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 int mrp_pdu_init(struct mrp_applicant *app)
 296 {
 297         struct sk_buff *skb;
 298         struct mrp_pdu_hdr *ph;
 299
 300         skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
 301                         GFP_ATOMIC);
 302         if (!skb)
 303                 return -ENOMEM;
 304
 305         skb->dev = app->dev;
 306         skb->protocol = app->app->pkttype.type;
 307         skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
 308         skb_reset_network_header(skb);
 309         skb_reset_transport_header(skb);
 310
 311         ph = __skb_put(skb, sizeof(*ph));
 312         ph->version = app->app->version;
 313
 314         app->pdu = skb;
 315         return 0;
 316 }
 317
 318 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
 319 {
 320         __be16 *endmark;
 321
 322         if (skb_tailroom(app->pdu) < sizeof(*endmark))
 323                 return -1;
 324         endmark = __skb_put(app->pdu, sizeof(*endmark));
 325         put_unaligned(MRP_END_MARK, endmark);
 326         return 0;
 327 }
 328
 329 static void mrp_pdu_queue(struct mrp_applicant *app)
 330 {
 331         if (!app->pdu)
 332                 return;
 333
 334         if (mrp_cb(app->pdu)->mh)
 335                 mrp_pdu_append_end_mark(app);
 336         mrp_pdu_append_end_mark(app);
 337
 338         dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
 339                         app->app->group_address, app->dev->dev_addr,
 340                         app->pdu->len);
 341
 342         skb_queue_tail(&app->queue, app->pdu);
 343         app->pdu = NULL;
 344 }
 345
 346 static void mrp_queue_xmit(struct mrp_applicant *app)
 347 {
 348         struct sk_buff *skb;
 349
 350         while ((skb = skb_dequeue(&app->queue)))
 351                 dev_queue_xmit(skb);
 352 }
 353
 354 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
 355                                   u8 attrtype, u8 attrlen)
 356 {
 357         struct mrp_msg_hdr *mh;
 358
 359         if (mrp_cb(app->pdu)->mh) {
 360                 if (mrp_pdu_append_end_mark(app) < 0)
 361                         return -1;
 362                 mrp_cb(app->pdu)->mh = NULL;
 363                 mrp_cb(app->pdu)->vah = NULL;
 364         }
 365
 366         if (skb_tailroom(app->pdu) < sizeof(*mh))
 367                 return -1;
 368         mh = __skb_put(app->pdu, sizeof(*mh));
 369         mh->attrtype = attrtype;
 370         mh->attrlen = attrlen;
 371         mrp_cb(app->pdu)->mh = mh;
 372         return 0;
 373 }
 374
 375 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
 376                                       const void *firstattrvalue, u8 attrlen)
 377 {
 378         struct mrp_vecattr_hdr *vah;
 379
 380         if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
 381                 return -1;
 382         vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
 383         put_unaligned(0, &vah->lenflags);
 384         memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
 385         mrp_cb(app->pdu)->vah = vah;
 386         memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
 387         return 0;
 388 }
 389
 390 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
 391                                         const struct mrp_attr *attr,
 392                                         enum mrp_vecattr_event vaevent)
 393 {
 394         u16 len, pos;
 395         u8 *vaevents;
 396         int err;
 397 again:
 398         if (!app->pdu) {
 399                 err = mrp_pdu_init(app);
 400                 if (err < 0)
 401                         return err;
 402         }
 403
 404         /* If there is no Message header in the PDU, or the Message header is
 405          * for a different attribute type, add an EndMark (if necessary) and a
 406          * new Message header to the PDU.
 407          */
 408         if (!mrp_cb(app->pdu)->mh ||
 409             mrp_cb(app->pdu)->mh->attrtype != attr->type ||
 410             mrp_cb(app->pdu)->mh->attrlen != attr->len) {
 411                 if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
 412                         goto queue;
 413         }
 414
 415         /* If there is no VectorAttribute header for this Message in the PDU,
 416          * or this attribute's value does not sequentially follow the previous
 417          * attribute's value, add a new VectorAttribute header to the PDU.
 418          */
 419         if (!mrp_cb(app->pdu)->vah ||
 420             memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
 421                 if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
 422                         goto queue;
 423         }
 424
 425         len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
 426         pos = len % 3;
 427
 428         /* Events are packed into Vectors in the PDU, three to a byte. Add a
 429          * byte to the end of the Vector if necessary.
 430          */
 431         if (!pos) {
 432                 if (skb_tailroom(app->pdu) < sizeof(u8))
 433                         goto queue;
 434                 vaevents = __skb_put(app->pdu, sizeof(u8));
 435         } else {
 436                 vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
 437         }
 438
 439         switch (pos) {
 440         case 0:
 441                 *vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
 442                                        __MRP_VECATTR_EVENT_MAX);
 443                 break;
 444         case 1:
 445                 *vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
 446                 break;
 447         case 2:
 448                 *vaevents += vaevent;
 449                 break;
 450         default:
 451                 WARN_ON(1);
 452         }
 453
 454         /* Increment the length of the VectorAttribute in the PDU, as well as
 455          * the value of the next attribute that would continue its Vector.
 456          */
 457         put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
 458         mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
 459
 460         return 0;
 461
 462 queue:
 463         mrp_pdu_queue(app);
 464         goto again;
 465 }
 466
 467 static void mrp_attr_event(struct mrp_applicant *app,
 468                            struct mrp_attr *attr, enum mrp_event event)
 469 {
 470         enum mrp_applicant_state state;
 471
 472         state = mrp_applicant_state_table[attr->state][event];
 473         if (state == MRP_APPLICANT_INVALID) {
 474                 WARN_ON(1);
 475                 return;
 476         }
 477
 478         if (event == MRP_EVENT_TX) {
 479                 /* When appending the attribute fails, don't update its state
 480                  * in order to retry at the next TX event.
 481                  */
 482
 483                 switch (mrp_tx_action_table[attr->state]) {
 484                 case MRP_TX_ACTION_NONE:
 485                 case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
 486                 case MRP_TX_ACTION_S_IN_OPTIONAL:
 487                         break;
 488                 case MRP_TX_ACTION_S_NEW:
 489                         if (mrp_pdu_append_vecattr_event(
 490                                     app, attr, MRP_VECATTR_EVENT_NEW) < 0)
 491                                 return;
 492                         break;
 493                 case MRP_TX_ACTION_S_JOIN_IN:
 494                         if (mrp_pdu_append_vecattr_event(
 495                                     app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
 496                                 return;
 497                         break;
 498                 case MRP_TX_ACTION_S_LV:
 499                         if (mrp_pdu_append_vecattr_event(
 500                                     app, attr, MRP_VECATTR_EVENT_LV) < 0)
 501                                 return;
 502                         /* As a pure applicant, sending a leave message
 503                          * implies that the attribute was unregistered and
 504                          * can be destroyed.
 505                          */
 506                         mrp_attr_destroy(app, attr);
 507                         return;
 508                 default:
 509                         WARN_ON(1);
 510                 }
 511         }
 512
 513         attr->state = state;
 514 }
 515
 516 int mrp_request_join(const struct net_device *dev,
 517                      const struct mrp_application *appl,
 518                      const void *value, u8 len, u8 type)
 519 {
 520         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 521         struct mrp_applicant *app = rtnl_dereference(
 522                 port->applicants[appl->type]);
 523         struct mrp_attr *attr;
 524
 525         if (sizeof(struct mrp_skb_cb) + len >
 526             sizeof_field(struct sk_buff, cb))
 527                 return -ENOMEM;
 528
 529         spin_lock_bh(&app->lock);
 530         attr = mrp_attr_create(app, value, len, type);
 531         if (!attr) {
 532                 spin_unlock_bh(&app->lock);
 533                 return -ENOMEM;
 534         }
 535         mrp_attr_event(app, attr, MRP_EVENT_JOIN);
 536         spin_unlock_bh(&app->lock);
 537         return 0;
 538 }
 539 EXPORT_SYMBOL_GPL(mrp_request_join);
 540
 541 void mrp_request_leave(const struct net_device *dev,
 542                        const struct mrp_application *appl,
 543                        const void *value, u8 len, u8 type)
 544 {
 545         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 546         struct mrp_applicant *app = rtnl_dereference(
 547                 port->applicants[appl->type]);
 548         struct mrp_attr *attr;
 549
 550         if (sizeof(struct mrp_skb_cb) + len >
 551             sizeof_field(struct sk_buff, cb))
 552                 return;
 553
 554         spin_lock_bh(&app->lock);
 555         attr = mrp_attr_lookup(app, value, len, type);
 556         if (!attr) {
 557                 spin_unlock_bh(&app->lock);
 558                 return;
 559         }
 560         mrp_attr_event(app, attr, MRP_EVENT_LV);
 561         spin_unlock_bh(&app->lock);
 562 }
 563 EXPORT_SYMBOL_GPL(mrp_request_leave);
 564
 565 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
 566 {
 567         struct rb_node *node, *next;
 568         struct mrp_attr *attr;
 569
 570         for (node = rb_first(&app->mad);
 571              next = node ? rb_next(node) : NULL, node != NULL;
 572              node = next) {
 573                 attr = rb_entry(node, struct mrp_attr, node);
 574                 mrp_attr_event(app, attr, event);
 575         }
 576 }
 577
 578 static void mrp_join_timer_arm(struct mrp_applicant *app)
 579 {
 580         unsigned long delay;
 581
 582         delay = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
 583         mod_timer(&app->join_timer, jiffies + delay);
 584 }
 585
 586 static void mrp_join_timer(struct timer_list *t)
 587 {
 588         struct mrp_applicant *app = from_timer(app, t, join_timer);
 589
 590         spin_lock(&app->lock);
 591         mrp_mad_event(app, MRP_EVENT_TX);
 592         mrp_pdu_queue(app);
 593         spin_unlock(&app->lock);
 594
 595         mrp_queue_xmit(app);
 596         mrp_join_timer_arm(app);
 597 }
 598
 599 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
 600 {
 601         mod_timer(&app->periodic_timer,
 602                   jiffies + msecs_to_jiffies(mrp_periodic_time));
 603 }
 604
 605 static void mrp_periodic_timer(struct timer_list *t)
 606 {
 607         struct mrp_applicant *app = from_timer(app, t, periodic_timer);
 608
 609         spin_lock(&app->lock);
 610         mrp_mad_event(app, MRP_EVENT_PERIODIC);
 611         mrp_pdu_queue(app);
 612         spin_unlock(&app->lock);
 613
 614         mrp_periodic_timer_arm(app);
 615 }
 616
 617 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
 618 {
 619         __be16 endmark;
 620
 621         if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
 622                 return -1;
 623         if (endmark == MRP_END_MARK) {
 624                 *offset += sizeof(endmark);
 625                 return -1;
 626         }
 627         return 0;
 628 }
 629
 630 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
 631                                         struct sk_buff *skb,
 632                                         enum mrp_vecattr_event vaevent)
 633 {
 634         struct mrp_attr *attr;
 635         enum mrp_event event;
 636
 637         attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
 638                                mrp_cb(skb)->mh->attrlen,
 639                                mrp_cb(skb)->mh->attrtype);
 640         if (attr == NULL)
 641                 return;
 642
 643         switch (vaevent) {
 644         case MRP_VECATTR_EVENT_NEW:
 645                 event = MRP_EVENT_R_NEW;
 646                 break;
 647         case MRP_VECATTR_EVENT_JOIN_IN:
 648                 event = MRP_EVENT_R_JOIN_IN;
 649                 break;
 650         case MRP_VECATTR_EVENT_IN:
 651                 event = MRP_EVENT_R_IN;
 652                 break;
 653         case MRP_VECATTR_EVENT_JOIN_MT:
 654                 event = MRP_EVENT_R_JOIN_MT;
 655                 break;
 656         case MRP_VECATTR_EVENT_MT:
 657                 event = MRP_EVENT_R_MT;
 658                 break;
 659         case MRP_VECATTR_EVENT_LV:
 660                 event = MRP_EVENT_R_LV;
 661                 break;
 662         default:
 663                 return;
 664         }
 665
 666         mrp_attr_event(app, attr, event);
 667 }
 668
 669 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
 670                                  struct sk_buff *skb, int *offset)
 671 {
 672         struct mrp_vecattr_hdr _vah;
 673         u16 valen;
 674         u8 vaevents, vaevent;
 675
 676         mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
 677                                               &_vah);
 678         if (!mrp_cb(skb)->vah)
 679                 return -1;
 680         *offset += sizeof(_vah);
 681
 682         if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 683             MRP_VECATTR_HDR_FLAG_LA)
 684                 mrp_mad_event(app, MRP_EVENT_R_LA);
 685         valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 686                             MRP_VECATTR_HDR_LEN_MASK);
 687
 688         /* The VectorAttribute structure in a PDU carries event information
 689          * about one or more attributes having consecutive values. Only the
 690          * value for the first attribute is contained in the structure. So
 691          * we make a copy of that value, and then increment it each time we
 692          * advance to the next event in its Vector.
 693          */
 694         if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
 695             sizeof_field(struct sk_buff, cb))
 696                 return -1;
 697         if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
 698                           mrp_cb(skb)->mh->attrlen) < 0)
 699                 return -1;
 700         *offset += mrp_cb(skb)->mh->attrlen;
 701
 702         /* In a VectorAttribute, the Vector contains events which are packed
 703          * three to a byte. We process one byte of the Vector at a time.
 704          */
 705         while (valen > 0) {
 706                 if (skb_copy_bits(skb, *offset, &vaevents,
 707                                   sizeof(vaevents)) < 0)
 708                         return -1;
 709                 *offset += sizeof(vaevents);
 710
 711                 /* Extract and process the first event. */
 712                 vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
 713                                       __MRP_VECATTR_EVENT_MAX);
 714                 if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
 715                         /* The byte is malformed; stop processing. */
 716                         return -1;
 717                 }
 718                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 719
 720                 /* If present, extract and process the second event. */
 721                 if (!--valen)
 722                         break;
 723                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 724                                   mrp_cb(skb)->mh->attrlen);
 725                 vaevents %= (__MRP_VECATTR_EVENT_MAX *
 726                              __MRP_VECATTR_EVENT_MAX);
 727                 vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
 728                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 729
 730                 /* If present, extract and process the third event. */
 731                 if (!--valen)
 732                         break;
 733                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 734                                   mrp_cb(skb)->mh->attrlen);
 735                 vaevents %= __MRP_VECATTR_EVENT_MAX;
 736                 vaevent = vaevents;
 737                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 738         }
 739         return 0;
 740 }
 741
 742 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
 743                              int *offset)
 744 {
 745         struct mrp_msg_hdr _mh;
 746
 747         mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
 748         if (!mrp_cb(skb)->mh)
 749                 return -1;
 750         *offset += sizeof(_mh);
 751
 752         if (mrp_cb(skb)->mh->attrtype == 0 ||
 753             mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
 754             mrp_cb(skb)->mh->attrlen == 0)
 755                 return -1;
 756
 757         while (skb->len > *offset) {
 758                 if (mrp_pdu_parse_end_mark(skb, offset) < 0)
 759                         break;
 760                 if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
 761                         return -1;
 762         }
 763         return 0;
 764 }
 765
 766 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
 767                    struct packet_type *pt, struct net_device *orig_dev)
 768 {
 769         struct mrp_application *appl = container_of(pt, struct mrp_application,
 770                                                     pkttype);
 771         struct mrp_port *port;
 772         struct mrp_applicant *app;
 773         struct mrp_pdu_hdr _ph;
 774         const struct mrp_pdu_hdr *ph;
 775         int offset = skb_network_offset(skb);
 776
 777         /* If the interface is in promiscuous mode, drop the packet if
 778          * it was unicast to another host.
 779          */
 780         if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
 781                 goto out;
 782         skb = skb_share_check(skb, GFP_ATOMIC);
 783         if (unlikely(!skb))
 784                 goto out;
 785         port = rcu_dereference(dev->mrp_port);
 786         if (unlikely(!port))
 787                 goto out;
 788         app = rcu_dereference(port->applicants[appl->type]);
 789         if (unlikely(!app))
 790                 goto out;
 791
 792         ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
 793         if (!ph)
 794                 goto out;
 795         offset += sizeof(_ph);
 796
 797         if (ph->version != app->app->version)
 798                 goto out;
 799
 800         spin_lock(&app->lock);
 801         while (skb->len > offset) {
 802                 if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
 803                         break;
 804                 if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
 805                         break;
 806         }
 807         spin_unlock(&app->lock);
 808 out:
 809         kfree_skb(skb);
 810         return 0;
 811 }
 812
 813 static int mrp_init_port(struct net_device *dev)
 814 {
 815         struct mrp_port *port;
 816
 817         port = kzalloc(sizeof(*port), GFP_KERNEL);
 818         if (!port)
 819                 return -ENOMEM;
 820         rcu_assign_pointer(dev->mrp_port, port);
 821         return 0;
 822 }
 823
 824 static void mrp_release_port(struct net_device *dev)
 825 {
 826         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 827         unsigned int i;
 828
 829         for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
 830                 if (rtnl_dereference(port->applicants[i]))
 831                         return;
 832         }
 833         RCU_INIT_POINTER(dev->mrp_port, NULL);
 834         kfree_rcu(port, rcu);
 835 }
 836
 837 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
 838 {
 839         struct mrp_applicant *app;
 840         int err;
 841
 842         ASSERT_RTNL();
 843
 844         if (!rtnl_dereference(dev->mrp_port)) {
 845                 err = mrp_init_port(dev);
 846                 if (err < 0)
 847                         goto err1;
 848         }
 849
 850         err = -ENOMEM;
 851         app = kzalloc(sizeof(*app), GFP_KERNEL);
 852         if (!app)
 853                 goto err2;
 854
 855         err = dev_mc_add(dev, appl->group_address);
 856         if (err < 0)
 857                 goto err3;
 858
 859         app->dev = dev;
 860         app->app = appl;
 861         app->mad = RB_ROOT;
 862         spin_lock_init(&app->lock);
 863         skb_queue_head_init(&app->queue);
 864         rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
 865         timer_setup(&app->join_timer, mrp_join_timer, 0);
 866         mrp_join_timer_arm(app);
 867         timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
 868         mrp_periodic_timer_arm(app);
 869         return 0;
 870
 871 err3:
 872         kfree(app);
 873 err2:
 874         mrp_release_port(dev);
 875 err1:
 876         return err;
 877 }
 878 EXPORT_SYMBOL_GPL(mrp_init_applicant);
 879
 880 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
 881 {
 882         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 883         struct mrp_applicant *app = rtnl_dereference(
 884                 port->applicants[appl->type]);
 885
 886         ASSERT_RTNL();
 887
 888         RCU_INIT_POINTER(port->applicants[appl->type], NULL);
 889
 890         /* Delete timer and generate a final TX event to flush out
 891          * all pending messages before the applicant is gone.
 892          */
 893         del_timer_sync(&app->join_timer);
 894         del_timer_sync(&app->periodic_timer);
 895
 896         spin_lock_bh(&app->lock);
 897         mrp_mad_event(app, MRP_EVENT_TX);
 898         mrp_pdu_queue(app);
 899         spin_unlock_bh(&app->lock);
 900
 901         mrp_queue_xmit(app);
 902
 903         dev_mc_del(dev, appl->group_address);
 904         kfree_rcu(app, rcu);
 905         mrp_release_port(dev);
 906 }
 907 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
 908
 909 int mrp_register_application(struct mrp_application *appl)
 910 {
 911         appl->pkttype.func = mrp_rcv;
 912         dev_add_pack(&appl->pkttype);
 913         return 0;
 914 }
 915 EXPORT_SYMBOL_GPL(mrp_register_application);
 916
 917 void mrp_unregister_application(struct mrp_application *appl)
 918 {
 919         dev_remove_pack(&appl->pkttype);
 920 }
 921 EXPORT_SYMBOL_GPL(mrp_unregister_application);