net/smc/smc_pnet.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Generic netlink support functions to configure an SMC-R PNET table
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Thomas Richter <tmricht@linux.vnet.ibm.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/list.h>
  14 #include <linux/ctype.h>
  15 #include <net/netlink.h>
  16 #include <net/genetlink.h>
  17
  18 #include <uapi/linux/if.h>
  19 #include <uapi/linux/smc.h>
  20
  21 #include <rdma/ib_verbs.h>
  22
  23 #include "smc_pnet.h"
  24 #include "smc_ib.h"
  25
  26 #define SMC_MAX_PNET_ID_LEN     16      /* Max. length of PNET id */
  27
  28 static struct nla_policy smc_pnet_policy[SMC_PNETID_MAX + 1] = {
  29         [SMC_PNETID_NAME] = {
  30                 .type = NLA_NUL_STRING,
  31                 .len = SMC_MAX_PNET_ID_LEN - 1
  32         },
  33         [SMC_PNETID_ETHNAME] = {
  34                 .type = NLA_NUL_STRING,
  35                 .len = IFNAMSIZ - 1
  36         },
  37         [SMC_PNETID_IBNAME] = {
  38                 .type = NLA_NUL_STRING,
  39                 .len = IB_DEVICE_NAME_MAX - 1
  40         },
  41         [SMC_PNETID_IBPORT] = { .type = NLA_U8 }
  42 };
  43
  44 static struct genl_family smc_pnet_nl_family;
  45
  46 /**
  47  * struct smc_pnettable - SMC PNET table anchor
  48  * @lock: Lock for list action
  49  * @pnetlist: List of PNETIDs
  50  */
  51 static struct smc_pnettable {
  52         rwlock_t lock;
  53         struct list_head pnetlist;
  54 } smc_pnettable = {
  55         .pnetlist = LIST_HEAD_INIT(smc_pnettable.pnetlist),
  56         .lock = __RW_LOCK_UNLOCKED(smc_pnettable.lock)
  57 };
  58
  59 /**
  60  * struct smc_pnetentry - pnet identifier name entry
  61  * @list: List node.
  62  * @pnet_name: Pnet identifier name
  63  * @ndev: pointer to network device.
  64  * @smcibdev: Pointer to IB device.
  65  */
  66 struct smc_pnetentry {
  67         struct list_head list;
  68         char pnet_name[SMC_MAX_PNET_ID_LEN + 1];
  69         struct net_device *ndev;
  70         struct smc_ib_device *smcibdev;
  71         u8 ib_port;
  72 };
  73
  74 /* Check if two RDMA device entries are identical. Use device name and port
  75  * number for comparison.
  76  */
  77 static bool smc_pnet_same_ibname(struct smc_pnetentry *pnetelem, char *ibname,
  78                                  u8 ibport)
  79 {
  80         return pnetelem->ib_port == ibport &&
  81                !strncmp(pnetelem->smcibdev->ibdev->name, ibname,
  82                         sizeof(pnetelem->smcibdev->ibdev->name));
  83 }
  84
  85 /* Find a pnetid in the pnet table.
  86  */
  87 static struct smc_pnetentry *smc_pnet_find_pnetid(char *pnet_name)
  88 {
  89         struct smc_pnetentry *pnetelem, *found_pnetelem = NULL;
  90
  91         read_lock(&smc_pnettable.lock);
  92         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
  93                 if (!strncmp(pnetelem->pnet_name, pnet_name,
  94                              sizeof(pnetelem->pnet_name))) {
  95                         found_pnetelem = pnetelem;
  96                         break;
  97                 }
  98         }
  99         read_unlock(&smc_pnettable.lock);
 100         return found_pnetelem;
 101 }
 102
 103 /* Remove a pnetid from the pnet table.
 104  */
 105 static int smc_pnet_remove_by_pnetid(char *pnet_name)
 106 {
 107         struct smc_pnetentry *pnetelem, *tmp_pe;
 108         int rc = -ENOENT;
 109
 110         write_lock(&smc_pnettable.lock);
 111         list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
 112                                  list) {
 113                 if (!strncmp(pnetelem->pnet_name, pnet_name,
 114                              sizeof(pnetelem->pnet_name))) {
 115                         list_del(&pnetelem->list);
 116                         dev_put(pnetelem->ndev);
 117                         kfree(pnetelem);
 118                         rc = 0;
 119                         break;
 120                 }
 121         }
 122         write_unlock(&smc_pnettable.lock);
 123         return rc;
 124 }
 125
 126 /* Remove a pnet entry mentioning a given network device from the pnet table.
 127  */
 128 static int smc_pnet_remove_by_ndev(struct net_device *ndev)
 129 {
 130         struct smc_pnetentry *pnetelem, *tmp_pe;
 131         int rc = -ENOENT;
 132
 133         write_lock(&smc_pnettable.lock);
 134         list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
 135                                  list) {
 136                 if (pnetelem->ndev == ndev) {
 137                         list_del(&pnetelem->list);
 138                         dev_put(pnetelem->ndev);
 139                         kfree(pnetelem);
 140                         rc = 0;
 141                         break;
 142                 }
 143         }
 144         write_unlock(&smc_pnettable.lock);
 145         return rc;
 146 }
 147
 148 /* Remove a pnet entry mentioning a given ib device from the pnet table.
 149  */
 150 int smc_pnet_remove_by_ibdev(struct smc_ib_device *ibdev)
 151 {
 152         struct smc_pnetentry *pnetelem, *tmp_pe;
 153         int rc = -ENOENT;
 154
 155         write_lock(&smc_pnettable.lock);
 156         list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
 157                                  list) {
 158                 if (pnetelem->smcibdev == ibdev) {
 159                         list_del(&pnetelem->list);
 160                         dev_put(pnetelem->ndev);
 161                         kfree(pnetelem);
 162                         rc = 0;
 163                         break;
 164                 }
 165         }
 166         write_unlock(&smc_pnettable.lock);
 167         return rc;
 168 }
 169
 170 /* Append a pnetid to the end of the pnet table if not already on this list.
 171  */
 172 static int smc_pnet_enter(struct smc_pnetentry *new_pnetelem)
 173 {
 174         struct smc_pnetentry *pnetelem;
 175         int rc = -EEXIST;
 176
 177         write_lock(&smc_pnettable.lock);
 178         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
 179                 if (!strncmp(pnetelem->pnet_name, new_pnetelem->pnet_name,
 180                              sizeof(new_pnetelem->pnet_name)) ||
 181                     !strncmp(pnetelem->ndev->name, new_pnetelem->ndev->name,
 182                              sizeof(new_pnetelem->ndev->name)) ||
 183                     smc_pnet_same_ibname(pnetelem,
 184                                          new_pnetelem->smcibdev->ibdev->name,
 185                                          new_pnetelem->ib_port)) {
 186                         dev_put(pnetelem->ndev);
 187                         goto found;
 188                 }
 189         }
 190         list_add_tail(&new_pnetelem->list, &smc_pnettable.pnetlist);
 191         rc = 0;
 192 found:
 193         write_unlock(&smc_pnettable.lock);
 194         return rc;
 195 }
 196
 197 /* The limit for pnetid is 16 characters.
 198  * Valid characters should be (single-byte character set) a-z, A-Z, 0-9.
 199  * Lower case letters are converted to upper case.
 200  * Interior blanks should not be used.
 201  */
 202 static bool smc_pnetid_valid(const char *pnet_name, char *pnetid)
 203 {
 204         char *bf = skip_spaces(pnet_name);
 205         size_t len = strlen(bf);
 206         char *end = bf + len;
 207
 208         if (!len)
 209                 return false;
 210         while (--end >= bf && isspace(*end))
 211                 ;
 212         if (end - bf >= SMC_MAX_PNET_ID_LEN)
 213                 return false;
 214         while (bf <= end) {
 215                 if (!isalnum(*bf))
 216                         return false;
 217                 *pnetid++ = islower(*bf) ? toupper(*bf) : *bf;
 218                 bf++;
 219         }
 220         *pnetid = '\0';
 221         return true;
 222 }
 223
 224 /* Find an infiniband device by a given name. The device might not exist. */
 225 static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 226 {
 227         struct smc_ib_device *ibdev;
 228
 229         spin_lock(&smc_ib_devices.lock);
 230         list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 231                 if (!strncmp(ibdev->ibdev->name, ib_name,
 232                              sizeof(ibdev->ibdev->name))) {
 233                         goto out;
 234                 }
 235         }
 236         ibdev = NULL;
 237 out:
 238         spin_unlock(&smc_ib_devices.lock);
 239         return ibdev;
 240 }
 241
 242 /* Parse the supplied netlink attributes and fill a pnetentry structure.
 243  * For ethernet and infiniband device names verify that the devices exist.
 244  */
 245 static int smc_pnet_fill_entry(struct net *net, struct smc_pnetentry *pnetelem,
 246                                struct nlattr *tb[])
 247 {
 248         char *string, *ibname;
 249         int rc;
 250
 251         memset(pnetelem, 0, sizeof(*pnetelem));
 252         INIT_LIST_HEAD(&pnetelem->list);
 253
 254         rc = -EINVAL;
 255         if (!tb[SMC_PNETID_NAME])
 256                 goto error;
 257         string = (char *)nla_data(tb[SMC_PNETID_NAME]);
 258         if (!smc_pnetid_valid(string, pnetelem->pnet_name))
 259                 goto error;
 260
 261         rc = -EINVAL;
 262         if (!tb[SMC_PNETID_ETHNAME])
 263                 goto error;
 264         rc = -ENOENT;
 265         string = (char *)nla_data(tb[SMC_PNETID_ETHNAME]);
 266         pnetelem->ndev = dev_get_by_name(net, string);
 267         if (!pnetelem->ndev)
 268                 goto error;
 269
 270         rc = -EINVAL;
 271         if (!tb[SMC_PNETID_IBNAME])
 272                 goto error;
 273         rc = -ENOENT;
 274         ibname = (char *)nla_data(tb[SMC_PNETID_IBNAME]);
 275         ibname = strim(ibname);
 276         pnetelem->smcibdev = smc_pnet_find_ib(ibname);
 277         if (!pnetelem->smcibdev)
 278                 goto error;
 279
 280         rc = -EINVAL;
 281         if (!tb[SMC_PNETID_IBPORT])
 282                 goto error;
 283         pnetelem->ib_port = nla_get_u8(tb[SMC_PNETID_IBPORT]);
 284         if (pnetelem->ib_port < 1 || pnetelem->ib_port > SMC_MAX_PORTS)
 285                 goto error;
 286
 287         return 0;
 288
 289 error:
 290         if (pnetelem->ndev)
 291                 dev_put(pnetelem->ndev);
 292         return rc;
 293 }
 294
 295 /* Convert an smc_pnetentry to a netlink attribute sequence */
 296 static int smc_pnet_set_nla(struct sk_buff *msg, struct smc_pnetentry *pnetelem)
 297 {
 298         if (nla_put_string(msg, SMC_PNETID_NAME, pnetelem->pnet_name) ||
 299             nla_put_string(msg, SMC_PNETID_ETHNAME, pnetelem->ndev->name) ||
 300             nla_put_string(msg, SMC_PNETID_IBNAME,
 301                            pnetelem->smcibdev->ibdev->name) ||
 302             nla_put_u8(msg, SMC_PNETID_IBPORT, pnetelem->ib_port))
 303                 return -1;
 304         return 0;
 305 }
 306
 307 /* Retrieve one PNETID entry */
 308 static int smc_pnet_get(struct sk_buff *skb, struct genl_info *info)
 309 {
 310         struct smc_pnetentry *pnetelem;
 311         struct sk_buff *msg;
 312         void *hdr;
 313         int rc;
 314
 315         if (!info->attrs[SMC_PNETID_NAME])
 316                 return -EINVAL;
 317         pnetelem = smc_pnet_find_pnetid(
 318                                 (char *)nla_data(info->attrs[SMC_PNETID_NAME]));
 319         if (!pnetelem)
 320                 return -ENOENT;
 321         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 322         if (!msg)
 323                 return -ENOMEM;
 324
 325         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
 326                           &smc_pnet_nl_family, 0, SMC_PNETID_GET);
 327         if (!hdr) {
 328                 rc = -EMSGSIZE;
 329                 goto err_out;
 330         }
 331
 332         if (smc_pnet_set_nla(msg, pnetelem)) {
 333                 rc = -ENOBUFS;
 334                 goto err_out;
 335         }
 336
 337         genlmsg_end(msg, hdr);
 338         return genlmsg_reply(msg, info);
 339
 340 err_out:
 341         nlmsg_free(msg);
 342         return rc;
 343 }
 344
 345 static int smc_pnet_add(struct sk_buff *skb, struct genl_info *info)
 346 {
 347         struct net *net = genl_info_net(info);
 348         struct smc_pnetentry *pnetelem;
 349         int rc;
 350
 351         pnetelem = kzalloc(sizeof(*pnetelem), GFP_KERNEL);
 352         if (!pnetelem)
 353                 return -ENOMEM;
 354         rc = smc_pnet_fill_entry(net, pnetelem, info->attrs);
 355         if (!rc)
 356                 rc = smc_pnet_enter(pnetelem);
 357         if (rc) {
 358                 kfree(pnetelem);
 359                 return rc;
 360         }
 361         rc = smc_ib_remember_port_attr(pnetelem->smcibdev, pnetelem->ib_port);
 362         if (rc)
 363                 smc_pnet_remove_by_pnetid(pnetelem->pnet_name);
 364         return rc;
 365 }
 366
 367 static int smc_pnet_del(struct sk_buff *skb, struct genl_info *info)
 368 {
 369         if (!info->attrs[SMC_PNETID_NAME])
 370                 return -EINVAL;
 371         return smc_pnet_remove_by_pnetid(
 372                                 (char *)nla_data(info->attrs[SMC_PNETID_NAME]));
 373 }
 374
 375 static int smc_pnet_dump_start(struct netlink_callback *cb)
 376 {
 377         cb->args[0] = 0;
 378         return 0;
 379 }
 380
 381 static int smc_pnet_dumpinfo(struct sk_buff *skb,
 382                              u32 portid, u32 seq, u32 flags,
 383                              struct smc_pnetentry *pnetelem)
 384 {
 385         void *hdr;
 386
 387         hdr = genlmsg_put(skb, portid, seq, &smc_pnet_nl_family,
 388                           flags, SMC_PNETID_GET);
 389         if (!hdr)
 390                 return -ENOMEM;
 391         if (smc_pnet_set_nla(skb, pnetelem) < 0) {
 392                 genlmsg_cancel(skb, hdr);
 393                 return -EMSGSIZE;
 394         }
 395         genlmsg_end(skb, hdr);
 396         return 0;
 397 }
 398
 399 static int smc_pnet_dump(struct sk_buff *skb, struct netlink_callback *cb)
 400 {
 401         struct smc_pnetentry *pnetelem;
 402         int idx = 0;
 403
 404         read_lock(&smc_pnettable.lock);
 405         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
 406                 if (idx++ < cb->args[0])
 407                         continue;
 408                 if (smc_pnet_dumpinfo(skb, NETLINK_CB(cb->skb).portid,
 409                                       cb->nlh->nlmsg_seq, NLM_F_MULTI,
 410                                       pnetelem)) {
 411                         --idx;
 412                         break;
 413                 }
 414         }
 415         cb->args[0] = idx;
 416         read_unlock(&smc_pnettable.lock);
 417         return skb->len;
 418 }
 419
 420 /* Remove and delete all pnetids from pnet table.
 421  */
 422 static int smc_pnet_flush(struct sk_buff *skb, struct genl_info *info)
 423 {
 424         struct smc_pnetentry *pnetelem, *tmp_pe;
 425
 426         write_lock(&smc_pnettable.lock);
 427         list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
 428                                  list) {
 429                 list_del(&pnetelem->list);
 430                 dev_put(pnetelem->ndev);
 431                 kfree(pnetelem);
 432         }
 433         write_unlock(&smc_pnettable.lock);
 434         return 0;
 435 }
 436
 437 /* SMC_PNETID generic netlink operation definition */
 438 static const struct genl_ops smc_pnet_ops[] = {
 439         {
 440                 .cmd = SMC_PNETID_GET,
 441                 .flags = GENL_ADMIN_PERM,
 442                 .policy = smc_pnet_policy,
 443                 .doit = smc_pnet_get,
 444                 .dumpit = smc_pnet_dump,
 445                 .start = smc_pnet_dump_start
 446         },
 447         {
 448                 .cmd = SMC_PNETID_ADD,
 449                 .flags = GENL_ADMIN_PERM,
 450                 .policy = smc_pnet_policy,
 451                 .doit = smc_pnet_add
 452         },
 453         {
 454                 .cmd = SMC_PNETID_DEL,
 455                 .flags = GENL_ADMIN_PERM,
 456                 .policy = smc_pnet_policy,
 457                 .doit = smc_pnet_del
 458         },
 459         {
 460                 .cmd = SMC_PNETID_FLUSH,
 461                 .flags = GENL_ADMIN_PERM,
 462                 .policy = smc_pnet_policy,
 463                 .doit = smc_pnet_flush
 464         }
 465 };
 466
 467 /* SMC_PNETID family definition */
 468 static struct genl_family smc_pnet_nl_family = {
 469         .hdrsize = 0,
 470         .name = SMCR_GENL_FAMILY_NAME,
 471         .version = SMCR_GENL_FAMILY_VERSION,
 472         .maxattr = SMC_PNETID_MAX,
 473         .netnsok = true,
 474         .module = THIS_MODULE,
 475         .ops = smc_pnet_ops,
 476         .n_ops =  ARRAY_SIZE(smc_pnet_ops)
 477 };
 478
 479 static int smc_pnet_netdev_event(struct notifier_block *this,
 480                                  unsigned long event, void *ptr)
 481 {
 482         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
 483
 484         switch (event) {
 485         case NETDEV_REBOOT:
 486         case NETDEV_UNREGISTER:
 487                 smc_pnet_remove_by_ndev(event_dev);
 488         default:
 489                 break;
 490         }
 491         return NOTIFY_DONE;
 492 }
 493
 494 static struct notifier_block smc_netdev_notifier = {
 495         .notifier_call = smc_pnet_netdev_event
 496 };
 497
 498 int __init smc_pnet_init(void)
 499 {
 500         int rc;
 501
 502         rc = genl_register_family(&smc_pnet_nl_family);
 503         if (rc)
 504                 return rc;
 505         rc = register_netdevice_notifier(&smc_netdev_notifier);
 506         if (rc)
 507                 genl_unregister_family(&smc_pnet_nl_family);
 508         return rc;
 509 }
 510
 511 void smc_pnet_exit(void)
 512 {
 513         smc_pnet_flush(NULL, NULL);
 514         unregister_netdevice_notifier(&smc_netdev_notifier);
 515         genl_unregister_family(&smc_pnet_nl_family);
 516 }
 517
 518 /* PNET table analysis for a given sock:
 519  * determine ib_device and port belonging to used internal TCP socket
 520  * ethernet interface.
 521  */
 522 void smc_pnet_find_roce_resource(struct sock *sk,
 523                                  struct smc_ib_device **smcibdev, u8 *ibport)
 524 {
 525         struct dst_entry *dst = sk_dst_get(sk);
 526         struct smc_pnetentry *pnetelem;
 527
 528         *smcibdev = NULL;
 529         *ibport = 0;
 530
 531         if (!dst)
 532                 return;
 533         if (!dst->dev)
 534                 goto out_rel;
 535         read_lock(&smc_pnettable.lock);
 536         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
 537                 if (dst->dev == pnetelem->ndev) {
 538                         if (smc_ib_port_active(pnetelem->smcibdev,
 539                                                pnetelem->ib_port)) {
 540                                 *smcibdev = pnetelem->smcibdev;
 541                                 *ibport = pnetelem->ib_port;
 542                         }
 543                         break;
 544                 }
 545         }
 546         read_unlock(&smc_pnettable.lock);
 547 out_rel:
 548         dst_release(dst);
 549 }