net/batman-adv/send.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "send.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/bug.h>
  12 #include <linux/byteorder/generic.h>
  13 #include <linux/errno.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/gfp.h>
  16 #include <linux/if.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/kernel.h>
  20 #include <linux/kref.h>
  21 #include <linux/list.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/printk.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rcupdate.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/stddef.h>
  30 #include <linux/workqueue.h>
  31
  32 #include "distributed-arp-table.h"
  33 #include "fragmentation.h"
  34 #include "gateway_client.h"
  35 #include "hard-interface.h"
  36 #include "log.h"
  37 #include "network-coding.h"
  38 #include "originator.h"
  39 #include "routing.h"
  40 #include "soft-interface.h"
  41 #include "translation-table.h"
  42
  43 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  44
  45 /**
  46  * batadv_send_skb_packet() - send an already prepared packet
  47  * @skb: the packet to send
  48  * @hard_iface: the interface to use to send the broadcast packet
  49  * @dst_addr: the payload destination
  50  *
  51  * Send out an already prepared packet to the given neighbor or broadcast it
  52  * using the specified interface. Either hard_iface or neigh_node must be not
  53  * NULL.
  54  * If neigh_node is NULL, then the packet is broadcasted using hard_iface,
  55  * otherwise it is sent as unicast to the given neighbor.
  56  *
  57  * Regardless of the return value, the skb is consumed.
  58  *
  59  * Return: A negative errno code is returned on a failure. A success does not
  60  * guarantee the frame will be transmitted as it may be dropped due
  61  * to congestion or traffic shaping.
  62  */
  63 int batadv_send_skb_packet(struct sk_buff *skb,
  64                            struct batadv_hard_iface *hard_iface,
  65                            const u8 *dst_addr)
  66 {
  67         struct batadv_priv *bat_priv;
  68         struct ethhdr *ethhdr;
  69         int ret;
  70
  71         bat_priv = netdev_priv(hard_iface->soft_iface);
  72
  73         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  74                 goto send_skb_err;
  75
  76         if (unlikely(!hard_iface->net_dev))
  77                 goto send_skb_err;
  78
  79         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  80                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  81                         hard_iface->net_dev->name);
  82                 goto send_skb_err;
  83         }
  84
  85         /* push to the ethernet header. */
  86         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  87                 goto send_skb_err;
  88
  89         skb_reset_mac_header(skb);
  90
  91         ethhdr = eth_hdr(skb);
  92         ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
  93         ether_addr_copy(ethhdr->h_dest, dst_addr);
  94         ethhdr->h_proto = htons(ETH_P_BATMAN);
  95
  96         skb_set_network_header(skb, ETH_HLEN);
  97         skb->protocol = htons(ETH_P_BATMAN);
  98
  99         skb->dev = hard_iface->net_dev;
 100
 101         /* Save a clone of the skb to use when decoding coded packets */
 102         batadv_nc_skb_store_for_decoding(bat_priv, skb);
 103
 104         /* dev_queue_xmit() returns a negative result on error.  However on
 105          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 106          * (which is > 0). This will not be treated as an error.
 107          */
 108         ret = dev_queue_xmit(skb);
 109         return net_xmit_eval(ret);
 110 send_skb_err:
 111         kfree_skb(skb);
 112         return NET_XMIT_DROP;
 113 }
 114
 115 /**
 116  * batadv_send_broadcast_skb() - Send broadcast packet via hard interface
 117  * @skb: packet to be transmitted (with batadv header and no outer eth header)
 118  * @hard_iface: outgoing interface
 119  *
 120  * Return: A negative errno code is returned on a failure. A success does not
 121  * guarantee the frame will be transmitted as it may be dropped due
 122  * to congestion or traffic shaping.
 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 /**
 131  * batadv_send_unicast_skb() - Send unicast packet to neighbor
 132  * @skb: packet to be transmitted (with batadv header and no outer eth header)
 133  * @neigh: neighbor which is used as next hop to destination
 134  *
 135  * Return: A negative errno code is returned on a failure. A success does not
 136  * guarantee the frame will be transmitted as it may be dropped due
 137  * to congestion or traffic shaping.
 138  */
 139 int batadv_send_unicast_skb(struct sk_buff *skb,
 140                             struct batadv_neigh_node *neigh)
 141 {
 142 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 143         struct batadv_hardif_neigh_node *hardif_neigh;
 144 #endif
 145         int ret;
 146
 147         ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
 148
 149 #ifdef CONFIG_BATMAN_ADV_BATMAN_V
 150         hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
 151
 152         if (hardif_neigh && ret != NET_XMIT_DROP)
 153                 hardif_neigh->bat_v.last_unicast_tx = jiffies;
 154
 155         if (hardif_neigh)
 156                 batadv_hardif_neigh_put(hardif_neigh);
 157 #endif
 158
 159         return ret;
 160 }
 161
 162 /**
 163  * batadv_send_skb_to_orig() - Lookup next-hop and transmit skb.
 164  * @skb: Packet to be transmitted.
 165  * @orig_node: Final destination of the packet.
 166  * @recv_if: Interface used when receiving the packet (can be NULL).
 167  *
 168  * Looks up the best next-hop towards the passed originator and passes the
 169  * skb on for preparation of MAC header. If the packet originated from this
 170  * host, NULL can be passed as recv_if and no interface alternating is
 171  * attempted.
 172  *
 173  * Return: negative errno code on a failure, -EINPROGRESS if the skb is
 174  * buffered for later transmit or the NET_XMIT status returned by the
 175  * lower routine if the packet has been passed down.
 176  */
 177 int batadv_send_skb_to_orig(struct sk_buff *skb,
 178                             struct batadv_orig_node *orig_node,
 179                             struct batadv_hard_iface *recv_if)
 180 {
 181         struct batadv_priv *bat_priv = orig_node->bat_priv;
 182         struct batadv_neigh_node *neigh_node;
 183         int ret;
 184
 185         /* batadv_find_router() increases neigh_nodes refcount if found. */
 186         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 187         if (!neigh_node) {
 188                 ret = -EINVAL;
 189                 goto free_skb;
 190         }
 191
 192         /* Check if the skb is too large to send in one piece and fragment
 193          * it if needed.
 194          */
 195         if (atomic_read(&bat_priv->fragmentation) &&
 196             skb->len > neigh_node->if_incoming->net_dev->mtu) {
 197                 /* Fragment and send packet. */
 198                 ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
 199                 /* skb was consumed */
 200                 skb = NULL;
 201
 202                 goto put_neigh_node;
 203         }
 204
 205         /* try to network code the packet, if it is received on an interface
 206          * (i.e. being forwarded). If the packet originates from this node or if
 207          * network coding fails, then send the packet as usual.
 208          */
 209         if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
 210                 ret = -EINPROGRESS;
 211         else
 212                 ret = batadv_send_unicast_skb(skb, neigh_node);
 213
 214         /* skb was consumed */
 215         skb = NULL;
 216
 217 put_neigh_node:
 218         batadv_neigh_node_put(neigh_node);
 219 free_skb:
 220         kfree_skb(skb);
 221
 222         return ret;
 223 }
 224
 225 /**
 226  * batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the
 227  *  common fields for unicast packets
 228  * @skb: the skb carrying the unicast header to initialize
 229  * @hdr_size: amount of bytes to push at the beginning of the skb
 230  * @orig_node: the destination node
 231  *
 232  * Return: false if the buffer extension was not possible or true otherwise.
 233  */
 234 static bool
 235 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
 236                                   struct batadv_orig_node *orig_node)
 237 {
 238         struct batadv_unicast_packet *unicast_packet;
 239         u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
 240
 241         if (batadv_skb_head_push(skb, hdr_size) < 0)
 242                 return false;
 243
 244         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 245         unicast_packet->version = BATADV_COMPAT_VERSION;
 246         /* batman packet type: unicast */
 247         unicast_packet->packet_type = BATADV_UNICAST;
 248         /* set unicast ttl */
 249         unicast_packet->ttl = BATADV_TTL;
 250         /* copy the destination for faster routing */
 251         ether_addr_copy(unicast_packet->dest, orig_node->orig);
 252         /* set the destination tt version number */
 253         unicast_packet->ttvn = ttvn;
 254
 255         return true;
 256 }
 257
 258 /**
 259  * batadv_send_skb_prepare_unicast() - encapsulate an skb with a unicast header
 260  * @skb: the skb containing the payload to encapsulate
 261  * @orig_node: the destination node
 262  *
 263  * Return: false if the payload could not be encapsulated or true otherwise.
 264  */
 265 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
 266                                             struct batadv_orig_node *orig_node)
 267 {
 268         size_t uni_size = sizeof(struct batadv_unicast_packet);
 269
 270         return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
 271 }
 272
 273 /**
 274  * batadv_send_skb_prepare_unicast_4addr() - encapsulate an skb with a
 275  *  unicast 4addr header
 276  * @bat_priv: the bat priv with all the soft interface information
 277  * @skb: the skb containing the payload to encapsulate
 278  * @orig: the destination node
 279  * @packet_subtype: the unicast 4addr packet subtype to use
 280  *
 281  * Return: false if the payload could not be encapsulated or true otherwise.
 282  */
 283 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 284                                            struct sk_buff *skb,
 285                                            struct batadv_orig_node *orig,
 286                                            int packet_subtype)
 287 {
 288         struct batadv_hard_iface *primary_if;
 289         struct batadv_unicast_4addr_packet *uc_4addr_packet;
 290         bool ret = false;
 291
 292         primary_if = batadv_primary_if_get_selected(bat_priv);
 293         if (!primary_if)
 294                 goto out;
 295
 296         /* Pull the header space and fill the unicast_packet substructure.
 297          * We can do that because the first member of the uc_4addr_packet
 298          * is of type struct unicast_packet
 299          */
 300         if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
 301                                                orig))
 302                 goto out;
 303
 304         uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 305         uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 306         ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
 307         uc_4addr_packet->subtype = packet_subtype;
 308         uc_4addr_packet->reserved = 0;
 309
 310         ret = true;
 311 out:
 312         if (primary_if)
 313                 batadv_hardif_put(primary_if);
 314         return ret;
 315 }
 316
 317 /**
 318  * batadv_send_skb_unicast() - encapsulate and send an skb via unicast
 319  * @bat_priv: the bat priv with all the soft interface information
 320  * @skb: payload to send
 321  * @packet_type: the batman unicast packet type to use
 322  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 323  *  4addr packets)
 324  * @orig_node: the originator to send the packet to
 325  * @vid: the vid to be used to search the translation table
 326  *
 327  * Wrap the given skb into a batman-adv unicast or unicast-4addr header
 328  * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
 329  * as packet_type. Then send this frame to the given orig_node.
 330  *
 331  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 332  */
 333 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 334                             struct sk_buff *skb, int packet_type,
 335                             int packet_subtype,
 336                             struct batadv_orig_node *orig_node,
 337                             unsigned short vid)
 338 {
 339         struct batadv_unicast_packet *unicast_packet;
 340         struct ethhdr *ethhdr;
 341         int ret = NET_XMIT_DROP;
 342
 343         if (!orig_node)
 344                 goto out;
 345
 346         switch (packet_type) {
 347         case BATADV_UNICAST:
 348                 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
 349                         goto out;
 350                 break;
 351         case BATADV_UNICAST_4ADDR:
 352                 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
 353                                                            orig_node,
 354                                                            packet_subtype))
 355                         goto out;
 356                 break;
 357         default:
 358                 /* this function supports UNICAST and UNICAST_4ADDR only. It
 359                  * should never be invoked with any other packet type
 360                  */
 361                 goto out;
 362         }
 363
 364         /* skb->data might have been reallocated by
 365          * batadv_send_skb_prepare_unicast{,_4addr}()
 366          */
 367         ethhdr = eth_hdr(skb);
 368         unicast_packet = (struct batadv_unicast_packet *)skb->data;
 369
 370         /* inform the destination node that we are still missing a correct route
 371          * for this client. The destination will receive this packet and will
 372          * try to reroute it because the ttvn contained in the header is less
 373          * than the current one
 374          */
 375         if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
 376                 unicast_packet->ttvn = unicast_packet->ttvn - 1;
 377
 378         ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
 379          /* skb was consumed */
 380         skb = NULL;
 381
 382 out:
 383         kfree_skb(skb);
 384         return ret;
 385 }
 386
 387 /**
 388  * batadv_send_skb_via_tt_generic() - send an skb via TT lookup
 389  * @bat_priv: the bat priv with all the soft interface information
 390  * @skb: payload to send
 391  * @packet_type: the batman unicast packet type to use
 392  * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
 393  *  4addr packets)
 394  * @dst_hint: can be used to override the destination contained in the skb
 395  * @vid: the vid to be used to search the translation table
 396  *
 397  * Look up the recipient node for the destination address in the ethernet
 398  * header via the translation table. Wrap the given skb into a batman-adv
 399  * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
 400  * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
 401  * to the according destination node.
 402  *
 403  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 404  */
 405 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 406                                    struct sk_buff *skb, int packet_type,
 407                                    int packet_subtype, u8 *dst_hint,
 408                                    unsigned short vid)
 409 {
 410         struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
 411         struct batadv_orig_node *orig_node;
 412         u8 *src, *dst;
 413         int ret;
 414
 415         src = ethhdr->h_source;
 416         dst = ethhdr->h_dest;
 417
 418         /* if we got an hint! let's send the packet to this client (if any) */
 419         if (dst_hint) {
 420                 src = NULL;
 421                 dst = dst_hint;
 422         }
 423         orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
 424
 425         ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
 426                                       packet_subtype, orig_node, vid);
 427
 428         if (orig_node)
 429                 batadv_orig_node_put(orig_node);
 430
 431         return ret;
 432 }
 433
 434 /**
 435  * batadv_send_skb_via_gw() - send an skb via gateway lookup
 436  * @bat_priv: the bat priv with all the soft interface information
 437  * @skb: payload to send
 438  * @vid: the vid to be used to search the translation table
 439  *
 440  * Look up the currently selected gateway. Wrap the given skb into a batman-adv
 441  * unicast header and send this frame to this gateway node.
 442  *
 443  * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
 444  */
 445 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 446                            unsigned short vid)
 447 {
 448         struct batadv_orig_node *orig_node;
 449         int ret;
 450
 451         orig_node = batadv_gw_get_selected_orig(bat_priv);
 452         ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
 453                                       BATADV_P_DATA, orig_node, vid);
 454
 455         if (orig_node)
 456                 batadv_orig_node_put(orig_node);
 457
 458         return ret;
 459 }
 460
 461 /**
 462  * batadv_forw_packet_free() - free a forwarding packet
 463  * @forw_packet: The packet to free
 464  * @dropped: whether the packet is freed because is dropped
 465  *
 466  * This frees a forwarding packet and releases any resources it might
 467  * have claimed.
 468  */
 469 void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
 470                              bool dropped)
 471 {
 472         if (dropped)
 473                 kfree_skb(forw_packet->skb);
 474         else
 475                 consume_skb(forw_packet->skb);
 476
 477         if (forw_packet->if_incoming)
 478                 batadv_hardif_put(forw_packet->if_incoming);
 479         if (forw_packet->if_outgoing)
 480                 batadv_hardif_put(forw_packet->if_outgoing);
 481         if (forw_packet->queue_left)
 482                 atomic_inc(forw_packet->queue_left);
 483         kfree(forw_packet);
 484 }
 485
 486 /**
 487  * batadv_forw_packet_alloc() - allocate a forwarding packet
 488  * @if_incoming: The (optional) if_incoming to be grabbed
 489  * @if_outgoing: The (optional) if_outgoing to be grabbed
 490  * @queue_left: The (optional) queue counter to decrease
 491  * @bat_priv: The bat_priv for the mesh of this forw_packet
 492  * @skb: The raw packet this forwarding packet shall contain
 493  *
 494  * Allocates a forwarding packet and tries to get a reference to the
 495  * (optional) if_incoming, if_outgoing and queue_left. If queue_left
 496  * is NULL then bat_priv is optional, too.
 497  *
 498  * Return: An allocated forwarding packet on success, NULL otherwise.
 499  */
 500 struct batadv_forw_packet *
 501 batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
 502                          struct batadv_hard_iface *if_outgoing,
 503                          atomic_t *queue_left,
 504                          struct batadv_priv *bat_priv,
 505                          struct sk_buff *skb)
 506 {
 507         struct batadv_forw_packet *forw_packet;
 508         const char *qname;
 509
 510         if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
 511                 qname = "unknown";
 512
 513                 if (queue_left == &bat_priv->bcast_queue_left)
 514                         qname = "bcast";
 515
 516                 if (queue_left == &bat_priv->batman_queue_left)
 517                         qname = "batman";
 518
 519                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 520                            "%s queue is full\n", qname);
 521
 522                 return NULL;
 523         }
 524
 525         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 526         if (!forw_packet)
 527                 goto err;
 528
 529         if (if_incoming)
 530                 kref_get(&if_incoming->refcount);
 531
 532         if (if_outgoing)
 533                 kref_get(&if_outgoing->refcount);
 534
 535         INIT_HLIST_NODE(&forw_packet->list);
 536         INIT_HLIST_NODE(&forw_packet->cleanup_list);
 537         forw_packet->skb = skb;
 538         forw_packet->queue_left = queue_left;
 539         forw_packet->if_incoming = if_incoming;
 540         forw_packet->if_outgoing = if_outgoing;
 541         forw_packet->num_packets = 0;
 542
 543         return forw_packet;
 544
 545 err:
 546         if (queue_left)
 547                 atomic_inc(queue_left);
 548
 549         return NULL;
 550 }
 551
 552 /**
 553  * batadv_forw_packet_was_stolen() - check whether someone stole this packet
 554  * @forw_packet: the forwarding packet to check
 555  *
 556  * This function checks whether the given forwarding packet was claimed by
 557  * someone else for free().
 558  *
 559  * Return: True if someone stole it, false otherwise.
 560  */
 561 static bool
 562 batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
 563 {
 564         return !hlist_unhashed(&forw_packet->cleanup_list);
 565 }
 566
 567 /**
 568  * batadv_forw_packet_steal() - claim a forw_packet for free()
 569  * @forw_packet: the forwarding packet to steal
 570  * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
 571  *
 572  * This function tries to steal a specific forw_packet from global
 573  * visibility for the purpose of getting it for free(). That means
 574  * the caller is *not* allowed to requeue it afterwards.
 575  *
 576  * Return: True if stealing was successful. False if someone else stole it
 577  * before us.
 578  */
 579 bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
 580                               spinlock_t *lock)
 581 {
 582         /* did purging routine steal it earlier? */
 583         spin_lock_bh(lock);
 584         if (batadv_forw_packet_was_stolen(forw_packet)) {
 585                 spin_unlock_bh(lock);
 586                 return false;
 587         }
 588
 589         hlist_del_init(&forw_packet->list);
 590
 591         /* Just to spot misuse of this function */
 592         hlist_add_fake(&forw_packet->cleanup_list);
 593
 594         spin_unlock_bh(lock);
 595         return true;
 596 }
 597
 598 /**
 599  * batadv_forw_packet_list_steal() - claim a list of forward packets for free()
 600  * @forw_list: the to be stolen forward packets
 601  * @cleanup_list: a backup pointer, to be able to dispose the packet later
 602  * @hard_iface: the interface to steal forward packets from
 603  *
 604  * This function claims responsibility to free any forw_packet queued on the
 605  * given hard_iface. If hard_iface is NULL forwarding packets on all hard
 606  * interfaces will be claimed.
 607  *
 608  * The packets are being moved from the forw_list to the cleanup_list. This
 609  * makes it possible for already running threads to notice the claim.
 610  */
 611 static void
 612 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
 613                               struct hlist_head *cleanup_list,
 614                               const struct batadv_hard_iface *hard_iface)
 615 {
 616         struct batadv_forw_packet *forw_packet;
 617         struct hlist_node *safe_tmp_node;
 618
 619         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 620                                   forw_list, list) {
 621                 /* if purge_outstanding_packets() was called with an argument
 622                  * we delete only packets belonging to the given interface
 623                  */
 624                 if (hard_iface &&
 625                     forw_packet->if_incoming != hard_iface &&
 626                     forw_packet->if_outgoing != hard_iface)
 627                         continue;
 628
 629                 hlist_del(&forw_packet->list);
 630                 hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
 631         }
 632 }
 633
 634 /**
 635  * batadv_forw_packet_list_free() - free a list of forward packets
 636  * @head: a list of to be freed forw_packets
 637  *
 638  * This function cancels the scheduling of any packet in the provided list,
 639  * waits for any possibly running packet forwarding thread to finish and
 640  * finally, safely frees this forward packet.
 641  *
 642  * This function might sleep.
 643  */
 644 static void batadv_forw_packet_list_free(struct hlist_head *head)
 645 {
 646         struct batadv_forw_packet *forw_packet;
 647         struct hlist_node *safe_tmp_node;
 648
 649         hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
 650                                   cleanup_list) {
 651                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 652
 653                 hlist_del(&forw_packet->cleanup_list);
 654                 batadv_forw_packet_free(forw_packet, true);
 655         }
 656 }
 657
 658 /**
 659  * batadv_forw_packet_queue() - try to queue a forwarding packet
 660  * @forw_packet: the forwarding packet to queue
 661  * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
 662  * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
 663  * @send_time: timestamp (jiffies) when the packet is to be sent
 664  *
 665  * This function tries to (re)queue a forwarding packet. Requeuing
 666  * is prevented if the according interface is shutting down
 667  * (e.g. if batadv_forw_packet_list_steal() was called for this
 668  * packet earlier).
 669  *
 670  * Calling batadv_forw_packet_queue() after a call to
 671  * batadv_forw_packet_steal() is forbidden!
 672  *
 673  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 674  */
 675 static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
 676                                      spinlock_t *lock, struct hlist_head *head,
 677                                      unsigned long send_time)
 678 {
 679         spin_lock_bh(lock);
 680
 681         /* did purging routine steal it from us? */
 682         if (batadv_forw_packet_was_stolen(forw_packet)) {
 683                 /* If you got it for free() without trouble, then
 684                  * don't get back into the queue after stealing...
 685                  */
 686                 WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
 687                           "Requeuing after batadv_forw_packet_steal() not allowed!\n");
 688
 689                 spin_unlock_bh(lock);
 690                 return;
 691         }
 692
 693         hlist_del_init(&forw_packet->list);
 694         hlist_add_head(&forw_packet->list, head);
 695
 696         queue_delayed_work(batadv_event_workqueue,
 697                            &forw_packet->delayed_work,
 698                            send_time - jiffies);
 699         spin_unlock_bh(lock);
 700 }
 701
 702 /**
 703  * batadv_forw_packet_bcast_queue() - try to queue a broadcast packet
 704  * @bat_priv: the bat priv with all the soft interface information
 705  * @forw_packet: the forwarding packet to queue
 706  * @send_time: timestamp (jiffies) when the packet is to be sent
 707  *
 708  * This function tries to (re)queue a broadcast packet.
 709  *
 710  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 711  */
 712 static void
 713 batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
 714                                struct batadv_forw_packet *forw_packet,
 715                                unsigned long send_time)
 716 {
 717         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
 718                                  &bat_priv->forw_bcast_list, send_time);
 719 }
 720
 721 /**
 722  * batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet
 723  * @bat_priv: the bat priv with all the soft interface information
 724  * @forw_packet: the forwarding packet to queue
 725  * @send_time: timestamp (jiffies) when the packet is to be sent
 726  *
 727  * This function tries to (re)queue an OGMv1 packet.
 728  *
 729  * Caller needs to ensure that forw_packet->delayed_work was initialized.
 730  */
 731 void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
 732                                     struct batadv_forw_packet *forw_packet,
 733                                     unsigned long send_time)
 734 {
 735         batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
 736                                  &bat_priv->forw_bat_list, send_time);
 737 }
 738
 739 /**
 740  * batadv_add_bcast_packet_to_list() - queue broadcast packet for multiple sends
 741  * @bat_priv: the bat priv with all the soft interface information
 742  * @skb: broadcast packet to add
 743  * @delay: number of jiffies to wait before sending
 744  * @own_packet: true if it is a self-generated broadcast packet
 745  *
 746  * add a broadcast packet to the queue and setup timers. broadcast packets
 747  * are sent multiple times to increase probability for being received.
 748  *
 749  * The skb is not consumed, so the caller should make sure that the
 750  * skb is freed.
 751  *
 752  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
 753  */
 754 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 755                                     const struct sk_buff *skb,
 756                                     unsigned long delay,
 757                                     bool own_packet)
 758 {
 759         struct batadv_hard_iface *primary_if;
 760         struct batadv_forw_packet *forw_packet;
 761         struct batadv_bcast_packet *bcast_packet;
 762         struct sk_buff *newskb;
 763
 764         primary_if = batadv_primary_if_get_selected(bat_priv);
 765         if (!primary_if)
 766                 goto err;
 767
 768         newskb = skb_copy(skb, GFP_ATOMIC);
 769         if (!newskb) {
 770                 batadv_hardif_put(primary_if);
 771                 goto err;
 772         }
 773
 774         forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
 775                                                &bat_priv->bcast_queue_left,
 776                                                bat_priv, newskb);
 777         batadv_hardif_put(primary_if);
 778         if (!forw_packet)
 779                 goto err_packet_free;
 780
 781         /* as we have a copy now, it is safe to decrease the TTL */
 782         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 783         bcast_packet->ttl--;
 784
 785         forw_packet->own = own_packet;
 786
 787         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 788                           batadv_send_outstanding_bcast_packet);
 789
 790         batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
 791         return NETDEV_TX_OK;
 792
 793 err_packet_free:
 794         kfree_skb(newskb);
 795 err:
 796         return NETDEV_TX_BUSY;
 797 }
 798
 799 /**
 800  * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
 801  * @forw_packet: the forwarding packet to check
 802  * @hard_iface: the interface to check on
 803  *
 804  * Checks whether a given packet has any (re)transmissions left on the provided
 805  * interface.
 806  *
 807  * hard_iface may be NULL: In that case the number of transmissions this skb had
 808  * so far is compared with the maximum amount of retransmissions independent of
 809  * any interface instead.
 810  *
 811  * Return: True if (re)transmissions are left, false otherwise.
 812  */
 813 static bool
 814 batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet,
 815                                struct batadv_hard_iface *hard_iface)
 816 {
 817         unsigned int max;
 818
 819         if (hard_iface)
 820                 max = hard_iface->num_bcasts;
 821         else
 822                 max = BATADV_NUM_BCASTS_MAX;
 823
 824         return BATADV_SKB_CB(forw_packet->skb)->num_bcasts < max;
 825 }
 826
 827 /**
 828  * batadv_forw_packet_bcasts_inc() - increment retransmission counter of a
 829  *  packet
 830  * @forw_packet: the packet to increase the counter for
 831  */
 832 static void
 833 batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
 834 {
 835         BATADV_SKB_CB(forw_packet->skb)->num_bcasts++;
 836 }
 837
 838 /**
 839  * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
 840  * @forw_packet: the packet to check
 841  *
 842  * Return: True if this packet was transmitted before, false otherwise.
 843  */
 844 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
 845 {
 846         return BATADV_SKB_CB(forw_packet->skb)->num_bcasts > 0;
 847 }
 848
 849 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 850 {
 851         struct batadv_hard_iface *hard_iface;
 852         struct batadv_hardif_neigh_node *neigh_node;
 853         struct delayed_work *delayed_work;
 854         struct batadv_forw_packet *forw_packet;
 855         struct batadv_bcast_packet *bcast_packet;
 856         struct sk_buff *skb1;
 857         struct net_device *soft_iface;
 858         struct batadv_priv *bat_priv;
 859         unsigned long send_time = jiffies + msecs_to_jiffies(5);
 860         bool dropped = false;
 861         u8 *neigh_addr;
 862         u8 *orig_neigh;
 863         int ret = 0;
 864
 865         delayed_work = to_delayed_work(work);
 866         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 867                                    delayed_work);
 868         soft_iface = forw_packet->if_incoming->soft_iface;
 869         bat_priv = netdev_priv(soft_iface);
 870
 871         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
 872                 dropped = true;
 873                 goto out;
 874         }
 875
 876         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
 877                 dropped = true;
 878                 goto out;
 879         }
 880
 881         bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
 882
 883         /* rebroadcast packet */
 884         rcu_read_lock();
 885         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 886                 if (hard_iface->soft_iface != soft_iface)
 887                         continue;
 888
 889                 if (!batadv_forw_packet_bcasts_left(forw_packet, hard_iface))
 890                         continue;
 891
 892                 if (forw_packet->own) {
 893                         neigh_node = NULL;
 894                 } else {
 895                         neigh_addr = eth_hdr(forw_packet->skb)->h_source;
 896                         neigh_node = batadv_hardif_neigh_get(hard_iface,
 897                                                              neigh_addr);
 898                 }
 899
 900                 orig_neigh = neigh_node ? neigh_node->orig : NULL;
 901
 902                 ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
 903                                                  orig_neigh);
 904
 905                 if (ret) {
 906                         char *type;
 907
 908                         switch (ret) {
 909                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 910                                 type = "no neighbor";
 911                                 break;
 912                         case BATADV_HARDIF_BCAST_DUPFWD:
 913                                 type = "single neighbor is source";
 914                                 break;
 915                         case BATADV_HARDIF_BCAST_DUPORIG:
 916                                 type = "single neighbor is originator";
 917                                 break;
 918                         default:
 919                                 type = "unknown";
 920                         }
 921
 922                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s suppressed: %s\n",
 923                                    bcast_packet->orig,
 924                                    hard_iface->net_dev->name, type);
 925
 926                         if (neigh_node)
 927                                 batadv_hardif_neigh_put(neigh_node);
 928
 929                         continue;
 930                 }
 931
 932                 if (neigh_node)
 933                         batadv_hardif_neigh_put(neigh_node);
 934
 935                 if (!kref_get_unless_zero(&hard_iface->refcount))
 936                         continue;
 937
 938                 /* send a copy of the saved skb */
 939                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 940                 if (skb1)
 941                         batadv_send_broadcast_skb(skb1, hard_iface);
 942
 943                 batadv_hardif_put(hard_iface);
 944         }
 945         rcu_read_unlock();
 946
 947         batadv_forw_packet_bcasts_inc(forw_packet);
 948
 949         /* if we still have some more bcasts to send */
 950         if (batadv_forw_packet_bcasts_left(forw_packet, NULL)) {
 951                 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
 952                                                send_time);
 953                 return;
 954         }
 955
 956 out:
 957         /* do we get something for free()? */
 958         if (batadv_forw_packet_steal(forw_packet,
 959                                      &bat_priv->forw_bcast_list_lock))
 960                 batadv_forw_packet_free(forw_packet, dropped);
 961 }
 962
 963 /**
 964  * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
 965  * @bat_priv: the bat priv with all the soft interface information
 966  * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
 967  *
 968  * This method cancels and purges any broadcast and OGMv1 packet on the given
 969  * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
 970  * interfaces will be canceled and purged.
 971  *
 972  * This function might sleep.
 973  */
 974 void
 975 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 976                                  const struct batadv_hard_iface *hard_iface)
 977 {
 978         struct hlist_head head = HLIST_HEAD_INIT;
 979
 980         if (hard_iface)
 981                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 982                            "%s(): %s\n",
 983                            __func__, hard_iface->net_dev->name);
 984         else
 985                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 986                            "%s()\n", __func__);
 987
 988         /* claim bcast list for free() */
 989         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 990         batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
 991                                       hard_iface);
 992         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 993
 994         /* claim batman packet list for free() */
 995         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 996         batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
 997                                       hard_iface);
 998         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 999
1000         /* then cancel or wait for packet workers to finish and free */
1001         batadv_forw_packet_list_free(&head);
1002 }