Function soreserve

freebsd/kern/uipc_sockbuf.c:561–587

* Socket buffer (struct sockbuf) utility routines. * * Each socket contains two socket buffers: one for sending data and one for * receiving data. Each buffer contains a queue of mbufs, information about * the number of mbufs and amount of data in the queue, and other fields * allowing select() statements and notification on data availability to be * implemented. * * Data stored in a sock

 * be released by calling sbrelease() when the socket is destroyed.
 */
int
soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
{
	struct thread *td = curthread;

	SOCKBUF_LOCK(&so->so_snd);
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
		goto bad;
	if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0)
		goto bad2;
	if (so->so_rcv.sb_lowat == 0)
		so->so_rcv.sb_lowat = 1;
	if (so->so_snd.sb_lowat == 0)
		so->so_snd.sb_lowat = MCLBYTES;
	if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
		so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (0);
bad2:
	sbrelease_locked(&so->so_snd, so);
bad:
	SOCKBUF_UNLOCK(&so->so_rcv);
	SOCKBUF_UNLOCK(&so->so_snd);
	return (ENOBUFS);
}

static int
sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)