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/* <DESC>
25 * Upload to FTP, resuming failed transfers. Active mode.
26 * </DESC>
27 */
28
29#include <stdlib.h>
30#include <stdio.h>
31#include <curl/curl.h>
32
33/* parse headers for Content-Length */
34static size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb,
35                                   void *stream)
36{
37  int r;
38  long len = 0;
39
40  r = sscanf(ptr, "Content-Length: %ld\n", &len);
41  if(r)
42    *((long *) stream) = len;
43
44  return size * nmemb;
45}
46
47/* discard downloaded data */
48static size_t discardfunc(void *ptr, size_t size, size_t nmemb, void *stream)
49{
50  (void)ptr;
51  (void)stream;
52  return size * nmemb;
53}
54
55/* read data to upload */
56static size_t readfunc(char *ptr, size_t size, size_t nmemb, void *stream)
57{
58  FILE *f = stream;
59  size_t n;
60
61  if(ferror(f))
62    return CURL_READFUNC_ABORT;
63
64  n = fread(ptr, size, nmemb, f) * size;
65
66  return n;
67}
68
69
70static int upload(CURL *curlhandle, const char *remotepath,
71                  const char *localpath, long timeout, long tries)
72{
73  FILE *f;
74  long uploaded_len = 0;
75  CURLcode r = CURLE_GOT_NOTHING;
76  int c;
77
78  f = fopen(localpath, "rb");
79  if(!f) {
80    perror(NULL);
81    return 0;
82  }
83
84  curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);
85
86  curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);
87
88  if(timeout)
89    curl_easy_setopt(curlhandle, CURLOPT_SERVER_RESPONSE_TIMEOUT, timeout);
90
91  curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
92  curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &uploaded_len);
93
94  curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, discardfunc);
95
96  curl_easy_setopt(curlhandle, CURLOPT_READFUNCTION, readfunc);
97  curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);
98
99  /* enable active mode */
100  curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-");
101
102  /* allow the server no more than 7 seconds to connect back */
103  curl_easy_setopt(curlhandle, CURLOPT_ACCEPTTIMEOUT_MS, 7000L);
104
105  curl_easy_setopt(curlhandle, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);
106
107  curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);
108
109  for(c = 0; (r != CURLE_OK) && (c < tries); c++) {
110    /* are we resuming? */
111    if(c) { /* yes */
112      /* determine the length of the file already written */
113
114      /*
115       * With NOBODY and NOHEADER, libcurl will issue a SIZE
116       * command, but the only way to retrieve the result is
117       * to parse the returned Content-Length header. Thus,
118       * getcontentlengthfunc(). We need discardfunc() above
119       * because HEADER will dump the headers to stdout
120       * without it.
121       */
122      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 1L);
123      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);
124
125      r = curl_easy_perform(curlhandle);
126      if(r != CURLE_OK)
127        continue;
128
129      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 0L);
130      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);
131
132      fseek(f, uploaded_len, SEEK_SET);
133
134      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 1L);
135    }
136    else { /* no */
137      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 0L);
138    }
139
140    r = curl_easy_perform(curlhandle);
141  }
142
143  fclose(f);
144
145  if(r == CURLE_OK)
146    return 1;
147  else {
148    fprintf(stderr, "%s\n", curl_easy_strerror(r));
149    return 0;
150  }
151}
152
153int main(void)
154{
155  CURL *curlhandle = NULL;
156
157  curl_global_init(CURL_GLOBAL_ALL);
158  curlhandle = curl_easy_init();
159
160  upload(curlhandle, "ftp://user:pass@example.com/path/file", "C:\\file",
161         0, 3);
162
163  curl_easy_cleanup(curlhandle);
164  curl_global_cleanup();
165
166  return 0;
167}
168