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linux/net/ipv4/ipmr.c
Changli Gao 5811662b15 net: use the macros defined for the members of flowi 
Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 12:27:45 -08:00

2470 lines
55 KiB
C
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/*
* IP multicast routing support for mrouted 3.6/3.8
*
* (c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
* Linux Consultancy and Custom Driver Development
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Fixes:
* Michael Chastain : Incorrect size of copying.
* Alan Cox : Added the cache manager code
* Alan Cox : Fixed the clone/copy bug and device race.
* Mike McLagan : Routing by source
* Malcolm Beattie : Buffer handling fixes.
* Alexey Kuznetsov : Double buffer free and other fixes.
* SVR Anand : Fixed several multicast bugs and problems.
* Alexey Kuznetsov : Status, optimisations and more.
* Brad Parker : Better behaviour on mrouted upcall
* overflow.
* Carlos Picoto : PIMv1 Support
* Pavlin Ivanov Radoslavov: PIMv2 Registers must checksum only PIM header
* Relax this requirement to work with older peers.
*
*/
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/types.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mroute.h>
#include <linux/init.h>
#include <linux/if_ether.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/route.h>
#include <net/sock.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/raw.h>
#include <linux/notifier.h>
#include <linux/if_arp.h>
#include <linux/netfilter_ipv4.h>
#include <net/ipip.h>
#include <net/checksum.h>
#include <net/netlink.h>
#include <net/fib_rules.h>
#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
#define CONFIG_IP_PIMSM 1
#endif
struct mr_table {
struct list_head list;
#ifdef CONFIG_NET_NS
struct net *net;
#endif
u32 id;
struct sock __rcu *mroute_sk;
struct timer_list ipmr_expire_timer;
struct list_head mfc_unres_queue;
struct list_head mfc_cache_array[MFC_LINES];
struct vif_device vif_table[MAXVIFS];
int maxvif;
atomic_t cache_resolve_queue_len;
int mroute_do_assert;
int mroute_do_pim;
#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
int mroute_reg_vif_num;
#endif
};
struct ipmr_rule {
struct fib_rule common;
};
struct ipmr_result {
struct mr_table *mrt;
};
/* Big lock, protecting vif table, mrt cache and mroute socket state.
* Note that the changes are semaphored via rtnl_lock.
*/
static DEFINE_RWLOCK(mrt_lock);
/*
* Multicast router control variables
*/
#define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
/* Special spinlock for queue of unresolved entries */
static DEFINE_SPINLOCK(mfc_unres_lock);
/* We return to original Alan's scheme. Hash table of resolved
* entries is changed only in process context and protected
* with weak lock mrt_lock. Queue of unresolved entries is protected
* with strong spinlock mfc_unres_lock.
*
* In this case data path is free of exclusive locks at all.
*/
static struct kmem_cache *mrt_cachep __read_mostly;
static struct mr_table *ipmr_new_table(struct net *net, u32 id);
static int ip_mr_forward(struct net *net, struct mr_table *mrt,
struct sk_buff *skb, struct mfc_cache *cache,
int local);
static int ipmr_cache_report(struct mr_table *mrt,
struct sk_buff *pkt, vifi_t vifi, int assert);
static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm);
static void ipmr_expire_process(unsigned long arg);
#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
#define ipmr_for_each_table(mrt, net) \
list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
static struct mr_table *ipmr_get_table(struct net *net, u32 id)
{
struct mr_table *mrt;
ipmr_for_each_table(mrt, net) {
if (mrt->id == id)
return mrt;
}
return NULL;
}
static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
struct mr_table **mrt)
{
struct ipmr_result res;
struct fib_lookup_arg arg = { .result = &res, };
int err;
err = fib_rules_lookup(net->ipv4.mr_rules_ops, flp, 0, &arg);
if (err < 0)
return err;
*mrt = res.mrt;
return 0;
}
static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
int flags, struct fib_lookup_arg *arg)
{
struct ipmr_result *res = arg->result;
struct mr_table *mrt;
switch (rule->action) {
case FR_ACT_TO_TBL:
break;
case FR_ACT_UNREACHABLE:
return -ENETUNREACH;
case FR_ACT_PROHIBIT:
return -EACCES;
case FR_ACT_BLACKHOLE:
default:
return -EINVAL;
}
mrt = ipmr_get_table(rule->fr_net, rule->table);
if (mrt == NULL)
return -EAGAIN;
res->mrt = mrt;
return 0;
}
static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
return 1;
}
static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
FRA_GENERIC_POLICY,
};
static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
struct fib_rule_hdr *frh, struct nlattr **tb)
{
return 0;
}
static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
struct nlattr **tb)
{
return 1;
}
static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
struct fib_rule_hdr *frh)
{
frh->dst_len = 0;
frh->src_len = 0;
frh->tos = 0;
return 0;
}
static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = {
.family = RTNL_FAMILY_IPMR,
.rule_size = sizeof(struct ipmr_rule),
.addr_size = sizeof(u32),
.action = ipmr_rule_action,
.match = ipmr_rule_match,
.configure = ipmr_rule_configure,
.compare = ipmr_rule_compare,
.default_pref = fib_default_rule_pref,
.fill = ipmr_rule_fill,
.nlgroup = RTNLGRP_IPV4_RULE,
.policy = ipmr_rule_policy,
.owner = THIS_MODULE,
};
static int __net_init ipmr_rules_init(struct net *net)
{
struct fib_rules_ops *ops;
struct mr_table *mrt;
int err;
ops = fib_rules_register(&ipmr_rules_ops_template, net);
if (IS_ERR(ops))
return PTR_ERR(ops);
INIT_LIST_HEAD(&net->ipv4.mr_tables);
mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
if (mrt == NULL) {
err = -ENOMEM;
goto err1;
}
err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
if (err < 0)
goto err2;
net->ipv4.mr_rules_ops = ops;
return 0;
err2:
kfree(mrt);
err1:
fib_rules_unregister(ops);
return err;
}
static void __net_exit ipmr_rules_exit(struct net *net)
{
struct mr_table *mrt, *next;
list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
list_del(&mrt->list);
kfree(mrt);
}
fib_rules_unregister(net->ipv4.mr_rules_ops);
}
#else
#define ipmr_for_each_table(mrt, net) \
for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
static struct mr_table *ipmr_get_table(struct net *net, u32 id)
{
return net->ipv4.mrt;
}
static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
struct mr_table **mrt)
{
*mrt = net->ipv4.mrt;
return 0;
}
static int __net_init ipmr_rules_init(struct net *net)
{
net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
return net->ipv4.mrt ? 0 : -ENOMEM;
}
static void __net_exit ipmr_rules_exit(struct net *net)
{
kfree(net->ipv4.mrt);
}
#endif
static struct mr_table *ipmr_new_table(struct net *net, u32 id)
{
struct mr_table *mrt;
unsigned int i;
mrt = ipmr_get_table(net, id);
if (mrt != NULL)
return mrt;
mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
if (mrt == NULL)
return NULL;
write_pnet(&mrt->net, net);
mrt->id = id;
/* Forwarding cache */
for (i = 0; i < MFC_LINES; i++)
INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
INIT_LIST_HEAD(&mrt->mfc_unres_queue);
setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
(unsigned long)mrt);
#ifdef CONFIG_IP_PIMSM
mrt->mroute_reg_vif_num = -1;
#endif
#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
#endif
return mrt;
}
/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
{
struct net *net = dev_net(dev);
dev_close(dev);
dev = __dev_get_by_name(net, "tunl0");
if (dev) {
const struct net_device_ops *ops = dev->netdev_ops;
struct ifreq ifr;
struct ip_tunnel_parm p;
memset(&p, 0, sizeof(p));
p.iph.daddr = v->vifc_rmt_addr.s_addr;
p.iph.saddr = v->vifc_lcl_addr.s_addr;
p.iph.version = 4;
p.iph.ihl = 5;
p.iph.protocol = IPPROTO_IPIP;
sprintf(p.name, "dvmrp%d", v->vifc_vifi);
ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
if (ops->ndo_do_ioctl) {
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
set_fs(oldfs);
}
}
}
static
struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
{
struct net_device *dev;
dev = __dev_get_by_name(net, "tunl0");
if (dev) {
const struct net_device_ops *ops = dev->netdev_ops;
int err;
struct ifreq ifr;
struct ip_tunnel_parm p;
struct in_device *in_dev;
memset(&p, 0, sizeof(p));
p.iph.daddr = v->vifc_rmt_addr.s_addr;
p.iph.saddr = v->vifc_lcl_addr.s_addr;
p.iph.version = 4;
p.iph.ihl = 5;
p.iph.protocol = IPPROTO_IPIP;
sprintf(p.name, "dvmrp%d", v->vifc_vifi);
ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
if (ops->ndo_do_ioctl) {
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
set_fs(oldfs);
} else {
err = -EOPNOTSUPP;
}
dev = NULL;
if (err == 0 &&
(dev = __dev_get_by_name(net, p.name)) != NULL) {
dev->flags |= IFF_MULTICAST;
in_dev = __in_dev_get_rtnl(dev);
if (in_dev == NULL)
goto failure;
ipv4_devconf_setall(in_dev);
IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
if (dev_open(dev))
goto failure;
dev_hold(dev);
}
}
return dev;
failure:
/* allow the register to be completed before unregistering. */
rtnl_unlock();
rtnl_lock();
unregister_netdevice(dev);
return NULL;
}
#ifdef CONFIG_IP_PIMSM
static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct net *net = dev_net(dev);
struct mr_table *mrt;
struct flowi fl = {
.oif = dev->ifindex,
.iif = skb->skb_iif,
.mark = skb->mark,
};
int err;
err = ipmr_fib_lookup(net, &fl, &mrt);
if (err < 0) {
kfree_skb(skb);
return err;
}
read_lock(&mrt_lock);
dev->stats.tx_bytes += skb->len;
dev->stats.tx_packets++;
ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
read_unlock(&mrt_lock);
kfree_skb(skb);
return NETDEV_TX_OK;
}
static const struct net_device_ops reg_vif_netdev_ops = {
.ndo_start_xmit = reg_vif_xmit,
};
static void reg_vif_setup(struct net_device *dev)
{
dev->type = ARPHRD_PIMREG;
dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
dev->flags = IFF_NOARP;
dev->netdev_ops = &reg_vif_netdev_ops,
dev->destructor = free_netdev;
dev->features |= NETIF_F_NETNS_LOCAL;
}
static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
{
struct net_device *dev;
struct in_device *in_dev;
char name[IFNAMSIZ];
if (mrt->id == RT_TABLE_DEFAULT)
sprintf(name, "pimreg");
else
sprintf(name, "pimreg%u", mrt->id);
dev = alloc_netdev(0, name, reg_vif_setup);
if (dev == NULL)
return NULL;
dev_net_set(dev, net);
if (register_netdevice(dev)) {
free_netdev(dev);
return NULL;
}
dev->iflink = 0;
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (!in_dev) {
rcu_read_unlock();
goto failure;
}
ipv4_devconf_setall(in_dev);
IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
rcu_read_unlock();
if (dev_open(dev))
goto failure;
dev_hold(dev);
return dev;
failure:
/* allow the register to be completed before unregistering. */
rtnl_unlock();
rtnl_lock();
unregister_netdevice(dev);
return NULL;
}
#endif
/*
* Delete a VIF entry
* @notify: Set to 1, if the caller is a notifier_call
*/
static int vif_delete(struct mr_table *mrt, int vifi, int notify,
struct list_head *head)
{
struct vif_device *v;
struct net_device *dev;
struct in_device *in_dev;
if (vifi < 0 || vifi >= mrt->maxvif)
return -EADDRNOTAVAIL;
v = &mrt->vif_table[vifi];
write_lock_bh(&mrt_lock);
dev = v->dev;
v->dev = NULL;
if (!dev) {
write_unlock_bh(&mrt_lock);
return -EADDRNOTAVAIL;
}
#ifdef CONFIG_IP_PIMSM
if (vifi == mrt->mroute_reg_vif_num)
mrt->mroute_reg_vif_num = -1;
#endif
if (vifi + 1 == mrt->maxvif) {
int tmp;
for (tmp = vifi - 1; tmp >= 0; tmp--) {
if (VIF_EXISTS(mrt, tmp))
break;
}
mrt->maxvif = tmp+1;
}
write_unlock_bh(&mrt_lock);
dev_set_allmulti(dev, -1);
in_dev = __in_dev_get_rtnl(dev);
if (in_dev) {
IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
ip_rt_multicast_event(in_dev);
}
if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
unregister_netdevice_queue(dev, head);
dev_put(dev);
return 0;
}
static void ipmr_cache_free_rcu(struct rcu_head *head)
{
struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
kmem_cache_free(mrt_cachep, c);
}
static inline void ipmr_cache_free(struct mfc_cache *c)
{
call_rcu(&c->rcu, ipmr_cache_free_rcu);
}
/* Destroy an unresolved cache entry, killing queued skbs
* and reporting error to netlink readers.
*/
static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
{
struct net *net = read_pnet(&mrt->net);
struct sk_buff *skb;
struct nlmsgerr *e;
atomic_dec(&mrt->cache_resolve_queue_len);
while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
if (ip_hdr(skb)->version == 0) {
struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
nlh->nlmsg_type = NLMSG_ERROR;
nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
skb_trim(skb, nlh->nlmsg_len);
e = NLMSG_DATA(nlh);
e->error = -ETIMEDOUT;
memset(&e->msg, 0, sizeof(e->msg));
rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
} else {
kfree_skb(skb);
}
}
ipmr_cache_free(c);
}
/* Timer process for the unresolved queue. */
static void ipmr_expire_process(unsigned long arg)
{
struct mr_table *mrt = (struct mr_table *)arg;
unsigned long now;
unsigned long expires;
struct mfc_cache *c, *next;
if (!spin_trylock(&mfc_unres_lock)) {
mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
return;
}
if (list_empty(&mrt->mfc_unres_queue))
goto out;
now = jiffies;
expires = 10*HZ;
list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
if (time_after(c->mfc_un.unres.expires, now)) {
unsigned long interval = c->mfc_un.unres.expires - now;
if (interval < expires)
expires = interval;
continue;
}
list_del(&c->list);
ipmr_destroy_unres(mrt, c);
}
if (!list_empty(&mrt->mfc_unres_queue))
mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
out:
spin_unlock(&mfc_unres_lock);
}
/* Fill oifs list. It is called under write locked mrt_lock. */
static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
unsigned char *ttls)
{
int vifi;
cache->mfc_un.res.minvif = MAXVIFS;
cache->mfc_un.res.maxvif = 0;
memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
for (vifi = 0; vifi < mrt->maxvif; vifi++) {
if (VIF_EXISTS(mrt, vifi) &&
ttls[vifi] && ttls[vifi] < 255) {
cache->mfc_un.res.ttls[vifi] = ttls[vifi];
if (cache->mfc_un.res.minvif > vifi)
cache->mfc_un.res.minvif = vifi;
if (cache->mfc_un.res.maxvif <= vifi)
cache->mfc_un.res.maxvif = vifi + 1;
}
}
}
static int vif_add(struct net *net, struct mr_table *mrt,
struct vifctl *vifc, int mrtsock)
{
int vifi = vifc->vifc_vifi;
struct vif_device *v = &mrt->vif_table[vifi];
struct net_device *dev;
struct in_device *in_dev;
int err;
/* Is vif busy ? */
if (VIF_EXISTS(mrt, vifi))
return -EADDRINUSE;
switch (vifc->vifc_flags) {
#ifdef CONFIG_IP_PIMSM
case VIFF_REGISTER:
/*
* Special Purpose VIF in PIM
* All the packets will be sent to the daemon
*/
if (mrt->mroute_reg_vif_num >= 0)
return -EADDRINUSE;
dev = ipmr_reg_vif(net, mrt);
if (!dev)
return -ENOBUFS;
err = dev_set_allmulti(dev, 1);
if (err) {
unregister_netdevice(dev);
dev_put(dev);
return err;
}
break;
#endif
case VIFF_TUNNEL:
dev = ipmr_new_tunnel(net, vifc);
if (!dev)
return -ENOBUFS;
err = dev_set_allmulti(dev, 1);
if (err) {
ipmr_del_tunnel(dev, vifc);
dev_put(dev);
return err;
}
break;
case VIFF_USE_IFINDEX:
case 0:
if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
if (dev && __in_dev_get_rtnl(dev) == NULL) {
dev_put(dev);
return -EADDRNOTAVAIL;
}
} else {
dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
}
if (!dev)
return -EADDRNOTAVAIL;
err = dev_set_allmulti(dev, 1);
if (err) {
dev_put(dev);
return err;
}
break;
default:
return -EINVAL;
}
in_dev = __in_dev_get_rtnl(dev);
if (!in_dev) {
dev_put(dev);
return -EADDRNOTAVAIL;
}
IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
ip_rt_multicast_event(in_dev);
/* Fill in the VIF structures */
v->rate_limit = vifc->vifc_rate_limit;
v->local = vifc->vifc_lcl_addr.s_addr;
v->remote = vifc->vifc_rmt_addr.s_addr;
v->flags = vifc->vifc_flags;
if (!mrtsock)
v->flags |= VIFF_STATIC;
v->threshold = vifc->vifc_threshold;
v->bytes_in = 0;
v->bytes_out = 0;
v->pkt_in = 0;
v->pkt_out = 0;
v->link = dev->ifindex;
if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
v->link = dev->iflink;
/* And finish update writing critical data */
write_lock_bh(&mrt_lock);
v->dev = dev;
#ifdef CONFIG_IP_PIMSM
if (v->flags & VIFF_REGISTER)
mrt->mroute_reg_vif_num = vifi;
#endif
if (vifi+1 > mrt->maxvif)
mrt->maxvif = vifi+1;
write_unlock_bh(&mrt_lock);
return 0;
}
/* called with rcu_read_lock() */
static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
__be32 origin,
__be32 mcastgrp)
{
int line = MFC_HASH(mcastgrp, origin);
struct mfc_cache *c;
list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
return c;
}
return NULL;
}
/*
* Allocate a multicast cache entry
*/
static struct mfc_cache *ipmr_cache_alloc(void)
{
struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
if (c)
c->mfc_un.res.minvif = MAXVIFS;
return c;
}
static struct mfc_cache *ipmr_cache_alloc_unres(void)
{
struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
if (c) {
skb_queue_head_init(&c->mfc_un.unres.unresolved);
c->mfc_un.unres.expires = jiffies + 10*HZ;
}
return c;
}
/*
* A cache entry has gone into a resolved state from queued
*/
static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
struct mfc_cache *uc, struct mfc_cache *c)
{
struct sk_buff *skb;
struct nlmsgerr *e;
/* Play the pending entries through our router */
while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
if (ip_hdr(skb)->version == 0) {
struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
nlh->nlmsg_len = skb_tail_pointer(skb) -
(u8 *)nlh;
} else {
nlh->nlmsg_type = NLMSG_ERROR;
nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
skb_trim(skb, nlh->nlmsg_len);
e = NLMSG_DATA(nlh);
e->error = -EMSGSIZE;
memset(&e->msg, 0, sizeof(e->msg));
}
rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
} else {
ip_mr_forward(net, mrt, skb, c, 0);
}
}
}
/*
* Bounce a cache query up to mrouted. We could use netlink for this but mrouted
* expects the following bizarre scheme.
*
* Called under mrt_lock.
*/
static int ipmr_cache_report(struct mr_table *mrt,
struct sk_buff *pkt, vifi_t vifi, int assert)
{
struct sk_buff *skb;
const int ihl = ip_hdrlen(pkt);
struct igmphdr *igmp;
struct igmpmsg *msg;
struct sock *mroute_sk;
int ret;
#ifdef CONFIG_IP_PIMSM
if (assert == IGMPMSG_WHOLEPKT)
skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
else
#endif
skb = alloc_skb(128, GFP_ATOMIC);
if (!skb)
return -ENOBUFS;
#ifdef CONFIG_IP_PIMSM
if (assert == IGMPMSG_WHOLEPKT) {
/* Ugly, but we have no choice with this interface.
* Duplicate old header, fix ihl, length etc.
* And all this only to mangle msg->im_msgtype and
* to set msg->im_mbz to "mbz" :-)
*/
skb_push(skb, sizeof(struct iphdr));
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
msg = (struct igmpmsg *)skb_network_header(skb);
memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
msg->im_msgtype = IGMPMSG_WHOLEPKT;
msg->im_mbz = 0;
msg->im_vif = mrt->mroute_reg_vif_num;
ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
sizeof(struct iphdr));
} else
#endif
{
/* Copy the IP header */
skb->network_header = skb->tail;
skb_put(skb, ihl);
skb_copy_to_linear_data(skb, pkt->data, ihl);
ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */
msg = (struct igmpmsg *)skb_network_header(skb);
msg->im_vif = vifi;
skb_dst_set(skb, dst_clone(skb_dst(pkt)));
/* Add our header */
igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
igmp->type =
msg->im_msgtype = assert;
igmp->code = 0;
ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */
skb->transport_header = skb->network_header;
}
rcu_read_lock();
mroute_sk = rcu_dereference(mrt->mroute_sk);
if (mroute_sk == NULL) {
rcu_read_unlock();
kfree_skb(skb);
return -EINVAL;
}
/* Deliver to mrouted */
ret = sock_queue_rcv_skb(mroute_sk, skb);
rcu_read_unlock();
if (ret < 0) {
if (net_ratelimit())
printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
kfree_skb(skb);
}
return ret;
}
/*
* Queue a packet for resolution. It gets locked cache entry!
*/
static int
ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
{
bool found = false;
int err;
struct mfc_cache *c;
const struct iphdr *iph = ip_hdr(skb);
spin_lock_bh(&mfc_unres_lock);
list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
if (c->mfc_mcastgrp == iph->daddr &&
c->mfc_origin == iph->saddr) {
found = true;
break;
}
}
if (!found) {
/* Create a new entry if allowable */
if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
(c = ipmr_cache_alloc_unres()) == NULL) {
spin_unlock_bh(&mfc_unres_lock);
kfree_skb(skb);
return -ENOBUFS;
}
/* Fill in the new cache entry */
c->mfc_parent = -1;
c->mfc_origin = iph->saddr;
c->mfc_mcastgrp = iph->daddr;
/* Reflect first query at mrouted. */
err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
if (err < 0) {
/* If the report failed throw the cache entry
out - Brad Parker
*/
spin_unlock_bh(&mfc_unres_lock);
ipmr_cache_free(c);
kfree_skb(skb);
return err;
}
atomic_inc(&mrt->cache_resolve_queue_len);
list_add(&c->list, &mrt->mfc_unres_queue);
if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
}
/* See if we can append the packet */
if (c->mfc_un.unres.unresolved.qlen > 3) {
kfree_skb(skb);
err = -ENOBUFS;
} else {
skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
err = 0;
}
spin_unlock_bh(&mfc_unres_lock);
return err;
}
/*
* MFC cache manipulation by user space mroute daemon
*/
static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
{
int line;
struct mfc_cache *c, *next;
line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
list_del_rcu(&c->list);
ipmr_cache_free(c);
return 0;
}
}
return -ENOENT;
}
static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
struct mfcctl *mfc, int mrtsock)
{
bool found = false;
int line;
struct mfc_cache *uc, *c;
if (mfc->mfcc_parent >= MAXVIFS)
return -ENFILE;
line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
found = true;
break;
}
}
if (found) {
write_lock_bh(&mrt_lock);
c->mfc_parent = mfc->mfcc_parent;
ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
if (!mrtsock)
c->mfc_flags |= MFC_STATIC;
write_unlock_bh(&mrt_lock);
return 0;
}
if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
return -EINVAL;
c = ipmr_cache_alloc();
if (c == NULL)
return -ENOMEM;
c->mfc_origin = mfc->mfcc_origin.s_addr;
c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
c->mfc_parent = mfc->mfcc_parent;
ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
if (!mrtsock)
c->mfc_flags |= MFC_STATIC;
list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
/*
* Check to see if we resolved a queued list. If so we
* need to send on the frames and tidy up.
*/
found = false;
spin_lock_bh(&mfc_unres_lock);
list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
if (uc->mfc_origin == c->mfc_origin &&
uc->mfc_mcastgrp == c->mfc_mcastgrp) {
list_del(&uc->list);
atomic_dec(&mrt->cache_resolve_queue_len);
found = true;
break;
}
}
if (list_empty(&mrt->mfc_unres_queue))
del_timer(&mrt->ipmr_expire_timer);
spin_unlock_bh(&mfc_unres_lock);
if (found) {
ipmr_cache_resolve(net, mrt, uc, c);
ipmr_cache_free(uc);
}
return 0;
}
/*
* Close the multicast socket, and clear the vif tables etc
*/
static void mroute_clean_tables(struct mr_table *mrt)
{
int i;
LIST_HEAD(list);
struct mfc_cache *c, *next;
/* Shut down all active vif entries */
for (i = 0; i < mrt->maxvif; i++) {
if (!(mrt->vif_table[i].flags & VIFF_STATIC))
vif_delete(mrt, i, 0, &list);
}
unregister_netdevice_many(&list);
/* Wipe the cache */
for (i = 0; i < MFC_LINES; i++) {
list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
if (c->mfc_flags & MFC_STATIC)
continue;
list_del_rcu(&c->list);
ipmr_cache_free(c);
}
}
if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
spin_lock_bh(&mfc_unres_lock);
list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
list_del(&c->list);
ipmr_destroy_unres(mrt, c);
}
spin_unlock_bh(&mfc_unres_lock);
}
}
/* called from ip_ra_control(), before an RCU grace period,
* we dont need to call synchronize_rcu() here
*/
static void mrtsock_destruct(struct sock *sk)
{
struct net *net = sock_net(sk);
struct mr_table *mrt;
rtnl_lock();
ipmr_for_each_table(mrt, net) {
if (sk == rtnl_dereference(mrt->mroute_sk)) {
IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
rcu_assign_pointer(mrt->mroute_sk, NULL);
mroute_clean_tables(mrt);
}
}
rtnl_unlock();
}
/*
* Socket options and virtual interface manipulation. The whole
* virtual interface system is a complete heap, but unfortunately
* that's how BSD mrouted happens to think. Maybe one day with a proper
* MOSPF/PIM router set up we can clean this up.
*/
int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
{
int ret;
struct vifctl vif;
struct mfcctl mfc;
struct net *net = sock_net(sk);
struct mr_table *mrt;
mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
if (mrt == NULL)
return -ENOENT;
if (optname != MRT_INIT) {
if (sk != rcu_dereference_raw(mrt->mroute_sk) &&
!capable(CAP_NET_ADMIN))
return -EACCES;
}
switch (optname) {
case MRT_INIT:
if (sk->sk_type != SOCK_RAW ||
inet_sk(sk)->inet_num != IPPROTO_IGMP)
return -EOPNOTSUPP;
if (optlen != sizeof(int))
return -ENOPROTOOPT;
rtnl_lock();
if (rtnl_dereference(mrt->mroute_sk)) {
rtnl_unlock();
return -EADDRINUSE;
}
ret = ip_ra_control(sk, 1, mrtsock_destruct);
if (ret == 0) {
rcu_assign_pointer(mrt->mroute_sk, sk);
IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
}
rtnl_unlock();
return ret;
case MRT_DONE:
if (sk != rcu_dereference_raw(mrt->mroute_sk))
return -EACCES;
return ip_ra_control(sk, 0, NULL);
case MRT_ADD_VIF:
case MRT_DEL_VIF:
if (optlen != sizeof(vif))
return -EINVAL;
if (copy_from_user(&vif, optval, sizeof(vif)))
return -EFAULT;
if (vif.vifc_vifi >= MAXVIFS)
return -ENFILE;
rtnl_lock();
if (optname == MRT_ADD_VIF) {
ret = vif_add(net, mrt, &vif,
sk == rtnl_dereference(mrt->mroute_sk));
} else {
ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
}
rtnl_unlock();
return ret;
/*
* Manipulate the forwarding caches. These live
* in a sort of kernel/user symbiosis.
*/
case MRT_ADD_MFC:
case MRT_DEL_MFC:
if (optlen != sizeof(mfc))
return -EINVAL;
if (copy_from_user(&mfc, optval, sizeof(mfc)))
return -EFAULT;
rtnl_lock();
if (optname == MRT_DEL_MFC)
ret = ipmr_mfc_delete(mrt, &mfc);
else
ret = ipmr_mfc_add(net, mrt, &mfc,
sk == rtnl_dereference(mrt->mroute_sk));
rtnl_unlock();
return ret;
/*
* Control PIM assert.
*/
case MRT_ASSERT:
{
int v;
if (get_user(v, (int __user *)optval))
return -EFAULT;
mrt->mroute_do_assert = (v) ? 1 : 0;
return 0;
}
#ifdef CONFIG_IP_PIMSM
case MRT_PIM:
{
int v;
if (get_user(v, (int __user *)optval))
return -EFAULT;
v = (v) ? 1 : 0;
rtnl_lock();
ret = 0;
if (v != mrt->mroute_do_pim) {
mrt->mroute_do_pim = v;
mrt->mroute_do_assert = v;
}
rtnl_unlock();
return ret;
}
#endif
#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
case MRT_TABLE:
{
u32 v;
if (optlen != sizeof(u32))
return -EINVAL;
if (get_user(v, (u32 __user *)optval))
return -EFAULT;
rtnl_lock();
ret = 0;
if (sk == rtnl_dereference(mrt->mroute_sk)) {
ret = -EBUSY;
} else {
if (!ipmr_new_table(net, v))
ret = -ENOMEM;
raw_sk(sk)->ipmr_table = v;
}
rtnl_unlock();
return ret;
}
#endif
/*
* Spurious command, or MRT_VERSION which you cannot
* set.
*/
default:
return -ENOPROTOOPT;
}
}
/*
* Getsock opt support for the multicast routing system.
*/
int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
{
int olr;
int val;
struct net *net = sock_net(sk);
struct mr_table *mrt;
mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
if (mrt == NULL)
return -ENOENT;
if (optname != MRT_VERSION &&
#ifdef CONFIG_IP_PIMSM
optname != MRT_PIM &&
#endif
optname != MRT_ASSERT)
return -ENOPROTOOPT;
if (get_user(olr, optlen))
return -EFAULT;
olr = min_t(unsigned int, olr, sizeof(int));
if (olr < 0)
return -EINVAL;
if (put_user(olr, optlen))
return -EFAULT;
if (optname == MRT_VERSION)
val = 0x0305;
#ifdef CONFIG_IP_PIMSM
else if (optname == MRT_PIM)
val = mrt->mroute_do_pim;
#endif
else
val = mrt->mroute_do_assert;
if (copy_to_user(optval, &val, olr))
return -EFAULT;
return 0;
}
/*
* The IP multicast ioctl support routines.
*/
int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
{
struct sioc_sg_req sr;
struct sioc_vif_req vr;
struct vif_device *vif;
struct mfc_cache *c;
struct net *net = sock_net(sk);
struct mr_table *mrt;
mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
if (mrt == NULL)
return -ENOENT;
switch (cmd) {
case SIOCGETVIFCNT:
if (copy_from_user(&vr, arg, sizeof(vr)))
return -EFAULT;
if (vr.vifi >= mrt->maxvif)
return -EINVAL;
read_lock(&mrt_lock);
vif = &mrt->vif_table[vr.vifi];
if (VIF_EXISTS(mrt, vr.vifi)) {
vr.icount = vif->pkt_in;
vr.ocount = vif->pkt_out;
vr.ibytes = vif->bytes_in;
vr.obytes = vif->bytes_out;
read_unlock(&mrt_lock);
if (copy_to_user(arg, &vr, sizeof(vr)))
return -EFAULT;
return 0;
}
read_unlock(&mrt_lock);
return -EADDRNOTAVAIL;
case SIOCGETSGCNT:
if (copy_from_user(&sr, arg, sizeof(sr)))
return -EFAULT;
rcu_read_lock();
c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
if (c) {
sr.pktcnt = c->mfc_un.res.pkt;
sr.bytecnt = c->mfc_un.res.bytes;
sr.wrong_if = c->mfc_un.res.wrong_if;
rcu_read_unlock();
if (copy_to_user(arg, &sr, sizeof(sr)))
return -EFAULT;
return 0;
}
rcu_read_unlock();
return -EADDRNOTAVAIL;
default:
return -ENOIOCTLCMD;
}
}
static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
struct net *net = dev_net(dev);
struct mr_table *mrt;
struct vif_device *v;
int ct;
LIST_HEAD(list);
if (event != NETDEV_UNREGISTER)
return NOTIFY_DONE;
ipmr_for_each_table(mrt, net) {
v = &mrt->vif_table[0];
for (ct = 0; ct < mrt->maxvif; ct++, v++) {
if (v->dev == dev)
vif_delete(mrt, ct, 1, &list);
}
}
unregister_netdevice_many(&list);
return NOTIFY_DONE;
}
static struct notifier_block ip_mr_notifier = {
.notifier_call = ipmr_device_event,
};
/*
* Encapsulate a packet by attaching a valid IPIP header to it.
* This avoids tunnel drivers and other mess and gives us the speed so
* important for multicast video.
*/
static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
{
struct iphdr *iph;
struct iphdr *old_iph = ip_hdr(skb);
skb_push(skb, sizeof(struct iphdr));
skb->transport_header = skb->network_header;
skb_reset_network_header(skb);
iph = ip_hdr(skb);
iph->version = 4;
iph->tos = old_iph->tos;
iph->ttl = old_iph->ttl;
iph->frag_off = 0;
iph->daddr = daddr;
iph->saddr = saddr;
iph->protocol = IPPROTO_IPIP;
iph->ihl = 5;
iph->tot_len = htons(skb->len);
ip_select_ident(iph, skb_dst(skb), NULL);
ip_send_check(iph);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
nf_reset(skb);
}
static inline int ipmr_forward_finish(struct sk_buff *skb)
{
struct ip_options *opt = &(IPCB(skb)->opt);
IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
if (unlikely(opt->optlen))
ip_forward_options(skb);
return dst_output(skb);
}
/*
* Processing handlers for ipmr_forward
*/
static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
struct sk_buff *skb, struct mfc_cache *c, int vifi)
{
const struct iphdr *iph = ip_hdr(skb);
struct vif_device *vif = &mrt->vif_table[vifi];
struct net_device *dev;
struct rtable *rt;
int encap = 0;
if (vif->dev == NULL)
goto out_free;
#ifdef CONFIG_IP_PIMSM
if (vif->flags & VIFF_REGISTER) {
vif->pkt_out++;
vif->bytes_out += skb->len;
vif->dev->stats.tx_bytes += skb->len;
vif->dev->stats.tx_packets++;
ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
goto out_free;
}
#endif
if (vif->flags & VIFF_TUNNEL) {
struct flowi fl = {
.oif = vif->link,
.fl4_dst = vif->remote,
.fl4_src = vif->local,
.fl4_tos = RT_TOS(iph->tos),
.proto = IPPROTO_IPIP
};
if (ip_route_output_key(net, &rt, &fl))
goto out_free;
encap = sizeof(struct iphdr);
} else {
struct flowi fl = {
.oif = vif->link,
.fl4_dst = iph->daddr,
.fl4_tos = RT_TOS(iph->tos),
.proto = IPPROTO_IPIP
};
if (ip_route_output_key(net, &rt, &fl))
goto out_free;
}
dev = rt->dst.dev;
if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
/* Do not fragment multicasts. Alas, IPv4 does not
* allow to send ICMP, so that packets will disappear
* to blackhole.
*/
IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
ip_rt_put(rt);
goto out_free;
}
encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
if (skb_cow(skb, encap)) {
ip_rt_put(rt);
goto out_free;
}
vif->pkt_out++;
vif->bytes_out += skb->len;
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
ip_decrease_ttl(ip_hdr(skb));
/* FIXME: forward and output firewalls used to be called here.
* What do we do with netfilter? -- RR
*/
if (vif->flags & VIFF_TUNNEL) {
ip_encap(skb, vif->local, vif->remote);
/* FIXME: extra output firewall step used to be here. --RR */
vif->dev->stats.tx_packets++;
vif->dev->stats.tx_bytes += skb->len;
}
IPCB(skb)->flags |= IPSKB_FORWARDED;
/*
* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
* not only before forwarding, but after forwarding on all output
* interfaces. It is clear, if mrouter runs a multicasting
* program, it should receive packets not depending to what interface
* program is joined.
* If we will not make it, the program will have to join on all
* interfaces. On the other hand, multihoming host (or router, but
* not mrouter) cannot join to more than one interface - it will
* result in receiving multiple packets.
*/
NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
ipmr_forward_finish);
return;
out_free:
kfree_skb(skb);
}
static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
{
int ct;
for (ct = mrt->maxvif-1; ct >= 0; ct--) {
if (mrt->vif_table[ct].dev == dev)
break;
}
return ct;
}
/* "local" means that we should preserve one skb (for local delivery) */
static int ip_mr_forward(struct net *net, struct mr_table *mrt,
struct sk_buff *skb, struct mfc_cache *cache,
int local)
{
int psend = -1;
int vif, ct;
vif = cache->mfc_parent;
cache->mfc_un.res.pkt++;
cache->mfc_un.res.bytes += skb->len;
/*
* Wrong interface: drop packet and (maybe) send PIM assert.
*/
if (mrt->vif_table[vif].dev != skb->dev) {
int true_vifi;
if (rt_is_output_route(skb_rtable(skb))) {
/* It is our own packet, looped back.
* Very complicated situation...
*
* The best workaround until routing daemons will be
* fixed is not to redistribute packet, if it was
* send through wrong interface. It means, that
* multicast applications WILL NOT work for
* (S,G), which have default multicast route pointing
* to wrong oif. In any case, it is not a good
* idea to use multicasting applications on router.
*/
goto dont_forward;
}
cache->mfc_un.res.wrong_if++;
true_vifi = ipmr_find_vif(mrt, skb->dev);
if (true_vifi >= 0 && mrt->mroute_do_assert &&
/* pimsm uses asserts, when switching from RPT to SPT,
* so that we cannot check that packet arrived on an oif.
* It is bad, but otherwise we would need to move pretty
* large chunk of pimd to kernel. Ough... --ANK
*/
(mrt->mroute_do_pim ||
cache->mfc_un.res.ttls[true_vifi] < 255) &&
time_after(jiffies,
cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
cache->mfc_un.res.last_assert = jiffies;
ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
}
goto dont_forward;
}
mrt->vif_table[vif].pkt_in++;
mrt->vif_table[vif].bytes_in += skb->len;
/*
* Forward the frame
*/
for (ct = cache->mfc_un.res.maxvif - 1;
ct >= cache->mfc_un.res.minvif; ct--) {
if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
if (psend != -1) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2)
ipmr_queue_xmit(net, mrt, skb2, cache,
psend);
}
psend = ct;
}
}
if (psend != -1) {
if (local) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2)
ipmr_queue_xmit(net, mrt, skb2, cache, psend);
} else {
ipmr_queue_xmit(net, mrt, skb, cache, psend);
return 0;
}
}
dont_forward:
if (!local)
kfree_skb(skb);
return 0;
}
/*
* Multicast packets for forwarding arrive here
* Called with rcu_read_lock();
*/
int ip_mr_input(struct sk_buff *skb)
{
struct mfc_cache *cache;
struct net *net = dev_net(skb->dev);
int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
struct mr_table *mrt;
int err;
/* Packet is looped back after forward, it should not be
* forwarded second time, but still can be delivered locally.
*/
if (IPCB(skb)->flags & IPSKB_FORWARDED)
goto dont_forward;
err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
if (err < 0) {
kfree_skb(skb);
return err;
}
if (!local) {
if (IPCB(skb)->opt.router_alert) {
if (ip_call_ra_chain(skb))
return 0;
} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
/* IGMPv1 (and broken IGMPv2 implementations sort of
* Cisco IOS <= 11.2(8)) do not put router alert
* option to IGMP packets destined to routable
* groups. It is very bad, because it means
* that we can forward NO IGMP messages.
*/
struct sock *mroute_sk;
mroute_sk = rcu_dereference(mrt->mroute_sk);
if (mroute_sk) {
nf_reset(skb);
raw_rcv(mroute_sk, skb);
return 0;
}
}
}
/* already under rcu_read_lock() */
cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
/*
* No usable cache entry
*/
if (cache == NULL) {
int vif;
if (local) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
ip_local_deliver(skb);
if (skb2 == NULL)
return -ENOBUFS;
skb = skb2;
}
read_lock(&mrt_lock);
vif = ipmr_find_vif(mrt, skb->dev);
if (vif >= 0) {
int err2 = ipmr_cache_unresolved(mrt, vif, skb);
read_unlock(&mrt_lock);
return err2;
}
read_unlock(&mrt_lock);
kfree_skb(skb);
return -ENODEV;
}
read_lock(&mrt_lock);
ip_mr_forward(net, mrt, skb, cache, local);
read_unlock(&mrt_lock);
if (local)
return ip_local_deliver(skb);
return 0;
dont_forward:
if (local)
return ip_local_deliver(skb);
kfree_skb(skb);
return 0;
}
#ifdef CONFIG_IP_PIMSM
/* called with rcu_read_lock() */
static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
unsigned int pimlen)
{
struct net_device *reg_dev = NULL;
struct iphdr *encap;
encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
/*
* Check that:
* a. packet is really sent to a multicast group
* b. packet is not a NULL-REGISTER
* c. packet is not truncated
*/
if (!ipv4_is_multicast(encap->daddr) ||
encap->tot_len == 0 ||
ntohs(encap->tot_len) + pimlen > skb->len)
return 1;
read_lock(&mrt_lock);
if (mrt->mroute_reg_vif_num >= 0)
reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
read_unlock(&mrt_lock);
if (reg_dev == NULL)
return 1;
skb->mac_header = skb->network_header;
skb_pull(skb, (u8 *)encap - skb->data);
skb_reset_network_header(skb);
skb->protocol = htons(ETH_P_IP);
skb->ip_summed = CHECKSUM_NONE;
skb->pkt_type = PACKET_HOST;
skb_tunnel_rx(skb, reg_dev);
netif_rx(skb);
return NET_RX_SUCCESS;
}
#endif
#ifdef CONFIG_IP_PIMSM_V1
/*
* Handle IGMP messages of PIMv1
*/
int pim_rcv_v1(struct sk_buff *skb)
{
struct igmphdr *pim;
struct net *net = dev_net(skb->dev);
struct mr_table *mrt;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
pim = igmp_hdr(skb);
if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
goto drop;
if (!mrt->mroute_do_pim ||
pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
goto drop;
if (__pim_rcv(mrt, skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
return 0;
}
#endif
#ifdef CONFIG_IP_PIMSM_V2
static int pim_rcv(struct sk_buff *skb)
{
struct pimreghdr *pim;
struct net *net = dev_net(skb->dev);
struct mr_table *mrt;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
pim = (struct pimreghdr *)skb_transport_header(skb);
if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
(pim->flags & PIM_NULL_REGISTER) ||
(ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
csum_fold(skb_checksum(skb, 0, skb->len, 0))))
goto drop;
if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
goto drop;
if (__pim_rcv(mrt, skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
return 0;
}
#endif
static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm)
{
int ct;
struct rtnexthop *nhp;
u8 *b = skb_tail_pointer(skb);
struct rtattr *mp_head;
/* If cache is unresolved, don't try to parse IIF and OIF */
if (c->mfc_parent >= MAXVIFS)
return -ENOENT;
if (VIF_EXISTS(mrt, c->mfc_parent))
RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].dev->ifindex);
mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
goto rtattr_failure;
nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
nhp->rtnh_flags = 0;
nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
nhp->rtnh_len = sizeof(*nhp);
}
}
mp_head->rta_type = RTA_MULTIPATH;
mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
rtm->rtm_type = RTN_MULTICAST;
return 1;
rtattr_failure:
nlmsg_trim(skb, b);
return -EMSGSIZE;
}
int ipmr_get_route(struct net *net,
struct sk_buff *skb, struct rtmsg *rtm, int nowait)
{
int err;
struct mr_table *mrt;
struct mfc_cache *cache;
struct rtable *rt = skb_rtable(skb);
mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
if (mrt == NULL)
return -ENOENT;
rcu_read_lock();
cache = ipmr_cache_find(mrt, rt->rt_src, rt->rt_dst);
if (cache == NULL) {
struct sk_buff *skb2;
struct iphdr *iph;
struct net_device *dev;
int vif = -1;
if (nowait) {
rcu_read_unlock();
return -EAGAIN;
}
dev = skb->dev;
read_lock(&mrt_lock);
if (dev)
vif = ipmr_find_vif(mrt, dev);
if (vif < 0) {
read_unlock(&mrt_lock);
rcu_read_unlock();
return -ENODEV;
}
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2) {
read_unlock(&mrt_lock);
rcu_read_unlock();
return -ENOMEM;
}
skb_push(skb2, sizeof(struct iphdr));
skb_reset_network_header(skb2);
iph = ip_hdr(skb2);
iph->ihl = sizeof(struct iphdr) >> 2;
iph->saddr = rt->rt_src;
iph->daddr = rt->rt_dst;
iph->version = 0;
err = ipmr_cache_unresolved(mrt, vif, skb2);
read_unlock(&mrt_lock);
rcu_read_unlock();
return err;
}
read_lock(&mrt_lock);
if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
cache->mfc_flags |= MFC_NOTIFY;
err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
read_unlock(&mrt_lock);
rcu_read_unlock();
return err;
}
static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
u32 pid, u32 seq, struct mfc_cache *c)
{
struct nlmsghdr *nlh;
struct rtmsg *rtm;
nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
if (nlh == NULL)
return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = RTNL_FAMILY_IPMR;
rtm->rtm_dst_len = 32;
rtm->rtm_src_len = 32;
rtm->rtm_tos = 0;
rtm->rtm_table = mrt->id;
NLA_PUT_U32(skb, RTA_TABLE, mrt->id);
rtm->rtm_type = RTN_MULTICAST;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_protocol = RTPROT_UNSPEC;
rtm->rtm_flags = 0;
NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);
NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);
if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
goto nla_put_failure;
return nlmsg_end(skb, nlh);
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct mr_table *mrt;
struct mfc_cache *mfc;
unsigned int t = 0, s_t;
unsigned int h = 0, s_h;
unsigned int e = 0, s_e;
s_t = cb->args[0];
s_h = cb->args[1];
s_e = cb->args[2];
rcu_read_lock();
ipmr_for_each_table(mrt, net) {
if (t < s_t)
goto next_table;
if (t > s_t)
s_h = 0;
for (h = s_h; h < MFC_LINES; h++) {
list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
if (e < s_e)
goto next_entry;
if (ipmr_fill_mroute(mrt, skb,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
mfc) < 0)
goto done;
next_entry:
e++;
}
e = s_e = 0;
}
s_h = 0;
next_table:
t++;
}
done:
rcu_read_unlock();
cb->args[2] = e;
cb->args[1] = h;
cb->args[0] = t;
return skb->len;
}
#ifdef CONFIG_PROC_FS
/*
* The /proc interfaces to multicast routing :
* /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
*/
struct ipmr_vif_iter {
struct seq_net_private p;
struct mr_table *mrt;
int ct;
};
static struct vif_device *ipmr_vif_seq_idx(struct net *net,
struct ipmr_vif_iter *iter,
loff_t pos)
{
struct mr_table *mrt = iter->mrt;
for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
if (!VIF_EXISTS(mrt, iter->ct))
continue;
if (pos-- == 0)
return &mrt->vif_table[iter->ct];
}
return NULL;
}
static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(mrt_lock)
{
struct ipmr_vif_iter *iter = seq->private;
struct net *net = seq_file_net(seq);
struct mr_table *mrt;
mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
if (mrt == NULL)
return ERR_PTR(-ENOENT);
iter->mrt = mrt;
read_lock(&mrt_lock);
return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
: SEQ_START_TOKEN;
}
static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ipmr_vif_iter *iter = seq->private;
struct net *net = seq_file_net(seq);
struct mr_table *mrt = iter->mrt;
++*pos;
if (v == SEQ_START_TOKEN)
return ipmr_vif_seq_idx(net, iter, 0);
while (++iter->ct < mrt->maxvif) {
if (!VIF_EXISTS(mrt, iter->ct))
continue;
return &mrt->vif_table[iter->ct];
}
return NULL;
}
static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
__releases(mrt_lock)
{
read_unlock(&mrt_lock);
}
static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
{
struct ipmr_vif_iter *iter = seq->private;
struct mr_table *mrt = iter->mrt;
if (v == SEQ_START_TOKEN) {
seq_puts(seq,
"Interface BytesIn PktsIn BytesOut PktsOut Flags Local Remote\n");
} else {
const struct vif_device *vif = v;
const char *name = vif->dev ? vif->dev->name : "none";
seq_printf(seq,
"%2Zd %-10s %8ld %7ld %8ld %7ld %05X %08X %08X\n",
vif - mrt->vif_table,
name, vif->bytes_in, vif->pkt_in,
vif->bytes_out, vif->pkt_out,
vif->flags, vif->local, vif->remote);
}
return 0;
}
static const struct seq_operations ipmr_vif_seq_ops = {
.start = ipmr_vif_seq_start,
.next = ipmr_vif_seq_next,
.stop = ipmr_vif_seq_stop,
.show = ipmr_vif_seq_show,
};
static int ipmr_vif_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &ipmr_vif_seq_ops,
sizeof(struct ipmr_vif_iter));
}
static const struct file_operations ipmr_vif_fops = {
.owner = THIS_MODULE,
.open = ipmr_vif_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
struct ipmr_mfc_iter {
struct seq_net_private p;
struct mr_table *mrt;
struct list_head *cache;
int ct;
};
static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
struct ipmr_mfc_iter *it, loff_t pos)
{
struct mr_table *mrt = it->mrt;
struct mfc_cache *mfc;
rcu_read_lock();
for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
it->cache = &mrt->mfc_cache_array[it->ct];
list_for_each_entry_rcu(mfc, it->cache, list)
if (pos-- == 0)
return mfc;
}
rcu_read_unlock();
spin_lock_bh(&mfc_unres_lock);
it->cache = &mrt->mfc_unres_queue;
list_for_each_entry(mfc, it->cache, list)
if (pos-- == 0)
return mfc;
spin_unlock_bh(&mfc_unres_lock);
it->cache = NULL;
return NULL;
}
static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
{
struct ipmr_mfc_iter *it = seq->private;
struct net *net = seq_file_net(seq);
struct mr_table *mrt;
mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
if (mrt == NULL)
return ERR_PTR(-ENOENT);
it->mrt = mrt;
it->cache = NULL;
it->ct = 0;
return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
: SEQ_START_TOKEN;
}
static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct mfc_cache *mfc = v;
struct ipmr_mfc_iter *it = seq->private;
struct net *net = seq_file_net(seq);
struct mr_table *mrt = it->mrt;
++*pos;
if (v == SEQ_START_TOKEN)
return ipmr_mfc_seq_idx(net, seq->private, 0);
if (mfc->list.next != it->cache)
return list_entry(mfc->list.next, struct mfc_cache, list);
if (it->cache == &mrt->mfc_unres_queue)
goto end_of_list;
BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
while (++it->ct < MFC_LINES) {
it->cache = &mrt->mfc_cache_array[it->ct];
if (list_empty(it->cache))
continue;
return list_first_entry(it->cache, struct mfc_cache, list);
}
/* exhausted cache_array, show unresolved */
rcu_read_unlock();
it->cache = &mrt->mfc_unres_queue;
it->ct = 0;
spin_lock_bh(&mfc_unres_lock);
if (!list_empty(it->cache))
return list_first_entry(it->cache, struct mfc_cache, list);
end_of_list:
spin_unlock_bh(&mfc_unres_lock);
it->cache = NULL;
return NULL;
}
static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
{
struct ipmr_mfc_iter *it = seq->private;
struct mr_table *mrt = it->mrt;
if (it->cache == &mrt->mfc_unres_queue)
spin_unlock_bh(&mfc_unres_lock);
else if (it->cache == &mrt->mfc_cache_array[it->ct])
rcu_read_unlock();
}
static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
{
int n;
if (v == SEQ_START_TOKEN) {
seq_puts(seq,
"Group Origin Iif Pkts Bytes Wrong Oifs\n");
} else {
const struct mfc_cache *mfc = v;
const struct ipmr_mfc_iter *it = seq->private;
const struct mr_table *mrt = it->mrt;
seq_printf(seq, "%08X %08X %-3hd",
(__force u32) mfc->mfc_mcastgrp,
(__force u32) mfc->mfc_origin,
mfc->mfc_parent);
if (it->cache != &mrt->mfc_unres_queue) {
seq_printf(seq, " %8lu %8lu %8lu",
mfc->mfc_un.res.pkt,
mfc->mfc_un.res.bytes,
mfc->mfc_un.res.wrong_if);
for (n = mfc->mfc_un.res.minvif;
n < mfc->mfc_un.res.maxvif; n++) {
if (VIF_EXISTS(mrt, n) &&
mfc->mfc_un.res.ttls[n] < 255)
seq_printf(seq,
" %2d:%-3d",
n, mfc->mfc_un.res.ttls[n]);
}
} else {
/* unresolved mfc_caches don't contain
* pkt, bytes and wrong_if values
*/
seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
}
seq_putc(seq, '\n');
}
return 0;
}
static const struct seq_operations ipmr_mfc_seq_ops = {
.start = ipmr_mfc_seq_start,
.next = ipmr_mfc_seq_next,
.stop = ipmr_mfc_seq_stop,
.show = ipmr_mfc_seq_show,
};
static int ipmr_mfc_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
sizeof(struct ipmr_mfc_iter));
}
static const struct file_operations ipmr_mfc_fops = {
.owner = THIS_MODULE,
.open = ipmr_mfc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif
#ifdef CONFIG_IP_PIMSM_V2
static const struct net_protocol pim_protocol = {
.handler = pim_rcv,
.netns_ok = 1,
};
#endif
/*
* Setup for IP multicast routing
*/
static int __net_init ipmr_net_init(struct net *net)
{
int err;
err = ipmr_rules_init(net);
if (err < 0)
goto fail;
#ifdef CONFIG_PROC_FS
err = -ENOMEM;
if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
goto proc_vif_fail;
if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
goto proc_cache_fail;
#endif
return 0;
#ifdef CONFIG_PROC_FS
proc_cache_fail:
proc_net_remove(net, "ip_mr_vif");
proc_vif_fail:
ipmr_rules_exit(net);
#endif
fail:
return err;
}
static void __net_exit ipmr_net_exit(struct net *net)
{
#ifdef CONFIG_PROC_FS
proc_net_remove(net, "ip_mr_cache");
proc_net_remove(net, "ip_mr_vif");
#endif
ipmr_rules_exit(net);
}
static struct pernet_operations ipmr_net_ops = {
.init = ipmr_net_init,
.exit = ipmr_net_exit,
};
int __init ip_mr_init(void)
{
int err;
mrt_cachep = kmem_cache_create("ip_mrt_cache",
sizeof(struct mfc_cache),
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
NULL);
if (!mrt_cachep)
return -ENOMEM;
err = register_pernet_subsys(&ipmr_net_ops);
if (err)
goto reg_pernet_fail;
err = register_netdevice_notifier(&ip_mr_notifier);
if (err)
goto reg_notif_fail;
#ifdef CONFIG_IP_PIMSM_V2
if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
printk(KERN_ERR "ip_mr_init: can't add PIM protocol\n");
err = -EAGAIN;
goto add_proto_fail;
}
#endif
rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
return 0;
#ifdef CONFIG_IP_PIMSM_V2
add_proto_fail:
unregister_netdevice_notifier(&ip_mr_notifier);
#endif
reg_notif_fail:
unregister_pernet_subsys(&ipmr_net_ops);
reg_pernet_fail:
kmem_cache_destroy(mrt_cachep);
return err;
}
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