Patch from Denis Vlasenko turning static const int (which gets emitted into
[oweals/busybox.git] / networking / nc.c
index fcacb0c45b45231f634fdc6317475dadf2a6e668..85148c4a713be973ae535e64af84c5c7dcfc6578 100644 (file)
@@ -4,7 +4,7 @@
 
     0.0.1   6K      It works.
     0.0.2   5K      Smaller and you can also check the exit condition if you wish.
-    0.0.3          Uses select()       
+    0.0.3           Uses select()
 
     19980918 Busy Boxed! Dave Cinege
     19990512 Uses Select. Charles P. Wright
     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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-
 */
-#include "busybox.h"
+
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
+#include <signal.h>
 
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
 #include <sys/time.h>
 #include <sys/ioctl.h>
+#include "busybox.h"
 
-#define BUFSIZE 100
+static void timeout(int signum)
+{
+       bb_error_msg_and_die("Timed out");
+}
 
 int nc_main(int argc, char **argv)
 {
-       int sfd;
-       int result;
-       int len;
-       char ch[BUFSIZE];
+       int do_listen = 0, lport = 0, delay = 0, wsecs = 0, tmpfd, opt, sfd, x;
+
+#define buf bb_common_bufsiz1
+
+#ifdef CONFIG_NC_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:w:")) > 0) {
+               switch (opt) {
+                       case 'l':
+                               do_listen++;
+                               break;
+                       case 'p':
+                               lport = bb_lookup_port(optarg, "tcp", 0);
+                               break;
+                       case 'i':
+                               delay = atoi(optarg);
+                               break;
+#ifdef CONFIG_NC_GAPING_SECURITY_HOLE
+                       case 'e':
+                               pr00gie = optarg;
+                               break;
+#endif
+                       case 'w':
+                               wsecs = atoi(optarg);
+                               break;
+                       default:
+                               bb_show_usage();
+               }
        }
 
-       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");
+       address.sin_family = AF_INET;
 
-       if (!hostinfo) {
-               fatalError("cannot resolve %s\n", *argv);
+       if (wsecs) {
+               signal(SIGALRM, timeout);
+               alarm(wsecs);
        }
 
-       address.sin_family = AF_INET;
-       address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
-       address.sin_port = htons(atoi(*(++argv)));
+       if (lport != 0) {
+               memset(&address.sin_addr, 0, sizeof(address.sin_addr));
+               address.sin_port = lport;
+
+               if (bind(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+                       bb_perror_msg_and_die("bind");
+       }
 
-       len = sizeof(address);
+       if (do_listen) {
+               socklen_t addrlen = sizeof(address);
 
-       result = connect(sfd, (struct sockaddr *) &address, len);
+               if (listen(sfd, 1) < 0)
+                       bb_perror_msg_and_die("listen");
 
-       if (result < 0) {
-               perror("nc: connect");
-               exit(2);
+               if ((tmpfd = accept(sfd, (struct sockaddr *) &address, &addrlen)) < 0)
+                       bb_perror_msg_and_die("accept");
+
+               close(sfd);
+               sfd = tmpfd;
+       } else {
+               hostinfo = xgethostbyname(argv[optind]);
+
+               address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
+               address.sin_port = bb_lookup_port(argv[optind+1], "tcp", 0);
+
+               if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+                       bb_perror_msg_and_die("connect");
+       }
+
+       if (wsecs) {
+               alarm(0);
+               signal(SIGALRM, SIG_DFL);
+       }
+
+#ifdef CONFIG_NC_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 /* CONFIG_NC_GAPING_SECURITY_HOLE */
 
        FD_ZERO(&readfds);
        FD_SET(sfd, &readfds);
-       FD_SET(fileno(stdin), &readfds);
+       FD_SET(STDIN_FILENO, &readfds);
 
        while (1) {
                int fd;
@@ -90,39 +157,32 @@ int nc_main(int argc, char **argv)
 
                testfds = readfds;
 
-               result =
-                       select(FD_SETSIZE, &testfds, (fd_set *) NULL, (fd_set *) NULL,
-                                  (struct timeval *) 0);
-
-               if (result < 1) {
-                       perror("nc: select");
-                       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(bb_msg_read_error);
 
                                if (fd == sfd) {
                                        if (nread == 0)
                                                exit(0);
-                                       ofd = fileno(stdout);
+                                       ofd = STDOUT_FILENO;
                                } else {
+                                       if (nread <= 0) {
+                                               shutdown(sfd, 1 /* send */ );
+                                               close(STDIN_FILENO);
+                                               FD_CLR(STDIN_FILENO, &readfds);
+                                       }
                                        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(bb_msg_write_error);
+                               if (delay > 0) {
+                                       sleep(delay);
                                }
-                               while (trn < nread);
                        }
                }
        }