[openssl-users] Openssl asynchronous operation in real network
Matt Caswell
matt at openssl.org
Mon Jan 14 12:02:53 UTC 2019
On 13/01/2019 04:36, Ananthu Unnikrishnan wrote:
> Hi Matt,
>
> Thanks a lot for the response. The alternative method to resume job
> operation is a good one.
>
> I need some more clarifications regarding the async job operation.
> Please help.
> In ssl/ss_lib.c, ssl_start_async_job() function found. In which
> ASYNC_start_job function is calling but no mechanism found for polling the fd's.
> Is it written elsewhere?.
You are supposed to write the fd polling code yourself, e.g. by using
SSL_get_all_async_fds() or SSL_get_changed_async_fds() to get hold of the fds,
and then followed by "select" or similar.
See:
https://www.openssl.org/docs/man1.1.1/man3/SSL_get_all_async_fds.html
mATT
>
>
> On Fri, Jan 11, 2019 at 3:12 PM Matt Caswell <matt at openssl.org
> <mailto:matt at openssl.org>> wrote:
>
>
>
> On 10/01/2019 18:09, Ananthu Unnikrishnan wrote:
> > Hi Matt,
> >
> > Thanks a lot for the reply.
> >
> > After calling ASYNC_pause_job() from the engine, control will
> transfer to
> > the place where we start the ASYNC_start_job right? So how can we write
> the code
> > to put a trigger on fd in the same thread?
>
> I'm not saying you can't use threads to do this - only that you need to be
> careful about using them and must obey the rules.
>
>
> > If I am wrong please correct me.
> > Also if u can suggest where resume operation should be done, it would be
> helpful.
>
> Typically the calling application will wait on the fd (e.g. using "select" or
> similar) until it is readable. Once it sees the fd as readable then it calls
> ASYNC_start_job() again.
>
>
> As an aside you may also be interested in this PR that is currently being
> reviewed:
>
> https://github.com/openssl/openssl/pull/7573
>
> This adds an alternative mechanism for signalling other than using fds (i.e. to
> use a callback instead) and will be available in OpenSSL 3.0 when it gets
> released.
>
> Matt
>
>
>
> >
> > On Thu, Jan 10, 2019 at 10:11 PM Matt Caswell <matt at openssl.org
> <mailto:matt at openssl.org>
> > <mailto:matt at openssl.org <mailto:matt at openssl.org>>> wrote:
> >
> >
> >
> > On 10/01/2019 09:39, Ananthu Unnikrishnan wrote:
> > > Hi all,
> > >
> > > We are not able to access the waitctx address from the job
> address
> > using
> > > ASYNC_get_wait_ctx(job) from a thread which starts in the bind
> section of the
> > > dynamic engine. The job address is the same as that we got
> > > using ASYNC_get_current_job. Can anyone help on this?
> >
> > It's very unclear from the your various emails what you are trying to
> achieve
> > and the problem that you are experiencing.
> >
> > From the above it sounds like you are starting threads from inside
> your dynamic
> > engine? ASYNC_JOBs are always local to a thread. When a job is started
> it is
> > associated with the current thread. So ASYNC_get_current_job() returns
> the job
> > associated with the current thread. Similarly if you pause a job,
> > ASYNC_pause_job() must be called from that same thread. Finally if you
> restart a
> > paused job it must also be restarted on the same thread.
> >
> > If you are starting new threads from within your engine then extreme
> care must
> > be taken to obey the above rules - otherwise you are likely to get strange
> > results.
> >
> > Matt
> >
> >
> > >
> > >
> > >
> > > On Tue, Jan 8, 2019 at 11:26 AM Ananthu Unnikrishnan
> > <ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>
> > > <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>>> wrote:
> > >
> > > Can anyone please help on this? If u need any additional information
> > please
> > > let me know.
> > >
> > > On Mon, Jan 7, 2019 at 6:25 PM Ananthu Unnikrishnan
> > <ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>
> > > <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>>> wrote:
> > >
> > > Hi all,
> > >
> > > Adding more details to the previous mail. We have edited the
> OpenSSL
> > > code for implementing the polling for changed fd's as in
> OpenSSL speed
> > > command. Attached the code snippet of the same along with
> this mail.
> > > Mentioned below some observations which found doubtful:
> > >
> > > 1) We have got prints in ASYNC_FINISH case, before getting
> print in
> > > ASYNC_PAUSE case. Attaching the log also, so you can understand
> > easily.
> > > 2) Shown below the code snippet which we have written to
> provide a
> > write
> > > on fd.
> > >
> > > if ((waitctx = ASYNC_get_wait_ctx((ASYNC_JOB *)job)) == NULL) {
> > > printf("In dynamic engine | waitctx == NULL : %d\n",
> > __LINE__);
> > > return ret;
> > > }
> > >
> > > printf("\n----- In dynamic engine | After pausing | job
> is %lx |
> > > waitctx in resume job %lx |-----\n", job, waitctx);
> > >
> > > if ((ret = ASYNC_WAIT_CTX_get_fd(waitctx, engine_id,
> &efd,
> > > &custom)) > 0) {
> > > if (write(efd, &buf, sizeof(uint64_t)) == -1) {
> > > printf("\nFailed to write\n");
> > > }
> > > }
> > >
> > > Here waitctx is getting NULL when we tried to fetch waitctx
> using
> > > ASYNC_get_wait_ctx(). We have printed data of sizeof(ASYNC_JOB)
> > ie.1176
> > > bytes contained in the job address from the engine, we got
> > correct data
> > > before calling ASYNC_pause() and but got half data zero data
> when we
> > > tried to access the same address after ASYNC_pause().
> > >
> > > Attaching both job structure contents before and after calling
> > > ASYNC_pause(). Also, we got the correct data in the same address
> > when we
> > > have printed from ssl_start_async_job() before polling starts,
> > where we
> > > have started the async_job
> > > .
> > > The prints starting with "In dynamic engine" are prints
> inside the
> > > engine, rest prints are from ss/ssl_lib.c. Kindly check this and
> > please
> > > point out if anything is wrong somewhere. Thanks in advance.
> > >
> > >
> > > On Sun, Jan 6, 2019 at 10:30 AM Ananthu Unnikrishnan
> > > <ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>
> > <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>
> <mailto:ananthuu741 at gmail.com <mailto:ananthuu741 at gmail.com>>>> wrote:
> > >
> > > Hi all,
> > >
> > > We have implemented a dynamic engine and tested
> in the
> > async
> > > mode using OpenSSL speed command. But in a real network
> > scenario, we
> > > have seen only starting the async_job(in file ssl/ssl_lib.c,
> > > function: ssl_start_async_job) in the OpenSSL. We
> haven't seen
> > > polling async_fd's for resuming the job as in
> apps/speed.c(in
> > speed
> > > command case).
> > > So can anyone please suggest any solution for
> resuming the
> > > async_jobs in real network scenario? Thanks in advance.
> > >
> > >
> > >
> > >
> > >
> > > --
> > > With best Regards,
> > >
> > > Ananthu
> > >
> > >
> > >
> > >
> > > --
> > > With best Regards,
> > >
> > > Ananthu
> > >
> > >
> > >
> > >
> > > --
> > > With best Regards,
> > >
> > > Ananthu
> > >
> > >
> > >
> > --
> > openssl-users mailing list
> > To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
> >
> >
> >
> > --
> > With best Regards,
> >
> > Ananthu
> >
> >
> >
> --
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>
>
>
> --
> With best Regards,
>
> Ananthu
>
>
>
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