linux/net/batman-adv/gateway_client.c
Sven Eckelmann 44c4349a2a batman-adv: Replace version info instead of appending them
The version number of modules build outside of the tree can get revision
numbers added. This is useful to give hints about the revision of a
distribution package and the used patchset. The prepended source number or
branch name doesn't add any additional information which would help to identify
problems and can therefore be omitted.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-07-05 14:48:56 +02:00

680 lines
16 KiB
C

/*
* Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
*
* Marek Lindner
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "main.h"
#include "bat_sysfs.h"
#include "gateway_client.h"
#include "gateway_common.h"
#include "hard-interface.h"
#include "originator.h"
#include "routing.h"
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <linux/if_vlan.h>
/* This is the offset of the options field in a dhcp packet starting at
* the beginning of the dhcp header */
#define DHCP_OPTIONS_OFFSET 240
#define DHCP_REQUEST 3
static void gw_node_free_ref(struct gw_node *gw_node)
{
if (atomic_dec_and_test(&gw_node->refcount))
kfree_rcu(gw_node, rcu);
}
static struct gw_node *gw_get_selected_gw_node(struct bat_priv *bat_priv)
{
struct gw_node *gw_node;
rcu_read_lock();
gw_node = rcu_dereference(bat_priv->curr_gw);
if (!gw_node)
goto out;
if (!atomic_inc_not_zero(&gw_node->refcount))
gw_node = NULL;
out:
rcu_read_unlock();
return gw_node;
}
struct orig_node *gw_get_selected_orig(struct bat_priv *bat_priv)
{
struct gw_node *gw_node;
struct orig_node *orig_node = NULL;
gw_node = gw_get_selected_gw_node(bat_priv);
if (!gw_node)
goto out;
rcu_read_lock();
orig_node = gw_node->orig_node;
if (!orig_node)
goto unlock;
if (!atomic_inc_not_zero(&orig_node->refcount))
orig_node = NULL;
unlock:
rcu_read_unlock();
out:
if (gw_node)
gw_node_free_ref(gw_node);
return orig_node;
}
static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
{
struct gw_node *curr_gw_node;
spin_lock_bh(&bat_priv->gw_list_lock);
if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
new_gw_node = NULL;
curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1);
rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
if (curr_gw_node)
gw_node_free_ref(curr_gw_node);
spin_unlock_bh(&bat_priv->gw_list_lock);
}
void gw_deselect(struct bat_priv *bat_priv)
{
atomic_set(&bat_priv->gw_reselect, 1);
}
static struct gw_node *gw_get_best_gw_node(struct bat_priv *bat_priv)
{
struct neigh_node *router;
struct hlist_node *node;
struct gw_node *gw_node, *curr_gw = NULL;
uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
uint8_t max_tq = 0;
int down, up;
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
if (gw_node->deleted)
continue;
router = orig_node_get_router(gw_node->orig_node);
if (!router)
continue;
if (!atomic_inc_not_zero(&gw_node->refcount))
goto next;
switch (atomic_read(&bat_priv->gw_sel_class)) {
case 1: /* fast connection */
gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
&down, &up);
tmp_gw_factor = (router->tq_avg * router->tq_avg *
down * 100 * 100) /
(TQ_LOCAL_WINDOW_SIZE *
TQ_LOCAL_WINDOW_SIZE * 64);
if ((tmp_gw_factor > max_gw_factor) ||
((tmp_gw_factor == max_gw_factor) &&
(router->tq_avg > max_tq))) {
if (curr_gw)
gw_node_free_ref(curr_gw);
curr_gw = gw_node;
atomic_inc(&curr_gw->refcount);
}
break;
default: /**
* 2: stable connection (use best statistic)
* 3: fast-switch (use best statistic but change as
* soon as a better gateway appears)
* XX: late-switch (use best statistic but change as
* soon as a better gateway appears which has
* $routing_class more tq points)
**/
if (router->tq_avg > max_tq) {
if (curr_gw)
gw_node_free_ref(curr_gw);
curr_gw = gw_node;
atomic_inc(&curr_gw->refcount);
}
break;
}
if (router->tq_avg > max_tq)
max_tq = router->tq_avg;
if (tmp_gw_factor > max_gw_factor)
max_gw_factor = tmp_gw_factor;
gw_node_free_ref(gw_node);
next:
neigh_node_free_ref(router);
}
rcu_read_unlock();
return curr_gw;
}
void gw_election(struct bat_priv *bat_priv)
{
struct gw_node *curr_gw = NULL, *next_gw = NULL;
struct neigh_node *router = NULL;
char gw_addr[18] = { '\0' };
/**
* The batman daemon checks here if we already passed a full originator
* cycle in order to make sure we don't choose the first gateway we
* hear about. This check is based on the daemon's uptime which we
* don't have.
**/
if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
goto out;
if (!atomic_dec_not_zero(&bat_priv->gw_reselect))
goto out;
curr_gw = gw_get_selected_gw_node(bat_priv);
next_gw = gw_get_best_gw_node(bat_priv);
if (curr_gw == next_gw)
goto out;
if (next_gw) {
sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
router = orig_node_get_router(next_gw->orig_node);
if (!router) {
gw_deselect(bat_priv);
goto out;
}
}
if ((curr_gw) && (!next_gw)) {
bat_dbg(DBG_BATMAN, bat_priv,
"Removing selected gateway - no gateway in range\n");
throw_uevent(bat_priv, UEV_GW, UEV_DEL, NULL);
} else if ((!curr_gw) && (next_gw)) {
bat_dbg(DBG_BATMAN, bat_priv,
"Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
next_gw->orig_node->orig,
next_gw->orig_node->gw_flags,
router->tq_avg);
throw_uevent(bat_priv, UEV_GW, UEV_ADD, gw_addr);
} else {
bat_dbg(DBG_BATMAN, bat_priv,
"Changing route to gateway %pM "
"(gw_flags: %i, tq: %i)\n",
next_gw->orig_node->orig,
next_gw->orig_node->gw_flags,
router->tq_avg);
throw_uevent(bat_priv, UEV_GW, UEV_CHANGE, gw_addr);
}
gw_select(bat_priv, next_gw);
out:
if (curr_gw)
gw_node_free_ref(curr_gw);
if (next_gw)
gw_node_free_ref(next_gw);
if (router)
neigh_node_free_ref(router);
}
void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
struct orig_node *curr_gw_orig;
struct neigh_node *router_gw = NULL, *router_orig = NULL;
uint8_t gw_tq_avg, orig_tq_avg;
curr_gw_orig = gw_get_selected_orig(bat_priv);
if (!curr_gw_orig)
goto deselect;
router_gw = orig_node_get_router(curr_gw_orig);
if (!router_gw)
goto deselect;
/* this node already is the gateway */
if (curr_gw_orig == orig_node)
goto out;
router_orig = orig_node_get_router(orig_node);
if (!router_orig)
goto out;
gw_tq_avg = router_gw->tq_avg;
orig_tq_avg = router_orig->tq_avg;
/* the TQ value has to be better */
if (orig_tq_avg < gw_tq_avg)
goto out;
/**
* if the routing class is greater than 3 the value tells us how much
* greater the TQ value of the new gateway must be
**/
if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
goto out;
bat_dbg(DBG_BATMAN, bat_priv,
"Restarting gateway selection: better gateway found (tq curr: "
"%i, tq new: %i)\n",
gw_tq_avg, orig_tq_avg);
deselect:
gw_deselect(bat_priv);
out:
if (curr_gw_orig)
orig_node_free_ref(curr_gw_orig);
if (router_gw)
neigh_node_free_ref(router_gw);
if (router_orig)
neigh_node_free_ref(router_orig);
return;
}
static void gw_node_add(struct bat_priv *bat_priv,
struct orig_node *orig_node, uint8_t new_gwflags)
{
struct gw_node *gw_node;
int down, up;
gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
if (!gw_node)
return;
INIT_HLIST_NODE(&gw_node->list);
gw_node->orig_node = orig_node;
atomic_set(&gw_node->refcount, 1);
spin_lock_bh(&bat_priv->gw_list_lock);
hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
spin_unlock_bh(&bat_priv->gw_list_lock);
gw_bandwidth_to_kbit(new_gwflags, &down, &up);
bat_dbg(DBG_BATMAN, bat_priv,
"Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
orig_node->orig, new_gwflags,
(down > 2048 ? down / 1024 : down),
(down > 2048 ? "MBit" : "KBit"),
(up > 2048 ? up / 1024 : up),
(up > 2048 ? "MBit" : "KBit"));
}
void gw_node_update(struct bat_priv *bat_priv,
struct orig_node *orig_node, uint8_t new_gwflags)
{
struct hlist_node *node;
struct gw_node *gw_node, *curr_gw;
/**
* Note: We don't need a NULL check here, since curr_gw never gets
* dereferenced. If curr_gw is NULL we also should not exit as we may
* have this gateway in our list (duplication check!) even though we
* have no currently selected gateway.
*/
curr_gw = gw_get_selected_gw_node(bat_priv);
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
if (gw_node->orig_node != orig_node)
continue;
bat_dbg(DBG_BATMAN, bat_priv,
"Gateway class of originator %pM changed from "
"%i to %i\n",
orig_node->orig, gw_node->orig_node->gw_flags,
new_gwflags);
gw_node->deleted = 0;
if (new_gwflags == NO_FLAGS) {
gw_node->deleted = jiffies;
bat_dbg(DBG_BATMAN, bat_priv,
"Gateway %pM removed from gateway list\n",
orig_node->orig);
if (gw_node == curr_gw)
goto deselect;
}
goto unlock;
}
if (new_gwflags == NO_FLAGS)
goto unlock;
gw_node_add(bat_priv, orig_node, new_gwflags);
goto unlock;
deselect:
gw_deselect(bat_priv);
unlock:
rcu_read_unlock();
if (curr_gw)
gw_node_free_ref(curr_gw);
}
void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
gw_node_update(bat_priv, orig_node, 0);
}
void gw_node_purge(struct bat_priv *bat_priv)
{
struct gw_node *gw_node, *curr_gw;
struct hlist_node *node, *node_tmp;
unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
int do_deselect = 0;
curr_gw = gw_get_selected_gw_node(bat_priv);
spin_lock_bh(&bat_priv->gw_list_lock);
hlist_for_each_entry_safe(gw_node, node, node_tmp,
&bat_priv->gw_list, list) {
if (((!gw_node->deleted) ||
(time_before(jiffies, gw_node->deleted + timeout))) &&
atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
continue;
if (curr_gw == gw_node)
do_deselect = 1;
hlist_del_rcu(&gw_node->list);
gw_node_free_ref(gw_node);
}
spin_unlock_bh(&bat_priv->gw_list_lock);
/* gw_deselect() needs to acquire the gw_list_lock */
if (do_deselect)
gw_deselect(bat_priv);
if (curr_gw)
gw_node_free_ref(curr_gw);
}
/**
* fails if orig_node has no router
*/
static int _write_buffer_text(struct bat_priv *bat_priv, struct seq_file *seq,
const struct gw_node *gw_node)
{
struct gw_node *curr_gw;
struct neigh_node *router;
int down, up, ret = -1;
gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
router = orig_node_get_router(gw_node->orig_node);
if (!router)
goto out;
curr_gw = gw_get_selected_gw_node(bat_priv);
ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
(curr_gw == gw_node ? "=>" : " "),
gw_node->orig_node->orig,
router->tq_avg, router->addr,
router->if_incoming->net_dev->name,
gw_node->orig_node->gw_flags,
(down > 2048 ? down / 1024 : down),
(down > 2048 ? "MBit" : "KBit"),
(up > 2048 ? up / 1024 : up),
(up > 2048 ? "MBit" : "KBit"));
neigh_node_free_ref(router);
if (curr_gw)
gw_node_free_ref(curr_gw);
out:
return ret;
}
int gw_client_seq_print_text(struct seq_file *seq, void *offset)
{
struct net_device *net_dev = (struct net_device *)seq->private;
struct bat_priv *bat_priv = netdev_priv(net_dev);
struct hard_iface *primary_if;
struct gw_node *gw_node;
struct hlist_node *node;
int gw_count = 0, ret = 0;
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if) {
ret = seq_printf(seq, "BATMAN mesh %s disabled - please "
"specify interfaces to enable it\n",
net_dev->name);
goto out;
}
if (primary_if->if_status != IF_ACTIVE) {
ret = seq_printf(seq, "BATMAN mesh %s disabled - "
"primary interface not active\n",
net_dev->name);
goto out;
}
seq_printf(seq, " %-12s (%s/%i) %17s [%10s]: gw_class ... "
"[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
"Gateway", "#", TQ_MAX_VALUE, "Nexthop",
"outgoingIF", SOURCE_VERSION, primary_if->net_dev->name,
primary_if->net_dev->dev_addr, net_dev->name);
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
if (gw_node->deleted)
continue;
/* fails if orig_node has no router */
if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
continue;
gw_count++;
}
rcu_read_unlock();
if (gw_count == 0)
seq_printf(seq, "No gateways in range ...\n");
out:
if (primary_if)
hardif_free_ref(primary_if);
return ret;
}
static bool is_type_dhcprequest(struct sk_buff *skb, int header_len)
{
int ret = false;
unsigned char *p;
int pkt_len;
if (skb_linearize(skb) < 0)
goto out;
pkt_len = skb_headlen(skb);
if (pkt_len < header_len + DHCP_OPTIONS_OFFSET + 1)
goto out;
p = skb->data + header_len + DHCP_OPTIONS_OFFSET;
pkt_len -= header_len + DHCP_OPTIONS_OFFSET + 1;
/* Access the dhcp option lists. Each entry is made up by:
* - octect 1: option type
* - octect 2: option data len (only if type != 255 and 0)
* - octect 3: option data */
while (*p != 255 && !ret) {
/* p now points to the first octect: option type */
if (*p == 53) {
/* type 53 is the message type option.
* Jump the len octect and go to the data octect */
if (pkt_len < 2)
goto out;
p += 2;
/* check if the message type is what we need */
if (*p == DHCP_REQUEST)
ret = true;
break;
} else if (*p == 0) {
/* option type 0 (padding), just go forward */
if (pkt_len < 1)
goto out;
pkt_len--;
p++;
} else {
/* This is any other option. So we get the length... */
if (pkt_len < 1)
goto out;
pkt_len--;
p++;
/* ...and then we jump over the data */
if (pkt_len < *p)
goto out;
pkt_len -= *p;
p += (*p);
}
}
out:
return ret;
}
int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb,
struct orig_node *old_gw)
{
struct ethhdr *ethhdr;
struct iphdr *iphdr;
struct ipv6hdr *ipv6hdr;
struct udphdr *udphdr;
struct gw_node *curr_gw;
struct neigh_node *neigh_curr = NULL, *neigh_old = NULL;
unsigned int header_len = 0;
int ret = 1;
if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
return 0;
/* check for ethernet header */
if (!pskb_may_pull(skb, header_len + ETH_HLEN))
return 0;
ethhdr = (struct ethhdr *)skb->data;
header_len += ETH_HLEN;
/* check for initial vlan header */
if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
return 0;
ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
header_len += VLAN_HLEN;
}
/* check for ip header */
switch (ntohs(ethhdr->h_proto)) {
case ETH_P_IP:
if (!pskb_may_pull(skb, header_len + sizeof(*iphdr)))
return 0;
iphdr = (struct iphdr *)(skb->data + header_len);
header_len += iphdr->ihl * 4;
/* check for udp header */
if (iphdr->protocol != IPPROTO_UDP)
return 0;
break;
case ETH_P_IPV6:
if (!pskb_may_pull(skb, header_len + sizeof(*ipv6hdr)))
return 0;
ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
header_len += sizeof(*ipv6hdr);
/* check for udp header */
if (ipv6hdr->nexthdr != IPPROTO_UDP)
return 0;
break;
default:
return 0;
}
if (!pskb_may_pull(skb, header_len + sizeof(*udphdr)))
return 0;
udphdr = (struct udphdr *)(skb->data + header_len);
header_len += sizeof(*udphdr);
/* check for bootp port */
if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
(ntohs(udphdr->dest) != 67))
return 0;
if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
(ntohs(udphdr->dest) != 547))
return 0;
if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
return -1;
curr_gw = gw_get_selected_gw_node(bat_priv);
if (!curr_gw)
return 0;
/* If old_gw != NULL then this packet is unicast.
* So, at this point we have to check the message type: if it is a
* DHCPREQUEST we have to decide whether to drop it or not */
if (old_gw && curr_gw->orig_node != old_gw) {
if (is_type_dhcprequest(skb, header_len)) {
/* If the dhcp packet has been sent to a different gw,
* we have to evaluate whether the old gw is still
* reliable enough */
neigh_curr = find_router(bat_priv, curr_gw->orig_node,
NULL);
neigh_old = find_router(bat_priv, old_gw, NULL);
if (!neigh_curr || !neigh_old)
goto free_neigh;
if (neigh_curr->tq_avg - neigh_old->tq_avg <
GW_THRESHOLD)
ret = -1;
}
}
free_neigh:
if (neigh_old)
neigh_node_free_ref(neigh_old);
if (neigh_curr)
neigh_node_free_ref(neigh_curr);
if (curr_gw)
gw_node_free_ref(curr_gw);
return ret;
}