Re: [Qemu-devel] [PULL] slirp: Fix issues with -mms-bitfields

[TeLeMan]

On Wed, Aug 24, 2011 at 17:11, Jan Kiszka <address@hidden> wrote:
> On 2011-08-23 12:49, TeLeMan wrote:
>> On Sun, Aug 21, 2011 at 04:00, Stefan Weil <address@hidden> wrote:
>>> Am 15.08.2011 08:39, schrieb Jan Kiszka:
>>>>
>>>> The following changes since commit
>>>> 3b6ffe50300f13240e1b46420ad05da1116df410:
>>>>
>>>> hw/scsi-bus.c: Fix use of uninitialised variable (2011-08-14 19:34:25
>>>> +0000)
>>>>
>>>> are available in the git repository at:
>>>> git://git.kiszka.org/qemu.git queues/slirp
>>>>
>>>> Jan Kiszka (1):
>>>> slirp: Fix bit field types in IP header structs
>>>>
>>>> slirp/ip.h | 8 ++++----
>>>> slirp/tcp.h | 4 ++--
>>>> 2 files changed, 6 insertions(+), 6 deletions(-)
>>>>
>>>> ---
>>>>
>>>> slirp: Fix bit field types in IP header structs
>>>>
>>>> -mms-bitfields prevents that the bitfields in current IP header structs
>>>> are packed into a single byte as it is required. Fix this by using
>>>> uint8_t as backing type.
>>>>
>>>> Signed-off-by: Jan Kiszka <address@hidden>
>>>> ---
>>>> slirp/ip.h | 8 ++++----
>>>> slirp/tcp.h | 4 ++--
>>>> 2 files changed, 6 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/slirp/ip.h b/slirp/ip.h
>>>> index 48ea38e..72dbe9a 100644
>>>> --- a/slirp/ip.h
>>>> +++ b/slirp/ip.h
>>>> @@ -74,10 +74,10 @@ typedef uint32_t n_long; /* long as received from the
>>>> net */
>>>> */
>>>> struct ip {
>>>> #ifdef HOST_WORDS_BIGENDIAN
>>>> - u_int ip_v:4, /* version */
>>>> + uint8_t ip_v:4, /* version */
>>>> ip_hl:4; /* header length */
>>>> #else
>>>> - u_int ip_hl:4, /* header length */
>>>> + uint8_t ip_hl:4, /* header length */
>>>> ip_v:4; /* version */
>>>> #endif
>>>> uint8_t ip_tos; /* type of service */
>>>> @@ -140,10 +140,10 @@ struct ip_timestamp {
>>>> uint8_t ipt_len; /* size of structure (variable) */
>>>> uint8_t ipt_ptr; /* index of current entry */
>>>> #ifdef HOST_WORDS_BIGENDIAN
>>>> - u_int ipt_oflw:4, /* overflow counter */
>>>> + uint8_t ipt_oflw:4, /* overflow counter */
>>>> ipt_flg:4; /* flags, see below */
>>>> #else
>>>> - u_int ipt_flg:4, /* flags, see below */
>>>> + uint8_t ipt_flg:4, /* flags, see below */
>>>> ipt_oflw:4; /* overflow counter */
>>>> #endif
>>>> union ipt_timestamp {
>>>> diff --git a/slirp/tcp.h b/slirp/tcp.h
>>>> index 9d06836..b3817cb 100644
>>>> --- a/slirp/tcp.h
>>>> +++ b/slirp/tcp.h
>>>> @@ -51,10 +51,10 @@ struct tcphdr {
>>>> tcp_seq th_seq; /* sequence number */
>>>> tcp_seq th_ack; /* acknowledgement number */
>>>> #ifdef HOST_WORDS_BIGENDIAN
>>>> - u_int th_off:4, /* data offset */
>>>> + uint8_t th_off:4, /* data offset */
>>>> th_x2:4; /* (unused) */
>>>> #else
>>>> - u_int th_x2:4, /* (unused) */
>>>> + uint8_t th_x2:4, /* (unused) */
>>>> th_off:4; /* data offset */
>>>> #endif
>>>> uint8_t th_flags;
>>>
>>> Tested-by: Stefan Weil <address@hidden>
>>>
>> slirp is still broken on my mingw32. I used "#progma
>> pack(push,1)/#progma pack(pop)" to resolve this issue.
>
> Can you drill down to the bottom of this problem? What fields in what
> struct are not properly packed? Maybe this is now a compiler bug, so
> comparing versions may make sense as well.
arphdr.ar_sip is not aligned on  a 4-byte boundary. See my previous post:
http://lists.gnu.org/archive/html/qemu-devel/2011-08/msg00964.html

>
> Jan
>
>