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Posted to cvs@httpd.apache.org by be...@apache.org on 2003/12/31 12:58:21 UTC

cvs commit: apache-1.3/src/support check_forensic

ben         2003/12/31 03:58:21

  Modified:    src      CHANGES Configuration.tmpl
  Added:       src/modules/standard mod_log_forensic.c
               src/support check_forensic
  Log:
  Add forensic logging module.
  
  Revision  Changes    Path
  1.1915    +3 -0      apache-1.3/src/CHANGES
  
  Index: CHANGES
  ===================================================================
  RCS file: /home/cvs/apache-1.3/src/CHANGES,v
  retrieving revision 1.1914
  retrieving revision 1.1915
  diff -u -r1.1914 -r1.1915
  --- CHANGES	14 Dec 2003 18:16:49 -0000	1.1914
  +++ CHANGES	31 Dec 2003 11:58:21 -0000	1.1915
  @@ -1,5 +1,8 @@
   Changes with Apache 1.3.30
   
  +  *) Forensic logging module added (mod_log_forensic).
  +     [Ben Laurie]
  +
     *) SECURITY [CAN-2003-0020]: Escape arbitrary data before writing
        into the errorlog.  [Andr� Malo]
   
  
  
  
  1.129     +9 -0      apache-1.3/src/Configuration.tmpl
  
  Index: Configuration.tmpl
  ===================================================================
  RCS file: /home/cvs/apache-1.3/src/Configuration.tmpl,v
  retrieving revision 1.128
  retrieving revision 1.129
  diff -u -r1.128 -r1.129
  --- Configuration.tmpl	17 Jan 2002 13:20:50 -0000	1.128
  +++ Configuration.tmpl	31 Dec 2003 11:58:21 -0000	1.129
  @@ -431,6 +431,15 @@
   
   # AddModule modules/example/mod_example.o
   
  +## mod_log_forensic logs a unique id, the request line and headers
  +## before processing starts, and again when processing completes. If
  +## processing does not complete due to a bug or an attack, this can be
  +## detected from the logs.  See support/check_forensic.
  +## If mod_unique_id is also included, then this will use its unique ID.
  +## Note that this must come before mod_unique_id.
  +
  +# AddModule modules/standard/mod_log_forensic.o
  +
   ## mod_unique_id generates unique identifiers for each hit, which are
   ## available in the environment variable UNIQUE_ID.  It may not work on all
   ## systems, hence it is not included by default.
  
  
  
  1.1                  apache-1.3/src/modules/standard/mod_log_forensic.c
  
  Index: mod_log_forensic.c
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2003 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache" and "Apache Software Foundation" must
   *    not be used to endorse or promote products derived from this
   *    software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    nor may "Apache" appear in their name, without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   * Portions of this software are based upon public domain software
   * originally written at the National Center for Supercomputing Applications,
   * University of Illinois, Urbana-Champaign.
   */
  
  /*
   * See also support/check_forensic.
   * Relate the forensic log to the transfer log by including
   * %{forensic-id}n in the custom log format, for example:
   * CustomLog logs/custom "%h %l %u %t \"%r\" %>s %b %{forensic-id}n"
   *
   * Credit is due to Tina Bird <tb...@precision-guesswork.com>, whose
   * idea this module was.
   *
   *   Ben Laurie 29/12/2003
   */
  
  #include "httpd.h"
  #include "http_config.h"
  #include "http_log.h"
  #include <assert.h>
  
  module MODULE_VAR_EXPORT log_forensic_module;
  
  typedef struct fcfg {
      char *logname;
      int fd;
  } fcfg;
  
  static int next_id;
  
  static void *make_forensic_log_scfg(pool *p, server_rec *s)
  {
      fcfg *cfg = ap_pcalloc(p, sizeof *cfg);
  
      cfg->logname = NULL;
      cfg->fd = -1;
  
      return cfg;
  }
  
  static void *merge_forensic_log_scfg(pool *p, void *parent, void *new)
  {
      fcfg *cfg = ap_pcalloc(p, sizeof *cfg);
      fcfg *pc = parent;
      fcfg *nc = new;
  
      cfg->logname = ap_pstrdup(p, nc->logname ? nc->logname : pc->logname);
      cfg->fd = -1;
  
      return cfg;
  }
  
  static void open_log(server_rec *s, pool *p)
  {
      fcfg *cfg = ap_get_module_config(s->module_config, &log_forensic_module);
  
      if (!cfg->logname || cfg->fd >= 0)
          return;
  
      if (*cfg->logname == '|') {
          piped_log *pl;
  
          pl = ap_open_piped_log(p, cfg->logname+1);
          if (pl == NULL) {
              ap_log_error(APLOG_MARK, APLOG_ERR, s,
                           "couldn't spawn forensic log pipe %s", cfg->logname);
              exit(1);
          }
          cfg->fd = ap_piped_log_write_fd(pl);
      }
      else {
          char *fname = ap_server_root_relative(p, cfg->logname);
  
          if ((cfg->fd = ap_popenf_ex(p, fname, O_WRONLY | O_APPEND | O_CREAT,
                                      S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, 1))
              < 0) {
              ap_log_error(APLOG_MARK, APLOG_ERR, s,
                           "could not open forensic log file %s.", fname);
              exit(1);
          }
      }
  }
  
  static void log_init(server_rec *s, pool *p)
  {
      for ( ; s ; s = s->next)
          open_log(s, p);
  }
  
    
  /* e is the first _invalid_ location in q
     N.B. returns the terminating NUL.
   */
  static char *log_escape(char *q, const char *e, const char *p)
  {
      for ( ; *p ; ++p) {
          assert(q < e);
          if (*p < ' ' || *p >= 0x7f || *p == '|' || *p == ':' || *p == '%') {
              assert(q+2 < e);
              *q++ = '%';
              sprintf(q, "%02x", *(unsigned char *)p);
              q += 2;
          }
          else
              *q++ = *p;
      }
      assert(q < e);
      *q = '\0';
  
      return q;
  }
  
  typedef struct hlog {
      char *log;
      char *pos;
      char *end;
      pool *p;
      int count;
  } hlog;
  
  static int count_string(const char *p)
  {
      int n;
  
      for (n = 0 ; *p ; ++p, ++n)
          if (*p < ' ' || *p >= 0x7f || *p == '|' || *p == ':' || *p == '%')
              n += 2;
      return n;
  }
  
  static int count_headers(void *h_, const char *key, const char *value)
  {
      hlog *h = h_;
  
      h->count += count_string(key)+count_string(value)+2;
  
      return 1;
  }
  
  static int log_headers(void *h_, const char *key, const char *value)
  {
      hlog *h = h_;
  
      /* note that we don't have to check h->pos here, coz its been done
         for us by log_escape */
      *h->pos++ = '|';
      h->pos = log_escape(h->pos, h->end, key);
      *h->pos++ = ':';
      h->pos = log_escape(h->pos, h->end, value);
  
      return 1;
  }
  
  /* this structure only exists to allow typesafety */
  typedef struct {
      const char *id;
  } rcfg;
  
  static int log_before(request_rec *r)
  {
      fcfg *cfg = ap_get_module_config(r->server->module_config,
                                       &log_forensic_module);
      static rcfg rcfg;
      const char *id;
      hlog h;
  
      if (cfg->fd < 0)
          return DECLINED;
  
      if (!(id = ap_table_get(r->subprocess_env, "UNIQUE_ID"))) {
          /* we make the assumption that we can't go through all the PIDs in
             under 1 second */
          id = ap_psprintf(r->pool, "%x:%lx:%x", getpid(), time(NULL), next_id++);
      }
      rcfg.id = id;
      ap_set_module_config(r->request_config, &log_forensic_module, &rcfg);
  
      h.p = r->pool;
      h.count = 0;
  
      ap_table_do(count_headers, &h, r->headers_in, NULL);
  
      h.count += 1+strlen(id)+1+count_string(r->the_request)+1+1;
      h.log = ap_palloc(r->pool, h.count);
      h.pos = h.log;
      h.end = h.log+h.count;
  
      *h.pos++ = '+';
      strcpy(h.pos, id);
      h.pos += strlen(h.pos);
      *h.pos++ = '|';
      h.pos = log_escape(h.pos, h.end, r->the_request);
  
      ap_table_do(log_headers, &h, r->headers_in, NULL);
  
      assert(h.pos < h.end);
      *h.pos++ = '\n';
  
      write(cfg->fd, h.log, h.count-1);
  
      ap_table_setn(r->notes, "forensic-id", id);
  
      return OK;
  }
  
  static int log_after(request_rec *r)
  {
      fcfg *cfg = ap_get_module_config(r->server->module_config,
                                       &log_forensic_module);
      char *s;
      rcfg *rcfg;
      
      if(cfg->fd < 0)
          return DECLINED;
  
      rcfg = ap_get_module_config(r->request_config, &log_forensic_module);
      s = ap_pstrcat(r->pool, "-", rcfg->id, "\n", NULL);
      write(cfg->fd, s, strlen(s));
  
      return OK;
  }
  
  static const char *set_forensic_log(cmd_parms *cmd,  void *dummy,  char *fn)
  {
      fcfg *cfg = ap_get_module_config(cmd->server->module_config,
                                       &log_forensic_module);
  
      cfg->logname = fn;
      return NULL;
  }
  
  static const command_rec forensic_log_cmds[] =
  {
      { "ForensicLog",  set_forensic_log,  NULL,  RSRC_CONF,  TAKE1,
        "the filename of the forensic log (default is logs/forensic_log" },
      { NULL }
  };
  
  module MODULE_VAR_EXPORT log_forensic_module =
  {
      STANDARD_MODULE_STUFF,
      log_init,                   /* initializer */
      NULL,                       /* create per-dir config */
      NULL,                       /* merge per-dir config */
      make_forensic_log_scfg,     /* server config */
      merge_forensic_log_scfg,    /* merge server config */
      forensic_log_cmds,          /* command table */
      NULL,                       /* handlers */
      NULL,                       /* filename translation */
      NULL,                       /* check_user_id */
      NULL,                       /* check auth */
      NULL,                       /* check access */
      NULL,                       /* type_checker */
      NULL,                       /* fixups */
      log_after,                  /* logger */
      NULL,                       /* header parser */
      NULL,                       /* child_init */
      NULL,                       /* child_exit */
      log_before                  /* post read-request */
  };
  
  
  
  1.1                  apache-1.3/src/support/check_forensic
  
  Index: check_forensic
  ===================================================================
  #!/bin/sh
  
  # check_forensic <forensic log file>
  
  # check the forensic log for requests that did not complete
  # output the request log for each one
  
  F=$1
  
  cut -f 1 -d '|' $F  > /tmp/fc-all.$$
  grep + < /tmp/fc-all.$$ | cut -c2- | sort > /tmp/fc-in.$$
  grep -- - < /tmp/fc-all.$$ | cut -c2- | sort > /tmp/fc-out.$$
  join -v 1 /tmp/fc-in.$$ /tmp/fc-out.$$ | xargs -I xx egrep "^\\+xx" $F
  rm /tmp/fc-all.$$ /tmp/fc-in.$$ /tmp/fc-out.$$