Contents of /tags/mkinitrd-6_3_5/busybox/networking/nc.c
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
File MIME type: text/plain
File size: 8104 byte(s)
tagged 'mkinitrd-6_3_5'
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 | //config:config NC |
13 | //config: bool "nc" |
14 | //config: default y |
15 | //config: help |
16 | //config: A simple Unix utility which reads and writes data across network |
17 | //config: connections. |
18 | //config: |
19 | //config:config NC_SERVER |
20 | //config: bool "Netcat server options (-l)" |
21 | //config: default y |
22 | //config: depends on NC |
23 | //config: help |
24 | //config: Allow netcat to act as a server. |
25 | //config: |
26 | //config:config NC_EXTRA |
27 | //config: bool "Netcat extensions (-eiw and filename)" |
28 | //config: default y |
29 | //config: depends on NC |
30 | //config: help |
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). |
34 | //config: |
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 |
39 | //config: help |
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. |
44 | |
45 | #if ENABLE_NC_110_COMPAT |
46 | # include "nc_bloaty.c" |
47 | #else |
48 | |
49 | //usage:#if !ENABLE_NC_110_COMPAT |
50 | //usage: |
51 | //usage:#if ENABLE_NC_SERVER || ENABLE_NC_EXTRA |
52 | //usage:#define NC_OPTIONS_STR "\n\nOptions:" |
53 | //usage:#else |
54 | //usage:#define NC_OPTIONS_STR |
55 | //usage:#endif |
56 | //usage: |
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 |
63 | //usage: IF_NC_EXTRA( |
64 | //usage: "\n -e PROG Run PROG after connect" |
65 | //usage: IF_NC_SERVER( |
66 | //usage: "\n -l Listen mode, for inbound connects" |
67 | //usage: IF_NC_EXTRA( |
68 | //usage: "\n (use -l twice with -e for persistent server)") |
69 | //usage: "\n -p PORT Local port" |
70 | //usage: ) |
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" |
74 | //usage: ) |
75 | //usage: |
76 | //usage:#define nc_notes_usage "" |
77 | //usage: IF_NC_EXTRA( |
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" |
81 | //usage: ) |
82 | //usage: |
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" |
86 | //usage: "help\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" |
90 | //usage: "quit\n" |
91 | //usage: "221 foobar closing connection\n" |
92 | //usage: |
93 | //usage:#endif |
94 | |
95 | /* Lots of small differences in features |
96 | * when compared to "standard" nc |
97 | */ |
98 | |
99 | static void timeout(int signum UNUSED_PARAM) |
100 | { |
101 | bb_error_msg_and_die("timed out"); |
102 | } |
103 | |
104 | int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
105 | int nc_main(int argc, char **argv) |
106 | { |
107 | /* sfd sits _here_ only because of "repeat" option (-l -l). */ |
108 | int sfd = sfd; /* for gcc */ |
109 | int cfd = 0; |
110 | unsigned lport = 0; |
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) */ |
118 | |
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 |
124 | ) { |
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"). */ |
140 | IF_NC_EXTRA( |
141 | char **p; |
142 | // +2: one for progname (optarg) and one for NULL |
143 | execparam = xzalloc(sizeof(char*) * (argc - optind + 2)); |
144 | p = execparam; |
145 | *p++ = optarg; |
146 | while (optind < argc) { |
147 | *p++ = argv[optind++]; |
148 | } |
149 | ) |
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(); |
156 | } |
157 | argv += optind; /* ... here! */ |
158 | argc -= optind; |
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 |
163 | if (cfd) { |
164 | if (argc) bb_show_usage(); |
165 | } else if (do_listen) { |
166 | if (argc > 1) bb_show_usage(); |
167 | } else { |
168 | if (!argc || argc > 2) bb_show_usage(); |
169 | } |
170 | } else { |
171 | if (argc != 3) bb_show_usage(); |
172 | argc--; |
173 | argv++; |
174 | } |
175 | |
176 | if (wsecs) { |
177 | signal(SIGALRM, timeout); |
178 | alarm(wsecs); |
179 | } |
180 | |
181 | if (!cfd) { |
182 | if (do_listen) { |
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() */ |
188 | if (!lport) { |
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)); |
194 | } |
195 | #endif |
196 | close_on_exec_on(sfd); |
197 | accept_again: |
198 | cfd = accept(sfd, NULL, 0); |
199 | if (cfd < 0) |
200 | bb_perror_msg_and_die("accept"); |
201 | if (!execparam) |
202 | close(sfd); |
203 | } else { |
204 | cfd = create_and_connect_stream_or_die(argv[0], |
205 | argv[1] ? bb_lookup_port(argv[1], "tcp", 0) : 0); |
206 | } |
207 | } |
208 | |
209 | if (wsecs) { |
210 | alarm(0); |
211 | /* Non-ignored signals revert to SIG_DFL on exec anyway */ |
212 | /*signal(SIGALRM, SIG_DFL);*/ |
213 | } |
214 | |
215 | /* -e given? */ |
216 | if (execparam) { |
217 | pid_t pid; |
218 | /* With more than one -l, repeatedly act as server */ |
219 | if (do_listen > 1 && (pid = xvfork()) != 0) { |
220 | /* parent */ |
221 | /* prevent zombies */ |
222 | signal(SIGCHLD, SIG_IGN); |
223 | close(cfd); |
224 | goto accept_again; |
225 | } |
226 | /* child, or main thread if only one -l */ |
227 | xmove_fd(cfd, 0); |
228 | xdup2(0, 1); |
229 | xdup2(0, 2); |
230 | IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);) |
231 | /* Don't print stuff or it will go over the wire... */ |
232 | _exit(127); |
233 | } |
234 | |
235 | /* Select loop copying stdin to cfd, and cfd to stdout */ |
236 | |
237 | FD_ZERO(&readfds); |
238 | FD_SET(cfd, &readfds); |
239 | FD_SET(STDIN_FILENO, &readfds); |
240 | |
241 | for (;;) { |
242 | int fd; |
243 | int ofd; |
244 | int nread; |
245 | |
246 | testfds = readfds; |
247 | |
248 | if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0) |
249 | bb_perror_msg_and_die("select"); |
250 | |
251 | #define iobuf bb_common_bufsiz1 |
252 | fd = STDIN_FILENO; |
253 | while (1) { |
254 | if (FD_ISSET(fd, &testfds)) { |
255 | nread = safe_read(fd, iobuf, sizeof(iobuf)); |
256 | if (fd == cfd) { |
257 | if (nread < 1) |
258 | exit(EXIT_SUCCESS); |
259 | ofd = STDOUT_FILENO; |
260 | } else { |
261 | if (nread < 1) { |
262 | /* Close outgoing half-connection so they get EOF, |
263 | * but leave incoming alone so we can see response */ |
264 | shutdown(cfd, 1); |
265 | FD_CLR(STDIN_FILENO, &readfds); |
266 | } |
267 | ofd = cfd; |
268 | } |
269 | xwrite(ofd, iobuf, nread); |
270 | if (delay > 0) |
271 | sleep(delay); |
272 | } |
273 | if (fd == cfd) |
274 | break; |
275 | fd = cfd; |
276 | } |
277 | } |
278 | } |
279 | #endif |