1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, 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 "rawstr.h"
59 #include "speedcheck.h"
60 #include "select.h"
61
62 /* The last 3 #include files should be in this order */
63 #include "curl_printf.h"
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 Curl_easy *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 Curl_easy *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 Curl_easy *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 Curl_easy *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 /* optional addition of TFTP options */
498 if(!data->set.tftp_no_options) {
499 /* add tsize option */
500 if(data->set.upload && (data->state.infilesize != -1))
501 snprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
502 data->state.infilesize);
503 else
504 strcpy(buf, "0"); /* the destination is large enough */
505
506 sbytes += tftp_option_add(state, sbytes,
507 (char *)state->spacket.data+sbytes,
508 TFTP_OPTION_TSIZE);
509 sbytes += tftp_option_add(state, sbytes,
510 (char *)state->spacket.data+sbytes, buf);
511 /* add blksize option */
512 snprintf(buf, sizeof(buf), "%d", state->requested_blksize);
513 sbytes += tftp_option_add(state, sbytes,
514 (char *)state->spacket.data+sbytes,
515 TFTP_OPTION_BLKSIZE);
516 sbytes += tftp_option_add(state, sbytes,
517 (char *)state->spacket.data+sbytes, buf);
518
519 /* add timeout option */
520 snprintf(buf, sizeof(buf), "%d", state->retry_time);
521 sbytes += tftp_option_add(state, sbytes,
522 (char *)state->spacket.data+sbytes,
523 TFTP_OPTION_INTERVAL);
524 sbytes += tftp_option_add(state, sbytes,
525 (char *)state->spacket.data+sbytes, buf);
526 }
527
528 /* the typecase for the 3rd argument is mostly for systems that do
529 not have a size_t argument, like older unixes that want an 'int' */
530 senddata = sendto(state->sockfd, (void *)state->spacket.data,
531 (SEND_TYPE_ARG3)sbytes, 0,
532 state->conn->ip_addr->ai_addr,
533 state->conn->ip_addr->ai_addrlen);
534 if(senddata != (ssize_t)sbytes) {
535 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
536 }
537 free(filename);
538 break;
539
540 case TFTP_EVENT_OACK:
541 if(data->set.upload) {
542 result = tftp_connect_for_tx(state, event);
543 }
544 else {
545 result = tftp_connect_for_rx(state, event);
546 }
547 break;
548
549 case TFTP_EVENT_ACK: /* Connected for transmit */
550 result = tftp_connect_for_tx(state, event);
551 break;
552
553 case TFTP_EVENT_DATA: /* Connected for receive */
554 result = tftp_connect_for_rx(state, event);
555 break;
556
557 case TFTP_EVENT_ERROR:
558 state->state = TFTP_STATE_FIN;
559 break;
560
561 default:
562 failf(state->conn->data, "tftp_send_first: internal error");
563 break;
564 }
565
566 return result;
567 }
568
569 /* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
570 boundary */
571 #define NEXT_BLOCKNUM(x) (((x)+1)&0xffff)
572
573 /**********************************************************
574 *
575 * tftp_rx
576 *
577 * Event handler for the RX state
578 *
579 **********************************************************/
tftp_rx(tftp_state_data_t * state,tftp_event_t event)580 static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
581 {
582 ssize_t sbytes;
583 int rblock;
584 struct Curl_easy *data = state->conn->data;
585
586 switch(event) {
587
588 case TFTP_EVENT_DATA:
589 /* Is this the block we expect? */
590 rblock = getrpacketblock(&state->rpacket);
591 if(NEXT_BLOCKNUM(state->block) == rblock) {
592 /* This is the expected block. Reset counters and ACK it. */
593 state->retries = 0;
594 }
595 else if(state->block == rblock) {
596 /* This is the last recently received block again. Log it and ACK it
597 again. */
598 infof(data, "Received last DATA packet block %d again.\n", rblock);
599 }
600 else {
601 /* totally unexpected, just log it */
602 infof(data,
603 "Received unexpected DATA packet block %d, expecting block %d\n",
604 rblock, NEXT_BLOCKNUM(state->block));
605 break;
606 }
607
608 /* ACK this block. */
609 state->block = (unsigned short)rblock;
610 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
611 setpacketblock(&state->spacket, state->block);
612 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
613 4, SEND_4TH_ARG,
614 (struct sockaddr *)&state->remote_addr,
615 state->remote_addrlen);
616 if(sbytes < 0) {
617 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
618 return CURLE_SEND_ERROR;
619 }
620
621 /* Check if completed (That is, a less than full packet is received) */
622 if(state->rbytes < (ssize_t)state->blksize+4) {
623 state->state = TFTP_STATE_FIN;
624 }
625 else {
626 state->state = TFTP_STATE_RX;
627 }
628 time(&state->rx_time);
629 break;
630
631 case TFTP_EVENT_OACK:
632 /* ACK option acknowledgement so we can move on to data */
633 state->block = 0;
634 state->retries = 0;
635 setpacketevent(&state->spacket, TFTP_EVENT_ACK);
636 setpacketblock(&state->spacket, state->block);
637 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
638 4, SEND_4TH_ARG,
639 (struct sockaddr *)&state->remote_addr,
640 state->remote_addrlen);
641 if(sbytes < 0) {
642 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
643 return CURLE_SEND_ERROR;
644 }
645
646 /* we're ready to RX data */
647 state->state = TFTP_STATE_RX;
648 time(&state->rx_time);
649 break;
650
651 case TFTP_EVENT_TIMEOUT:
652 /* Increment the retry count and fail if over the limit */
653 state->retries++;
654 infof(data,
655 "Timeout waiting for block %d ACK. Retries = %d\n",
656 NEXT_BLOCKNUM(state->block), state->retries);
657 if(state->retries > state->retry_max) {
658 state->error = TFTP_ERR_TIMEOUT;
659 state->state = TFTP_STATE_FIN;
660 }
661 else {
662 /* Resend the previous ACK */
663 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
664 4, SEND_4TH_ARG,
665 (struct sockaddr *)&state->remote_addr,
666 state->remote_addrlen);
667 if(sbytes<0) {
668 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
669 return CURLE_SEND_ERROR;
670 }
671 }
672 break;
673
674 case TFTP_EVENT_ERROR:
675 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
676 setpacketblock(&state->spacket, state->block);
677 (void)sendto(state->sockfd, (void *)state->spacket.data,
678 4, SEND_4TH_ARG,
679 (struct sockaddr *)&state->remote_addr,
680 state->remote_addrlen);
681 /* don't bother with the return code, but if the socket is still up we
682 * should be a good TFTP client and let the server know we're done */
683 state->state = TFTP_STATE_FIN;
684 break;
685
686 default:
687 failf(data, "%s", "tftp_rx: internal error");
688 return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
689 this */
690 }
691 return CURLE_OK;
692 }
693
694 /**********************************************************
695 *
696 * tftp_tx
697 *
698 * Event handler for the TX state
699 *
700 **********************************************************/
tftp_tx(tftp_state_data_t * state,tftp_event_t event)701 static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
702 {
703 struct Curl_easy *data = state->conn->data;
704 ssize_t sbytes;
705 int rblock;
706 CURLcode result = CURLE_OK;
707 struct SingleRequest *k = &data->req;
708
709 switch(event) {
710
711 case TFTP_EVENT_ACK:
712 case TFTP_EVENT_OACK:
713 if(event == TFTP_EVENT_ACK) {
714 /* Ack the packet */
715 rblock = getrpacketblock(&state->rpacket);
716
717 if(rblock != state->block &&
718 /* There's a bug in tftpd-hpa that causes it to send us an ack for
719 * 65535 when the block number wraps to 0. So when we're expecting
720 * 0, also accept 65535. See
721 * http://syslinux.zytor.com/archives/2010-September/015253.html
722 * */
723 !(state->block == 0 && rblock == 65535)) {
724 /* This isn't the expected block. Log it and up the retry counter */
725 infof(data, "Received ACK for block %d, expecting %d\n",
726 rblock, state->block);
727 state->retries++;
728 /* Bail out if over the maximum */
729 if(state->retries>state->retry_max) {
730 failf(data, "tftp_tx: giving up waiting for block %d ack",
731 state->block);
732 result = CURLE_SEND_ERROR;
733 }
734 else {
735 /* Re-send the data packet */
736 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
737 4+state->sbytes, SEND_4TH_ARG,
738 (struct sockaddr *)&state->remote_addr,
739 state->remote_addrlen);
740 /* Check all sbytes were sent */
741 if(sbytes<0) {
742 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
743 result = CURLE_SEND_ERROR;
744 }
745 }
746
747 return result;
748 }
749 /* This is the expected packet. Reset the counters and send the next
750 block */
751 time(&state->rx_time);
752 state->block++;
753 }
754 else
755 state->block = 1; /* first data block is 1 when using OACK */
756
757 state->retries = 0;
758 setpacketevent(&state->spacket, TFTP_EVENT_DATA);
759 setpacketblock(&state->spacket, state->block);
760 if(state->block > 1 && state->sbytes < (int)state->blksize) {
761 state->state = TFTP_STATE_FIN;
762 return CURLE_OK;
763 }
764
765 result = Curl_fillreadbuffer(state->conn, state->blksize, &state->sbytes);
766 if(result)
767 return result;
768
769 sbytes = sendto(state->sockfd, (void *) state->spacket.data,
770 4 + state->sbytes, SEND_4TH_ARG,
771 (struct sockaddr *)&state->remote_addr,
772 state->remote_addrlen);
773 /* Check all sbytes were sent */
774 if(sbytes<0) {
775 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
776 return CURLE_SEND_ERROR;
777 }
778 /* Update the progress meter */
779 k->writebytecount += state->sbytes;
780 Curl_pgrsSetUploadCounter(data, k->writebytecount);
781 break;
782
783 case TFTP_EVENT_TIMEOUT:
784 /* Increment the retry counter and log the timeout */
785 state->retries++;
786 infof(data, "Timeout waiting for block %d ACK. "
787 " Retries = %d\n", NEXT_BLOCKNUM(state->block), state->retries);
788 /* Decide if we've had enough */
789 if(state->retries > state->retry_max) {
790 state->error = TFTP_ERR_TIMEOUT;
791 state->state = TFTP_STATE_FIN;
792 }
793 else {
794 /* Re-send the data packet */
795 sbytes = sendto(state->sockfd, (void *)state->spacket.data,
796 4+state->sbytes, SEND_4TH_ARG,
797 (struct sockaddr *)&state->remote_addr,
798 state->remote_addrlen);
799 /* Check all sbytes were sent */
800 if(sbytes<0) {
801 failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
802 return CURLE_SEND_ERROR;
803 }
804 /* since this was a re-send, we remain at the still byte position */
805 Curl_pgrsSetUploadCounter(data, k->writebytecount);
806 }
807 break;
808
809 case TFTP_EVENT_ERROR:
810 state->state = TFTP_STATE_FIN;
811 setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
812 setpacketblock(&state->spacket, state->block);
813 (void)sendto(state->sockfd, (void *)state->spacket.data, 4, SEND_4TH_ARG,
814 (struct sockaddr *)&state->remote_addr,
815 state->remote_addrlen);
816 /* don't bother with the return code, but if the socket is still up we
817 * should be a good TFTP client and let the server know we're done */
818 state->state = TFTP_STATE_FIN;
819 break;
820
821 default:
822 failf(data, "tftp_tx: internal error, event: %i", (int)(event));
823 break;
824 }
825
826 return result;
827 }
828
829 /**********************************************************
830 *
831 * tftp_translate_code
832 *
833 * Translate internal error codes to CURL error codes
834 *
835 **********************************************************/
tftp_translate_code(tftp_error_t error)836 static CURLcode tftp_translate_code(tftp_error_t error)
837 {
838 CURLcode result = CURLE_OK;
839
840 if(error != TFTP_ERR_NONE) {
841 switch(error) {
842 case TFTP_ERR_NOTFOUND:
843 result = CURLE_TFTP_NOTFOUND;
844 break;
845 case TFTP_ERR_PERM:
846 result = CURLE_TFTP_PERM;
847 break;
848 case TFTP_ERR_DISKFULL:
849 result = CURLE_REMOTE_DISK_FULL;
850 break;
851 case TFTP_ERR_UNDEF:
852 case TFTP_ERR_ILLEGAL:
853 result = CURLE_TFTP_ILLEGAL;
854 break;
855 case TFTP_ERR_UNKNOWNID:
856 result = CURLE_TFTP_UNKNOWNID;
857 break;
858 case TFTP_ERR_EXISTS:
859 result = CURLE_REMOTE_FILE_EXISTS;
860 break;
861 case TFTP_ERR_NOSUCHUSER:
862 result = CURLE_TFTP_NOSUCHUSER;
863 break;
864 case TFTP_ERR_TIMEOUT:
865 result = CURLE_OPERATION_TIMEDOUT;
866 break;
867 case TFTP_ERR_NORESPONSE:
868 result = CURLE_COULDNT_CONNECT;
869 break;
870 default:
871 result = CURLE_ABORTED_BY_CALLBACK;
872 break;
873 }
874 }
875 else
876 result = CURLE_OK;
877
878 return result;
879 }
880
881 /**********************************************************
882 *
883 * tftp_state_machine
884 *
885 * The tftp state machine event dispatcher
886 *
887 **********************************************************/
tftp_state_machine(tftp_state_data_t * state,tftp_event_t event)888 static CURLcode tftp_state_machine(tftp_state_data_t *state,
889 tftp_event_t event)
890 {
891 CURLcode result = CURLE_OK;
892 struct Curl_easy *data = state->conn->data;
893
894 switch(state->state) {
895 case TFTP_STATE_START:
896 DEBUGF(infof(data, "TFTP_STATE_START\n"));
897 result = tftp_send_first(state, event);
898 break;
899 case TFTP_STATE_RX:
900 DEBUGF(infof(data, "TFTP_STATE_RX\n"));
901 result = tftp_rx(state, event);
902 break;
903 case TFTP_STATE_TX:
904 DEBUGF(infof(data, "TFTP_STATE_TX\n"));
905 result = tftp_tx(state, event);
906 break;
907 case TFTP_STATE_FIN:
908 infof(data, "%s\n", "TFTP finished");
909 break;
910 default:
911 DEBUGF(infof(data, "STATE: %d\n", state->state));
912 failf(data, "%s", "Internal state machine error");
913 result = CURLE_TFTP_ILLEGAL;
914 break;
915 }
916
917 return result;
918 }
919
920 /**********************************************************
921 *
922 * tftp_disconnect
923 *
924 * The disconnect callback
925 *
926 **********************************************************/
tftp_disconnect(struct connectdata * conn,bool dead_connection)927 static CURLcode tftp_disconnect(struct connectdata *conn, bool dead_connection)
928 {
929 tftp_state_data_t *state = conn->proto.tftpc;
930 (void) dead_connection;
931
932 /* done, free dynamically allocated pkt buffers */
933 if(state) {
934 Curl_safefree(state->rpacket.data);
935 Curl_safefree(state->spacket.data);
936 free(state);
937 }
938
939 return CURLE_OK;
940 }
941
942 /**********************************************************
943 *
944 * tftp_connect
945 *
946 * The connect callback
947 *
948 **********************************************************/
tftp_connect(struct connectdata * conn,bool * done)949 static CURLcode tftp_connect(struct connectdata *conn, bool *done)
950 {
951 tftp_state_data_t *state;
952 int blksize, rc;
953
954 blksize = TFTP_BLKSIZE_DEFAULT;
955
956 state = conn->proto.tftpc = calloc(1, sizeof(tftp_state_data_t));
957 if(!state)
958 return CURLE_OUT_OF_MEMORY;
959
960 /* alloc pkt buffers based on specified blksize */
961 if(conn->data->set.tftp_blksize) {
962 blksize = (int)conn->data->set.tftp_blksize;
963 if(blksize > TFTP_BLKSIZE_MAX || blksize < TFTP_BLKSIZE_MIN)
964 return CURLE_TFTP_ILLEGAL;
965 }
966
967 if(!state->rpacket.data) {
968 state->rpacket.data = calloc(1, blksize + 2 + 2);
969
970 if(!state->rpacket.data)
971 return CURLE_OUT_OF_MEMORY;
972 }
973
974 if(!state->spacket.data) {
975 state->spacket.data = calloc(1, blksize + 2 + 2);
976
977 if(!state->spacket.data)
978 return CURLE_OUT_OF_MEMORY;
979 }
980
981 /* we don't keep TFTP connections up basically because there's none or very
982 * little gain for UDP */
983 connclose(conn, "TFTP");
984
985 state->conn = conn;
986 state->sockfd = state->conn->sock[FIRSTSOCKET];
987 state->state = TFTP_STATE_START;
988 state->error = TFTP_ERR_NONE;
989 state->blksize = TFTP_BLKSIZE_DEFAULT;
990 state->requested_blksize = blksize;
991
992 ((struct sockaddr *)&state->local_addr)->sa_family =
993 (unsigned short)(conn->ip_addr->ai_family);
994
995 tftp_set_timeouts(state);
996
997 if(!conn->bits.bound) {
998 /* If not already bound, bind to any interface, random UDP port. If it is
999 * reused or a custom local port was desired, this has already been done!
1000 *
1001 * We once used the size of the local_addr struct as the third argument
1002 * for bind() to better work with IPv6 or whatever size the struct could
1003 * have, but we learned that at least Tru64, AIX and IRIX *requires* the
1004 * size of that argument to match the exact size of a 'sockaddr_in' struct
1005 * when running IPv4-only.
1006 *
1007 * Therefore we use the size from the address we connected to, which we
1008 * assume uses the same IP version and thus hopefully this works for both
1009 * IPv4 and IPv6...
1010 */
1011 rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
1012 conn->ip_addr->ai_addrlen);
1013 if(rc) {
1014 failf(conn->data, "bind() failed; %s",
1015 Curl_strerror(conn, SOCKERRNO));
1016 return CURLE_COULDNT_CONNECT;
1017 }
1018 conn->bits.bound = TRUE;
1019 }
1020
1021 Curl_pgrsStartNow(conn->data);
1022
1023 *done = TRUE;
1024
1025 return CURLE_OK;
1026 }
1027
1028 /**********************************************************
1029 *
1030 * tftp_done
1031 *
1032 * The done callback
1033 *
1034 **********************************************************/
tftp_done(struct connectdata * conn,CURLcode status,bool premature)1035 static CURLcode tftp_done(struct connectdata *conn, CURLcode status,
1036 bool premature)
1037 {
1038 CURLcode result = CURLE_OK;
1039 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1040
1041 (void)status; /* unused */
1042 (void)premature; /* not used */
1043
1044 if(Curl_pgrsDone(conn))
1045 return CURLE_ABORTED_BY_CALLBACK;
1046
1047 /* If we have encountered an error */
1048 if(state)
1049 result = tftp_translate_code(state->error);
1050
1051 return result;
1052 }
1053
1054 /**********************************************************
1055 *
1056 * tftp_getsock
1057 *
1058 * The getsock callback
1059 *
1060 **********************************************************/
tftp_getsock(struct connectdata * conn,curl_socket_t * socks,int numsocks)1061 static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks,
1062 int numsocks)
1063 {
1064 if(!numsocks)
1065 return GETSOCK_BLANK;
1066
1067 socks[0] = conn->sock[FIRSTSOCKET];
1068
1069 return GETSOCK_READSOCK(0);
1070 }
1071
1072 /**********************************************************
1073 *
1074 * tftp_receive_packet
1075 *
1076 * Called once select fires and data is ready on the socket
1077 *
1078 **********************************************************/
tftp_receive_packet(struct connectdata * conn)1079 static CURLcode tftp_receive_packet(struct connectdata *conn)
1080 {
1081 struct Curl_sockaddr_storage fromaddr;
1082 curl_socklen_t fromlen;
1083 CURLcode result = CURLE_OK;
1084 struct Curl_easy *data = conn->data;
1085 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1086 struct SingleRequest *k = &data->req;
1087
1088 /* Receive the packet */
1089 fromlen = sizeof(fromaddr);
1090 state->rbytes = (int)recvfrom(state->sockfd,
1091 (void *)state->rpacket.data,
1092 state->blksize+4,
1093 0,
1094 (struct sockaddr *)&fromaddr,
1095 &fromlen);
1096 if(state->remote_addrlen==0) {
1097 memcpy(&state->remote_addr, &fromaddr, fromlen);
1098 state->remote_addrlen = fromlen;
1099 }
1100
1101 /* Sanity check packet length */
1102 if(state->rbytes < 4) {
1103 failf(data, "Received too short packet");
1104 /* Not a timeout, but how best to handle it? */
1105 state->event = TFTP_EVENT_TIMEOUT;
1106 }
1107 else {
1108 /* The event is given by the TFTP packet time */
1109 state->event = (tftp_event_t)getrpacketevent(&state->rpacket);
1110
1111 switch(state->event) {
1112 case TFTP_EVENT_DATA:
1113 /* Don't pass to the client empty or retransmitted packets */
1114 if(state->rbytes > 4 &&
1115 (NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
1116 result = Curl_client_write(conn, CLIENTWRITE_BODY,
1117 (char *)state->rpacket.data+4,
1118 state->rbytes-4);
1119 if(result) {
1120 tftp_state_machine(state, TFTP_EVENT_ERROR);
1121 return result;
1122 }
1123 k->bytecount += state->rbytes-4;
1124 Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount);
1125 }
1126 break;
1127 case TFTP_EVENT_ERROR:
1128 state->error = (tftp_error_t)getrpacketblock(&state->rpacket);
1129 infof(data, "%s\n", (const char *)state->rpacket.data+4);
1130 break;
1131 case TFTP_EVENT_ACK:
1132 break;
1133 case TFTP_EVENT_OACK:
1134 result = tftp_parse_option_ack(state,
1135 (const char *)state->rpacket.data+2,
1136 state->rbytes-2);
1137 if(result)
1138 return result;
1139 break;
1140 case TFTP_EVENT_RRQ:
1141 case TFTP_EVENT_WRQ:
1142 default:
1143 failf(data, "%s", "Internal error: Unexpected packet");
1144 break;
1145 }
1146
1147 /* Update the progress meter */
1148 if(Curl_pgrsUpdate(conn)) {
1149 tftp_state_machine(state, TFTP_EVENT_ERROR);
1150 return CURLE_ABORTED_BY_CALLBACK;
1151 }
1152 }
1153 return result;
1154 }
1155
1156 /**********************************************************
1157 *
1158 * tftp_state_timeout
1159 *
1160 * Check if timeouts have been reached
1161 *
1162 **********************************************************/
tftp_state_timeout(struct connectdata * conn,tftp_event_t * event)1163 static long tftp_state_timeout(struct connectdata *conn, tftp_event_t *event)
1164 {
1165 time_t current;
1166 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1167
1168 if(event)
1169 *event = TFTP_EVENT_NONE;
1170
1171 time(¤t);
1172 if(current > state->max_time) {
1173 DEBUGF(infof(conn->data, "timeout: %ld > %ld\n",
1174 (long)current, (long)state->max_time));
1175 state->error = TFTP_ERR_TIMEOUT;
1176 state->state = TFTP_STATE_FIN;
1177 return 0;
1178 }
1179 else if(current > state->rx_time+state->retry_time) {
1180 if(event)
1181 *event = TFTP_EVENT_TIMEOUT;
1182 time(&state->rx_time); /* update even though we received nothing */
1183 }
1184
1185 /* there's a typecast below here since 'time_t' may in fact be larger than
1186 'long', but we estimate that a 'long' will still be able to hold number
1187 of seconds even if "only" 32 bit */
1188 return (long)(state->max_time - current);
1189 }
1190
1191 /**********************************************************
1192 *
1193 * tftp_multi_statemach
1194 *
1195 * Handle single RX socket event and return
1196 *
1197 **********************************************************/
tftp_multi_statemach(struct connectdata * conn,bool * done)1198 static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done)
1199 {
1200 int rc;
1201 tftp_event_t event;
1202 CURLcode result = CURLE_OK;
1203 struct Curl_easy *data = conn->data;
1204 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1205 long timeout_ms = tftp_state_timeout(conn, &event);
1206
1207 *done = FALSE;
1208
1209 if(timeout_ms <= 0) {
1210 failf(data, "TFTP response timeout");
1211 return CURLE_OPERATION_TIMEDOUT;
1212 }
1213 else if(event != TFTP_EVENT_NONE) {
1214 result = tftp_state_machine(state, event);
1215 if(result)
1216 return result;
1217 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1218 if(*done)
1219 /* Tell curl we're done */
1220 Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1221 }
1222 else {
1223 /* no timeouts to handle, check our socket */
1224 rc = Curl_socket_ready(state->sockfd, CURL_SOCKET_BAD, 0);
1225
1226 if(rc == -1) {
1227 /* bail out */
1228 int error = SOCKERRNO;
1229 failf(data, "%s", Curl_strerror(conn, error));
1230 state->event = TFTP_EVENT_ERROR;
1231 }
1232 else if(rc != 0) {
1233 result = tftp_receive_packet(conn);
1234 if(result)
1235 return result;
1236 result = tftp_state_machine(state, state->event);
1237 if(result)
1238 return result;
1239 *done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
1240 if(*done)
1241 /* Tell curl we're done */
1242 Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1243 }
1244 /* if rc == 0, then select() timed out */
1245 }
1246
1247 return result;
1248 }
1249
1250 /**********************************************************
1251 *
1252 * tftp_doing
1253 *
1254 * Called from multi.c while DOing
1255 *
1256 **********************************************************/
tftp_doing(struct connectdata * conn,bool * dophase_done)1257 static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done)
1258 {
1259 CURLcode result;
1260 result = tftp_multi_statemach(conn, dophase_done);
1261
1262 if(*dophase_done) {
1263 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1264 }
1265 else if(!result) {
1266 /* The multi code doesn't have this logic for the DOING state so we
1267 provide it for TFTP since it may do the entire transfer in this
1268 state. */
1269 if(Curl_pgrsUpdate(conn))
1270 result = CURLE_ABORTED_BY_CALLBACK;
1271 else
1272 result = Curl_speedcheck(conn->data, Curl_tvnow());
1273 }
1274 return result;
1275 }
1276
1277 /**********************************************************
1278 *
1279 * tftp_peform
1280 *
1281 * Entry point for transfer from tftp_do, sarts state mach
1282 *
1283 **********************************************************/
tftp_perform(struct connectdata * conn,bool * dophase_done)1284 static CURLcode tftp_perform(struct connectdata *conn, bool *dophase_done)
1285 {
1286 CURLcode result = CURLE_OK;
1287 tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1288
1289 *dophase_done = FALSE;
1290
1291 result = tftp_state_machine(state, TFTP_EVENT_INIT);
1292
1293 if((state->state == TFTP_STATE_FIN) || result)
1294 return result;
1295
1296 tftp_multi_statemach(conn, dophase_done);
1297
1298 if(*dophase_done)
1299 DEBUGF(infof(conn->data, "DO phase is complete\n"));
1300
1301 return result;
1302 }
1303
1304
1305 /**********************************************************
1306 *
1307 * tftp_do
1308 *
1309 * The do callback
1310 *
1311 * This callback initiates the TFTP transfer
1312 *
1313 **********************************************************/
1314
tftp_do(struct connectdata * conn,bool * done)1315 static CURLcode tftp_do(struct connectdata *conn, bool *done)
1316 {
1317 tftp_state_data_t *state;
1318 CURLcode result;
1319
1320 *done = FALSE;
1321
1322 if(!conn->proto.tftpc) {
1323 result = tftp_connect(conn, done);
1324 if(result)
1325 return result;
1326 }
1327
1328 state = (tftp_state_data_t *)conn->proto.tftpc;
1329 if(!state)
1330 return CURLE_BAD_CALLING_ORDER;
1331
1332 result = tftp_perform(conn, done);
1333
1334 /* If tftp_perform() returned an error, use that for return code. If it
1335 was OK, see if tftp_translate_code() has an error. */
1336 if(!result)
1337 /* If we have encountered an internal tftp error, translate it. */
1338 result = tftp_translate_code(state->error);
1339
1340 return result;
1341 }
1342
tftp_setup_connection(struct connectdata * conn)1343 static CURLcode tftp_setup_connection(struct connectdata * conn)
1344 {
1345 struct Curl_easy *data = conn->data;
1346 char * type;
1347 char command;
1348
1349 conn->socktype = SOCK_DGRAM; /* UDP datagram based */
1350
1351 /* TFTP URLs support an extension like ";mode=<typecode>" that
1352 * we'll try to get now! */
1353 type = strstr(data->state.path, ";mode=");
1354
1355 if(!type)
1356 type = strstr(conn->host.rawalloc, ";mode=");
1357
1358 if(type) {
1359 *type = 0; /* it was in the middle of the hostname */
1360 command = Curl_raw_toupper(type[6]);
1361
1362 switch (command) {
1363 case 'A': /* ASCII mode */
1364 case 'N': /* NETASCII mode */
1365 data->set.prefer_ascii = TRUE;
1366 break;
1367
1368 case 'O': /* octet mode */
1369 case 'I': /* binary mode */
1370 default:
1371 /* switch off ASCII */
1372 data->set.prefer_ascii = FALSE;
1373 break;
1374 }
1375 }
1376
1377 return CURLE_OK;
1378 }
1379 #endif
1380