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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)tftp.c   8.1 (Berkeley) 6/6/93
  30  * $FreeBSD: src/usr.bin/tftp/tftp.c,v 1.5.2.3 2002/05/14 22:08:07 bsd Exp $
  31  * $DragonFly: src/usr.bin/tftp/tftp.c,v 1.6 2008/10/16 01:52:33 swildner Exp $
  32  */
  33
  34 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
  35
  36 /*
  37  * TFTP User Program -- Protocol Machines
  38  */
  39 #include <sys/types.h>
  40 #include <sys/socket.h>
  41 #include <sys/time.h>
  42
  43 #include <netinet/in.h>
  44
  45 #include <arpa/tftp.h>
  46
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <setjmp.h>
  50 #include <signal.h>
  51 #include <stdio.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54 #include <netdb.h>
  55
  56 #include "extern.h"
  57 #include "tftpsubs.h"
  58
  59 extern  struct sockaddr_storage peeraddr; /* filled in by main */
  60 extern  int     f;                      /* the opened socket */
  61 extern  int     tftp_trace;
  62 extern  int     verbose;
  63 extern  int     rexmtval;
  64 extern  int     maxtimeout;
  65 extern  volatile int txrx_error;
  66
  67 #define PKTSIZE    SEGSIZE+4
  68 char    ackbuf[PKTSIZE];
  69 int     timeout;
  70 jmp_buf toplevel;
  71 jmp_buf timeoutbuf;
  72
  73 static void nak(int, struct sockaddr *);
  74 static int makerequest(int, const char *, struct tftphdr *, const char *);
  75 static void printstats(const char *, unsigned long);
  76 static void startclock(void);
  77 static void stopclock(void);
  78 static void timer(int);
  79 static void tpacket(const char *, struct tftphdr *, int);
  80 static int cmpport(struct sockaddr *, struct sockaddr *);
  81
  82 /*
  83  * Send the requested file.
  84  */
  85 void
  86 xmitfile(int fd, char *name, char *mode)
  87 {
  88         struct tftphdr *ap;             /* data and ack packets */
  89         struct tftphdr *dp;
  90         int n;
  91         volatile unsigned short block;
  92         volatile int size, convert;
  93         volatile unsigned long amount;
  94         struct sockaddr_storage from;
  95         int fromlen;
  96         FILE *file;
  97         struct sockaddr_storage peer;
  98         struct sockaddr_storage serv;   /* valid server port number */
  99
 100         startclock();           /* start stat's clock */
 101         dp = r_init();          /* reset fillbuf/read-ahead code */
 102         ap = (struct tftphdr *)ackbuf;
 103         file = fdopen(fd, "r");
 104         convert = !strcmp(mode, "netascii");
 105         block = 0;
 106         amount = 0;
 107         memcpy(&peer, &peeraddr, peeraddr.ss_len);
 108         memset(&serv, 0, sizeof(serv));
 109
 110         signal(SIGALRM, timer);
 111         do {
 112                 if (block == 0)
 113                         size = makerequest(WRQ, name, dp, mode) - 4;
 114                 else {
 115                 /*      size = read(fd, dp->th_data, SEGSIZE);   */
 116                         size = readit(file, &dp, convert);
 117                         if (size < 0) {
 118                                 nak(errno + 100, (struct sockaddr *)&peer);
 119                                 break;
 120                         }
 121                         dp->th_opcode = htons((u_short)DATA);
 122                         dp->th_block = htons((u_short)block);
 123                 }
 124                 timeout = 0;
 125                 (void) setjmp(timeoutbuf);
 126 send_data:
 127                 if (tftp_trace)
 128                         tpacket("sent", dp, size + 4);
 129                 n = sendto(f, dp, size + 4, 0,
 130                     (struct sockaddr *)&peer, peer.ss_len);
 131                 if (n != size + 4) {
 132                         warn("sendto");
 133                         goto abort;
 134                 }
 135                 read_ahead(file, convert);
 136                 for ( ; ; ) {
 137                         alarm(rexmtval);
 138                         do {
 139                                 fromlen = sizeof(from);
 140                                 n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
 141                                     (struct sockaddr *)&from, &fromlen);
 142                         } while (n <= 0);
 143                         alarm(0);
 144                         if (n < 0) {
 145                                 warn("recvfrom");
 146                                 goto abort;
 147                         }
 148                         if (!serv.ss_family)
 149                                 serv = from;
 150                         else if (!cmpport((struct sockaddr *)&serv,
 151                             (struct sockaddr *)&from)) {
 152                                 warn("server port mismatch");
 153                                 goto abort;
 154                         }
 155                         peer = from;
 156                         if (tftp_trace)
 157                                 tpacket("received", ap, n);
 158                         /* should verify packet came from server */
 159                         ap->th_opcode = ntohs(ap->th_opcode);
 160                         ap->th_block = ntohs(ap->th_block);
 161                         if (ap->th_opcode == ERROR) {
 162                                 printf("Error code %d: %s\n", ap->th_code,
 163                                         ap->th_msg);
 164                                 txrx_error = 1;
 165                                 goto abort;
 166                         }
 167                         if (ap->th_opcode == ACK) {
 168                                 int j;
 169
 170                                 if (ap->th_block == block) {
 171                                         break;
 172                                 }
 173                                 /* On an error, try to synchronize
 174                                  * both sides.
 175                                  */
 176                                 j = synchnet(f);
 177                                 if (j && tftp_trace) {
 178                                         printf("discarded %d packets\n",
 179                                                         j);
 180                                 }
 181                                 if (ap->th_block == (block-1)) {
 182                                         goto send_data;
 183                                 }
 184                         }
 185                 }
 186                 if (block > 0)
 187                         amount += size;
 188                 block++;
 189         } while (size == SEGSIZE || block == 1);
 190 abort:
 191         fclose(file);
 192         stopclock();
 193         if (amount > 0)
 194                 printstats("Sent", amount);
 195 }
 196
 197 /*
 198  * Receive a file.
 199  */
 200 void
 201 recvfile(int fd, char *name, char *mode)
 202 {
 203         struct tftphdr *ap;
 204         struct tftphdr *dp;
 205         int n;
 206         volatile unsigned short block;
 207         volatile int size, firsttrip;
 208         volatile unsigned long amount;
 209         struct sockaddr_storage from;
 210         int fromlen;
 211         FILE *file;
 212         volatile int convert;           /* true if converting crlf -> lf */
 213         struct sockaddr_storage peer;
 214         struct sockaddr_storage serv;   /* valid server port number */
 215
 216         startclock();
 217         dp = w_init();
 218         ap = (struct tftphdr *)ackbuf;
 219         file = fdopen(fd, "w");
 220         convert = !strcmp(mode, "netascii");
 221         block = 1;
 222         firsttrip = 1;
 223         amount = 0;
 224         memcpy(&peer, &peeraddr, peeraddr.ss_len);
 225         memset(&serv, 0, sizeof(serv));
 226
 227         signal(SIGALRM, timer);
 228         do {
 229                 if (firsttrip) {
 230                         size = makerequest(RRQ, name, ap, mode);
 231                         firsttrip = 0;
 232                 } else {
 233                         ap->th_opcode = htons((u_short)ACK);
 234                         ap->th_block = htons((u_short)(block));
 235                         size = 4;
 236                         block++;
 237                 }
 238                 timeout = 0;
 239                 (void) setjmp(timeoutbuf);
 240 send_ack:
 241                 if (tftp_trace)
 242                         tpacket("sent", ap, size);
 243                 if (sendto(f, ackbuf, size, 0, (struct sockaddr *)&peer,
 244                     peer.ss_len) != size) {
 245                         alarm(0);
 246                         warn("sendto");
 247                         goto abort;
 248                 }
 249                 write_behind(file, convert);
 250                 for ( ; ; ) {
 251                         alarm(rexmtval);
 252                         do  {
 253                                 fromlen = sizeof(from);
 254                                 n = recvfrom(f, dp, PKTSIZE, 0,
 255                                     (struct sockaddr *)&from, &fromlen);
 256                         } while (n <= 0);
 257                         alarm(0);
 258                         if (n < 0) {
 259                                 warn("recvfrom");
 260                                 goto abort;
 261                         }
 262                         if (!serv.ss_family)
 263                                 serv = from;
 264                         else if (!cmpport((struct sockaddr *)&serv,
 265                             (struct sockaddr *)&from)) {
 266                                 warn("server port mismatch");
 267                                 goto abort;
 268                         }
 269                         peer = from;
 270                         if (tftp_trace)
 271                                 tpacket("received", dp, n);
 272                         /* should verify client address */
 273                         dp->th_opcode = ntohs(dp->th_opcode);
 274                         dp->th_block = ntohs(dp->th_block);
 275                         if (dp->th_opcode == ERROR) {
 276                                 printf("Error code %d: %s\n", dp->th_code,
 277                                         dp->th_msg);
 278                                 txrx_error = 1;
 279                                 goto abort;
 280                         }
 281                         if (dp->th_opcode == DATA) {
 282                                 int j;
 283
 284                                 if (dp->th_block == block) {
 285                                         break;          /* have next packet */
 286                                 }
 287                                 /* On an error, try to synchronize
 288                                  * both sides.
 289                                  */
 290                                 j = synchnet(f);
 291                                 if (j && tftp_trace) {
 292                                         printf("discarded %d packets\n", j);
 293                                 }
 294                                 if (dp->th_block == (block-1)) {
 295                                         goto send_ack;  /* resend ack */
 296                                 }
 297                         }
 298                 }
 299         /*      size = write(fd, dp->th_data, n - 4); */
 300                 size = writeit(file, &dp, n - 4, convert);
 301                 if (size < 0) {
 302                         nak(errno + 100, (struct sockaddr *)&peer);
 303                         break;
 304                 }
 305                 amount += size;
 306         } while (size == SEGSIZE);
 307 abort:                                          /* ok to ack, since user */
 308         ap->th_opcode = htons((u_short)ACK);    /* has seen err msg */
 309         ap->th_block = htons((u_short)block);
 310         (void) sendto(f, ackbuf, 4, 0, (struct sockaddr *)&peer,
 311             peer.ss_len);
 312         write_behind(file, convert);            /* flush last buffer */
 313         fclose(file);
 314         stopclock();
 315         if (amount > 0)
 316                 printstats("Received", amount);
 317 }
 318
 319 static int
 320 makerequest(int request, const char *name, struct tftphdr *tp, const char *mode)
 321 {
 322         char *cp;
 323
 324         tp->th_opcode = htons((u_short)request);
 325         cp = tp->th_stuff;
 326         strcpy(cp, name);
 327         cp += strlen(name);
 328         *cp++ = '\0';
 329         strcpy(cp, mode);
 330         cp += strlen(mode);
 331         *cp++ = '\0';
 332         return (cp - (char *)tp);
 333 }
 334
 335 struct errmsg {
 336         int     e_code;
 337         const char *e_msg;
 338 } errmsgs[] = {
 339         { EUNDEF,       "Undefined error code" },
 340         { ENOTFOUND,    "File not found" },
 341         { EACCESS,      "Access violation" },
 342         { ENOSPACE,     "Disk full or allocation exceeded" },
 343         { EBADOP,       "Illegal TFTP operation" },
 344         { EBADID,       "Unknown transfer ID" },
 345         { EEXISTS,      "File already exists" },
 346         { ENOUSER,      "No such user" },
 347         { -1,           0 }
 348 };
 349
 350 /*
 351  * Send a nak packet (error message).
 352  * Error code passed in is one of the
 353  * standard TFTP codes, or a UNIX errno
 354  * offset by 100.
 355  */
 356 static void
 357 nak(int error, struct sockaddr *peer)
 358 {
 359         struct errmsg *pe;
 360         struct tftphdr *tp;
 361         int length;
 362
 363         tp = (struct tftphdr *)ackbuf;
 364         tp->th_opcode = htons((u_short)ERROR);
 365         tp->th_code = htons((u_short)error);
 366         for (pe = errmsgs; pe->e_code >= 0; pe++)
 367                 if (pe->e_code == error)
 368                         break;
 369         if (pe->e_code < 0) {
 370                 pe->e_msg = strerror(error - 100);
 371                 tp->th_code = EUNDEF;
 372         }
 373         strcpy(tp->th_msg, pe->e_msg);
 374         length = strlen(pe->e_msg) + 4;
 375         if (tftp_trace)
 376                 tpacket("sent", tp, length);
 377         if (sendto(f, ackbuf, length, 0, peer, peer->sa_len) != length)
 378                 warn("nak");
 379 }
 380
 381 static void
 382 tpacket(const char *s, struct tftphdr *tp, int n)
 383 {
 384         static const char *opcodes[] =
 385            { "#0", "RRQ", "WRQ", "DATA", "ACK", "ERROR" };
 386         char *cp, *file;
 387         u_short op = ntohs(tp->th_opcode);
 388
 389         if (op < RRQ || op > ERROR)
 390                 printf("%s opcode=%x ", s, op);
 391         else
 392                 printf("%s %s ", s, opcodes[op]);
 393         switch (op) {
 394
 395         case RRQ:
 396         case WRQ:
 397                 n -= 2;
 398                 file = cp = tp->th_stuff;
 399                 cp = strchr(cp, '\0');
 400                 printf("<file=%s, mode=%s>\n", file, cp + 1);
 401                 break;
 402
 403         case DATA:
 404                 printf("<block=%d, %d bytes>\n", ntohs(tp->th_block), n - 4);
 405                 break;
 406
 407         case ACK:
 408                 printf("<block=%d>\n", ntohs(tp->th_block));
 409                 break;
 410
 411         case ERROR:
 412                 printf("<code=%d, msg=%s>\n", ntohs(tp->th_code), tp->th_msg);
 413                 break;
 414         }
 415 }
 416
 417 struct timeval tstart;
 418 struct timeval tstop;
 419
 420 static void
 421 startclock(void)
 422 {
 423
 424         (void)gettimeofday(&tstart, NULL);
 425 }
 426
 427 static void
 428 stopclock(void)
 429 {
 430
 431         (void)gettimeofday(&tstop, NULL);
 432 }
 433
 434 static void
 435 printstats(const char *direction, unsigned long amount)
 436 {
 437         double delta;
 438                         /* compute delta in 1/10's second units */
 439         delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -
 440                 ((tstart.tv_sec*10.)+(tstart.tv_usec/100000));
 441         delta = delta/10.;      /* back to seconds */
 442         printf("%s %lu bytes in %.1f seconds", direction, amount, delta);
 443         if (verbose)
 444                 printf(" [%.0f bits/sec]", (amount*8.)/delta);
 445         putchar('\n');
 446 }
 447
 448 static void
 449 timer(int sig __unused)
 450 {
 451
 452         timeout += rexmtval;
 453         if (timeout >= maxtimeout) {
 454                 printf("Transfer timed out.\n");
 455                 longjmp(toplevel, -1);
 456         }
 457         txrx_error = 1;
 458         longjmp(timeoutbuf, 1);
 459 }
 460
 461 static int
 462 cmpport(struct sockaddr *sa, struct sockaddr *sb)
 463 {
 464         char a[NI_MAXSERV], b[NI_MAXSERV];
 465
 466         if (getnameinfo(sa, sa->sa_len, NULL, 0, a, sizeof(a), NI_NUMERICSERV))
 467                 return 0;
 468         if (getnameinfo(sb, sb->sa_len, NULL, 0, b, sizeof(b), NI_NUMERICSERV))
 469                 return 0;
 470         if (strcmp(a, b) != 0)
 471                 return 0;
 472
 473         return 1;
 474 }