aboutsummaryrefslogtreecommitdiff
path: root/src/tool_cb_wrt.c
blob: a055b444e73c4d9c8c40493b1e786429dbff8f63 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/
#include "tool_setup.h"

#define ENABLE_CURLX_PRINTF
/* use our own printf() functions */
#include "curlx.h"

#include "tool_cfgable.h"
#include "tool_msgs.h"
#include "tool_cb_wrt.h"

#include "curl_memdebug.h" /* keep this as LAST include */

/*
** callback for CURLOPT_WRITEFUNCTION
*/

size_t tool_write_cb(void *buffer, size_t sz, size_t nmemb, void *userdata)
{
  size_t rc;
  struct OutStruct *outs = userdata;
  struct Configurable *config = outs->config;

  /*
   * Once that libcurl has called back tool_write_cb() the returned value
   * is checked against the amount that was intended to be written, if
   * it does not match then it fails with CURLE_WRITE_ERROR. So at this
   * point returning a value different from sz*nmemb indicates failure.
   */
  const size_t failure = (sz * nmemb) ? 0 : 1;

  if(!config)
    return failure;

#ifdef DEBUGBUILD
  if(config->include_headers) {
    if(sz * nmemb > (size_t)CURL_MAX_HTTP_HEADER) {
      warnf(config, "Header data size exceeds single call write limit!\n");
      return failure;
    }
  }
  else {
    if(sz * nmemb > (size_t)CURL_MAX_WRITE_SIZE) {
      warnf(config, "Data size exceeds single call write limit!\n");
      return failure;
    }
  }

  {
    /* Some internal congruency checks on received OutStruct */
    bool check_fails = FALSE;
    if(outs->filename) {
      /* regular file */
      if(!*outs->filename)
        check_fails = TRUE;
      if(!outs->s_isreg)
        check_fails = TRUE;
      if(outs->fopened && !outs->stream)
        check_fails = TRUE;
      if(!outs->fopened && outs->stream)
        check_fails = TRUE;
      if(!outs->fopened && outs->bytes)
        check_fails = TRUE;
    }
    else {
      /* standard stream */
      if(!outs->stream || outs->s_isreg || outs->fopened)
        check_fails = TRUE;
      if(outs->alloc_filename || outs->is_cd_filename || outs->init)
        check_fails = TRUE;
    }
    if(check_fails) {
      warnf(config, "Invalid output struct data for write callback\n");
      return failure;
    }
  }
#endif

  if(!outs->stream) {
    FILE *file;

    if(!outs->filename || !*outs->filename) {
      warnf(config, "Remote filename has no length!\n");
      return failure;
    }

    if(outs->is_cd_filename) {
      /* don't overwrite existing files */
      file = fopen(outs->filename, "rb");
      if(file) {
        fclose(file);
        warnf(config, "Refusing to overwrite %s: %s\n", outs->filename,
              strerror(EEXIST));
        return failure;
      }
    }

    /* open file for writing */
    file = fopen(outs->filename, "wb");
    if(!file) {
      warnf(config, "Failed to create the file %s: %s\n", outs->filename,
            strerror(errno));
      return failure;
    }
    outs->s_isreg = TRUE;
    outs->fopened = TRUE;
    outs->stream = file;
    outs->bytes = 0;
    outs->init = 0;
  }

  rc = fwrite(buffer, sz, nmemb, outs->stream);

  if((sz * nmemb) == rc)
    /* we added this amount of data to the output */
    outs->bytes += (sz * nmemb);

  if(config->readbusy) {
    config->readbusy = FALSE;
    curl_easy_pause(config->easy, CURLPAUSE_CONT);
  }

  if(config->nobuffer) {
    /* output buffering disabled */
    int res = fflush(outs->stream);
    if(res)
      return failure;
  }

  return rc;
}