/*
* tcping.c
*
* Copyright (c) 2002-2008 Marc Kirchner <mail(at)marc(dash)kirchner(dot)de>
*
* tcping is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* tcping 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with ms++. If not, see <http://www.gnu.org/licenses/>.
*
* tcping does a nonblocking connect to test if a port is reachable.
* Its exit codes are:
* -1 an error occured
* 0 port is open
* 1 port is closed
* 2 user timeout
*/
#define VERSION 1.3.5
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#include <unistd.h>
#include <sys/time.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <netdb.h>
void usage();
int main (int argc, char *argv[]) {
int sockfd;
struct sockaddr_in addr;
struct hostent *host;
int error = 0;
int ret;
socklen_t errlen;
struct timeval timeout;
fd_set fdrset, fdwset;
int verbose=1;
int c;
char *cptr;
long timeout_sec=0, timeout_usec=0;
int port=0;
if (argc < 3) {
usage(argv[0]);
}
while((c = getopt(argc, argv, "qt:u:")) != -1) {
switch(c) {
case 'q':
verbose = 0;
break;
case 't':
cptr = NULL;
timeout_sec = strtol(optarg, &cptr, 10);
if (cptr == optarg)
usage(argv[0]);
break;
case 'u':
cptr = NULL;
timeout_usec = strtol(optarg, &cptr, 10);
if (cptr == optarg)
usage(argv[0]);
break;
default:
usage(argv[0]);
break;
}
}
sockfd = socket (AF_INET, SOCK_STREAM, 0);
memset(&addr, 0, sizeof(addr));
if ((host = gethostbyname(argv[optind])) == NULL) {
if (verbose)
#ifdef HAVE_HSTRERROR
fprintf(stderr, "error: %s\n", hstrerror(h_errno));
#else
fprintf(stderr, "error: host not found");
#endif
exit(-1);
}
memcpy(&addr.sin_addr, host->h_addr_list[0], host->h_length);
addr.sin_family = host->h_addrtype; /* always AF_INET */
if (argv[optind+1]) {
cptr = NULL;
port = strtol(argv[optind+1], &cptr, 10);
if (cptr == argv[optind+1])
usage(argv[0]);
} else {
usage(argv[0]);
}
addr.sin_port = htons(port);
fcntl(sockfd, F_SETFL, O_NONBLOCK);
if ((ret = connect(sockfd, (struct sockaddr *) &addr, sizeof(addr))) != 0) {
if (errno != EINPROGRESS) {
#ifdef HAVE_SOLARIS
/* solaris immediately returns ECONNREFUSED on local ports */
if (errno == ECONNREFUSED) {
if (verbose)
fprintf(stdout, "%s port %s closed.\n", argv[optind], argv[optind+1]);
close(sockfd);
return(1);
} else {
#endif
if (verbose)
fprintf(stderr, "error: %s port %s: %s\n", argv[optind], argv[optind+1], strerror(errno));
return (-1);
#ifdef HAVE_SOLARIS
}
#endif
}
FD_ZERO(&fdrset);
FD_SET(sockfd, &fdrset);
fdwset = fdrset;
timeout.tv_sec=timeout_sec + timeout_usec / 1000000;
timeout.tv_usec=timeout_usec % 1000000;
if ((ret = select(sockfd+1, &fdrset, &fdwset, NULL, timeout.tv_sec+timeout.tv_usec > 0 ? &timeout : NULL)) == 0) {
/* timeout */
close(sockfd);
if (verbose)
fprintf(stdout, "%s port %s user timeout.\n", argv[optind], argv[optind+1]);
return(2);
}
if (FD_ISSET(sockfd, &fdrset) || FD_ISSET(sockfd, &fdwset)) {
errlen = sizeof(error);
if ((ret=getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &errlen)) != 0) {
/* getsockopt error */
if (verbose)
fprintf(stderr, "error: %s port %s: getsockopt: %s\n", argv[optind], argv[optind+1], strerror(errno));
close(sockfd);
return(-1);
}
if (error != 0) {
if (verbose)
fprintf(stdout, "%s port %s closed.\n", argv[optind], argv[optind+1]);
close(sockfd);
return(1);
}
} else {
if (verbose)
fprintf(stderr, "error: select: sockfd not set\n");
exit(-1);
}
}
/* OK, connection established */
close(sockfd);
if (verbose)
fprintf(stdout, "%s port %s open.\n", argv[optind], argv[optind+1]);
return 0;
}
void usage(char *prog) {
fprintf(stderr, "error: Usage: %s [-q] [-t timeout_sec] [-u timeout_usec] <host> <port>\n", prog);
exit(-1);
}
