diff options
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.c | 139 | ||||
| -rw-r--r-- | net/batman-adv/main.h | 4 | ||||
| -rw-r--r-- | net/batman-adv/packet.h | 1 | ||||
| -rw-r--r-- | net/batman-adv/sysfs.c | 6 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 8 |
5 files changed, 156 insertions, 2 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 2c9aa671a49b..5064ae5e9b34 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -50,6 +50,7 @@ #include "hash.h" #include "originator.h" #include "packet.h" +#include "sysfs.h" #include "translation-table.h" static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05}; @@ -407,6 +408,14 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac, ethhdr->h_source, ethhdr->h_dest, BATADV_PRINT_VID(vid)); break; + case BATADV_CLAIM_TYPE_LOOPDETECT: + ether_addr_copy(ethhdr->h_source, mac); + batadv_dbg(BATADV_DBG_BLA, bat_priv, + "bla_send_claim(): LOOPDETECT of %pM to %pM on vid %d\n", + ethhdr->h_source, ethhdr->h_dest, + BATADV_PRINT_VID(vid)); + + break; } if (vid & BATADV_VLAN_HAS_TAG) @@ -427,6 +436,36 @@ out: } /** + * batadv_bla_loopdetect_report - worker for reporting the loop + * @work: work queue item + * + * Throws an uevent, as the loopdetect check function can't do that itself + * since the kernel may sleep while throwing uevents. + */ +static void batadv_bla_loopdetect_report(struct work_struct *work) +{ + struct batadv_bla_backbone_gw *backbone_gw; + struct batadv_priv *bat_priv; + char vid_str[6] = { '\0' }; + + backbone_gw = container_of(work, struct batadv_bla_backbone_gw, + report_work); + bat_priv = backbone_gw->bat_priv; + + batadv_info(bat_priv->soft_iface, + "Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n", + BATADV_PRINT_VID(backbone_gw->vid)); + snprintf(vid_str, sizeof(vid_str), "%d", + BATADV_PRINT_VID(backbone_gw->vid)); + vid_str[sizeof(vid_str) - 1] = 0; + + batadv_throw_uevent(bat_priv, BATADV_UEV_BLA, BATADV_UEV_LOOPDETECT, + vid_str); + + batadv_backbone_gw_put(backbone_gw); +} + +/** * batadv_bla_get_backbone_gw - finds or creates a backbone gateway * @bat_priv: the bat priv with all the soft interface information * @orig: the mac address of the originator @@ -464,6 +503,7 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig, atomic_set(&entry->request_sent, 0); atomic_set(&entry->wait_periods, 0); ether_addr_copy(entry->orig, orig); + INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report); /* one for the hash, one for returning */ kref_init(&entry->refcount); @@ -1060,6 +1100,10 @@ static int batadv_bla_process_claim(struct batadv_priv *bat_priv, if (vlan_depth > 1) return 1; + /* Let the loopdetect frames on the mesh in any case. */ + if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT) + return 0; + /* check if it is a claim frame. */ ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst, ethhdr); @@ -1265,6 +1309,26 @@ void batadv_bla_update_orig_address(struct batadv_priv *bat_priv, } /** + * batadv_bla_send_loopdetect - send a loopdetect frame + * @bat_priv: the bat priv with all the soft interface information + * @backbone_gw: the backbone gateway for which a loop should be detected + * + * To detect loops that the bridge loop avoidance can't handle, send a loop + * detection packet on the backbone. Unlike other BLA frames, this frame will + * be allowed on the mesh by other nodes. If it is received on the mesh, this + * indicates that there is a loop. + */ +static void +batadv_bla_send_loopdetect(struct batadv_priv *bat_priv, + struct batadv_bla_backbone_gw *backbone_gw) +{ + batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n", + backbone_gw->vid); + batadv_bla_send_claim(bat_priv, bat_priv->bla.loopdetect_addr, + backbone_gw->vid, BATADV_CLAIM_TYPE_LOOPDETECT); +} + +/** * batadv_bla_status_update - purge bla interfaces if necessary * @net_dev: the soft interface net device */ @@ -1301,6 +1365,7 @@ static void batadv_bla_periodic_work(struct work_struct *work) struct batadv_bla_backbone_gw *backbone_gw; struct batadv_hashtable *hash; struct batadv_hard_iface *primary_if; + bool send_loopdetect = false; int i; delayed_work = to_delayed_work(work); @@ -1316,6 +1381,22 @@ static void batadv_bla_periodic_work(struct work_struct *work) if (!atomic_read(&bat_priv->bridge_loop_avoidance)) goto out; + if (atomic_dec_and_test(&bat_priv->bla.loopdetect_next)) { + /* set a new random mac address for the next bridge loop + * detection frames. Set the locally administered bit to avoid + * collisions with users mac addresses. + */ + random_ether_addr(bat_priv->bla.loopdetect_addr); + bat_priv->bla.loopdetect_addr[0] = 0xba; + bat_priv->bla.loopdetect_addr[1] = 0xbe; + bat_priv->bla.loopdetect_lasttime = jiffies; + atomic_set(&bat_priv->bla.loopdetect_next, + BATADV_BLA_LOOPDETECT_PERIODS); + + /* mark for sending loop detect on all VLANs */ + send_loopdetect = true; + } + hash = bat_priv->bla.backbone_hash; if (!hash) goto out; @@ -1332,6 +1413,9 @@ static void batadv_bla_periodic_work(struct work_struct *work) backbone_gw->lasttime = jiffies; batadv_bla_send_announce(bat_priv, backbone_gw); + if (send_loopdetect) + batadv_bla_send_loopdetect(bat_priv, + backbone_gw); /* request_sent is only set after creation to avoid * problems when we are not yet known as backbone gw @@ -1405,6 +1489,9 @@ int batadv_bla_init(struct batadv_priv *bat_priv) bat_priv->bla.bcast_duplist[i].entrytime = entrytime; bat_priv->bla.bcast_duplist_curr = 0; + atomic_set(&bat_priv->bla.loopdetect_next, + BATADV_BLA_LOOPDETECT_PERIODS); + if (bat_priv->bla.claim_hash) return 0; @@ -1602,6 +1689,55 @@ void batadv_bla_free(struct batadv_priv *bat_priv) } /** + * batadv_bla_loopdetect_check - check and handle a detected loop + * @bat_priv: the bat priv with all the soft interface information + * @skb: the packet to check + * @primary_if: interface where the request came on + * @vid: the VLAN ID of the frame + * + * Checks if this packet is a loop detect frame which has been sent by us, + * throw an uevent and log the event if that is the case. + * + * Return: true if it is a loop detect frame which is to be dropped, false + * otherwise. + */ +static bool +batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, + struct batadv_hard_iface *primary_if, + unsigned short vid) +{ + struct batadv_bla_backbone_gw *backbone_gw; + struct ethhdr *ethhdr; + + ethhdr = eth_hdr(skb); + + /* Only check for the MAC address and skip more checks here for + * performance reasons - this function is on the hotpath, after all. + */ + if (!batadv_compare_eth(ethhdr->h_source, + bat_priv->bla.loopdetect_addr)) + return false; + + /* If the packet came too late, don't forward it on the mesh + * but don't consider that as loop. It might be a coincidence. + */ + if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime, + BATADV_BLA_LOOPDETECT_TIMEOUT)) + return true; + + backbone_gw = batadv_bla_get_backbone_gw(bat_priv, + primary_if->net_dev->dev_addr, + vid, true); + if (unlikely(!backbone_gw)) + return true; + + queue_work(batadv_event_workqueue, &backbone_gw->report_work); + /* backbone_gw is unreferenced in the report work function function */ + + return true; +} + +/** * batadv_bla_rx - check packets coming from the mesh. * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked @@ -1634,6 +1770,9 @@ int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, if (!atomic_read(&bat_priv->bridge_loop_avoidance)) goto allow; + if (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid)) + goto handled; + if (unlikely(atomic_read(&bat_priv->bla.num_requests))) /* don't allow broadcasts while requests are in flight */ if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 07a6042d0ad6..090c6f0f2398 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -120,6 +120,8 @@ #define BATADV_BLA_BACKBONE_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 6) #define BATADV_BLA_CLAIM_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 10) #define BATADV_BLA_WAIT_PERIODS 3 +#define BATADV_BLA_LOOPDETECT_PERIODS 6 +#define BATADV_BLA_LOOPDETECT_TIMEOUT 3000 /* 3 seconds */ #define BATADV_DUPLIST_SIZE 16 #define BATADV_DUPLIST_TIMEOUT 500 /* 500 ms */ @@ -142,10 +144,12 @@ enum batadv_uev_action { BATADV_UEV_ADD = 0, BATADV_UEV_DEL, BATADV_UEV_CHANGE, + BATADV_UEV_LOOPDETECT, }; enum batadv_uev_type { BATADV_UEV_GW = 0, + BATADV_UEV_BLA, }; #define BATADV_GW_THRESHOLD 50 diff --git a/net/batman-adv/packet.h b/net/batman-adv/packet.h index 0796dfdfbb60..372128ddb474 100644 --- a/net/batman-adv/packet.h +++ b/net/batman-adv/packet.h @@ -175,6 +175,7 @@ enum batadv_bla_claimframe { BATADV_CLAIM_TYPE_UNCLAIM = 0x01, BATADV_CLAIM_TYPE_ANNOUNCE = 0x02, BATADV_CLAIM_TYPE_REQUEST = 0x03, + BATADV_CLAIM_TYPE_LOOPDETECT = 0x04, }; /** diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index 6b1e54f3250a..414b2074165f 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -116,11 +116,13 @@ batadv_kobj_to_vlan(struct batadv_priv *bat_priv, struct kobject *obj) static char *batadv_uev_action_str[] = { "add", "del", - "change" + "change", + "loopdetect", }; static char *batadv_uev_type_str[] = { - "gw" + "gw", + "bla", }; /* Use this, if you have customized show and store functions for vlan attrs */ diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 1e47fbe8bb7b..6a577f4f8ba7 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -657,6 +657,9 @@ struct batadv_priv_tt { * @num_requests: number of bla requests in flight * @claim_hash: hash table containing mesh nodes this host has claimed * @backbone_hash: hash table containing all detected backbone gateways + * @loopdetect_addr: MAC address used for own loopdetection frames + * @loopdetect_lasttime: time when the loopdetection frames were sent + * @loopdetect_next: how many periods to wait for the next loopdetect process * @bcast_duplist: recently received broadcast packets array (for broadcast * duplicate suppression) * @bcast_duplist_curr: index of last broadcast packet added to bcast_duplist @@ -668,6 +671,9 @@ struct batadv_priv_bla { atomic_t num_requests; struct batadv_hashtable *claim_hash; struct batadv_hashtable *backbone_hash; + u8 loopdetect_addr[ETH_ALEN]; + unsigned long loopdetect_lasttime; + atomic_t loopdetect_next; struct batadv_bcast_duplist_entry bcast_duplist[BATADV_DUPLIST_SIZE]; int bcast_duplist_curr; /* protects bcast_duplist & bcast_duplist_curr */ @@ -1012,6 +1018,7 @@ struct batadv_socket_packet { * resolved * @crc: crc16 checksum over all claims * @crc_lock: lock protecting crc + * @report_work: work struct for reporting detected loops * @refcount: number of contexts the object is used * @rcu: struct used for freeing in an RCU-safe manner */ @@ -1025,6 +1032,7 @@ struct batadv_bla_backbone_gw { atomic_t request_sent; u16 crc; spinlock_t crc_lock; /* protects crc */ + struct work_struct report_work; struct kref refcount; struct rcu_head rcu; }; |