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author	Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>	2019-05-28 17:03:50 +0000
committer	David S. Miller <davem@davemloft.net>	2019-05-29 21:43:54 -0700
commit	24ec483cec981618f8a4782a36d1e3f319d42cad (patch)
tree	ae1e11b19d8cd1055258eafa6842afa7194a2b3f /net/sched/act_ctinfo.c
parent	a6851c613fd7fccc5d1f28d5d8a0cbe9b0f4e8cc (diff)
download	linux-24ec483cec981618f8a4782a36d1e3f319d42cad.tar.gz

net: sched: Introduce act_ctinfo action

ctinfo is a new tc filter action module. It is designed to restore information contained in firewall conntrack marks to other packet fields and is typically used on packet ingress paths. At present it has two independent sub-functions or operating modes, DSCP restoration mode & skb mark restoration mode. The DSCP restore mode: This mode copies DSCP values that have been placed in the firewall conntrack mark back into the IPv4/v6 diffserv fields of relevant packets. The DSCP restoration is intended for use and has been found useful for restoring ingress classifications based on egress classifications across links that bleach or otherwise change DSCP, typically home ISP Internet links. Restoring DSCP on ingress on the WAN link allows qdiscs such as but by no means limited to CAKE to shape inbound packets according to policies that are easier to set & mark on egress. Ingress classification is traditionally a challenging task since iptables rules haven't yet run and tc filter/eBPF programs are pre-NAT lookups, hence are unable to see internal IPv4 addresses as used on the typical home masquerading gateway. Thus marking the connection in some manner on egress for later restoration of classification on ingress is easier to implement. Parameters related to DSCP restore mode: dscpmask - a 32 bit mask of 6 contiguous bits and indicate bits of the conntrack mark field contain the DSCP value to be restored. statemask - a 32 bit mask of (usually) 1 bit length, outside the area specified by dscpmask. This represents a conditional operation flag whereby the DSCP is only restored if the flag is set. This is useful to implement a 'one shot' iptables based classification where the 'complicated' iptables rules are only run once to classify the connection on initial (egress) packet and subsequent packets are all marked/restored with the same DSCP. A mask of zero disables the conditional behaviour ie. the conntrack mark DSCP bits are always restored to the ip diffserv field (assuming the conntrack entry is found & the skb is an ipv4/ipv6 type) e.g. dscpmask 0xfc000000 statemask 0x01000000 |----0xFC----conntrack mark----000000---| | Bits 31-26 | bit 25 | bit24 |~~~ Bit 0| | DSCP | unused | flag |unused | |-----------------------0x01---000000---| | | | | ---| Conditional flag v only restore if set |-ip diffserv-| | 6 bits | |-------------| The skb mark restore mode (cpmark): This mode copies the firewall conntrack mark to the skb's mark field. It is completely the functional equivalent of the existing act_connmark action with the additional feature of being able to apply a mask to the restored value. Parameters related to skb mark restore mode: mask - a 32 bit mask applied to the firewall conntrack mark to mask out bits unwanted for restoration. This can be useful where the conntrack mark is being used for different purposes by different applications. If not specified and by default the whole mark field is copied (i.e. default mask of 0xffffffff) e.g. mask 0x00ffffff to mask out the top 8 bits being used by the aforementioned DSCP restore mode. |----0x00----conntrack mark----ffffff---| | Bits 31-24 | | | DSCP & flag| some value here | |---------------------------------------| | | v |------------skb mark-------------------| | | | | zeroed | | |---------------------------------------| Overall parameters: zone - conntrack zone control - action related control (reclassify | pipe | drop | continue | ok | goto chain <CHAIN_INDEX>) Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Diffstat (limited to 'net/sched/act_ctinfo.c')

-rw-r--r--

net/sched/act_ctinfo.c

396

1 files changed, 396 insertions, 0 deletions

// SPDX-License-Identifier: GPL-2.0 /* Copyright (C) 2011-2020 B.A.T.M.A.N. contributors: * * Simon Wunderlich */ #include "bridge_loop_avoidance.h" #include "main.h" #include <linux/atomic.h> #include <linux/byteorder/generic.h> #include <linux/compiler.h> #include <linux/crc16.h> #include <linux/errno.h> #include <linux/etherdevice.h> #include <linux/gfp.h> #include <linux/if_arp.h> #include <linux/if_ether.h> #include <linux/if_vlan.h> #include <linux/jhash.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/netdevice.h> #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> #include <linux/stddef.h> #include <linux/string.h> #include <linux/workqueue.h> #include <net/arp.h> #include <net/genetlink.h> #include <net/netlink.h> #include <net/sock.h> #include <uapi/linux/batadv_packet.h> #include <uapi/linux/batman_adv.h> #include "hard-interface.h" #include "hash.h" #include "log.h" #include "netlink.h" #include "originator.h" #include "soft-interface.h" #include "translation-table.h" static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05}; static void batadv_bla_periodic_work(struct work_struct *work); static void batadv_bla_send_announce(struct batadv_priv *bat_priv, struct batadv_bla_backbone_gw *backbone_gw); /** * batadv_choose_claim() - choose the right bucket for a claim. * @data: data to hash * @size: size of the hash table * * Return: the hash index of the claim */ static inline u32 batadv_choose_claim(const void *data, u32 size) { struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data; u32 hash = 0; hash = jhash(&claim->addr, sizeof(claim->addr), hash); hash = jhash(&claim->vid, sizeof(claim->vid), hash); return hash % size; } /** * batadv_choose_backbone_gw() - choose the right bucket for a backbone gateway. * @data: data to hash * @size: size of the hash table * * Return: the hash index of the backbone gateway */ static inline u32 batadv_choose_backbone_gw(const void *data, u32 size) { const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data; u32 hash = 0; hash = jhash(&claim->addr, sizeof(claim->addr), hash); hash = jhash(&claim->vid, sizeof(claim->vid), hash); return hash % size; } /** * batadv_compare_backbone_gw() - compare address and vid of two backbone gws * @node: list node of the first entry to compare * @data2: pointer to the second backbone gateway * * Return: true if the backbones have the same data, false otherwise */ static bool batadv_compare_backbone_gw(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_bla_backbone_gw, hash_entry); const struct batadv_bla_backbone_gw *gw1 = data1; const struct batadv_bla_backbone_gw *gw2 = data2; if (!batadv_compare_eth(gw1->orig, gw2->orig)) return false; if (gw1->vid != gw2->vid) return false; return true; } /** * batadv_compare_claim() - compare address and vid of two claims * @node: list node of the first entry to compare * @data2: pointer to the second claims * * Return: true if the claim have the same data, 0 otherwise */ static bool batadv_compare_claim(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_bla_claim, hash_entry); const struct batadv_bla_claim *cl1 = data1; const struct batadv_bla_claim *cl2 = data2; if (!batadv_compare_eth(cl1->addr, cl2->addr)) return false; if (cl1->vid != cl2->vid) return false; return true; } /** * batadv_backbone_gw_release() - release backbone gw from lists and queue for * free after rcu grace period * @ref: kref pointer of the backbone gw */ static void batadv_backbone_gw_release(struct kref *ref) { struct batadv_bla_backbone_gw *backbone_gw; backbone_gw = container_of(ref, struct batadv_bla_backbone_gw, refcount); kfree_rcu(backbone_gw, rcu); } /** * batadv_backbone_gw_put() - decrement the backbone gw refcounter and possibly * release it * @backbone_gw: backbone gateway to be free'd */ static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw) { kref_put(&backbone_gw->refcount, batadv_backbone_gw_release); } /** * batadv_claim_release() - release claim from lists and queue for free after * rcu grace period * @ref: kref pointer of the claim */ static void batadv_claim_release(struct kref *ref) { struct batadv_bla_claim *claim; struct batadv_bla_backbone_gw *old_backbone_gw; claim = container_of(ref, struct batadv_bla_claim, refcount); spin_lock_bh(&claim->backbone_lock); old_backbone_gw = claim->backbone_gw; claim->backbone_gw = NULL; spin_unlock_bh(&claim->backbone_lock); spin_lock_bh(&old_backbone_gw->crc_lock); old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&old_backbone_gw->crc_lock); batadv_backbone_gw_put(old_backbone_gw); kfree_rcu(claim, rcu); } /** * batadv_claim_put() - decrement the claim refcounter and possibly release it * @claim: claim to be free'd */ static void batadv_claim_put(struct batadv_bla_claim *claim) { kref_put(&claim->refcount, batadv_claim_release); } /** * batadv_claim_hash_find() - looks for a claim in the claim hash * @bat_priv: the bat priv with all the soft interface information * @data: search data (may be local/static data) * * Return: claim if found or NULL otherwise. */ static struct batadv_bla_claim * batadv_claim_hash_find(struct batadv_priv *bat_priv, struct batadv_bla_claim *data) { struct batadv_hashtable *hash = bat_priv->bla.claim_hash; struct hlist_head *head; struct batadv_bla_claim *claim; struct batadv_bla_claim *claim_tmp = NULL; int index; if (!hash) return NULL; index = batadv_choose_claim(data, hash->size); head = &hash->table[index]; rcu_read_lock(); hlist_for_each_entry_rcu(claim, head, hash_entry) { if (!batadv_compare_claim(&claim->hash_entry, data)) continue; if (!kref_get_unless_zero(&claim->refcount)) continue; claim_tmp = claim; break; } rcu_read_unlock(); return claim_tmp; } /** * batadv_backbone_hash_find() - looks for a backbone gateway in the hash * @bat_priv: the bat priv with all the soft interface information * @addr: the address of the originator * @vid: the VLAN ID * * 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, unsigned short vid) { struct batadv_hashtable *hash = bat_priv->bla.backbone_hash; struct hlist_head *head; struct batadv_bla_backbone_gw search_entry, *backbone_gw; struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL; int index; if (!hash) return NULL; ether_addr_copy(search_entry.orig, addr); search_entry.vid = vid; index = batadv_choose_backbone_gw(&search_entry, hash->size); head = &hash->table[index]; rcu_read_lock(); hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) { if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry, &search_entry)) continue; if (!kref_get_unless_zero(&backbone_gw->refcount)) continue; backbone_gw_tmp = backbone_gw; break; } rcu_read_unlock(); return backbone_gw_tmp; } /** * batadv_bla_del_backbone_claims() - delete all claims for a backbone * @backbone_gw: backbone gateway where the claims should be removed */ static void batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw) { struct batadv_hashtable *hash; struct hlist_node *node_tmp; struct hlist_head *head; struct batadv_bla_claim *claim; int i; spinlock_t *list_lock; /* protects write access to the hash lists */ hash = backbone_gw->bat_priv->bla.claim_hash; if (!hash) return; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; list_lock = &hash->list_locks[i]; spin_lock_bh(list_lock); hlist_for_each_entry_safe(claim, node_tmp, head, hash_entry) { if (claim->backbone_gw != backbone_gw) continue; batadv_claim_put(claim); hlist_del_rcu(&claim->hash_entry); } spin_unlock_bh(list_lock); } /* all claims gone, initialize CRC */ spin_lock_bh(&backbone_gw->crc_lock); backbone_gw->crc = BATADV_BLA_CRC_INIT; spin_unlock_bh(&backbone_gw->crc_lock); } /** * batadv_bla_send_claim() - sends a claim frame according to the provided info * @bat_priv: the bat priv with all the soft interface information * @mac: the mac address to be announced within the claim * @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, unsigned short vid, int claimtype) { struct sk_buff *skb; struct ethhdr *ethhdr; struct batadv_hard_iface *primary_if; struct net_device *soft_iface; u8 *hw_src; struct batadv_bla_claim_dst local_claim_dest; __be32 zeroip = 0; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) return; memcpy(&local_claim_dest, &bat_priv->bla.claim_dest, sizeof(local_claim_dest)); local_claim_dest.type = claimtype; soft_iface = primary_if->soft_iface; skb = arp_create(ARPOP_REPLY, ETH_P_ARP, /* IP DST: 0.0.0.0 */ zeroip, primary_if->soft_iface, /* IP SRC: 0.0.0.0 */ zeroip, /* Ethernet DST: Broadcast */ NULL, /* Ethernet SRC/HW SRC: originator mac */ primary_if->net_dev->dev_addr, /* HW DST: FF:43:05:XX:YY:YY * with XX = claim type * and YY:YY = group id */ (u8 *)&local_claim_dest); if (!skb) goto out; ethhdr = (struct ethhdr *)skb->data; hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr); /* now we pretend that the client would have sent this ... */ switch (claimtype) { case BATADV_CLAIM_TYPE_CLAIM: /* normal claim frame * set Ethernet SRC to the clients mac */ ether_addr_copy(ethhdr->h_source, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): CLAIM %pM on vid %d\n", __func__, mac, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_UNCLAIM: /* unclaim frame * set HW SRC to the clients mac */ ether_addr_copy(hw_src, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): UNCLAIM %pM on vid %d\n", __func__, mac, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_ANNOUNCE: /* announcement frame * set HW SRC to the special mac containg the crc */ ether_addr_copy(hw_src, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ANNOUNCE of %pM on vid %d\n", __func__, ethhdr->h_source, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_REQUEST: /* request frame * set HW SRC and header destination to the receiving backbone * gws mac */ ether_addr_copy(hw_src, mac); ether_addr_copy(ethhdr->h_dest, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): REQUEST of %pM to %pM on vid %d\n", __func__, 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, "%s(): LOOPDETECT of %pM to %pM on vid %d\n", __func__, ethhdr->h_source, ethhdr->h_dest, batadv_print_vid(vid)); break; } if (vid & BATADV_VLAN_HAS_TAG) { skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); if (!skb) goto out; } skb_reset_mac_header(skb); skb->protocol = eth_type_trans(skb, soft_iface); batadv_inc_counter(bat_priv, BATADV_CNT_RX); batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES, skb->len + ETH_HLEN); netif_rx(skb); out: if (primary_if) batadv_hardif_put(primary_if); } /** * 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 * @vid: the VLAN ID * @own_backbone: set if the requested backbone is local * * 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, unsigned short vid, bool own_backbone) { struct batadv_bla_backbone_gw *entry; struct batadv_orig_node *orig_node; int hash_added; entry = batadv_backbone_hash_find(bat_priv, orig, vid); if (entry) return entry; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): not found (%pM, %d), creating new entry\n", __func__, orig, batadv_print_vid(vid)); entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) return NULL; entry->vid = vid; entry->lasttime = jiffies; entry->crc = BATADV_BLA_CRC_INIT; entry->bat_priv = bat_priv; spin_lock_init(&entry->crc_lock); 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); kref_init(&entry->refcount); kref_get(&entry->refcount); hash_added = batadv_hash_add(bat_priv->bla.backbone_hash, batadv_compare_backbone_gw, batadv_choose_backbone_gw, entry, &entry->hash_entry); if (unlikely(hash_added != 0)) { /* hash failed, free the structure */ kfree(entry); return NULL; } /* this is a gateway now, remove any TT entry on this VLAN */ orig_node = batadv_orig_hash_find(bat_priv, orig); if (orig_node) { batadv_tt_global_del_orig(bat_priv, orig_node, vid, "became a backbone gateway"); batadv_orig_node_put(orig_node); } if (own_backbone) { batadv_bla_send_announce(bat_priv, entry); /* this will be decreased in the worker thread */ atomic_inc(&entry->request_sent); atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS); atomic_inc(&bat_priv->bla.num_requests); } return entry; } /** * batadv_bla_update_own_backbone_gw() - updates the own backbone gw for a VLAN * @bat_priv: the bat priv with all the soft interface information * @primary_if: the selected primary interface * @vid: VLAN identifier * * update or add the own backbone gw to make sure we announce * where we receive other backbone gws */ static void batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, primary_if->net_dev->dev_addr, vid, true); if (unlikely(!backbone_gw)) return; backbone_gw->lasttime = jiffies; batadv_backbone_gw_put(backbone_gw); } /** * batadv_bla_answer_request() - answer a bla request by sending own claims * @bat_priv: the bat priv with all the soft interface information * @primary_if: interface where the request came on * @vid: the vid where the request came on * * Repeat all of our own claims, and finally send an ANNOUNCE frame * to allow the requester another check if the CRC is correct now. */ static void batadv_bla_answer_request(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, unsigned short vid) { struct hlist_head *head; struct batadv_hashtable *hash; struct batadv_bla_claim *claim; struct batadv_bla_backbone_gw *backbone_gw; int i; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): received a claim request, send all of our own claims again\n", __func__); backbone_gw = batadv_backbone_hash_find(bat_priv, primary_if->net_dev->dev_addr, vid); if (!backbone_gw) return; hash = bat_priv->bla.claim_hash; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; rcu_read_lock(); hlist_for_each_entry_rcu(claim, head, hash_entry) { /* only own claims are interesting */ if (claim->backbone_gw != backbone_gw) continue; batadv_bla_send_claim(bat_priv, claim->addr, claim->vid, BATADV_CLAIM_TYPE_CLAIM); } rcu_read_unlock(); } /* finally, send an announcement frame */ batadv_bla_send_announce(bat_priv, backbone_gw); batadv_backbone_gw_put(backbone_gw); } /** * batadv_bla_send_request() - send a request to repeat claims * @backbone_gw: the backbone gateway from whom we are out of sync * * When the crc is wrong, ask the backbone gateway for a full table update. * After the request, it will repeat all of his own claims and finally * send an announcement claim with which we can check again. */ static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw) { /* first, remove all old entries */ batadv_bla_del_backbone_claims(backbone_gw); batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, "Sending REQUEST to %pM\n", backbone_gw->orig); /* send request */ batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig, backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST); /* no local broadcasts should be sent or received, for now. */ if (!atomic_read(&backbone_gw->request_sent)) { atomic_inc(&backbone_gw->bat_priv->bla.num_requests); atomic_set(&backbone_gw->request_sent, 1); } } /** * batadv_bla_send_announce() - Send an announcement frame * @bat_priv: the bat priv with all the soft interface information * @backbone_gw: our backbone gateway which should be announced */ static void batadv_bla_send_announce(struct batadv_priv *bat_priv, struct batadv_bla_backbone_gw *backbone_gw) { u8 mac[ETH_ALEN]; __be16 crc; memcpy(mac, batadv_announce_mac, 4); spin_lock_bh(&backbone_gw->crc_lock); crc = htons(backbone_gw->crc); spin_unlock_bh(&backbone_gw->crc_lock); memcpy(&mac[4], &crc, 2); batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid, BATADV_CLAIM_TYPE_ANNOUNCE); } /** * batadv_bla_add_claim() - Adds a claim in the claim hash * @bat_priv: the bat priv with all the soft interface information * @mac: the mac address of the claim * @vid: the VLAN ID of the frame * @backbone_gw: the backbone gateway which claims it */ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, const u8 *mac, const unsigned short vid, struct batadv_bla_backbone_gw *backbone_gw) { struct batadv_bla_backbone_gw *old_backbone_gw; struct batadv_bla_claim *claim; struct batadv_bla_claim search_claim; bool remove_crc = false; int hash_added; ether_addr_copy(search_claim.addr, mac); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); /* create a new claim entry if it does not exist yet. */ if (!claim) { claim = kzalloc(sizeof(*claim), GFP_ATOMIC); if (!claim) return; ether_addr_copy(claim->addr, mac); spin_lock_init(&claim->backbone_lock); claim->vid = vid; claim->lasttime = jiffies; kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; kref_init(&claim->refcount); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): adding new entry %pM, vid %d to hash ...\n", __func__, mac, batadv_print_vid(vid)); kref_get(&claim->refcount); hash_added = batadv_hash_add(bat_priv->bla.claim_hash, batadv_compare_claim, batadv_choose_claim, claim, &claim->hash_entry); if (unlikely(hash_added != 0)) { /* only local changes happened. */ kfree(claim); return; } } else { claim->lasttime = jiffies; if (claim->backbone_gw == backbone_gw) /* no need to register a new backbone */ goto claim_free_ref; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): changing ownership for %pM, vid %d to gw %pM\n", __func__, mac, batadv_print_vid(vid), backbone_gw->orig); remove_crc = true; } /* replace backbone_gw atomically and adjust reference counters */ spin_lock_bh(&claim->backbone_lock); old_backbone_gw = claim->backbone_gw; kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; spin_unlock_bh(&claim->backbone_lock); if (remove_crc) { /* remove claim address from old backbone_gw */ spin_lock_bh(&old_backbone_gw->crc_lock); old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&old_backbone_gw->crc_lock); } batadv_backbone_gw_put(old_backbone_gw); /* add claim address to new backbone_gw */ spin_lock_bh(&backbone_gw->crc_lock); backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&backbone_gw->crc_lock); backbone_gw->lasttime = jiffies; claim_free_ref: batadv_claim_put(claim); } /** * batadv_bla_claim_get_backbone_gw() - Get valid reference for backbone_gw of * claim * @claim: claim whose backbone_gw should be returned * * Return: valid reference to claim::backbone_gw */ static struct batadv_bla_backbone_gw * batadv_bla_claim_get_backbone_gw(struct batadv_bla_claim *claim) { struct batadv_bla_backbone_gw *backbone_gw; spin_lock_bh(&claim->backbone_lock); backbone_gw = claim->backbone_gw; kref_get(&backbone_gw->refcount); spin_unlock_bh(&claim->backbone_lock); return backbone_gw; } /** * batadv_bla_del_claim() - delete a claim from the claim hash * @bat_priv: the bat priv with all the soft interface information * @mac: mac address of the claim to be removed * @vid: VLAN id for the claim to be removed */ static void batadv_bla_del_claim(struct batadv_priv *bat_priv, const u8 *mac, const unsigned short vid) { struct batadv_bla_claim search_claim, *claim; struct batadv_bla_claim *claim_removed_entry; struct hlist_node *claim_removed_node; ether_addr_copy(search_claim.addr, mac); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) return; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__, mac, batadv_print_vid(vid)); claim_removed_node = batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim, batadv_choose_claim, claim); if (!claim_removed_node) goto free_claim; /* reference from the hash is gone */ claim_removed_entry = hlist_entry(claim_removed_node, struct batadv_bla_claim, hash_entry); batadv_claim_put(claim_removed_entry); free_claim: /* don't need the reference from hash_find() anymore */ batadv_claim_put(claim); } /** * batadv_handle_announce() - check for ANNOUNCE frame * @bat_priv: the bat priv with all the soft interface information * @an_addr: announcement mac address (ARP Sender HW address) * @backbone_addr: originator address of the sender (Ethernet source MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr, u8 *backbone_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; u16 backbone_crc, crc; if (memcmp(an_addr, batadv_announce_mac, 4) != 0) return false; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid, false); if (unlikely(!backbone_gw)) return true; /* handle as ANNOUNCE frame */ backbone_gw->lasttime = jiffies; crc = ntohs(*((__force __be16 *)(&an_addr[4]))); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n", __func__, batadv_print_vid(vid), backbone_gw->orig, crc); spin_lock_bh(&backbone_gw->crc_lock); backbone_crc = backbone_gw->crc; spin_unlock_bh(&backbone_gw->crc_lock); if (backbone_crc != crc) { batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, "%s(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n", __func__, backbone_gw->orig, batadv_print_vid(backbone_gw->vid), backbone_crc, crc); batadv_bla_send_request(backbone_gw); } else { /* if we have sent a request and the crc was OK, * we can allow traffic again. */ if (atomic_read(&backbone_gw->request_sent)) { atomic_dec(&backbone_gw->bat_priv->bla.num_requests); atomic_set(&backbone_gw->request_sent, 0); } } batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_handle_request() - check for REQUEST frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: backbone address to be requested (ARP sender HW MAC) * @ethhdr: ethernet header of a packet * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_request(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, u8 *backbone_addr, struct ethhdr *ethhdr, unsigned short vid) { /* check for REQUEST frame */ if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest)) return false; /* sanity check, this should not happen on a normal switch, * we ignore it in this case. */ if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr)) return true; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): REQUEST vid %d (sent by %pM)...\n", __func__, batadv_print_vid(vid), ethhdr->h_source); batadv_bla_answer_request(bat_priv, primary_if, vid); return true; } /** * batadv_handle_unclaim() - check for UNCLAIM frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: originator address of the backbone (Ethernet source) * @claim_addr: Client to be unclaimed (ARP sender HW MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_unclaim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, u8 *backbone_addr, u8 *claim_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; /* unclaim in any case if it is our own */ if (primary_if && batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) batadv_bla_send_claim(bat_priv, claim_addr, vid, BATADV_CLAIM_TYPE_UNCLAIM); backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid); if (!backbone_gw) return true; /* this must be an UNCLAIM frame */ batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): UNCLAIM %pM on vid %d (sent by %pM)...\n", __func__, claim_addr, batadv_print_vid(vid), backbone_gw->orig); batadv_bla_del_claim(bat_priv, claim_addr, vid); batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_handle_claim() - check for CLAIM frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: originator address of the backbone (Ethernet Source) * @claim_addr: client mac address to be claimed (ARP sender HW MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, u8 *backbone_addr, u8 *claim_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; /* register the gateway if not yet available, and add the claim. */ backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid, false); if (unlikely(!backbone_gw)) return true; /* this must be a CLAIM frame */ batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw); if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) batadv_bla_send_claim(bat_priv, claim_addr, vid, BATADV_CLAIM_TYPE_CLAIM); /* TODO: we could call something like tt_local_del() here. */ batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_check_claim_group() - check for claim group membership * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary interface of this batman interface * @hw_src: the Hardware source in the ARP Header * @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 it's on the same group. * This function also applies the group ID of the sender * if it is in the same mesh. * * Return: * 2 - if it is a claim packet and on the same group * 1 - if is a claim packet from another group * 0 - if it is not a claim packet */ static int batadv_check_claim_group(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, u8 *hw_src, u8 *hw_dst, struct ethhdr *ethhdr) { u8 *backbone_addr; struct batadv_orig_node *orig_node; struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; bla_dst = (struct batadv_bla_claim_dst *)hw_dst; bla_dst_own = &bat_priv->bla.claim_dest; /* if announcement packet, use the source, * otherwise assume it is in the hw_src */ switch (bla_dst->type) { case BATADV_CLAIM_TYPE_CLAIM: backbone_addr = hw_src; break; case BATADV_CLAIM_TYPE_REQUEST: case BATADV_CLAIM_TYPE_ANNOUNCE: case BATADV_CLAIM_TYPE_UNCLAIM: backbone_addr = ethhdr->h_source; break; default: return 0; } /* don't accept claim frames from ourselves */ if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) return 0; /* if its already the same group, it is fine. */ if (bla_dst->group == bla_dst_own->group) return 2; /* 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 * the same mesh or group. */ if (!orig_node) return 1; /* if our mesh friends mac is bigger, use it for ourselves. */ if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) { batadv_dbg(BATADV_DBG_BLA, bat_priv, "taking other backbones claim group: %#.4x\n", ntohs(bla_dst->group)); bla_dst_own->group = bla_dst->group; } batadv_orig_node_put(orig_node); return 2; } /** * batadv_bla_process_claim() - Check if this is a claim frame, and process it * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @skb: the frame to be checked * * Return: true if it was a claim frame, otherwise return false to * tell the callee that it can use the frame on its own. */ static bool batadv_bla_process_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, struct sk_buff *skb) { struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; u8 *hw_src, *hw_dst; struct vlan_hdr *vhdr, vhdr_buf; struct ethhdr *ethhdr; struct arphdr *arphdr; unsigned short vid; int vlan_depth = 0; __be16 proto; int headlen; int ret; vid = batadv_get_vid(skb, 0); ethhdr = eth_hdr(skb); proto = ethhdr->h_proto; headlen = ETH_HLEN; if (vid & BATADV_VLAN_HAS_TAG) { /* Traverse the VLAN/Ethertypes. * * At this point it is known that the first protocol is a VLAN * header, so start checking at the encapsulated protocol. * * The depth of the VLAN headers is recorded to drop BLA claim * frames encapsulated into multiple VLAN headers (QinQ). */ do { vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN, &vhdr_buf); if (!vhdr) return false; proto = vhdr->h_vlan_encapsulated_proto; headlen += VLAN_HLEN; vlan_depth++; } while (proto == htons(ETH_P_8021Q)); } if (proto != htons(ETH_P_ARP)) return false; /* not a claim frame */ /* this must be a ARP frame. check if it is a claim. */ if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev)))) return false; /* pskb_may_pull() may have modified the pointers, get ethhdr again */ ethhdr = eth_hdr(skb); arphdr = (struct arphdr *)((u8 *)ethhdr + headlen); /* Check whether the ARP frame carries a valid * IP information */ if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) return false; if (arphdr->ar_pro != htons(ETH_P_IP)) return false; if (arphdr->ar_hln != ETH_ALEN) return false; if (arphdr->ar_pln != 4) return false; hw_src = (u8 *)arphdr + sizeof(struct arphdr); hw_dst = hw_src + ETH_ALEN + 4; bla_dst = (struct batadv_bla_claim_dst *)hw_dst; bla_dst_own = &bat_priv->bla.claim_dest; /* check if it is a claim frame in general */ if (memcmp(bla_dst->magic, bla_dst_own->magic, sizeof(bla_dst->magic)) != 0) return false; /* check if there is a claim frame encapsulated deeper in (QinQ) and * drop that, as this is not supported by BLA but should also not be * sent via the mesh. */ if (vlan_depth > 1) return true; /* Let the loopdetect frames on the mesh in any case. */ if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT) return false; /* check if it is a claim frame. */ ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst, ethhdr); if (ret == 1) batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", __func__, ethhdr->h_source, batadv_print_vid(vid), hw_src, hw_dst); if (ret < 2) return !!ret; /* become a backbone gw ourselves on this vlan if not happened yet */ batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); /* check for the different types of claim frames ... */ switch (bla_dst->type) { case BATADV_CLAIM_TYPE_CLAIM: if (batadv_handle_claim(bat_priv, primary_if, hw_src, ethhdr->h_source, vid)) return true; break; case BATADV_CLAIM_TYPE_UNCLAIM: if (batadv_handle_unclaim(bat_priv, primary_if, ethhdr->h_source, hw_src, vid)) return true; break; case BATADV_CLAIM_TYPE_ANNOUNCE: if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source, vid)) return true; break; case BATADV_CLAIM_TYPE_REQUEST: if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr, vid)) return true; break; } batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", __func__, ethhdr->h_source, batadv_print_vid(vid), hw_src, hw_dst); return true; } /** * batadv_bla_purge_backbone_gw() - Remove backbone gateways after a timeout or * immediately * @bat_priv: the bat priv with all the soft interface information * @now: whether the whole hash shall be wiped now * * Check when we last heard from other nodes, and remove them in case of * a time out, or clean all backbone gws if now is set. */ static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) { struct batadv_bla_backbone_gw *backbone_gw; struct hlist_node *node_tmp; struct hlist_head *head; struct batadv_hashtable *hash; spinlock_t *list_lock; /* protects write access to the hash lists */ int i; hash = bat_priv->bla.backbone_hash; if (!hash) return; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; list_lock = &hash->list_locks[i]; spin_lock_bh(list_lock); hlist_for_each_entry_safe(backbone_gw, node_tmp, head, hash_entry) { if (now) goto purge_now; if (!batadv_has_timed_out(backbone_gw->lasttime, BATADV_BLA_BACKBONE_TIMEOUT)) continue; batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, "%s(): backbone gw %pM timed out\n", __func__, backbone_gw->orig); purge_now: /* don't wait for the pending request anymore */ if (atomic_read(&backbone_gw->request_sent)) atomic_dec(&bat_priv->bla.num_requests); batadv_bla_del_backbone_claims(backbone_gw); hlist_del_rcu(&backbone_gw->hash_entry); batadv_backbone_gw_put(backbone_gw); } spin_unlock_bh(list_lock); } } /** * batadv_bla_purge_claims() - Remove claims after a timeout or immediately * @bat_priv: the bat priv with all the soft interface information * @primary_if: the selected primary interface, may be NULL if now is set * @now: whether the whole hash shall be wiped now * * Check when we heard last time from our own claims, and remove them in case of * a time out, or clean all claims if now is set */ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, int now) { struct batadv_bla_backbone_gw *backbone_gw; struct batadv_bla_claim *claim; struct hlist_head *head; struct batadv_hashtable *hash; int i; hash = bat_priv->bla.claim_hash; if (!hash) return; 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); if (now) goto purge_now; if (!batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr)) goto skip; if (!batadv_has_timed_out(claim->lasttime, BATADV_BLA_CLAIM_TIMEOUT)) goto skip; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): timed out.\n", __func__); purge_now: batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__, claim->addr, claim->vid); batadv_handle_unclaim(bat_priv, primary_if, backbone_gw->orig, claim->addr, claim->vid); skip: batadv_backbone_gw_put(backbone_gw); } rcu_read_unlock(); } } /** * batadv_bla_update_orig_address() - Update the backbone gateways when the own * originator address changes * @bat_priv: the bat priv with all the soft interface information * @primary_if: the new selected primary_if * @oldif: the old primary interface, may be NULL */ void batadv_bla_update_orig_address(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, struct batadv_hard_iface *oldif) { struct batadv_bla_backbone_gw *backbone_gw; struct hlist_head *head; struct batadv_hashtable *hash; __be16 group; int i; /* reset bridge loop avoidance group id */ group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN)); bat_priv->bla.claim_dest.group = group; /* purge everything when bridge loop avoidance is turned off */ if (!atomic_read(&bat_priv->bridge_loop_avoidance)) oldif = NULL; if (!oldif) { batadv_bla_purge_claims(bat_priv, NULL, 1); batadv_bla_purge_backbone_gw(bat_priv, 1); return; } hash = bat_priv->bla.backbone_hash; if (!hash) return; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; rcu_read_lock(); hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) { /* own orig still holds the old value. */ if (!batadv_compare_eth(backbone_gw->orig, oldif->net_dev->dev_addr)) continue; ether_addr_copy(backbone_gw->orig, primary_if->net_dev->dev_addr); /* send an announce frame so others will ask for our * claims and update their tables. */ batadv_bla_send_announce(bat_priv, backbone_gw); } rcu_read_unlock(); } } /** * 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 */ void batadv_bla_status_update(struct net_device *net_dev) { struct batadv_priv *bat_priv = netdev_priv(net_dev); struct batadv_hard_iface *primary_if; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) return; /* this function already purges everything when bla is disabled, * so just call that one. */ batadv_bla_update_orig_address(bat_priv, primary_if, primary_if); batadv_hardif_put(primary_if); } /** * batadv_bla_periodic_work() - performs periodic bla work * @work: kernel work struct * * periodic work to do: * * purge structures when they are too old * * send announcements */ static void batadv_bla_periodic_work(struct work_struct *work) { struct delayed_work *delayed_work; struct batadv_priv *bat_priv; struct batadv_priv_bla *priv_bla; struct hlist_head *head; 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); priv_bla = container_of(delayed_work, struct batadv_priv_bla, work); bat_priv = container_of(priv_bla, struct batadv_priv, bla); primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; batadv_bla_purge_claims(bat_priv, primary_if, 0); batadv_bla_purge_backbone_gw(bat_priv, 0); 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. */ eth_random_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; for (i = 0; i < hash->size; i++) {


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