t6recvfrom(3N)							t6recvfrom(3N)

NAME    [Toc]    [Back]

     t6recvfrom	- Read security	attributes and data from a trusted endpoint

SYNOPSIS    [Toc]    [Back]

     cc	[ flags	... ] file

     #include <sys/t6attrs.h>

     int t6recvfrom(int	fd, char *buf, int len,	int flags,
	  struct sockaddr *from, int *fromlen,
	  t6attr_t attr_ptr, t6mask_t *new_attrs);

DESCRIPTION    [Toc]    [Back]

     t6recvfrom	receives data and its associated security attributes from a
     communication endpoint.  The from and fromlen parameters are only used if
     you wish to receive the source address for	the data.  This	may not	be
     applicable	for some trusted endpoints.  If	not used, these	fields should
     be	set to 0.  If from is not a NULL pointer, the source address of	the
     message is	filled in.  fromlen is a value-result parameter, initialized
     to	the size of the	buffer associated with from, and modified on return to
     indicate the actual size of the address stored there.  The	length of the
     message is	returned.  If a	message	is too long to fit in the supplied
     buffer, excess bytes may be discarded depending on	the type of socket the
     message is	received from (see socket(3N)).

     The flags parameter is formed by ORing one	or more	of the following:

     MSG_OOB
	  Read any out-of-band data present on the socket rather than the
	  regular in-band data.	 If attr_ptr is	non-NULL, out-of-band data
	  security attributes are also retrieved.

     MSG_PEEK
	  Peek at the data present on the socket; the data is returned,	but
	  not consumed,	so that	a subsequent receive operation will see	the
	  same data.  If attr_ptr is non-NULL, security	attributes of the data
	  are also peeked.

     attr_ptr specifies	a control structure in which to	store those attributes
     the caller	wishes to retrieve. To get an attribute	from the control
     structure,	see t6get_attr(3N).  Any attribute that	the receiving process
     does not care to receive may not be specified in the control structure.
     This minimizes the	attribute translation time when	passing	the attributes
     out of the	kernel.

     Note that the following attributes	will never be returned in the argument
     t6attr_t: T6_NAT_CAVEATS, T6_ACL, T6_IL, T6_PID, T6_RESV10,
     T6_AUDIT_INFO, T6_CLEARANCE.

     If	the t6new_attr(3N) call	was made previously with a setting of ON, the
     security attributes of the	received data will be returned only if they
     have changed from the last	set read.  *new_attrs is set to	the mask of



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t6recvfrom(3N)							t6recvfrom(3N)



     those attributes actually returned. If new	attributes are detected, all
     attributes	requested by the receiving process are returned, not just
     those that	have changed.

     Again, it is critical that	the return value always	be checked.  It	is the
     number of bytes actually received,	or -1 with the error code stored in
     errno.  Revocation	of access is possible if the received data changes to
     a level not accessible to the receiving process.

RETURN VALUE    [Toc]    [Back]

     t6recvfrom	returns	the appropriate	error code on failure, and the number
     of	bytes read on successful completion.

ERRORS    [Toc]    [Back]

     [EBADF]	    fd is an invalid file descriptor.

     [EINTR]	    The	operation was interrupted by delivery of a signal
		    before any data was	available to be	received.

     [EIO]	    An I/O error occurred while	reading	from or	writing	to the
		    file system.

     [ENOMEM]	    There was insufficient user	memory available for the
		    operation to complete.

     [ENOSR]	    There were insufficient STREAMS resources available	for
		    the	operation to complete.

     [ENOTSOCK]	    fd is not a	socket.

     [ESTALE]	    A stale NFS	file handle exists.

SEE ALSO    [Toc]    [Back]

     libt6(3N),	t6get_attr(3N),	t6sendto(3N).

SOURCE    [Toc]    [Back]

     Trusted Systems Interoperability Group

NOTES    [Toc]    [Back]

									PPPPaaaaggggeeee 2222