Method push

api/src/syscall/net/cmsg.rs:62–86

(
        &mut self,
        level: u32,
        ty: u32,
        body: impl FnOnce(&mut [u8]) -> AxResult<usize>,
    )

    }

    pub fn push(
        &mut self,
        level: u32,
        ty: u32,
        body: impl FnOnce(&mut [u8]) -> AxResult<usize>,
    ) -> AxResult<bool> {
        let Some(body_capacity) = (self.capacity - *self.len).checked_sub(size_of::<cmsghdr>())
        else {
            return Ok(false);
        };

        let hdr = self.hdr.get_as_mut()?;
        hdr.cmsg_level = level as _;
        hdr.cmsg_type = ty as _;

        let data = UserPtr::<u8>::from(self.hdr.address().as_usize() + size_of::<cmsghdr>())
            .get_as_mut_slice(body_capacity)?;
        let body_len = body(data)?;

        let cmsg_len = size_of::<cmsghdr>() + body_len;
        hdr.cmsg_len = cmsg_len;
        self.hdr = UserPtr::from(hdr as *const _ as usize + cmsg_len);
        *self.len += cmsg_len;
        Ok(true)
    }
}