As str structure has been replaced by coap_string_t, remove it from the code
as it is no longer required, has been deprecated for some time and can cause
clashes with other str definitions.
Tidy up comment referring to str.
For any TLS implementation, it is possible to crash the coap-server by
initiating (D)TLS handshakes but never completing them, thus continuing to use
more RAM. Each partially completed handshake is left in the endpoint->sessions
chain in a state of COAP_SESSION_STATE_HANDSHAKE and unless
endpoint->max_idle_sessions is deliberately configured, these sessions will
never get deleted.
A cause of partially completed handshakes is when there is a PSK mismatch.
Furthermore, unnecessary CPU usage is used to search down long lists held in
endpoint->sessions.
This fix limits the number of these sessions in a handshake state to the
number defined by endpoint->max_handshake_sessions if non zero or 100 to prevent
memory exhaustion. By default, endpoint->max_handshake_sessions is 0.
Sessions in state COAP_SESSION_STATE_HANDSHAKE will get timed out after 30
seconds of inactivity.
This does not prevent a DOS attack by creating max_handshake_sessions as a
genuine new session will fail to get responded to until the number of current
COAP_SESSION_STATE_HANDSHAKE sessions drop. However, the use of Cookie
exchanges by the underlying TLS library prior to a new session being created
and added into endpoint->sessions will filter out a lot of the DOS attacks.
include/coap2/coap_session.h
New default definition for COAP_DEFAULT_MAX_HANDSHAKE_SESSIONS
New default definition for COAP_PARTIAL_SESSION_TIMEOUT_TICKS
include/coap2/net.h
Include max_handshake_sessions in coap_context_t
src/coap_session.c
In coap_endpoint_get_session() check the number of sessions in
COAP_SESSION_STATE_HANDSHAKE and handle accordingly when limits are hit, or
they need to be timed out.
Information set up in the pseudo session held in endpoint->hello is not freed
off when coap_free_endpoint() is called.
A solution is to split coap_session_free() into two parts with
coap_session_free() calling a new function coap_session_mfree().
Then coap_mfree_endpoint() can call coap_session_mfree() to free off the
endpoint specific hello information.
Makefile.am
Add coap_mfree_endpoint and coap_session_mfree to the CTAGS_IGNORE list.
libcoap-2.{map|sym}
Remove coap_mfree_endpoint as it is not a public function
include/coap2/coap_session.h
Add in new coap_session_mfree() function definition
src/coap_io.c
Call coap_session_mfree() from within coap_mfree_endpoint()
src/coap_session.c
Move some of the functionality out of coap_session_free() into a new
function coap_session_mfree() and call coap_session_mfree().
These new functions can be used to either update a buffer with, or coap_log()
out the current runtime TLS library along with the version of the library
that libcoap was built against.
include/coap2/debug.h
src/debug.c
libcoap-2.map
libcoap-2.sym
Support for the new functions coap_show_tls_version() and coap_string_tls_version().
This allows an application to determine what the built version is
as well as what the runtime version of a TLS library is.
include/coap2/coap_dtls.h
Add built_version to coap_tls_version_t
src/coap_openssl.c
src/coap_tinydtls.c
Additionally populate coap_tls_version_t with build_version when
coap_get_tls_library_version() is called.
src/coap_tinydtls.c
Correct the version returned as actual TinyDTLS version instead the
binary value of a DTLS packet type.
This then removes the need for name polution/confict of debug(), info() and
warn() when building other projects that use libcoap and need to #include the
libcoap header files
Updated:
examples/client.c
examples/contiki/coap-observer.c
examples/etsi_iot_01.c
include/coap2/debug.h
src/async.c
src/block.c
src/coap_io.c
src/coap_openssl.c
src/coap_session.c
src/coap_tinydtls.c
src/debug.c
src/mem.c
src/net.c
src/option.c
src/pdu.c
src/resource.c
src/uri.c
If the debug() etc. macros are still required, then the change to
include/coap2/debug.h just needs to be reverted.
There are also a couple of space changes - to cause log output to be columnar
e.g "ERR" was padded to "ERR ", so that "EMRG" or "ERR " log output output was
aligned in the same way.
This is a replacement for PR#51, and partially deals with name polution issues
raised in Issue #50.
Parameter re-aligned some long strings, splitting strings across multiple lines
Automake is using the variable 'libcoap_include_HEADERS' as the list to
install the header files and is this list installing to $(prefix)
basically.
This commit is changing the primary installation folder for the header
files in addition to the previous commit.
Jon Shallow