1a93e73402
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). |
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| .. | ||
| README.md | ||
| ss-h1.c | ||
| ss-h2.c | ||
| ss-mqtt.c | ||
| ss-raw.c | ||
| ss-ws.c | ||
Lws Protocol bindings for Secure Streams
This directory contains the code wiring up normal lws protocols to Secure Streams.
The lws_protocols callback
This is the normal lws struct lws_protocols callback that handles events and traffic on the lws protocol being supported.
The various events and traffic are converted into calls using the Secure Streams api, and Secure Streams events.
The connect_munge helper
Different protocols have different semantics in the arguments to the client connect function, this protocol-specific helper is called to munge the connect_info struct to match the details of the protocol selected.
The ss->policy->aux string is used to hold protocol-specific information
passed in the from the policy, eg, the URL path or websockets subprotocol
name.
The (library-private) ss_pcols export
Each protocol binding exports two things to other parts of lws (they are not exported to user code)
-
a struct lws_protocols, including a pointer to the callback
-
a struct ss_pcols describing how secure_streams should use, including a pointer to the related connect_munge helper.
In ./lib/core-net/vhost.c, enabled protocols are added to vhost protcols lists so they may be used. And in ./lib/secure-streams/secure-streams.c, enabled struct ss_pcols are listed and checked for matches when the user creates a new Secure Stream.