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137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
/* vi: set sw=4 ts=4: */
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/* nc: mini-netcat - built from the ground up for LRP
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Copyright (C) 1998 Charles P. Wright
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0.0.1 6K It works.
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0.0.2 5K Smaller and you can also check the exit condition if you wish.
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0.0.3 Uses select()
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19980918 Busy Boxed! Dave Cinege
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19990512 Uses Select. Charles P. Wright
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19990513 Fixes stdin stupidity and uses buffers. Charles P. Wright
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <sys/time.h>
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#include <sys/ioctl.h>
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#include "busybox.h"
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int nc_main(int argc, char **argv)
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{
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int do_listen = 0, lport = 0, tmpfd, opt, sfd;
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char buf[BUFSIZ];
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struct sockaddr_in address;
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struct hostent *hostinfo;
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fd_set readfds, testfds;
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while ((opt = getopt(argc, argv, "lp:")) > 0) {
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switch (opt) {
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case 'l':
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do_listen++;
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break;
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case 'p':
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lport = atoi(optarg);
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break;
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default:
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show_usage();
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}
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}
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if ((do_listen && optind != argc) || (!do_listen && optind + 2 != argc))
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show_usage();
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if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
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perror_msg_and_die("socket");
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address.sin_family = AF_INET;
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if (lport != 0) {
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memset(&address.sin_addr, 0, sizeof(address.sin_addr));
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address.sin_port = htons(lport);
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if (bind(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
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perror_msg_and_die("bind");
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}
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if (do_listen) {
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if (listen(sfd, 1) < 0)
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perror_msg_and_die("listen");
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if ((tmpfd = accept(sfd, (struct sockaddr *) &address, &opt)) < 0)
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perror_msg_and_die("accept");
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close(sfd);
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sfd = tmpfd;
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} else {
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if ((hostinfo = gethostbyname(argv[optind])) == NULL)
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error_msg_and_die("cannot resolve %s\n", argv[optind]);
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address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
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address.sin_port = htons(atoi(argv[optind+1]));
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if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
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perror_msg_and_die("connect");
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}
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FD_ZERO(&readfds);
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FD_SET(sfd, &readfds);
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FD_SET(STDIN_FILENO, &readfds);
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while (1) {
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int fd;
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int ofd;
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int nread;
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testfds = readfds;
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if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
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perror_msg_and_die("select");
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for (fd = 0; fd < FD_SETSIZE; fd++) {
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if (FD_ISSET(fd, &testfds)) {
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if ((nread = safe_read(fd, buf, sizeof(buf))) < 0)
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perror_msg_and_die("read");
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if (fd == sfd) {
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if (nread == 0)
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exit(0);
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ofd = STDOUT_FILENO;
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} else {
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if (nread == 0)
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shutdown(sfd, 1);
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ofd = sfd;
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}
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if (full_write(ofd, buf, nread) < 0)
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perror_msg_and_die("write");
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}
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}
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}
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}
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