sofia-sip/msg_header.h File Reference

Detailed Description

Message headers.

Author:: Pekka Pessi <Pekka.Pessi@nokia-email.address.hidden>

Date:: Created: Mon Aug 27 15:44:27 2001 ppessi

#include <stdarg.h>
#include <string.h>
#include <sofia-sip/su_types.h>
#include <sofia-sip/su_alloc.h>
#include <sofia-sip/msg.h>
#include <sofia-sip/url.h>
#include <sofia-sip/msg_protos.h>

Include dependency graph for msg_header.h:

Go to the source code of this file.

Defines

#define MSG_CHUNK_BUFFER(pl)

Get pointer to beginning of available buffer space.

#define MSG_CHUNK_AVAIL(pl)

Get size of available buffer space.

#define MSG_CHUNK_NEXT(pl)

Get next chunk in list.

#define MSG_HEADER_INIT(h, msg_class, size)

Initialize a header structure.

#define MSG_HEADER_NONE

No header.

Functions

msg_header_t * msg_header_alloc (su_home_t *, msg_hclass_t *hc, isize_t extra))

Allocate a header structure.

isize_t msg_header_size (msg_header_t const *h)

Calculate the size of a duplicate of a header structure.

msg_header_t ** msg_header_offset (msg_t const *, msg_pub_t const *, msg_header_t const *)

Get offset of header h from structure mo.

msg_header_t ** msg_hclass_offset (msg_mclass_t const *, msg_pub_t const *, msg_hclass_t *)

Find place to insert header of the class hc.

msg_header_t * msg_header_access (msg_pub_t const *pub, msg_hclass_t *hc)

Get a header from the public message structure.

msg_header_t * msg_header_copy_as (su_home_t *home, msg_hclass_t *hc, msg_header_t const *o))

Copy a list of header objects.

msg_header_t * msg_header_copy (su_home_t *home, msg_header_t const *o))

Copy a header list.

msg_header_t * msg_header_copy_one (su_home_t *home, msg_header_t const *o))

Copy a single header.

msg_header_t * msg_header_dup_as (su_home_t *home, msg_hclass_t *hc, msg_header_t const *o))

Duplicate a header as class hc.

msg_header_t * msg_header_dup (su_home_t *home, msg_header_t const *h))

Duplicate a header list.

msg_header_t * msg_header_dup_one (su_home_t *home, msg_header_t const *h))

Duplicate a sigle header.

msg_header_t * msg_header_d (su_home_t *home, msg_t const *msg, char const *b)

Decode a message header.

issize_t msg_header_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)

Encode a header.

issize_t msg_object_e (char b[], isize_t size, msg_pub_t const *mo, int flags)

Encode a message to the buffer.

issize_t msg_header_field_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)

Encode header contents.

int msg_header_remove (msg_t *msg, msg_pub_t *mo, msg_header_t *h)

Remove a header from the header structure and fragment chain.

int msg_header_remove_all (msg_t *msg, msg_pub_t *mo, msg_header_t *h)

Remove a header list from the header structure and fragment chain.

int msg_header_insert (msg_t *msg, msg_pub_t *mo, msg_header_t *h)

Insert a (list of) header(s) to the fragment chain.

int msg_header_replace (msg_t *msg, msg_pub_t *mo, msg_header_t *old_header, msg_header_t *new_header)

Replace a header item with a (list of) header(s).

int msg_header_add_dup (msg_t *msg, msg_pub_t *pub, msg_header_t const *o)

Duplicate and add a (list of) header(s) to the message.

int msg_header_add_str (msg_t *msg, msg_pub_t *pub, char const *str)

Add string contents to message.

int msg_header_parse_str (msg_t *msg, msg_pub_t *pub, char *s)

Add string to message.

int msg_header_add_dup_as (msg_t *msg, msg_pub_t *pub, msg_hclass_t *hc, msg_header_t const *o)

Duplicate a header as a given type and add the duplicate into message.

int msg_header_add_make (msg_t *msg, msg_pub_t *pub, msg_hclass_t *hc, char const *s)

Parse a string as a given header field and add result to the message.

int msg_header_add_format (msg_t *msg, msg_pub_t *pub, msg_hclass_t *hc, char const *fmt,...)

Add formatting result to message.

int msg_header_prepend (msg_t *msg, msg_pub_t *pub, msg_header_t **hh, msg_header_t *h)

Prepend a (list of) header(s) to the header structure and fragment chain.

msg_header_t * msg_header_make (su_home_t *home, msg_hclass_t *hc, char const *s))

Make a header from a value string.

msg_header_t * msg_header_vformat (su_home_t *home, msg_hclass_t *hc, char const *fmt, va_list ap))

Make a MSG header with formatting provided.

void msg_header_free (su_home_t *home, msg_header_t *h)

Free a header structure.

void msg_header_free_all (su_home_t *home, msg_header_t *h)

Free a (list of) header structures.

msg_payload_t * msg_payload_create (su_home_t *home, void const *data, usize_t len))

Create a MIME payload.

issize_t msg_headers_prepare (msg_t *, msg_header_t *headers, int flags)

Encode headers in chain.

void msg_fragment_clear (msg_common_t *h)

Clear encoded data from header structure.

msg_param_t ** msg_header_params (msg_common_t const *h)

Pointer to header parameters.

char const * msg_header_find_param (msg_common_t const *, char const *name)

Find a header parameter.

int msg_header_add_param (su_home_t *, msg_common_t *h, char const *param)

Add a parameter to a header.

int msg_header_replace_param (su_home_t *, msg_common_t *h, char const *param)

Replace or add a parameter to a header.

int msg_header_remove_param (msg_common_t *h, char const *name)

Remove a parameter from header.

char const * msg_header_find_item (msg_common_t const *h, char const *item)

Find a header item.

int msg_header_replace_item (su_home_t *, msg_common_t *h, char const *item)

Add an item to a header.

int msg_header_remove_item (msg_common_t *h, char const *name)

Remove an item from a header.

int msg_list_append_items (su_home_t *home, msg_list_t *k, msg_param_t const items[])

Append a list of constant items to a list.

int msg_list_replace_items (su_home_t *home, msg_list_t *k, msg_param_t const items[])

Replace a list of constant items on a list.

int msg_header_join_items (su_home_t *home, msg_common_t *dst, msg_common_t const *src, int duplicate)

Join header item lists.

issize_t msg_random_token (char token[], isize_t tlen, void const *d, isize_t dlen)

Generates a random token.

int msg_params_cmp (char const *const a[], char const *const b[])

Compare parameter lists.

size_t msg_params_length (char const *const *params)

Calculate number of parameters in a parameter list.

char * msg_unquote_dup (su_home_t *home, char const *q))

Unquote a string, return a duplicate.

char * msg_unquote (char *dst, char const *s)

Unquote string.

unsigned long msg_hash_string (char const *id)

Calculate a hash over a string.

Function Documentation

msg_header_t* msg_header_access ( msg_pub_t const * pub,

msg_hclass_t * hc

)

Get a header from the public message structure.
Gets a pointer to header from a message structure.

Parameters:

pub public message structure from which header is obtained

hc header class

int msg_header_add_dup ( msg_t * msg,

msg_pub_t * pub,

msg_header_t const * src

)

Duplicate and add a (list of) header(s) to the message.
The function msg_header_add_dup() duplicates and adds a (list of) header(s) into a message structure.
When inserting headers into the fragment chain, a request (or status) is inserted first and replaces the existing request (or status). Other headers are inserted after the request or status.
If the header is a singleton, existing headers with the same class are removed.

Parameters:

msg message owning the fragment chain

pub public message structure to which header is added

src list of header(s) to be added

int msg_header_add_dup_as ( msg_t * msg,

msg_pub_t * pub,

msg_hclass_t * hc,

msg_header_t const * src

)

Duplicate a header as a given type and add the duplicate into message.
The function msg_header_add_dup_as() duplicates a header as a instance of the given header class. It adds the new copy into the message.
When inserting headers into the fragment chain, a request (or status) is inserted first and replaces the existing request (or status). Other headers are inserted after the request or status.
If the header is a singleton, existing headers with the same class are removed.

Parameters:

msg message owning the fragment chain

pub public message structure to which header is added

hc header class for header target type

src list of header(s) to be duplicated and added

int msg_header_add_format ( msg_t * msg,

msg_pub_t * pub,

msg_hclass_t * hc,

char const * fmt,

...

)

Add formatting result to message.
Parse result from printf-formatted params as a given header field and add result to the message.

Since:
New in 1.12.10

int msg_header_add_param ( su_home_t * home,

msg_common_t * h,

char const * param

)

Add a parameter to a header.
You should use this function only when the header accepts multiple parameters (or list items) with the same name. If that is not the case, you should use msg_header_replace_param().

Note:
This function does not duplicate param. The caller should have allocated the param from the memory home associated with header h.
The possible shortcuts to parameter values are updated. For example, the "received" parameter in Via header has shortcut in structure sip_via_t, the v_received field. The shortcut is usully a pointer to the parameter value. If the parameter was "received=127.0.0.1" the v_received field would be a pointer to "127.0.0.1". If the parameter was "received=" or "received", the shortcut would be a pointer to an empty string, "".

Parameters:

home memory home used to re-allocate parameter list in header

h pointer to a header

param parameter to be replaced or added

Return values:

0 if parameter was added

-1 upon an error

See also:
msg_header_replace_param(), msg_header_remove_param(), msg_header_update_params(), msg_common_t, msg_header_t, msg_hclass_t, msg_hclass_t::hc_params, msg_hclass_t::hc_update

int msg_header_add_str ( msg_t * msg,

msg_pub_t * pub,

char const * str

)

Add string contents to message.
Duplicate a string containing headers (or a message body, if the string starts with linefeed), parse it and add resulting header objects to the message object.

Parameters:

msg message object

pub message header structure where heades are added (may be NULL)

str string to be copied and parsed (not modified, may be NULL)

Return values:

0 when succesful

-1 upon an error

msg_header_t* msg_header_alloc ( su_home_t * home,

msg_hclass_t * hc,

isize_t extra

)

Allocate a header structure.
The msg_header_alloc() function allocates a generic MO header structure and returns a pointer to it.

Parameters:

home memory home

hc header class

extra amount of extra memory to be allocated after header structure

Returns:
A pointer to the newly created header object, or NULL upon an error.

msg_header_t* msg_header_copy_as ( su_home_t * home,

msg_hclass_t * hc,

msg_header_t const * src

)

Copy a list of header objects.
The function msg_header_copy_as() shallowly copies a list of header objects, and casts them to the given header class.

Parameters:

home pointer to the memory home

hc header class

src pointer to a list of header objects to be copied

Returns:
The function msg_header_copy_as() returns a pointer to the first of the copied msg header object(s), or NULL upon an error.

msg_header_t* msg_header_dup ( su_home_t * home,

msg_header_t const * h

)

Duplicate a header list.
The function msg_header_dup() deeply copies a list of message headers objects.

Parameters:

home pointer to the memory home

h pointer to a list of header objects to be copied

Returns:
The function msg_header_dup() returns a pointer to the first of the copied message header object(s), or NULL upon an error.

msg_header_t* msg_header_dup_as ( su_home_t * home,

msg_hclass_t * hc,

msg_header_t const * src

)

Duplicate a header as class hc.
The function msg_header_dup_as() casts a list of header headers to given type, and then deeply copies the list.

Parameters:

home pointer to the memory home

hc header class

src pointer to a list of header objects to be copied

Returns:
The function msg_header_copy_as() returns a pointer to the first of the copied msg header object(s), or NULL upon an error.

msg_header_t* msg_header_dup_one ( su_home_t * home,

msg_header_t const * src

)

Duplicate a sigle header.
Deeply copy a single header.

Parameters:

home pointer to the memory home

src pointer to asingle header object to be copied

Returns:
Return a pointer to the the duplicated msg header object(s), or NULL upon an error.

issize_t msg_header_e ( char b[],

isize_t bsiz,

msg_header_t const * h,

int flags

)

Encode a header.
The function msg_header_e() encodes a header field in the buffer b[]. The encoding includes its name and trailing CRLF. The function returns the length of the encoding in bytes, excluding the final NUL. The buffer b must be large enough for whole encoding, including the final NUL.
The flags parameter define how the encoding is done. If the flags specify MSG_DO_COMPACT, the encoding is compact (short form with minimal whitespace).

char const* msg_header_find_item ( msg_common_t const * h,

char const * item

)

Find a header item.
Searches for given item name from the header. If item is found, the function returns a non-NULL pointer to the item.

Parameters:

h pointer to header structure

item item

Returns:
A pointer to item, or NULL if it was not found.

Since:
New in 1.12.4

See also:
msg_header_replace_item(), msg_header_remove_item(), Allow, Allow-Events

char const* msg_header_find_param ( msg_common_t const * h,

char const * name

)

Find a header parameter.
Searches for given parameter name from the header. If parameter is found, it returns a non-NULL pointer to the parameter value. If there is no value for the name (in form "name" or "name=value"), the returned pointer points to a NUL character.

Parameters:

h pointer to header structure

name parameter name (with or without "=" sign)

Returns:
A pointer to parameter value, or NULL if parameter was not found.

int msg_header_insert ( msg_t * msg,

msg_pub_t * pub,

msg_header_t * h

)

Insert a (list of) header(s) to the fragment chain.
The function msg_header_insert() inserts header or list of headers into a message structure. It also inserts them into the the message fragment chain, if it exists.
When inserting headers into the fragment chain, a request (or status) is inserted first and replaces the existing request (or status). Other headers are inserted after the request or status.
If there can be only one header field of this type (hc_kind is msg_kind_single), existing header objects with the same class are removed.

Parameters:

msg message object owning the fragment chain

pub public message structure to which header is added

h list of header(s) to be added

int msg_header_join_items ( su_home_t * home,

msg_common_t * dst,

msg_common_t const * src,

int duplicate

)

Join header item lists.
Join items from a source header to the destination header. The item are compared with the existing ones. If a match is found, it is not added to the list. If duplicate is true, the entries are duplicated while they are added to the list.

Parameters:

home memory home

dst destination header

src source header

duplicate if true, allocate and copy items that are added

Returns:

Return values:

>= 0 when successful

-1 upon an error

Since:
New in 1.12.5.

int msg_header_parse_str ( msg_t * msg,

msg_pub_t * pub,

char * s

)

Add string to message.
Parse a string containing headers (or a message body, if the string starts with linefeed) and add resulting header objects to the message object.

Parameters:

msg message object

pub message header structure where heades are added (may be NULL)

s string to be parsed (and modified)

Return values:

0 when succesful

-1 upon an error

See also:
msg_header_add_str(), url_headers_as_string()

Since:
New in 1.12.4.

int msg_header_prepend ( msg_t * msg,

msg_pub_t * pub,

msg_header_t ** hh,

msg_header_t * h

)

Prepend a (list of) header(s) to the header structure and fragment chain.
The function msg_header_prepend() adds a header or list of headers into the given place within the message structure. It also inserts the headers into the the message fragment chain, if it exists.
Unlike msg_header_add(), msg_header_prepend() always inserts header h before other headers of the same class. If the header is a singleton, existing headers of the same class are removed. If the header is a list header, the values in the new header are prepended to the existing list.

Parameters:

msg message owning the fragment chain

pub public message structure

hh place in message structure to which header is added

h list of header(s) to be added

int msg_header_remove ( msg_t * msg,

msg_pub_t * pub,

msg_header_t * h

)

Remove a header from the header structure and fragment chain.
The function msg_header_remove() removes a header from a message structure. It also removes the message from the message fragment chain and clears the encoding of other headers objects that share same encoding.

Parameters:

msg message owning the fragment chain

pub public message structure to which header is added

h header to be removed

int msg_header_remove_all ( msg_t * msg,

msg_pub_t * pub,

msg_header_t * h

)

Remove a header list from the header structure and fragment chain.
The function msg_header_remove_all() removes a list of headers from a message structure. It also removes the message from the message fragment chain and clears the encoding of other headers objects that share same encoding.

Parameters:

msg message owning the fragment chain

pub public message structure to which header is added

h header list to be removed

int msg_header_remove_item ( msg_common_t * h,

char const * name

)

Remove an item from a header.
This function treats a msg_header_t as set of C strings. The item is a C string. If identical string is found from the list, it is removed.
The shortcuts, if any, to item values are updated accordingly.

Parameters:

h pointer to a header

name item to be removed

Return values:

0 if item was added

1 if item was replaced

-1 upon an error

Since:
New in 1.12.4.

See also:
msg_header_replace_item(), Allow, Allow-Events, msg_header_replace_param(), msg_header_remove_param(), msg_common_t, msg_header_t, msg_list_t msg_hclass_t, msg_hclass_t::hc_params

int msg_header_remove_param ( msg_common_t * h,

char const * name

)

Remove a parameter from header.
The parameter name is given as token optionally followed by "=" sign and value. The "=" and value after it are ignored when selecting a parameter to remove.
The possible shortcuts to parameter values are updated. For example, the "received" parameter in Via header has shortcut in structure sip_via_t, the v_received field. The shortcut to removed parameter would be set to NULL.

Parameters:

h pointer to a header

name name of parameter to be removed

Return values:

1 if a parameter was removed

0 if no parameter was not removed

-1 upon an error

See also:
msg_header_add_param(), msg_header_replace_param(), msg_header_update_params(), msg_common_t, msg_header_t, msg_hclass_t, msg_hclass_t::hc_params, msg_hclass_t::hc_update

int msg_header_replace ( msg_t * msg,

msg_pub_t * pub,

msg_header_t * replaced,

msg_header_t * h

)

Replace a header item with a (list of) header(s).
The function msg_header_replace() removes a header structure from message and replaces it with a new one or a list of headers. It inserts the new headers into the the message fragment chain, if it exists.

Parameters:

msg message object owning the fragment chain

pub public message structure to which header is added

replaced old header to be removed

h list of header(s) to be added

int msg_header_replace_item ( su_home_t * home,

msg_common_t * h,

char const * item

)

Add an item to a header.
This function treats a msg_header_t as set of C strings. The item is a C string. If no identical string is found from the list, it is added to the list.
The shortcuts, if any, to item values are updated accordingly.

Parameters:

home memory home used to re-allocate list in header

h pointer to a header

item item to be removed

Return values:

0 if item was added

1 if item was replaced

-1 upon an error

Since:
New in 1.12.4.

See also:
msg_header_remove_item(), Allow, Allow-Events, msg_header_replace_param(), msg_header_remove_param(), msg_common_t, msg_header_t, msg_list_t msg_hclass_t, msg_hclass_t::hc_params

int msg_header_replace_param ( su_home_t * home,

msg_common_t * h,

char const * param

)

Replace or add a parameter to a header.
A header parameter param is a string of format name "=" value or just name. The value part following "=" is ignored when selecting a parameter to replace.

Note:
This function does not duplicate param. The caller should have allocated the param from the memory home associated with header h.
The possible shortcuts to parameter values are updated. For example, the "received" parameter in Via header has shortcut in structure sip_via_t, the v_received field.

Parameters:

home memory home used to re-allocate parameter list in header

h pointer to a header

param parameter to be replaced or added

Return values:

0 if parameter was added

1 if parameter was replaced

-1 upon an error

See also:
msg_header_add_param(), msg_header_remove_param(), msg_header_update_params(), msg_common_t, msg_header_t, msg_hclass_t, msg_hclass_t::hc_params, msg_hclass_t::hc_update

issize_t msg_headers_prepare ( msg_t * msg,

msg_header_t * headers,

int flags

)

Encode headers in chain.
The function msg_headers_prepare() encodes all the headers in the header chain. You have to call msg_serialize() before calling msg_headers_prepare() in order to make sure that all the heades and other message fragments are included in the chain.

Returns:
The size of all the headers in chain, or -1 upon an error.

int msg_list_append_items ( su_home_t * home,

msg_list_t * k,

msg_param_t const items[]

)

Append a list of constant items to a list.

Return values:

0 when successful

-1 upon an error

int msg_list_replace_items ( su_home_t * home,

msg_list_t * k,

msg_param_t const items[]

)

Replace a list of constant items on a list.

Return values:

0 when successful

-1 upon an error

issize_t msg_object_e ( char b[],

isize_t size,

msg_pub_t const * mo,

int flags

)

Encode a message to the buffer.
The function msg_encode_e encodes a message to a given buffer. It returns the length of the message to be encoded, even if the buffer is too small (just like snprintf() is supposed to do).

Parameters:

b buffer (may be NULL)

size size of buffer

mo public message structure (sip_t, http_t)

flags see #

int msg_params_cmp ( char const *const a[],

char const *const b[]

)

Compare parameter lists.
Compares parameter lists.

Parameters:

a pointer to a parameter list

b pointer to a parameter list

Return values:

an integer less than zero if is less than b

an integer zero if match with b

an integer greater than zero if is greater than b

char* msg_unquote_dup ( su_home_t * home,

char const * q

)

Unquote a string, return a duplicate.
Duplicates the string q in unquoted form.


Defines
#define	MSG_CHUNK_BUFFER(pl)
	Get pointer to beginning of available buffer space.
#define	MSG_CHUNK_AVAIL(pl)
	Get size of available buffer space.
#define	MSG_CHUNK_NEXT(pl)
	Get next chunk in list.
#define	MSG_HEADER_INIT(h, msg_class, size)
	Initialize a header structure.
#define	MSG_HEADER_NONE
	No header.
Functions
msg_header_t *	msg_header_alloc (su_home_t , msg_hclass_t hc, isize_t extra))
	Allocate a header structure.
isize_t	msg_header_size (msg_header_t const *h)
	Calculate the size of a duplicate of a header structure.
msg_header_t **	msg_header_offset (msg_t const , msg_pub_t const , msg_header_t const *)
	Get offset of header h from structure mo.
msg_header_t **	msg_hclass_offset (msg_mclass_t const , msg_pub_t const , msg_hclass_t *)
	Find place to insert header of the class hc.
msg_header_t *	msg_header_access (msg_pub_t const pub, msg_hclass_t hc)
	Get a header from the public message structure.
msg_header_t *	msg_header_copy_as (su_home_t home, msg_hclass_t hc, msg_header_t const *o))
	Copy a list of header objects.
msg_header_t *	msg_header_copy (su_home_t home, msg_header_t const o))
	Copy a header list.
msg_header_t *	msg_header_copy_one (su_home_t home, msg_header_t const o))
	Copy a single header.
msg_header_t *	msg_header_dup_as (su_home_t home, msg_hclass_t hc, msg_header_t const *o))
	Duplicate a header as class hc.
msg_header_t *	msg_header_dup (su_home_t home, msg_header_t const h))
	Duplicate a header list.
msg_header_t *	msg_header_dup_one (su_home_t home, msg_header_t const h))
	Duplicate a sigle header.
msg_header_t *	msg_header_d (su_home_t home, msg_t const msg, char const *b)
	Decode a message header.
issize_t	msg_header_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Encode a header.
issize_t	msg_object_e (char b[], isize_t size, msg_pub_t const *mo, int flags)
	Encode a message to the buffer.
issize_t	msg_header_field_e (char b[], isize_t bsiz, msg_header_t const *h, int flags)
	Encode header contents.
int	msg_header_remove (msg_t msg, msg_pub_t mo, msg_header_t *h)
	Remove a header from the header structure and fragment chain.
int	msg_header_remove_all (msg_t msg, msg_pub_t mo, msg_header_t *h)
	Remove a header list from the header structure and fragment chain.
int	msg_header_insert (msg_t msg, msg_pub_t mo, msg_header_t *h)
	Insert a (list of) header(s) to the fragment chain.
int	msg_header_replace (msg_t msg, msg_pub_t mo, msg_header_t old_header, msg_header_t new_header)
	Replace a header item with a (list of) header(s).
int	msg_header_add_dup (msg_t msg, msg_pub_t pub, msg_header_t const *o)
	Duplicate and add a (list of) header(s) to the message.
int	msg_header_add_str (msg_t msg, msg_pub_t pub, char const *str)
	Add string contents to message.
int	msg_header_parse_str (msg_t msg, msg_pub_t pub, char *s)
	Add string to message.
int	msg_header_add_dup_as (msg_t msg, msg_pub_t pub, msg_hclass_t hc, msg_header_t const o)
	Duplicate a header as a given type and add the duplicate into message.
int	msg_header_add_make (msg_t msg, msg_pub_t pub, msg_hclass_t hc, char const s)
	Parse a string as a given header field and add result to the message.
int	msg_header_add_format (msg_t msg, msg_pub_t pub, msg_hclass_t hc, char const fmt,...)
	Add formatting result to message.
int	msg_header_prepend (msg_t msg, msg_pub_t pub, msg_header_t *hh, msg_header_t h)
	Prepend a (list of) header(s) to the header structure and fragment chain.
msg_header_t *	msg_header_make (su_home_t home, msg_hclass_t hc, char const *s))
	Make a header from a value string.
msg_header_t *	msg_header_vformat (su_home_t home, msg_hclass_t hc, char const *fmt, va_list ap))
	Make a MSG header with formatting provided.
void	msg_header_free (su_home_t home, msg_header_t h)
	Free a header structure.
void	msg_header_free_all (su_home_t home, msg_header_t h)
	Free a (list of) header structures.
msg_payload_t *	msg_payload_create (su_home_t home, void const data, usize_t len))
	Create a MIME payload.
issize_t	msg_headers_prepare (msg_t , msg_header_t headers, int flags)
	Encode headers in chain.
void	msg_fragment_clear (msg_common_t *h)
	Clear encoded data from header structure.
msg_param_t **	msg_header_params (msg_common_t const *h)
	Pointer to header parameters.
char const *	msg_header_find_param (msg_common_t const , char const name)
	Find a header parameter.
int	msg_header_add_param (su_home_t , msg_common_t h, char const *param)
	Add a parameter to a header.
int	msg_header_replace_param (su_home_t , msg_common_t h, char const *param)
	Replace or add a parameter to a header.
int	msg_header_remove_param (msg_common_t h, char const name)
	Remove a parameter from header.
char const *	msg_header_find_item (msg_common_t const h, char const item)
	Find a header item.
int	msg_header_replace_item (su_home_t , msg_common_t h, char const *item)
	Add an item to a header.
int	msg_header_remove_item (msg_common_t h, char const name)
	Remove an item from a header.
int	msg_list_append_items (su_home_t home, msg_list_t k, msg_param_t const items[])
	Append a list of constant items to a list.
int	msg_list_replace_items (su_home_t home, msg_list_t k, msg_param_t const items[])
	Replace a list of constant items on a list.
int	msg_header_join_items (su_home_t home, msg_common_t dst, msg_common_t const *src, int duplicate)
	Join header item lists.
issize_t	msg_random_token (char token[], isize_t tlen, void const *d, isize_t dlen)
	Generates a random token.
int	msg_params_cmp (char const const a[], char const const b[])
	Compare parameter lists.
size_t	msg_params_length (char const const params)
	Calculate number of parameters in a parameter list.
char *	msg_unquote_dup (su_home_t home, char const q))
	Unquote a string, return a duplicate.
char *	msg_unquote (char dst, char const s)
	Unquote string.
unsigned long	msg_hash_string (char const *id)
	Calculate a hash over a string.