diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-04-05 20:26:28 +0000 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-04-05 20:26:28 +0000 |
commit | 29fe7265b8c1917ebc03283f22a3eb61e9195979 (patch) | |
tree | 231771f61046cc95c765fc91f65cff26081d8fab /networking | |
parent | 00c2c4868a5bd90fe36beaf9236f23f60cd5e8e1 (diff) | |
download | busybox-w32-29fe7265b8c1917ebc03283f22a3eb61e9195979.tar.gz busybox-w32-29fe7265b8c1917ebc03283f22a3eb61e9195979.tar.bz2 busybox-w32-29fe7265b8c1917ebc03283f22a3eb61e9195979.zip |
nc: port nc 1.10 to busybox
Diffstat (limited to 'networking')
-rw-r--r-- | networking/Config.in | 2 | ||||
-rw-r--r-- | networking/nc.c | 5 | ||||
-rw-r--r-- | networking/nc_bloaty.c | 799 |
3 files changed, 805 insertions, 1 deletions
diff --git a/networking/Config.in b/networking/Config.in index f78056827..a40770540 100644 --- a/networking/Config.in +++ b/networking/Config.in | |||
@@ -467,7 +467,7 @@ config NC | |||
467 | connections. | 467 | connections. |
468 | 468 | ||
469 | config NC_SERVER | 469 | config NC_SERVER |
470 | bool "Netcat server options (-lp)" | 470 | bool "Netcat server options (-l)" |
471 | default n | 471 | default n |
472 | depends on NC | 472 | depends on NC |
473 | help | 473 | help |
diff --git a/networking/nc.c b/networking/nc.c index bc7c701fe..e89eb7615 100644 --- a/networking/nc.c +++ b/networking/nc.c | |||
@@ -9,6 +9,10 @@ | |||
9 | 9 | ||
10 | #include "busybox.h" | 10 | #include "busybox.h" |
11 | 11 | ||
12 | #if ENABLE_DESKTOP | ||
13 | #include "nc_bloaty.c" | ||
14 | #else | ||
15 | |||
12 | /* Lots of small differences in features | 16 | /* Lots of small differences in features |
13 | * when compared to "standard" nc | 17 | * when compared to "standard" nc |
14 | */ | 18 | */ |
@@ -195,3 +199,4 @@ int nc_main(int argc, char **argv) | |||
195 | } | 199 | } |
196 | } | 200 | } |
197 | } | 201 | } |
202 | #endif | ||
diff --git a/networking/nc_bloaty.c b/networking/nc_bloaty.c new file mode 100644 index 000000000..260d2057a --- /dev/null +++ b/networking/nc_bloaty.c | |||
@@ -0,0 +1,799 @@ | |||
1 | /* Based on netcat 1.10 RELEASE 960320 written by hobbit@avian.org. | ||
2 | * Released into public domain by the author. | ||
3 | * | ||
4 | * Copyright (C) 2007 Denis Vlasenko. | ||
5 | * | ||
6 | * Licensed under GPLv2, see file LICENSE in this tarball for details. | ||
7 | */ | ||
8 | |||
9 | /* Author's comments from nc 1.10: | ||
10 | * ===================== | ||
11 | * Netcat is entirely my own creation, although plenty of other code was used as | ||
12 | * examples. It is freely given away to the Internet community in the hope that | ||
13 | * it will be useful, with no restrictions except giving credit where it is due. | ||
14 | * No GPLs, Berkeley copyrights or any of that nonsense. The author assumes NO | ||
15 | * responsibility for how anyone uses it. If netcat makes you rich somehow and | ||
16 | * you're feeling generous, mail me a check. If you are affiliated in any way | ||
17 | * with Microsoft Network, get a life. Always ski in control. Comments, | ||
18 | * questions, and patches to hobbit@avian.org. | ||
19 | * ... | ||
20 | * Netcat and the associated package is a product of Avian Research, and is freely | ||
21 | * available in full source form with no restrictions save an obligation to give | ||
22 | * credit where due. | ||
23 | * ... | ||
24 | * A damn useful little "backend" utility begun 950915 or thereabouts, | ||
25 | * as *Hobbit*'s first real stab at some sockets programming. Something that | ||
26 | * should have and indeed may have existed ten years ago, but never became a | ||
27 | * standard Unix utility. IMHO, "nc" could take its place right next to cat, | ||
28 | * cp, rm, mv, dd, ls, and all those other cryptic and Unix-like things. | ||
29 | * ===================== | ||
30 | * | ||
31 | * Much of author's comments are still retained in the code. | ||
32 | * | ||
33 | * Functionality removed (rationale): | ||
34 | * - miltiple-port ranges, randomized port scanning (use nmap) | ||
35 | * - telnet support (use telnet) | ||
36 | * - source routing | ||
37 | * - multiple DNS checks | ||
38 | * Functionalty which is different from nc 1.10: | ||
39 | * - Prog in '-e prog' can have prog's parameters and options. | ||
40 | * Because of this -e option must be last. | ||
41 | * - nc doesn't redirect stderr to the network socket for the -e prog. | ||
42 | */ | ||
43 | |||
44 | /* done in nc.c: #include "busybox.h" */ | ||
45 | |||
46 | #define SLEAZE_PORT 31337 /* for UDP-scan RTT trick, change if ya want */ | ||
47 | #define BIGSIZ 8192 /* big buffers */ | ||
48 | |||
49 | struct globals { | ||
50 | int netfd; | ||
51 | int ofd; /* hexdump output fd */ | ||
52 | #if ENABLE_LFS | ||
53 | #define SENT_N_RECV_M "sent %llu, rcvd %llu\n" | ||
54 | unsigned long long wrote_out; /* total stdout bytes */ | ||
55 | unsigned long long wrote_net; /* total net bytes */ | ||
56 | #else | ||
57 | #define SENT_N_RECV_M "sent %u, rcvd %u" | ||
58 | unsigned wrote_out; /* total stdout bytes */ | ||
59 | unsigned wrote_net; /* total net bytes */ | ||
60 | #endif | ||
61 | /* ouraddr is never NULL and goes thru three states as we progress: | ||
62 | 1 - local address before bind (IP/port possibly zero) | ||
63 | 2 - local address after bind (port is nonzero) | ||
64 | 3 - local address after connect??/recv/accept (IP and port are nonzero) */ | ||
65 | struct len_and_sockaddr *ouraddr; | ||
66 | /* themaddr is NULL if no peer hostname[:port] specified on command line */ | ||
67 | struct len_and_sockaddr *themaddr; | ||
68 | /* remend is set after connect/recv/accept to the actual ip:port of peer */ | ||
69 | struct len_and_sockaddr remend; | ||
70 | |||
71 | /* global cmd flags: */ | ||
72 | unsigned o_verbose; | ||
73 | unsigned o_wait; | ||
74 | #if ENABLE_NC_EXTRA | ||
75 | unsigned o_interval; | ||
76 | #endif | ||
77 | |||
78 | jmp_buf jbuf; /* timer crud */ | ||
79 | unsigned char *stage; /* hexdump line buffer */ | ||
80 | |||
81 | /* will malloc up the following globals: */ | ||
82 | fd_set ding1; /* for select loop */ | ||
83 | fd_set ding2; | ||
84 | char bigbuf_in[BIGSIZ]; /* data buffers */ | ||
85 | char bigbuf_net[BIGSIZ]; | ||
86 | }; | ||
87 | |||
88 | #define G (*ptr_to_globals) | ||
89 | |||
90 | #define netfd (G.netfd ) | ||
91 | #define ofd (G.ofd ) | ||
92 | #define wrote_out (G.wrote_out ) | ||
93 | #define wrote_net (G.wrote_net ) | ||
94 | #define ouraddr (G.ouraddr ) | ||
95 | #define themaddr (G.themaddr ) | ||
96 | #define remend (G.remend ) | ||
97 | #define jbuf (G.jbuf ) | ||
98 | #define stage (G.stage ) | ||
99 | #define ding1 (G.ding1 ) | ||
100 | #define ding2 (G.ding2 ) | ||
101 | #define bigbuf_in (G.bigbuf_in ) | ||
102 | #define bigbuf_net (G.bigbuf_net) | ||
103 | #define o_verbose (G.o_verbose ) | ||
104 | #define o_wait (G.o_wait ) | ||
105 | #if ENABLE_NC_EXTRA | ||
106 | #define o_interval (G.o_interval) | ||
107 | #else | ||
108 | #define o_interval 0 | ||
109 | #endif | ||
110 | |||
111 | /* Must match getopt32 call! */ | ||
112 | enum { | ||
113 | OPT_h = (1 << 0), | ||
114 | OPT_n = (1 << 1), | ||
115 | OPT_p = (1 << 2), | ||
116 | OPT_s = (1 << 3), | ||
117 | OPT_u = (1 << 4), | ||
118 | OPT_v = (1 << 5), | ||
119 | OPT_w = (1 << 6), | ||
120 | OPT_l = (1 << 7) * ENABLE_NC_SERVER, | ||
121 | OPT_i = (1 << (7+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, | ||
122 | OPT_o = (1 << (8+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, | ||
123 | OPT_z = (1 << (9+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, | ||
124 | }; | ||
125 | |||
126 | #define o_nflag (option_mask32 & OPT_n) | ||
127 | #define o_udpmode (option_mask32 & OPT_u) | ||
128 | #if ENABLE_NC_EXTRA | ||
129 | #define o_wfile (option_mask32 & OPT_o) | ||
130 | #define o_listen (option_mask32 & OPT_l) | ||
131 | #define o_zero (option_mask32 & OPT_z) | ||
132 | #else | ||
133 | #define o_wfile 0 | ||
134 | #define o_listen 0 | ||
135 | #define o_zero 0 | ||
136 | #endif | ||
137 | |||
138 | /* Debug macro: squirt whatever message and sleep a bit so we can see it go | ||
139 | by. need to call like Debug((stuff)) [with no ; ] so macro args match! | ||
140 | Beware: writes to stdOUT... */ | ||
141 | #if 0 | ||
142 | #define Debug(x) printf x; printf("\n"); fflush(stdout); sleep(1); | ||
143 | #else | ||
144 | #define Debug(x) /* nil... */ | ||
145 | #endif | ||
146 | |||
147 | #define holler_error(...) do { if (o_verbose) bb_error_msg(__VA_ARGS__); } while(0) | ||
148 | #define holler_perror(...) do { if (o_verbose) bb_perror_msg(__VA_ARGS__); } while(0) | ||
149 | |||
150 | /* catch: no-brainer interrupt handler */ | ||
151 | static void catch(int sig) | ||
152 | { | ||
153 | errno = 0; | ||
154 | if (o_verbose > 1) /* normally we don't care */ | ||
155 | fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); | ||
156 | fprintf(stderr, "punt!\n"); | ||
157 | } | ||
158 | |||
159 | /* timeout and other signal handling cruft */ | ||
160 | static void tmtravel(int sig) | ||
161 | { | ||
162 | signal(SIGALRM, SIG_IGN); | ||
163 | alarm(0); | ||
164 | longjmp(jbuf, 1); | ||
165 | } | ||
166 | |||
167 | /* arm: set the timer. */ | ||
168 | static void arm(unsigned secs) | ||
169 | { | ||
170 | signal(SIGALRM, tmtravel); | ||
171 | alarm(secs); | ||
172 | } | ||
173 | |||
174 | /* unarm */ | ||
175 | static void unarm(void) | ||
176 | { | ||
177 | signal(SIGALRM, SIG_IGN); | ||
178 | alarm(0); | ||
179 | } | ||
180 | |||
181 | /* findline: | ||
182 | find the next newline in a buffer; return inclusive size of that "line", | ||
183 | or the entire buffer size, so the caller knows how much to then write(). | ||
184 | Not distinguishing \n vs \r\n for the nonce; it just works as is... */ | ||
185 | static unsigned findline(char *buf, unsigned siz) | ||
186 | { | ||
187 | char * p; | ||
188 | int x; | ||
189 | if (!buf) /* various sanity checks... */ | ||
190 | return 0; | ||
191 | if (siz > BIGSIZ) | ||
192 | return 0; | ||
193 | x = siz; | ||
194 | for (p = buf; x > 0; x--) { | ||
195 | if (*p == '\n') { | ||
196 | x = (int) (p - buf); | ||
197 | x++; /* 'sokay if it points just past the end! */ | ||
198 | Debug(("findline returning %d", x)) | ||
199 | return x; | ||
200 | } | ||
201 | p++; | ||
202 | } /* for */ | ||
203 | Debug(("findline returning whole thing: %d", siz)) | ||
204 | return siz; | ||
205 | } /* findline */ | ||
206 | |||
207 | /* doexec: | ||
208 | fiddle all the file descriptors around, and hand off to another prog. Sort | ||
209 | of like a one-off "poor man's inetd". This is the only section of code | ||
210 | that would be security-critical, which is why it's ifdefed out by default. | ||
211 | Use at your own hairy risk; if you leave shells lying around behind open | ||
212 | listening ports you deserve to lose!! */ | ||
213 | static int doexec(char **proggie) ATTRIBUTE_NORETURN; | ||
214 | static int doexec(char **proggie) | ||
215 | { | ||
216 | xmove_fd(netfd, 0); | ||
217 | dup2(0, 1); | ||
218 | /* dup2(0, 2); - do we *really* want this? NO! | ||
219 | * exec'ed prog can do it yourself, if needed */ | ||
220 | execvp(proggie[0], proggie); | ||
221 | bb_perror_msg_and_die("exec"); | ||
222 | } | ||
223 | |||
224 | /* connect_w_timeout: | ||
225 | return an fd for one of | ||
226 | an open outbound TCP connection, a UDP stub-socket thingie, or | ||
227 | an unconnected TCP or UDP socket to listen on. | ||
228 | Examines various global o_blah flags to figure out what to do. | ||
229 | lad can be NULL, then socket is not bound to any local ip[:port] */ | ||
230 | static int connect_w_timeout(int fd) | ||
231 | { | ||
232 | int rr; | ||
233 | |||
234 | /* wrap connect inside a timer, and hit it */ | ||
235 | arm(o_wait); | ||
236 | if (setjmp(jbuf) == 0) { | ||
237 | rr = connect(fd, &themaddr->sa, themaddr->len); | ||
238 | } else { /* setjmp: connect failed... */ | ||
239 | rr = -1; | ||
240 | errno = ETIMEDOUT; /* fake it */ | ||
241 | } | ||
242 | unarm(); | ||
243 | return rr; | ||
244 | } | ||
245 | |||
246 | /* dolisten: | ||
247 | listens for | ||
248 | incoming and returns an open connection *from* someplace. If we were | ||
249 | given host/port args, any connections from elsewhere are rejected. This | ||
250 | in conjunction with local-address binding should limit things nicely... */ | ||
251 | static void dolisten(void) | ||
252 | { | ||
253 | int rr; | ||
254 | const char *errmsg = errmsg; /* gcc */ | ||
255 | |||
256 | if (!o_udpmode) | ||
257 | xlisten(netfd, 1); /* TCP: gotta listen() before we can get */ | ||
258 | |||
259 | /* Various things that follow temporarily trash bigbuf_net, which might contain | ||
260 | a copy of any recvfrom()ed packet, but we'll read() another copy later. */ | ||
261 | |||
262 | /* I can't believe I have to do all this to get my own goddamn bound address | ||
263 | and port number. It should just get filled in during bind() or something. | ||
264 | All this is only useful if we didn't say -p for listening, since if we | ||
265 | said -p we *know* what port we're listening on. At any rate we won't bother | ||
266 | with it all unless we wanted to see it, although listening quietly on a | ||
267 | random unknown port is probably not very useful without "netstat". */ | ||
268 | if (o_verbose) { | ||
269 | char *addr; | ||
270 | rr = getsockname(netfd, &ouraddr->sa, &ouraddr->len); | ||
271 | if (rr < 0) | ||
272 | bb_perror_msg_and_die("getsockname after bind"); | ||
273 | addr = xmalloc_sockaddr2dotted(&ouraddr->sa, ouraddr->len); | ||
274 | fprintf(stderr, "listening on [%s] ...\n", addr); | ||
275 | free(addr); | ||
276 | } | ||
277 | |||
278 | if (o_udpmode) { | ||
279 | /* UDP is a speeeeecial case -- we have to do I/O *and* get the calling | ||
280 | party's particulars all at once, listen() and accept() don't apply. | ||
281 | At least in the BSD universe, however, recvfrom/PEEK is enough to tell | ||
282 | us something came in, and we can set things up so straight read/write | ||
283 | actually does work after all. Yow. YMMV on strange platforms! */ | ||
284 | |||
285 | /* I'm not completely clear on how this works -- BSD seems to make UDP | ||
286 | just magically work in a connect()ed context, but we'll undoubtedly run | ||
287 | into systems this deal doesn't work on. For now, we apparently have to | ||
288 | issue a connect() on our just-tickled socket so we can write() back. | ||
289 | Again, why the fuck doesn't it just get filled in and taken care of?! | ||
290 | This hack is anything but optimal. Basically, if you want your listener | ||
291 | to also be able to send data back, you need this connect() line, which | ||
292 | also has the side effect that now anything from a different source or even a | ||
293 | different port on the other end won't show up and will cause ICMP errors. | ||
294 | I guess that's what they meant by "connect". | ||
295 | Let's try to remember what the "U" is *really* for, eh? */ | ||
296 | |||
297 | /* If peer address is specified, connect to it */ | ||
298 | if (themaddr) { | ||
299 | remend = *themaddr; | ||
300 | xconnect(netfd, &themaddr->sa, themaddr->len); | ||
301 | rr = 0; | ||
302 | } else { /* peek first packet and remember peer addr */ | ||
303 | arm(o_wait); /* might as well timeout this, too */ | ||
304 | if (setjmp(jbuf) == 0) { /* do timeout for initial connect */ | ||
305 | /* (*ouraddr) is prefilled with "default" address */ | ||
306 | /* and here we block... */ | ||
307 | rr = recv_from_to(netfd, NULL, 0, MSG_PEEK, /*was bigbuf_net, BIGSIZ*/ | ||
308 | &remend.sa, &ouraddr->sa, ouraddr->len); | ||
309 | if (rr < 0) | ||
310 | bb_perror_msg_and_die("recvfrom"); | ||
311 | } else | ||
312 | bb_error_msg_and_die("timeout"); | ||
313 | unarm(); | ||
314 | rr = connect(netfd, &remend.sa, ouraddr->len); | ||
315 | errmsg = "connect"; | ||
316 | } | ||
317 | } else { | ||
318 | /* TCP */ | ||
319 | arm(o_wait); /* wrap this in a timer, too; 0 = forever */ | ||
320 | if (setjmp(jbuf) == 0) { | ||
321 | remend.len = LSA_SIZEOF_SA; | ||
322 | rr = accept(netfd, &remend.sa, &remend.len); | ||
323 | } else | ||
324 | bb_error_msg_and_die("timeout"); | ||
325 | unarm(); | ||
326 | errmsg = "accept"; | ||
327 | if (rr >= 0) { | ||
328 | close(netfd); /* dump the old socket */ | ||
329 | netfd = rr; /* here's our new one */ | ||
330 | /* find out what address the connection was *to* on our end, in case we're | ||
331 | doing a listen-on-any on a multihomed machine. This allows one to | ||
332 | offer different services via different alias addresses, such as the | ||
333 | "virtual web site" hack. */ | ||
334 | rr = getsockname(netfd, &ouraddr->sa, &ouraddr->len); | ||
335 | errmsg = "getsockname after accept"; | ||
336 | } | ||
337 | } | ||
338 | if (rr < 0) | ||
339 | bb_perror_msg_and_die(errmsg); | ||
340 | |||
341 | #if ENABLE_NC_EXTRA && defined(IP_OPTIONS) | ||
342 | /* If we can, look for any IP options. Useful for testing the receiving end of | ||
343 | such things, and is a good exercise in dealing with it. We do this before | ||
344 | the connect message, to ensure that the connect msg is uniformly the LAST | ||
345 | thing to emerge after all the intervening crud. Doesn't work for UDP on | ||
346 | any machines I've tested, but feel free to surprise me. */ | ||
347 | if (o_verbose) { | ||
348 | char optbuf[40]; | ||
349 | int x = sizeof(optbuf); | ||
350 | rr = getsockopt(netfd, IPPROTO_IP, IP_OPTIONS, optbuf, &x); | ||
351 | if (rr < 0) | ||
352 | bb_perror_msg("getsockopt failed"); | ||
353 | else if (x) { /* we've got options, lessee em... */ | ||
354 | bin2hex(bigbuf_net, optbuf, x); | ||
355 | bigbuf_net[2*x] = '\0'; | ||
356 | fprintf(stderr, "IP options: %s\n", bigbuf_net); | ||
357 | } | ||
358 | } | ||
359 | #endif | ||
360 | |||
361 | /* now check out who it is. We don't care about mismatched DNS names here, | ||
362 | but any ADDR and PORT we specified had better fucking well match the caller. | ||
363 | Converting from addr to inet_ntoa and back again is a bit of a kludge, but | ||
364 | gethostpoop wants a string and there's much gnarlier code out there already, | ||
365 | so I don't feel bad. | ||
366 | The *real* question is why BFD sockets wasn't designed to allow listens for | ||
367 | connections *from* specific hosts/ports, instead of requiring the caller to | ||
368 | accept the connection and then reject undesireable ones by closing. | ||
369 | In other words, we need a TCP MSG_PEEK. */ | ||
370 | /* bbox: removed most of it */ | ||
371 | if (o_verbose) { | ||
372 | char *lcladdr = xmalloc_sockaddr2dotted(&ouraddr->sa, ouraddr->len); | ||
373 | char *remaddr = xmalloc_sockaddr2dotted(&remend.sa, remend.len); | ||
374 | char *remhostname = o_nflag ? remaddr : xmalloc_sockaddr2host(&remend.sa, remend.len); | ||
375 | fprintf(stderr, "connect to [%s] from %s [%s]\n", | ||
376 | lcladdr, remhostname, remaddr); | ||
377 | free(lcladdr); | ||
378 | free(remaddr); | ||
379 | if (!o_nflag) | ||
380 | free(remhostname); | ||
381 | } | ||
382 | } | ||
383 | |||
384 | /* udptest: | ||
385 | fire a couple of packets at a UDP target port, just to see if it's really | ||
386 | there. On BSD kernels, ICMP host/port-unreachable errors get delivered to | ||
387 | our socket as ECONNREFUSED write errors. On SV kernels, we lose; we'll have | ||
388 | to collect and analyze raw ICMP ourselves a la satan's probe_udp_ports | ||
389 | backend. Guess where one could swipe the appropriate code from... | ||
390 | |||
391 | Use the time delay between writes if given, otherwise use the "tcp ping" | ||
392 | trick for getting the RTT. [I got that idea from pluvius, and warped it.] | ||
393 | Return either the original fd, or clean up and return -1. */ | ||
394 | static int udptest(void) | ||
395 | { | ||
396 | int rr; | ||
397 | |||
398 | rr = write(netfd, bigbuf_in, 1); | ||
399 | if (rr != 1) | ||
400 | bb_perror_msg("udptest first write"); | ||
401 | |||
402 | if (o_wait) | ||
403 | sleep(o_wait); | ||
404 | else { | ||
405 | /* use the tcp-ping trick: try connecting to a normally refused port, which | ||
406 | causes us to block for the time that SYN gets there and RST gets back. | ||
407 | Not completely reliable, but it *does* mostly work. */ | ||
408 | /* Set a temporary connect timeout, so packet filtration doesnt cause | ||
409 | us to hang forever, and hit it */ | ||
410 | o_wait = 5; /* enough that we'll notice?? */ | ||
411 | rr = xsocket(ouraddr->sa.sa_family, SOCK_STREAM, 0); | ||
412 | set_nport(themaddr, htons(SLEAZE_PORT)); | ||
413 | connect_w_timeout(rr); | ||
414 | //need to restore port? | ||
415 | close(rr); | ||
416 | o_wait = 0; /* reset it */ | ||
417 | } | ||
418 | |||
419 | rr = write(netfd, bigbuf_in, 1); | ||
420 | return (rr != 1); /* if rr == 1, return 0 (success) */ | ||
421 | } | ||
422 | |||
423 | /* oprint: | ||
424 | Hexdump bytes shoveled either way to a running logfile, in the format: | ||
425 | D offset - - - - --- 16 bytes --- - - - - # .... ascii ..... | ||
426 | where "which" sets the direction indicator, D: | ||
427 | 0 -- sent to network, or ">" | ||
428 | 1 -- rcvd and printed to stdout, or "<" | ||
429 | and "buf" and "n" are data-block and length. If the current block generates | ||
430 | a partial line, so be it; we *want* that lockstep indication of who sent | ||
431 | what when. Adapted from dgaudet's original example -- but must be ripping | ||
432 | *fast*, since we don't want to be too disk-bound... */ | ||
433 | static void oprint(int which, char *buf, int n) | ||
434 | { | ||
435 | int bc; /* in buffer count */ | ||
436 | int obc; /* current "global" offset */ | ||
437 | int soc; /* stage write count */ | ||
438 | unsigned char *p; /* main buf ptr; m.b. unsigned here */ | ||
439 | unsigned char *op; /* out hexdump ptr */ | ||
440 | unsigned char *a; /* out asc-dump ptr */ | ||
441 | int x; | ||
442 | |||
443 | if (n == 0) | ||
444 | return; | ||
445 | |||
446 | op = stage; | ||
447 | if (which) { | ||
448 | *op = '<'; | ||
449 | obc = wrote_out; /* use the globals! */ | ||
450 | } else { | ||
451 | *op = '>'; | ||
452 | obc = wrote_net; | ||
453 | } | ||
454 | op++; /* preload "direction" */ | ||
455 | *op = ' '; | ||
456 | p = (unsigned char *) buf; | ||
457 | bc = n; | ||
458 | stage[59] = '#'; /* preload separator */ | ||
459 | stage[60] = ' '; | ||
460 | |||
461 | while (bc) { /* for chunk-o-data ... */ | ||
462 | x = 16; | ||
463 | soc = 78; /* len of whole formatted line */ | ||
464 | if (bc < x) { | ||
465 | soc = soc - 16 + bc; /* fiddle for however much is left */ | ||
466 | x = (bc * 3) + 11; /* 2 digits + space per, after D & offset */ | ||
467 | op = &stage[x]; | ||
468 | x = 16 - bc; | ||
469 | while (x) { | ||
470 | *op++ = ' '; /* preload filler spaces */ | ||
471 | *op++ = ' '; | ||
472 | *op++ = ' '; | ||
473 | x--; | ||
474 | } | ||
475 | x = bc; /* re-fix current linecount */ | ||
476 | } /* if bc < x */ | ||
477 | |||
478 | bc -= x; /* fix wrt current line size */ | ||
479 | sprintf(&stage[2], "%8.8x ", obc); /* xxx: still slow? */ | ||
480 | obc += x; /* fix current offset */ | ||
481 | op = &stage[11]; /* where hex starts */ | ||
482 | a = &stage[61]; /* where ascii starts */ | ||
483 | |||
484 | while (x) { /* for line of dump, however long ... */ | ||
485 | *op++ = 0x20 | bb_hexdigits_upcase[*p >> 4]; | ||
486 | *op++ = 0x20 | bb_hexdigits_upcase[*p & 0x0f]; | ||
487 | *op++ = ' '; | ||
488 | if ((*p > 31) && (*p < 127)) | ||
489 | *a = *p; /* printing */ | ||
490 | else | ||
491 | *a = '.'; /* nonprinting, loose def */ | ||
492 | a++; | ||
493 | p++; | ||
494 | x--; | ||
495 | } /* while x */ | ||
496 | *a = '\n'; /* finish the line */ | ||
497 | xwrite(ofd, stage, soc); | ||
498 | } /* while bc */ | ||
499 | } | ||
500 | |||
501 | /* readwrite: | ||
502 | handle stdin/stdout/network I/O. Bwahaha!! -- the select loop from hell. | ||
503 | In this instance, return what might become our exit status. */ | ||
504 | static int readwrite(void) | ||
505 | { | ||
506 | int rr; | ||
507 | char *zp = zp; /* gcc */ /* stdin buf ptr */ | ||
508 | char *np = np; /* net-in buf ptr */ | ||
509 | unsigned rzleft; | ||
510 | unsigned rnleft; | ||
511 | unsigned netretry; /* net-read retry counter */ | ||
512 | unsigned wretry; /* net-write sanity counter */ | ||
513 | unsigned wfirst; /* one-shot flag to skip first net read */ | ||
514 | |||
515 | /* if you don't have all this FD_* macro hair in sys/types.h, you'll have to | ||
516 | either find it or do your own bit-bashing: *ding1 |= (1 << fd), etc... */ | ||
517 | FD_SET(netfd, &ding1); /* global: the net is open */ | ||
518 | netretry = 2; | ||
519 | wfirst = 0; | ||
520 | rzleft = rnleft = 0; | ||
521 | if (o_interval) | ||
522 | sleep(o_interval); /* pause *before* sending stuff, too */ | ||
523 | |||
524 | errno = 0; /* clear from sleep, close, whatever */ | ||
525 | /* and now the big ol' select shoveling loop ... */ | ||
526 | while (FD_ISSET(netfd, &ding1)) { /* i.e. till the *net* closes! */ | ||
527 | wretry = 8200; /* more than we'll ever hafta write */ | ||
528 | if (wfirst) { /* any saved stdin buffer? */ | ||
529 | wfirst = 0; /* clear flag for the duration */ | ||
530 | goto shovel; /* and go handle it first */ | ||
531 | } | ||
532 | ding2 = ding1; /* FD_COPY ain't portable... */ | ||
533 | /* some systems, notably linux, crap into their select timers on return, so | ||
534 | we create a expendable copy and give *that* to select. */ | ||
535 | if (o_wait) { | ||
536 | struct timeval tmp_timer; | ||
537 | tmp_timer.tv_sec = o_wait; | ||
538 | tmp_timer.tv_usec = 0; | ||
539 | rr = select(16, &ding2, NULL, NULL, &tmp_timer); | ||
540 | } else | ||
541 | rr = select(16, &ding2, NULL, NULL, NULL); | ||
542 | if (rr < 0 && errno != EINTR) { /* might have gotten ^Zed, etc */ | ||
543 | holler_perror("select"); | ||
544 | close(netfd); | ||
545 | return 1; | ||
546 | } | ||
547 | /* if we have a timeout AND stdin is closed AND we haven't heard anything | ||
548 | from the net during that time, assume it's dead and close it too. */ | ||
549 | if (rr == 0) { | ||
550 | if (!FD_ISSET(0, &ding1)) | ||
551 | netretry--; /* we actually try a coupla times. */ | ||
552 | if (!netretry) { | ||
553 | if (o_verbose > 1) /* normally we don't care */ | ||
554 | fprintf(stderr, "net timeout\n"); | ||
555 | close(netfd); | ||
556 | return 0; /* not an error! */ | ||
557 | } | ||
558 | } /* select timeout */ | ||
559 | /* xxx: should we check the exception fds too? The read fds seem to give | ||
560 | us the right info, and none of the examples I found bothered. */ | ||
561 | |||
562 | /* Ding!! Something arrived, go check all the incoming hoppers, net first */ | ||
563 | if (FD_ISSET(netfd, &ding2)) { /* net: ding! */ | ||
564 | rr = read(netfd, bigbuf_net, BIGSIZ); | ||
565 | if (rr <= 0) { | ||
566 | FD_CLR(netfd, &ding1); /* net closed, we'll finish up... */ | ||
567 | rzleft = 0; /* can't write anymore: broken pipe */ | ||
568 | } else { | ||
569 | rnleft = rr; | ||
570 | np = bigbuf_net; | ||
571 | } | ||
572 | Debug(("got %d from the net, errno %d", rr, errno)) | ||
573 | } /* net:ding */ | ||
574 | |||
575 | /* if we're in "slowly" mode there's probably still stuff in the stdin | ||
576 | buffer, so don't read unless we really need MORE INPUT! MORE INPUT! */ | ||
577 | if (rzleft) | ||
578 | goto shovel; | ||
579 | |||
580 | /* okay, suck more stdin */ | ||
581 | if (FD_ISSET(0, &ding2)) { /* stdin: ding! */ | ||
582 | rr = read(0, bigbuf_in, BIGSIZ); | ||
583 | /* Considered making reads here smaller for UDP mode, but 8192-byte | ||
584 | mobygrams are kinda fun and exercise the reassembler. */ | ||
585 | if (rr <= 0) { /* at end, or fukt, or ... */ | ||
586 | FD_CLR(0, &ding1); /* disable and close stdin */ | ||
587 | close(0); | ||
588 | } else { | ||
589 | rzleft = rr; | ||
590 | zp = bigbuf_in; | ||
591 | } | ||
592 | } /* stdin:ding */ | ||
593 | shovel: | ||
594 | /* now that we've dingdonged all our thingdings, send off the results. | ||
595 | Geez, why does this look an awful lot like the big loop in "rsh"? ... | ||
596 | not sure if the order of this matters, but write net -> stdout first. */ | ||
597 | |||
598 | /* sanity check. Works because they're both unsigned... */ | ||
599 | if ((rzleft > 8200) || (rnleft > 8200)) { | ||
600 | holler_error("bogus buffers: %u, %u", rzleft, rnleft); | ||
601 | rzleft = rnleft = 0; | ||
602 | } | ||
603 | /* net write retries sometimes happen on UDP connections */ | ||
604 | if (!wretry) { /* is something hung? */ | ||
605 | holler_error("too many output retries"); | ||
606 | return 1; | ||
607 | } | ||
608 | if (rnleft) { | ||
609 | rr = write(1, np, rnleft); | ||
610 | if (rr > 0) { | ||
611 | if (o_wfile) | ||
612 | oprint(1, np, rr); /* log the stdout */ | ||
613 | np += rr; /* fix up ptrs and whatnot */ | ||
614 | rnleft -= rr; /* will get sanity-checked above */ | ||
615 | wrote_out += rr; /* global count */ | ||
616 | } | ||
617 | Debug(("wrote %d to stdout, errno %d", rr, errno)) | ||
618 | } /* rnleft */ | ||
619 | if (rzleft) { | ||
620 | if (o_interval) /* in "slowly" mode ?? */ | ||
621 | rr = findline(zp, rzleft); | ||
622 | else | ||
623 | rr = rzleft; | ||
624 | rr = write(netfd, zp, rr); /* one line, or the whole buffer */ | ||
625 | if (rr > 0) { | ||
626 | if (o_wfile) | ||
627 | oprint(0, zp, rr); /* log what got sent */ | ||
628 | zp += rr; | ||
629 | rzleft -= rr; | ||
630 | wrote_net += rr; /* global count */ | ||
631 | } | ||
632 | Debug(("wrote %d to net, errno %d", rr, errno)) | ||
633 | } /* rzleft */ | ||
634 | if (o_interval) { /* cycle between slow lines, or ... */ | ||
635 | sleep(o_interval); | ||
636 | errno = 0; /* clear from sleep */ | ||
637 | continue; /* ...with hairy select loop... */ | ||
638 | } | ||
639 | if ((rzleft) || (rnleft)) { /* shovel that shit till they ain't */ | ||
640 | wretry--; /* none left, and get another load */ | ||
641 | goto shovel; | ||
642 | } | ||
643 | } /* while ding1:netfd is open */ | ||
644 | |||
645 | /* XXX: maybe want a more graceful shutdown() here, or screw around with | ||
646 | linger times?? I suspect that I don't need to since I'm always doing | ||
647 | blocking reads and writes and my own manual "last ditch" efforts to read | ||
648 | the net again after a timeout. I haven't seen any screwups yet, but it's | ||
649 | not like my test network is particularly busy... */ | ||
650 | close(netfd); | ||
651 | return 0; | ||
652 | } /* readwrite */ | ||
653 | |||
654 | /* main: now we pull it all together... */ | ||
655 | int nc_main(int argc, char **argv); | ||
656 | int nc_main(int argc, char **argv) | ||
657 | { | ||
658 | char *str_p, *str_s, *str_w; | ||
659 | USE_NC_EXTRA(char *str_i;) | ||
660 | char *themdotted = themdotted; /* gcc */ | ||
661 | char **proggie; | ||
662 | int x; | ||
663 | unsigned o_lport = 0; | ||
664 | |||
665 | /* I was in this barbershop quartet in Skokie IL ... */ | ||
666 | /* round up the usual suspects, i.e. malloc up all the stuff we need */ | ||
667 | PTR_TO_GLOBALS = xzalloc(sizeof(G)); | ||
668 | |||
669 | /* catch a signal or two for cleanup */ | ||
670 | signal(SIGINT, catch); | ||
671 | signal(SIGQUIT, catch); | ||
672 | signal(SIGTERM, catch); | ||
673 | /* and suppress others... */ | ||
674 | #ifdef SIGURG | ||
675 | signal(SIGURG, SIG_IGN); | ||
676 | #endif | ||
677 | signal(SIGPIPE, SIG_IGN); /* important! */ | ||
678 | |||
679 | proggie = argv; | ||
680 | while (*++proggie) { | ||
681 | if (strcmp(*proggie, "-e") == 0) { | ||
682 | *proggie = NULL; | ||
683 | argc = proggie - argv; | ||
684 | proggie++; | ||
685 | goto e_found; | ||
686 | } | ||
687 | } | ||
688 | proggie = NULL; | ||
689 | e_found: | ||
690 | |||
691 | // -g -G -t -r deleted, unimplemented -a deleted too | ||
692 | opt_complementary = "?2:vv"; /* max 2 params, -v is a counter */ | ||
693 | getopt32(argc, argv, "hnp:s:uvw:" USE_NC_SERVER("l") | ||
694 | USE_NC_EXTRA("i:o:z"), | ||
695 | &str_p, &str_s, &str_w | ||
696 | USE_NC_EXTRA(, &str_i, &stage, &o_verbose)); | ||
697 | argv += optind; | ||
698 | #if ENABLE_NC_EXTRA | ||
699 | if (option_mask32 & OPT_i) /* line-interval time */ | ||
700 | o_interval = xatou_range(str_i, 1, 0xffff); | ||
701 | #endif | ||
702 | //if (option_mask32 & OPT_l) /* listen mode */ | ||
703 | //if (option_mask32 & OPT_n) /* numeric-only, no DNS lookups */ | ||
704 | //if (option_mask32 & OPT_o) /* hexdump log */ | ||
705 | if (option_mask32 & OPT_p) { /* local source port */ | ||
706 | o_lport = bb_lookup_port(str_p, o_udpmode ? "udp" : "tcp", 0); | ||
707 | if (!o_lport) | ||
708 | bb_error_msg_and_die("bad local port '%s'", str_p); | ||
709 | } | ||
710 | //if (option_mask32 & OPT_r) /* randomize various things */ | ||
711 | //if (option_mask32 & OPT_u) /* use UDP */ | ||
712 | //if (option_mask32 & OPT_v) /* verbose */ | ||
713 | if (option_mask32 & OPT_w) { /* wait time */ | ||
714 | o_wait = xatoi_u(str_w); | ||
715 | } | ||
716 | //if (option_mask32 & OPT_z) /* little or no data xfer */ | ||
717 | |||
718 | bb_sanitize_stdio(); | ||
719 | |||
720 | /* create & bind network socket */ | ||
721 | if (option_mask32 & OPT_s) { /* local address */ | ||
722 | /* if o_port is still 0, then we will use random port */ | ||
723 | ouraddr = xhost2sockaddr(str_s, o_lport); | ||
724 | netfd = xsocket(ouraddr->sa.sa_family, o_udpmode ? SOCK_DGRAM : SOCK_STREAM, 0); //// 0? | ||
725 | } else { | ||
726 | netfd = xsocket_type(&ouraddr, o_udpmode ? SOCK_DGRAM : SOCK_STREAM); | ||
727 | if (o_lport) | ||
728 | set_nport(ouraddr, htons(o_lport)); | ||
729 | } | ||
730 | setsockopt_reuseaddr(netfd); | ||
731 | if (o_udpmode) | ||
732 | socket_want_pktinfo(netfd); | ||
733 | xbind(netfd, &ouraddr->sa, ouraddr->len); | ||
734 | #if 0 | ||
735 | setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &o_rcvbuf, sizeof o_rcvbuf); | ||
736 | setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf); | ||
737 | #endif | ||
738 | |||
739 | if (o_udpmode) { /* apparently UDP can listen ON */ | ||
740 | if (!o_lport) /* "port 0", but that's not useful */ | ||
741 | bb_error_msg_and_die("UDP listen needs -p arg"); | ||
742 | } | ||
743 | |||
744 | FD_SET(0, &ding1); /* stdin *is* initially open */ | ||
745 | if (proggie) { | ||
746 | close(0); /* won't need stdin */ | ||
747 | option_mask32 &= ~OPT_o; /* -o with -e is meaningless! */ | ||
748 | ofd = 0; | ||
749 | } | ||
750 | if (o_wfile) { | ||
751 | ofd = xopen(stage, O_WRONLY|O_CREAT|O_TRUNC); | ||
752 | stage = xzalloc(100); | ||
753 | } | ||
754 | |||
755 | if (argv[0]) { | ||
756 | themaddr = xhost2sockaddr(argv[0], | ||
757 | argv[1] | ||
758 | ? bb_lookup_port(argv[1], o_udpmode ? "udp" : "tcp", 0) | ||
759 | : 0); | ||
760 | ///what if sa_family won't match?? | ||
761 | } | ||
762 | |||
763 | if (o_listen) { | ||
764 | dolisten(); | ||
765 | /* dolisten does its own connect reporting */ | ||
766 | if (proggie) /* -e given? */ | ||
767 | doexec(proggie); | ||
768 | x = readwrite(); /* it even works with UDP! */ | ||
769 | } else { | ||
770 | /* Outbound connects. Now we're more picky about args... */ | ||
771 | if (!themaddr) | ||
772 | bb_error_msg_and_die("no destination"); | ||
773 | |||
774 | remend = *themaddr; | ||
775 | if (o_verbose) | ||
776 | themdotted = xmalloc_sockaddr2dotted(&themaddr->sa, themaddr->len); | ||
777 | |||
778 | x = connect_w_timeout(netfd); | ||
779 | if (o_zero && x == 0 && o_udpmode) /* if UDP scanning... */ | ||
780 | x = udptest(); | ||
781 | if (x == 0) { /* Yow, are we OPEN YET?! */ | ||
782 | if (o_verbose) | ||
783 | fprintf(stderr, "%s [%s] open\n", argv[0], themdotted); | ||
784 | if (proggie) /* exec is valid for outbound, too */ | ||
785 | doexec(proggie); | ||
786 | if (!o_zero) | ||
787 | x = readwrite(); | ||
788 | } else { /* connect or udptest wasn't successful */ | ||
789 | x = 1; /* exit status */ | ||
790 | /* if we're scanning at a "one -v" verbosity level, don't print refusals. | ||
791 | Give it another -v if you want to see everything. */ | ||
792 | if (o_verbose > 1 || (o_verbose && errno != ECONNREFUSED)) | ||
793 | bb_perror_msg("%s [%s]", argv[0], themdotted); | ||
794 | } | ||
795 | } | ||
796 | if (o_verbose > 1) /* normally we don't care */ | ||
797 | fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); | ||
798 | return x; | ||
799 | } | ||