* [PATCH] net:ipv4: Packet is not forwarded when ingress interface is not configured with bc_forwarding
@ 2021-03-01 0:53 Henry Shen
2021-03-01 0:53 ` [PATCH] net:ipv4: Packet is not forwarded if bc_forwarding not configured on ingress interface Henry Shen
0 siblings, 1 reply; 3+ messages in thread
From: Henry Shen @ 2021-03-01 0:53 UTC (permalink / raw)
To: davem
Cc: yoshfuji, dsahern, kuba, netdev, linux-kernel, chris.packham, Henry Shen
Allow an IPv4 packet with a destination address of broadcast to be forwarded
if the ingress interface is not configured with bc_forwarding but the egress
interface is. This is inline with Cisco's implementation of directed
broadcast.
Henry Shen (1):
net:ipv4: Fix pakcet not forwarded when ingress interface is not
configured with bc_forwarding
net/ipv4/route.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--
2.30.1
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] net:ipv4: Packet is not forwarded if bc_forwarding not configured on ingress interface
2021-03-01 0:53 [PATCH] net:ipv4: Packet is not forwarded when ingress interface is not configured with bc_forwarding Henry Shen
@ 2021-03-01 0:53 ` Henry Shen
2021-03-01 3:20 ` David Ahern
0 siblings, 1 reply; 3+ messages in thread
From: Henry Shen @ 2021-03-01 0:53 UTC (permalink / raw)
To: davem
Cc: yoshfuji, dsahern, kuba, netdev, linux-kernel, chris.packham, Henry Shen
When an IPv4 packet with a destination address of broadcast is received
on an ingress interface, it will not be forwarded out of the egress
interface if the ingress interface is not configured with bc_forwarding
but the egress interface is. If both the ingress and egress interfaces
are configured with bc_forwarding, the packet can be forwarded
successfully.
This patch is to be inline with Cisco's implementation that packet can be
forwarded if ingress interface is NOT configured with bc_forwarding,
but egress interface is.
Signed-off-by: Henry Shen <henry.shen@alliedtelesis.co.nz>
---
net/ipv4/route.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 02d81d79deeb..d082b199b8c6 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2101,6 +2101,8 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
struct rtable *rth;
struct flowi4 fl4;
bool do_cache = true;
+ struct in_device *out_dev;
+ int rcv_local = 0;
/* IP on this device is disabled. */
@@ -2176,12 +2178,20 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
}
if (res->type == RTN_BROADCAST) {
+ out_dev = in_dev_get(FIB_RES_DEV(*res));
+ if (!out_dev)
+ goto out;
+
+ if (in_dev == out_dev)
+ rcv_local = 1;
+ in_dev_put(out_dev);
if (IN_DEV_BFORWARD(in_dev))
goto make_route;
/* not do cache if bc_forwarding is enabled */
if (IPV4_DEVCONF_ALL(net, BC_FORWARDING))
do_cache = false;
- goto brd_input;
+ if (rcv_local)
+ goto brd_input;
}
if (res->type == RTN_LOCAL) {
@@ -2197,7 +2207,8 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
goto no_route;
}
if (res->type != RTN_UNICAST)
- goto martian_destination;
+ if (res->type != RTN_BROADCAST)
+ goto martian_destination;
make_route:
err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
--
2.30.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] net:ipv4: Packet is not forwarded if bc_forwarding not configured on ingress interface
2021-03-01 0:53 ` [PATCH] net:ipv4: Packet is not forwarded if bc_forwarding not configured on ingress interface Henry Shen
@ 2021-03-01 3:20 ` David Ahern
0 siblings, 0 replies; 3+ messages in thread
From: David Ahern @ 2021-03-01 3:20 UTC (permalink / raw)
To: Henry Shen, davem
Cc: yoshfuji, dsahern, kuba, netdev, linux-kernel, chris.packham
On 2/28/21 5:53 PM, Henry Shen wrote:
> When an IPv4 packet with a destination address of broadcast is received
> on an ingress interface, it will not be forwarded out of the egress
> interface if the ingress interface is not configured with bc_forwarding
> but the egress interface is. If both the ingress and egress interfaces
> are configured with bc_forwarding, the packet can be forwarded
> successfully.
>
> This patch is to be inline with Cisco's implementation that packet can be
> forwarded if ingress interface is NOT configured with bc_forwarding,
> but egress interface is.
>
In Linux, forwarding decisions are made based on the ingress device, not
the egress device.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-03-01 3:21 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-01 0:53 [PATCH] net:ipv4: Packet is not forwarded when ingress interface is not configured with bc_forwarding Henry Shen
2021-03-01 0:53 ` [PATCH] net:ipv4: Packet is not forwarded if bc_forwarding not configured on ingress interface Henry Shen
2021-03-01 3:20 ` David Ahern
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).