Update networking layer w/ CURL and emscripten impl

External/curl-8.17.0/docs/examples/ftpuploadresume.c

@@ -0,0 +1,169 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 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 https://curl.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.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+/* <DESC>
+ * Upload to FTP, resuming failed transfers. Active mode.
+ * </DESC>
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <curl/curl.h>
+
+/* parse headers for Content-Length */
+static size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb,
+                                   void *stream)
+{
+  int r;
+  long len = 0;
+
+  r = sscanf(ptr, "Content-Length: %ld\n", &len);
+  if(r == 1)
+    *((long *) stream) = len;
+
+  return size * nmemb;
+}
+
+/* discard downloaded data */
+static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *stream)
+{
+  (void)ptr;
+  (void)stream;
+  return size * nmemb;
+}
+
+/* read data to upload */
+static size_t read_cb(char *ptr, size_t size, size_t nmemb, void *stream)
+{
+  FILE *f = stream;
+  size_t n;
+
+  if(ferror(f))
+    return CURL_READFUNC_ABORT;
+
+  n = fread(ptr, size, nmemb, f) * size;
+
+  return n;
+}
+
+
+static int upload(CURL *curl, const char *remotepath,
+                  const char *localpath, long timeout, long tries)
+{
+  FILE *f;
+  long uploaded_len = 0;
+  CURLcode res = CURLE_GOT_NOTHING;
+  int c;
+
+  f = fopen(localpath, "rb");
+  if(!f) {
+#ifndef UNDER_CE
+    perror(NULL);
+#endif
+    return 0;
+  }
+
+  curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
+
+  curl_easy_setopt(curl, CURLOPT_URL, remotepath);
+
+  if(timeout)
+    curl_easy_setopt(curl, CURLOPT_SERVER_RESPONSE_TIMEOUT, timeout);
+
+  curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
+  curl_easy_setopt(curl, CURLOPT_HEADERDATA, &uploaded_len);
+
+  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_cb);
+
+  curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_cb);
+  curl_easy_setopt(curl, CURLOPT_READDATA, f);
+
+  /* enable active mode */
+  curl_easy_setopt(curl, CURLOPT_FTPPORT, "-");
+
+  /* allow the server no more than 7 seconds to connect back */
+  curl_easy_setopt(curl, CURLOPT_ACCEPTTIMEOUT_MS, 7000L);
+
+  curl_easy_setopt(curl, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);
+
+  curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
+
+  for(c = 0; (res != CURLE_OK) && (c < tries); c++) {
+    /* are we resuming? */
+    if(c) { /* yes */
+      /* determine the length of the file already written */
+
+      /*
+       * With NOBODY and NOHEADER, libcurl issues a SIZE command, but the only
+       * way to retrieve the result is to parse the returned Content-Length
+       * header. Thus, getcontentlengthfunc(). We need write_cb() above
+       * because HEADER dumps the headers to stdout without it.
+       */
+      curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);
+      curl_easy_setopt(curl, CURLOPT_HEADER, 1L);
+
+      res = curl_easy_perform(curl);
+      if(res != CURLE_OK)
+        continue;
+
+      curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
+      curl_easy_setopt(curl, CURLOPT_HEADER, 0L);
+
+      fseek(f, uploaded_len, SEEK_SET);
+
+      curl_easy_setopt(curl, CURLOPT_APPEND, 1L);
+    }
+    else { /* no */
+      curl_easy_setopt(curl, CURLOPT_APPEND, 0L);
+    }
+
+    res = curl_easy_perform(curl);
+  }
+
+  fclose(f);
+
+  if(res == CURLE_OK)
+    return 1;
+  else {
+    fprintf(stderr, "%s\n", curl_easy_strerror(res));
+    return 0;
+  }
+}
+
+int main(void)
+{
+  CURL *curl = NULL;
+
+  CURLcode res = curl_global_init(CURL_GLOBAL_ALL);
+  if(res)
+    return (int)res;
+
+  curl = curl_easy_init();
+  if(curl) {
+    upload(curl, "ftp://user:pass@example.com/path/file", "C:\\file", 0, 3);
+    curl_easy_cleanup(curl);
+  }
+  curl_global_cleanup();
+
+  return 0;
+}