1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23 #include "curl_setup.h"
24
25 #ifndef CURL_DISABLE_TFTP
26
27 #ifdef HAVE_NETINET_IN_H
28 #include <netinet/in.h>
29 #endif
30 #ifdef HAVE_NETDB_H
31 #include <netdb.h>
32 #endif
33 #ifdef HAVE_ARPA_INET_H
34 #include <arpa/inet.h>
35 #endif
36 #ifdef HAVE_NET_IF_H
37 #include <net/if.h>
38 #endif
39 #ifdef HAVE_SYS_IOCTL_H
40 #include <sys/ioctl.h>
41 #endif
42
43 #ifdef HAVE_SYS_PARAM_H
44 #include <sys/param.h>
45 #endif
46
47 #include "urldata.h"
48 #include <curl/curl.h>
49 #include "transfer.h"
50 #include "sendf.h"
51 #include "tftp.h"
52 #include "progress.h"
53 #include "connect.h"
54 #include "strerror.h"
55 #include "sockaddr.h" /* required for Curl_sockaddr_storage */
56 #include "multiif.h"
57 #include "url.h"
58 #include "rawstr.h"
59 #include "speedcheck.h"
60 #include "curl_printf.h"
61 #include "select.h"
62
63 /* The last #include files should be: */
64 #include "curl_memory.h"
65 #include "memdebug.h"
66
67 /* RFC2348 allows the block size to be negotiated */
68 #define TFTP_BLKSIZE_DEFAULT 512
69 #define TFTP_BLKSIZE_MIN 8
70 #define TFTP_BLKSIZE_MAX 65464
71 #define TFTP_OPTION_BLKSIZE "blksize"
72
73 /* from RFC2349: */
74 #define TFTP_OPTION_TSIZE "tsize"
75 #define TFTP_OPTION_INTERVAL "timeout"
76
77 typedef enum {
78 TFTP_MODE_NETASCII=0,
79 TFTP_MODE_OCTET
80 } tftp_mode_t;
81
82 typedef enum {
83 TFTP_STATE_START=0,
84 TFTP_STATE_RX,
85 TFTP_STATE_TX,
86 TFTP_STATE_FIN
87 } tftp_state_t;
88
89 typedef enum {
90 TFTP_EVENT_NONE = -1,
91 TFTP_EVENT_INIT = 0,
92 TFTP_EVENT_RRQ = 1,
93 TFTP_EVENT_WRQ = 2,
94 TFTP_EVENT_DATA = 3,
95 TFTP_EVENT_ACK = 4,
96 TFTP_EVENT_ERROR = 5,
97 TFTP_EVENT_OACK = 6,
98 TFTP_EVENT_TIMEOUT
99 } tftp_event_t;
100
101 typedef enum {
102 TFTP_ERR_UNDEF=0,
103 TFTP_ERR_NOTFOUND,
104 TFTP_ERR_PERM,
105 TFTP_ERR_DISKFULL,
106 TFTP_ERR_ILLEGAL,
107 TFTP_ERR_UNKNOWNID,
108 TFTP_ERR_EXISTS,
109 TFTP_ERR_NOSUCHUSER, /* This will never be triggered by this code */
110
111 /* The remaining error codes are internal to curl */
112 TFTP_ERR_NONE = -100,
113 TFTP_ERR_TIMEOUT,
114 TFTP_ERR_NORESPONSE
115 } tftp_error_t;
116
117 typedef struct tftp_packet {
118 unsigned char *data;
119 } tftp_packet_t;
120
121 typedef struct tftp_state_data {
122 tftp_state_t state;
123 tftp_mode_t mode;
124 tftp_error_t error;
125 tftp_event_t event;
126 struct connectdata *conn;
127 curl_socket_t sockfd;
128 int retries;
129 int retry_time;
130 int retry_max;
131 time_t start_time;
132 time_t max_time;
133 time_t rx_time;
134 unsigned short block;
135 struct Curl_sockaddr_storage local_addr;
136 struct Curl_sockaddr_storage remote_addr;
137 curl_socklen_t remote_addrlen;
138 int rbytes;
139 int sbytes;
140 int blksize;
141 int requested_blksize;
142 tftp_packet_t rpacket;
143 tftp_packet_t spacket;
144 } tftp_state_data_t;
145
146
147 /* Forward declarations */
148 static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event);
149 static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event);
150 static CURLcode tftp_connect(struct connectdata *conn, bool *done);
151 static CURLcode tftp_disconnect(struct connectdata *conn,
152 bool dead_connection);
153 static CURLcode tftp_do(struct connectdata *conn, bool *done);
154 static CURLcode tftp_done(struct connectdata *conn,
155 CURLcode, bool premature);
156 static CURLcode tftp_setup_connection(struct connectdata * conn);
157 static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done);
158 static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done);
159 static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks,
160 int numsocks);
161 static CURLcode tftp_translate_code(tftp_error_t error);
162
163
164 /*
165 * TFTP protocol handler.
166 */
167
168 const struct Curl_handler Curl_handler_tftp = {
169 "TFTP", /* scheme */
170 tftp_setup_connection, /* setup_connection */
171 tftp_do, /* do_it */
172 tftp_done, /* done */
173 ZERO_NULL, /* do_more */
174 tftp_connect, /* connect_it */
175 tftp_multi_statemach, /* connecting */
176 tftp_doing, /* doing */
177 tftp_getsock, /* proto_getsock */
178 tftp_getsock, /* doing_getsock */
179 ZERO_NULL, /* domore_getsock */
180 ZERO_NULL, /* perform_getsock */
181 tftp_disconnect, /* disconnect */
182 ZERO_NULL, /* readwrite */
183 PORT_TFTP, /* defport */
184 CURLPROTO_TFTP, /* protocol */
185 PROTOPT_NONE | PROTOPT_NOURLQUERY /* flags */
186 };
187
188 /**********************************************************
189 *
190 * tftp_set_timeouts -
191 *
192 * Set timeouts based on state machine state.
193 * Use user provided connect timeouts until DATA or ACK
194 * packet is received, then use user-provided transfer timeouts
195 *
196 *
197 **********************************************************/
tftp_set_timeouts(tftp_state_data_t * state)198 static CURLcode tftp_set_timeouts(tftp_state_data_t *state)
199 {
200 time_t maxtime, timeout;
201 long timeout_ms;
202 bool start = (state->state == TFTP_STATE_START) ? TRUE : FALSE;
203
204 time(&state->start_time);
205
206 /* Compute drop-dead time */
207 timeout_ms = Curl_timeleft(state->conn->data, NULL, start);
208
209 if(timeout_ms < 0) {
210 /* time-out, bail out, go home */
211 failf(state->conn->data, "Connection time-out");
212 return CURLE_OPERATION_TIMEDOUT;
213 }
214
215 if(start) {
216
217 maxtime = (time_t)(timeout_ms + 500) / 1000;
218 state->max_time = state->start_time+maxtime;
219
220 /* Set per-block timeout to total */
221 timeout = maxtime;
222
223 /* Average restart after 5 seconds */
224 state->retry_max = (int)timeout/5;
225
226 if(state->retry_max < 1)
227 /* avoid division by zero below */
228 state->retry_max = 1;
229
230 /* Compute the re-start interval to suit the timeout */
231 state->retry_time = (int)timeout/state->retry_max;
232 if(state->retry_time<1)
233 state->retry_time=1;
234
235 }
236 else {
237 if(timeout_ms > 0)
238 maxtime = (time_t)(timeout_ms + 500) / 1000;
239 else
240 maxtime = 3600;
241
242 state->max_time = state->start_time+maxtime;
243
244 /* Set per-block timeout to total */
245 timeout = maxtime;
246
247 /* Average reposting an ACK after 5 seconds */
248 state->retry_max = (int)timeout/5;
249 }
250 /* But bound the total number */
251 if(state->retry_max<3)
252 state->retry_max=3;
253
254 if(state->retry_max>50)
255 state->retry_max=50;
256
257 /* Compute the re-ACK interval to suit the timeout */
258 state->retry_time = (int)(timeout/state->retry_max);
259 if(state->retry_time<1)
260 state->retry_time=1;
261
262 infof(state->conn->data,
263 "set timeouts for state %d; Total %ld, retry %d maxtry %d\n",
264 (int)state->state, (long)(state->max_time-state->start_time),
265 state->retry_time, state->retry_max);
266
267 /* init RX time */
268 time(&state->rx_time);
269
270 return CURLE_OK;
271 }
272
273 /**********************************************************
274 *
275 * tftp_set_send_first
276 *
277 * Event handler for the START state
278 *
279 **********************************************************/
280
setpacketevent(tftp_packet_t * packet,unsigned short num)281 static void setpacketevent(tftp_packet_t *packet, unsigned short num)
282 {
283 packet->data[0] = (unsigned char)(num >> 8);
284 packet->data[1] = (unsigned char)(num & 0xff);
285 }
286
287
setpacketblock(tftp_packet_t * packet,unsigned short num)288 static void setpacketblock(tftp_packet_t *packet, unsigned short num)
289 {
290 packet->data[2] = (unsigned char)(num >> 8);
291 packet->data[3] = (unsigned char)(num & 0xff);
292 }
293
getrpacketevent(const tftp_packet_t * packet)294 static unsigned short getrpacketevent(const tftp_packet_t *packet)
295 {
296 return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
297 }
298
getrpacketblock(const tftp_packet_t * packet)299 static unsigned short getrpacketblock(const tftp_packet_t *packet)
300 {
301 return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
302 }
303
Curl_strnlen(const char * string,size_t maxlen)304 static size_t Curl_strnlen(const char *string, size_t maxlen)
305 {
306 const char *end = memchr (string, '\0', maxlen);
307 return end ? (size_t) (end - string) : maxlen;
308 }
309
tftp_option_get(const char * buf,size_t len,const char ** option,const char ** value)310 static const char *tftp_option_get(const char *buf, size_t len,
311 const char **option, const char **value)
312 {
313 size_t loc;
314
315 loc = Curl_strnlen( buf, len );
316 loc++; /* NULL term */
317
318 if(loc >= len)
319 return NULL;
320 *option = buf;
321
322 loc += Curl_strnlen( buf+loc, len-loc );
323 loc++; /* NULL term */
324
325 if(loc > len)
326 return NULL;
327 *value = &buf[strlen(*option) + 1];
328
329 return &buf[loc];
330 }
331
tftp_parse_option_ack(tftp_state_data_t * state,const char * ptr,int len)332 static CURLcode tftp_parse_option_ack(tftp_state_data_t *state,
333 const char *ptr, int len)
334 {
335 const char *tmp = ptr;
336 struct SessionHandle *data = state->conn->data;
337
338 /* if OACK doesn't contain blksize option, the default (512) must be used */
339 state->blksize = TFTP_BLKSIZE_DEFAULT;
340
341 while(tmp < ptr + len) {
342 const char *option, *value;
343
344 tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
345 if(tmp == NULL) {
346 failf(data, "Malformed ACK packet, rejecting");
347 return CURLE_TFTP_ILLEGAL;
348 }
349
350 infof(data, "got option=(%s) value=(%s)\n", option, value);
351
352 if(checkprefix(option, TFTP_OPTION_BLKSIZE)) {
353 long blksize;
354
355 blksize = strtol( value, NULL, 10 );
356
357 if(!blksize) {
358 failf(data, "invalid blocksize value in OACK packet");
359 return CURLE_TFTP_ILLEGAL;
360 }
361 else if(blksize > TFTP_BLKSIZE_MAX) {
362 failf(data, "%s (%d)", "blksize is larger than max supported",
363 TFTP_BLKSIZE_MAX);
364 return CURLE_TFTP_ILLEGAL;
365 }
366 else if(blksize < TFTP_BLKSIZE_MIN) {
367 failf(data, "%s (%d)", "blksize is smaller than min supported",
368 TFTP_BLKSIZE_MIN);
369 return CURLE_TFTP_ILLEGAL;
370 }
371 else if(blksize > state->requested_blksize) {
372 /* could realloc pkt buffers here, but the spec doesn't call out
373 * support for the server requesting a bigger blksize than the client
374 * requests */
375 failf(data, "%s (%ld)",
376 "server requested blksize larger than allocated", blksize);
377 return CURLE_TFTP_ILLEGAL;
378 }
379
380 state->blksize = (int)blksize;
381 infof(data, "%s (%d) %s (%d)\n", "blksize parsed from OACK",
382 state->blksize, "requested", state->requested_blksize);
383 }
384 else if(checkprefix(option, TFTP_OPTION_TSIZE)) {
385 long tsize = 0;
386
387 tsize = strtol( value, NULL, 10 );
388 infof(data, "%s (%ld)\n", "tsize parsed from OACK", tsize);
389
390 /* tsize should be ignored on upload: Who cares about the size of the
391 remote file? */
392 if(!data->set.upload) {
393 if(!tsize) {
394 failf(data, "invalid tsize -:%s:- value in OACK packet", value);
395 return CURLE_TFTP_ILLEGAL;
396 }
397 Curl_pgrsSetDownloadSize(data, tsize);
398 }
399 }
400 }
401
402 return CURLE_OK;
403 }
404
tftp_option_add(tftp_state_data_t * state,size_t csize,char * buf,const char * option)405 static size_t tftp_option_add(tftp_state_data_t *state, size_t csize,
406 char *buf, const char *option)
407 {
408 if(( strlen(option) + csize + 1 ) > (size_t)state->blksize)
409 return 0;
410 strcpy(buf, option);
411 return strlen(option) + 1;
412 }
413
tftp_connect_for_tx(tftp_state_data_t * state,tftp_event_t event)414 static CURLcode tftp_connect_for_tx(tftp_state_data_t *state,
415 tftp_event_t event)
416 {
417 CURLcode result;
418 #ifndef CURL_DISABLE_VERBOSE_STRINGS
419 struct SessionHandle *data = state->conn->data;
420
421 infof(data, "%s\n", "Connected for transmit");
422 #endif
423 state->state = TFTP_STATE_TX;
424 result = tftp_set_timeouts(state);
425 if(result)
426 return result;
427 return tftp_tx(state, event);
428 }
429
tftp_connect_for_rx(tftp_state_data_t * state,tftp_event_t event)430 static CURLcode tftp_connect_for_rx(tftp_state_data_t *state,
431 tftp_event_t event)
432 {
433 CURLcode result;
434 #ifndef CURL_DISABLE_VERBOSE_STRINGS
435 struct SessionHandle *data = state->conn->data;
436
437 infof(data, "%s\n", "Connected for receive");
438 #endif
439 state->state = TFTP_STATE_RX;
440 result = tftp_set_timeouts(state);
441 if(result)
442 return result;
443 return tftp_rx(state, event);
444 }
445
tftp_send_first(tftp_state_data_t * state,tftp_event_t event)446 static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
447 {
448 size_t sbytes;
449 ssize_t senddata;
450 const char *mode = "octet";
451 char *filename;
452 char buf[64];
453 struct SessionHandle *data = state->conn->data;
454 CURLcode result = CURLE_OK;
455
456 /* Set ascii mode if -B flag was used */
457 if(data->set.prefer_ascii)
458 mode = "netascii";
459
460 switch(event) {
461
462 case TFTP_EVENT_INIT: /* Send the first packet out */
463 case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
464 /* Increment the retry counter, quit if over the limit */
465 state->retries++;
466 if(state->retries>state->retry_max) {
467 state->error = TFTP_ERR_NORESPONSE;
468 state->state = TFTP_STATE_FIN;
469 return result;
470 }
471
472 if(data->set.upload) {
473 /* If we are uploading, send an WRQ */
474 setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
475 state->conn->data->req.upload_fromhere =
476 (char *)state->spacket.data+4;
477 if(data->state.infilesize != -1)
478 Curl_pgrsSetUploadSize(data, data->state.infilesize);
479 }
480 else {
481 /* If we are downloading, send an RRQ */
482 setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
483 }
484 /* As RFC3617 describes the separator slash is not actually part of the
485 file name so we skip the always-present first letter of the path
486 string. */
487 filename = curl_easy_unescape(data, &state->conn->data->state.path[1], 0,
488 NULL);
489 if(!filename)
490 return CURLE_OUT_OF_MEMORY;
491
492 snprintf((char *)state->spacket.data+2,
493 state->blksize,
494 "%s%c%s%c", filename, '\0', mode, '\0');
495 sbytes = 4 + strlen(filename) + strlen(mode);
496
497 /* add tsize option */
498 if(data->set.upload && (data->state.infilesize != -1))
499 snprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
500 data->state.infilesize);
501 else
502 strcpy(buf, "0"); /* the destination is large enough */
503
504 sbytes += tftp_option_add(state, sbytes,
505 (char *)state->spacket.data+sbytes,
506 TFTP_OPTION_TSIZE);
507 sbytes += tftp_option_add(state, sbytes,
508 (char *)state->spacket.data+sbytes, buf);
509 /* add blksize option */
510 snprintf( buf, sizeof(buf), "%d", state->requested_blksize );
511 sbytes += tftp_option_add(state, sbytes,
512 (char *)state->spacket.data+sbytes,
513 TFTP_OPTION_BLKSIZE);
514 sbytes += tftp_option_add(state, sbytes,
515 (char *)state->spacket.data+sbytes, buf );
516
517 /* add timeout option */
518 snprintf( buf, sizeof(buf), "%d", state->retry_time);
519 sbytes += tftp_option_add(state, sbytes,
520 (char *)state->spacket.data+sbytes,
521 TFTP_OPTION_INTERVAL);
522 sbytes += tftp_option_add(state, sbytes,
523 (char *)state->spacket.data+sbytes, buf );
524
525 /* the typecase for the 3rd argument is mostly for systems that do
526 not have a size_t argument, like older unixes that want an 'int' */
527 senddata = sendto(state->sockfd, (void *)state->spacket.data,
528 (SEND_TYPE_ARG3)sbytes, 0,
529 state->conn->ip_addr->ai_addr,
530 state->conn->ip_addr->ai_addrlen);
531 if(senddata != (ssize_t)sbytes) {
532 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
533 }
534 free(filename);
535 break;
536
537 case TFTP_EVENT_OACK:
538 if(data->set.upload) {
539 result = tftp_connect_for_tx(state, event);
540 }
541 else {
542 result = tftp_connect_for_rx(state, event);
543 }
544 break;
545
546 case TFTP_EVENT_ACK: /* Connected for transmit */
547 result = tftp_connect_for_tx(state, event);
548 break;
549
550 case TFTP_EVENT_DATA: /* Connected for receive */
551 result = tftp_connect_for_rx(state, event);
552 break;
553
554 case TFTP_EVENT_ERROR:
555 state->state = TFTP_STATE_FIN;
556 break;
557
558 default:
559 failf(state->conn->data, "tftp_send_first: internal error");
560 break;
561 }
562
563 return result;
564 }
565
566 /* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
567 boundary */
568 #define NEXT_BLOCKNUM(x) (((x)+1)&0xffff)
569
570 /**********************************************************
571 *
572 * tftp_rx
573 *
574 * Event handler for the RX state
575 *
576 **********************************************************/
tftp_rx(tftp_state_data_t * state,tftp_event_t event)577 static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
578 {
579 ssize_t sbytes;
580 int rblock;
581 struct SessionHandle *data = state->conn->data;
582
583 switch(event) {
584
585 case TFTP_EVENT_DATA:
586 /* Is this the block we expect? */
587 rblock = getrpacketblock(&state->rpacket);
588 if(NEXT_BLOCKNUM(state->block) == rblock) {
589 /* This is the expected block. Reset counters and ACK it. */
590 state->retries = 0;
591 }
592 else if(state->block == rblock) {
593 /* This is the last recently received block again. Log it and ACK it
594 again. */
595 infof(data, "Received last DATA packet block %d again.\n", rblock);
596 }
597 else {
598 /* totally unexpected, just log it */
599 infof(data,
600 "Received unexpected DATA packet block %d, expecting block %d\n",
601 rblock, NEXT_BLOCKNUM(state->block));
602 break;
603 }
604
605 /* ACK this block. */
606 state->block = (unsigned short)rblock;
607 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
608 setpacketblock(&state->spacket, state->block);
609 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
610 4, SEND_4TH_ARG,
611 (struct sockaddr *)&state->remote_addr,
612 state->remote_addrlen);
613 if(sbytes < 0) {
614 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
615 return CURLE_SEND_ERROR;
616 }
617
618 /* Check if completed (That is, a less than full packet is received) */
619 if(state->rbytes < (ssize_t)state->blksize+4) {
620 state->state = TFTP_STATE_FIN;
621 }
622 else {
623 state->state = TFTP_STATE_RX;
624 }
625 time(&state->rx_time);
626 break;
627
628 case TFTP_EVENT_OACK:
629 /* ACK option acknowledgement so we can move on to data */
630 state->block = 0;
631 state->retries = 0;
632 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
633 setpacketblock(&state->spacket, state->block);
634 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
635 4, SEND_4TH_ARG,
636 (struct sockaddr *)&state->remote_addr,
637 state->remote_addrlen);
638 if(sbytes < 0) {
639 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
640 return CURLE_SEND_ERROR;
641 }
642
643 /* we're ready to RX data */
644 state->state = TFTP_STATE_RX;
645 time(&state->rx_time);
646 break;
647
648 case TFTP_EVENT_TIMEOUT:
649 /* Increment the retry count and fail if over the limit */
650 state->retries++;
651 infof(data,
652 "Timeout waiting for block %d ACK. Retries = %d\n",
653 NEXT_BLOCKNUM(state->block), state->retries);
654 if(state->retries > state->retry_max) {
655 state->error = TFTP_ERR_TIMEOUT;
656 state->state = TFTP_STATE_FIN;
657 }
658 else {
659 /* Resend the previous ACK */
660 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
661 4, SEND_4TH_ARG,
662 (struct sockaddr *)&state->remote_addr,
663 state->remote_addrlen);
664 if(sbytes<0) {
665 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
666 return CURLE_SEND_ERROR;
667 }
668 }
669 break;
670
671 case TFTP_EVENT_ERROR:
672 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
673 setpacketblock(&state->spacket, state->block);
674 (void)sendto(state->sockfd, (void *)state->spacket.data,
675 4, SEND_4TH_ARG,
676 (struct sockaddr *)&state->remote_addr,
677 state->remote_addrlen);
678 /* don't bother with the return code, but if the socket is still up we
679 * should be a good TFTP client and let the server know we're done */
680 state->state = TFTP_STATE_FIN;
681 break;
682
683 default:
684 failf(data, "%s", "tftp_rx: internal error");
685 return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
686 this */
687 }
688 return CURLE_OK;
689 }
690
691 /**********************************************************
692 *
693 * tftp_tx
694 *
695 * Event handler for the TX state
696 *
697 **********************************************************/
tftp_tx(tftp_state_data_t * state,tftp_event_t event)698 static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
699 {
700 struct SessionHandle *data = state->conn->data;
701 ssize_t sbytes;
702 int rblock;
703 CURLcode result = CURLE_OK;
704 struct SingleRequest *k = &data->req;
705
706 switch(event) {
707
708 case TFTP_EVENT_ACK:
709 case TFTP_EVENT_OACK:
710 if(event == TFTP_EVENT_ACK) {
711 /* Ack the packet */
712 rblock = getrpacketblock(&state->rpacket);
713
714 if(rblock != state->block &&
715 /* There's a bug in tftpd-hpa that causes it to send us an ack for
716 * 65535 when the block number wraps to 0. So when we're expecting
717 * 0, also accept 65535. See
718 * http://syslinux.zytor.com/archives/2010-September/015253.html
719 * */
720 !(state->block == 0 && rblock == 65535)) {
721 /* This isn't the expected block. Log it and up the retry counter */
722 infof(data, "Received ACK for block %d, expecting %d\n",
723 rblock, state->block);
724 state->retries++;
725 /* Bail out if over the maximum */
726 if(state->retries>state->retry_max) {
727 failf(data, "tftp_tx: giving up waiting for block %d ack",
728 state->block);
729 result = CURLE_SEND_ERROR;
730 }
731 else {
732 /* Re-send the data packet */
733 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
734 4+state->sbytes, SEND_4TH_ARG,
735 (struct sockaddr *)&state->remote_addr,
736 state->remote_addrlen);
737 /* Check all sbytes were sent */
738 if(sbytes<0) {
739 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
740 result = CURLE_SEND_ERROR;
741 }
742 }
743
744 return result;
745 }
746 /* This is the expected packet. Reset the counters and send the next
747 block */
748 time(&state->rx_time);
749 state->block++;
750 }
751 else
752 state->block = 1; /* first data block is 1 when using OACK */
753
754 state->retries = 0;
755 setpacketevent(&state->spacket, TFTP_EVENT_DATA);
756 setpacketblock(&state->spacket, state->block);
757 if(state->block > 1 && state->sbytes < (int)state->blksize) {
758 state->state = TFTP_STATE_FIN;
759 return CURLE_OK;
760 }
761
762 result = Curl_fillreadbuffer(state->conn, state->blksize, &state->sbytes);
763 if(result)
764 return result;
765
766 sbytes = sendto(state->sockfd, (void *) state->spacket.data,
767 4 + state->sbytes, SEND_4TH_ARG,
768 (struct sockaddr *)&state->remote_addr,
769 state->remote_addrlen);
770 /* Check all sbytes were sent */
771 if(sbytes<0) {
772 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
773 return CURLE_SEND_ERROR;
774 }
775 /* Update the progress meter */
776 k->writebytecount += state->sbytes;
777 Curl_pgrsSetUploadCounter(data, k->writebytecount);
778 break;
779
780 case TFTP_EVENT_TIMEOUT:
781 /* Increment the retry counter and log the timeout */
782 state->retries++;
783 infof(data, "Timeout waiting for block %d ACK. "
784 " Retries = %d\n", NEXT_BLOCKNUM(state->block), state->retries);
785 /* Decide if we've had enough */
786 if(state->retries > state->retry_max) {
787 state->error = TFTP_ERR_TIMEOUT;
788 state->state = TFTP_STATE_FIN;
789 }
790 else {
791 /* Re-send the data packet */
792 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
793 4+state->sbytes, SEND_4TH_ARG,
794 (struct sockaddr *)&state->remote_addr,
795 state->remote_addrlen);
796 /* Check all sbytes were sent */
797 if(sbytes<0) {
798 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
799 return CURLE_SEND_ERROR;
800 }
801 /* since this was a re-send, we remain at the still byte position */
802 Curl_pgrsSetUploadCounter(data, k->writebytecount);
803 }
804 break;
805
806 case TFTP_EVENT_ERROR:
807 state->state = TFTP_STATE_FIN;
808 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
809 setpacketblock(&state->spacket, state->block);
810 (void)sendto(state->sockfd, (void *)state->spacket.data, 4, SEND_4TH_ARG,
811 (struct sockaddr *)&state->remote_addr,
812 state->remote_addrlen);
813 /* don't bother with the return code, but if the socket is still up we
814 * should be a good TFTP client and let the server know we're done */
815 state->state = TFTP_STATE_FIN;
816 break;
817
818 default:
819 failf(data, "tftp_tx: internal error, event: %i", (int)(event));
820 break;
821 }
822
823 return result;
824 }
825
826 /**********************************************************
827 *
828 * tftp_translate_code
829 *
830 * Translate internal error codes to CURL error codes
831 *
832 **********************************************************/
tftp_translate_code(tftp_error_t error)833 static CURLcode tftp_translate_code(tftp_error_t error)
834 {
835 CURLcode result = CURLE_OK;
836
837 if(error != TFTP_ERR_NONE) {
838 switch(error) {
839 case TFTP_ERR_NOTFOUND:
840 result = CURLE_TFTP_NOTFOUND;
841 break;
842 case TFTP_ERR_PERM:
843 result = CURLE_TFTP_PERM;
844 break;
845 case TFTP_ERR_DISKFULL:
846 result = CURLE_REMOTE_DISK_FULL;
847 break;
848 case TFTP_ERR_UNDEF:
849 case TFTP_ERR_ILLEGAL:
850 result = CURLE_TFTP_ILLEGAL;
851 break;
852 case TFTP_ERR_UNKNOWNID:
853 result = CURLE_TFTP_UNKNOWNID;
854 break;
855 case TFTP_ERR_EXISTS:
856 result = CURLE_REMOTE_FILE_EXISTS;
857 break;
858 case TFTP_ERR_NOSUCHUSER:
859 result = CURLE_TFTP_NOSUCHUSER;
860 break;
861 case TFTP_ERR_TIMEOUT:
862 result = CURLE_OPERATION_TIMEDOUT;
863 break;
864 case TFTP_ERR_NORESPONSE:
865 result = CURLE_COULDNT_CONNECT;
866 break;
867 default:
868 result = CURLE_ABORTED_BY_CALLBACK;
869 break;
870 }
871 }
872 else
873 result = CURLE_OK;
874
875 return result;
876 }
877
878 /**********************************************************
879 *
880 * tftp_state_machine
881 *
882 * The tftp state machine event dispatcher
883 *
884 **********************************************************/
tftp_state_machine(tftp_state_data_t * state,tftp_event_t event)885 static CURLcode tftp_state_machine(tftp_state_data_t *state,
886 tftp_event_t event)
887 {
888 CURLcode result = CURLE_OK;
889 struct SessionHandle *data = state->conn->data;
890
891 switch(state->state) {
892 case TFTP_STATE_START:
893 DEBUGF(infof(data, "TFTP_STATE_START\n"));
894 result = tftp_send_first(state, event);
895 break;
896 case TFTP_STATE_RX:
897 DEBUGF(infof(data, "TFTP_STATE_RX\n"));
898 result = tftp_rx(state, event);
899 break;
900 case TFTP_STATE_TX:
901 DEBUGF(infof(data, "TFTP_STATE_TX\n"));
902 result = tftp_tx(state, event);
903 break;
904 case TFTP_STATE_FIN:
905 infof(data, "%s\n", "TFTP finished");
906 break;
907 default:
908 DEBUGF(infof(data, "STATE: %d\n", state->state));
909 failf(data, "%s", "Internal state machine error");
910 result = CURLE_TFTP_ILLEGAL;
911 break;
912 }
913
914 return result;
915 }
916
917 /**********************************************************
918 *
919 * tftp_disconnect
920 *
921 * The disconnect callback
922 *
923 **********************************************************/
tftp_disconnect(struct connectdata * conn,bool dead_connection)924 static CURLcode tftp_disconnect(struct connectdata *conn, bool dead_connection)
925 {
926 tftp_state_data_t *state = conn->proto.tftpc;
927 (void) dead_connection;
928
929 /* done, free dynamically allocated pkt buffers */
930 if(state) {
931 Curl_safefree(state->rpacket.data);
932 Curl_safefree(state->spacket.data);
933 free(state);
934 }
935
936 return CURLE_OK;
937 }
938
939 /**********************************************************
940 *
941 * tftp_connect
942 *
943 * The connect callback
944 *
945 **********************************************************/
tftp_connect(struct connectdata * conn,bool * done)946 static CURLcode tftp_connect(struct connectdata *conn, bool *done)
947 {
948 tftp_state_data_t *state;
949 int blksize, rc;
950
951 blksize = TFTP_BLKSIZE_DEFAULT;
952
953 state = conn->proto.tftpc = calloc(1, sizeof(tftp_state_data_t));
954 if(!state)
955 return CURLE_OUT_OF_MEMORY;
956
957 /* alloc pkt buffers based on specified blksize */
958 if(conn->data->set.tftp_blksize) {
959 blksize = (int)conn->data->set.tftp_blksize;
960 if(blksize > TFTP_BLKSIZE_MAX || blksize < TFTP_BLKSIZE_MIN )
961 return CURLE_TFTP_ILLEGAL;
962 }
963
964 if(!state->rpacket.data) {
965 state->rpacket.data = calloc(1, blksize + 2 + 2);
966
967 if(!state->rpacket.data)
968 return CURLE_OUT_OF_MEMORY;
969 }
970
971 if(!state->spacket.data) {
972 state->spacket.data = calloc(1, blksize + 2 + 2);
973
974 if(!state->spacket.data)
975 return CURLE_OUT_OF_MEMORY;
976 }
977
978 /* we don't keep TFTP connections up bascially because there's none or very
979 * little gain for UDP */
980 connclose(conn, "TFTP");
981
982 state->conn = conn;
983 state->sockfd = state->conn->sock[FIRSTSOCKET];
984 state->state = TFTP_STATE_START;
985 state->error = TFTP_ERR_NONE;
986 state->blksize = TFTP_BLKSIZE_DEFAULT;
987 state->requested_blksize = blksize;
988
989 ((struct sockaddr *)&state->local_addr)->sa_family =
990 (unsigned short)(conn->ip_addr->ai_family);
991
992 tftp_set_timeouts(state);
993
994 if(!conn->bits.bound) {
995 /* If not already bound, bind to any interface, random UDP port. If it is
996 * reused or a custom local port was desired, this has already been done!
997 *
998 * We once used the size of the local_addr struct as the third argument
999 * for bind() to better work with IPv6 or whatever size the struct could
1000 * have, but we learned that at least Tru64, AIX and IRIX *requires* the
1001 * size of that argument to match the exact size of a 'sockaddr_in' struct
1002 * when running IPv4-only.
1003 *
1004 * Therefore we use the size from the address we connected to, which we
1005 * assume uses the same IP version and thus hopefully this works for both
1006 * IPv4 and IPv6...
1007 */
1008 rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
1009 conn->ip_addr->ai_addrlen);
1010 if(rc) {
1011 failf(conn->data, "bind() failed; %s",
1012 Curl_strerror(conn, SOCKERRNO));
1013 return CURLE_COULDNT_CONNECT;
1014 }
1015 conn->bits.bound = TRUE;
1016 }
1017
1018 Curl_pgrsStartNow(conn->data);
1019
1020 *done = TRUE;
1021
1022 return CURLE_OK;
1023 }
1024
1025 /**********************************************************
1026 *
1027 * tftp_done
1028 *
1029 * The done callback
1030 *
1031 **********************************************************/
tftp_done(struct connectdata * conn,CURLcode status,bool premature)1032 static CURLcode tftp_done(struct connectdata *conn, CURLcode status,
1033 bool premature)
1034 {
1035 CURLcode result = CURLE_OK;
1036 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1037
1038 (void)status; /* unused */
1039 (void)premature; /* not used */
1040
1041 if(Curl_pgrsDone(conn))
1042 return CURLE_ABORTED_BY_CALLBACK;
1043
1044 /* If we have encountered an error */
1045 if(state)
1046 result = tftp_translate_code(state->error);
1047
1048 return result;
1049 }
1050
1051 /**********************************************************
1052 *
1053 * tftp_getsock
1054 *
1055 * The getsock callback
1056 *
1057 **********************************************************/
tftp_getsock(struct connectdata * conn,curl_socket_t * socks,int numsocks)1058 static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks,
1059 int numsocks)
1060 {
1061 if(!numsocks)
1062 return GETSOCK_BLANK;
1063
1064 socks[0] = conn->sock[FIRSTSOCKET];
1065
1066 return GETSOCK_READSOCK(0);
1067 }
1068
1069 /**********************************************************
1070 *
1071 * tftp_receive_packet
1072 *
1073 * Called once select fires and data is ready on the socket
1074 *
1075 **********************************************************/
tftp_receive_packet(struct connectdata * conn)1076 static CURLcode tftp_receive_packet(struct connectdata *conn)
1077 {
1078 struct Curl_sockaddr_storage fromaddr;
1079 curl_socklen_t fromlen;
1080 CURLcode result = CURLE_OK;
1081 struct SessionHandle *data = conn->data;
1082 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1083 struct SingleRequest *k = &data->req;
1084
1085 /* Receive the packet */
1086 fromlen = sizeof(fromaddr);
1087 state->rbytes = (int)recvfrom(state->sockfd,
1088 (void *)state->rpacket.data,
1089 state->blksize+4,
1090 0,
1091 (struct sockaddr *)&fromaddr,
1092 &fromlen);
1093 if(state->remote_addrlen==0) {
1094 memcpy(&state->remote_addr, &fromaddr, fromlen);
1095 state->remote_addrlen = fromlen;
1096 }
1097
1098 /* Sanity check packet length */
1099 if(state->rbytes < 4) {
1100 failf(data, "Received too short packet");
1101 /* Not a timeout, but how best to handle it? */
1102 state->event = TFTP_EVENT_TIMEOUT;
1103 }
1104 else {
1105 /* The event is given by the TFTP packet time */
1106 state->event = (tftp_event_t)getrpacketevent(&state->rpacket);
1107
1108 switch(state->event) {
1109 case TFTP_EVENT_DATA:
1110 /* Don't pass to the client empty or retransmitted packets */
1111 if(state->rbytes > 4 &&
1112 (NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
1113 result = Curl_client_write(conn, CLIENTWRITE_BODY,
1114 (char *)state->rpacket.data+4,
1115 state->rbytes-4);
1116 if(result) {
1117 tftp_state_machine(state, TFTP_EVENT_ERROR);
1118 return result;
1119 }
1120 k->bytecount += state->rbytes-4;
1121 Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount);
1122 }
1123 break;
1124 case TFTP_EVENT_ERROR:
1125 state->error = (tftp_error_t)getrpacketblock(&state->rpacket);
1126 infof(data, "%s\n", (const char *)state->rpacket.data+4);
1127 break;
1128 case TFTP_EVENT_ACK:
1129 break;
1130 case TFTP_EVENT_OACK:
1131 result = tftp_parse_option_ack(state,
1132 (const char *)state->rpacket.data+2,
1133 state->rbytes-2);
1134 if(result)
1135 return result;
1136 break;
1137 case TFTP_EVENT_RRQ:
1138 case TFTP_EVENT_WRQ:
1139 default:
1140 failf(data, "%s", "Internal error: Unexpected packet");
1141 break;
1142 }
1143
1144 /* Update the progress meter */
1145 if(Curl_pgrsUpdate(conn)) {
1146 tftp_state_machine(state, TFTP_EVENT_ERROR);
1147 return CURLE_ABORTED_BY_CALLBACK;
1148 }
1149 }
1150 return result;
1151 }
1152
1153 /**********************************************************
1154 *
1155 * tftp_state_timeout
1156 *
1157 * Check if timeouts have been reached
1158 *
1159 **********************************************************/
tftp_state_timeout(struct connectdata * conn,tftp_event_t * event)1160 static long tftp_state_timeout(struct connectdata *conn, tftp_event_t *event)
1161 {
1162 time_t current;
1163 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1164
1165 if(event)
1166 *event = TFTP_EVENT_NONE;
1167
1168 time(¤t);
1169 if(current > state->max_time) {
1170 DEBUGF(infof(conn->data, "timeout: %ld > %ld\n",
1171 (long)current, (long)state->max_time));
1172 state->error = TFTP_ERR_TIMEOUT;
1173 state->state = TFTP_STATE_FIN;
1174 return 0;
1175 }
1176 else if(current > state->rx_time+state->retry_time) {
1177 if(event)
1178 *event = TFTP_EVENT_TIMEOUT;
1179 time(&state->rx_time); /* update even though we received nothing */
1180 }
1181
1182 /* there's a typecast below here since 'time_t' may in fact be larger than
1183 'long', but we estimate that a 'long' will still be able to hold number
1184 of seconds even if "only" 32 bit */
1185 return (long)(state->max_time - current);
1186 }
1187
1188 /**********************************************************
1189 *
1190 * tftp_multi_statemach
1191 *
1192 * Handle single RX socket event and return
1193 *
1194 **********************************************************/
tftp_multi_statemach(struct connectdata * conn,bool * done)1195 static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done)
1196 {
1197 int rc;
1198 tftp_event_t event;
1199 CURLcode result = CURLE_OK;
1200 struct SessionHandle *data = conn->data;
1201 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1202 long timeout_ms = tftp_state_timeout(conn, &event);
1203
1204 *done = FALSE;
1205
1206 if(timeout_ms <= 0) {
1207 failf(data, "TFTP response timeout");
1208 return CURLE_OPERATION_TIMEDOUT;
1209 }
1210 else if(event != TFTP_EVENT_NONE) {
1211 result = tftp_state_machine(state, event);
1212 if(result)
1213 return result;
1214 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1215 if(*done)
1216 /* Tell curl we're done */
1217 Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1218 }
1219 else {
1220 /* no timeouts to handle, check our socket */
1221 rc = Curl_socket_ready(state->sockfd, CURL_SOCKET_BAD, 0);
1222
1223 if(rc == -1) {
1224 /* bail out */
1225 int error = SOCKERRNO;
1226 failf(data, "%s", Curl_strerror(conn, error));
1227 state->event = TFTP_EVENT_ERROR;
1228 }
1229 else if(rc != 0) {
1230 result = tftp_receive_packet(conn);
1231 if(result)
1232 return result;
1233 result = tftp_state_machine(state, state->event);
1234 if(result)
1235 return result;
1236 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1237 if(*done)
1238 /* Tell curl we're done */
1239 Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1240 }
1241 /* if rc == 0, then select() timed out */
1242 }
1243
1244 return result;
1245 }
1246
1247 /**********************************************************
1248 *
1249 * tftp_doing
1250 *
1251 * Called from multi.c while DOing
1252 *
1253 **********************************************************/
tftp_doing(struct connectdata * conn,bool * dophase_done)1254 static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done)
1255 {
1256 CURLcode result;
1257 result = tftp_multi_statemach(conn, dophase_done);
1258
1259 if(*dophase_done) {
1260 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1261 }
1262 else if(!result) {
1263 /* The multi code doesn't have this logic for the DOING state so we
1264 provide it for TFTP since it may do the entire transfer in this
1265 state. */
1266 if(Curl_pgrsUpdate(conn))
1267 result = CURLE_ABORTED_BY_CALLBACK;
1268 else
1269 result = Curl_speedcheck(conn->data, Curl_tvnow());
1270 }
1271 return result;
1272 }
1273
1274 /**********************************************************
1275 *
1276 * tftp_peform
1277 *
1278 * Entry point for transfer from tftp_do, sarts state mach
1279 *
1280 **********************************************************/
tftp_perform(struct connectdata * conn,bool * dophase_done)1281 static CURLcode tftp_perform(struct connectdata *conn, bool *dophase_done)
1282 {
1283 CURLcode result = CURLE_OK;
1284 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1285
1286 *dophase_done = FALSE;
1287
1288 result = tftp_state_machine(state, TFTP_EVENT_INIT);
1289
1290 if((state->state == TFTP_STATE_FIN) || result)
1291 return result;
1292
1293 tftp_multi_statemach(conn, dophase_done);
1294
1295 if(*dophase_done)
1296 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1297
1298 return result;
1299 }
1300
1301
1302 /**********************************************************
1303 *
1304 * tftp_do
1305 *
1306 * The do callback
1307 *
1308 * This callback initiates the TFTP transfer
1309 *
1310 **********************************************************/
1311
tftp_do(struct connectdata * conn,bool * done)1312 static CURLcode tftp_do(struct connectdata *conn, bool *done)
1313 {
1314 tftp_state_data_t *state;
1315 CURLcode result;
1316
1317 *done = FALSE;
1318
1319 if(!conn->proto.tftpc) {
1320 result = tftp_connect(conn, done);
1321 if(result)
1322 return result;
1323 }
1324
1325 state = (tftp_state_data_t *)conn->proto.tftpc;
1326 if(!state)
1327 return CURLE_BAD_CALLING_ORDER;
1328
1329 result = tftp_perform(conn, done);
1330
1331 /* If tftp_perform() returned an error, use that for return code. If it
1332 was OK, see if tftp_translate_code() has an error. */
1333 if(!result)
1334 /* If we have encountered an internal tftp error, translate it. */
1335 result = tftp_translate_code(state->error);
1336
1337 return result;
1338 }
1339
tftp_setup_connection(struct connectdata * conn)1340 static CURLcode tftp_setup_connection(struct connectdata * conn)
1341 {
1342 struct SessionHandle *data = conn->data;
1343 char * type;
1344 char command;
1345
1346 conn->socktype = SOCK_DGRAM; /* UDP datagram based */
1347
1348 /* TFTP URLs support an extension like ";mode=<typecode>" that
1349 * we'll try to get now! */
1350 type = strstr(data->state.path, ";mode=");
1351
1352 if(!type)
1353 type = strstr(conn->host.rawalloc, ";mode=");
1354
1355 if(type) {
1356 *type = 0; /* it was in the middle of the hostname */
1357 command = Curl_raw_toupper(type[6]);
1358
1359 switch (command) {
1360 case 'A': /* ASCII mode */
1361 case 'N': /* NETASCII mode */
1362 data->set.prefer_ascii = TRUE;
1363 break;
1364
1365 case 'O': /* octet mode */
1366 case 'I': /* binary mode */
1367 default:
1368 /* switch off ASCII */
1369 data->set.prefer_ascii = FALSE;
1370 break;
1371 }
1372 }
1373
1374 return CURLE_OK;
1375 }
1376 #endif
1377