tftp.c revision 5ab5018bf8f0e39957d264f33c3eeddd958ed5d8
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "setup.h"
24
25#ifndef CURL_DISABLE_TFTP
26/* -- WIN32 approved -- */
27#include <stdio.h>
28#include <stdarg.h>
29#include <stdlib.h>
30#include <ctype.h>
31
32#if defined(WIN32)
33#include <time.h>
34#include <io.h>
35#else
36#ifdef HAVE_SYS_SOCKET_H
37#include <sys/socket.h>
38#endif
39#include <netinet/in.h>
40#ifdef HAVE_SYS_TIME_H
41#include <sys/time.h>
42#endif
43#ifdef HAVE_UNISTD_H
44#include <unistd.h>
45#endif
46#include <netdb.h>
47#ifdef HAVE_ARPA_INET_H
48#include <arpa/inet.h>
49#endif
50#ifdef HAVE_NET_IF_H
51#include <net/if.h>
52#endif
53#ifdef HAVE_SYS_IOCTL_H
54#include <sys/ioctl.h>
55#endif
56
57#ifdef HAVE_SYS_PARAM_H
58#include <sys/param.h>
59#endif
60
61#endif /* WIN32 */
62
63#include "urldata.h"
64#include <curl/curl.h>
65#include "transfer.h"
66#include "sendf.h"
67#include "tftp.h"
68#include "progress.h"
69#include "connect.h"
70#include "strerror.h"
71#include "sockaddr.h" /* required for Curl_sockaddr_storage */
72#include "multiif.h"
73#include "url.h"
74#include "rawstr.h"
75
76#define _MPRINTF_REPLACE /* use our functions only */
77#include <curl/mprintf.h>
78
79#include "curl_memory.h"
80#include "select.h"
81
82/* The last #include file should be: */
83#include "memdebug.h"
84
85/* RFC2348 allows the block size to be negotiated */
86#define TFTP_BLKSIZE_DEFAULT 512
87#define TFTP_BLKSIZE_MIN 8
88#define TFTP_BLKSIZE_MAX 65464
89#define TFTP_OPTION_BLKSIZE "blksize"
90#define TFTP_OPTION_TSIZE "tsize"
91#define TFTP_OPTION_INTERVAL "interval"
92
93typedef enum {
94  TFTP_MODE_NETASCII=0,
95  TFTP_MODE_OCTET
96} tftp_mode_t;
97
98typedef enum {
99  TFTP_STATE_START=0,
100  TFTP_STATE_RX,
101  TFTP_STATE_TX,
102  TFTP_STATE_FIN
103} tftp_state_t;
104
105typedef enum {
106  TFTP_EVENT_NONE = -1,
107  TFTP_EVENT_INIT = 0,
108  TFTP_EVENT_RRQ = 1,
109  TFTP_EVENT_WRQ = 2,
110  TFTP_EVENT_DATA = 3,
111  TFTP_EVENT_ACK = 4,
112  TFTP_EVENT_ERROR = 5,
113  TFTP_EVENT_OACK = 6,
114  TFTP_EVENT_TIMEOUT
115} tftp_event_t;
116
117typedef enum {
118  TFTP_ERR_UNDEF=0,
119  TFTP_ERR_NOTFOUND,
120  TFTP_ERR_PERM,
121  TFTP_ERR_DISKFULL,
122  TFTP_ERR_ILLEGAL,
123  TFTP_ERR_UNKNOWNID,
124  TFTP_ERR_EXISTS,
125  TFTP_ERR_NOSUCHUSER,  /* This will never be triggered by this code */
126
127  /* The remaining error codes are internal to curl */
128  TFTP_ERR_NONE = -100,
129  TFTP_ERR_TIMEOUT,
130  TFTP_ERR_NORESPONSE
131} tftp_error_t;
132
133typedef struct tftp_packet {
134  unsigned char *data;
135} tftp_packet_t;
136
137typedef struct tftp_state_data {
138  tftp_state_t    state;
139  tftp_mode_t     mode;
140  tftp_error_t    error;
141  tftp_event_t    event;
142  struct connectdata      *conn;
143  curl_socket_t   sockfd;
144  int             retries;
145  int             retry_time;
146  int             retry_max;
147  time_t          start_time;
148  time_t          max_time;
149  time_t          rx_time;
150  unsigned short  block;
151  struct Curl_sockaddr_storage   local_addr;
152  struct Curl_sockaddr_storage   remote_addr;
153  curl_socklen_t  remote_addrlen;
154  int             rbytes;
155  int             sbytes;
156  int             blksize;
157  int             requested_blksize;
158  tftp_packet_t   rpacket;
159  tftp_packet_t   spacket;
160} tftp_state_data_t;
161
162
163/* Forward declarations */
164static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event) ;
165static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event) ;
166static CURLcode tftp_connect(struct connectdata *conn, bool *done);
167static CURLcode tftp_disconnect(struct connectdata *conn);
168static CURLcode tftp_do(struct connectdata *conn, bool *done);
169static CURLcode tftp_done(struct connectdata *conn,
170                               CURLcode, bool premature);
171static CURLcode tftp_setup_connection(struct connectdata * conn);
172static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done);
173static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done);
174static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks,
175                        int numsocks);
176static CURLcode tftp_translate_code(tftp_error_t error);
177
178
179/*
180 * TFTP protocol handler.
181 */
182
183const struct Curl_handler Curl_handler_tftp = {
184  "TFTP",                               /* scheme */
185  tftp_setup_connection,                /* setup_connection */
186  tftp_do,                              /* do_it */
187  tftp_done,                            /* done */
188  ZERO_NULL,                            /* do_more */
189  tftp_connect,                         /* connect_it */
190  tftp_multi_statemach,                 /* connecting */
191  tftp_doing,                           /* doing */
192  tftp_getsock,                         /* proto_getsock */
193  tftp_getsock,                         /* doing_getsock */
194  ZERO_NULL,                            /* perform_getsock */
195  tftp_disconnect,                      /* disconnect */
196  PORT_TFTP,                            /* defport */
197  PROT_TFTP                             /* protocol */
198};
199
200/**********************************************************
201 *
202 * tftp_set_timeouts -
203 *
204 * Set timeouts based on state machine state.
205 * Use user provided connect timeouts until DATA or ACK
206 * packet is received, then use user-provided transfer timeouts
207 *
208 *
209 **********************************************************/
210static CURLcode tftp_set_timeouts(tftp_state_data_t *state)
211{
212  time_t maxtime, timeout;
213  long timeout_ms;
214  bool start = (bool)(state->state == TFTP_STATE_START);
215
216  time(&state->start_time);
217
218  /* Compute drop-dead time */
219  timeout_ms = Curl_timeleft(state->conn, NULL, start);
220
221  if(timeout_ms < 0) {
222    /* time-out, bail out, go home */
223    failf(state->conn->data, "Connection time-out");
224    return CURLE_OPERATION_TIMEDOUT;
225  }
226
227  if(start) {
228
229    maxtime = (time_t)(timeout_ms + 500) / 1000;
230    state->max_time = state->start_time+maxtime;
231
232    /* Set per-block timeout to total */
233    timeout = maxtime ;
234
235    /* Average restart after 5 seconds */
236    state->retry_max = (int)timeout/5;
237
238    if(state->retry_max < 1)
239      /* avoid division by zero below */
240      state->retry_max = 1;
241
242    /* Compute the re-start interval to suit the timeout */
243    state->retry_time = (int)timeout/state->retry_max;
244    if(state->retry_time<1)
245      state->retry_time=1;
246
247  }
248  else {
249    if(timeout_ms > 0)
250      maxtime = (time_t)(timeout_ms + 500) / 1000;
251    else
252      maxtime = 3600;
253
254    state->max_time = state->start_time+maxtime;
255
256    /* Set per-block timeout to 10% of total */
257    timeout = maxtime/10 ;
258
259    /* Average reposting an ACK after 15 seconds */
260    state->retry_max = (int)timeout/15;
261  }
262  /* But bound the total number */
263  if(state->retry_max<3)
264    state->retry_max=3;
265
266  if(state->retry_max>50)
267    state->retry_max=50;
268
269  /* Compute the re-ACK interval to suit the timeout */
270  state->retry_time = (int)(timeout/state->retry_max);
271  if(state->retry_time<1)
272    state->retry_time=1;
273
274  infof(state->conn->data,
275        "set timeouts for state %d; Total %ld, retry %d maxtry %d\n",
276        (int)state->state, (long)(state->max_time-state->start_time),
277        state->retry_time, state->retry_max);
278
279  /* init RX time */
280  time(&state->rx_time);
281
282  return CURLE_OK;
283}
284
285/**********************************************************
286 *
287 * tftp_set_send_first
288 *
289 * Event handler for the START state
290 *
291 **********************************************************/
292
293static void setpacketevent(tftp_packet_t *packet, unsigned short num)
294{
295  packet->data[0] = (unsigned char)(num >> 8);
296  packet->data[1] = (unsigned char)(num & 0xff);
297}
298
299
300static void setpacketblock(tftp_packet_t *packet, unsigned short num)
301{
302  packet->data[2] = (unsigned char)(num >> 8);
303  packet->data[3] = (unsigned char)(num & 0xff);
304}
305
306static unsigned short getrpacketevent(const tftp_packet_t *packet)
307{
308  return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
309}
310
311static unsigned short getrpacketblock(const tftp_packet_t *packet)
312{
313  return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
314}
315
316static size_t Curl_strnlen(const char *string, size_t maxlen)
317{
318  const char *end = memchr (string, '\0', maxlen);
319  return end ? (size_t) (end - string) : maxlen;
320}
321
322static const char *tftp_option_get(const char *buf, size_t len,
323                                   const char **option, const char **value)
324{
325  size_t loc;
326
327  loc = Curl_strnlen( buf, len );
328  loc++; /* NULL term */
329
330  if (loc >= len)
331    return NULL;
332  *option = buf;
333
334  loc += Curl_strnlen( buf+loc, len-loc );
335  loc++; /* NULL term */
336
337  if (loc > len)
338    return NULL;
339  *value = &buf[strlen(*option) + 1];
340
341  return &buf[loc];
342}
343
344static CURLcode tftp_parse_option_ack(tftp_state_data_t *state,
345                                      const char *ptr, int len)
346{
347  const char *tmp = ptr;
348  struct SessionHandle *data = state->conn->data;
349
350  /* if OACK doesn't contain blksize option, the default (512) must be used */
351  state->blksize = TFTP_BLKSIZE_DEFAULT;
352
353  while (tmp < ptr + len) {
354    const char *option, *value;
355
356    tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
357    if(tmp == NULL) {
358      failf(data, "Malformed ACK packet, rejecting");
359      return CURLE_TFTP_ILLEGAL;
360    }
361
362    infof(data, "got option=(%s) value=(%s)\n", option, value);
363
364    if(checkprefix(option, TFTP_OPTION_BLKSIZE)) {
365      long blksize;
366
367      blksize = strtol( value, NULL, 10 );
368
369      if(!blksize) {
370        failf(data, "invalid blocksize value in OACK packet");
371        return CURLE_TFTP_ILLEGAL;
372      }
373      else if(blksize > TFTP_BLKSIZE_MAX) {
374        failf(data, "%s (%d)", "blksize is larger than max supported",
375                TFTP_BLKSIZE_MAX);
376        return CURLE_TFTP_ILLEGAL;
377      }
378      else if(blksize < TFTP_BLKSIZE_MIN) {
379        failf(data, "%s (%d)", "blksize is smaller than min supported",
380                TFTP_BLKSIZE_MIN);
381        return CURLE_TFTP_ILLEGAL;
382      }
383      else if (blksize > state->requested_blksize) {
384        /* could realloc pkt buffers here, but the spec doesn't call out
385         * support for the server requesting a bigger blksize than the client
386         * requests */
387        failf(data, "%s (%ld)",
388                "server requested blksize larger than allocated", blksize);
389        return CURLE_TFTP_ILLEGAL;
390      }
391
392      state->blksize = (int)blksize;
393      infof(data, "%s (%d) %s (%d)\n", "blksize parsed from OACK",
394        state->blksize, "requested", state->requested_blksize);
395    }
396    else if(checkprefix(option, TFTP_OPTION_TSIZE)) {
397      long tsize = 0;
398
399      tsize = strtol( value, NULL, 10 );
400      infof(data, "%s (%ld)\n", "tsize parsed from OACK", tsize);
401
402      /* tsize should be ignored on upload: Who cares about the size of the
403         remote file? */
404      if (!data->set.upload) {
405        if(!tsize) {
406          failf(data, "invalid tsize -:%s:- value in OACK packet", value);
407          return CURLE_TFTP_ILLEGAL;
408        }
409        Curl_pgrsSetDownloadSize(data, tsize);
410      }
411    }
412  }
413
414  return CURLE_OK;
415}
416
417static size_t tftp_option_add(tftp_state_data_t *state, size_t csize,
418                              char *buf, const char *option)
419{
420  if( ( strlen(option) + csize + 1 ) > (size_t)state->blksize )
421    return 0;
422  strcpy(buf, option);
423  return( strlen(option) + 1 );
424}
425
426static CURLcode tftp_connect_for_tx(tftp_state_data_t *state,
427                                    tftp_event_t event)
428{
429  CURLcode res;
430#ifndef CURL_DISABLE_VERBOSE_STRINGS
431  struct SessionHandle *data = state->conn->data;
432
433  infof(data, "%s\n", "Connected for transmit");
434#endif
435  state->state = TFTP_STATE_TX;
436  res = tftp_set_timeouts(state);
437  if(res != CURLE_OK)
438    return(res);
439  return tftp_tx(state, event);
440}
441
442static CURLcode tftp_connect_for_rx(tftp_state_data_t *state,
443                                    tftp_event_t event)
444{
445  CURLcode res;
446#ifndef CURL_DISABLE_VERBOSE_STRINGS
447  struct SessionHandle *data = state->conn->data;
448
449  infof(data, "%s\n", "Connected for receive");
450#endif
451  state->state = TFTP_STATE_RX;
452  res = tftp_set_timeouts(state);
453  if(res != CURLE_OK)
454    return(res);
455  return tftp_rx(state, event);
456}
457
458static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
459{
460  size_t sbytes;
461  ssize_t senddata;
462  const char *mode = "octet";
463  char *filename;
464  char buf[64];
465  struct SessionHandle *data = state->conn->data;
466  CURLcode res = CURLE_OK;
467
468  /* Set ascii mode if -B flag was used */
469  if(data->set.prefer_ascii)
470    mode = "netascii";
471
472  switch(event) {
473
474  case TFTP_EVENT_INIT:    /* Send the first packet out */
475  case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
476    /* Increment the retry counter, quit if over the limit */
477    state->retries++;
478    if(state->retries>state->retry_max) {
479      state->error = TFTP_ERR_NORESPONSE;
480      state->state = TFTP_STATE_FIN;
481      return res;
482    }
483
484    if(data->set.upload) {
485      /* If we are uploading, send an WRQ */
486      setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
487      state->conn->data->req.upload_fromhere =
488        (char *)state->spacket.data+4;
489      if(data->set.infilesize != -1)
490        Curl_pgrsSetUploadSize(data, data->set.infilesize);
491    }
492    else {
493      /* If we are downloading, send an RRQ */
494      setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
495    }
496    /* As RFC3617 describes the separator slash is not actually part of the
497       file name so we skip the always-present first letter of the path
498       string. */
499    filename = curl_easy_unescape(data, &state->conn->data->state.path[1], 0,
500                                  NULL);
501    if(!filename)
502      return CURLE_OUT_OF_MEMORY;
503
504    snprintf((char *)state->spacket.data+2,
505             state->blksize,
506             "%s%c%s%c", filename, '\0',  mode, '\0');
507    sbytes = 4 + strlen(filename) + strlen(mode);
508
509    /* add tsize option */
510    if(data->set.upload && (data->set.infilesize != -1))
511      snprintf( buf, sizeof(buf), "%" FORMAT_OFF_T, data->set.infilesize );
512    else
513      strcpy(buf, "0"); /* the destination is large enough */
514
515    sbytes += tftp_option_add(state, sbytes,
516                              (char *)state->spacket.data+sbytes,
517                              TFTP_OPTION_TSIZE);
518    sbytes += tftp_option_add(state, sbytes,
519                              (char *)state->spacket.data+sbytes, buf);
520    /* add blksize option */
521    snprintf( buf, sizeof(buf), "%d", state->requested_blksize );
522    sbytes += tftp_option_add(state, sbytes,
523                              (char *)state->spacket.data+sbytes,
524                              TFTP_OPTION_BLKSIZE);
525    sbytes += tftp_option_add(state, sbytes,
526                              (char *)state->spacket.data+sbytes, buf );
527    /* add timeout option, this is the max time the session may live */
528    snprintf( buf, sizeof(buf), "%d", state->retry_time*state->retry_max );
529    sbytes += tftp_option_add(state, sbytes,
530                              (char *)state->spacket.data+sbytes,
531                              TFTP_OPTION_INTERVAL);
532    sbytes += tftp_option_add(state, sbytes,
533                              (char *)state->spacket.data+sbytes, buf );
534
535    senddata = sendto(state->sockfd, (void *)state->spacket.data,
536                    sbytes, 0,
537                    state->conn->ip_addr->ai_addr,
538                    state->conn->ip_addr->ai_addrlen);
539    if(senddata != (ssize_t)sbytes) {
540      failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
541    }
542    Curl_safefree(filename);
543    break;
544
545  case TFTP_EVENT_OACK:
546    if(data->set.upload) {
547      res = tftp_connect_for_tx(state, event);
548    }
549    else {
550      res = tftp_connect_for_rx(state, event);
551    }
552    break;
553
554  case TFTP_EVENT_ACK: /* Connected for transmit */
555    res = tftp_connect_for_tx(state, event);
556    break;
557
558  case TFTP_EVENT_DATA: /* Connected for receive */
559    res = tftp_connect_for_rx(state, event);
560    break;
561
562  case TFTP_EVENT_ERROR:
563    state->state = TFTP_STATE_FIN;
564    break;
565
566  default:
567    failf(state->conn->data, "tftp_send_first: internal error");
568    break;
569  }
570  return res;
571}
572
573/**********************************************************
574 *
575 * tftp_rx
576 *
577 * Event handler for the RX state
578 *
579 **********************************************************/
580static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
581{
582  ssize_t sbytes;
583  int rblock;
584  struct SessionHandle *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((state->block+1) != rblock) {
592      /* No, log it, up the retry count and fail if over the limit */
593      infof(data,
594            "Received unexpected DATA packet block %d\n", rblock);
595      state->retries++;
596      if(state->retries>state->retry_max) {
597        failf(data, "tftp_rx: giving up waiting for block %d",
598              state->block+1);
599        return CURLE_TFTP_ILLEGAL;
600      }
601    }
602    /* This is the expected block.  Reset counters and ACK it. */
603    state->block = (unsigned short)rblock;
604    state->retries = 0;
605    setpacketevent(&state->spacket, TFTP_EVENT_ACK);
606    setpacketblock(&state->spacket, state->block);
607    sbytes = sendto(state->sockfd, (void *)state->spacket.data,
608                    4, SEND_4TH_ARG,
609                    (struct sockaddr *)&state->remote_addr,
610                    state->remote_addrlen);
611    if(sbytes < 0) {
612      failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
613      return CURLE_SEND_ERROR;
614    }
615
616    /* Check if completed (That is, a less than full packet is received) */
617    if(state->rbytes < (ssize_t)state->blksize+4){
618      state->state = TFTP_STATE_FIN;
619    }
620    else {
621      state->state = TFTP_STATE_RX;
622    }
623    time(&state->rx_time);
624    break;
625
626  case TFTP_EVENT_OACK:
627    /* ACK option acknowledgement so we can move on to data */
628    state->block = 0;
629    state->retries = 0;
630    setpacketevent(&state->spacket, TFTP_EVENT_ACK);
631    setpacketblock(&state->spacket, state->block);
632    sbytes = sendto(state->sockfd, (void *)state->spacket.data,
633                    4, SEND_4TH_ARG,
634                    (struct sockaddr *)&state->remote_addr,
635                    state->remote_addrlen);
636    if(sbytes < 0) {
637      failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
638      return CURLE_SEND_ERROR;
639    }
640
641    /* we're ready to RX data */
642    state->state = TFTP_STATE_RX;
643    time(&state->rx_time);
644    break;
645
646  case TFTP_EVENT_TIMEOUT:
647    /* Increment the retry count and fail if over the limit */
648    state->retries++;
649    infof(data,
650          "Timeout waiting for block %d ACK.  Retries = %d\n",
651          state->block+1, state->retries);
652    if(state->retries > state->retry_max) {
653      state->error = TFTP_ERR_TIMEOUT;
654      state->state = TFTP_STATE_FIN;
655    }
656    else {
657      /* Resend the previous ACK */
658      sbytes = sendto(state->sockfd, (void *)state->spacket.data,
659                      4, SEND_4TH_ARG,
660                      (struct sockaddr *)&state->remote_addr,
661                      state->remote_addrlen);
662      /* Check all sbytes were sent */
663      if(sbytes<0) {
664        failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
665        return CURLE_SEND_ERROR;
666      }
667    }
668    break;
669
670  case TFTP_EVENT_ERROR:
671    setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
672    setpacketblock(&state->spacket, state->block);
673    sbytes = sendto(state->sockfd, (void *)state->spacket.data,
674                    4, SEND_4TH_ARG,
675                    (struct sockaddr *)&state->remote_addr,
676                    state->remote_addrlen);
677    /* don't bother with the return code, but if the socket is still up we
678     * should be a good TFTP client and let the server know we're done */
679    state->state = TFTP_STATE_FIN;
680    break;
681
682  default:
683    failf(data, "%s", "tftp_rx: internal error");
684    return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
685                                  this */
686  }
687  return CURLE_OK;
688}
689
690/**********************************************************
691 *
692 * tftp_tx
693 *
694 * Event handler for the TX state
695 *
696 **********************************************************/
697static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
698{
699  struct SessionHandle *data = state->conn->data;
700  ssize_t sbytes;
701  int rblock;
702  CURLcode res = CURLE_OK;
703  struct SingleRequest *k = &data->req;
704
705  switch(event) {
706
707  case TFTP_EVENT_ACK:
708  case TFTP_EVENT_OACK:
709    if (event == TFTP_EVENT_ACK) {
710       /* Ack the packet */
711       rblock = getrpacketblock(&state->rpacket);
712
713       if(rblock != state->block) {
714          /* This isn't the expected block.  Log it and up the retry counter */
715          infof(data, "Received ACK for block %d, expecting %d\n",
716                rblock, state->block);
717          state->retries++;
718          /* Bail out if over the maximum */
719          if(state->retries>state->retry_max) {
720             failf(data, "tftp_tx: giving up waiting for block %d ack",
721                   state->block);
722             res = CURLE_SEND_ERROR;
723          }
724          else {
725             /* Re-send the data packet */
726             sbytes = sendto(state->sockfd, (void *)&state->spacket,
727                             4+state->sbytes, SEND_4TH_ARG,
728                             (struct sockaddr *)&state->remote_addr,
729                             state->remote_addrlen);
730             /* Check all sbytes were sent */
731             if(sbytes<0) {
732                failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
733                res = CURLE_SEND_ERROR;
734             }
735          }
736          return res;
737       }
738       /* This is the expected packet.  Reset the counters and send the next
739          block */
740       time(&state->rx_time);
741       state->block++;
742    }
743    else {
744       state->block = 1; /* first data block is 1 when using OACK */
745    }
746    state->retries = 0;
747    setpacketevent(&state->spacket, TFTP_EVENT_DATA);
748    setpacketblock(&state->spacket, state->block);
749    if(state->block > 1 && state->sbytes < (int)state->blksize) {
750      state->state = TFTP_STATE_FIN;
751      return CURLE_OK;
752    }
753    res = Curl_fillreadbuffer(state->conn, (size_t)state->blksize,
754                              &state->sbytes);
755    if(res)
756      return res;
757    sbytes = sendto(state->sockfd, (void *)state->spacket.data,
758                    4+state->sbytes, SEND_4TH_ARG,
759                    (struct sockaddr *)&state->remote_addr,
760                    state->remote_addrlen);
761    /* Check all sbytes were sent */
762    if(sbytes<0) {
763      failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
764      return CURLE_SEND_ERROR;
765    }
766    /* Update the progress meter */
767    k->writebytecount += state->sbytes;
768    Curl_pgrsSetUploadCounter(data, k->writebytecount);
769    break;
770
771  case TFTP_EVENT_TIMEOUT:
772    /* Increment the retry counter and log the timeout */
773    state->retries++;
774    infof(data, "Timeout waiting for block %d ACK. "
775          " Retries = %d\n", state->block+1, state->retries);
776    /* Decide if we've had enough */
777    if(state->retries > state->retry_max) {
778      state->error = TFTP_ERR_TIMEOUT;
779      state->state = TFTP_STATE_FIN;
780    }
781    else {
782      /* Re-send the data packet */
783      sbytes = sendto(state->sockfd, (void *)state->spacket.data,
784                      4+state->sbytes, SEND_4TH_ARG,
785                      (struct sockaddr *)&state->remote_addr,
786                      state->remote_addrlen);
787      /* Check all sbytes were sent */
788      if(sbytes<0) {
789        failf(data, "%s", Curl_strerror(state->conn, SOCKERRNO));
790        return CURLE_SEND_ERROR;
791      }
792      /* since this was a re-send, we remain at the still byte position */
793      Curl_pgrsSetUploadCounter(data, k->writebytecount);
794    }
795    break;
796
797  case TFTP_EVENT_ERROR:
798    state->state = TFTP_STATE_FIN;
799    setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
800    setpacketblock(&state->spacket, state->block);
801    sbytes = sendto(state->sockfd, (void *)state->spacket.data,
802                    4, SEND_4TH_ARG,
803                    (struct sockaddr *)&state->remote_addr,
804                    state->remote_addrlen);
805    /* don't bother with the return code, but if the socket is still up we
806     * should be a good TFTP client and let the server know we're done */
807    state->state = TFTP_STATE_FIN;
808    break;
809
810  default:
811    failf(data, "tftp_tx: internal error, event: %i", (int)(event));
812    break;
813  }
814
815  return res;
816}
817
818/**********************************************************
819 *
820 * tftp_translate_code
821 *
822 * Translate internal error codes to CURL error codes
823 *
824 **********************************************************/
825static CURLcode tftp_translate_code(tftp_error_t error)
826{
827  CURLcode code = CURLE_OK;
828
829  if(error != TFTP_ERR_NONE) {
830    switch(error) {
831    case TFTP_ERR_NOTFOUND:
832      code = CURLE_TFTP_NOTFOUND;
833      break;
834    case TFTP_ERR_PERM:
835      code = CURLE_TFTP_PERM;
836      break;
837    case TFTP_ERR_DISKFULL:
838      code = CURLE_REMOTE_DISK_FULL;
839      break;
840    case TFTP_ERR_UNDEF:
841    case TFTP_ERR_ILLEGAL:
842      code = CURLE_TFTP_ILLEGAL;
843      break;
844    case TFTP_ERR_UNKNOWNID:
845      code = CURLE_TFTP_UNKNOWNID;
846      break;
847    case TFTP_ERR_EXISTS:
848      code = CURLE_REMOTE_FILE_EXISTS;
849      break;
850    case TFTP_ERR_NOSUCHUSER:
851      code = CURLE_TFTP_NOSUCHUSER;
852      break;
853    case TFTP_ERR_TIMEOUT:
854      code = CURLE_OPERATION_TIMEDOUT;
855      break;
856    case TFTP_ERR_NORESPONSE:
857      code = CURLE_COULDNT_CONNECT;
858      break;
859    default:
860      code= CURLE_ABORTED_BY_CALLBACK;
861      break;
862    }
863  }
864  else {
865    code = CURLE_OK;
866  }
867
868  return(code);
869}
870
871/**********************************************************
872 *
873 * tftp_state_machine
874 *
875 * The tftp state machine event dispatcher
876 *
877 **********************************************************/
878static CURLcode tftp_state_machine(tftp_state_data_t *state,
879                                   tftp_event_t event)
880{
881  CURLcode res = CURLE_OK;
882  struct SessionHandle *data = state->conn->data;
883  switch(state->state) {
884  case TFTP_STATE_START:
885    DEBUGF(infof(data, "TFTP_STATE_START\n"));
886    res = tftp_send_first(state, event);
887    break;
888  case TFTP_STATE_RX:
889    DEBUGF(infof(data, "TFTP_STATE_RX\n"));
890    res = tftp_rx(state, event);
891    break;
892  case TFTP_STATE_TX:
893    DEBUGF(infof(data, "TFTP_STATE_TX\n"));
894    res = tftp_tx(state, event);
895    break;
896  case TFTP_STATE_FIN:
897    infof(data, "%s\n", "TFTP finished");
898    break;
899  default:
900    DEBUGF(infof(data, "STATE: %d\n", state->state));
901    failf(data, "%s", "Internal state machine error");
902    res = CURLE_TFTP_ILLEGAL;
903    break;
904  }
905  return res;
906}
907
908/**********************************************************
909 *
910 * tftp_disconnect
911 *
912 * The disconnect callback
913 *
914 **********************************************************/
915static CURLcode tftp_disconnect(struct connectdata *conn)
916{
917  tftp_state_data_t *state = conn->proto.tftpc;
918
919  /* done, free dynamically allocated pkt buffers */
920  if(state) {
921    Curl_safefree(state->rpacket.data);
922    Curl_safefree(state->spacket.data);
923    free(state);
924  }
925
926  return CURLE_OK;
927}
928
929/**********************************************************
930 *
931 * tftp_connect
932 *
933 * The connect callback
934 *
935 **********************************************************/
936static CURLcode tftp_connect(struct connectdata *conn, bool *done)
937{
938  CURLcode code;
939  tftp_state_data_t *state;
940  int blksize, rc;
941
942  blksize = TFTP_BLKSIZE_DEFAULT;
943
944  /* If there already is a protocol-specific struct allocated for this
945     sessionhandle, deal with it */
946  Curl_reset_reqproto(conn);
947
948  state = conn->proto.tftpc = calloc(1, sizeof(tftp_state_data_t));
949  if(!state)
950    return CURLE_OUT_OF_MEMORY;
951
952  /* alloc pkt buffers based on specified blksize */
953  if(conn->data->set.tftp_blksize) {
954    blksize = (int)conn->data->set.tftp_blksize;
955    if(blksize > TFTP_BLKSIZE_MAX || blksize < TFTP_BLKSIZE_MIN )
956      return CURLE_TFTP_ILLEGAL;
957  }
958
959  if(!state->rpacket.data) {
960    state->rpacket.data = calloc(1, blksize + 2 + 2);
961
962    if(!state->rpacket.data)
963      return CURLE_OUT_OF_MEMORY;
964  }
965
966  if(!state->spacket.data) {
967    state->spacket.data = calloc(1, blksize + 2 + 2);
968
969    if(!state->spacket.data)
970      return CURLE_OUT_OF_MEMORY;
971  }
972
973  conn->bits.close = TRUE; /* we don't keep TFTP connections up bascially
974                              because there's none or very little gain for UDP
975                           */
976
977  state->conn = conn;
978  state->sockfd = state->conn->sock[FIRSTSOCKET];
979  state->state = TFTP_STATE_START;
980  state->error = TFTP_ERR_NONE;
981  state->blksize = TFTP_BLKSIZE_DEFAULT;
982  state->requested_blksize = blksize;
983
984  ((struct sockaddr *)&state->local_addr)->sa_family =
985    (unsigned short)(conn->ip_addr->ai_family);
986
987  tftp_set_timeouts(state);
988
989  if(!conn->bits.bound) {
990    /* If not already bound, bind to any interface, random UDP port. If it is
991     * reused or a custom local port was desired, this has already been done!
992     *
993     * We once used the size of the local_addr struct as the third argument
994     * for bind() to better work with IPv6 or whatever size the struct could
995     * have, but we learned that at least Tru64, AIX and IRIX *requires* the
996     * size of that argument to match the exact size of a 'sockaddr_in' struct
997     * when running IPv4-only.
998     *
999     * Therefore we use the size from the address we connected to, which we
1000     * assume uses the same IP version and thus hopefully this works for both
1001     * IPv4 and IPv6...
1002     */
1003    rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
1004              conn->ip_addr->ai_addrlen);
1005    if(rc) {
1006      failf(conn->data, "bind() failed; %s",
1007            Curl_strerror(conn, SOCKERRNO));
1008      return CURLE_COULDNT_CONNECT;
1009    }
1010    conn->bits.bound = TRUE;
1011  }
1012
1013  Curl_pgrsStartNow(conn->data);
1014
1015  *done = TRUE;
1016  code = CURLE_OK;
1017  return(code);
1018}
1019
1020/**********************************************************
1021 *
1022 * tftp_done
1023 *
1024 * The done callback
1025 *
1026 **********************************************************/
1027static CURLcode tftp_done(struct connectdata *conn, CURLcode status,
1028                               bool premature)
1029{
1030  CURLcode code = CURLE_OK;
1031  tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
1032
1033  (void)status; /* unused */
1034  (void)premature; /* not used */
1035
1036  Curl_pgrsDone(conn);
1037
1038  /* If we have encountered an error */
1039  code = tftp_translate_code(state->error);
1040
1041  return code;
1042}
1043
1044/**********************************************************
1045 *
1046 * tftp_getsock
1047 *
1048 * The getsock callback
1049 *
1050 **********************************************************/
1051static int tftp_getsock(struct connectdata *conn, curl_socket_t *socks,
1052                       int numsocks)
1053{
1054  if(!numsocks)
1055    return GETSOCK_BLANK;
1056
1057  socks[0] = conn->sock[FIRSTSOCKET];
1058
1059  return GETSOCK_READSOCK(0);
1060}
1061
1062/**********************************************************
1063 *
1064 * tftp_receive_packet
1065 *
1066 * Called once select fires and data is ready on the socket
1067 *
1068 **********************************************************/
1069static CURLcode tftp_receive_packet(struct connectdata *conn)
1070{
1071  struct Curl_sockaddr_storage fromaddr;
1072  curl_socklen_t        fromlen;
1073  CURLcode              result = CURLE_OK;
1074  struct SessionHandle  *data = conn->data;
1075  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
1076  struct SingleRequest  *k = &data->req;
1077
1078  /* Receive the packet */
1079  fromlen = sizeof(fromaddr);
1080  state->rbytes = (int)recvfrom(state->sockfd,
1081                                   (void *)state->rpacket.data,
1082                                   state->blksize+4,
1083                                   0,
1084                                   (struct sockaddr *)&fromaddr,
1085                                   &fromlen);
1086  if(state->remote_addrlen==0) {
1087    memcpy(&state->remote_addr, &fromaddr, fromlen);
1088    state->remote_addrlen = fromlen;
1089  }
1090
1091  /* Sanity check packet length */
1092  if(state->rbytes < 4) {
1093    failf(data, "Received too short packet");
1094    /* Not a timeout, but how best to handle it? */
1095    state->event = TFTP_EVENT_TIMEOUT;
1096  }
1097  else {
1098    /* The event is given by the TFTP packet time */
1099    state->event = (tftp_event_t)getrpacketevent(&state->rpacket);
1100
1101    switch(state->event) {
1102    case TFTP_EVENT_DATA:
1103      /* Don't pass to the client empty or retransmitted packets */
1104      if(state->rbytes > 4 &&
1105          ((state->block+1) == getrpacketblock(&state->rpacket))) {
1106        result = Curl_client_write(conn, CLIENTWRITE_BODY,
1107                                 (char *)state->rpacket.data+4,
1108                                 state->rbytes-4);
1109        if(result) {
1110          tftp_state_machine(state, TFTP_EVENT_ERROR);
1111          return result;
1112        }
1113        k->bytecount += state->rbytes-4;
1114        Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount);
1115      }
1116      break;
1117    case TFTP_EVENT_ERROR:
1118      state->error = (tftp_error_t)getrpacketblock(&state->rpacket);
1119      infof(data, "%s\n", (const char *)state->rpacket.data+4);
1120      break;
1121    case TFTP_EVENT_ACK:
1122      break;
1123    case TFTP_EVENT_OACK:
1124      result = tftp_parse_option_ack(state,
1125                                   (const char *)state->rpacket.data+2,
1126                                   state->rbytes-2);
1127      if(result)
1128        return result;
1129      break;
1130    case TFTP_EVENT_RRQ:
1131    case TFTP_EVENT_WRQ:
1132    default:
1133      failf(data, "%s", "Internal error: Unexpected packet");
1134      break;
1135    }
1136
1137    /* Update the progress meter */
1138    if(Curl_pgrsUpdate(conn)) {
1139      tftp_state_machine(state, TFTP_EVENT_ERROR);
1140      return CURLE_ABORTED_BY_CALLBACK;
1141    }
1142  }
1143  return result;
1144}
1145
1146/**********************************************************
1147 *
1148 * tftp_state_timeout
1149 *
1150 * Check if timeouts have been reached
1151 *
1152 **********************************************************/
1153static long tftp_state_timeout(struct connectdata *conn, tftp_event_t *event)
1154{
1155  time_t                current;
1156  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
1157
1158  if (event)
1159    *event = TFTP_EVENT_NONE;
1160
1161  time(&current);
1162  if(current > state->max_time) {
1163    DEBUGF(infof(conn->data, "timeout: %ld > %ld\n",
1164                 (long)current, (long)state->max_time));
1165    state->error = TFTP_ERR_TIMEOUT;
1166    state->state = TFTP_STATE_FIN;
1167    return(0);
1168  }
1169  else if (current > state->rx_time+state->retry_time) {
1170    if (event)
1171      *event = TFTP_EVENT_TIMEOUT;
1172    time(&state->rx_time); /* update even though we received nothing */
1173    return(state->max_time-current);
1174  }
1175  else {
1176    return(state->max_time-current);
1177  }
1178}
1179
1180
1181/**********************************************************
1182 *
1183 * tftp_easy_statemach
1184 *
1185 * Handle easy request until completion
1186 *
1187 **********************************************************/
1188static CURLcode tftp_easy_statemach(struct connectdata *conn)
1189{
1190  int                   rc;
1191  int                   check_time = 0;
1192  CURLcode              result = CURLE_OK;
1193  struct SessionHandle  *data = conn->data;
1194  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
1195  int                   fd_read;
1196  long                  timeout_ms;
1197  struct SingleRequest  *k = &data->req;
1198  struct timeval        transaction_start = Curl_tvnow();
1199
1200  k->start = transaction_start;
1201  k->now = transaction_start;
1202
1203  /* Run the TFTP State Machine */
1204  for(; (state->state != TFTP_STATE_FIN) && (result == CURLE_OK); ) {
1205
1206    timeout_ms = state->retry_time * 1000;
1207
1208    if (data->set.upload) {
1209      if (data->set.max_send_speed &&
1210          (data->progress.ulspeed > data->set.max_send_speed)) {
1211        fd_read = CURL_SOCKET_BAD;
1212        timeout_ms = Curl_sleep_time(data->set.max_send_speed,
1213                                     data->progress.ulspeed, state->blksize);
1214      }
1215      else {
1216        fd_read = state->sockfd;
1217      }
1218    }
1219    else {
1220      if (data->set.max_recv_speed &&
1221          (data->progress.dlspeed > data->set.max_recv_speed)) {
1222        fd_read = CURL_SOCKET_BAD;
1223        timeout_ms = Curl_sleep_time(data->set.max_recv_speed,
1224                                     data->progress.dlspeed, state->blksize);
1225      }
1226      else {
1227        fd_read = state->sockfd;
1228      }
1229    }
1230
1231    if(data->set.timeout) {
1232      timeout_ms = data->set.timeout - Curl_tvdiff(k->now, k->start);
1233      if (timeout_ms > state->retry_time * 1000)
1234        timeout_ms = state->retry_time * 1000;
1235      else if(timeout_ms < 0)
1236        timeout_ms = 0;
1237    }
1238
1239
1240    /* Wait until ready to read or timeout occurs */
1241    rc = Curl_socket_ready(fd_read, CURL_SOCKET_BAD, (int)(timeout_ms));
1242
1243    k->now = Curl_tvnow();
1244
1245    /* Force a progress callback if it's been too long */
1246    if (Curl_tvdiff(k->now, k->start) >= data->set.timeout) {
1247       if(Curl_pgrsUpdate(conn)) {
1248          tftp_state_machine(state, TFTP_EVENT_ERROR);
1249          return CURLE_ABORTED_BY_CALLBACK;
1250       }
1251       k->start = k->now;
1252    }
1253
1254    if(rc == -1) {
1255      /* bail out */
1256      int error = SOCKERRNO;
1257      failf(data, "%s", Curl_strerror(conn, error));
1258      state->event = TFTP_EVENT_ERROR;
1259    }
1260    else {
1261
1262      if(rc==0) {
1263        /* A timeout occured, but our timeout is variable, so maybe
1264           just continue? */
1265        long rtms = state->retry_time * 1000;
1266        if (Curl_tvdiff(k->now, transaction_start) > rtms) {
1267          state->event = TFTP_EVENT_TIMEOUT;
1268          /* Force a look at transfer timeouts */
1269          check_time = 1;
1270        }
1271        else {
1272          continue; /* skip state machine */
1273        }
1274      }
1275      else {
1276        result = tftp_receive_packet(conn);
1277        if (result == CURLE_OK)
1278           transaction_start = Curl_tvnow();
1279
1280        if(k->bytecountp)
1281          *k->bytecountp = k->bytecount; /* read count */
1282        if(k->writebytecountp)
1283          *k->writebytecountp = k->writebytecount; /* write count */
1284      }
1285    }
1286
1287    if(check_time) {
1288      tftp_state_timeout(conn, NULL);
1289      check_time = 0;
1290    }
1291
1292    if(result)
1293      return(result);
1294
1295    result = tftp_state_machine(state, state->event);
1296  }
1297
1298  /* Tell curl we're done */
1299  result = Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1300
1301  return(result);
1302}
1303
1304/**********************************************************
1305 *
1306 * tftp_multi_statemach
1307 *
1308 * Handle single RX socket event and return
1309 *
1310 **********************************************************/
1311static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done)
1312{
1313  int                   rc;
1314  tftp_event_t          event;
1315  CURLcode              result = CURLE_OK;
1316  struct SessionHandle  *data = conn->data;
1317  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
1318  long                  timeout_ms = tftp_state_timeout(conn, &event);
1319
1320  *done = FALSE;
1321
1322  if(timeout_ms <= 0) {
1323    failf(data, "TFTP response timeout");
1324    return CURLE_OPERATION_TIMEDOUT;
1325  }
1326  else if (event != TFTP_EVENT_NONE) {
1327    result = tftp_state_machine(state, event);
1328    if(result != CURLE_OK)
1329      return(result);
1330    *done = (bool)(state->state == TFTP_STATE_FIN);
1331    if(*done)
1332      /* Tell curl we're done */
1333      result = Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1334  }
1335  else {
1336    /* no timeouts to handle, check our socket */
1337    rc = Curl_socket_ready(state->sockfd, CURL_SOCKET_BAD, 0);
1338
1339    if(rc == -1) {
1340      /* bail out */
1341      int error = SOCKERRNO;
1342      failf(data, "%s", Curl_strerror(conn, error));
1343      state->event = TFTP_EVENT_ERROR;
1344    }
1345    else if(rc != 0) {
1346      result = tftp_receive_packet(conn);
1347      if(result != CURLE_OK)
1348        return(result);
1349      result = tftp_state_machine(state, state->event);
1350      if(result != CURLE_OK)
1351        return(result);
1352      *done = (bool)(state->state == TFTP_STATE_FIN);
1353      if(*done)
1354        /* Tell curl we're done */
1355        result = Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
1356    }
1357    /* if rc == 0, then select() timed out */
1358  }
1359
1360  return result;
1361}
1362
1363/**********************************************************
1364 *
1365 * tftp_doing
1366 *
1367 * Called from multi.c while DOing
1368 *
1369 **********************************************************/
1370static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done)
1371{
1372  CURLcode result;
1373  result = tftp_multi_statemach(conn, dophase_done);
1374
1375  if(*dophase_done) {
1376    DEBUGF(infof(conn->data, "DO phase is complete\n"));
1377  }
1378  return result;
1379}
1380
1381/**********************************************************
1382 *
1383 * tftp_peform
1384 *
1385 * Entry point for transfer from tftp_do, sarts state mach
1386 *
1387 **********************************************************/
1388static CURLcode tftp_perform(struct connectdata *conn, bool *dophase_done)
1389{
1390  CURLcode              result = CURLE_OK;
1391  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
1392
1393  *dophase_done = FALSE;
1394
1395  result = tftp_state_machine(state, TFTP_EVENT_INIT);
1396
1397  if(state->state == TFTP_STATE_FIN || result != CURLE_OK)
1398    return(result);
1399
1400  if(conn->data->state.used_interface == Curl_if_multi)
1401    tftp_multi_statemach(conn, dophase_done);
1402  else {
1403    result = tftp_easy_statemach(conn);
1404    *dophase_done = TRUE; /* with the easy interface we are done here */
1405  }
1406
1407  if(*dophase_done)
1408    DEBUGF(infof(conn->data, "DO phase is complete\n"));
1409
1410  return result;
1411}
1412
1413
1414/**********************************************************
1415 *
1416 * tftp_do
1417 *
1418 * The do callback
1419 *
1420 * This callback initiates the TFTP transfer
1421 *
1422 **********************************************************/
1423
1424static CURLcode tftp_do(struct connectdata *conn, bool *done)
1425{
1426  tftp_state_data_t     *state;
1427  CURLcode              code;
1428
1429  *done = FALSE;
1430
1431  /*
1432    Since connections can be re-used between SessionHandles, this might be a
1433    connection already existing but on a fresh SessionHandle struct so we must
1434    make sure we have a good 'struct TFTP' to play with. For new connections,
1435    the struct TFTP is allocated and setup in the tftp_connect() function.
1436  */
1437  Curl_reset_reqproto(conn);
1438
1439  if(!conn->proto.tftpc) {
1440    code = tftp_connect(conn, done);
1441    if(code)
1442      return code;
1443  }
1444  state = (tftp_state_data_t *)conn->proto.tftpc;
1445
1446  code = tftp_perform(conn, done);
1447
1448  /* If tftp_perform() returned an error, use that for return code. If it
1449     was OK, see if tftp_translate_code() has an error. */
1450  if (code == CURLE_OK)
1451    /* If we have encountered an internal tftp error, translate it. */
1452    code = tftp_translate_code(state->error);
1453
1454  return code;
1455}
1456
1457static CURLcode tftp_setup_connection(struct connectdata * conn)
1458{
1459  struct SessionHandle *data = conn->data;
1460  char * type;
1461  char command;
1462
1463  conn->socktype = SOCK_DGRAM;   /* UDP datagram based */
1464
1465  /* TFTP URLs support an extension like ";mode=<typecode>" that
1466   * we'll try to get now! */
1467  type = strstr(data->state.path, ";mode=");
1468
1469  if(!type)
1470    type = strstr(conn->host.rawalloc, ";mode=");
1471
1472  if(type) {
1473    *type = 0;                   /* it was in the middle of the hostname */
1474    command = Curl_raw_toupper(type[6]);
1475
1476    switch (command) {
1477    case 'A': /* ASCII mode */
1478    case 'N': /* NETASCII mode */
1479      data->set.prefer_ascii = TRUE;
1480      break;
1481
1482    case 'O': /* octet mode */
1483    case 'I': /* binary mode */
1484    default:
1485      /* switch off ASCII */
1486      data->set.prefer_ascii = FALSE;
1487      break;
1488    }
1489  }
1490
1491  return CURLE_OK;
1492}
1493#endif
1494