net/802/mrp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *      IEEE 802.1Q Multiple Registration Protocol (MRP)
   4  *
   5  *      Copyright (c) 2012 Massachusetts Institute of Technology
   6  *
   7  *      Adapted from code in net/802/garp.c
   8  *      Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/timer.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <net/mrp.h>
  19 #include <asm/unaligned.h>
  20
  21 static unsigned int mrp_join_time __read_mostly = 200;
  22 module_param(mrp_join_time, uint, 0644);
  23 MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
  24
  25 static unsigned int mrp_periodic_time __read_mostly = 1000;
  26 module_param(mrp_periodic_time, uint, 0644);
  27 MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
  28
  29 MODULE_LICENSE("GPL");
  30
  31 static const u8
  32 mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
  33         [MRP_APPLICANT_VO] = {
  34                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  35                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
  36                 [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
  37                 [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
  38                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VO,
  39                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AO,
  40                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VO,
  41                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VO,
  42                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VO,
  43                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
  44                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
  45                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
  46                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VO,
  47         },
  48         [MRP_APPLICANT_VP] = {
  49                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  50                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
  51                 [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
  52                 [MRP_EVENT_TX]          = MRP_APPLICANT_AA,
  53                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VP,
  54                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AP,
  55                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VP,
  56                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VP,
  57                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VP,
  58                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
  59                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
  60                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
  61                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VP,
  62         },
  63         [MRP_APPLICANT_VN] = {
  64                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  65                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VN,
  66                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
  67                 [MRP_EVENT_TX]          = MRP_APPLICANT_AN,
  68                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VN,
  69                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_VN,
  70                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VN,
  71                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VN,
  72                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VN,
  73                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
  74                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
  75                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
  76                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VN,
  77         },
  78         [MRP_APPLICANT_AN] = {
  79                 [MRP_EVENT_NEW]         = MRP_APPLICANT_AN,
  80                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AN,
  81                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
  82                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
  83                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AN,
  84                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AN,
  85                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AN,
  86                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AN,
  87                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AN,
  88                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
  89                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
  90                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
  91                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AN,
  92         },
  93         [MRP_APPLICANT_AA] = {
  94                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  95                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
  96                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
  97                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
  98                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AA,
  99                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
 100                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AA,
 101                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
 102                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
 103                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 104                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 105                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 106                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
 107         },
 108         [MRP_APPLICANT_QA] = {
 109                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 110                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QA,
 111                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
 112                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
 113                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QA,
 114                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
 115                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QA,
 116                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
 117                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
 118                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 119                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 120                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 121                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
 122         },
 123         [MRP_APPLICANT_LA] = {
 124                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 125                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
 126                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
 127                 [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
 128                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_LA,
 129                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_LA,
 130                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_LA,
 131                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_LA,
 132                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_LA,
 133                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_LA,
 134                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_LA,
 135                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_LA,
 136                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_LA,
 137         },
 138         [MRP_APPLICANT_AO] = {
 139                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 140                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
 141                 [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
 142                 [MRP_EVENT_TX]          = MRP_APPLICANT_AO,
 143                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AO,
 144                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
 145                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AO,
 146                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
 147                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
 148                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
 149                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
 150                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
 151                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AO,
 152         },
 153         [MRP_APPLICANT_QO] = {
 154                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 155                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
 156                 [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
 157                 [MRP_EVENT_TX]          = MRP_APPLICANT_QO,
 158                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QO,
 159                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
 160                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QO,
 161                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
 162                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
 163                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
 164                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
 165                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
 166                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_QO,
 167         },
 168         [MRP_APPLICANT_AP] = {
 169                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 170                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
 171                 [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
 172                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
 173                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AP,
 174                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
 175                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AP,
 176                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
 177                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
 178                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 179                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 180                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 181                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
 182         },
 183         [MRP_APPLICANT_QP] = {
 184                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 185                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
 186                 [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
 187                 [MRP_EVENT_TX]          = MRP_APPLICANT_QP,
 188                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QP,
 189                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
 190                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QP,
 191                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
 192                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
 193                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 194                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 195                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 196                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
 197         },
 198 };
 199
 200 static const u8
 201 mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
 202         [MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 203         [MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
 204         [MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
 205         [MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
 206         [MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
 207         [MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
 208         [MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
 209         [MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 210         [MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 211         [MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
 212         [MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
 213 };
 214
 215 static void mrp_attrvalue_inc(void *value, u8 len)
 216 {
 217         u8 *v = (u8 *)value;
 218
 219         /* Add 1 to the last byte. If it becomes zero,
 220          * go to the previous byte and repeat.
 221          */
 222         while (len > 0 && !++v[--len])
 223                 ;
 224 }
 225
 226 static int mrp_attr_cmp(const struct mrp_attr *attr,
 227                          const void *value, u8 len, u8 type)
 228 {
 229         if (attr->type != type)
 230                 return attr->type - type;
 231         if (attr->len != len)
 232                 return attr->len - len;
 233         return memcmp(attr->value, value, len);
 234 }
 235
 236 static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
 237                                         const void *value, u8 len, u8 type)
 238 {
 239         struct rb_node *parent = app->mad.rb_node;
 240         struct mrp_attr *attr;
 241         int d;
 242
 243         while (parent) {
 244                 attr = rb_entry(parent, struct mrp_attr, node);
 245                 d = mrp_attr_cmp(attr, value, len, type);
 246                 if (d > 0)
 247                         parent = parent->rb_left;
 248                 else if (d < 0)
 249                         parent = parent->rb_right;
 250                 else
 251                         return attr;
 252         }
 253         return NULL;
 254 }
 255
 256 static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
 257                                         const void *value, u8 len, u8 type)
 258 {
 259         struct rb_node *parent = NULL, **p = &app->mad.rb_node;
 260         struct mrp_attr *attr;
 261         int d;
 262
 263         while (*p) {
 264                 parent = *p;
 265                 attr = rb_entry(parent, struct mrp_attr, node);
 266                 d = mrp_attr_cmp(attr, value, len, type);
 267                 if (d > 0)
 268                         p = &parent->rb_left;
 269                 else if (d < 0)
 270                         p = &parent->rb_right;
 271                 else {
 272                         /* The attribute already exists; re-use it. */
 273                         return attr;
 274                 }
 275         }
 276         attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
 277         if (!attr)
 278                 return attr;
 279         attr->state = MRP_APPLICANT_VO;
 280         attr->type  = type;
 281         attr->len   = len;
 282         memcpy(attr->value, value, len);
 283
 284         rb_link_node(&attr->node, parent, p);
 285         rb_insert_color(&attr->node, &app->mad);
 286         return attr;
 287 }
 288
 289 static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
 290 {
 291         rb_erase(&attr->node, &app->mad);
 292         kfree(attr);
 293 }
 294
 295 static void mrp_attr_destroy_all(struct mrp_applicant *app)
 296 {
 297         struct rb_node *node, *next;
 298         struct mrp_attr *attr;
 299
 300         for (node = rb_first(&app->mad);
 301              next = node ? rb_next(node) : NULL, node != NULL;
 302              node = next) {
 303                 attr = rb_entry(node, struct mrp_attr, node);
 304                 mrp_attr_destroy(app, attr);
 305         }
 306 }
 307
 308 static int mrp_pdu_init(struct mrp_applicant *app)
 309 {
 310         struct sk_buff *skb;
 311         struct mrp_pdu_hdr *ph;
 312
 313         skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
 314                         GFP_ATOMIC);
 315         if (!skb)
 316                 return -ENOMEM;
 317
 318         skb->dev = app->dev;
 319         skb->protocol = app->app->pkttype.type;
 320         skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
 321         skb_reset_network_header(skb);
 322         skb_reset_transport_header(skb);
 323
 324         ph = __skb_put(skb, sizeof(*ph));
 325         ph->version = app->app->version;
 326
 327         app->pdu = skb;
 328         return 0;
 329 }
 330
 331 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
 332 {
 333         __be16 *endmark;
 334
 335         if (skb_tailroom(app->pdu) < sizeof(*endmark))
 336                 return -1;
 337         endmark = __skb_put(app->pdu, sizeof(*endmark));
 338         put_unaligned(MRP_END_MARK, endmark);
 339         return 0;
 340 }
 341
 342 static void mrp_pdu_queue(struct mrp_applicant *app)
 343 {
 344         if (!app->pdu)
 345                 return;
 346
 347         if (mrp_cb(app->pdu)->mh)
 348                 mrp_pdu_append_end_mark(app);
 349         mrp_pdu_append_end_mark(app);
 350
 351         dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
 352                         app->app->group_address, app->dev->dev_addr,
 353                         app->pdu->len);
 354
 355         skb_queue_tail(&app->queue, app->pdu);
 356         app->pdu = NULL;
 357 }
 358
 359 static void mrp_queue_xmit(struct mrp_applicant *app)
 360 {
 361         struct sk_buff *skb;
 362
 363         while ((skb = skb_dequeue(&app->queue)))
 364                 dev_queue_xmit(skb);
 365 }
 366
 367 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
 368                                   u8 attrtype, u8 attrlen)
 369 {
 370         struct mrp_msg_hdr *mh;
 371
 372         if (mrp_cb(app->pdu)->mh) {
 373                 if (mrp_pdu_append_end_mark(app) < 0)
 374                         return -1;
 375                 mrp_cb(app->pdu)->mh = NULL;
 376                 mrp_cb(app->pdu)->vah = NULL;
 377         }
 378
 379         if (skb_tailroom(app->pdu) < sizeof(*mh))
 380                 return -1;
 381         mh = __skb_put(app->pdu, sizeof(*mh));
 382         mh->attrtype = attrtype;
 383         mh->attrlen = attrlen;
 384         mrp_cb(app->pdu)->mh = mh;
 385         return 0;
 386 }
 387
 388 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
 389                                       const void *firstattrvalue, u8 attrlen)
 390 {
 391         struct mrp_vecattr_hdr *vah;
 392
 393         if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
 394                 return -1;
 395         vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
 396         put_unaligned(0, &vah->lenflags);
 397         memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
 398         mrp_cb(app->pdu)->vah = vah;
 399         memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
 400         return 0;
 401 }
 402
 403 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
 404                                         const struct mrp_attr *attr,
 405                                         enum mrp_vecattr_event vaevent)
 406 {
 407         u16 len, pos;
 408         u8 *vaevents;
 409         int err;
 410 again:
 411         if (!app->pdu) {
 412                 err = mrp_pdu_init(app);
 413                 if (err < 0)
 414                         return err;
 415         }
 416
 417         /* If there is no Message header in the PDU, or the Message header is
 418          * for a different attribute type, add an EndMark (if necessary) and a
 419          * new Message header to the PDU.
 420          */
 421         if (!mrp_cb(app->pdu)->mh ||
 422             mrp_cb(app->pdu)->mh->attrtype != attr->type ||
 423             mrp_cb(app->pdu)->mh->attrlen != attr->len) {
 424                 if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
 425                         goto queue;
 426         }
 427
 428         /* If there is no VectorAttribute header for this Message in the PDU,
 429          * or this attribute's value does not sequentially follow the previous
 430          * attribute's value, add a new VectorAttribute header to the PDU.
 431          */
 432         if (!mrp_cb(app->pdu)->vah ||
 433             memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
 434                 if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
 435                         goto queue;
 436         }
 437
 438         len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
 439         pos = len % 3;
 440
 441         /* Events are packed into Vectors in the PDU, three to a byte. Add a
 442          * byte to the end of the Vector if necessary.
 443          */
 444         if (!pos) {
 445                 if (skb_tailroom(app->pdu) < sizeof(u8))
 446                         goto queue;
 447                 vaevents = __skb_put(app->pdu, sizeof(u8));
 448         } else {
 449                 vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
 450         }
 451
 452         switch (pos) {
 453         case 0:
 454                 *vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
 455                                        __MRP_VECATTR_EVENT_MAX);
 456                 break;
 457         case 1:
 458                 *vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
 459                 break;
 460         case 2:
 461                 *vaevents += vaevent;
 462                 break;
 463         default:
 464                 WARN_ON(1);
 465         }
 466
 467         /* Increment the length of the VectorAttribute in the PDU, as well as
 468          * the value of the next attribute that would continue its Vector.
 469          */
 470         put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
 471         mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
 472
 473         return 0;
 474
 475 queue:
 476         mrp_pdu_queue(app);
 477         goto again;
 478 }
 479
 480 static void mrp_attr_event(struct mrp_applicant *app,
 481                            struct mrp_attr *attr, enum mrp_event event)
 482 {
 483         enum mrp_applicant_state state;
 484
 485         state = mrp_applicant_state_table[attr->state][event];
 486         if (state == MRP_APPLICANT_INVALID) {
 487                 WARN_ON(1);
 488                 return;
 489         }
 490
 491         if (event == MRP_EVENT_TX) {
 492                 /* When appending the attribute fails, don't update its state
 493                  * in order to retry at the next TX event.
 494                  */
 495
 496                 switch (mrp_tx_action_table[attr->state]) {
 497                 case MRP_TX_ACTION_NONE:
 498                 case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
 499                 case MRP_TX_ACTION_S_IN_OPTIONAL:
 500                         break;
 501                 case MRP_TX_ACTION_S_NEW:
 502                         if (mrp_pdu_append_vecattr_event(
 503                                     app, attr, MRP_VECATTR_EVENT_NEW) < 0)
 504                                 return;
 505                         break;
 506                 case MRP_TX_ACTION_S_JOIN_IN:
 507                         if (mrp_pdu_append_vecattr_event(
 508                                     app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
 509                                 return;
 510                         break;
 511                 case MRP_TX_ACTION_S_LV:
 512                         if (mrp_pdu_append_vecattr_event(
 513                                     app, attr, MRP_VECATTR_EVENT_LV) < 0)
 514                                 return;
 515                         /* As a pure applicant, sending a leave message
 516                          * implies that the attribute was unregistered and
 517                          * can be destroyed.
 518                          */
 519                         mrp_attr_destroy(app, attr);
 520                         return;
 521                 default:
 522                         WARN_ON(1);
 523                 }
 524         }
 525
 526         attr->state = state;
 527 }
 528
 529 int mrp_request_join(const struct net_device *dev,
 530                      const struct mrp_application *appl,
 531                      const void *value, u8 len, u8 type)
 532 {
 533         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 534         struct mrp_applicant *app = rtnl_dereference(
 535                 port->applicants[appl->type]);
 536         struct mrp_attr *attr;
 537
 538         if (sizeof(struct mrp_skb_cb) + len >
 539             sizeof_field(struct sk_buff, cb))
 540                 return -ENOMEM;
 541
 542         spin_lock_bh(&app->lock);
 543         attr = mrp_attr_create(app, value, len, type);
 544         if (!attr) {
 545                 spin_unlock_bh(&app->lock);
 546                 return -ENOMEM;
 547         }
 548         mrp_attr_event(app, attr, MRP_EVENT_JOIN);
 549         spin_unlock_bh(&app->lock);
 550         return 0;
 551 }
 552 EXPORT_SYMBOL_GPL(mrp_request_join);
 553
 554 void mrp_request_leave(const struct net_device *dev,
 555                        const struct mrp_application *appl,
 556                        const void *value, u8 len, u8 type)
 557 {
 558         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 559         struct mrp_applicant *app = rtnl_dereference(
 560                 port->applicants[appl->type]);
 561         struct mrp_attr *attr;
 562
 563         if (sizeof(struct mrp_skb_cb) + len >
 564             sizeof_field(struct sk_buff, cb))
 565                 return;
 566
 567         spin_lock_bh(&app->lock);
 568         attr = mrp_attr_lookup(app, value, len, type);
 569         if (!attr) {
 570                 spin_unlock_bh(&app->lock);
 571                 return;
 572         }
 573         mrp_attr_event(app, attr, MRP_EVENT_LV);
 574         spin_unlock_bh(&app->lock);
 575 }
 576 EXPORT_SYMBOL_GPL(mrp_request_leave);
 577
 578 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
 579 {
 580         struct rb_node *node, *next;
 581         struct mrp_attr *attr;
 582
 583         for (node = rb_first(&app->mad);
 584              next = node ? rb_next(node) : NULL, node != NULL;
 585              node = next) {
 586                 attr = rb_entry(node, struct mrp_attr, node);
 587                 mrp_attr_event(app, attr, event);
 588         }
 589 }
 590
 591 static void mrp_join_timer_arm(struct mrp_applicant *app)
 592 {
 593         unsigned long delay;
 594
 595         delay = get_random_u32_below(msecs_to_jiffies(mrp_join_time));
 596         mod_timer(&app->join_timer, jiffies + delay);
 597 }
 598
 599 static void mrp_join_timer(struct timer_list *t)
 600 {
 601         struct mrp_applicant *app = from_timer(app, t, join_timer);
 602
 603         spin_lock(&app->lock);
 604         mrp_mad_event(app, MRP_EVENT_TX);
 605         mrp_pdu_queue(app);
 606         spin_unlock(&app->lock);
 607
 608         mrp_queue_xmit(app);
 609         spin_lock(&app->lock);
 610         if (likely(app->active))
 611                 mrp_join_timer_arm(app);
 612         spin_unlock(&app->lock);
 613 }
 614
 615 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
 616 {
 617         mod_timer(&app->periodic_timer,
 618                   jiffies + msecs_to_jiffies(mrp_periodic_time));
 619 }
 620
 621 static void mrp_periodic_timer(struct timer_list *t)
 622 {
 623         struct mrp_applicant *app = from_timer(app, t, periodic_timer);
 624
 625         spin_lock(&app->lock);
 626         if (likely(app->active)) {
 627                 mrp_mad_event(app, MRP_EVENT_PERIODIC);
 628                 mrp_pdu_queue(app);
 629                 mrp_periodic_timer_arm(app);
 630         }
 631         spin_unlock(&app->lock);
 632 }
 633
 634 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
 635 {
 636         __be16 endmark;
 637
 638         if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
 639                 return -1;
 640         if (endmark == MRP_END_MARK) {
 641                 *offset += sizeof(endmark);
 642                 return -1;
 643         }
 644         return 0;
 645 }
 646
 647 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
 648                                         struct sk_buff *skb,
 649                                         enum mrp_vecattr_event vaevent)
 650 {
 651         struct mrp_attr *attr;
 652         enum mrp_event event;
 653
 654         attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
 655                                mrp_cb(skb)->mh->attrlen,
 656                                mrp_cb(skb)->mh->attrtype);
 657         if (attr == NULL)
 658                 return;
 659
 660         switch (vaevent) {
 661         case MRP_VECATTR_EVENT_NEW:
 662                 event = MRP_EVENT_R_NEW;
 663                 break;
 664         case MRP_VECATTR_EVENT_JOIN_IN:
 665                 event = MRP_EVENT_R_JOIN_IN;
 666                 break;
 667         case MRP_VECATTR_EVENT_IN:
 668                 event = MRP_EVENT_R_IN;
 669                 break;
 670         case MRP_VECATTR_EVENT_JOIN_MT:
 671                 event = MRP_EVENT_R_JOIN_MT;
 672                 break;
 673         case MRP_VECATTR_EVENT_MT:
 674                 event = MRP_EVENT_R_MT;
 675                 break;
 676         case MRP_VECATTR_EVENT_LV:
 677                 event = MRP_EVENT_R_LV;
 678                 break;
 679         default:
 680                 return;
 681         }
 682
 683         mrp_attr_event(app, attr, event);
 684 }
 685
 686 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
 687                                  struct sk_buff *skb, int *offset)
 688 {
 689         struct mrp_vecattr_hdr _vah;
 690         u16 valen;
 691         u8 vaevents, vaevent;
 692
 693         mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
 694                                               &_vah);
 695         if (!mrp_cb(skb)->vah)
 696                 return -1;
 697         *offset += sizeof(_vah);
 698
 699         if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 700             MRP_VECATTR_HDR_FLAG_LA)
 701                 mrp_mad_event(app, MRP_EVENT_R_LA);
 702         valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 703                             MRP_VECATTR_HDR_LEN_MASK);
 704
 705         /* The VectorAttribute structure in a PDU carries event information
 706          * about one or more attributes having consecutive values. Only the
 707          * value for the first attribute is contained in the structure. So
 708          * we make a copy of that value, and then increment it each time we
 709          * advance to the next event in its Vector.
 710          */
 711         if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
 712             sizeof_field(struct sk_buff, cb))
 713                 return -1;
 714         if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
 715                           mrp_cb(skb)->mh->attrlen) < 0)
 716                 return -1;
 717         *offset += mrp_cb(skb)->mh->attrlen;
 718
 719         /* In a VectorAttribute, the Vector contains events which are packed
 720          * three to a byte. We process one byte of the Vector at a time.
 721          */
 722         while (valen > 0) {
 723                 if (skb_copy_bits(skb, *offset, &vaevents,
 724                                   sizeof(vaevents)) < 0)
 725                         return -1;
 726                 *offset += sizeof(vaevents);
 727
 728                 /* Extract and process the first event. */
 729                 vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
 730                                       __MRP_VECATTR_EVENT_MAX);
 731                 if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
 732                         /* The byte is malformed; stop processing. */
 733                         return -1;
 734                 }
 735                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 736
 737                 /* If present, extract and process the second event. */
 738                 if (!--valen)
 739                         break;
 740                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 741                                   mrp_cb(skb)->mh->attrlen);
 742                 vaevents %= (__MRP_VECATTR_EVENT_MAX *
 743                              __MRP_VECATTR_EVENT_MAX);
 744                 vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
 745                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 746
 747                 /* If present, extract and process the third event. */
 748                 if (!--valen)
 749                         break;
 750                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 751                                   mrp_cb(skb)->mh->attrlen);
 752                 vaevents %= __MRP_VECATTR_EVENT_MAX;
 753                 vaevent = vaevents;
 754                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 755         }
 756         return 0;
 757 }
 758
 759 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
 760                              int *offset)
 761 {
 762         struct mrp_msg_hdr _mh;
 763
 764         mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
 765         if (!mrp_cb(skb)->mh)
 766                 return -1;
 767         *offset += sizeof(_mh);
 768
 769         if (mrp_cb(skb)->mh->attrtype == 0 ||
 770             mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
 771             mrp_cb(skb)->mh->attrlen == 0)
 772                 return -1;
 773
 774         while (skb->len > *offset) {
 775                 if (mrp_pdu_parse_end_mark(skb, offset) < 0)
 776                         break;
 777                 if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
 778                         return -1;
 779         }
 780         return 0;
 781 }
 782
 783 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
 784                    struct packet_type *pt, struct net_device *orig_dev)
 785 {
 786         struct mrp_application *appl = container_of(pt, struct mrp_application,
 787                                                     pkttype);
 788         struct mrp_port *port;
 789         struct mrp_applicant *app;
 790         struct mrp_pdu_hdr _ph;
 791         const struct mrp_pdu_hdr *ph;
 792         int offset = skb_network_offset(skb);
 793
 794         /* If the interface is in promiscuous mode, drop the packet if
 795          * it was unicast to another host.
 796          */
 797         if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
 798                 goto out;
 799         skb = skb_share_check(skb, GFP_ATOMIC);
 800         if (unlikely(!skb))
 801                 goto out;
 802         port = rcu_dereference(dev->mrp_port);
 803         if (unlikely(!port))
 804                 goto out;
 805         app = rcu_dereference(port->applicants[appl->type]);
 806         if (unlikely(!app))
 807                 goto out;
 808
 809         ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
 810         if (!ph)
 811                 goto out;
 812         offset += sizeof(_ph);
 813
 814         if (ph->version != app->app->version)
 815                 goto out;
 816
 817         spin_lock(&app->lock);
 818         while (skb->len > offset) {
 819                 if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
 820                         break;
 821                 if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
 822                         break;
 823         }
 824         spin_unlock(&app->lock);
 825 out:
 826         kfree_skb(skb);
 827         return 0;
 828 }
 829
 830 static int mrp_init_port(struct net_device *dev)
 831 {
 832         struct mrp_port *port;
 833
 834         port = kzalloc(sizeof(*port), GFP_KERNEL);
 835         if (!port)
 836                 return -ENOMEM;
 837         rcu_assign_pointer(dev->mrp_port, port);
 838         return 0;
 839 }
 840
 841 static void mrp_release_port(struct net_device *dev)
 842 {
 843         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 844         unsigned int i;
 845
 846         for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
 847                 if (rtnl_dereference(port->applicants[i]))
 848                         return;
 849         }
 850         RCU_INIT_POINTER(dev->mrp_port, NULL);
 851         kfree_rcu(port, rcu);
 852 }
 853
 854 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
 855 {
 856         struct mrp_applicant *app;
 857         int err;
 858
 859         ASSERT_RTNL();
 860
 861         if (!rtnl_dereference(dev->mrp_port)) {
 862                 err = mrp_init_port(dev);
 863                 if (err < 0)
 864                         goto err1;
 865         }
 866
 867         err = -ENOMEM;
 868         app = kzalloc(sizeof(*app), GFP_KERNEL);
 869         if (!app)
 870                 goto err2;
 871
 872         err = dev_mc_add(dev, appl->group_address);
 873         if (err < 0)
 874                 goto err3;
 875
 876         app->dev = dev;
 877         app->app = appl;
 878         app->mad = RB_ROOT;
 879         app->active = true;
 880         spin_lock_init(&app->lock);
 881         skb_queue_head_init(&app->queue);
 882         rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
 883         timer_setup(&app->join_timer, mrp_join_timer, 0);
 884         mrp_join_timer_arm(app);
 885         timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
 886         mrp_periodic_timer_arm(app);
 887         return 0;
 888
 889 err3:
 890         kfree(app);
 891 err2:
 892         mrp_release_port(dev);
 893 err1:
 894         return err;
 895 }
 896 EXPORT_SYMBOL_GPL(mrp_init_applicant);
 897
 898 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
 899 {
 900         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 901         struct mrp_applicant *app = rtnl_dereference(
 902                 port->applicants[appl->type]);
 903
 904         ASSERT_RTNL();
 905
 906         RCU_INIT_POINTER(port->applicants[appl->type], NULL);
 907
 908         spin_lock_bh(&app->lock);
 909         app->active = false;
 910         spin_unlock_bh(&app->lock);
 911         /* Delete timer and generate a final TX event to flush out
 912          * all pending messages before the applicant is gone.
 913          */
 914         del_timer_sync(&app->join_timer);
 915         del_timer_sync(&app->periodic_timer);
 916
 917         spin_lock_bh(&app->lock);
 918         mrp_mad_event(app, MRP_EVENT_TX);
 919         mrp_attr_destroy_all(app);
 920         mrp_pdu_queue(app);
 921         spin_unlock_bh(&app->lock);
 922
 923         mrp_queue_xmit(app);
 924
 925         dev_mc_del(dev, appl->group_address);
 926         kfree_rcu(app, rcu);
 927         mrp_release_port(dev);
 928 }
 929 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
 930
 931 int mrp_register_application(struct mrp_application *appl)
 932 {
 933         appl->pkttype.func = mrp_rcv;
 934         dev_add_pack(&appl->pkttype);
 935         return 0;
 936 }
 937 EXPORT_SYMBOL_GPL(mrp_register_application);
 938
 939 void mrp_unregister_application(struct mrp_application *appl)
 940 {
 941         dev_remove_pack(&appl->pkttype);
 942 }
 943 EXPORT_SYMBOL_GPL(mrp_unregister_application);