#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <arpa/inet.h>

#define ERROR(_line...) \
do { \
    fprintf(stderr, _line); \
    fprintf(stderr, "\n"); \
    assert(0); \
} while (0)

#define ERROR_CL(_line...) \
do { \
    close(sock); \
    ERROR(_line); \
} while (0)

#define WARN(_line...) \
do { \
    printf(_line); \
    printf("\n"); \
} while (0)

#define MCAST_GROUP "229.17.88.168"
#define GROUP_PORT 12345

#define LOCAL_PORT 23456
#define LOCAL_ADDR1 "10.208.14.2"
#define LOCAL_ADDR2 "10.208.15.2"

#define VLAN1 "999"
#define VLAN2 "1001"
#define VLAN_IF_STR(_vlan) "eth3." _vlan
#define VLAN_IF1 VLAN_IF_STR(VLAN1)
#define VLAN_IF2 VLAN_IF_STR(VLAN2)

static int
init_socket_send(const char *ifname, const char *local_addr)
{
    int                 sock;
    struct sockaddr_in  addr;
    struct in_addr      ifaddr;

    if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
        ERROR("Can't open socket: %s", strerror(errno));

    WARN("if %s, addr %s", ifname, local_addr);
    if (inet_aton(local_addr, &ifaddr) == 0)
        ERROR_CL("inet_aton failed: %s", strerror(errno));

    if (setsockopt(sock, SOL_IP, IP_MULTICAST_IF, &ifaddr, sizeof(ifaddr)) != 0)
        ERROR_CL("IP_MULTICAST_IF failed: %s", strerror(errno));

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(LOCAL_PORT);
    if (inet_pton(AF_INET, local_addr, &addr.sin_addr) != 1)
        ERROR_CL("Can't convert mcast group address: %s", strerror(errno));

    if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) != 0)
        ERROR_CL("bind failed: %s", strerror(errno));

    return sock;
}

int
main(void)
{
    int     sock1;
    int     sock2;
    char    buf[100];

    struct sockaddr_in addr;

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(GROUP_PORT);
    if (inet_pton(AF_INET, MCAST_GROUP, &addr.sin_addr) != 1)
        ERROR("Can't convert mcast group address: %s", strerror(errno));

    sock1 = init_socket_send(VLAN_IF1, LOCAL_ADDR1);
    sock2 = init_socket_send(VLAN_IF2, LOCAL_ADDR2);

    if (sendto(sock1, buf, 99, 0, (struct sockaddr *)&addr, sizeof(addr)) != 99 ||
        sendto(sock2, buf, 98, 0, (struct sockaddr *)&addr, sizeof(addr)) != 98)
        WARN("send failed: %s", strerror(errno));

    sleep(1);

    if (sendto(sock1, buf, 97, 0, (struct sockaddr *)&addr, sizeof(addr)) != 97 ||
        sendto(sock2, buf, 96, 0, (struct sockaddr *)&addr, sizeof(addr)) != 96)
        WARN("send failed: %s", strerror(errno));


    close(sock1);
    close(sock2);

    return EXIT_SUCCESS;
}