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ipmr.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 *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 = ®_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();
if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
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);
if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
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 inline void ipmr_cache_free(struct mfc_cache *c)
{
kmem_cache_free(mrt_cachep, c);
}
/* 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 && dev->ip_ptr == 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;
}
if ((in_dev = __in_dev_get_rtnl(dev)) == NULL) {
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;
}
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(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 == NULL)
return NULL;
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 == NULL)
return NULL;
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;
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;
}
if (mrt->mroute_sk == NULL) {
kfree_skb(skb);
return -EINVAL;
}
/*
* Deliver to mrouted
*/
ret = sock_queue_rcv_skb(mrt->mroute_sk, skb);
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;
}