/* 
 * fping: fast-ping, file-ping, favorite-ping, funky-ping
 *
 *   Ping a list of target hosts in a round robin fashion.
 *   A better ping overall.
 *
 * fping website:  http://www.fping.org
 *
 * Current maintainer of fping: David Schweikert
 * Please send suggestions and patches to: david@schweikert.ch
 *
 *
 * Original author:  Roland Schemers  <schemers@stanford.edu>
 * IPv6 Support:     Jeroen Massar    <jeroen@unfix.org / jeroen@ipng.nl>
 * Improved main loop: David Schweikert <david@schweikert.ch>
 * Debian Merge, TOS settings: Tobi Oetiker <tobi@oetiker.ch>
 * Bugfixes, byte order & senseful seq.-numbers: Stephan Fuhrmann (stephan.fuhrmann AT 1und1.de)
 *
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Stanford University.  The name of the University may not be used 
 * to endorse or promote products derived from this software without 
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "fping.h"
#include "config.h"

#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char *ping_buffer = 0;
size_t ping_pkt_size;

int open_ping_socket_ipv4()
{
    struct protoent *proto;
    int s;

    /* confirm that ICMP is available on this machine */
    if( ( proto = getprotobyname( "icmp" ) ) == NULL ) 
        crash_and_burn( "icmp: unknown protocol" );

    /* create raw socket for ICMP calls (ping) */
    s = socket( AF_INET, SOCK_RAW, proto->p_proto );
    if( s < 0 ) {
        /* try non-privileged icmp (works on Mac OSX without privileges, for example) */
        s = socket( AF_INET, SOCK_DGRAM, proto->p_proto );
        if( s < 0 ) {
            errno_crash_and_burn( "can't create socket (must run as root?)" );
        }
    }

    return s;
}

void init_ping_buffer_ipv4(size_t ping_data_size)
{
    /* allocate ping buffer */
    ping_pkt_size = ping_data_size + ICMP_MINLEN;
    ping_buffer = (char *) calloc(1, ping_pkt_size);
    if(!ping_buffer)
        crash_and_burn( "can't malloc ping packet" );
}

void socket_set_src_addr_ipv4(int s, FPING_INADDR src_addr)
{
    struct sockaddr_in sa;
    memset( &sa, 0, sizeof( sa ) );
    sa.sin_family = AF_INET;
    sa.sin_addr = src_addr;

    if ( bind( s, (struct sockaddr *)&sa, sizeof( sa ) ) < 0 )
        errno_crash_and_burn( "cannot bind source address" );
}

int socket_sendto_ping_ipv4(int s, struct sockaddr *saddr, socklen_t saddr_len, uint16_t icmp_seq_nr, uint16_t icmp_id_nr)
{
    struct icmp *icp;
    int n;

    icp = (struct icmp *) ping_buffer;

    icp->icmp_type = ICMP_ECHO;
    icp->icmp_code = 0;
    icp->icmp_seq = htons(icmp_seq_nr);
    icp->icmp_id = htons(icmp_id_nr);

    if (random_data_flag) {
        for (n = ((void*)&icp->icmp_data - (void *)icp); n < ping_pkt_size; ++n) {
            ping_buffer[n] = random() & 0xFF;
        }
    }

    icp->icmp_cksum = in_cksum((unsigned short*) icp, ping_pkt_size );

    n = sendto(s, icp, ping_pkt_size, 0, saddr, saddr_len);

    return n;
}