Hello,

On Mon, 5 Feb 2024 23:24:39 +0200
Clima Gabriel <clima.gabrielphoto@gmail.com> wrote:

> Hello everyone,
>
> (the code is probably clearer and attached below)
> This function modifies what ngx_connection_t->data points to.
> ngx_connection_t->data is initially *ngx_http_connection_t.
> The *ngx_http_connection_t is assigned to
> ngx_http_v3_session_t->http_connection
> And the *ngx_http_v3_session_t assigned to ngx_connection_t->data.
>
> Result: before ngx_connection_t->data is *ngx_http_connection_t
> after ngx_connection_t->data is *ngx_http_v3_session_t

In C, a pointer to struct can be cast to a pointer to the first member
of that struct, as there is no padding before the first member per the
standard.

The first member of ngx_http_v3_session_t is *ngx_http_connection_t.

Here is the commit where this was implemented.

https://mailman.nginx.org/pipermail/nginx-devel/2023-September/BWH23FTMRUWCUZSNKXJJXEEN76ZYOK62.html

[...]
_______________________________________________
nginx mailing list
nginx@nginx.org
https://mailman.nginx.org/mailman/listinfo/nginx