mirror of
https://github.com/troglobit/finit.git
synced 2026-10-01 05:22:48 +07:00
Joachim Nilsson
0e02429e75
Lots of cleanup and simplification of the main code in this commit. Most notably libev has been added to take care of the main loop and monitor services. Still TODO is migrating to use the libev signal handling. Convert initctl.c:listen_initctl() to a plugin instead. This also meant introducing a new form of I/O plugin to finit, also handled by libev. Load plugins *after* we've setup the base filesystem (BASEFS) in case plugins reside on a filesystem not reachable before "mount -a" has run. This also has the side effect of lining up nicely with the first level plugin hooks. If a plugin wants to hook up with a loded service we connect them by their respective numeric IDs in plugin_register(). I.e., the service monitor checks if a service has a registered callback, which in turn decides if a service should be started, stopped or reloaded. Rip out old EeePC distribution defines from finit.h, none of it really applies anymore. If you need distribution specific settings this is the place to put them. Make hookpoint names (#defines) clearer: after BASEFS, after networking, after all setup, etc. Use #inlude_next <signal.h> in signal.h to include system header file! Simplify service monitor: move essential code to svc.c and rip out the TIPC dependency. Write your own service.so plugin, or wait for a more complete example of how to extend service monitoring using the primitives in svc.c Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
122 lines
4.0 KiB
C
122 lines
4.0 KiB
C
/* Plugin based services architecture for finit
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*
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* Copyright (c) 2012 Joachim Nilsson <troglobit@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef FINIT_PLUGIN_H_
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#define FINIT_PLUGIN_H_
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#include <ev.h>
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#include <sys/queue.h> /* BSD sys/queue.h API */
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#define PLUGIN_IO_READ EV_READ
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#define PLUGIN_IO_WRITE EV_READ
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#define PLUGIN_INIT(x) static void __attribute__ ((constructor)) x(void)
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#define PLUGIN_EXIT(x) static void __attribute__ ((destructor)) x(void)
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#define PLUGIN_ITERATOR(x) LIST_FOREACH(x, &plugins, link)
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/*
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* Predefined hook points for easier plugin debugging
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*/
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typedef enum {
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HOOK_BASEFS_UP = 0,
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HOOK_NETWORK_UP,
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HOOK_SYSTEM_UP,
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HOOK_SHUTDOWN,
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HOOK_MAX_NUM
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} hook_point_t;
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/**
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* plugin_t - Finit &plugin_t object
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* @link: BSD sys/queue.h linked list node
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* @name: Plugin name, or identifier to match against a &svc_t object
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* @svc: Service callback for a loaded &svc_t object
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* @hook: Hook callback definitions
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* @io: I/O hook callback
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*
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* To setup an &svc_t object callback for a service monitor the @name
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* must match the @svc_t @cmd exactly for them to "pair".
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*
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* A &plugin_t object may contain a service callback, several hooks
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* and/or an I/O callback as well. This way all critical extensions
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* to finit can fit in one single plugin, if needed.
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*
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* The "dynamic events" discussed in the svc callback is for external
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* service plugins to implement. However, it can be anything that
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* can cause a service to need to SIGHUP at runtime. E.g., acquiring
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* a DHCP lease, or an interface going UP/DOWN.
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*
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* It is up to the external service plugin to track these events and
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* relay them to each @dynamic service plugins' callback. I.e., to
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* all those with the dynamic flag set.
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*/
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typedef struct plugin {
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/* BSD sys/queue.h linked list node. */
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LIST_ENTRY(plugin) link;
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/* Plugin name, defaults to plugin path if unset.
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* NOTE: Must be same as @cmd for service plugins! */
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char *name;
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/* Service callback to be called once per lap of runloop. */
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struct plugin_svc {
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/* Private */
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int id; /* Service ID# to match this service plugin against, set on installation. */
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/* Public */
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void *arg; /* Optional argument to callback func, set by plugin. */
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int dynamic; /* Reload (SIGHUP) on dynamic event? Set by plugin. */
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int private; /* For callbacks to use freely, possibly to store "states", set by plugin. */
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int (*cb)(void *arg, int event);
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} svc;
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/* List of hook callbacks. */
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struct {
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void *arg; /* Optional argument to callback func. */
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void (*cb)(void *arg);
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} hook[HOOK_MAX_NUM];
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/* I/O Plugin */
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struct {
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int fd, flags; /* 1:READ, 2:WRITE */
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void *arg;
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void (*cb)(void *arg, int fd, int events);
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} io;
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} plugin_t;
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/* Used by svc.h */
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typedef struct plugin_svc plugin_svc_t;
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/* Public plugin API */
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int plugin_register (plugin_t *plugin);
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int plugin_unregister (plugin_t *plugin);
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#endif /* FINIT_PLUGIN_H_ */
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/**
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* Local Variables:
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* version-control: t
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* indent-tabs-mode: t
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* c-file-style: "linux"
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* End:
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*/
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