So far, if an MGCP message is sent, the transaction gets enqueued, but there is
no way to end the transaction other than receiving a valid reply. So, if the
caller decides that the transaction timed out and tears down the priv pointer
passed to mgcp_client_tx, and if then a late reply arrives, the callback will
dereference the invalid priv pointer and cause a segfault. Hence it is possible
to crash an mgcp_client program by sending a late response.
Furthermore, if no reply ever arrives, we would keep the pending response in
the list forever, amounting to a "memory leak".
Add mgcp_client_cancel() to discard a pending transaction. The caller can now
decide to discard a pending response when it sees fit (e.g. the caller's
timeout expired). This needs to be added to OsmoMSC and OsmoBSC.
Add mgcp_msg_trans_id() to provide an obvious way to obtain the transaction id
from a generated MGCP message.
No public API is broken; but refine the negative return code from
mgcp_client_rx(): return -ENOENT if no such transaction ID is found, and still
-1 if decoding failed. This is mainly for mgcp_client_test.
Implement a test for mgcp_client_cancel() in mgcp_client_test.c.
Tweak internal mgcp_client_response_pending_get() to take only the transaction
id as argument instead of the entire mgcp message struct.
Found-by: dexter
Related: OS#2695 OS#2696
Change-Id: I16811e168a46a82a05943252a737b3434143f4bd
currently the only way to generate MGCP messages is to use
mgcp_msg_crcx(), mgcp_msg_mdcx() and mgcp_msg_dlcx(). All
three function take a fixed set of parameters via their
parameter list. There is no way to add or leave away optional
parameters.
add function mgcp_msg_gen(), this function takes a unified
message struct. The struct features a presence bitmask which
allows to enable and disable parameters as needed. It is also
possible to add new parameters in the future without breaking
the API.
Depends: libosmocore I15e1af68616309555d0ed9ac5da027c9833d42e3
Change-Id: I29c5e2fb972896faeb771ba040f015592487fcbe
The name "mgcpgw_client" referred to an MGCP gateway, which is rather an MGW
(Media Gateway). But this client code is more generally a client for the MGCP
protocol, independently from what the server program is called.
Rename the files as well as the function prefixes to drop the "gw". It is
purely cosmetic and not strictly necessary, but a good point in time for fixes
like this.
osmo-msc build will be adjusted by I093ad02ca0e532f659447c785e09678b3e6f220d.
osmo-bsc build will be adjusted by I6402c7cbe58dacae7630f7f03819f8102e54c699.
These should be applied right after this here is merged to avoid fallout.
Change-Id: I99f7faab637cfcc22ece64a1dbcbe590f2042187
Neels Hofmeyr
Philipp Maier