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