Click here to Skip to main content
15,895,709 members
Articles / Web Development / HTML

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

Rate me:
Please Sign up or sign in to vote.
4.98/5 (240 votes)
7 Aug 2014LGPL310 min read 598.9K   18.4K   352  
Modify methods' IL codes on runtime even if they have been JIT-compiled, supports release mode / x64 & x86, and variants of .NET versions, from 2.0 to 4.5.
/***************************************************************************
 *                                  _   _ ____  _
 *  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 "curl_setup.h"

#ifndef CURL_DISABLE_DICT

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#include "urldata.h"
#include <curl/curl.h>
#include "transfer.h"
#include "sendf.h"

#include "progress.h"
#include "strequal.h"
#include "dict.h"
#include "rawstr.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"

/*
 * Forward declarations.
 */

static CURLcode dict_do(struct connectdata *conn, bool *done);

/*
 * DICT protocol handler.
 */

const struct Curl_handler Curl_handler_dict = {
  "DICT",                               /* scheme */
  ZERO_NULL,                            /* setup_connection */
  dict_do,                              /* do_it */
  ZERO_NULL,                            /* done */
  ZERO_NULL,                            /* do_more */
  ZERO_NULL,                            /* connect_it */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  ZERO_NULL,                            /* doing_getsock */
  ZERO_NULL,                            /* domore_getsock */
  ZERO_NULL,                            /* perform_getsock */
  ZERO_NULL,                            /* disconnect */
  ZERO_NULL,                            /* readwrite */
  PORT_DICT,                            /* defport */
  CURLPROTO_DICT,                       /* protocol */
  PROTOPT_NONE | PROTOPT_NOURLQUERY      /* flags */
};

static char *unescape_word(struct SessionHandle *data, const char *inputbuff)
{
  char *newp;
  char *dictp;
  char *ptr;
  int len;
  char byte;
  int olen=0;

  newp = curl_easy_unescape(data, inputbuff, 0, &len);
  if(!newp)
    return NULL;

  dictp = malloc(((size_t)len)*2 + 1); /* add one for terminating zero */
  if(dictp) {
    /* According to RFC2229 section 2.2, these letters need to be escaped with
       \[letter] */
    for(ptr = newp;
        (byte = *ptr) != 0;
        ptr++) {
      if((byte <= 32) || (byte == 127) ||
          (byte == '\'') || (byte == '\"') || (byte == '\\')) {
        dictp[olen++] = '\\';
      }
      dictp[olen++] = byte;
    }
    dictp[olen]=0;

    free(newp);
  }
  return dictp;
}

static CURLcode dict_do(struct connectdata *conn, bool *done)
{
  char *word;
  char *eword;
  char *ppath;
  char *database = NULL;
  char *strategy = NULL;
  char *nthdef = NULL; /* This is not part of the protocol, but required
                          by RFC 2229 */
  CURLcode result=CURLE_OK;
  struct SessionHandle *data=conn->data;
  curl_socket_t sockfd = conn->sock[FIRSTSOCKET];

  char *path = data->state.path;
  curl_off_t *bytecount = &data->req.bytecount;

  *done = TRUE; /* unconditionally */

  if(conn->bits.user_passwd) {
    /* AUTH is missing */
  }

  if(Curl_raw_nequal(path, DICT_MATCH, sizeof(DICT_MATCH)-1) ||
      Curl_raw_nequal(path, DICT_MATCH2, sizeof(DICT_MATCH2)-1) ||
      Curl_raw_nequal(path, DICT_MATCH3, sizeof(DICT_MATCH3)-1)) {

    word = strchr(path, ':');
    if(word) {
      word++;
      database = strchr(word, ':');
      if(database) {
        *database++ = (char)0;
        strategy = strchr(database, ':');
        if(strategy) {
          *strategy++ = (char)0;
          nthdef = strchr(strategy, ':');
          if(nthdef) {
            *nthdef = (char)0;
          }
        }
      }
    }

    if((word == NULL) || (*word == (char)0)) {
      infof(data, "lookup word is missing\n");
      word=(char *)"default";
    }
    if((database == NULL) || (*database == (char)0)) {
      database = (char *)"!";
    }
    if((strategy == NULL) || (*strategy == (char)0)) {
      strategy = (char *)".";
    }

    eword = unescape_word(data, word);
    if(!eword)
      return CURLE_OUT_OF_MEMORY;

    result = Curl_sendf(sockfd, conn,
                        "CLIENT " LIBCURL_NAME " " LIBCURL_VERSION "\r\n"
                        "MATCH "
                        "%s "    /* database */
                        "%s "    /* strategy */
                        "%s\r\n" /* word */
                        "QUIT\r\n",

                        database,
                        strategy,
                        eword
                        );

    free(eword);

    if(result) {
      failf(data, "Failed sending DICT request");
      return result;
    }
    Curl_setup_transfer(conn, FIRSTSOCKET, -1, FALSE, bytecount,
                        -1, NULL); /* no upload */
  }
  else if(Curl_raw_nequal(path, DICT_DEFINE, sizeof(DICT_DEFINE)-1) ||
           Curl_raw_nequal(path, DICT_DEFINE2, sizeof(DICT_DEFINE2)-1) ||
           Curl_raw_nequal(path, DICT_DEFINE3, sizeof(DICT_DEFINE3)-1)) {

    word = strchr(path, ':');
    if(word) {
      word++;
      database = strchr(word, ':');
      if(database) {
        *database++ = (char)0;
        nthdef = strchr(database, ':');
        if(nthdef) {
          *nthdef = (char)0;
        }
      }
    }

    if((word == NULL) || (*word == (char)0)) {
      infof(data, "lookup word is missing\n");
      word=(char *)"default";
    }
    if((database == NULL) || (*database == (char)0)) {
      database = (char *)"!";
    }

    eword = unescape_word(data, word);
    if(!eword)
      return CURLE_OUT_OF_MEMORY;

    result = Curl_sendf(sockfd, conn,
                        "CLIENT " LIBCURL_NAME " " LIBCURL_VERSION "\r\n"
                        "DEFINE "
                        "%s "     /* database */
                        "%s\r\n"  /* word */
                        "QUIT\r\n",
                        database,
                        eword);

    free(eword);

    if(result) {
      failf(data, "Failed sending DICT request");
      return result;
    }
    Curl_setup_transfer(conn, FIRSTSOCKET, -1, FALSE, bytecount,
                        -1, NULL); /* no upload */
  }
  else {

    ppath = strchr(path, '/');
    if(ppath) {
      int i;

      ppath++;
      for(i = 0; ppath[i]; i++) {
        if(ppath[i] == ':')
          ppath[i] = ' ';
      }
      result = Curl_sendf(sockfd, conn,
                          "CLIENT " LIBCURL_NAME " " LIBCURL_VERSION "\r\n"
                          "%s\r\n"
                          "QUIT\r\n", ppath);
      if(result) {
        failf(data, "Failed sending DICT request");
        return result;
      }

      Curl_setup_transfer(conn, FIRSTSOCKET, -1, FALSE, bytecount, -1, NULL);
    }
  }

  return CURLE_OK;
}
#endif /*CURL_DISABLE_DICT*/

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The GNU Lesser General Public License (LGPLv3)


Written By
Team Leader
China China
Jerry is from China. He was captivated by computer programming since 13 years old when first time played with Q-Basic.



  • Windows / Linux & C++
  • iOS & Obj-C
  • .Net & C#
  • Flex/Flash & ActionScript
  • HTML / CSS / Javascript
  • Gaming Server programming / video, audio processing / image & graphics


Contact: vcer(at)qq.com
Chinese Blog: http://blog.csdn.net/wangjia184

Comments and Discussions