1 /* vi: set sw=4 ts=4: */
2 /* nc: mini-netcat - built from the ground up for LRP
4 * Copyright (C) 1998, 1999 Charles P. Wright
5 * Copyright (C) 1998 Dave Cinege
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
16 //config: A simple Unix utility which reads and writes data across network
17 //config: connections.
19 //config:config NC_SERVER
20 //config: bool "Netcat server options (-l)"
22 //config: depends on NC
24 //config: Allow netcat to act as a server.
26 //config:config NC_EXTRA
27 //config: bool "Netcat extensions (-eiw and filename)"
29 //config: depends on NC
31 //config: Add -e (support for executing the rest of the command line after
32 //config: making or receiving a successful connection), -i (delay interval for
33 //config: lines sent), -w (timeout for initial connection).
35 //config:config NC_110_COMPAT
36 //config: bool "Netcat 1.10 compatibility (+2.5k)"
37 //config: default n # off specially for Rob
38 //config: depends on NC
40 //config: This option makes nc closely follow original nc-1.10.
41 //config: The code is about 2.5k bigger. It enables
42 //config: -s ADDR, -n, -u, -v, -o FILE, -z options, but loses
43 //config: busybox-specific extensions: -f FILE and -ll.
45 #if ENABLE_NC_110_COMPAT
46 # include "nc_bloaty.c"
49 //usage:#if !ENABLE_NC_110_COMPAT
51 //usage:#if ENABLE_NC_SERVER || ENABLE_NC_EXTRA
52 //usage:#define NC_OPTIONS_STR "\n"
54 //usage:#define NC_OPTIONS_STR
57 //usage:#define nc_trivial_usage
58 //usage: IF_NC_EXTRA("[-iN] [-wN] ")IF_NC_SERVER("[-l] [-p PORT] ")
59 //usage: "["IF_NC_EXTRA("-f FILE|")"IPADDR PORT]"IF_NC_EXTRA(" [-e PROG]")
60 //usage:#define nc_full_usage "\n\n"
61 //usage: "Open a pipe to IP:PORT" IF_NC_EXTRA(" or FILE")
62 //usage: NC_OPTIONS_STR
64 //usage: "\n -e PROG Run PROG after connect"
65 //usage: IF_NC_SERVER(
66 //usage: "\n -l Listen mode, for inbound connects"
68 //usage: "\n (use -l twice with -e for persistent server)")
69 //usage: "\n -p PORT Local port"
71 //usage: "\n -w SEC Timeout for connect"
72 //usage: "\n -i SEC Delay interval for lines sent"
73 //usage: "\n -f FILE Use file (ala /dev/ttyS0) instead of network"
76 //usage:#define nc_notes_usage ""
78 //usage: "To use netcat as a terminal emulator on a serial port:\n\n"
79 //usage: "$ stty 115200 -F /dev/ttyS0\n"
80 //usage: "$ stty raw -echo -ctlecho && nc -f /dev/ttyS0\n"
83 //usage:#define nc_example_usage
84 //usage: "$ nc foobar.somedomain.com 25\n"
85 //usage: "220 foobar ESMTP Exim 3.12 #1 Sat, 15 Apr 2000 00:03:02 -0600\n"
87 //usage: "214-Commands supported:\n"
88 //usage: "214- HELO EHLO MAIL RCPT DATA AUTH\n"
89 //usage: "214 NOOP QUIT RSET HELP\n"
91 //usage: "221 foobar closing connection\n"
95 /* Lots of small differences in features
96 * when compared to "standard" nc
99 static void timeout(int signum UNUSED_PARAM)
101 bb_error_msg_and_die("timed out");
104 int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
105 int nc_main(int argc, char **argv)
107 /* sfd sits _here_ only because of "repeat" option (-l -l). */
108 int sfd = sfd; /* for gcc */
111 IF_NOT_NC_SERVER(const) unsigned do_listen = 0;
112 IF_NOT_NC_EXTRA (const) unsigned wsecs = 0;
113 IF_NOT_NC_EXTRA (const) unsigned delay = 0;
114 IF_NOT_NC_EXTRA (const int execparam = 0;)
115 IF_NC_EXTRA (char **execparam = NULL;)
116 fd_set readfds, testfds;
117 int opt; /* must be signed (getopt returns -1) */
119 if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
120 /* getopt32 is _almost_ usable:
121 ** it cannot handle "... -e PROG -prog-opt" */
122 while ((opt = getopt(argc, argv,
123 "" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0
125 if (ENABLE_NC_SERVER && opt == 'l')
126 IF_NC_SERVER(do_listen++);
127 else if (ENABLE_NC_SERVER && opt == 'p')
128 IF_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
129 else if (ENABLE_NC_EXTRA && opt == 'w')
130 IF_NC_EXTRA( wsecs = xatou(optarg));
131 else if (ENABLE_NC_EXTRA && opt == 'i')
132 IF_NC_EXTRA( delay = xatou(optarg));
133 else if (ENABLE_NC_EXTRA && opt == 'f')
134 IF_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
135 else if (ENABLE_NC_EXTRA && opt == 'e' && optind <= argc) {
136 /* We cannot just 'break'. We should let getopt finish.
137 ** Or else we won't be able to find where
138 ** 'host' and 'port' params are
139 ** (think "nc -w 60 host port -e PROG"). */
142 // +2: one for progname (optarg) and one for NULL
143 execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
146 while (optind < argc) {
147 *p++ = argv[optind++];
150 /* optind points to argv[arvc] (NULL) now.
151 ** FIXME: we assume that getopt will not count options
152 ** possibly present on "-e PROG ARGS" and will not
153 ** include them into final value of optind
154 ** which is to be used ... */
155 } else bb_show_usage();
157 argv += optind; /* ... here! */
159 // -l and -f don't mix
160 if (do_listen && cfd) bb_show_usage();
161 // File mode needs need zero arguments, listen mode needs zero or one,
162 // client mode needs one or two
164 if (argc) bb_show_usage();
165 } else if (do_listen) {
166 if (argc > 1) bb_show_usage();
168 if (!argc || argc > 2) bb_show_usage();
171 if (argc != 3) bb_show_usage();
177 signal(SIGALRM, timeout);
183 sfd = create_and_bind_stream_or_die(argv[0], lport);
184 xlisten(sfd, do_listen); /* can be > 1 */
185 #if 0 /* nc-1.10 does not do this (without -v) */
186 /* If we didn't specify a port number,
187 * query and print it after listen() */
189 len_and_sockaddr lsa;
190 lsa.len = LSA_SIZEOF_SA;
191 getsockname(sfd, &lsa.u.sa, &lsa.len);
192 lport = get_nport(&lsa.u.sa);
193 fdprintf(2, "%d\n", ntohs(lport));
196 close_on_exec_on(sfd);
198 cfd = accept(sfd, NULL, 0);
200 bb_perror_msg_and_die("accept");
204 cfd = create_and_connect_stream_or_die(argv[0],
205 argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
211 /* Non-ignored signals revert to SIG_DFL on exec anyway */
212 /*signal(SIGALRM, SIG_DFL);*/
218 /* With more than one -l, repeatedly act as server */
219 if (do_listen > 1 && (pid = xvfork()) != 0) {
221 /* prevent zombies */
222 signal(SIGCHLD, SIG_IGN);
226 /* child, or main thread if only one -l */
230 IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
231 /* Don't print stuff or it will go over the wire... */
235 /* Select loop copying stdin to cfd, and cfd to stdout */
238 FD_SET(cfd, &readfds);
239 FD_SET(STDIN_FILENO, &readfds);
248 if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0)
249 bb_perror_msg_and_die("select");
251 #define iobuf bb_common_bufsiz1
254 if (FD_ISSET(fd, &testfds)) {
255 nread = safe_read(fd, iobuf, sizeof(iobuf));
262 /* Close outgoing half-connection so they get EOF,
263 * but leave incoming alone so we can see response */
265 FD_CLR(STDIN_FILENO, &readfds);
269 xwrite(ofd, iobuf, nread);