// 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);
const struct in_ifaddr *ifa;
if (!in_dev)
return -ENODEV;
in_dev_for_each_ifa_rcu(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;
}
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([31mCONFIG_IPV6[0m)
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 */
kernel_getsockname(clcsock, (struct sockaddr *)&addrs);
/* 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);
const struct in_ifaddr *ifa;
if (!in_dev)
return -ENODEV;
in_dev_for_each_ifa_rcu(ifa, in_dev) {
if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
inet_ifa_match(prop->outgoing_subnet, ifa))
return 0;
}
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([31mCONFIG_IPV6[0m)
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, unsigned long timeout)
{
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;
clc_sk->sk_rcvtimeo = timeout;
iov_iter_kvec(&msg.msg_iter, READ, &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;
if (clc_sk->sk_err == EAGAIN &&
expected_type == SMC_CLC_DECLINE)
clc_sk->sk_err = 0; /* reset for fallback usage */
else
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) {
if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
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, &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:
clc_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;
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 < 0 || len < sizeof(struct smc_clc_msg_decline))
len = -EPROTO;
return len > 0 ? 0 : len;
}
/* send CLC PROPOSAL message across internal TCP socket */
int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
struct smc_init_info *ini)
{
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, ini->ib_gid, SMC_GID_SIZE);
memcpy(&pclc.lcl.mac, &ini->ib_dev->mac[ini->ib_port - 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 = ini->ism_dev->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 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))
len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
return len > 0 ? 0 : len;
}