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)
22 bb_error_msg_and_die("timed out");
25 int nc_main(int argc, char **argv);
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 SKIP_NC_SERVER(const) unsigned do_listen = 0;
33 SKIP_NC_EXTRA (const) unsigned wsecs = 0;
34 SKIP_NC_EXTRA (const) unsigned delay = 0;
35 SKIP_NC_EXTRA (const int execparam = 0;)
36 USE_NC_EXTRA (char **execparam = NULL;)
37 len_and_sockaddr *lsa;
38 fd_set readfds, testfds;
39 int opt; /* must be signed (getopt returns -1) */
41 if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
42 /* getopt32 is _almost_ usable:
43 ** it cannot handle "... -e prog -prog-opt" */
44 while ((opt = getopt(argc, argv,
45 "" USE_NC_SERVER("lp:") USE_NC_EXTRA("w:i:f:e:") )) > 0
47 if (ENABLE_NC_SERVER && opt=='l') USE_NC_SERVER(do_listen++);
48 else if (ENABLE_NC_SERVER && opt=='p') {
49 USE_NC_SERVER(lport = bb_lookup_port(optarg, "tcp", 0));
51 else if (ENABLE_NC_EXTRA && opt=='w') USE_NC_EXTRA( wsecs = xatou(optarg));
52 else if (ENABLE_NC_EXTRA && opt=='i') USE_NC_EXTRA( delay = xatou(optarg));
53 else if (ENABLE_NC_EXTRA && opt=='f') USE_NC_EXTRA( cfd = xopen(optarg, O_RDWR));
54 else if (ENABLE_NC_EXTRA && opt=='e' && optind<=argc) {
55 /* We cannot just 'break'. We should let getopt finish.
56 ** Or else we won't be able to find where
57 ** 'host' and 'port' params are
58 ** (think "nc -w 60 host port -e prog"). */
61 // +2: one for progname (optarg) and one for NULL
62 execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
65 while (optind < argc) {
66 *p++ = argv[optind++];
69 /* optind points to argv[arvc] (NULL) now.
70 ** FIXME: we assume that getopt will not count options
71 ** possibly present on "-e prog args" and will not
72 ** include them into final value of optind
73 ** which is to be used ... */
74 } else bb_show_usage();
76 argv += optind; /* ... here! */
78 // -l and -f don't mix
79 if (do_listen && cfd) bb_show_usage();
80 // Listen or file modes need zero arguments, client mode needs 2
81 if (do_listen || cfd) {
82 if (argc) bb_show_usage();
84 if (!argc || argc > 2) bb_show_usage();
87 if (argc != 3) bb_show_usage();
93 signal(SIGALRM, timeout);
99 /* create_and_bind_stream_or_die(NULL, lport)
100 * would've work wonderfully, but we need
102 sfd = xsocket_stream(&lsa);
104 set_nport(lsa, htons(lport));
105 setsockopt_reuseaddr(sfd);
106 xbind(sfd, &lsa->sa, lsa->len);
107 xlisten(sfd, do_listen); /* can be > 1 */
108 /* If we didn't specify a port number,
109 * query and print it after listen() */
111 socklen_t addrlen = lsa->len;
112 getsockname(sfd, &lsa->sa, &addrlen);
113 lport = get_nport(&lsa->sa);
114 fdprintf(2, "%d\n", ntohs(lport));
116 fcntl(sfd, F_SETFD, FD_CLOEXEC);
118 cfd = accept(sfd, NULL, 0);
120 bb_perror_msg_and_die("accept");
124 cfd = create_and_connect_stream_or_die(argv[0],
125 argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
131 signal(SIGALRM, SIG_DFL);
136 signal(SIGCHLD, SIG_IGN);
137 // With more than one -l, repeatedly act as server.
138 if (do_listen > 1 && vfork()) {
140 // This is a bit weird as cleanup goes, since we wind up with no
141 // stdin/stdout/stderr. But it's small and shouldn't hurt anything.
142 // We check for cfd == 0 above.
143 logmode = LOGMODE_NONE;
149 /* child (or main thread if no multiple -l) */
156 USE_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
157 /* Don't print stuff or it will go over the wire.... */
161 // Select loop copying stdin to cfd, and cfd to stdout.
164 FD_SET(cfd, &readfds);
165 FD_SET(STDIN_FILENO, &readfds);
174 if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
175 bb_perror_msg_and_die("select");
177 for (fd = 0; fd < FD_SETSIZE; fd++) {
178 if (FD_ISSET(fd, &testfds)) {
179 nread = safe_read(fd, bb_common_bufsiz1,
180 sizeof(bb_common_bufsiz1));
188 // Close outgoing half-connection so they get EOF, but
189 // leave incoming alone so we can see response.
191 FD_CLR(STDIN_FILENO, &readfds);
196 xwrite(ofd, bb_common_bufsiz1, nread);
197 if (delay > 0) sleep(delay);