net/batman-adv/send.c

   1 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "send.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/bug.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/etherdevice.h>
  26 #include <linux/fs.h>
  27 #include <linux/if.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/kernel.h>
  31 #include <linux/kref.h>
  32 #include <linux/list.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/printk.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rcupdate.h>
  37 #include <linux/skbuff.h>
  38 #include <linux/slab.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/stddef.h>
  41 #include <linux/workqueue.h>
  42
  43 #include "distributed-arp-table.h"
  44 #include "fragmentation.h"
  45 #include "gateway_client.h"
  46 #include "hard-interface.h"
  47 #include "log.h"
  48 #include "network-coding.h"
  49 #include "originator.h"
  50 #include "routing.h"
  51 #include "soft-interface.h"
  52 #include "translation-table.h"
  53
  54 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  55
  56 /**
  57  * batadv_send_skb_packet - send an already prepared packet
  58  * @skb: the packet to send
  59  * @hard_iface: the interface to use to send the broadcast packet
  60  * @dst_addr: the payload destination
  61  *
  62  * Send out an already prepared packet to the given neighbor or broadcast it
  63  * using the specified interface. Either hard_iface or neigh_node must be not
  64  * NULL.
  65  * If neigh_node is NULL, then the packet is broadcasted using hard_iface,
  66  * otherwise it is sent as unicast to the given neighbor.
  67  *
  68  * Regardless of the return value, the skb is consumed.
  69  *
  70  * Return: A negative errno code is returned on a failure. A success does not
  71  * guarantee the frame will be transmitted as it may be dropped due
  72  * to congestion or traffic shaping.
  73  */
  74 int batadv_send_skb_packet(struct sk_buff *skb,
  75                            struct batadv_hard_iface *hard_iface,
  76                            const u8 *dst_addr)
  77 {
  78         struct batadv_priv *bat_priv;
  79         struct ethhdr *ethhdr;
  80         int ret;
  81
  82         bat_priv = netdev_priv(hard_iface->soft_iface);
  83
  84         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  85                 goto send_skb_err;
  86
  87         if (unlikely(!hard_iface->net_dev))
  88                 goto send_skb_err;
  89
  90         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  91                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  92                         hard_iface->net_dev->name);
  93                 goto send_skb_err;
  94         }
  95
  96         /* push to the ethernet header. */
  97         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  98                 goto send_skb_err;
  99
 100         skb_reset_mac_header(skb);
 101
 102         ethhdr = eth_hdr(skb);
 103         ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
 104         ether_addr_copy(ethhdr->h_dest, dst_addr);
 105         ethhdr->h_proto = htons(ETH_P_BATMAN);
 106
 107         skb_set_network_header(skb, ETH_HLEN);
 108         skb->protocol = htons(ETH_P_BATMAN);
 109
 110         skb->dev = hard_iface->net_dev;
 111
 112         /* Save a clone of the skb to use when decoding coded packets */
 113         batadv_nc_skb_store_for_decoding(bat_priv, skb);
 114
 115         /* dev_queue_xmit() returns a negative result on error.  However on
 116          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 117          * (which is > 0). This will not be treated as an error.
 118          */
 119         ret = dev_queue_xmit(skb);
 120         return net_xmit_eval(ret);
 121 send_skb_err:
 122         kfree_skb(skb);
 123         return NET_XMIT_DROP;
 124 }
 125
 126 int batadv_send_broadcast_skb(struct sk_buff *skb,
 127                               struct batadv_hard_iface *hard_iface)
 128 {
 129         return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
 130 }
 131
 132 int batadv_send_unicast_skb(struct sk_buff *skb,
 133                             struct batadv_neigh_node *neigh)
 134 {
 135 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 136         struct batadv_hardif_neigh_node *hardif_neigh;
 137 #endif
 138         int ret;
 139
 140         ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
 141
 142 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 143         hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
 144
 145         if ((hardif_neigh) && (ret != NET_XMIT_DROP))
 146                 hardif_neigh->bat_v.last_unicast_tx = jiffies;
 147
 148         if (hardif_neigh)
 149                 batadv_hardif_neigh_put(hardif_neigh);
 150 #endif
 151
 152         return ret;
 153 }
 154
 155 /**
 156  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
 157  * @skb: Packet to be transmitted.
 158  * @orig_node: Final destination of the packet.
 159  * @recv_if: Interface used when receiving the packet (can be NULL).
 160  *
 161  * Looks up the best next-hop towards the passed originator and passes the
 162  * skb on for preparation of MAC header. If the packet originated from this
 163  * host, NULL can be passed as recv_if and no interface alternating is
 164  * attempted.
 165  *
 166  * Return: negative errno code on a failure, -EINPROGRESS if the skb is
 167  * buffered for later transmit or the NET_XMIT status returned by the
 168  * lower routine if the packet has been passed down.
 169  */
 170 int batadv_send_skb_to_orig(struct sk_buff *skb,
 171                             struct batadv_orig_node *orig_node,
 172                             struct batadv_hard_iface *recv_if)
 173 {
 174         struct batadv_priv *bat_priv = orig_node->bat_priv;
 175         struct batadv_neigh_node *neigh_node;
 176         int ret;
 177
 178         /* batadv_find_router() increases neigh_nodes refcount if found. */
 179         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 180         if (!neigh_node) {
 181                 ret = -EINVAL;
 182                 goto free_skb;
 183         }
 184
 185         /* Check if the skb is too large to send in one piece and fragment
 186          * it if needed.
 187          */
 188         if (atomic_read(&bat_priv->fragmentation) &&
 189             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 190                 /* Fragment and send packet. */
 191                 ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
 192                 /* skb was consumed */
 193                 skb = NULL;
 194
 195                 goto put_neigh_node;
 196         }
 197
 198         /* try to network code the packet, if it is received on an interface
 199          * (i.e. being forwarded). If the packet originates from this node or if
 200          * network coding fails, then send the packet as usual.
 201          */
 202         if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
 203                 ret = -EINPROGRESS;
 204         else
 205                 ret = batadv_send_unicast_skb(skb, neigh_node);
 206
 207         /* skb was consumed */
 208         skb = NULL;
 209
 210 put_neigh_node:
 211         batadv_neigh_node_put(neigh_node);
 212 free_skb:
 213         kfree_skb(skb);
 214
 215         return ret;
 216 }
 217
 218 /**
 219  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
 220  *  common fields for unicast packets
 221  * @skb: the skb carrying the unicast header to initialize
 222  * @hdr_size: amount of bytes to push at the beginning of the skb
 223  * @orig_node: the destination node
 224  *
 225  * Return: false if the buffer extension was not possible or true otherwise.
 226  */
 227 static bool
 228 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 229                                   struct batadv_orig_node *orig_node)
 230 {
 231         struct batadv_unicast_packet *unicast_packet;
 232         u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 233
 234         if (batadv_skb_head_push(skb, hdr_size) < 0)
 235                 return false;
 236
 237         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 238         unicast_packet->version = BATADV_COMPAT_VERSION;
 239         /* batman packet type: unicast */
 240         unicast_packet->packet_type = BATADV_UNICAST;
 241         /* set unicast ttl */
 242         unicast_packet->ttl = BATADV_TTL;
 243         /* copy the destination for faster routing */
 244         ether_addr_copy(unicast_packet->dest, orig_node->orig);
 245         /* set the destination tt version number */
 246         unicast_packet->ttvn = ttvn;
 247
 248         return true;
 249 }
 250
 251 /**
 252  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
 253  * @skb: the skb containing the payload to encapsulate
 254  * @orig_node: the destination node
 255  *
 256  * Return: false if the payload could not be encapsulated or true otherwise.
 257  */
 258 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 259                                             struct batadv_orig_node *orig_node)
 260 {
 261         size_t uni_size = sizeof(struct batadv_unicast_packet);
 262
 263         return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 264 }
 265
 266 /**
 267  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
 268  *  unicast 4addr header
 269  * @bat_priv: the bat priv with all the soft interface information
 270  * @skb: the skb containing the payload to encapsulate
 271  * @orig: the destination node
 272  * @packet_subtype: the unicast 4addr packet subtype to use
 273  *
 274  * Return: false if the payload could not be encapsulated or true otherwise.
 275  */
 276 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 277                                            struct sk_buff *skb,
 278                                            struct batadv_orig_node *orig,
 279                                            int packet_subtype)
 280 {
 281         struct batadv_hard_iface *primary_if;
 282         struct batadv_unicast_4addr_packet *uc_4addr_packet;
 283         bool ret = false;
 284
 285         primary_if = batadv_primary_if_get_selected(bat_priv);
 286         if (!primary_if)
 287                 goto out;
 288
 289         /* Pull the header space and fill the unicast_packet substructure.
 290          * We can do that because the first member of the uc_4addr_packet
 291          * is of type struct unicast_packet
 292          */
 293         if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 294                                                orig))
 295                 goto out;
 296
 297         uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 298         uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 299         ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 300         uc_4addr_packet->subtype = packet_subtype;
 301         uc_4addr_packet->reserved = 0;
 302
 303         ret = true;
 304 out:
 305         if (primary_if)
 306                 batadv_hardif_put(primary_if);
 307         return ret;
 308 }
 309
 310 /**
 311  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
 312  * @bat_priv: the bat priv with all the soft interface information
 313  * @skb: payload to send
 314  * @packet_type: the batman unicast packet type to use
 315  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 316  *  4addr packets)
 317  * @orig_node: the originator to send the packet to
 318  * @vid: the vid to be used to search the translation table
 319  *
 320  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
 321  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
 322  * as packet_type. Then send this frame to the given orig_node.
 323  *
 324  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 325  */
 326 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 327                             struct sk_buff *skb, int packet_type,
 328                             int packet_subtype,
 329                             struct batadv_orig_node *orig_node,
 330                             unsigned short vid)
 331 {
 332         struct batadv_unicast_packet *unicast_packet;
 333         struct ethhdr *ethhdr;
 334         int ret = NET_XMIT_DROP;
 335
 336         if (!orig_node)
 337                 goto out;
 338
 339         switch (packet_type) {
 340         case BATADV_UNICAST:
 341                 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 342                         goto out;
 343                 break;
 344         case BATADV_UNICAST_4ADDR:
 345                 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 346                                                            orig_node,
 347                                                            packet_subtype))
 348                         goto out;
 349                 break;
 350         default:
 351                 /* this function supports UNICAST and UNICAST_4ADDR only. It
 352                  * should never be invoked with any other packet type
 353                  */
 354                 goto out;
 355         }
 356
 357         /* skb->data might have been reallocated by
 358          * batadv_send_skb_prepare_unicast{,_4addr}()
 359          */
 360         ethhdr = eth_hdr(skb);
 361         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 362
 363         /* inform the destination node that we are still missing a correct route
 364          * for this client. The destination will receive this packet and will
 365          * try to reroute it because the ttvn contained in the header is less
 366          * than the current one
 367          */
 368         if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 369                 unicast_packet->ttvn = unicast_packet->ttvn - 1;
 370
 371         ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
 372          /* skb was consumed */
 373         skb = NULL;
 374
 375 out:
 376         kfree_skb(skb);
 377         return ret;
 378 }
 379
 380 /**
 381  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
 382  * @bat_priv: the bat priv with all the soft interface information
 383  * @skb: payload to send
 384  * @packet_type: the batman unicast packet type to use
 385  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 386  *  4addr packets)
 387  * @dst_hint: can be used to override the destination contained in the skb
 388  * @vid: the vid to be used to search the translation table
 389  *
 390  * Look up the recipient node for the destination address in the ethernet
 391  * header via the translation table. Wrap the given skb into a batman-adv
 392  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
 393  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
 394  * to the according destination node.
 395  *
 396  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 397  */
 398 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 399                                    struct sk_buff *skb, int packet_type,
 400                                    int packet_subtype, u8 *dst_hint,
 401                                    unsigned short vid)
 402 {
 403         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 404         struct batadv_orig_node *orig_node;
 405         u8 *src, *dst;
 406         int ret;
 407
 408         src = ethhdr->h_source;
 409         dst = ethhdr->h_dest;
 410
 411         /* if we got an hint! let's send the packet to this client (if any) */
 412         if (dst_hint) {
 413                 src = NULL;
 414                 dst = dst_hint;
 415         }
 416         orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 417
 418         ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
 419                                       packet_subtype, orig_node, vid);
 420
 421         if (orig_node)
 422                 batadv_orig_node_put(orig_node);
 423
 424         return ret;
 425 }
 426
 427 /**
 428  * batadv_send_skb_via_gw - send an skb via gateway lookup
 429  * @bat_priv: the bat priv with all the soft interface information
 430  * @skb: payload to send
 431  * @vid: the vid to be used to search the translation table
 432  *
 433  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
 434  * unicast header and send this frame to this gateway node.
 435  *
 436  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 437  */
 438 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 439                            unsigned short vid)
 440 {
 441         struct batadv_orig_node *orig_node;
 442         int ret;
 443
 444         orig_node = batadv_gw_get_selected_orig(bat_priv);
 445         ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
 446                                       BATADV_P_DATA, orig_node, vid);
 447
 448         if (orig_node)
 449                 batadv_orig_node_put(orig_node);
 450
 451         return ret;
 452 }
 453
 454 /**
 455  * batadv_forw_packet_free - free a forwarding packet
 456  * @forw_packet: The packet to free
 457  * @dropped: whether the packet is freed because is is dropped
 458  *
 459  * This frees a forwarding packet and releases any resources it might
 460  * have claimed.
 461  */
 462 void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
 463                              bool dropped)
 464 {
 465         if (dropped)
 466                 kfree_skb(forw_packet->skb);
 467         else
 468                 consume_skb(forw_packet->skb);
 469
 470         if (forw_packet->if_incoming)
 471                 batadv_hardif_put(forw_packet->if_incoming);
 472         if (forw_packet->if_outgoing)
 473                 batadv_hardif_put(forw_packet->if_outgoing);
 474         if (forw_packet->queue_left)
 475                 atomic_inc(forw_packet->queue_left);
 476         kfree(forw_packet);
 477 }
 478
 479 /**
 480  * batadv_forw_packet_alloc - allocate a forwarding packet
 481  * @if_incoming: The (optional) if_incoming to be grabbed
 482  * @if_outgoing: The (optional) if_outgoing to be grabbed
 483  * @queue_left: The (optional) queue counter to decrease
 484  * @bat_priv: The bat_priv for the mesh of this forw_packet
 485  * @skb: The raw packet this forwarding packet shall contain
 486  *
 487  * Allocates a forwarding packet and tries to get a reference to the
 488  * (optional) if_incoming, if_outgoing and queue_left. If queue_left
 489  * is NULL then bat_priv is optional, too.
 490  *
 491  * Return: An allocated forwarding packet on success, NULL otherwise.
 492  */
 493 struct batadv_forw_packet *
 494 batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
 495                          struct batadv_hard_iface *if_outgoing,
 496                          atomic_t *queue_left,
 497                          struct batadv_priv *bat_priv,
 498                          struct sk_buff *skb)
 499 {
 500         struct batadv_forw_packet *forw_packet;
 501         const char *qname;
 502
 503         if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
 504                 qname = "unknown";
 505
 506                 if (queue_left == &bat_priv->bcast_queue_left)
 507                         qname = "bcast";
 508
 509                 if (queue_left == &bat_priv->batman_queue_left)
 510                         qname = "batman";
 511
 512                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 513                            "%s queue is full\n", qname);
 514
 515                 return NULL;
 516         }
 517
 518         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 519         if (!forw_packet)
 520                 goto err;
 521
 522         if (if_incoming)
 523                 kref_get(&if_incoming->refcount);
 524
 525         if (if_outgoing)
 526                 kref_get(&if_outgoing->refcount);
 527
 528         INIT_HLIST_NODE(&forw_packet->list);
 529         INIT_HLIST_NODE(&forw_packet->cleanup_list);
 530         forw_packet->skb = skb;
 531         forw_packet->queue_left = queue_left;
 532         forw_packet->if_incoming = if_incoming;
 533         forw_packet->if_outgoing = if_outgoing;
 534         forw_packet->num_packets = 0;
 535
 536         return forw_packet;
 537
 538 err:
 539         if (queue_left)
 540                 atomic_inc(queue_left);
 541
 542         return NULL;
 543 }
 544
 545 /**
 546  * batadv_forw_packet_was_stolen - check whether someone stole this packet
 547  * @forw_packet: the forwarding packet to check
 548  *
 549  * This function checks whether the given forwarding packet was claimed by
 550  * someone else for free().
 551  *
 552  * Return: True if someone stole it, false otherwise.
 553  */
 554 static bool
 555 batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
 556 {
 557         return !hlist_unhashed(&forw_packet->cleanup_list);
 558 }
 559
 560 /**
 561  * batadv_forw_packet_steal - claim a forw_packet for free()
 562  * @forw_packet: the forwarding packet to steal
 563  * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
 564  *
 565  * This function tries to steal a specific forw_packet from global
 566  * visibility for the purpose of getting it for free(). That means
 567  * the caller is *not* allowed to requeue it afterwards.
 568  *
 569  * Return: True if stealing was successful. False if someone else stole it
 570  * before us.
 571  */
 572 bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
 573                               spinlock_t *lock)
 574 {
 575         /* did purging routine steal it earlier? */
 576         spin_lock_bh(lock);
 577         if (batadv_forw_packet_was_stolen(forw_packet)) {
 578                 spin_unlock_bh(lock);
 579                 return false;
 580         }
 581
 582         hlist_del_init(&forw_packet->list);
 583
 584         /* Just to spot misuse of this function */
 585         hlist_add_fake(&forw_packet->cleanup_list);
 586
 587         spin_unlock_bh(lock);
 588         return true;
 589 }
 590
 591 /**
 592  * batadv_forw_packet_list_steal - claim a list of forward packets for free()
 593  * @forw_list: the to be stolen forward packets
 594  * @cleanup_list: a backup pointer, to be able to dispose the packet later
 595  * @hard_iface: the interface to steal forward packets from
 596  *
 597  * This function claims responsibility to free any forw_packet queued on the
 598  * given hard_iface. If hard_iface is NULL forwarding packets on all hard
 599  * interfaces will be claimed.
 600  *
 601  * The packets are being moved from the forw_list to the cleanup_list and
 602  * by that allows already running threads to notice the claiming.
 603  */
 604 static void
 605 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
 606                               struct hlist_head *cleanup_list,
 607                               const struct batadv_hard_iface *hard_iface)
 608 {
 609         struct batadv_forw_packet *forw_packet;
 610         struct hlist_node *safe_tmp_node;
 611
 612         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 613                                   forw_list, list) {
 614                 /* if purge_outstanding_packets() was called with an argument
 615                  * we delete only packets belonging to the given interface
 616                  */
 617                 if (hard_iface &&
 618                     (forw_packet->if_incoming != hard_iface) &&
 619                     (forw_packet->if_outgoing != hard_iface))
 620                         continue;
 621
 622                 hlist_del(&forw_packet->list);
 623                 hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
 624         }
 625 }
 626
 627 /**
 628  * batadv_forw_packet_list_free - free a list of forward packets
 629  * @head: a list of to be freed forw_packets
 630  *
 631  * This function cancels the scheduling of any packet in the provided list,
 632  * waits for any possibly running packet forwarding thread to finish and
 633  * finally, safely frees this forward packet.
 634  *
 635  * This function might sleep.
 636  */
 637 static void batadv_forw_packet_list_free(struct hlist_head *head)
 638 {
 639         struct batadv_forw_packet *forw_packet;
 640         struct hlist_node *safe_tmp_node;
 641
 642         hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
 643                                   cleanup_list) {
 644                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 645
 646                 hlist_del(&forw_packet->cleanup_list);
 647                 batadv_forw_packet_free(forw_packet, true);
 648         }
 649 }
 650
 651 /**
 652  * batadv_forw_packet_queue - try to queue a forwarding packet
 653  * @forw_packet: the forwarding packet to queue
 654  * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
 655  * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
 656  * @send_time: timestamp (jiffies) when the packet is to be sent
 657  *
 658  * This function tries to (re)queue a forwarding packet. Requeuing
 659  * is prevented if the according interface is shutting down
 660  * (e.g. if batadv_forw_packet_list_steal() was called for this
 661  * packet earlier).
 662  *
 663  * Calling batadv_forw_packet_queue() after a call to
 664  * batadv_forw_packet_steal() is forbidden!
 665  *
 666  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 667  */
 668 static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
 669                                      spinlock_t *lock, struct hlist_head *head,
 670                                      unsigned long send_time)
 671 {
 672         spin_lock_bh(lock);
 673
 674         /* did purging routine steal it from us? */
 675         if (batadv_forw_packet_was_stolen(forw_packet)) {
 676                 /* If you got it for free() without trouble, then
 677                  * don't get back into the queue after stealing...
 678                  */
 679                 WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
 680                           "Requeuing after batadv_forw_packet_steal() not allowed!\n");
 681
 682                 spin_unlock_bh(lock);
 683                 return;
 684         }
 685
 686         hlist_del_init(&forw_packet->list);
 687         hlist_add_head(&forw_packet->list, head);
 688
 689         queue_delayed_work(batadv_event_workqueue,
 690                            &forw_packet->delayed_work,
 691                            send_time - jiffies);
 692         spin_unlock_bh(lock);
 693 }
 694
 695 /**
 696  * batadv_forw_packet_bcast_queue - try to queue a broadcast packet
 697  * @bat_priv: the bat priv with all the soft interface information
 698  * @forw_packet: the forwarding packet to queue
 699  * @send_time: timestamp (jiffies) when the packet is to be sent
 700  *
 701  * This function tries to (re)queue a broadcast packet.
 702  *
 703  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 704  */
 705 static void
 706 batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
 707                                struct batadv_forw_packet *forw_packet,
 708                                unsigned long send_time)
 709 {
 710         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
 711                                  &bat_priv->forw_bcast_list, send_time);
 712 }
 713
 714 /**
 715  * batadv_forw_packet_ogmv1_queue - try to queue an OGMv1 packet
 716  * @bat_priv: the bat priv with all the soft interface information
 717  * @forw_packet: the forwarding packet to queue
 718  * @send_time: timestamp (jiffies) when the packet is to be sent
 719  *
 720  * This function tries to (re)queue an OGMv1 packet.
 721  *
 722  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 723  */
 724 void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
 725                                     struct batadv_forw_packet *forw_packet,
 726                                     unsigned long send_time)
 727 {
 728         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
 729                                  &bat_priv->forw_bat_list, send_time);
 730 }
 731
 732 /**
 733  * batadv_add_bcast_packet_to_list - queue broadcast packet for multiple sends
 734  * @bat_priv: the bat priv with all the soft interface information
 735  * @skb: broadcast packet to add
 736  * @delay: number of jiffies to wait before sending
 737  * @own_packet: true if it is a self-generated broadcast packet
 738  *
 739  * add a broadcast packet to the queue and setup timers. broadcast packets
 740  * are sent multiple times to increase probability for being received.
 741  *
 742  * The skb is not consumed, so the caller should make sure that the
 743  * skb is freed.
 744  *
 745  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
 746  */
 747 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 748                                     const struct sk_buff *skb,
 749                                     unsigned long delay,
 750                                     bool own_packet)
 751 {
 752         struct batadv_hard_iface *primary_if;
 753         struct batadv_forw_packet *forw_packet;
 754         struct batadv_bcast_packet *bcast_packet;
 755         struct sk_buff *newskb;
 756
 757         primary_if = batadv_primary_if_get_selected(bat_priv);
 758         if (!primary_if)
 759                 goto err;
 760
 761         newskb = skb_copy(skb, GFP_ATOMIC);
 762         if (!newskb) {
 763                 batadv_hardif_put(primary_if);
 764                 goto err;
 765         }
 766
 767         forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
 768                                                &bat_priv->bcast_queue_left,
 769                                                bat_priv, newskb);
 770         batadv_hardif_put(primary_if);
 771         if (!forw_packet)
 772                 goto err_packet_free;
 773
 774         /* as we have a copy now, it is safe to decrease the TTL */
 775         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 776         bcast_packet->ttl--;
 777
 778         forw_packet->own = own_packet;
 779
 780         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 781                           batadv_send_outstanding_bcast_packet);
 782
 783         batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
 784         return NETDEV_TX_OK;
 785
 786 err_packet_free:
 787         kfree_skb(newskb);
 788 err:
 789         return NETDEV_TX_BUSY;
 790 }
 791
 792 /**
 793  * batadv_forw_packet_bcasts_left - check if a retransmission is necessary
 794  * @forw_packet: the forwarding packet to check
 795  * @hard_iface: the interface to check on
 796  *
 797  * Checks whether a given packet has any (re)transmissions left on the provided
 798  * interface.
 799  *
 800  * hard_iface may be NULL: In that case the number of transmissions this skb had
 801  * so far is compared with the maximum amount of retransmissions independent of
 802  * any interface instead.
 803  *
 804  * Return: True if (re)transmissions are left, false otherwise.
 805  */
 806 static bool
 807 batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet,
 808                                struct batadv_hard_iface *hard_iface)
 809 {
 810         unsigned int max;
 811
 812         if (hard_iface)
 813                 max = hard_iface->num_bcasts;
 814         else
 815                 max = BATADV_NUM_BCASTS_MAX;
 816
 817         return BATADV_SKB_CB(forw_packet->skb)->num_bcasts < max;
 818 }
 819
 820 /**
 821  * batadv_forw_packet_bcasts_inc - increment retransmission counter of a packet
 822  * @forw_packet: the packet to increase the counter for
 823  */
 824 static void
 825 batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
 826 {
 827         BATADV_SKB_CB(forw_packet->skb)->num_bcasts++;
 828 }
 829
 830 /**
 831  * batadv_forw_packet_is_rebroadcast - check packet for previous transmissions
 832  * @forw_packet: the packet to check
 833  *
 834  * Return: True if this packet was transmitted before, false otherwise.
 835  */
 836 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
 837 {
 838         return BATADV_SKB_CB(forw_packet->skb)->num_bcasts > 0;
 839 }
 840
 841 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 842 {
 843         struct batadv_hard_iface *hard_iface;
 844         struct batadv_hardif_neigh_node *neigh_node;
 845         struct delayed_work *delayed_work;
 846         struct batadv_forw_packet *forw_packet;
 847         struct batadv_bcast_packet *bcast_packet;
 848         struct sk_buff *skb1;
 849         struct net_device *soft_iface;
 850         struct batadv_priv *bat_priv;
 851         unsigned long send_time = jiffies + msecs_to_jiffies(5);
 852         bool dropped = false;
 853         u8 *neigh_addr;
 854         u8 *orig_neigh;
 855         int ret = 0;
 856
 857         delayed_work = to_delayed_work(work);
 858         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 859                                    delayed_work);
 860         soft_iface = forw_packet->if_incoming->soft_iface;
 861         bat_priv = netdev_priv(soft_iface);
 862
 863         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
 864                 dropped = true;
 865                 goto out;
 866         }
 867
 868         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
 869                 dropped = true;
 870                 goto out;
 871         }
 872
 873         bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
 874
 875         /* rebroadcast packet */
 876         rcu_read_lock();
 877         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 878                 if (hard_iface->soft_iface != soft_iface)
 879                         continue;
 880
 881                 if (!batadv_forw_packet_bcasts_left(forw_packet, hard_iface))
 882                         continue;
 883
 884                 if (forw_packet->own) {
 885                         neigh_node = NULL;
 886                 } else {
 887                         neigh_addr = eth_hdr(forw_packet->skb)->h_source;
 888                         neigh_node = batadv_hardif_neigh_get(hard_iface,
 889                                                              neigh_addr);
 890                 }
 891
 892                 orig_neigh = neigh_node ? neigh_node->orig : NULL;
 893
 894                 ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
 895                                                  orig_neigh);
 896
 897                 if (ret) {
 898                         char *type;
 899
 900                         switch (ret) {
 901                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 902                                 type = "no neighbor";
 903                                 break;
 904                         case BATADV_HARDIF_BCAST_DUPFWD:
 905                                 type = "single neighbor is source";
 906                                 break;
 907                         case BATADV_HARDIF_BCAST_DUPORIG:
 908                                 type = "single neighbor is originator";
 909                                 break;
 910                         default:
 911                                 type = "unknown";
 912                         }
 913
 914                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s suppressed: %s\n",
 915                                    bcast_packet->orig,
 916                                    hard_iface->net_dev->name, type);
 917
 918                         if (neigh_node)
 919                                 batadv_hardif_neigh_put(neigh_node);
 920
 921                         continue;
 922                 }
 923
 924                 if (neigh_node)
 925                         batadv_hardif_neigh_put(neigh_node);
 926
 927                 if (!kref_get_unless_zero(&hard_iface->refcount))
 928                         continue;
 929
 930                 /* send a copy of the saved skb */
 931                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 932                 if (skb1)
 933                         batadv_send_broadcast_skb(skb1, hard_iface);
 934
 935                 batadv_hardif_put(hard_iface);
 936         }
 937         rcu_read_unlock();
 938
 939         batadv_forw_packet_bcasts_inc(forw_packet);
 940
 941         /* if we still have some more bcasts to send */
 942         if (batadv_forw_packet_bcasts_left(forw_packet, NULL)) {
 943                 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
 944                                                send_time);
 945                 return;
 946         }
 947
 948 out:
 949         /* do we get something for free()? */
 950         if (batadv_forw_packet_steal(forw_packet,
 951                                      &bat_priv->forw_bcast_list_lock))
 952                 batadv_forw_packet_free(forw_packet, dropped);
 953 }
 954
 955 /**
 956  * batadv_purge_outstanding_packets - stop/purge scheduled bcast/OGMv1 packets
 957  * @bat_priv: the bat priv with all the soft interface information
 958  * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
 959  *
 960  * This method cancels and purges any broadcast and OGMv1 packet on the given
 961  * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
 962  * interfaces will be canceled and purged.
 963  *
 964  * This function might sleep.
 965  */
 966 void
 967 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 968                                  const struct batadv_hard_iface *hard_iface)
 969 {
 970         struct hlist_head head = HLIST_HEAD_INIT;
 971
 972         if (hard_iface)
 973                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 974                            "%s(): %s\n",
 975                            __func__, hard_iface->net_dev->name);
 976         else
 977                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 978                            "%s()\n", __func__);
 979
 980         /* claim bcast list for free() */
 981         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 982         batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
 983                                       hard_iface);
 984         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 985
 986         /* claim batman packet list for free() */
 987         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 988         batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
 989                                       hard_iface);
 990         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 991
 992         /* then cancel or wait for packet workers to finish and free */
 993         batadv_forw_packet_list_free(&head);
 994 }