The HTTP layer used to make a copy of each incoming header and its
value for a request. Stop doing that and make HTTP headers zero-copy
all across the board.
This change comes with some api function changes, notably the
http_request_header() function which now takes a const char ** rather
than a char ** out pointer.
This commit also constifies several members of http_request, beware.
Additional rework how the worker processes deal with the accept lock.
Before:
if a worker held the accept lock and it accepted a new connection
it would release the lock for others and back off for 500ms before
attempting to grab the lock again.
This approach worked but under high load this starts becoming obvious.
Now:
- workers not holding the accept lock and not having any connections
will wait less long before returning from kore_platform_event_wait().
- workers not holding the accept lock will no longer blindly wait
an arbitrary amount in kore_platform_event_wait() but will look
at how long until the next lock grab is and base their timeout
on that.
- if a worker its next_lock timeout is up and failed to grab the
lock it will try again in half the time again.
- the worker process holding the lock will when releasing the lock
double check if it still has space for newer connections, if it does
it will keep the lock until it is full. This prevents the lock from
bouncing between several non busy worker processes all the time.
Additional fixes:
- Reduce the number of times we check the timeout list, only do it twice
per second rather then every event tick.
- Fix solo worker count for TLS (we actually hold two processes, not one).
- Make sure we don't accidentally miscalculate the idle time causing new
connections under heavy load to instantly drop.
- Swap from gettimeofday() to clock_gettime() now that MacOS caught up.
LibreSSL defines OPENSSL_VERSION_NUMBER as 0x20000000L but does not have
the 1.1.0 API so we have to carefully check for LIBRESSL_VERSION_TEXT as
well before using that new API.
Eventually I will phase out 1.0.2 down the line to get rid of the
nightmare that is the 2 different APIs.
This commit adds full support for building kore with 1.1.0e while
retaining the privsep keymanager support.
based on excellent work done by @hiwk.
At bootup and every 1800 seconds after that the worker processes will
ask the keymgr for new entropy that they will seed into their PRNG.
Additionally once received the worker calls RAND_poll() to grab
more entropy from the system to be mixed in.
This option allows the user to specify a file to be used for
seeding the PRNG initially and to write random bytes at exit.
The option is only available if kore has TLS enabled (by default).
If you enable this option Kore will refuse to start if there is
a problem with the file specified (not found, not a file, invalid size, etc).
While here let the keymgr process call RAND_poll() every half hour
to grab more system entropy and seed it into the PRNG.
- Change pools to use mmap() for allocating regions.
- Change kore_malloc() to use pools for commonly sized objects.
(split into multiple of 2 buckets, starting at 8 bytes up to 8192).
- Rename kore_mem_free() to kore_free().
The preallocated pools will hold up to 128K of elements per block size.
In case a larger object is to be allocated kore_malloc() will use
malloc() instead.
Kore will now isolate RSA private keys to a separate process (keymgr).
Worker processes that require RSA signing for TLS connections will
communicate with this keymgr process in order to do so.
This behaviour cannot be disabled and is always turned on.
