modem: cmux: Handle C/R bit from address field #96617
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bjarki-andreasen
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tomi-font
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Good idea. ZTEST(modem_cmux, test_modem_cmux_invalid_cr)
{
uint32_t events;
int ret;
/* We are initiator, so any CMD with CR set, should be dropped */
modem_backend_mock_put(&bus_mock, cmux_frame_control_cld_cmd,
sizeof(cmux_frame_control_cld_cmd));
modem_backend_mock_put(&bus_mock, cmux_frame_control_sabm_cmd,
sizeof(cmux_frame_control_sabm_cmd));
events = k_event_wait_all(&cmux_event, (MODEM_CMUX_EVENT_CONNECTED | MODEM_CMUX_EVENT_DISCONNECTED),
false, K_MSEC(100));
zassert_false(events, "Wrong CMD should have been ignored");
}So the mock tries to send Close-Down command and open command, but C/R bit set, so those should be ignored because in the test setup the mock is not an initiator, so C/R should be 0. |
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tomi-font
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| uint32_t events; | ||
| int ret; | ||
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| /* We are initiator, so any CMD with CR set, should be dropped */ |
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Suggested change
| /* We are initiator, so any CMD with CR set, should be dropped */ | |
| /* We are initiator, so any CMD with CR set should be dropped */ |
The C/R bit in the address field should be handled as explained in 5.2.1.2 in the spec (3GPP TS 127.010). To detect if the frame is a command or a response, we need to know who was the initiator of the CMUX channel. > Initiator is the station that take the initiative to initialize > the multiplexer (i.e. sends the SABM command at DLCI 0 ) See the table from given section of the specification. Also, on UIH frames 5.4.3.1 says > The frames sent by the initiating station have the C/R bit set to 1 > and those sent by the responding station have the C/R bit set to 0. NOTE: This is different than a C/R bit in the Type field. Signed-off-by: Seppo Takalo <[email protected]>
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tomi-font
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rerickson1
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The C/R bit in the address field should be handled as explained in 5.2.1.2 in the spec (3GPP TS 127.010).
To detect if the frame is a command or a response, we need to know who was the initiator of the CMUX channel.
See the table from given section of the specification.
Also, on UIH frames 5.4.3.1 says
NOTE: This is different than a C/R bit in the Type field.