Subject Header [SIP Headers]

The Subject header provides a summary or indicates the nature of the request. More...

Defines
#define	sip_subject(sip)
	Access a SIP Subject header structure sip_subject_t from sip_t.
#define	SIP_SUBJECT_INIT()
	Initializer for structure sip_subject_t.
#define	SIPTAG_SUBJECT(x)
	Tag list item for pointer to a Subject header structure sip_subject_t.
#define	SIPTAG_SUBJECT_REF(x)
	Tag list item for reference to a Subject header pointer.
#define	SIPTAG_SUBJECT_STR(s)
	Tag list item for string with Subject header value.
#define	SIPTAG_SUBJECT_STR_REF(x)
	Tag list item for reference to a Subject header string.
Typedefs
typedef struct msg_generic_s	sip_subject_t
	The structure sip_subject_t contains representation of a SIP Subject header.
Functions
issize_t	sip_subject_d (su_home_t *, msg_header_t *, char *s, isize_t slen)
	Parse a SIP Subject header.
issize_t	sip_subject_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Print a SIP Subject header.
sip_subject_t *	sip_subject_init (sip_subject_t x[1])
	Initialize a structure sip_subject_t.
int	sip_is_subject (sip_header_t const *header)
	Test if header object is instance of sip_subject_t.
sip_subject_t *	sip_subject_dup (su_home_t *home, sip_subject_t const *hdr))
	Duplicate a list of Subject header header structures sip_subject_t.
sip_subject_t *	sip_subject_copy (su_home_t *home, sip_subject_t const *hdr))
	Copy a list of Subject header header structures sip_subject_t.
sip_subject_t *	sip_subject_make (su_home_t *home, char const *s))
	Make a Subject header structure sip_subject_t.
sip_subject_t *	sip_subject_format (su_home_t *home, char const *fmt,...)))
	Make a Subject header from formatting result.
Variables
msg_hclass_t	sip_subject_class []
	Header class for Subject header.
tag_typedef_t	siptag_subject
	Tag for Subject header object.
tag_typedef_t	siptag_subject_str
	Tag for string with Subject header value.

---

Detailed Description

The Subject header provides a summary or indicates the nature of the request.

Its syntax is defined in RFC 3261 as follows:

    Subject  =  ( "Subject" / "s" ) HCOLON [TEXT-UTF8-TRIM]

The parsed Subject header is stored in sip_subject_t structure.

---

Define Documentation

#define SIP_SUBJECT_INIT

(

)

Initializer for structure sip_subject_t.

A static sip_subject_t structure for Subject header must be initialized with the SIP_SUBJECT_INIT() macro. For instance,

  sip_subject_t sip_subject = SIP_SUBJECT_INIT;

#define SIPTAG_SUBJECT

(

x

)

Tag list item for pointer to a Subject header structure sip_subject_t.

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

Parameters:

x

pointer to a sip_subject_t structure, or NULL.

The corresponding tag taking reference parameter is SIPTAG_SUBJECT_REF().

#define SIPTAG_SUBJECT_STR

(

s

)

Tag list item for string with Subject header value.

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

Parameters:

s

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

The string in SIPTAG_SUBJECT_STR() can be converted to a sip_subject_t header structure by giving the string s has second argument to function sip_subject_make().

The corresponding tag taking reference parameter is SIPTAG_SUBJECT_STR_REF().

---

Typedef Documentation

struct msg_generic_s sip_subject_t

The structure sip_subject_t contains representation of a SIP Subject header.

The sip_subject_t is defined as follows:

 typedef struct msg_generic_s
 {
   msg_common_t   g_common[1];    // Common fragment info
   msg_generic_t *g_next;           // Link to next header
   char const    *g_string;         // Subject text
 } sip_subject_t;

---

Function Documentation

int sip_is_subject

(

sip_header_t const *

header

)

[inline]

Test if header object is instance of sip_subject_t.

Check if the header class is an instance of Subject 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 subject
	0	(false) otherwise

sip_subject_t * sip_subject_copy	(	su_home_t *	home,
		sip_subject_t const *	hdr
	)			[inline]

Copy a list of Subject header header structures sip_subject_t.

The function sip_subject_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

   subject = sip_subject_copy(home, sip->sip_subject);

Returns:

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

sip_subject_t * sip_subject_dup	(	su_home_t *	home,
		sip_subject_t const *	hdr
	)			[inline]

Duplicate a list of Subject header header structures sip_subject_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

   subject = sip_subject_dup(home, sip->sip_subject);

Returns:

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

sip_subject_t * sip_subject_format	(	su_home_t *	home,
		char const *	fmt,
			...
	)			[inline]

Make a Subject header from formatting result.

Make a new sip_subject_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_subject_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_subject_t* sip_subject_init

(

sip_subject_t

x[1]

)

[inline]

Initialize a structure sip_subject_t.

An sip_subject_t structure for Subject header can be initialized with the sip_subject_init() function/macro. For instance,

  sip_subject_t sip_subject;

  sip_subject_init(&sip_subject);

sip_subject_t * sip_subject_make	(	su_home_t *	home,
		char const *	s
	)			[inline]

Make a Subject header structure sip_subject_t.

The function sip_subject_make() makes a new sip_subject_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_subject_t header structure, or NULL upon an error.

---

Variable Documentation

msg_hclass_t sip_subject_class[]

Header class for Subject header.

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