role ops are usually only sparsely filled, there are currently 20
function pointers but several roles only fill in two. No single
role has more than 14 of the ops. On a 32/64 bit build this part
of the ops struct takes a fixed 80 / 160 bytes then.
First reduce the type of the callback reason part from uint16_t to
uint8_t, this saves 12 bytes unconditionally.
Change to a separate function pointer array with a nybble index
array, it costs 10 bytes for the index and a pointer to the
separate array, for 32-bit the cost is
2 + (4 x ops_used)
and for 64-bit
6 + (8 x ops_used)
for 2 x ops_used it means 32-bit: 10 vs 80 / 64-bit: 22 vs 160
For a typical system with h1 (9), h2 (14), listen (2), netlink (2),
pipe (1), raw_skt (3), ws (12), == 43 ops_used out of 140, it means
the .rodata for this reduced from 32-bit: 560 -> 174 (386 byte
saving) and 64-bit: 1120 -> 350 (770 byte saving)
This doesn't account for the changed function ops calling code, two
ways were tried, a preprocessor macro and explicit functions
For an x86_64 gcc 10 build with most options, release mode,
.text + .rodata
before patch: 553282
accessor macro: 552714 (568 byte saving)
accessor functions: 553674 (392 bytes worse than without patch)
therefore we went with the macros
They have been in lib/roles/http for historical reasons, and all
ended up in client-handshake.c that doesn't describe what they
actually do any more. Separate out the staged client connect
related stage functions into
lib/core-net/client/client2.c: lws_client_connect_2_dnsreq()
lib/core-net/client/client3.c: lws_client_connect_3_connect()
lib/core-net/client/client4.c: lws_client_connect_4_established()
Move a couple of other functions from there that don't belong out to
tls-client.c and client-http.c, which is related to http and remains
in the http role dir.
This is complicated by the fact extern on a function declaration implies
visibility... we have to make LWS_EXTERN empty when building static.
And, setting target_compile_definitions() doesn't work inside macros,
so it has to be set explicitly for the plugins.
Checking the symbol status needs nm -C -D as per
https://stackoverflow.com/questions/37934388/symbol-visibility-not-working-as-expected
after this patch, libwebsockets.a shows no symbols when checked like that and
the static-linked minimal examples only show -U for their other dynamic
imports.
In a handful of cases we use LWS_EXTERN on extern data declarations,
those then need to change to explicit extern.
Coverity sees we sometimes check if header length is 0 and extrapolates
from that not checking header length return is a violation. But often
we are OK if the header length is 0 and there is no error return to
check from that.
It also doesn't understand that if we saw a nonzero length for a header,
then we are going to get a non-null simple_ptr() return for sure. Just
give up and explicitly, unneccessarily check everything so coverity can
stop telling us about it.
We can't get here without testing for COLON_PATH existing in http2.c as part of
the h2spec pass code.
if (!lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_PATH) ||
!lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_METHOD) ||
!lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_SCHEME) ||
lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_STATUS) ||
lws_hdr_extant(h2n->swsi, WSI_TOKEN_CONNECTION)) {
lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
"Pseudoheader checks");
break;
}
So there is no issue. But show Coverity what it wants so we don't keep getting this
false positive reported by different coverity users.
Add initial support for defining servers using Secure Streams
policy and api semantics.
Serving h1, h2 and ws should be functional, the new minimal
example shows a combined http + SS server with an incrementing
ws message shown in the browser over tls, in around 200 lines
of user code.
NOP out anything to do with plugins, they're not currently used.
Update the docs correspondingly.
Currently we always reserve a fakewsi per pt so events that don't have a related actual
wsi, like vhost-protocol-init or vhost cert init via protocol callback can make callbacks
that look reasonable to user protocol handler code expecting a valid wsi every time.
This patch splits out stuff that user callbacks often unconditionally expect to be in
a wsi, like context pointer, vhost pointer etc into a substructure, which is composed
into struct lws at the top of it. Internal references (struct lws is opaque, so there
are only internal references) are all updated to go via the substructre, the compiler
should make that a NOP.
Helpers are added when fakewsi is used and referenced.
If not PLAT_FREERTOS, we continue to provide a full fakewsi in the pt as before,
although the helpers improve consistency by zeroing down the substructure. There is
a huge amount of user code out there over the last 10 years that did not always have
the minimal examples to follow, some of it does some unexpected things.
If it is PLAT_FREERTOS, that is a newer thing in lws and users have the benefit of
being able to follow the minimal examples' approach. For PLAT_FREERTOS we don't
reserve the fakewsi in the pt any more, saving around 800 bytes. The helpers then
create a struct lws_a (the substructure) on the stack, zero it down (but it is only
like 4 pointers) and prepare it with whatever we know like the context.
Then we cast it to a struct lws * and use it in the user protocol handler call.
In this case, the remainder of the struct lws is undefined. However the amount of
old protocol handlers that might touch things outside of the substructure in
PLAT_FREERTOS is very limited compared to legacy lws user code and the saving is
significant on constrained devices.
User handlers should not be touching everything in a wsi every time anyway, there
are several cases where there is no valid wsi to do the call with. Dereference of
things outside the substructure should only happen when the callback reason shows
there is a valid wsi bound to the activity (as in all the minimal examples).
Establish a new distributed CMake architecture with CMake code related to
a source directory moving to be in the subdir in its own CMakeLists.txt.
In particular, there's now one in ./lib which calls through to ones
further down the directory tree like ./lib/plat/xxx, ./lib/roles/xxx etc.
This cuts the main CMakelists.txt from 98KB -> 33KB, about a 66% reduction,
and it's much easier to maintain sub-CMakeLists.txt that are in the same
directory as the sources they manage, and conceal all the details that that
level.
Child CMakelists.txt become responsible for:
- include_directories() definition (this is not supported by CMake
directly, it passes it back up via PARENT_SCOPE vars in helper
macros)
- Addition child CMakeLists.txt inclusion, for example toplevel ->
role -> role subdir
- Source file addition to the build
- Dependent library path resolution... this is now a private thing
in the child CMakeLists.txt, it just passes back any adaptations
to include_directories() and the LIB_LIST without filling the
parent namespace with the details
There is no way to allocate a client wsi mux sid before the headers are
send, because we don't know the order in which new wsi headers will be sent
and so seen by the peer.
The peer inisists that sid indexes only increase... we cannot allocat sids
monotonically at the client and then send them disordered...
Lws now strips out http headers releated to h2, ws and unusual headers
based on cmake config settings for those features... it saves some heap
for the ah and reduces the table size in .rodata.
It's possible code might have some external dependency on the original
header indexes, but, eg, you don't enable h2 so those indexes are
optimized with the h2 ones taken out.
This introduces a cmake option "LWS_HTTP_HEADERS_ALL", default-OFF, that
defeats the header table optimization for compatibility with older
versions in the case the client software can't be adapted to use the
lws-exported matching header enums.
You probably don't need this.
This leads to problems at the moment with sticky mux.requested_POLLOUT
causing writeable to not be sent.
Remove it and always set writeable on parents for now.
Secure Streams is an optional layer on top of lws that separates policy
like endpoint selection and tls cert validation into a device JSON
policy document.
Code that wants to open a client connection just specifies a streamtype name,
and no longer deals with details like the endpoint, the protocol (!) or anything
else other than payloads and optionally generic metadata; the JSON policy
contains all the details for each streamtype. h1, h2, ws and mqtt client
connections are supported.
Logical secure streams outlive any particular connection and supports "nailed-up"
connectivity regardless of underlying connection stability.
Headers related to ws or h2 are now elided if the ws or h2 role
is not enabled for build. In addition, a new build-time option
LWS_WITH_HTTP_UNCOMMON_HEADERS on by default allows removal of
less-common http headers to shrink the parser footprint.
Minilex is adapted to produce 8 different versions of the lex
table, chosen at build-time according to which headers are
included in the build.
If you don't need the unusual headers, or aren't using h2 or ws,
this chops down the size of the ah and the rodata needed to hold
the parsing table from 87 strings / pointers to 49, and the
parsing table from 1177 to 696 bytes.
This adds support for POST in both h1 and h2 queues / stream binding.
The previous queueing tried to keep the "leader" wsi who made the
actual connection around and have it act on the transaction queue
tail if it had done its own thing.
This refactors it so instead, who is the "leader" moves down the
queue and the queued guys inherit the fd, SSL * and queue from the
old leader as they take over.
This lets them operate in their own wsi identity directly and gets
rid of all the "effective wsi" checks, which was applied incompletely
and getting out of hand considering the separate lws_mux checks for
h2 and other muxed protocols alongside it.
This change also allows one wsi at a time to own the transaction for
POST. --post is added as an option to lws-minimal-http-client-multi
and 6 extra selftests with POST on h1/h2, pipelined or not and
staggered or not are added to the CI.
Add selectable event lib support to minimal-http-client-multi and
clean up context destroy flow so we can use lws_destroy_context() from
inside the callback to indicate we want to end the event loop, without
using the traditional "interrupted" flag and in a way that works no
matter which event loop backend is being used.
This provides support to build lws using the linkit 7697 public SDK
from here https://docs.labs.mediatek.com/resource/mt7687-mt7697/en/downloads
This toolchain has some challenges, its int32_t / uint32_t are long,
so assumptions about format strings for those being %u / %d / %x all
break. This fixes all the cases for the features enabled by the
default cmake settings.
There are some minor public api type improvements rather than cast everywhere
inside lws and user code to work around them... these changed from int to
size_t
- lws_buflist_use_segment() return
- lws_tokenize_t .len and .token_len
- lws_tokenize_cstr() length
- lws_get_peer_simple() namelen
- lws_get_peer_simple_fd() namelen, int fd -> lws_sockfd_type fd
- lws_write_numeric_address() len
- lws_sa46_write_numeric_address() len
These changes are typically a NOP for user code
This changes the approach of tx credit management to set the
initial stream tx credit window to zero. This is the only way
with RFC7540 to gain the ability to selectively precisely rx
flow control incoming streams.
At the time the headers are sent, a WINDOW_UPDATE is sent with
the initial tx credit towards us for that specific stream. By
default, this acts as before with a 256KB window added for both
the stream and the nwsi, and additional window management sent
as stuff is received.
It's now also possible to set a member in the client info
struct and a new option LCCSCF_H2_MANUAL_RXFLOW to precisely
manage both the initial tx credit for a specific stream and
the ongoing rate limit by meting out further tx credit
manually.
Add another minimal example http-client-h2-rxflow demonstrating how
to force a connection's peer's initial budget to transmit to us
and control it during the connection lifetime to restrict the amount
of incoming data we have to buffer.
This should be a NOP for h2 support and only affects internal
apis. But it lets us reuse the working and reliable h2 mux
arrangements directly in other protocols later, and share code
so building for h2 + new protocols can take advantage of common
mux child handling struct and code.
Break out common mux handling struct into its own type.
Convert all uses of members that used to be in wsi->h2 to wsi->mux
Audit all references to the members and break out generic helpers
for anything that is useful for other mux-capable protocols to
reuse wsi->mux related features.
