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 tarball for details.
13 #include "nc_bloaty.c"
16 /* Lots of small differences in features
17 * when compared to "standard" nc
20 static void timeout(int signum UNUSED_PARAM)
22 bb_error_msg_and_die("timed out");
25 int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
26 int nc_main(int argc, char **argv)
28 /* sfd sits _here_ only because of "repeat" option (-l -l). */
29 int sfd = sfd; /* for gcc */
32 IF_NOT_NC_SERVER(const) unsigned do_listen = 0;
33 IF_NOT_NC_EXTRA (const) unsigned wsecs = 0;
34 IF_NOT_NC_EXTRA (const) unsigned delay = 0;
35 IF_NOT_NC_EXTRA (const int execparam = 0;)
36 IF_NC_EXTRA (char **execparam = NULL;)
37 fd_set readfds, testfds;
38 int opt; /* must be signed (getopt returns -1) */
40 if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
41 /* getopt32 is _almost_ usable:
42 ** it cannot handle "... -e prog -prog-opt" */
43 while ((opt = getopt(argc, argv,
44 "" IF_NC_SERVER("lp:") IF_NC_EXTRA("w:i:f:e:") )) > 0
46 if (ENABLE_NC_SERVER && opt == 'l')
47 IF_NC_SERVER(do_listen++);
48 else if (ENABLE_NC_SERVER && opt == 'p')
49 IF_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
50 else if (ENABLE_NC_EXTRA && opt == 'w')
51 IF_NC_EXTRA( wsecs = xatou(optarg));
52 else if (ENABLE_NC_EXTRA && opt == 'i')
53 IF_NC_EXTRA( delay = xatou(optarg));
54 else if (ENABLE_NC_EXTRA && opt == 'f')
55 IF_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
56 else if (ENABLE_NC_EXTRA && opt == 'e' && optind <= argc) {
57 /* We cannot just 'break'. We should let getopt finish.
58 ** Or else we won't be able to find where
59 ** 'host' and 'port' params are
60 ** (think "nc -w 60 host port -e prog"). */
63 // +2: one for progname (optarg) and one for NULL
64 execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
67 while (optind < argc) {
68 *p++ = argv[optind++];
71 /* optind points to argv[arvc] (NULL) now.
72 ** FIXME: we assume that getopt will not count options
73 ** possibly present on "-e prog args" and will not
74 ** include them into final value of optind
75 ** which is to be used ... */
76 } else bb_show_usage();
78 argv += optind; /* ... here! */
80 // -l and -f don't mix
81 if (do_listen && cfd) bb_show_usage();
82 // File mode needs need zero arguments, listen mode needs zero or one,
83 // client mode needs one or two
85 if (argc) bb_show_usage();
86 } else if (do_listen) {
87 if (argc > 1) bb_show_usage();
89 if (!argc || argc > 2) bb_show_usage();
92 if (argc != 3) bb_show_usage();
98 signal(SIGALRM, timeout);
104 sfd = create_and_bind_stream_or_die(argv[0], lport);
105 xlisten(sfd, do_listen); /* can be > 1 */
106 #if 0 /* nc-1.10 does not do this (without -v) */
107 /* If we didn't specify a port number,
108 * query and print it after listen() */
110 len_and_sockaddr lsa;
111 lsa.len = LSA_SIZEOF_SA;
112 getsockname(sfd, &lsa.u.sa, &lsa.len);
113 lport = get_nport(&lsa.u.sa);
114 fdprintf(2, "%d\n", ntohs(lport));
117 close_on_exec_on(sfd);
119 cfd = accept(sfd, NULL, 0);
121 bb_perror_msg_and_die("accept");
125 cfd = create_and_connect_stream_or_die(argv[0],
126 argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
132 /* Non-ignored siganls revert to SIG_DFL on exec anyway */
133 /*signal(SIGALRM, SIG_DFL);*/
138 signal(SIGCHLD, SIG_IGN);
139 // With more than one -l, repeatedly act as server.
140 if (do_listen > 1 && vfork()) {
142 // This is a bit weird as cleanup goes, since we wind up with no
143 // stdin/stdout/stderr. But it's small and shouldn't hurt anything.
144 // We check for cfd == 0 above.
145 logmode = LOGMODE_NONE;
151 /* child (or main thread if no multiple -l) */
155 IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
156 /* Don't print stuff or it will go over the wire.... */
160 // Select loop copying stdin to cfd, and cfd to stdout.
163 FD_SET(cfd, &readfds);
164 FD_SET(STDIN_FILENO, &readfds);
173 if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
174 bb_perror_msg_and_die("select");
176 #define iobuf bb_common_bufsiz1
177 for (fd = 0; fd < FD_SETSIZE; fd++) {
178 if (FD_ISSET(fd, &testfds)) {
179 nread = safe_read(fd, iobuf, sizeof(iobuf));
186 // Close outgoing half-connection so they get EOF, but
187 // leave incoming alone so we can see response.
189 FD_CLR(STDIN_FILENO, &readfds);
193 xwrite(ofd, iobuf, nread);
194 if (delay > 0) sleep(delay);