.\"  Automatically generated man page, do not edit
.TH KNET_SEND_SYNC 3 2020-10-19 "kronosnet" "Kronosnet Programmer's Manual"
.SH NAME
knet_send_sync \- Synchronously send data to knet nodes. 

.SH SYNOPSIS
.nf
.B #include <libknet.h>
.sp
\fBint knet_send_sync\fP(
    \fBknet_handle_t  \fP\fIknet_h\fP,
    \fBconst char    *\fP\fIbuff\fP,
    \fBconst size_t   \fP\fIbuff_len\fP,
    \fBconst int8_t   \fP\fIchannel\fP
);
.fi
.SH DESCRIPTION
.PP
knet_send_sync
.PP
knet_h - pointer to knet_handle_t
.PP
buff - pointer to the buffer of data to send
.PP
buff_len - length of data to send
.PP
channel - data channel to use (see knet_handle_add_datafd(3))
.PP
All knet RX/TX operations are async for performance reasons. There are applications that might need a sync version of data transmission and receive errors in case of failure to deliver to another host. knet_send_sync bypasses the whole TX async layer and delivers data directly to the link layer, and returns errors accordingly. knet_send_sync sends only one packet to one host at a time. It does NOT support multiple destinations or multicast packets. Decision is still based on dst_host_filter_fn.
.SH RETURN VALUE
.PP
knet_send_sync returns 0 on success and -1 on error. In addition to normal sendmmsg errors, knet_send_sync can fail due to:
.PP
\fBECANCELED  \fP- data forward is disabled 
.PP
\fBEFAULT     \fP- dst_host_filter fatal error 
.PP
\fBEINVAL     \fP- dst_host_filter did not provide dst_host_ids_entries on unicast pckts 
.PP
\fBE2BIG      \fP- dst_host_filter did return more than one dst_host_ids_entries on unicast pckts 
.PP
\fBENOMSG     \fP- received unknown message type 
.PP
\fBEHOSTDOWN  \fP- unicast pckt cannot be delivered because dest host is not connected yet 
.PP
\fBECHILD     \fP- crypto failed 
.PP
\fBEAGAIN     \fP- sendmmsg was unable to send all messages and there was no progress during retry 
.PP
.SH SEE ALSO
.PP
.nh
.ad l
\fIknet_handle_remove_datafd\fR(3), \fIknet_handle_get_stats\fR(3), \fIknet_host_add\fR(3), \fIknet_handle_pmtud_setfreq\fR(3), \fIknet_handle_pmtud_get\fR(3), \fIknet_handle_crypto_use_config\fR(3), \fIknet_host_get_id_by_host_name\fR(3), \fIknet_host_get_status\fR(3), \fIknet_link_add_acl\fR(3), \fIknet_link_get_pong_count\fR(3), \fIknet_link_get_priority\fR(3), \fIknet_handle_free\fR(3), \fIknet_handle_enable_sock_notify\fR(3), \fIknet_handle_get_datafd\fR(3), \fIknet_recv\fR(3), \fIknet_link_get_ping_timers\fR(3), \fIknet_log_get_subsystem_id\fR(3), \fIknet_host_remove\fR(3), \fIknet_host_enable_status_change_notify\fR(3), \fIknet_strtoaddr\fR(3), \fIknet_link_rm_acl\fR(3), \fIknet_send\fR(3), \fIknet_handle_enable_pmtud_notify\fR(3), \fIknet_handle_get_transport_reconnect_interval\fR(3), \fIknet_link_get_enable\fR(3), \fIknet_link_set_priority\fR(3), \fIknet_log_set_loglevel\fR(3), \fIknet_handle_get_channel\fR(3), \fIknet_link_get_config\fR(3), \fIknet_link_get_link_list\fR(3), \fIknet_get_transport_list\fR(3), \fIknet_get_transport_id_by_name\fR(3), \fIknet_log_get_loglevel_id\fR(3), \fIknet_handle_new_ex\fR(3), \fIknet_host_set_name\fR(3), \fIknet_addrtostr\fR(3), \fIknet_handle_setfwd\fR(3), \fIknet_get_compress_list\fR(3), \fIknet_host_set_policy\fR(3), \fIknet_get_transport_name_by_id\fR(3), \fIknet_handle_enable_filter\fR(3), \fIknet_handle_crypto_rx_clear_traffic\fR(3), \fIknet_handle_compress\fR(3), \fIknet_link_get_status\fR(3), \fIknet_handle_add_datafd\fR(3), \fIknet_log_get_loglevel_name\fR(3), \fIknet_handle_enable_access_lists\fR(3), \fIknet_host_get_host_list\fR(3), \fIknet_host_get_policy\fR(3), \fIknet_link_set_enable\fR(3), \fIknet_link_set_pong_count\fR(3), \fIknet_log_get_subsystem_name\fR(3), \fIknet_host_get_name_by_host_id\fR(3), \fIknet_link_clear_config\fR(3), \fIknet_log_get_loglevel\fR(3), \fIknet_handle_new\fR(3), \fIknet_handle_pmtud_getfreq\fR(3), \fIknet_handle_pmtud_set\fR(3), \fIknet_handle_clear_stats\fR(3), \fIknet_link_set_config\fR(3), \fIknet_handle_crypto_set_config\fR(3), \fIknet_handle_crypto\fR(3), \fIknet_get_crypto_list\fR(3), \fIknet_handle_set_transport_reconnect_interval\fR(3), \fIknet_link_clear_acl\fR(3), \fIknet_link_set_ping_timers\fR(3), \fIknet_link_insert_acl\fR(3)
.ad
.hy
.SH "COPYRIGHT"
.PP
Copyright (C) 2010-2020 Red Hat, Inc. All rights reserved.