i2p.itoopie/apps/sam/c/examples/dgram-server.c

/*
 * Copyright (c) 2004, Matthew P. Cashdollar <mpc@innographx.com>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *     * Neither the name of the author nor the names of any contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "sam.h"

static void dgramback(sam_pubkey_t dest, void *data, size_t size);
static void diedback(void);
static void logback(char *s);
static void namingback(char *name, sam_pubkey_t pubkey, samerr_t result);

/*
 * This is an extremely simple echo server which shows you how LibSAM
 * datagrams work.  We echo back every datagram that is sent to us.
 */
int main(int argc, char* argv[])
{
	samerr_t rc;

	/* Hook up the callback functions */
	sam_dgramback = &dgramback;
	sam_diedback = &diedback;
	sam_logback = &logback;
	sam_namingback = &namingback;

	/* Connect to the SAM server -- you can use either an IP or DNS name */
	rc = sam_connect("127.0.0.1", 7656, "dgram-server", SAM_DGRAM, 0);
	if (rc != SAM_OK) {
		fprintf(stderr, "SAM connection failed: %s\n", sam_strerror(rc));
		exit(1);
	}

	/*
	 * At this point we just keep polling the buffer, which causes the
	 * appropriate callbacks to be called whenever something happens
	 */
	while (true)
		sam_read_buffer();

	return 0;
}

/*
 * When we receive some data, we just ECHO the exact same data back to them
 */
static void dgramback(sam_pubkey_t dest, void *data, size_t size)
{
	puts("Echoing datagram");
	sam_dgram_send(dest, data, size);
	free(data);
}

/*
 * This is called whenever the SAM connection fails (like if the I2P router is
 * shut down)
 */
static void diedback(void)
{
	fprintf(stderr, "Lost SAM connection!\n");
	exit(1);
}

/*
 * The logging callback prints any logging messages from LibSAM
 */
static void logback(char *s)
{
	fprintf(stderr, "LibSAM: %s\n", s);
}

/*
 * Not used, but the function has to be in the program anyway
 */
static void namingback(char *name, sam_pubkey_t pubkey, samerr_t result)
{
	assert(false);  /* we don't do any naming lookups in this program */
}