Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
-#include "internal.h"
+
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <netdb.h>
#include <sys/time.h>
#include <sys/ioctl.h>
+#include "busybox.h"
-#define BUFSIZE 100
-
-static const char nc_usage[] = "nc [IP] [port]\n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
- "\nNetcat opens a pipe to IP:port\n"
-#endif
- ;
+#define GAPING_SECURITY_HOLE
int nc_main(int argc, char **argv)
{
- int sfd;
- int result;
- int len;
- char ch[BUFSIZE];
+ int do_listen = 0, lport = 0, delay = 0, tmpfd, opt, sfd, x;
+ char buf[BUFSIZ];
+#ifdef GAPING_SECURITY_HOLE
+ char * pr00gie = NULL;
+#endif
struct sockaddr_in address;
struct hostent *hostinfo;
fd_set readfds, testfds;
- argc--;
- argv++;
- if (argc < 2 || **(argv + 1) == '-') {
- usage(nc_usage);
+ while ((opt = getopt(argc, argv, "lp:i:e:")) > 0) {
+ switch (opt) {
+ case 'l':
+ do_listen++;
+ break;
+ case 'p':
+ lport = atoi(optarg);
+ break;
+ case 'i':
+ delay = atoi(optarg);
+ break;
+#ifdef GAPING_SECURITY_HOLE
+ case 'e':
+ pr00gie = optarg;
+ break;
+#endif
+ default:
+ bb_show_usage();
+ }
+ }
+
+#ifdef GAPING_SECURITY_HOLE
+ if (pr00gie) {
+ /* won't need stdin */
+ close (fileno(stdin));
}
+#endif /* GAPING_SECURITY_HOLE */
+
- sfd = socket(AF_INET, SOCK_STREAM, 0);
+ if ((do_listen && optind != argc) || (!do_listen && optind + 2 != argc))
+ bb_show_usage();
- hostinfo = (struct hostent *) gethostbyname(*argv);
+ if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+ bb_perror_msg_and_die("socket");
+ x = 1;
+ if (setsockopt (sfd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof (x)) == -1)
+ bb_perror_msg_and_die ("reuseaddr failed");
+ address.sin_family = AF_INET;
+
+ if (lport != 0) {
+ memset(&address.sin_addr, 0, sizeof(address.sin_addr));
+ address.sin_port = htons(lport);
- if (!hostinfo) {
- exit(1);
+ if (bind(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+ bb_perror_msg_and_die("bind");
}
- address.sin_family = AF_INET;
- address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
- address.sin_port = htons(atoi(*(++argv)));
+ if (do_listen) {
+ socklen_t addrlen = sizeof(address);
- len = sizeof(address);
+ if (listen(sfd, 1) < 0)
+ bb_perror_msg_and_die("listen");
- result = connect(sfd, (struct sockaddr *) &address, len);
+ if ((tmpfd = accept(sfd, (struct sockaddr *) &address, &addrlen)) < 0)
+ bb_perror_msg_and_die("accept");
- if (result < 0) {
- exit(2);
+ close(sfd);
+ sfd = tmpfd;
+ } else {
+ hostinfo = xgethostbyname(argv[optind]);
+
+ address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
+ address.sin_port = htons(atoi(argv[optind+1]));
+
+ if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+ bb_perror_msg_and_die("connect");
+ }
+
+#ifdef GAPING_SECURITY_HOLE
+ /* -e given? */
+ if (pr00gie) {
+ dup2(sfd, 0);
+ close(sfd);
+ dup2 (0, 1);
+ dup2 (0, 2);
+ execl (pr00gie, pr00gie, NULL);
+ /* Don't print stuff or it will go over the wire.... */
+ _exit(-1);
}
+#endif /* GAPING_SECURITY_HOLE */
+
FD_ZERO(&readfds);
FD_SET(sfd, &readfds);
- FD_SET(fileno(stdin), &readfds);
+ FD_SET(STDIN_FILENO, &readfds);
while (1) {
int fd;
testfds = readfds;
- result =
- select(FD_SETSIZE, &testfds, (fd_set *) NULL, (fd_set *) NULL,
- (struct timeval *) 0);
-
- if (result < 1) {
- exit(3);
- }
+ if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
+ bb_perror_msg_and_die("select");
for (fd = 0; fd < FD_SETSIZE; fd++) {
if (FD_ISSET(fd, &testfds)) {
- int trn = 0;
- int rn;
-
- ioctl(fd, FIONREAD, &nread);
+ if ((nread = safe_read(fd, buf, sizeof(buf))) < 0)
+ bb_perror_msg_and_die("read");
if (fd == sfd) {
if (nread == 0)
exit(0);
- ofd = fileno(stdout);
+ ofd = STDOUT_FILENO;
} else {
+ if (nread == 0)
+ shutdown(sfd, 1);
ofd = sfd;
}
-
-
- do {
- rn = (BUFSIZE < nread - trn) ? BUFSIZE : nread - trn;
- trn += rn;
- read(fd, ch, rn);
- write(ofd, ch, rn);
+ if (bb_full_write(ofd, buf, nread) < 0)
+ bb_perror_msg_and_die("write");
+ if (delay > 0) {
+ sleep(delay);
}
- while (trn < nread);
}
}
}