Session-Expires Header [SIP Headers]

The Session-Expires header is used to convey the lifetime of the session. More...

Data Structures
struct	sip_session_expires_s
	Structure for Session-Expires header. More...
Defines
#define	sip_session_expires(sip)
	Access a SIP Session-Expires header structure sip_session_expires_t from sip_t.
#define	SIP_SESSION_EXPIRES_INIT()
	Initializer for structure sip_session_expires_t.
#define	SIPTAG_SESSION_EXPIRES(x)
	Tag list item for pointer to a Session-Expires header structure sip_session_expires_t.
#define	SIPTAG_SESSION_EXPIRES_REF(x)
	Tag list item for reference to a Session-Expires header pointer.
#define	SIPTAG_SESSION_EXPIRES_STR(s)
	Tag list item for string with Session-Expires header value.
#define	SIPTAG_SESSION_EXPIRES_STR_REF(x)
	Tag list item for reference to a Session-Expires header string.
Typedefs
typedef struct sip_session_expires_s	sip_session_expires_t
	The structure sip_session_expires_t contains representation of the SIP Session-Expires header.
Functions
issize_t	sip_session_expires_d (su_home_t *, msg_header_t *, char *s, isize_t slen)
	Parse a SIP Session-Expires header.
issize_t	sip_session_expires_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Print a SIP Session-Expires header.
sip_session_expires_t *	sip_session_expires_init (sip_session_expires_t x[1])
	Initialize a structure sip_session_expires_t.
int	sip_is_session_expires (sip_header_t const *header)
	Test if header object is instance of sip_session_expires_t.
sip_session_expires_t *	sip_session_expires_dup (su_home_t *home, sip_session_expires_t const *hdr))
	Duplicate a list of Session-Expires header header structures sip_session_expires_t.
sip_session_expires_t *	sip_session_expires_copy (su_home_t *home, sip_session_expires_t const *hdr))
	Copy a list of Session-Expires header header structures sip_session_expires_t.
sip_session_expires_t *	sip_session_expires_make (su_home_t *home, char const *s))
	Make a Session-Expires header structure sip_session_expires_t.
sip_session_expires_t *	sip_session_expires_format (su_home_t *home, char const *fmt,...)))
	Make a Session-Expires header from formatting result.
Variables
msg_hclass_t	sip_session_expires_class []
	Header class for Session-Expires header.
tag_typedef_t	siptag_session_expires
	Tag for Session-Expires header object.
tag_typedef_t	siptag_session_expires_str
	Tag for string with Session-Expires header value.

---

Detailed Description

The Session-Expires header is used to convey the lifetime of the session.

Its syntax is defined in RFC 4028 as follows:

      Session-Expires  =  ("Session-Expires" | "x") HCOLON delta-seconds
                           *(SEMI se-params)
      se-params        = refresher-param / generic-param
      refresher-param  = "refresher" EQUAL  ("uas" / "uac")

The parsed Session-Expires header is stored in sip_session_expires_t structure.

---

Define Documentation

#define SIP_SESSION_EXPIRES_INIT

(

)

Initializer for structure sip_session_expires_t.

A static sip_session_expires_t structure for Session-Expires header must be initialized with the SIP_SESSION_EXPIRES_INIT() macro. For instance,

  sip_session_expires_t sip_session_expires = SIP_SESSION_EXPIRES_INIT;

#define SIPTAG_SESSION_EXPIRES

(

x

)

Tag list item for pointer to a Session-Expires header structure sip_session_expires_t.

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

Parameters:

x

pointer to a sip_session_expires_t structure, or NULL.

The corresponding tag taking reference parameter is SIPTAG_SESSION_EXPIRES_REF().

#define SIPTAG_SESSION_EXPIRES_STR

(

s

)

Tag list item for string with Session-Expires header value.

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

Parameters:

s

pointer to a string containing Session-Expires header value, or NULL.

The string in SIPTAG_SESSION_EXPIRES_STR() can be converted to a sip_session_expires_t header structure by giving the string s has second argument to function sip_session_expires_make().

The corresponding tag taking reference parameter is SIPTAG_SESSION_EXPIRES_STR_REF().

---

Typedef Documentation

typedef struct sip_session_expires_s sip_session_expires_t

The structure sip_session_expires_t contains representation of the SIP Session-Expires header.

The sip_session_expires_t is defined as follows:

 typedef struct sip_session_expires_s
 {
  sip_common_t    x_common[1];
  sip_unknown_t  *x_next;
  unsigned long   x_delta; //Delta Seconds
  msg_param_t    *x_params;
  char const     *x_refresher; //Who will send the refresh UAS or UAC
 } sip_session_expires_t;

---

Function Documentation

int sip_is_session_expires

(

sip_header_t const *

header

)

[inline]

Test if header object is instance of sip_session_expires_t.

Check if the header class is an instance of Session-Expires 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 session_expires
	0	(false) otherwise

sip_session_expires_t * sip_session_expires_copy	(	su_home_t *	home,
		sip_session_expires_t const *	hdr
	)			[inline]

Copy a list of Session-Expires header header structures sip_session_expires_t.

The function sip_session_expires_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

   session_expires = sip_session_expires_copy(home, sip->sip_session_expires);

Returns:

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

sip_session_expires_t * sip_session_expires_dup	(	su_home_t *	home,
		sip_session_expires_t const *	hdr
	)			[inline]

Duplicate a list of Session-Expires header header structures sip_session_expires_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

   session_expires = sip_session_expires_dup(home, sip->sip_session_expires);

Returns:

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

sip_session_expires_t * sip_session_expires_format	(	su_home_t *	home,
		char const *	fmt,
			...
	)			[inline]

Make a Session-Expires header from formatting result.

Make a new sip_session_expires_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_session_expires_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_session_expires_t* sip_session_expires_init

(

sip_session_expires_t

x[1]

)

[inline]

Initialize a structure sip_session_expires_t.

An sip_session_expires_t structure for Session-Expires header can be initialized with the sip_session_expires_init() function/macro. For instance,

  sip_session_expires_t sip_session_expires;

  sip_session_expires_init(&sip_session_expires);

sip_session_expires_t * sip_session_expires_make	(	su_home_t *	home,
		char const *	s
	)			[inline]

Make a Session-Expires header structure sip_session_expires_t.

The function sip_session_expires_make() makes a new sip_session_expires_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_session_expires_t header structure, or NULL upon an error.

---

Variable Documentation

msg_hclass_t sip_session_expires_class[]

Header class for Session-Expires header.

The header class sip_session_expires_class defines how a SIP Session-Expires header is parsed and printed. It also contains methods used by SIP parser and other functions to manipulate the sip_session_expires_t header structure.