NAME¶

sctp_sendmsg - Send a message from a SCTP socket.

SYNOPSIS¶

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/sctp.h>

int sctp_sendmsg(int sd, const void * msg, size_t len,
                 struct sockaddr *to, socklen_t tolen,
                 uint32_t ppid, uint32_t flags,
                 uint16_t stream_no, uint32_t timetolive,
                 uint32_t context);

DESCRIPTION¶

sctp_sendmsg is a wrapper library function that can be used to send a message from a socket while using the advanced features of SCTP. sd is the socket descriptor from which the message pointed to by msg of length len is sent. to is the destination address of the message and tolen is the length of the destination address. stream_no identifies the stream number that the application wishes to send this message to. flags parameter is composed of a bitwise OR of the following values.

SCTP_UNORDERED

This flags requests the un-ordered delivery of the message.

SCTP_ADDR_OVER

This flag, in the one-to-many style, requests the SCTP stack to override the primary destination address with address specified in to.

SCTP_ABORT

Setting this flag causes the specified association to abort by sending an ABORT message to the peer(one-to-many style only). The ABORT chunk will contain an error cause 'User Initiated Abort' with cause code 12. The cause specific information of this error cause is provided in msg.

SCTP_EOF

Setting this flag invokes the SCTP graceful shutdown procedure on the specific association(one-to-many style only).

SCTP_SENDALL

This flag, if set, will cause a one-to-many style socket to send the message to all associations that are currently established on this socket. For the one-to-one style socket, this flag has no effect.

SCTP_SACK_IMMEDIATELY

This flag allows the application to set the I bit of the last DATA chunk when sending each user message to make sure the corresponding SACK can be sent by peer without delay.

SCTP_PR_SCTP_{TTL|RTX|PRIO}

One of these 3 pr_policies can be used through this flag with its pr_value set in timetolive parameter for this message. Note that sctp_sendv(3) with infotype SCTP_SENDV_PRINFO also works for PR-SCTP.

timetolive specifies the time duration in milliseconds. The sending side will expire the message if the message has not been sent to the peer within this time period. A value of 0 indicates that no timeout should occur on this message. It also works as the pr_value if flags parameter is set to pr_policy. ppid is an opaque unsigned value that is passed to the remote end along with the message. context is a 32 bit opaque value that is passed back to the upper layer along with the undelivered message if an error occurs on the send of the message.

RETURN VALUE¶

On success, sctp_sendmsg returns the number of bytes sent or -1 if an error occurred.

SEE ALSO¶

sctp(7) sctp_bindx(3), sctp_connectx(3), sctp_sendv(3), sctp_send(3), sctp_recvmsg(3), sctp_recvv(3), sctp_peeloff(3), sctp_getpaddrs(3), sctp_getladdrs(3), sctp_opt_info(3),