Fix segfault when restarting worker MPM. We can not examine the POD as

[apache] / STATUS

APACHE 2.0 STATUS:                                              -*-text-*-
Last modified at [$Date: 2001/12/08 01:38:04 $]

Release:

    2.0.30  : In development
    2.0.29  : tagged November 27, 2001
    2.0.28  : released November 13, 2001
    2.0.27  : rolled November 6, 2001
    2.0.26  : tagged October 16, 2001.  not rolled.
    2.0.25  : rolled August 29, 2001
    2.0.24  : rolled August 18, 2001
    2.0.23  : rolled August 9, 2001
    2.0.22  : rolled July 29, 2001
    2.0.21  : rolled July 20, 2001
    2.0.20  : rolled July 8, 2001
    2.0.19  : rolled June 27, 2001
    2.0.18  : rolled May 18, 2001
    2.0.17  : rolled April 17, 2001
    2.0.16  : rolled April 4, 2001
    2.0.15  : rolled March 21, 2001
    2.0.14  : rolled March 7, 2001
    2.0a9   : released December 12, 2000
    2.0a8   : released November 20, 2000
    2.0a7   : released October 8, 2000
    2.0a6   : released August 18, 2000
    2.0a5   : released August 4, 2000
    2.0a4   : released June 7, 2000
    2.0a3   : released April 28, 2000
    2.0a2   : released March 31, 2000
    2.0a1   : released March 10, 2000

Please consult the following STATUS files for information
on related projects:

    * srclib/apr/STATUS
    * srclib/apr-util/STATUS
    * docs/STATUS

RELEASE SHOWSTOPPERS:

    * If any request gets to the core handler, without a flag that this 
      r->filename was tested by dir/file_walk, we need to 500 at the very 
      end of the ap_process_request_internal() processing.  This provides
      authors of older modules better compatibility, while still improving
      the security and robustness of 2.0. 
        Status: still need to decide where this goes, OtherBill comments...
        Message-ID: <065701c14526$495203b0$96c0b0d0@roweclan.net>
        we need to look at halting this in the 'default handler' case,
        and that implies pushing the 'handler election' into the request
        internal processing phase from the run request phase.

    * There is a bug in how we sort some hooks, at least the pre-config
      hook.  The first time we call the hooks, they are in the correct 
      order, but the second time, we don't sort them correctly.  Currently,
      the modules/http/config.m4 file has been renamed to 
      modules/http/config2.m4 to work around this problem, it should moved
      back when this is fixed.    rbb

    * The Add...Filter and Set...Filter directives do not allow the
      administrator to order filters, beyond the order of filename (mime)
      extensions.  It isn't clear if Set...Filter(s) should be inserted 
      before or after the Add...Filter(s) which are ordered by sequence of
      filename extensions.  At minimum, some sort of +-[0-10] syntax seems
      like the quickest fix for a 2.0 gold release.

    * mod_negotiation needs a new option or directive, something like
      ForceLanguagePriority, to fall back to the LanguagePriority
      directive instead of returning a "no acceptable variant" error.
        Status: Bill has some code in his tree that accomplishes
                this, and will commit it Friday after it's tested.

    * Fold mod_auth_db features back into mod_auth_dbm, and depricate it.
        This can't wait until we have a 2.0-gold release, if folks need
        to move over to auth_dbm, we can't do that to them after 2.0 gold.
      Status: Ian says.. now that apr-util can handle multiple DBM types 
              we can probably deprecate it completly by adding a directive 
              'AuthDBMType' to mod_auth_dbm.

    * Convert all instances of the old apr_lock_t type to the new
      types (once they are fully supported in APR).
        Status: Aaron is working on converting INTRAPROCESS
                to apr_thread_mutex_t types. Full replacements for
                LOCKALL and CROSS_PROCESS are not yet complete on all
                platforms, and should only be used in MPMs like worker
                with limited OS exposure.

    * make_exports.awk doesn't handle declarations that span multiple
      lines.  Thus, stuff like ap_hook_error_log doesn't end up in
      exports.c and httpd.exp.  This can cause DSO modules which call
      ap_hook_error_log (or other missing functions -- if there are
      any) to segfault on AIX and can probably cause load or other
      errors on some other platforms.

RELEASE NON-SHOWSTOPPERS BUT WOULD BE REAL NICE TO WRAP THESE UP:

    * There is increasing demand from module writers for an API
      that will allow them to control the server à la apachectl.
      Reasons include sole-function servers that need to die if
      an external dependency (e.g., a database) fails, et cetera.
      Perhaps something in the (ever more abused) scoreboard?
        rbb:  I don't believe the scoreboard is the correct mechanism
        for this.  We already have a pipe that goes between parent
        and child for graceful shutdown events, along with an API that
        can be used to send a message down that pipe.  In threaded MPMs,
        it is easy enough to make that one pipe be used for graceful
        and graceless events, and it is also easy to open that pipe
        to both parent and child for writing.  Then we just need to figure
        out how to do graceless on non-threaded MPMs.

    * revamp the input filter behavior, per discussions since
      February (and especially at the hackathon last
      April). Specifically, ap_get_brigade will return a brigade with
      *up to* a specific number of bytes, or a "line" of data. The
      read may be blocking or nonblocking. ap_getline() will be
      refactored into apr_brigade_getline(), and then DECHUNK can use
      f->next (ap_getline will always read "top of input stack"). Also 
      fix the bug where request body content will end up closing the
      connection (buggering up persistent conns).
      Status: Justin is working on this as fast as he can.
              The core input filters, HTTP-related filters, mod_ssl, and
              mod_proxy are switched to the new logic.  
              However, ap_getline() still needs to be refactored out.  But, 
              there's a problem there: ap_getline() peeks ahead for MIME
              continuation (first character on line is space or \t) and 
              stores unused data in core_request_config which violates the
              abstraction.  That's cheating.  So, we may not be able to 
              implement this without setting some data aside (yuck!).
              I believe this is OtherBill's main complaint with the current
              filtering.
              AIUI (correct me if I'm wrong!), OtherBill believes we 
              should have a pushback option so that we can return unread 
              data - this would solve this case.  However, my question to 
              him is how do we handle stuff like mod_ssl - we can't "unread"
              data.  So, do we have two brigades for each filter?  An in
              brigade and a returned brigade?  That seems messy.  To
              everyone else, can we refactor ap_getline() without pushback 
              and how?

      - socket bucket and core input filter changes. see end of
        message ID (Feb 27): <20010227075326.S2297@lyra.org>

      - fix up ap_get_brigade() semantics, fix bug in DECHUNK /
        ap_getline. many messages (plus their threads) (Apr/May):
          Message-ID: <20010402101207.J27539@lyra.org>
          Message-ID: <3AF7F921.D2EEC41A@algroup.co.uk>
          Message-ID: <20010508190029.E18404@lyra.org>

      - further work with combining/tweaking the builtin filters:
          Message-ID: <20010509115445.D1374@lyra.org>

      - thoughts on filter modes:
          Message-ID: <021b01c14dee$09782af0$93c0b0d0@roweclan.net>

    * Allow the DocumentRoot directive within <Location > scopes?  This
      allows the beloved (crusty) Alias /foo/ /somepath/foo/ followed
      by a <Directory /somepath/foo> to become simply 
      <Location /foo/> DocumentRoot /somefile/foo (IMHO a bit more legible
      and in-your-face.)  DocumentRoot unset would be accepted [and would
      not permit content to be served, only virtual resources such as
      server-info or server-status.
        This proposed change would _not_ depricate Alias.

    * daedalus: mod_cgid and suexec have a problem co-existing.  suexec 
      sees a null command string sometimes.  The problem happens when
      you access bugs.apache.org, then click on the "search the bug db"
      button.

    * Win32: Rotatelogs sometimes is not terminated when Apache
      goes down hard.  FirstBill was looking at possibly tracking the 
      child's-child processes in the parent process.
        OtherBill asks, wasn't this fixed?

    * Win32: Add a simple hold console open patch (wait for close or
        the ESC key, with a nice message) if the server died a bad 
        death (non-zero exit code) in console mode.
        Resolution: bring forward same ugly hacks from 1.3.13-.20

    * Port of mod_ssl to Apache 2.0:

      The current porting state is summarized in modules/ssl/README. The
      remaining work includes:
      (1) stablizing/optimizing the SSL filter logic
      (2) Enabling the various SSL caching mechanisms (shmcb, shmht)
      (3) Enabling SSL extentions
      (4) Trying to seperate the https filter logic from mod_ssl -
          This is to facilitate other modules that wish to use the https
          filter or the mod_ssl logic or both as required.
        Justin: mod_ssl filter logic is redone, so that should be fine.
                Madhu has submitted a patch for SSL caching - however, I
                am -0 on that patch as I *think* we could implement the
                shared memory another way that is much cleaner (i.e.
                treat shmem directly as a dbm via APR routines).  Justin 
                also thinks that the https filter logic may be sufficiently
                decoupled now, but isn't really sure.

    * Performance: Get the SINGLE_LISTEN_UNSERIALIZED_ACCEPT
      optimization working in worker.  prefork's new design for how
      to notice data on the pod should be sufficient.

    * Performance & Debug: Eliminate most (and perhaps all) of the 
      malloc/free calls in the bucket brigade code.  Need some 
      light weight memory management functions that allow freeing 
      memory (putting it back into a memory pool) when it is no 
      longer needed. Enabling simple debugging features like guard
      bands, double free detection, etc. would be cool but certainly
      not a hard requirement.

          Status: Cliff started to implement this using SMS as has
                  been discussed at length for months, but since
                  SMS is not being used anywhere else in the server,
                  several people expressed the opinion that we should
                  get rid of it entirely, meaning that the buckets
                  need their own memory management (free list) functions.
                  Cliff will implement that this weekend so we at least
                  have something to look at/compare with.

    * Eliminate unnecessary creation of pipes in mod_cgid

    * the autoconf setup should be fixed to default to using the 
      "Apache" layout from config.layout, and each variable settable
      in a layout should be overridable on the command line.  Plus,
      what we do right now just doesn't seem to fully fit into how autoconf
      works, eg. AC_PREFIX_DEFAULT issues.
        Message-ID: <Pine.BSF.4.20.0104031557420.20876-100000@alive.znep.com>

    * Combine log_child and piped_log_spawn. Clean up http_log.c.
      Common logging API.

    * Document mod_file_cache.

    * OS/2: Make mod_status work for spmt_os2 MPM.

    * Platforms that do not support fork (primarily Win32 and AS/400)
      Architect start-up code that avoids initializing all the modules 
      in the parent process on platforms that do not support fork.

    * Win32: Migrate the MPM over to use APR thread/process calls. This
      would eliminate some code in the Win32 branch that essentially
      duplicates what is in APR.

    * There are still a number of places in the code where we are
      losing error status (i.e. throwing away the error returned by a
      system call and replacing it with a generic error code)

    * Mass vhosting version of suEXEC.

    * All DBMs suffer from confusion in support/dbmmanage (perl script) since 
        the dbmmanage employs the first-matched dbm format.  This is not
        necessarily the library that Apache was built with.  Aught to
        rewrite dbmmanage upon installation to bin/ with the proper library 
        for predictable mod_auth_db/dbm administration.
        Status: Mladen Turk has posted several patches and ideas.
                Key question, part of htpasswd, or a seperate utility?
                prefer htpasswd:
                prefer seperate: OtherBill

    * use apu_dbm in mod_auth_dbm
        Status: Greg +1 (low-priority volunteer)
        Justin says: "Seems like this is already there, so should we just 
                      remove the other DBM code in that file?  If you want 
                      to use gdbm, or dbm, etc, you should tell apr-util."
        Will says: "bs - I may choose the fastest - most efficient native
                    dbm implementation, for shared proc caches, ssl session
                    caching, etc, but that has nothing to do with maintaining
                    a userlist via dbm, which has to remain readable between
                    builds/machines, etc.  The use-multiple database schema
                    for apr-util would let us do this with just apr, though."

    * Integrate mod_dav.
        Some additional items remaining:
        - case_preserved_filename stuff
            (use the new canonical name stuff?)
        - find a new home for ap_text(_header)
        - is it possible to remove the DAV: namespace stuff from util_xml?

    * ap_core_translate() and its use by mod_mmap_static and mod_file_cache
      are a bit wonky.  The function should probably be exposed as a utility 
      function (such as ap_translate_url2fs() or ap_validate_fs_url() or 
      something).  Another approach would be a new hook phase after
      "translate" which would allow the module to munge what the
      translation has decided to do.
        Status: Greg +1 (volunteers), Ryan +1

    * Explore use of a post-config hook for the code in http_main.c which
      calls ap_fixup_virutal_hosts(), ap_fini_vhost_config(), and
      ap_sort_hooks()  [to reduce the logic in main()]

    * read the config tree just once, and process N times (as necessary)

    * (possibly) use UUIDs in mod_unique_id and/or mod_usertrack

    * (possibly) port the bug fix for PR 6942 (segv when LoadModule is put
      into a VirtualHost container) to 2.0.

    * shift stuff to mod_core.h

    * callers of ap_run_create_request() should check the return value
      for failure (Doug volunteers)

    * Win32: Get Apache working on Windows 95/98. The following work
        (at least) needs to be done:
        - winnt MPM: Fix 95/98 code paths in the winnt MPM. There is some NT
        specific code that is still not in NT only code paths
        - IOL binds to APR sendfile, implemented with TransmitFile, which 
        is not available on 95/98.
        - Document warning that OSR2 is required (for Crypt functions, in
        rand.c, at least.)  This could be resolved with an SSL library, or
        randomization in APR itself.
        - Bring the Win9xConHook.dll from 1.3 into 2.0 (no sense till it
        actually works) and add in a splash of Win9x service code.

    * In order to use a DSO version of mod_ssl we have to link with
      -lssl and -lcrypto. A workaround is in place right now where the
      entire EXTRA_LIBS macro is being appended to the objects list, but
      this is a hack. We should either revamp the APACHE_CHECK_SSL_TOOLKIT
      autoconf function or come up with some other autoconf checks to
      search for libssl and libcrypto and properly add them to mod_ssl's
      link flags.

    * Make the worker MPM the default MPM for threaded Unix boxes.
      +1:   Justin, Jeff, Ian
      -0:   Aaron (premature decision, needs more discussion)
      -0:   Cliff (I think the default config should be the safest possible)

PRs that have been suspended forever waiting for someone to
put them into 'the next release':

    * PR#76: general
      missing call to "setlocale();"
        Status: 

    * PR#78: mod_include
      Additional status for XBitHack directive
        Status: 

    * PR#362: mod_proxy
      Mod_proxy doesn't allow change of error pages
        Status: 

    * PR#370: mod_env
      Modified PATH environemnt variable is not passed, instead
      system's is used
        Status: 

    * PR#440: mod_proxy
      Proxy doesn't deliver documents if not connected
        Status: 

    * PR#534: mod_proxy
      proxy converts ~name to %7Ename when name starts with a dot (.)
        Status: 

    * PR#537: mod_access
      mod_access syntax allows hosts that should be restricted
        Status: 

    * PR#557: mod_auth-any
      ~UserHome directories are not honored in absolute pathname
      requests (.htaccess)
        Status: 

    * PR#612: mod_proxy
      Proxy FTP Authentication Fails
        Status: 

    * PR#623: mod_include
      A smarter "Last Modified" value for SSI documents (see PR number 600)
        Status: 

    * PR#628: config
      Request of "Options SymLinksIfGroupMatch"
        Status: 

    * PR#700: mod_proxy
      Proxy doesn't do links right for OpenVMS files through ftp:
        Status: 

    * PR#759: mod_imap
      imap should read <MAP><AREA>*</MAP> too!
        Status: 

    * PR#793: general
      RLimitCPU and RLimitMEM don't apply to all children like they should
        Status: 

    * PR#921: suexec
      Uses cwd before filling it in, doesn't use syslog
        Status: 

    * PR#922: config
      it is useful to allow specifiction that root-owned symlinks
      should always be followed
        Status: 

    * PR#980: mod_proxy
      Controlling Access to Remote Proxies would be nice...
        Status: 

    * PR#994: mod_proxy
      Adding authentication "on the fly" through the proxy module
        Status: 

    * PR#1004: apache-api
      request_config field in request_rec is moderately bogus
        Status: 

    * PR#1028: other
      DoS attacks involving memory consumption
        Status: 

    * PR#1050: mod_log-any
      Logging of virtual server to error_log as well
        Status: 

    * PR#1085: mod_proxy
      ProxyRemote make a dead cycle.
        Status: 

    * PR#1117: mod_auth-any
      Using NIS passwd.byname dbm files with AuthDBMUserFile
        Status: 

    * PR#1120: suexec
      suexec does not parse arguments to #exec cmd
        Status: 

    * PR#1145: mod_include
      Allow for Last-Modified: without resorting to XBitHack
        Status: 

    * PR#1158: apache-api
      improvements to child spawning API
        Status: 

    * PR#1166: mod_proxy
      ``nph-'' not honored (no buffering) for ProxyRemote mapping
        Status: 

    * PR#1176: mod_cgi
      Apache cannot handle continuation line in headers
        Status: 

    * PR#1191: general
      setlogin() is not called, causing problems with e.g. identd
        Status: 

    * PR#1204: general
      regerror() exists, use it
        Status: 

    * PR#1233: apache-api
      there is no way to keep per-connection per-module state
        Status: 

    * PR#1263: mod_autoexec
      Add frame-safe anchor attribute to mod_autoindex links
        Status: 

    * PR#1268: suexec
      CGI scripts running as Apache user: security (suexec etc.)
        Status: 

    * PR#1285: suexec
      Error messages could be easier to spot in cgi.log file for suexec.c
        Status: 

    * PR#1287: mod_access
      add allow,deny/deny,allow warning to mod_access
        Status: 

    * PR#1290: mod_proxy
      Need to know "hit-rate" on proxy cache
        Status: 

    * PR#1358: mod_log-any
      Selective url-encode of log fields (or maybe a pseudo
      log_rewrite module?)
        Status: 

    * PR#1383: mod_headers
      I make mod_headers to modify request headers as well as
      response ones.
        Status: 

    * PR#1532: mod_proxy
      Proxy transfer logging
        Status: 

    * PR#1547: mod_proxy
      No HTTP_X_FORWARDED_FOR set...
        Status: 

    * PR#1567: mod_proxy
      ProxyRemote proxy requests fail authentication by firewall
        Status: 

    * PR#1582: mod_rewrite
      mod_rewrite forms REQUEST_URI different than mod_cgi does
        Status: 

    * PR#1677: mod_headers
      mod_headers should allow mod_log_config-style formats in
      header values
        Status: 

    * PR#1702: mod_proxy
      mod_proxy to support persistent conns?
        Status: 

    * PR#1803: mod_include
      patches to mod_include to allow for file tests
        Status: 

    * PR#1809: mod_auth-any
      Suggestion for improving authentication modules and core source
      code, problem with 401 and ErrorDocument
        Status: 

    * PR#1878: mod_proxy
      listing of proxy cache content
        Status: 

    * PR#1905: suexec
      Allow modules to set user:group for execution.
        Status: 

    * PR#2024: apache-api
      adding auth_why to conn_rec
        Status: 

    * PR#2073: mod_log-any
      pipelined connections are not logged correctly
        Status: 

    * PR#2074: mod_rewrite
      mod_rewrite doesn't pass Proxy Throughput on internal subrequests
        Status: 

    * PR#2113: config
      HTTP Server Rebuild Line Needs Changing for the better
        Status: 

    * PR#2138: mod_status
      mod_status always displays 256 possible connection slots
        Status: 

    * PR#2221: documentation
      Make online documentation search link back to my installation
        Status: 

    * PR#2284: general
      Can not POST to ErrorDocument - Apache/1.3b6
        Status: 

    * PR#2314: mod_proxy
      patterns in ProxyRemote
        Status: 

    * PR#2343: mod_status
      Status module averages are for entire uptime
        Status: 

    * PR#2360: suexec
      suexec for general access of user content?
        Status: 

    * PR#2396: general
      Proposal for TimeZone directive
        Status: 

    * PR#2415: mod_info
      /server-info doesn't check for the virtual host to list the info
        Status: 

    * PR#2421: config
      problem specifying ndbm library for build ?with autoconfigure
        Status: 

    * PR#2431: general
      A small addition to rotatelogs.c to improve program functionality.
        Status: 

    * PR#2446: config
      AllowOverride FileInfo is too coarse
        Status: 

    * PR#2460: mod_cgi
      TimeOut applies to output of CGI scripts
        Status: 

    * PR#2512: mod_access
      &lt;IfDenied&gt; directive wanted
        Status: 

    * PR#2573: suexec
      CGI's for general use still have to be run as another user
      with suExec
        Status: 

    * PR#2648: general
      Cache file names in Proxy module
        Status: 

    * PR#2760: config
      [PATCH] User/Group for <Directory> and <Location> i.e. not only
      in global and <Virtual>.
        Status: 

    * PR#2763: general
      mailto tags and bundling bug report script
        Status: 

    * PR#2785: os-aix
      Support for System Resource Controller
        Status: 

    * PR#2793: protocol
      When will Apache support P3P? Any Plans?
        Status: 

    * PR#2873: config
      Feedback/Comment on APACI
        Status: 

    * PR#2889: general
      Inclusion of RPM spec file in CVS/distributions
        Status: 

    * PR#2906: general
      Propose that Apache recommend $UNIQUE_ID for all "session id"
      algorithms
        Status: 

    * PR#2907: config
      suggestion: power up your Include directive :)
        Status: 

    * PR#3018: general
      cannot limit some HTTP methods
        Status: 

    * PR#3143: apache-api
      No module specific data hook for per-connection data
        Status: 

    * PR#3191: mod_negotiation
      no way to set global quality-of-source (qs) coneg values
      with multiviews
        Status: 

    * PR#3568: mod_proxy
      Accessing URL through proxy server corrupts data.
        Status: 

    * PR#3605: mod_proxy
      Some anonymous FTP URLs ask for authentication
        Status: 

    * PR#3677: general
      New ErrorDocumentMatch directive
        Status: 

    * PR#4241: config
      Need to be able to override shebang line to make CGI scripts
      more portable.
        Status: 

    * PR#4244: config
      "Files" and "FilesMatch" regexp does not recognize bang as
      negation operator
        Status: 

    * PR#4448: mod_log-any
      Please allow CGI env variables (QUERY_STRING, ...) to be logged
      with %{}e
        Status: 

    * PR#4459: mod_include
      Suggestion for better handling of Last-modified headers
        Status: 

    * PR#4490: mod_cgi
      mod_cgi prevents handling of OPTIONS requests
        Status: 

    * PR#5713: os-windows
      [PATCH] install as win32 service with domain account
        Status: 

    * PR#5993: general
      AllowOverride should have a 'CheckNone' and 'AllowNone' argument
      instead of only 'None'
        Status: 

Other bugs that need fixing:

    * MaxRequestsPerChild measures connections, not requests.
        Until someone has a better way, we'll probably just rename it
        "MaxConnectionsPerChild".
    
    * Regex containers don't work in an intutive way
        Status: No one has come up with an efficient way to fix this
        behavior. Dean has suggested getting rid of regex containers
        completely.

    * SIGSEGV on Linux (glibc 2.1.2) isn't caught properly by a
      sigwaiting thread. We need to work around this, perhaps unless
      there is hope soon for a fixed glibc.

    * orig_ct in the byterange/multipart handling may not be
      needed. Apache 1.3 just never stashed "multipart" into
      r->content_type. We should probably follow suit since the
      byterange stuff doesn't want the rest of the code to see the
      multipart content-type; the other code should still think it is
      dealing with the <orig_ct> stuff.
        Status: Greg volunteers to investigate (esp. since he was most 
                likely the one to break it :-)

Other features that need writing:

    * Finish infrastructure in core for async MPMs
        Status: post 2.0

    * TODO in source -- just do an egrep on "TODO" and see what's there

Available Patches:

   * Jon Travis's <jtravis@covalent.net> patch to deal with thread-safe
     issues with inet_ntoa.  See message <20001201163220.A12827@covalent.net>
        Status:  This is being set aside until the IPv6 work is finished
                 so that we know exactly what is required.

   * Martin Sojka <msojka@gmx.de>'s patch to add error reporting for failed 
     htpasswd actions due to a full /tmp volume (other programs may have
     similar problems?)
        PR: 6475
        Status:

   * Mike Abbott's <mja@trudge.engr.sgi.com> patches to improve
     performance
       Status: These were written for 1.3, and are awaiting a port to
       2.0
 
   * Jim Winstead's <jimw@trainedmonkey.com> patch to add CookieDomain and 
     other small mod_usertrack features

   * Dan Rench's <drench@xnet.com> patch to add allow the errmsg and timefmt 
     of SSI's to be modified in the config file.  Patch is available in 
     PR6193

Open issues:

   * Which MPMs will be included with Apache 2.0?