[PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Sricharan Ramabadhran]

On the remote side, when QRTR socket is removed, af_qrtr will call
qrtr_port_remove() which broadcasts the DEL_CLIENT packet to all neighbours
including local NS. NS upon receiving the DEL_CLIENT packet, will remove
the lookups associated with the node:port and broadcasts the DEL_SERVER
packet.

But on the host side, due to the arrival of the DEL_CLIENT packet, the NS
would've already deleted the server belonging to that port. So when the
remote's NS again broadcasts the DEL_SERVER for that port, it throws below
error message on the host:

"failed while handling packet from 2:-2"

So fix this error by not broadcasting the DEL_SERVER packet when the
DEL_CLIENT packet gets processed."

Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Signed-off-by: Ram Kumar Dharuman <quic_ramd@quicinc.com>
---
[v2] Fixed comments from Manivannan and Jakub Kicinski
Note: Functionally tested on 5.4 and compile tested on 6.3 TOT

 net/qrtr/ns.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
index 722936f..0f25a38 100644
--- a/net/qrtr/ns.c
+++ b/net/qrtr/ns.c
@@ -274,7 +274,7 @@ static struct qrtr_server *server_add(unsigned int service,
 	return NULL;
 }
 
-static int server_del(struct qrtr_node *node, unsigned int port)
+static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
 {
 	struct qrtr_lookup *lookup;
 	struct qrtr_server *srv;
@@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
 	radix_tree_delete(&node->servers, port);
 
 	/* Broadcast the removal of local servers */
-	if (srv->node == qrtr_ns.local_node)
+	if (srv->node == qrtr_ns.local_node && bcast)
 		service_announce_del(&qrtr_ns.bcast_sq, srv);
 
 	/* Announce the service's disappearance to observers */
@@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
 		}
 		slot = radix_tree_iter_resume(slot, &iter);
 		rcu_read_unlock();
-		server_del(node, srv->port);
+		server_del(node, srv->port, true);
 		rcu_read_lock();
 	}
 	rcu_read_unlock();
@@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
 		kfree(lookup);
 	}
 
-	/* Remove the server belonging to this port */
+	/* Remove the server belonging to this port but don't broadcast
+	 * DEL_SERVER. Neighbours would've already removed the server belonging
+	 * to this port due to the DEL_CLIENT broadcast from qrtr_port_remove().
+	 */
 	node = node_get(node_id);
 	if (node)
-		server_del(node, port);
+		server_del(node, port, false);
 
 	/* Advertise the removal of this client to all local servers */
 	local_node = node_get(qrtr_ns.local_node);
@@ -567,7 +570,7 @@ static int ctrl_cmd_del_server(struct sockaddr_qrtr *from,
 	if (!node)
 		return -ENOENT;
 
-	return server_del(node, port);
+	return server_del(node, port, true);
 }
 
 static int ctrl_cmd_new_lookup(struct sockaddr_qrtr *from,
-- 
2.7.4

Re: [PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Manivannan Sadhasivam]

On Fri, Mar 31, 2023 at 01:18:57PM +0530, Sricharan Ramabadhran wrote:
> On the remote side, when QRTR socket is removed, af_qrtr will call
> qrtr_port_remove() which broadcasts the DEL_CLIENT packet to all neighbours
> including local NS. NS upon receiving the DEL_CLIENT packet, will remove
> the lookups associated with the node:port and broadcasts the DEL_SERVER
> packet.
> 
> But on the host side, due to the arrival of the DEL_CLIENT packet, the NS
> would've already deleted the server belonging to that port. So when the
> remote's NS again broadcasts the DEL_SERVER for that port, it throws below
> error message on the host:
> 
> "failed while handling packet from 2:-2"
> 
> So fix this error by not broadcasting the DEL_SERVER packet when the
> DEL_CLIENT packet gets processed."
> 
> Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Signed-off-by: Ram Kumar Dharuman <quic_ramd@quicinc.com>
> ---
> [v2] Fixed comments from Manivannan and Jakub Kicinski
> Note: Functionally tested on 5.4 and compile tested on 6.3 TOT
> 
>  net/qrtr/ns.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
> index 722936f..0f25a38 100644
> --- a/net/qrtr/ns.c
> +++ b/net/qrtr/ns.c
> @@ -274,7 +274,7 @@ static struct qrtr_server *server_add(unsigned int service,
>  	return NULL;
>  }
>  
> -static int server_del(struct qrtr_node *node, unsigned int port)
> +static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
>  {
>  	struct qrtr_lookup *lookup;
>  	struct qrtr_server *srv;
> @@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
>  	radix_tree_delete(&node->servers, port);
>  
>  	/* Broadcast the removal of local servers */
> -	if (srv->node == qrtr_ns.local_node)
> +	if (srv->node == qrtr_ns.local_node && bcast)
>  		service_announce_del(&qrtr_ns.bcast_sq, srv);
>  
>  	/* Announce the service's disappearance to observers */
> @@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
>  		}
>  		slot = radix_tree_iter_resume(slot, &iter);
>  		rcu_read_unlock();
> -		server_del(node, srv->port);
> +		server_del(node, srv->port, true);
>  		rcu_read_lock();
>  	}
>  	rcu_read_unlock();
> @@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
>  		kfree(lookup);
>  	}
>  
> -	/* Remove the server belonging to this port */
> +	/* Remove the server belonging to this port but don't broadcast

This is still not as per the multi line comment style perferred in kernel.
Please read: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting

- Mani

> +	 * DEL_SERVER. Neighbours would've already removed the server belonging
> +	 * to this port due to the DEL_CLIENT broadcast from qrtr_port_remove().
> +	 */
>  	node = node_get(node_id);
>  	if (node)
> -		server_del(node, port);
> +		server_del(node, port, false);
>  
>  	/* Advertise the removal of this client to all local servers */
>  	local_node = node_get(qrtr_ns.local_node);
> @@ -567,7 +570,7 @@ static int ctrl_cmd_del_server(struct sockaddr_qrtr *from,
>  	if (!node)
>  		return -ENOENT;
>  
> -	return server_del(node, port);
> +	return server_del(node, port, true);
>  }
>  
>  static int ctrl_cmd_new_lookup(struct sockaddr_qrtr *from,
> -- 
> 2.7.4
> 

-- 
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Re: [PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Sricharan Ramabadhran]

<..>

>>   
>> -static int server_del(struct qrtr_node *node, unsigned int port)
>> +static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
>>   {
>>   	struct qrtr_lookup *lookup;
>>   	struct qrtr_server *srv;
>> @@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
>>   	radix_tree_delete(&node->servers, port);
>>   
>>   	/* Broadcast the removal of local servers */
>> -	if (srv->node == qrtr_ns.local_node)
>> +	if (srv->node == qrtr_ns.local_node && bcast)
>>   		service_announce_del(&qrtr_ns.bcast_sq, srv);
>>   
>>   	/* Announce the service's disappearance to observers */
>> @@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
>>   		}
>>   		slot = radix_tree_iter_resume(slot, &iter);
>>   		rcu_read_unlock();
>> -		server_del(node, srv->port);
>> +		server_del(node, srv->port, true);
>>   		rcu_read_lock();
>>   	}
>>   	rcu_read_unlock();
>> @@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
>>   		kfree(lookup);
>>   	}
>>   
>> -	/* Remove the server belonging to this port */
>> +	/* Remove the server belonging to this port but don't broadcast
> 
> This is still not as per the multi line comment style perferred in kernel.
> Please read: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
> 

  Ho, i had it like first style and checkpatch cribbed. Then changed it
  as per the second style for net/ format. You mean we should stick to
  1 st style ?

Regards,
  Sricharan

Re: [PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Manivannan Sadhasivam]

On Fri, Mar 31, 2023 at 02:02:04PM +0530, Sricharan Ramabadhran wrote:
> <..>
> 
> > > -static int server_del(struct qrtr_node *node, unsigned int port)
> > > +static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
> > >   {
> > >   	struct qrtr_lookup *lookup;
> > >   	struct qrtr_server *srv;
> > > @@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
> > >   	radix_tree_delete(&node->servers, port);
> > >   	/* Broadcast the removal of local servers */
> > > -	if (srv->node == qrtr_ns.local_node)
> > > +	if (srv->node == qrtr_ns.local_node && bcast)
> > >   		service_announce_del(&qrtr_ns.bcast_sq, srv);
> > >   	/* Announce the service's disappearance to observers */
> > > @@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
> > >   		}
> > >   		slot = radix_tree_iter_resume(slot, &iter);
> > >   		rcu_read_unlock();
> > > -		server_del(node, srv->port);
> > > +		server_del(node, srv->port, true);
> > >   		rcu_read_lock();
> > >   	}
> > >   	rcu_read_unlock();
> > > @@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
> > >   		kfree(lookup);
> > >   	}
> > > -	/* Remove the server belonging to this port */
> > > +	/* Remove the server belonging to this port but don't broadcast
> > 
> > This is still not as per the multi line comment style perferred in kernel.
> > Please read: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
> > 
> 
>  Ho, i had it like first style and checkpatch cribbed. Then changed it
>  as per the second style for net/ format. You mean we should stick to
>  1 st style ?
> 

Oops, sorry I forgot the fact that the networking code uses a different style.
Ignore my above comment.

- Mani

> Regards,
>  Sricharan

-- 
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Re: [PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Simon Horman]

On Fri, Mar 31, 2023 at 02:02:04PM +0530, Sricharan Ramabadhran wrote:
> <..>
> 
> > > -static int server_del(struct qrtr_node *node, unsigned int port)
> > > +static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
> > >   {
> > >   	struct qrtr_lookup *lookup;
> > >   	struct qrtr_server *srv;
> > > @@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
> > >   	radix_tree_delete(&node->servers, port);
> > >   	/* Broadcast the removal of local servers */
> > > -	if (srv->node == qrtr_ns.local_node)
> > > +	if (srv->node == qrtr_ns.local_node && bcast)
> > >   		service_announce_del(&qrtr_ns.bcast_sq, srv);
> > >   	/* Announce the service's disappearance to observers */
> > > @@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
> > >   		}
> > >   		slot = radix_tree_iter_resume(slot, &iter);
> > >   		rcu_read_unlock();
> > > -		server_del(node, srv->port);
> > > +		server_del(node, srv->port, true);
> > >   		rcu_read_lock();
> > >   	}
> > >   	rcu_read_unlock();
> > > @@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
> > >   		kfree(lookup);
> > >   	}
> > > -	/* Remove the server belonging to this port */
> > > +	/* Remove the server belonging to this port but don't broadcast
> > 
> > This is still not as per the multi line comment style perferred in kernel.
> > Please read: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
> > 
> 
>  Ho, i had it like first style and checkpatch cribbed. Then changed it
>  as per the second style for net/ format. You mean we should stick to
>  1 st style ?

I think that what you have matches the preferred style for net/ code,
and thus is correct for this patch.

https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html#multi-line-comments

Re: [PATCH V2] net: qrtr: Do not do DEL_SERVER broadcast after DEL_CLIENT

[Manivannan Sadhasivam]

On Fri, Mar 31, 2023 at 01:18:57PM +0530, Sricharan Ramabadhran wrote:
> On the remote side, when QRTR socket is removed, af_qrtr will call
> qrtr_port_remove() which broadcasts the DEL_CLIENT packet to all neighbours
> including local NS. NS upon receiving the DEL_CLIENT packet, will remove
> the lookups associated with the node:port and broadcasts the DEL_SERVER
> packet.
> 
> But on the host side, due to the arrival of the DEL_CLIENT packet, the NS
> would've already deleted the server belonging to that port. So when the
> remote's NS again broadcasts the DEL_SERVER for that port, it throws below
> error message on the host:
> 
> "failed while handling packet from 2:-2"
> 
> So fix this error by not broadcasting the DEL_SERVER packet when the
> DEL_CLIENT packet gets processed."
> 
> Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> Signed-off-by: Ram Kumar Dharuman <quic_ramd@quicinc.com>

Sender's Signed-off-by should come last. With that fixed,

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> ---
> [v2] Fixed comments from Manivannan and Jakub Kicinski
> Note: Functionally tested on 5.4 and compile tested on 6.3 TOT
> 
>  net/qrtr/ns.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
> index 722936f..0f25a38 100644
> --- a/net/qrtr/ns.c
> +++ b/net/qrtr/ns.c
> @@ -274,7 +274,7 @@ static struct qrtr_server *server_add(unsigned int service,
>  	return NULL;
>  }
>  
> -static int server_del(struct qrtr_node *node, unsigned int port)
> +static int server_del(struct qrtr_node *node, unsigned int port, bool bcast)
>  {
>  	struct qrtr_lookup *lookup;
>  	struct qrtr_server *srv;
> @@ -287,7 +287,7 @@ static int server_del(struct qrtr_node *node, unsigned int port)
>  	radix_tree_delete(&node->servers, port);
>  
>  	/* Broadcast the removal of local servers */
> -	if (srv->node == qrtr_ns.local_node)
> +	if (srv->node == qrtr_ns.local_node && bcast)
>  		service_announce_del(&qrtr_ns.bcast_sq, srv);
>  
>  	/* Announce the service's disappearance to observers */
> @@ -373,7 +373,7 @@ static int ctrl_cmd_bye(struct sockaddr_qrtr *from)
>  		}
>  		slot = radix_tree_iter_resume(slot, &iter);
>  		rcu_read_unlock();
> -		server_del(node, srv->port);
> +		server_del(node, srv->port, true);
>  		rcu_read_lock();
>  	}
>  	rcu_read_unlock();
> @@ -459,10 +459,13 @@ static int ctrl_cmd_del_client(struct sockaddr_qrtr *from,
>  		kfree(lookup);
>  	}
>  
> -	/* Remove the server belonging to this port */
> +	/* Remove the server belonging to this port but don't broadcast
> +	 * DEL_SERVER. Neighbours would've already removed the server belonging
> +	 * to this port due to the DEL_CLIENT broadcast from qrtr_port_remove().
> +	 */
>  	node = node_get(node_id);
>  	if (node)
> -		server_del(node, port);
> +		server_del(node, port, false);
>  
>  	/* Advertise the removal of this client to all local servers */
>  	local_node = node_get(qrtr_ns.local_node);
> @@ -567,7 +570,7 @@ static int ctrl_cmd_del_server(struct sockaddr_qrtr *from,
>  	if (!node)
>  		return -ENOENT;
>  
> -	return server_del(node, port);
> +	return server_del(node, port, true);
>  }
>  
>  static int ctrl_cmd_new_lookup(struct sockaddr_qrtr *from,
> -- 
> 2.7.4
> 

-- 
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