2021-10-21 13:56:28

by Zhang Changzhong

[permalink] [raw]
Subject: [PATCH net 0/3] can: j1939: fix some standard conformance problems

This patchset fixes 3 standard conformance problems in the j1939 stack.

Zhang Changzhong (3):
can: j1939: j1939_tp_cmd_recv(): ignore abort message in the BAM
transport
can: j1939: j1939_can_recv(): ignore messages with invalid source
address
can: j1939: j1939_tp_cmd_recv(): check the dst address of TP.CM_BAM

net/can/j1939/main.c | 4 ++++
net/can/j1939/transport.c | 5 +++++
2 files changed, 9 insertions(+)

--
2.9.5


2021-10-21 13:56:48

by Zhang Changzhong

[permalink] [raw]
Subject: [PATCH net 3/3] can: j1939: j1939_tp_cmd_recv(): check the dst address of TP.CM_BAM

The TP.CM_BAM message must be sent to the global address [1], so add a
check to drop TP.CM_BAM sent to a non-global address.

Without this patch, the receiver will treat the following packets as
normal RTS/CTS tranport:
18EC0102#20090002FF002301
18EB0102#0100000000000000
18EB0102#020000FFFFFFFFFF

[1] SAE-J1939-82 2015 A.3.3 Row 1.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <[email protected]>
---
net/can/j1939/transport.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 2efa606..93ec0c3 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -2019,6 +2019,8 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
extd = J1939_ETP;
fallthrough;
case J1939_TP_CMD_BAM:
+ if (!j1939_cb_is_broadcast(skcb))
+ return;
fallthrough;
case J1939_TP_CMD_RTS:
if (skcb->addr.type != extd)
--
2.9.5

2021-10-21 13:57:02

by Zhang Changzhong

[permalink] [raw]
Subject: [PATCH net 1/3] can: j1939: j1939_tp_cmd_recv(): ignore abort message in the BAM transport

This patch prevents BAM transport from being closed by receiving abort
message, as specified in SAE-J1939-82 2015 (A.3.3 Row 4).

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <[email protected]>
---
net/can/j1939/transport.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index bb5c4b8..2efa606 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -2081,6 +2081,9 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
break;

case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
+ if (j1939_cb_is_broadcast(skcb))
+ return;
+
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_abort(priv, skb, true);

--
2.9.5

2021-10-21 13:58:42

by Zhang Changzhong

[permalink] [raw]
Subject: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
send TP.CM_CTS to the global address, so we can add a check in
j1939_can_recv() to drop messages with invalid source address.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <[email protected]>
---
net/can/j1939/main.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index 08c8606..4f1e4bb 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -75,6 +75,10 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
/* set default message type */
skcb->addr.type = J1939_TP;
+ if (!j1939_address_is_valid(skcb->addr.sa))
+ /* ignore messages whose sa is broadcast address */
+ goto done;
+
if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
/* Type 1: with destination address */
skcb->addr.da = skcb->addr.pgn;
--
2.9.5

2021-10-22 09:56:57

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 1/3] can: j1939: j1939_tp_cmd_recv(): ignore abort message in the BAM transport

On Thu, Oct 21, 2021 at 10:04:15PM +0800, Zhang Changzhong wrote:
> This patch prevents BAM transport from being closed by receiving abort
> message, as specified in SAE-J1939-82 2015 (A.3.3 Row 4).
>
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Signed-off-by: Zhang Changzhong <[email protected]>

Acked-by: Oleksij Rempel <[email protected]>

Thank you!

> ---
> net/can/j1939/transport.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
> index bb5c4b8..2efa606 100644
> --- a/net/can/j1939/transport.c
> +++ b/net/can/j1939/transport.c
> @@ -2081,6 +2081,9 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
> break;
>
> case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
> + if (j1939_cb_is_broadcast(skcb))
> + return;
> +
> if (j1939_tp_im_transmitter(skcb))
> j1939_xtp_rx_abort(priv, skb, true);
>
> --
> 2.9.5
>
>

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

2021-10-22 10:25:24

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

On Thu, Oct 21, 2021 at 10:04:16PM +0800, Zhang Changzhong wrote:
> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
> send TP.CM_CTS to the global address, so we can add a check in
> j1939_can_recv() to drop messages with invalid source address.
>
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Signed-off-by: Zhang Changzhong <[email protected]>

NACK. This will break Address Claiming, where first message is SA == 0xff

> ---
> net/can/j1939/main.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
> index 08c8606..4f1e4bb 100644
> --- a/net/can/j1939/main.c
> +++ b/net/can/j1939/main.c
> @@ -75,6 +75,10 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
> skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
> /* set default message type */
> skcb->addr.type = J1939_TP;
> + if (!j1939_address_is_valid(skcb->addr.sa))
> + /* ignore messages whose sa is broadcast address */
> + goto done;
> +
> if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
> /* Type 1: with destination address */
> skcb->addr.da = skcb->addr.pgn;
> --
> 2.9.5
>
>
>

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

2021-10-22 10:33:47

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 3/3] can: j1939: j1939_tp_cmd_recv(): check the dst address of TP.CM_BAM

On Thu, Oct 21, 2021 at 10:04:17PM +0800, Zhang Changzhong wrote:
> The TP.CM_BAM message must be sent to the global address [1], so add a
> check to drop TP.CM_BAM sent to a non-global address.
>
> Without this patch, the receiver will treat the following packets as
> normal RTS/CTS tranport:
> 18EC0102#20090002FF002301
> 18EB0102#0100000000000000
> 18EB0102#020000FFFFFFFFFF
>
> [1] SAE-J1939-82 2015 A.3.3 Row 1.
>
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Signed-off-by: Zhang Changzhong <[email protected]>
> ---
> net/can/j1939/transport.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
> index 2efa606..93ec0c3 100644
> --- a/net/can/j1939/transport.c
> +++ b/net/can/j1939/transport.c
> @@ -2019,6 +2019,8 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
> extd = J1939_ETP;
> fallthrough;
> case J1939_TP_CMD_BAM:
> + if (!j1939_cb_is_broadcast(skcb))

Please add here netdev_err_once("with some message"), we need to know if
some MCU makes bad things.

> + return;
> fallthrough;
> case J1939_TP_CMD_RTS:
> if (skcb->addr.type != extd)
> --
> 2.9.5
>
>

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

2021-10-22 10:35:14

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 1/3] can: j1939: j1939_tp_cmd_recv(): ignore abort message in the BAM transport

On Thu, Oct 21, 2021 at 10:04:15PM +0800, Zhang Changzhong wrote:
> This patch prevents BAM transport from being closed by receiving abort
> message, as specified in SAE-J1939-82 2015 (A.3.3 Row 4).
>
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Signed-off-by: Zhang Changzhong <[email protected]>
> ---
> net/can/j1939/transport.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
> index bb5c4b8..2efa606 100644
> --- a/net/can/j1939/transport.c
> +++ b/net/can/j1939/transport.c
> @@ -2081,6 +2081,9 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
> break;
>
> case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
> + if (j1939_cb_is_broadcast(skcb))

Please add here netdev_err_once("Abort to broadcast, ignoring!"), or
something like this.

> + return;
> +
> if (j1939_tp_im_transmitter(skcb))
> j1939_xtp_rx_abort(priv, skb, true);
>
> --
> 2.9.5
>
>

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

2021-10-25 07:33:39

by Zhang Changzhong

[permalink] [raw]
Subject: Re: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

On 2021/10/22 18:23, Oleksij Rempel wrote:
> On Thu, Oct 21, 2021 at 10:04:16PM +0800, Zhang Changzhong wrote:
>> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
>> send TP.CM_CTS to the global address, so we can add a check in
>> j1939_can_recv() to drop messages with invalid source address.
>>
>> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
>> Signed-off-by: Zhang Changzhong <[email protected]>
>
> NACK. This will break Address Claiming, where first message is SA == 0xff

I know that 0xfe can be used as a source address, but which message has a source
address of 0xff?

According to SAE-J1939-81 2017 4.2.2.8:

The network address 255, also known as the Global address, is permitted in the
Destination Address field of the SAE J1939 message identifier but never in the
Source Address field.

>
>> ---
>> net/can/j1939/main.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
>> index 08c8606..4f1e4bb 100644
>> --- a/net/can/j1939/main.c
>> +++ b/net/can/j1939/main.c
>> @@ -75,6 +75,10 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
>> skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
>> /* set default message type */
>> skcb->addr.type = J1939_TP;
>> + if (!j1939_address_is_valid(skcb->addr.sa))
>> + /* ignore messages whose sa is broadcast address */
>> + goto done;
>> +
>> if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
>> /* Type 1: with destination address */
>> skcb->addr.da = skcb->addr.pgn;
>> --
>> 2.9.5
>>
>>
>>
>

2021-10-25 10:48:02

by Zhang Changzhong

[permalink] [raw]
Subject: Re: [PATCH net 3/3] can: j1939: j1939_tp_cmd_recv(): check the dst address of TP.CM_BAM

On 2021/10/22 18:28, Oleksij Rempel wrote:
> On Thu, Oct 21, 2021 at 10:04:17PM +0800, Zhang Changzhong wrote:
>> The TP.CM_BAM message must be sent to the global address [1], so add a
>> check to drop TP.CM_BAM sent to a non-global address.
>>
>> Without this patch, the receiver will treat the following packets as
>> normal RTS/CTS tranport:
>> 18EC0102#20090002FF002301
>> 18EB0102#0100000000000000
>> 18EB0102#020000FFFFFFFFFF
>>
>> [1] SAE-J1939-82 2015 A.3.3 Row 1.
>>
>> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
>> Signed-off-by: Zhang Changzhong <[email protected]>
>> ---
>> net/can/j1939/transport.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
>> index 2efa606..93ec0c3 100644
>> --- a/net/can/j1939/transport.c
>> +++ b/net/can/j1939/transport.c
>> @@ -2019,6 +2019,8 @@ static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
>> extd = J1939_ETP;
>> fallthrough;
>> case J1939_TP_CMD_BAM:
>> + if (!j1939_cb_is_broadcast(skcb))
>
> Please add here netdev_err_once("with some message"), we need to know if
> some MCU makes bad things.

Ok, will do.

The current patch breaks ETP functionality as the J1939_ETP_CMD_RTS fallthrough
to J1939_TP_CMD_BAM, this will also be fixed in v2.

>
>> + return;
>> fallthrough;
>> case J1939_TP_CMD_RTS:
>> if (skcb->addr.type != extd)
>> --
>> 2.9.5
>>
>>
>

2021-10-28 06:54:00

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

Hi,

On Mon, Oct 25, 2021 at 03:30:57PM +0800, Zhang Changzhong wrote:
> On 2021/10/22 18:23, Oleksij Rempel wrote:
> > On Thu, Oct 21, 2021 at 10:04:16PM +0800, Zhang Changzhong wrote:
> >> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
> >> send TP.CM_CTS to the global address, so we can add a check in
> >> j1939_can_recv() to drop messages with invalid source address.
> >>
> >> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> >> Signed-off-by: Zhang Changzhong <[email protected]>
> >
> > NACK. This will break Address Claiming, where first message is SA == 0xff
>
> I know that 0xfe can be used as a source address, but which message has a source
> address of 0xff?
>
> According to SAE-J1939-81 2017 4.2.2.8:
>
> The network address 255, also known as the Global address, is permitted in the
> Destination Address field of the SAE J1939 message identifier but never in the
> Source Address field.

You are right. Thx!

Are you using any testing frameworks?
Can you please take a look here:
https://github.com/linux-can/can-tests/tree/master/j1939

We are using this scripts for regression testing of some know bugs.

>
> >
> >> ---
> >> net/can/j1939/main.c | 4 ++++
> >> 1 file changed, 4 insertions(+)
> >>
> >> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
> >> index 08c8606..4f1e4bb 100644
> >> --- a/net/can/j1939/main.c
> >> +++ b/net/can/j1939/main.c
> >> @@ -75,6 +75,10 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
> >> skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
> >> /* set default message type */
> >> skcb->addr.type = J1939_TP;
> >> + if (!j1939_address_is_valid(skcb->addr.sa))
> >> + /* ignore messages whose sa is broadcast address */
> >> + goto done;

Please add some warning once message here. We wont to know if something bad
is happening on the bus.

> >> +
> >> if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
> >> /* Type 1: with destination address */
> >> skcb->addr.da = skcb->addr.pgn;
> >> --
> >> 2.9.5
> >>
> >>
> >>
> >
>
>

Regards,
Oleksij
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

2021-10-28 07:35:40

by Zhang Changzhong

[permalink] [raw]
Subject: Re: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

On 2021/10/28 14:51, Oleksij Rempel wrote:
> Hi,
>
> On Mon, Oct 25, 2021 at 03:30:57PM +0800, Zhang Changzhong wrote:
>> On 2021/10/22 18:23, Oleksij Rempel wrote:
>>> On Thu, Oct 21, 2021 at 10:04:16PM +0800, Zhang Changzhong wrote:
>>>> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
>>>> send TP.CM_CTS to the global address, so we can add a check in
>>>> j1939_can_recv() to drop messages with invalid source address.
>>>>
>>>> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
>>>> Signed-off-by: Zhang Changzhong <[email protected]>
>>>
>>> NACK. This will break Address Claiming, where first message is SA == 0xff
>>
>> I know that 0xfe can be used as a source address, but which message has a source
>> address of 0xff?
>>
>> According to SAE-J1939-81 2017 4.2.2.8:
>>
>> The network address 255, also known as the Global address, is permitted in the
>> Destination Address field of the SAE J1939 message identifier but never in the
>> Source Address field.
>
> You are right. Thx!
>
> Are you using any testing frameworks?
> Can you please take a look here:
> https://github.com/linux-can/can-tests/tree/master/j1939
>
> We are using this scripts for regression testing of some know bugs.

Great! I'll run these scripts before posting patches.

>
>>
>>>
>>>> ---
>>>> net/can/j1939/main.c | 4 ++++
>>>> 1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
>>>> index 08c8606..4f1e4bb 100644
>>>> --- a/net/can/j1939/main.c
>>>> +++ b/net/can/j1939/main.c
>>>> @@ -75,6 +75,10 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
>>>> skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
>>>> /* set default message type */
>>>> skcb->addr.type = J1939_TP;
>>>> + if (!j1939_address_is_valid(skcb->addr.sa))
>>>> + /* ignore messages whose sa is broadcast address */
>>>> + goto done;
>
> Please add some warning once message here. We wont to know if something bad
> is happening on the bus.

Will do. Thanks for your suggestions.

Regards,
Changzhong

>
>>>> +
>>>> if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
>>>> /* Type 1: with destination address */
>>>> skcb->addr.da = skcb->addr.pgn;
>>>> --
>>>> 2.9.5
>>>>
>>>>
>>>>
>>>
>>
>>
>
> Regards,
> Oleksij
>

2021-10-28 08:33:22

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [PATCH net 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

On Thu, Oct 28, 2021 at 03:33:21PM +0800, Zhang Changzhong wrote:
> On 2021/10/28 14:51, Oleksij Rempel wrote:
> > Hi,
> >
> > On Mon, Oct 25, 2021 at 03:30:57PM +0800, Zhang Changzhong wrote:
> >> On 2021/10/22 18:23, Oleksij Rempel wrote:
> >>> On Thu, Oct 21, 2021 at 10:04:16PM +0800, Zhang Changzhong wrote:
> >>>> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
> >>>> send TP.CM_CTS to the global address, so we can add a check in
> >>>> j1939_can_recv() to drop messages with invalid source address.
> >>>>
> >>>> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> >>>> Signed-off-by: Zhang Changzhong <[email protected]>
> >>>
> >>> NACK. This will break Address Claiming, where first message is SA == 0xff
> >>
> >> I know that 0xfe can be used as a source address, but which message has a source
> >> address of 0xff?
> >>
> >> According to SAE-J1939-81 2017 4.2.2.8:
> >>
> >> The network address 255, also known as the Global address, is permitted in the
> >> Destination Address field of the SAE J1939 message identifier but never in the
> >> Source Address field.
> >
> > You are right. Thx!
> >
> > Are you using any testing frameworks?
> > Can you please take a look here:
> > https://github.com/linux-can/can-tests/tree/master/j1939
> >
> > We are using this scripts for regression testing of some know bugs.
>
> Great! I'll run these scripts before posting patches.

You are welcome to extend this tests :)

Regards,
Oleksij
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |