From: Alexander Bluhm <alexander.bluhm@gmx.net>
Subject: assert inp has correct IPv6 flag
To: tech@openbsd.org
Date: Fri, 19 Jan 2024 17:50:57 +0100

Hi,

Since inpcb tables for UDP and Raw IP have been split into IPv4 and
IPv6, we can assert that INP_IPV6 flag is correct instead of checking
it.

While there give the table variable a nicer name.

ok?

bluhm

Index: netinet/raw_ip.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/raw_ip.c,v
diff -u -p -r1.153 raw_ip.c
--- netinet/raw_ip.c	15 Dec 2023 00:24:56 -0000	1.153
+++ netinet/raw_ip.c	19 Jan 2024 16:02:22 -0000
@@ -171,12 +171,10 @@ rip_input(struct mbuf **mp, int *offp, i
 	rw_enter_write(&rawcbtable.inpt_notify);
 	mtx_enter(&rawcbtable.inpt_mtx);
 	TAILQ_FOREACH(inp, &rawcbtable.inpt_queue, inp_queue) {
+		KASSERT(!ISSET(inp->inp_flags, INP_IPV6));
+
 		if (inp->inp_socket->so_rcv.sb_state & SS_CANTRCVMORE)
 			continue;
-#ifdef INET6
-		if (inp->inp_flags & INP_IPV6)
-			continue;
-#endif
 		if (rtable_l2(inp->inp_rtableid) !=
 		    rtable_l2(m->m_pkthdr.ph_rtableid))
 			continue;
Index: netinet/udp_usrreq.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/udp_usrreq.c,v
diff -u -p -r1.314 udp_usrreq.c
--- netinet/udp_usrreq.c	19 Jan 2024 02:24:07 -0000	1.314
+++ netinet/udp_usrreq.c	19 Jan 2024 16:00:13 -0000
@@ -381,7 +381,7 @@ udp_input(struct mbuf **mp, int *offp, i
 
 	if (m->m_flags & (M_BCAST|M_MCAST)) {
 		SIMPLEQ_HEAD(, inpcb) inpcblist;
-		struct inpcbtable *tb;
+		struct inpcbtable *table;
 
 		/*
 		 * Deliver a multicast or broadcast datagram to *all* sockets
@@ -406,23 +406,21 @@ udp_input(struct mbuf **mp, int *offp, i
 		SIMPLEQ_INIT(&inpcblist);
 #ifdef INET6
 		if (ip6)
-			tb = &udb6table;
+			table = &udb6table;
 		else
 #endif
-			tb = &udbtable;
+			table = &udbtable;
 
-		rw_enter_write(&tb->inpt_notify);
-		mtx_enter(&tb->inpt_mtx);
-		TAILQ_FOREACH(inp, &tb->inpt_queue, inp_queue) {
-			if (inp->inp_socket->so_rcv.sb_state & SS_CANTRCVMORE)
-				continue;
-#ifdef INET6
-			/* table is per AF, panic if it does not match */
+		rw_enter_write(&table->inpt_notify);
+		mtx_enter(&table->inpt_mtx);
+		TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
 			if (ip6)
 				KASSERT(ISSET(inp->inp_flags, INP_IPV6));
 			else
 				KASSERT(!ISSET(inp->inp_flags, INP_IPV6));
-#endif
+
+			if (inp->inp_socket->so_rcv.sb_state & SS_CANTRCVMORE)
+				continue;
 			if (rtable_l2(inp->inp_rtableid) !=
 			    rtable_l2(m->m_pkthdr.ph_rtableid))
 				continue;
@@ -481,10 +479,10 @@ udp_input(struct mbuf **mp, int *offp, i
 			    SO_REUSEADDR)) == 0)
 				break;
 		}
-		mtx_leave(&tb->inpt_mtx);
+		mtx_leave(&table->inpt_mtx);
 
 		if (SIMPLEQ_EMPTY(&inpcblist)) {
-			rw_exit_write(&tb->inpt_notify);
+			rw_exit_write(&table->inpt_notify);
 
 			/*
 			 * No matching pcb found; discard datagram.
@@ -509,7 +507,7 @@ udp_input(struct mbuf **mp, int *offp, i
 			}
 			in_pcbunref(inp);
 		}
-		rw_exit_write(&tb->inpt_notify);
+		rw_exit_write(&table->inpt_notify);
 
 		return IPPROTO_DONE;
 	}
@@ -1098,7 +1096,7 @@ release:
 int
 udp_attach(struct socket *so, int proto, int wait)
 {
-	struct inpcbtable *tb;
+	struct inpcbtable *table;
 	int error;
 
 	if (so->so_pcb != NULL)
@@ -1110,11 +1108,11 @@ udp_attach(struct socket *so, int proto,
 	NET_ASSERT_LOCKED();
 #ifdef INET6
 	if (so->so_proto->pr_domain->dom_family == PF_INET6)
-		tb = &udb6table;
+		table = &udb6table;
 	else
 #endif
-		tb = &udbtable;
-	if ((error = in_pcballoc(so, tb, wait)))
+		table = &udbtable;
+	if ((error = in_pcballoc(so, table, wait)))
 		return error;
 #ifdef INET6
 	if (sotoinpcb(so)->inp_flags & INP_IPV6)
Index: netinet6/raw_ip6.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/raw_ip6.c,v
diff -u -p -r1.178 raw_ip6.c
--- netinet6/raw_ip6.c	15 Dec 2023 00:24:56 -0000	1.178
+++ netinet6/raw_ip6.c	19 Jan 2024 16:00:05 -0000
@@ -183,14 +183,14 @@ rip6_input(struct mbuf **mp, int *offp, 
 	rw_enter_write(&rawin6pcbtable.inpt_notify);
 	mtx_enter(&rawin6pcbtable.inpt_mtx);
 	TAILQ_FOREACH(inp, &rawin6pcbtable.inpt_queue, inp_queue) {
+		KASSERT(ISSET(inp->inp_flags, INP_IPV6));
+
 		if (inp->inp_socket->so_rcv.sb_state & SS_CANTRCVMORE)
 			continue;
 		if (rtable_l2(inp->inp_rtableid) !=
 		    rtable_l2(m->m_pkthdr.ph_rtableid))
 			continue;
 
-		if (!(inp->inp_flags & INP_IPV6))
-			continue;
 		if ((inp->inp_ipv6.ip6_nxt || proto == IPPROTO_ICMPV6) &&
 		    inp->inp_ipv6.ip6_nxt != proto)
 			continue;