Replaces Header [SIP Headers]

The Replaces header indicates that a single dialog identified by the header field is to be shut down and logically replaced by the incoming INVITE in which it is contained. More...

Data Structures
struct	sip_replaces_s
	Structure for Replaces header. More...
Defines
#define	sip_replaces(sip)
	Access a SIP Replaces header structure sip_replaces_t from sip_t.
#define	SIP_REPLACES_INIT()
	Initializer for structure sip_replaces_t.
#define	SIPTAG_REPLACES(x)
	Tag list item for pointer to a Replaces header structure sip_replaces_t.
#define	SIPTAG_REPLACES_REF(x)
	Tag list item for reference to a Replaces header pointer.
#define	SIPTAG_REPLACES_STR(s)
	Tag list item for string with Replaces header value.
#define	SIPTAG_REPLACES_STR_REF(x)
	Tag list item for reference to a Replaces header string.
Typedefs
typedef struct sip_replaces_s	sip_replaces_t
	The structure sip_replaces_t contains representation of Replaces header.
Functions
issize_t	sip_replaces_d (su_home_t *, msg_header_t *, char *s, isize_t slen)
	Parse a SIP Replaces header.
issize_t	sip_replaces_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Print a SIP Replaces header.
sip_replaces_t *	sip_replaces_init (sip_replaces_t x[1])
	Initialize a structure sip_replaces_t.
int	sip_is_replaces (sip_header_t const *header)
	Test if header object is instance of sip_replaces_t.
sip_replaces_t *	sip_replaces_dup (su_home_t *home, sip_replaces_t const *hdr))
	Duplicate a list of Replaces header header structures sip_replaces_t.
sip_replaces_t *	sip_replaces_copy (su_home_t *home, sip_replaces_t const *hdr))
	Copy a list of Replaces header header structures sip_replaces_t.
sip_replaces_t *	sip_replaces_make (su_home_t *home, char const *s))
	Make a Replaces header structure sip_replaces_t.
sip_replaces_t *	sip_replaces_format (su_home_t *home, char const *fmt,...)))
	Make a Replaces header from formatting result.
Variables
msg_hclass_t	sip_replaces_class []
	Header class for Replaces header.
tag_typedef_t	siptag_replaces
	Tag for Replaces header object.
tag_typedef_t	siptag_replaces_str
	Tag for string with Replaces header value.

---

Detailed Description

The Replaces header indicates that a single dialog identified by the header field is to be shut down and logically replaced by the incoming INVITE in which it is contained.

Its syntax is defined in RFC 3891 section 6.1 as follows:

    Replaces        = "Replaces" HCOLON callid *(SEMI replaces-param)
    replaces-param  = to-tag / from-tag / early-flag / generic-param
    to-tag          = "to-tag" EQUAL token
    from-tag        = "from-tag" EQUAL token
    early-flag      = "early-only"

A Replaces header field MUST contain exactly one <to-tag> and exactly one <from-tag>, as they are required for unique dialog matching. For compatibility with dialogs initiated by RFC 2543 compliant UAs, a tag of zero ("0") matches both tags of zero and null. A Replaces header field MAY contain the <early-only> flag.

The parsed Replaces header is stored in sip_replaces_t structure.

See also:

RFC 3891, nta_leg_by_replaces(), nta_leg_make_replaces()

---

Define Documentation

#define SIP_REPLACES_INIT

(

)

Initializer for structure sip_replaces_t.

A static sip_replaces_t structure for Replaces header must be initialized with the SIP_REPLACES_INIT() macro. For instance,

  sip_replaces_t sip_replaces = SIP_REPLACES_INIT;

#define SIPTAG_REPLACES

(

x

)

Tag list item for pointer to a Replaces header structure sip_replaces_t.

The SIPTAG_REPLACES() macro is used to include a tag item with a pointer to a sip_replaces_t structure in a tag list.

Parameters:

x

pointer to a sip_replaces_t structure, or NULL.

The corresponding tag taking reference parameter is SIPTAG_REPLACES_REF().

#define SIPTAG_REPLACES_STR

(

s

)

Tag list item for string with Replaces header value.

The SIPTAG_REPLACES_STR() macro is used to include a tag item with a string containing value of a sip_replaces_t header in a tag list.

Parameters:

s

pointer to a string containing Replaces header value, or NULL.

The string in SIPTAG_REPLACES_STR() can be converted to a sip_replaces_t header structure by giving the string s has second argument to function sip_replaces_make().

The corresponding tag taking reference parameter is SIPTAG_REPLACES_STR_REF().

---

Typedef Documentation

typedef struct sip_replaces_s sip_replaces_t

The structure sip_replaces_t contains representation of Replaces header.

The sip_replaces_t is defined as follows:

 typedef struct sip_replaces_s
 {
   sip_common_t        rp_common[1];   // Common fragment info
   sip_error_t        *rp_next;  // Dummy link to next
   char const         *rp_call_id;     // @CallID of dialog to replace
   msg_param_t const  *rp_params;      // List of parameters
   char const         *rp_to_tag;      // Value of "to-tag" parameter
   char const         *rp_from_tag;    // Value of "from-tag" parameter
   unsigned            rp_early_only;  // early-only parameter
 } sip_replaces_t;

---

Function Documentation

int sip_is_replaces

(

sip_header_t const *

header

)

[inline]

Test if header object is instance of sip_replaces_t.

Check if the header class is an instance of Replaces header object and return true (nonzero), otherwise return false (zero).

Parameters:

header

pointer to the header structure to be tested

Return values:

	1	(true) if the header is an instance of header replaces
	0	(false) otherwise

sip_replaces_t * sip_replaces_copy	(	su_home_t *	home,
		sip_replaces_t const *	hdr
	)			[inline]

Copy a list of Replaces header header structures sip_replaces_t.

The function sip_replaces_copy() copies a header structure hdr. If the header structure hdr contains a reference (hdr->h_next) to a list of headers, all the headers in that list are copied, too. The function uses given memory home to allocate all the memory areas used to copy the list of header structure hdr.

Parameters:

	home	memory home used to allocate new structure
	hdr	pointer to the header structure to be copied

When copying, only the header structure and parameter lists attached to it are duplicated. The new header structure retains all the references to the strings within the old hdr header, including the encoding of the old header, if present.

Example

   replaces = sip_replaces_copy(home, sip->sip_replaces);

Returns:

A pointer to newly copied header structure, or NULL upon an error.

sip_replaces_t * sip_replaces_dup	(	su_home_t *	home,
		sip_replaces_t const *	hdr
	)			[inline]

Duplicate a list of Replaces header header structures sip_replaces_t.

Duplicate a header structure hdr. If the header structure hdr contains a reference (hdr->x_next) to a list of headers, all the headers in the list are duplicated, too.

Parameters:

	home	memory home used to allocate new structure
	hdr	header structure to be duplicated

When duplicating, all parameter lists and non-constant strings attached to the header are copied, too. The function uses given memory home to allocate all the memory areas used to copy the header.

Example

   replaces = sip_replaces_dup(home, sip->sip_replaces);

Returns:

A pointer to the newly duplicated sip_replaces_t header structure, or NULL upon an error.

sip_replaces_t * sip_replaces_format	(	su_home_t *	home,
		char const *	fmt,
			...
	)			[inline]

Make a Replaces header from formatting result.

Make a new sip_replaces_t object using formatting result as its value. The function first prints the arguments according to the format fmt specified. Then it allocates a new header structure, and parses the formatting result to the structure sip_replaces_t.

Parameters:

	home	memory home used to allocate new header structure.
	fmt	string used as a printf()-style format
	...	argument list for format

Returns:

A pointer to newly makes header structure, or NULL upon an error.

sip_replaces_t* sip_replaces_init

(

sip_replaces_t

x[1]

)

[inline]

Initialize a structure sip_replaces_t.

An sip_replaces_t structure for Replaces header can be initialized with the sip_replaces_init() function/macro. For instance,

  sip_replaces_t sip_replaces;

  sip_replaces_init(&sip_replaces);

sip_replaces_t * sip_replaces_make	(	su_home_t *	home,
		char const *	s
	)			[inline]

Make a Replaces header structure sip_replaces_t.

The function sip_replaces_make() makes a new sip_replaces_t header structure. It allocates a new header structure, and decodes the string s as the value of the structure.

Parameters:

	home	memory home used to allocate new header structure.
	s	string to be decoded as value of the new header structure

Returns:

A pointer to newly maked sip_replaces_t header structure, or NULL upon an error.

---

Variable Documentation

msg_hclass_t sip_replaces_class[]

Header class for Replaces header.

The header class sip_replaces_class defines how a SIP Replaces header is parsed and printed. It also contains methods used by SIP parser and other functions to manipulate the sip_replaces_t header structure.