path: root/contrib/ngatm/man/unisap.3

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.\" Author: Hartmut Brandt <harti@freebsd.org>
.\"
.\" $Begemot: libunimsg/man/unisap.3,v 1.2 2003/08/21 16:01:08 hbb Exp $
.\"
.Dd August 23, 2002
.Dt unisap 3
.Os
.Sh NAME
.Nm unimsg ,
.Nm unisve_check_addr ,
.Nm unisve_check_selector ,
.Nm unisve_check_blli_id2 ,
.Nm unisve_check_blli_id3 ,
.Nm unisve_check_bhli ,
.Nm unisve_check_sap ,
.Nm unisve_overlap_addr ,
.Nm unisve_overlap_selector ,
.Nm unisve_overlap_blli_id2 ,
.Nm unisve_overlap_blli_id3 ,
.Nm unisve_overlap_bhli ,
.Nm unisve_overlap_sap ,
.Nm unisve_is_catchall ,
.Nm unisve_match
.Nd "ATM signalling library - ATM SAP handling"
.Sh LIBRARY
Begemot ATM signalling library
.Pq libunimsg, -lunimsg
.Sh SYNOPSIS
.In uni4/unisap.h
.Ft int
.Fn unisve_check_addr "const struct unisve_addr *sve"
.Ft int
.Fn unisve_check_selector "const struct unisve_selector *sve"
.Ft int
.Fn unisve_check_blli_id2 "const struct unisve_blli_id2 *sve"
.Ft int
.Fn unisve_check_blli_id3 "const struct unisve_blli_id3 *sve"
.Ft int
.Fn unisve_check_bhli "const struct unisve_bhli *sve"
.Ft int
.Fn unisve_check_sap "const struct uni_sap *sve"
.Ft int
.Fn unisve_overlap_addr "const struct unisve_addr *sve1" "const struct unisve_addr *sve2"
.Ft int
.Fn unisve_overlap_selector "const struct unisve_selector *sve1" "const struct unisve_selector *sve2"
.Ft int
.Fn unisve_overlap_blli_id2 "const struct unisve_blli_id2 *sve1" "const struct unisve_blli_id2 *sve2"
.Ft int
.Fn unisve_overlap_blli_id3 "const struct unisve_blli_id3 *sve1" "const struct unisve_blli_id3 *sve2"
.Ft int
.Fn unisve_overlap_bhli "const struct unisve_bhli *sve1" "const struct unisve_bhli *sve2"
.Ft int
.Fn unisve_overlap_sap "const struct uni_sap *sap1" "const struct uni_sap *sap2"
.Ft int
.Fn unisve_is_catchall "const struct uni_sap *sap"
.Ft int
.Fn unisve_match "const struct uni_sap *sap" \
"const struct uni_ie_called *called" "const struct uni_ie_blli *blli" \
"const struct uni_ie_bhli *bhli"
.Sh DESCRIPTION
The
.Nm
library contains functions to handle Service Access Points (SAP) and SAP Vector
Elements (SVE) as specified in the ATM Forum ATM API Semantic Description.
SAPs are the analog of TCP and UDP ports in the ATM world. As usually in ATM
they are a couple of orders of magnitude more complex as their Internet
equivalent. See the ATM Forum document for a description.
.Pp
A SAP is a data structure:
.Bd -literal -offset indent
struct uni_sap {
	struct unisve_addr	addr;
	struct unisve_selector	selector;
	struct unisve_blli_id2	blli_id2;
	struct unisve_blli_id3	blli_id3;
	struct unisve_bhli	bhli;
};
.Ed
.Pp
that consists of 5 elements matching different information elements in
the SETUP message. Each of these elements has a tag that defines how
the SVE is to be matched with the information element. The tag is one of
.Bl -tag -widht ".It Dv UNISVE_PRESENT"
.It Dv UNISVE_ABSENT
The information element has to absent from the SETUP message.
.It Dv UNISVE_PRESENT
The information element has to be present in the SETUP message and must
match the SVE.
.It Dv UNISVE_ANY
The information element may be absent from the SETUP message or may
have any value.
.El
.Pp
The called address is matched by a
.Bd -literal -offset indent
struct unisve_addr {
	enum unisve_tag	tag;
	enum uni_addr_type type;/* type of address */
	enum uni_addr_plan plan;/* addressing plan */
	u_int32_t	len;	/* length of address */
	u_char		addr[UNI_ADDR_MAXLEN];
};
.Ed
.Pp
Here
.Fa type
is the type of address and
.Fa plan
is the address plan.
.Fa len
is the length of the address (for ATME addresses not counting the selector byte)
and
.Fa addr is the address itself.
.Pp
In case of ATME addresses the selector byte is matched by a
.Bd -literal -offset indent
struct unisve_selector {
	enum unisve_tag	tag;
	u_int8_t	selector;
};
.Ed
.Pp
Here
.Fa selector
is the selector byte that must match the 20th byte of the ATME calling address
from the SETUP message.
.Pp
The BLLI information element is matched by two SVEs: one for layer 2 options
and one for layer 3 options. The layer 2 SVE is:
.Bd -literal -offset indent
struct unisve_blli_id2 {
	enum unisve_tag	tag;
	u_int8_t	proto:5;/* the protocol */
	u_int8_t	user:7;	/* user specific protocol */
};
.Ed
.Pp
Where the
.Fa user
fields is matched only if the
.Fa proto
field specifies 
.Dv UNI_BLLI_L2_USER .
The layer 3 SVE is:
.Bd -literal -offset indent
struct unisve_blli_id3 {
	enum unisve_tag	tag;
	u_int8_t	proto:5;/* L3 protocol */
	u_int8_t	user:7;	/* user specific protocol */
	u_int8_t	ipi:8;	/* ISO/IEC TR 9557 IPI */
	u_int32_t	oui:24;	/* IEEE 802.1 OUI */
	u_int32_t	pid:16;	/* IEEE 802.1 PID */
	u_int32_t	noipi;	/* ISO/IEC TR 9557 per frame */
};
.Ed
For the exact rules how matching occures refer to the source code or the
ATM Forum document.
.Pp
Finally the BHLI information element is matched with a
.Bd -literal -offset indent
struct unisve_bhli {
	enum unisve_tag	tag;
	enum uni_bhli	type;	/* type of info */
	u_int32_t	len;	/* length of info */
	u_int8_t	info[8];/* info itself */
};
.Ed
.Pp
For each SVE type there is a function that checks whether the SVE is correct
specified. The functions
.Fn unisve_check_addr ,
.Fn unisve_check_selector ,
.Fn unisve_check_blli_id2 ,
.Fn unisve_check_blli_id3 ,
and
.Fn unisve_check_bhli
return one of the following error codes:
.Bd -literal -offset indent
enum {
	UNISVE_OK = 0,
	UNISVE_ERROR_BAD_TAG,
	UNISVE_ERROR_TYPE_PLAN_CONFLICT,
	UNISVE_ERROR_ADDR_SEL_CONFLICT,
	UNISVE_ERROR_ADDR_LEN,
	UNISVE_ERROR_BAD_ADDR_TYPE,
	UNISVE_ERROR_BAD_BHLI_TYPE,
	UNISVE_ERROR_BAD_BHLI_LEN,
};
.Ed
.Pp
A code of
.Li UNISVE_OK
means that the SVE has no error.
The function
.Fn unisve_check_sap
checks a complete SAP and returns one of the above codes.
.Pp
There is a definition
.Dv UNISVE_ERRSTR					
that evaluates to a comma separated list of strings that can be used
to initializes an array of char pointers to map the error codes into
human readable strings.
.Pp
The ATM Forum document defines the concept of overlaping SAPs. This basically
means, that an incoming SETUP could match more than one SAP (and more than
one application) to receive the SETUP. For each SVE type there is a function
that checks whether two SVEs overlap and there is a function that checks whether
two SAPs overlap. The functions
.Fn unisve_overlap_addr ,
.Fn unisve_overlap_selector ,
.Fn unisve_overlap_blli_id2 ,
.Fn unisve_overlap_blli_id3 ,
.Fn unisve_overlap_bhli , and
.Fn unisve_overlap_sap
return 1 if the SVEs or SAPs overlap and 0 if they do not. They assume, that
the SAPs are correct.
.Pp
The ATM Forum document specifies a catch-all SAP. The function
.Fn unisve_is_catchall
returns 1 if the SAP is the catch-all SAP and 0 otherwise.
.Pp
Finally the function
.Fn unisve_match
is used to match a SAP against the information elements from a SETUP message.
It returns 1 if they match and 0 otherwise.
.Sh SEE ALSO
.Xr libunimsg 3 ,
.Sh AUTHORS
.An Hartmut Brandt Aq harti@freebsd.org