diff options
Diffstat (limited to 'net/batman-adv/distributed-arp-table.c')
| -rw-r--r-- | net/batman-adv/distributed-arp-table.c | 784 |
1 files changed, 635 insertions, 149 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 6930d6b50f99..8b8132eb0a79 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -1,18 +1,7 @@ -/* Copyright (C) 2011-2017 B.A.T.M.A.N. contributors: +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) B.A.T.M.A.N. contributors: * * Antonio Quartulli - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "distributed-arp-table.h" @@ -21,52 +10,102 @@ #include <linux/atomic.h> #include <linux/bitops.h> #include <linux/byteorder/generic.h> +#include <linux/container_of.h> +#include <linux/err.h> #include <linux/errno.h> #include <linux/etherdevice.h> -#include <linux/fs.h> +#include <linux/gfp.h> #include <linux/if_arp.h> #include <linux/if_ether.h> #include <linux/if_vlan.h> #include <linux/in.h> +#include <linux/ip.h> #include <linux/jiffies.h> -#include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.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/udp.h> +#include <linux/unaligned.h> #include <linux/workqueue.h> #include <net/arp.h> +#include <net/genetlink.h> +#include <net/netlink.h> +#include <uapi/linux/batman_adv.h> #include "bridge_loop_avoidance.h" #include "hard-interface.h" #include "hash.h" #include "log.h" +#include "netlink.h" #include "originator.h" #include "send.h" #include "translation-table.h" #include "tvlv.h" +enum batadv_bootpop { + BATADV_BOOTREPLY = 2, +}; + +enum batadv_boothtype { + BATADV_HTYPE_ETHERNET = 1, +}; + +enum batadv_dhcpoptioncode { + BATADV_DHCP_OPT_PAD = 0, + BATADV_DHCP_OPT_MSG_TYPE = 53, + BATADV_DHCP_OPT_END = 255, +}; + +enum batadv_dhcptype { + BATADV_DHCPACK = 5, +}; + +/* { 99, 130, 83, 99 } */ +#define BATADV_DHCP_MAGIC 1669485411 + +struct batadv_dhcp_packet { + __u8 op; + __u8 htype; + __u8 hlen; + __u8 hops; + __be32 xid; + __be16 secs; + __be16 flags; + __be32 ciaddr; + __be32 yiaddr; + __be32 siaddr; + __be32 giaddr; + __u8 chaddr[16]; + __u8 sname[64]; + __u8 file[128]; + __be32 magic; + /* __u8 options[]; */ +}; + +#define BATADV_DHCP_YIADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->yiaddr) +#define BATADV_DHCP_CHADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->chaddr) + static void batadv_dat_purge(struct work_struct *work); /** - * batadv_dat_start_timer - initialise the DAT periodic worker - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_start_timer() - initialise the DAT periodic worker + * @bat_priv: the bat priv with all the mesh interface information */ static void batadv_dat_start_timer(struct batadv_priv *bat_priv) { - INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, msecs_to_jiffies(10000)); } /** - * batadv_dat_entry_release - release dat_entry from lists and queue for free + * batadv_dat_entry_release() - release dat_entry from lists and queue for free * after rcu grace period * @ref: kref pointer of the dat_entry */ @@ -80,17 +119,20 @@ static void batadv_dat_entry_release(struct kref *ref) } /** - * batadv_dat_entry_put - decrement the dat_entry refcounter and possibly + * batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly * release it * @dat_entry: dat_entry to be free'd */ static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) { + if (!dat_entry) + return; + kref_put(&dat_entry->refcount, batadv_dat_entry_release); } /** - * batadv_dat_to_purge - check whether a dat_entry has to be purged or not + * batadv_dat_to_purge() - check whether a dat_entry has to be purged or not * @dat_entry: the entry to check * * Return: true if the entry has to be purged now, false otherwise. @@ -102,8 +144,8 @@ static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) } /** - * __batadv_dat_purge - delete entries from the DAT local storage - * @bat_priv: the bat priv with all the soft interface information + * __batadv_dat_purge() - delete entries from the DAT local storage + * @bat_priv: the bat priv with all the mesh interface information * @to_purge: function in charge to decide whether an entry has to be purged or * not. This function takes the dat_entry as argument and has to * returns a boolean value: true is the entry has to be deleted, @@ -145,8 +187,8 @@ static void __batadv_dat_purge(struct batadv_priv *bat_priv, } /** - * batadv_dat_purge - periodic task that deletes old entries from the local DAT - * hash table + * batadv_dat_purge() - periodic task that deletes old entries from the local + * DAT hash table * @work: kernel work struct */ static void batadv_dat_purge(struct work_struct *work) @@ -164,7 +206,7 @@ static void batadv_dat_purge(struct work_struct *work) } /** - * batadv_compare_dat - comparing function used in the local DAT hash table + * batadv_compare_dat() - comparing function used in the local DAT hash table * @node: node in the local table * @data2: second object to compare the node to * @@ -179,7 +221,7 @@ static bool batadv_compare_dat(const struct hlist_node *node, const void *data2) } /** - * batadv_arp_hw_src - extract the hw_src field from an ARP packet + * batadv_arp_hw_src() - extract the hw_src field from an ARP packet * @skb: ARP packet * @hdr_size: size of the possible header before the ARP packet * @@ -196,7 +238,7 @@ static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) } /** - * batadv_arp_ip_src - extract the ip_src field from an ARP packet + * batadv_arp_ip_src() - extract the ip_src field from an ARP packet * @skb: ARP packet * @hdr_size: size of the possible header before the ARP packet * @@ -204,11 +246,11 @@ static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) */ static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) { - return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); + return *(__force __be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); } /** - * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet + * batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet * @skb: ARP packet * @hdr_size: size of the possible header before the ARP packet * @@ -220,7 +262,7 @@ static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) } /** - * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet + * batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet * @skb: ARP packet * @hdr_size: size of the possible header before the ARP packet * @@ -228,11 +270,13 @@ static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) */ static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) { - return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); + u8 *dst = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4; + + return *(__force __be32 *)dst; } /** - * batadv_hash_dat - compute the hash value for an IP address + * batadv_hash_dat() - compute the hash value for an IP address * @data: data to hash * @size: size of the hash table * @@ -243,16 +287,18 @@ static u32 batadv_hash_dat(const void *data, u32 size) u32 hash = 0; const struct batadv_dat_entry *dat = data; const unsigned char *key; + __be16 vid; u32 i; - key = (const unsigned char *)&dat->ip; + key = (__force const unsigned char *)&dat->ip; for (i = 0; i < sizeof(dat->ip); i++) { hash += key[i]; hash += (hash << 10); hash ^= (hash >> 6); } - key = (const unsigned char *)&dat->vid; + vid = htons(dat->vid); + key = (__force const unsigned char *)&vid; for (i = 0; i < sizeof(dat->vid); i++) { hash += key[i]; hash += (hash << 10); @@ -267,9 +313,9 @@ static u32 batadv_hash_dat(const void *data, u32 size) } /** - * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash + * batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash * table - * @bat_priv: the bat priv with all the soft interface information + * @bat_priv: the bat priv with all the mesh interface information * @ip: search key * @vid: VLAN identifier * @@ -310,8 +356,8 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, } /** - * batadv_dat_entry_add - add a new dat entry or update it if already exists - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_entry_add() - add a new dat entry or update it if already exists + * @bat_priv: the bat priv with all the mesh interface information * @ip: ipv4 to add/edit * @mac_addr: mac address to assign to the given ipv4 * @vid: VLAN identifier @@ -360,15 +406,15 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid)); out: - if (dat_entry) - batadv_dat_entry_put(dat_entry); + batadv_dat_entry_put(dat_entry); } #ifdef CONFIG_BATMAN_ADV_DEBUG /** - * batadv_dbg_arp - print a debug message containing all the ARP packet details - * @bat_priv: the bat priv with all the soft interface information + * batadv_dbg_arp() - print a debug message containing all the ARP packet + * details + * @bat_priv: the bat priv with all the mesh interface information * @skb: ARP packet * @hdr_size: size of the possible header before the ARP packet * @msg: message to print together with the debugging information @@ -391,7 +437,7 @@ static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, batadv_arp_hw_src(skb, hdr_size), &ip_src, batadv_arp_hw_dst(skb, hdr_size), &ip_dst); - if (hdr_size == 0) + if (hdr_size < sizeof(struct batadv_unicast_packet)) return; unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; @@ -448,7 +494,7 @@ static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, #endif /* CONFIG_BATMAN_ADV_DEBUG */ /** - * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate + * batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate * @res: the array with the already selected candidates * @select: number of already selected candidates * @tmp_max: address of the currently evaluated node @@ -492,8 +538,8 @@ static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, /* this is an hash collision with the temporary selected node. Choose * the one with the lowest address */ - if ((tmp_max == max) && max_orig_node && - (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) + if (tmp_max == max && max_orig_node && + batadv_compare_eth(candidate->orig, max_orig_node->orig)) goto out; ret = true; @@ -502,8 +548,8 @@ out: } /** - * batadv_choose_next_candidate - select the next DHT candidate - * @bat_priv: the bat priv with all the soft interface information + * batadv_choose_next_candidate() - select the next DHT candidate + * @bat_priv: the bat priv with all the mesh interface information * @cands: candidates array * @select: number of candidates already present in the array * @ip_key: key to look up in the DHT @@ -548,8 +594,7 @@ static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, continue; max = tmp_max; - if (max_orig_node) - batadv_orig_node_put(max_orig_node); + batadv_orig_node_put(max_orig_node); max_orig_node = orig_node; } rcu_read_unlock(); @@ -566,9 +611,9 @@ static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, } /** - * batadv_dat_select_candidates - select the nodes which the DHT message has to - * be sent to - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_select_candidates() - select the nodes which the DHT message has + * to be sent to + * @bat_priv: the bat priv with all the mesh interface information * @ip_dst: ipv4 to look up in the DHT * @vid: VLAN identifier * @@ -612,22 +657,22 @@ batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst, } /** - * batadv_dat_send_data - send a payload to the selected candidates - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_forward_data() - copy and send payload to the selected candidates + * @bat_priv: the bat priv with all the mesh interface information * @skb: payload to send * @ip: the DHT key * @vid: VLAN identifier * @packet_subtype: unicast4addr packet subtype to use * - * This function copies the skb with pskb_copy() and is sent as unicast packet + * This function copies the skb with pskb_copy() and is sent as a unicast packet * to each of the selected candidates. * * Return: true if the packet is sent to at least one candidate, false * otherwise. */ -static bool batadv_dat_send_data(struct batadv_priv *bat_priv, - struct sk_buff *skb, __be32 ip, - unsigned short vid, int packet_subtype) +static bool batadv_dat_forward_data(struct batadv_priv *bat_priv, + struct sk_buff *skb, __be32 ip, + unsigned short vid, int packet_subtype) { int i; bool ret = false; @@ -638,7 +683,7 @@ static bool batadv_dat_send_data(struct batadv_priv *bat_priv, cand = batadv_dat_select_candidates(bat_priv, ip, vid); if (!cand) - goto out; + return ret; batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); @@ -682,15 +727,14 @@ free_orig: batadv_orig_node_put(cand[i].orig_node); } -out: kfree(cand); return ret; } /** - * batadv_dat_tvlv_container_update - update the dat tvlv container after dat + * batadv_dat_tvlv_container_update() - update the dat tvlv container after dat * setting change - * @bat_priv: the bat priv with all the soft interface information + * @bat_priv: the bat priv with all the mesh interface information */ static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) { @@ -710,9 +754,9 @@ static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) } /** - * batadv_dat_status_update - update the dat tvlv container after dat + * batadv_dat_status_update() - update the dat tvlv container after dat * setting change - * @net_dev: the soft interface net device + * @net_dev: the mesh interface net device */ void batadv_dat_status_update(struct net_device *net_dev) { @@ -722,8 +766,8 @@ void batadv_dat_status_update(struct net_device *net_dev) } /** - * batadv_dat_tvlv_ogm_handler_v1 - process incoming dat tvlv container - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container + * @bat_priv: the bat priv with all the mesh interface information * @orig: the orig_node of the ogm * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) * @tvlv_value: tvlv buffer containing the gateway data @@ -741,8 +785,8 @@ static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, } /** - * batadv_dat_hash_free - free the local DAT hash table - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_hash_free() - free the local DAT hash table + * @bat_priv: the bat priv with all the mesh interface information */ static void batadv_dat_hash_free(struct batadv_priv *bat_priv) { @@ -757,8 +801,8 @@ static void batadv_dat_hash_free(struct batadv_priv *bat_priv) } /** - * batadv_dat_init - initialise the DAT internals - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_init() - initialise the DAT internals + * @bat_priv: the bat priv with all the mesh interface information * * Return: 0 in case of success, a negative error code otherwise */ @@ -772,18 +816,19 @@ int batadv_dat_init(struct batadv_priv *bat_priv) if (!bat_priv->dat.hash) return -ENOMEM; + INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); batadv_dat_start_timer(bat_priv); batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, - NULL, BATADV_TVLV_DAT, 1, + NULL, NULL, BATADV_TVLV_DAT, 1, BATADV_TVLV_HANDLER_OGM_CIFNOTFND); batadv_dat_tvlv_container_update(bat_priv); return 0; } /** - * batadv_dat_free - free the DAT internals - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_free() - free the DAT internals + * @bat_priv: the bat priv with all the mesh interface information */ void batadv_dat_free(struct batadv_priv *bat_priv) { @@ -795,63 +840,147 @@ void batadv_dat_free(struct batadv_priv *bat_priv) batadv_dat_hash_free(bat_priv); } -#ifdef CONFIG_BATMAN_ADV_DEBUGFS /** - * batadv_dat_cache_seq_print_text - print the local DAT hash table - * @seq: seq file to print on - * @offset: not used + * batadv_dat_cache_dump_entry() - dump one entry of the DAT cache table to a + * netlink socket + * @msg: buffer for the message + * @portid: netlink port + * @cb: Control block containing additional options + * @dat_entry: entry to dump * - * Return: always 0 + * Return: 0 or error code. */ -int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) +static int +batadv_dat_cache_dump_entry(struct sk_buff *msg, u32 portid, + struct netlink_callback *cb, + struct batadv_dat_entry *dat_entry) +{ + int msecs; + void *hdr; + + hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq, + &batadv_netlink_family, NLM_F_MULTI, + BATADV_CMD_GET_DAT_CACHE); + if (!hdr) + return -ENOBUFS; + + genl_dump_check_consistent(cb, hdr); + + msecs = jiffies_to_msecs(jiffies - dat_entry->last_update); + + if (nla_put_in_addr(msg, BATADV_ATTR_DAT_CACHE_IP4ADDRESS, + dat_entry->ip) || + nla_put(msg, BATADV_ATTR_DAT_CACHE_HWADDRESS, ETH_ALEN, + dat_entry->mac_addr) || + nla_put_u16(msg, BATADV_ATTR_DAT_CACHE_VID, dat_entry->vid) || + nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) { + genlmsg_cancel(msg, hdr); + return -EMSGSIZE; + } + + genlmsg_end(msg, hdr); + return 0; +} + +/** + * batadv_dat_cache_dump_bucket() - dump one bucket of the DAT cache table to + * a netlink socket + * @msg: buffer for the message + * @portid: netlink port + * @cb: Control block containing additional options + * @hash: hash to dump + * @bucket: bucket index to dump + * @idx_skip: How many entries to skip + * + * Return: 0 or error code. + */ +static int +batadv_dat_cache_dump_bucket(struct sk_buff *msg, u32 portid, + struct netlink_callback *cb, + struct batadv_hashtable *hash, unsigned int bucket, + int *idx_skip) { - 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->dat.hash; struct batadv_dat_entry *dat_entry; - struct batadv_hard_iface *primary_if; - struct hlist_head *head; - unsigned long last_seen_jiffies; - int last_seen_msecs, last_seen_secs, last_seen_mins; - u32 i; + int idx = 0; - primary_if = batadv_seq_print_text_primary_if_get(seq); - if (!primary_if) - goto out; + spin_lock_bh(&hash->list_locks[bucket]); + cb->seq = atomic_read(&hash->generation) << 1 | 1; - seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); - seq_puts(seq, - " IPv4 MAC VID last-seen\n"); + hlist_for_each_entry(dat_entry, &hash->table[bucket], hash_entry) { + if (idx < *idx_skip) + goto skip; - for (i = 0; i < hash->size; i++) { - head = &hash->table[i]; + if (batadv_dat_cache_dump_entry(msg, portid, cb, dat_entry)) { + spin_unlock_bh(&hash->list_locks[bucket]); + *idx_skip = idx; - rcu_read_lock(); - hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { - last_seen_jiffies = jiffies - dat_entry->last_update; - last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); - last_seen_mins = last_seen_msecs / 60000; - last_seen_msecs = last_seen_msecs % 60000; - last_seen_secs = last_seen_msecs / 1000; - - seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", - &dat_entry->ip, dat_entry->mac_addr, - batadv_print_vid(dat_entry->vid), - last_seen_mins, last_seen_secs); + return -EMSGSIZE; } - rcu_read_unlock(); + +skip: + idx++; } + spin_unlock_bh(&hash->list_locks[bucket]); -out: - if (primary_if) - batadv_hardif_put(primary_if); return 0; } -#endif /** - * batadv_arp_get_type - parse an ARP packet and gets the type - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_cache_dump() - dump DAT cache table to a netlink socket + * @msg: buffer for the message + * @cb: callback structure containing arguments + * + * Return: message length. + */ +int batadv_dat_cache_dump(struct sk_buff *msg, struct netlink_callback *cb) +{ + struct batadv_hard_iface *primary_if = NULL; + int portid = NETLINK_CB(cb->skb).portid; + struct net_device *mesh_iface; + struct batadv_hashtable *hash; + struct batadv_priv *bat_priv; + int bucket = cb->args[0]; + int idx = cb->args[1]; + int ret = 0; + + mesh_iface = batadv_netlink_get_meshif(cb); + if (IS_ERR(mesh_iface)) + return PTR_ERR(mesh_iface); + + bat_priv = netdev_priv(mesh_iface); + hash = bat_priv->dat.hash; + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) { + ret = -ENOENT; + goto out; + } + + while (bucket < hash->size) { + if (batadv_dat_cache_dump_bucket(msg, portid, cb, hash, bucket, + &idx)) + break; + + bucket++; + idx = 0; + } + + cb->args[0] = bucket; + cb->args[1] = idx; + + ret = msg->len; + +out: + batadv_hardif_put(primary_if); + + dev_put(mesh_iface); + + return ret; +} + +/** + * batadv_arp_get_type() - parse an ARP packet and gets the type + * @bat_priv: the bat priv with all the mesh interface information * @skb: packet to analyse * @hdr_size: size of the possible header before the ARP packet in the skb * @@ -924,7 +1053,7 @@ out: } /** - * batadv_dat_get_vid - extract the VLAN identifier from skb if any + * batadv_dat_get_vid() - extract the VLAN identifier from skb if any * @skb: the buffer containing the packet to extract the VID from * @hdr_size: the size of the batman-adv header encapsulating the packet * @@ -950,8 +1079,8 @@ static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) } /** - * batadv_dat_arp_create_reply - create an ARP Reply - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_arp_create_reply() - create an ARP Reply + * @bat_priv: the bat priv with all the mesh interface information * @ip_src: ARP sender IP * @ip_dst: ARP target IP * @hw_src: Ethernet source and ARP sender MAC @@ -970,7 +1099,7 @@ batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src, { struct sk_buff *skb; - skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface, + skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->mesh_iface, ip_src, hw_dst, hw_src, hw_dst); if (!skb) return NULL; @@ -985,9 +1114,9 @@ batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src, } /** - * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to + * batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to * answer using DAT - * @bat_priv: the bat priv with all the soft interface information + * @bat_priv: the bat priv with all the mesh interface information * @skb: packet to check * * Return: true if the message has been sent to the dht candidates, false @@ -1003,7 +1132,7 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, bool ret = false; struct batadv_dat_entry *dat_entry = NULL; struct sk_buff *skb_new; - struct net_device *soft_iface = bat_priv->soft_iface; + struct net_device *mesh_iface = bat_priv->mesh_iface; int hdr_size = 0; unsigned short vid; @@ -1033,7 +1162,7 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, * client will answer itself. DAT would only generate a * duplicate packet. * - * Moreover, if the soft-interface is enslaved into a bridge, an + * Moreover, if the mesh-interface is enslaved into a bridge, an * additional DAT answer may trigger kernel warnings about * a packet coming from the wrong port. */ @@ -1062,7 +1191,7 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, if (!skb_new) goto out; - skb_new->protocol = eth_type_trans(skb_new, soft_iface); + skb_new->protocol = eth_type_trans(skb_new, mesh_iface); batadv_inc_counter(bat_priv, BATADV_CNT_RX); batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES, @@ -1073,19 +1202,18 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, ret = true; } else { /* Send the request to the DHT */ - ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid, - BATADV_P_DAT_DHT_GET); + ret = batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_GET); } out: - if (dat_entry) - batadv_dat_entry_put(dat_entry); + batadv_dat_entry_put(dat_entry); return ret; } /** - * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to + * batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to * answer using the local DAT storage - * @bat_priv: the bat priv with all the soft interface information + * @bat_priv: the bat priv with all the mesh interface information * @skb: packet to check * @hdr_size: size of the encapsulation header * @@ -1145,16 +1273,15 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, ret = true; } out: - if (dat_entry) - batadv_dat_entry_put(dat_entry); + batadv_dat_entry_put(dat_entry); if (ret) kfree_skb(skb); return ret; } /** - * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT + * @bat_priv: the bat priv with all the mesh interface information * @skb: packet to check */ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, @@ -1188,14 +1315,16 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, /* Send the ARP reply to the candidates for both the IP addresses that * the node obtained from the ARP reply */ - batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT); - batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_src, vid, + BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_PUT); } /** - * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local - * DAT storage only - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the + * local DAT storage only + * @bat_priv: the bat priv with all the mesh interface information * @skb: packet to check * @hdr_size: size of the encapsulation header * @@ -1240,7 +1369,6 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, hw_src, &ip_src, hw_dst, &ip_dst, dat_entry->mac_addr, &dat_entry->ip); dropped = true; - goto out; } /* Update our internal cache with both the IP addresses the node got @@ -1249,6 +1377,9 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + if (dropped) + goto out; + /* If BLA is enabled, only forward ARP replies if we have claimed the * source of the ARP reply or if no one else of the same backbone has * already claimed that client. This prevents that different gateways @@ -1275,16 +1406,372 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, out: if (dropped) kfree_skb(skb); - if (dat_entry) - batadv_dat_entry_put(dat_entry); + batadv_dat_entry_put(dat_entry); /* if dropped == false -> deliver to the interface */ return dropped; } /** - * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped - * (because the node has already obtained the reply via DAT) or not - * @bat_priv: the bat priv with all the soft interface information + * batadv_dat_check_dhcp_ipudp() - check skb for IP+UDP headers valid for DHCP + * @skb: the packet to check + * @ip_src: a buffer to store the IPv4 source address in + * + * Checks whether the given skb has an IP and UDP header valid for a DHCP + * message from a DHCP server. And if so, stores the IPv4 source address in + * the provided buffer. + * + * Return: True if valid, false otherwise. + */ +static bool +batadv_dat_check_dhcp_ipudp(struct sk_buff *skb, __be32 *ip_src) +{ + unsigned int offset = skb_network_offset(skb); + struct udphdr *udphdr, _udphdr; + struct iphdr *iphdr, _iphdr; + + iphdr = skb_header_pointer(skb, offset, sizeof(_iphdr), &_iphdr); + if (!iphdr || iphdr->version != 4 || iphdr->ihl * 4 < sizeof(_iphdr)) + return false; + + if (iphdr->protocol != IPPROTO_UDP) + return false; + + offset += iphdr->ihl * 4; + skb_set_transport_header(skb, offset); + + udphdr = skb_header_pointer(skb, offset, sizeof(_udphdr), &_udphdr); + if (!udphdr || udphdr->source != htons(67)) + return false; + + *ip_src = get_unaligned(&iphdr->saddr); + + return true; +} + +/** + * batadv_dat_check_dhcp() - examine packet for valid DHCP message + * @skb: the packet to check + * @proto: ethernet protocol hint (behind a potential vlan) + * @ip_src: a buffer to store the IPv4 source address in + * + * Checks whether the given skb is a valid DHCP packet. And if so, stores the + * IPv4 source address in the provided buffer. + * + * Caller needs to ensure that the skb network header is set correctly. + * + * Return: If skb is a valid DHCP packet, then returns its op code + * (e.g. BOOTREPLY vs. BOOTREQUEST). Otherwise returns -EINVAL. + */ +static int +batadv_dat_check_dhcp(struct sk_buff *skb, __be16 proto, __be32 *ip_src) +{ + __be32 *magic, _magic; + unsigned int offset; + struct { + __u8 op; + __u8 htype; + __u8 hlen; + __u8 hops; + } *dhcp_h, _dhcp_h; + + if (proto != htons(ETH_P_IP)) + return -EINVAL; + + if (!batadv_dat_check_dhcp_ipudp(skb, ip_src)) + return -EINVAL; + + offset = skb_transport_offset(skb) + sizeof(struct udphdr); + if (skb->len < offset + sizeof(struct batadv_dhcp_packet)) + return -EINVAL; + + dhcp_h = skb_header_pointer(skb, offset, sizeof(_dhcp_h), &_dhcp_h); + if (!dhcp_h || dhcp_h->htype != BATADV_HTYPE_ETHERNET || + dhcp_h->hlen != ETH_ALEN) + return -EINVAL; + + offset += offsetof(struct batadv_dhcp_packet, magic); + + magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic); + if (!magic || get_unaligned(magic) != htonl(BATADV_DHCP_MAGIC)) + return -EINVAL; + + return dhcp_h->op; +} + +/** + * batadv_dat_get_dhcp_message_type() - get message type of a DHCP packet + * @skb: the DHCP packet to parse + * + * Iterates over the DHCP options of the given DHCP packet to find a + * DHCP Message Type option and parse it. + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: The found DHCP message type value, if found. -EINVAL otherwise. + */ +static int batadv_dat_get_dhcp_message_type(struct sk_buff *skb) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + u8 *type, _type; + struct { + u8 type; + u8 len; + } *tl, _tl; + + offset += sizeof(struct batadv_dhcp_packet); + + while ((tl = skb_header_pointer(skb, offset, sizeof(_tl), &_tl))) { + if (tl->type == BATADV_DHCP_OPT_MSG_TYPE) + break; + + if (tl->type == BATADV_DHCP_OPT_END) + break; + + if (tl->type == BATADV_DHCP_OPT_PAD) + offset++; + else + offset += tl->len + sizeof(_tl); + } + + /* Option Overload Code not supported */ + if (!tl || tl->type != BATADV_DHCP_OPT_MSG_TYPE || + tl->len != sizeof(_type)) + return -EINVAL; + + offset += sizeof(_tl); + + type = skb_header_pointer(skb, offset, sizeof(_type), &_type); + if (!type) + return -EINVAL; + + return *type; +} + +/** + * batadv_dat_dhcp_get_yiaddr() - get yiaddr from a DHCP packet + * @skb: the DHCP packet to parse + * @buf: a buffer to store the yiaddr in + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: True on success, false otherwise. + */ +static bool batadv_dat_dhcp_get_yiaddr(struct sk_buff *skb, __be32 *buf) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + __be32 *yiaddr; + + offset += offsetof(struct batadv_dhcp_packet, yiaddr); + yiaddr = skb_header_pointer(skb, offset, BATADV_DHCP_YIADDR_LEN, buf); + + if (!yiaddr) + return false; + + if (yiaddr != buf) + *buf = get_unaligned(yiaddr); + + return true; +} + +/** + * batadv_dat_get_dhcp_chaddr() - get chaddr from a DHCP packet + * @skb: the DHCP packet to parse + * @buf: a buffer to store the chaddr in + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: True on success, false otherwise + */ +static bool batadv_dat_get_dhcp_chaddr(struct sk_buff *skb, u8 *buf) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + u8 *chaddr; + + offset += offsetof(struct batadv_dhcp_packet, chaddr); + chaddr = skb_header_pointer(skb, offset, BATADV_DHCP_CHADDR_LEN, buf); + + if (!chaddr) + return false; + + if (chaddr != buf) + memcpy(buf, chaddr, BATADV_DHCP_CHADDR_LEN); + + return true; +} + +/** + * batadv_dat_put_dhcp() - puts addresses from a DHCP packet into the DHT and + * DAT cache + * @bat_priv: the bat priv with all the mesh interface information + * @chaddr: the DHCP client MAC address + * @yiaddr: the DHCP client IP address + * @hw_dst: the DHCP server MAC address + * @ip_dst: the DHCP server IP address + * @vid: VLAN identifier + * + * Adds given MAC/IP pairs to the local DAT cache and propagates them further + * into the DHT. + * + * For the DHT propagation, client MAC + IP will appear as the ARP Reply + * transmitter (and hw_dst/ip_dst as the target). + */ +static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr, + __be32 yiaddr, u8 *hw_dst, __be32 ip_dst, + unsigned short vid) +{ + struct sk_buff *skb; + + skb = batadv_dat_arp_create_reply(bat_priv, yiaddr, ip_dst, chaddr, + hw_dst, vid); + if (!skb) + return; + + skb_set_network_header(skb, ETH_HLEN); + + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + + batadv_dat_forward_data(bat_priv, skb, yiaddr, vid, + BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_PUT); + + consume_skb(skb); + + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from outgoing DHCPACK (server address): %pI4, %pM (vid: %i)\n", + &ip_dst, hw_dst, batadv_print_vid(vid)); + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from outgoing DHCPACK (client address): %pI4, %pM (vid: %i)\n", + &yiaddr, chaddr, batadv_print_vid(vid)); +} + +/** + * batadv_dat_check_dhcp_ack() - examine packet for valid DHCP message + * @skb: the packet to check + * @proto: ethernet protocol hint (behind a potential vlan) + * @ip_src: a buffer to store the IPv4 source address in + * @chaddr: a buffer to store the DHCP Client Hardware Address in + * @yiaddr: a buffer to store the DHCP Your IP Address in + * + * Checks whether the given skb is a valid DHCPACK. And if so, stores the + * IPv4 server source address (ip_src), client MAC address (chaddr) and client + * IPv4 address (yiaddr) in the provided buffers. + * + * Caller needs to ensure that the skb network header is set correctly. + * + * Return: True if the skb is a valid DHCPACK. False otherwise. + */ +static bool +batadv_dat_check_dhcp_ack(struct sk_buff *skb, __be16 proto, __be32 *ip_src, + u8 *chaddr, __be32 *yiaddr) +{ + int type; + + type = batadv_dat_check_dhcp(skb, proto, ip_src); + if (type != BATADV_BOOTREPLY) + return false; + + type = batadv_dat_get_dhcp_message_type(skb); + if (type != BATADV_DHCPACK) + return false; + + if (!batadv_dat_dhcp_get_yiaddr(skb, yiaddr)) + return false; + + if (!batadv_dat_get_dhcp_chaddr(skb, chaddr)) + return false; + + return true; +} + +/** + * batadv_dat_snoop_outgoing_dhcp_ack() - snoop DHCPACK and fill DAT with it + * @bat_priv: the bat priv with all the mesh interface information + * @skb: the packet to snoop + * @proto: ethernet protocol hint (behind a potential vlan) + * @vid: VLAN identifier + * + * This function first checks whether the given skb is a valid DHCPACK. If + * so then its source MAC and IP as well as its DHCP Client Hardware Address + * field and DHCP Your IP Address field are added to the local DAT cache and + * propagated into the DHT. + * + * Caller needs to ensure that the skb mac and network headers are set + * correctly. + */ +void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, + struct sk_buff *skb, + __be16 proto, + unsigned short vid) +{ + u8 chaddr[BATADV_DHCP_CHADDR_LEN]; + __be32 ip_src, yiaddr; + + if (!atomic_read(&bat_priv->distributed_arp_table)) + return; + + if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr)) + return; + + batadv_dat_put_dhcp(bat_priv, chaddr, yiaddr, eth_hdr(skb)->h_source, + ip_src, vid); +} + +/** + * batadv_dat_snoop_incoming_dhcp_ack() - snoop DHCPACK and fill DAT cache + * @bat_priv: the bat priv with all the mesh interface information + * @skb: the packet to snoop + * @hdr_size: header size, up to the tail of the batman-adv header + * + * This function first checks whether the given skb is a valid DHCPACK. If + * so then its source MAC and IP as well as its DHCP Client Hardware Address + * field and DHCP Your IP Address field are added to the local DAT cache. + */ +void batadv_dat_snoop_incoming_dhcp_ack(struct batadv_priv *bat_priv, + struct sk_buff *skb, int hdr_size) +{ + u8 chaddr[BATADV_DHCP_CHADDR_LEN]; + struct ethhdr *ethhdr; + __be32 ip_src, yiaddr; + unsigned short vid; + __be16 proto; + u8 *hw_src; + + if (!atomic_read(&bat_priv->distributed_arp_table)) + return; + + if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) + return; + + ethhdr = (struct ethhdr *)(skb->data + hdr_size); + skb_set_network_header(skb, hdr_size + ETH_HLEN); + proto = ethhdr->h_proto; + + if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr)) + return; + + hw_src = ethhdr->h_source; + vid = batadv_dat_get_vid(skb, &hdr_size); + + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from incoming DHCPACK (server address): %pI4, %pM (vid: %i)\n", + &ip_src, hw_src, batadv_print_vid(vid)); + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from incoming DHCPACK (client address): %pI4, %pM (vid: %i)\n", + &yiaddr, chaddr, batadv_print_vid(vid)); +} + +/** + * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be + * dropped (because the node has already obtained the reply via DAT) or not + * @bat_priv: the bat priv with all the mesh interface information * @forw_packet: the broadcast packet * * Return: true if the node can drop the packet, false otherwise. @@ -1328,7 +1815,6 @@ bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, ret = true; out: - if (dat_entry) - batadv_dat_entry_put(dat_entry); + batadv_dat_entry_put(dat_entry); return ret; } |