text: /* Copyright (C) 2007-2014 Open Information Security Foundation
   *
   * You can copy, redistribute or modify this Program under the terms of
   * the GNU General Public License version 2 as published by the Free
   * Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * version 2 along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301, USA.
   */
  
  /**
   * \file
   *
   * \author Victor Julien <victor@inliniac.net>
   * \author Pablo Rincon <pablo.rincon.crespo@gmail.com>
   *
   */
  
  #include "suricata-common.h"
  #include "threads.h"
  #include "debug.h"
  #include "decode.h"
  
  #include "detect.h"
  #include "detect-parse.h"
  
  #include "detect-engine.h"
  #include "detect-engine-mpm.h"
  #include "detect-engine-state.h"
  #include "detect-engine-file.h"
  
  #include "flow.h"
  #include "flow-var.h"
  #include "flow-util.h"
  
  #include "util-debug.h"
  #include "util-spm-bm.h"
  #include "util-unittest.h"
  #include "util-unittest-helper.h"
  
  #include "app-layer.h"
  
  #include "stream-tcp.h"
  
  #include "detect-filename.h"
  #include "app-layer-parser.h"
  
  static int DetectFilenameMatch (ThreadVars *, DetectEngineThreadCtx *, Flow *,
          uint8_t, File *, Signature *, SigMatch *);
  static int DetectFilenameSetup (DetectEngineCtx *, Signature *, char *);
  static void DetectFilenameRegisterTests(void);
  static void DetectFilenameFree(void *);
  
  /**
   * \brief Registration function for keyword: filename
   */
  void DetectFilenameRegister(void)
  {
      sigmatch_table[DETECT_FILENAME].name = "filename";
      sigmatch_table[DETECT_FILENAME].desc = "match on the file name";
      sigmatch_table[DETECT_FILENAME].url = DOC_URL DOC_VERSION "/rules/file-keywords.html#filename";
      sigmatch_table[DETECT_FILENAME].FileMatch = DetectFilenameMatch;
      sigmatch_table[DETECT_FILENAME].Setup = DetectFilenameSetup;
      sigmatch_table[DETECT_FILENAME].Free  = DetectFilenameFree;
      sigmatch_table[DETECT_FILENAME].RegisterTests = DetectFilenameRegisterTests;
  
      DetectAppLayerInspectEngineRegister(ALPROTO_HTTP, SIG_FLAG_TOSERVER,
              DETECT_SM_LIST_FILEMATCH,
              DetectFileInspectHttp);
      DetectAppLayerInspectEngineRegister(ALPROTO_HTTP, SIG_FLAG_TOCLIENT,
              DETECT_SM_LIST_FILEMATCH,
              DetectFileInspectHttp);
  
      DetectAppLayerInspectEngineRegister(ALPROTO_SMTP, SIG_FLAG_TOSERVER,
              DETECT_SM_LIST_FILEMATCH,
              DetectFileInspectSmtp);
  
  	SCLogDebug("registering filename rule option");
      return;
  }
  
  /**
   * \brief match the specified filename
   *
   * \param t thread local vars
   * \param det_ctx pattern matcher thread local data
   * \param f *LOCKED* flow
   * \param flags direction flags
   * \param file file being inspected
   * \param s signature being inspected
   * \param m sigmatch that we will cast into DetectFilenameData
   *
   * \retval 0 no match
   * \retval 1 match
   */
  static int DetectFilenameMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx,
          Flow *f, uint8_t flags, File *file, Signature *s, SigMatch *m)
  {
      SCEnter();
      int ret = 0;
  
      DetectFilenameData *filename = (DetectFilenameData *)m->ctx;
  
      if (file->name == NULL)
          SCReturnInt(0);
  
      if (file->txid < det_ctx->tx_id)
          SCReturnInt(0);
  
      if (file->txid > det_ctx->tx_id)
          SCReturnInt(0);
  
      if (BoyerMooreNocase(filename->name, filename->len, file->name,
                  file->name_len, filename->bm_ctx) != NULL)
      {
  #ifdef DEBUG
          if (SCLogDebugEnabled()) {
              char *name = SCMalloc(filename->len + 1);
              if (name != NULL) {
                  memcpy(name, filename->name, filename->len);
                  name[filename->len] = '\0';
                  SCLogDebug("will look for filename %s", name);
              }
          }
  #endif
  
          if (!(filename->flags & DETECT_CONTENT_NEGATED)) {
              ret = 1;
          }
      }
  
      if (ret == 0 && (filename->flags & DETECT_CONTENT_NEGATED)) {
          SCLogDebug("negated match");
          ret = 1;
      }
  
      SCReturnInt(ret);
  }
  
  /**
   * \brief Parse the filename keyword
   *
   * \param idstr Pointer to the user provided option
   *
   * \retval filename pointer to DetectFilenameData on success
   * \retval NULL on failure
   */
  static DetectFilenameData *DetectFilenameParse (char *str)
  {
      DetectFilenameData *filename = NULL;
  
      /* We have a correct filename option */
      filename = SCMalloc(sizeof(DetectFilenameData));
      if (unlikely(filename == NULL))
          goto error;
  
      memset(filename, 0x00, sizeof(DetectFilenameData));
  
      if (DetectContentDataParse ("filename", str, &filename->name, &filename->len, &filename->flags) == -1) {
          goto error;
      }
  
      filename->bm_ctx = BoyerMooreNocaseCtxInit(filename->name, filename->len);
      if (filename->bm_ctx == NULL) {
          goto error;
      }
  
      SCLogDebug("flags %02X", filename->flags);
      if (filename->flags & DETECT_CONTENT_NEGATED) {
          SCLogDebug("negated filename");
      }
  
  #ifdef DEBUG
      if (SCLogDebugEnabled()) {
          char *name = SCMalloc(filename->len + 1);
          if (name != NULL) {
              memcpy(name, filename->name, filename->len);
              name[filename->len] = '\0';
              SCLogDebug("will look for filename %s", name);
          }
      }
  #endif
  
      return filename;
  
  error:
      if (filename != NULL)
          DetectFilenameFree(filename);
      return NULL;
  }
  
  /**
   * \brief this function is used to parse filename options
   * \brief into the current signature
   *
   * \param de_ctx pointer to the Detection Engine Context
   * \param s pointer to the Current Signature
   * \param str pointer to the user provided "filename" option
   *
   * \retval 0 on Success
   * \retval -1 on Failure
   */
  static int DetectFilenameSetup (DetectEngineCtx *de_ctx, Signature *s, char *str)
  {
      DetectFilenameData *filename = NULL;
      SigMatch *sm = NULL;
  
      filename = DetectFilenameParse(str);
      if (filename == NULL)
          goto error;
  
      /* Okay so far so good, lets get this into a SigMatch
       * and put it in the Signature. */
      sm = SigMatchAlloc();
      if (sm == NULL)
          goto error;
  
      sm->type = DETECT_FILENAME;
      sm->ctx = (void *)filename;
  
      SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_FILEMATCH);
  
      s->file_flags |= (FILE_SIG_NEED_FILE|FILE_SIG_NEED_FILENAME);
      return 0;
  
  error:
      if (filename != NULL)
          DetectFilenameFree(filename);
      if (sm != NULL)
          SCFree(sm);
      return -1;
  }
  
  /**
   * \brief this function will free memory associated with DetectFilenameData
   *
   * \param filename pointer to DetectFilenameData
   */
  static void DetectFilenameFree(void *ptr)
  {
      if (ptr != NULL) {
          DetectFilenameData *filename = (DetectFilenameData *)ptr;
          if (filename->bm_ctx != NULL) {
              BoyerMooreCtxDeInit(filename->bm_ctx);
          }
          if (filename->name != NULL)
              SCFree(filename->name);
          SCFree(filename);
      }
  }
  
  #ifdef UNITTESTS /* UNITTESTS */
  
  /**
   * \test DetectFilenameTestParse01
   */
  int DetectFilenameTestParse01 (void)
  {
      DetectFilenameData *dnd = DetectFilenameParse("\"secret.pdf\"");
      if (dnd != NULL) {
          DetectFilenameFree(dnd);
          return 1;
      }
      return 0;
  }
  
  /**
   * \test DetectFilenameTestParse02
   */
  int DetectFilenameTestParse02 (void)
  {
      int result = 0;
  
      DetectFilenameData *dnd = DetectFilenameParse("\"backup.tar.gz\"");
      if (dnd != NULL) {
          if (dnd->len == 13 && memcmp(dnd->name, "backup.tar.gz", 13) == 0) {
              result = 1;
          }
  
          DetectFilenameFree(dnd);
          return result;
      }
      return 0;
  }
  
  /**
   * \test DetectFilenameTestParse03
   */
  int DetectFilenameTestParse03 (void)
  {
      int result = 0;
  
      DetectFilenameData *dnd = DetectFilenameParse("\"cmd.exe\"");
      if (dnd != NULL) {
          if (dnd->len == 7 && memcmp(dnd->name, "cmd.exe", 7) == 0) {
              result = 1;
          }
  
          DetectFilenameFree(dnd);
          return result;
      }
      return 0;
  }
  
  #endif /* UNITTESTS */
  
  /**
   * \brief this function registers unit tests for DetectFilename
   */
  void DetectFilenameRegisterTests(void)
  {
  #ifdef UNITTESTS /* UNITTESTS */
      UtRegisterTest("DetectFilenameTestParse01", DetectFilenameTestParse01);
      UtRegisterTest("DetectFilenameTestParse02", DetectFilenameTestParse02);
      UtRegisterTest("DetectFilenameTestParse03", DetectFilenameTestParse03);
  #endif /* UNITTESTS */
  }
  