.NET CLR Injection: Modify IL Code during Run-time

/***************************************************************************
 *                                  _   _ ____  _
 *  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 "test.h"

#include "memdebug.h"

static const char *post[]={
  "one",
  "two",
  "three",
  "and a final longer crap: four",
  NULL
};


struct WriteThis {
  int counter;
};

static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *userp)
{
  struct WriteThis *pooh = (struct WriteThis *)userp;
  const char *data;

  if(size*nmemb < 1)
    return 0;

  data = post[pooh->counter];

  if(data) {
    size_t len = strlen(data);
    memcpy(ptr, data, len);
    pooh->counter++; /* advance pointer */
    return len;
  }
  return 0;                         /* no more data left to deliver */
}

int test(char *URL)
{
  CURL *curl;
  CURLcode res=CURLE_OK;
  struct curl_slist *slist = NULL;
  struct WriteThis pooh;
  pooh.counter = 0;

  if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
    fprintf(stderr, "curl_global_init() failed\n");
    return TEST_ERR_MAJOR_BAD;
  }

  if ((curl = curl_easy_init()) == NULL) {
    fprintf(stderr, "curl_easy_init() failed\n");
    curl_global_cleanup();
    return TEST_ERR_MAJOR_BAD;
  }

  slist = curl_slist_append(slist, "Transfer-Encoding: chunked");
  if (slist == NULL) {
    fprintf(stderr, "curl_slist_append() failed\n");
    curl_easy_cleanup(curl);
    curl_global_cleanup();
    return TEST_ERR_MAJOR_BAD;
  }

  /* First set the URL that is about to receive our POST. */
  test_setopt(curl, CURLOPT_URL, URL);

  /* Now specify we want to POST data */
  test_setopt(curl, CURLOPT_POST, 1L);

#ifdef CURL_DOES_CONVERSIONS
  /* Convert the POST data to ASCII */
  test_setopt(curl, CURLOPT_TRANSFERTEXT, 1L);
#endif

  /* we want to use our own read function */
  test_setopt(curl, CURLOPT_READFUNCTION, read_callback);

  /* pointer to pass to our read function */
  test_setopt(curl, CURLOPT_INFILE, &pooh);

  /* get verbose debug output please */
  test_setopt(curl, CURLOPT_VERBOSE, 1L);

  /* include headers in the output */
  test_setopt(curl, CURLOPT_HEADER, 1L);

  /* enforce chunked transfer by setting the header */
  test_setopt(curl, CURLOPT_HTTPHEADER, slist);

#ifdef LIB565
  test_setopt(curl, CURLOPT_HTTPAUTH, (long)CURLAUTH_DIGEST);
  test_setopt(curl, CURLOPT_USERPWD, "foo:bar");
#endif

  /* Perform the request, res will get the return code */
  res = curl_easy_perform(curl);

test_cleanup:

  /* clean up the headers list */
  if(slist)
    curl_slist_free_all(slist);

  /* always cleanup */
  curl_easy_cleanup(curl);
  curl_global_cleanup();

  return res;
}