Collaboration diagram for Via Header:
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Via headers can be used to prevent request looping and ensure replies take the same path as the requests. The Via syntax is defined in RFC 3261 as follows:
Via = ( "Via" / "v" ) HCOLON via-parm *(COMMA via-parm) via-parm = sent-protocol LWS sent-by *( SEMI via-params ) via-params = via-ttl / via-maddr / via-received / via-branch / via-extension via-ttl = "ttl" EQUAL ttl via-maddr = "maddr" EQUAL host via-received = "received" EQUAL (IPv4address / IPv6address) via-branch = "branch" EQUAL token via-extension = generic-param sent-protocol = protocol-name SLASH protocol-version SLASH transport protocol-name = "SIP" / token protocol-version = token transport = "UDP" / "TCP" / "TLS" / "SCTP" / other-transport sent-by = host [ COLON port ] ttl = 1*3DIGIT ; 0 to 255
via-compression = "comp" EQUAL ("sigcomp" / other-compression) via-params /= via-compression
RFC 3581 defines a parameter "rport":
response-port = "rport" [EQUAL 1*DIGIT]
via-params /= response-port
Data Structures | |
struct | sip_via_s |
Structure for Via header. More... | |
Defines | |
#define | sip_via(sip) |
Access a sip_via_t from sip_t. | |
#define | SIP_VIA_INIT() |
Initializer for structure sip_via_t. | |
#define | SIPTAG_VIA(x) |
Tag list item for pointer to a Via header structure. | |
#define | SIPTAG_VIA_REF(x) |
Tag list item for reference to a a Via header pointer. | |
#define | SIPTAG_VIA_STR(s) |
Tag list item for string with Via header value. | |
#define | SIPTAG_VIA_STR_REF(x) |
Tag list item for reference to a a Via header string. | |
Typedefs | |
typedef sip_via_s | sip_via_t |
The structure sip_via_t contains representation of SIP Via header. | |
Enumerator | |
sip_via_hash | |
@ | |
Functions | |
int | sip_via_add_param (su_home_t *home, sip_via_t *v, char const *param) |
Add a parameter to a Via header object. | |
sip_via_t * | sip_via_create (su_home_t *home, char const *host, char const *port, char const *transport,...) |
Create a Via object. | |
char const * | sip_via_port (sip_via_t const *v, int *using_rport) |
Get port number corresponding to a Via line. | |
sip_via_t * | sip_via_remove (msg_t *msg, sip_t *sip) |
Get first via header and remove it from its fragment chain. | |
SOFIAPUBFUN int | sip_via_d (su_home_t *, msg_header_t *, char *s, int slen) |
Parse a Via header. | |
SOFIAPUBFUN int | sip_via_e (char b[], int bsiz, msg_header_t const *h, int flags) |
Print a Via header. | |
sip_via_t * | sip_via_init (sip_via_t x[1]) |
Initialize a structure sip_via_t. | |
int | sip_is_via (sip_header_t const *header) |
Test if header object is instance of sip_via_t. | |
sip_via_t * | sip_via_dup (su_home_t *home, sip_via_t const *hdr)) |
Duplicate (deep copy) sip_via_t . | |
sip_via_t * | sip_via_copy (su_home_t *home, sip_via_t const *hdr)) |
Copy a sip_via_t header structure. | |
sip_via_t * | sip_via_make (su_home_t *home, char const *s)) |
Make a header structure sip_via_t. | |
sip_via_t * | sip_via_format (su_home_t *home, char const *fmt,...))) |
Make a Via header from formatting result. | |
Variables | |
tag_typedef_t | siptag_via |
Tag for Via header object. | |
tag_typedef_t | siptag_via_str |
Tag for string with Via header value. | |
msg_hclass_t | sip_via_class [] |
Header class for SIP Via header. |
#define SIP_VIA_INIT | ( | ) |
Initializer for structure sip_via_t.
A static sip_via_t structure must be initialized. The SIP_VIA_INIT() macro provides initialization value. For instance,
#define SIPTAG_VIA | ( | x | ) |
Tag list item for pointer to a Via header structure.
The SIPTAG_VIA() macro is used to include a tag item with a pointer to a sip_via_t object in a tag list.
x | pointer to a sip_via_t header structure, or NULL. |
#define SIPTAG_VIA_STR | ( | s | ) |
Tag list item for string with Via header value.
The SIPTAG_VIA_STR() macro is used to include a tag item with a string containing value of a sip_via_t header in a tag list.
s | pointer to a string containing sip_via_t value, or NULL. |
The corresponding tag taking reference parameter is SIPTAG_VIA_STR_REF().
The structure sip_via_t contains representation of SIP Via header.
The sip_via_t is defined as follows:
typedef struct sip_via_s { sip_common_t v_common[1]; // Common fragment info sip_via_t *v_next; // Link to next Via header char const *v_protocol; // Application and transport protocol char const *v_host; // Hostname char const *v_port; // Port number msg_param_t const *v_params; // List of via-params char const *v_comment; // Comment char const *v_ttl; // "ttl" parameter char const *v_maddr; // "maddr" parameter char const *v_received; // "received" parameter char const *v_branch; // "branch" parameter char const *v_comp; // "comp" parameter char const *v_rport; // "rport" parameter } sip_via_t;
sip_via_hash |
@
Hash of Via header.
int sip_is_via | ( | sip_header_t const * | header | ) | [inline] |
Test if header object is instance of sip_via_t.
The function sip_is_via() returns true (nonzero) if the header class is an instance of Via header object and false (zero) otherwise.
header | pointer to the header structure to be tested |
Add a parameter to a Via header object.
param
.home | memory home | |
v | sip_via_t object | |
param | parameter string |
0 | when successful | |
-1 | upon an error. |
Copy a sip_via_t header structure.
The function sip_via_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 header structure hdr.
home | memory home used to allocate new structure | |
hdr | pointer to the header structure to be copied |
via = sip_via_copy(home, sip->sip_via);
sip_via_t* sip_via_create | ( | su_home_t * | home, | |
char const * | host, | |||
char const * | port, | |||
char const * | transport, | |||
... | ||||
) |
Create a Via object.
The function sip_via_create() creates a new Via header object with given parameters. If transport is NULL, the default transport "SIP/2.0/UDP" is used. A NULL-terminated list of parameters can be specified after transport.
home | memory home | |
host | host name | |
port | protocol port number | |
transport | transport protocol (default is "SIP/2.0/UDP") | |
... | NULL-terminated list of parameters |
Duplicate (deep copy) sip_via_t
.
The function sip_via_dup() duplicates 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.
home | memory home used to allocate new structure | |
hdr | header structure to be duplicated |
via = sip_via_dup(home, sip->sip_via);
Make a Via header from formatting result.
The function sip_via_format() makes a new Via header 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 uses the formatting result as the header value.
home | memory home used to allocate new header structure. | |
fmt | string used as a printf()-style format | |
... | argument list for format |
Initialize a structure sip_via_t.
An sip_via_t structure can be initialized with the sip_via_init() function/macro. For instance,
Make a header structure sip_via_t.
The function sip_via_make() makes a new sip_via_t header structure. It allocates a new header structure, and decodes the string s as the value of the structure.
home | memory home used to allocate new header structure. | |
s | string to be decoded as value of the new header structure |
char const* sip_via_port | ( | sip_via_t const * | v, | |
int * | using_rport | |||
) |
Get port number corresponding to a Via line.
If using_rport is non-null, try rport. If *using_rport is non-zero, try rport even if <protocol> is not UDP. If <protocol> is UDP, set *using_rport to zero.
Header class for SIP Via header.
The header class sip_via_class defines how a SIP Via header is parsed and printed. It also contains methods used by SIP parser and other functions to manipulate the sip_via_t header structure.