* [PATCH v3 net] r8169: work around RTL8125 UDP hw bug
@ 2021-01-28 7:44 Heiner Kallweit
2021-01-28 18:36 ` Willem de Bruijn
0 siblings, 1 reply; 4+ messages in thread
From: Heiner Kallweit @ 2021-01-28 7:44 UTC (permalink / raw)
To: Jakub Kicinski, David Miller, Realtek linux nic maintainers
Cc: netdev, Willem de Bruijn
It was reported that on RTL8125 network breaks under heavy UDP load,
e.g. torrent traffic ([0], from comment 27). Realtek confirmed a hw bug
and provided me with a test version of the r8125 driver including a
workaround. Tests confirmed that the workaround fixes the issue.
I modified the original version of the workaround to meet mainline
code style.
[0] https://bugzilla.kernel.org/show_bug.cgi?id=209839
v2:
- rebased to net
v3:
- make rtl_skb_is_udp() more robust and use skb_header_pointer()
to access the ip(v6) header
Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125")
Tested-by: xplo <xplo.bn@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
drivers/net/ethernet/realtek/r8169_main.c | 70 +++++++++++++++++++++--
1 file changed, 64 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index a569abe7f..457fa1404 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -28,6 +28,7 @@
#include <linux/bitfield.h>
#include <linux/prefetch.h>
#include <linux/ipv6.h>
+#include <linux/ptp_classify.h>
#include <net/ip6_checksum.h>
#include "r8169.h"
@@ -4046,17 +4047,70 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
return -EIO;
}
-static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp)
+static bool rtl_skb_is_udp(struct sk_buff *skb)
{
+ int no = skb_network_offset(skb);
+ struct ipv6hdr *i6h, _i6h;
+ struct iphdr *ih, _ih;
+
+ switch (vlan_get_protocol(skb)) {
+ case htons(ETH_P_IP):
+ ih = skb_header_pointer(skb, no, sizeof(_ih), &_ih);
+ return ih && ih->protocol == IPPROTO_UDP;
+ case htons(ETH_P_IPV6):
+ i6h = skb_header_pointer(skb, no, sizeof(_i6h), &_i6h);
+ return i6h && i6h->nexthdr == IPPROTO_UDP;
+ default:
+ return false;
+ }
+}
+
+#define RTL_MIN_PATCH_LEN 47
+#define PTP_GEN_PORT 320
+
+/* see rtl8125_get_patch_pad_len() in r8125 vendor driver */
+static unsigned int rtl8125_quirk_udp_padto(struct rtl8169_private *tp,
+ struct sk_buff *skb)
+{
+ unsigned int padto = 0, len = skb->len;
+
+ if (rtl_is_8125(tp) && len < 128 + RTL_MIN_PATCH_LEN &&
+ rtl_skb_is_udp(skb) && skb_transport_header_was_set(skb)) {
+ unsigned int trans_data_len = skb_tail_pointer(skb) -
+ skb_transport_header(skb);
+
+ if (trans_data_len > 3 && trans_data_len < RTL_MIN_PATCH_LEN) {
+ u16 dest = ntohs(udp_hdr(skb)->dest);
+
+ if (dest == PTP_EV_PORT || dest == PTP_GEN_PORT)
+ padto = len + RTL_MIN_PATCH_LEN - trans_data_len;
+ }
+
+ if (trans_data_len < UDP_HLEN)
+ padto = max(padto, len + UDP_HLEN - trans_data_len);
+ }
+
+ return padto;
+}
+
+static unsigned int rtl_quirk_packet_padto(struct rtl8169_private *tp,
+ struct sk_buff *skb)
+{
+ unsigned int padto;
+
+ padto = rtl8125_quirk_udp_padto(tp, skb);
+
switch (tp->mac_version) {
case RTL_GIGA_MAC_VER_34:
case RTL_GIGA_MAC_VER_60:
case RTL_GIGA_MAC_VER_61:
case RTL_GIGA_MAC_VER_63:
- return true;
+ padto = max_t(unsigned int, padto, ETH_ZLEN);
default:
- return false;
+ break;
}
+
+ return padto;
}
static void rtl8169_tso_csum_v1(struct sk_buff *skb, u32 *opts)
@@ -4128,9 +4182,10 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
opts[1] |= transport_offset << TCPHO_SHIFT;
} else {
- if (unlikely(skb->len < ETH_ZLEN && rtl_test_hw_pad_bug(tp)))
- /* eth_skb_pad would free the skb on error */
- return !__skb_put_padto(skb, ETH_ZLEN, false);
+ unsigned int padto = rtl_quirk_packet_padto(tp, skb);
+
+ /* skb_padto would free the skb on error */
+ return !__skb_put_padto(skb, padto, false);
}
return true;
@@ -4307,6 +4362,9 @@ static netdev_features_t rtl8169_features_check(struct sk_buff *skb,
if (skb->len < ETH_ZLEN)
features &= ~NETIF_F_CSUM_MASK;
+ if (rtl_quirk_packet_padto(tp, skb))
+ features &= ~NETIF_F_CSUM_MASK;
+
if (transport_offset > TCPHO_MAX &&
rtl_chip_supports_csum_v2(tp))
features &= ~NETIF_F_CSUM_MASK;
--
2.30.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v3 net] r8169: work around RTL8125 UDP hw bug
2021-01-28 7:44 [PATCH v3 net] r8169: work around RTL8125 UDP hw bug Heiner Kallweit
@ 2021-01-28 18:36 ` Willem de Bruijn
2021-01-28 20:17 ` Heiner Kallweit
0 siblings, 1 reply; 4+ messages in thread
From: Willem de Bruijn @ 2021-01-28 18:36 UTC (permalink / raw)
To: Heiner Kallweit
Cc: Jakub Kicinski, David Miller, Realtek linux nic maintainers, netdev
On Thu, Jan 28, 2021 at 2:44 AM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>
> It was reported that on RTL8125 network breaks under heavy UDP load,
> e.g. torrent traffic ([0], from comment 27). Realtek confirmed a hw bug
> and provided me with a test version of the r8125 driver including a
> workaround. Tests confirmed that the workaround fixes the issue.
> I modified the original version of the workaround to meet mainline
> code style.
>
> [0] https://bugzilla.kernel.org/show_bug.cgi?id=209839
>
> v2:
> - rebased to net
> v3:
> - make rtl_skb_is_udp() more robust and use skb_header_pointer()
> to access the ip(v6) header
>
> Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125")
> Tested-by: xplo <xplo.bn@gmail.com>
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
> drivers/net/ethernet/realtek/r8169_main.c | 70 +++++++++++++++++++++--
> 1 file changed, 64 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index a569abe7f..457fa1404 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -28,6 +28,7 @@
> #include <linux/bitfield.h>
> #include <linux/prefetch.h>
> #include <linux/ipv6.h>
> +#include <linux/ptp_classify.h>
this is only for UDP_HLEN? perhaps use sizeof(struct udphdr) instead
to remove the dependency.
> #include <net/ip6_checksum.h>
>
> #include "r8169.h"
> @@ -4046,17 +4047,70 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
> return -EIO;
> }
>
> -static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp)
> +static bool rtl_skb_is_udp(struct sk_buff *skb)
> {
> + int no = skb_network_offset(skb);
> + struct ipv6hdr *i6h, _i6h;
> + struct iphdr *ih, _ih;
> +
> + switch (vlan_get_protocol(skb)) {
> + case htons(ETH_P_IP):
> + ih = skb_header_pointer(skb, no, sizeof(_ih), &_ih);
> + return ih && ih->protocol == IPPROTO_UDP;
> + case htons(ETH_P_IPV6):
> + i6h = skb_header_pointer(skb, no, sizeof(_i6h), &_i6h);
> + return i6h && i6h->nexthdr == IPPROTO_UDP;
> + default:
> + return false;
> + }
> +}
> +
> +#define RTL_MIN_PATCH_LEN 47
> +#define PTP_GEN_PORT 320
> +
> +/* see rtl8125_get_patch_pad_len() in r8125 vendor driver */
> +static unsigned int rtl8125_quirk_udp_padto(struct rtl8169_private *tp,
> + struct sk_buff *skb)
> +{
> + unsigned int padto = 0, len = skb->len;
> +
> + if (rtl_is_8125(tp) && len < 128 + RTL_MIN_PATCH_LEN &&
> + rtl_skb_is_udp(skb) && skb_transport_header_was_set(skb)) {
> + unsigned int trans_data_len = skb_tail_pointer(skb) -
> + skb_transport_header(skb);
> +
> + if (trans_data_len > 3 && trans_data_len < RTL_MIN_PATCH_LEN) {
trans_data_len > 3
here probably means
trans_data_len >= offsetof(struct udphdr, len)
to safely access dest. Then that is a bit more self documenting
> + u16 dest = ntohs(udp_hdr(skb)->dest);
> +
> + if (dest == PTP_EV_PORT || dest == PTP_GEN_PORT)
> + padto = len + RTL_MIN_PATCH_LEN - trans_data_len;
> + }
> +
> + if (trans_data_len < UDP_HLEN)
nit: else if ?
> + padto = max(padto, len + UDP_HLEN - trans_data_len);
> + }
> +
> + return padto;
> +}
> +
> +static unsigned int rtl_quirk_packet_padto(struct rtl8169_private *tp,
> + struct sk_buff *skb)
> +{
> + unsigned int padto;
> +
> + padto = rtl8125_quirk_udp_padto(tp, skb);
> +
> switch (tp->mac_version) {
> case RTL_GIGA_MAC_VER_34:
> case RTL_GIGA_MAC_VER_60:
> case RTL_GIGA_MAC_VER_61:
> case RTL_GIGA_MAC_VER_63:
> - return true;
> + padto = max_t(unsigned int, padto, ETH_ZLEN);
> default:
> - return false;
> + break;
> }
> +
> + return padto;
> }
>
> static void rtl8169_tso_csum_v1(struct sk_buff *skb, u32 *opts)
> @@ -4128,9 +4182,10 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
>
> opts[1] |= transport_offset << TCPHO_SHIFT;
> } else {
> - if (unlikely(skb->len < ETH_ZLEN && rtl_test_hw_pad_bug(tp)))
> - /* eth_skb_pad would free the skb on error */
> - return !__skb_put_padto(skb, ETH_ZLEN, false);
> + unsigned int padto = rtl_quirk_packet_padto(tp, skb);
> +
> + /* skb_padto would free the skb on error */
> + return !__skb_put_padto(skb, padto, false);
should this path still pad to ETH_ZLEN as a minimum when the other
cases do not hit?
> }
>
> return true;
> @@ -4307,6 +4362,9 @@ static netdev_features_t rtl8169_features_check(struct sk_buff *skb,
> if (skb->len < ETH_ZLEN)
> features &= ~NETIF_F_CSUM_MASK;
>
> + if (rtl_quirk_packet_padto(tp, skb))
> + features &= ~NETIF_F_CSUM_MASK;
> +
> if (transport_offset > TCPHO_MAX &&
> rtl_chip_supports_csum_v2(tp))
> features &= ~NETIF_F_CSUM_MASK;
> --
> 2.30.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3 net] r8169: work around RTL8125 UDP hw bug
2021-01-28 18:36 ` Willem de Bruijn
@ 2021-01-28 20:17 ` Heiner Kallweit
2021-01-28 20:27 ` Heiner Kallweit
0 siblings, 1 reply; 4+ messages in thread
From: Heiner Kallweit @ 2021-01-28 20:17 UTC (permalink / raw)
To: Willem de Bruijn
Cc: Jakub Kicinski, David Miller, Realtek linux nic maintainers, netdev
On 28.01.2021 19:36, Willem de Bruijn wrote:
> On Thu, Jan 28, 2021 at 2:44 AM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>>
>> It was reported that on RTL8125 network breaks under heavy UDP load,
>> e.g. torrent traffic ([0], from comment 27). Realtek confirmed a hw bug
>> and provided me with a test version of the r8125 driver including a
>> workaround. Tests confirmed that the workaround fixes the issue.
>> I modified the original version of the workaround to meet mainline
>> code style.
>>
>> [0] https://bugzilla.kernel.org/show_bug.cgi?id=209839
>>
>> v2:
>> - rebased to net
>> v3:
>> - make rtl_skb_is_udp() more robust and use skb_header_pointer()
>> to access the ip(v6) header
>>
>> Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125")
>> Tested-by: xplo <xplo.bn@gmail.com>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> ---
>> drivers/net/ethernet/realtek/r8169_main.c | 70 +++++++++++++++++++++--
>> 1 file changed, 64 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
>> index a569abe7f..457fa1404 100644
>> --- a/drivers/net/ethernet/realtek/r8169_main.c
>> +++ b/drivers/net/ethernet/realtek/r8169_main.c
>> @@ -28,6 +28,7 @@
>> #include <linux/bitfield.h>
>> #include <linux/prefetch.h>
>> #include <linux/ipv6.h>
>> +#include <linux/ptp_classify.h>
>
> this is only for UDP_HLEN? perhaps use sizeof(struct udphdr) instead
> to remove the dependency.
>
It's also for PTP_EV_PORT. But yes, we can define this locally to
remove the dependency.
>> #include <net/ip6_checksum.h>
>>
>> #include "r8169.h"
>> @@ -4046,17 +4047,70 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
>> return -EIO;
>> }
>>
>> -static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp)
>> +static bool rtl_skb_is_udp(struct sk_buff *skb)
>> {
>> + int no = skb_network_offset(skb);
>> + struct ipv6hdr *i6h, _i6h;
>> + struct iphdr *ih, _ih;
>> +
>> + switch (vlan_get_protocol(skb)) {
>> + case htons(ETH_P_IP):
>> + ih = skb_header_pointer(skb, no, sizeof(_ih), &_ih);
>> + return ih && ih->protocol == IPPROTO_UDP;
>> + case htons(ETH_P_IPV6):
>> + i6h = skb_header_pointer(skb, no, sizeof(_i6h), &_i6h);
>> + return i6h && i6h->nexthdr == IPPROTO_UDP;
>> + default:
>> + return false;
>> + }
>> +}
>> +
>> +#define RTL_MIN_PATCH_LEN 47
>> +#define PTP_GEN_PORT 320
>> +
>> +/* see rtl8125_get_patch_pad_len() in r8125 vendor driver */
>> +static unsigned int rtl8125_quirk_udp_padto(struct rtl8169_private *tp,
>> + struct sk_buff *skb)
>> +{
>> + unsigned int padto = 0, len = skb->len;
>> +
>> + if (rtl_is_8125(tp) && len < 128 + RTL_MIN_PATCH_LEN &&
>> + rtl_skb_is_udp(skb) && skb_transport_header_was_set(skb)) {
>> + unsigned int trans_data_len = skb_tail_pointer(skb) -
>> + skb_transport_header(skb);
>> +
>> + if (trans_data_len > 3 && trans_data_len < RTL_MIN_PATCH_LEN) {
>
> trans_data_len > 3
>
> here probably means
>
> trans_data_len >= offsetof(struct udphdr, len)
>
offsetof(struct udphdr, len) = 5
Presumably the check ensures that udphdr->dest is accessible. I think we should
use skb_header_pointer() here too.
> to safely access dest. Then that is a bit more self documenting
>
>> + u16 dest = ntohs(udp_hdr(skb)->dest);
>> +
>> + if (dest == PTP_EV_PORT || dest == PTP_GEN_PORT)
>> + padto = len + RTL_MIN_PATCH_LEN - trans_data_len;
>> + }
>> +
>> + if (trans_data_len < UDP_HLEN)
>
> nit: else if ?
>
I don't think so. If e.g. trans_data_len == 5 and dest port isn't a PTP port,
then the trans_data_len < UDP_HLEN branch wouldn't be execeuted.
>> + padto = max(padto, len + UDP_HLEN - trans_data_len);
>> + }
>> +
>> + return padto;
>> +}
>> +
>> +static unsigned int rtl_quirk_packet_padto(struct rtl8169_private *tp,
>> + struct sk_buff *skb)
>> +{
>> + unsigned int padto;
>> +
>> + padto = rtl8125_quirk_udp_padto(tp, skb);
>> +
>> switch (tp->mac_version) {
>> case RTL_GIGA_MAC_VER_34:
>> case RTL_GIGA_MAC_VER_60:
>> case RTL_GIGA_MAC_VER_61:
>> case RTL_GIGA_MAC_VER_63:
>> - return true;
>> + padto = max_t(unsigned int, padto, ETH_ZLEN);
>> default:
>> - return false;
>> + break;
>> }
>> +
>> + return padto;
>> }
>>
>> static void rtl8169_tso_csum_v1(struct sk_buff *skb, u32 *opts)
>> @@ -4128,9 +4182,10 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
>>
>> opts[1] |= transport_offset << TCPHO_SHIFT;
>> } else {
>> - if (unlikely(skb->len < ETH_ZLEN && rtl_test_hw_pad_bug(tp)))
>> - /* eth_skb_pad would free the skb on error */
>> - return !__skb_put_padto(skb, ETH_ZLEN, false);
>> + unsigned int padto = rtl_quirk_packet_padto(tp, skb);
>> +
>> + /* skb_padto would free the skb on error */
>> + return !__skb_put_padto(skb, padto, false);
>
> should this path still pad to ETH_ZLEN as a minimum when the other
> cases do not hit?
>
For most chip versions that's not needed because hw does the padding
to ETH_ZLEN. Few chip versions have a hw bug and padding needs to be
done in sw, that's handled in rtl_quirk_packet_padto().
>> }
>>
>> return true;
>> @@ -4307,6 +4362,9 @@ static netdev_features_t rtl8169_features_check(struct sk_buff *skb,
>> if (skb->len < ETH_ZLEN)
>> features &= ~NETIF_F_CSUM_MASK;
>>
>> + if (rtl_quirk_packet_padto(tp, skb))
>> + features &= ~NETIF_F_CSUM_MASK;
>> +
>> if (transport_offset > TCPHO_MAX &&
>> rtl_chip_supports_csum_v2(tp))
>> features &= ~NETIF_F_CSUM_MASK;
>> --
>> 2.30.0
>>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3 net] r8169: work around RTL8125 UDP hw bug
2021-01-28 20:17 ` Heiner Kallweit
@ 2021-01-28 20:27 ` Heiner Kallweit
0 siblings, 0 replies; 4+ messages in thread
From: Heiner Kallweit @ 2021-01-28 20:27 UTC (permalink / raw)
To: Willem de Bruijn
Cc: Jakub Kicinski, David Miller, Realtek linux nic maintainers, netdev
On 28.01.2021 21:17, Heiner Kallweit wrote:
> On 28.01.2021 19:36, Willem de Bruijn wrote:
>> On Thu, Jan 28, 2021 at 2:44 AM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>>>
>>> It was reported that on RTL8125 network breaks under heavy UDP load,
>>> e.g. torrent traffic ([0], from comment 27). Realtek confirmed a hw bug
>>> and provided me with a test version of the r8125 driver including a
>>> workaround. Tests confirmed that the workaround fixes the issue.
>>> I modified the original version of the workaround to meet mainline
>>> code style.
>>>
>>> [0] https://bugzilla.kernel.org/show_bug.cgi?id=209839
>>>
>>> v2:
>>> - rebased to net
>>> v3:
>>> - make rtl_skb_is_udp() more robust and use skb_header_pointer()
>>> to access the ip(v6) header
>>>
>>> Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125")
>>> Tested-by: xplo <xplo.bn@gmail.com>
>>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>>> ---
>>> drivers/net/ethernet/realtek/r8169_main.c | 70 +++++++++++++++++++++--
>>> 1 file changed, 64 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
>>> index a569abe7f..457fa1404 100644
>>> --- a/drivers/net/ethernet/realtek/r8169_main.c
>>> +++ b/drivers/net/ethernet/realtek/r8169_main.c
>>> @@ -28,6 +28,7 @@
>>> #include <linux/bitfield.h>
>>> #include <linux/prefetch.h>
>>> #include <linux/ipv6.h>
>>> +#include <linux/ptp_classify.h>
>>
>> this is only for UDP_HLEN? perhaps use sizeof(struct udphdr) instead
>> to remove the dependency.
>>
>
> It's also for PTP_EV_PORT. But yes, we can define this locally to
> remove the dependency.
>
>>> #include <net/ip6_checksum.h>
>>>
>>> #include "r8169.h"
>>> @@ -4046,17 +4047,70 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
>>> return -EIO;
>>> }
>>>
>>> -static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp)
>>> +static bool rtl_skb_is_udp(struct sk_buff *skb)
>>> {
>>> + int no = skb_network_offset(skb);
>>> + struct ipv6hdr *i6h, _i6h;
>>> + struct iphdr *ih, _ih;
>>> +
>>> + switch (vlan_get_protocol(skb)) {
>>> + case htons(ETH_P_IP):
>>> + ih = skb_header_pointer(skb, no, sizeof(_ih), &_ih);
>>> + return ih && ih->protocol == IPPROTO_UDP;
>>> + case htons(ETH_P_IPV6):
>>> + i6h = skb_header_pointer(skb, no, sizeof(_i6h), &_i6h);
>>> + return i6h && i6h->nexthdr == IPPROTO_UDP;
>>> + default:
>>> + return false;
>>> + }
>>> +}
>>> +
>>> +#define RTL_MIN_PATCH_LEN 47
>>> +#define PTP_GEN_PORT 320
>>> +
>>> +/* see rtl8125_get_patch_pad_len() in r8125 vendor driver */
>>> +static unsigned int rtl8125_quirk_udp_padto(struct rtl8169_private *tp,
>>> + struct sk_buff *skb)
>>> +{
>>> + unsigned int padto = 0, len = skb->len;
>>> +
>>> + if (rtl_is_8125(tp) && len < 128 + RTL_MIN_PATCH_LEN &&
>>> + rtl_skb_is_udp(skb) && skb_transport_header_was_set(skb)) {
>>> + unsigned int trans_data_len = skb_tail_pointer(skb) -
>>> + skb_transport_header(skb);
>>> +
>>> + if (trans_data_len > 3 && trans_data_len < RTL_MIN_PATCH_LEN) {
>>
>> trans_data_len > 3
>>
>> here probably means
>>
>> trans_data_len >= offsetof(struct udphdr, len)
>>
>
> offsetof(struct udphdr, len) = 5
> Presumably the check ensures that udphdr->dest is accessible. I think we should
> use skb_header_pointer() here too.
>
Uups, sorry, you' right here of course. My bad.
>> to safely access dest. Then that is a bit more self documenting
>>
>>> + u16 dest = ntohs(udp_hdr(skb)->dest);
>>> +
>>> + if (dest == PTP_EV_PORT || dest == PTP_GEN_PORT)
>>> + padto = len + RTL_MIN_PATCH_LEN - trans_data_len;
>>> + }
>>> +
>>> + if (trans_data_len < UDP_HLEN)
>>
>> nit: else if ?
>>
> I don't think so. If e.g. trans_data_len == 5 and dest port isn't a PTP port,
> then the trans_data_len < UDP_HLEN branch wouldn't be execeuted.
>
>>> + padto = max(padto, len + UDP_HLEN - trans_data_len);
>>> + }
>>> +
>>> + return padto;
>>> +}
>>> +
>>> +static unsigned int rtl_quirk_packet_padto(struct rtl8169_private *tp,
>>> + struct sk_buff *skb)
>>> +{
>>> + unsigned int padto;
>>> +
>>> + padto = rtl8125_quirk_udp_padto(tp, skb);
>>> +
>>> switch (tp->mac_version) {
>>> case RTL_GIGA_MAC_VER_34:
>>> case RTL_GIGA_MAC_VER_60:
>>> case RTL_GIGA_MAC_VER_61:
>>> case RTL_GIGA_MAC_VER_63:
>>> - return true;
>>> + padto = max_t(unsigned int, padto, ETH_ZLEN);
>>> default:
>>> - return false;
>>> + break;
>>> }
>>> +
>>> + return padto;
>>> }
>>>
>>> static void rtl8169_tso_csum_v1(struct sk_buff *skb, u32 *opts)
>>> @@ -4128,9 +4182,10 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
>>>
>>> opts[1] |= transport_offset << TCPHO_SHIFT;
>>> } else {
>>> - if (unlikely(skb->len < ETH_ZLEN && rtl_test_hw_pad_bug(tp)))
>>> - /* eth_skb_pad would free the skb on error */
>>> - return !__skb_put_padto(skb, ETH_ZLEN, false);
>>> + unsigned int padto = rtl_quirk_packet_padto(tp, skb);
>>> +
>>> + /* skb_padto would free the skb on error */
>>> + return !__skb_put_padto(skb, padto, false);
>>
>> should this path still pad to ETH_ZLEN as a minimum when the other
>> cases do not hit?
>>
> For most chip versions that's not needed because hw does the padding
> to ETH_ZLEN. Few chip versions have a hw bug and padding needs to be
> done in sw, that's handled in rtl_quirk_packet_padto().
>
>>> }
>>>
>>> return true;
>>> @@ -4307,6 +4362,9 @@ static netdev_features_t rtl8169_features_check(struct sk_buff *skb,
>>> if (skb->len < ETH_ZLEN)
>>> features &= ~NETIF_F_CSUM_MASK;
>>>
>>> + if (rtl_quirk_packet_padto(tp, skb))
>>> + features &= ~NETIF_F_CSUM_MASK;
>>> +
>>> if (transport_offset > TCPHO_MAX &&
>>> rtl_chip_supports_csum_v2(tp))
>>> features &= ~NETIF_F_CSUM_MASK;
>>> --
>>> 2.30.0
>>>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-01-28 20:29 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-28 7:44 [PATCH v3 net] r8169: work around RTL8125 UDP hw bug Heiner Kallweit
2021-01-28 18:36 ` Willem de Bruijn
2021-01-28 20:17 ` Heiner Kallweit
2021-01-28 20:27 ` Heiner Kallweit
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