[v2] gso: fix pyld_unit_size issue for udp gso
diff mbox series

Message ID 20200917021249.191088-1-yang_y_yi@163.com
State Accepted, archived
Delegated to: Ferruh Yigit
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Series
  • [v2] gso: fix pyld_unit_size issue for udp gso
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ci/travis-robot success Travis build: passed
ci/Intel-compilation success Compilation OK
ci/iol-testing success Testing PASS
ci/checkpatch warning coding style issues

Commit Message

yang_y_yi Sept. 17, 2020, 2:12 a.m. UTC
From: Yi Yang <yangyi01@inspur.com>

Fragment offset of IPv4 header is measured in units of
8 bytes. Fragment offset of UDP fragments will be wrong
after GSO if pyld_unit_size isn't multiple of 8. Say
pyld_unit_size is 1500, fragment offset of the second
UDP fragment will be 187 (i.e. 1500 / 8), which means 1496,
and it will result in 4-byte data loss (1500 - 1496 = 4).
So UDP GRO will reassemble out a wrong packet.

Fixes: b166d4f30b66 ("gso: support UDP/IPv4 fragmentation")

Signed-off-by: Yi Yang <yangyi01@inspur.com>
---
 lib/librte_gso/gso_udp4.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Hu, Jiayu Sept. 17, 2020, 2:16 a.m. UTC | #1
Acked-by: Jiayu Hu <jiayu.hu@intel.com>

> -----Original Message-----
> From: yang_y_yi@163.com <yang_y_yi@163.com>
> Sent: Thursday, September 17, 2020 10:13 AM
> To: dev@dpdk.org
> Cc: Hu, Jiayu <jiayu.hu@intel.com>; thomas@monjalon.net;
> yangyi01@inspur.com; yang_y_yi@163.com
> Subject: [PATCH v2] gso: fix pyld_unit_size issue for udp gso
> 
> From: Yi Yang <yangyi01@inspur.com>
> 
> Fragment offset of IPv4 header is measured in units of
> 8 bytes. Fragment offset of UDP fragments will be wrong
> after GSO if pyld_unit_size isn't multiple of 8. Say
> pyld_unit_size is 1500, fragment offset of the second
> UDP fragment will be 187 (i.e. 1500 / 8), which means 1496,
> and it will result in 4-byte data loss (1500 - 1496 = 4).
> So UDP GRO will reassemble out a wrong packet.
> 
> Fixes: b166d4f30b66 ("gso: support UDP/IPv4 fragmentation")
> 
> Signed-off-by: Yi Yang <yangyi01@inspur.com>
> ---
>  lib/librte_gso/gso_udp4.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_gso/gso_udp4.c b/lib/librte_gso/gso_udp4.c
> index 21fea09..6fa68f2 100644
> --- a/lib/librte_gso/gso_udp4.c
> +++ b/lib/librte_gso/gso_udp4.c
> @@ -69,7 +69,10 @@
>  		return 1;
>  	}
> 
> -	pyld_unit_size = gso_size - hdr_offset;
> +	/* pyld_unit_size must be a multiple of 8 because frag_off
> +	 * uses 8 bytes as unit.
> +	 */
> +	pyld_unit_size = (gso_size - hdr_offset) & ~7U;
> 
>  	/* Segment the payload */
>  	ret = gso_do_segment(pkt, hdr_offset, pyld_unit_size, direct_pool,
> --
> 1.8.3.1
Ferruh Yigit Sept. 17, 2020, 3:01 p.m. UTC | #2
On 9/17/2020 3:16 AM, Hu, Jiayu wrote:

>> -----Original Message-----
>> From: yang_y_yi@163.com <yang_y_yi@163.com>
>> Sent: Thursday, September 17, 2020 10:13 AM
>> To: dev@dpdk.org
>> Cc: Hu, Jiayu <jiayu.hu@intel.com>; thomas@monjalon.net;
>> yangyi01@inspur.com; yang_y_yi@163.com
>> Subject: [PATCH v2] gso: fix pyld_unit_size issue for udp gso
>>
>> From: Yi Yang <yangyi01@inspur.com>
>>
>> Fragment offset of IPv4 header is measured in units of
>> 8 bytes. Fragment offset of UDP fragments will be wrong
>> after GSO if pyld_unit_size isn't multiple of 8. Say
>> pyld_unit_size is 1500, fragment offset of the second
>> UDP fragment will be 187 (i.e. 1500 / 8), which means 1496,
>> and it will result in 4-byte data loss (1500 - 1496 = 4).
>> So UDP GRO will reassemble out a wrong packet.
>>
>> Fixes: b166d4f30b66 ("gso: support UDP/IPv4 fragmentation")
>>
>> Signed-off-by: Yi Yang <yangyi01@inspur.com>
>
 > Acked-by: Jiayu Hu <jiayu.hu@intel.com>
 >

Applied to dpdk-next-net/main, thanks.

Patch
diff mbox series

diff --git a/lib/librte_gso/gso_udp4.c b/lib/librte_gso/gso_udp4.c
index 21fea09..6fa68f2 100644
--- a/lib/librte_gso/gso_udp4.c
+++ b/lib/librte_gso/gso_udp4.c
@@ -69,7 +69,10 @@ 
 		return 1;
 	}
 
-	pyld_unit_size = gso_size - hdr_offset;
+	/* pyld_unit_size must be a multiple of 8 because frag_off
+	 * uses 8 bytes as unit.
+	 */
+	pyld_unit_size = (gso_size - hdr_offset) & ~7U;
 
 	/* Segment the payload */
 	ret = gso_do_segment(pkt, hdr_offset, pyld_unit_size, direct_pool,