net/802/mrp.c

   1 /*
   2  *      IEEE 802.1Q Multiple Registration Protocol (MRP)
   3  *
   4  *      Copyright (c) 2012 Massachusetts Institute of Technology
   5  *
   6  *      Adapted from code in net/802/garp.c
   7  *      Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      version 2 as published by the Free Software Foundation.
  12  */
  13 #include <linux/kernel.h>
  14 #include <linux/timer.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <net/mrp.h>
  22 #include <asm/unaligned.h>
  23
  24 static unsigned int mrp_join_time __read_mostly = 200;
  25 module_param(mrp_join_time, uint, 0644);
  26 MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
  27
  28 static unsigned int mrp_periodic_time __read_mostly = 1000;
  29 module_param(mrp_periodic_time, uint, 0644);
  30 MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
  31
  32 MODULE_LICENSE("GPL");
  33
  34 static const u8
  35 mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
  36         [MRP_APPLICANT_VO] = {
  37                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  38                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
  39                 [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
  40                 [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
  41                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VO,
  42                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AO,
  43                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VO,
  44                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VO,
  45                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VO,
  46                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
  47                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
  48                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
  49                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VO,
  50         },
  51         [MRP_APPLICANT_VP] = {
  52                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  53                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
  54                 [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
  55                 [MRP_EVENT_TX]          = MRP_APPLICANT_AA,
  56                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VP,
  57                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AP,
  58                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VP,
  59                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VP,
  60                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VP,
  61                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
  62                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
  63                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
  64                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VP,
  65         },
  66         [MRP_APPLICANT_VN] = {
  67                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  68                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_VN,
  69                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
  70                 [MRP_EVENT_TX]          = MRP_APPLICANT_AN,
  71                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VN,
  72                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_VN,
  73                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_VN,
  74                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VN,
  75                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_VN,
  76                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
  77                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
  78                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
  79                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VN,
  80         },
  81         [MRP_APPLICANT_AN] = {
  82                 [MRP_EVENT_NEW]         = MRP_APPLICANT_AN,
  83                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AN,
  84                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
  85                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
  86                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AN,
  87                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AN,
  88                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AN,
  89                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AN,
  90                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AN,
  91                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
  92                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
  93                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
  94                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AN,
  95         },
  96         [MRP_APPLICANT_AA] = {
  97                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
  98                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
  99                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
 100                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
 101                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AA,
 102                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
 103                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AA,
 104                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
 105                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
 106                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 107                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 108                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 109                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
 110         },
 111         [MRP_APPLICANT_QA] = {
 112                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 113                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QA,
 114                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
 115                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
 116                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QA,
 117                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
 118                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QA,
 119                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
 120                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
 121                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 122                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 123                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 124                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
 125         },
 126         [MRP_APPLICANT_LA] = {
 127                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 128                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
 129                 [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
 130                 [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
 131                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_LA,
 132                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_LA,
 133                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_LA,
 134                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_LA,
 135                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_LA,
 136                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_LA,
 137                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_LA,
 138                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_LA,
 139                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_LA,
 140         },
 141         [MRP_APPLICANT_AO] = {
 142                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 143                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
 144                 [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
 145                 [MRP_EVENT_TX]          = MRP_APPLICANT_AO,
 146                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AO,
 147                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
 148                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AO,
 149                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
 150                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
 151                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
 152                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
 153                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
 154                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AO,
 155         },
 156         [MRP_APPLICANT_QO] = {
 157                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 158                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
 159                 [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
 160                 [MRP_EVENT_TX]          = MRP_APPLICANT_QO,
 161                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QO,
 162                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
 163                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QO,
 164                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
 165                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
 166                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
 167                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
 168                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
 169                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_QO,
 170         },
 171         [MRP_APPLICANT_AP] = {
 172                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 173                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
 174                 [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
 175                 [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
 176                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AP,
 177                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
 178                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_AP,
 179                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
 180                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
 181                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 182                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 183                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 184                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
 185         },
 186         [MRP_APPLICANT_QP] = {
 187                 [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
 188                 [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
 189                 [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
 190                 [MRP_EVENT_TX]          = MRP_APPLICANT_QP,
 191                 [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QP,
 192                 [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
 193                 [MRP_EVENT_R_IN]        = MRP_APPLICANT_QP,
 194                 [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
 195                 [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
 196                 [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
 197                 [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
 198                 [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
 199                 [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
 200         },
 201 };
 202
 203 static const u8
 204 mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
 205         [MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 206         [MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
 207         [MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
 208         [MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
 209         [MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
 210         [MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
 211         [MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
 212         [MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 213         [MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
 214         [MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
 215         [MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
 216 };
 217
 218 static void mrp_attrvalue_inc(void *value, u8 len)
 219 {
 220         u8 *v = (u8 *)value;
 221
 222         /* Add 1 to the last byte. If it becomes zero,
 223          * go to the previous byte and repeat.
 224          */
 225         while (len > 0 && !++v[--len])
 226                 ;
 227 }
 228
 229 static int mrp_attr_cmp(const struct mrp_attr *attr,
 230                          const void *value, u8 len, u8 type)
 231 {
 232         if (attr->type != type)
 233                 return attr->type - type;
 234         if (attr->len != len)
 235                 return attr->len - len;
 236         return memcmp(attr->value, value, len);
 237 }
 238
 239 static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
 240                                         const void *value, u8 len, u8 type)
 241 {
 242         struct rb_node *parent = app->mad.rb_node;
 243         struct mrp_attr *attr;
 244         int d;
 245
 246         while (parent) {
 247                 attr = rb_entry(parent, struct mrp_attr, node);
 248                 d = mrp_attr_cmp(attr, value, len, type);
 249                 if (d > 0)
 250                         parent = parent->rb_left;
 251                 else if (d < 0)
 252                         parent = parent->rb_right;
 253                 else
 254                         return attr;
 255         }
 256         return NULL;
 257 }
 258
 259 static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
 260                                         const void *value, u8 len, u8 type)
 261 {
 262         struct rb_node *parent = NULL, **p = &app->mad.rb_node;
 263         struct mrp_attr *attr;
 264         int d;
 265
 266         while (*p) {
 267                 parent = *p;
 268                 attr = rb_entry(parent, struct mrp_attr, node);
 269                 d = mrp_attr_cmp(attr, value, len, type);
 270                 if (d > 0)
 271                         p = &parent->rb_left;
 272                 else if (d < 0)
 273                         p = &parent->rb_right;
 274                 else {
 275                         /* The attribute already exists; re-use it. */
 276                         return attr;
 277                 }
 278         }
 279         attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
 280         if (!attr)
 281                 return attr;
 282         attr->state = MRP_APPLICANT_VO;
 283         attr->type  = type;
 284         attr->len   = len;
 285         memcpy(attr->value, value, len);
 286
 287         rb_link_node(&attr->node, parent, p);
 288         rb_insert_color(&attr->node, &app->mad);
 289         return attr;
 290 }
 291
 292 static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
 293 {
 294         rb_erase(&attr->node, &app->mad);
 295         kfree(attr);
 296 }
 297
 298 static int mrp_pdu_init(struct mrp_applicant *app)
 299 {
 300         struct sk_buff *skb;
 301         struct mrp_pdu_hdr *ph;
 302
 303         skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
 304                         GFP_ATOMIC);
 305         if (!skb)
 306                 return -ENOMEM;
 307
 308         skb->dev = app->dev;
 309         skb->protocol = app->app->pkttype.type;
 310         skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
 311         skb_reset_network_header(skb);
 312         skb_reset_transport_header(skb);
 313
 314         ph = (struct mrp_pdu_hdr *)__skb_put(skb, sizeof(*ph));
 315         ph->version = app->app->version;
 316
 317         app->pdu = skb;
 318         return 0;
 319 }
 320
 321 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
 322 {
 323         __be16 *endmark;
 324
 325         if (skb_tailroom(app->pdu) < sizeof(*endmark))
 326                 return -1;
 327         endmark = (__be16 *)__skb_put(app->pdu, sizeof(*endmark));
 328         put_unaligned(MRP_END_MARK, endmark);
 329         return 0;
 330 }
 331
 332 static void mrp_pdu_queue(struct mrp_applicant *app)
 333 {
 334         if (!app->pdu)
 335                 return;
 336
 337         if (mrp_cb(app->pdu)->mh)
 338                 mrp_pdu_append_end_mark(app);
 339         mrp_pdu_append_end_mark(app);
 340
 341         dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
 342                         app->app->group_address, app->dev->dev_addr,
 343                         app->pdu->len);
 344
 345         skb_queue_tail(&app->queue, app->pdu);
 346         app->pdu = NULL;
 347 }
 348
 349 static void mrp_queue_xmit(struct mrp_applicant *app)
 350 {
 351         struct sk_buff *skb;
 352
 353         while ((skb = skb_dequeue(&app->queue)))
 354                 dev_queue_xmit(skb);
 355 }
 356
 357 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
 358                                   u8 attrtype, u8 attrlen)
 359 {
 360         struct mrp_msg_hdr *mh;
 361
 362         if (mrp_cb(app->pdu)->mh) {
 363                 if (mrp_pdu_append_end_mark(app) < 0)
 364                         return -1;
 365                 mrp_cb(app->pdu)->mh = NULL;
 366                 mrp_cb(app->pdu)->vah = NULL;
 367         }
 368
 369         if (skb_tailroom(app->pdu) < sizeof(*mh))
 370                 return -1;
 371         mh = (struct mrp_msg_hdr *)__skb_put(app->pdu, sizeof(*mh));
 372         mh->attrtype = attrtype;
 373         mh->attrlen = attrlen;
 374         mrp_cb(app->pdu)->mh = mh;
 375         return 0;
 376 }
 377
 378 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
 379                                       const void *firstattrvalue, u8 attrlen)
 380 {
 381         struct mrp_vecattr_hdr *vah;
 382
 383         if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
 384                 return -1;
 385         vah = (struct mrp_vecattr_hdr *)__skb_put(app->pdu,
 386                                                   sizeof(*vah) + attrlen);
 387         put_unaligned(0, &vah->lenflags);
 388         memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
 389         mrp_cb(app->pdu)->vah = vah;
 390         memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
 391         return 0;
 392 }
 393
 394 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
 395                                         const struct mrp_attr *attr,
 396                                         enum mrp_vecattr_event vaevent)
 397 {
 398         u16 len, pos;
 399         u8 *vaevents;
 400         int err;
 401 again:
 402         if (!app->pdu) {
 403                 err = mrp_pdu_init(app);
 404                 if (err < 0)
 405                         return err;
 406         }
 407
 408         /* If there is no Message header in the PDU, or the Message header is
 409          * for a different attribute type, add an EndMark (if necessary) and a
 410          * new Message header to the PDU.
 411          */
 412         if (!mrp_cb(app->pdu)->mh ||
 413             mrp_cb(app->pdu)->mh->attrtype != attr->type ||
 414             mrp_cb(app->pdu)->mh->attrlen != attr->len) {
 415                 if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
 416                         goto queue;
 417         }
 418
 419         /* If there is no VectorAttribute header for this Message in the PDU,
 420          * or this attribute's value does not sequentially follow the previous
 421          * attribute's value, add a new VectorAttribute header to the PDU.
 422          */
 423         if (!mrp_cb(app->pdu)->vah ||
 424             memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
 425                 if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
 426                         goto queue;
 427         }
 428
 429         len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
 430         pos = len % 3;
 431
 432         /* Events are packed into Vectors in the PDU, three to a byte. Add a
 433          * byte to the end of the Vector if necessary.
 434          */
 435         if (!pos) {
 436                 if (skb_tailroom(app->pdu) < sizeof(u8))
 437                         goto queue;
 438                 vaevents = (u8 *)__skb_put(app->pdu, sizeof(u8));
 439         } else {
 440                 vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
 441         }
 442
 443         switch (pos) {
 444         case 0:
 445                 *vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
 446                                        __MRP_VECATTR_EVENT_MAX);
 447                 break;
 448         case 1:
 449                 *vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
 450                 break;
 451         case 2:
 452                 *vaevents += vaevent;
 453                 break;
 454         default:
 455                 WARN_ON(1);
 456         }
 457
 458         /* Increment the length of the VectorAttribute in the PDU, as well as
 459          * the value of the next attribute that would continue its Vector.
 460          */
 461         put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
 462         mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
 463
 464         return 0;
 465
 466 queue:
 467         mrp_pdu_queue(app);
 468         goto again;
 469 }
 470
 471 static void mrp_attr_event(struct mrp_applicant *app,
 472                            struct mrp_attr *attr, enum mrp_event event)
 473 {
 474         enum mrp_applicant_state state;
 475
 476         state = mrp_applicant_state_table[attr->state][event];
 477         if (state == MRP_APPLICANT_INVALID) {
 478                 WARN_ON(1);
 479                 return;
 480         }
 481
 482         if (event == MRP_EVENT_TX) {
 483                 /* When appending the attribute fails, don't update its state
 484                  * in order to retry at the next TX event.
 485                  */
 486
 487                 switch (mrp_tx_action_table[attr->state]) {
 488                 case MRP_TX_ACTION_NONE:
 489                 case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
 490                 case MRP_TX_ACTION_S_IN_OPTIONAL:
 491                         break;
 492                 case MRP_TX_ACTION_S_NEW:
 493                         if (mrp_pdu_append_vecattr_event(
 494                                     app, attr, MRP_VECATTR_EVENT_NEW) < 0)
 495                                 return;
 496                         break;
 497                 case MRP_TX_ACTION_S_JOIN_IN:
 498                         if (mrp_pdu_append_vecattr_event(
 499                                     app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
 500                                 return;
 501                         break;
 502                 case MRP_TX_ACTION_S_LV:
 503                         if (mrp_pdu_append_vecattr_event(
 504                                     app, attr, MRP_VECATTR_EVENT_LV) < 0)
 505                                 return;
 506                         /* As a pure applicant, sending a leave message
 507                          * implies that the attribute was unregistered and
 508                          * can be destroyed.
 509                          */
 510                         mrp_attr_destroy(app, attr);
 511                         return;
 512                 default:
 513                         WARN_ON(1);
 514                 }
 515         }
 516
 517         attr->state = state;
 518 }
 519
 520 int mrp_request_join(const struct net_device *dev,
 521                      const struct mrp_application *appl,
 522                      const void *value, u8 len, u8 type)
 523 {
 524         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 525         struct mrp_applicant *app = rtnl_dereference(
 526                 port->applicants[appl->type]);
 527         struct mrp_attr *attr;
 528
 529         if (sizeof(struct mrp_skb_cb) + len >
 530             FIELD_SIZEOF(struct sk_buff, cb))
 531                 return -ENOMEM;
 532
 533         spin_lock_bh(&app->lock);
 534         attr = mrp_attr_create(app, value, len, type);
 535         if (!attr) {
 536                 spin_unlock_bh(&app->lock);
 537                 return -ENOMEM;
 538         }
 539         mrp_attr_event(app, attr, MRP_EVENT_JOIN);
 540         spin_unlock_bh(&app->lock);
 541         return 0;
 542 }
 543 EXPORT_SYMBOL_GPL(mrp_request_join);
 544
 545 void mrp_request_leave(const struct net_device *dev,
 546                        const struct mrp_application *appl,
 547                        const void *value, u8 len, u8 type)
 548 {
 549         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 550         struct mrp_applicant *app = rtnl_dereference(
 551                 port->applicants[appl->type]);
 552         struct mrp_attr *attr;
 553
 554         if (sizeof(struct mrp_skb_cb) + len >
 555             FIELD_SIZEOF(struct sk_buff, cb))
 556                 return;
 557
 558         spin_lock_bh(&app->lock);
 559         attr = mrp_attr_lookup(app, value, len, type);
 560         if (!attr) {
 561                 spin_unlock_bh(&app->lock);
 562                 return;
 563         }
 564         mrp_attr_event(app, attr, MRP_EVENT_LV);
 565         spin_unlock_bh(&app->lock);
 566 }
 567 EXPORT_SYMBOL_GPL(mrp_request_leave);
 568
 569 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
 570 {
 571         struct rb_node *node, *next;
 572         struct mrp_attr *attr;
 573
 574         for (node = rb_first(&app->mad);
 575              next = node ? rb_next(node) : NULL, node != NULL;
 576              node = next) {
 577                 attr = rb_entry(node, struct mrp_attr, node);
 578                 mrp_attr_event(app, attr, event);
 579         }
 580 }
 581
 582 static void mrp_join_timer_arm(struct mrp_applicant *app)
 583 {
 584         unsigned long delay;
 585
 586         delay = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
 587         mod_timer(&app->join_timer, jiffies + delay);
 588 }
 589
 590 static void mrp_join_timer(unsigned long data)
 591 {
 592         struct mrp_applicant *app = (struct mrp_applicant *)data;
 593
 594         spin_lock(&app->lock);
 595         mrp_mad_event(app, MRP_EVENT_TX);
 596         mrp_pdu_queue(app);
 597         spin_unlock(&app->lock);
 598
 599         mrp_queue_xmit(app);
 600         mrp_join_timer_arm(app);
 601 }
 602
 603 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
 604 {
 605         mod_timer(&app->periodic_timer,
 606                   jiffies + msecs_to_jiffies(mrp_periodic_time));
 607 }
 608
 609 static void mrp_periodic_timer(unsigned long data)
 610 {
 611         struct mrp_applicant *app = (struct mrp_applicant *)data;
 612
 613         spin_lock(&app->lock);
 614         mrp_mad_event(app, MRP_EVENT_PERIODIC);
 615         mrp_pdu_queue(app);
 616         spin_unlock(&app->lock);
 617
 618         mrp_periodic_timer_arm(app);
 619 }
 620
 621 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
 622 {
 623         __be16 endmark;
 624
 625         if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
 626                 return -1;
 627         if (endmark == MRP_END_MARK) {
 628                 *offset += sizeof(endmark);
 629                 return -1;
 630         }
 631         return 0;
 632 }
 633
 634 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
 635                                         struct sk_buff *skb,
 636                                         enum mrp_vecattr_event vaevent)
 637 {
 638         struct mrp_attr *attr;
 639         enum mrp_event event;
 640
 641         attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
 642                                mrp_cb(skb)->mh->attrlen,
 643                                mrp_cb(skb)->mh->attrtype);
 644         if (attr == NULL)
 645                 return;
 646
 647         switch (vaevent) {
 648         case MRP_VECATTR_EVENT_NEW:
 649                 event = MRP_EVENT_R_NEW;
 650                 break;
 651         case MRP_VECATTR_EVENT_JOIN_IN:
 652                 event = MRP_EVENT_R_JOIN_IN;
 653                 break;
 654         case MRP_VECATTR_EVENT_IN:
 655                 event = MRP_EVENT_R_IN;
 656                 break;
 657         case MRP_VECATTR_EVENT_JOIN_MT:
 658                 event = MRP_EVENT_R_JOIN_MT;
 659                 break;
 660         case MRP_VECATTR_EVENT_MT:
 661                 event = MRP_EVENT_R_MT;
 662                 break;
 663         case MRP_VECATTR_EVENT_LV:
 664                 event = MRP_EVENT_R_LV;
 665                 break;
 666         default:
 667                 return;
 668         }
 669
 670         mrp_attr_event(app, attr, event);
 671 }
 672
 673 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
 674                                  struct sk_buff *skb, int *offset)
 675 {
 676         struct mrp_vecattr_hdr _vah;
 677         u16 valen;
 678         u8 vaevents, vaevent;
 679
 680         mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
 681                                               &_vah);
 682         if (!mrp_cb(skb)->vah)
 683                 return -1;
 684         *offset += sizeof(_vah);
 685
 686         if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 687             MRP_VECATTR_HDR_FLAG_LA)
 688                 mrp_mad_event(app, MRP_EVENT_R_LA);
 689         valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
 690                             MRP_VECATTR_HDR_LEN_MASK);
 691
 692         /* The VectorAttribute structure in a PDU carries event information
 693          * about one or more attributes having consecutive values. Only the
 694          * value for the first attribute is contained in the structure. So
 695          * we make a copy of that value, and then increment it each time we
 696          * advance to the next event in its Vector.
 697          */
 698         if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
 699             FIELD_SIZEOF(struct sk_buff, cb))
 700                 return -1;
 701         if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
 702                           mrp_cb(skb)->mh->attrlen) < 0)
 703                 return -1;
 704         *offset += mrp_cb(skb)->mh->attrlen;
 705
 706         /* In a VectorAttribute, the Vector contains events which are packed
 707          * three to a byte. We process one byte of the Vector at a time.
 708          */
 709         while (valen > 0) {
 710                 if (skb_copy_bits(skb, *offset, &vaevents,
 711                                   sizeof(vaevents)) < 0)
 712                         return -1;
 713                 *offset += sizeof(vaevents);
 714
 715                 /* Extract and process the first event. */
 716                 vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
 717                                       __MRP_VECATTR_EVENT_MAX);
 718                 if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
 719                         /* The byte is malformed; stop processing. */
 720                         return -1;
 721                 }
 722                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 723
 724                 /* If present, extract and process the second event. */
 725                 if (!--valen)
 726                         break;
 727                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 728                                   mrp_cb(skb)->mh->attrlen);
 729                 vaevents %= (__MRP_VECATTR_EVENT_MAX *
 730                              __MRP_VECATTR_EVENT_MAX);
 731                 vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
 732                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 733
 734                 /* If present, extract and process the third event. */
 735                 if (!--valen)
 736                         break;
 737                 mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
 738                                   mrp_cb(skb)->mh->attrlen);
 739                 vaevents %= __MRP_VECATTR_EVENT_MAX;
 740                 vaevent = vaevents;
 741                 mrp_pdu_parse_vecattr_event(app, skb, vaevent);
 742         }
 743         return 0;
 744 }
 745
 746 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
 747                              int *offset)
 748 {
 749         struct mrp_msg_hdr _mh;
 750
 751         mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
 752         if (!mrp_cb(skb)->mh)
 753                 return -1;
 754         *offset += sizeof(_mh);
 755
 756         if (mrp_cb(skb)->mh->attrtype == 0 ||
 757             mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
 758             mrp_cb(skb)->mh->attrlen == 0)
 759                 return -1;
 760
 761         while (skb->len > *offset) {
 762                 if (mrp_pdu_parse_end_mark(skb, offset) < 0)
 763                         break;
 764                 if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
 765                         return -1;
 766         }
 767         return 0;
 768 }
 769
 770 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
 771                    struct packet_type *pt, struct net_device *orig_dev)
 772 {
 773         struct mrp_application *appl = container_of(pt, struct mrp_application,
 774                                                     pkttype);
 775         struct mrp_port *port;
 776         struct mrp_applicant *app;
 777         struct mrp_pdu_hdr _ph;
 778         const struct mrp_pdu_hdr *ph;
 779         int offset = skb_network_offset(skb);
 780
 781         /* If the interface is in promiscuous mode, drop the packet if
 782          * it was unicast to another host.
 783          */
 784         if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
 785                 goto out;
 786         skb = skb_share_check(skb, GFP_ATOMIC);
 787         if (unlikely(!skb))
 788                 goto out;
 789         port = rcu_dereference(dev->mrp_port);
 790         if (unlikely(!port))
 791                 goto out;
 792         app = rcu_dereference(port->applicants[appl->type]);
 793         if (unlikely(!app))
 794                 goto out;
 795
 796         ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
 797         if (!ph)
 798                 goto out;
 799         offset += sizeof(_ph);
 800
 801         if (ph->version != app->app->version)
 802                 goto out;
 803
 804         spin_lock(&app->lock);
 805         while (skb->len > offset) {
 806                 if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
 807                         break;
 808                 if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
 809                         break;
 810         }
 811         spin_unlock(&app->lock);
 812 out:
 813         kfree_skb(skb);
 814         return 0;
 815 }
 816
 817 static int mrp_init_port(struct net_device *dev)
 818 {
 819         struct mrp_port *port;
 820
 821         port = kzalloc(sizeof(*port), GFP_KERNEL);
 822         if (!port)
 823                 return -ENOMEM;
 824         rcu_assign_pointer(dev->mrp_port, port);
 825         return 0;
 826 }
 827
 828 static void mrp_release_port(struct net_device *dev)
 829 {
 830         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 831         unsigned int i;
 832
 833         for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
 834                 if (rtnl_dereference(port->applicants[i]))
 835                         return;
 836         }
 837         RCU_INIT_POINTER(dev->mrp_port, NULL);
 838         kfree_rcu(port, rcu);
 839 }
 840
 841 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
 842 {
 843         struct mrp_applicant *app;
 844         int err;
 845
 846         ASSERT_RTNL();
 847
 848         if (!rtnl_dereference(dev->mrp_port)) {
 849                 err = mrp_init_port(dev);
 850                 if (err < 0)
 851                         goto err1;
 852         }
 853
 854         err = -ENOMEM;
 855         app = kzalloc(sizeof(*app), GFP_KERNEL);
 856         if (!app)
 857                 goto err2;
 858
 859         err = dev_mc_add(dev, appl->group_address);
 860         if (err < 0)
 861                 goto err3;
 862
 863         app->dev = dev;
 864         app->app = appl;
 865         app->mad = RB_ROOT;
 866         spin_lock_init(&app->lock);
 867         skb_queue_head_init(&app->queue);
 868         rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
 869         setup_timer(&app->join_timer, mrp_join_timer, (unsigned long)app);
 870         mrp_join_timer_arm(app);
 871         setup_timer(&app->periodic_timer, mrp_periodic_timer,
 872                     (unsigned long)app);
 873         mrp_periodic_timer_arm(app);
 874         return 0;
 875
 876 err3:
 877         kfree(app);
 878 err2:
 879         mrp_release_port(dev);
 880 err1:
 881         return err;
 882 }
 883 EXPORT_SYMBOL_GPL(mrp_init_applicant);
 884
 885 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
 886 {
 887         struct mrp_port *port = rtnl_dereference(dev->mrp_port);
 888         struct mrp_applicant *app = rtnl_dereference(
 889                 port->applicants[appl->type]);
 890
 891         ASSERT_RTNL();
 892
 893         RCU_INIT_POINTER(port->applicants[appl->type], NULL);
 894
 895         /* Delete timer and generate a final TX event to flush out
 896          * all pending messages before the applicant is gone.
 897          */
 898         del_timer_sync(&app->join_timer);
 899         del_timer_sync(&app->periodic_timer);
 900
 901         spin_lock_bh(&app->lock);
 902         mrp_mad_event(app, MRP_EVENT_TX);
 903         mrp_pdu_queue(app);
 904         spin_unlock_bh(&app->lock);
 905
 906         mrp_queue_xmit(app);
 907
 908         dev_mc_del(dev, appl->group_address);
 909         kfree_rcu(app, rcu);
 910         mrp_release_port(dev);
 911 }
 912 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
 913
 914 int mrp_register_application(struct mrp_application *appl)
 915 {
 916         appl->pkttype.func = mrp_rcv;
 917         dev_add_pack(&appl->pkttype);
 918         return 0;
 919 }
 920 EXPORT_SYMBOL_GPL(mrp_register_application);
 921
 922 void mrp_unregister_application(struct mrp_application *appl)
 923 {
 924         dev_remove_pack(&appl->pkttype);
 925 }
 926 EXPORT_SYMBOL_GPL(mrp_unregister_application);