sctp_recvmsg() Function

ssize_t sctp_recvmsg(s, *msg, len, *from, *fromlen, *sinfo, *msg_flags);
int s, void *msg, size_t len, struct sockaddr *from, socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo, int *msg_flags;

The sctp_recvmsg() function enables receipt of a message from the SCTP endpoint specified by the s parameter. The calling program can specify the following attributes:

msg

This parameter is the address of the message buffer.

len

This parameter is the length of the message buffer.

from

This parameter is a pointer to an address that contains the sender's address.

fromlen

This parameter is the size of the buffer associated with the address in the from parameter.

sinfo

This parameter is only active if the calling program enables sctp_data_io_events. To enable sctp_data_io_events, call the setsockopt() function with the socket option SCTP_EVENTS. When sctp_data_io_events is enabled, the application receives the contents of the sctp_sndrcvinfo structure for each incoming message. This parameter is a pointer to a sctp_sndrcvinfo structure. The structure is populated upon receipt of the message.

msg_flags

This parameter contains any message flags that are present.

The sctp_recvmsg() function returns the number of bytes it receives. The sctp_recvmsg() function returns -1 when an error occurs.

If the file descriptor passed in the s parameter is not valid, the sctp_recvmsg() function fails and sets the value of errno to EBADF. If the file descriptor passed in the s parameter does not describe a socket, the sctp_recvmsg() function fails and sets the value of errno to ENOTSOCK. If the msg_flags parameter includes the value MSG_OOB, the sctp_recvmsg() function fails and sets the value of errno to EOPNOTSUPP. If there is no established association, the sctp_recvmsg() function fails and sets the value of errno to ENOTCONN.