xref: /netbsd-src/usr.bin/tftp/tftp.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: tftp.c,v 1.22 2005/11/20 19:28:23 ross Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
36 #else
37 __RCSID("$NetBSD: tftp.c,v 1.22 2005/11/20 19:28:23 ross Exp $");
38 #endif
39 #endif /* not lint */
40 
41 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
42 
43 /*
44  * TFTP User Program -- Protocol Machines
45  */
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/socket.h>
49 #include <sys/stat.h>
50 #include <sys/time.h>
51 
52 #include <netinet/in.h>
53 
54 #include <arpa/tftp.h>
55 
56 #include <err.h>
57 #include <errno.h>
58 #include <setjmp.h>
59 #include <signal.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 #include <netdb.h>
65 
66 #include "extern.h"
67 #include "tftpsubs.h"
68 
69 char    ackbuf[PKTSIZE];
70 int	timeout;
71 jmp_buf	toplevel;
72 jmp_buf	timeoutbuf;
73 
74 static void nak __P((int, struct sockaddr *));
75 static int makerequest __P((int, const char *, struct tftphdr *, const char *, off_t));
76 static void printstats __P((const char *, unsigned long));
77 static void startclock __P((void));
78 static void stopclock __P((void));
79 static void timer __P((int));
80 static void tpacket __P((const char *, struct tftphdr *, int));
81 static int cmpport __P((struct sockaddr *, struct sockaddr *));
82 
83 static void get_options(struct tftphdr *, int);
84 
85 static void
86 get_options(struct tftphdr *ap, int size)
87 {
88 	unsigned long val;
89 	char *opt, *endp, *nextopt, *valp;
90 	int l;
91 
92 	size -= 2;	/* skip over opcode */
93 	opt = ap->th_stuff;
94 	endp = opt + size - 1;
95 	*endp = '\0';
96 
97 	while (opt < endp) {
98 		l = strlen(opt) + 1;
99 		valp = opt + l;
100 		if (valp < endp) {
101 			val = strtoul(valp, NULL, 10);
102 			l = strlen(valp) + 1;
103 			nextopt = valp + l;
104 			if (val == ULONG_MAX && errno == ERANGE) {
105 				/* Report illegal value */
106 				opt = nextopt;
107 				continue;
108 			}
109 		} else {
110 			/* Badly formed OACK */
111 			break;
112 		}
113 		if (strcmp(opt, "tsize") == 0) {
114 			/* cool, but we'll ignore it */
115 		} else if (strcmp(opt, "timeout") == 0) {
116 			if (val >= 1 && val <= 255) {
117 				rexmtval = val;
118 			} else {
119 				/* Report error? */
120 			}
121 		} else if (strcmp(opt, "blksize") == 0) {
122 			if (val >= 8 && val <= MAXSEGSIZE) {
123 				blksize = val;
124 			} else {
125 				/* Report error? */
126 			}
127 		} else {
128 			/* unknown option */
129 		}
130 		opt = nextopt;
131 	}
132 }
133 
134 /*
135  * Send the requested file.
136  */
137 void
138 sendfile(fd, name, mode)
139 	int fd;
140 	char *name;
141 	char *mode;
142 {
143 	struct tftphdr *ap;	   /* data and ack packets */
144 	struct tftphdr *dp;
145 	int j, n;
146 	volatile unsigned int block;
147 	volatile int size, convert;
148 	volatile unsigned long amount;
149 	struct sockaddr_storage from;
150 	struct stat sbuf;
151 	off_t filesize=0;
152 	int fromlen;
153 	FILE *file;
154 	struct sockaddr_storage peer;
155 	struct sockaddr_storage serv;	/* valid server port number */
156 
157 	startclock();		/* start stat's clock */
158 	dp = r_init();		/* reset fillbuf/read-ahead code */
159 	ap = (struct tftphdr *)ackbuf;
160 	if (tsize) {
161 		if (fstat(fd, &sbuf) == 0) {
162 			filesize = sbuf.st_size;
163 		} else {
164 			filesize = -1ULL;
165 		}
166 	}
167 	file = fdopen(fd, "r");
168 	convert = !strcmp(mode, "netascii");
169 	block = 0;
170 	amount = 0;
171 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
172 	memset(&serv, 0, sizeof(serv));
173 
174 	signal(SIGALRM, timer);
175 	do {
176 		if (block == 0)
177 			size = makerequest(WRQ, name, dp, mode, filesize) - 4;
178 		else {
179 		/*	size = read(fd, dp->th_data, SEGSIZE);	 */
180 			size = readit(file, &dp, blksize, convert);
181 			if (size < 0) {
182 				nak(errno + 100, (struct sockaddr *)&peer);
183 				break;
184 			}
185 			dp->th_opcode = htons((u_short)DATA);
186 			dp->th_block = htons((u_short)block);
187 		}
188 		timeout = 0;
189 		(void) setjmp(timeoutbuf);
190 send_data:
191 		if (trace)
192 			tpacket("sent", dp, size + 4);
193 		n = sendto(f, dp, size + 4, 0,
194 		    (struct sockaddr *)&peer, peer.ss_len);
195 		if (n != size + 4) {
196 			warn("sendto");
197 			goto abort;
198 		}
199 		if (block)
200 			read_ahead(file, blksize, convert);
201 		for ( ; ; ) {
202 			alarm(rexmtval);
203 			do {
204 				fromlen = sizeof(from);
205 				n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
206 				    (struct sockaddr *)&from, &fromlen);
207 			} while (n <= 0);
208 			alarm(0);
209 			if (n < 0) {
210 				warn("recvfrom");
211 				goto abort;
212 			}
213 			if (!serv.ss_family)
214 				serv = from;
215 			else if (!cmpport((struct sockaddr *)&serv,
216 			    (struct sockaddr *)&from)) {
217 				warn("server port mismatch");
218 				goto abort;
219 			}
220 			peer = from;
221 			if (trace)
222 				tpacket("received", ap, n);
223 			/* should verify packet came from server */
224 			ap->th_opcode = ntohs(ap->th_opcode);
225 			if (ap->th_opcode == ERROR) {
226 				printf("Error code %d: %s\n", ap->th_code,
227 					ap->th_msg);
228 				goto abort;
229 			}
230 			if (ap->th_opcode == ACK) {
231 				ap->th_block = ntohs(ap->th_block);
232 
233 				if (ap->th_block == 0) {
234 					/*
235 					 * If the extended options are enabled,
236 					 * the server just refused 'em all.
237 					 * The only one that _really_
238 					 * matters is blksize, but we'll
239 					 * clear timeout, too.
240 					 */
241 					blksize = def_blksize;
242 					rexmtval = def_rexmtval;
243 				}
244 				if (ap->th_block == block) {
245 					break;
246 				}
247 				/* On an error, try to synchronize
248 				 * both sides.
249 				 */
250 				j = synchnet(f, blksize+4);
251 				if (j && trace) {
252 					printf("discarded %d packets\n",
253 							j);
254 				}
255 				if (ap->th_block == (block-1)) {
256 					goto send_data;
257 				}
258 			}
259 			if (ap->th_opcode == OACK) {
260 				if (block == 0) {
261 					blksize = def_blksize;
262 					rexmtval = def_rexmtval;
263 					get_options(ap, n);
264 					break;
265 				}
266 			}
267 		}
268 		if (block > 0)
269 			amount += size;
270 		block++;
271 	} while (size == blksize || block == 1);
272 abort:
273 	fclose(file);
274 	stopclock();
275 	if (amount > 0)
276 		printstats("Sent", amount);
277 }
278 
279 /*
280  * Receive a file.
281  */
282 void
283 recvfile(fd, name, mode)
284 	int fd;
285 	char *name;
286 	char *mode;
287 {
288 	struct tftphdr *ap;
289 	struct tftphdr *dp;
290 	int j, n, oack=0;
291 	volatile unsigned int block;
292 	volatile int size, firsttrip;
293 	volatile unsigned long amount;
294 	struct sockaddr_storage from;
295 	int fromlen, readlen;
296 	FILE *file;
297 	volatile int convert;		/* true if converting crlf -> lf */
298 	struct sockaddr_storage peer;
299 	struct sockaddr_storage serv;	/* valid server port number */
300 
301 	startclock();
302 	dp = w_init();
303 	ap = (struct tftphdr *)ackbuf;
304 	file = fdopen(fd, "w");
305 	convert = !strcmp(mode, "netascii");
306 	block = 1;
307 	firsttrip = 1;
308 	amount = 0;
309 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
310 	memset(&serv, 0, sizeof(serv));
311 
312 	signal(SIGALRM, timer);
313 	do {
314 		if (firsttrip) {
315 			size = makerequest(RRQ, name, ap, mode, 0);
316 			readlen = PKTSIZE;
317 			firsttrip = 0;
318 		} else {
319 			ap->th_opcode = htons((u_short)ACK);
320 			ap->th_block = htons((u_short)(block));
321 			readlen = blksize+4;
322 			size = 4;
323 			block++;
324 		}
325 		timeout = 0;
326 		(void) setjmp(timeoutbuf);
327 send_ack:
328 		if (trace)
329 			tpacket("sent", ap, size);
330 		if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
331 		    peer.ss_len) != size) {
332 			alarm(0);
333 			warn("sendto");
334 			goto abort;
335 		}
336 		write_behind(file, convert);
337 		for ( ; ; ) {
338 			alarm(rexmtval);
339 			do  {
340 				fromlen = sizeof(from);
341 				n = recvfrom(f, dp, readlen, 0,
342 				    (struct sockaddr *)&from, &fromlen);
343 			} while (n <= 0);
344 			alarm(0);
345 			if (n < 0) {
346 				warn("recvfrom");
347 				goto abort;
348 			}
349 			if (!serv.ss_family)
350 				serv = from;
351 			else if (!cmpport((struct sockaddr *)&serv,
352 			    (struct sockaddr *)&from)) {
353 				warn("server port mismatch");
354 				goto abort;
355 			}
356 			peer = from;
357 			if (trace)
358 				tpacket("received", dp, n);
359 			/* should verify client address */
360 			dp->th_opcode = ntohs(dp->th_opcode);
361 			if (dp->th_opcode == ERROR) {
362 				printf("Error code %d: %s\n", dp->th_code,
363 					dp->th_msg);
364 				goto abort;
365 			}
366 			if (dp->th_opcode == DATA) {
367 				dp->th_block = ntohs(dp->th_block);
368 
369 				if (dp->th_block == 1 && !oack) {
370 					/* no OACK, revert to defaults */
371 					blksize = def_blksize;
372 					rexmtval = def_rexmtval;
373 				}
374 				if (dp->th_block == block) {
375 					break;		/* have next packet */
376 				}
377 				/* On an error, try to synchronize
378 				 * both sides.
379 				 */
380 				j = synchnet(f, blksize);
381 				if (j && trace) {
382 					printf("discarded %d packets\n", j);
383 				}
384 				if (dp->th_block == (block-1)) {
385 					goto send_ack;	/* resend ack */
386 				}
387 			}
388 			if (dp->th_opcode == OACK) {
389 				if (block == 1) {
390 					oack = 1;
391 					blksize = def_blksize;
392 					rexmtval = def_rexmtval;
393 					get_options(dp, n);
394 					ap->th_opcode = htons(ACK);
395 					ap->th_block = 0;
396 					readlen = blksize+4;
397 					size = 4;
398 					goto send_ack;
399 				}
400 			}
401 		}
402 	/*	size = write(fd, dp->th_data, n - 4); */
403 		size = writeit(file, &dp, n - 4, convert);
404 		if (size < 0) {
405 			nak(errno + 100, (struct sockaddr *)&peer);
406 			break;
407 		}
408 		amount += size;
409 	} while (size == blksize);
410 abort:						/* ok to ack, since user */
411 	ap->th_opcode = htons((u_short)ACK);	/* has seen err msg */
412 	ap->th_block = htons((u_short)block);
413 	(void) sendto(f, ackbuf, 4, 0, (struct sockaddr *)&peer,
414 	    peer.ss_len);
415 	write_behind(file, convert);		/* flush last buffer */
416 	fclose(file);
417 	stopclock();
418 	if (amount > 0)
419 		printstats("Received", amount);
420 }
421 
422 static int
423 makerequest(request, name, tp, mode, filesize)
424 	int request;
425 	const char *name;
426 	struct tftphdr *tp;
427 	const char *mode;
428 	off_t filesize;
429 {
430 	char *cp;
431 
432 	tp->th_opcode = htons((u_short)request);
433 #ifndef __SVR4
434 	cp = tp->th_stuff;
435 #else
436 	cp = (void *)&tp->th_stuff;
437 #endif
438 	strcpy(cp, name);
439 	cp += strlen(name);
440 	*cp++ = '\0';
441 	strcpy(cp, mode);
442 	cp += strlen(mode);
443 	*cp++ = '\0';
444 	if (tsize) {
445 		strcpy(cp, "tsize");
446 		cp += strlen(cp);
447 		*cp++ = '\0';
448 		sprintf(cp, "%lu", (unsigned long) filesize);
449 		cp += strlen(cp);
450 		*cp++ = '\0';
451 	}
452 	if (tout) {
453 		strcpy(cp, "timeout");
454 		cp += strlen(cp);
455 		*cp++ = '\0';
456 		sprintf(cp, "%d", rexmtval);
457 		cp += strlen(cp);
458 		*cp++ = '\0';
459 	}
460 	if (blksize != SEGSIZE) {
461 		strcpy(cp, "blksize");
462 		cp += strlen(cp);
463 		*cp++ = '\0';
464 		sprintf(cp, "%d", blksize);
465 		cp += strlen(cp);
466 		*cp++ = '\0';
467 	}
468 	return (cp - (char *)tp);
469 }
470 
471 const struct errmsg {
472 	int	e_code;
473 	const char *e_msg;
474 } errmsgs[] = {
475 	{ EUNDEF,	"Undefined error code" },
476 	{ ENOTFOUND,	"File not found" },
477 	{ EACCESS,	"Access violation" },
478 	{ ENOSPACE,	"Disk full or allocation exceeded" },
479 	{ EBADOP,	"Illegal TFTP operation" },
480 	{ EBADID,	"Unknown transfer ID" },
481 	{ EEXISTS,	"File already exists" },
482 	{ ENOUSER,	"No such user" },
483 	{ EOPTNEG,	"Option negotiation failed" },
484 	{ -1,		0 }
485 };
486 
487 /*
488  * Send a nak packet (error message).
489  * Error code passed in is one of the
490  * standard TFTP codes, or a UNIX errno
491  * offset by 100.
492  */
493 static void
494 nak(error, peer)
495 	int error;
496 	struct sockaddr *peer;
497 {
498 	const struct errmsg *pe;
499 	struct tftphdr *tp;
500 	int length;
501 	size_t msglen;
502 
503 	tp = (struct tftphdr *)ackbuf;
504 	tp->th_opcode = htons((u_short)ERROR);
505 	msglen = sizeof(ackbuf) - (&tp->th_msg[0] - ackbuf);
506 	for (pe = errmsgs; pe->e_code >= 0; pe++)
507 		if (pe->e_code == error)
508 			break;
509 	if (pe->e_code < 0) {
510 		tp->th_code = EUNDEF;
511 		strlcpy(tp->th_msg, strerror(error - 100), msglen);
512 	} else {
513 		tp->th_code = htons((u_short)error);
514 		strlcpy(tp->th_msg, pe->e_msg, msglen);
515 	}
516 	length = strlen(tp->th_msg);
517 	msglen = &tp->th_msg[length + 1] - ackbuf;
518 	if (trace)
519 		tpacket("sent", tp, (int)msglen);
520 	if (sendto(f, ackbuf, msglen, 0, peer, peer->sa_len) != msglen)
521 		warn("nak");
522 }
523 
524 static void
525 tpacket(s, tp, n)
526 	const char *s;
527 	struct tftphdr *tp;
528 	int n;
529 {
530 	static const char *opcodes[] =
531 	   { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR", "OACK" };
532 	char *cp, *file, *endp, *opt = NULL;
533 	const char *spc;
534 	u_short op = ntohs(tp->th_opcode);
535 	int i, o;
536 
537 	if (op < RRQ || op > OACK)
538 		printf("%s opcode=%x ", s, op);
539 	else
540 		printf("%s %s ", s, opcodes[op]);
541 	switch (op) {
542 
543 	case RRQ:
544 	case WRQ:
545 		n -= 2;
546 #ifndef __SVR4
547 		cp = tp->th_stuff;
548 #else
549 		cp = (void *) &tp->th_stuff;
550 #endif
551 		endp = cp + n - 1;
552 		if (*endp != '\0') {	/* Shouldn't happen, but... */
553 			*endp = '\0';
554 		}
555 		file = cp;
556 		cp = strchr(cp, '\0') + 1;
557 		printf("<file=%s, mode=%s", file, cp);
558 		cp = strchr(cp, '\0') + 1;
559 		o = 0;
560 		while (cp < endp) {
561 			i = strlen(cp) + 1;
562 			if (o) {
563 				printf(", %s=%s", opt, cp);
564 			} else {
565 				opt = cp;
566 			}
567 			o = (o+1) % 2;
568 			cp += i;
569 		}
570 		printf(">\n");
571 		break;
572 
573 	case DATA:
574 		printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
575 		break;
576 
577 	case ACK:
578 		printf("<block=%d>\n", ntohs(tp->th_block));
579 		break;
580 
581 	case ERROR:
582 		printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
583 		break;
584 
585 	case OACK:
586 		o = 0;
587 		n -= 2;
588 		cp = tp->th_stuff;
589 		endp = cp + n - 1;
590 		if (*endp != '\0') {	/* Shouldn't happen, but... */
591 			*endp = '\0';
592 		}
593 		printf("<");
594 		spc = "";
595 		while (cp < endp) {
596 			i = strlen(cp) + 1;
597 			if (o) {
598 				printf("%s%s=%s", spc, opt, cp);
599 				spc = ", ";
600 			} else {
601 				opt = cp;
602 			}
603 			o = (o+1) % 2;
604 			cp += i;
605 		}
606 		printf(">\n");
607 		break;
608 	}
609 }
610 
611 struct timeval tstart;
612 struct timeval tstop;
613 
614 static void
615 startclock()
616 {
617 
618 	(void)gettimeofday(&tstart, NULL);
619 }
620 
621 static void
622 stopclock()
623 {
624 
625 	(void)gettimeofday(&tstop, NULL);
626 }
627 
628 static void
629 printstats(direction, amount)
630 	const char *direction;
631 	unsigned long amount;
632 {
633 	double delta;
634 
635 	/* compute delta in 1/10's second units */
636 	delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
637 		((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
638 	delta = delta/10.;      /* back to seconds */
639 	printf("%s %ld bytes in %.1f seconds", direction, amount, delta);
640 	if (verbose)
641 		printf(" [%.0f bits/sec]", (amount*8.)/delta);
642 	putchar('\n');
643 }
644 
645 static void
646 timer(sig)
647 	int sig;
648 {
649 
650 	timeout += rexmtval;
651 	if (timeout >= maxtimeout) {
652 		printf("Transfer timed out.\n");
653 		longjmp(toplevel, -1);
654 	}
655 	longjmp(timeoutbuf, 1);
656 }
657 
658 static int
659 cmpport(sa, sb)
660 	struct sockaddr *sa;
661 	struct sockaddr *sb;
662 {
663 	char a[NI_MAXSERV], b[NI_MAXSERV];
664 
665 	if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
666 		return 0;
667 	if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
668 		return 0;
669 	if (strcmp(a, b) != 0)
670 		return 0;
671 
672 	return 1;
673 }
674