Update in_pcb-derived basic socket types following changes to

pru_abort(), pru_detach(), and in_pcbdetach():

- Universally support and enforce the invariant that so_pcb is
  never NULL, converting dozens of unnecessary NULL checks into
  assertions, and eliminating dozens of unnecessary error handling
  cases in protocol code.

- In some cases, eliminate unnecessary pcbinfo locking, as it is no
  longer required to ensure so_pcb != NULL.  For example, in protocol
  shutdown methods, and in raw IP send.

- Abort and detach protocol switch methods no longer return failures,
  nor attempt to free sockets, as the socket layer does this.

- Invoke in_pcbfree() after in_pcbdetach() in order to free the
  detached in_pcb structure for a socket.

MFC after:	3 months

5 files changed, 86 insertions, 199 deletions

diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c
index bb31630..89aa4e4 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -394,21 +394,14 @@ div_attach(struct socket *so, int proto, struct thread *td)
 	struct inpcb *inp;
 	int error;
 
-	INP_INFO_WLOCK(&divcbinfo);
 	inp  = sotoinpcb(so);
-	if (inp != 0) {
-		INP_INFO_WUNLOCK(&divcbinfo);
-		return EINVAL;
-	}
-	if (td && (error = suser(td)) != 0) {
-		INP_INFO_WUNLOCK(&divcbinfo);
+	KASSERT(inp == NULL, ("div_attach: inp != NULL"));
+	if (td && (error = suser(td)) != 0)
 		return error;
-	}
 	error = soreserve(so, div_sendspace, div_recvspace);
-	if (error) {
-		INP_INFO_WUNLOCK(&divcbinfo);
+	if (error)
 		return error;
-	}
+	INP_INFO_WLOCK(&divcbinfo);
 	error = in_pcballoc(so, &divcbinfo, "divinp");
 	if (error) {
 		INP_INFO_WUNLOCK(&divcbinfo);
@@ -429,14 +422,12 @@ div_detach(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&divcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&divcbinfo);
-		return;
-	}
+	KASSERT(inp != NULL, ("div_detach: inp == NULL"));
+	INP_INFO_WLOCK(&divcbinfo);
 	INP_LOCK(inp);
 	in_pcbdetach(inp);
+	in_pcbfree(inp);
 	INP_INFO_WUNLOCK(&divcbinfo);
 }
 
@@ -446,12 +437,8 @@ div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct inpcb *inp;
 	int error;
 
-	INP_INFO_WLOCK(&divcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&divcbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp == NULL, ("div_bind: inp == NULL"));
 	/* in_pcbbind assumes that nam is a sockaddr_in
 	 * and in_pcbbind requires a valid address. Since divert
 	 * sockets don't we need to make sure the address is
@@ -460,13 +447,12 @@ div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	 * and should probably have its own family.
 	 */
 	if (nam->sa_family != AF_INET)
-		error = EAFNOSUPPORT;
-	else {
-		((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
-		INP_LOCK(inp);
-		error = in_pcbbind(inp, nam, td->td_ucred);
-		INP_UNLOCK(inp);
-	}
+		return EAFNOSUPPORT;
+	((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
+	INP_INFO_WLOCK(&divcbinfo);
+	INP_LOCK(inp);
+	error = in_pcbbind(inp, nam, td->td_ucred);
+	INP_UNLOCK(inp);
 	INP_INFO_WUNLOCK(&divcbinfo);
 	return error;
 }
@@ -476,14 +462,9 @@ div_shutdown(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_RLOCK(&divcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_RUNLOCK(&divcbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("div_shutdown: inp == NULL"));
 	INP_LOCK(inp);
-	INP_INFO_RUNLOCK(&divcbinfo);
 	socantsendmore(so);
 	INP_UNLOCK(inp);
 	return 0;
diff --git a/sys/netinet/raw_ip.c b/sys/netinet/raw_ip.c
index b6cf708..7d6e5b3 100644
--- a/sys/netinet/raw_ip.c
+++ b/sys/netinet/raw_ip.c
@@ -578,32 +578,18 @@ rip_attach(struct socket *so, int proto, struct thread *td)
 	struct inpcb *inp;
 	int error;
 
-	/* XXX why not lower? */
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp) {
-		/* XXX counter, printf */
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		return EINVAL;
-	}
-	if (jailed(td->td_ucred) && !jail_allow_raw_sockets) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	KASSERT(inp == NULL, ("rip_attach: inp != NULL"));
+	if (jailed(td->td_ucred) && !jail_allow_raw_sockets)
 		return (EPERM);
-	}
-	if ((error = suser_cred(td->td_ucred, SUSER_ALLOWJAIL)) != 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	if ((error = suser_cred(td->td_ucred, SUSER_ALLOWJAIL)) != 0)
 		return error;
-	}
-	if (proto >= IPPROTO_MAX || proto < 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	if (proto >= IPPROTO_MAX || proto < 0)
 		return EPROTONOSUPPORT;
-	}
-
 	error = soreserve(so, rip_sendspace, rip_recvspace);
-	if (error) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	if (error)
 		return error;
-	}
+	INP_INFO_WLOCK(&ripcbinfo);
 	error = in_pcballoc(so, &ripcbinfo, "rawinp");
 	if (error) {
 		INP_INFO_WUNLOCK(&ripcbinfo);
@@ -633,6 +619,7 @@ rip_pcbdetach(struct socket *so, struct inpcb *inp)
 	if (so == ip_rsvpd)
 		ip_rsvp_done();
 	in_pcbdetach(inp);
+	in_pcbfree(inp);
 }
 
 static void
@@ -640,13 +627,9 @@ rip_detach(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		/* XXX counter, printf */
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		return;
-	}
+	KASSERT(inp != NULL, ("rip_detach: inp == NULL"));
+	INP_INFO_WLOCK(&ripcbinfo);
 	INP_LOCK(inp);
 	rip_pcbdetach(so, inp);
 	INP_INFO_WUNLOCK(&ripcbinfo);
@@ -657,18 +640,12 @@ rip_abort(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		return;	/* ??? possible? panic instead? */
-	}
+	KASSERT(inp != NULL, ("rip_abort: inp == NULL"));
+	INP_INFO_WLOCK(&ripcbinfo);
 	INP_LOCK(inp);
 	soisdisconnected(so);
-	if (so->so_state & SS_NOFDREF)
-		rip_pcbdetach(so, inp);
-	else
-		INP_UNLOCK(inp);
+	rip_pcbdetach(so, inp);
 	INP_INFO_WUNLOCK(&ripcbinfo);
 }
 
@@ -678,7 +655,7 @@ rip_disconnect(struct socket *so)
 	if ((so->so_state & SS_ISCONNECTED) == 0)
 		return ENOTCONN;
 	rip_abort(so);
-	return 0;
+	return (0);
 }
 
 static int
@@ -704,12 +681,9 @@ rip_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	     ifa_ifwithaddr((struct sockaddr *)addr) == 0))
 		return EADDRNOTAVAIL;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("rip_bind: inp == NULL"));
+	INP_INFO_WLOCK(&ripcbinfo);
 	INP_LOCK(inp);
 	inp->inp_laddr = addr->sin_addr;
 	INP_UNLOCK(inp);
@@ -730,12 +704,9 @@ rip_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	if (addr->sin_family != AF_INET && addr->sin_family != AF_IMPLINK)
 		return EAFNOSUPPORT;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("rip_connect: inp == NULL"));
+	INP_INFO_WLOCK(&ripcbinfo);
 	INP_LOCK(inp);
 	inp->inp_faddr = addr->sin_addr;
 	soisconnected(so);
@@ -749,14 +720,9 @@ rip_shutdown(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_RLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_RUNLOCK(&ripcbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("rip_shutdown: inp == NULL"));
 	INP_LOCK(inp);
-	INP_INFO_RUNLOCK(&ripcbinfo);
 	socantsendmore(so);
 	INP_UNLOCK(inp);
 	return 0;
@@ -768,28 +734,26 @@ rip_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 {
 	struct inpcb *inp;
 	u_long dst;
-	int ret;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
+	KASSERT(inp != NULL, ("rip_send: inp == NULL"));
+	/*
+	 * Note: 'dst' reads below are unlocked.
+	 */
 	if (so->so_state & SS_ISCONNECTED) {
 		if (nam) {
-			INP_INFO_WUNLOCK(&ripcbinfo);
 			m_freem(m);
 			return EISCONN;
 		}
-		dst = inp->inp_faddr.s_addr;
+		dst = inp->inp_faddr.s_addr;	/* Unlocked read. */
 	} else {
 		if (nam == NULL) {
-			INP_INFO_WUNLOCK(&ripcbinfo);
 			m_freem(m);
 			return ENOTCONN;
 		}
 		dst = ((struct sockaddr_in *)nam)->sin_addr.s_addr;
 	}
-	ret = rip_output(m, so, dst);
-	INP_INFO_WUNLOCK(&ripcbinfo);
-	return ret;
+	return rip_output(m, so, dst);
 }
 
 static int
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index 23d4301..e00892d 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -934,15 +934,13 @@ udp_abort(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return;	/* ??? possible? panic instead? */
-	}
+	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 	soisdisconnected(so);
 	in_pcbdetach(inp);
+	in_pcbfree(inp);
 	INP_INFO_WUNLOCK(&udbinfo);
 }
 
@@ -952,12 +950,9 @@ udp_attach(struct socket *so, int proto, struct thread *td)
 	struct inpcb *inp;
 	int error;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp != 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	error = soreserve(so, udp_sendspace, udp_recvspace);
 	if (error) {
 		INP_INFO_WUNLOCK(&udbinfo);
@@ -984,12 +979,9 @@ udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct inpcb *inp;
 	int error;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 	error = in_pcbbind(inp, nam, td->td_ucred);
 	INP_UNLOCK(inp);
@@ -1004,12 +996,9 @@ udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	int error;
 	struct sockaddr_in *sin;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
 		INP_UNLOCK(inp);
@@ -1032,13 +1021,12 @@ udp_detach(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-	}
+	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 	in_pcbdetach(inp);
+	in_pcbfree(inp);
 	INP_INFO_WUNLOCK(&udbinfo);
 }
 
@@ -1047,12 +1035,9 @@ udp_disconnect(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
 		INP_INFO_WUNLOCK(&udbinfo);
@@ -1075,6 +1060,7 @@ udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
 	struct inpcb *inp;
 
 	inp = sotoinpcb(so);
+	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
 	return udp_output(inp, m, addr, control, td);
 }
 
@@ -1083,14 +1069,9 @@ udp_shutdown(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_RLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_RUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
 	INP_LOCK(inp);
-	INP_INFO_RUNLOCK(&udbinfo);
 	socantsendmore(so);
 	INP_UNLOCK(inp);
 	return 0;
diff --git a/sys/netinet6/raw_ip6.c b/sys/netinet6/raw_ip6.c
index 5b6daac..76fb495 100644
--- a/sys/netinet6/raw_ip6.c
+++ b/sys/netinet6/raw_ip6.c
@@ -549,27 +549,18 @@ rip6_attach(struct socket *so, int proto, struct thread *td)
 	struct icmp6_filter *filter;
 	int error, s;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		panic("rip6_attach");
-	}
-	if (td && (error = suser(td)) != 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	KASSERT(inp == NULL, ("rip6_attach: inp != NULL"));
+	if (td && (error = suser(td)) != 0)
 		return error;
-	}
 	error = soreserve(so, rip_sendspace, rip_recvspace);
-	if (error) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	if (error)
 		return error;
-	}
 	MALLOC(filter, struct icmp6_filter *,
 	       sizeof(struct icmp6_filter), M_PCB, M_NOWAIT);
-	if (filter == NULL) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
+	if (filter == NULL)
 		return ENOMEM;
-	}
+	INP_INFO_WLOCK(&ripcbinfo);
 	s = splnet();
 	error = in_pcballoc(so, &ripcbinfo, "raw6inp");
 	splx(s);
@@ -596,12 +587,8 @@ rip6_detach(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_WLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&ripcbinfo);
-		panic("rip6_detach");
-	}
+	KASSERT(inp != NULL, ("rip6_detach: inp == NULL"));
 	/* xxx: RSVP */
 	if (so == ip6_mrouter)
 		ip6_mrouter_done();
@@ -609,8 +596,10 @@ rip6_detach(struct socket *so)
 		FREE(inp->in6p_icmp6filt, M_PCB);
 		inp->in6p_icmp6filt = NULL;
 	}
+	INP_INFO_WLOCK(&ripcbinfo);
 	INP_LOCK(inp);
 	in6_pcbdetach(inp);
+	in6_pcbfree(inp);
 	INP_INFO_WUNLOCK(&ripcbinfo);
 }
 
@@ -630,7 +619,7 @@ rip6_disconnect(struct socket *so)
 		return ENOTCONN;
 	inp->in6p_faddr = in6addr_any;
 	rip6_abort(so);
-	return 0;
+	return (0);
 }
 
 static int
@@ -641,6 +630,7 @@ rip6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct ifaddr *ia = NULL;
 	int error = 0;
 
+	KASSERT(inp != NULL, ("rip6_bind: inp == NULL"));
 	if (nam->sa_len != sizeof(*addr))
 		return EINVAL;
 	if (TAILQ_EMPTY(&ifnet) || addr->sin6_family != AF_INET6)
@@ -674,6 +664,7 @@ rip6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct ifnet *ifp = NULL;
 	int error = 0, scope_ambiguous = 0;
 
+	KASSERT(inp != NULL, ("rip6_connect: inp == NULL"));
 	if (nam->sa_len != sizeof(*addr))
 		return EINVAL;
 	if (TAILQ_EMPTY(&ifnet))
@@ -726,10 +717,9 @@ rip6_shutdown(struct socket *so)
 {
 	struct inpcb *inp;
 
-	INP_INFO_RLOCK(&ripcbinfo);
 	inp = sotoinpcb(so);
+	KASSERT(inp != NULL, ("rip6_shutdown: inp == NULL"));
 	INP_LOCK(inp);
-	INP_INFO_RUNLOCK(&ripcbinfo);
 	socantsendmore(so);
 	INP_UNLOCK(inp);
 	return 0;
@@ -744,6 +734,7 @@ rip6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 	struct sockaddr_in6 *dst;
 	int ret;
 
+	KASSERT(inp != NULL, ("rip6_send: inp == NULL"));
 	INP_INFO_WLOCK(&ripcbinfo);
 	/* always copy sockaddr to avoid overwrites */
 	/* Unlocked read. */
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 19b894f..e51f0da 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -501,20 +501,15 @@ static void
 udp6_abort(struct socket *so)
 {
 	struct inpcb *inp;
-	int s;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return;	/* ??? possible? panic instead? */
-	}
-	soisdisconnected(so);
-	s = splnet();
+	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
+	soisdisconnected(so);
 	in6_pcbdetach(inp);
+	in6_pcbfree(inp);
 	INP_INFO_WUNLOCK(&udbinfo);
-	splx(s);
 }
 
 static int
@@ -523,21 +518,15 @@ udp6_attach(struct socket *so, int proto, struct thread *td)
 	struct inpcb *inp;
 	int s, error;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp != 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
-
+	KASSERT(inp == NULL, ("udp6_attach: inp == NULL"));
 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 		error = soreserve(so, udp_sendspace, udp_recvspace);
-		if (error) {
-			INP_INFO_WUNLOCK(&udbinfo);
+		if (error)
 			return error;
-		}
 	}
 	s = splnet();
+	INP_INFO_WLOCK(&udbinfo);
 	error = in_pcballoc(so, &udbinfo, "udp6inp");
 	splx(s);
 	if (error) {
@@ -569,12 +558,9 @@ udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct inpcb *inp;
 	int s, error;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 
 	inp->inp_vflag &= ~INP_IPV4;
@@ -614,14 +600,10 @@ udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	struct inpcb *inp;
 	int s, error;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
-
 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 		struct sockaddr_in6 *sin6_p;
 
@@ -669,18 +651,13 @@ static void
 udp6_detach(struct socket *so)
 {
 	struct inpcb *inp;
-	int s;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return;
-	}
+	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
-	s = splnet();
 	in6_pcbdetach(inp);
-	splx(s);
+	in6_pcbfree(inp);
 	INP_INFO_WUNLOCK(&udbinfo);
 }
 
@@ -690,12 +667,9 @@ udp6_disconnect(struct socket *so)
 	struct inpcb *inp;
 	int error, s;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 
 #ifdef INET
@@ -732,13 +706,9 @@ udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
 	struct inpcb *inp;
 	int error = 0;
 
-	INP_INFO_WLOCK(&udbinfo);
 	inp = sotoinpcb(so);
-	if (inp == 0) {
-		INP_INFO_WUNLOCK(&udbinfo);
-		m_freem(m);
-		return EINVAL;
-	}
+	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
+	INP_INFO_WLOCK(&udbinfo);
 	INP_LOCK(inp);
 
 	if (addr) {