Min-Expires Header [SIP Headers]

The Min-Expires header is used to limit the number of proxies or gateways that can forward the request. More...

Data Structures
struct	sip_min_expires_s
	Structure for Min-Expires header. More...
Defines
#define	sip_min_expires(sip)
	Access a SIP Min-Expires header structure sip_min_expires_t from sip_t.
#define	SIP_MIN_EXPIRES_INIT()
	Initializer for structure sip_min_expires_t.
#define	SIPTAG_MIN_EXPIRES(x)
	Tag list item for pointer to a Min-Expires header structure sip_min_expires_t.
#define	SIPTAG_MIN_EXPIRES_REF(x)
	Tag list item for reference to a Min-Expires header pointer.
#define	SIPTAG_MIN_EXPIRES_STR(s)
	Tag list item for string with Min-Expires header value.
#define	SIPTAG_MIN_EXPIRES_STR_REF(x)
	Tag list item for reference to a Min-Expires header string.
Typedefs
typedef struct sip_min_expires_s	sip_min_expires_t
	The structure sip_min_expires_t contains representation of SIP Min-Expires header.
Functions
issize_t	sip_min_expires_d (su_home_t *, msg_header_t *, char *s, isize_t slen)
	Parse a SIP Min-Expires header.
issize_t	sip_min_expires_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Print a SIP Min-Expires header.
sip_min_expires_t *	sip_min_expires_init (sip_min_expires_t x[1])
	Initialize a structure sip_min_expires_t.
int	sip_is_min_expires (sip_header_t const *header)
	Test if header object is instance of sip_min_expires_t.
sip_min_expires_t *	sip_min_expires_dup (su_home_t *home, sip_min_expires_t const *hdr))
	Duplicate a list of Min-Expires header header structures sip_min_expires_t.
sip_min_expires_t *	sip_min_expires_copy (su_home_t *home, sip_min_expires_t const *hdr))
	Copy a list of Min-Expires header header structures sip_min_expires_t.
sip_min_expires_t *	sip_min_expires_make (su_home_t *home, char const *s))
	Make a Min-Expires header structure sip_min_expires_t.
sip_min_expires_t *	sip_min_expires_format (su_home_t *home, char const *fmt,...)))
	Make a Min-Expires header from formatting result.
Variables
msg_hclass_t	sip_min_expires_class []
	Header class for Min-Expires header.
tag_typedef_t	siptag_min_expires
	Tag for Min-Expires header object.
tag_typedef_t	siptag_min_expires_str
	Tag for string with Min-Expires header value.

---

Detailed Description

The Min-Expires header is used to limit the number of proxies or gateways that can forward the request.

The Min-Expires syntax is defined in RFC 3261 as follows:

    Min-Expires  =  "Min-Expires" HCOLON delta-seconds

The parsed Min-Expires header is stored in sip_min_expires_t structure.

---

Define Documentation

#define SIP_MIN_EXPIRES_INIT

(

)

Initializer for structure sip_min_expires_t.

A static sip_min_expires_t structure for Min-Expires header must be initialized with the SIP_MIN_EXPIRES_INIT() macro. For instance,

  sip_min_expires_t sip_min_expires = SIP_MIN_EXPIRES_INIT;

#define SIPTAG_MIN_EXPIRES

(

x

)

Tag list item for pointer to a Min-Expires header structure sip_min_expires_t.

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

Parameters:

x

pointer to a sip_min_expires_t structure, or NULL.

The corresponding tag taking reference parameter is SIPTAG_MIN_EXPIRES_REF().

#define SIPTAG_MIN_EXPIRES_STR

(

s

)

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

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

Parameters:

s

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

The string in SIPTAG_MIN_EXPIRES_STR() can be converted to a sip_min_expires_t header structure by giving the string s has second argument to function sip_min_expires_make().

The corresponding tag taking reference parameter is SIPTAG_MIN_EXPIRES_STR_REF().

---

Typedef Documentation

typedef struct sip_min_expires_s sip_min_expires_t

The structure sip_min_expires_t contains representation of SIP Min-Expires header.

The sip_min_expires_t is defined as follows:

 typedef struct sip_min_expires_s {
   sip_common_t        me_common[1];  // Common fragment info
   sip_error_t        *me_next;       // Link to next (dummy)
   unsigned long       me_delta;      // Seconds
 } sip_min_expires_t;

---

Function Documentation

int sip_is_min_expires

(

sip_header_t const *

header

)

[inline]

Test if header object is instance of sip_min_expires_t.

Check if the header class is an instance of Min-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 min_expires
	0	(false) otherwise

sip_min_expires_t * sip_min_expires_copy	(	su_home_t *	home,
		sip_min_expires_t const *	hdr
	)			[inline]

Copy a list of Min-Expires header header structures sip_min_expires_t.

The function sip_min_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

   min_expires = sip_min_expires_copy(home, sip->sip_min_expires);

Returns:

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

sip_min_expires_t * sip_min_expires_dup	(	su_home_t *	home,
		sip_min_expires_t const *	hdr
	)			[inline]

Duplicate a list of Min-Expires header header structures sip_min_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

   min_expires = sip_min_expires_dup(home, sip->sip_min_expires);

Returns:

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

sip_min_expires_t * sip_min_expires_format	(	su_home_t *	home,
		char const *	fmt,
			...
	)			[inline]

Make a Min-Expires header from formatting result.

Make a new sip_min_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_min_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_min_expires_t* sip_min_expires_init

(

sip_min_expires_t

x[1]

)

[inline]

Initialize a structure sip_min_expires_t.

An sip_min_expires_t structure for Min-Expires header can be initialized with the sip_min_expires_init() function/macro. For instance,

  sip_min_expires_t sip_min_expires;

  sip_min_expires_init(&sip_min_expires);

sip_min_expires_t * sip_min_expires_make	(	su_home_t *	home,
		char const *	s
	)			[inline]

Make a Min-Expires header structure sip_min_expires_t.

The function sip_min_expires_make() makes a new sip_min_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_min_expires_t header structure, or NULL upon an error.

---

Variable Documentation

msg_hclass_t sip_min_expires_class[]

Header class for Min-Expires header.

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