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Hi Jaco,<br>
<br>
if I understand correctly, your segfault did not happen during in
T38gateway, but while receiving fax to tiff file (ReceiveFax), am I
right?<br>
I haven't checked neither patched this (because my Asterisks are
only relaying faxes, not terminating/originating to/from tiff file),
but if your segfault happen when data are passed to libspandsp, it
should be the same situation as mine was. Code in res_fax allows
slinear/alaw/ulaw frames to be passed to res_fax_spandsp and then to
libspandsp, but libspandsp accepts only slinear. When ulaw/alaw
frames are passed here, bad things can happen.<br>
<pre class="moz-signature" cols="72">--
Regards,
Michal Rybarik</pre>
<br>
<br>
Dňa 6. 2. 2014 12:07, Jaco Kroon wrote / napísal(a):
<blockquote cite="mid:52F36CDD.5060608@uls.co.za" type="cite">
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http-equiv="Content-Type">
<div class="moz-cite-prefix"><font face="Helvetica, Arial,
sans-serif">Hi All,<br>
<br>
Could this backtrace possibly be related?<br>
<br>
#0 process_rx_data (t=0x7fae54c698a8, user_data=0x2,
data_type=1, field_type=<optimized out>,
buf=0x7fae11c58cda "cng", len=0) at t38_terminal.c:314<br>
#1 0x00007fae11c22c7d in t38_core_rx_ifp_packet
(s=0x7fae54c698a8, buf=0x7fae54c8475b "\002", len=1,
seq_no=<optimized out>) at t38_core.c:459<br>
#2 0x00007fae50ea96c5 in generic_fax_exec
(chan=chan@entry=0x7fadc4548c18,
details=details@entry=0x7fad50602c28,
reserved=reserved@entry=0x7fad50155478, token=<optimized
out>) at res_fax.c:1498<br>
#3 0x00007fae50eaea9e in receivefax_exec
(chan=0x7fadc4548c18, data=<optimized out>) at
res_fax.c:1932<br>
#4 0x0000000000530fdd in pbx_exec (c=c@entry=0x7fadc4548c18,
app=app@entry=0x2ddca60, data=data@entry=0x7fad838b6cd0
"/tmp/morpheus-1391681512.850.tiff") at pbx.c:1622<br>
#5 0x000000000053656f in pbx_extension_helper
(c=c@entry=0x7fadc4548c18, context=<optimized out>,
exten=exten@entry=0x7fadc4549ab8 "0123489251",
priority=priority@entry=6, label=label@entry=0x0,
callerid=callerid@entry=0x7fadc44757b0 "0126413300",
action=action@entry=E_SPAWN, found=found@entry=0x7fad838bad60,
<br>
combined_find_spawn=combined_find_spawn@entry=1, con=0x0)
at pbx.c:4922<br>
#6 0x00000000005404a4 in ast_spawn_extension
(found=0x7fad838bad60, callerid=0x7fadc44757b0 "0126413300",
priority=6, exten=0x7fadc4549ab8 "0123489251",
context=<optimized out>, c=0x7fadc4548c18,
combined_find_spawn=<optimized out>) at pbx.c:6038<br>
#7 __ast_pbx_run (c=c@entry=0x7fadc4548c18,
args=args@entry=0x0) at pbx.c:6513<br>
#8 0x0000000000541c0b in pbx_thread
(data=data@entry=0x7fadc4548c18) at pbx.c:6843<br>
#9 0x0000000000587c5a in dummy_start (data=<optimized
out>) at utils.c:1162<br>
#10 0x00007fae530f2f3a in start_thread (arg=0x7fad838bb700) at
pthread_create.c:308<br>
#11 0x00007fae54754dad in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:113<br>
<br>
Had about 11 of those this morning on asterisk 11.7.0.
Codec's that's allowed on SIP though is g729 and gsm only, so
no ulaw/alaw allowed. Actually, just double checked,
ulaw/alaw is (was now) allowed, so someone is possibly trying
to run in bypass mode, resulting in the t38 gateway instead of
t38 pass through. I downgraded to 11.6.0 and hadn't had a
crash since but I opted to disable ulaw+alaw in any case, just
to be on the safer side.<br>
<br>
</font>
<div class="moz-signature">Kind Regards,<br>
Jaco Kroon<br>
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On 01/02/2014 06:49, Michal Rybárik wrote:<br>
</div>
<blockquote cite="mid:52EC7CE6.7000208@rybarik.sk" type="cite">Hello
Pavel, <br>
<br>
On 01/31/2014 07:59 AM, Pavel Troller wrote: <br>
<blockquote type="cite">
<blockquote type="cite">This code will translate non-slinear
frames to slinear, just before they <br>
are sent to libspandsp for v21detection. With this patch
applied, v21 <br>
detection is done also for RTP (SIP) alaw/ulaw frames, so
maybe SIP/G711 <br>
<-> SIP/T38 gateway will work too. I tested
DAHDI<-> SIP/T38, gateway <br>
works both ways, voice calls too. Is it better now? :o) <br>
</blockquote>
I fully understand the code, but I'm not trained enough in the
Asterisk <br>
internals to respond to questions, which immediately appeared
in my head: <br>
1) In the original code, the result from
fax_gateway_detect_v21() is returned. <br>
Now, you are returning the original frame. I quickly looked at
the above <br>
routine and it in turn calls fax_gateway_request_t38() and
returns its <br>
result (but not always), and in the fax_gateway_request_t38()
function <br>
they are also returning different things according to results
of the <br>
program flow. So, is it really safe to do this ? Are you sure,
that the <br>
real result is really unneccessary ? <br>
2) Are you sure, that ast_translate() will always allocate a
new buffer for <br>
tmpframe ? Is it written somewhere ? Isn't it possible that it
will just <br>
reallocate the buffer for the original frame to increase its
size and return <br>
its pointer, so by doing ast_frfree() you would just
deallocate the same <br>
buffer, thus making big troubles ? You would find it by
checking that <br>
tmpframe != f... <br>
As you can see, I'm very careful, or maybe even a bit
conservative, with <br>
patching things, unless I really DEEPLY understand, how they
are going... <br>
So, I believe, that you really studied the code enough to be
sure, that <br>
you can really clear my doubts by your deep knowledge... I
didn't have time <br>
to study the code to such extent... <br>
</blockquote>
<br>
Answering these questions is not easy for me too, there are some
parts of res_fax code which I don't fully understand. So I
rather reworked the patch and moved it to another place, where
functionality is easier to understand, and when it shouldn't
harm anything. I uploaded diff to JIRA -
https://issues.asterisk.org/jira/browse/ASTERISK-20149 <br>
<br>
Regards, <br>
Michal Rybarik <br>
<br>
</blockquote>
<br>
</blockquote>
<br>
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