This is the same as evbuffer_add_reference(), but allows to specify
offset in the @data
v2: rename evbuffer_add_reference_misalign() to evbuffer_add_reference_with_offset()
Replace evws_send with evws_send_text, and introduce new API -
evws_send_binary, that can be used to send binary frames.
But note, that this commit breaks the ABI compatibility, but it should be OK,
since there was only alpha release with evws_send, and nobody should rely on
this, and I hope nobody does (we decided to go this way to avoid supporting
deprecated API).
signalfd may behave differently to sigaction/signal, so to avoid
breaking libevent users (like [1], [2]) disable it by default.
[1]: https://github.com/tmux/tmux/pull/3621
[2]: https://github.com/tmux/tmux/pull/3626
Also signalfd is not that perfect:
- you need to SIG_BLOCK the signal before
- blocked signals are not reset on exec
- blocked signals are allowed to coalesce - so in case of multiple
signals sent you may get the signal only once (ok for most of the
signals, but may be a problem for SIGCHLD, though you may call
waitpid() in a loop or use pidfd)
- and also one implementation problem -
sigprocmask is unspecified in a multithreaded process
Refs:
- https://lwn.net/Articles/415684/
- https://ldpreload.com/blog/signalfd-is-useless
Refs: https://github.com/libevent/libevent/issues/1460
Refs: #1342 (cc @dmantipov)
When libevent doesn't provide random the arc4 function, but they come from libc, there is no need to call this function, so make it do nothing.
Fixes: #1393
Libevent introduced the LEV_OPT_BIND_IPV6ONLY to pass to evconnlistener_new_bind to make it automatically set the underlying socket as accepting ipv6 requests. This works fine on posix compliant platforms as by the standard every new AF_INET6 socket is created as both supporting ipv6 and ipv4 connections. But on windows the default is the opposite, with the flag IPV6_V6ONLY being always enabled by default.
This makes creating a listener to supports both protocols a bit more tricky as winsock doesn't allow changing this flag after evconnlistener_new_bind does all the initial setup because as stated in the docs, you can't change it after the sonnect connected, so one would have to manually create the socket beforehand and set the flag and then call evconnlistener_new with the socket itself.
It would be nice to have libevent keep a consistent behaviour across the platforms in this scenario, maybe or by making it always set IPV6_V6ONLY to false unless LEV_OPT_BIND_IPV6ONLY is passed, in which case it's set to true, or add another flag to forcefully set it to false and keep the system dependent behaviour as default.
So this patch add new option for libevent listeners to bind to both - LEV_OPT_BIND_IPV4_AND_IPV6
Linux-specific signal handling backend based on signalfd(2)
system call, and public function event_base_get_signal_method()
to obtain an underlying kernel signal handling mechanism.
Signed-off-by: Dmitry Antipov <dantipov@cloudlinux.com>
This adds few functions to use evhttp-based webserver to handle incoming
WebSockets connections. We've tried to use both libevent and libwebsockets in
our application, but found that we need to have different ports at the same
time to handle standard HTTP and WebSockets traffic. This change can help to
stick only with libevent library.
Implementation was inspired by modified Libevent source code in ipush project
[1].
[1]: https://github.com/sqfasd/ipush/tree/master/deps/libevent-2.0.21-stable
Also, WebSocket-based chat server was added as a sample.
There are no standard for encoding a unix socket in an url. nginx uses:
http://unix:/path/to/unix/socket:/httppath
The second colon is needed to delimit where the unix path ends and where
the rest of the url continues.
Signed-off-by: Sean Young <sean@mess.org>
Add new flag (DNS_CNAME_CALLBACK) for
evdns_base_resolve_ipv4()/evdns_base_resolve_ipv6().
If set, you will get one more callback with type == DNS_CNAME and CNAME
in addrs argument.
Looks like a `splice` implementation was planned, but has clearly never
eventuated (the TODO comment is from ~12 years ago, in
8b5bd77415fb6634fadf08357676926fecf5f032). For now, it's probably better
to remove the unused code/correct the docs.
The conflict cast convertion between the return value of
bufferevent_read() and evbuffer_remove(), int(-1)->size_t(An undefined
maximum)
Add test case of bufferevent_read() should return 0 in case of
evbuffer_remove() returns -1
Fixes: #1132
I recently found that when the network status changed when calling
bufferevent_socket_connect_hostname (e.g. switching between several
WIFIs), all DNS servers would fail, and the timeout of probe would be
very long if there were many DNS requests. I want libevent to support
manual setting of MAX_PROBE_TIMEOUT and TIMEOUT_BACKOFF_FACTOR
So move hardcoded MAX_PROBE_TIMEOUT and TIMEOUT_BACKOFF_FACTOR into
struct, and allow changing them.
At the very beginning we reset the bufferevent fd (if bev has it), which
is not a good idea, since if user passes bufferevent with existing fd he
has some intention.
So we need to:
- use BEV_OPT_CLOSE_ON_FREE for default bufferevent_socket_new() (to
avoid manual shutdown/closee)
- drop getsockopt(SOL_SOCKET, SO_ERROR), since bufferevent already has
evutil_socket_finished_connecting_()
- drop supperior bufferevent_setfd(bev, -1) in
evhttp_connection_connect_()
Closes: #795
Refs: #875
Added new option `edns-udp-size` for evdns_base which allows
to control maximum allowed size of UDP DNS messages. This
maximum size is passed to the DNS server via edns mechanism.
@jcoffland:
"When the max connection limit is enabled and the limit is reached, the
server will respond immediately with 503 Service Unavailable. This can
be used to prevent servers from running out of file descriptors. This is
better than request limiting because clients may make more than one
request over a single connection. Blocking a request does not
necessarily close the connection and free up a socket."
* http-max_connections-pr-592:
test: cover evhttp max connections
Added evhttp max simultaneous connection limiting
By default we are using CLOCK_MONOTONIC_COARSE, but if
EVENT_BASE_FLAG_PRECISE_TIMER isset, then CLOCK_MONOTONIC will be used,
however this will also enable timerfd, while this is not always what
someone wants, hence add a flag to control this (by default the old
behavior is preserved, set new flag to change it).
