gnutls_record_send — API function


#include <gnutls/gnutls.h>
ssize_t gnutls_record_send( gnutls_session_t session,
  const void * data,
  size_t data_size);


gnutls_session_t session

is a gnutls_session_t structure.

const void * data

contains the data to send

size_t data_size

is the length of the data


This function has the similar semantics with send(). The only difference is that it accepts a GnuTLS session, and uses different error codes. Note that if the send buffer is full, send() will block this function. See the send() documentation for full information. You can replace the default push function by using gnutls_transport_set_ptr2() with a call to send() with a MSG_DONTWAIT flag if blocking is a problem. If the EINTR is returned by the internal push function (the default is send()) then GNUTLS_E_INTERRUPTED will be returned. If GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN is returned, you must call this function again, with the same parameters; alternatively you could provide a NULL pointer for data, and 0 for size. cf. gnutls_record_get_direction().

Note that in DTLS this function will return the GNUTLS_E_LARGE_PACKET error code if the send data exceed the data MTU value − as returned by gnutls_dtls_get_data_mtu(). The errno value EMSGSIZE also maps to GNUTLS_E_LARGE_PACKET.


The number of bytes sent, or a negative error code. The number of bytes sent might be less than data_size . The maximum number of bytes this function can send in a single call depends on the negotiated maximum record size.


Report bugs to <>.

General guidelines for reporting bugs:

GnuTLS home page:


The full documentation for gnutls is maintained as a Texinfo manual. If the info and gnutls programs are properly installed at your site, the command

info gnutls

should give you access to the complete manual. As an alternative you may obtain the manual from:


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