See 04.80[1], section 3.4: the highest two bits are used as counter or ignored
and do not contribute to the SS "Miscellaneous message group". Previous mask of
0xbf included the highest bit, fix to 0x3f.
Observed a value of 0xbb that should mean 0x3b="Register" during testing of 3G
USSD requests, which seem to be the first to send a nonzero highest bit to our
code. The erratic mask of 0xbf lead to an unhandled message type of 0xbb.
[1] 3GPP TS 24.080 version 7.2.0 Release 7 / ETSI TS 124 080 V7.2.0 (2006-09)
Change-Id: I299001a9e36c16f55622a0acd5d4a55ca49d0055
Add inline functions for both release <= 98 and release >= 99 as well as a
default define. Use the release 98 by default since the current code base uses
the r98 bitmasks.
These inline functions relieve callers of the decision on masking bits of the
protocol discriminator and message type octets.
Also add a define for the protocol discriminator extension to one octet length
(GSM48_PDISC_EXTEND).
Apply new pdisc function in gsm0480.c.
[hfreyther: Make the hdr param const]
These patches enhance the Supplementary Service (SS) processing from
only being able to handle USSD to other SS, specifically activation,
deactivation and interrogation of those SS. Registration is not yet
implemented.
include/osmocom/gsm/protocol/gsm_09_02.h has been added with needed
values for SS.
Modified by Harald Welte to keep the old ussd-only functiosn for API/ABI
stability.
The 7bit<->8bit encoding/decoding functions didn't check whether
there is still enough space in the destination buffer. Therefore a
buffer size parameter has been added to each of the functions which
is used to truncate the output if the buffer is too small.
In addition, the return value of the decoding functions has been
changed to number of characters written (excluding \0), so this
value is always equal to strlen(decoded).
The old functions are still available as wrapper functions.
Handling 7-bit coding is a little different for USSD, as TS 03.38
states:
To avoid the situation where the receiving entity confuses 7 binary
zero pad bits as the @ character, the carriage return or <CR>
character shall be used for padding in this situation [...].
If <CR> is intended to be the last character and the message
(including the wanted <CR>) ends on an octet boundary, then another
<CR> must be added together with a padding bit 0. The receiving entity
will perform the carriage return function twice, but this will not
result in misoperation as the definition of <CR> [...] is identical to
the definition of <CR><CR>.
The receiving entity shall remove the final <CR> character where the
message ends on an octet boundary with <CR> as the last character.
Jacob has verified the fix with fakeBTS and the wireshark dissector.
Fixes: OW#947
Reviewed-by: Jacob Erlbeck <jerlbeck@sysmocom.de>
This reverts commit f996b05dbd
and 2b0cac4ef8. A detailed
explanation can be found here:
http://lists.osmocom.org/pipermail/openbsc/2013-July/004737.html
The short description is that:
1.) The API should return (as out parameter) the number of
octets used.
2.) The handling for the <CR> encoding only applies to USSD
and it is incomplete. On top of that it broke the SMS test.
This patch moves all GSM-specific definitions to include/osmocom/gsm.
Moreover, the headers in include/osmocore/ have been moved to
include/osmocom/core.
This has been proposed by Harald Welte and Sylvain Munaunt.
Tested with `make distcheck'.
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
libosmogsm which is provided by libosmocore.
I have also moved generate_backtrace() to backtrace.c instead
of gsm_utils.c, otherwise the timer and msgfile tests depend on
libosmogsm.
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
Neels Hofmeyr
Tobias Engel
Alexander Huemer