The sockaddr_in is missing documentation of the `sin_len` field.

The following code

use libc::{socket, bind, accept, listen, connect, close};
use libc::{sockaddr_in, sockaddr, in_addr};
use libc::{AF_INET, SOCK_STREAM, INADDR_ANY};
use std::os::fd::RawFd;


fn main() {
    unsafe {
        let sock:RawFd = socket(AF_INET, SOCK_STREAM, 0);
        let servaddr = sockaddr_in{sin_zero:[0;8],
                                   sin_family:AF_INET as u8, 
                                   sin_port:u16::from_le_bytes((12001 as u16).to_ne_bytes()), 
                                   sin_addr:in_addr{s_addr:INADDR_ANY}
                               };
        close(sock);
    }
}

Fails to compile with

error[E0063]: missing field `sin_len` in initializer of `sockaddr_in`
  --> src/main.rs:10:24
   |
10 |         let servaddr = sockaddr_in{sin_zero:[0;8],
   |                        ^^^^^^^^^^^ missing `sin_len`

For more information about this error, try `rustc --explain E0063`.
warning: `hello_world` (bin "hello_world") generated 2 warnings
error: could not compile `hello_world` (bin "hello_world") due to previous error; 2 warnings emitted

In https://docs.rs/libc/latest/libc/struct.sockaddr_in.html , there is no documentation of the sin_len field of the struct.

Also i have never heard of this field in C types themselves for sockaddr_in , https://man7.org/linux/man-pages/man3/sockaddr.3type.html so unclear what this field is or does.

Start by comparing the sockaddr_in documentation on docs.rs with the platform definitions referenced by the man7 sockaddr page, focusing on the undocumented sin_len field. Document what the field is and when it applies, then verify that the generated sockaddr_in documentation explains it accurately.