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tftp.c revision 1.16
      1 /*	$NetBSD: tftp.c,v 1.16 2003/02/01 16:42:31 wiz 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
     40 #else
     41 __RCSID("$NetBSD: tftp.c,v 1.16 2003/02/01 16:42:31 wiz Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
     46 
     47 /*
     48  * TFTP User Program -- Protocol Machines
     49  */
     50 #include <sys/types.h>
     51 #include <sys/socket.h>
     52 #include <sys/time.h>
     53 
     54 #include <netinet/in.h>
     55 
     56 #include <arpa/tftp.h>
     57 
     58 #include <err.h>
     59 #include <errno.h>
     60 #include <setjmp.h>
     61 #include <signal.h>
     62 #include <stdio.h>
     63 #include <string.h>
     64 #include <unistd.h>
     65 #include <netdb.h>
     66 
     67 #include "extern.h"
     68 #include "tftpsubs.h"
     69 
     70 extern  struct sockaddr_storage peeraddr; /* filled in by main */
     71 extern  int     f;			/* the opened socket */
     72 extern  int     trace;
     73 extern  int     verbose;
     74 extern  int     rexmtval;
     75 extern  int     maxtimeout;
     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 __P((int, struct sockaddr *));
     84 static int makerequest __P((int, const char *, struct tftphdr *, const char *));
     85 static void printstats __P((const char *, unsigned long));
     86 static void startclock __P((void));
     87 static void stopclock __P((void));
     88 static void timer __P((int));
     89 static void tpacket __P((const char *, struct tftphdr *, int));
     90 static int cmpport __P((struct sockaddr *, struct sockaddr *));
     91 
     92 /*
     93  * Send the requested file.
     94  */
     95 void
     96 sendfile(fd, name, mode)
     97 	int fd;
     98 	char *name;
     99 	char *mode;
    100 {
    101 	struct tftphdr *ap;	   /* data and ack packets */
    102 	struct tftphdr *dp;
    103 	int n;
    104 	volatile unsigned int block;
    105 	volatile int size, convert;
    106 	volatile unsigned long amount;
    107 	struct sockaddr_storage from;
    108 	int fromlen;
    109 	FILE *file;
    110 	struct sockaddr_storage peer;
    111 	struct sockaddr_storage serv;	/* valid server port number */
    112 
    113 	startclock();		/* start stat's clock */
    114 	dp = r_init();		/* reset fillbuf/read-ahead code */
    115 	ap = (struct tftphdr *)ackbuf;
    116 	file = fdopen(fd, "r");
    117 	convert = !strcmp(mode, "netascii");
    118 	block = 0;
    119 	amount = 0;
    120 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
    121 	memset(&serv, 0, sizeof(serv));
    122 
    123 	signal(SIGALRM, timer);
    124 	do {
    125 		if (block == 0)
    126 			size = makerequest(WRQ, name, dp, mode) - 4;
    127 		else {
    128 		/*	size = read(fd, dp->th_data, SEGSIZE);	 */
    129 			size = readit(file, &dp, convert);
    130 			if (size < 0) {
    131 				nak(errno + 100, (struct sockaddr *)&peer);
    132 				break;
    133 			}
    134 			dp->th_opcode = htons((u_short)DATA);
    135 			dp->th_block = htons((u_short)block);
    136 		}
    137 		timeout = 0;
    138 		(void) setjmp(timeoutbuf);
    139 send_data:
    140 		if (trace)
    141 			tpacket("sent", dp, size + 4);
    142 		n = sendto(f, dp, size + 4, 0,
    143 		    (struct sockaddr *)&peer, peer.ss_len);
    144 		if (n != size + 4) {
    145 			warn("sendto");
    146 			goto abort;
    147 		}
    148 		read_ahead(file, convert);
    149 		for ( ; ; ) {
    150 			alarm(rexmtval);
    151 			do {
    152 				fromlen = sizeof(from);
    153 				n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
    154 				    (struct sockaddr *)&from, &fromlen);
    155 			} while (n <= 0);
    156 			alarm(0);
    157 			if (n < 0) {
    158 				warn("recvfrom");
    159 				goto abort;
    160 			}
    161 			if (!serv.ss_family)
    162 				serv = from;
    163 			else if (!cmpport((struct sockaddr *)&serv,
    164 			    (struct sockaddr *)&from)) {
    165 				warn("server port mismatch");
    166 				goto abort;
    167 			}
    168 			peer = from;
    169 			if (trace)
    170 				tpacket("received", ap, n);
    171 			/* should verify packet came from server */
    172 			ap->th_opcode = ntohs(ap->th_opcode);
    173 			ap->th_block = ntohs(ap->th_block);
    174 			if (ap->th_opcode == ERROR) {
    175 				printf("Error code %d: %s\n", ap->th_code,
    176 					ap->th_msg);
    177 				goto abort;
    178 			}
    179 			if (ap->th_opcode == ACK) {
    180 				int j;
    181 
    182 				if (ap->th_block == block) {
    183 					break;
    184 				}
    185 				/* On an error, try to synchronize
    186 				 * both sides.
    187 				 */
    188 				j = synchnet(f);
    189 				if (j && trace) {
    190 					printf("discarded %d packets\n",
    191 							j);
    192 				}
    193 				if (ap->th_block == (block-1)) {
    194 					goto send_data;
    195 				}
    196 			}
    197 		}
    198 		if (block > 0)
    199 			amount += size;
    200 		block++;
    201 	} while (size == SEGSIZE || block == 1);
    202 abort:
    203 	fclose(file);
    204 	stopclock();
    205 	if (amount > 0)
    206 		printstats("Sent", amount);
    207 }
    208 
    209 /*
    210  * Receive a file.
    211  */
    212 void
    213 recvfile(fd, name, mode)
    214 	int fd;
    215 	char *name;
    216 	char *mode;
    217 {
    218 	struct tftphdr *ap;
    219 	struct tftphdr *dp;
    220 	int n;
    221 	volatile unsigned int block;
    222 	volatile int size, firsttrip;
    223 	volatile unsigned long amount;
    224 	struct sockaddr_storage from;
    225 	int fromlen;
    226 	FILE *file;
    227 	volatile int convert;		/* true if converting crlf -> lf */
    228 	struct sockaddr_storage peer;
    229 	struct sockaddr_storage serv;	/* valid server port number */
    230 
    231 	startclock();
    232 	dp = w_init();
    233 	ap = (struct tftphdr *)ackbuf;
    234 	file = fdopen(fd, "w");
    235 	convert = !strcmp(mode, "netascii");
    236 	block = 1;
    237 	firsttrip = 1;
    238 	amount = 0;
    239 	memcpy(&peer, &peeraddr, peeraddr.ss_len);
    240 	memset(&serv, 0, sizeof(serv));
    241 
    242 	signal(SIGALRM, timer);
    243 	do {
    244 		if (firsttrip) {
    245 			size = makerequest(RRQ, name, ap, mode);
    246 			firsttrip = 0;
    247 		} else {
    248 			ap->th_opcode = htons((u_short)ACK);
    249 			ap->th_block = htons((u_short)(block));
    250 			size = 4;
    251 			block++;
    252 		}
    253 		timeout = 0;
    254 		(void) setjmp(timeoutbuf);
    255 send_ack:
    256 		if (trace)
    257 			tpacket("sent", ap, size);
    258 		if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
    259 		    peer.ss_len) != size) {
    260 			alarm(0);
    261 			warn("sendto");
    262 			goto abort;
    263 		}
    264 		write_behind(file, convert);
    265 		for ( ; ; ) {
    266 			alarm(rexmtval);
    267 			do  {
    268 				fromlen = sizeof(from);
    269 				n = recvfrom(f, dp, PKTSIZE, 0,
    270 				    (struct sockaddr *)&from, &fromlen);
    271 			} while (n <= 0);
    272 			alarm(0);
    273 			if (n < 0) {
    274 				warn("recvfrom");
    275 				goto abort;
    276 			}
    277 			if (!serv.ss_family)
    278 				serv = from;
    279 			else if (!cmpport((struct sockaddr *)&serv,
    280 			    (struct sockaddr *)&from)) {
    281 				warn("server port mismatch");
    282 				goto abort;
    283 			}
    284 			peer = from;
    285 			if (trace)
    286 				tpacket("received", dp, n);
    287 			/* should verify client address */
    288 			dp->th_opcode = ntohs(dp->th_opcode);
    289 			dp->th_block = ntohs(dp->th_block);
    290 			if (dp->th_opcode == ERROR) {
    291 				printf("Error code %d: %s\n", dp->th_code,
    292 					dp->th_msg);
    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 	char *cp;
    341 
    342 	tp->th_opcode = htons((u_short)request);
    343 #ifndef __SVR4
    344 	cp = tp->th_stuff;
    345 #else
    346 	cp = (void *)&tp->th_stuff;
    347 #endif
    348 	strcpy(cp, name);
    349 	cp += strlen(name);
    350 	*cp++ = '\0';
    351 	strcpy(cp, mode);
    352 	cp += strlen(mode);
    353 	*cp++ = '\0';
    354 	return (cp - (char *)tp);
    355 }
    356 
    357 const struct errmsg {
    358 	int	e_code;
    359 	const char *e_msg;
    360 } errmsgs[] = {
    361 	{ EUNDEF,	"Undefined error code" },
    362 	{ ENOTFOUND,	"File not found" },
    363 	{ EACCESS,	"Access violation" },
    364 	{ ENOSPACE,	"Disk full or allocation exceeded" },
    365 	{ EBADOP,	"Illegal TFTP operation" },
    366 	{ EBADID,	"Unknown transfer ID" },
    367 	{ EEXISTS,	"File already exists" },
    368 	{ ENOUSER,	"No such user" },
    369 	{ -1,		0 }
    370 };
    371 
    372 /*
    373  * Send a nak packet (error message).
    374  * Error code passed in is one of the
    375  * standard TFTP codes, or a UNIX errno
    376  * offset by 100.
    377  */
    378 static void
    379 nak(error, peer)
    380 	int error;
    381 	struct sockaddr *peer;
    382 {
    383 	const struct errmsg *pe;
    384 	struct tftphdr *tp;
    385 	int length;
    386 	size_t msglen;
    387 
    388 	tp = (struct tftphdr *)ackbuf;
    389 	tp->th_opcode = htons((u_short)ERROR);
    390 	msglen = sizeof(ackbuf) - (&tp->th_msg[0] - ackbuf);
    391 	for (pe = errmsgs; pe->e_code >= 0; pe++)
    392 		if (pe->e_code == error)
    393 			break;
    394 	if (pe->e_code < 0) {
    395 		tp->th_code = EUNDEF;
    396 		strlcpy(tp->th_msg, strerror(error - 100), msglen);
    397 	} else {
    398 		tp->th_code = htons((u_short)error);
    399 		strlcpy(tp->th_msg, pe->e_msg, msglen);
    400 	}
    401 	length = strlen(tp->th_msg);
    402 	msglen = &tp->th_msg[length + 1] - ackbuf;
    403 	if (trace)
    404 		tpacket("sent", tp, (int)msglen);
    405 	if (sendto(f, ackbuf, msglen, 0, peer, peer->sa_len) != msglen)
    406 		warn("nak");
    407 }
    408 
    409 static void
    410 tpacket(s, tp, n)
    411 	const char *s;
    412 	struct tftphdr *tp;
    413 	int n;
    414 {
    415 	static char *opcodes[] =
    416 	   { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR" };
    417 	char *cp, *file;
    418 	u_short op = ntohs(tp->th_opcode);
    419 
    420 	if (op < RRQ || op > ERROR)
    421 		printf("%s opcode=%x ", s, op);
    422 	else
    423 		printf("%s %s ", s, opcodes[op]);
    424 	switch (op) {
    425 
    426 	case RRQ:
    427 	case WRQ:
    428 		n -= 2;
    429 #ifndef __SVR4
    430 		cp = tp->th_stuff;
    431 #else
    432 		cp = (void *) &tp->th_stuff;
    433 #endif
    434 		file = cp;
    435 		cp = strchr(cp, '\0');
    436 		printf("<file=%s, mode=%s>\n", file, cp + 1);
    437 		break;
    438 
    439 	case DATA:
    440 		printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
    441 		break;
    442 
    443 	case ACK:
    444 		printf("<block=%d>\n", ntohs(tp->th_block));
    445 		break;
    446 
    447 	case ERROR:
    448 		printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
    449 		break;
    450 	}
    451 }
    452 
    453 struct timeval tstart;
    454 struct timeval tstop;
    455 
    456 static void
    457 startclock()
    458 {
    459 
    460 	(void)gettimeofday(&tstart, NULL);
    461 }
    462 
    463 static void
    464 stopclock()
    465 {
    466 
    467 	(void)gettimeofday(&tstop, NULL);
    468 }
    469 
    470 static void
    471 printstats(direction, amount)
    472 	const char *direction;
    473 	unsigned long amount;
    474 {
    475 	double delta;
    476 
    477 	/* compute delta in 1/10's second units */
    478 	delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
    479 		((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
    480 	delta = delta/10.;      /* back to seconds */
    481 	printf("%s %ld bytes in %.1f seconds", direction, amount, delta);
    482 	if (verbose)
    483 		printf(" [%.0f bits/sec]", (amount*8.)/delta);
    484 	putchar('\n');
    485 }
    486 
    487 static void
    488 timer(sig)
    489 	int sig;
    490 {
    491 
    492 	timeout += rexmtval;
    493 	if (timeout >= maxtimeout) {
    494 		printf("Transfer timed out.\n");
    495 		longjmp(toplevel, -1);
    496 	}
    497 	longjmp(timeoutbuf, 1);
    498 }
    499 
    500 static int
    501 cmpport(sa, sb)
    502 	struct sockaddr *sa;
    503 	struct sockaddr *sb;
    504 {
    505 	char a[NI_MAXSERV], b[NI_MAXSERV];
    506 
    507 	if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
    508 		return 0;
    509 	if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
    510 		return 0;
    511 	if (strcmp(a, b) != 0)
    512 		return 0;
    513 
    514 	return 1;
    515 }
    516