/* vi: set sw=4 ts=4: */
/* nc: mini-netcat - built from the ground up for LRP
- Copyright (C) 1998 Charles P. Wright
-
- 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()
-
- 19980918 Busy Boxed! Dave Cinege
- 19990512 Uses Select. Charles P. Wright
- 19990513 Fixes stdin stupidity and uses buffers. Charles P. Wright
-
- 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-
-*/
-#include "internal.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-#include <sys/time.h>
-#include <sys/ioctl.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
- ;
-
-int nc_main(int argc, char **argv)
-{
- int sfd;
- int result;
- int len;
- char ch[BUFSIZE];
+ *
+ * Copyright (C) 1998, 1999 Charles P. Wright
+ * Copyright (C) 1998 Dave Cinege
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
- struct sockaddr_in address;
- struct hostent *hostinfo;
+#include "libbb.h"
- fd_set readfds, testfds;
-
- argc--;
- argv++;
- if (argc < 2 || **(argv + 1) == '-') {
- usage(nc_usage);
- }
+#if ENABLE_DESKTOP
+#include "nc_bloaty.c"
+#else
- sfd = socket(AF_INET, SOCK_STREAM, 0);
+/* Lots of small differences in features
+ * when compared to "standard" nc
+ */
- hostinfo = (struct hostent *) gethostbyname(*argv);
+static void timeout(int signum)
+{
+ bb_error_msg_and_die("timed out");
+}
- if (!hostinfo) {
- fatalError("nc: cannot resolve %s\n", *argv);
+int nc_main(int argc, char **argv);
+int nc_main(int argc, char **argv)
+{
+ /* sfd sits _here_ only because of "repeat" option (-l -l). */
+ int sfd = sfd; /* for gcc */
+ int cfd = 0;
+ unsigned lport = 0;
+ SKIP_NC_SERVER(const) unsigned do_listen = 0;
+ SKIP_NC_EXTRA (const) unsigned wsecs = 0;
+ SKIP_NC_EXTRA (const) unsigned delay = 0;
+ SKIP_NC_EXTRA (const int execparam = 0;)
+ USE_NC_EXTRA (char **execparam = NULL;)
+ len_and_sockaddr *lsa;
+ fd_set readfds, testfds;
+ int opt; /* must be signed (getopt returns -1) */
+
+ if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
+ /* getopt32 is _almost_ usable:
+ ** it cannot handle "... -e prog -prog-opt" */
+ while ((opt = getopt(argc, argv,
+ "" USE_NC_SERVER("lp:") USE_NC_EXTRA("w:i:f:e:") )) > 0
+ ) {
+ if (ENABLE_NC_SERVER && opt=='l') USE_NC_SERVER(do_listen++);
+ else if (ENABLE_NC_SERVER && opt=='p') {
+ USE_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
+ }
+ else if (ENABLE_NC_EXTRA && opt=='w') USE_NC_EXTRA( wsecs = xatou(optarg));
+ else if (ENABLE_NC_EXTRA && opt=='i') USE_NC_EXTRA( delay = xatou(optarg));
+ else if (ENABLE_NC_EXTRA && opt=='f') USE_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
+ else if (ENABLE_NC_EXTRA && opt=='e' && optind<=argc) {
+ /* We cannot just 'break'. We should let getopt finish.
+ ** Or else we won't be able to find where
+ ** 'host' and 'port' params are
+ ** (think "nc -w 60 host port -e prog"). */
+ USE_NC_EXTRA(
+ char **p;
+ // +2: one for progname (optarg) and one for NULL
+ execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
+ p = execparam;
+ *p++ = optarg;
+ while (optind < argc) {
+ *p++ = argv[optind++];
+ }
+ )
+ /* optind points to argv[arvc] (NULL) now.
+ ** FIXME: we assume that getopt will not count options
+ ** possibly present on "-e prog args" and will not
+ ** include them into final value of optind
+ ** which is to be used ... */
+ } else bb_show_usage();
+ }
+ argv += optind; /* ... here! */
+ argc -= optind;
+ // -l and -f don't mix
+ if (do_listen && cfd) bb_show_usage();
+ // Listen or file modes need zero arguments, client mode needs 2
+ if (do_listen || cfd) {
+ if (argc) bb_show_usage();
+ } else {
+ if (!argc || argc > 2) bb_show_usage();
+ }
+ } else {
+ if (argc != 3) bb_show_usage();
+ argc--;
+ argv++;
}
- address.sin_family = AF_INET;
- address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
- address.sin_port = htons(atoi(*(++argv)));
+ if (wsecs) {
+ signal(SIGALRM, timeout);
+ alarm(wsecs);
+ }
- len = sizeof(address);
+ if (!cfd) {
+ if (do_listen) {
+ /* create_and_bind_stream_or_die(NULL, lport)
+ * would've work wonderfully, but we need
+ * to know lsa */
+ sfd = xsocket_stream(&lsa);
+ if (lport)
+ set_nport(lsa, htons(lport));
+ setsockopt_reuseaddr(sfd);
+ xbind(sfd, &lsa->sa, lsa->len);
+ xlisten(sfd, do_listen); /* can be > 1 */
+ /* If we didn't specify a port number,
+ * query and print it after listen() */
+ if (!lport) {
+ socklen_t addrlen = lsa->len;
+ getsockname(sfd, &lsa->sa, &addrlen);
+ lport = get_nport(&lsa->sa);
+ fdprintf(2, "%d\n", ntohs(lport));
+ }
+ fcntl(sfd, F_SETFD, FD_CLOEXEC);
+ accept_again:
+ cfd = accept(sfd, NULL, 0);
+ if (cfd < 0)
+ bb_perror_msg_and_die("accept");
+ if (!execparam)
+ close(sfd);
+ } else {
+ cfd = create_and_connect_stream_or_die(argv[0],
+ argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
+ }
+ }
- result = connect(sfd, (struct sockaddr *) &address, len);
+ if (wsecs) {
+ alarm(0);
+ signal(SIGALRM, SIG_DFL);
+ }
- if (result < 0) {
- perror("nc: connect");
- exit(2);
+ /* -e given? */
+ if (execparam) {
+ signal(SIGCHLD, SIG_IGN);
+ // With more than one -l, repeatedly act as server.
+ if (do_listen > 1 && vfork()) {
+ /* parent */
+ // This is a bit weird as cleanup goes, since we wind up with no
+ // stdin/stdout/stderr. But it's small and shouldn't hurt anything.
+ // We check for cfd == 0 above.
+ logmode = LOGMODE_NONE;
+ close(0);
+ close(1);
+ close(2);
+ goto accept_again;
+ }
+ /* child (or main thread if no multiple -l) */
+ if (cfd) {
+ dup2(cfd, 0);
+ close(cfd);
+ }
+ dup2(0, 1);
+ dup2(0, 2);
+ USE_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
+ /* Don't print stuff or it will go over the wire.... */
+ _exit(127);
}
+ // Select loop copying stdin to cfd, and cfd to stdout.
+
FD_ZERO(&readfds);
- FD_SET(sfd, &readfds);
- FD_SET(fileno(stdin), &readfds);
+ FD_SET(cfd, &readfds);
+ FD_SET(STDIN_FILENO, &readfds);
- while (1) {
+ for (;;) {
int fd;
int ofd;
int nread;
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");
+#define iobuf bb_common_bufsiz1
for (fd = 0; fd < FD_SETSIZE; fd++) {
if (FD_ISSET(fd, &testfds)) {
- int trn = 0;
- int rn;
-
- ioctl(fd, FIONREAD, &nread);
-
- if (fd == sfd) {
- if (nread == 0)
+ nread = safe_read(fd, iobuf, sizeof(iobuf));
+ if (fd == cfd) {
+ if (nread < 1)
exit(0);
- ofd = fileno(stdout);
+ ofd = STDOUT_FILENO;
} else {
- ofd = sfd;
- }
-
-
-
- do {
- rn = (BUFSIZE < nread - trn) ? BUFSIZE : nread - trn;
- trn += rn;
- read(fd, ch, rn);
- write(ofd, ch, rn);
+ if (nread<1) {
+ // Close outgoing half-connection so they get EOF, but
+ // leave incoming alone so we can see response.
+ shutdown(cfd, 1);
+ FD_CLR(STDIN_FILENO, &readfds);
+ }
+ ofd = cfd;
}
- while (trn < nread);
+ xwrite(ofd, iobuf, nread);
+ if (delay > 0) sleep(delay);
}
}
}
}
+#endif