1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2017, 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 /* <DESC>
23  * Upload to FTP, resuming failed transfers.
24  * </DESC>
25  */
26 
27 #include <stdlib.h>
28 #include <stdio.h>
29 #include <curl/curl.h>
30 
31 /* parse headers for Content-Length */
32 static size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb,
33                                    void *stream)
34 {
35   int r;
36   long len = 0;
37 
38   r = sscanf(ptr, "Content-Length: %ld\n", &len);
39   if(r)
40     *((long *) stream) = len;
41 
42   return size * nmemb;
43 }
44 
45 /* discard downloaded data */
46 static size_t discardfunc(void *ptr, size_t size, size_t nmemb, void *stream)
47 {
48   (void)ptr;
49   (void)stream;
50   return size * nmemb;
51 }
52 
53 /* read data to upload */
54 static size_t readfunc(void *ptr, size_t size, size_t nmemb, void *stream)
55 {
56   FILE *f = stream;
57   size_t n;
58 
59   if(ferror(f))
60     return CURL_READFUNC_ABORT;
61 
62   n = fread(ptr, size, nmemb, f) * size;
63 
64   return n;
65 }
66 
67 
68 static int upload(CURL *curlhandle, const char *remotepath,
69                   const char *localpath, long timeout, long tries)
70 {
71   FILE *f;
72   long uploaded_len = 0;
73   CURLcode r = CURLE_GOT_NOTHING;
74   int c;
75 
76   f = fopen(localpath, "rb");
77   if(!f) {
78     perror(NULL);
79     return 0;
80   }
81 
82   curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);
83 
84   curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);
85 
86   if(timeout)
87     curl_easy_setopt(curlhandle, CURLOPT_FTP_RESPONSE_TIMEOUT, timeout);
88 
89   curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
90   curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &uploaded_len);
91 
92   curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, discardfunc);
93 
94   curl_easy_setopt(curlhandle, CURLOPT_READFUNCTION, readfunc);
95   curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);
96 
97   /* disable passive mode */
98   curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-");
99   curl_easy_setopt(curlhandle, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);
100 
101   curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);
102 
103   for(c = 0; (r != CURLE_OK) && (c < tries); c++) {
104     /* are we resuming? */
105     if(c) { /* yes */
106       /* determine the length of the file already written */
107 
108       /*
109        * With NOBODY and NOHEADER, libcurl will issue a SIZE
110        * command, but the only way to retrieve the result is
111        * to parse the returned Content-Length header. Thus,
112        * getcontentlengthfunc(). We need discardfunc() above
113        * because HEADER will dump the headers to stdout
114        * without it.
115        */
116       curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 1L);
117       curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);
118 
119       r = curl_easy_perform(curlhandle);
120       if(r != CURLE_OK)
121         continue;
122 
123       curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 0L);
124       curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);
125 
126       fseek(f, uploaded_len, SEEK_SET);
127 
128       curl_easy_setopt(curlhandle, CURLOPT_APPEND, 1L);
129     }
130     else { /* no */
131       curl_easy_setopt(curlhandle, CURLOPT_APPEND, 0L);
132     }
133 
134     r = curl_easy_perform(curlhandle);
135   }
136 
137   fclose(f);
138 
139   if(r == CURLE_OK)
140     return 1;
141   else {
142     fprintf(stderr, "%s\n", curl_easy_strerror(r));
143     return 0;
144   }
145 }
146 
147 int main(void)
148 {
149   CURL *curlhandle = NULL;
150 
151   curl_global_init(CURL_GLOBAL_ALL);
152   curlhandle = curl_easy_init();
153 
154   upload(curlhandle, "ftp://user:pass@example.com/path/file", "C:\\file",
155          0, 3);
156 
157   curl_easy_cleanup(curlhandle);
158   curl_global_cleanup();
159 
160   return 0;
161 }
162