1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25 #include "curl_setup.h"
26
27 #ifndef CURL_DISABLE_TFTP
28
29 #ifdef HAVE_NETINET_IN_H
30 #include <netinet/in.h>
31 #endif
32 #ifdef HAVE_NETDB_H
33 #include <netdb.h>
34 #endif
35 #ifdef HAVE_ARPA_INET_H
36 #include <arpa/inet.h>
37 #endif
38 #ifdef HAVE_NET_IF_H
39 #include <net/if.h>
40 #endif
41 #ifdef HAVE_SYS_IOCTL_H
42 #include <sys/ioctl.h>
43 #endif
44
45 #ifdef HAVE_SYS_PARAM_H
46 #include <sys/param.h>
47 #endif
48
49 #include "urldata.h"
50 #include <curl/curl.h>
51 #include "cf-socket.h"
52 #include "transfer.h"
53 #include "sendf.h"
54 #include "tftp.h"
55 #include "progress.h"
56 #include "connect.h"
57 #include "strerror.h"
58 #include "sockaddr.h" /* required for Curl_sockaddr_storage */
59 #include "multiif.h"
60 #include "url.h"
61 #include "strcase.h"
62 #include "speedcheck.h"
63 #include "select.h"
64 #include "escape.h"
65
66 /* The last 3 #include files should be in this order */
67 #include "curl_printf.h"
68 #include "curl_memory.h"
69 #include "memdebug.h"
70
71 /* RFC2348 allows the block size to be negotiated */
72 #define TFTP_BLKSIZE_DEFAULT 512
73 #define TFTP_OPTION_BLKSIZE "blksize"
74
75 /* from RFC2349: */
76 #define TFTP_OPTION_TSIZE "tsize"
77 #define TFTP_OPTION_INTERVAL "timeout"
78
79 typedef enum {
80 TFTP_MODE_NETASCII = 0,
81 TFTP_MODE_OCTET
82 } tftp_mode_t;
83
84 typedef enum {
85 TFTP_STATE_START = 0,
86 TFTP_STATE_RX,
87 TFTP_STATE_TX,
88 TFTP_STATE_FIN
89 } tftp_state_t;
90
91 typedef enum {
92 TFTP_EVENT_NONE = -1,
93 TFTP_EVENT_INIT = 0,
94 TFTP_EVENT_RRQ = 1,
95 TFTP_EVENT_WRQ = 2,
96 TFTP_EVENT_DATA = 3,
97 TFTP_EVENT_ACK = 4,
98 TFTP_EVENT_ERROR = 5,
99 TFTP_EVENT_OACK = 6,
100 TFTP_EVENT_TIMEOUT
101 } tftp_event_t;
102
103 typedef enum {
104 TFTP_ERR_UNDEF = 0,
105 TFTP_ERR_NOTFOUND,
106 TFTP_ERR_PERM,
107 TFTP_ERR_DISKFULL,
108 TFTP_ERR_ILLEGAL,
109 TFTP_ERR_UNKNOWNID,
110 TFTP_ERR_EXISTS,
111 TFTP_ERR_NOSUCHUSER, /* This will never be triggered by this code */
112
113 /* The remaining error codes are internal to curl */
114 TFTP_ERR_NONE = -100,
115 TFTP_ERR_TIMEOUT,
116 TFTP_ERR_NORESPONSE
117 } tftp_error_t;
118
119 struct tftp_packet {
120 unsigned char *data;
121 };
122
123 struct tftp_state_data {
124 tftp_state_t state;
125 tftp_mode_t mode;
126 tftp_error_t error;
127 tftp_event_t event;
128 struct Curl_easy *data;
129 curl_socket_t sockfd;
130 int retries;
131 int retry_time;
132 int retry_max;
133 time_t rx_time;
134 struct Curl_sockaddr_storage local_addr;
135 struct Curl_sockaddr_storage remote_addr;
136 curl_socklen_t remote_addrlen;
137 int rbytes;
138 int sbytes;
139 int blksize;
140 int requested_blksize;
141 unsigned short block;
142 struct tftp_packet rpacket;
143 struct tftp_packet spacket;
144 };
145
146
147 /* Forward declarations */
148 static CURLcode tftp_rx(struct tftp_state_data *state, tftp_event_t event);
149 static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event);
150 static CURLcode tftp_connect(struct Curl_easy *data, bool *done);
151 static CURLcode tftp_disconnect(struct Curl_easy *data,
152 struct connectdata *conn,
153 bool dead_connection);
154 static CURLcode tftp_do(struct Curl_easy *data, bool *done);
155 static CURLcode tftp_done(struct Curl_easy *data,
156 CURLcode, bool premature);
157 static CURLcode tftp_setup_connection(struct Curl_easy *data,
158 struct connectdata *conn);
159 static CURLcode tftp_multi_statemach(struct Curl_easy *data, bool *done);
160 static CURLcode tftp_doing(struct Curl_easy *data, bool *dophase_done);
161 static int tftp_getsock(struct Curl_easy *data, struct connectdata *conn,
162 curl_socket_t *socks);
163 static CURLcode tftp_translate_code(tftp_error_t error);
164
165
166 /*
167 * TFTP protocol handler.
168 */
169
170 const struct Curl_handler Curl_handler_tftp = {
171 "TFTP", /* scheme */
172 tftp_setup_connection, /* setup_connection */
173 tftp_do, /* do_it */
174 tftp_done, /* done */
175 ZERO_NULL, /* do_more */
176 tftp_connect, /* connect_it */
177 tftp_multi_statemach, /* connecting */
178 tftp_doing, /* doing */
179 tftp_getsock, /* proto_getsock */
180 tftp_getsock, /* doing_getsock */
181 ZERO_NULL, /* domore_getsock */
182 ZERO_NULL, /* perform_getsock */
183 tftp_disconnect, /* disconnect */
184 ZERO_NULL, /* write_resp */
185 ZERO_NULL, /* write_resp_hd */
186 ZERO_NULL, /* connection_check */
187 ZERO_NULL, /* attach connection */
188 PORT_TFTP, /* defport */
189 CURLPROTO_TFTP, /* protocol */
190 CURLPROTO_TFTP, /* family */
191 PROTOPT_NOTCPPROXY | PROTOPT_NOURLQUERY /* flags */
192 };
193
194 /**********************************************************
195 *
196 * tftp_set_timeouts -
197 *
198 * Set timeouts based on state machine state.
199 * Use user provided connect timeouts until DATA or ACK
200 * packet is received, then use user-provided transfer timeouts
201 *
202 *
203 **********************************************************/
tftp_set_timeouts(struct tftp_state_data * state)204 static CURLcode tftp_set_timeouts(struct tftp_state_data *state)
205 {
206 time_t maxtime, timeout;
207 timediff_t timeout_ms;
208 bool start = (state->state == TFTP_STATE_START) ? TRUE : FALSE;
209
210 /* Compute drop-dead time */
211 timeout_ms = Curl_timeleft(state->data, NULL, start);
212
213 if(timeout_ms < 0) {
214 /* time-out, bail out, go home */
215 failf(state->data, "Connection time-out");
216 return CURLE_OPERATION_TIMEDOUT;
217 }
218
219 if(timeout_ms > 0)
220 maxtime = (time_t)(timeout_ms + 500) / 1000;
221 else
222 maxtime = 3600; /* use for calculating block timeouts */
223
224 /* Set per-block timeout to total */
225 timeout = maxtime;
226
227 /* Average reposting an ACK after 5 seconds */
228 state->retry_max = (int)timeout/5;
229
230 /* But bound the total number */
231 if(state->retry_max<3)
232 state->retry_max = 3;
233
234 if(state->retry_max>50)
235 state->retry_max = 50;
236
237 /* Compute the re-ACK interval to suit the timeout */
238 state->retry_time = (int)(timeout/state->retry_max);
239 if(state->retry_time<1)
240 state->retry_time = 1;
241
242 infof(state->data,
243 "set timeouts for state %d; Total % " CURL_FORMAT_CURL_OFF_T
244 ", retry %d maxtry %d",
245 (int)state->state, timeout_ms, state->retry_time, state->retry_max);
246
247 /* init RX time */
248 time(&state->rx_time);
249
250 return CURLE_OK;
251 }
252
253 /**********************************************************
254 *
255 * tftp_set_send_first
256 *
257 * Event handler for the START state
258 *
259 **********************************************************/
260
setpacketevent(struct tftp_packet * packet,unsigned short num)261 static void setpacketevent(struct tftp_packet *packet, unsigned short num)
262 {
263 packet->data[0] = (unsigned char)(num >> 8);
264 packet->data[1] = (unsigned char)(num & 0xff);
265 }
266
267
setpacketblock(struct tftp_packet * packet,unsigned short num)268 static void setpacketblock(struct tftp_packet *packet, unsigned short num)
269 {
270 packet->data[2] = (unsigned char)(num >> 8);
271 packet->data[3] = (unsigned char)(num & 0xff);
272 }
273
getrpacketevent(const struct tftp_packet * packet)274 static unsigned short getrpacketevent(const struct tftp_packet *packet)
275 {
276 return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
277 }
278
getrpacketblock(const struct tftp_packet * packet)279 static unsigned short getrpacketblock(const struct tftp_packet *packet)
280 {
281 return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
282 }
283
tftp_strnlen(const char * string,size_t maxlen)284 static size_t tftp_strnlen(const char *string, size_t maxlen)
285 {
286 const char *end = memchr(string, '\0', maxlen);
287 return end ? (size_t) (end - string) : maxlen;
288 }
289
tftp_option_get(const char * buf,size_t len,const char ** option,const char ** value)290 static const char *tftp_option_get(const char *buf, size_t len,
291 const char **option, const char **value)
292 {
293 size_t loc;
294
295 loc = tftp_strnlen(buf, len);
296 loc++; /* NULL term */
297
298 if(loc >= len)
299 return NULL;
300 *option = buf;
301
302 loc += tftp_strnlen(buf + loc, len-loc);
303 loc++; /* NULL term */
304
305 if(loc > len)
306 return NULL;
307 *value = &buf[strlen(*option) + 1];
308
309 return &buf[loc];
310 }
311
tftp_parse_option_ack(struct tftp_state_data * state,const char * ptr,int len)312 static CURLcode tftp_parse_option_ack(struct tftp_state_data *state,
313 const char *ptr, int len)
314 {
315 const char *tmp = ptr;
316 struct Curl_easy *data = state->data;
317
318 /* if OACK doesn't contain blksize option, the default (512) must be used */
319 state->blksize = TFTP_BLKSIZE_DEFAULT;
320
321 while(tmp < ptr + len) {
322 const char *option, *value;
323
324 tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
325 if(!tmp) {
326 failf(data, "Malformed ACK packet, rejecting");
327 return CURLE_TFTP_ILLEGAL;
328 }
329
330 infof(data, "got option=(%s) value=(%s)", option, value);
331
332 if(checkprefix(TFTP_OPTION_BLKSIZE, option)) {
333 long blksize;
334
335 blksize = strtol(value, NULL, 10);
336
337 if(!blksize) {
338 failf(data, "invalid blocksize value in OACK packet");
339 return CURLE_TFTP_ILLEGAL;
340 }
341 if(blksize > TFTP_BLKSIZE_MAX) {
342 failf(data, "%s (%d)", "blksize is larger than max supported",
343 TFTP_BLKSIZE_MAX);
344 return CURLE_TFTP_ILLEGAL;
345 }
346 else if(blksize < TFTP_BLKSIZE_MIN) {
347 failf(data, "%s (%d)", "blksize is smaller than min supported",
348 TFTP_BLKSIZE_MIN);
349 return CURLE_TFTP_ILLEGAL;
350 }
351 else if(blksize > state->requested_blksize) {
352 /* could realloc pkt buffers here, but the spec doesn't call out
353 * support for the server requesting a bigger blksize than the client
354 * requests */
355 failf(data, "%s (%ld)",
356 "server requested blksize larger than allocated", blksize);
357 return CURLE_TFTP_ILLEGAL;
358 }
359
360 state->blksize = (int)blksize;
361 infof(data, "%s (%d) %s (%d)", "blksize parsed from OACK",
362 state->blksize, "requested", state->requested_blksize);
363 }
364 else if(checkprefix(TFTP_OPTION_TSIZE, option)) {
365 long tsize = 0;
366
367 tsize = strtol(value, NULL, 10);
368 infof(data, "%s (%ld)", "tsize parsed from OACK", tsize);
369
370 /* tsize should be ignored on upload: Who cares about the size of the
371 remote file? */
372 if(!data->state.upload) {
373 if(!tsize) {
374 failf(data, "invalid tsize -:%s:- value in OACK packet", value);
375 return CURLE_TFTP_ILLEGAL;
376 }
377 Curl_pgrsSetDownloadSize(data, tsize);
378 }
379 }
380 }
381
382 return CURLE_OK;
383 }
384
tftp_option_add(struct tftp_state_data * state,size_t * csize,char * buf,const char * option)385 static CURLcode tftp_option_add(struct tftp_state_data *state, size_t *csize,
386 char *buf, const char *option)
387 {
388 if(( strlen(option) + *csize + 1) > (size_t)state->blksize)
389 return CURLE_TFTP_ILLEGAL;
390 strcpy(buf, option);
391 *csize += strlen(option) + 1;
392 return CURLE_OK;
393 }
394
tftp_connect_for_tx(struct tftp_state_data * state,tftp_event_t event)395 static CURLcode tftp_connect_for_tx(struct tftp_state_data *state,
396 tftp_event_t event)
397 {
398 CURLcode result;
399 #ifndef CURL_DISABLE_VERBOSE_STRINGS
400 struct Curl_easy *data = state->data;
401
402 infof(data, "%s", "Connected for transmit");
403 #endif
404 state->state = TFTP_STATE_TX;
405 result = tftp_set_timeouts(state);
406 if(result)
407 return result;
408 return tftp_tx(state, event);
409 }
410
tftp_connect_for_rx(struct tftp_state_data * state,tftp_event_t event)411 static CURLcode tftp_connect_for_rx(struct tftp_state_data *state,
412 tftp_event_t event)
413 {
414 CURLcode result;
415 #ifndef CURL_DISABLE_VERBOSE_STRINGS
416 struct Curl_easy *data = state->data;
417
418 infof(data, "%s", "Connected for receive");
419 #endif
420 state->state = TFTP_STATE_RX;
421 result = tftp_set_timeouts(state);
422 if(result)
423 return result;
424 return tftp_rx(state, event);
425 }
426
tftp_send_first(struct tftp_state_data * state,tftp_event_t event)427 static CURLcode tftp_send_first(struct tftp_state_data *state,
428 tftp_event_t event)
429 {
430 size_t sbytes;
431 ssize_t senddata;
432 const char *mode = "octet";
433 char *filename;
434 struct Curl_easy *data = state->data;
435 CURLcode result = CURLE_OK;
436
437 /* Set ascii mode if -B flag was used */
438 if(data->state.prefer_ascii)
439 mode = "netascii";
440
441 switch(event) {
442
443 case TFTP_EVENT_INIT: /* Send the first packet out */
444 case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
445 /* Increment the retry counter, quit if over the limit */
446 state->retries++;
447 if(state->retries>state->retry_max) {
448 state->error = TFTP_ERR_NORESPONSE;
449 state->state = TFTP_STATE_FIN;
450 return result;
451 }
452
453 if(data->state.upload) {
454 /* If we are uploading, send an WRQ */
455 setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
456 if(data->state.infilesize != -1)
457 Curl_pgrsSetUploadSize(data, data->state.infilesize);
458 }
459 else {
460 /* If we are downloading, send an RRQ */
461 setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
462 }
463 /* As RFC3617 describes the separator slash is not actually part of the
464 file name so we skip the always-present first letter of the path
465 string. */
466 result = Curl_urldecode(&state->data->state.up.path[1], 0,
467 &filename, NULL, REJECT_ZERO);
468 if(result)
469 return result;
470
471 if(strlen(filename) > (state->blksize - strlen(mode) - 4)) {
472 failf(data, "TFTP file name too long");
473 free(filename);
474 return CURLE_TFTP_ILLEGAL; /* too long file name field */
475 }
476
477 msnprintf((char *)state->spacket.data + 2,
478 state->blksize,
479 "%s%c%s%c", filename, '\0', mode, '\0');
480 sbytes = 4 + strlen(filename) + strlen(mode);
481
482 /* optional addition of TFTP options */
483 if(!data->set.tftp_no_options) {
484 char buf[64];
485 /* add tsize option */
486 if(data->state.upload && (data->state.infilesize != -1))
487 msnprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
488 data->state.infilesize);
489 else
490 strcpy(buf, "0"); /* the destination is large enough */
491
492 result = tftp_option_add(state, &sbytes,
493 (char *)state->spacket.data + sbytes,
494 TFTP_OPTION_TSIZE);
495 if(result == CURLE_OK)
496 result = tftp_option_add(state, &sbytes,
497 (char *)state->spacket.data + sbytes, buf);
498
499 /* add blksize option */
500 msnprintf(buf, sizeof(buf), "%d", state->requested_blksize);
501 if(result == CURLE_OK)
502 result = tftp_option_add(state, &sbytes,
503 (char *)state->spacket.data + sbytes,
504 TFTP_OPTION_BLKSIZE);
505 if(result == CURLE_OK)
506 result = tftp_option_add(state, &sbytes,
507 (char *)state->spacket.data + sbytes, buf);
508
509 /* add timeout option */
510 msnprintf(buf, sizeof(buf), "%d", state->retry_time);
511 if(result == CURLE_OK)
512 result = tftp_option_add(state, &sbytes,
513 (char *)state->spacket.data + sbytes,
514 TFTP_OPTION_INTERVAL);
515 if(result == CURLE_OK)
516 result = tftp_option_add(state, &sbytes,
517 (char *)state->spacket.data + sbytes, buf);
518
519 if(result != CURLE_OK) {
520 failf(data, "TFTP buffer too small for options");
521 free(filename);
522 return CURLE_TFTP_ILLEGAL;
523 }
524 }
525
526 /* the typecase for the 3rd argument is mostly for systems that do
527 not have a size_t argument, like older unixes that want an 'int' */
528 senddata = sendto(state->sockfd, (void *)state->spacket.data,
529 (SEND_TYPE_ARG3)sbytes, 0,
530 &data->conn->remote_addr->sa_addr,
531 data->conn->remote_addr->addrlen);
532 if(senddata != (ssize_t)sbytes) {
533 char buffer[STRERROR_LEN];
534 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
535 }
536 free(filename);
537 break;
538
539 case TFTP_EVENT_OACK:
540 if(data->state.upload) {
541 result = tftp_connect_for_tx(state, event);
542 }
543 else {
544 result = tftp_connect_for_rx(state, event);
545 }
546 break;
547
548 case TFTP_EVENT_ACK: /* Connected for transmit */
549 result = tftp_connect_for_tx(state, event);
550 break;
551
552 case TFTP_EVENT_DATA: /* Connected for receive */
553 result = tftp_connect_for_rx(state, event);
554 break;
555
556 case TFTP_EVENT_ERROR:
557 state->state = TFTP_STATE_FIN;
558 break;
559
560 default:
561 failf(state->data, "tftp_send_first: internal error");
562 break;
563 }
564
565 return result;
566 }
567
568 /* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
569 boundary */
570 #define NEXT_BLOCKNUM(x) (((x) + 1)&0xffff)
571
572 /**********************************************************
573 *
574 * tftp_rx
575 *
576 * Event handler for the RX state
577 *
578 **********************************************************/
tftp_rx(struct tftp_state_data * state,tftp_event_t event)579 static CURLcode tftp_rx(struct tftp_state_data *state,
580 tftp_event_t event)
581 {
582 ssize_t sbytes;
583 int rblock;
584 struct Curl_easy *data = state->data;
585 char buffer[STRERROR_LEN];
586
587 switch(event) {
588
589 case TFTP_EVENT_DATA:
590 /* Is this the block we expect? */
591 rblock = getrpacketblock(&state->rpacket);
592 if(NEXT_BLOCKNUM(state->block) == rblock) {
593 /* This is the expected block. Reset counters and ACK it. */
594 state->retries = 0;
595 }
596 else if(state->block == rblock) {
597 /* This is the last recently received block again. Log it and ACK it
598 again. */
599 infof(data, "Received last DATA packet block %d again.", rblock);
600 }
601 else {
602 /* totally unexpected, just log it */
603 infof(data,
604 "Received unexpected DATA packet block %d, expecting block %d",
605 rblock, NEXT_BLOCKNUM(state->block));
606 break;
607 }
608
609 /* ACK this block. */
610 state->block = (unsigned short)rblock;
611 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
612 setpacketblock(&state->spacket, state->block);
613 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
614 4, SEND_4TH_ARG,
615 (struct sockaddr *)&state->remote_addr,
616 state->remote_addrlen);
617 if(sbytes < 0) {
618 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
619 return CURLE_SEND_ERROR;
620 }
621
622 /* Check if completed (That is, a less than full packet is received) */
623 if(state->rbytes < (ssize_t)state->blksize + 4) {
624 state->state = TFTP_STATE_FIN;
625 }
626 else {
627 state->state = TFTP_STATE_RX;
628 }
629 time(&state->rx_time);
630 break;
631
632 case TFTP_EVENT_OACK:
633 /* ACK option acknowledgement so we can move on to data */
634 state->block = 0;
635 state->retries = 0;
636 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
637 setpacketblock(&state->spacket, state->block);
638 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
639 4, SEND_4TH_ARG,
640 (struct sockaddr *)&state->remote_addr,
641 state->remote_addrlen);
642 if(sbytes < 0) {
643 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
644 return CURLE_SEND_ERROR;
645 }
646
647 /* we're ready to RX data */
648 state->state = TFTP_STATE_RX;
649 time(&state->rx_time);
650 break;
651
652 case TFTP_EVENT_TIMEOUT:
653 /* Increment the retry count and fail if over the limit */
654 state->retries++;
655 infof(data,
656 "Timeout waiting for block %d ACK. Retries = %d",
657 NEXT_BLOCKNUM(state->block), state->retries);
658 if(state->retries > state->retry_max) {
659 state->error = TFTP_ERR_TIMEOUT;
660 state->state = TFTP_STATE_FIN;
661 }
662 else {
663 /* Resend the previous ACK */
664 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
665 4, SEND_4TH_ARG,
666 (struct sockaddr *)&state->remote_addr,
667 state->remote_addrlen);
668 if(sbytes<0) {
669 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
670 return CURLE_SEND_ERROR;
671 }
672 }
673 break;
674
675 case TFTP_EVENT_ERROR:
676 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
677 setpacketblock(&state->spacket, state->block);
678 (void)sendto(state->sockfd, (void *)state->spacket.data,
679 4, SEND_4TH_ARG,
680 (struct sockaddr *)&state->remote_addr,
681 state->remote_addrlen);
682 /* don't bother with the return code, but if the socket is still up we
683 * should be a good TFTP client and let the server know we're done */
684 state->state = TFTP_STATE_FIN;
685 break;
686
687 default:
688 failf(data, "%s", "tftp_rx: internal error");
689 return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
690 this */
691 }
692 return CURLE_OK;
693 }
694
695 /**********************************************************
696 *
697 * tftp_tx
698 *
699 * Event handler for the TX state
700 *
701 **********************************************************/
tftp_tx(struct tftp_state_data * state,tftp_event_t event)702 static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event)
703 {
704 struct Curl_easy *data = state->data;
705 ssize_t sbytes;
706 CURLcode result = CURLE_OK;
707 struct SingleRequest *k = &data->req;
708 size_t cb; /* Bytes currently read */
709 char buffer[STRERROR_LEN];
710 char *bufptr;
711 bool eos;
712
713 switch(event) {
714
715 case TFTP_EVENT_ACK:
716 case TFTP_EVENT_OACK:
717 if(event == TFTP_EVENT_ACK) {
718 /* Ack the packet */
719 int rblock = getrpacketblock(&state->rpacket);
720
721 if(rblock != state->block &&
722 /* There's a bug in tftpd-hpa that causes it to send us an ack for
723 * 65535 when the block number wraps to 0. So when we're expecting
724 * 0, also accept 65535. See
725 * https://www.syslinux.org/archives/2010-September/015612.html
726 * */
727 !(state->block == 0 && rblock == 65535)) {
728 /* This isn't the expected block. Log it and up the retry counter */
729 infof(data, "Received ACK for block %d, expecting %d",
730 rblock, state->block);
731 state->retries++;
732 /* Bail out if over the maximum */
733 if(state->retries>state->retry_max) {
734 failf(data, "tftp_tx: giving up waiting for block %d ack",
735 state->block);
736 result = CURLE_SEND_ERROR;
737 }
738 else {
739 /* Re-send the data packet */
740 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
741 4 + state->sbytes, SEND_4TH_ARG,
742 (struct sockaddr *)&state->remote_addr,
743 state->remote_addrlen);
744 /* Check all sbytes were sent */
745 if(sbytes<0) {
746 failf(data, "%s", Curl_strerror(SOCKERRNO,
747 buffer, sizeof(buffer)));
748 result = CURLE_SEND_ERROR;
749 }
750 }
751
752 return result;
753 }
754 /* This is the expected packet. Reset the counters and send the next
755 block */
756 time(&state->rx_time);
757 state->block++;
758 }
759 else
760 state->block = 1; /* first data block is 1 when using OACK */
761
762 state->retries = 0;
763 setpacketevent(&state->spacket, TFTP_EVENT_DATA);
764 setpacketblock(&state->spacket, state->block);
765 if(state->block > 1 && state->sbytes < state->blksize) {
766 state->state = TFTP_STATE_FIN;
767 return CURLE_OK;
768 }
769
770 /* TFTP considers data block size < 512 bytes as an end of session. So
771 * in some cases we must wait for additional data to build full (512 bytes)
772 * data block.
773 * */
774 state->sbytes = 0;
775 bufptr = (char *)state->spacket.data + 4;
776 do {
777 result = Curl_client_read(data, bufptr, state->blksize - state->sbytes,
778 &cb, &eos);
779 if(result)
780 return result;
781 state->sbytes += (int)cb;
782 bufptr += cb;
783 } while(state->sbytes < state->blksize && cb);
784
785 sbytes = sendto(state->sockfd, (void *) state->spacket.data,
786 4 + state->sbytes, SEND_4TH_ARG,
787 (struct sockaddr *)&state->remote_addr,
788 state->remote_addrlen);
789 /* Check all sbytes were sent */
790 if(sbytes<0) {
791 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
792 return CURLE_SEND_ERROR;
793 }
794 /* Update the progress meter */
795 k->writebytecount += state->sbytes;
796 Curl_pgrsSetUploadCounter(data, k->writebytecount);
797 break;
798
799 case TFTP_EVENT_TIMEOUT:
800 /* Increment the retry counter and log the timeout */
801 state->retries++;
802 infof(data, "Timeout waiting for block %d ACK. "
803 " Retries = %d", NEXT_BLOCKNUM(state->block), state->retries);
804 /* Decide if we've had enough */
805 if(state->retries > state->retry_max) {
806 state->error = TFTP_ERR_TIMEOUT;
807 state->state = TFTP_STATE_FIN;
808 }
809 else {
810 /* Re-send the data packet */
811 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
812 4 + state->sbytes, SEND_4TH_ARG,
813 (struct sockaddr *)&state->remote_addr,
814 state->remote_addrlen);
815 /* Check all sbytes were sent */
816 if(sbytes<0) {
817 failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
818 return CURLE_SEND_ERROR;
819 }
820 /* since this was a re-send, we remain at the still byte position */
821 Curl_pgrsSetUploadCounter(data, k->writebytecount);
822 }
823 break;
824
825 case TFTP_EVENT_ERROR:
826 state->state = TFTP_STATE_FIN;
827 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
828 setpacketblock(&state->spacket, state->block);
829 (void)sendto(state->sockfd, (void *)state->spacket.data, 4, SEND_4TH_ARG,
830 (struct sockaddr *)&state->remote_addr,
831 state->remote_addrlen);
832 /* don't bother with the return code, but if the socket is still up we
833 * should be a good TFTP client and let the server know we're done */
834 state->state = TFTP_STATE_FIN;
835 break;
836
837 default:
838 failf(data, "tftp_tx: internal error, event: %i", (int)(event));
839 break;
840 }
841
842 return result;
843 }
844
845 /**********************************************************
846 *
847 * tftp_translate_code
848 *
849 * Translate internal error codes to CURL error codes
850 *
851 **********************************************************/
tftp_translate_code(tftp_error_t error)852 static CURLcode tftp_translate_code(tftp_error_t error)
853 {
854 CURLcode result = CURLE_OK;
855
856 if(error != TFTP_ERR_NONE) {
857 switch(error) {
858 case TFTP_ERR_NOTFOUND:
859 result = CURLE_TFTP_NOTFOUND;
860 break;
861 case TFTP_ERR_PERM:
862 result = CURLE_TFTP_PERM;
863 break;
864 case TFTP_ERR_DISKFULL:
865 result = CURLE_REMOTE_DISK_FULL;
866 break;
867 case TFTP_ERR_UNDEF:
868 case TFTP_ERR_ILLEGAL:
869 result = CURLE_TFTP_ILLEGAL;
870 break;
871 case TFTP_ERR_UNKNOWNID:
872 result = CURLE_TFTP_UNKNOWNID;
873 break;
874 case TFTP_ERR_EXISTS:
875 result = CURLE_REMOTE_FILE_EXISTS;
876 break;
877 case TFTP_ERR_NOSUCHUSER:
878 result = CURLE_TFTP_NOSUCHUSER;
879 break;
880 case TFTP_ERR_TIMEOUT:
881 result = CURLE_OPERATION_TIMEDOUT;
882 break;
883 case TFTP_ERR_NORESPONSE:
884 result = CURLE_COULDNT_CONNECT;
885 break;
886 default:
887 result = CURLE_ABORTED_BY_CALLBACK;
888 break;
889 }
890 }
891 else
892 result = CURLE_OK;
893
894 return result;
895 }
896
897 /**********************************************************
898 *
899 * tftp_state_machine
900 *
901 * The tftp state machine event dispatcher
902 *
903 **********************************************************/
tftp_state_machine(struct tftp_state_data * state,tftp_event_t event)904 static CURLcode tftp_state_machine(struct tftp_state_data *state,
905 tftp_event_t event)
906 {
907 CURLcode result = CURLE_OK;
908 struct Curl_easy *data = state->data;
909
910 switch(state->state) {
911 case TFTP_STATE_START:
912 DEBUGF(infof(data, "TFTP_STATE_START"));
913 result = tftp_send_first(state, event);
914 break;
915 case TFTP_STATE_RX:
916 DEBUGF(infof(data, "TFTP_STATE_RX"));
917 result = tftp_rx(state, event);
918 break;
919 case TFTP_STATE_TX:
920 DEBUGF(infof(data, "TFTP_STATE_TX"));
921 result = tftp_tx(state, event);
922 break;
923 case TFTP_STATE_FIN:
924 infof(data, "%s", "TFTP finished");
925 break;
926 default:
927 DEBUGF(infof(data, "STATE: %d", state->state));
928 failf(data, "%s", "Internal state machine error");
929 result = CURLE_TFTP_ILLEGAL;
930 break;
931 }
932
933 return result;
934 }
935
936 /**********************************************************
937 *
938 * tftp_disconnect
939 *
940 * The disconnect callback
941 *
942 **********************************************************/
tftp_disconnect(struct Curl_easy * data,struct connectdata * conn,bool dead_connection)943 static CURLcode tftp_disconnect(struct Curl_easy *data,
944 struct connectdata *conn, bool dead_connection)
945 {
946 struct tftp_state_data *state = conn->proto.tftpc;
947 (void) data;
948 (void) dead_connection;
949
950 /* done, free dynamically allocated pkt buffers */
951 if(state) {
952 Curl_safefree(state->rpacket.data);
953 Curl_safefree(state->spacket.data);
954 free(state);
955 }
956
957 return CURLE_OK;
958 }
959
960 /**********************************************************
961 *
962 * tftp_connect
963 *
964 * The connect callback
965 *
966 **********************************************************/
tftp_connect(struct Curl_easy * data,bool * done)967 static CURLcode tftp_connect(struct Curl_easy *data, bool *done)
968 {
969 struct tftp_state_data *state;
970 int blksize;
971 int need_blksize;
972 struct connectdata *conn = data->conn;
973
974 blksize = TFTP_BLKSIZE_DEFAULT;
975
976 state = conn->proto.tftpc = calloc(1, sizeof(struct tftp_state_data));
977 if(!state)
978 return CURLE_OUT_OF_MEMORY;
979
980 /* alloc pkt buffers based on specified blksize */
981 if(data->set.tftp_blksize)
982 /* range checked when set */
983 blksize = (int)data->set.tftp_blksize;
984
985 need_blksize = blksize;
986 /* default size is the fallback when no OACK is received */
987 if(need_blksize < TFTP_BLKSIZE_DEFAULT)
988 need_blksize = TFTP_BLKSIZE_DEFAULT;
989
990 if(!state->rpacket.data) {
991 state->rpacket.data = calloc(1, need_blksize + 2 + 2);
992
993 if(!state->rpacket.data)
994 return CURLE_OUT_OF_MEMORY;
995 }
996
997 if(!state->spacket.data) {
998 state->spacket.data = calloc(1, need_blksize + 2 + 2);
999
1000 if(!state->spacket.data)
1001 return CURLE_OUT_OF_MEMORY;
1002 }
1003
1004 /* we don't keep TFTP connections up basically because there's none or very
1005 * little gain for UDP */
1006 connclose(conn, "TFTP");
1007
1008 state->data = data;
1009 state->sockfd = conn->sock[FIRSTSOCKET];
1010 state->state = TFTP_STATE_START;
1011 state->error = TFTP_ERR_NONE;
1012 state->blksize = TFTP_BLKSIZE_DEFAULT; /* Unless updated by OACK response */
1013 state->requested_blksize = blksize;
1014
1015 ((struct sockaddr *)&state->local_addr)->sa_family =
1016 (CURL_SA_FAMILY_T)(conn->remote_addr->family);
1017
1018 tftp_set_timeouts(state);
1019
1020 if(!conn->bits.bound) {
1021 /* If not already bound, bind to any interface, random UDP port. If it is
1022 * reused or a custom local port was desired, this has already been done!
1023 *
1024 * We once used the size of the local_addr struct as the third argument
1025 * for bind() to better work with IPv6 or whatever size the struct could
1026 * have, but we learned that at least Tru64, AIX and IRIX *requires* the
1027 * size of that argument to match the exact size of a 'sockaddr_in' struct
1028 * when running IPv4-only.
1029 *
1030 * Therefore we use the size from the address we connected to, which we
1031 * assume uses the same IP version and thus hopefully this works for both
1032 * IPv4 and IPv6...
1033 */
1034 int rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
1035 conn->remote_addr->addrlen);
1036 if(rc) {
1037 char buffer[STRERROR_LEN];
1038 failf(data, "bind() failed; %s",
1039 Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
1040 return CURLE_COULDNT_CONNECT;
1041 }
1042 conn->bits.bound = TRUE;
1043 }
1044
1045 Curl_pgrsStartNow(data);
1046
1047 *done = TRUE;
1048
1049 return CURLE_OK;
1050 }
1051
1052 /**********************************************************
1053 *
1054 * tftp_done
1055 *
1056 * The done callback
1057 *
1058 **********************************************************/
tftp_done(struct Curl_easy * data,CURLcode status,bool premature)1059 static CURLcode tftp_done(struct Curl_easy *data, CURLcode status,
1060 bool premature)
1061 {
1062 CURLcode result = CURLE_OK;
1063 struct connectdata *conn = data->conn;
1064 struct tftp_state_data *state = conn->proto.tftpc;
1065
1066 (void)status; /* unused */
1067 (void)premature; /* not used */
1068
1069 if(Curl_pgrsDone(data))
1070 return CURLE_ABORTED_BY_CALLBACK;
1071
1072 /* If we have encountered an error */
1073 if(state)
1074 result = tftp_translate_code(state->error);
1075
1076 return result;
1077 }
1078
1079 /**********************************************************
1080 *
1081 * tftp_getsock
1082 *
1083 * The getsock callback
1084 *
1085 **********************************************************/
tftp_getsock(struct Curl_easy * data,struct connectdata * conn,curl_socket_t * socks)1086 static int tftp_getsock(struct Curl_easy *data,
1087 struct connectdata *conn, curl_socket_t *socks)
1088 {
1089 (void)data;
1090 socks[0] = conn->sock[FIRSTSOCKET];
1091 return GETSOCK_READSOCK(0);
1092 }
1093
1094 /**********************************************************
1095 *
1096 * tftp_receive_packet
1097 *
1098 * Called once select fires and data is ready on the socket
1099 *
1100 **********************************************************/
tftp_receive_packet(struct Curl_easy * data)1101 static CURLcode tftp_receive_packet(struct Curl_easy *data)
1102 {
1103 struct Curl_sockaddr_storage fromaddr;
1104 curl_socklen_t fromlen;
1105 CURLcode result = CURLE_OK;
1106 struct connectdata *conn = data->conn;
1107 struct tftp_state_data *state = conn->proto.tftpc;
1108
1109 /* Receive the packet */
1110 fromlen = sizeof(fromaddr);
1111 state->rbytes = (int)recvfrom(state->sockfd,
1112 (void *)state->rpacket.data,
1113 state->blksize + 4,
1114 0,
1115 (struct sockaddr *)&fromaddr,
1116 &fromlen);
1117 if(state->remote_addrlen == 0) {
1118 memcpy(&state->remote_addr, &fromaddr, fromlen);
1119 state->remote_addrlen = fromlen;
1120 }
1121
1122 /* Sanity check packet length */
1123 if(state->rbytes < 4) {
1124 failf(data, "Received too short packet");
1125 /* Not a timeout, but how best to handle it? */
1126 state->event = TFTP_EVENT_TIMEOUT;
1127 }
1128 else {
1129 /* The event is given by the TFTP packet time */
1130 unsigned short event = getrpacketevent(&state->rpacket);
1131 state->event = (tftp_event_t)event;
1132
1133 switch(state->event) {
1134 case TFTP_EVENT_DATA:
1135 /* Don't pass to the client empty or retransmitted packets */
1136 if(state->rbytes > 4 &&
1137 (NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
1138 result = Curl_client_write(data, CLIENTWRITE_BODY,
1139 (char *)state->rpacket.data + 4,
1140 state->rbytes-4);
1141 if(result) {
1142 tftp_state_machine(state, TFTP_EVENT_ERROR);
1143 return result;
1144 }
1145 }
1146 break;
1147 case TFTP_EVENT_ERROR:
1148 {
1149 unsigned short error = getrpacketblock(&state->rpacket);
1150 char *str = (char *)state->rpacket.data + 4;
1151 size_t strn = state->rbytes - 4;
1152 state->error = (tftp_error_t)error;
1153 if(tftp_strnlen(str, strn) < strn)
1154 infof(data, "TFTP error: %s", str);
1155 break;
1156 }
1157 case TFTP_EVENT_ACK:
1158 break;
1159 case TFTP_EVENT_OACK:
1160 result = tftp_parse_option_ack(state,
1161 (const char *)state->rpacket.data + 2,
1162 state->rbytes-2);
1163 if(result)
1164 return result;
1165 break;
1166 case TFTP_EVENT_RRQ:
1167 case TFTP_EVENT_WRQ:
1168 default:
1169 failf(data, "%s", "Internal error: Unexpected packet");
1170 break;
1171 }
1172
1173 /* Update the progress meter */
1174 if(Curl_pgrsUpdate(data)) {
1175 tftp_state_machine(state, TFTP_EVENT_ERROR);
1176 return CURLE_ABORTED_BY_CALLBACK;
1177 }
1178 }
1179 return result;
1180 }
1181
1182 /**********************************************************
1183 *
1184 * tftp_state_timeout
1185 *
1186 * Check if timeouts have been reached
1187 *
1188 **********************************************************/
tftp_state_timeout(struct Curl_easy * data,tftp_event_t * event)1189 static timediff_t tftp_state_timeout(struct Curl_easy *data,
1190 tftp_event_t *event)
1191 {
1192 time_t current;
1193 struct connectdata *conn = data->conn;
1194 struct tftp_state_data *state = conn->proto.tftpc;
1195 timediff_t timeout_ms;
1196
1197 if(event)
1198 *event = TFTP_EVENT_NONE;
1199
1200 timeout_ms = Curl_timeleft(state->data, NULL,
1201 (state->state == TFTP_STATE_START));
1202 if(timeout_ms < 0) {
1203 state->error = TFTP_ERR_TIMEOUT;
1204 state->state = TFTP_STATE_FIN;
1205 return 0;
1206 }
1207 time(¤t);
1208 if(current > state->rx_time + state->retry_time) {
1209 if(event)
1210 *event = TFTP_EVENT_TIMEOUT;
1211 time(&state->rx_time); /* update even though we received nothing */
1212 }
1213
1214 return timeout_ms;
1215 }
1216
1217 /**********************************************************
1218 *
1219 * tftp_multi_statemach
1220 *
1221 * Handle single RX socket event and return
1222 *
1223 **********************************************************/
tftp_multi_statemach(struct Curl_easy * data,bool * done)1224 static CURLcode tftp_multi_statemach(struct Curl_easy *data, bool *done)
1225 {
1226 tftp_event_t event;
1227 CURLcode result = CURLE_OK;
1228 struct connectdata *conn = data->conn;
1229 struct tftp_state_data *state = conn->proto.tftpc;
1230 timediff_t timeout_ms = tftp_state_timeout(data, &event);
1231
1232 *done = FALSE;
1233
1234 if(timeout_ms < 0) {
1235 failf(data, "TFTP response timeout");
1236 return CURLE_OPERATION_TIMEDOUT;
1237 }
1238 if(event != TFTP_EVENT_NONE) {
1239 result = tftp_state_machine(state, event);
1240 if(result)
1241 return result;
1242 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1243 if(*done)
1244 /* Tell curl we're done */
1245 Curl_xfer_setup(data, -1, -1, FALSE, -1);
1246 }
1247 else {
1248 /* no timeouts to handle, check our socket */
1249 int rc = SOCKET_READABLE(state->sockfd, 0);
1250
1251 if(rc == -1) {
1252 /* bail out */
1253 int error = SOCKERRNO;
1254 char buffer[STRERROR_LEN];
1255 failf(data, "%s", Curl_strerror(error, buffer, sizeof(buffer)));
1256 state->event = TFTP_EVENT_ERROR;
1257 }
1258 else if(rc) {
1259 result = tftp_receive_packet(data);
1260 if(result)
1261 return result;
1262 result = tftp_state_machine(state, state->event);
1263 if(result)
1264 return result;
1265 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1266 if(*done)
1267 /* Tell curl we're done */
1268 Curl_xfer_setup(data, -1, -1, FALSE, -1);
1269 }
1270 /* if rc == 0, then select() timed out */
1271 }
1272
1273 return result;
1274 }
1275
1276 /**********************************************************
1277 *
1278 * tftp_doing
1279 *
1280 * Called from multi.c while DOing
1281 *
1282 **********************************************************/
tftp_doing(struct Curl_easy * data,bool * dophase_done)1283 static CURLcode tftp_doing(struct Curl_easy *data, bool *dophase_done)
1284 {
1285 CURLcode result;
1286 result = tftp_multi_statemach(data, dophase_done);
1287
1288 if(*dophase_done) {
1289 DEBUGF(infof(data, "DO phase is complete"));
1290 }
1291 else if(!result) {
1292 /* The multi code doesn't have this logic for the DOING state so we
1293 provide it for TFTP since it may do the entire transfer in this
1294 state. */
1295 if(Curl_pgrsUpdate(data))
1296 result = CURLE_ABORTED_BY_CALLBACK;
1297 else
1298 result = Curl_speedcheck(data, Curl_now());
1299 }
1300 return result;
1301 }
1302
1303 /**********************************************************
1304 *
1305 * tftp_perform
1306 *
1307 * Entry point for transfer from tftp_do, starts state mach
1308 *
1309 **********************************************************/
tftp_perform(struct Curl_easy * data,bool * dophase_done)1310 static CURLcode tftp_perform(struct Curl_easy *data, bool *dophase_done)
1311 {
1312 CURLcode result = CURLE_OK;
1313 struct connectdata *conn = data->conn;
1314 struct tftp_state_data *state = conn->proto.tftpc;
1315
1316 *dophase_done = FALSE;
1317
1318 result = tftp_state_machine(state, TFTP_EVENT_INIT);
1319
1320 if((state->state == TFTP_STATE_FIN) || result)
1321 return result;
1322
1323 tftp_multi_statemach(data, dophase_done);
1324
1325 if(*dophase_done)
1326 DEBUGF(infof(data, "DO phase is complete"));
1327
1328 return result;
1329 }
1330
1331
1332 /**********************************************************
1333 *
1334 * tftp_do
1335 *
1336 * The do callback
1337 *
1338 * This callback initiates the TFTP transfer
1339 *
1340 **********************************************************/
1341
tftp_do(struct Curl_easy * data,bool * done)1342 static CURLcode tftp_do(struct Curl_easy *data, bool *done)
1343 {
1344 struct tftp_state_data *state;
1345 CURLcode result;
1346 struct connectdata *conn = data->conn;
1347
1348 *done = FALSE;
1349
1350 if(!conn->proto.tftpc) {
1351 result = tftp_connect(data, done);
1352 if(result)
1353 return result;
1354 }
1355
1356 state = conn->proto.tftpc;
1357 if(!state)
1358 return CURLE_TFTP_ILLEGAL;
1359
1360 result = tftp_perform(data, done);
1361
1362 /* If tftp_perform() returned an error, use that for return code. If it
1363 was OK, see if tftp_translate_code() has an error. */
1364 if(!result)
1365 /* If we have encountered an internal tftp error, translate it. */
1366 result = tftp_translate_code(state->error);
1367
1368 return result;
1369 }
1370
tftp_setup_connection(struct Curl_easy * data,struct connectdata * conn)1371 static CURLcode tftp_setup_connection(struct Curl_easy *data,
1372 struct connectdata *conn)
1373 {
1374 char *type;
1375
1376 conn->transport = TRNSPRT_UDP;
1377
1378 /* TFTP URLs support an extension like ";mode=<typecode>" that
1379 * we'll try to get now! */
1380 type = strstr(data->state.up.path, ";mode=");
1381
1382 if(!type)
1383 type = strstr(conn->host.rawalloc, ";mode=");
1384
1385 if(type) {
1386 char command;
1387 *type = 0; /* it was in the middle of the hostname */
1388 command = Curl_raw_toupper(type[6]);
1389
1390 switch(command) {
1391 case 'A': /* ASCII mode */
1392 case 'N': /* NETASCII mode */
1393 data->state.prefer_ascii = TRUE;
1394 break;
1395
1396 case 'O': /* octet mode */
1397 case 'I': /* binary mode */
1398 default:
1399 /* switch off ASCII */
1400 data->state.prefer_ascii = FALSE;
1401 break;
1402 }
1403 }
1404
1405 return CURLE_OK;
1406 }
1407 #endif
1408
