xref: /dragonfly/usr.bin/tftp/tftp.c (revision 984263bc)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
37 #endif
38 static const char rcsid[] =
39   "$FreeBSD: src/usr.bin/tftp/tftp.c,v 1.5.2.3 2002/05/14 22:08:07 bsd Exp $";
40 #endif /* not lint */
41 
42 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
43 
44 /*
45  * TFTP User Program -- Protocol Machines
46  */
47 #include <sys/types.h>
48 #include <sys/socket.h>
49 #include <sys/time.h>
50 
51 #include <netinet/in.h>
52 
53 #include <arpa/tftp.h>
54 
55 #include <err.h>
56 #include <errno.h>
57 #include <setjmp.h>
58 #include <signal.h>
59 #include <stdio.h>
60 #include <string.h>
61 #include <unistd.h>
62 #include <netdb.h>
63 
64 #include "extern.h"
65 #include "tftpsubs.h"
66 
67 extern  struct sockaddr_storage peeraddr; /* filled in by main */
68 extern  int     f;			/* the opened socket */
69 extern  int     trace;
70 extern  int     verbose;
71 extern  int     rexmtval;
72 extern  int     maxtimeout;
73 extern  volatile int txrx_error;
74 
75 #define PKTSIZE    SEGSIZE+4
76 char    ackbuf[PKTSIZE];
77 int	timeout;
78 jmp_buf	toplevel;
79 jmp_buf	timeoutbuf;
80 
81 static void nak __P((int, struct sockaddr *));
82 static int makerequest __P((int, const char *, struct tftphdr *, const char *));
83 static void printstats __P((const char *, unsigned long));
84 static void startclock __P((void));
85 static void stopclock __P((void));
86 static void timer __P((int));
87 static void tpacket __P((const char *, struct tftphdr *, int));
88 static int cmpport __P((struct sockaddr *, struct sockaddr *));
89 
90 /*
91  * Send the requested file.
92  */
93 void
94 xmitfile(fd, name, mode)
95 	int fd;
96 	char *name;
97 	char *mode;
98 {
99 	register struct tftphdr *ap;	   /* data and ack packets */
100 	struct tftphdr *r_init(), *dp;
101 	register int n;
102 	volatile unsigned short block;
103 	volatile int size, convert;
104 	volatile unsigned long amount;
105 	struct sockaddr_storage from;
106 	int fromlen;
107 	FILE *file;
108 	struct sockaddr_storage peer;
109 	struct sockaddr_storage serv;	/* valid server port number */
110 
111 	startclock();		/* start stat's clock */
112 	dp = r_init();		/* reset fillbuf/read-ahead code */
113 	ap = (struct tftphdr *)ackbuf;
114 	file = fdopen(fd, "r");
115 	convert = !strcmp(mode, "netascii");
116 	block = 0;
117 	amount = 0;
118 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
119 	memset(&serv, 0, sizeof(serv));
120 
121 	signal(SIGALRM, timer);
122 	do {
123 		if (block == 0)
124 			size = makerequest(WRQ, name, dp, mode) - 4;
125 		else {
126 		/*	size = read(fd, dp->th_data, SEGSIZE);	 */
127 			size = readit(file, &dp, convert);
128 			if (size < 0) {
129 				nak(errno + 100, (struct sockaddr *)&peer);
130 				break;
131 			}
132 			dp->th_opcode = htons((u_short)DATA);
133 			dp->th_block = htons((u_short)block);
134 		}
135 		timeout = 0;
136 		(void) setjmp(timeoutbuf);
137 send_data:
138 		if (trace)
139 			tpacket("sent", dp, size + 4);
140 		n = sendto(f, dp, size + 4, 0,
141 		    (struct sockaddr *)&peer, peer.ss_len);
142 		if (n != size + 4) {
143 			warn("sendto");
144 			goto abort;
145 		}
146 		read_ahead(file, convert);
147 		for ( ; ; ) {
148 			alarm(rexmtval);
149 			do {
150 				fromlen = sizeof(from);
151 				n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
152 				    (struct sockaddr *)&from, &fromlen);
153 			} while (n <= 0);
154 			alarm(0);
155 			if (n < 0) {
156 				warn("recvfrom");
157 				goto abort;
158 			}
159 			if (!serv.ss_family)
160 				serv = from;
161 			else if (!cmpport((struct sockaddr *)&serv,
162 			    (struct sockaddr *)&from)) {
163 				warn("server port mismatch");
164 				goto abort;
165 			}
166 			peer = from;
167 			if (trace)
168 				tpacket("received", ap, n);
169 			/* should verify packet came from server */
170 			ap->th_opcode = ntohs(ap->th_opcode);
171 			ap->th_block = ntohs(ap->th_block);
172 			if (ap->th_opcode == ERROR) {
173 				printf("Error code %d: %s\n", ap->th_code,
174 					ap->th_msg);
175 				txrx_error = 1;
176 				goto abort;
177 			}
178 			if (ap->th_opcode == ACK) {
179 				int j;
180 
181 				if (ap->th_block == block) {
182 					break;
183 				}
184 				/* On an error, try to synchronize
185 				 * both sides.
186 				 */
187 				j = synchnet(f);
188 				if (j && trace) {
189 					printf("discarded %d packets\n",
190 							j);
191 				}
192 				if (ap->th_block == (block-1)) {
193 					goto send_data;
194 				}
195 			}
196 		}
197 		if (block > 0)
198 			amount += size;
199 		block++;
200 	} while (size == SEGSIZE || block == 1);
201 abort:
202 	fclose(file);
203 	stopclock();
204 	if (amount > 0)
205 		printstats("Sent", amount);
206 }
207 
208 /*
209  * Receive a file.
210  */
211 void
212 recvfile(fd, name, mode)
213 	int fd;
214 	char *name;
215 	char *mode;
216 {
217 	register struct tftphdr *ap;
218 	struct tftphdr *dp, *w_init();
219 	register int n;
220 	volatile unsigned short block;
221 	volatile int size, firsttrip;
222 	volatile unsigned long amount;
223 	struct sockaddr_storage from;
224 	int fromlen;
225 	FILE *file;
226 	volatile int convert;		/* true if converting crlf -> lf */
227 	struct sockaddr_storage peer;
228 	struct sockaddr_storage serv;	/* valid server port number */
229 
230 	startclock();
231 	dp = w_init();
232 	ap = (struct tftphdr *)ackbuf;
233 	file = fdopen(fd, "w");
234 	convert = !strcmp(mode, "netascii");
235 	block = 1;
236 	firsttrip = 1;
237 	amount = 0;
238 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
239 	memset(&serv, 0, sizeof(serv));
240 
241 	signal(SIGALRM, timer);
242 	do {
243 		if (firsttrip) {
244 			size = makerequest(RRQ, name, ap, mode);
245 			firsttrip = 0;
246 		} else {
247 			ap->th_opcode = htons((u_short)ACK);
248 			ap->th_block = htons((u_short)(block));
249 			size = 4;
250 			block++;
251 		}
252 		timeout = 0;
253 		(void) setjmp(timeoutbuf);
254 send_ack:
255 		if (trace)
256 			tpacket("sent", ap, size);
257 		if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
258 		    peer.ss_len) != size) {
259 			alarm(0);
260 			warn("sendto");
261 			goto abort;
262 		}
263 		write_behind(file, convert);
264 		for ( ; ; ) {
265 			alarm(rexmtval);
266 			do  {
267 				fromlen = sizeof(from);
268 				n = recvfrom(f, dp, PKTSIZE, 0,
269 				    (struct sockaddr *)&from, &fromlen);
270 			} while (n <= 0);
271 			alarm(0);
272 			if (n < 0) {
273 				warn("recvfrom");
274 				goto abort;
275 			}
276 			if (!serv.ss_family)
277 				serv = from;
278 			else if (!cmpport((struct sockaddr *)&serv,
279 			    (struct sockaddr *)&from)) {
280 				warn("server port mismatch");
281 				goto abort;
282 			}
283 			peer = from;
284 			if (trace)
285 				tpacket("received", dp, n);
286 			/* should verify client address */
287 			dp->th_opcode = ntohs(dp->th_opcode);
288 			dp->th_block = ntohs(dp->th_block);
289 			if (dp->th_opcode == ERROR) {
290 				printf("Error code %d: %s\n", dp->th_code,
291 					dp->th_msg);
292 				txrx_error = 1;
293 				goto abort;
294 			}
295 			if (dp->th_opcode == DATA) {
296 				int j;
297 
298 				if (dp->th_block == block) {
299 					break;		/* have next packet */
300 				}
301 				/* On an error, try to synchronize
302 				 * both sides.
303 				 */
304 				j = synchnet(f);
305 				if (j && trace) {
306 					printf("discarded %d packets\n", j);
307 				}
308 				if (dp->th_block == (block-1)) {
309 					goto send_ack;	/* resend ack */
310 				}
311 			}
312 		}
313 	/*	size = write(fd, dp->th_data, n - 4); */
314 		size = writeit(file, &dp, n - 4, convert);
315 		if (size < 0) {
316 			nak(errno + 100, (struct sockaddr *)&peer);
317 			break;
318 		}
319 		amount += size;
320 	} while (size == SEGSIZE);
321 abort:						/* ok to ack, since user */
322 	ap->th_opcode = htons((u_short)ACK);	/* has seen err msg */
323 	ap->th_block = htons((u_short)block);
324 	(void) sendto(f, ackbuf, 4, 0, (struct sockaddr *)&peer,
325 	    peer.ss_len);
326 	write_behind(file, convert);		/* flush last buffer */
327 	fclose(file);
328 	stopclock();
329 	if (amount > 0)
330 		printstats("Received", amount);
331 }
332 
333 static int
334 makerequest(request, name, tp, mode)
335 	int request;
336 	const char *name;
337 	struct tftphdr *tp;
338 	const char *mode;
339 {
340 	register char *cp;
341 
342 	tp->th_opcode = htons((u_short)request);
343 	cp = tp->th_stuff;
344 	strcpy(cp, name);
345 	cp += strlen(name);
346 	*cp++ = '\0';
347 	strcpy(cp, mode);
348 	cp += strlen(mode);
349 	*cp++ = '\0';
350 	return (cp - (char *)tp);
351 }
352 
353 struct errmsg {
354 	int	e_code;
355 	char	*e_msg;
356 } errmsgs[] = {
357 	{ EUNDEF,	"Undefined error code" },
358 	{ ENOTFOUND,	"File not found" },
359 	{ EACCESS,	"Access violation" },
360 	{ ENOSPACE,	"Disk full or allocation exceeded" },
361 	{ EBADOP,	"Illegal TFTP operation" },
362 	{ EBADID,	"Unknown transfer ID" },
363 	{ EEXISTS,	"File already exists" },
364 	{ ENOUSER,	"No such user" },
365 	{ -1,		0 }
366 };
367 
368 /*
369  * Send a nak packet (error message).
370  * Error code passed in is one of the
371  * standard TFTP codes, or a UNIX errno
372  * offset by 100.
373  */
374 static void
375 nak(error, peer)
376 	int error;
377 	struct sockaddr *peer;
378 {
379 	register struct errmsg *pe;
380 	register struct tftphdr *tp;
381 	int length;
382 	char *strerror();
383 
384 	tp = (struct tftphdr *)ackbuf;
385 	tp->th_opcode = htons((u_short)ERROR);
386 	tp->th_code = htons((u_short)error);
387 	for (pe = errmsgs; pe->e_code >= 0; pe++)
388 		if (pe->e_code == error)
389 			break;
390 	if (pe->e_code < 0) {
391 		pe->e_msg = strerror(error - 100);
392 		tp->th_code = EUNDEF;
393 	}
394 	strcpy(tp->th_msg, pe->e_msg);
395 	length = strlen(pe->e_msg) + 4;
396 	if (trace)
397 		tpacket("sent", tp, length);
398 	if (sendto(f, ackbuf, length, 0, peer, peer->sa_len) != length)
399 		warn("nak");
400 }
401 
402 static void
403 tpacket(s, tp, n)
404 	const char *s;
405 	struct tftphdr *tp;
406 	int n;
407 {
408 	static char *opcodes[] =
409 	   { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR" };
410 	register char *cp, *file;
411 	u_short op = ntohs(tp->th_opcode);
412 	char *index();
413 
414 	if (op < RRQ || op > ERROR)
415 		printf("%s opcode=%x ", s, op);
416 	else
417 		printf("%s %s ", s, opcodes[op]);
418 	switch (op) {
419 
420 	case RRQ:
421 	case WRQ:
422 		n -= 2;
423 		file = cp = tp->th_stuff;
424 		cp = index(cp, '\0');
425 		printf("<file=%s, mode=%s>\n", file, cp + 1);
426 		break;
427 
428 	case DATA:
429 		printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
430 		break;
431 
432 	case ACK:
433 		printf("<block=%d>\n", ntohs(tp->th_block));
434 		break;
435 
436 	case ERROR:
437 		printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
438 		break;
439 	}
440 }
441 
442 struct timeval tstart;
443 struct timeval tstop;
444 
445 static void
446 startclock()
447 {
448 
449 	(void)gettimeofday(&tstart, NULL);
450 }
451 
452 static void
453 stopclock()
454 {
455 
456 	(void)gettimeofday(&tstop, NULL);
457 }
458 
459 static void
460 printstats(direction, amount)
461 	const char *direction;
462 	unsigned long amount;
463 {
464 	double delta;
465 			/* compute delta in 1/10's second units */
466 	delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
467 		((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
468 	delta = delta/10.;      /* back to seconds */
469 	printf("%s %d bytes in %.1f seconds", direction, amount, delta);
470 	if (verbose)
471 		printf(" [%.0f bits/sec]", (amount*8.)/delta);
472 	putchar('\n');
473 }
474 
475 static void
476 timer(sig)
477 	int sig;
478 {
479 
480 	timeout += rexmtval;
481 	if (timeout >= maxtimeout) {
482 		printf("Transfer timed out.\n");
483 		longjmp(toplevel, -1);
484 	}
485 	txrx_error = 1;
486 	longjmp(timeoutbuf, 1);
487 }
488 
489 static int
490 cmpport(sa, sb)
491 	struct sockaddr *sa;
492 	struct sockaddr *sb;
493 {
494 	char a[NI_MAXSERV], b[NI_MAXSERV];
495 
496 	if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
497 		return 0;
498 	if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
499 		return 0;
500 	if (strcmp(a, b) != 0)
501 		return 0;
502 
503 	return 1;
504 }
505