diff options
Diffstat (limited to 'net/batman-adv/send.c')
| -rw-r--r-- | net/batman-adv/send.c | 1135 |
1 files changed, 1135 insertions, 0 deletions
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c new file mode 100644 index 000000000..0379b1268 --- /dev/null +++ b/net/batman-adv/send.c @@ -0,0 +1,1135 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) B.A.T.M.A.N. contributors: + * + * Marek Lindner, Simon Wunderlich + */ + +#include "send.h" +#include "main.h" + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/byteorder/generic.h> +#include <linux/container_of.h> +#include <linux/errno.h> +#include <linux/etherdevice.h> +#include <linux/gfp.h> +#include <linux/if.h> +#include <linux/if_ether.h> +#include <linux/jiffies.h> +#include <linux/kref.h> +#include <linux/list.h> +#include <linux/netdevice.h> +#include <linux/printk.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stddef.h> +#include <linux/workqueue.h> + +#include "distributed-arp-table.h" +#include "fragmentation.h" +#include "gateway_client.h" +#include "hard-interface.h" +#include "log.h" +#include "network-coding.h" +#include "originator.h" +#include "routing.h" +#include "soft-interface.h" +#include "translation-table.h" + +static void batadv_send_outstanding_bcast_packet(struct work_struct *work); + +/** + * batadv_send_skb_packet() - send an already prepared packet + * @skb: the packet to send + * @hard_iface: the interface to use to send the broadcast packet + * @dst_addr: the payload destination + * + * Send out an already prepared packet to the given neighbor or broadcast it + * using the specified interface. Either hard_iface or neigh_node must be not + * NULL. + * If neigh_node is NULL, then the packet is broadcasted using hard_iface, + * otherwise it is sent as unicast to the given neighbor. + * + * Regardless of the return value, the skb is consumed. + * + * Return: A negative errno code is returned on a failure. A success does not + * guarantee the frame will be transmitted as it may be dropped due + * to congestion or traffic shaping. + */ +int batadv_send_skb_packet(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface, + const u8 *dst_addr) +{ + struct batadv_priv *bat_priv; + struct ethhdr *ethhdr; + int ret; + + bat_priv = netdev_priv(hard_iface->soft_iface); + + if (hard_iface->if_status != BATADV_IF_ACTIVE) + goto send_skb_err; + + if (unlikely(!hard_iface->net_dev)) + goto send_skb_err; + + if (!(hard_iface->net_dev->flags & IFF_UP)) { + pr_warn("Interface %s is not up - can't send packet via that interface!\n", + hard_iface->net_dev->name); + goto send_skb_err; + } + + /* push to the ethernet header. */ + if (batadv_skb_head_push(skb, ETH_HLEN) < 0) + goto send_skb_err; + + skb_reset_mac_header(skb); + + ethhdr = eth_hdr(skb); + ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr); + ether_addr_copy(ethhdr->h_dest, dst_addr); + ethhdr->h_proto = htons(ETH_P_BATMAN); + + skb_set_network_header(skb, ETH_HLEN); + skb->protocol = htons(ETH_P_BATMAN); + + skb->dev = hard_iface->net_dev; + + /* Save a clone of the skb to use when decoding coded packets */ + batadv_nc_skb_store_for_decoding(bat_priv, skb); + + /* dev_queue_xmit() returns a negative result on error. However on + * congestion and traffic shaping, it drops and returns NET_XMIT_DROP + * (which is > 0). This will not be treated as an error. + */ + ret = dev_queue_xmit(skb); + return net_xmit_eval(ret); +send_skb_err: + kfree_skb(skb); + return NET_XMIT_DROP; +} + +/** + * batadv_send_broadcast_skb() - Send broadcast packet via hard interface + * @skb: packet to be transmitted (with batadv header and no outer eth header) + * @hard_iface: outgoing interface + * + * Return: A negative errno code is returned on a failure. A success does not + * guarantee the frame will be transmitted as it may be dropped due + * to congestion or traffic shaping. + */ +int batadv_send_broadcast_skb(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface) +{ + return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr); +} + +/** + * batadv_send_unicast_skb() - Send unicast packet to neighbor + * @skb: packet to be transmitted (with batadv header and no outer eth header) + * @neigh: neighbor which is used as next hop to destination + * + * Return: A negative errno code is returned on a failure. A success does not + * guarantee the frame will be transmitted as it may be dropped due + * to congestion or traffic shaping. + */ +int batadv_send_unicast_skb(struct sk_buff *skb, + struct batadv_neigh_node *neigh) +{ +#ifdef CONFIG_BATMAN_ADV_BATMAN_V + struct batadv_hardif_neigh_node *hardif_neigh; +#endif + int ret; + + ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr); + +#ifdef CONFIG_BATMAN_ADV_BATMAN_V + hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr); + + if (hardif_neigh && ret != NET_XMIT_DROP) + hardif_neigh->bat_v.last_unicast_tx = jiffies; + + batadv_hardif_neigh_put(hardif_neigh); +#endif + + return ret; +} + +/** + * batadv_send_skb_to_orig() - Lookup next-hop and transmit skb. + * @skb: Packet to be transmitted. + * @orig_node: Final destination of the packet. + * @recv_if: Interface used when receiving the packet (can be NULL). + * + * Looks up the best next-hop towards the passed originator and passes the + * skb on for preparation of MAC header. If the packet originated from this + * host, NULL can be passed as recv_if and no interface alternating is + * attempted. + * + * Return: negative errno code on a failure, -EINPROGRESS if the skb is + * buffered for later transmit or the NET_XMIT status returned by the + * lower routine if the packet has been passed down. + */ +int batadv_send_skb_to_orig(struct sk_buff *skb, + struct batadv_orig_node *orig_node, + struct batadv_hard_iface *recv_if) +{ + struct batadv_priv *bat_priv = orig_node->bat_priv; + struct batadv_neigh_node *neigh_node; + int ret; + + /* batadv_find_router() increases neigh_nodes refcount if found. */ + neigh_node = batadv_find_router(bat_priv, orig_node, recv_if); + if (!neigh_node) { + ret = -EINVAL; + goto free_skb; + } + + /* Check if the skb is too large to send in one piece and fragment + * it if needed. + */ + if (atomic_read(&bat_priv->fragmentation) && + skb->len > neigh_node->if_incoming->net_dev->mtu) { + /* Fragment and send packet. */ + ret = batadv_frag_send_packet(skb, orig_node, neigh_node); + /* skb was consumed */ + skb = NULL; + + goto put_neigh_node; + } + + /* try to network code the packet, if it is received on an interface + * (i.e. being forwarded). If the packet originates from this node or if + * network coding fails, then send the packet as usual. + */ + if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) + ret = -EINPROGRESS; + else + ret = batadv_send_unicast_skb(skb, neigh_node); + + /* skb was consumed */ + skb = NULL; + +put_neigh_node: + batadv_neigh_node_put(neigh_node); +free_skb: + kfree_skb(skb); + + return ret; +} + +/** + * batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the + * common fields for unicast packets + * @skb: the skb carrying the unicast header to initialize + * @hdr_size: amount of bytes to push at the beginning of the skb + * @orig_node: the destination node + * + * Return: false if the buffer extension was not possible or true otherwise. + */ +static bool +batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size, + struct batadv_orig_node *orig_node) +{ + struct batadv_unicast_packet *unicast_packet; + u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn); + + if (batadv_skb_head_push(skb, hdr_size) < 0) + return false; + + unicast_packet = (struct batadv_unicast_packet *)skb->data; + unicast_packet->version = BATADV_COMPAT_VERSION; + /* batman packet type: unicast */ + unicast_packet->packet_type = BATADV_UNICAST; + /* set unicast ttl */ + unicast_packet->ttl = BATADV_TTL; + /* copy the destination for faster routing */ + ether_addr_copy(unicast_packet->dest, orig_node->orig); + /* set the destination tt version number */ + unicast_packet->ttvn = ttvn; + + return true; +} + +/** + * batadv_send_skb_prepare_unicast() - encapsulate an skb with a unicast header + * @skb: the skb containing the payload to encapsulate + * @orig_node: the destination node + * + * Return: false if the payload could not be encapsulated or true otherwise. + */ +static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb, + struct batadv_orig_node *orig_node) +{ + size_t uni_size = sizeof(struct batadv_unicast_packet); + + return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node); +} + +/** + * batadv_send_skb_prepare_unicast_4addr() - encapsulate an skb with a + * unicast 4addr header + * @bat_priv: the bat priv with all the soft interface information + * @skb: the skb containing the payload to encapsulate + * @orig: the destination node + * @packet_subtype: the unicast 4addr packet subtype to use + * + * Return: false if the payload could not be encapsulated or true otherwise. + */ +bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv, + struct sk_buff *skb, + struct batadv_orig_node *orig, + int packet_subtype) +{ + struct batadv_hard_iface *primary_if; + struct batadv_unicast_4addr_packet *uc_4addr_packet; + bool ret = false; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out; + + /* Pull the header space and fill the unicast_packet substructure. + * We can do that because the first member of the uc_4addr_packet + * is of type struct unicast_packet + */ + if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet), + orig)) + goto out; + + uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; + uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR; + ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr); + uc_4addr_packet->subtype = packet_subtype; + uc_4addr_packet->reserved = 0; + + ret = true; +out: + batadv_hardif_put(primary_if); + return ret; +} + +/** + * batadv_send_skb_unicast() - encapsulate and send an skb via unicast + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @packet_type: the batman unicast packet type to use + * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast + * 4addr packets) + * @orig_node: the originator to send the packet to + * @vid: the vid to be used to search the translation table + * + * Wrap the given skb into a batman-adv unicast or unicast-4addr header + * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied + * as packet_type. Then send this frame to the given orig_node. + * + * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_unicast(struct batadv_priv *bat_priv, + struct sk_buff *skb, int packet_type, + int packet_subtype, + struct batadv_orig_node *orig_node, + unsigned short vid) +{ + struct batadv_unicast_packet *unicast_packet; + struct ethhdr *ethhdr; + int ret = NET_XMIT_DROP; + + if (!orig_node) + goto out; + + switch (packet_type) { + case BATADV_UNICAST: + if (!batadv_send_skb_prepare_unicast(skb, orig_node)) + goto out; + break; + case BATADV_UNICAST_4ADDR: + if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb, + orig_node, + packet_subtype)) + goto out; + break; + default: + /* this function supports UNICAST and UNICAST_4ADDR only. It + * should never be invoked with any other packet type + */ + goto out; + } + + /* skb->data might have been reallocated by + * batadv_send_skb_prepare_unicast{,_4addr}() + */ + ethhdr = eth_hdr(skb); + unicast_packet = (struct batadv_unicast_packet *)skb->data; + + /* inform the destination node that we are still missing a correct route + * for this client. The destination will receive this packet and will + * try to reroute it because the ttvn contained in the header is less + * than the current one + */ + if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) + unicast_packet->ttvn = unicast_packet->ttvn - 1; + + ret = batadv_send_skb_to_orig(skb, orig_node, NULL); + /* skb was consumed */ + skb = NULL; + +out: + kfree_skb(skb); + return ret; +} + +/** + * batadv_send_skb_via_tt_generic() - send an skb via TT lookup + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @packet_type: the batman unicast packet type to use + * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast + * 4addr packets) + * @dst_hint: can be used to override the destination contained in the skb + * @vid: the vid to be used to search the translation table + * + * Look up the recipient node for the destination address in the ethernet + * header via the translation table. Wrap the given skb into a batman-adv + * unicast or unicast-4addr header depending on whether BATADV_UNICAST or + * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame + * to the according destination node. + * + * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, + struct sk_buff *skb, int packet_type, + int packet_subtype, u8 *dst_hint, + unsigned short vid) +{ + struct ethhdr *ethhdr = (struct ethhdr *)skb->data; + struct batadv_orig_node *orig_node; + u8 *src, *dst; + int ret; + + src = ethhdr->h_source; + dst = ethhdr->h_dest; + + /* if we got an hint! let's send the packet to this client (if any) */ + if (dst_hint) { + src = NULL; + dst = dst_hint; + } + orig_node = batadv_transtable_search(bat_priv, src, dst, vid); + + ret = batadv_send_skb_unicast(bat_priv, skb, packet_type, + packet_subtype, orig_node, vid); + + batadv_orig_node_put(orig_node); + + return ret; +} + +/** + * batadv_send_skb_via_gw() - send an skb via gateway lookup + * @bat_priv: the bat priv with all the soft interface information + * @skb: payload to send + * @vid: the vid to be used to search the translation table + * + * Look up the currently selected gateway. Wrap the given skb into a batman-adv + * unicast header and send this frame to this gateway node. + * + * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. + */ +int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ + struct batadv_orig_node *orig_node; + int ret; + + orig_node = batadv_gw_get_selected_orig(bat_priv); + ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR, + BATADV_P_DATA, orig_node, vid); + + batadv_orig_node_put(orig_node); + + return ret; +} + +/** + * batadv_forw_packet_free() - free a forwarding packet + * @forw_packet: The packet to free + * @dropped: whether the packet is freed because is dropped + * + * This frees a forwarding packet and releases any resources it might + * have claimed. + */ +void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet, + bool dropped) +{ + if (dropped) + kfree_skb(forw_packet->skb); + else + consume_skb(forw_packet->skb); + + batadv_hardif_put(forw_packet->if_incoming); + batadv_hardif_put(forw_packet->if_outgoing); + if (forw_packet->queue_left) + atomic_inc(forw_packet->queue_left); + kfree(forw_packet); +} + +/** + * batadv_forw_packet_alloc() - allocate a forwarding packet + * @if_incoming: The (optional) if_incoming to be grabbed + * @if_outgoing: The (optional) if_outgoing to be grabbed + * @queue_left: The (optional) queue counter to decrease + * @bat_priv: The bat_priv for the mesh of this forw_packet + * @skb: The raw packet this forwarding packet shall contain + * + * Allocates a forwarding packet and tries to get a reference to the + * (optional) if_incoming, if_outgoing and queue_left. If queue_left + * is NULL then bat_priv is optional, too. + * + * Return: An allocated forwarding packet on success, NULL otherwise. + */ +struct batadv_forw_packet * +batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing, + atomic_t *queue_left, + struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct batadv_forw_packet *forw_packet; + const char *qname; + + if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) { + qname = "unknown"; + + if (queue_left == &bat_priv->bcast_queue_left) + qname = "bcast"; + + if (queue_left == &bat_priv->batman_queue_left) + qname = "batman"; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "%s queue is full\n", qname); + + return NULL; + } + + forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); + if (!forw_packet) + goto err; + + if (if_incoming) + kref_get(&if_incoming->refcount); + + if (if_outgoing) + kref_get(&if_outgoing->refcount); + + INIT_HLIST_NODE(&forw_packet->list); + INIT_HLIST_NODE(&forw_packet->cleanup_list); + forw_packet->skb = skb; + forw_packet->queue_left = queue_left; + forw_packet->if_incoming = if_incoming; + forw_packet->if_outgoing = if_outgoing; + forw_packet->num_packets = 0; + + return forw_packet; + +err: + if (queue_left) + atomic_inc(queue_left); + + return NULL; +} + +/** + * batadv_forw_packet_was_stolen() - check whether someone stole this packet + * @forw_packet: the forwarding packet to check + * + * This function checks whether the given forwarding packet was claimed by + * someone else for free(). + * + * Return: True if someone stole it, false otherwise. + */ +static bool +batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet) +{ + return !hlist_unhashed(&forw_packet->cleanup_list); +} + +/** + * batadv_forw_packet_steal() - claim a forw_packet for free() + * @forw_packet: the forwarding packet to steal + * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock) + * + * This function tries to steal a specific forw_packet from global + * visibility for the purpose of getting it for free(). That means + * the caller is *not* allowed to requeue it afterwards. + * + * Return: True if stealing was successful. False if someone else stole it + * before us. + */ +bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet, + spinlock_t *lock) +{ + /* did purging routine steal it earlier? */ + spin_lock_bh(lock); + if (batadv_forw_packet_was_stolen(forw_packet)) { + spin_unlock_bh(lock); + return false; + } + + hlist_del_init(&forw_packet->list); + + /* Just to spot misuse of this function */ + hlist_add_fake(&forw_packet->cleanup_list); + + spin_unlock_bh(lock); + return true; +} + +/** + * batadv_forw_packet_list_steal() - claim a list of forward packets for free() + * @forw_list: the to be stolen forward packets + * @cleanup_list: a backup pointer, to be able to dispose the packet later + * @hard_iface: the interface to steal forward packets from + * + * This function claims responsibility to free any forw_packet queued on the + * given hard_iface. If hard_iface is NULL forwarding packets on all hard + * interfaces will be claimed. + * + * The packets are being moved from the forw_list to the cleanup_list. This + * makes it possible for already running threads to notice the claim. + */ +static void +batadv_forw_packet_list_steal(struct hlist_head *forw_list, + struct hlist_head *cleanup_list, + const struct batadv_hard_iface *hard_iface) +{ + struct batadv_forw_packet *forw_packet; + struct hlist_node *safe_tmp_node; + + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, + forw_list, list) { + /* if purge_outstanding_packets() was called with an argument + * we delete only packets belonging to the given interface + */ + if (hard_iface && + forw_packet->if_incoming != hard_iface && + forw_packet->if_outgoing != hard_iface) + continue; + + hlist_del(&forw_packet->list); + hlist_add_head(&forw_packet->cleanup_list, cleanup_list); + } +} + +/** + * batadv_forw_packet_list_free() - free a list of forward packets + * @head: a list of to be freed forw_packets + * + * This function cancels the scheduling of any packet in the provided list, + * waits for any possibly running packet forwarding thread to finish and + * finally, safely frees this forward packet. + * + * This function might sleep. + */ +static void batadv_forw_packet_list_free(struct hlist_head *head) +{ + struct batadv_forw_packet *forw_packet; + struct hlist_node *safe_tmp_node; + + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head, + cleanup_list) { + cancel_delayed_work_sync(&forw_packet->delayed_work); + + hlist_del(&forw_packet->cleanup_list); + batadv_forw_packet_free(forw_packet, true); + } +} + +/** + * batadv_forw_packet_queue() - try to queue a forwarding packet + * @forw_packet: the forwarding packet to queue + * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock) + * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list) + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue a forwarding packet. Requeuing + * is prevented if the according interface is shutting down + * (e.g. if batadv_forw_packet_list_steal() was called for this + * packet earlier). + * + * Calling batadv_forw_packet_queue() after a call to + * batadv_forw_packet_steal() is forbidden! + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet, + spinlock_t *lock, struct hlist_head *head, + unsigned long send_time) +{ + spin_lock_bh(lock); + + /* did purging routine steal it from us? */ + if (batadv_forw_packet_was_stolen(forw_packet)) { + /* If you got it for free() without trouble, then + * don't get back into the queue after stealing... + */ + WARN_ONCE(hlist_fake(&forw_packet->cleanup_list), + "Requeuing after batadv_forw_packet_steal() not allowed!\n"); + + spin_unlock_bh(lock); + return; + } + + hlist_del_init(&forw_packet->list); + hlist_add_head(&forw_packet->list, head); + + queue_delayed_work(batadv_event_workqueue, + &forw_packet->delayed_work, + send_time - jiffies); + spin_unlock_bh(lock); +} + +/** + * batadv_forw_packet_bcast_queue() - try to queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @forw_packet: the forwarding packet to queue + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue a broadcast packet. + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +static void +batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time) +{ + batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock, + &bat_priv->forw_bcast_list, send_time); +} + +/** + * batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet + * @bat_priv: the bat priv with all the soft interface information + * @forw_packet: the forwarding packet to queue + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue an OGMv1 packet. + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time) +{ + batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock, + &bat_priv->forw_bat_list, send_time); +} + +/** + * batadv_forw_bcast_packet_to_list() - queue broadcast packet for transmissions + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to add + * @delay: number of jiffies to wait before sending + * @own_packet: true if it is a self-generated broadcast packet + * @if_in: the interface where the packet was received on + * @if_out: the outgoing interface to queue on + * + * Adds a broadcast packet to the queue and sets up timers. Broadcast packets + * are sent multiple times to increase probability for being received. + * + * This call clones the given skb, hence the caller needs to take into + * account that the data segment of the original skb might not be + * modifiable anymore. + * + * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors. + */ +static int batadv_forw_bcast_packet_to_list(struct batadv_priv *bat_priv, + struct sk_buff *skb, + unsigned long delay, + bool own_packet, + struct batadv_hard_iface *if_in, + struct batadv_hard_iface *if_out) +{ + struct batadv_forw_packet *forw_packet; + unsigned long send_time = jiffies; + struct sk_buff *newskb; + + newskb = skb_clone(skb, GFP_ATOMIC); + if (!newskb) + goto err; + + forw_packet = batadv_forw_packet_alloc(if_in, if_out, + &bat_priv->bcast_queue_left, + bat_priv, newskb); + if (!forw_packet) + goto err_packet_free; + + forw_packet->own = own_packet; + + INIT_DELAYED_WORK(&forw_packet->delayed_work, + batadv_send_outstanding_bcast_packet); + + send_time += delay ? delay : msecs_to_jiffies(5); + + batadv_forw_packet_bcast_queue(bat_priv, forw_packet, send_time); + return NETDEV_TX_OK; + +err_packet_free: + kfree_skb(newskb); +err: + return NETDEV_TX_BUSY; +} + +/** + * batadv_forw_bcast_packet_if() - forward and queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to add + * @delay: number of jiffies to wait before sending + * @own_packet: true if it is a self-generated broadcast packet + * @if_in: the interface where the packet was received on + * @if_out: the outgoing interface to forward to + * + * Transmits a broadcast packet on the specified interface either immediately + * or if a delay is given after that. Furthermore, queues additional + * retransmissions if this interface is a wireless one. + * + * This call clones the given skb, hence the caller needs to take into + * account that the data segment of the original skb might not be + * modifiable anymore. + * + * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors. + */ +static int batadv_forw_bcast_packet_if(struct batadv_priv *bat_priv, + struct sk_buff *skb, + unsigned long delay, + bool own_packet, + struct batadv_hard_iface *if_in, + struct batadv_hard_iface *if_out) +{ + unsigned int num_bcasts = if_out->num_bcasts; + struct sk_buff *newskb; + int ret = NETDEV_TX_OK; + + if (!delay) { + newskb = skb_clone(skb, GFP_ATOMIC); + if (!newskb) + return NETDEV_TX_BUSY; + + batadv_send_broadcast_skb(newskb, if_out); + num_bcasts--; + } + + /* delayed broadcast or rebroadcasts? */ + if (num_bcasts >= 1) { + BATADV_SKB_CB(skb)->num_bcasts = num_bcasts; + + ret = batadv_forw_bcast_packet_to_list(bat_priv, skb, delay, + own_packet, if_in, + if_out); + } + + return ret; +} + +/** + * batadv_send_no_broadcast() - check whether (re)broadcast is necessary + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to check + * @own_packet: true if it is a self-generated broadcast packet + * @if_out: the outgoing interface checked and considered for (re)broadcast + * + * Return: False if a packet needs to be (re)broadcasted on the given interface, + * true otherwise. + */ +static bool batadv_send_no_broadcast(struct batadv_priv *bat_priv, + struct sk_buff *skb, bool own_packet, + struct batadv_hard_iface *if_out) +{ + struct batadv_hardif_neigh_node *neigh_node = NULL; + struct batadv_bcast_packet *bcast_packet; + u8 *orig_neigh; + u8 *neigh_addr; + char *type; + int ret; + + if (!own_packet) { + neigh_addr = eth_hdr(skb)->h_source; + neigh_node = batadv_hardif_neigh_get(if_out, + neigh_addr); + } + + bcast_packet = (struct batadv_bcast_packet *)skb->data; + orig_neigh = neigh_node ? neigh_node->orig : NULL; + + ret = batadv_hardif_no_broadcast(if_out, bcast_packet->orig, + orig_neigh); + + batadv_hardif_neigh_put(neigh_node); + + /* ok, may broadcast */ + if (!ret) + return false; + + /* no broadcast */ + switch (ret) { + case BATADV_HARDIF_BCAST_NORECIPIENT: + type = "no neighbor"; + break; + case BATADV_HARDIF_BCAST_DUPFWD: + type = "single neighbor is source"; + break; + case BATADV_HARDIF_BCAST_DUPORIG: + type = "single neighbor is originator"; + break; + default: + type = "unknown"; + } + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "BCAST packet from orig %pM on %s suppressed: %s\n", + bcast_packet->orig, + if_out->net_dev->name, type); + + return true; +} + +/** + * __batadv_forw_bcast_packet() - forward and queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to add + * @delay: number of jiffies to wait before sending + * @own_packet: true if it is a self-generated broadcast packet + * + * Transmits a broadcast packet either immediately or if a delay is given + * after that. Furthermore, queues additional retransmissions on wireless + * interfaces. + * + * This call clones the given skb, hence the caller needs to take into + * account that the data segment of the given skb might not be + * modifiable anymore. + * + * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors. + */ +static int __batadv_forw_bcast_packet(struct batadv_priv *bat_priv, + struct sk_buff *skb, + unsigned long delay, + bool own_packet) +{ + struct batadv_hard_iface *hard_iface; + struct batadv_hard_iface *primary_if; + int ret = NETDEV_TX_OK; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + return NETDEV_TX_BUSY; + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->soft_iface != bat_priv->soft_iface) + continue; + + if (!kref_get_unless_zero(&hard_iface->refcount)) + continue; + + if (batadv_send_no_broadcast(bat_priv, skb, own_packet, + hard_iface)) { + batadv_hardif_put(hard_iface); + continue; + } + + ret = batadv_forw_bcast_packet_if(bat_priv, skb, delay, + own_packet, primary_if, + hard_iface); + batadv_hardif_put(hard_iface); + + if (ret == NETDEV_TX_BUSY) + break; + } + rcu_read_unlock(); + + batadv_hardif_put(primary_if); + return ret; +} + +/** + * batadv_forw_bcast_packet() - forward and queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to add + * @delay: number of jiffies to wait before sending + * @own_packet: true if it is a self-generated broadcast packet + * + * Transmits a broadcast packet either immediately or if a delay is given + * after that. Furthermore, queues additional retransmissions on wireless + * interfaces. + * + * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors. + */ +int batadv_forw_bcast_packet(struct batadv_priv *bat_priv, + struct sk_buff *skb, + unsigned long delay, + bool own_packet) +{ + return __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet); +} + +/** + * batadv_send_bcast_packet() - send and queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @skb: broadcast packet to add + * @delay: number of jiffies to wait before sending + * @own_packet: true if it is a self-generated broadcast packet + * + * Transmits a broadcast packet either immediately or if a delay is given + * after that. Furthermore, queues additional retransmissions on wireless + * interfaces. + * + * Consumes the provided skb. + */ +void batadv_send_bcast_packet(struct batadv_priv *bat_priv, + struct sk_buff *skb, + unsigned long delay, + bool own_packet) +{ + __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet); + consume_skb(skb); +} + +/** + * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary + * @forw_packet: the forwarding packet to check + * + * Checks whether a given packet has any (re)transmissions left on the provided + * interface. + * + * hard_iface may be NULL: In that case the number of transmissions this skb had + * so far is compared with the maximum amount of retransmissions independent of + * any interface instead. + * + * Return: True if (re)transmissions are left, false otherwise. + */ +static bool +batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet) +{ + return BATADV_SKB_CB(forw_packet->skb)->num_bcasts; +} + +/** + * batadv_forw_packet_bcasts_dec() - decrement retransmission counter of a + * packet + * @forw_packet: the packet to decrease the counter for + */ +static void +batadv_forw_packet_bcasts_dec(struct batadv_forw_packet *forw_packet) +{ + BATADV_SKB_CB(forw_packet->skb)->num_bcasts--; +} + +/** + * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions + * @forw_packet: the packet to check + * + * Return: True if this packet was transmitted before, false otherwise. + */ +bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet) +{ + unsigned char num_bcasts = BATADV_SKB_CB(forw_packet->skb)->num_bcasts; + + return num_bcasts != forw_packet->if_outgoing->num_bcasts; +} + +/** + * batadv_send_outstanding_bcast_packet() - transmit a queued broadcast packet + * @work: work queue item + * + * Transmits a queued broadcast packet and if necessary reschedules it. + */ +static void batadv_send_outstanding_bcast_packet(struct work_struct *work) +{ + unsigned long send_time = jiffies + msecs_to_jiffies(5); + struct batadv_forw_packet *forw_packet; + struct delayed_work *delayed_work; + struct batadv_priv *bat_priv; + struct sk_buff *skb1; + bool dropped = false; + + delayed_work = to_delayed_work(work); + forw_packet = container_of(delayed_work, struct batadv_forw_packet, + delayed_work); + bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface); + + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) { + dropped = true; + goto out; + } + + if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) { + dropped = true; + goto out; + } + + /* send a copy of the saved skb */ + skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC); + if (!skb1) + goto out; + + batadv_send_broadcast_skb(skb1, forw_packet->if_outgoing); + batadv_forw_packet_bcasts_dec(forw_packet); + + if (batadv_forw_packet_bcasts_left(forw_packet)) { + batadv_forw_packet_bcast_queue(bat_priv, forw_packet, + send_time); + return; + } + +out: + /* do we get something for free()? */ + if (batadv_forw_packet_steal(forw_packet, + &bat_priv->forw_bcast_list_lock)) + batadv_forw_packet_free(forw_packet, dropped); +} + +/** + * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets + * @bat_priv: the bat priv with all the soft interface information + * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on + * + * This method cancels and purges any broadcast and OGMv1 packet on the given + * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard + * interfaces will be canceled and purged. + * + * This function might sleep. + */ +void +batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, + const struct batadv_hard_iface *hard_iface) +{ + struct hlist_head head = HLIST_HEAD_INIT; + + if (hard_iface) + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "%s(): %s\n", + __func__, hard_iface->net_dev->name); + else + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "%s()\n", __func__); + + /* claim bcast list for free() */ + spin_lock_bh(&bat_priv->forw_bcast_list_lock); + batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head, + hard_iface); + spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + + /* claim batman packet list for free() */ + spin_lock_bh(&bat_priv->forw_bat_list_lock); + batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head, + hard_iface); + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + /* then cancel or wait for packet workers to finish and free */ + batadv_forw_packet_list_free(&head); +} |