srv->lim_conns tracks remaining conns until limit is reached,
replacing (srv->max_conns - srv->conns.used)
srv->srvconf.max_conns is now updated at startup, so
srv->srvconf.max_conns serves as srv->max_conns
This commit is a large set of code changes and results in removal of
hundreds, perhaps thousands, of CPU instructions, a portion of which
are on hot code paths.
Most (buffer *) used by lighttpd are not NULL, especially since buffers
were inlined into numerous larger structs such as request_st and chunk.
In the small number of instances where that is not the case, a NULL
check is often performed earlier in a function where that buffer is
later used with a buffer_* func. In the handful of cases that remained,
a NULL check was added, e.g. with r->http_host and r->conf.server_tag.
- check for empty strings at config time and set value to NULL if blank
string will be ignored at runtime; at runtime, simple pointer check
for NULL can be used to check for a value that has been set and is not
blank ("")
- use buffer_is_blank() instead of buffer_string_is_empty(),
and use buffer_is_unset() instead of buffer_is_empty(),
where buffer is known not to be NULL so that NULL check can be skipped
- use buffer_clen() instead of buffer_string_length() when buffer is
known not to be NULL (to avoid NULL check at runtime)
- use buffer_truncate() instead of buffer_string_set_length() to
truncate string, and use buffer_extend() to extend
Examples where buffer known not to be NULL:
- cpv->v.b from config_plugin_values_init is not NULL if T_CONFIG_BOOL
(though we might set it to NULL if buffer_is_blank(cpv->v.b))
- address of buffer is arg (&foo)
(compiler optimizer detects this in most, but not all, cases)
- buffer is checked for NULL earlier in func
- buffer is accessed in same scope without a NULL check (e.g. b->ptr)
internal behavior change:
callers must not pass a NULL buffer to some funcs.
- buffer_init_buffer() requires non-null args
- buffer_copy_buffer() requires non-null args
- buffer_append_string_buffer() requires non-null args
- buffer_string_space() requires non-null arg
merge connection_accept() into network_server_handle_fdevent()
(possible since connection_accepted() was split out from
connection_accept() a long time ago)
save parsed listen addrs at startup for reuse at runtime
srv_socket->srv_token is normalized at startup and contains IP and port.
save offset to colon, if present, or else length of string (unix socket)
At runtime, srv_token_colon can be quickly used as length of IP string
(without port) or, if not length of string, offset of stringified port
following the colon.
If server.systemd-socket-activation = "enable" and one or more of the
sockets is not listed in lighttpd.conf, then when the server is shutting
down, a buffer from the config file is free()d twice.
For IPv6 listen addresses:
server.v4mapped = "disable" results in IPV6_V6ONLY socket opt set to 0
server.v4mapped = "enable" results in IPV6_V6ONLY socket opt set to 1
server.v4mapped has an effect only if explicitly set in lighttpd.conf.
If not set, the socket option is inherited from kernel defaults, which
may vary on different OS.
server.v4mapped takes priority over server.set_v6only
server.set_v6only behavior is inconsistent and depreacted.
server.set_v6only behavior differs from server.v4mapped in that
server.set_v6only = "enable" will cause the IPV6_V6ONLY socket
option to be set to 1 for IPv6 listening sockets configured via
$SERVER["socket"] in lighttpd.conf, is enabled by default, and
has no effect if set to "disable"
Note: IPv4-mapped addresses may bring potential security issues,
depending on the situation. For example, lighttpd does not attempt
to match IPv4 addresses with IPv4-mapped addresses. Other writings:
https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02.html
graceful and (nearly) immediate lighttpd restart option
For *some* configurations, it *may* be safe to background the current
lighttpd server (or workers) to continue processing active requests
and, in parallel, to start up a new lighttpd server with a new
configuration. For other configurations, doing so might not be safe!
Therefore, this option must be explicitly configured to enable:
server.feature-flags += ("server.graceful-restart-bg" => "enable")
server.systemd-socket-activation = "enable"
Along with enabling server.feature-flags "server.graceful-restart-bg",
enabling server.systemd-socket-activation allows transfer of open
listening sockets to the new lighttpd server instance, and occurs
without closing the listening sockets and without destroying the
kernel listen backlog queue on the socket.
Safe configurations may include lighttpd.conf which connect to
standalone backend daemons, e.g. proxying to other servers,
including PHP-FPM backends.
Unsafe configurations include lighttpd.conf which use "bin-path" option
in *.server configs, instructing lighttpd to execute the backends.
Using the graceful-and-immediate-restart option is likely *unsafe* if
the backend daemon expects only one instance of itself to run at a time.
Current implementation of graceful and immediate restart option keeps
the backgrounded lighttpd in the same process group, so that subsequent
SIGINT or SIGTERM will shut down both the new and the backgrounded
servers. (An alternative option (commented out in the code) is to
background and detach from the new lighttpd process.) Regardless,
existing subprocesses, such as CGI, remain in original process group.
As a result, the new lighttpd server may receive SIGCHLD for unknown
processes inherited from the old server, which the new lighttpd server
will reap and discard. The original lighttpd server, now a child, will
be unable to detect exit or reap and report status on those pre-existing
subprocesses.
Graceful restart is triggered in lighttpd by sending lighttpd SIGUSR1.
If lighttpd is configured with workers, then SIGINT (not SIGUSR1) is
sent to the process group, including other processes started by
lighttpd, e.g. CGI. To work well with graceful restart, CGI scripts and
other processes should trap SIGINT (and SIGUSR1 for good measure).
Long-running scripts may want to checkpoint and close, e.g. a CGI script
implementing a long-running websocket connection.
(experimental)
mod_mbedtls supports most ssl.* config options supported by mod_openssl
thx Ward Willats for the initial discussion and attempt in the comments
https://redmine.lighttpd.net/boards/3/topics/7029
NB: r->tmp_buf == srv->tmp_buf (pointer is copied for quicker access)
NB: request read and write chunkqueues currently point to connection
chunkqueues; per-request and per-connection chunkqueues are
not distinct from one another
con->read_queue == r->read_queue
con->write_queue == r->write_queue
NB: in the future, a separate connection config may be needed for
connection-level module hooks. Similarly, might need to have
per-request chunkqueues separate from per-connection chunkqueues.
Should probably also have a request_reset() which is distinct from
connection_reset().
convert all log_error_write() to log_error() and pass (log_error_st *)
use con->errh in preference to srv->errh (even though currently same)
avoid passing (server *) when previously used only for logging (errh)
even 2 billion is way larger than even extreme operating values
expected for the members in base.h
include some structs directly in struct server, rather than by ptr
reduce code duplication in list resizing
realloc() of NULL ptr has behavior similar to malloc()
Note that if initial size == 0, then code used to adjust size
must be += x to ensure the size is non-zero for reallocation.
(Multiplying 0 * x, e.g. power-2 resizing, will result in 0.)
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
fix implicit wildcard IPv4 and IPv6 listening (regression in 1.4.46)
(broken in commit:5248b46c)
workaround (without this patch): server.set-v6only = "disable"
(which may produce a warning when lighttpd parses config)
x-ref:
https://redmine.lighttpd.net/boards/2/topics/7720
address strings need to have DNS resolved and port added
for consistency when matching other config conditionals
x-ref:
"1.4.46 regression: $SERVER["socket"] matches when it shouldn't"
https://redmine.lighttpd.net/issues/2830
address strings need to have DNS resolved and port added
for consistency when matching other config conditionals
x-ref:
"1.4.46 regression: $SERVER["socket"] matches when it shouldn't"
https://redmine.lighttpd.net/issues/2830
address strings need to have DNS resolved and port added
for consistency when matching other config conditionals
x-ref:
"1.4.46 regression: $SERVER["socket"] matches when it shouldn't"
https://redmine.lighttpd.net/issues/2830
server.bind = "/dev/stdin" for use with inetd wait yes
(experimental)
x-ref:
"inetd/wait mode with auto-shutdown after idle timeout"
https://redmine.lighttpd.net/issues/2824
nicorac