/******************************************************************************/
/* */
/* Copyright (c) International Business Machines Corp., 2006 */
/* */
/* This program is free software; you can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation; either version 2 of the License, or */
/* (at your option) any later version. */
/* */
/* This program is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
/* the GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public License */
/* along with this program; if not, write to the Free Software */
/* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
/* */
/******************************************************************************/
/*
* File:
* ns-mcast_join.c
*
* Description:
* This is an assistant tool to join multicast groups
*
* Author:
* Mitsuru Chinen <mitch@jp.ibm.com>
*
* History:
* May 1 2006 - Created (Mitsuru Chinen)
*---------------------------------------------------------------------------*/
/*
* Header Files
*/
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <netdb.h>
#include <signal.h>
#include <time.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include "ns-mcast.h"
#include "ns-traffic.h"
#define ADDR_STR_MAXSIZE 80
#define OPEN_SOCK_MIN 6
/*
* Gloval variables
*/
char *program_name; /* program name */
struct sigaction handler; /* Behavior for a signal */
volatile int catch_sighup; /* When catch the SIGHUP, set to non-zero */
sa_family_t family; /* protocol family */
int level; /* protocol levels */
uint32_t ifindex; /* interface index where listening multicast */
size_t num_group; /* Number of the groups */
char *mcast_prefix; /* Prefix of the multicast address */
uint32_t fmode; /* filter mode */
char *saddrs; /* comma separated array of source addresses */
int is_multi_socket; /* If non-zero, multi-socket mode */
size_t join_leave_times; /* If non-zero, join-leave mode */
/* the value is times of join/leave */
char *mcast_addr; /* multicast address to join/leave */
struct timespec interval; /* interval for join-leave mode */
/*
* Function: usage()
*
* Descripton:
* Print the usage of this program. Then, terminate this program with
* the specified exit value.
*
* Argument:
* exit_value: exit value
*
* Return value:
* This function does not return.
*/
void usage(char *program_name, int exit_value)
{
FILE *stream = stdout; /* stream where the usage is output */
if (exit_value == EXIT_FAILURE)
stream = stderr;
fprintf(stream, "%s [OPTION]\n"
"\t-f num\tprotocol family\n"
"\t\t 4 : IPv4\n"
"\t\t 6 : IPv6\n"
"\t-I ifname\tname of listening interface\n"
"\t-a addr\tmulticast address for join-leave mode\n"
"\t-F mode\tfilter mode\n"
"\t\t include : include mode\n"
"\t\t exclude : exclude mode\n"
"\t-s addrs\tcomma separated array of Source Addresses\n"
"\t-d\t\tdisplay debug informations\n"
"\t-h\t\tdisplay this usage\n"
"\n"
"\t[multiple join mode]\n"
"\t -n num\tnumber of multicast address\n"
"\t -p prefix\tprefix of the multicast address\n"
"\t -m\t\tmultiple socket mode\n"
"\t\t 4 : a.b(.x.y) - x y is defined automatically\n"
"\t\t 6 : {prefix}::z - z is defined automatically\n"
"\n"
"\t[join-leave mode]\n"
"\t -l times of join/leave\n"
"\t -i nsec\tinterval for join-leave mode\n", program_name);
exit(exit_value);
}
/*
* Function: set_signal_flag()
*
* Description:
* This function sets global variables accordig to signal
*
* Argument:
* type: type of signal
*
* Return value:
* None
*/
void set_signal_flag(int type)
{
if (debug)
fprintf(stderr, "Catch signal. type is %d\n", type);
switch (type) {
case SIGHUP:
catch_sighup = 1;
handler.sa_handler = SIG_IGN;
if (sigaction(type, &handler, NULL) < 0)
fatal_error("sigaction()");
break;
default:
fprintf(stderr, "Unexpected signal (%d) is caught\n", type);
exit(EXIT_FAILURE);
}
}
/*
* Function: parse_options()
*
* Description:
* This function parse the options
*
* Argument:
* argc: the number of argument
* argv: arguments
*
* Return value:
* None
*/
void parse_options(int argc, char *argv[])
{
int optc; /* option */
unsigned long opt_ul; /* option value in unsigned long */
while ((optc = getopt(argc, argv, "f:I:p:F:s:n:ml:i:a:dh")) != EOF) {
switch (optc) {
case 'f':
if (optarg[0] == '4') {
family = PF_INET; /* IPv4 */
level = IPPROTO_IP;
} else if (optarg[0] == '6') {
family = PF_INET6; /* IPv6 */
level = IPPROTO_IPV6;
} else {
fprintf(stderr,
"protocol family should be 4 or 6.\n");
usage(program_name, EXIT_FAILURE);
}
break;
case 'I':
ifindex = if_nametoindex(optarg);
if (ifindex == 0) {
fprintf(stderr,
"specified interface is incorrect\n");
usage(program_name, EXIT_FAILURE);
}
break;
case 'p':
mcast_prefix = strdup(optarg);
break;
case 'F':
if (strncmp(optarg, "exclude", 8) == 0)
fmode = MCAST_EXCLUDE;
else if (strncmp(optarg, "include", 8) == 0)
fmode = MCAST_INCLUDE;
else {
fprintf(stderr,
"specified filter mode is incorrect\n");
usage(program_name, EXIT_FAILURE);
}
break;
case 'l':
join_leave_times = strtoul(optarg, NULL, 0);
break;
case 'i':
if (strtotimespec(optarg, &interval)) {
fprintf(stderr,
"Interval is something wrong\n");
usage(program_name, EXIT_FAILURE);
}
break;
case 'a':
mcast_addr = strdup(optarg);
break;
case 's':
saddrs = strdup(optarg);
if (saddrs == NULL)
fatal_error("strdup()");
break;
case 'n':
opt_ul = strtoul(optarg, NULL, 0);
if (opt_ul > 255 * 254) {
fprintf(stderr,
"The number of group shoud be less than %u\n",
255 * 254);
usage(program_name, EXIT_FAILURE);
}
num_group = opt_ul;
break;
case 'm':
is_multi_socket = 1;
break;
case 'd':
debug = 1;
break;
case 'h':
usage(program_name, EXIT_SUCCESS);
break;
default:
usage(program_name, EXIT_FAILURE);
}
}
if (ifindex == 0) {
fprintf(stderr, "specified interface seems incorrect\n");
usage(program_name, EXIT_FAILURE);
}
if (saddrs) {
if (fmode != MCAST_EXCLUDE && fmode != MCAST_INCLUDE) {
fprintf(stderr, "filter mode is wrong\n");
usage(program_name, EXIT_FAILURE);
}
}
}
/*
* Function: join_group()
*
* Description:
* This function make sockets to join the groups
*
* Return value:
* None
*/
void join_group(void)
{
int sd; /* socket file descriptor */
int *sock_array; /* socket descriptor array */
size_t num_sock; /* number of the socket */
char maddr[ADDR_STR_MAXSIZE]; /* multicast address in string */
int idx;
struct addrinfo *maddr_info;
struct group_req *grp_info;
struct group_filter *gsf;
if (!is_multi_socket)
num_sock = 1;
else
num_sock = num_group;
/* Allocate socket array */
sock_array = calloc(num_sock, sizeof(int));
if (sock_array == NULL)
fatal_error("calloc()");
for (idx = 0; idx < num_sock; idx++) {
sock_array[idx] = socket(family, SOCK_DGRAM, IPPROTO_UDP);
if (sock_array[idx] < 0) {
if (idx < OPEN_SOCK_MIN)
fatal_error("socket()");
else {
int j; /* Closed some sockets for daemon() */
for (j = 0; j < OPEN_SOCK_MIN; j++)
close(sock_array[idx - 1 - j]);
num_group = idx - j - 1;
break;
}
}
if (!is_multi_socket)
maximize_sockbuf(sock_array[idx]);
}
sd = sock_array[0];
if (mcast_addr) {
strncpy(maddr, mcast_addr, ADDR_STR_MAXSIZE);
if (debug)
fprintf(stderr, "multicast address is %s\n", maddr);
}
for (idx = 0; idx < num_group; idx++) {
if (is_multi_socket)
sd = sock_array[idx];
if (debug)
fprintf(stderr, "socket: %d\n", sd);
if (mcast_prefix) {
switch (family) {
case PF_INET:
{
unsigned int x, y;
x = idx / 254;
y = idx % 254 + 1;
sprintf(maddr, "%s.%d.%d", mcast_prefix,
x, y);
}
break;
case PF_INET6:
sprintf(maddr, "%s:%x", mcast_prefix, idx + 1);
break;
}
if (debug)
fprintf(stderr, "multicast address is %s\n",
maddr);
}
maddr_info = get_maddrinfo(family, maddr, NULL);
grp_info = create_group_info(ifindex, maddr_info);
if (setsockopt(sd, level, MCAST_JOIN_GROUP, grp_info,
sizeof(struct group_req)) == -1) {
if (idx == 0)
fatal_error("setsockopt(): Join no group");
else {
num_group--;
free(grp_info);
freeaddrinfo(maddr_info);
break;
}
free(grp_info);
}
if (saddrs) {
gsf =
create_source_filter(ifindex, maddr_info, fmode,
saddrs);
if (setsockopt
(sd, level, MCAST_MSFILTER, gsf,
GROUP_FILTER_SIZE(gsf->gf_numsrc)) == -1) {
if (idx == 0)
fatal_error
("setsockopt(): Add no group filter");
else {
num_group--;
free(gsf);
freeaddrinfo(maddr_info);
break;
}
free(gsf);
}
}
freeaddrinfo(maddr_info);
}
fprintf(stdout, "%zu groups\n", num_group);
fflush(stdout);
/* Become a daemon for the next step in shell script */
if (daemon(0, 0) < 0)
fatal_error("daemon()");
/* Waiting for SIGHUP */
handler.sa_handler = set_signal_flag;
handler.sa_flags = 0;
if (sigfillset(&handler.sa_mask) < 0)
fatal_error("sigfillset()");
if (sigaction(SIGHUP, &handler, NULL) < 0)
fatal_error("sigfillset()");
for (;;)
if (catch_sighup)
break;
}
/*
* Function: join_leave_group()
*
* Description:
* This function make sockets to join the groups then leave it
*
* Return value:
* None
*/
void join_leave_group(void)
{
int sd; /* socket file descriptor */
struct addrinfo *maddr_info;
struct group_req *grp_info;
struct group_filter *gsf;
size_t cnt;
sd = socket(family, SOCK_DGRAM, IPPROTO_UDP);
if (sd < 0)
fatal_error("socket()");
maddr_info = get_maddrinfo(family, mcast_addr, NULL);
grp_info = create_group_info(ifindex, maddr_info);
if (saddrs)
gsf = create_source_filter(ifindex, maddr_info, fmode, saddrs);
else
gsf = NULL;
/* Waiting for SIGHUP */
handler.sa_handler = set_signal_flag;
handler.sa_flags = 0;
if (sigfillset(&handler.sa_mask) < 0)
fatal_error("sigfillset()");
if (sigaction(SIGHUP, &handler, NULL) < 0)
fatal_error("sigfillset()");
for (cnt = 0; cnt < join_leave_times; cnt++) {
/* Join */
if (setsockopt(sd, level, MCAST_JOIN_GROUP, grp_info,
sizeof(struct group_req)) == -1)
fatal_error("setsockopt(): Failed to join a group");
if (gsf)
if (setsockopt(sd, level, MCAST_MSFILTER, gsf,
GROUP_FILTER_SIZE(gsf->gf_numsrc)) == -1)
fatal_error
("setsockopt(): Failed to add a group filter");
nanosleep(&interval, NULL);
/* Leave */
if (setsockopt(sd, level, MCAST_LEAVE_GROUP, grp_info,
sizeof(struct group_req)) == -1)
fatal_error("setsockopt(): Failed to leave a group");
nanosleep(&interval, NULL);
if (catch_sighup)
break;
}
free(grp_info);
if (gsf)
free(gsf);
freeaddrinfo(maddr_info);
}
/*
*
* Function: main()
*
*/
int main(int argc, char *argv[])
{
debug = 0;
program_name = strdup(argv[0]);
parse_options(argc, argv);
if (!join_leave_times) {
if (mcast_prefix == NULL && mcast_addr == NULL) {
fprintf(stderr, "multicast address is not specified\n");
usage(program_name, EXIT_FAILURE);
}
join_group();
} else {
if (mcast_addr == NULL) {
fprintf(stderr, "multicast address is not specified\n");
usage(program_name, EXIT_FAILURE);
}
join_leave_group();
}
exit(EXIT_SUCCESS);
}