libtnfctl(3TNF) 					       TNF Library Functions						   libtnfctl(3TNF)

NAME

       libtnfctl - library for TNF probe control in a process or the kernel

SYNOPSIS

       cc [ flag ... ] file ... -ltnfctl [ library ... ]
       #include <tnf/tnfctl.h>

DESCRIPTION

       The  libtnfctl library provides an  API to control  TNF ("Trace Normal Form") probes within a process or the kernel.  See tracing(3TNF) for
       an overview of the Solaris tracing architecture. The client of libtnfctl controls probes in one of four modes:

       internal mode   The target is the controlling process itself; that is, the client controls its own probes.

       direct mode     The target is a separate process; a client can either  exec(2) a program or attach to a running process for probe  control.
		       The  libtnfctl library uses proc(4) on the target process for probe and process control in this mode, and additionally pro-
		       vides basic process control features.

       indirect mode   The target is a separate process, but the controlling process is already using proc(4) to control  the  target,	and  hence
		       libtnfctl  cannot use those interfaces directly.  Use this mode to control probes from within a debugger. In this mode, the
		       client must provide a set of functions that libtnfctl can use to query and update the target process.

       kernel mode     The target is the Solaris kernel.

       A process is controlled "externally" if it is being controlled in either direct mode or indirect mode. Alternatively,  a  process  is  con-
       trolled "internally" when it uses internal mode to control its own probes.

       There can be only one client at a time doing probe control on a given process. Therefore, it is not possible for a process to be controlled
       internally while it is being controlled externally. It is also not possible to have a process controlled by  multiple  external	processes.
       Similarly,  there  can  be only one process at a time doing kernel probe control. Note, however, that while a given target may only be con-
       trolled by one libtnfctl client, a single client may control an arbitrary number of targets. That is, it  is  possible  for  a  process	to
       simultaneously control its own probes, probes in other processes, and probes in the kernel.

       The following tables denotes the modes applicable to all libtnfctl interfaces (INT = internal mode; D = direct mode; IND = indirect mode; K
       = kernel mode).

       These interfaces create handles in the specified modes:

       tnfctl_internal_open()	   INT
       tnfctl_exec_open()		     D
       tnfctl_pid_open()		     D
       tnfctl_indirect_open()				IND
       tnfctl_kernel_open()					   K

       These interfaces are used with the specified modes:

       tnfctl_continue()			   D
       tnfctl_probe_connect()		INT	   D	      IND
       tnfctl_probe_disconnect_all ()	INT	   D	      IND
       tnfctl_trace_attrs_get() 	INT	   D	      IND	K
       tnfctl_buffer_alloc()		INT	   D	      IND	K

       tnfctl_register_funcs()		INT	   D	      IND	K
       tnfctl_probe_apply()		INT	   D	      IND	K
       tnfctl_probe_apply_ids() 	INT	   D	      IND	K
       tnfctl_probe_state_get ()	INT	   D	      IND	K
       tnfctl_probe_enable()		INT	   D	      IND	K
       tnfctl_probe_disable()		INT	   D	      IND	K
       tnfctl_probe_trace()		INT	   D	      IND	K
       tnfctl_probe_untrace()		INT	   D	      IND	K
       tnfctl_check_libs()		INT	   D	      IND	K
       tnfctl_close()			INT	   D	      IND	K
       tnfctl_strerror()		INT	   D	      IND	K
       tnfctl_buffer_dealloc()						K
       tnfctl_trace_state_set() 					K
       tnfctl_filter_state_set()					K
       tnfctl_filter_list_get() 					K
       tnfctl_filter_list_add() 					K
       tnfctl_filter_list_delete()					K

       When using libtnfctl, the first task is to create a handle for controlling probes. The tnfctl_internal_open() function creates an  internal
       mode  handle  for controlling probes in the same process, as described above. The tnfctl_pid_open() and tnfctl_exec_open() functions create
       handles in direct mode. The tnfctl_indirect_open() function creates an indirect mode handle, and the tnfctl_kernel_open() function  creates
       a  kernel  mode	handle.  A  handle  is required for use in nearly all other  libtnfctl functions. The tnfctl_close() function releases the
       resources associated with a handle.

       The tnfctl_continue() function is used in direct mode to resume execution of the target process.

       The tnfctl_buffer_alloc() function allocates a trace file or, in kernel mode, a trace buffer.

       The tnfctl_probe_apply() and tnfctl_probe_apply_ids() functions call a specified function for each probe or for a designated set of probes.

       The tnfctl_register_funcs() function registers functions to be called whenever new probes are seen or probes have disappeared, providing an
       opportunity to do one-time processing for each probe.

       The  tnfctl_check_libs() function is used primarily in indirect mode to check whether any new probes have appeared, that is, they have been
       made available by  dlopen(3C), or have disappeared, that is, they have disassociated from the process by dlclose(3C).

       The tnfctl_probe_enable() and tnfctl_probe_disable() functions control whether the probe, when hit, will be ignored.

       The tnfctl_probe_trace() and tnfctl_probe_untrace() functions control whether an enabled probe, when hit, will cause an entry to be made in
       the trace file.

       The tnfctl_probe_connect() and tnfctl_probe_disconnect_all() functions control which functions, if any, are called when an enabled probe is
       hit.

       The tnfctl_probe_state_get() function returns information about the status of a probe, such as whether it is currently enabled.

       The tnfctl_trace_attrs_get() function returns information about the tracing session, such as the  size of the trace buffer or trace file.

       The tnfctl_strerror() function maps a  tnfctl error code to a string, for reporting purposes.

       The remaining functions apply only to kernel mode.

       The tnfctl_trace_state_set() function controls the master switch for kernel tracing.  See prex(1) for more details.

       The tnfctl_filter_state_set(), tnfctl_filter_list_get(), tnfctl_filter_list_add(), and tnfctl_filter_list_delete() functions allow a set of
       processes  to  be  specified for which probes will not be ignored when hit. This prevents kernel activity caused by uninteresting processes
       from cluttering up the kernel's trace buffer.

       The tnfctl_buffer_dealloc() function deallocates the kernel's internal trace buffer.

RETURN VALUES

       Upon successful completion, these functions returnTNFCTL_ERR_NONE.

ERRORS

       The error codes for  libtnfctl are:

       TNFCTL_ERR_ACCES 	       Permission denied.

       TNFCTL_ERR_NOTARGET	       The target process completed.

       TNFCTL_ERR_ALLOCFAIL	       A memory allocation failure occurred.

       TNFCTL_ERR_INTERNAL	       An internal error occurred.

       TNFCTL_ERR_SIZETOOSMALL	       The requested trace size is too small.

       TNFCTL_ERR_SIZETOOBIG	       The requested trace size is too big.

       TNFCTL_ERR_BADARG	       Bad input argument.

       TNFCTL_ERR_NOTDYNAMIC	       The target is not a dynamic executable.

       TNFCTL_ERR_NOLIBTNFPROBE        libtnfprobe.so not linked in target.

       TNFCTL_ERR_BUFBROKEN	       Tracing is broken in the target.

       TNFCTL_ERR_BUFEXISTS	       A buffer already exists.

       TNFCTL_ERR_NOBUF 	       No buffer exists.

       TNFCTL_ERR_BADDEALLOC	       Cannot deallocate buffer.

       TNFCTL_ERR_NOPROCESS	       No such target process exists.

       TNFCTL_ERR_FILENOTFOUND	       File not found.

       TNFCTL_ERR_BUSY		       Cannot attach to process or kernel because it is already tracing.

       TNFCTL_ERR_INVALIDPROBE	       Probe no longer valid.

       TNFCTL_ERR_USR1		       Error code reserved for user.

       TNFCTL_ERR_USR2		       Error code reserved for user.

       TNFCTL_ERR_USR3		       Error code reserved for user.

       TNFCTL_ERR_USR4		       Error code reserved for user.

       TNFCTL_ERR_USR5		       Error code reserved for user.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWtnfc			   |
       +-----------------------------+-----------------------------+
       |MT Level		     |MT-Safe with exceptions	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       prex(1),     exec(2),	 dlclose(3C),	  dlopen(3C),	  TNF_PROBE(3TNF),     tnfctl_buffer_alloc(3TNF),     tnfctl_buffer_dealloc(3TNF),
       tnfctl_check_libs(3TNF),   tnfctl_close(3TNF),	tnfctl_continue(3TNF),	 tnfctl_internal_open(3TNF),  tnfctl_exec_open(3TNF),  tnfctl_fil-
       ter_list_add(3TNF),    tnfctl_filter_list_delete(3TNF),	  tnfctl_filter_list_get(3TNF),    tnfctl_filter_state_set(3TNF),      tnfctl_ker-
       nel_open(3TNF),	    tnfctl_pid_open(3TNF),     tnfctl_probe_apply(3TNF),     tnfctl_probe_apply_ids(3TNF),     tnfctl_probe_connect(3TNF),
       tnfctl_probe_disable(3TNF), tnfctl_probe_enable(3TNF), tnfctl_probe_state_get(3TNF), tnfctl_probe_trace(3TNF),  tnfctl_probe_untrace(3TNF),
       tnfctl_indirect_open(3TNF), tnfctl_register_funcs(3TNF), tnfctl_strerror(3TNF), tnfctl_trace_attrs_get(3TNF), tnfctl_trace_state_set(3TNF),
       libtnfctl(3LIB), proc(4), attributes(5)

       Linker and Libraries Guide

NOTES

       This  API is MT-Safe.  Multiple threads may concurrently operate on independent tnfctl handles, which is  the  typical  behavior  expected.
       The  libtnfctl  library	does  not  support  multiple  threads operating on the same tnfctl handle.  If this is desired, it is the client's
       responsibility to implement  locking to ensure that two threads that use the same tnfctl handle	are  not  simultaneously  in  a  libtnfctl
       interface.

SunOS 5.10							    1 Mar 2004							   libtnfctl(3TNF)