out:
+ return rc;
+}
+
+static void __exit smc_exit(void)
+{
+ sock_unregister(PF_SMC);
+ proto_unregister(&smc_proto);
+}
+
+module_init(smc_init);
+module_exit(smc_exit);
+
+MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("smc socket address family");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_SMC);
diff --git a/net/smc/smc.h b/net/smc/smc.h
new file mode 100644
index 0000000..46f562d
--- /dev/null
+++ b/net/smc/smc.h
@@ -0,0 +1,36 @@
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Definitions for the SMC module (socket related)
+ *
+ * Copyright IBM Corp. 2016
+ *
+ * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+#ifndef _SMC_H
+#define _SMC_H
+
+#include <linux/socket.h>
+#include <linux/types.h>
+#include <net/sock.h>
+
+#define SMCPROTO_SMC 0 /* SMC protocol */
+
+enum smc_state { /* possible states of an SMC socket */
+ SMC_ACTIVE = 1,
+ SMC_INIT = 2,
+ SMC_CLOSED = 7,
+ SMC_LISTEN = 10,
+};
+
+struct smc_sock { /* smc sock container */
+ struct sock sk;
+ struct socket *clcsock; /* internal tcp socket */
+ u8 use_fallback : 1; /* fallback to tcp */
+};
+
+static inline struct smc_sock *smc_sk(const struct sock *sk)
+{
+ return (struct smc_sock *)sk;
+}
+#endif /* _SMC_H */
--
2.8.4