xref: /curl/lib/curl_range.c (revision 2bc1d775)
1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  * SPDX-License-Identifier: curl
22  *
23  ***************************************************************************/
24 
25 #include "curl_setup.h"
26 #include <curl/curl.h>
27 #include "curl_range.h"
28 #include "sendf.h"
29 #include "strtoofft.h"
30 
31 /* Only include this function if one or more of FTP, FILE are enabled. */
32 #if !defined(CURL_DISABLE_FTP) || !defined(CURL_DISABLE_FILE)
33 
34  /*
35   Check if this is a range download, and if so, set the internal variables
36   properly.
37  */
Curl_range(struct Curl_easy * data)38 CURLcode Curl_range(struct Curl_easy *data)
39 {
40   curl_off_t from, to;
41   char *ptr;
42   char *ptr2;
43 
44   if(data->state.use_range && data->state.range) {
45     CURLofft from_t;
46     CURLofft to_t;
47     from_t = curlx_strtoofft(data->state.range, &ptr, 10, &from);
48     if(from_t == CURL_OFFT_FLOW)
49       return CURLE_RANGE_ERROR;
50     while(*ptr && (ISBLANK(*ptr) || (*ptr == '-')))
51       ptr++;
52     to_t = curlx_strtoofft(ptr, &ptr2, 10, &to);
53     if(to_t == CURL_OFFT_FLOW)
54       return CURLE_RANGE_ERROR;
55     if((to_t == CURL_OFFT_INVAL) && !from_t) {
56       /* X - */
57       data->state.resume_from = from;
58       DEBUGF(infof(data, "RANGE %" CURL_FORMAT_CURL_OFF_T " to end of file",
59                    from));
60     }
61     else if((from_t == CURL_OFFT_INVAL) && !to_t) {
62       /* -Y */
63       data->req.maxdownload = to;
64       data->state.resume_from = -to;
65       DEBUGF(infof(data, "RANGE the last %" CURL_FORMAT_CURL_OFF_T " bytes",
66                    to));
67     }
68     else {
69       /* X-Y */
70       curl_off_t totalsize;
71 
72       /* Ensure the range is sensible - to should follow from. */
73       if(from > to)
74         return CURLE_RANGE_ERROR;
75 
76       totalsize = to - from;
77       if(totalsize == CURL_OFF_T_MAX)
78         return CURLE_RANGE_ERROR;
79 
80       data->req.maxdownload = totalsize + 1; /* include last byte */
81       data->state.resume_from = from;
82       DEBUGF(infof(data, "RANGE from %" CURL_FORMAT_CURL_OFF_T
83                    " getting %" CURL_FORMAT_CURL_OFF_T " bytes",
84                    from, data->req.maxdownload));
85     }
86     DEBUGF(infof(data, "range-download from %" CURL_FORMAT_CURL_OFF_T
87                  " to %" CURL_FORMAT_CURL_OFF_T ", totally %"
88                  CURL_FORMAT_CURL_OFF_T " bytes",
89                  from, to, data->req.maxdownload));
90   }
91   else
92     data->req.maxdownload = -1;
93   return CURLE_OK;
94 }
95 
96 #endif
97