net: Loopback ifindex is constant now
As pointed out, there are places, that access net->loopback_dev->ifindex
and after ifindex generation is made per-net this value becomes constant
equals 1. So go ahead and introduce the LOOPBACK_IFINDEX constant and use
it where appropriate.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index e2a06fd..4a075ba 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -197,6 +197,7 @@
if (err)
goto out_free_netdev;
+ BUG_ON(dev->ifindex != LOOPBACK_IFINDEX);
net->loopback_dev = dev;
return 0;
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 6dc3db3..97e4419 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -105,6 +105,13 @@
struct sock *diag_nlsk;
};
+/*
+ * ifindex generation is per-net namespace, and loopback is
+ * always the 1st device in ns (see net_dev_init), thus any
+ * loopback device should get ifindex 1
+ */
+
+#define LOOPBACK_IFINDEX 1
#include <linux/seq_file_net.h>
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 85a3604..c855e8d 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -961,7 +961,7 @@
.saddr = oldflp->saddr,
.flowidn_scope = RT_SCOPE_UNIVERSE,
.flowidn_mark = oldflp->flowidn_mark,
- .flowidn_iif = init_net.loopback_dev->ifindex,
+ .flowidn_iif = LOOPBACK_IFINDEX,
.flowidn_oif = oldflp->flowidn_oif,
};
struct dn_route *rt = NULL;
@@ -979,7 +979,7 @@
"dn_route_output_slow: dst=%04x src=%04x mark=%d"
" iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
le16_to_cpu(oldflp->saddr),
- oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
+ oldflp->flowidn_mark, LOOPBACK_IFINDEX,
oldflp->flowidn_oif);
/* If we have an output interface, verify its a DECnet device */
@@ -1042,7 +1042,7 @@
if (!fld.daddr)
goto out;
}
- fld.flowidn_oif = init_net.loopback_dev->ifindex;
+ fld.flowidn_oif = LOOPBACK_IFINDEX;
res.type = RTN_LOCAL;
goto make_route;
}
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c43ae3f..7f073a3 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -218,7 +218,7 @@
scope = RT_SCOPE_UNIVERSE;
if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
fl4.flowi4_oif = 0;
- fl4.flowi4_iif = net->loopback_dev->ifindex;
+ fl4.flowi4_iif = LOOPBACK_IFINDEX;
fl4.daddr = ip_hdr(skb)->saddr;
fl4.saddr = 0;
fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 8eec8f4..3a57570 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1798,7 +1798,7 @@
.flowi4_oif = (rt_is_output_route(rt) ?
skb->dev->ifindex : 0),
.flowi4_iif = (rt_is_output_route(rt) ?
- net->loopback_dev->ifindex :
+ LOOPBACK_IFINDEX :
skb->dev->ifindex),
.flowi4_mark = skb->mark,
};
diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c
index 31371be..c301300 100644
--- a/net/ipv4/netfilter/ipt_rpfilter.c
+++ b/net/ipv4/netfilter/ipt_rpfilter.c
@@ -85,7 +85,7 @@
return ipv4_is_local_multicast(iph->daddr) ^ invert;
flow.flowi4_iif = 0;
} else {
- flow.flowi4_iif = dev_net(par->in)->loopback_dev->ifindex;
+ flow.flowi4_iif = LOOPBACK_IFINDEX;
}
flow.daddr = iph->saddr;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 21ad369..c581373 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1619,7 +1619,7 @@
if (res.type == RTN_LOCAL) {
err = fib_validate_source(skb, saddr, daddr, tos,
- net->loopback_dev->ifindex,
+ LOOPBACK_IFINDEX,
dev, in_dev, &itag);
if (err < 0)
goto martian_source_keep_err;
@@ -1895,7 +1895,7 @@
orig_oif = fl4->flowi4_oif;
- fl4->flowi4_iif = net->loopback_dev->ifindex;
+ fl4->flowi4_iif = LOOPBACK_IFINDEX;
fl4->flowi4_tos = tos & IPTOS_RT_MASK;
fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
@@ -1984,7 +1984,7 @@
if (!fl4->daddr)
fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
dev_out = net->loopback_dev;
- fl4->flowi4_oif = net->loopback_dev->ifindex;
+ fl4->flowi4_oif = LOOPBACK_IFINDEX;
res.type = RTN_LOCAL;
flags |= RTCF_LOCAL;
goto make_route;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 8e80fd2..0ddf2d1 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -965,7 +965,7 @@
{
int flags = 0;
- fl6->flowi6_iif = net->loopback_dev->ifindex;
+ fl6->flowi6_iif = LOOPBACK_IFINDEX;
if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
flags |= RT6_LOOKUP_F_IFACE;