1 files changed, 604 insertions, 0 deletions

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
new file mode 100644
index 000000000..063acfbdc
--- /dev/null
+++ b/net/smc/smc_clc.c
@@ -0,0 +1,604 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  CLC (connection layer control) handshake over initial TCP socket to
+ *  prepare for RDMA traffic
+ *
+ *  Copyright IBM Corp. 2016, 2018
+ *
+ *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/in.h>
+#include <linux/inetdevice.h>
+#include <linux/if_ether.h>
+#include <linux/sched/signal.h>
+
+#include <net/addrconf.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+
+#include "smc.h"
+#include "smc_core.h"
+#include "smc_clc.h"
+#include "smc_ib.h"
+#include "smc_ism.h"
+
+#define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
+#define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
+
+/* eye catcher "SMCR" EBCDIC for CLC messages */
+static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
+/* eye catcher "SMCD" EBCDIC for CLC messages */
+static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
+
+/* check if received message has a correct header length and contains valid
+ * heading and trailing eyecatchers
+ */
+static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
+{
+	struct smc_clc_msg_proposal_prefix *pclc_prfx;
+	struct smc_clc_msg_accept_confirm *clc;
+	struct smc_clc_msg_proposal *pclc;
+	struct smc_clc_msg_decline *dclc;
+	struct smc_clc_msg_trail *trl;
+
+	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
+	    memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
+		return false;
+	switch (clcm->type) {
+	case SMC_CLC_PROPOSAL:
+		if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
+		    clcm->path != SMC_TYPE_B)
+			return false;
+		pclc = (struct smc_clc_msg_proposal *)clcm;
+		pclc_prfx = smc_clc_proposal_get_prefix(pclc);
+		if (ntohs(pclc->hdr.length) !=
+			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
+			sizeof(*pclc_prfx) +
+			pclc_prfx->ipv6_prefixes_cnt *
+				sizeof(struct smc_clc_ipv6_prefix) +
+			sizeof(*trl))
+			return false;
+		trl = (struct smc_clc_msg_trail *)
+			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
+		break;
+	case SMC_CLC_ACCEPT:
+	case SMC_CLC_CONFIRM:
+		if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D)
+			return false;
+		clc = (struct smc_clc_msg_accept_confirm *)clcm;
+		if ((clcm->path == SMC_TYPE_R &&
+		     ntohs(clc->hdr.length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
+		    (clcm->path == SMC_TYPE_D &&
+		     ntohs(clc->hdr.length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
+			return false;
+		trl = (struct smc_clc_msg_trail *)
+			((u8 *)clc + ntohs(clc->hdr.length) - sizeof(*trl));
+		break;
+	case SMC_CLC_DECLINE:
+		dclc = (struct smc_clc_msg_decline *)clcm;
+		if (ntohs(dclc->hdr.length) != sizeof(*dclc))
+			return false;
+		trl = &dclc->trl;
+		break;
+	default:
+		return false;
+	}
+	if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
+	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
+		return false;
+	return true;
+}
+
+/* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
+static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
+				 struct smc_clc_msg_proposal_prefix *prop)
+{
+	struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
+
+	if (!in_dev)
+		return -ENODEV;
+	for_ifa(in_dev) {
+		if (!inet_ifa_match(ipv4, ifa))
+			continue;
+		prop->prefix_len = inet_mask_len(ifa->ifa_mask);
+		prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
+		/* prop->ipv6_prefixes_cnt = 0; already done by memset before */
+		return 0;
+	} endfor_ifa(in_dev);
+	return -ENOENT;
+}
+
+/* fill CLC proposal msg with ipv6 prefixes from device */
+static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
+				 struct smc_clc_msg_proposal_prefix *prop,
+				 struct smc_clc_ipv6_prefix *ipv6_prfx)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
+	struct inet6_ifaddr *ifa;
+	int cnt = 0;
+
+	if (!in6_dev)
+		return -ENODEV;
+	/* use a maximum of 8 IPv6 prefixes from device */
+	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
+		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
+			continue;
+		ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
+				 &ifa->addr, ifa->prefix_len);
+		ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
+		cnt++;
+		if (cnt == SMC_CLC_MAX_V6_PREFIX)
+			break;
+	}
+	prop->ipv6_prefixes_cnt = cnt;
+	if (cnt)
+		return 0;
+#endif
+	return -ENOENT;
+}
+
+/* retrieve and set prefixes in CLC proposal msg */
+static int smc_clc_prfx_set(struct socket *clcsock,
+			    struct smc_clc_msg_proposal_prefix *prop,
+			    struct smc_clc_ipv6_prefix *ipv6_prfx)
+{
+	struct dst_entry *dst = sk_dst_get(clcsock->sk);
+	struct sockaddr_storage addrs;
+	struct sockaddr_in6 *addr6;
+	struct sockaddr_in *addr;
+	int rc = -ENOENT;
+
+	memset(prop, 0, sizeof(*prop));
+	if (!dst) {
+		rc = -ENOTCONN;
+		goto out;
+	}
+	if (!dst->dev) {
+		rc = -ENODEV;
+		goto out_rel;
+	}
+	/* get address to which the internal TCP socket is bound */
+	if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
+		goto out_rel;
+	/* analyze IP specific data of net_device belonging to TCP socket */
+	addr6 = (struct sockaddr_in6 *)&addrs;
+	rcu_read_lock();
+	if (addrs.ss_family == PF_INET) {
+		/* IPv4 */
+		addr = (struct sockaddr_in *)&addrs;
+		rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
+	} else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
+		/* mapped IPv4 address - peer is IPv4 only */
+		rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
+					   prop);
+	} else {
+		/* IPv6 */
+		rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
+	}
+	rcu_read_unlock();
+out_rel:
+	dst_release(dst);
+out:
+	return rc;
+}
+
+/* match ipv4 addrs of dev against addr in CLC proposal */
+static int smc_clc_prfx_match4_rcu(struct net_device *dev,
+				   struct smc_clc_msg_proposal_prefix *prop)
+{
+	struct in_device *in_dev = __in_dev_get_rcu(dev);
+
+	if (!in_dev)
+		return -ENODEV;
+	for_ifa(in_dev) {
+		if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
+		    inet_ifa_match(prop->outgoing_subnet, ifa))
+			return 0;
+	} endfor_ifa(in_dev);
+
+	return -ENOENT;
+}
+
+/* match ipv6 addrs of dev against addrs in CLC proposal */
+static int smc_clc_prfx_match6_rcu(struct net_device *dev,
+				   struct smc_clc_msg_proposal_prefix *prop)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	struct inet6_dev *in6_dev = __in6_dev_get(dev);
+	struct smc_clc_ipv6_prefix *ipv6_prfx;
+	struct inet6_ifaddr *ifa;
+	int i, max;
+
+	if (!in6_dev)
+		return -ENODEV;
+	/* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
+	ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
+	max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
+	list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
+		if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
+			continue;
+		for (i = 0; i < max; i++) {
+			if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
+			    ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
+					      ifa->prefix_len))
+				return 0;
+		}
+	}
+#endif
+	return -ENOENT;
+}
+
+/* check if proposed prefixes match one of our device prefixes */
+int smc_clc_prfx_match(struct socket *clcsock,
+		       struct smc_clc_msg_proposal_prefix *prop)
+{
+	struct dst_entry *dst = sk_dst_get(clcsock->sk);
+	int rc;
+
+	if (!dst) {
+		rc = -ENOTCONN;
+		goto out;
+	}
+	if (!dst->dev) {
+		rc = -ENODEV;
+		goto out_rel;
+	}
+	rcu_read_lock();
+	if (!prop->ipv6_prefixes_cnt)
+		rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
+	else
+		rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
+	rcu_read_unlock();
+out_rel:
+	dst_release(dst);
+out:
+	return rc;
+}
+
+/* Wait for data on the tcp-socket, analyze received data
+ * Returns:
+ * 0 if success and it was not a decline that we received.
+ * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
+ * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
+ */
+int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
+		     u8 expected_type)
+{
+	long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
+	struct sock *clc_sk = smc->clcsock->sk;
+	struct smc_clc_msg_hdr *clcm = buf;
+	struct msghdr msg = {NULL, 0};
+	int reason_code = 0;
+	struct kvec vec = {buf, buflen};
+	int len, datlen;
+	int krflags;
+
+	/* peek the first few bytes to determine length of data to receive
+	 * so we don't consume any subsequent CLC message or payload data
+	 * in the TCP byte stream
+	 */
+	/*
+	 * Caller must make sure that buflen is no less than
+	 * sizeof(struct smc_clc_msg_hdr)
+	 */
+	krflags = MSG_PEEK | MSG_WAITALL;
+	smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
+	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1,
+			sizeof(struct smc_clc_msg_hdr));
+	len = sock_recvmsg(smc->clcsock, &msg, krflags);
+	if (signal_pending(current)) {
+		reason_code = -EINTR;
+		clc_sk->sk_err = EINTR;
+		smc->sk.sk_err = EINTR;
+		goto out;
+	}
+	if (clc_sk->sk_err) {
+		reason_code = -clc_sk->sk_err;
+		smc->sk.sk_err = clc_sk->sk_err;
+		goto out;
+	}
+	if (!len) { /* peer has performed orderly shutdown */
+		smc->sk.sk_err = ECONNRESET;
+		reason_code = -ECONNRESET;
+		goto out;
+	}
+	if (len < 0) {
+		smc->sk.sk_err = -len;
+		reason_code = len;
+		goto out;
+	}
+	datlen = ntohs(clcm->length);
+	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
+	    (datlen > buflen) ||
+	    (clcm->version != SMC_CLC_V1) ||
+	    (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
+	     clcm->path != SMC_TYPE_B) ||
+	    ((clcm->type != SMC_CLC_DECLINE) &&
+	     (clcm->type != expected_type))) {
+		smc->sk.sk_err = EPROTO;
+		reason_code = -EPROTO;
+		goto out;
+	}
+
+	/* receive the complete CLC message */
+	memset(&msg, 0, sizeof(struct msghdr));
+	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, datlen);
+	krflags = MSG_WAITALL;
+	len = sock_recvmsg(smc->clcsock, &msg, krflags);
+	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
+		smc->sk.sk_err = EPROTO;
+		reason_code = -EPROTO;
+		goto out;
+	}
+	if (clcm->type == SMC_CLC_DECLINE) {
+		struct smc_clc_msg_decline *dclc;
+
+		dclc = (struct smc_clc_msg_decline *)clcm;
+		reason_code = SMC_CLC_DECL_PEERDECL;
+		smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
+		if (((struct smc_clc_msg_decline *)buf)->hdr.flag) {
+			smc->conn.lgr->sync_err = 1;
+			smc_lgr_terminate(smc->conn.lgr);
+		}
+	}
+
+out:
+	smc->clcsock->sk->sk_rcvtimeo = rcvtimeo;
+	return reason_code;
+}
+
+/* send CLC DECLINE message across internal TCP socket */
+int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
+{
+	struct smc_clc_msg_decline dclc;
+	struct msghdr msg;
+	struct kvec vec;
+	int len;
+
+	memset(&dclc, 0, sizeof(dclc));
+	memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+	dclc.hdr.type = SMC_CLC_DECLINE;
+	dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
+	dclc.hdr.version = SMC_CLC_V1;
+	dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0;
+	if (smc->conn.lgr && !smc->conn.lgr->is_smcd)
+		memcpy(dclc.id_for_peer, local_systemid,
+		       sizeof(local_systemid));
+	dclc.peer_diagnosis = htonl(peer_diag_info);
+	memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+
+	memset(&msg, 0, sizeof(msg));
+	vec.iov_base = &dclc;
+	vec.iov_len = sizeof(struct smc_clc_msg_decline);
+	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
+			     sizeof(struct smc_clc_msg_decline));
+	if (len < sizeof(struct smc_clc_msg_decline))
+		smc->sk.sk_err = EPROTO;
+	if (len < 0)
+		smc->sk.sk_err = -len;
+	return sock_error(&smc->sk);
+}
+
+/* send CLC PROPOSAL message across internal TCP socket */
+int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
+			  struct smc_ib_device *ibdev, u8 ibport, u8 gid[],
+			  struct smcd_dev *ismdev)
+{
+	struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
+	struct smc_clc_msg_proposal_prefix pclc_prfx;
+	struct smc_clc_msg_smcd pclc_smcd;
+	struct smc_clc_msg_proposal pclc;
+	struct smc_clc_msg_trail trl;
+	int len, i, plen, rc;
+	int reason_code = 0;
+	struct kvec vec[5];
+	struct msghdr msg;
+
+	/* retrieve ip prefixes for CLC proposal msg */
+	rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
+	if (rc)
+		return SMC_CLC_DECL_CNFERR; /* configuration error */
+
+	/* send SMC Proposal CLC message */
+	plen = sizeof(pclc) + sizeof(pclc_prfx) +
+	       (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
+	       sizeof(trl);
+	memset(&pclc, 0, sizeof(pclc));
+	memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+	pclc.hdr.type = SMC_CLC_PROPOSAL;
+	pclc.hdr.version = SMC_CLC_V1;		/* SMC version */
+	pclc.hdr.path = smc_type;
+	if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
+		/* add SMC-R specifics */
+		memcpy(pclc.lcl.id_for_peer, local_systemid,
+		       sizeof(local_systemid));
+		memcpy(&pclc.lcl.gid, gid, SMC_GID_SIZE);
+		memcpy(&pclc.lcl.mac, &ibdev->mac[ibport - 1], ETH_ALEN);
+		pclc.iparea_offset = htons(0);
+	}
+	if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
+		/* add SMC-D specifics */
+		memset(&pclc_smcd, 0, sizeof(pclc_smcd));
+		plen += sizeof(pclc_smcd);
+		pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
+		pclc_smcd.gid = ismdev->local_gid;
+	}
+	pclc.hdr.length = htons(plen);
+
+	memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+	memset(&msg, 0, sizeof(msg));
+	i = 0;
+	vec[i].iov_base = &pclc;
+	vec[i++].iov_len = sizeof(pclc);
+	if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
+		vec[i].iov_base = &pclc_smcd;
+		vec[i++].iov_len = sizeof(pclc_smcd);
+	}
+	vec[i].iov_base = &pclc_prfx;
+	vec[i++].iov_len = sizeof(pclc_prfx);
+	if (pclc_prfx.ipv6_prefixes_cnt > 0) {
+		vec[i].iov_base = &ipv6_prfx[0];
+		vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
+				   sizeof(ipv6_prfx[0]);
+	}
+	vec[i].iov_base = &trl;
+	vec[i++].iov_len = sizeof(trl);
+	/* due to the few bytes needed for clc-handshake this cannot block */
+	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
+	if (len < 0) {
+		smc->sk.sk_err = smc->clcsock->sk->sk_err;
+		reason_code = -smc->sk.sk_err;
+	} else if (len < (int)sizeof(pclc)) {
+		reason_code = -ENETUNREACH;
+		smc->sk.sk_err = -reason_code;
+	}
+
+	return reason_code;
+}
+
+/* send CLC CONFIRM message across internal TCP socket */
+int smc_clc_send_confirm(struct smc_sock *smc)
+{
+	struct smc_connection *conn = &smc->conn;
+	struct smc_clc_msg_accept_confirm cclc;
+	struct smc_link *link;
+	int reason_code = 0;
+	struct msghdr msg;
+	struct kvec vec;
+	int len;
+
+	/* send SMC Confirm CLC msg */
+	memset(&cclc, 0, sizeof(cclc));
+	cclc.hdr.type = SMC_CLC_CONFIRM;
+	cclc.hdr.version = SMC_CLC_V1;		/* SMC version */
+	if (smc->conn.lgr->is_smcd) {
+		/* SMC-D specific settings */
+		memcpy(cclc.hdr.eyecatcher, SMCD_EYECATCHER,
+		       sizeof(SMCD_EYECATCHER));
+		cclc.hdr.path = SMC_TYPE_D;
+		cclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
+		cclc.gid = conn->lgr->smcd->local_gid;
+		cclc.token = conn->rmb_desc->token;
+		cclc.dmbe_size = conn->rmbe_size_short;
+		cclc.dmbe_idx = 0;
+		memcpy(&cclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
+		memcpy(cclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
+		       sizeof(SMCD_EYECATCHER));
+	} else {
+		/* SMC-R specific settings */
+		link = &conn->lgr->lnk[SMC_SINGLE_LINK];
+		memcpy(cclc.hdr.eyecatcher, SMC_EYECATCHER,
+		       sizeof(SMC_EYECATCHER));
+		cclc.hdr.path = SMC_TYPE_R;
+		cclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
+		memcpy(cclc.lcl.id_for_peer, local_systemid,
+		       sizeof(local_systemid));
+		memcpy(&cclc.lcl.gid, link->gid, SMC_GID_SIZE);
+		memcpy(&cclc.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
+		       ETH_ALEN);
+		hton24(cclc.qpn, link->roce_qp->qp_num);
+		cclc.rmb_rkey =
+			htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+		cclc.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
+		cclc.rmbe_alert_token = htonl(conn->alert_token_local);
+		cclc.qp_mtu = min(link->path_mtu, link->peer_mtu);
+		cclc.rmbe_size = conn->rmbe_size_short;
+		cclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
+				(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
+		hton24(cclc.psn, link->psn_initial);
+		memcpy(cclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
+		       sizeof(SMC_EYECATCHER));
+	}
+
+	memset(&msg, 0, sizeof(msg));
+	vec.iov_base = &cclc;
+	vec.iov_len = ntohs(cclc.hdr.length);
+	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
+			     ntohs(cclc.hdr.length));
+	if (len < ntohs(cclc.hdr.length)) {
+		if (len >= 0) {
+			reason_code = -ENETUNREACH;
+			smc->sk.sk_err = -reason_code;
+		} else {
+			smc->sk.sk_err = smc->clcsock->sk->sk_err;
+			reason_code = -smc->sk.sk_err;
+		}
+	}
+	return reason_code;
+}
+
+/* send CLC ACCEPT message across internal TCP socket */
+int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
+{
+	struct smc_connection *conn = &new_smc->conn;
+	struct smc_clc_msg_accept_confirm aclc;
+	struct smc_link *link;
+	struct msghdr msg;
+	struct kvec vec;
+	int rc = 0;
+	int len;
+
+	memset(&aclc, 0, sizeof(aclc));
+	aclc.hdr.type = SMC_CLC_ACCEPT;
+	aclc.hdr.version = SMC_CLC_V1;		/* SMC version */
+	if (srv_first_contact)
+		aclc.hdr.flag = 1;
+
+	if (new_smc->conn.lgr->is_smcd) {
+		/* SMC-D specific settings */
+		aclc.hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
+		memcpy(aclc.hdr.eyecatcher, SMCD_EYECATCHER,
+		       sizeof(SMCD_EYECATCHER));
+		aclc.hdr.path = SMC_TYPE_D;
+		aclc.gid = conn->lgr->smcd->local_gid;
+		aclc.token = conn->rmb_desc->token;
+		aclc.dmbe_size = conn->rmbe_size_short;
+		aclc.dmbe_idx = 0;
+		memcpy(&aclc.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
+		memcpy(aclc.smcd_trl.eyecatcher, SMCD_EYECATCHER,
+		       sizeof(SMCD_EYECATCHER));
+	} else {
+		/* SMC-R specific settings */
+		aclc.hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
+		memcpy(aclc.hdr.eyecatcher, SMC_EYECATCHER,
+		       sizeof(SMC_EYECATCHER));
+		aclc.hdr.path = SMC_TYPE_R;
+		link = &conn->lgr->lnk[SMC_SINGLE_LINK];
+		memcpy(aclc.lcl.id_for_peer, local_systemid,
+		       sizeof(local_systemid));
+		memcpy(&aclc.lcl.gid, link->gid, SMC_GID_SIZE);
+		memcpy(&aclc.lcl.mac, link->smcibdev->mac[link->ibport - 1],
+		       ETH_ALEN);
+		hton24(aclc.qpn, link->roce_qp->qp_num);
+		aclc.rmb_rkey =
+			htonl(conn->rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+		aclc.rmbe_idx = 1;		/* as long as 1 RMB = 1 RMBE */
+		aclc.rmbe_alert_token = htonl(conn->alert_token_local);
+		aclc.qp_mtu = link->path_mtu;
+		aclc.rmbe_size = conn->rmbe_size_short,
+		aclc.rmb_dma_addr = cpu_to_be64((u64)sg_dma_address
+				(conn->rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
+		hton24(aclc.psn, link->psn_initial);
+		memcpy(aclc.smcr_trl.eyecatcher, SMC_EYECATCHER,
+		       sizeof(SMC_EYECATCHER));
+	}
+
+	memset(&msg, 0, sizeof(msg));
+	vec.iov_base = &aclc;
+	vec.iov_len = ntohs(aclc.hdr.length);
+	len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
+			     ntohs(aclc.hdr.length));
+	if (len < ntohs(aclc.hdr.length)) {
+		if (len >= 0)
+			new_smc->sk.sk_err = EPROTO;
+		else
+			new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
+		rc = sock_error(&new_smc->sk);
+	}
+
+	return rc;
+}