usr.bin/tftp/tftp.c

   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  * @(#)tftp.c   8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/usr.bin/tftp/tftp.c,v 1.5.2.3 2002/05/14 22:08:07 bsd Exp $
  35  * $DragonFly: src/usr.bin/tftp/tftp.c,v 1.5 2004/09/03 20:38:01 dillon Exp $
  36  */
  37
  38 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
  39
  40 /*
  41  * TFTP User Program -- Protocol Machines
  42  */
  43 #include <sys/types.h>
  44 #include <sys/socket.h>
  45 #include <sys/time.h>
  46
  47 #include <netinet/in.h>
  48
  49 #include <arpa/tftp.h>
  50
  51 #include <err.h>
  52 #include <errno.h>
  53 #include <setjmp.h>
  54 #include <signal.h>
  55 #include <stdio.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58 #include <netdb.h>
  59
  60 #include "extern.h"
  61 #include "tftpsubs.h"
  62
  63 extern  struct sockaddr_storage peeraddr; /* filled in by main */
  64 extern  int     f;                      /* the opened socket */
  65 extern  int     trace;
  66 extern  int     verbose;
  67 extern  int     rexmtval;
  68 extern  int     maxtimeout;
  69 extern  volatile int txrx_error;
  70
  71 #define PKTSIZE    SEGSIZE+4
  72 char    ackbuf[PKTSIZE];
  73 int     timeout;
  74 jmp_buf toplevel;
  75 jmp_buf timeoutbuf;
  76
  77 static void nak(int, struct sockaddr *);
  78 static int makerequest(int, const char *, struct tftphdr *, const char *);
  79 static void printstats(const char *, unsigned long);
  80 static void startclock(void);
  81 static void stopclock(void);
  82 static void timer(int);
  83 static void tpacket(const char *, struct tftphdr *, int);
  84 static int cmpport(struct sockaddr *, struct sockaddr *);
  85
  86 /*
  87  * Send the requested file.
  88  */
  89 void
  90 xmitfile(int fd, char *name, char *mode)
  91 {
  92         register struct tftphdr *ap;       /* data and ack packets */
  93         struct tftphdr *r_init(), *dp;
  94         register int n;
  95         volatile unsigned short block;
  96         volatile int size, convert;
  97         volatile unsigned long amount;
  98         struct sockaddr_storage from;
  99         int fromlen;
 100         FILE *file;
 101         struct sockaddr_storage peer;
 102         struct sockaddr_storage serv;   /* valid server port number */
 103
 104         startclock();           /* start stat's clock */
 105         dp = r_init();          /* reset fillbuf/read-ahead code */
 106         ap = (struct tftphdr *)ackbuf;
 107         file = fdopen(fd, "r");
 108         convert = !strcmp(mode, "netascii");
 109         block = 0;
 110         amount = 0;
 111         memcpy(&peer, &peeraddr, peeraddr.ss_len);
 112         memset(&serv, 0, sizeof(serv));
 113
 114         signal(SIGALRM, timer);
 115         do {
 116                 if (block == 0)
 117                         size = makerequest(WRQ, name, dp, mode) - 4;
 118                 else {
 119                 /*      size = read(fd, dp->th_data, SEGSIZE);   */
 120                         size = readit(file, &dp, convert);
 121                         if (size < 0) {
 122                                 nak(errno + 100, (struct sockaddr *)&peer);
 123                                 break;
 124                         }
 125                         dp->th_opcode = htons((u_short)DATA);
 126                         dp->th_block = htons((u_short)block);
 127                 }
 128                 timeout = 0;
 129                 (void) setjmp(timeoutbuf);
 130 send_data:
 131                 if (trace)
 132                         tpacket("sent", dp, size + 4);
 133                 n = sendto(f, dp, size + 4, 0,
 134                     (struct sockaddr *)&peer, peer.ss_len);
 135                 if (n != size + 4) {
 136                         warn("sendto");
 137                         goto abort;
 138                 }
 139                 read_ahead(file, convert);
 140                 for ( ; ; ) {
 141                         alarm(rexmtval);
 142                         do {
 143                                 fromlen = sizeof(from);
 144                                 n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
 145                                     (struct sockaddr *)&from, &fromlen);
 146                         } while (n <= 0);
 147                         alarm(0);
 148                         if (n < 0) {
 149                                 warn("recvfrom");
 150                                 goto abort;
 151                         }
 152                         if (!serv.ss_family)
 153                                 serv = from;
 154                         else if (!cmpport((struct sockaddr *)&serv,
 155                             (struct sockaddr *)&from)) {
 156                                 warn("server port mismatch");
 157                                 goto abort;
 158                         }
 159                         peer = from;
 160                         if (trace)
 161                                 tpacket("received", ap, n);
 162                         /* should verify packet came from server */
 163                         ap->th_opcode = ntohs(ap->th_opcode);
 164                         ap->th_block = ntohs(ap->th_block);
 165                         if (ap->th_opcode == ERROR) {
 166                                 printf("Error code %d: %s\n", ap->th_code,
 167                                         ap->th_msg);
 168                                 txrx_error = 1;
 169                                 goto abort;
 170                         }
 171                         if (ap->th_opcode == ACK) {
 172                                 int j;
 173
 174                                 if (ap->th_block == block) {
 175                                         break;
 176                                 }
 177                                 /* On an error, try to synchronize
 178                                  * both sides.
 179                                  */
 180                                 j = synchnet(f);
 181                                 if (j && trace) {
 182                                         printf("discarded %d packets\n",
 183                                                         j);
 184                                 }
 185                                 if (ap->th_block == (block-1)) {
 186                                         goto send_data;
 187                                 }
 188                         }
 189                 }
 190                 if (block > 0)
 191                         amount += size;
 192                 block++;
 193         } while (size == SEGSIZE || block == 1);
 194 abort:
 195         fclose(file);
 196         stopclock();
 197         if (amount > 0)
 198                 printstats("Sent", amount);
 199 }
 200
 201 /*
 202  * Receive a file.
 203  */
 204 void
 205 recvfile(int fd, char *name, char *mode)
 206 {
 207         register struct tftphdr *ap;
 208         struct tftphdr *dp, *w_init();
 209         register int n;
 210         volatile unsigned short block;
 211         volatile int size, firsttrip;
 212         volatile unsigned long amount;
 213         struct sockaddr_storage from;
 214         int fromlen;
 215         FILE *file;
 216         volatile int convert;           /* true if converting crlf -> lf */
 217         struct sockaddr_storage peer;
 218         struct sockaddr_storage serv;   /* valid server port number */
 219
 220         startclock();
 221         dp = w_init();
 222         ap = (struct tftphdr *)ackbuf;
 223         file = fdopen(fd, "w");
 224         convert = !strcmp(mode, "netascii");
 225         block = 1;
 226         firsttrip = 1;
 227         amount = 0;
 228         memcpy(&peer, &peeraddr, peeraddr.ss_len);
 229         memset(&serv, 0, sizeof(serv));
 230
 231         signal(SIGALRM, timer);
 232         do {
 233                 if (firsttrip) {
 234                         size = makerequest(RRQ, name, ap, mode);
 235                         firsttrip = 0;
 236                 } else {
 237                         ap->th_opcode = htons((u_short)ACK);
 238                         ap->th_block = htons((u_short)(block));
 239                         size = 4;
 240                         block++;
 241                 }
 242                 timeout = 0;
 243                 (void) setjmp(timeoutbuf);
 244 send_ack:
 245                 if (trace)
 246                         tpacket("sent", ap, size);
 247                 if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
 248                     peer.ss_len) != size) {
 249                         alarm(0);
 250                         warn("sendto");
 251                         goto abort;
 252                 }
 253                 write_behind(file, convert);
 254                 for ( ; ; ) {
 255                         alarm(rexmtval);
 256                         do  {
 257                                 fromlen = sizeof(from);
 258                                 n = recvfrom(f, dp, PKTSIZE, 0,
 259                                     (struct sockaddr *)&from, &fromlen);
 260                         } while (n <= 0);
 261                         alarm(0);
 262                         if (n < 0) {
 263                                 warn("recvfrom");
 264                                 goto abort;
 265                         }
 266                         if (!serv.ss_family)
 267                                 serv = from;
 268                         else if (!cmpport((struct sockaddr *)&serv,
 269                             (struct sockaddr *)&from)) {
 270                                 warn("server port mismatch");
 271                                 goto abort;
 272                         }
 273                         peer = from;
 274                         if (trace)
 275                                 tpacket("received", dp, n);
 276                         /* should verify client address */
 277                         dp->th_opcode = ntohs(dp->th_opcode);
 278                         dp->th_block = ntohs(dp->th_block);
 279                         if (dp->th_opcode == ERROR) {
 280                                 printf("Error code %d: %s\n", dp->th_code,
 281                                         dp->th_msg);
 282                                 txrx_error = 1;
 283                                 goto abort;
 284                         }
 285                         if (dp->th_opcode == DATA) {
 286                                 int j;
 287
 288                                 if (dp->th_block == block) {
 289                                         break;          /* have next packet */
 290                                 }
 291                                 /* On an error, try to synchronize
 292                                  * both sides.
 293                                  */
 294                                 j = synchnet(f);
 295                                 if (j && trace) {
 296                                         printf("discarded %d packets\n", j);
 297                                 }
 298                                 if (dp->th_block == (block-1)) {
 299                                         goto send_ack;  /* resend ack */
 300                                 }
 301                         }
 302                 }
 303         /*      size = write(fd, dp->th_data, n - 4); */
 304                 size = writeit(file, &dp, n - 4, convert);
 305                 if (size < 0) {
 306                         nak(errno + 100, (struct sockaddr *)&peer);
 307                         break;
 308                 }
 309                 amount += size;
 310         } while (size == SEGSIZE);
 311 abort:                                          /* ok to ack, since user */
 312         ap->th_opcode = htons((u_short)ACK);    /* has seen err msg */
 313         ap->th_block = htons((u_short)block);
 314         (void) sendto(f, ackbuf, 4, 0, (struct sockaddr *)&peer,
 315             peer.ss_len);
 316         write_behind(file, convert);            /* flush last buffer */
 317         fclose(file);
 318         stopclock();
 319         if (amount > 0)
 320                 printstats("Received", amount);
 321 }
 322
 323 static int
 324 makerequest(int request, const char *name, struct tftphdr *tp, const char *mode)
 325 {
 326         register char *cp;
 327
 328         tp->th_opcode = htons((u_short)request);
 329         cp = tp->th_stuff;
 330         strcpy(cp, name);
 331         cp += strlen(name);
 332         *cp++ = '\0';
 333         strcpy(cp, mode);
 334         cp += strlen(mode);
 335         *cp++ = '\0';
 336         return (cp - (char *)tp);
 337 }
 338
 339 struct errmsg {
 340         int     e_code;
 341         char    *e_msg;
 342 } errmsgs[] = {
 343         { EUNDEF,       "Undefined error code" },
 344         { ENOTFOUND,    "File not found" },
 345         { EACCESS,      "Access violation" },
 346         { ENOSPACE,     "Disk full or allocation exceeded" },
 347         { EBADOP,       "Illegal TFTP operation" },
 348         { EBADID,       "Unknown transfer ID" },
 349         { EEXISTS,      "File already exists" },
 350         { ENOUSER,      "No such user" },
 351         { -1,           0 }
 352 };
 353
 354 /*
 355  * Send a nak packet (error message).
 356  * Error code passed in is one of the
 357  * standard TFTP codes, or a UNIX errno
 358  * offset by 100.
 359  */
 360 static void
 361 nak(int error, struct sockaddr *peer)
 362 {
 363         register struct errmsg *pe;
 364         register struct tftphdr *tp;
 365         int length;
 366         char *strerror();
 367
 368         tp = (struct tftphdr *)ackbuf;
 369         tp->th_opcode = htons((u_short)ERROR);
 370         tp->th_code = htons((u_short)error);
 371         for (pe = errmsgs; pe->e_code >= 0; pe++)
 372                 if (pe->e_code == error)
 373                         break;
 374         if (pe->e_code < 0) {
 375                 pe->e_msg = strerror(error - 100);
 376                 tp->th_code = EUNDEF;
 377         }
 378         strcpy(tp->th_msg, pe->e_msg);
 379         length = strlen(pe->e_msg) + 4;
 380         if (trace)
 381                 tpacket("sent", tp, length);
 382         if (sendto(f, ackbuf, length, 0, peer, peer->sa_len) != length)
 383                 warn("nak");
 384 }
 385
 386 static void
 387 tpacket(const char *s, struct tftphdr *tp, int n)
 388 {
 389         static char *opcodes[] =
 390            { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR" };
 391         register char *cp, *file;
 392         u_short op = ntohs(tp->th_opcode);
 393
 394         if (op < RRQ || op > ERROR)
 395                 printf("%s opcode=%x ", s, op);
 396         else
 397                 printf("%s %s ", s, opcodes[op]);
 398         switch (op) {
 399
 400         case RRQ:
 401         case WRQ:
 402                 n -= 2;
 403                 file = cp = tp->th_stuff;
 404                 cp = strchr(cp, '\0');
 405                 printf("<file=%s, mode=%s>\n", file, cp + 1);
 406                 break;
 407
 408         case DATA:
 409                 printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
 410                 break;
 411
 412         case ACK:
 413                 printf("<block=%d>\n", ntohs(tp->th_block));
 414                 break;
 415
 416         case ERROR:
 417                 printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
 418                 break;
 419         }
 420 }
 421
 422 struct timeval tstart;
 423 struct timeval tstop;
 424
 425 static void
 426 startclock(void)
 427 {
 428
 429         (void)gettimeofday(&tstart, NULL);
 430 }
 431
 432 static void
 433 stopclock(void)
 434 {
 435
 436         (void)gettimeofday(&tstop, NULL);
 437 }
 438
 439 static void
 440 printstats(const char *direction, unsigned long amount)
 441 {
 442         double delta;
 443                         /* compute delta in 1/10's second units */
 444         delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
 445                 ((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
 446         delta = delta/10.;      /* back to seconds */
 447         printf("%s %d bytes in %.1f seconds", direction, amount, delta);
 448         if (verbose)
 449                 printf(" [%.0f bits/sec]", (amount*8.)/delta);
 450         putchar('\n');
 451 }
 452
 453 static void
 454 timer(int sig)
 455 {
 456
 457         timeout += rexmtval;
 458         if (timeout >= maxtimeout) {
 459                 printf("Transfer timed out.\n");
 460                 longjmp(toplevel, -1);
 461         }
 462         txrx_error = 1;
 463         longjmp(timeoutbuf, 1);
 464 }
 465
 466 static int
 467 cmpport(struct sockaddr *sa, struct sockaddr *sb)
 468 {
 469         char a[NI_MAXSERV], b[NI_MAXSERV];
 470
 471         if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
 472                 return 0;
 473         if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
 474                 return 0;
 475         if (strcmp(a, b) != 0)
 476                 return 0;
 477
 478         return 1;
 479 }