w-level general upgrades and as a complement to module-specific upgrade.
* Called on startup after initial XML parsing, but before module-specific upgrades
* Enabled by definign the `.ca_datastore_upgrade`
* [General-purpose upgrade documentation](https://clixon-docs.readthedocs.io/en/latest/backend.html#ge
neral-purpose)
* JSON parse error messages change from ` on line x: syntax error,..` to `json_parse: line x: syntax err
or`
* Unknown-element error message is more descriptive, eg from `namespace is: urn:example:clixon` to: `Fai
led to find YANG spec of XML node: x with parent: xp in namespace urn:example:clixon`.
* C-API parse and validation API more capable
* `xml_spec_populate` family of functions extended with three-value return values
* -1: error, 0: parse OK, 1: parse and YANG binding OK.
* `xml_parse` and `json_parse` API changes
* Three value returns: -1: error, 0: parse OK, 1: parse and YANG binding OK.
* Extended `xml_parse_file2` and `xml_parse_string2` extended API functions with all options available.
* New concept called `yang_bind` that defines how XML symbols are bound to YANG after parsing
* Existing API same except `xml_parse_file` `endtag` argument moved to `xml_parse_file2`
* C-API: Added instrumentation: `xml_size` and `xml_stats_get`.
* Fixed: Enabling modstate (CLICON_XMLDB_MODSTATE), changing a revision on a yang, and restarting made the backend daemon exit at start (thanks Matt)
* Also: ensure to load `ietf-yang-library.yang ` if CLICON_XMLDB_MODSTATE is set
* Restconf RFC 8040 increased feature compliance
* Cache-Control: no-cache added in HTTP responses (RFC Section 5.5)
* Restconf monitoring capabilities (RFC Section 9.1)
* Added support for Yang extensions
* New plugin callback: ca_extension
* Main backend example includes example code on how to implement a Yang extension in a plugin.
* JSON changes
* Non-pretty-print output removed all extra spaces.
* Example: `{"nacm-example:x": 42}` --> {"nacm-example:x":42}`
* Empty JSON container changed from `null` to `{}`.
* Empty list and leafs remain as `null`
* Removed unnecessary configure dependencies
* libnsl, libcrypt, libm, if_vlan,...
* pseudo-plugin added, to enable callbacks also for main programs. Useful for extensions
* Yang Unique statements with multiple schema identifiers did not work on some platforms due to memory error.
* Extra RPC:s will be called _after_ the basic ones.
* One specific usecase is hook for `copy-config` (see [doc/ROADMAP.md] that can be implemented thus way.
* `rpc_callback_register` added a namespace parameter. Example:
```
rpc_callback_register(h, empty_rpc, NULL, "urn:example:clixon", "empty");
```
* `CLICON_YANG_DIR` is changed from a single directory to a path of directories
* Note CLIXON_DATADIR (=/usr/local/share/clixon) need to be in the list
* CLICON_YANG_MAIN_FILE Provides a filename with a single module filename.
* CLICON_YANG_MAIN_DIR Provides a directory where all yang modules should be loaded.
* Change all @datamodel:tree to @datamodel in all CLI specification files
* If you generate CLI code from the model (CLIXON_CLI_GENMODEL).
* For backward compatibility, define CLICON_CLI_MODEL_TREENAME_PATCH in clixon_custom.h
* Removed return value ymodp from yang parse functions (eg yang_parse()).
* New config option: CLICON_CLI_MODEL_TREENAME defining name of generated syntax tree if CLIXON_CLI_GENMODEL is set.
* CLICON_NACM_MODE config option, default is disabled.
* Added username attribute to all rpc:s from frontend to backend
* Added NACM backend module in example
* Backend RPC register callback function (Netconf RPC or restconf operation POST) has been changed from: `backend_rpc_cb_register()` to `rpc_callback_register()`
* Backend RPC callback signature has been changed from: `int cb(clicon_handle h, cxobj *xe, struct client_entry *ce, cbuf *cbret, void *arg)` has been changed to : `int cb(clicon_handle h, cxobj *xe, struct client_entry *ce, cbuf *cbret, void *arg)`
* Frontend netconf and restconf plugins can register callbacks as well with same API as backends.
* For preparation for authorization RFC8341
* Plugins add clixon_plugin_init() and api struct for function pointers, eg:
```
static const struct clixon_plugin_api api = {
"example",
clixon_plugin_init,
...
}
clixon_plugin_api *clixon_plugin_init(clicon_handle h)
{
return (void*)&api;
}
```
* Moved specific plugin functions from apps/ to generic functions in lib/
* New generic plugin load function: clixon_plugins_load()
* Removed client-local netconf plugins netconf_plugin_callbacks()
* This was code used before generic YANG rpc calls
* Added username to clixon handle:
* clicon_username_get() / clicon_username_set()
* Added authentication plugin callback
* Removed some obscure plugin code that seem not to be used (please report if needed!)
* CLI parse hook
* CLICON_FIND_PLUGIN
* clicon_valcb()
* Removed username to rpc calls (added below)
