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                         dev_put(pnetelem->ndev);
 186                         goto found;
 187                 }
 188         }
 189         list_add_tail(&new_pnetelem->list, &smc_pnettable.pnetlist);
 190         rc = 0;
 191 found:
 192         write_unlock(&smc_pnettable.lock);
 193         return rc;
 194 }
 195
 196 /* The limit for pnetid is 16 characters.
 197  * Valid characters should be (single-byte character set) a-z, A-Z, 0-9.
 198  * Lower case letters are converted to upper case.
 199  * Interior blanks should not be used.
 200  */
 201 static bool smc_pnetid_valid(const char *pnet_name, char *pnetid)
 202 {
 203         char *bf = skip_spaces(pnet_name);
 204         size_t len = strlen(bf);
 205         char *end = bf + len;
 206
 207         if (!len)
 208                 return false;
 209         while (--end >= bf && isspace(*end))
 210                 ;
 211         if (end - bf >= SMC_MAX_PNET_ID_LEN)
 212                 return false;
 213         while (bf <= end) {
 214                 if (!isalnum(*bf))
 215                         return false;
 216                 *pnetid++ = islower(*bf) ? toupper(*bf) : *bf;
 217                 bf++;
 218         }
 219         *pnetid = '\0';
 220         return true;
 221 }
 222
 223 /* Find an infiniband device by a given name. The device might not exist. */
 224 static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 225 {
 226         struct smc_ib_device *ibdev;
 227
 228         spin_lock(&smc_ib_devices.lock);
 229         list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 230                 if (!strncmp(ibdev->ibdev->name, ib_name,
 231                              sizeof(ibdev->ibdev->name))) {
 232                         goto out;
 233                 }
 234         }
 235         ibdev = NULL;
 236 out:
 237         spin_unlock(&smc_ib_devices.lock);
 238         return ibdev;
 239 }
 240
 241 /* Parse the supplied netlink attributes and fill a pnetentry structure.
 242  * For ethernet and infiniband device names verify that the devices exist.
 243  */
 244 static int smc_pnet_fill_entry(struct net *net, struct smc_pnetentry *pnetelem,
 245                                struct nlattr *tb[])
 246 {
 247         char *string, *ibname = NULL;
 248         int rc = 0;
 249
 250         memset(pnetelem, 0, sizeof(*pnetelem));
 251         INIT_LIST_HEAD(&pnetelem->list);
 252         if (tb[SMC_PNETID_NAME]) {
 253                 string = (char *)nla_data(tb[SMC_PNETID_NAME]);
 254                 if (!smc_pnetid_valid(string, pnetelem->pnet_name)) {
 255                         rc = -EINVAL;
 256                         goto error;
 257                 }
 258         }
 259         if (tb[SMC_PNETID_ETHNAME]) {
 260                 string = (char *)nla_data(tb[SMC_PNETID_ETHNAME]);
 261                 pnetelem->ndev = dev_get_by_name(net, string);
 262                 if (!pnetelem->ndev)
 263                         return -ENOENT;
 264         }
 265         if (tb[SMC_PNETID_IBNAME]) {
 266                 ibname = (char *)nla_data(tb[SMC_PNETID_IBNAME]);
 267                 ibname = strim(ibname);
 268                 pnetelem->smcibdev = smc_pnet_find_ib(ibname);
 269                 if (!pnetelem->smcibdev) {
 270                         rc = -ENOENT;
 271                         goto error;
 272                 }
 273         }
 274         if (tb[SMC_PNETID_IBPORT]) {
 275                 pnetelem->ib_port = nla_get_u8(tb[SMC_PNETID_IBPORT]);
 276                 if (pnetelem->ib_port > SMC_MAX_PORTS) {
 277                         rc = -EINVAL;
 278                         goto error;
 279                 }
 280         }
 281         return 0;
 282
 283 error:
 284         if (pnetelem->ndev)
 285                 dev_put(pnetelem->ndev);
 286         return rc;
 287 }
 288
 289 /* Convert an smc_pnetentry to a netlink attribute sequence */
 290 static int smc_pnet_set_nla(struct sk_buff *msg, struct smc_pnetentry *pnetelem)
 291 {
 292         if (nla_put_string(msg, SMC_PNETID_NAME, pnetelem->pnet_name) ||
 293             nla_put_string(msg, SMC_PNETID_ETHNAME, pnetelem->ndev->name) ||
 294             nla_put_string(msg, SMC_PNETID_IBNAME,
 295                            pnetelem->smcibdev->ibdev->name) ||
 296             nla_put_u8(msg, SMC_PNETID_IBPORT, pnetelem->ib_port))
 297                 return -1;
 298         return 0;
 299 }
 300
 301 /* Retrieve one PNETID entry */
 302 static int smc_pnet_get(struct sk_buff *skb, struct genl_info *info)
 303 {
 304         struct smc_pnetentry *pnetelem;
 305         struct sk_buff *msg;
 306         void *hdr;
 307         int rc;
 308
 309         pnetelem = smc_pnet_find_pnetid(
 310                                 (char *)nla_data(info->attrs[SMC_PNETID_NAME]));
 311         if (!pnetelem)
 312                 return -ENOENT;
 313         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 314         if (!msg)
 315                 return -ENOMEM;
 316
 317         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
 318                           &smc_pnet_nl_family, 0, SMC_PNETID_GET);
 319         if (!hdr) {
 320                 rc = -EMSGSIZE;
 321                 goto err_out;
 322         }
 323
 324         if (smc_pnet_set_nla(msg, pnetelem)) {
 325                 rc = -ENOBUFS;
 326                 goto err_out;
 327         }
 328
 329         genlmsg_end(msg, hdr);
 330         return genlmsg_reply(msg, info);
 331
 332 err_out:
 333         nlmsg_free(msg);
 334         return rc;
 335 }
 336
 337 static int smc_pnet_add(struct sk_buff *skb, struct genl_info *info)
 338 {
 339         struct net *net = genl_info_net(info);
 340         struct smc_pnetentry *pnetelem;
 341         int rc;
 342
 343         pnetelem = kzalloc(sizeof(*pnetelem), GFP_KERNEL);
 344         if (!pnetelem)
 345                 return -ENOMEM;
 346         rc = smc_pnet_fill_entry(net, pnetelem, info->attrs);
 347         if (!rc)
 348                 rc = smc_pnet_enter(pnetelem);
 349         if (rc) {
 350                 kfree(pnetelem);
 351                 return rc;
 352         }
 353         rc = smc_ib_remember_port_attr(pnetelem->smcibdev, pnetelem->ib_port);
 354         if (rc)
 355                 smc_pnet_remove_by_pnetid(pnetelem->pnet_name);
 356         return rc;
 357 }
 358
 359 static int smc_pnet_del(struct sk_buff *skb, struct genl_info *info)
 360 {
 361         return smc_pnet_remove_by_pnetid(
 362                                 (char *)nla_data(info->attrs[SMC_PNETID_NAME]));
 363 }
 364
 365 static int smc_pnet_dump_start(struct netlink_callback *cb)
 366 {
 367         cb->args[0] = 0;
 368         return 0;
 369 }
 370
 371 static int smc_pnet_dumpinfo(struct sk_buff *skb,
 372                              u32 portid, u32 seq, u32 flags,
 373                              struct smc_pnetentry *pnetelem)
 374 {
 375         void *hdr;
 376
 377         hdr = genlmsg_put(skb, portid, seq, &smc_pnet_nl_family,
 378                           flags, SMC_PNETID_GET);
 379         if (!hdr)
 380                 return -ENOMEM;
 381         if (smc_pnet_set_nla(skb, pnetelem) < 0) {
 382                 genlmsg_cancel(skb, hdr);
 383                 return -EMSGSIZE;
 384         }
 385         genlmsg_end(skb, hdr);
 386         return 0;
 387 }
 388
 389 static int smc_pnet_dump(struct sk_buff *skb, struct netlink_callback *cb)
 390 {
 391         struct smc_pnetentry *pnetelem;
 392         int idx = 0;
 393
 394         read_lock(&smc_pnettable.lock);
 395         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
 396                 if (idx++ < cb->args[0])
 397                         continue;
 398                 if (smc_pnet_dumpinfo(skb, NETLINK_CB(cb->skb).portid,
 399                                       cb->nlh->nlmsg_seq, NLM_F_MULTI,
 400                                       pnetelem)) {
 401                         --idx;
 402                         break;
 403                 }
 404         }
 405         cb->args[0] = idx;
 406         read_unlock(&smc_pnettable.lock);
 407         return skb->len;
 408 }
 409
 410 /* Remove and delete all pnetids from pnet table.
 411  */
 412 static int smc_pnet_flush(struct sk_buff *skb, struct genl_info *info)
 413 {
 414         struct smc_pnetentry *pnetelem, *tmp_pe;
 415
 416         write_lock(&smc_pnettable.lock);
 417         list_for_each_entry_safe(pnetelem, tmp_pe, &smc_pnettable.pnetlist,
 418                                  list) {
 419                 list_del(&pnetelem->list);
 420                 dev_put(pnetelem->ndev);
 421                 kfree(pnetelem);
 422         }
 423         write_unlock(&smc_pnettable.lock);
 424         return 0;
 425 }
 426
 427 /* SMC_PNETID generic netlink operation definition */
 428 static const struct genl_ops smc_pnet_ops[] = {
 429         {
 430                 .cmd = SMC_PNETID_GET,
 431                 .flags = GENL_ADMIN_PERM,
 432                 .policy = smc_pnet_policy,
 433                 .doit = smc_pnet_get,
 434                 .dumpit = smc_pnet_dump,
 435                 .start = smc_pnet_dump_start
 436         },
 437         {
 438                 .cmd = SMC_PNETID_ADD,
 439                 .flags = GENL_ADMIN_PERM,
 440                 .policy = smc_pnet_policy,
 441                 .doit = smc_pnet_add
 442         },
 443         {
 444                 .cmd = SMC_PNETID_DEL,
 445                 .flags = GENL_ADMIN_PERM,
 446                 .policy = smc_pnet_policy,
 447                 .doit = smc_pnet_del
 448         },
 449         {
 450                 .cmd = SMC_PNETID_FLUSH,
 451                 .flags = GENL_ADMIN_PERM,
 452                 .policy = smc_pnet_policy,
 453                 .doit = smc_pnet_flush
 454         }
 455 };
 456
 457 /* SMC_PNETID family definition */
 458 static struct genl_family smc_pnet_nl_family = {
 459         .hdrsize = 0,
 460         .name = SMCR_GENL_FAMILY_NAME,
 461         .version = SMCR_GENL_FAMILY_VERSION,
 462         .maxattr = SMC_PNETID_MAX,
 463         .netnsok = true,
 464         .module = THIS_MODULE,
 465         .ops = smc_pnet_ops,
 466         .n_ops =  ARRAY_SIZE(smc_pnet_ops)
 467 };
 468
 469 static int smc_pnet_netdev_event(struct notifier_block *this,
 470                                  unsigned long event, void *ptr)
 471 {
 472         struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
 473
 474         switch (event) {
 475         case NETDEV_REBOOT:
 476         case NETDEV_UNREGISTER:
 477                 smc_pnet_remove_by_ndev(event_dev);
 478         default:
 479                 break;
 480         }
 481         return NOTIFY_DONE;
 482 }
 483
 484 static struct notifier_block smc_netdev_notifier = {
 485         .notifier_call = smc_pnet_netdev_event
 486 };
 487
 488 int __init smc_pnet_init(void)
 489 {
 490         int rc;
 491
 492         rc = genl_register_family(&smc_pnet_nl_family);
 493         if (rc)
 494                 return rc;
 495         rc = register_netdevice_notifier(&smc_netdev_notifier);
 496         if (rc)
 497                 genl_unregister_family(&smc_pnet_nl_family);
 498         return rc;
 499 }
 500
 501 void smc_pnet_exit(void)
 502 {
 503         smc_pnet_flush(NULL, NULL);
 504         unregister_netdevice_notifier(&smc_netdev_notifier);
 505         genl_unregister_family(&smc_pnet_nl_family);
 506 }
 507
 508 /* PNET table analysis for a given sock:
 509  * determine ib_device and port belonging to used internal TCP socket
 510  * ethernet interface.
 511  */
 512 void smc_pnet_find_roce_resource(struct sock *sk,
 513                                  struct smc_ib_device **smcibdev, u8 *ibport)
 514 {
 515         struct dst_entry *dst = sk_dst_get(sk);
 516         struct smc_pnetentry *pnetelem;
 517
 518         *smcibdev = NULL;
 519         *ibport = 0;
 520
 521         if (!dst)
 522                 return;
 523         if (!dst->dev)
 524                 goto out_rel;
 525         read_lock(&smc_pnettable.lock);
 526         list_for_each_entry(pnetelem, &smc_pnettable.pnetlist, list) {
 527                 if (dst->dev == pnetelem->ndev) {
 528                         if (smc_ib_port_active(pnetelem->smcibdev,
 529                                                pnetelem->ib_port)) {
 530                                 *smcibdev = pnetelem->smcibdev;
 531                                 *ibport = pnetelem->ib_port;
 532                         }
 533                         break;
 534                 }
 535         }
 536         read_unlock(&smc_pnettable.lock);
 537 out_rel:
 538         dst_release(dst);
 539 }