[net-next,0/2] net: qrtr: Few qrtr fixes

Patch #1 fixes a race condition between qrtr driver and ns opening and
sending data to a control port.

Patch #2 address the issue with legacy targets sending the SSR
notifications using DEL_PROC control message.

Sricharan Ramabadhran (1):
  net: qrtr: Add support for processing DEL_PROC type control message

Vignesh Viswanathan (1):
  net: qrtr: Prevent stale ports from sending

 include/uapi/linux/qrtr.h |  1 +
 net/qrtr/af_qrtr.c        | 75 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

Hi Bjorn,

On 9/1/2023 7:41 PM, Bjorn Andersson wrote:
> On Fri, Sep 01, 2023 at 03:50:20PM +0530, Sricharan Ramabadhran wrote:
>> From: Vignesh Viswanathan <quic_viswanat@quicinc.com>
>>
>> If qrtr and some other process try to bind to the QMI Control port at
> 
> It's unclear to me which "qrtr" is being referred here, could it be
> "qrtr-ns", if so could we express that as "the name server".
> 

  yes, its name-space server. Will put it explicitly.

> We only allow one bind on the qrtr control port, so could it be that
> "QMI Control port" refer to the control socket in the userspace QC[CS]I
> libraries, if so that's just any random socket sending out a control
> message.
> 
> Can we please rephrase this problem description to make the chain of
> events clear?
> 

   In this case we are talking about a client connecting/sending to QRTR
   socket and the 'NS' doing a qrtr_bind during its init. There is
   possibility that a client tries to send to the 'NS' before  processing
   the ENETRESET. In the case of a NEW_SERVER control message will
   reach the 'NS' and be forwarded to the firmware. The client will then
   process the ENETRESET closing and re-opening the socket which triggers
   a DEL_SERVER and then a second NEW_SERVER. This scenario will give an
   unnecessary disconnect to the clients on the firmware who were able to
   initialize on the first NEW_SERVER.

   Also about the patch #2, i guess QRTR_BYE/DEL_PROC should also be
   broadcasted, right now we are only listening on DEL_PROC sent by
   legacy kernels like SDX modems. Without that modem SSR feature is
   broken on IPQ + SDX targets.

>> the same time, NEW_SERVER might come before ENETRESET is given to the
>> socket. This might cause a socket down/up when ENETRESET is received as
>> per the protocol and this triggers a DEL_SERVER and a second NEW_SERVER.
>>
>> In order to prevent such messages from stale sockets being sent, check
>> if ENETRESET has been set on the socket and drop the packet.
>>
>> Signed-off-by: Chris Lew <quic_clew@quicinc.com>
>> Signed-off-by: Vignesh Viswanathan <quic_viswanat@quicinc.com>
> 
> The first person to certify the patch's origin, must be the author, and
> when you pick the patch to send it you need to add your s-o-b.
> 
> So please fix the author, and add your s-o-b.
> 

  ok sure, will fix.

> 
> Let's add Chris to the recipients list as well.
> 

  ok.

>> ---
>>   net/qrtr/af_qrtr.c | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c
>> index 41ece61..26197a0 100644
>> --- a/net/qrtr/af_qrtr.c
>> +++ b/net/qrtr/af_qrtr.c
>> @@ -851,6 +851,7 @@ static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb,
>>   {
>>   	struct qrtr_sock *ipc;
>>   	struct qrtr_cb *cb;
>> +	struct sock *sk = skb->sk;
>>   
>>   	ipc = qrtr_port_lookup(to->sq_port);
>>   	if (!ipc || &ipc->sk == skb->sk) { /* do not send to self */
>> @@ -860,6 +861,15 @@ static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb,
>>   		return -ENODEV;
>>   	}
>>   
>> +	/* Keep resetting NETRESET until socket is closed */
>> +	if (sk && sk->sk_err == ENETRESET) {
>> +		sk->sk_err = ENETRESET;
> 
> Isn't this line unnecessary?
> 

  yup, will be removed in V2.

Regards,
  Sricharan

Hi Simon,

On 9/1/2023 7:49 PM, Simon Horman wrote:
> On Fri, Sep 01, 2023 at 03:50:19PM +0530, Sricharan Ramabadhran wrote:
>> Patch #1 fixes a race condition between qrtr driver and ns opening and
>> sending data to a control port.
>>
>> Patch #2 address the issue with legacy targets sending the SSR
>> notifications using DEL_PROC control message.
> 
> Hi Sricharan,
> 
> if these are fixes then they should be targeted at 'net' rather than
> 'net-next', and consideration should be given to supplying Fixes tags.
> 
  There is as such no existing feature broken without these 2 patches
  today. Then they might qualify as preparatory patches for adding
  some features.

> If these are not fixes, then please don't describe them as such.
> In this case targeting net-next is correct, but it is currently closed,
> as per the form letter below.
> 
   Sure, then in that case looks like it belongs to 'net-next' and will
   post V2 once the net-next is opened again.

> In either case please consider:
> 
> * Arranging local variables for new Networking code in
>    reverse xmas tree order - longest line to shortest
> 
> * Avoiding introducing new Sparse warnings
> 
>   ok.

> ## Form letter - net-next-closed
> 
> The merge window for v6.6 has begun and therefore net-next is closed
> for new drivers, features, code refactoring and optimizations.
> We are currently accepting bug fixes only.
> 
> Please repost when net-next reopens after Sept 11th.
> 

  ok, sure.

Regards,
  Sricharan