net: llc: remove init_net check

PATCH In review Alexander Aring 2 participants 3 messages Nov 30, 2017 – Dec 13, 2017

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Networking Network drivers LLC (802.2)

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Alexander Aring

author

2017-11-30 19:46 UTC #0 lore raw

PATCH 1/1 net: llc: remove init_net check

Commit e730c15519d09 ("[NET]: Make packet reception network namespace safe") added several init_net compares to protocols with unknown net namespace support. The idea was as users started using the different protocols they would test and enable them.
In our use-case we generate STP enabled Linux bridges in different namespaces. The bridges are connected via veth interfaces. This patch makes STP work in such a setup.

Signed-off-by Alexander Aring <[email protected]>

---
 net/llc/llc_input.c | 4 ----
 1 file changed, 4 deletions(-)

net/llc/llc_input.c +0 -4

index 82cb93f66b9b..09b530d90610 100644
@@ -14,7 +14,6 @@
 #include <linux/netdevice.h>
 #include <linux/slab.h>
 #include <linux/export.h>
-#include <net/net_namespace.h>
 #include <net/llc.h>
 #include <net/llc_pdu.h>
 #include <net/llc_sap.h>

@@ -162,9 +161,6 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev,
 	void (*sta_handler)(struct sk_buff *skb);
 	void (*sap_handler)(struct llc_sap *sap, struct sk_buff *skb);
 
-	if (!net_eq(dev_net(dev), &init_net))
-		goto drop;
-
 	/*
 	 * When the interface is in promisc. mode, drop all the crap that it
 	 * receives, do not try to analyse it.

Signature · 1 line

2.11.0

Eric Dumazet

2017-11-30 20:12 UTC #1 lore raw

Quoted 35 lines · Alexander Aring

Commit e730c15519d09 ("[NET]: Make packet reception network namespace safe") added several init_net compares to protocols with unknown net namespace support. The idea was as users started using the different
protocols they would test and enable them.
In our use-case we generate STP enabled Linux bridges in different namespaces. The bridges are connected via veth interfaces. This patch makes STP work in such a setup.
Signed-off-by Alexander Aring <[email protected]>
---
net/llc/llc_input.c | 4 ----
 1 file changed, 4 deletions(-)
net/llc/llc_input.c +0 -1
index 82cb93f66b9b..09b530d90610 100644
@@ -14,7 +14,6 @@
  #include <linux/netdevice.h>
  #include <linux/slab.h>
  #include <linux/export.h>
-#include <net/net_namespace.h>
  #include <net/llc.h>
  #include <net/llc_pdu.h>
  #include <net/llc_sap.h>
@@ -162,9 +161,6 @@ int llc_rcv(struct sk_buff *skb, struct
 net_device *dev,
  	void (*sta_handler)(struct sk_buff *skb);
void (*sap_handler)(struct llc_sap *sap, struct sk_buff *skb);
net/llc/llc_input.c +0 -3
-	if (!net_eq(dev_net(dev), &init_net))
-		goto drop;
-

Quoted 4 lines

/*
* When the interface is in promisc. mode, drop all the crap that it
* receives, do not try to analyse it.

Well, we use different netns for isolation.

You need more changes than simply removing this check, I guess.

__llc_sap_find() would need a per netns list, or proper netns checks.

Alexander Aring

author

2017-12-13 19:09 UTC #2 lore raw

Hi,

Quoted 1 line · Eric Dumazet

...

Quoted 8 lines

Well, we use different netns for isolation.
You need more changes than simply removing this check, I guess.
__llc_sap_find() would need a per netns list, or proper netns checks.

I looked deeper into this and try to move the list from global resource to net struct and use per netns init... it's just a very big task and I try to do my best there...
Also I figured out that the bridge code use a lot of global resources which should also be per netns as well and I am worried that you can actually move bridges to different namespaces. :-/

Just a status update - when I have time I try to do that... just need time and it's not simple to do this change in llc.

- Alex