diff options
Diffstat (limited to 'net/batman-adv/bat_v_ogm.c')
| -rw-r--r-- | net/batman-adv/bat_v_ogm.c | 556 |
1 files changed, 555 insertions, 1 deletions
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 23932f9b85ec..22dda0e079a5 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -26,6 +26,7 @@ #include <linux/if_ether.h> #include <linux/jiffies.h> #include <linux/kernel.h> +#include <linux/list.h> #include <linux/netdevice.h> #include <linux/random.h> #include <linux/rculist.h> @@ -38,12 +39,52 @@ #include <linux/workqueue.h> #include "hard-interface.h" +#include "hash.h" +#include "originator.h" #include "packet.h" #include "routing.h" #include "send.h" #include "translation-table.h" /** + * batadv_v_ogm_orig_get - retrieve and possibly create an originator node + * @bat_priv: the bat priv with all the soft interface information + * @addr: the address of the originator + * + * Return: the orig_node corresponding to the specified address. If such object + * does not exist it is allocated here. In case of allocation failure returns + * NULL. + */ +struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, + const u8 *addr) +{ + struct batadv_orig_node *orig_node; + int hash_added; + + orig_node = batadv_orig_hash_find(bat_priv, addr); + if (orig_node) + return orig_node; + + orig_node = batadv_orig_node_new(bat_priv, addr); + if (!orig_node) + return NULL; + + hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, + batadv_choose_orig, orig_node, + &orig_node->hash_entry); + if (hash_added != 0) { + /* orig_node->refcounter is initialised to 2 by + * batadv_orig_node_new() + */ + batadv_orig_node_put(orig_node); + batadv_orig_node_put(orig_node); + orig_node = NULL; + } + + return orig_node; +} + +/** * batadv_v_ogm_start_timer - restart the OGM sending timer * @bat_priv: the bat priv with all the soft interface information */ @@ -193,6 +234,500 @@ void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) } /** + * batadv_v_ogm_orig_update - update the originator status based on the received + * OGM + * @bat_priv: the bat priv with all the soft interface information + * @orig_node: the originator to update + * @neigh_node: the neighbour the OGM has been received from (to update) + * @ogm2: the received OGM + * @if_outgoing: the interface where this OGM is going to be forwarded through + */ +static void +batadv_v_ogm_orig_update(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + const struct batadv_ogm2_packet *ogm2, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; + struct batadv_neigh_node *router = NULL; + s32 neigh_seq_diff; + u32 neigh_last_seqno; + u32 router_last_seqno; + u32 router_throughput, neigh_throughput; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Searching and updating originator entry of received packet\n"); + + /* if this neighbor already is our next hop there is nothing + * to change + */ + router = batadv_orig_router_get(orig_node, if_outgoing); + if (router == neigh_node) + goto out; + + /* don't consider neighbours with worse throughput. + * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than + * the last received seqno from our best next hop. + */ + if (router) { + router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); + neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); + + /* if these are not allocated, something is wrong. */ + if (!router_ifinfo || !neigh_ifinfo) + goto out; + + neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; + router_last_seqno = router_ifinfo->bat_v.last_seqno; + neigh_seq_diff = neigh_last_seqno - router_last_seqno; + router_throughput = router_ifinfo->bat_v.throughput; + neigh_throughput = neigh_ifinfo->bat_v.throughput; + + if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) && + (router_throughput >= neigh_throughput)) + goto out; + } + + batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); + +out: + if (router_ifinfo) + batadv_neigh_ifinfo_put(router_ifinfo); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); + if (router) + batadv_neigh_node_put(router); +} + +/** + * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded + * with B.A.T.M.A.N. V OGMs + * @bat_priv: the bat priv with all the soft interface information + * @if_incoming: the interface where the OGM has been received + * @if_outgoing: the interface where the OGM has to be forwarded to + * @throughput: the current throughput + * + * Apply a penalty on the current throughput metric value based on the + * characteristic of the interface where the OGM has been received. The return + * value is computed as follows: + * - throughput * 50% if the incoming and outgoing interface are the + * same WiFi interface and the throughput is above + * 1MBit/s + * - throughput if the outgoing interface is the default + * interface (i.e. this OGM is processed for the + * internal table and not forwarded) + * - throughput * hop penalty otherwise + * + * Return: the penalised throughput metric. + */ +static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing, + u32 throughput) +{ + int hop_penalty = atomic_read(&bat_priv->hop_penalty); + int hop_penalty_max = BATADV_TQ_MAX_VALUE; + + /* Don't apply hop penalty in default originator table. */ + if (if_outgoing == BATADV_IF_DEFAULT) + return throughput; + + /* Forwarding on the same WiFi interface cuts the throughput in half + * due to the store & forward characteristics of WIFI. + * Very low throughput values are the exception. + */ + if ((throughput > 10) && + (if_incoming == if_outgoing) && + (batadv_is_wifi_netdev(if_incoming->net_dev))) + return throughput / 2; + + /* hop penalty of 255 equals 100% */ + return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; +} + +/** + * batadv_v_ogm_forward - forward an OGM to the given outgoing interface + * @bat_priv: the bat priv with all the soft interface information + * @ogm_received: previously received OGM to be forwarded + * @throughput: throughput to announce, may vary per outgoing interface + * @if_incoming: the interface on which this OGM was received on + * @if_outgoing: the interface to which the OGM has to be forwarded to + * + * Forward an OGM to an interface after having altered the throughput metric and + * the TTL value contained in it. The original OGM isn't modified. + */ +static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, + const struct batadv_ogm2_packet *ogm_received, + u32 throughput, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_ogm2_packet *ogm_forward; + unsigned char *skb_buff; + struct sk_buff *skb; + size_t packet_len; + u16 tvlv_len; + + if (ogm_received->ttl <= 1) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); + return; + } + + tvlv_len = ntohs(ogm_received->tvlv_len); + + packet_len = BATADV_OGM2_HLEN + tvlv_len; + skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, + ETH_HLEN + packet_len); + if (!skb) + return; + + skb_reserve(skb, ETH_HLEN); + skb_buff = skb_put(skb, packet_len); + memcpy(skb_buff, ogm_received, packet_len); + + /* apply forward penalty */ + ogm_forward = (struct batadv_ogm2_packet *)skb_buff; + ogm_forward->throughput = htonl(throughput); + ogm_forward->ttl--; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", + if_outgoing->net_dev->name, throughput, ogm_forward->ttl, + if_incoming->net_dev->name); + + batadv_v_ogm_send_to_if(skb, if_outgoing); +} + +/** + * batadv_v_ogm_metric_update - update route metric based on OGM + * @bat_priv: the bat priv with all the soft interface information + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + * + * Return: + * 1 if the OGM is new, + * 0 if it is not new but valid, + * <0 on error (e.g. old OGM) + */ +static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_orig_ifinfo *orig_ifinfo = NULL; + struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; + bool protection_started = false; + int ret = -EINVAL; + u32 path_throughput; + s32 seq_diff; + + orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); + if (!orig_ifinfo) + goto out; + + seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; + + if (!hlist_empty(&orig_node->neigh_list) && + batadv_window_protected(bat_priv, seq_diff, + BATADV_OGM_MAX_AGE, + &orig_ifinfo->batman_seqno_reset, + &protection_started)) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: packet within window protection time from %pM\n", + ogm2->orig); + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Last reset: %ld, %ld\n", + orig_ifinfo->batman_seqno_reset, jiffies); + goto out; + } + + /* drop packets with old seqnos, however accept the first packet after + * a host has been rebooted. + */ + if ((seq_diff < 0) && !protection_started) + goto out; + + neigh_node->last_seen = jiffies; + + orig_node->last_seen = jiffies; + + orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); + orig_ifinfo->last_ttl = ogm2->ttl; + + neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); + if (!neigh_ifinfo) + goto out; + + path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, + if_outgoing, + ntohl(ogm2->throughput)); + neigh_ifinfo->bat_v.throughput = path_throughput; + neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); + neigh_ifinfo->last_ttl = ogm2->ttl; + + if (seq_diff > 0 || protection_started) + ret = 1; + else + ret = 0; +out: + if (orig_ifinfo) + batadv_orig_ifinfo_put(orig_ifinfo); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); + + return ret; +} + +/** + * batadv_v_ogm_route_update - update routes based on OGM + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: the Ethernet header of the OGM2 + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + */ +static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv, + const struct ethhdr *ethhdr, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_node *router = NULL; + struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; + struct batadv_orig_node *orig_neigh_node = NULL; + struct batadv_orig_ifinfo *orig_ifinfo = NULL; + struct batadv_neigh_node *orig_neigh_router = NULL; + + neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); + if (!neigh_ifinfo) + goto out; + + orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); + if (!orig_neigh_node) + goto out; + + orig_neigh_router = batadv_orig_router_get(orig_neigh_node, + if_outgoing); + + /* drop packet if sender is not a direct neighbor and if we + * don't route towards it + */ + router = batadv_orig_router_get(orig_node, if_outgoing); + if (router && router->orig_node != orig_node && !orig_neigh_router) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: OGM via unknown neighbor!\n"); + goto out; + } + + if (router) + batadv_neigh_node_put(router); + + /* Update routes, and check if the OGM is from the best next hop */ + batadv_v_ogm_orig_update(bat_priv, orig_node, neigh_node, ogm2, + if_outgoing); + + orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); + if (!orig_ifinfo) + goto out; + + /* don't forward the same seqno twice on one interface */ + if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm2->seqno)) + goto out; + + /* acquire possibly updated router */ + router = batadv_orig_router_get(orig_node, if_outgoing); + + /* strict rule: forward packets coming from the best next hop only */ + if (neigh_node != router) + goto out; + + /* only forward for specific interface, not for the default one. */ + if (if_outgoing != BATADV_IF_DEFAULT) { + orig_ifinfo->last_seqno_forwarded = ntohl(ogm2->seqno); + batadv_v_ogm_forward(bat_priv, ogm2, + neigh_ifinfo->bat_v.throughput, + if_incoming, if_outgoing); + } + +out: + if (orig_ifinfo) + batadv_orig_ifinfo_put(orig_ifinfo); + if (router) + batadv_neigh_node_put(router); + if (orig_neigh_router) + batadv_neigh_node_put(orig_neigh_router); + if (orig_neigh_node) + batadv_orig_node_put(orig_neigh_node); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); +} + +/** + * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: the Ethernet header of the OGM2 + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + */ +static void +batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, + const struct ethhdr *ethhdr, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + int seqno_age; + + /* first, update the metric with according sanity checks */ + seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, + neigh_node, if_incoming, + if_outgoing); + + /* outdated sequence numbers are to be discarded */ + if (seqno_age < 0) + return; + + /* only unknown & newer OGMs contain TVLVs we are interested in */ + if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT)) + batadv_tvlv_containers_process(bat_priv, true, orig_node, + NULL, NULL, + (unsigned char *)(ogm2 + 1), + ntohs(ogm2->tvlv_len)); + + /* if the metric update went through, update routes if needed */ + batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, + neigh_node, if_incoming, if_outgoing); +} + +/** + * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated + * @buff_pos: current position in the skb + * @packet_len: total length of the skb + * @tvlv_len: tvlv length of the previously considered OGM + * + * Return: true if there is enough space for another OGM, false otherwise. + */ +static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, + __be16 tvlv_len) +{ + int next_buff_pos = 0; + + next_buff_pos += buff_pos + BATADV_OGM2_HLEN; + next_buff_pos += ntohs(tvlv_len); + + return (next_buff_pos <= packet_len) && + (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); +} + +/** + * batadv_v_ogm_process - process an incoming batman v OGM + * @skb: the skb containing the OGM + * @ogm_offset: offset to the OGM which should be processed (for aggregates) + * @if_incoming: the interface where this packet was receved + */ +static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, + struct batadv_hard_iface *if_incoming) +{ + struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); + struct ethhdr *ethhdr; + struct batadv_orig_node *orig_node = NULL; + struct batadv_hardif_neigh_node *hardif_neigh = NULL; + struct batadv_neigh_node *neigh_node = NULL; + struct batadv_hard_iface *hard_iface; + struct batadv_ogm2_packet *ogm_packet; + u32 ogm_throughput, link_throughput, path_throughput; + + ethhdr = eth_hdr(skb); + ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset); + + ogm_throughput = ntohl(ogm_packet->throughput); + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n", + ethhdr->h_source, if_incoming->net_dev->name, + if_incoming->net_dev->dev_addr, ogm_packet->orig, + ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, + ogm_packet->version, ntohs(ogm_packet->tvlv_len)); + + /* If the troughput metric is 0, immediately drop the packet. No need to + * create orig_node / neigh_node for an unusable route. + */ + if (ogm_throughput == 0) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: originator packet with troughput metric of 0\n"); + return; + } + + /* require ELP packets be to received from this neighbor first */ + hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source); + if (!hardif_neigh) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: OGM via unknown neighbor!\n"); + goto out; + } + + orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig); + if (!orig_node) + return; + + neigh_node = batadv_neigh_node_new(orig_node, if_incoming, + ethhdr->h_source); + if (!neigh_node) + goto out; + + /* Update the received throughput metric to match the link + * characteristic: + * - If this OGM traveled one hop so far (emitted by single hop + * neighbor) the path throughput metric equals the link throughput. + * - For OGMs traversing more than hop the path throughput metric is + * the smaller of the path throughput and the link throughput. + */ + link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput); + path_throughput = min_t(u32, link_throughput, ogm_throughput); + ogm_packet->throughput = htonl(path_throughput); + + batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node, + neigh_node, if_incoming, + BATADV_IF_DEFAULT); + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->if_status != BATADV_IF_ACTIVE) + continue; + + if (hard_iface->soft_iface != bat_priv->soft_iface) + continue; + + batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, + orig_node, neigh_node, + if_incoming, hard_iface); + } + rcu_read_unlock(); +out: + if (orig_node) + batadv_orig_node_put(orig_node); + if (neigh_node) + batadv_neigh_node_put(neigh_node); + if (hardif_neigh) + batadv_hardif_neigh_put(hardif_neigh); +} + +/** * batadv_v_ogm_packet_recv - OGM2 receiving handler * @skb: the received OGM * @if_incoming: the interface where this OGM has been received @@ -206,6 +741,9 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); struct batadv_ogm2_packet *ogm_packet; struct ethhdr *ethhdr = eth_hdr(skb); + int ogm_offset; + u8 *packet_pos; + int ret = NET_RX_DROP; /* did we receive a OGM2 packet on an interface that does not have * B.A.T.M.A.N. V enabled ? @@ -228,8 +766,24 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, skb->len + ETH_HLEN); + ogm_offset = 0; + ogm_packet = (struct batadv_ogm2_packet *)skb->data; + + while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), + ogm_packet->tvlv_len)) { + batadv_v_ogm_process(skb, ogm_offset, if_incoming); + + ogm_offset += BATADV_OGM2_HLEN; + ogm_offset += ntohs(ogm_packet->tvlv_len); + + packet_pos = skb->data + ogm_offset; + ogm_packet = (struct batadv_ogm2_packet *)packet_pos; + } + + ret = NET_RX_SUCCESS; consume_skb(skb); - return NET_RX_SUCCESS; + + return ret; } /** |