[PATCH 1/1] Dynamically allocate the loopback device
dlezcano at fr.ibm.com
dlezcano at fr.ibm.com
Fri Aug 24 08:36:43 PDT 2007
From: Daniel Lezcano <dlezcano at fr.ibm.com>
Doing this makes loopback.c a better example of how to do a
simple network device, and it removes the special case
single static allocation of a struct net_device, hopefully
making maintenance easier.
Applies against net-2.6.24
Tested on i386, x86_64
Compiled on ia64, sparc
Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano at fr.ibm.com>
Acked-By: Kirill Korotaev <dev at sw.ru>
Acked-by: Benjamin Thery <benjamin.thery at bull.net>
---
drivers/net/loopback.c | 63 +++++++++++++++++++++++---------------
include/linux/netdevice.h | 2 +-
net/core/dst.c | 8 ++--
net/decnet/dn_dev.c | 4 +-
net/decnet/dn_route.c | 14 ++++----
net/ipv4/devinet.c | 6 ++--
net/ipv4/ipconfig.c | 6 ++--
net/ipv4/ipvs/ip_vs_core.c | 2 +-
net/ipv4/route.c | 18 +++++-----
net/ipv4/xfrm4_policy.c | 2 +-
net/ipv6/addrconf.c | 15 +++++---
net/ipv6/ip6_input.c | 2 +-
net/ipv6/netfilter/ip6t_REJECT.c | 2 +-
net/ipv6/route.c | 15 +++-----
net/ipv6/xfrm6_policy.c | 2 +-
net/xfrm/xfrm_policy.c | 4 +-
16 files changed, 89 insertions(+), 76 deletions(-)
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 5106c23..3642aff 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -199,44 +199,57 @@ static const struct ethtool_ops loopback_ethtool_ops = {
.get_rx_csum = always_on,
};
-/*
- * The loopback device is special. There is only one instance and
- * it is statically allocated. Don't do this for other devices.
- */
-struct net_device loopback_dev = {
- .name = "lo",
- .get_stats = &get_stats,
- .mtu = (16 * 1024) + 20 + 20 + 12,
- .hard_start_xmit = loopback_xmit,
- .hard_header = eth_header,
- .hard_header_cache = eth_header_cache,
- .header_cache_update = eth_header_cache_update,
- .hard_header_len = ETH_HLEN, /* 14 */
- .addr_len = ETH_ALEN, /* 6 */
- .tx_queue_len = 0,
- .type = ARPHRD_LOOPBACK, /* 0x0001*/
- .rebuild_header = eth_rebuild_header,
- .flags = IFF_LOOPBACK,
- .features = NETIF_F_SG | NETIF_F_FRAGLIST
+static void loopback_setup(struct net_device *dev)
+{
+ dev->get_stats = &get_stats;
+ dev->mtu = (16 * 1024) + 20 + 20 + 12;
+ dev->hard_start_xmit = loopback_xmit;
+ dev->hard_header = eth_header;
+ dev->hard_header_cache = eth_header_cache;
+ dev->header_cache_update = eth_header_cache_update;
+ dev->hard_header_len = ETH_HLEN; /* 14 */
+ dev->addr_len = ETH_ALEN; /* 6 */
+ dev->tx_queue_len = 0;
+ dev->type = ARPHRD_LOOPBACK; /* 0x0001*/
+ dev->rebuild_header = eth_rebuild_header;
+ dev->flags = IFF_LOOPBACK;
+ dev->features = NETIF_F_SG | NETIF_F_FRAGLIST
#ifdef LOOPBACK_TSO
| NETIF_F_TSO
#endif
| NETIF_F_NO_CSUM | NETIF_F_HIGHDMA
- | NETIF_F_LLTX,
- .ethtool_ops = &loopback_ethtool_ops,
-};
+ | NETIF_F_LLTX;
+ dev->ethtool_ops = &loopback_ethtool_ops;
+}
/* Setup and register the loopback device. */
static int __init loopback_init(void)
{
- int err = register_netdev(&loopback_dev);
+ struct net_device *dev;
+ int err;
+
+ err = -ENOMEM;
+ dev = alloc_netdev(0, "lo", loopback_setup);
+ if (!dev)
+ goto out;
+
+ err = register_netdev(dev);
+ if (err)
+ goto out_free_netdev;
+ err = 0;
+ loopback_dev = dev;
+
+out:
if (err)
panic("loopback: Failed to register netdevice: %d\n", err);
-
return err;
+out_free_netdev:
+ free_netdev(dev);
+ goto out;
};
-module_init(loopback_init);
+fs_initcall(loopback_init);
+struct net_device *loopback_dev;
EXPORT_SYMBOL(loopback_dev);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8d12f02..7cd0641 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -680,7 +680,7 @@ struct packet_type {
#include <linux/interrupt.h>
#include <linux/notifier.h>
-extern struct net_device loopback_dev; /* The loopback */
+extern struct net_device *loopback_dev; /* The loopback */
extern struct list_head dev_base_head; /* All devices */
extern rwlock_t dev_base_lock; /* Device list lock */
diff --git a/net/core/dst.c b/net/core/dst.c
index c6a0587..ad8549e 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -236,13 +236,13 @@ static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
if (!unregister) {
dst->input = dst->output = dst_discard;
} else {
- dst->dev = &loopback_dev;
- dev_hold(&loopback_dev);
+ dst->dev = loopback_dev;
+ dev_hold(dst->dev);
dev_put(dev);
if (dst->neighbour && dst->neighbour->dev == dev) {
- dst->neighbour->dev = &loopback_dev;
+ dst->neighbour->dev = loopback_dev;
dev_put(dev);
- dev_hold(&loopback_dev);
+ dev_hold(dst->neighbour->dev);
}
}
}
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index fa6604f..9fea83e 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -868,10 +868,10 @@ last_chance:
rv = dn_dev_get_first(dev, addr);
read_unlock(&dev_base_lock);
dev_put(dev);
- if (rv == 0 || dev == &loopback_dev)
+ if (rv == 0 || dev == loopback_dev)
return rv;
}
- dev = &loopback_dev;
+ dev = loopback_dev;
dev_hold(dev);
goto last_chance;
}
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index a4a6209..8c04ebc 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -883,7 +883,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
.scope = RT_SCOPE_UNIVERSE,
} },
.mark = oldflp->mark,
- .iif = loopback_dev.ifindex,
+ .iif = loopback_dev->ifindex,
.oif = oldflp->oif };
struct dn_route *rt = NULL;
struct net_device *dev_out = NULL, *dev;
@@ -900,7 +900,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
"dn_route_output_slow: dst=%04x src=%04x mark=%d"
" iif=%d oif=%d\n", dn_ntohs(oldflp->fld_dst),
dn_ntohs(oldflp->fld_src),
- oldflp->mark, loopback_dev.ifindex, oldflp->oif);
+ oldflp->mark, loopback_dev->ifindex, oldflp->oif);
/* If we have an output interface, verify its a DECnet device */
if (oldflp->oif) {
@@ -953,7 +953,7 @@ source_ok:
err = -EADDRNOTAVAIL;
if (dev_out)
dev_put(dev_out);
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
dev_hold(dev_out);
if (!fl.fld_dst) {
fl.fld_dst =
@@ -962,7 +962,7 @@ source_ok:
if (!fl.fld_dst)
goto out;
}
- fl.oif = loopback_dev.ifindex;
+ fl.oif = loopback_dev->ifindex;
res.type = RTN_LOCAL;
goto make_route;
}
@@ -1008,7 +1008,7 @@ source_ok:
if (dev_out)
dev_put(dev_out);
if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
res.type = RTN_LOCAL;
} else {
dev_out = neigh->dev;
@@ -1029,7 +1029,7 @@ source_ok:
/* Possible improvement - check all devices for local addr */
if (dn_dev_islocal(dev_out, fl.fld_dst)) {
dev_put(dev_out);
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
dev_hold(dev_out);
res.type = RTN_LOCAL;
goto select_source;
@@ -1065,7 +1065,7 @@ select_source:
fl.fld_src = fl.fld_dst;
if (dev_out)
dev_put(dev_out);
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
dev_hold(dev_out);
fl.oif = dev_out->ifindex;
if (res.fi)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 5b77bda..808f529 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -203,7 +203,7 @@ static void inetdev_destroy(struct in_device *in_dev)
ASSERT_RTNL();
dev = in_dev->dev;
- if (dev == &loopback_dev)
+ if (dev == loopback_dev)
return;
in_dev->dead = 1;
@@ -1058,7 +1058,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
in_dev = inetdev_init(dev);
if (!in_dev)
return notifier_from_errno(-ENOMEM);
- if (dev == &loopback_dev) {
+ if (dev == loopback_dev) {
IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
}
@@ -1074,7 +1074,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
case NETDEV_UP:
if (dev->mtu < 68)
break;
- if (dev == &loopback_dev) {
+ if (dev == loopback_dev) {
struct in_ifaddr *ifa;
if ((ifa = inet_alloc_ifa()) != NULL) {
ifa->ifa_local =
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index c5b2470..3ec7690 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -189,11 +189,11 @@ static int __init ic_open_devs(void)
rtnl_lock();
/* bring loopback device up first */
- if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0)
- printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name);
+ if (dev_change_flags(loopback_dev, loopback_dev->flags | IFF_UP) < 0)
+ printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev->name);
for_each_netdev(dev) {
- if (dev == &loopback_dev)
+ if (dev == loopback_dev)
continue;
if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
(!(dev->flags & IFF_LOOPBACK) &&
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index f005a2f..7450326 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -961,7 +961,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff **pskb,
* ... don't know why 1st test DOES NOT include 2nd (?)
*/
if (unlikely(skb->pkt_type != PACKET_HOST
- || skb->dev == &loopback_dev || skb->sk)) {
+ || skb->dev == loopback_dev || skb->sk)) {
IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
skb->pkt_type,
ip_hdr(skb)->protocol,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c7ca94b..4f13385 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1404,8 +1404,8 @@ static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
{
struct rtable *rt = (struct rtable *) dst;
struct in_device *idev = rt->idev;
- if (dev != &loopback_dev && idev && idev->dev == dev) {
- struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+ if (dev != loopback_dev && idev && idev->dev == dev) {
+ struct in_device *loopback_idev = in_dev_get(loopback_dev);
if (loopback_idev) {
rt->idev = loopback_idev;
in_dev_put(idev);
@@ -1557,7 +1557,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
#endif
rth->rt_iif =
rth->fl.iif = dev->ifindex;
- rth->u.dst.dev = &loopback_dev;
+ rth->u.dst.dev = loopback_dev;
dev_hold(rth->u.dst.dev);
rth->idev = in_dev_get(rth->u.dst.dev);
rth->fl.oif = 0;
@@ -1814,7 +1814,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
if (res.type == RTN_LOCAL) {
int result;
result = fib_validate_source(saddr, daddr, tos,
- loopback_dev.ifindex,
+ loopback_dev->ifindex,
dev, &spec_dst, &itag);
if (result < 0)
goto martian_source;
@@ -1881,7 +1881,7 @@ local_input:
#endif
rth->rt_iif =
rth->fl.iif = dev->ifindex;
- rth->u.dst.dev = &loopback_dev;
+ rth->u.dst.dev = loopback_dev;
dev_hold(rth->u.dst.dev);
rth->idev = in_dev_get(rth->u.dst.dev);
rth->rt_gateway = daddr;
@@ -2151,7 +2151,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
RT_SCOPE_UNIVERSE),
} },
.mark = oldflp->mark,
- .iif = loopback_dev.ifindex,
+ .iif = loopback_dev->ifindex,
.oif = oldflp->oif };
struct fib_result res;
unsigned flags = 0;
@@ -2245,9 +2245,9 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
if (dev_out)
dev_put(dev_out);
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
dev_hold(dev_out);
- fl.oif = loopback_dev.ifindex;
+ fl.oif = loopback_dev->ifindex;
res.type = RTN_LOCAL;
flags |= RTCF_LOCAL;
goto make_route;
@@ -2292,7 +2292,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
fl.fl4_src = fl.fl4_dst;
if (dev_out)
dev_put(dev_out);
- dev_out = &loopback_dev;
+ dev_out = loopback_dev;
dev_hold(dev_out);
fl.oif = dev_out->ifindex;
if (res.fi)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 4ff8ed3..29ab3de 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -306,7 +306,7 @@ static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
xdst = (struct xfrm_dst *)dst;
if (xdst->u.rt.idev->dev == dev) {
- struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+ struct in_device *loopback_idev = in_dev_get(loopback_dev);
BUG_ON(!loopback_idev);
do {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 91ef3be..d806f89 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2399,7 +2399,7 @@ static int addrconf_ifdown(struct net_device *dev, int how)
ASSERT_RTNL();
- if (dev == &loopback_dev && how == 1)
+ if (dev == loopback_dev && how == 1)
how = 0;
rt6_ifdown(dev);
@@ -4203,16 +4203,19 @@ int __init addrconf_init(void)
* device and it being up should be removed.
*/
rtnl_lock();
- if (!ipv6_add_dev(&loopback_dev))
+ if (!ipv6_add_dev(loopback_dev))
err = -ENOMEM;
rtnl_unlock();
if (err)
return err;
- ip6_null_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+ ip6_null_entry.u.dst.dev = loopback_dev;
+ ip6_null_entry.rt6i_idev = in6_dev_get(loopback_dev);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
- ip6_prohibit_entry.rt6i_idev = in6_dev_get(&loopback_dev);
- ip6_blk_hole_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+ ip6_prohibit_entry.u.dst.dev = loopback_dev;
+ ip6_prohibit_entry.rt6i_idev = in6_dev_get(loopback_dev);
+ ip6_blk_hole_entry.u.dst.dev = loopback_dev;
+ ip6_blk_hole_entry.rt6i_idev = in6_dev_get(loopback_dev);
#endif
register_netdevice_notifier(&ipv6_dev_notf);
@@ -4267,7 +4270,7 @@ void __exit addrconf_cleanup(void)
continue;
addrconf_ifdown(dev, 1);
}
- addrconf_ifdown(&loopback_dev, 2);
+ addrconf_ifdown(loopback_dev, 2);
/*
* Check hash table.
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 30a5cb1..15d7910 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -86,7 +86,7 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
*
* BTW, when we send a packet for our own local address on a
* non-loopback interface (e.g. ethX), it is being delivered
- * via the loopback interface (lo) here; skb->dev = &loopback_dev.
+ * via the loopback interface (lo) here; skb->dev = loopback_dev.
* It, however, should be considered as if it is being
* arrived via the sending interface (ethX), because of the
* nature of scoping architecture. --yoshfuji
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index 2f487cd..5086053 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -167,7 +167,7 @@ static inline void
send_unreach(struct sk_buff *skb_in, unsigned char code, unsigned int hooknum)
{
if (hooknum == NF_IP6_LOCAL_OUT && skb_in->dev == NULL)
- skb_in->dev = &loopback_dev;
+ skb_in->dev = loopback_dev;
icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0, NULL);
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 55ea80f..3f5c65f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -137,7 +137,6 @@ struct rt6_info ip6_null_entry = {
.dst = {
.__refcnt = ATOMIC_INIT(1),
.__use = 1,
- .dev = &loopback_dev,
.obsolete = -1,
.error = -ENETUNREACH,
.metrics = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -163,7 +162,6 @@ struct rt6_info ip6_prohibit_entry = {
.dst = {
.__refcnt = ATOMIC_INIT(1),
.__use = 1,
- .dev = &loopback_dev,
.obsolete = -1,
.error = -EACCES,
.metrics = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -183,7 +181,6 @@ struct rt6_info ip6_blk_hole_entry = {
.dst = {
.__refcnt = ATOMIC_INIT(1),
.__use = 1,
- .dev = &loopback_dev,
.obsolete = -1,
.error = -EINVAL,
.metrics = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -223,8 +220,8 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
struct rt6_info *rt = (struct rt6_info *)dst;
struct inet6_dev *idev = rt->rt6i_idev;
- if (dev != &loopback_dev && idev != NULL && idev->dev == dev) {
- struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+ if (dev != loopback_dev && idev != NULL && idev->dev == dev) {
+ struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
if (loopback_idev != NULL) {
rt->rt6i_idev = loopback_idev;
in6_dev_put(idev);
@@ -1187,12 +1184,12 @@ int ip6_route_add(struct fib6_config *cfg)
if ((cfg->fc_flags & RTF_REJECT) ||
(dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) {
/* hold loopback dev/idev if we haven't done so. */
- if (dev != &loopback_dev) {
+ if (dev != loopback_dev) {
if (dev) {
dev_put(dev);
in6_dev_put(idev);
}
- dev = &loopback_dev;
+ dev = loopback_dev;
dev_hold(dev);
idev = in6_dev_get(dev);
if (!idev) {
@@ -1896,13 +1893,13 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
if (rt == NULL)
return ERR_PTR(-ENOMEM);
- dev_hold(&loopback_dev);
+ dev_hold(loopback_dev);
in6_dev_hold(idev);
rt->u.dst.flags = DST_HOST;
rt->u.dst.input = ip6_input;
rt->u.dst.output = ip6_output;
- rt->rt6i_dev = &loopback_dev;
+ rt->rt6i_dev = loopback_dev;
rt->rt6i_idev = idev;
rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 3ec0c47..cc07216 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -375,7 +375,7 @@ static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
xdst = (struct xfrm_dst *)dst;
if (xdst->u.rt6.rt6i_idev->dev == dev) {
- struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+ struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
BUG_ON(!loopback_idev);
do {
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c7b2503..ca37eec 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1947,8 +1947,8 @@ static int stale_bundle(struct dst_entry *dst)
void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
{
while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
- dst->dev = &loopback_dev;
- dev_hold(&loopback_dev);
+ dst->dev = loopback_dev;
+ dev_hold(dst->dev);
dev_put(dev);
}
}
--
1.5.2.4
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