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From: Laurent Vivier <lvivier@redhat.com>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: passt-dev@passt.top
Subject: Re: [PATCH v4 5/8] checksum: use csum_ip4_header() in udp.c and tcp.c
Date: Fri, 1 Mar 2024 13:31:11 +0100	[thread overview]
Message-ID: <ecd5773c-bf24-44b1-a200-a333062dffa5@redhat.com> (raw)
In-Reply-To: <ZeESTj6olXE6NGti@zatzit>

On 3/1/24 00:25, David Gibson wrote:
> On Thu, Feb 29, 2024 at 05:59:52PM +0100, Laurent Vivier wrote:
>> We can find the same function to compute the IPv4 header
>> checksum in tcp.c, udp.c and tap.c
>>
>> Use the function defined for tap.c, csum_ip4_header(), but
>> with the code used in tcp.c and udp.c as it doesn't need a fully
>> initialiazed IPv4 header, only protocol, tot_len, saddr and daddr.
>>
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
>> ---
>>
>> Notes:
>>      v4:
>>        - rebase
>>      
>>      v3:
>>        - function parameters provide tot_len, saddr, daddr and protocol
>>         rather than an iphdr
>>      
>>      v2:
>>        - use csum_ip4_header() from checksum.c
>>        - use code from tcp.c and udp.c in csum_ip4_header()
>>        - use "const struct iphfr *", check is not updated by the
>>          function but by the caller.
>>
>>   checksum.c | 17 +++++++++++++----
>>   checksum.h |  3 ++-
>>   tap.c      |  3 ++-
>>   tcp.c      | 24 +++---------------------
>>   udp.c      | 20 ++------------------
>>   5 files changed, 22 insertions(+), 45 deletions(-)
>>
>> diff --git a/checksum.c b/checksum.c
>> index 74e3742bc6f6..511b296a9a80 100644
>> --- a/checksum.c
>> +++ b/checksum.c
>> @@ -57,6 +57,7 @@
>>   #include <linux/icmpv6.h>
>>   
>>   #include "util.h"
>> +#include "ip.h"
>>   #include "checksum.h"
>>   
>>   /* Checksums are optional for UDP over IPv4, so we usually just set
>> @@ -116,13 +117,21 @@ uint16_t csum_fold(uint32_t sum)
>>   uint16_t csum(const void *buf, size_t len, uint32_t init);
>>   
>>   /**
>> - * csum_ip4_header() - Calculate and set IPv4 header checksum
>> + * csum_ip4_header() - Calculate IPv4 header checksum
>>    * @ip4h:	IPv4 header
> 
> Function comment needs to be updated for the new parameters.  In
> particular it needs to note that tot_len, saddr and daddr are all
> passed in network order.
> 
> As noted elsewhere, I kind of hate passing non-host-endian values in
> plain integer types, but I can see why doing otherwise here would be
> very awkward.

Perhaps we can use __be16 and __be32 types to really show the endianness in the code?

Thanks,
Laurent


  reply	other threads:[~2024-03-01 12:31 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-29 16:59 [PATCH v4 0/8] Add vhost-user support to passt (part 1) Laurent Vivier
2024-02-29 16:59 ` [PATCH v4 1/8] pcap: add pcap_iov() Laurent Vivier
2024-02-29 23:16   ` David Gibson
2024-02-29 16:59 ` [PATCH v4 2/8] checksum: align buffers Laurent Vivier
2024-02-29 16:59 ` [PATCH v4 3/8] checksum: add csum_iov() Laurent Vivier
2024-02-29 16:59 ` [PATCH v4 4/8] util: move IP stuff from util.[ch] to ip.[ch] Laurent Vivier
2024-02-29 23:19   ` David Gibson
2024-03-01 12:06     ` Laurent Vivier
2024-02-29 16:59 ` [PATCH v4 5/8] checksum: use csum_ip4_header() in udp.c and tcp.c Laurent Vivier
2024-02-29 23:25   ` David Gibson
2024-03-01 12:31     ` Laurent Vivier [this message]
2024-02-29 16:59 ` [PATCH v4 6/8] checksum: introduce functions to compute the header part checksum for TCP/UDP Laurent Vivier
2024-02-29 23:42   ` David Gibson
2024-02-29 16:59 ` [PATCH v4 7/8] tap: make tap_update_mac() generic Laurent Vivier
2024-02-29 16:59 ` [PATCH v4 8/8] tcp: Introduce ipv4_fill_headers()/ipv6_fill_headers() Laurent Vivier
2024-02-29 23:54   ` David Gibson
2024-03-03 13:50     ` Laurent Vivier

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