net/smc/smc_clc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  CLC (connection layer control) handshake over initial TCP socket to
   6  *  prepare for RDMA traffic
   7  *
   8  *  Copyright IBM Corp. 2016, 2018
   9  *
  10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  11  */
  12
  13 #include <linux/in.h>
  14 #include <linux/inetdevice.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/utsname.h>
  18 #include <linux/ctype.h>
  19
  20 #include <net/addrconf.h>
  21 #include <net/sock.h>
  22 #include <net/tcp.h>
  23
  24 #include "smc.h"
  25 #include "smc_core.h"
  26 #include "smc_clc.h"
  27 #include "smc_ib.h"
  28 #include "smc_ism.h"
  29 #include "smc_netlink.h"
  30
  31 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
  32 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
  33 #define SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 78
  34 #define SMCR_CLC_ACCEPT_CONFIRM_LEN_V2 108
  35 #define SMC_CLC_RECV_BUF_LEN    100
  36
  37 /* eye catcher "SMCR" EBCDIC for CLC messages */
  38 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
  39 /* eye catcher "SMCD" EBCDIC for CLC messages */
  40 static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
  41
  42 static u8 smc_hostname[SMC_MAX_HOSTNAME_LEN];
  43
  44 struct smc_clc_eid_table {
  45         rwlock_t lock;
  46         struct list_head list;
  47         u8 ueid_cnt;
  48         u8 seid_enabled;
  49 };
  50
  51 static struct smc_clc_eid_table smc_clc_eid_table;
  52
  53 struct smc_clc_eid_entry {
  54         struct list_head list;
  55         u8 eid[SMC_MAX_EID_LEN];
  56 };
  57
  58 /* The size of a user EID is 32 characters.
  59  * Valid characters should be (single-byte character set) A-Z, 0-9, '.' and '-'.
  60  * Blanks should only be used to pad to the expected size.
  61  * First character must be alphanumeric.
  62  */
  63 static bool smc_clc_ueid_valid(char *ueid)
  64 {
  65         char *end = ueid + SMC_MAX_EID_LEN;
  66
  67         while (--end >= ueid && isspace(*end))
  68                 ;
  69         if (end < ueid)
  70                 return false;
  71         if (!isalnum(*ueid) || islower(*ueid))
  72                 return false;
  73         while (ueid <= end) {
  74                 if ((!isalnum(*ueid) || islower(*ueid)) && *ueid != '.' &&
  75                     *ueid != '-')
  76                         return false;
  77                 ueid++;
  78         }
  79         return true;
  80 }
  81
  82 static int smc_clc_ueid_add(char *ueid)
  83 {
  84         struct smc_clc_eid_entry *new_ueid, *tmp_ueid;
  85         int rc;
  86
  87         if (!smc_clc_ueid_valid(ueid))
  88                 return -EINVAL;
  89
  90         /* add a new ueid entry to the ueid table if there isn't one */
  91         new_ueid = kzalloc(sizeof(*new_ueid), GFP_KERNEL);
  92         if (!new_ueid)
  93                 return -ENOMEM;
  94         memcpy(new_ueid->eid, ueid, SMC_MAX_EID_LEN);
  95
  96         write_lock(&smc_clc_eid_table.lock);
  97         if (smc_clc_eid_table.ueid_cnt >= SMC_MAX_UEID) {
  98                 rc = -ERANGE;
  99                 goto err_out;
 100         }
 101         list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
 102                 if (!memcmp(tmp_ueid->eid, ueid, SMC_MAX_EID_LEN)) {
 103                         rc = -EEXIST;
 104                         goto err_out;
 105                 }
 106         }
 107         list_add_tail(&new_ueid->list, &smc_clc_eid_table.list);
 108         smc_clc_eid_table.ueid_cnt++;
 109         write_unlock(&smc_clc_eid_table.lock);
 110         return 0;
 111
 112 err_out:
 113         write_unlock(&smc_clc_eid_table.lock);
 114         kfree(new_ueid);
 115         return rc;
 116 }
 117
 118 int smc_clc_ueid_count(void)
 119 {
 120         int count;
 121
 122         read_lock(&smc_clc_eid_table.lock);
 123         count = smc_clc_eid_table.ueid_cnt;
 124         read_unlock(&smc_clc_eid_table.lock);
 125
 126         return count;
 127 }
 128
 129 int smc_nl_add_ueid(struct sk_buff *skb, struct genl_info *info)
 130 {
 131         struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
 132         char *ueid;
 133
 134         if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
 135                 return -EINVAL;
 136         ueid = (char *)nla_data(nla_ueid);
 137
 138         return smc_clc_ueid_add(ueid);
 139 }
 140
 141 /* remove one or all ueid entries from the table */
 142 static int smc_clc_ueid_remove(char *ueid)
 143 {
 144         struct smc_clc_eid_entry *lst_ueid, *tmp_ueid;
 145         int rc = -ENOENT;
 146
 147         /* remove table entry */
 148         write_lock(&smc_clc_eid_table.lock);
 149         list_for_each_entry_safe(lst_ueid, tmp_ueid, &smc_clc_eid_table.list,
 150                                  list) {
 151                 if (!ueid || !memcmp(lst_ueid->eid, ueid, SMC_MAX_EID_LEN)) {
 152                         list_del(&lst_ueid->list);
 153                         smc_clc_eid_table.ueid_cnt--;
 154                         kfree(lst_ueid);
 155                         rc = 0;
 156                 }
 157         }
 158 #if IS_ENABLED(CONFIG_S390)
 159         if (!rc && !smc_clc_eid_table.ueid_cnt) {
 160                 smc_clc_eid_table.seid_enabled = 1;
 161                 rc = -EAGAIN;   /* indicate success and enabling of seid */
 162         }
 163 #endif
 164         write_unlock(&smc_clc_eid_table.lock);
 165         return rc;
 166 }
 167
 168 int smc_nl_remove_ueid(struct sk_buff *skb, struct genl_info *info)
 169 {
 170         struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
 171         char *ueid;
 172
 173         if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
 174                 return -EINVAL;
 175         ueid = (char *)nla_data(nla_ueid);
 176
 177         return smc_clc_ueid_remove(ueid);
 178 }
 179
 180 int smc_nl_flush_ueid(struct sk_buff *skb, struct genl_info *info)
 181 {
 182         smc_clc_ueid_remove(NULL);
 183         return 0;
 184 }
 185
 186 static int smc_nl_ueid_dumpinfo(struct sk_buff *skb, u32 portid, u32 seq,
 187                                 u32 flags, char *ueid)
 188 {
 189         char ueid_str[SMC_MAX_EID_LEN + 1];
 190         void *hdr;
 191
 192         hdr = genlmsg_put(skb, portid, seq, &smc_gen_nl_family,
 193                           flags, SMC_NETLINK_DUMP_UEID);
 194         if (!hdr)
 195                 return -ENOMEM;
 196         memcpy(ueid_str, ueid, SMC_MAX_EID_LEN);
 197         ueid_str[SMC_MAX_EID_LEN] = 0;
 198         if (nla_put_string(skb, SMC_NLA_EID_TABLE_ENTRY, ueid_str)) {
 199                 genlmsg_cancel(skb, hdr);
 200                 return -EMSGSIZE;
 201         }
 202         genlmsg_end(skb, hdr);
 203         return 0;
 204 }
 205
 206 static int _smc_nl_ueid_dump(struct sk_buff *skb, u32 portid, u32 seq,
 207                              int start_idx)
 208 {
 209         struct smc_clc_eid_entry *lst_ueid;
 210         int idx = 0;
 211
 212         read_lock(&smc_clc_eid_table.lock);
 213         list_for_each_entry(lst_ueid, &smc_clc_eid_table.list, list) {
 214                 if (idx++ < start_idx)
 215                         continue;
 216                 if (smc_nl_ueid_dumpinfo(skb, portid, seq, NLM_F_MULTI,
 217                                          lst_ueid->eid)) {
 218                         --idx;
 219                         break;
 220                 }
 221         }
 222         read_unlock(&smc_clc_eid_table.lock);
 223         return idx;
 224 }
 225
 226 int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb)
 227 {
 228         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 229         int idx;
 230
 231         idx = _smc_nl_ueid_dump(skb, NETLINK_CB(cb->skb).portid,
 232                                 cb->nlh->nlmsg_seq, cb_ctx->pos[0]);
 233
 234         cb_ctx->pos[0] = idx;
 235         return skb->len;
 236 }
 237
 238 int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)
 239 {
 240         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 241         char seid_str[SMC_MAX_EID_LEN + 1];
 242         u8 seid_enabled;
 243         void *hdr;
 244         u8 *seid;
 245
 246         if (cb_ctx->pos[0])
 247                 return skb->len;
 248
 249         hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 250                           &smc_gen_nl_family, NLM_F_MULTI,
 251                           SMC_NETLINK_DUMP_SEID);
 252         if (!hdr)
 253                 return -ENOMEM;
 254         if (!smc_ism_is_v2_capable())
 255                 goto end;
 256
 257         smc_ism_get_system_eid(&seid);
 258         memcpy(seid_str, seid, SMC_MAX_EID_LEN);
 259         seid_str[SMC_MAX_EID_LEN] = 0;
 260         if (nla_put_string(skb, SMC_NLA_SEID_ENTRY, seid_str))
 261                 goto err;
 262         read_lock(&smc_clc_eid_table.lock);
 263         seid_enabled = smc_clc_eid_table.seid_enabled;
 264         read_unlock(&smc_clc_eid_table.lock);
 265         if (nla_put_u8(skb, SMC_NLA_SEID_ENABLED, seid_enabled))
 266                 goto err;
 267 end:
 268         genlmsg_end(skb, hdr);
 269         cb_ctx->pos[0]++;
 270         return skb->len;
 271 err:
 272         genlmsg_cancel(skb, hdr);
 273         return -EMSGSIZE;
 274 }
 275
 276 int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
 277 {
 278 #if IS_ENABLED(CONFIG_S390)
 279         write_lock(&smc_clc_eid_table.lock);
 280         smc_clc_eid_table.seid_enabled = 1;
 281         write_unlock(&smc_clc_eid_table.lock);
 282         return 0;
 283 #else
 284         return -EOPNOTSUPP;
 285 #endif
 286 }
 287
 288 int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
 289 {
 290         int rc = 0;
 291
 292 #if IS_ENABLED(CONFIG_S390)
 293         write_lock(&smc_clc_eid_table.lock);
 294         if (!smc_clc_eid_table.ueid_cnt)
 295                 rc = -ENOENT;
 296         else
 297                 smc_clc_eid_table.seid_enabled = 0;
 298         write_unlock(&smc_clc_eid_table.lock);
 299 #else
 300         rc = -EOPNOTSUPP;
 301 #endif
 302         return rc;
 303 }
 304
 305 static bool _smc_clc_match_ueid(u8 *peer_ueid)
 306 {
 307         struct smc_clc_eid_entry *tmp_ueid;
 308
 309         list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
 310                 if (!memcmp(tmp_ueid->eid, peer_ueid, SMC_MAX_EID_LEN))
 311                         return true;
 312         }
 313         return false;
 314 }
 315
 316 bool smc_clc_match_eid(u8 *negotiated_eid,
 317                        struct smc_clc_v2_extension *smc_v2_ext,
 318                        u8 *peer_eid, u8 *local_eid)
 319 {
 320         bool match = false;
 321         int i;
 322
 323         negotiated_eid[0] = 0;
 324         read_lock(&smc_clc_eid_table.lock);
 325         if (peer_eid && local_eid &&
 326             smc_clc_eid_table.seid_enabled &&
 327             smc_v2_ext->hdr.flag.seid &&
 328             !memcmp(peer_eid, local_eid, SMC_MAX_EID_LEN)) {
 329                 memcpy(negotiated_eid, peer_eid, SMC_MAX_EID_LEN);
 330                 match = true;
 331                 goto out;
 332         }
 333
 334         for (i = 0; i < smc_v2_ext->hdr.eid_cnt; i++) {
 335                 if (_smc_clc_match_ueid(smc_v2_ext->user_eids[i])) {
 336                         memcpy(negotiated_eid, smc_v2_ext->user_eids[i],
 337                                SMC_MAX_EID_LEN);
 338                         match = true;
 339                         goto out;
 340                 }
 341         }
 342 out:
 343         read_unlock(&smc_clc_eid_table.lock);
 344         return match;
 345 }
 346
 347 /* check arriving CLC proposal */
 348 static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
 349 {
 350         struct smc_clc_msg_proposal_prefix *pclc_prfx;
 351         struct smc_clc_smcd_v2_extension *smcd_v2_ext;
 352         struct smc_clc_msg_hdr *hdr = &pclc->hdr;
 353         struct smc_clc_v2_extension *v2_ext;
 354
 355         v2_ext = smc_get_clc_v2_ext(pclc);
 356         pclc_prfx = smc_clc_proposal_get_prefix(pclc);
 357         if (hdr->version == SMC_V1) {
 358                 if (hdr->typev1 == SMC_TYPE_N)
 359                         return false;
 360                 if (ntohs(hdr->length) !=
 361                         sizeof(*pclc) + ntohs(pclc->iparea_offset) +
 362                         sizeof(*pclc_prfx) +
 363                         pclc_prfx->ipv6_prefixes_cnt *
 364                                 sizeof(struct smc_clc_ipv6_prefix) +
 365                         sizeof(struct smc_clc_msg_trail))
 366                         return false;
 367         } else {
 368                 if (ntohs(hdr->length) !=
 369                         sizeof(*pclc) +
 370                         sizeof(struct smc_clc_msg_smcd) +
 371                         (hdr->typev1 != SMC_TYPE_N ?
 372                                 sizeof(*pclc_prfx) +
 373                                 pclc_prfx->ipv6_prefixes_cnt *
 374                                 sizeof(struct smc_clc_ipv6_prefix) : 0) +
 375                         (hdr->typev2 != SMC_TYPE_N ?
 376                                 sizeof(*v2_ext) +
 377                                 v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN : 0) +
 378                         (smcd_indicated(hdr->typev2) ?
 379                                 sizeof(*smcd_v2_ext) + v2_ext->hdr.ism_gid_cnt *
 380                                         sizeof(struct smc_clc_smcd_gid_chid) :
 381                                 0) +
 382                         sizeof(struct smc_clc_msg_trail))
 383                         return false;
 384         }
 385         return true;
 386 }
 387
 388 /* check arriving CLC accept or confirm */
 389 static bool
 390 smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
 391 {
 392         struct smc_clc_msg_hdr *hdr = &clc_v2->hdr;
 393
 394         if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
 395                 return false;
 396         if (hdr->version == SMC_V1) {
 397                 if ((hdr->typev1 == SMC_TYPE_R &&
 398                      ntohs(hdr->length) != SMCR_CLC_ACCEPT_CONFIRM_LEN) ||
 399                     (hdr->typev1 == SMC_TYPE_D &&
 400                      ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN))
 401                         return false;
 402         } else {
 403                 if (hdr->typev1 == SMC_TYPE_D &&
 404                     ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
 405                     (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
 406                                 sizeof(struct smc_clc_first_contact_ext)))
 407                         return false;
 408                 if (hdr->typev1 == SMC_TYPE_R &&
 409                     ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
 410                         return false;
 411         }
 412         return true;
 413 }
 414
 415 /* check arriving CLC decline */
 416 static bool
 417 smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 418 {
 419         struct smc_clc_msg_hdr *hdr = &dclc->hdr;
 420
 421         if (hdr->typev1 != SMC_TYPE_R && hdr->typev1 != SMC_TYPE_D)
 422                 return false;
 423         if (hdr->version == SMC_V1) {
 424                 if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline))
 425                         return false;
 426         } else {
 427                 if (ntohs(hdr->length) != sizeof(struct smc_clc_msg_decline_v2))
 428                         return false;
 429         }
 430         return true;
 431 }
 432
 433 static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
 434 {
 435         memset(fce, 0, sizeof(*fce));
 436         fce->os_type = SMC_CLC_OS_LINUX;
 437         fce->release = SMC_RELEASE;
 438         memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
 439         (*len) += sizeof(*fce);
 440 }
 441
 442 /* check if received message has a correct header length and contains valid
 443  * heading and trailing eyecatchers
 444  */
 445 static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
 446 {
 447         struct smc_clc_msg_accept_confirm_v2 *clc_v2;
 448         struct smc_clc_msg_proposal *pclc;
 449         struct smc_clc_msg_decline *dclc;
 450         struct smc_clc_msg_trail *trl;
 451
 452         if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
 453             memcmp(clcm->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
 454                 return false;
 455         switch (clcm->type) {
 456         case SMC_CLC_PROPOSAL:
 457                 pclc = (struct smc_clc_msg_proposal *)clcm;
 458                 if (!smc_clc_msg_prop_valid(pclc))
 459                         return false;
 460                 trl = (struct smc_clc_msg_trail *)
 461                         ((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
 462                 break;
 463         case SMC_CLC_ACCEPT:
 464         case SMC_CLC_CONFIRM:
 465                 clc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)clcm;
 466                 if (!smc_clc_msg_acc_conf_valid(clc_v2))
 467                         return false;
 468                 trl = (struct smc_clc_msg_trail *)
 469                         ((u8 *)clc_v2 + ntohs(clc_v2->hdr.length) -
 470                                                         sizeof(*trl));
 471                 break;
 472         case SMC_CLC_DECLINE:
 473                 dclc = (struct smc_clc_msg_decline *)clcm;
 474                 if (!smc_clc_msg_decl_valid(dclc))
 475                         return false;
 476                 check_trl = false;
 477                 break;
 478         default:
 479                 return false;
 480         }
 481         if (check_trl &&
 482             memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
 483             memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
 484                 return false;
 485         return true;
 486 }
 487
 488 /* find ipv4 addr on device and get the prefix len, fill CLC proposal msg */
 489 static int smc_clc_prfx_set4_rcu(struct dst_entry *dst, __be32 ipv4,
 490                                  struct smc_clc_msg_proposal_prefix *prop)
 491 {
 492         struct in_device *in_dev = __in_dev_get_rcu(dst->dev);
 493         const struct in_ifaddr *ifa;
 494
 495         if (!in_dev)
 496                 return -ENODEV;
 497
 498         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 499                 if (!inet_ifa_match(ipv4, ifa))
 500                         continue;
 501                 prop->prefix_len = inet_mask_len(ifa->ifa_mask);
 502                 prop->outgoing_subnet = ifa->ifa_address & ifa->ifa_mask;
 503                 /* prop->ipv6_prefixes_cnt = 0; already done by memset before */
 504                 return 0;
 505         }
 506         return -ENOENT;
 507 }
 508
 509 /* fill CLC proposal msg with ipv6 prefixes from device */
 510 static int smc_clc_prfx_set6_rcu(struct dst_entry *dst,
 511                                  struct smc_clc_msg_proposal_prefix *prop,
 512                                  struct smc_clc_ipv6_prefix *ipv6_prfx)
 513 {
 514 #if IS_ENABLED(CONFIG_IPV6)
 515         struct inet6_dev *in6_dev = __in6_dev_get(dst->dev);
 516         struct inet6_ifaddr *ifa;
 517         int cnt = 0;
 518
 519         if (!in6_dev)
 520                 return -ENODEV;
 521         /* use a maximum of 8 IPv6 prefixes from device */
 522         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 523                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 524                         continue;
 525                 ipv6_addr_prefix(&ipv6_prfx[cnt].prefix,
 526                                  &ifa->addr, ifa->prefix_len);
 527                 ipv6_prfx[cnt].prefix_len = ifa->prefix_len;
 528                 cnt++;
 529                 if (cnt == SMC_CLC_MAX_V6_PREFIX)
 530                         break;
 531         }
 532         prop->ipv6_prefixes_cnt = cnt;
 533         if (cnt)
 534                 return 0;
 535 #endif
 536         return -ENOENT;
 537 }
 538
 539 /* retrieve and set prefixes in CLC proposal msg */
 540 static int smc_clc_prfx_set(struct socket *clcsock,
 541                             struct smc_clc_msg_proposal_prefix *prop,
 542                             struct smc_clc_ipv6_prefix *ipv6_prfx)
 543 {
 544         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 545         struct sockaddr_storage addrs;
 546         struct sockaddr_in6 *addr6;
 547         struct sockaddr_in *addr;
 548         int rc = -ENOENT;
 549
 550         if (!dst) {
 551                 rc = -ENOTCONN;
 552                 goto out;
 553         }
 554         if (!dst->dev) {
 555                 rc = -ENODEV;
 556                 goto out_rel;
 557         }
 558         /* get address to which the internal TCP socket is bound */
 559         if (kernel_getsockname(clcsock, (struct sockaddr *)&addrs) < 0)
 560                 goto out_rel;
 561         /* analyze IP specific data of net_device belonging to TCP socket */
 562         addr6 = (struct sockaddr_in6 *)&addrs;
 563         rcu_read_lock();
 564         if (addrs.ss_family == PF_INET) {
 565                 /* IPv4 */
 566                 addr = (struct sockaddr_in *)&addrs;
 567                 rc = smc_clc_prfx_set4_rcu(dst, addr->sin_addr.s_addr, prop);
 568         } else if (ipv6_addr_v4mapped(&addr6->sin6_addr)) {
 569                 /* mapped IPv4 address - peer is IPv4 only */
 570                 rc = smc_clc_prfx_set4_rcu(dst, addr6->sin6_addr.s6_addr32[3],
 571                                            prop);
 572         } else {
 573                 /* IPv6 */
 574                 rc = smc_clc_prfx_set6_rcu(dst, prop, ipv6_prfx);
 575         }
 576         rcu_read_unlock();
 577 out_rel:
 578         dst_release(dst);
 579 out:
 580         return rc;
 581 }
 582
 583 /* match ipv4 addrs of dev against addr in CLC proposal */
 584 static int smc_clc_prfx_match4_rcu(struct net_device *dev,
 585                                    struct smc_clc_msg_proposal_prefix *prop)
 586 {
 587         struct in_device *in_dev = __in_dev_get_rcu(dev);
 588         const struct in_ifaddr *ifa;
 589
 590         if (!in_dev)
 591                 return -ENODEV;
 592         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 593                 if (prop->prefix_len == inet_mask_len(ifa->ifa_mask) &&
 594                     inet_ifa_match(prop->outgoing_subnet, ifa))
 595                         return 0;
 596         }
 597
 598         return -ENOENT;
 599 }
 600
 601 /* match ipv6 addrs of dev against addrs in CLC proposal */
 602 static int smc_clc_prfx_match6_rcu(struct net_device *dev,
 603                                    struct smc_clc_msg_proposal_prefix *prop)
 604 {
 605 #if IS_ENABLED(CONFIG_IPV6)
 606         struct inet6_dev *in6_dev = __in6_dev_get(dev);
 607         struct smc_clc_ipv6_prefix *ipv6_prfx;
 608         struct inet6_ifaddr *ifa;
 609         int i, max;
 610
 611         if (!in6_dev)
 612                 return -ENODEV;
 613         /* ipv6 prefix list starts behind smc_clc_msg_proposal_prefix */
 614         ipv6_prfx = (struct smc_clc_ipv6_prefix *)((u8 *)prop + sizeof(*prop));
 615         max = min_t(u8, prop->ipv6_prefixes_cnt, SMC_CLC_MAX_V6_PREFIX);
 616         list_for_each_entry(ifa, &in6_dev->addr_list, if_list) {
 617                 if (ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)
 618                         continue;
 619                 for (i = 0; i < max; i++) {
 620                         if (ifa->prefix_len == ipv6_prfx[i].prefix_len &&
 621                             ipv6_prefix_equal(&ifa->addr, &ipv6_prfx[i].prefix,
 622                                               ifa->prefix_len))
 623                                 return 0;
 624                 }
 625         }
 626 #endif
 627         return -ENOENT;
 628 }
 629
 630 /* check if proposed prefixes match one of our device prefixes */
 631 int smc_clc_prfx_match(struct socket *clcsock,
 632                        struct smc_clc_msg_proposal_prefix *prop)
 633 {
 634         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 635         int rc;
 636
 637         if (!dst) {
 638                 rc = -ENOTCONN;
 639                 goto out;
 640         }
 641         if (!dst->dev) {
 642                 rc = -ENODEV;
 643                 goto out_rel;
 644         }
 645         rcu_read_lock();
 646         if (!prop->ipv6_prefixes_cnt)
 647                 rc = smc_clc_prfx_match4_rcu(dst->dev, prop);
 648         else
 649                 rc = smc_clc_prfx_match6_rcu(dst->dev, prop);
 650         rcu_read_unlock();
 651 out_rel:
 652         dst_release(dst);
 653 out:
 654         return rc;
 655 }
 656
 657 /* Wait for data on the tcp-socket, analyze received data
 658  * Returns:
 659  * 0 if success and it was not a decline that we received.
 660  * SMC_CLC_DECL_REPLY if decline received for fallback w/o another decl send.
 661  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
 662  */
 663 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 664                      u8 expected_type, unsigned long timeout)
 665 {
 666         long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
 667         struct sock *clc_sk = smc->clcsock->sk;
 668         struct smc_clc_msg_hdr *clcm = buf;
 669         struct msghdr msg = {NULL, 0};
 670         int reason_code = 0;
 671         struct kvec vec = {buf, buflen};
 672         int len, datlen, recvlen;
 673         bool check_trl = true;
 674         int krflags;
 675
 676         /* peek the first few bytes to determine length of data to receive
 677          * so we don't consume any subsequent CLC message or payload data
 678          * in the TCP byte stream
 679          */
 680         /*
 681          * Caller must make sure that buflen is no less than
 682          * sizeof(struct smc_clc_msg_hdr)
 683          */
 684         krflags = MSG_PEEK | MSG_WAITALL;
 685         clc_sk->sk_rcvtimeo = timeout;
 686         iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1,
 687                         sizeof(struct smc_clc_msg_hdr));
 688         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 689         if (signal_pending(current)) {
 690                 reason_code = -EINTR;
 691                 clc_sk->sk_err = EINTR;
 692                 smc->sk.sk_err = EINTR;
 693                 goto out;
 694         }
 695         if (clc_sk->sk_err) {
 696                 reason_code = -clc_sk->sk_err;
 697                 if (clc_sk->sk_err == EAGAIN &&
 698                     expected_type == SMC_CLC_DECLINE)
 699                         clc_sk->sk_err = 0; /* reset for fallback usage */
 700                 else
 701                         smc->sk.sk_err = clc_sk->sk_err;
 702                 goto out;
 703         }
 704         if (!len) { /* peer has performed orderly shutdown */
 705                 smc->sk.sk_err = ECONNRESET;
 706                 reason_code = -ECONNRESET;
 707                 goto out;
 708         }
 709         if (len < 0) {
 710                 if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
 711                         smc->sk.sk_err = -len;
 712                 reason_code = len;
 713                 goto out;
 714         }
 715         datlen = ntohs(clcm->length);
 716         if ((len < sizeof(struct smc_clc_msg_hdr)) ||
 717             (clcm->version < SMC_V1) ||
 718             ((clcm->type != SMC_CLC_DECLINE) &&
 719              (clcm->type != expected_type))) {
 720                 smc->sk.sk_err = EPROTO;
 721                 reason_code = -EPROTO;
 722                 goto out;
 723         }
 724
 725         /* receive the complete CLC message */
 726         memset(&msg, 0, sizeof(struct msghdr));
 727         if (datlen > buflen) {
 728                 check_trl = false;
 729                 recvlen = buflen;
 730         } else {
 731                 recvlen = datlen;
 732         }
 733         iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
 734         krflags = MSG_WAITALL;
 735         len = sock_recvmsg(smc->clcsock, &msg, krflags);
 736         if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
 737                 smc->sk.sk_err = EPROTO;
 738                 reason_code = -EPROTO;
 739                 goto out;
 740         }
 741         datlen -= len;
 742         while (datlen) {
 743                 u8 tmp[SMC_CLC_RECV_BUF_LEN];
 744
 745                 vec.iov_base = &tmp;
 746                 vec.iov_len = SMC_CLC_RECV_BUF_LEN;
 747                 /* receive remaining proposal message */
 748                 recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
 749                                                 SMC_CLC_RECV_BUF_LEN : datlen;
 750                 iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, recvlen);
 751                 len = sock_recvmsg(smc->clcsock, &msg, krflags);
 752                 datlen -= len;
 753         }
 754         if (clcm->type == SMC_CLC_DECLINE) {
 755                 struct smc_clc_msg_decline *dclc;
 756
 757                 dclc = (struct smc_clc_msg_decline *)clcm;
 758                 reason_code = SMC_CLC_DECL_PEERDECL;
 759                 smc->peer_diagnosis = ntohl(dclc->peer_diagnosis);
 760                 if (((struct smc_clc_msg_decline *)buf)->hdr.typev2 &
 761                                                 SMC_FIRST_CONTACT_MASK) {
 762                         smc->conn.lgr->sync_err = 1;
 763                         smc_lgr_terminate_sched(smc->conn.lgr);
 764                 }
 765         }
 766
 767 out:
 768         clc_sk->sk_rcvtimeo = rcvtimeo;
 769         return reason_code;
 770 }
 771
 772 /* send CLC DECLINE message across internal TCP socket */
 773 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
 774 {
 775         struct smc_clc_msg_decline *dclc_v1;
 776         struct smc_clc_msg_decline_v2 dclc;
 777         struct msghdr msg;
 778         int len, send_len;
 779         struct kvec vec;
 780
 781         dclc_v1 = (struct smc_clc_msg_decline *)&dclc;
 782         memset(&dclc, 0, sizeof(dclc));
 783         memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 784         dclc.hdr.type = SMC_CLC_DECLINE;
 785         dclc.hdr.version = version;
 786         dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
 787         dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
 788                                                 SMC_FIRST_CONTACT_MASK : 0;
 789         if ((!smc_conn_lgr_valid(&smc->conn) || !smc->conn.lgr->is_smcd) &&
 790             smc_ib_is_valid_local_systemid())
 791                 memcpy(dclc.id_for_peer, local_systemid,
 792                        sizeof(local_systemid));
 793         dclc.peer_diagnosis = htonl(peer_diag_info);
 794         if (version == SMC_V1) {
 795                 memcpy(dclc_v1->trl.eyecatcher, SMC_EYECATCHER,
 796                        sizeof(SMC_EYECATCHER));
 797                 send_len = sizeof(*dclc_v1);
 798         } else {
 799                 memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER,
 800                        sizeof(SMC_EYECATCHER));
 801                 send_len = sizeof(dclc);
 802         }
 803         dclc.hdr.length = htons(send_len);
 804
 805         memset(&msg, 0, sizeof(msg));
 806         vec.iov_base = &dclc;
 807         vec.iov_len = send_len;
 808         len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, send_len);
 809         if (len < 0 || len < send_len)
 810                 len = -EPROTO;
 811         return len > 0 ? 0 : len;
 812 }
 813
 814 /* send CLC PROPOSAL message across internal TCP socket */
 815 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
 816 {
 817         struct smc_clc_smcd_v2_extension *smcd_v2_ext;
 818         struct smc_clc_msg_proposal_prefix *pclc_prfx;
 819         struct smc_clc_msg_proposal *pclc_base;
 820         struct smc_clc_smcd_gid_chid *gidchids;
 821         struct smc_clc_msg_proposal_area *pclc;
 822         struct smc_clc_ipv6_prefix *ipv6_prfx;
 823         struct smc_clc_v2_extension *v2_ext;
 824         struct smc_clc_msg_smcd *pclc_smcd;
 825         struct smc_clc_msg_trail *trl;
 826         int len, i, plen, rc;
 827         int reason_code = 0;
 828         struct kvec vec[8];
 829         struct msghdr msg;
 830
 831         pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
 832         if (!pclc)
 833                 return -ENOMEM;
 834
 835         pclc_base = &pclc->pclc_base;
 836         pclc_smcd = &pclc->pclc_smcd;
 837         pclc_prfx = &pclc->pclc_prfx;
 838         ipv6_prfx = pclc->pclc_prfx_ipv6;
 839         v2_ext = &pclc->pclc_v2_ext;
 840         smcd_v2_ext = &pclc->pclc_smcd_v2_ext;
 841         gidchids = pclc->pclc_gidchids;
 842         trl = &pclc->pclc_trl;
 843
 844         pclc_base->hdr.version = SMC_V2;
 845         pclc_base->hdr.typev1 = ini->smc_type_v1;
 846         pclc_base->hdr.typev2 = ini->smc_type_v2;
 847         plen = sizeof(*pclc_base) + sizeof(*pclc_smcd) + sizeof(*trl);
 848
 849         /* retrieve ip prefixes for CLC proposal msg */
 850         if (ini->smc_type_v1 != SMC_TYPE_N) {
 851                 rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
 852                 if (rc) {
 853                         if (ini->smc_type_v2 == SMC_TYPE_N) {
 854                                 kfree(pclc);
 855                                 return SMC_CLC_DECL_CNFERR;
 856                         }
 857                         pclc_base->hdr.typev1 = SMC_TYPE_N;
 858                 } else {
 859                         pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
 860                         plen += sizeof(*pclc_prfx) +
 861                                         pclc_prfx->ipv6_prefixes_cnt *
 862                                         sizeof(ipv6_prfx[0]);
 863                 }
 864         }
 865
 866         /* build SMC Proposal CLC message */
 867         memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
 868                sizeof(SMC_EYECATCHER));
 869         pclc_base->hdr.type = SMC_CLC_PROPOSAL;
 870         if (smcr_indicated(ini->smc_type_v1)) {
 871                 /* add SMC-R specifics */
 872                 memcpy(pclc_base->lcl.id_for_peer, local_systemid,
 873                        sizeof(local_systemid));
 874                 memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
 875                 memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
 876                        ETH_ALEN);
 877         }
 878         if (smcd_indicated(ini->smc_type_v1)) {
 879                 /* add SMC-D specifics */
 880                 if (ini->ism_dev[0]) {
 881                         pclc_smcd->ism.gid = htonll(ini->ism_dev[0]->local_gid);
 882                         pclc_smcd->ism.chid =
 883                                 htons(smc_ism_get_chid(ini->ism_dev[0]));
 884                 }
 885         }
 886         if (ini->smc_type_v2 == SMC_TYPE_N) {
 887                 pclc_smcd->v2_ext_offset = 0;
 888         } else {
 889                 struct smc_clc_eid_entry *ueident;
 890                 u16 v2_ext_offset;
 891
 892                 v2_ext->hdr.flag.release = SMC_RELEASE;
 893                 v2_ext_offset = sizeof(*pclc_smcd) -
 894                         offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
 895                 if (ini->smc_type_v1 != SMC_TYPE_N)
 896                         v2_ext_offset += sizeof(*pclc_prfx) +
 897                                                 pclc_prfx->ipv6_prefixes_cnt *
 898                                                 sizeof(ipv6_prfx[0]);
 899                 pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
 900                 plen += sizeof(*v2_ext);
 901
 902                 read_lock(&smc_clc_eid_table.lock);
 903                 v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
 904                 plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
 905                 i = 0;
 906                 list_for_each_entry(ueident, &smc_clc_eid_table.list, list) {
 907                         memcpy(v2_ext->user_eids[i++], ueident->eid,
 908                                sizeof(ueident->eid));
 909                 }
 910                 read_unlock(&smc_clc_eid_table.lock);
 911         }
 912         if (smcd_indicated(ini->smc_type_v2)) {
 913                 u8 *eid = NULL;
 914
 915                 v2_ext->hdr.flag.seid = smc_clc_eid_table.seid_enabled;
 916                 v2_ext->hdr.ism_gid_cnt = ini->ism_offered_cnt;
 917                 v2_ext->hdr.smcd_v2_ext_offset = htons(sizeof(*v2_ext) -
 918                                 offsetofend(struct smc_clnt_opts_area_hdr,
 919                                             smcd_v2_ext_offset) +
 920                                 v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
 921                 smc_ism_get_system_eid(&eid);
 922                 if (eid && v2_ext->hdr.flag.seid)
 923                         memcpy(smcd_v2_ext->system_eid, eid, SMC_MAX_EID_LEN);
 924                 plen += sizeof(*smcd_v2_ext);
 925                 if (ini->ism_offered_cnt) {
 926                         for (i = 1; i <= ini->ism_offered_cnt; i++) {
 927                                 gidchids[i - 1].gid =
 928                                         htonll(ini->ism_dev[i]->local_gid);
 929                                 gidchids[i - 1].chid =
 930                                         htons(smc_ism_get_chid(ini->ism_dev[i]));
 931                         }
 932                         plen += ini->ism_offered_cnt *
 933                                 sizeof(struct smc_clc_smcd_gid_chid);
 934                 }
 935         }
 936         if (smcr_indicated(ini->smc_type_v2))
 937                 memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
 938
 939         pclc_base->hdr.length = htons(plen);
 940         memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 941
 942         /* send SMC Proposal CLC message */
 943         memset(&msg, 0, sizeof(msg));
 944         i = 0;
 945         vec[i].iov_base = pclc_base;
 946         vec[i++].iov_len = sizeof(*pclc_base);
 947         vec[i].iov_base = pclc_smcd;
 948         vec[i++].iov_len = sizeof(*pclc_smcd);
 949         if (ini->smc_type_v1 != SMC_TYPE_N) {
 950                 vec[i].iov_base = pclc_prfx;
 951                 vec[i++].iov_len = sizeof(*pclc_prfx);
 952                 if (pclc_prfx->ipv6_prefixes_cnt > 0) {
 953                         vec[i].iov_base = ipv6_prfx;
 954                         vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
 955                                            sizeof(ipv6_prfx[0]);
 956                 }
 957         }
 958         if (ini->smc_type_v2 != SMC_TYPE_N) {
 959                 vec[i].iov_base = v2_ext;
 960                 vec[i++].iov_len = sizeof(*v2_ext) +
 961                                    (v2_ext->hdr.eid_cnt * SMC_MAX_EID_LEN);
 962                 if (smcd_indicated(ini->smc_type_v2)) {
 963                         vec[i].iov_base = smcd_v2_ext;
 964                         vec[i++].iov_len = sizeof(*smcd_v2_ext);
 965                         if (ini->ism_offered_cnt) {
 966                                 vec[i].iov_base = gidchids;
 967                                 vec[i++].iov_len = ini->ism_offered_cnt *
 968                                         sizeof(struct smc_clc_smcd_gid_chid);
 969                         }
 970                 }
 971         }
 972         vec[i].iov_base = trl;
 973         vec[i++].iov_len = sizeof(*trl);
 974         /* due to the few bytes needed for clc-handshake this cannot block */
 975         len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
 976         if (len < 0) {
 977                 smc->sk.sk_err = smc->clcsock->sk->sk_err;
 978                 reason_code = -smc->sk.sk_err;
 979         } else if (len < ntohs(pclc_base->hdr.length)) {
 980                 reason_code = -ENETUNREACH;
 981                 smc->sk.sk_err = -reason_code;
 982         }
 983
 984         kfree(pclc);
 985         return reason_code;
 986 }
 987
 988 /* build and send CLC CONFIRM / ACCEPT message */
 989 static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 990                                        struct smc_clc_msg_accept_confirm_v2 *clc_v2,
 991                                        int first_contact, u8 version,
 992                                        u8 *eid, struct smc_init_info *ini)
 993 {
 994         struct smc_connection *conn = &smc->conn;
 995         struct smc_clc_msg_accept_confirm *clc;
 996         struct smc_clc_first_contact_ext fce;
 997         struct smc_clc_fce_gid_ext gle;
 998         struct smc_clc_msg_trail trl;
 999         struct kvec vec[5];
1000         struct msghdr msg;
1001         int i, len;
1002
1003         /* send SMC Confirm CLC msg */
1004         clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
1005         clc->hdr.version = version;     /* SMC version */
1006         if (first_contact)
1007                 clc->hdr.typev2 |= SMC_FIRST_CONTACT_MASK;
1008         if (conn->lgr->is_smcd) {
1009                 /* SMC-D specific settings */
1010                 memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
1011                        sizeof(SMCD_EYECATCHER));
1012                 clc->hdr.typev1 = SMC_TYPE_D;
1013                 clc->d0.gid = conn->lgr->smcd->local_gid;
1014                 clc->d0.token = conn->rmb_desc->token;
1015                 clc->d0.dmbe_size = conn->rmbe_size_comp;
1016                 clc->d0.dmbe_idx = 0;
1017                 memcpy(&clc->d0.linkid, conn->lgr->id, SMC_LGR_ID_SIZE);
1018                 if (version == SMC_V1) {
1019                         clc->hdr.length = htons(SMCD_CLC_ACCEPT_CONFIRM_LEN);
1020                 } else {
1021                         clc_v2->d1.chid =
1022                                 htons(smc_ism_get_chid(conn->lgr->smcd));
1023                         if (eid && eid[0])
1024                                 memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
1025                         len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
1026                         if (first_contact)
1027                                 smc_clc_fill_fce(&fce, &len);
1028                         clc_v2->hdr.length = htons(len);
1029                 }
1030                 memcpy(trl.eyecatcher, SMCD_EYECATCHER,
1031                        sizeof(SMCD_EYECATCHER));
1032         } else {
1033                 struct smc_link *link = conn->lnk;
1034
1035                 /* SMC-R specific settings */
1036                 memcpy(clc->hdr.eyecatcher, SMC_EYECATCHER,
1037                        sizeof(SMC_EYECATCHER));
1038                 clc->hdr.typev1 = SMC_TYPE_R;
1039                 clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1040                 memcpy(clc->r0.lcl.id_for_peer, local_systemid,
1041                        sizeof(local_systemid));
1042                 memcpy(&clc->r0.lcl.gid, link->gid, SMC_GID_SIZE);
1043                 memcpy(&clc->r0.lcl.mac, &link->smcibdev->mac[link->ibport - 1],
1044                        ETH_ALEN);
1045                 hton24(clc->r0.qpn, link->roce_qp->qp_num);
1046                 clc->r0.rmb_rkey =
1047                         htonl(conn->rmb_desc->mr[link->link_idx]->rkey);
1048                 clc->r0.rmbe_idx = 1; /* for now: 1 RMB = 1 RMBE */
1049                 clc->r0.rmbe_alert_token = htonl(conn->alert_token_local);
1050                 switch (clc->hdr.type) {
1051                 case SMC_CLC_ACCEPT:
1052                         clc->r0.qp_mtu = link->path_mtu;
1053                         break;
1054                 case SMC_CLC_CONFIRM:
1055                         clc->r0.qp_mtu = min(link->path_mtu, link->peer_mtu);
1056                         break;
1057                 }
1058                 clc->r0.rmbe_size = conn->rmbe_size_comp;
1059                 clc->r0.rmb_dma_addr = conn->rmb_desc->is_vm ?
1060                         cpu_to_be64((uintptr_t)conn->rmb_desc->cpu_addr) :
1061                         cpu_to_be64((u64)sg_dma_address
1062                                     (conn->rmb_desc->sgt[link->link_idx].sgl));
1063                 hton24(clc->r0.psn, link->psn_initial);
1064                 if (version == SMC_V1) {
1065                         clc->hdr.length = htons(SMCR_CLC_ACCEPT_CONFIRM_LEN);
1066                 } else {
1067                         if (eid && eid[0])
1068                                 memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
1069                         len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
1070                         if (first_contact) {
1071                                 smc_clc_fill_fce(&fce, &len);
1072                                 fce.v2_direct = !link->lgr->uses_gateway;
1073                                 memset(&gle, 0, sizeof(gle));
1074                                 if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
1075                                         gle.gid_cnt = ini->smcrv2.gidlist.len;
1076                                         len += sizeof(gle);
1077                                         len += gle.gid_cnt * sizeof(gle.gid[0]);
1078                                 } else {
1079                                         len += sizeof(gle.reserved);
1080                                 }
1081                         }
1082                         clc_v2->hdr.length = htons(len);
1083                 }
1084                 memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
1085         }
1086
1087         memset(&msg, 0, sizeof(msg));
1088         i = 0;
1089         vec[i].iov_base = clc_v2;
1090         if (version > SMC_V1)
1091                 vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1092                                         SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 :
1093                                         SMCR_CLC_ACCEPT_CONFIRM_LEN_V2) -
1094                                    sizeof(trl);
1095         else
1096                 vec[i++].iov_len = (clc->hdr.typev1 == SMC_TYPE_D ?
1097                                                 SMCD_CLC_ACCEPT_CONFIRM_LEN :
1098                                                 SMCR_CLC_ACCEPT_CONFIRM_LEN) -
1099                                    sizeof(trl);
1100         if (version > SMC_V1 && first_contact) {
1101                 vec[i].iov_base = &fce;
1102                 vec[i++].iov_len = sizeof(fce);
1103                 if (!conn->lgr->is_smcd) {
1104                         if (clc->hdr.type == SMC_CLC_CONFIRM) {
1105                                 vec[i].iov_base = &gle;
1106                                 vec[i++].iov_len = sizeof(gle);
1107                                 vec[i].iov_base = &ini->smcrv2.gidlist.list;
1108                                 vec[i++].iov_len = gle.gid_cnt *
1109                                                    sizeof(gle.gid[0]);
1110                         } else {
1111                                 vec[i].iov_base = &gle.reserved;
1112                                 vec[i++].iov_len = sizeof(gle.reserved);
1113                         }
1114                 }
1115         }
1116         vec[i].iov_base = &trl;
1117         vec[i++].iov_len = sizeof(trl);
1118         return kernel_sendmsg(smc->clcsock, &msg, vec, 1,
1119                               ntohs(clc->hdr.length));
1120 }
1121
1122 /* send CLC CONFIRM message across internal TCP socket */
1123 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
1124                          u8 version, u8 *eid, struct smc_init_info *ini)
1125 {
1126         struct smc_clc_msg_accept_confirm_v2 cclc_v2;
1127         int reason_code = 0;
1128         int len;
1129
1130         /* send SMC Confirm CLC msg */
1131         memset(&cclc_v2, 0, sizeof(cclc_v2));
1132         cclc_v2.hdr.type = SMC_CLC_CONFIRM;
1133         len = smc_clc_send_confirm_accept(smc, &cclc_v2, clnt_first_contact,
1134                                           version, eid, ini);
1135         if (len < ntohs(cclc_v2.hdr.length)) {
1136                 if (len >= 0) {
1137                         reason_code = -ENETUNREACH;
1138                         smc->sk.sk_err = -reason_code;
1139                 } else {
1140                         smc->sk.sk_err = smc->clcsock->sk->sk_err;
1141                         reason_code = -smc->sk.sk_err;
1142                 }
1143         }
1144         return reason_code;
1145 }
1146
1147 /* send CLC ACCEPT message across internal TCP socket */
1148 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
1149                         u8 version, u8 *negotiated_eid)
1150 {
1151         struct smc_clc_msg_accept_confirm_v2 aclc_v2;
1152         int len;
1153
1154         memset(&aclc_v2, 0, sizeof(aclc_v2));
1155         aclc_v2.hdr.type = SMC_CLC_ACCEPT;
1156         len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
1157                                           version, negotiated_eid, NULL);
1158         if (len < ntohs(aclc_v2.hdr.length))
1159                 len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
1160
1161         return len > 0 ? 0 : len;
1162 }
1163
1164 void smc_clc_get_hostname(u8 **host)
1165 {
1166         *host = &smc_hostname[0];
1167 }
1168
1169 void __init smc_clc_init(void)
1170 {
1171         struct new_utsname *u;
1172
1173         memset(smc_hostname, _S, sizeof(smc_hostname)); /* ASCII blanks */
1174         u = utsname();
1175         memcpy(smc_hostname, u->nodename,
1176                min_t(size_t, strlen(u->nodename), sizeof(smc_hostname)));
1177
1178         INIT_LIST_HEAD(&smc_clc_eid_table.list);
1179         rwlock_init(&smc_clc_eid_table.lock);
1180         smc_clc_eid_table.ueid_cnt = 0;
1181 #if IS_ENABLED(CONFIG_S390)
1182         smc_clc_eid_table.seid_enabled = 1;
1183 #else
1184         smc_clc_eid_table.seid_enabled = 0;
1185 #endif
1186 }
1187
1188 void smc_clc_exit(void)
1189 {
1190         smc_clc_ueid_remove(NULL);
1191 }