net/smc/smc_pnet.c

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