source: MondoRescue/branches/2.2.5/mindi-busybox/networking/nc.c@ 1765

Last change on this file since 1765 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 5.2 KB
Line 
1/* vi: set sw=4 ts=4: */
2/* nc: mini-netcat - built from the ground up for LRP
3 *
4 * Copyright (C) 1998, 1999 Charles P. Wright
5 * Copyright (C) 1998 Dave Cinege
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12#if ENABLE_DESKTOP
13#include "nc_bloaty.c"
14#else
15
16/* Lots of small differences in features
17 * when compared to "standard" nc
18 */
19
20static void timeout(int signum)
21{
22 bb_error_msg_and_die("timed out");
23}
24
25int nc_main(int argc, char **argv);
26int nc_main(int argc, char **argv)
27{
28 /* sfd sits _here_ only because of "repeat" option (-l -l). */
29 int sfd = sfd; /* for gcc */
30 int cfd = 0;
31 unsigned lport = 0;
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) */
40
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
46 ) {
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));
50 }
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"). */
59 USE_NC_EXTRA(
60 char **p;
61 // +2: one for progname (optarg) and one for NULL
62 execparam = xzalloc(sizeof(char*) * (argc - optind + 2));
63 p = execparam;
64 *p++ = optarg;
65 while (optind < argc) {
66 *p++ = argv[optind++];
67 }
68 )
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();
75 }
76 argv += optind; /* ... here! */
77 argc -= optind;
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();
83 } else {
84 if (!argc || argc > 2) bb_show_usage();
85 }
86 } else {
87 if (argc != 3) bb_show_usage();
88 argc--;
89 argv++;
90 }
91
92 if (wsecs) {
93 signal(SIGALRM, timeout);
94 alarm(wsecs);
95 }
96
97 if (!cfd) {
98 if (do_listen) {
99 /* create_and_bind_stream_or_die(NULL, lport)
100 * would've work wonderfully, but we need
101 * to know lsa */
102 sfd = xsocket_stream(&lsa);
103 if (lport)
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() */
110 if (!lport) {
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));
115 }
116 fcntl(sfd, F_SETFD, FD_CLOEXEC);
117 accept_again:
118 cfd = accept(sfd, NULL, 0);
119 if (cfd < 0)
120 bb_perror_msg_and_die("accept");
121 if (!execparam)
122 close(sfd);
123 } else {
124 cfd = create_and_connect_stream_or_die(argv[0],
125 argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0);
126 }
127 }
128
129 if (wsecs) {
130 alarm(0);
131 signal(SIGALRM, SIG_DFL);
132 }
133
134 /* -e given? */
135 if (execparam) {
136 signal(SIGCHLD, SIG_IGN);
137 // With more than one -l, repeatedly act as server.
138 if (do_listen > 1 && vfork()) {
139 /* parent */
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;
144 close(0);
145 close(1);
146 close(2);
147 goto accept_again;
148 }
149 /* child (or main thread if no multiple -l) */
150 if (cfd) {
151 dup2(cfd, 0);
152 close(cfd);
153 }
154 dup2(0, 1);
155 dup2(0, 2);
156 USE_NC_EXTRA(BB_EXECVP(execparam[0], execparam);)
157 /* Don't print stuff or it will go over the wire.... */
158 _exit(127);
159 }
160
161 // Select loop copying stdin to cfd, and cfd to stdout.
162
163 FD_ZERO(&readfds);
164 FD_SET(cfd, &readfds);
165 FD_SET(STDIN_FILENO, &readfds);
166
167 for (;;) {
168 int fd;
169 int ofd;
170 int nread;
171
172 testfds = readfds;
173
174 if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
175 bb_perror_msg_and_die("select");
176
177#define iobuf bb_common_bufsiz1
178 for (fd = 0; fd < FD_SETSIZE; fd++) {
179 if (FD_ISSET(fd, &testfds)) {
180 nread = safe_read(fd, iobuf, sizeof(iobuf));
181 if (fd == cfd) {
182 if (nread < 1)
183 exit(0);
184 ofd = STDOUT_FILENO;
185 } else {
186 if (nread<1) {
187 // Close outgoing half-connection so they get EOF, but
188 // leave incoming alone so we can see response.
189 shutdown(cfd, 1);
190 FD_CLR(STDIN_FILENO, &readfds);
191 }
192 ofd = cfd;
193 }
194 xwrite(ofd, iobuf, nread);
195 if (delay > 0) sleep(delay);
196 }
197 }
198 }
199}
200#endif
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