net/batman-adv/send.c

   1 /* Copyright (C) 2007-2016  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
  81         bat_priv = netdev_priv(hard_iface->soft_iface);
  82
  83         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  84                 goto send_skb_err;
  85
  86         if (unlikely(!hard_iface->net_dev))
  87                 goto send_skb_err;
  88
  89         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  90                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  91                         hard_iface->net_dev->name);
  92                 goto send_skb_err;
  93         }
  94
  95         /* push to the ethernet header. */
  96         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  97                 goto send_skb_err;
  98
  99         skb_reset_mac_header(skb);
 100
 101         ethhdr = eth_hdr(skb);
 102         ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
 103         ether_addr_copy(ethhdr->h_dest, dst_addr);
 104         ethhdr->h_proto = htons(ETH_P_BATMAN);
 105
 106         skb_set_network_header(skb, ETH_HLEN);
 107         skb->protocol = htons(ETH_P_BATMAN);
 108
 109         skb->dev = hard_iface->net_dev;
 110
 111         /* Save a clone of the skb to use when decoding coded packets */
 112         batadv_nc_skb_store_for_decoding(bat_priv, skb);
 113
 114         /* dev_queue_xmit() returns a negative result on error.  However on
 115          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 116          * (which is > 0). This will not be treated as an error.
 117          */
 118         return dev_queue_xmit(skb);
 119 send_skb_err:
 120         kfree_skb(skb);
 121         return NET_XMIT_DROP;
 122 }
 123
 124 int batadv_send_broadcast_skb(struct sk_buff *skb,
 125                               struct batadv_hard_iface *hard_iface)
 126 {
 127         return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
 128 }
 129
 130 int batadv_send_unicast_skb(struct sk_buff *skb,
 131                             struct batadv_neigh_node *neigh)
 132 {
 133 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 134         struct batadv_hardif_neigh_node *hardif_neigh;
 135 #endif
 136         int ret;
 137
 138         ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
 139
 140 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 141         hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
 142
 143         if ((hardif_neigh) && (ret != NET_XMIT_DROP))
 144                 hardif_neigh->bat_v.last_unicast_tx = jiffies;
 145
 146         if (hardif_neigh)
 147                 batadv_hardif_neigh_put(hardif_neigh);
 148 #endif
 149
 150         return ret;
 151 }
 152
 153 /**
 154  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
 155  * @skb: Packet to be transmitted.
 156  * @orig_node: Final destination of the packet.
 157  * @recv_if: Interface used when receiving the packet (can be NULL).
 158  *
 159  * Looks up the best next-hop towards the passed originator and passes the
 160  * skb on for preparation of MAC header. If the packet originated from this
 161  * host, NULL can be passed as recv_if and no interface alternating is
 162  * attempted.
 163  *
 164  * Return: negative errno code on a failure, -EINPROGRESS if the skb is
 165  * buffered for later transmit or the NET_XMIT status returned by the
 166  * lower routine if the packet has been passed down.
 167  */
 168 int batadv_send_skb_to_orig(struct sk_buff *skb,
 169                             struct batadv_orig_node *orig_node,
 170                             struct batadv_hard_iface *recv_if)
 171 {
 172         struct batadv_priv *bat_priv = orig_node->bat_priv;
 173         struct batadv_neigh_node *neigh_node;
 174         int ret;
 175
 176         /* batadv_find_router() increases neigh_nodes refcount if found. */
 177         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 178         if (!neigh_node) {
 179                 ret = -EINVAL;
 180                 goto free_skb;
 181         }
 182
 183         /* Check if the skb is too large to send in one piece and fragment
 184          * it if needed.
 185          */
 186         if (atomic_read(&bat_priv->fragmentation) &&
 187             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 188                 /* Fragment and send packet. */
 189                 ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
 190                 /* skb was consumed */
 191                 skb = NULL;
 192
 193                 goto put_neigh_node;
 194         }
 195
 196         /* try to network code the packet, if it is received on an interface
 197          * (i.e. being forwarded). If the packet originates from this node or if
 198          * network coding fails, then send the packet as usual.
 199          */
 200         if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
 201                 ret = -EINPROGRESS;
 202         else
 203                 ret = batadv_send_unicast_skb(skb, neigh_node);
 204
 205         /* skb was consumed */
 206         skb = NULL;
 207
 208 put_neigh_node:
 209         batadv_neigh_node_put(neigh_node);
 210 free_skb:
 211         kfree_skb(skb);
 212
 213         return ret;
 214 }
 215
 216 /**
 217  * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
 218  *  common fields for unicast packets
 219  * @skb: the skb carrying the unicast header to initialize
 220  * @hdr_size: amount of bytes to push at the beginning of the skb
 221  * @orig_node: the destination node
 222  *
 223  * Return: false if the buffer extension was not possible or true otherwise.
 224  */
 225 static bool
 226 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 227                                   struct batadv_orig_node *orig_node)
 228 {
 229         struct batadv_unicast_packet *unicast_packet;
 230         u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 231
 232         if (batadv_skb_head_push(skb, hdr_size) < 0)
 233                 return false;
 234
 235         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 236         unicast_packet->version = BATADV_COMPAT_VERSION;
 237         /* batman packet type: unicast */
 238         unicast_packet->packet_type = BATADV_UNICAST;
 239         /* set unicast ttl */
 240         unicast_packet->ttl = BATADV_TTL;
 241         /* copy the destination for faster routing */
 242         ether_addr_copy(unicast_packet->dest, orig_node->orig);
 243         /* set the destination tt version number */
 244         unicast_packet->ttvn = ttvn;
 245
 246         return true;
 247 }
 248
 249 /**
 250  * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
 251  * @skb: the skb containing the payload to encapsulate
 252  * @orig_node: the destination node
 253  *
 254  * Return: false if the payload could not be encapsulated or true otherwise.
 255  */
 256 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 257                                             struct batadv_orig_node *orig_node)
 258 {
 259         size_t uni_size = sizeof(struct batadv_unicast_packet);
 260
 261         return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 262 }
 263
 264 /**
 265  * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
 266  *  unicast 4addr header
 267  * @bat_priv: the bat priv with all the soft interface information
 268  * @skb: the skb containing the payload to encapsulate
 269  * @orig: the destination node
 270  * @packet_subtype: the unicast 4addr packet subtype to use
 271  *
 272  * Return: false if the payload could not be encapsulated or true otherwise.
 273  */
 274 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 275                                            struct sk_buff *skb,
 276                                            struct batadv_orig_node *orig,
 277                                            int packet_subtype)
 278 {
 279         struct batadv_hard_iface *primary_if;
 280         struct batadv_unicast_4addr_packet *uc_4addr_packet;
 281         bool ret = false;
 282
 283         primary_if = batadv_primary_if_get_selected(bat_priv);
 284         if (!primary_if)
 285                 goto out;
 286
 287         /* Pull the header space and fill the unicast_packet substructure.
 288          * We can do that because the first member of the uc_4addr_packet
 289          * is of type struct unicast_packet
 290          */
 291         if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 292                                                orig))
 293                 goto out;
 294
 295         uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 296         uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 297         ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 298         uc_4addr_packet->subtype = packet_subtype;
 299         uc_4addr_packet->reserved = 0;
 300
 301         ret = true;
 302 out:
 303         if (primary_if)
 304                 batadv_hardif_put(primary_if);
 305         return ret;
 306 }
 307
 308 /**
 309  * batadv_send_skb_unicast - encapsulate and send an skb via unicast
 310  * @bat_priv: the bat priv with all the soft interface information
 311  * @skb: payload to send
 312  * @packet_type: the batman unicast packet type to use
 313  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 314  *  4addr packets)
 315  * @orig_node: the originator to send the packet to
 316  * @vid: the vid to be used to search the translation table
 317  *
 318  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
 319  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
 320  * as packet_type. Then send this frame to the given orig_node.
 321  *
 322  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 323  */
 324 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 325                             struct sk_buff *skb, int packet_type,
 326                             int packet_subtype,
 327                             struct batadv_orig_node *orig_node,
 328                             unsigned short vid)
 329 {
 330         struct batadv_unicast_packet *unicast_packet;
 331         struct ethhdr *ethhdr;
 332         int ret = NET_XMIT_DROP;
 333
 334         if (!orig_node)
 335                 goto out;
 336
 337         switch (packet_type) {
 338         case BATADV_UNICAST:
 339                 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 340                         goto out;
 341                 break;
 342         case BATADV_UNICAST_4ADDR:
 343                 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 344                                                            orig_node,
 345                                                            packet_subtype))
 346                         goto out;
 347                 break;
 348         default:
 349                 /* this function supports UNICAST and UNICAST_4ADDR only. It
 350                  * should never be invoked with any other packet type
 351                  */
 352                 goto out;
 353         }
 354
 355         /* skb->data might have been reallocated by
 356          * batadv_send_skb_prepare_unicast{,_4addr}()
 357          */
 358         ethhdr = eth_hdr(skb);
 359         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 360
 361         /* inform the destination node that we are still missing a correct route
 362          * for this client. The destination will receive this packet and will
 363          * try to reroute it because the ttvn contained in the header is less
 364          * than the current one
 365          */
 366         if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 367                 unicast_packet->ttvn = unicast_packet->ttvn - 1;
 368
 369         ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
 370          /* skb was consumed */
 371         skb = NULL;
 372
 373 out:
 374         kfree_skb(skb);
 375         return ret;
 376 }
 377
 378 /**
 379  * batadv_send_skb_via_tt_generic - send an skb via TT lookup
 380  * @bat_priv: the bat priv with all the soft interface information
 381  * @skb: payload to send
 382  * @packet_type: the batman unicast packet type to use
 383  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 384  *  4addr packets)
 385  * @dst_hint: can be used to override the destination contained in the skb
 386  * @vid: the vid to be used to search the translation table
 387  *
 388  * Look up the recipient node for the destination address in the ethernet
 389  * header via the translation table. Wrap the given skb into a batman-adv
 390  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
 391  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
 392  * to the according destination node.
 393  *
 394  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 395  */
 396 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 397                                    struct sk_buff *skb, int packet_type,
 398                                    int packet_subtype, u8 *dst_hint,
 399                                    unsigned short vid)
 400 {
 401         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 402         struct batadv_orig_node *orig_node;
 403         u8 *src, *dst;
 404         int ret;
 405
 406         src = ethhdr->h_source;
 407         dst = ethhdr->h_dest;
 408
 409         /* if we got an hint! let's send the packet to this client (if any) */
 410         if (dst_hint) {
 411                 src = NULL;
 412                 dst = dst_hint;
 413         }
 414         orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 415
 416         ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
 417                                       packet_subtype, orig_node, vid);
 418
 419         if (orig_node)
 420                 batadv_orig_node_put(orig_node);
 421
 422         return ret;
 423 }
 424
 425 /**
 426  * batadv_send_skb_via_gw - send an skb via gateway lookup
 427  * @bat_priv: the bat priv with all the soft interface information
 428  * @skb: payload to send
 429  * @vid: the vid to be used to search the translation table
 430  *
 431  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
 432  * unicast header and send this frame to this gateway node.
 433  *
 434  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 435  */
 436 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 437                            unsigned short vid)
 438 {
 439         struct batadv_orig_node *orig_node;
 440         int ret;
 441
 442         orig_node = batadv_gw_get_selected_orig(bat_priv);
 443         ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
 444                                       BATADV_P_DATA, orig_node, vid);
 445
 446         if (orig_node)
 447                 batadv_orig_node_put(orig_node);
 448
 449         return ret;
 450 }
 451
 452 /**
 453  * batadv_forw_packet_free - free a forwarding packet
 454  * @forw_packet: The packet to free
 455  * @dropped: whether the packet is freed because is is dropped
 456  *
 457  * This frees a forwarding packet and releases any resources it might
 458  * have claimed.
 459  */
 460 void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
 461                              bool dropped)
 462 {
 463         if (dropped)
 464                 kfree_skb(forw_packet->skb);
 465         else
 466                 consume_skb(forw_packet->skb);
 467
 468         if (forw_packet->if_incoming)
 469                 batadv_hardif_put(forw_packet->if_incoming);
 470         if (forw_packet->if_outgoing)
 471                 batadv_hardif_put(forw_packet->if_outgoing);
 472         if (forw_packet->queue_left)
 473                 atomic_inc(forw_packet->queue_left);
 474         kfree(forw_packet);
 475 }
 476
 477 /**
 478  * batadv_forw_packet_alloc - allocate a forwarding packet
 479  * @if_incoming: The (optional) if_incoming to be grabbed
 480  * @if_outgoing: The (optional) if_outgoing to be grabbed
 481  * @queue_left: The (optional) queue counter to decrease
 482  * @bat_priv: The bat_priv for the mesh of this forw_packet
 483  *
 484  * Allocates a forwarding packet and tries to get a reference to the
 485  * (optional) if_incoming, if_outgoing and queue_left. If queue_left
 486  * is NULL then bat_priv is optional, too.
 487  *
 488  * Return: An allocated forwarding packet on success, NULL otherwise.
 489  */
 490 struct batadv_forw_packet *
 491 batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
 492                          struct batadv_hard_iface *if_outgoing,
 493                          atomic_t *queue_left,
 494                          struct batadv_priv *bat_priv)
 495 {
 496         struct batadv_forw_packet *forw_packet;
 497         const char *qname;
 498
 499         if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
 500                 qname = "unknown";
 501
 502                 if (queue_left == &bat_priv->bcast_queue_left)
 503                         qname = "bcast";
 504
 505                 if (queue_left == &bat_priv->batman_queue_left)
 506                         qname = "batman";
 507
 508                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 509                            "%s queue is full\n", qname);
 510
 511                 return NULL;
 512         }
 513
 514         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 515         if (!forw_packet)
 516                 goto err;
 517
 518         if (if_incoming)
 519                 kref_get(&if_incoming->refcount);
 520
 521         if (if_outgoing)
 522                 kref_get(&if_outgoing->refcount);
 523
 524         INIT_HLIST_NODE(&forw_packet->list);
 525         INIT_HLIST_NODE(&forw_packet->cleanup_list);
 526         forw_packet->skb = NULL;
 527         forw_packet->queue_left = queue_left;
 528         forw_packet->if_incoming = if_incoming;
 529         forw_packet->if_outgoing = if_outgoing;
 530         forw_packet->num_packets = 0;
 531
 532         return forw_packet;
 533
 534 err:
 535         if (queue_left)
 536                 atomic_inc(queue_left);
 537
 538         return NULL;
 539 }
 540
 541 /**
 542  * batadv_forw_packet_was_stolen - check whether someone stole this packet
 543  * @forw_packet: the forwarding packet to check
 544  *
 545  * This function checks whether the given forwarding packet was claimed by
 546  * someone else for free().
 547  *
 548  * Return: True if someone stole it, false otherwise.
 549  */
 550 static bool
 551 batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
 552 {
 553         return !hlist_unhashed(&forw_packet->cleanup_list);
 554 }
 555
 556 /**
 557  * batadv_forw_packet_steal - claim a forw_packet for free()
 558  * @forw_packet: the forwarding packet to steal
 559  * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
 560  *
 561  * This function tries to steal a specific forw_packet from global
 562  * visibility for the purpose of getting it for free(). That means
 563  * the caller is *not* allowed to requeue it afterwards.
 564  *
 565  * Return: True if stealing was successful. False if someone else stole it
 566  * before us.
 567  */
 568 bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
 569                               spinlock_t *lock)
 570 {
 571         /* did purging routine steal it earlier? */
 572         spin_lock_bh(lock);
 573         if (batadv_forw_packet_was_stolen(forw_packet)) {
 574                 spin_unlock_bh(lock);
 575                 return false;
 576         }
 577
 578         hlist_del_init(&forw_packet->list);
 579
 580         /* Just to spot misuse of this function */
 581         hlist_add_fake(&forw_packet->cleanup_list);
 582
 583         spin_unlock_bh(lock);
 584         return true;
 585 }
 586
 587 /**
 588  * batadv_forw_packet_list_steal - claim a list of forward packets for free()
 589  * @forw_list: the to be stolen forward packets
 590  * @cleanup_list: a backup pointer, to be able to dispose the packet later
 591  * @hard_iface: the interface to steal forward packets from
 592  *
 593  * This function claims responsibility to free any forw_packet queued on the
 594  * given hard_iface. If hard_iface is NULL forwarding packets on all hard
 595  * interfaces will be claimed.
 596  *
 597  * The packets are being moved from the forw_list to the cleanup_list and
 598  * by that allows already running threads to notice the claiming.
 599  */
 600 static void
 601 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
 602                               struct hlist_head *cleanup_list,
 603                               const struct batadv_hard_iface *hard_iface)
 604 {
 605         struct batadv_forw_packet *forw_packet;
 606         struct hlist_node *safe_tmp_node;
 607
 608         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 609                                   forw_list, list) {
 610                 /* if purge_outstanding_packets() was called with an argument
 611                  * we delete only packets belonging to the given interface
 612                  */
 613                 if (hard_iface &&
 614                     (forw_packet->if_incoming != hard_iface) &&
 615                     (forw_packet->if_outgoing != hard_iface))
 616                         continue;
 617
 618                 hlist_del(&forw_packet->list);
 619                 hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
 620         }
 621 }
 622
 623 /**
 624  * batadv_forw_packet_list_free - free a list of forward packets
 625  * @head: a list of to be freed forw_packets
 626  *
 627  * This function cancels the scheduling of any packet in the provided list,
 628  * waits for any possibly running packet forwarding thread to finish and
 629  * finally, safely frees this forward packet.
 630  *
 631  * This function might sleep.
 632  */
 633 static void batadv_forw_packet_list_free(struct hlist_head *head)
 634 {
 635         struct batadv_forw_packet *forw_packet;
 636         struct hlist_node *safe_tmp_node;
 637
 638         hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
 639                                   cleanup_list) {
 640                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 641
 642                 hlist_del(&forw_packet->cleanup_list);
 643                 batadv_forw_packet_free(forw_packet, true);
 644         }
 645 }
 646
 647 /**
 648  * batadv_forw_packet_queue - try to queue a forwarding packet
 649  * @forw_packet: the forwarding packet to queue
 650  * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
 651  * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
 652  * @send_time: timestamp (jiffies) when the packet is to be sent
 653  *
 654  * This function tries to (re)queue a forwarding packet. Requeuing
 655  * is prevented if the according interface is shutting down
 656  * (e.g. if batadv_forw_packet_list_steal() was called for this
 657  * packet earlier).
 658  *
 659  * Calling batadv_forw_packet_queue() after a call to
 660  * batadv_forw_packet_steal() is forbidden!
 661  *
 662  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 663  */
 664 static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
 665                                      spinlock_t *lock, struct hlist_head *head,
 666                                      unsigned long send_time)
 667 {
 668         spin_lock_bh(lock);
 669
 670         /* did purging routine steal it from us? */
 671         if (batadv_forw_packet_was_stolen(forw_packet)) {
 672                 /* If you got it for free() without trouble, then
 673                  * don't get back into the queue after stealing...
 674                  */
 675                 WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
 676                           "Requeuing after batadv_forw_packet_steal() not allowed!\n");
 677
 678                 spin_unlock_bh(lock);
 679                 return;
 680         }
 681
 682         hlist_del_init(&forw_packet->list);
 683         hlist_add_head(&forw_packet->list, head);
 684
 685         queue_delayed_work(batadv_event_workqueue,
 686                            &forw_packet->delayed_work,
 687                            send_time - jiffies);
 688         spin_unlock_bh(lock);
 689 }
 690
 691 /**
 692  * batadv_forw_packet_bcast_queue - try to queue a broadcast packet
 693  * @bat_priv: the bat priv with all the soft interface information
 694  * @forw_packet: the forwarding packet to queue
 695  * @send_time: timestamp (jiffies) when the packet is to be sent
 696  *
 697  * This function tries to (re)queue a broadcast packet.
 698  *
 699  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 700  */
 701 static void
 702 batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
 703                                struct batadv_forw_packet *forw_packet,
 704                                unsigned long send_time)
 705 {
 706         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
 707                                  &bat_priv->forw_bcast_list, send_time);
 708 }
 709
 710 /**
 711  * batadv_forw_packet_ogmv1_queue - try to queue an OGMv1 packet
 712  * @bat_priv: the bat priv with all the soft interface information
 713  * @forw_packet: the forwarding packet to queue
 714  * @send_time: timestamp (jiffies) when the packet is to be sent
 715  *
 716  * This function tries to (re)queue an OGMv1 packet.
 717  *
 718  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 719  */
 720 void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
 721                                     struct batadv_forw_packet *forw_packet,
 722                                     unsigned long send_time)
 723 {
 724         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
 725                                  &bat_priv->forw_bat_list, send_time);
 726 }
 727
 728 /**
 729  * batadv_add_bcast_packet_to_list - queue broadcast packet for multiple sends
 730  * @bat_priv: the bat priv with all the soft interface information
 731  * @skb: broadcast packet to add
 732  * @delay: number of jiffies to wait before sending
 733  * @own_packet: true if it is a self-generated broadcast packet
 734  *
 735  * add a broadcast packet to the queue and setup timers. broadcast packets
 736  * are sent multiple times to increase probability for being received.
 737  *
 738  * The skb is not consumed, so the caller should make sure that the
 739  * skb is freed.
 740  *
 741  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
 742  */
 743 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 744                                     const struct sk_buff *skb,
 745                                     unsigned long delay,
 746                                     bool own_packet)
 747 {
 748         struct batadv_hard_iface *primary_if;
 749         struct batadv_forw_packet *forw_packet;
 750         struct batadv_bcast_packet *bcast_packet;
 751         struct sk_buff *newskb;
 752
 753         primary_if = batadv_primary_if_get_selected(bat_priv);
 754         if (!primary_if)
 755                 goto err;
 756
 757         forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
 758                                                &bat_priv->bcast_queue_left,
 759                                                bat_priv);
 760         batadv_hardif_put(primary_if);
 761         if (!forw_packet)
 762                 goto err;
 763
 764         newskb = skb_copy(skb, GFP_ATOMIC);
 765         if (!newskb)
 766                 goto err_packet_free;
 767
 768         /* as we have a copy now, it is safe to decrease the TTL */
 769         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 770         bcast_packet->ttl--;
 771
 772         forw_packet->skb = newskb;
 773         forw_packet->own = own_packet;
 774
 775         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 776                           batadv_send_outstanding_bcast_packet);
 777
 778         batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
 779         return NETDEV_TX_OK;
 780
 781 err_packet_free:
 782         batadv_forw_packet_free(forw_packet, true);
 783 err:
 784         return NETDEV_TX_BUSY;
 785 }
 786
 787 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 788 {
 789         struct batadv_hard_iface *hard_iface;
 790         struct batadv_hardif_neigh_node *neigh_node;
 791         struct delayed_work *delayed_work;
 792         struct batadv_forw_packet *forw_packet;
 793         struct batadv_bcast_packet *bcast_packet;
 794         struct sk_buff *skb1;
 795         struct net_device *soft_iface;
 796         struct batadv_priv *bat_priv;
 797         unsigned long send_time = jiffies + msecs_to_jiffies(5);
 798         bool dropped = false;
 799         u8 *neigh_addr;
 800         u8 *orig_neigh;
 801         int ret = 0;
 802
 803         delayed_work = to_delayed_work(work);
 804         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 805                                    delayed_work);
 806         soft_iface = forw_packet->if_incoming->soft_iface;
 807         bat_priv = netdev_priv(soft_iface);
 808
 809         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
 810                 dropped = true;
 811                 goto out;
 812         }
 813
 814         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
 815                 dropped = true;
 816                 goto out;
 817         }
 818
 819         bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
 820
 821         /* rebroadcast packet */
 822         rcu_read_lock();
 823         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 824                 if (hard_iface->soft_iface != soft_iface)
 825                         continue;
 826
 827                 if (forw_packet->num_packets >= hard_iface->num_bcasts)
 828                         continue;
 829
 830                 if (forw_packet->own) {
 831                         neigh_node = NULL;
 832                 } else {
 833                         neigh_addr = eth_hdr(forw_packet->skb)->h_source;
 834                         neigh_node = batadv_hardif_neigh_get(hard_iface,
 835                                                              neigh_addr);
 836                 }
 837
 838                 orig_neigh = neigh_node ? neigh_node->orig : NULL;
 839
 840                 ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
 841                                                  orig_neigh);
 842
 843                 if (ret) {
 844                         char *type;
 845
 846                         switch (ret) {
 847                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 848                                 type = "no neighbor";
 849                                 break;
 850                         case BATADV_HARDIF_BCAST_DUPFWD:
 851                                 type = "single neighbor is source";
 852                                 break;
 853                         case BATADV_HARDIF_BCAST_DUPORIG:
 854                                 type = "single neighbor is originator";
 855                                 break;
 856                         default:
 857                                 type = "unknown";
 858                         }
 859
 860                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s surpressed: %s\n",
 861                                    bcast_packet->orig,
 862                                    hard_iface->net_dev->name, type);
 863
 864                         if (neigh_node)
 865                                 batadv_hardif_neigh_put(neigh_node);
 866
 867                         continue;
 868                 }
 869
 870                 if (neigh_node)
 871                         batadv_hardif_neigh_put(neigh_node);
 872
 873                 if (!kref_get_unless_zero(&hard_iface->refcount))
 874                         continue;
 875
 876                 /* send a copy of the saved skb */
 877                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 878                 if (skb1)
 879                         batadv_send_broadcast_skb(skb1, hard_iface);
 880
 881                 batadv_hardif_put(hard_iface);
 882         }
 883         rcu_read_unlock();
 884
 885         forw_packet->num_packets++;
 886
 887         /* if we still have some more bcasts to send */
 888         if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 889                 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
 890                                                send_time);
 891                 return;
 892         }
 893
 894 out:
 895         /* do we get something for free()? */
 896         if (batadv_forw_packet_steal(forw_packet,
 897                                      &bat_priv->forw_bcast_list_lock))
 898                 batadv_forw_packet_free(forw_packet, dropped);
 899 }
 900
 901 /**
 902  * batadv_purge_outstanding_packets - stop/purge scheduled bcast/OGMv1 packets
 903  * @bat_priv: the bat priv with all the soft interface information
 904  * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
 905  *
 906  * This method cancels and purges any broadcast and OGMv1 packet on the given
 907  * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
 908  * interfaces will be canceled and purged.
 909  *
 910  * This function might sleep.
 911  */
 912 void
 913 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 914                                  const struct batadv_hard_iface *hard_iface)
 915 {
 916         struct hlist_head head = HLIST_HEAD_INIT;
 917
 918         if (hard_iface)
 919                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 920                            "purge_outstanding_packets(): %s\n",
 921                            hard_iface->net_dev->name);
 922         else
 923                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 924                            "purge_outstanding_packets()\n");
 925
 926         /* claim bcast list for free() */
 927         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 928         batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
 929                                       hard_iface);
 930         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 931
 932         /* claim batman packet list for free() */
 933         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 934         batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
 935                                       hard_iface);
 936         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 937
 938         /* then cancel or wait for packet workers to finish and free */
 939         batadv_forw_packet_list_free(&head);
 940 }