net/smc: fix link lookup for new rdma connections

For new rdma connections the SMC server assigns the link and sends the
link data in the clc accept message. To match the correct link use not
only the qp_num but also the gid and the mac of the links. If there are
equal qp_nums for different links the wrong link would be chosen.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Fixes: 0fb0b02b ("net/smc: adapt SMC client code to use the LLC flow")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/smc/af_smc.c

@@ -632,7 +632,9 @@ static int smc_connect_rdma(struct smc_sock *smc,
 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 			struct smc_link *l = &smc->conn.lgr->lnk[i];
 
-			if (l->peer_qpn == ntoh24(aclc->qpn)) {
+			if (l->peer_qpn == ntoh24(aclc->qpn) &&
+			    !memcmp(l->peer_gid, &aclc->lcl.gid, SMC_GID_SIZE) &&
+			    !memcmp(l->peer_mac, &aclc->lcl.mac, sizeof(l->peer_mac))) {
 				link = l;
 				break;
 			}