1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2019, 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 https://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 "strcase.h"
59#include "speedcheck.h"
60#include "select.h"
61#include "escape.h"
62
63/* The last 3 #include files should be in this order */
64#include "curl_printf.h"
65#include "curl_memory.h"
66#include "memdebug.h"
67
68/* RFC2348 allows the block size to be negotiated */
69#define TFTP_BLKSIZE_DEFAULT 512
70#define TFTP_BLKSIZE_MIN 8
71#define TFTP_BLKSIZE_MAX 65464
72#define TFTP_OPTION_BLKSIZE "blksize"
73
74/* from RFC2349: */
75#define TFTP_OPTION_TSIZE "tsize"
76#define TFTP_OPTION_INTERVAL "timeout"
77
78typedef enum {
79 TFTP_MODE_NETASCII = 0,
80 TFTP_MODE_OCTET
81} tftp_mode_t;
82
83typedef enum {
84 TFTP_STATE_START = 0,
85 TFTP_STATE_RX,
86 TFTP_STATE_TX,
87 TFTP_STATE_FIN
88} tftp_state_t;
89
90typedef enum {
91 TFTP_EVENT_NONE = -1,
92 TFTP_EVENT_INIT = 0,
93 TFTP_EVENT_RRQ = 1,
94 TFTP_EVENT_WRQ = 2,
95 TFTP_EVENT_DATA = 3,
96 TFTP_EVENT_ACK = 4,
97 TFTP_EVENT_ERROR = 5,
98 TFTP_EVENT_OACK = 6,
99 TFTP_EVENT_TIMEOUT
100} tftp_event_t;
101
102typedef enum {
103 TFTP_ERR_UNDEF = 0,
104 TFTP_ERR_NOTFOUND,
105 TFTP_ERR_PERM,
106 TFTP_ERR_DISKFULL,
107 TFTP_ERR_ILLEGAL,
108 TFTP_ERR_UNKNOWNID,
109 TFTP_ERR_EXISTS,
110 TFTP_ERR_NOSUCHUSER, /* This will never be triggered by this code */
111
112 /* The remaining error codes are internal to curl */
113 TFTP_ERR_NONE = -100,
114 TFTP_ERR_TIMEOUT,
115 TFTP_ERR_NORESPONSE
116} tftp_error_t;
117
118typedef struct tftp_packet {
119 unsigned char *data;
120} tftp_packet_t;
121
122typedef struct tftp_state_data {
123 tftp_state_t state;
124 tftp_mode_t mode;
125 tftp_error_t error;
126 tftp_event_t event;
127 struct connectdata *conn;
128 curl_socket_t sockfd;
129 int retries;
130 int retry_time;
131 int retry_max;
132 time_t start_time;
133 time_t max_time;
134 time_t rx_time;
135 unsigned short block;
136 struct Curl_sockaddr_storage local_addr;
137 struct Curl_sockaddr_storage remote_addr;
138 curl_socklen_t remote_addrlen;
139 int rbytes;
140 int sbytes;
141 int blksize;
142 int requested_blksize;
143 tftp_packet_t rpacket;
144 tftp_packet_t spacket;
145} tftp_state_data_t;
146
147
148/* Forward declarations */
149static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event);
150static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event);
151static CURLcode tftp_connect(struct connectdata *conn, bool *done);
152static CURLcode tftp_disconnect(struct connectdata *conn,
153 bool dead_connection);
154static CURLcode tftp_do(struct connectdata *conn, bool *done);
155static CURLcode tftp_done(struct connectdata *conn,
156 CURLcode, bool premature);
157static CURLcode tftp_setup_connection(struct connectdata * conn);
158static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done);
159static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done);
160static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks);
161static CURLcode tftp_translate_code(tftp_error_t error);
162
163
164/*
165 * TFTP protocol handler.
166 */
167
168const 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 ZERO_NULL, /* connection_check */
184 PORT_TFTP, /* defport */
185 CURLPROTO_TFTP, /* protocol */
186 PROTOPT_NONE | PROTOPT_NOURLQUERY /* flags */
187};
188
189/**********************************************************
190 *
191 * tftp_set_timeouts -
192 *
193 * Set timeouts based on state machine state.
194 * Use user provided connect timeouts until DATA or ACK
195 * packet is received, then use user-provided transfer timeouts
196 *
197 *
198 **********************************************************/
199static CURLcode tftp_set_timeouts(tftp_state_data_t *state)
200{
201 time_t maxtime, timeout;
202 timediff_t timeout_ms;
203 bool start = (state->state == TFTP_STATE_START) ? TRUE : FALSE;
204
205 time(&state->start_time);
206
207 /* Compute drop-dead time */
208 timeout_ms = Curl_timeleft(state->conn->data, NULL, start);
209
210 if(timeout_ms < 0) {
211 /* time-out, bail out, go home */
212 failf(state->conn->data, "Connection time-out");
213 return CURLE_OPERATION_TIMEDOUT;
214 }
215
216 if(start) {
217
218 maxtime = (time_t)(timeout_ms + 500) / 1000;
219 state->max_time = state->start_time + maxtime;
220
221 /* Set per-block timeout to total */
222 timeout = maxtime;
223
224 /* Average restart after 5 seconds */
225 state->retry_max = (int)timeout/5;
226
227 if(state->retry_max < 1)
228 /* avoid division by zero below */
229 state->retry_max = 1;
230
231 /* Compute the re-start interval to suit the timeout */
232 state->retry_time = (int)timeout/state->retry_max;
233 if(state->retry_time<1)
234 state->retry_time = 1;
235
236 }
237 else {
238 if(timeout_ms > 0)
239 maxtime = (time_t)(timeout_ms + 500) / 1000;
240 else
241 maxtime = 3600;
242
243 state->max_time = state->start_time + maxtime;
244
245 /* Set per-block timeout to total */
246 timeout = maxtime;
247
248 /* Average reposting an ACK after 5 seconds */
249 state->retry_max = (int)timeout/5;
250 }
251 /* But bound the total number */
252 if(state->retry_max<3)
253 state->retry_max = 3;
254
255 if(state->retry_max>50)
256 state->retry_max = 50;
257
258 /* Compute the re-ACK interval to suit the timeout */
259 state->retry_time = (int)(timeout/state->retry_max);
260 if(state->retry_time<1)
261 state->retry_time = 1;
262
263 infof(state->conn->data,
264 "set timeouts for state %d; Total %ld, retry %d maxtry %d\n",
265 (int)state->state, (long)(state->max_time-state->start_time),
266 state->retry_time, state->retry_max);
267
268 /* init RX time */
269 time(&state->rx_time);
270
271 return CURLE_OK;
272}
273
274/**********************************************************
275 *
276 * tftp_set_send_first
277 *
278 * Event handler for the START state
279 *
280 **********************************************************/
281
282static void setpacketevent(tftp_packet_t *packet, unsigned short num)
283{
284 packet->data[0] = (unsigned char)(num >> 8);
285 packet->data[1] = (unsigned char)(num & 0xff);
286}
287
288
289static void setpacketblock(tftp_packet_t *packet, unsigned short num)
290{
291 packet->data[2] = (unsigned char)(num >> 8);
292 packet->data[3] = (unsigned char)(num & 0xff);
293}
294
295static unsigned short getrpacketevent(const tftp_packet_t *packet)
296{
297 return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
298}
299
300static unsigned short getrpacketblock(const tftp_packet_t *packet)
301{
302 return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
303}
304
305static size_t Curl_strnlen(const char *string, size_t maxlen)
306{
307 const char *end = memchr(string, '\0', maxlen);
308 return end ? (size_t) (end - string) : maxlen;
309}
310
311static const char *tftp_option_get(const char *buf, size_t len,
312 const char **option, const char **value)
313{
314 size_t loc;
315
316 loc = Curl_strnlen(buf, len);
317 loc++; /* NULL term */
318
319 if(loc >= len)
320 return NULL;
321 *option = buf;
322
323 loc += Curl_strnlen(buf + loc, len-loc);
324 loc++; /* NULL term */
325
326 if(loc > len)
327 return NULL;
328 *value = &buf[strlen(*option) + 1];
329
330 return &buf[loc];
331}
332
333static CURLcode tftp_parse_option_ack(tftp_state_data_t *state,
334 const char *ptr, int len)
335{
336 const char *tmp = ptr;
337 struct Curl_easy *data = state->conn->data;
338
339 /* if OACK doesn't contain blksize option, the default (512) must be used */
340 state->blksize = TFTP_BLKSIZE_DEFAULT;
341
342 while(tmp < ptr + len) {
343 const char *option, *value;
344
345 tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
346 if(tmp == NULL) {
347 failf(data, "Malformed ACK packet, rejecting");
348 return CURLE_TFTP_ILLEGAL;
349 }
350
351 infof(data, "got option=(%s) value=(%s)\n", option, value);
352
353 if(checkprefix(option, TFTP_OPTION_BLKSIZE)) {
354 long blksize;
355
356 blksize = strtol(value, NULL, 10);
357
358 if(!blksize) {
359 failf(data, "invalid blocksize value in OACK packet");
360 return CURLE_TFTP_ILLEGAL;
361 }
362 if(blksize > TFTP_BLKSIZE_MAX) {
363 failf(data, "%s (%d)", "blksize is larger than max supported",
364 TFTP_BLKSIZE_MAX);
365 return CURLE_TFTP_ILLEGAL;
366 }
367 else if(blksize < TFTP_BLKSIZE_MIN) {
368 failf(data, "%s (%d)", "blksize is smaller than min supported",
369 TFTP_BLKSIZE_MIN);
370 return CURLE_TFTP_ILLEGAL;
371 }
372 else if(blksize > state->requested_blksize) {
373 /* could realloc pkt buffers here, but the spec doesn't call out
374 * support for the server requesting a bigger blksize than the client
375 * requests */
376 failf(data, "%s (%ld)",
377 "server requested blksize larger than allocated", blksize);
378 return CURLE_TFTP_ILLEGAL;
379 }
380
381 state->blksize = (int)blksize;
382 infof(data, "%s (%d) %s (%d)\n", "blksize parsed from OACK",
383 state->blksize, "requested", state->requested_blksize);
384 }
385 else if(checkprefix(option, TFTP_OPTION_TSIZE)) {
386 long tsize = 0;
387
388 tsize = strtol(value, NULL, 10);
389 infof(data, "%s (%ld)\n", "tsize parsed from OACK", tsize);
390
391 /* tsize should be ignored on upload: Who cares about the size of the
392 remote file? */
393 if(!data->set.upload) {
394 if(!tsize) {
395 failf(data, "invalid tsize -:%s:- value in OACK packet", value);
396 return CURLE_TFTP_ILLEGAL;
397 }
398 Curl_pgrsSetDownloadSize(data, tsize);
399 }
400 }
401 }
402
403 return CURLE_OK;
404}
405
406static CURLcode tftp_option_add(tftp_state_data_t *state, size_t *csize,
407 char *buf, const char *option)
408{
409 if(( strlen(option) + *csize + 1) > (size_t)state->blksize)
410 return CURLE_TFTP_ILLEGAL;
411 strcpy(buf, option);
412 *csize += strlen(option) + 1;
413 return CURLE_OK;
414}
415
416static CURLcode tftp_connect_for_tx(tftp_state_data_t *state,
417 tftp_event_t event)
418{
419 CURLcode result;
420#ifndef CURL_DISABLE_VERBOSE_STRINGS
421 struct Curl_easy *data = state->conn->data;
422
423 infof(data, "%s\n", "Connected for transmit");
424#endif
425 state->state = TFTP_STATE_TX;
426 result = tftp_set_timeouts(state);
427 if(result)
428 return result;
429 return tftp_tx(state, event);
430}
431
432static CURLcode tftp_connect_for_rx(tftp_state_data_t *state,
433 tftp_event_t event)
434{
435 CURLcode result;
436#ifndef CURL_DISABLE_VERBOSE_STRINGS
437 struct Curl_easy *data = state->conn->data;
438
439 infof(data, "%s\n", "Connected for receive");
440#endif
441 state->state = TFTP_STATE_RX;
442 result = tftp_set_timeouts(state);
443 if(result)
444 return result;
445 return tftp_rx(state, event);
446}
447
448static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
449{
450 size_t sbytes;
451 ssize_t senddata;
452 const char *mode = "octet";
453 char *filename;
454 struct Curl_easy *data = state->conn->data;
455 CURLcode result = CURLE_OK;
456
457 /* Set ascii mode if -B flag was used */
458 if(data->set.prefer_ascii)
459 mode = "netascii";
460
461 switch(event) {
462
463 case TFTP_EVENT_INIT: /* Send the first packet out */
464 case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
465 /* Increment the retry counter, quit if over the limit */
466 state->retries++;
467 if(state->retries>state->retry_max) {
468 state->error = TFTP_ERR_NORESPONSE;
469 state->state = TFTP_STATE_FIN;
470 return result;
471 }
472
473 if(data->set.upload) {
474 /* If we are uploading, send an WRQ */
475 setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
476 state->conn->data->req.upload_fromhere =
477 (char *)state->spacket.data + 4;
478 if(data->state.infilesize != -1)
479 Curl_pgrsSetUploadSize(data, data->state.infilesize);
480 }
481 else {
482 /* If we are downloading, send an RRQ */
483 setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
484 }
485 /* As RFC3617 describes the separator slash is not actually part of the
486 file name so we skip the always-present first letter of the path
487 string. */
488 result = Curl_urldecode(data, &state->conn->data->state.up.path[1], 0,
489 &filename, NULL, FALSE);
490 if(result)
491 return result;
492
493 if(strlen(filename) > (state->blksize - strlen(mode) - 4)) {
494 failf(data, "TFTP file name too long\n");
495 free(filename);
496 return CURLE_TFTP_ILLEGAL; /* too long file name field */
497 }
498
499 msnprintf((char *)state->spacket.data + 2,
500 state->blksize,
501 "%s%c%s%c", filename, '\0', mode, '\0');
502 sbytes = 4 + strlen(filename) + strlen(mode);
503
504 /* optional addition of TFTP options */
505 if(!data->set.tftp_no_options) {
506 char buf[64];
507 /* add tsize option */
508 if(data->set.upload && (data->state.infilesize != -1))
509 msnprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
510 data->state.infilesize);
511 else
512 strcpy(buf, "0"); /* the destination is large enough */
513
514 result = tftp_option_add(state, &sbytes,
515 (char *)state->spacket.data + sbytes,
516 TFTP_OPTION_TSIZE);
517 if(result == CURLE_OK)
518 result = tftp_option_add(state, &sbytes,
519 (char *)state->spacket.data + sbytes, buf);
520
521 /* add blksize option */
522 msnprintf(buf, sizeof(buf), "%d", state->requested_blksize);
523 if(result == CURLE_OK)
524 result = tftp_option_add(state, &sbytes,
525 (char *)state->spacket.data + sbytes,
526 TFTP_OPTION_BLKSIZE);
527 if(result == CURLE_OK)
528 result = tftp_option_add(state, &sbytes,
529 (char *)state->spacket.data + sbytes, buf);
530
531 /* add timeout option */
532 msnprintf(buf, sizeof(buf), "%d", state->retry_time);
533 if(result == CURLE_OK)
534 result = tftp_option_add(state, &sbytes,
535 (char *)state->spacket.data + sbytes,
536 TFTP_OPTION_INTERVAL);
537 if(result == CURLE_OK)
538 result = tftp_option_add(state, &sbytes,
539 (char *)state->spacket.data + sbytes, buf);
540
541 if(result != CURLE_OK) {
542 failf(data, "TFTP buffer too small for options");
543 free(filename);
544 return CURLE_TFTP_ILLEGAL;
545 }
546 }
547
548 /* the typecase for the 3rd argument is mostly for systems that do
549 not have a size_t argument, like older unixes that want an 'int' */
550 senddata = sendto(state->sockfd, (void *)state->spacket.data,
551 (SEND_TYPE_ARG3)sbytes, 0,
552 state->conn->ip_addr->ai_addr,
553 state->conn->ip_addr->ai_addrlen);
554 if(senddata != (ssize_t)sbytes) {
555 char buffer[STRERROR_LEN];
556 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
557 }
558 free(filename);
559 break;
560
561 case TFTP_EVENT_OACK:
562 if(data->set.upload) {
563 result = tftp_connect_for_tx(state, event);
564 }
565 else {
566 result = tftp_connect_for_rx(state, event);
567 }
568 break;
569
570 case TFTP_EVENT_ACK: /* Connected for transmit */
571 result = tftp_connect_for_tx(state, event);
572 break;
573
574 case TFTP_EVENT_DATA: /* Connected for receive */
575 result = tftp_connect_for_rx(state, event);
576 break;
577
578 case TFTP_EVENT_ERROR:
579 state->state = TFTP_STATE_FIN;
580 break;
581
582 default:
583 failf(state->conn->data, "tftp_send_first: internal error");
584 break;
585 }
586
587 return result;
588}
589
590/* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
591 boundary */
592#define NEXT_BLOCKNUM(x) (((x) + 1)&0xffff)
593
594/**********************************************************
595 *
596 * tftp_rx
597 *
598 * Event handler for the RX state
599 *
600 **********************************************************/
601static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
602{
603 ssize_t sbytes;
604 int rblock;
605 struct Curl_easy *data = state->conn->data;
606 char buffer[STRERROR_LEN];
607
608 switch(event) {
609
610 case TFTP_EVENT_DATA:
611 /* Is this the block we expect? */
612 rblock = getrpacketblock(&state->rpacket);
613 if(NEXT_BLOCKNUM(state->block) == rblock) {
614 /* This is the expected block. Reset counters and ACK it. */
615 state->retries = 0;
616 }
617 else if(state->block == rblock) {
618 /* This is the last recently received block again. Log it and ACK it
619 again. */
620 infof(data, "Received last DATA packet block %d again.\n", rblock);
621 }
622 else {
623 /* totally unexpected, just log it */
624 infof(data,
625 "Received unexpected DATA packet block %d, expecting block %d\n",
626 rblock, NEXT_BLOCKNUM(state->block));
627 break;
628 }
629
630 /* ACK this block. */
631 state->block = (unsigned short)rblock;
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(SOCKERRNO, buffer, sizeof(buffer)));
640 return CURLE_SEND_ERROR;
641 }
642
643 /* Check if completed (That is, a less than full packet is received) */
644 if(state->rbytes < (ssize_t)state->blksize + 4) {
645 state->state = TFTP_STATE_FIN;
646 }
647 else {
648 state->state = TFTP_STATE_RX;
649 }
650 time(&state->rx_time);
651 break;
652
653 case TFTP_EVENT_OACK:
654 /* ACK option acknowledgement so we can move on to data */
655 state->block = 0;
656 state->retries = 0;
657 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
658 setpacketblock(&state->spacket, state->block);
659 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
660 4, SEND_4TH_ARG,
661 (struct sockaddr *)&state->remote_addr,
662 state->remote_addrlen);
663 if(sbytes < 0) {
664 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
665 return CURLE_SEND_ERROR;
666 }
667
668 /* we're ready to RX data */
669 state->state = TFTP_STATE_RX;
670 time(&state->rx_time);
671 break;
672
673 case TFTP_EVENT_TIMEOUT:
674 /* Increment the retry count and fail if over the limit */
675 state->retries++;
676 infof(data,
677 "Timeout waiting for block %d ACK. Retries = %d\n",
678 NEXT_BLOCKNUM(state->block), state->retries);
679 if(state->retries > state->retry_max) {
680 state->error = TFTP_ERR_TIMEOUT;
681 state->state = TFTP_STATE_FIN;
682 }
683 else {
684 /* Resend the previous ACK */
685 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
686 4, SEND_4TH_ARG,
687 (struct sockaddr *)&state->remote_addr,
688 state->remote_addrlen);
689 if(sbytes<0) {
690 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
691 return CURLE_SEND_ERROR;
692 }
693 }
694 break;
695
696 case TFTP_EVENT_ERROR:
697 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
698 setpacketblock(&state->spacket, state->block);
699 (void)sendto(state->sockfd, (void *)state->spacket.data,
700 4, SEND_4TH_ARG,
701 (struct sockaddr *)&state->remote_addr,
702 state->remote_addrlen);
703 /* don't bother with the return code, but if the socket is still up we
704 * should be a good TFTP client and let the server know we're done */
705 state->state = TFTP_STATE_FIN;
706 break;
707
708 default:
709 failf(data, "%s", "tftp_rx: internal error");
710 return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
711 this */
712 }
713 return CURLE_OK;
714}
715
716/**********************************************************
717 *
718 * tftp_tx
719 *
720 * Event handler for the TX state
721 *
722 **********************************************************/
723static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
724{
725 struct Curl_easy *data = state->conn->data;
726 ssize_t sbytes;
727 CURLcode result = CURLE_OK;
728 struct SingleRequest *k = &data->req;
729 size_t cb; /* Bytes currently read */
730 char buffer[STRERROR_LEN];
731
732 switch(event) {
733
734 case TFTP_EVENT_ACK:
735 case TFTP_EVENT_OACK:
736 if(event == TFTP_EVENT_ACK) {
737 /* Ack the packet */
738 int rblock = getrpacketblock(&state->rpacket);
739
740 if(rblock != state->block &&
741 /* There's a bug in tftpd-hpa that causes it to send us an ack for
742 * 65535 when the block number wraps to 0. So when we're expecting
743 * 0, also accept 65535. See
744 * http://syslinux.zytor.com/archives/2010-September/015253.html
745 * */
746 !(state->block == 0 && rblock == 65535)) {
747 /* This isn't the expected block. Log it and up the retry counter */
748 infof(data, "Received ACK for block %d, expecting %d\n",
749 rblock, state->block);
750 state->retries++;
751 /* Bail out if over the maximum */
752 if(state->retries>state->retry_max) {
753 failf(data, "tftp_tx: giving up waiting for block %d ack",
754 state->block);
755 result = CURLE_SEND_ERROR;
756 }
757 else {
758 /* Re-send the data packet */
759 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
760 4 + state->sbytes, SEND_4TH_ARG,
761 (struct sockaddr *)&state->remote_addr,
762 state->remote_addrlen);
763 /* Check all sbytes were sent */
764 if(sbytes<0) {
765 failf(data, "%s", Curl_strerror(SOCKERRNO,
766 buffer, sizeof(buffer)));
767 result = CURLE_SEND_ERROR;
768 }
769 }
770
771 return result;
772 }
773 /* This is the expected packet. Reset the counters and send the next
774 block */
775 time(&state->rx_time);
776 state->block++;
777 }
778 else
779 state->block = 1; /* first data block is 1 when using OACK */
780
781 state->retries = 0;
782 setpacketevent(&state->spacket, TFTP_EVENT_DATA);
783 setpacketblock(&state->spacket, state->block);
784 if(state->block > 1 && state->sbytes < state->blksize) {
785 state->state = TFTP_STATE_FIN;
786 return CURLE_OK;
787 }
788
789 /* TFTP considers data block size < 512 bytes as an end of session. So
790 * in some cases we must wait for additional data to build full (512 bytes)
791 * data block.
792 * */
793 state->sbytes = 0;
794 state->conn->data->req.upload_fromhere = (char *)state->spacket.data + 4;
795 do {
796 result = Curl_fillreadbuffer(state->conn, state->blksize - state->sbytes,
797 &cb);
798 if(result)
799 return result;
800 state->sbytes += (int)cb;
801 state->conn->data->req.upload_fromhere += cb;
802 } while(state->sbytes < state->blksize && cb != 0);
803
804 sbytes = sendto(state->sockfd, (void *) state->spacket.data,
805 4 + state->sbytes, SEND_4TH_ARG,
806 (struct sockaddr *)&state->remote_addr,
807 state->remote_addrlen);
808 /* Check all sbytes were sent */
809 if(sbytes<0) {
810 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
811 return CURLE_SEND_ERROR;
812 }
813 /* Update the progress meter */
814 k->writebytecount += state->sbytes;
815 Curl_pgrsSetUploadCounter(data, k->writebytecount);
816 break;
817
818 case TFTP_EVENT_TIMEOUT:
819 /* Increment the retry counter and log the timeout */
820 state->retries++;
821 infof(data, "Timeout waiting for block %d ACK. "
822 " Retries = %d\n", NEXT_BLOCKNUM(state->block), state->retries);
823 /* Decide if we've had enough */
824 if(state->retries > state->retry_max) {
825 state->error = TFTP_ERR_TIMEOUT;
826 state->state = TFTP_STATE_FIN;
827 }
828 else {
829 /* Re-send the data packet */
830 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
831 4 + state->sbytes, SEND_4TH_ARG,
832 (struct sockaddr *)&state->remote_addr,
833 state->remote_addrlen);
834 /* Check all sbytes were sent */
835 if(sbytes<0) {
836 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
837 return CURLE_SEND_ERROR;
838 }
839 /* since this was a re-send, we remain at the still byte position */
840 Curl_pgrsSetUploadCounter(data, k->writebytecount);
841 }
842 break;
843
844 case TFTP_EVENT_ERROR:
845 state->state = TFTP_STATE_FIN;
846 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
847 setpacketblock(&state->spacket, state->block);
848 (void)sendto(state->sockfd, (void *)state->spacket.data, 4, SEND_4TH_ARG,
849 (struct sockaddr *)&state->remote_addr,
850 state->remote_addrlen);
851 /* don't bother with the return code, but if the socket is still up we
852 * should be a good TFTP client and let the server know we're done */
853 state->state = TFTP_STATE_FIN;
854 break;
855
856 default:
857 failf(data, "tftp_tx: internal error, event: %i", (int)(event));
858 break;
859 }
860
861 return result;
862}
863
864/**********************************************************
865 *
866 * tftp_translate_code
867 *
868 * Translate internal error codes to CURL error codes
869 *
870 **********************************************************/
871static CURLcode tftp_translate_code(tftp_error_t error)
872{
873 CURLcode result = CURLE_OK;
874
875 if(error != TFTP_ERR_NONE) {
876 switch(error) {
877 case TFTP_ERR_NOTFOUND:
878 result = CURLE_TFTP_NOTFOUND;
879 break;
880 case TFTP_ERR_PERM:
881 result = CURLE_TFTP_PERM;
882 break;
883 case TFTP_ERR_DISKFULL:
884 result = CURLE_REMOTE_DISK_FULL;
885 break;
886 case TFTP_ERR_UNDEF:
887 case TFTP_ERR_ILLEGAL:
888 result = CURLE_TFTP_ILLEGAL;
889 break;
890 case TFTP_ERR_UNKNOWNID:
891 result = CURLE_TFTP_UNKNOWNID;
892 break;
893 case TFTP_ERR_EXISTS:
894 result = CURLE_REMOTE_FILE_EXISTS;
895 break;
896 case TFTP_ERR_NOSUCHUSER:
897 result = CURLE_TFTP_NOSUCHUSER;
898 break;
899 case TFTP_ERR_TIMEOUT:
900 result = CURLE_OPERATION_TIMEDOUT;
901 break;
902 case TFTP_ERR_NORESPONSE:
903 result = CURLE_COULDNT_CONNECT;
904 break;
905 default:
906 result = CURLE_ABORTED_BY_CALLBACK;
907 break;
908 }
909 }
910 else
911 result = CURLE_OK;
912
913 return result;
914}
915
916/**********************************************************
917 *
918 * tftp_state_machine
919 *
920 * The tftp state machine event dispatcher
921 *
922 **********************************************************/
923static CURLcode tftp_state_machine(tftp_state_data_t *state,
924 tftp_event_t event)
925{
926 CURLcode result = CURLE_OK;
927 struct Curl_easy *data = state->conn->data;
928
929 switch(state->state) {
930 case TFTP_STATE_START:
931 DEBUGF(infof(data, "TFTP_STATE_START\n"));
932 result = tftp_send_first(state, event);
933 break;
934 case TFTP_STATE_RX:
935 DEBUGF(infof(data, "TFTP_STATE_RX\n"));
936 result = tftp_rx(state, event);
937 break;
938 case TFTP_STATE_TX:
939 DEBUGF(infof(data, "TFTP_STATE_TX\n"));
940 result = tftp_tx(state, event);
941 break;
942 case TFTP_STATE_FIN:
943 infof(data, "%s\n", "TFTP finished");
944 break;
945 default:
946 DEBUGF(infof(data, "STATE: %d\n", state->state));
947 failf(data, "%s", "Internal state machine error");
948 result = CURLE_TFTP_ILLEGAL;
949 break;
950 }
951
952 return result;
953}
954
955/**********************************************************
956 *
957 * tftp_disconnect
958 *
959 * The disconnect callback
960 *
961 **********************************************************/
962static CURLcode tftp_disconnect(struct connectdata *conn, bool dead_connection)
963{
964 tftp_state_data_t *state = conn->proto.tftpc;
965 (void) dead_connection;
966
967 /* done, free dynamically allocated pkt buffers */
968 if(state) {
969 Curl_safefree(state->rpacket.data);
970 Curl_safefree(state->spacket.data);
971 free(state);
972 }
973
974 return CURLE_OK;
975}
976
977/**********************************************************
978 *
979 * tftp_connect
980 *
981 * The connect callback
982 *
983 **********************************************************/
984static CURLcode tftp_connect(struct connectdata *conn, bool *done)
985{
986 tftp_state_data_t *state;
987 int blksize;
988 int need_blksize;
989
990 blksize = TFTP_BLKSIZE_DEFAULT;
991
992 state = conn->proto.tftpc = calloc(1, sizeof(tftp_state_data_t));
993 if(!state)
994 return CURLE_OUT_OF_MEMORY;
995
996 /* alloc pkt buffers based on specified blksize */
997 if(conn->data->set.tftp_blksize) {
998 blksize = (int)conn->data->set.tftp_blksize;
999 if(blksize > TFTP_BLKSIZE_MAX || blksize < TFTP_BLKSIZE_MIN)
1000 return CURLE_TFTP_ILLEGAL;
1001 }
1002
1003 need_blksize = blksize;
1004 /* default size is the fallback when no OACK is received */
1005 if(need_blksize < TFTP_BLKSIZE_DEFAULT)
1006 need_blksize = TFTP_BLKSIZE_DEFAULT;
1007
1008 if(!state->rpacket.data) {
1009 state->rpacket.data = calloc(1, need_blksize + 2 + 2);
1010
1011 if(!state->rpacket.data)
1012 return CURLE_OUT_OF_MEMORY;
1013 }
1014
1015 if(!state->spacket.data) {
1016 state->spacket.data = calloc(1, need_blksize + 2 + 2);
1017
1018 if(!state->spacket.data)
1019 return CURLE_OUT_OF_MEMORY;
1020 }
1021
1022 /* we don't keep TFTP connections up basically because there's none or very
1023 * little gain for UDP */
1024 connclose(conn, "TFTP");
1025
1026 state->conn = conn;
1027 state->sockfd = state->conn->sock[FIRSTSOCKET];
1028 state->state = TFTP_STATE_START;
1029 state->error = TFTP_ERR_NONE;
1030 state->blksize = TFTP_BLKSIZE_DEFAULT; /* Unless updated by OACK response */
1031 state->requested_blksize = blksize;
1032
1033 ((struct sockaddr *)&state->local_addr)->sa_family =
1034 (CURL_SA_FAMILY_T)(conn->ip_addr->ai_family);
1035
1036 tftp_set_timeouts(state);
1037
1038 if(!conn->bits.bound) {
1039 /* If not already bound, bind to any interface, random UDP port. If it is
1040 * reused or a custom local port was desired, this has already been done!
1041 *
1042 * We once used the size of the local_addr struct as the third argument
1043 * for bind() to better work with IPv6 or whatever size the struct could
1044 * have, but we learned that at least Tru64, AIX and IRIX *requires* the
1045 * size of that argument to match the exact size of a 'sockaddr_in' struct
1046 * when running IPv4-only.
1047 *
1048 * Therefore we use the size from the address we connected to, which we
1049 * assume uses the same IP version and thus hopefully this works for both
1050 * IPv4 and IPv6...
1051 */
1052 int rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
1053 conn->ip_addr->ai_addrlen);
1054 if(rc) {
1055 char buffer[STRERROR_LEN];
1056 failf(conn->data, "bind() failed; %s",
1057 Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
1058 return CURLE_COULDNT_CONNECT;
1059 }
1060 conn->bits.bound = TRUE;
1061 }
1062
1063 Curl_pgrsStartNow(conn->data);
1064
1065 *done = TRUE;
1066
1067 return CURLE_OK;
1068}
1069
1070/**********************************************************
1071 *
1072 * tftp_done
1073 *
1074 * The done callback
1075 *
1076 **********************************************************/
1077static CURLcode tftp_done(struct connectdata *conn, CURLcode status,
1078 bool premature)
1079{
1080 CURLcode result = CURLE_OK;
1081 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1082
1083 (void)status; /* unused */
1084 (void)premature; /* not used */
1085
1086 if(Curl_pgrsDone(conn))
1087 return CURLE_ABORTED_BY_CALLBACK;
1088
1089 /* If we have encountered an error */
1090 if(state)
1091 result = tftp_translate_code(state->error);
1092
1093 return result;
1094}
1095
1096/**********************************************************
1097 *
1098 * tftp_getsock
1099 *
1100 * The getsock callback
1101 *
1102 **********************************************************/
1103static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks)
1104{
1105 socks[0] = conn->sock[FIRSTSOCKET];
1106 return GETSOCK_READSOCK(0);
1107}
1108
1109/**********************************************************
1110 *
1111 * tftp_receive_packet
1112 *
1113 * Called once select fires and data is ready on the socket
1114 *
1115 **********************************************************/
1116static CURLcode tftp_receive_packet(struct connectdata *conn)
1117{
1118 struct Curl_sockaddr_storage fromaddr;
1119 curl_socklen_t fromlen;
1120 CURLcode result = CURLE_OK;
1121 struct Curl_easy *data = conn->data;
1122 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1123 struct SingleRequest *k = &data->req;
1124
1125 /* Receive the packet */
1126 fromlen = sizeof(fromaddr);
1127 state->rbytes = (int)recvfrom(state->sockfd,
1128 (void *)state->rpacket.data,
1129 state->blksize + 4,
1130 0,
1131 (struct sockaddr *)&fromaddr,
1132 &fromlen);
1133 if(state->remote_addrlen == 0) {
1134 memcpy(&state->remote_addr, &fromaddr, fromlen);
1135 state->remote_addrlen = fromlen;
1136 }
1137
1138 /* Sanity check packet length */
1139 if(state->rbytes < 4) {
1140 failf(data, "Received too short packet");
1141 /* Not a timeout, but how best to handle it? */
1142 state->event = TFTP_EVENT_TIMEOUT;
1143 }
1144 else {
1145 /* The event is given by the TFTP packet time */
1146 unsigned short event = getrpacketevent(&state->rpacket);
1147 state->event = (tftp_event_t)event;
1148
1149 switch(state->event) {
1150 case TFTP_EVENT_DATA:
1151 /* Don't pass to the client empty or retransmitted packets */
1152 if(state->rbytes > 4 &&
1153 (NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
1154 result = Curl_client_write(conn, CLIENTWRITE_BODY,
1155 (char *)state->rpacket.data + 4,
1156 state->rbytes-4);
1157 if(result) {
1158 tftp_state_machine(state, TFTP_EVENT_ERROR);
1159 return result;
1160 }
1161 k->bytecount += state->rbytes-4;
1162 Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount);
1163 }
1164 break;
1165 case TFTP_EVENT_ERROR:
1166 {
1167 unsigned short error = getrpacketblock(&state->rpacket);
1168 char *str = (char *)state->rpacket.data + 4;
1169 size_t strn = state->rbytes - 4;
1170 state->error = (tftp_error_t)error;
1171 if(Curl_strnlen(str, strn) < strn)
1172 infof(data, "TFTP error: %s\n", str);
1173 break;
1174 }
1175 case TFTP_EVENT_ACK:
1176 break;
1177 case TFTP_EVENT_OACK:
1178 result = tftp_parse_option_ack(state,
1179 (const char *)state->rpacket.data + 2,
1180 state->rbytes-2);
1181 if(result)
1182 return result;
1183 break;
1184 case TFTP_EVENT_RRQ:
1185 case TFTP_EVENT_WRQ:
1186 default:
1187 failf(data, "%s", "Internal error: Unexpected packet");
1188 break;
1189 }
1190
1191 /* Update the progress meter */
1192 if(Curl_pgrsUpdate(conn)) {
1193 tftp_state_machine(state, TFTP_EVENT_ERROR);
1194 return CURLE_ABORTED_BY_CALLBACK;
1195 }
1196 }
1197 return result;
1198}
1199
1200/**********************************************************
1201 *
1202 * tftp_state_timeout
1203 *
1204 * Check if timeouts have been reached
1205 *
1206 **********************************************************/
1207static long tftp_state_timeout(struct connectdata *conn, tftp_event_t *event)
1208{
1209 time_t current;
1210 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1211
1212 if(event)
1213 *event = TFTP_EVENT_NONE;
1214
1215 time(&current);
1216 if(current > state->max_time) {
1217 DEBUGF(infof(conn->data, "timeout: %ld > %ld\n",
1218 (long)current, (long)state->max_time));
1219 state->error = TFTP_ERR_TIMEOUT;
1220 state->state = TFTP_STATE_FIN;
1221 return 0;
1222 }
1223 if(current > state->rx_time + state->retry_time) {
1224 if(event)
1225 *event = TFTP_EVENT_TIMEOUT;
1226 time(&state->rx_time); /* update even though we received nothing */
1227 }
1228
1229 /* there's a typecast below here since 'time_t' may in fact be larger than
1230 'long', but we estimate that a 'long' will still be able to hold number
1231 of seconds even if "only" 32 bit */
1232 return (long)(state->max_time - current);
1233}
1234
1235/**********************************************************
1236 *
1237 * tftp_multi_statemach
1238 *
1239 * Handle single RX socket event and return
1240 *
1241 **********************************************************/
1242static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done)
1243{
1244 tftp_event_t event;
1245 CURLcode result = CURLE_OK;
1246 struct Curl_easy *data = conn->data;
1247 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1248 long timeout_ms = tftp_state_timeout(conn, &event);
1249
1250 *done = FALSE;
1251
1252 if(timeout_ms <= 0) {
1253 failf(data, "TFTP response timeout");
1254 return CURLE_OPERATION_TIMEDOUT;
1255 }
1256 if(event != TFTP_EVENT_NONE) {
1257 result = tftp_state_machine(state, event);
1258 if(result)
1259 return result;
1260 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1261 if(*done)
1262 /* Tell curl we're done */
1263 Curl_setup_transfer(data, -1, -1, FALSE, -1);
1264 }
1265 else {
1266 /* no timeouts to handle, check our socket */
1267 int rc = SOCKET_READABLE(state->sockfd, 0);
1268
1269 if(rc == -1) {
1270 /* bail out */
1271 int error = SOCKERRNO;
1272 char buffer[STRERROR_LEN];
1273 failf(data, "%s", Curl_strerror(error, buffer, sizeof(buffer)));
1274 state->event = TFTP_EVENT_ERROR;
1275 }
1276 else if(rc != 0) {
1277 result = tftp_receive_packet(conn);
1278 if(result)
1279 return result;
1280 result = tftp_state_machine(state, state->event);
1281 if(result)
1282 return result;
1283 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1284 if(*done)
1285 /* Tell curl we're done */
1286 Curl_setup_transfer(data, -1, -1, FALSE, -1);
1287 }
1288 /* if rc == 0, then select() timed out */
1289 }
1290
1291 return result;
1292}
1293
1294/**********************************************************
1295 *
1296 * tftp_doing
1297 *
1298 * Called from multi.c while DOing
1299 *
1300 **********************************************************/
1301static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done)
1302{
1303 CURLcode result;
1304 result = tftp_multi_statemach(conn, dophase_done);
1305
1306 if(*dophase_done) {
1307 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1308 }
1309 else if(!result) {
1310 /* The multi code doesn't have this logic for the DOING state so we
1311 provide it for TFTP since it may do the entire transfer in this
1312 state. */
1313 if(Curl_pgrsUpdate(conn))
1314 result = CURLE_ABORTED_BY_CALLBACK;
1315 else
1316 result = Curl_speedcheck(conn->data, Curl_now());
1317 }
1318 return result;
1319}
1320
1321/**********************************************************
1322 *
1323 * tftp_peform
1324 *
1325 * Entry point for transfer from tftp_do, sarts state mach
1326 *
1327 **********************************************************/
1328static CURLcode tftp_perform(struct connectdata *conn, bool *dophase_done)
1329{
1330 CURLcode result = CURLE_OK;
1331 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1332
1333 *dophase_done = FALSE;
1334
1335 result = tftp_state_machine(state, TFTP_EVENT_INIT);
1336
1337 if((state->state == TFTP_STATE_FIN) || result)
1338 return result;
1339
1340 tftp_multi_statemach(conn, dophase_done);
1341
1342 if(*dophase_done)
1343 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1344
1345 return result;
1346}
1347
1348
1349/**********************************************************
1350 *
1351 * tftp_do
1352 *
1353 * The do callback
1354 *
1355 * This callback initiates the TFTP transfer
1356 *
1357 **********************************************************/
1358
1359static CURLcode tftp_do(struct connectdata *conn, bool *done)
1360{
1361 tftp_state_data_t *state;
1362 CURLcode result;
1363
1364 *done = FALSE;
1365
1366 if(!conn->proto.tftpc) {
1367 result = tftp_connect(conn, done);
1368 if(result)
1369 return result;
1370 }
1371
1372 state = (tftp_state_data_t *)conn->proto.tftpc;
1373 if(!state)
1374 return CURLE_TFTP_ILLEGAL;
1375
1376 result = tftp_perform(conn, done);
1377
1378 /* If tftp_perform() returned an error, use that for return code. If it
1379 was OK, see if tftp_translate_code() has an error. */
1380 if(!result)
1381 /* If we have encountered an internal tftp error, translate it. */
1382 result = tftp_translate_code(state->error);
1383
1384 return result;
1385}
1386
1387static CURLcode tftp_setup_connection(struct connectdata * conn)
1388{
1389 struct Curl_easy *data = conn->data;
1390 char *type;
1391
1392 conn->transport = TRNSPRT_UDP;
1393
1394 /* TFTP URLs support an extension like ";mode=<typecode>" that
1395 * we'll try to get now! */
1396 type = strstr(data->state.up.path, ";mode=");
1397
1398 if(!type)
1399 type = strstr(conn->host.rawalloc, ";mode=");
1400
1401 if(type) {
1402 char command;
1403 *type = 0; /* it was in the middle of the hostname */
1404 command = Curl_raw_toupper(type[6]);
1405
1406 switch(command) {
1407 case 'A': /* ASCII mode */
1408 case 'N': /* NETASCII mode */
1409 data->set.prefer_ascii = TRUE;
1410 break;
1411
1412 case 'O': /* octet mode */
1413 case 'I': /* binary mode */
1414 default:
1415 /* switch off ASCII */
1416 data->set.prefer_ascii = FALSE;
1417 break;
1418 }
1419 }
1420
1421 return CURLE_OK;
1422}
1423#endif
1424