diff options
Diffstat (limited to 'net/batman-adv/bridge_loop_avoidance.c')
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.c | 352 |
1 files changed, 155 insertions, 197 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 41cc87f06b14..37ce6cfb3520 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1,5 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 -/* Copyright (C) 2011-2020 B.A.T.M.A.N. contributors: +/* Copyright (C) B.A.T.M.A.N. contributors: * * Simon Wunderlich */ @@ -10,6 +10,7 @@ #include <linux/atomic.h> #include <linux/byteorder/generic.h> #include <linux/compiler.h> +#include <linux/container_of.h> #include <linux/crc16.h> #include <linux/errno.h> #include <linux/etherdevice.h> @@ -27,7 +28,6 @@ #include <linux/netlink.h> #include <linux/rculist.h> #include <linux/rcupdate.h> -#include <linux/seq_file.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <linux/spinlock.h> @@ -65,7 +65,7 @@ batadv_bla_send_announce(struct batadv_priv *bat_priv, */ static inline u32 batadv_choose_claim(const void *data, u32 size) { - struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data; + const struct batadv_bla_claim *claim = data; u32 hash = 0; hash = jhash(&claim->addr, sizeof(claim->addr), hash); @@ -83,11 +83,12 @@ static inline u32 batadv_choose_claim(const void *data, u32 size) */ static inline u32 batadv_choose_backbone_gw(const void *data, u32 size) { - const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data; + const struct batadv_bla_backbone_gw *gw; u32 hash = 0; - hash = jhash(&claim->addr, sizeof(claim->addr), hash); - hash = jhash(&claim->vid, sizeof(claim->vid), hash); + gw = data; + hash = jhash(&gw->orig, sizeof(gw->orig), hash); + hash = jhash(&gw->vid, sizeof(gw->vid), hash); return hash % size; } @@ -162,6 +163,9 @@ static void batadv_backbone_gw_release(struct kref *ref) */ static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw) { + if (!backbone_gw) + return; + kref_put(&backbone_gw->refcount, batadv_backbone_gw_release); } @@ -197,6 +201,9 @@ static void batadv_claim_release(struct kref *ref) */ static void batadv_claim_put(struct batadv_bla_claim *claim) { + if (!claim) + return; + kref_put(&claim->refcount, batadv_claim_release); } @@ -248,7 +255,7 @@ batadv_claim_hash_find(struct batadv_priv *bat_priv, * Return: backbone gateway if found or NULL otherwise */ static struct batadv_bla_backbone_gw * -batadv_backbone_hash_find(struct batadv_priv *bat_priv, u8 *addr, +batadv_backbone_hash_find(struct batadv_priv *bat_priv, const u8 *addr, unsigned short vid) { struct batadv_hashtable *hash = bat_priv->bla.backbone_hash; @@ -330,7 +337,7 @@ batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw) * @vid: the VLAN ID * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...) */ -static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac, +static void batadv_bla_send_claim(struct batadv_priv *bat_priv, const u8 *mac, unsigned short vid, int claimtype) { struct sk_buff *skb; @@ -395,7 +402,7 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac, break; case BATADV_CLAIM_TYPE_ANNOUNCE: /* announcement frame - * set HW SRC to the special mac containg the crc + * set HW SRC to the special mac containing the crc */ ether_addr_copy(hw_src, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, @@ -439,8 +446,7 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac, netif_rx(skb); out: - if (primary_if) - batadv_hardif_put(primary_if); + batadv_hardif_put(primary_if); } /** @@ -483,7 +489,7 @@ static void batadv_bla_loopdetect_report(struct work_struct *work) * Return: the (possibly created) backbone gateway or NULL on error */ static struct batadv_bla_backbone_gw * -batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig, +batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig, unsigned short vid, bool own_backbone) { struct batadv_bla_backbone_gw *entry; @@ -921,7 +927,7 @@ static bool batadv_handle_request(struct batadv_priv *bat_priv, */ static bool batadv_handle_unclaim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, - u8 *backbone_addr, u8 *claim_addr, + const u8 *backbone_addr, const u8 *claim_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; @@ -959,7 +965,7 @@ static bool batadv_handle_unclaim(struct batadv_priv *bat_priv, */ static bool batadv_handle_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, - u8 *backbone_addr, u8 *claim_addr, + const u8 *backbone_addr, const u8 *claim_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; @@ -992,7 +998,7 @@ static bool batadv_handle_claim(struct batadv_priv *bat_priv, * @hw_dst: the Hardware destination in the ARP Header * @ethhdr: pointer to the Ethernet header of the claim frame * - * checks if it is a claim packet and if its on the same group. + * checks if it is a claim packet and if it's on the same group. * This function also applies the group ID of the sender * if it is in the same mesh. * @@ -1040,7 +1046,7 @@ static int batadv_check_claim_group(struct batadv_priv *bat_priv, /* lets see if this originator is in our mesh */ orig_node = batadv_orig_hash_find(bat_priv, backbone_addr); - /* dont accept claims from gateways which are not in + /* don't accept claims from gateways which are not in * the same mesh or group. */ if (!orig_node) @@ -1498,8 +1504,7 @@ static void batadv_bla_periodic_work(struct work_struct *work) rcu_read_unlock(); } out: - if (primary_if) - batadv_hardif_put(primary_if); + batadv_hardif_put(primary_if); queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work, msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH)); @@ -1556,10 +1561,14 @@ int batadv_bla_init(struct batadv_priv *bat_priv) return 0; bat_priv->bla.claim_hash = batadv_hash_new(128); - bat_priv->bla.backbone_hash = batadv_hash_new(32); + if (!bat_priv->bla.claim_hash) + return -ENOMEM; - if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash) + bat_priv->bla.backbone_hash = batadv_hash_new(32); + if (!bat_priv->bla.backbone_hash) { + batadv_hash_destroy(bat_priv->bla.claim_hash); return -ENOMEM; + } batadv_hash_set_lock_class(bat_priv->bla.claim_hash, &batadv_claim_hash_lock_class_key); @@ -1576,13 +1585,16 @@ int batadv_bla_init(struct batadv_priv *bat_priv) } /** - * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup. + * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the soft interface information - * @skb: contains the bcast_packet to be checked + * @skb: contains the multicast packet to be checked + * @payload_ptr: pointer to position inside the head buffer of the skb + * marking the start of the data to be CRC'ed + * @orig: originator mac address, NULL if unknown * - * check if it is on our broadcast list. Another gateway might - * have sent the same packet because it is connected to the same backbone, - * so we have to remove this duplicate. + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. * * This is performed by checking the CRC, which will tell us * with a good chance that it is the same packet. If it is furthermore @@ -1591,19 +1603,17 @@ int batadv_bla_init(struct batadv_priv *bat_priv) * * Return: true if a packet is in the duplicate list, false otherwise. */ -bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, - struct sk_buff *skb) +static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb, u8 *payload_ptr, + const u8 *orig) { - int i, curr; - __be32 crc; - struct batadv_bcast_packet *bcast_packet; struct batadv_bcast_duplist_entry *entry; bool ret = false; - - bcast_packet = (struct batadv_bcast_packet *)skb->data; + int i, curr; + __be32 crc; /* calculate the crc ... */ - crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1)); + crc = batadv_skb_crc32(skb, payload_ptr); spin_lock_bh(&bat_priv->bla.bcast_duplist_lock); @@ -1622,8 +1632,21 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, if (entry->crc != crc) continue; - if (batadv_compare_eth(entry->orig, bcast_packet->orig)) - continue; + /* are the originators both known and not anonymous? */ + if (orig && !is_zero_ether_addr(orig) && + !is_zero_ether_addr(entry->orig)) { + /* If known, check if the new frame came from + * the same originator: + * We are safe to take identical frames from the + * same orig, if known, as multiplications in + * the mesh are detected via the (orig, seqno) pair. + * So we can be a bit more liberal here and allow + * identical frames from the same orig which the source + * host might have sent multiple times on purpose. + */ + if (batadv_compare_eth(entry->orig, orig)) + continue; + } /* this entry seems to match: same crc, not too old, * and from another gw. therefore return true to forbid it. @@ -1639,7 +1662,14 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, entry = &bat_priv->bla.bcast_duplist[curr]; entry->crc = crc; entry->entrytime = jiffies; - ether_addr_copy(entry->orig, bcast_packet->orig); + + /* known originator */ + if (orig) + ether_addr_copy(entry->orig, orig); + /* anonymous originator */ + else + eth_zero_addr(entry->orig); + bat_priv->bla.bcast_duplist_curr = curr; out: @@ -1649,6 +1679,48 @@ out: } /** + * batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup. + * @bat_priv: the bat priv with all the soft interface information + * @skb: contains the multicast packet to be checked, decapsulated from a + * unicast_packet + * + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. + * + * Return: true if a packet is in the duplicate list, false otherwise. + */ +static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, NULL); +} + +/** + * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup. + * @bat_priv: the bat priv with all the soft interface information + * @skb: contains the bcast_packet to be checked + * + * Check if it is on our broadcast list. Another gateway might have sent the + * same packet because it is connected to the same backbone, so we have to + * remove this duplicate. + * + * Return: true if a packet is in the duplicate list, false otherwise. + */ +bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct batadv_bcast_packet *bcast_packet; + u8 *payload_ptr; + + bcast_packet = (struct batadv_bcast_packet *)skb->data; + payload_ptr = (u8 *)(bcast_packet + 1); + + return batadv_bla_check_duplist(bat_priv, skb, payload_ptr, + bcast_packet->orig); +} + +/** * batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for * the VLAN identified by vid. * @bat_priv: the bat priv with all the soft interface information @@ -1745,8 +1817,7 @@ void batadv_bla_free(struct batadv_priv *bat_priv) batadv_hash_destroy(bat_priv->bla.backbone_hash); bat_priv->bla.backbone_hash = NULL; } - if (primary_if) - batadv_hardif_put(primary_if); + batadv_hardif_put(primary_if); } /** @@ -1757,7 +1828,7 @@ void batadv_bla_free(struct batadv_priv *bat_priv) * @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. + * throws an uevent and logs the event if that is the case. * * Return: true if it is a loop detect frame which is to be dropped, false * otherwise. @@ -1795,7 +1866,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, ret = queue_work(batadv_event_workqueue, &backbone_gw->report_work); - /* backbone_gw is unreferenced in the report work function function + /* backbone_gw is unreferenced in the report work function * if queue_work() call was successful */ if (!ret) @@ -1809,19 +1880,19 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame - * @is_bcast: the packet came in a broadcast packet type. + * @packet_type: the batman packet type this frame came in * * batadv_bla_rx avoidance checks if: * * we have to race for a claim * * if the frame is allowed on the LAN * - * in these cases, the skb is further handled by this function + * In these cases, the skb is further handled by this function * * Return: true if handled, otherwise it returns false and the caller shall * further process the skb. */ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, - unsigned short vid, bool is_bcast) + unsigned short vid, int packet_type) { struct batadv_bla_backbone_gw *backbone_gw; struct ethhdr *ethhdr; @@ -1843,9 +1914,32 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, 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) - goto handled; + /* don't allow multicast packets while requests are in flight */ + if (is_multicast_ether_addr(ethhdr->h_dest)) + /* Both broadcast flooding or multicast-via-unicasts + * delivery might send to multiple backbone gateways + * sharing the same LAN and therefore need to coordinate + * which backbone gateway forwards into the LAN, + * by claiming the payload source address. + * + * Broadcast flooding and multicast-via-unicasts + * delivery use the following two batman packet types. + * Note: explicitly exclude BATADV_UNICAST_4ADDR, + * as the DHCP gateway feature will send explicitly + * to only one BLA gateway, so the claiming process + * should be avoided there. + */ + if (packet_type == BATADV_BCAST || + packet_type == BATADV_UNICAST) + goto handled; + + /* potential duplicates from foreign BLA backbone gateways via + * multicast-in-unicast packets + */ + if (is_multicast_ether_addr(ethhdr->h_dest) && + packet_type == BATADV_UNICAST && + batadv_bla_check_ucast_duplist(bat_priv, skb)) + goto handled; ether_addr_copy(search_claim.addr, ethhdr->h_source); search_claim.vid = vid; @@ -1880,13 +1974,14 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, goto allow; } - /* if it is a broadcast ... */ - if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { + /* if it is a multicast ... */ + if (is_multicast_ether_addr(ethhdr->h_dest) && + (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) { /* ... drop it. the responsible gateway is in charge. * - * We need to check is_bcast because with the gateway + * We need to check packet type because with the gateway * feature, broadcasts (like DHCP requests) may be sent - * using a unicast packet type. + * using a unicast 4 address packet type. See comment above. */ goto handled; } else { @@ -1909,10 +2004,8 @@ handled: ret = true; out: - if (primary_if) - batadv_hardif_put(primary_if); - if (claim) - batadv_claim_put(claim); + batadv_hardif_put(primary_if); + batadv_claim_put(claim); return ret; } @@ -2016,76 +2109,11 @@ allow: handled: ret = true; out: - if (primary_if) - batadv_hardif_put(primary_if); - if (claim) - batadv_claim_put(claim); + batadv_hardif_put(primary_if); + batadv_claim_put(claim); return ret; } -#ifdef CONFIG_BATMAN_ADV_DEBUGFS -/** - * batadv_bla_claim_table_seq_print_text() - print the claim table in a seq file - * @seq: seq file to print on - * @offset: not used - * - * Return: always 0 - */ -int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset) -{ - struct net_device *net_dev = (struct net_device *)seq->private; - struct batadv_priv *bat_priv = netdev_priv(net_dev); - struct batadv_hashtable *hash = bat_priv->bla.claim_hash; - struct batadv_bla_backbone_gw *backbone_gw; - struct batadv_bla_claim *claim; - struct batadv_hard_iface *primary_if; - struct hlist_head *head; - u16 backbone_crc; - u32 i; - bool is_own; - u8 *primary_addr; - - primary_if = batadv_seq_print_text_primary_if_get(seq); - if (!primary_if) - goto out; - - primary_addr = primary_if->net_dev->dev_addr; - seq_printf(seq, - "Claims announced for the mesh %s (orig %pM, group id %#.4x)\n", - net_dev->name, primary_addr, - ntohs(bat_priv->bla.claim_dest.group)); - seq_puts(seq, - " Client VID Originator [o] (CRC )\n"); - for (i = 0; i < hash->size; i++) { - head = &hash->table[i]; - - rcu_read_lock(); - hlist_for_each_entry_rcu(claim, head, hash_entry) { - backbone_gw = batadv_bla_claim_get_backbone_gw(claim); - - is_own = batadv_compare_eth(backbone_gw->orig, - primary_addr); - - spin_lock_bh(&backbone_gw->crc_lock); - backbone_crc = backbone_gw->crc; - spin_unlock_bh(&backbone_gw->crc_lock); - seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n", - claim->addr, batadv_print_vid(claim->vid), - backbone_gw->orig, - (is_own ? 'x' : ' '), - backbone_crc); - - batadv_backbone_gw_put(backbone_gw); - } - rcu_read_unlock(); - } -out: - if (primary_if) - batadv_hardif_put(primary_if); - return 0; -} -#endif - /** * batadv_bla_claim_dump_entry() - dump one entry of the claim table * to a netlink socket @@ -2103,7 +2131,7 @@ batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid, struct batadv_hard_iface *primary_if, struct batadv_bla_claim *claim) { - u8 *primary_addr = primary_if->net_dev->dev_addr; + const u8 *primary_addr = primary_if->net_dev->dev_addr; u16 backbone_crc; bool is_own; void *hdr; @@ -2247,81 +2275,13 @@ int batadv_bla_claim_dump(struct sk_buff *msg, struct netlink_callback *cb) ret = msg->len; out: - if (primary_if) - batadv_hardif_put(primary_if); + batadv_hardif_put(primary_if); - if (soft_iface) - dev_put(soft_iface); + dev_put(soft_iface); return ret; } -#ifdef CONFIG_BATMAN_ADV_DEBUGFS -/** - * batadv_bla_backbone_table_seq_print_text() - print the backbone table in a - * seq file - * @seq: seq file to print on - * @offset: not used - * - * Return: always 0 - */ -int batadv_bla_backbone_table_seq_print_text(struct seq_file *seq, void *offset) -{ - struct net_device *net_dev = (struct net_device *)seq->private; - struct batadv_priv *bat_priv = netdev_priv(net_dev); - struct batadv_hashtable *hash = bat_priv->bla.backbone_hash; - struct batadv_bla_backbone_gw *backbone_gw; - struct batadv_hard_iface *primary_if; - struct hlist_head *head; - int secs, msecs; - u16 backbone_crc; - u32 i; - bool is_own; - u8 *primary_addr; - - primary_if = batadv_seq_print_text_primary_if_get(seq); - if (!primary_if) - goto out; - - primary_addr = primary_if->net_dev->dev_addr; - seq_printf(seq, - "Backbones announced for the mesh %s (orig %pM, group id %#.4x)\n", - net_dev->name, primary_addr, - ntohs(bat_priv->bla.claim_dest.group)); - seq_puts(seq, " Originator VID last seen (CRC )\n"); - for (i = 0; i < hash->size; i++) { - head = &hash->table[i]; - - rcu_read_lock(); - hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) { - msecs = jiffies_to_msecs(jiffies - - backbone_gw->lasttime); - secs = msecs / 1000; - msecs = msecs % 1000; - - is_own = batadv_compare_eth(backbone_gw->orig, - primary_addr); - if (is_own) - continue; - - spin_lock_bh(&backbone_gw->crc_lock); - backbone_crc = backbone_gw->crc; - spin_unlock_bh(&backbone_gw->crc_lock); - - seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n", - backbone_gw->orig, - batadv_print_vid(backbone_gw->vid), secs, - msecs, backbone_crc); - } - rcu_read_unlock(); - } -out: - if (primary_if) - batadv_hardif_put(primary_if); - return 0; -} -#endif - /** * batadv_bla_backbone_dump_entry() - dump one entry of the backbone table to a * netlink socket @@ -2339,7 +2299,7 @@ batadv_bla_backbone_dump_entry(struct sk_buff *msg, u32 portid, struct batadv_hard_iface *primary_if, struct batadv_bla_backbone_gw *backbone_gw) { - u8 *primary_addr = primary_if->net_dev->dev_addr; + const u8 *primary_addr = primary_if->net_dev->dev_addr; u16 backbone_crc; bool is_own; int msecs; @@ -2485,11 +2445,9 @@ int batadv_bla_backbone_dump(struct sk_buff *msg, struct netlink_callback *cb) ret = msg->len; out: - if (primary_if) - batadv_hardif_put(primary_if); + batadv_hardif_put(primary_if); - if (soft_iface) - dev_put(soft_iface); + dev_put(soft_iface); return ret; } |