[Sheepdog] [PATCH] fix a bug in rx() when read() returns 0 but connection is not marked as closed.

[MORITA Kazutaka]

On Tue, Apr 24, 2012 at 5:40 PM, Huxinwei <huxinwei at huawei.com> wrote:
> I proposed something similar a while ago.
> The connection is actually staying in CLOSE_WAIT status while this happens. I'd suggest you consider something more reliable.

Is there any case that read() returns zero but the connection is not closed?

Thanks,

Kazutaka

>
> +               else if (!ret) { //FIXME: is this the best place to check?
> +                       int r;
> +                       struct tcp_info ti;
> +                       socklen_t l = sizeof(struct tcp_info);
> +                       r = getsockopt(conn->fd, SOL_TCP, TCP_INFO, (void*)&ti, &l);
> +                       if (r < 0) panic("this is really wired");
> +                       if (ti.tcpi_state == TCP_CLOSE_WAIT) {
> +                               conn->c_rx_state = C_IO_CLOSED;
> +                               conn->c_tx_state = C_IO_CLOSED;
> +                       }
> +               }
>
> FYI.
>
>> -----Original Message-----
>> From: sheepdog-bounces at lists.wpkg.org
>> [mailto:sheepdog-bounces at lists.wpkg.org] On Behalf Of Li Wenpeng
>> Sent: Tuesday, April 24, 2012 4:00 PM
>> To: sheepdog at lists.wpkg.org
>> Subject: [Sheepdog] [PATCH] fix a bug in rx() when read() returns 0 but
>> connection is not marked as closed.
>>
>> From: levin li <xingke.lwp at taobao.com>
>>
>> if read() returns 0，it means connection closed, but previous
>> read() may set errno to EAGAIN, in which case rx() would just
>> return 0 without set connection state as C_IO_CLOSED
>>
>> Signed-off-by: levin li <xingke.lwp at taobao.com>
>> ---
>>  lib/net.c |    7 ++++++-
>>  1 files changed, 6 insertions(+), 1 deletions(-)
>>
>> diff --git a/lib/net.c b/lib/net.c
>> index 260ae38..8ac7c9e 100644
>> --- a/lib/net.c
>> +++ b/lib/net.c
>> @@ -70,7 +70,12 @@ int rx(struct connection *conn, enum conn_state
>> next_state)
>>       int ret;
>>
>>       ret = read(conn->fd, conn->rx_buf, conn->rx_length);
>> -     if (!ret || ret < 0) {
>> +     if (!ret) {
>> +             conn->c_rx_state = C_IO_CLOSED;
>> +             return 0;
>> +     }
>> +
>> +     if (ret < 0) {
>>               if (errno != EAGAIN)
>>                       conn->c_rx_state = C_IO_CLOSED;
>>               return 0;
>> --
>> 1.7.1
>>
>> --
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