Annotation of src/usr.bin/nc/netcat.c, Revision 1.12
1.12 ! ericj 1: /* $OpenBSD: netcat.c,v 1.11 2000/09/26 01:15:49 ericj Exp $ */
1.11 ericj 2:
1.1 deraadt 3: /* Netcat 1.10 RELEASE 960320
1.7 deraadt 4: *
5: * A damn useful little "backend" utility begun 950915 or thereabouts,
6: * as *Hobbit*'s first real stab at some sockets programming. Something that
7: * should have and indeed may have existed ten years ago, but never became a
8: * standard Unix utility. IMHO, "nc" could take its place right next to cat,
9: * cp, rm, mv, dd, ls, and all those other cryptic and Unix-like things.
10: *
11: * Read the README for the whole story, doc, applications, etc.
12: *
13: * Layout:
14: * conditional includes:
15: * includes:
16: * handy defines:
17: * globals:
18: * malloced globals:
19: * cmd-flag globals:
20: * support routines:
21: * readwrite select loop:
22: * main:
23: *
24: * bluesky:
25: * parse ranges of IP address as well as ports, perhaps
26: * RAW mode!
27: * backend progs to grab a pty and look like a real telnetd?!
28: * backend progs to do various encryption modes??!?!
1.1 deraadt 29: */
30:
31:
32: #define HAVE_BIND /* ASSUMPTION -- seems to work everywhere! */
33:
1.7 deraadt 34: #include <sys/types.h>
35: #include <sys/time.h>
36: #include <sys/select.h>
37: #include <sys/socket.h>
38: #include <netinet/in.h>
39: #include <netinet/in_systm.h>
40: #include <netinet/ip.h>
41: #include <arpa/inet.h>
42: #include <netdb.h> /* hostent, gethostby*, getservby* */
43: #include <stdio.h>
44: #include <string.h>
1.11 ericj 45: #include <err.h>
1.7 deraadt 46: #include <errno.h>
47: #include <setjmp.h>
48: #include <signal.h>
49: #include <fcntl.h>
1.1 deraadt 50: #include <stdlib.h>
1.5 art 51: #include <unistd.h>
1.1 deraadt 52:
1.11 ericj 53: /* Random Numbers aren't too needed here */
54: #define SRAND srandom
55: #define RAND random
1.1 deraadt 56:
57: #define SLEAZE_PORT 31337 /* for UDP-scan RTT trick, change if ya want */
58: #define BIGSIZ 8192 /* big buffers */
59:
1.7 deraadt 60: struct host_info {
1.11 ericj 61: char name[MAXHOSTNAMELEN]; /* DNS name */
62: char addrs[8][24]; /* ascii-format IP addresses */
63: struct in_addr iaddrs[8]; /* in_addr.s_addr: ulong */
1.1 deraadt 64: };
65:
1.7 deraadt 66: struct port_info {
1.6 deraadt 67: char name[64]; /* name in /etc/services */
68: char anum[8]; /* ascii-format number */
1.7 deraadt 69: u_short num; /* real host-order number */
1.1 deraadt 70: };
71:
72: /* globals: */
1.11 ericj 73: jmp_buf jbuf; /* timer jump buffer*/
1.6 deraadt 74: int jval = 0; /* timer crud */
75: int netfd = -1;
76: int ofd = 0; /* hexdump output fd */
1.7 deraadt 77:
1.1 deraadt 78: extern int h_errno;
79: /* stolen almost wholesale from bsd herror.c */
1.6 deraadt 80: static char *h_errs[] = {
1.11 ericj 81: "Error 0", /* but we *don't* use this */
82: "Unknown host", /* 1 HOST_NOT_FOUND */
83: "Host name lookup failure", /* 2 TRY_AGAIN */
84: "Unknown server error", /* 3 NO_RECOVERY */
1.6 deraadt 85: "No address associated with name", /* 4 NO_ADDRESS */
1.1 deraadt 86: };
1.7 deraadt 87:
1.6 deraadt 88: int gatesidx = 0; /* LSRR hop count */
89: int gatesptr = 4; /* initial LSRR pointer, settable */
1.7 deraadt 90: u_short Single = 1; /* zero if scanning */
1.1 deraadt 91: unsigned int insaved = 0; /* stdin-buffer size for multi-mode */
92: unsigned int wrote_out = 0; /* total stdout bytes */
93: unsigned int wrote_net = 0; /* total net bytes */
94: static char hexnibs[20] = "0123456789abcdef ";
95:
96: /* will malloc up the following globals: */
1.7 deraadt 97: struct timeval timer1, timer2;
1.11 ericj 98: struct sockaddr_in *lclend = NULL; /* sockaddr_in structs */
1.7 deraadt 99: struct sockaddr_in *remend = NULL;
1.11 ericj 100: struct host_info **gates = NULL; /* LSRR hop hinfo */
101: char *optbuf = NULL; /* LSRR or sockopts */
102: char *bigbuf_in; /* data buffers */
1.6 deraadt 103: char *bigbuf_net;
1.7 deraadt 104: fd_set fds1, fds2;
1.11 ericj 105: struct port_info *pinfo = NULL; /* for getpinfo / getservby* */
106: unsigned char *stage = NULL; /* hexdump line buffer */
1.1 deraadt 107:
108: /* global cmd flags: */
1.7 deraadt 109: u_short o_alla = 0;
1.1 deraadt 110: unsigned int o_interval = 0;
1.7 deraadt 111: u_short o_listen = 0;
112: u_short o_nflag = 0;
113: u_short o_wfile = 0;
114: u_short o_random = 0;
115: u_short o_udpmode = 0;
116: u_short o_verbose = 0;
1.1 deraadt 117: unsigned int o_wait = 0;
1.7 deraadt 118: u_short o_zero = 0;
1.1 deraadt 119:
1.11 ericj 120: /* Function Prototype's */
121: void usage __P((int));
122: void help __P(());
123:
124: /*
125: * support routines -- the bulk of this thing. Placed in such an order that
126: * we don't have to forward-declare anything:
127: */
128:
129: /*
130: * catch :
131: * no-brainer interrupt handler
132: */
1.6 deraadt 133: void
134: catch()
1.1 deraadt 135: {
1.6 deraadt 136: errno = 0;
137: if (o_verbose > 1) /* normally we don't care */
1.11 ericj 138: errx(1, "Sent %i Rcvd %i", wrote_net, wrote_out);
139: errx(1, " punt!");
1.1 deraadt 140: }
141:
142: /* timeout and other signal handling cruft */
1.6 deraadt 143: void
144: tmtravel()
1.1 deraadt 145: {
1.6 deraadt 146: signal(SIGALRM, SIG_IGN);
147: alarm(0);
148: if (jval == 0)
1.11 ericj 149: errx(1, "spurious timer interrupt!");
1.6 deraadt 150: longjmp(jbuf, jval);
1.1 deraadt 151: }
152:
1.11 ericj 153: /*
154: * arm :
155: * set the timer. Zero secs arg means unarm
156: */
1.6 deraadt 157: void
158: arm(num, secs)
159: unsigned int num;
160: unsigned int secs;
161: {
1.11 ericj 162: if (secs == 0) {
1.6 deraadt 163: signal(SIGALRM, SIG_IGN);
164: alarm(0);
165: jval = 0;
1.11 ericj 166: } else {
1.6 deraadt 167: signal(SIGALRM, tmtravel);
168: alarm(secs);
169: jval = num;
1.11 ericj 170: }
1.7 deraadt 171: }
1.1 deraadt 172:
1.11 ericj 173: /*
174: * findline :
175: * find the next newline in a buffer; return inclusive size of that "line",
176: * or the entire buffer size, so the caller knows how much to then write().
177: * Not distinguishing \n vs \r\n for the nonce; it just works as is...
178: */
1.6 deraadt 179: unsigned int
180: findline(buf, siz)
181: char *buf;
182: unsigned int siz;
183: {
1.11 ericj 184: char *p;
185: int x;
1.6 deraadt 186: if (!buf) /* various sanity checks... */
187: return (0);
188: if (siz > BIGSIZ)
189: return (0);
190: x = siz;
191: for (p = buf; x > 0; x--) {
192: if (*p == '\n') {
193: x = (int) (p - buf);
194: x++; /* 'sokay if it points just past the end! */
195: return (x);
196: }
197: p++;
1.11 ericj 198: }
1.6 deraadt 199: return (siz);
1.7 deraadt 200: }
1.1 deraadt 201:
1.11 ericj 202: /*
203: * comparehosts :
204: * cross-check the host_info we have so far against new gethostby*() info,
205: * and holler about mismatches. Perhaps gratuitous, but it can't hurt to
206: * point out when someone's DNS is fukt. Returns 1 if mismatch, in case
207: * someone else wants to do something about it.
208: */
1.6 deraadt 209: int
1.11 ericj 210: comparehosts(hinfo, hp)
211: struct host_info *hinfo;
1.6 deraadt 212: struct hostent *hp;
213: {
214: errno = 0;
215: h_errno = 0;
1.11 ericj 216: if (strcasecmp(hinfo->name, hp->h_name) != 0) {
217: warn("DNS fwd/rev mismatch: %s != %s", hinfo->name, hp->h_name);
1.6 deraadt 218: return (1);
219: }
220: return (0);
1.7 deraadt 221: }
1.1 deraadt 222:
1.11 ericj 223: /*
224: * gethinfo:
225: * resolve a host 8 ways from sunday; return a new host_info struct with its
226: * info. The argument can be a name or [ascii] IP address; it will try its
227: * damndest to deal with it. "numeric" governs whether we do any DNS at all,
228: * and we also check o_verbose for what's appropriate work to do.
229: */
1.7 deraadt 230: struct host_info *
1.11 ericj 231: gethinfo(name, numeric)
1.6 deraadt 232: char *name;
1.7 deraadt 233: u_short numeric;
1.6 deraadt 234: {
235: struct hostent *hostent;
236: struct in_addr iaddr;
1.11 ericj 237: struct host_info *hinfo = NULL;
238: int x;
1.1 deraadt 239:
1.6 deraadt 240: errno = 0;
241: h_errno = 0;
242: if (name)
1.11 ericj 243: hinfo = (struct host_info *) calloc(1, sizeof(struct host_info));
244:
245: if (!hinfo)
246: errx(1, "error obtaining host information");
247:
248: strlcpy(hinfo->name, "(UNKNOWN)", sizeof(hinfo->name));
1.7 deraadt 249: if (inet_aton(name, &iaddr) == 0) {
1.11 ericj 250: if (numeric)
251: errx(1, "Can't parse %s as an IP address", name);
1.6 deraadt 252:
1.11 ericj 253: /*
254: * failure to look up a name is fatal,
255: * since we can't do anything with it.
256: */
1.6 deraadt 257: hostent = gethostbyname(name);
258: if (!hostent)
1.11 ericj 259: errx(1, "%s: forward host lookup failed: ", name);
260:
261: strlcpy(hinfo->name, hostent->h_name, MAXHOSTNAMELEN);
1.6 deraadt 262: for (x = 0; hostent->h_addr_list[x] && (x < 8); x++) {
1.11 ericj 263: memcpy(&hinfo->iaddrs[x], hostent->h_addr_list[x],
1.7 deraadt 264: sizeof(struct in_addr));
1.11 ericj 265: strlcpy(hinfo->addrs[x], inet_ntoa(hinfo->iaddrs[x]),
266: sizeof(hinfo->addrs[0]));
1.7 deraadt 267: }
1.11 ericj 268: /* Go ahead and return if we don't want to view more */
269: if (!o_verbose)
270: return (hinfo);
271:
272: /*
273: * Do inverse lookups in separate loop based on our collected
274: * forward addrs, since gethostby* tends to crap into the same
275: * buffer over and over.
276: */
277: for (x = 0; hinfo->iaddrs[x].s_addr && (x < 8); x++) {
278: hostent = gethostbyaddr((char *) &hinfo->iaddrs[x],
1.7 deraadt 279: sizeof(struct in_addr), AF_INET);
1.6 deraadt 280: if ((!hostent) || (!hostent->h_name))
1.11 ericj 281: warn("Warning: inverse host lookup failed for %s: ",
282: hinfo->addrs[x]);
1.6 deraadt 283: else
1.11 ericj 284: (void) comparehosts(hinfo, hostent);
285: }
1.6 deraadt 286:
287: } else { /* not INADDR_NONE: numeric addresses... */
1.11 ericj 288: memcpy(hinfo->iaddrs, &iaddr, sizeof(struct in_addr));
289: strlcpy(hinfo->addrs[0], inet_ntoa(iaddr), sizeof(hinfo->addrs));
290: /* If all that's wanted is numeric IP, go ahead and leave */
291: if (numeric)
292: return (hinfo);
293:
294: /* Go ahead and return if we don't want to view more */
295: if (!o_verbose)
296: return (hinfo);
297:
298: hostent = gethostbyaddr((char *) &iaddr,
299: sizeof(struct in_addr), AF_INET);
300:
301: /*
302: * numeric or not, failure to look up a PTR is
303: * *not* considered fatal
304: */
1.6 deraadt 305: if (!hostent)
1.11 ericj 306: warn("%s: inverse host lookup failed: ", name);
1.6 deraadt 307: else {
1.11 ericj 308: strlcpy(hinfo->name, hostent->h_name, MAXHOSTNAMELEN);
309: hostent = gethostbyname(hinfo->name);
1.6 deraadt 310: if ((!hostent) || (!hostent->h_addr_list[0]))
1.11 ericj 311: warn("Warning: forward host lookup failed for %s: ",
312: hinfo->name);
1.6 deraadt 313: else
1.11 ericj 314: (void) comparehosts(hinfo, hostent);
315: }
316: }
1.1 deraadt 317:
1.11 ericj 318: /*
319: * Whatever-all went down previously, we should now have a host_info
320: * struct with at least one IP address in it.
321: */
1.6 deraadt 322: h_errno = 0;
1.11 ericj 323: return (hinfo);
1.7 deraadt 324: }
1.1 deraadt 325:
1.11 ericj 326: /*
327: * getpinfo:
328: * Same general idea as gethinfo-- look up a port in /etc/services, fill
329: * in global port_info, but return the actual port *number*. Pass ONE of:
330: * pstring to resolve stuff like "23" or "exec";
331: * pnum to reverse-resolve something that's already a number.
332: * If o_nflag is on, fill in what we can but skip the getservby??? stuff.
333: * Might as well have consistent behavior here, and it *is* faster.
334: */
1.7 deraadt 335: u_short
1.11 ericj 336: getpinfo(pstring, pnum)
1.6 deraadt 337: char *pstring;
338: unsigned int pnum;
339: {
340: struct servent *servent;
1.11 ericj 341: int x;
342: int y;
1.7 deraadt 343: char *whichp = "tcp";
1.6 deraadt 344: if (o_udpmode)
1.7 deraadt 345: whichp = "udp";
1.1 deraadt 346:
1.11 ericj 347: pinfo->name[0] = '?';/* fast preload */
348: pinfo->name[1] = '\0';
349:
350: /*
351: * case 1: reverse-lookup of a number; placed first since this case
352: * is much more frequent if we're scanning.
353: */
1.6 deraadt 354: if (pnum) {
1.11 ericj 355: /* Can't be both */
356: if (pstring)
1.6 deraadt 357: return (0);
1.11 ericj 358:
1.6 deraadt 359: x = pnum;
360: if (o_nflag) /* go faster, skip getservbyblah */
361: goto gp_finish;
362: y = htons(x); /* gotta do this -- see Fig.1 below */
363: servent = getservbyport(y, whichp);
364: if (servent) {
365: y = ntohs(servent->s_port);
366: if (x != y) /* "never happen" */
1.11 ericj 367: warn("Warning: port-bynum mismatch, %d != %d", x, y);
368: strlcpy(pinfo->name, servent->s_name,
369: sizeof(pinfo->name));
1.7 deraadt 370: }
1.6 deraadt 371: goto gp_finish;
1.11 ericj 372: }
373: /*
374: * case 2: resolve a string, but we still give preference to numbers
1.6 deraadt 375: * instead of trying to resolve conflicts. None of the entries in *my*
376: * extensive /etc/services begins with a digit, so this should "always
377: * work" unless you're at 3com and have some company-internal services
1.11 ericj 378: * defined.
379: */
1.6 deraadt 380: if (pstring) {
1.11 ericj 381: /* Can't be both */
382: if (pnum)
1.6 deraadt 383: return (0);
1.11 ericj 384:
1.6 deraadt 385: x = atoi(pstring);
386: if (x)
1.11 ericj 387: return (getpinfo(NULL, x)); /* recurse for
1.6 deraadt 388: * numeric-string-arg */
389: if (o_nflag) /* can't use names! */
390: return (0);
391: servent = getservbyname(pstring, whichp);
392: if (servent) {
1.11 ericj 393: strlcpy(pinfo->name, servent->s_name,
394: sizeof(pinfo->name));
1.6 deraadt 395: x = ntohs(servent->s_port);
396: goto gp_finish;
397: } /* if servent */
398: } /* if pstring */
399: return (0); /* catches any problems so far */
1.1 deraadt 400:
401: gp_finish:
1.11 ericj 402: /*
403: * Fall here whether or not we have a valid servent at this point, with
404: * x containing our [host-order and therefore useful, dammit] port number.
405: */
406: sprintf(pinfo->anum, "%d", x); /* always load any numeric
1.6 deraadt 407: * specs! */
1.11 ericj 408: pinfo->num = (x & 0xffff); /* u_short, remember... */
409: return (pinfo->num);
1.7 deraadt 410: }
1.1 deraadt 411:
1.11 ericj 412: /*
413: * nextport :
414: * Come up with the next port to try, be it random or whatever. "block" is
415: * a ptr to randports array, whose bytes [so far] carry these meanings:
416: * 0 ignore
417: * 1 to be tested
418: * 2 tested [which is set as we find them here]
419: * returns a u_short random port, or 0 if all the t-b-t ones are used up.
420: */
1.7 deraadt 421: u_short
1.6 deraadt 422: nextport(block)
423: char *block;
424: {
1.11 ericj 425: unsigned int x;
426: unsigned int y;
1.6 deraadt 427:
1.11 ericj 428: y = 70000; /* high safety count for rnd-tries */
1.6 deraadt 429: while (y > 0) {
430: x = (RAND() & 0xffff);
431: if (block[x] == 1) { /* try to find a not-done one... */
432: block[x] = 2;
433: break;
434: }
1.11 ericj 435: x = 0;
1.6 deraadt 436: y--;
1.11 ericj 437: }
1.6 deraadt 438: if (x)
439: return (x);
440:
441: y = 65535; /* no random one, try linear downsearch */
442: while (y > 0) { /* if they're all used, we *must* be sure! */
443: if (block[y] == 1) {
444: block[y] = 2;
445: break;
446: }
447: y--;
1.11 ericj 448: }
1.6 deraadt 449: if (y)
450: return (y); /* at least one left */
1.1 deraadt 451:
1.11 ericj 452: return (0);
1.7 deraadt 453: }
1.1 deraadt 454:
1.11 ericj 455: /*
456: * loadports :
457: * set "to be tested" indications in BLOCK, from LO to HI. Almost too small
458: * to be a separate routine, but makes main() a little cleaner.
459: */
1.6 deraadt 460: void
461: loadports(block, lo, hi)
462: char *block;
1.7 deraadt 463: u_short lo;
464: u_short hi;
1.6 deraadt 465: {
1.7 deraadt 466: u_short x;
1.6 deraadt 467:
468: if (!block)
1.11 ericj 469: errx(1, "loadports: no block?!");
1.6 deraadt 470: if ((!lo) || (!hi))
1.11 ericj 471: errx(1, "loadports: bogus values %d, %d", lo, hi);
1.6 deraadt 472: x = hi;
473: while (lo <= x) {
474: block[x] = 1;
475: x--;
476: }
1.7 deraadt 477: }
478:
1.1 deraadt 479:
1.11 ericj 480: /*
481: * doconnect :
482: * do all the socket stuff, and return an fd for one of
483: * an open outbound TCP connection
484: * a UDP stub-socket thingie
485: * with appropriate socket options set up if we wanted source-routing, or
486: * an unconnected TCP or UDP socket to listen on.
487: * Examines various global o_blah flags to figure out what-all to do.
488: */
1.6 deraadt 489: int
490: doconnect(rad, rp, lad, lp)
1.7 deraadt 491: struct in_addr *rad;
492: u_short rp;
493: struct in_addr *lad;
494: u_short lp;
1.6 deraadt 495: {
1.11 ericj 496: int nnetfd;
497: int rr;
1.6 deraadt 498: int x, y;
499: errno = 0;
1.1 deraadt 500:
1.11 ericj 501: /* grab a socket; set opts */
1.1 deraadt 502: newskt:
1.6 deraadt 503: if (o_udpmode)
504: nnetfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
505: else
506: nnetfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
507: if (nnetfd < 0)
1.11 ericj 508: errx(1, "Can't get socket");
1.6 deraadt 509: if (nnetfd == 0) /* if stdin was closed this might *be* 0, */
510: goto newskt; /* so grab another. See text for why... */
511: x = 1;
512: rr = setsockopt(nnetfd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
513: if (rr == -1)
1.12 ! ericj 514: errx(1, NULL);
1.6 deraadt 515:
516: /* fill in all the right sockaddr crud */
517: lclend->sin_family = AF_INET;
1.1 deraadt 518:
1.11 ericj 519: /* fill in all the right sockaddr crud */
1.6 deraadt 520: lclend->sin_family = AF_INET;
521: remend->sin_family = AF_INET;
1.1 deraadt 522:
1.11 ericj 523: /* if lad/lp, do appropriate binding */
1.6 deraadt 524: if (lad)
1.7 deraadt 525: memcpy(&lclend->sin_addr.s_addr, lad, sizeof(struct in_addr));
1.6 deraadt 526: if (lp)
527: lclend->sin_port = htons(lp);
1.11 ericj 528:
1.6 deraadt 529: rr = 0;
530: if (lad || lp) {
531: x = (int) lp;
1.11 ericj 532: /* try a few times for the local bind, a la ftp-data-port... */
1.6 deraadt 533: for (y = 4; y > 0; y--) {
1.7 deraadt 534: rr = bind(nnetfd, (struct sockaddr *) lclend,
535: sizeof(struct sockaddr_in));
1.6 deraadt 536: if (rr == 0)
537: break;
538: if (errno != EADDRINUSE)
539: break;
540: else {
1.11 ericj 541: warn("retrying local %s:%d", inet_ntoa(lclend->sin_addr), lp);
1.6 deraadt 542: sleep(2);
543: errno = 0; /* clear from sleep */
1.11 ericj 544: }
545: }
546: }
1.6 deraadt 547: if (rr)
1.11 ericj 548: errx(1, "Can't grab %s:%d with bind",
1.6 deraadt 549: inet_ntoa(lclend->sin_addr), lp);
1.1 deraadt 550:
1.6 deraadt 551: if (o_listen)
552: return (nnetfd);/* thanks, that's all for today */
1.1 deraadt 553:
1.7 deraadt 554: memcpy(&remend->sin_addr.s_addr, rad, sizeof(struct in_addr));
1.6 deraadt 555: remend->sin_port = htons(rp);
1.1 deraadt 556:
1.6 deraadt 557: /* wrap connect inside a timer, and hit it */
558: arm(1, o_wait);
559: if (setjmp(jbuf) == 0) {
1.11 ericj 560: rr = connect(nnetfd, (struct sockaddr *) remend,
561: sizeof(struct sockaddr));
562: } else {
1.6 deraadt 563: rr = -1;
1.11 ericj 564: errno = ETIMEDOUT;
1.6 deraadt 565: }
566: arm(0, 0);
567: if (rr == 0)
568: return (nnetfd);
1.11 ericj 569: close(nnetfd);
1.6 deraadt 570: return (-1);
1.7 deraadt 571: }
1.1 deraadt 572:
1.11 ericj 573: /*
574: * dolisten :
575: * just like doconnect, and in fact calls a hunk of doconnect, but listens for
576: * incoming and returns an open connection *from* someplace. If we were
577: * given host/port args, any connections from elsewhere are rejected. This
578: * in conjunction with local-address binding should limit things nicely.
579: */
1.6 deraadt 580: int
581: dolisten(rad, rp, lad, lp)
1.7 deraadt 582: struct in_addr *rad;
583: u_short rp;
584: struct in_addr *lad;
585: u_short lp;
1.6 deraadt 586: {
1.11 ericj 587: int nnetfd;
588: int rr;
1.7 deraadt 589: struct host_info *whozis = NULL;
1.6 deraadt 590: int x;
591: char *cp;
1.7 deraadt 592: u_short z;
1.6 deraadt 593: errno = 0;
1.1 deraadt 594:
1.11 ericj 595: /*
596: * Pass everything off to doconnect,
597: * who in o_listen mode just gets a socket
598: */
1.6 deraadt 599: nnetfd = doconnect(rad, rp, lad, lp);
600: if (nnetfd <= 0)
601: return (-1);
1.11 ericj 602: if (o_udpmode) {
603: if (!lp)
604: errx(1, "UDP listen needs -p arg");
1.6 deraadt 605: } else {
1.11 ericj 606: rr = listen(nnetfd, 1);
607: if (rr < 0)
608: errx(1, "error listening");
1.6 deraadt 609: }
1.1 deraadt 610:
1.6 deraadt 611: if (o_verbose) {
1.11 ericj 612: x = sizeof(struct sockaddr);
1.7 deraadt 613: rr = getsockname(nnetfd, (struct sockaddr *) lclend, &x);
1.6 deraadt 614: if (rr < 0)
1.11 ericj 615: warn("local getsockname failed");
1.6 deraadt 616: strcpy(bigbuf_net, "listening on ["); /* buffer reuse... */
617: if (lclend->sin_addr.s_addr)
618: strcat(bigbuf_net, inet_ntoa(lclend->sin_addr));
619: else
620: strcat(bigbuf_net, "any");
621: strcat(bigbuf_net, "] %d ...");
622: z = ntohs(lclend->sin_port);
1.12 ! ericj 623: warn("%s %d", bigbuf_net, z);
1.6 deraadt 624: } /* verbose -- whew!! */
1.11 ericj 625: /*
626: * UDP is a speeeeecial case -- we have to do I/O *and* get the
1.6 deraadt 627: * calling party's particulars all at once, listen() and accept()
628: * don't apply. At least in the BSD universe, however, recvfrom/PEEK
629: * is enough to tell us something came in, and we can set things up so
630: * straight read/write actually does work after all. Yow. YMMV on
1.11 ericj 631: * strange platforms!
632: */
1.6 deraadt 633: if (o_udpmode) {
1.7 deraadt 634: x = sizeof(struct sockaddr); /* retval for recvfrom */
1.6 deraadt 635: arm(2, o_wait); /* might as well timeout this, too */
636: if (setjmp(jbuf) == 0) { /* do timeout for initial
637: * connect */
1.11 ericj 638: rr = recvfrom(nnetfd, bigbuf_net, BIGSIZ, MSG_PEEK,
639: (struct sockaddr *)remend, &x);
1.6 deraadt 640: } else
1.11 ericj 641: goto dol_tmo;
1.6 deraadt 642: arm(0, 0);
1.11 ericj 643: rr = connect(nnetfd, (struct sockaddr *)remend,
644: sizeof(struct sockaddr));
1.6 deraadt 645: goto whoisit;
1.11 ericj 646: }
1.6 deraadt 647: /* fall here for TCP */
1.11 ericj 648: x = sizeof(struct sockaddr);
649: arm(2, o_wait);
1.6 deraadt 650: if (setjmp(jbuf) == 0) {
1.7 deraadt 651: rr = accept(nnetfd, (struct sockaddr *) remend, &x);
1.6 deraadt 652: } else
1.11 ericj 653: goto dol_tmo;
1.6 deraadt 654: arm(0, 0);
655: close(nnetfd); /* dump the old socket */
656: nnetfd = rr; /* here's our new one */
1.1 deraadt 657:
658: whoisit:
1.6 deraadt 659: if (rr < 0)
660: goto dol_err; /* bail out if any errors so far */
1.1 deraadt 661:
1.11 ericj 662: /*
663: * Find out what address the connection was *to* on
664: * our end, in case we're doing a listen-on-any on
665: * a multihomed machine. This allows one to offer
666: * different services via different alias addresses,
667: * such as the "virtual web site" hack.
668: */
1.6 deraadt 669: memset(bigbuf_net, 0, 64);
670: cp = &bigbuf_net[32];
1.7 deraadt 671: x = sizeof(struct sockaddr);
672: rr = getsockname(nnetfd, (struct sockaddr *) lclend, &x);
1.12 ! ericj 673: if (rr < 0 && o_verbose)
1.11 ericj 674: warn("post-rcv getsockname failed");
1.6 deraadt 675: strcpy(cp, inet_ntoa(lclend->sin_addr));
1.1 deraadt 676:
1.6 deraadt 677: z = ntohs(remend->sin_port);
678: strcpy(bigbuf_net, inet_ntoa(remend->sin_addr));
1.11 ericj 679: whozis = gethinfo(bigbuf_net, o_nflag);
1.6 deraadt 680: errno = 0;
1.11 ericj 681: x = 0;
1.6 deraadt 682: if (rad) /* xxx: fix to go down the *list* if we have
683: * one? */
1.7 deraadt 684: if (memcmp(rad, whozis->iaddrs, sizeof(struct sockaddr)))
1.6 deraadt 685: x = 1;
1.11 ericj 686: if (rp) {
1.6 deraadt 687: if (z != rp)
688: x = 1;
1.11 ericj 689: }
690: if (x) {
691: errx(1, "invalid connection to [%s] from %s [%s] %d",
1.6 deraadt 692: cp, whozis->name, whozis->addrs[0], z);
1.11 ericj 693: }
1.12 ! ericj 694: if (o_verbose) {
! 695: warn("connect to [%s] from %s [%s] %d",
! 696: cp, whozis->name, whozis->addrs[0], z);
! 697: }
1.11 ericj 698: return (nnetfd);
1.1 deraadt 699:
700: dol_tmo:
1.11 ericj 701: errno = ETIMEDOUT;
1.1 deraadt 702: dol_err:
1.6 deraadt 703: close(nnetfd);
704: return (-1);
1.7 deraadt 705: }
1.1 deraadt 706:
1.11 ericj 707: /*
708: * udptest :
709: * fire a couple of packets at a UDP target port, just to see if it's really
710: * there. On BSD kernels, ICMP host/port-unreachable errors get delivered to
711: * our socket as ECONNREFUSED write errors. On SV kernels, we lose; we'll have
712: * to collect and analyze raw ICMP ourselves a la satan's probe_udp_ports
713: * backend. Guess where one could swipe the appropriate code from...
714: *
715: * Use the time delay between writes if given, otherwise use the "tcp ping"
716: * trick for getting the RTT. [I got that idea from pluvius, and warped it.]
717: * Return either the original fd, or clean up and return -1.
718: */
1.6 deraadt 719: udptest(fd, where)
720: int fd;
1.7 deraadt 721: struct in_addr *where;
1.6 deraadt 722: {
1.11 ericj 723: int rr;
1.6 deraadt 724:
725: rr = write(fd, bigbuf_in, 1);
1.12 ! ericj 726: if (rr != 1 && o_verbose)
1.11 ericj 727: warn("udptest first write failed?! errno %d", errno);
1.6 deraadt 728: if (o_wait)
729: sleep(o_wait);
730: else {
1.11 ericj 731: o_udpmode = 0;
732: o_wait = 5;
1.6 deraadt 733: rr = doconnect(where, SLEAZE_PORT, 0, 0);
734: if (rr > 0)
1.11 ericj 735: close(rr);
736: o_wait = 0;
737: o_udpmode++;
738: }
739: errno = 0;
1.6 deraadt 740: rr = write(fd, bigbuf_in, 1);
1.11 ericj 741: if (rr == 1)
1.6 deraadt 742: return (fd);
1.11 ericj 743: close(fd);
1.6 deraadt 744: return (-1);
1.7 deraadt 745: }
746:
1.11 ericj 747: /*
748: * oprint :
749: * Hexdump bytes shoveled either way to a running logfile, in the format:
750: * D offset - - - - --- 16 bytes --- - - - - # .... ascii .....
751: * where "which" sets the direction indicator, D:
752: * 0 -- sent to network, or ">"
753: * 1 -- rcvd and printed to stdout, or "<"
754: * and "buf" and "n" are data-block and length. If the current block generates
755: * a partial line, so be it; we *want* that lockstep indication of who sent
756: * what when. Adapted from dgaudet's original example -- but must be ripping
757: * *fast*, since we don't want to be too disk-bound.
758: */
1.6 deraadt 759: void
760: oprint(which, buf, n)
761: int which;
762: char *buf;
763: int n;
764: {
765: int bc; /* in buffer count */
766: int obc; /* current "global" offset */
767: int soc; /* stage write count */
1.11 ericj 768: unsigned char *p; /* main buf ptr; m.b. unsigned here */
769: unsigned char *op; /* out hexdump ptr */
770: unsigned char *a; /* out asc-dump ptr */
771: int x;
772: unsigned int y;
1.6 deraadt 773:
774: if (!ofd)
1.11 ericj 775: errx(1, "oprint called with no open fd?!");
1.6 deraadt 776: if (n == 0)
777: return;
778:
779: op = stage;
780: if (which) {
781: *op = '<';
782: obc = wrote_out;/* use the globals! */
783: } else {
784: *op = '>';
785: obc = wrote_net;
786: }
787: op++; /* preload "direction" */
788: *op = ' ';
789: p = (unsigned char *) buf;
790: bc = n;
791: stage[59] = '#'; /* preload separator */
792: stage[60] = ' ';
793:
794: while (bc) { /* for chunk-o-data ... */
795: x = 16;
796: soc = 78; /* len of whole formatted line */
797: if (bc < x) {
798: soc = soc - 16 + bc; /* fiddle for however much is
799: * left */
800: x = (bc * 3) + 11; /* 2 digits + space per, after
801: * D & offset */
802: op = &stage[x];
803: x = 16 - bc;
804: while (x) {
805: *op++ = ' '; /* preload filler spaces */
806: *op++ = ' ';
807: *op++ = ' ';
808: x--;
809: }
810: x = bc; /* re-fix current linecount */
811: } /* if bc < x */
812: bc -= x; /* fix wrt current line size */
813: sprintf(&stage[2], "%8.8x ", obc); /* xxx: still slow? */
814: obc += x; /* fix current offset */
815: op = &stage[11];/* where hex starts */
816: a = &stage[61]; /* where ascii starts */
817:
818: while (x) { /* for line of dump, however long ... */
819: y = (int) (*p >> 4); /* hi half */
820: *op = hexnibs[y];
821: op++;
822: y = (int) (*p & 0x0f); /* lo half */
823: *op = hexnibs[y];
824: op++;
825: *op = ' ';
826: op++;
827: if ((*p > 31) && (*p < 127))
828: *a = *p; /* printing */
829: else
830: *a = '.'; /* nonprinting, loose def */
831: a++;
832: p++;
833: x--;
834: } /* while x */
835: *a = '\n'; /* finish the line */
836: x = write(ofd, stage, soc);
837: if (x < 0)
1.11 ericj 838: errx(1, "ofd write err");
839: }
1.7 deraadt 840: }
841:
1.1 deraadt 842: #ifdef TELNET
1.7 deraadt 843: u_short o_tn = 0; /* global -t option */
1.1 deraadt 844:
1.11 ericj 845: /*
846: * atelnet :
847: * Answer anything that looks like telnet negotiation with don't/won't.
848: * This doesn't modify any data buffers, update the global output count,
849: * or show up in a hexdump -- it just shits into the outgoing stream.
850: * Idea and codebase from Mudge@l0pht.com.
851: */
1.6 deraadt 852: void
853: atelnet(buf, size)
854: unsigned char *buf; /* has to be unsigned here! */
855: unsigned int size;
856: {
857: static unsigned char obuf[4]; /* tiny thing to build responses into */
1.11 ericj 858: int x;
859: unsigned char y;
860: unsigned char *p;
1.6 deraadt 861:
862: y = 0;
863: p = buf;
864: x = size;
865: while (x > 0) {
866: if (*p != 255) /* IAC? */
867: goto notiac;
868: obuf[0] = 255;
869: p++;
870: x--;
871: if ((*p == 251) || (*p == 252)) /* WILL or WONT */
872: y = 254;/* -> DONT */
873: if ((*p == 253) || (*p == 254)) /* DO or DONT */
874: y = 252;/* -> WONT */
875: if (y) {
876: obuf[1] = y;
877: p++;
878: x--;
1.11 ericj 879: obuf[2] = *p;
1.6 deraadt 880: (void) write(netfd, obuf, 3);
1.11 ericj 881: /*
882: * if one wanted to bump wrote_net or do
883: * a hexdump line, here's the place.
884: */
1.6 deraadt 885: y = 0;
1.11 ericj 886: }
1.1 deraadt 887: notiac:
1.6 deraadt 888: p++;
889: x--;
1.11 ericj 890: }
1.7 deraadt 891: }
1.11 ericj 892: #endif /* TELNET */
1.7 deraadt 893:
1.11 ericj 894: /*
895: * readwrite :
896: * handle stdin/stdout/network I/O. Bwahaha!! -- the select loop from hell.
897: * In this instance, return what might become our exit status.
898: */
1.6 deraadt 899: int
900: readwrite(fd)
901: int fd;
902: {
1.11 ericj 903: int rr;
904: char *zp; /* stdin buf ptr */
905: char *np; /* net-in buf ptr */
1.6 deraadt 906: unsigned int rzleft;
907: unsigned int rnleft;
1.7 deraadt 908: u_short netretry; /* net-read retry counter */
1.11 ericj 909: u_short wretry; /* net-write sanity counter */
910: u_short wfirst; /* one-shot flag to skip first net read */
1.1 deraadt 911:
1.11 ericj 912: /*
913: * if you don't have all this FD_* macro hair in sys/types.h,
914: * you'll have to either find it or do your own bit-bashing:
915: * *ds1 |= (1 << fd), etc.
916: */
1.6 deraadt 917: if (fd > FD_SETSIZE) {
1.11 ericj 918: warn("Preposterous fd value %d", fd);
1.6 deraadt 919: return (1);
920: }
1.11 ericj 921: FD_SET(fd, &fds1);
1.6 deraadt 922: netretry = 2;
923: wfirst = 0;
924: rzleft = rnleft = 0;
925: if (insaved) {
926: rzleft = insaved; /* preload multi-mode fakeouts */
927: zp = bigbuf_in;
928: wfirst = 1;
1.11 ericj 929: /* If not scanning, this is a one-off first */
930: if (Single)
931: insaved = 0;
1.6 deraadt 932: else {
1.11 ericj 933: FD_CLR(0, &fds1);
934: close(0);
935: }
936: }
1.6 deraadt 937: if (o_interval)
1.11 ericj 938: sleep(o_interval);
939: errno = 0;
1.1 deraadt 940:
1.7 deraadt 941: while (FD_ISSET(fd, &fds1)) { /* i.e. till the *net* closes! */
1.9 art 942: struct timeval *tv;
943:
1.11 ericj 944: wretry = 8200; /* more than we'll ever hafta write */
945: if (wfirst) { /* any saved stdin buffer? */
1.6 deraadt 946: wfirst = 0; /* clear flag for the duration */
947: goto shovel; /* and go handle it first */
948: }
1.7 deraadt 949: fds2 = fds1;
1.9 art 950: if (timer1.tv_sec > 0 || timer1.tv_usec > 0) {
951: memcpy(&timer2, &timer1, sizeof(struct timeval));
952: tv = &timer2;
953: } else
954: tv = NULL;
955: rr = select(getdtablesize(), &fds2, 0, 0, tv);
1.6 deraadt 956: if (rr < 0) {
1.11 ericj 957: if (errno != EINTR) {
958: warn("Select Failure");
1.6 deraadt 959: close(fd);
960: return (1);
961: }
1.11 ericj 962: }
1.6 deraadt 963: /* if we have a timeout AND stdin is closed AND we haven't
964: * heard anything from the net during that time, assume it's
965: * dead and close it too. */
966: if (rr == 0) {
1.7 deraadt 967: if (!FD_ISSET(0, &fds1))
1.6 deraadt 968: netretry--; /* we actually try a coupla
969: * times. */
970: if (!netretry) {
1.12 ! ericj 971: if (o_verbose) /* normally we don't
1.6 deraadt 972: * care */
1.11 ericj 973: warn("net timeout");
1.6 deraadt 974: close(fd);
975: return (0); /* not an error! */
976: }
977: } /* select timeout */
1.11 ericj 978: /* XXX: should we check the exception fds too? The read fds
1.6 deraadt 979: * seem to give us the right info, and none of the examples I
980: * found bothered. */
981: /* Ding!! Something arrived, go check all the incoming
982: * hoppers, net first */
1.7 deraadt 983: if (FD_ISSET(fd, &fds2)) { /* net: ding! */
1.6 deraadt 984: rr = read(fd, bigbuf_net, BIGSIZ);
985: if (rr <= 0) {
1.7 deraadt 986: FD_CLR(fd, &fds1); /* net closed, we'll
1.6 deraadt 987: * finish up... */
988: rzleft = 0; /* can't write anymore: broken
989: * pipe */
990: } else {
991: rnleft = rr;
992: np = bigbuf_net;
1.1 deraadt 993: #ifdef TELNET
1.6 deraadt 994: if (o_tn)
995: atelnet(np, rr); /* fake out telnet stuff */
1.11 ericj 996: #endif /* TELNET */
997: }
998: }
1.6 deraadt 999: /* if we're in "slowly" mode there's probably still stuff in
1000: * the stdin buffer, so don't read unless we really need MORE
1001: * INPUT! MORE INPUT! */
1002: if (rzleft)
1003: goto shovel;
1.1 deraadt 1004:
1.11 ericj 1005: if (FD_ISSET(0, &fds2)) {
1.6 deraadt 1006: rr = read(0, bigbuf_in, BIGSIZ);
1.11 ericj 1007: if (rr <= 0) {
1008: FD_CLR(0, &fds1); /* disable and close */
1.6 deraadt 1009: close(0);
1010: } else {
1011: rzleft = rr;
1012: zp = bigbuf_in;
1.11 ericj 1013: if (!Single) {
1014: insaved = rr;
1015: FD_CLR(0, &fds1);
1016: close(0);
1017: }
1018: }
1019: }
1.1 deraadt 1020: shovel:
1.11 ericj 1021: /* sanity check. Works because they're both unsigned... */
1.6 deraadt 1022: if ((rzleft > 8200) || (rnleft > 8200)) {
1023: rzleft = rnleft = 0;
1024: }
1.11 ericj 1025: /* net write retries sometimes happen on UDP connections */
1.6 deraadt 1026: if (!wretry) { /* is something hung? */
1.11 ericj 1027: warn("too many output retries");
1.6 deraadt 1028: return (1);
1029: }
1030: if (rnleft) {
1031: rr = write(1, np, rnleft);
1032: if (rr > 0) {
1033: if (o_wfile)
1.11 ericj 1034: oprint(1, np, rr);
1035: np += rr;
1036: rnleft -= rr;
1.6 deraadt 1037: wrote_out += rr; /* global count */
1038: }
1.11 ericj 1039: }
1.6 deraadt 1040: if (rzleft) {
1.11 ericj 1041: if (o_interval)
1.6 deraadt 1042: rr = findline(zp, rzleft);
1043: else
1044: rr = rzleft;
1.11 ericj 1045: rr = write(fd, zp, rr);
1.6 deraadt 1046: if (rr > 0) {
1047: if (o_wfile)
1.11 ericj 1048: oprint(0, zp, rr);
1.6 deraadt 1049: zp += rr;
1050: rzleft -= rr;
1.11 ericj 1051: wrote_net += rr;
1.6 deraadt 1052: }
1.11 ericj 1053: }
1054: if (o_interval) {
1.6 deraadt 1055: sleep(o_interval);
1.11 ericj 1056: errno = 0;
1057: continue;
1.6 deraadt 1058: }
1.11 ericj 1059: if ((rzleft) || (rnleft)) {
1060: wretry--;
1.6 deraadt 1061: goto shovel;
1062: }
1.11 ericj 1063: }
1.1 deraadt 1064:
1.6 deraadt 1065: close(fd);
1066: return (0);
1.7 deraadt 1067: }
1.1 deraadt 1068:
1069: /* main :
1070: now we pull it all together... */
1.6 deraadt 1071: main(argc, argv)
1072: int argc;
1073: char **argv;
1.1 deraadt 1074: {
1.11 ericj 1075: int x, ch;
1076: char *cp;
1.7 deraadt 1077: struct host_info *gp;
1078: struct host_info *whereto = NULL;
1079: struct host_info *wherefrom = NULL;
1080: struct in_addr *ouraddr = NULL;
1081: struct in_addr *themaddr = NULL;
1082: u_short o_lport = 0;
1083: u_short ourport = 0;
1084: u_short loport = 0; /* for scanning stuff */
1085: u_short hiport = 0;
1086: u_short curport = 0;
1.6 deraadt 1087: char *randports = NULL;
1.1 deraadt 1088:
1089: #ifdef HAVE_BIND
1.6 deraadt 1090: res_init();
1.1 deraadt 1091: #endif
1.7 deraadt 1092: lclend = (struct sockaddr_in *) calloc(1, sizeof(struct sockaddr));
1093: remend = (struct sockaddr_in *) calloc(1, sizeof(struct sockaddr));
1094: bigbuf_in = calloc(1, BIGSIZ);
1095: bigbuf_net = calloc(1, BIGSIZ);
1.11 ericj 1096: pinfo= (struct port_info *) calloc(1, sizeof(struct port_info));
1.6 deraadt 1097:
1098: errno = 0;
1099: gatesptr = 4;
1100: h_errno = 0;
1.1 deraadt 1101:
1.11 ericj 1102: /*
1103: * We want to catch a few of these signals.
1104: * Others we disgard.
1105: */
1.6 deraadt 1106: signal(SIGINT, catch);
1107: signal(SIGQUIT, catch);
1108: signal(SIGTERM, catch);
1109: signal(SIGURG, SIG_IGN);
1110: signal(SIGPIPE, SIG_IGN); /* important! */
1.1 deraadt 1111:
1.11 ericj 1112: /*
1113: * If no args given at all, get 'em from stdin, construct an argv,
1114: * and hand anything left over to readwrite().
1115: */
1.6 deraadt 1116: if (argc == 1) {
1117: cp = argv[0];
1.11 ericj 1118: /* XXX - 128 ? */
1119: argv = (char **) calloc(1, 128 * sizeof(char *));
1.6 deraadt 1120: argv[0] = cp; /* leave old prog name intact */
1.7 deraadt 1121: cp = calloc(1, BIGSIZ);
1.6 deraadt 1122: argv[1] = cp; /* head of new arg block */
1123: fprintf(stderr, "Cmd line: ");
1124: fflush(stderr); /* I dont care if it's unbuffered or not! */
1.10 deraadt 1125: insaved = read(0, cp, BIGSIZ-1); /* we're gonna fake fgets()
1.6 deraadt 1126: * here */
1.10 deraadt 1127: cp[BIGSIZ-1] = '\0';
1.6 deraadt 1128: if (insaved <= 0)
1.11 ericj 1129: errx(1, "wrong");
1.6 deraadt 1130: x = findline(cp, insaved);
1131: if (x)
1132: insaved -= x; /* remaining chunk size to be sent */
1133: if (insaved) /* which might be zero... */
1134: memcpy(bigbuf_in, &cp[x], insaved);
1135: cp = strchr(argv[1], '\n');
1136: if (cp)
1137: *cp = '\0';
1138: cp = strchr(argv[1], '\r'); /* look for ^M too */
1139: if (cp)
1140: *cp = '\0';
1.1 deraadt 1141:
1.11 ericj 1142: /*
1143: * Find and stash pointers to remaining new "args"
1144: */
1.6 deraadt 1145: cp = argv[1];
1146: cp++; /* skip past first char */
1147: x = 2; /* we know argv 0 and 1 already */
1148: for (; *cp != '\0'; cp++) {
1149: if (*cp == ' ') {
1150: *cp = '\0'; /* smash all spaces */
1151: continue;
1152: } else {
1153: if (*(cp - 1) == '\0') {
1154: argv[x] = cp;
1155: x++;
1156: }
1157: } /* if space */
1158: } /* for cp */
1159: argc = x;
1.11 ericj 1160: }
1161:
1162: while ((ch = getopt(argc, argv, "g:G:hi:lno:p:rs:tuvw:z")) != -1) {
1163: switch (ch) {
1164: case 'G': /* srcrt gateways pointer val */
1.6 deraadt 1165: x = atoi(optarg);
1.11 ericj 1166: /* Mask of bits */
1167: if ((x) && (x == (x & 0x1c)))
1.6 deraadt 1168: gatesptr = x;
1169: else
1.11 ericj 1170: errx(1, "invalid hop pointer %d, must be multiple of 4 <= 28", x);
1.6 deraadt 1171: break;
1.11 ericj 1172: case 'g': /* srcroute hop[s] */
1.6 deraadt 1173: if (gatesidx > 8)
1.11 ericj 1174: errx(1, "Too many -g hops!");
1175: if (gates == NULL)
1176: gates = (struct host_info **) calloc(1,
1177: sizeof(struct host_info *) * 10);
1178: gp = gethinfo(optarg, o_nflag);
1.6 deraadt 1179: if (gp)
1180: gates[gatesidx] = gp;
1181: gatesidx++;
1182: break;
1183: case 'h':
1.11 ericj 1184: help();
1185: break;
1186: case 'i': /* line-interval time */
1.6 deraadt 1187: o_interval = atoi(optarg) & 0xffff;
1188: if (!o_interval)
1.11 ericj 1189: errx(1, "invalid interval time %s", optarg);
1.6 deraadt 1190: break;
1.11 ericj 1191: case 'l': /* listen mode */
1.6 deraadt 1192: o_listen++;
1193: break;
1.11 ericj 1194: case 'n': /* numeric-only, no DNS lookups */
1.6 deraadt 1195: o_nflag++;
1196: break;
1.11 ericj 1197: case 'o': /* hexdump log */
1.6 deraadt 1198: stage = (unsigned char *) optarg;
1199: o_wfile++;
1200: break;
1.11 ericj 1201: case 'p': /* local source port */
1202: o_lport = getpinfo(optarg, 0);
1.6 deraadt 1203: if (o_lport == 0)
1.11 ericj 1204: errx(1, "invalid local port %s", optarg);
1.6 deraadt 1205: break;
1.11 ericj 1206: case 'r': /* randomize various things */
1.6 deraadt 1207: o_random++;
1208: break;
1.11 ericj 1209: /*
1210: * Do a full lookup [since everything else goes through the same
1211: * mill], unless -n was previously specified. In fact, careful
1212: * placement of -n can be useful, so we'll still pass o_nflag
1213: * here instead of forcing numeric.
1214: */
1215: case 's': /* local source address */
1216: wherefrom = gethinfo(optarg, o_nflag);
1.6 deraadt 1217: ouraddr = &wherefrom->iaddrs[0];
1218: break;
1.1 deraadt 1219: #ifdef TELNET
1.11 ericj 1220: case 't': /* do telnet fakeout */
1.6 deraadt 1221: o_tn++;
1222: break;
1.11 ericj 1223: #endif
1224: case 'u': /* use UDP */
1.6 deraadt 1225: o_udpmode++;
1226: break;
1.11 ericj 1227: case 'v': /* verbose */
1.6 deraadt 1228: o_verbose++;
1229: break;
1.11 ericj 1230: case 'w': /* wait time */
1.6 deraadt 1231: o_wait = atoi(optarg);
1232: if (o_wait <= 0)
1.11 ericj 1233: errx(1, "invalid wait-time %s", optarg);
1.7 deraadt 1234: timer1.tv_sec = o_wait;
1235: timer1.tv_usec = 0;
1.6 deraadt 1236: break;
1.11 ericj 1237: case 'z': /* little or no data xfer */
1.6 deraadt 1238: o_zero++;
1239: break;
1240: default:
1.11 ericj 1241: usage(1);
1242: }
1243: }
1.1 deraadt 1244:
1.11 ericj 1245: /* other misc initialization */
1.7 deraadt 1246: FD_SET(0, &fds1); /* stdin *is* initially open */
1.6 deraadt 1247: if (o_random) {
1248: SRAND(time(0));
1.11 ericj 1249: randports = calloc(1, 65536); /* big flag array for ports */
1.6 deraadt 1250: }
1251: if (o_wfile) {
1252: ofd = open(stage, O_WRONLY | O_CREAT | O_TRUNC, 0664);
1253: if (ofd <= 0) /* must be > extant 0/1/2 */
1.11 ericj 1254: errx(1, "Can't open %s", stage);
1.7 deraadt 1255: stage = (unsigned char *) calloc(1, 100);
1.6 deraadt 1256: }
1.11 ericj 1257: /* optind is now index of first non -x arg */
1258: if (argv[optind])
1259: whereto = gethinfo(argv[optind], o_nflag);
1.6 deraadt 1260: if (whereto && whereto->iaddrs)
1261: themaddr = &whereto->iaddrs[0];
1262: if (themaddr)
1263: optind++; /* skip past valid host lookup */
1264: errno = 0;
1265: h_errno = 0;
1.1 deraadt 1266:
1.11 ericj 1267: /*
1268: * Handle listen mode here, and exit afterward. Only does one connect;
1269: * this is arguably the right thing to do. A "persistent listen-and-fork"
1270: * mode a la inetd has been thought about, but not implemented. A tiny
1271: * wrapper script can handle such things.
1272: */
1.6 deraadt 1273: if (o_listen) {
1.11 ericj 1274: curport = 0;
1275: if (argv[optind]) {
1276: curport = getpinfo(argv[optind], 0);
1277: if (curport == 0)
1278: errx(1, "invalid port %s", argv[optind]);
1279: }
1.6 deraadt 1280: netfd = dolisten(themaddr, curport, ouraddr, o_lport);
1281: if (netfd > 0) {
1.11 ericj 1282: x = readwrite(netfd);
1.12 ! ericj 1283: if (o_verbose)
1.11 ericj 1284: warn("Sent %i Rcvd %i", wrote_net, wrote_out);
1285: exit(x);
1286: } else
1287: errx(1, "no connection");
1288: }
1.6 deraadt 1289: /* fall thru to outbound connects. Now we're more picky about args... */
1290: if (!themaddr)
1.11 ericj 1291: errx(1, "no destination");
1.6 deraadt 1292: if (argv[optind] == NULL)
1.11 ericj 1293: errx(1, "no port[s] to connect to");
1294: if (argv[optind + 1])
1295: Single = 0;
1296: ourport = o_lport;
1297:
1.6 deraadt 1298: while (argv[optind]) {
1299: hiport = loport = 0;
1.11 ericj 1300: cp = strchr(argv[optind], '-');
1.6 deraadt 1301: if (cp) {
1302: *cp = '\0';
1303: cp++;
1.11 ericj 1304: hiport = getpinfo(cp, 0);
1.6 deraadt 1305: if (hiport == 0)
1.11 ericj 1306: errx(1, "invalid port %s", cp);
1.6 deraadt 1307: } /* if found a dash */
1.11 ericj 1308: loport = getpinfo(argv[optind], 0);
1.6 deraadt 1309: if (loport == 0)
1.11 ericj 1310: errx(1, "invalid port %s", argv[optind]);
1.6 deraadt 1311: if (hiport > loport) { /* was it genuinely a range? */
1312: Single = 0; /* multi-mode, case B */
1313: if (o_random) { /* maybe populate the random array */
1314: loadports(randports, loport, hiport);
1315: curport = nextport(randports);
1.11 ericj 1316: } else
1317: curport = hiport;
1.6 deraadt 1318: } else /* not a range, including args like "25-25" */
1319: curport = loport;
1.11 ericj 1320: /*
1321: * Now start connecting to these things.
1322: * curport is already preloaded.
1323: */
1.6 deraadt 1324: while (loport <= curport) {
1.11 ericj 1325: curport = getpinfo(NULL, curport);
1.6 deraadt 1326: netfd = doconnect(themaddr, curport, ouraddr, ourport);
1.11 ericj 1327: if (netfd > 0)
1328: if (o_zero && o_udpmode)
1.6 deraadt 1329: netfd = udptest(netfd, themaddr);
1.11 ericj 1330: if (netfd > 0) {
1331: x = 0;
1332: if (o_verbose) {
1333: warn("%s [%s] %d (%s) open",
1334: whereto->name,
1335: whereto->addrs[0], curport,
1336: pinfo->name);
1337: }
1.6 deraadt 1338: if (!o_zero)
1.11 ericj 1339: x = readwrite(netfd);
1340: } else {
1341: x = 1;
1342: if ((Single || (o_verbose > 1))
1343: || (errno != ECONNREFUSED)) {
1344: warn("%s [%s] %d (%s)",
1345: whereto->name, whereto->addrs[0],
1346: curport, pinfo->name);
1347: }
1348: }
1349: close(netfd);
1.6 deraadt 1350: if (o_interval)
1.11 ericj 1351: sleep(o_interval);
1.6 deraadt 1352: if (o_random)
1353: curport = nextport(randports);
1354: else
1.11 ericj 1355: curport--;
1356: }
1.6 deraadt 1357: optind++;
1.11 ericj 1358: }
1.6 deraadt 1359:
1360: errno = 0;
1.11 ericj 1361: if (o_verbose > 1)
1362: warn("Sent %i Rcvd %i", wrote_net, wrote_out);
1.6 deraadt 1363: if (Single)
1.11 ericj 1364: exit(x);
1365: exit(0);
1.7 deraadt 1366: }
1.1 deraadt 1367:
1.11 ericj 1368: void
1369: usage(doexit)
1.1 deraadt 1370: {
1.11 ericj 1371: fprintf(stderr, "netcat - [v1.10]\n");
1372: fprintf(stderr, "nc [-lnrtuvz] [-e command] [-g intermediates]\n");
1373: fprintf(stderr, " [-G hopcount] [-i interval] [-o filename] [-p source port]\n");
1374: fprintf(stderr, " [-s ip address] [-w timeout] [hostname] [port[s...]]\n");
1375: if (doexit)
1376: exit(1);
1377: }
1378:
1379: void
1380: help()
1381: {
1382: usage(0);
1383: fprintf(stderr, "\tCommand Summary:\n\
1384: \t-g gateway source-routing hop point[s], up to 8\n\
1385: \t-G num\t source-routing pointer: 4, 8, 12, ...\n\
1386: \t-h this help text\n\
1387: \t-i secs\t delay interval for lines sent, ports scanned\n\
1388: \t-l listen mode, for inbound connects\n\
1389: \t-n numeric-only IP addresses, no DNS\n\
1390: \t-o file\t hex dump of traffic\n\
1391: \t-r randomize local and remote ports\n\
1392: \t-s addr\t local source address\n");
1.1 deraadt 1393: #ifdef TELNET
1.11 ericj 1394: fprintf(stderr, "\t\t-t answer TELNET negotiation\n");
1.1 deraadt 1395: #endif
1.11 ericj 1396: fprintf(stderr, "\t\t-u UDP mode\n\
1397: \t-v verbose [use twice to be more verbose]\n\
1398: \t-w secs\t timeout for connects and final net reads\n\
1399: \t-z zero-I/O mode [used for scanning]\n\
1400: Port numbers can be individual or ranges: lo-hi [inclusive]\n");
1401: exit(1);
1.7 deraadt 1402: }
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