Exemplo n.º 1
0
/*
  in6_pcblookup_local_and_cleanup does everything
  in6_pcblookup_local does but it checks for a socket
  that's going away. Since we know that the lock is
  held read+write when this function is called, we
  can safely dispose of this socket like the slow
  timer would usually do and return NULL. This is
  great for bind.
*/
static struct inpcb*
in6_pcblookup_local_and_cleanup(
	struct inpcbinfo *pcbinfo,
	struct in6_addr *laddr,
	u_int lport_arg,
	int wild_okay)
{
	struct inpcb *inp;
	
	/* Perform normal lookup */
	inp = in6_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay);
	
	/* Check if we found a match but it's waiting to be disposed */
	if (inp && inp->inp_wantcnt == WNT_STOPUSING) {
		struct socket *so = inp->inp_socket;
		
		lck_mtx_lock(inp->inpcb_mtx);
		
		if (so->so_usecount == 0) {
			in_pcbdispose(inp);
			inp = NULL;
		}
		else {
			lck_mtx_unlock(inp->inpcb_mtx);
		}
	}
	
	return inp;
}
Exemplo n.º 2
0
Arquivo: in6_src.c Projeto: Prajna/xnu
/*
 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
 * share this function by all *bsd*...
 */
int
in6_pcbsetport(
	__unused struct in6_addr *laddr,
	struct inpcb *inp,
	struct proc *p,
	int locked)
{
	struct socket *so = inp->inp_socket;
	u_int16_t lport = 0, first, last, *lastport;
	int count, error = 0, wild = 0;
	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
	kauth_cred_t cred;
	if (!locked) { /* Make sure we don't run into a deadlock: 4052373 */
		if (!lck_rw_try_lock_exclusive(pcbinfo->mtx)) {
			socket_unlock(inp->inp_socket, 0);
			lck_rw_lock_exclusive(pcbinfo->mtx);
			socket_lock(inp->inp_socket, 0);
		}
	}

	/* XXX: this is redundant when called from in6_pcbbind */
	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
		wild = INPLOOKUP_WILDCARD;

	inp->inp_flags |= INP_ANONPORT;

	if (inp->inp_flags & INP_HIGHPORT) {
		first = ipport_hifirstauto;	/* sysctl */
		last  = ipport_hilastauto;
		lastport = &pcbinfo->lasthi;
	} else if (inp->inp_flags & INP_LOWPORT) {
		cred = kauth_cred_proc_ref(p);
		error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
		kauth_cred_unref(&cred);
		if (error != 0) {
			if (!locked)
				lck_rw_done(pcbinfo->mtx);
			return error;
		}
		first = ipport_lowfirstauto;	/* 1023 */
		last  = ipport_lowlastauto;	/* 600 */
		lastport = &pcbinfo->lastlow;
	} else {
		first = ipport_firstauto;	/* sysctl */
		last  = ipport_lastauto;
		lastport = &pcbinfo->lastport;
	}
	/*
	 * Simple check to ensure all ports are not used up causing
	 * a deadlock here.
	 *
	 * We split the two cases (up and down) so that the direction
	 * is not being tested on each round of the loop.
	 */
	if (first > last) {
		/*
		 * counting down
		 */
		count = first - last;

		do {
			if (count-- < 0) {	/* completely used? */
				/*
				 * Undo any address bind that may have
				 * occurred above.
				 */
				inp->in6p_laddr = in6addr_any;
				inp->in6p_last_outif = 0;
				if (!locked)
					lck_rw_done(pcbinfo->mtx);
				return (EAGAIN);
			}
			--*lastport;
			if (*lastport > first || *lastport < last)
				*lastport = first;
			lport = htons(*lastport);
		} while (in6_pcblookup_local(pcbinfo,
					     &inp->in6p_laddr, lport, wild));
	} else {
		/*
			 * counting up
			 */
		count = last - first;

		do {
			if (count-- < 0) {	/* completely used? */
				/*
				 * Undo any address bind that may have
				 * occurred above.
				 */
				inp->in6p_laddr = in6addr_any;
				inp->in6p_last_outif = 0;
				if (!locked)
					lck_rw_done(pcbinfo->mtx);
				return (EAGAIN);
			}
			++*lastport;
			if (*lastport < first || *lastport > last)
				*lastport = first;
			lport = htons(*lastport);
		} while (in6_pcblookup_local(pcbinfo,
					     &inp->in6p_laddr, lport, wild));
	}

	inp->inp_lport = lport;
	if (in_pcbinshash(inp, 1) != 0) {
		inp->in6p_laddr = in6addr_any;
		inp->inp_lport = 0;
		inp->in6p_last_outif = 0;
		if (!locked)
			lck_rw_done(pcbinfo->mtx);
		return (EAGAIN);
	}

	if (!locked)
		lck_rw_done(pcbinfo->mtx);
	return(0);
}