- send an outbound SIP message to the SIP stack for processing
cc [ flag ... ] file ... -lsip [ library ... ] #include <sip.h> int sip_sendmsg(sip_conn_object_t obj, sip_msg_t sip_msg, sip_dialog_t dialog, uint32_t flags);
The sip_sendmsg() function is used to send an outbound SIP message sip_msg to the SIP stack on its way to the peer. The connection object for the SIP message is passed as obj. The caller also provides the dialog associated with the message, if one exists. The value of flags is the result of ORing the following, as required:
Send the request or response statefully. This results in the stack creating and maintaining a transaction for this request/response. If this flag is not set transactions are not created for the request/response.
When this flag is set, the stack may create multiple dialogs for a dialog completing response. This may result due to forking of the dialog creating request. If this flag is not set, the first response to a dialog creating request creates a dialog, but subsequent ones do not. It is only meaningful if the stack is configured to maintain dialogs.
The sip_sendmsg() function returns 0 on success and the appropriate error on failure.
The value of errno is not changed by these calls in the event of an error.
The sip_sendmsg() function can return one of the following errors on failure:
If a message is being statefully sent and the branchid in the VIA header does not conform to RFC 3261 or when accessing CSEQ header while creating a transaction.
If a message is being statefully sent, error getting the CSEQ header while creating a transaction.
If a message is being statefully sent, error getting the CSEQ value while creating a transaction.
If the message is being statefully sent, error allocating memory for creating or adding a transaction or during transaction related processing.
See attributes(5) for descriptions of the following attributes: