77 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
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cinit commands,
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Nico Schottelius 2005-04-28 (Last Modified: 2005-06-11)
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cinit allows communication through a socket (see ipc.thoughs for reasons).
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Sockets allow to find out the accessing uid, gid and pid (uses SO_PEERCRED as
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socketoption).
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The communication-protocol is binary, the implementation can be found
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in comm/* mostly (clients use begin_msg() and server sigio() additonally).
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Protocol overview
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Any communication begins with a command. A command is a one byte
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unsigned char. Depending on the command, the communication has its own
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semantics.
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Commands are: (values can be found in cinit.h)
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   CMD_START_SVC:    I want to start a service.
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   CMD_CHG_STATUS:   I want to change the status of a service.
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   CMD_STOP_SVC:     Please shutdown a service. **)
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   CMD_RESCUE:       Kill everything, and spawn a sulogin shell.**)
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   CMD_INIT:         Start all services (again possibly).**)
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   CMD_HALT:         Halt the system*)
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   CMD_REBOOT:       Reboot the system*)
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   CMD_POWEROFF:     Power-off the system*)
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      *) The commands are not and maybe will never be implemented,
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         as they are realized another way (using signals).
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      **) Not yet implemented.
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Detailled command-listing
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CMD_START_SVC
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   1. int len;       /* length of service name, including \0 */
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   2. char *svc;     /* name of the service, absolute pathname */ 
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   cinit returns:
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      a) status of service
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      b) fail
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CMD_CHG_STATUS:   I want to change the status of a service.
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   0. int len;
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   1. char *svc;
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   2. char status;   /* status:
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                        once: started successfully the service once.
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                        fail: tried to start once, but the service exit ungracefully
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                        respawn: I am on it, as soon it exists I'll restart! */
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   2. pid_t pid      /* the pid of the service, if started once
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                        or the pid of the service watcher, if respawning */
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   cinit returns: MSG_OK|MSG_FAIL (char)
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CMD_STOP_SVC:     Please shutdown a service and its dependencies.
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   1. int len;       /* length of service name, including \0 */
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   2. char *svc;     /* name of the service, absolute pathname */ 
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   cinit returns: Status of service (should be ST_OFF)
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The following commands do not return anything nor do they need any parameter:
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CMD_RESCUE:       Kill everything, and spawn a sulogin shell. Irreversible.
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CMD_HALT:         Halt the system.
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CMD_REBOOT:       Reboot the system.
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CMD_POWEROFF:     Power-off the system.
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