improve FAM monitoring to use reference counting in internal cache
revalidate entries upon use after 16 sec to recover from missed events
(see comments in commit for more details about limitations)
do not open file in stat_cache_get_entry()
no longer stat() followed by open() and close() just for stat()
callers should open() file to validate readability (and then reuse fd)
fdevent_open_cloexec() opens files O_BINARY for consistency,
and with O_NONBLOCK, so that the server will not block if the
target file to open is a fifo.
quickly clear buffer instead of buffer_string_set_length(b, 0) or
buffer_reset(b). Avoids free() of large buffers about to be reused,
or buffers that are module-scoped, persistent, and reused.
(buffer_reset() should still be used with buffers in connection *con
when the data in the buffers is supplied by external, untrusted source)
provide standard types in first.h instead of base.h
provide lighttpd types in base_decls.h instead of settings.h
reduce headers exposed by headers for core data structures
do not expose <pcre.h> or <stdlib.h> in headers
move stat_cache_entry to stat_cache.h
reduce use of "server.h" and "base.h" in headers
silence compiler warnings if HAVE_FORK is not set
However, if HAVE_FORK is not set, then -Werror was probably passed to
./configure, which is currently a mistake. lighttpd can successfully
compiles src/ with -Werror on many platforms, but ./configure tests
should not be run with -Werror. [gstrauss]
github: closes #81
x-ref:
"Fix warnings"
https://github.com/lighttpd/lighttpd1.4/pull/81
shared code to get mimetype string via longest extension match
(attempts to match file basename, then longest ext, then "")
Note: this is a behavior change from simple suffix match
if there are 16 or more entries in mimetypes.assign
disable stat_cache if server.follow-symlink = "disable"
if server.stat-cache-engine = "simple". Caching is still enabled
for server.stat-cache-engine = "fam" since the FAM notification is
almost immediate, however there is still a small race condition.
NOTE: server.follow-symlink = "disable" implementation still has
time-of-check versus time-of-use (ToC-ToU) race conditions and
its use is *not recommended* except to discourage symlinking.
It *does not* prevent symlinking by a determined attacker with
the ability to create files on the server.
server.stat-cache-engine = "disable" can also be used to discourage
symlinking, and also does not eliminate ToC-ToU race conditions.
While more modern systems might use openat() and other *at() routines
to eliminate the ToC-ToU race conditions, this is not currently
implemented in lighttpd. Besides, for systems needing such
protections against actors able to modify local files, it would be
better to set up multiple lighttpd servers running in separate user
contexts with filesystem permissions preventing access, rather than
giving a single lighttpd server running under a single lighttpd user
access to files across security boundaries, and trying to prevent
access by lighttpd user if a file is a symlink.
Note that there are performance implications to setting either of
server.follow-symlink = "disable"
server.stat-cache-engine = "disable"
since stat cache normally reduces filesystem overhead for
frequently-accessed files.
x-ref:
"security: stat cache *very large* race condition if caching when
follow_symlink disabled"
https://redmine.lighttpd.net/issues/2724
http_chunk_append_file() opens fd when appending file to chunkqueue.
Defers calculation of content length until response is finished.
This reduces race conditions pertaining to stat() and then (later)
open(), when the result of the stat() was used for Content-Length
or to generate chunked headers.
Note: this does not change how lighttpd handles files that are modified
in-place by another process after having been opened by lighttpd --
don't do that. This *does* improve handling of files that are
frequently modified via a temporary file and then atomically renamed
into place.
mod_fastcgi has been modified to use http_chunk_append_file_range() with
X-Sendfile2 and will open the target file multiple times if there are
multiple ranges.
Note: (future todo) not implemented for chunk.[ch] interfaces used by
range requests in mod_staticfile or by mod_ssi. Those uses could lead
to too many open fds. For mod_staticfile, limits should be put in place
for max number of ranges accepted by mod_staticfile. For mod_ssi,
limits would need to be placed on the maximum number of includes, and
the primary SSI file split across lots of SSI directives should either
copy the pieces or perhaps chunk.h could be extended to allow for an
open fd to be shared across multiple chunks. Doing either of these
would improve the performance of SSI since they would replace many file
opens on the pieces of the SSI file around the SSI directives.
x-ref:
"Serving a file that is getting updated can cause an empty response or incorrect content-length error"
https://redmine.lighttpd.net/issues/2655
github:
Closes #49
For backwards compatibility with existing lighttpd configs, default is
mimetype.xattr-name = "Content-Type"
Those who wish to use the freedesktop.org definition of xattr mimetype
can set the following in the global lighttpd config:
mimetype.xattr-name = "user.mime_type"
From: Glenn Strauss <gstrauss@gluelogic.com>
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3131 152afb58-edef-0310-8abb-c4023f1b3aa9
- don't remember splay_tree nodes for long (dir_node, file_node) after
cache lookup; only remember the data they pointed to (sce for file
entries, fam_node for dir entries)
- unset sce / fam_node when a collision (not matching path) is detected
- check again for collision before splaytree_insert; the entry in
question is already at the top because it was splayed before. simply
replace the data on collisions (and release the old data).
- check fam_node for collisions too
- splaytree_size handles NULL nodes too
- enable some force_assert lines (were in #ifdef DEBUG_STAT_CACHE before)
Differential Revision: https://review.lighttpd.net/D1
From: Stefan Bühler <stbuehler@web.de>
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3039 152afb58-edef-0310-8abb-c4023f1b3aa9
Gaël PORTAY
