xref: /third_party/curl/src/tool_ipfs.c (revision 13498266)
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#include "tool_setup.h"
25
26#define ENABLE_CURLX_PRINTF
27/* use our own printf() functions */
28#include "curlx.h"
29#include "dynbuf.h"
30
31#include "tool_cfgable.h"
32#include "tool_msgs.h"
33#include "tool_ipfs.h"
34
35#include "memdebug.h" /* keep this as LAST include */
36
37/* ensure input ends in slash */
38static CURLcode ensure_trailing_slash(char **input)
39{
40  if(*input && **input) {
41    size_t len = strlen(*input);
42    if(((*input)[len - 1] != '/')) {
43      struct curlx_dynbuf dyn;
44      curlx_dyn_init(&dyn, len + 2);
45
46      if(curlx_dyn_addn(&dyn, *input, len)) {
47        Curl_safefree(*input);
48        return CURLE_OUT_OF_MEMORY;
49      }
50
51      Curl_safefree(*input);
52
53      if(curlx_dyn_addn(&dyn, "/", 1))
54        return CURLE_OUT_OF_MEMORY;
55
56      *input = curlx_dyn_ptr(&dyn);
57    }
58  }
59
60  return CURLE_OK;
61}
62
63static char *ipfs_gateway(void)
64{
65  char *ipfs_path = NULL;
66  char *gateway_composed_file_path = NULL;
67  FILE *gateway_file = NULL;
68  char *gateway = curlx_getenv("IPFS_GATEWAY");
69
70  /* Gateway is found from environment variable. */
71  if(gateway) {
72    if(ensure_trailing_slash(&gateway))
73      goto fail;
74    return gateway;
75  }
76
77  /* Try to find the gateway in the IPFS data folder. */
78  ipfs_path = curlx_getenv("IPFS_PATH");
79
80  if(!ipfs_path) {
81    char *home = curlx_getenv("HOME");
82    if(home && *home)
83      ipfs_path = aprintf("%s/.ipfs/", home);
84    /* fallback to "~/.ipfs", as that's the default location. */
85
86    Curl_safefree(home);
87  }
88
89  if(!ipfs_path || ensure_trailing_slash(&ipfs_path))
90    goto fail;
91
92  gateway_composed_file_path = aprintf("%sgateway", ipfs_path);
93
94  if(!gateway_composed_file_path)
95    goto fail;
96
97  gateway_file = fopen(gateway_composed_file_path, FOPEN_READTEXT);
98  Curl_safefree(gateway_composed_file_path);
99
100  if(gateway_file) {
101    int c;
102    struct curlx_dynbuf dyn;
103    curlx_dyn_init(&dyn, MAX_GATEWAY_URL_LEN);
104
105    /* get the first line of the gateway file, ignore the rest */
106    while((c = getc(gateway_file)) != EOF && c != '\n' && c != '\r') {
107      char c_char = (char)c;
108      if(curlx_dyn_addn(&dyn, &c_char, 1))
109        goto fail;
110    }
111
112    fclose(gateway_file);
113    gateway_file = NULL;
114
115    if(curlx_dyn_len(&dyn))
116      gateway = curlx_dyn_ptr(&dyn);
117
118    if(gateway)
119      ensure_trailing_slash(&gateway);
120
121    if(!gateway)
122      goto fail;
123
124    Curl_safefree(ipfs_path);
125
126    return gateway;
127  }
128fail:
129  if(gateway_file)
130    fclose(gateway_file);
131  Curl_safefree(gateway);
132  Curl_safefree(ipfs_path);
133  return NULL;
134}
135
136/*
137 * Rewrite ipfs://<cid> and ipns://<cid> to a HTTP(S)
138 * URL that can be handled by an IPFS gateway.
139 */
140CURLcode ipfs_url_rewrite(CURLU *uh, const char *protocol, char **url,
141                          struct OperationConfig *config)
142{
143  CURLcode result = CURLE_URL_MALFORMAT;
144  CURLUcode getResult;
145  char *gateway = NULL;
146  char *gwhost = NULL;
147  char *gwpath = NULL;
148  char *gwquery = NULL;
149  char *gwscheme = NULL;
150  char *gwport = NULL;
151  char *inputpath = NULL;
152  char *cid = NULL;
153  char *pathbuffer = NULL;
154  char *cloneurl;
155  CURLU *gatewayurl = curl_url();
156
157  if(!gatewayurl) {
158    result = CURLE_FAILED_INIT;
159    goto clean;
160  }
161
162  getResult = curl_url_get(uh, CURLUPART_HOST, &cid, CURLU_URLDECODE);
163  if(getResult || !cid)
164    goto clean;
165
166  /* We might have a --ipfs-gateway argument. Check it first and use it. Error
167   * if we do have something but if it's an invalid url.
168   */
169  if(config->ipfs_gateway) {
170    /* ensure the gateway ends in a trailing / */
171    if(ensure_trailing_slash(&config->ipfs_gateway) != CURLE_OK) {
172      result = CURLE_OUT_OF_MEMORY;
173      goto clean;
174    }
175
176    if(!curl_url_set(gatewayurl, CURLUPART_URL, config->ipfs_gateway,
177                    CURLU_GUESS_SCHEME)) {
178      gateway = strdup(config->ipfs_gateway);
179      if(!gateway) {
180        result = CURLE_URL_MALFORMAT;
181        goto clean;
182      }
183
184    }
185    else {
186      result = CURLE_BAD_FUNCTION_ARGUMENT;
187      goto clean;
188    }
189  }
190  else {
191    /* this is ensured to end in a trailing / within ipfs_gateway() */
192    gateway = ipfs_gateway();
193    if(!gateway) {
194      result = CURLE_FILE_COULDNT_READ_FILE;
195      goto clean;
196    }
197
198    if(curl_url_set(gatewayurl, CURLUPART_URL, gateway, 0)) {
199      result = CURLE_URL_MALFORMAT;
200      goto clean;
201    }
202  }
203
204  /* check for unsupported gateway parts */
205  if(curl_url_get(gatewayurl, CURLUPART_QUERY, &gwquery, 0)
206                  != CURLUE_NO_QUERY) {
207    result = CURLE_URL_MALFORMAT;
208    goto clean;
209  }
210
211  /* get gateway parts */
212  if(curl_url_get(gatewayurl, CURLUPART_HOST,
213                  &gwhost, CURLU_URLDECODE)) {
214    goto clean;
215  }
216
217  if(curl_url_get(gatewayurl, CURLUPART_SCHEME,
218                  &gwscheme, CURLU_URLDECODE)) {
219    goto clean;
220  }
221
222  curl_url_get(gatewayurl, CURLUPART_PORT, &gwport, CURLU_URLDECODE);
223  curl_url_get(gatewayurl, CURLUPART_PATH, &gwpath, CURLU_URLDECODE);
224
225  /* get the path from user input */
226  curl_url_get(uh, CURLUPART_PATH, &inputpath, CURLU_URLDECODE);
227  /* inputpath might be NULL or a valid pointer now */
228
229  /* set gateway parts in input url */
230  if(curl_url_set(uh, CURLUPART_SCHEME, gwscheme, CURLU_URLENCODE) ||
231     curl_url_set(uh, CURLUPART_HOST, gwhost, CURLU_URLENCODE) ||
232     curl_url_set(uh, CURLUPART_PORT, gwport, CURLU_URLENCODE))
233    goto clean;
234
235  /* if the input path is just a slash, clear it */
236  if(inputpath && (inputpath[0] == '/') && !inputpath[1])
237    *inputpath = '\0';
238
239  /* ensure the gateway path ends with a trailing slash */
240  ensure_trailing_slash(&gwpath);
241
242  pathbuffer = aprintf("%s%s/%s%s", gwpath, protocol, cid,
243                       inputpath ? inputpath : "");
244  if(!pathbuffer) {
245    goto clean;
246  }
247
248  if(curl_url_set(uh, CURLUPART_PATH, pathbuffer, CURLU_URLENCODE)) {
249    goto clean;
250  }
251
252  /* Free whatever it has now, rewriting is next */
253  Curl_safefree(*url);
254
255  if(curl_url_get(uh, CURLUPART_URL, &cloneurl, CURLU_URLENCODE)) {
256    goto clean;
257  }
258  /* we need to strdup the URL so that we can call free() on it later */
259  *url = strdup(cloneurl);
260  curl_free(cloneurl);
261  if(!*url)
262    goto clean;
263
264  result = CURLE_OK;
265
266clean:
267  free(gateway);
268  curl_free(gwhost);
269  curl_free(gwpath);
270  curl_free(gwquery);
271  curl_free(inputpath);
272  curl_free(gwscheme);
273  curl_free(gwport);
274  curl_free(cid);
275  curl_free(pathbuffer);
276  curl_url_cleanup(gatewayurl);
277  {
278    switch(result) {
279    case CURLE_URL_MALFORMAT:
280      helpf(tool_stderr, "malformed target URL");
281      break;
282    case CURLE_FILE_COULDNT_READ_FILE:
283      helpf(tool_stderr, "IPFS automatic gateway detection failed");
284      break;
285    case CURLE_BAD_FUNCTION_ARGUMENT:
286      helpf(tool_stderr, "--ipfs-gateway was given a malformed URL");
287      break;
288    default:
289      break;
290    }
291  }
292  return result;
293}
294