xref: /freebsd/usr.bin/tftp/tftp.c (revision 830940567b49bb0c08dfaed40418999e76616909)
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 #if 0
35 #ifndef lint
36 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
37 #endif /* not lint */
38 #endif
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
44 
45 /*
46  * TFTP User Program -- Protocol Machines
47  */
48 #include <sys/types.h>
49 #include <sys/socket.h>
50 #include <sys/time.h>
51 
52 #include <netinet/in.h>
53 
54 #include <arpa/inet.h>
55 #include <arpa/tftp.h>
56 
57 #include <err.h>
58 #include <errno.h>
59 #include <setjmp.h>
60 #include <signal.h>
61 #include <stdio.h>
62 #include <string.h>
63 #include <unistd.h>
64 #include <netdb.h>
65 
66 #include "extern.h"
67 #include "tftpsubs.h"
68 
69 extern  struct sockaddr_storage peeraddr; /* filled in by main */
70 extern  int     f;			/* the opened socket */
71 extern  int     trace;
72 extern  int     verbose;
73 extern  int     rexmtval;
74 extern  int     maxtimeout;
75 extern  volatile int txrx_error;
76 
77 #define PKTSIZE    SEGSIZE+4
78 char    ackbuf[PKTSIZE];
79 int	timeout;
80 jmp_buf	toplevel;
81 jmp_buf	timeoutbuf;
82 
83 static void nak(int, const struct sockaddr *);
84 static int makerequest(int, const char *, struct tftphdr *, const char *);
85 static void printstats(const char *, unsigned long);
86 static void startclock(void);
87 static void stopclock(void);
88 static void timer(int);
89 static void tpacket(const char *, struct tftphdr *, int);
90 static int cmpport(const struct sockaddr *, const struct sockaddr *);
91 
92 /*
93  * Send the requested file.
94  */
95 void
96 xmitfile(int fd, const char *name, const char *mode)
97 {
98 	struct tftphdr *ap;	   /* data and ack packets */
99 	struct tftphdr *dp;
100 	int n;
101 	volatile unsigned short block;
102 	volatile int size, convert;
103 	volatile unsigned long amount;
104 	struct sockaddr_storage from;
105 	socklen_t fromlen;
106 	FILE *file;
107 	struct sockaddr_storage peer;
108 	struct sockaddr_storage serv;	/* valid server port number */
109 
110 	startclock();		/* start stat's clock */
111 	dp = r_init();		/* reset fillbuf/read-ahead code */
112 	ap = (struct tftphdr *)ackbuf;
113 	file = fdopen(fd, "r");
114 	convert = !strcmp(mode, "netascii");
115 	block = 0;
116 	amount = 0;
117 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
118 	memset(&serv, 0, sizeof(serv));
119 
120 	signal(SIGALRM, timer);
121 	do {
122 		if (block == 0)
123 			size = makerequest(WRQ, name, dp, mode) - 4;
124 		else {
125 		/*	size = read(fd, dp->th_data, SEGSIZE);	 */
126 			size = readit(file, &dp, convert);
127 			if (size < 0) {
128 				nak(errno + 100, (struct sockaddr *)&peer);
129 				break;
130 			}
131 			dp->th_opcode = htons((u_short)DATA);
132 			dp->th_block = htons((u_short)block);
133 		}
134 		timeout = 0;
135 		(void) setjmp(timeoutbuf);
136 send_data:
137 		if (trace)
138 			tpacket("sent", dp, size + 4);
139 		n = sendto(f, dp, size + 4, 0,
140 		    (struct sockaddr *)&peer, peer.ss_len);
141 		if (n != size + 4) {
142 			warn("sendto");
143 			goto abort;
144 		}
145 		read_ahead(file, convert);
146 		for ( ; ; ) {
147 			alarm(rexmtval);
148 			do {
149 				fromlen = sizeof(from);
150 				n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
151 				    (struct sockaddr *)&from, &fromlen);
152 			} while (n <= 0);
153 			alarm(0);
154 			if (n < 0) {
155 				warn("recvfrom");
156 				goto abort;
157 			}
158 			if (!serv.ss_family)
159 				serv = from;
160 			else if (!cmpport((struct sockaddr *)&serv,
161 			    (struct sockaddr *)&from)) {
162 				warn("server port mismatch");
163 				goto abort;
164 			}
165 			peer = from;
166 			if (trace)
167 				tpacket("received", ap, n);
168 			/* should verify packet came from server */
169 			ap->th_opcode = ntohs(ap->th_opcode);
170 			ap->th_block = ntohs(ap->th_block);
171 			if (ap->th_opcode == ERROR) {
172 				printf("Error code %d: %s\n", ap->th_code,
173 					ap->th_msg);
174 				txrx_error = 1;
175 				goto abort;
176 			}
177 			if (ap->th_opcode == ACK) {
178 				int j;
179 
180 				if (ap->th_block == block) {
181 					break;
182 				}
183 				/* On an error, try to synchronize
184 				 * both sides.
185 				 */
186 				j = synchnet(f);
187 				if (j && trace) {
188 					printf("discarded %d packets\n",
189 							j);
190 				}
191 				if (ap->th_block == (block-1)) {
192 					goto send_data;
193 				}
194 			}
195 		}
196 		if (block > 0)
197 			amount += size;
198 		block++;
199 	} while (size == SEGSIZE || block == 1);
200 abort:
201 	fclose(file);
202 	stopclock();
203 	if (amount > 0)
204 		printstats("Sent", amount);
205 	txrx_error = 1;
206 }
207 
208 /*
209  * Receive a file.
210  */
211 void
212 recvfile(int fd, const char *name, const char *mode)
213 {
214 	struct tftphdr *ap;
215 	struct tftphdr *dp;
216 	int n;
217 	volatile unsigned short block;
218 	volatile int size, firsttrip;
219 	volatile unsigned long amount;
220 	struct sockaddr_storage from;
221 	socklen_t fromlen;
222 	FILE *file;
223 	volatile int convert;		/* true if converting crlf -> lf */
224 	struct sockaddr_storage peer;
225 	struct sockaddr_storage serv;	/* valid server port number */
226 
227 	startclock();
228 	dp = w_init();
229 	ap = (struct tftphdr *)ackbuf;
230 	file = fdopen(fd, "w");
231 	convert = !strcmp(mode, "netascii");
232 	block = 1;
233 	firsttrip = 1;
234 	amount = 0;
235 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
236 	memset(&serv, 0, sizeof(serv));
237 
238 	signal(SIGALRM, timer);
239 	do {
240 		if (firsttrip) {
241 			size = makerequest(RRQ, name, ap, mode);
242 			firsttrip = 0;
243 		} else {
244 			ap->th_opcode = htons((u_short)ACK);
245 			ap->th_block = htons((u_short)(block));
246 			size = 4;
247 			block++;
248 		}
249 		timeout = 0;
250 		(void) setjmp(timeoutbuf);
251 send_ack:
252 		if (trace)
253 			tpacket("sent", ap, size);
254 		if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
255 		    peer.ss_len) != size) {
256 			alarm(0);
257 			warn("sendto");
258 			goto abort;
259 		}
260 		write_behind(file, convert);
261 		for ( ; ; ) {
262 			alarm(rexmtval);
263 			do  {
264 				fromlen = sizeof(from);
265 				n = recvfrom(f, dp, PKTSIZE, 0,
266 				    (struct sockaddr *)&from, &fromlen);
267 			} while (n <= 0);
268 			alarm(0);
269 			if (n < 0) {
270 				warn("recvfrom");
271 				goto abort;
272 			}
273 			if (!serv.ss_family)
274 				serv = from;
275 			else if (!cmpport((struct sockaddr *)&serv,
276 			    (struct sockaddr *)&from)) {
277 				warn("server port mismatch");
278 				goto abort;
279 			}
280 			peer = from;
281 			if (trace)
282 				tpacket("received", dp, n);
283 			/* should verify client address */
284 			dp->th_opcode = ntohs(dp->th_opcode);
285 			dp->th_block = ntohs(dp->th_block);
286 			if (dp->th_opcode == ERROR) {
287 				printf("Error code %d: %s\n", dp->th_code,
288 					dp->th_msg);
289 				txrx_error = 1;
290 				goto abort;
291 			}
292 			if (dp->th_opcode == DATA) {
293 				int j;
294 
295 				if (dp->th_block == block) {
296 					break;		/* have next packet */
297 				}
298 				/* On an error, try to synchronize
299 				 * both sides.
300 				 */
301 				j = synchnet(f);
302 				if (j && trace) {
303 					printf("discarded %d packets\n", j);
304 				}
305 				if (dp->th_block == (block-1)) {
306 					goto send_ack;	/* resend ack */
307 				}
308 			}
309 		}
310 	/*	size = write(fd, dp->th_data, n - 4); */
311 		size = writeit(file, &dp, n - 4, convert);
312 		if (size < 0) {
313 			nak(errno + 100, (struct sockaddr *)&peer);
314 			break;
315 		}
316 		amount += size;
317 	} while (size == SEGSIZE);
318 abort:						/* ok to ack, since user */
319 	ap->th_opcode = htons((u_short)ACK);	/* has seen err msg */
320 	ap->th_block = htons((u_short)block);
321 	(void) sendto(f, ackbuf, 4, 0, (struct sockaddr *)&peer,
322 	    peer.ss_len);
323 	write_behind(file, convert);		/* flush last buffer */
324 	fclose(file);
325 	stopclock();
326 	if (amount > 0)
327 		printstats("Received", amount);
328 	txrx_error = 1;
329 }
330 
331 static int
332 makerequest(int request, const char *name, struct tftphdr *tp, const char *mode)
333 {
334 	char *cp;
335 
336 	tp->th_opcode = htons((u_short)request);
337 	cp = tp->th_stuff;
338 	strcpy(cp, name);
339 	cp += strlen(name);
340 	*cp++ = '\0';
341 	strcpy(cp, mode);
342 	cp += strlen(mode);
343 	*cp++ = '\0';
344 	return (cp - (char *)tp);
345 }
346 
347 struct errmsg {
348 	int	e_code;
349 	const char	*e_msg;
350 } errmsgs[] = {
351 	{ EUNDEF,	"Undefined error code" },
352 	{ ENOTFOUND,	"File not found" },
353 	{ EACCESS,	"Access violation" },
354 	{ ENOSPACE,	"Disk full or allocation exceeded" },
355 	{ EBADOP,	"Illegal TFTP operation" },
356 	{ EBADID,	"Unknown transfer ID" },
357 	{ EEXISTS,	"File already exists" },
358 	{ ENOUSER,	"No such user" },
359 	{ -1,		0 }
360 };
361 
362 /*
363  * Send a nak packet (error message).
364  * Error code passed in is one of the
365  * standard TFTP codes, or a UNIX errno
366  * offset by 100.
367  */
368 static void
369 nak(int error, const struct sockaddr *peer)
370 {
371 	struct errmsg *pe;
372 	struct tftphdr *tp;
373 	int length;
374 
375 	tp = (struct tftphdr *)ackbuf;
376 	tp->th_opcode = htons((u_short)ERROR);
377 	tp->th_code = htons((u_short)error);
378 	for (pe = errmsgs; pe->e_code >= 0; pe++)
379 		if (pe->e_code == error)
380 			break;
381 	if (pe->e_code < 0) {
382 		pe->e_msg = strerror(error - 100);
383 		tp->th_code = EUNDEF;
384 	}
385 	strcpy(tp->th_msg, pe->e_msg);
386 	length = strlen(pe->e_msg) + 4;
387 	if (trace)
388 		tpacket("sent", tp, length);
389 	if (sendto(f, ackbuf, length, 0, peer, peer->sa_len) != length)
390 		warn("nak");
391 }
392 
393 static void
394 tpacket(const char *s, struct tftphdr *tp, int n)
395 {
396 	static const char *opcodes[] =
397 	   { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR" };
398 	char *cp, *file;
399 	u_short op = ntohs(tp->th_opcode);
400 
401 	if (op < RRQ || op > ERROR)
402 		printf("%s opcode=%x ", s, op);
403 	else
404 		printf("%s %s ", s, opcodes[op]);
405 	switch (op) {
406 
407 	case RRQ:
408 	case WRQ:
409 		n -= 2;
410 		file = cp = tp->th_stuff;
411 		cp = index(cp, '\0');
412 		printf("<file=%s, mode=%s>\n", file, cp + 1);
413 		break;
414 
415 	case DATA:
416 		printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
417 		break;
418 
419 	case ACK:
420 		printf("<block=%d>\n", ntohs(tp->th_block));
421 		break;
422 
423 	case ERROR:
424 		printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
425 		break;
426 	}
427 }
428 
429 struct timeval tstart;
430 struct timeval tstop;
431 
432 static void
433 startclock(void)
434 {
435 
436 	(void)gettimeofday(&tstart, NULL);
437 }
438 
439 static void
440 stopclock(void)
441 {
442 
443 	(void)gettimeofday(&tstop, NULL);
444 }
445 
446 static void
447 printstats(const char *direction, unsigned long amount)
448 {
449 	double delta;
450 			/* compute delta in 1/10's second units */
451 	delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
452 		((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
453 	delta = delta/10.;      /* back to seconds */
454 	printf("%s %ld bytes in %.1f seconds", direction, amount, delta);
455 	if (verbose)
456 		printf(" [%.0f bits/sec]", (amount*8.)/delta);
457 	putchar('\n');
458 }
459 
460 static void
461 timer(int sig __unused)
462 {
463 
464 	timeout += rexmtval;
465 	if (timeout >= maxtimeout) {
466 		printf("Transfer timed out.\n");
467 		longjmp(toplevel, -1);
468 	}
469         txrx_error = 1;
470 	longjmp(timeoutbuf, 1);
471 }
472 
473 static int
474 cmpport(const struct sockaddr *sa, const struct sockaddr *sb)
475 {
476 	char a[NI_MAXSERV], b[NI_MAXSERV];
477 
478 	if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
479 		return 0;
480 	if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
481 		return 0;
482 	if (strcmp(a, b) != 0)
483 		return 0;
484 
485 	return 1;
486 }
487